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February, 2008 132 - 1Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Technical Introduction to CDMA
Technical Introduction to CDMA
Course 132
IS-95, CDMA2000 and a glimpse of 1xEV
February, 2008 132 - 2Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Course Outline
Basic CDMA Principles• Coding• Forward and Reverse Channels
CDMA Operational Details• Multiplexing, Forward and Power Control
CDMA Network ArchitectureCDMA MessagingCDMA Handset ArchitectureCDMA Handoff PrinciplesCDMA System Acquisition and Call Flow ExamplesIntroduction to Optimization and Optimization ToolsWhat’s New in CDMA2000?
• 1xEV-DO, 1xEV-DV features and internal structure
February, 2008 132 - 3Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Section A
How Does CDMA Work?Introduction to Basic Principles
How Does CDMA Work?Introduction to Basic Principles
February, 2008 132 - 4Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Claude Shannon: The Einstein of Information Theory
The core idea that makes CDMA possible was first explained by Claude Shannon, a Bell Labs research mathematicianShannon's work relates amount of information carried, channel bandwidth, signal-to-noise-ratio, and detection error probability
• It shows the theoretical upper limit attainable
In 1948 Claude Shannon published his landmark paper on information theory, A Mathematical Theory of Communication. He observed that "the fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point." His paper so clearly established the foundations of information theory that his framework and terminology are standard today.Shannon died Feb. 24, 2001, at age 84.
SHANNON’S CAPACITY EQUATION
C = Bω log2 [ 1 + ]S N
Bω = bandwidth in HertzC = channel capacity in bits/secondS = signal powerN = noise power
February, 2008 132 - 5Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA: Using A New Dimension
All CDMA users occupy the same frequency at the same time! Frequency and time are not used as discriminatorsCDMA operates by using CODING to discriminate between usersCDMA interference comes mainly from nearby usersEach user is a small voice in a roaring crowd -- but with a uniquely recoverable code
CDMA
Figure of Merit: C/I(carrier/interference ratio)
AMPS: +17 dBTDMA: +14 to +17 dB
GSM: +7 to 9 dB.CDMA: -10 to -17 dB.CDMA: Eb/No ~+6 dB.
February, 2008 132 - 6Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Two Types of CDMA
There are Two types of CDMA:Frequency-Hopping
• Each user’s narrowband signal hops among discrete frequencies, and the receiver follows in sequence
• Frequency-Hopping Spread Spectrum (FHSS) CDMA is NOTcurrently used in wireless systems, although used by the military
Direct Sequence• narrowband input from a user is
coded (“spread”) by a user-unique broadband code, then transmitted
• broadband signal is received; receiver knows, applies user’s code, recovers users’ data
• Direct Sequence Spread Spectrum(DSSS) CDMA IS the method used in IS-95 commercial systems
User 1
Code 1
Composite
Time Frequency
+=
Direct Sequence CDMA
User 1 User 2 User 3 User 4 Frequency Hopping CDMA
User 3 User 4 User 1 unused User 2
User 1 User 4 User 3 User 2 unused
Frequency
unused User 1 User 2 User 4 User 3
February, 2008 132 - 7Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
DSSS Spreading: Time-Domain View
At Originating Site:Input A: User’s Data @ 19,200 bits/secondInput B: Walsh Code #23 @ 1.2288 McpsOutput: Spread spectrum signal
At Destination Site:Input A: Received spread spectrum signalInput B: Walsh Code #23 @ 1.2288 McpsOutput: User’s Data @ 19,200 bits/second just as originally sent Drawn to actual scale and time alignment
via air interface
XORExclusive-OR
Gate
1
1
Input A: Received Signal
Input B: Spreading Code
Output: User’s Original Data
Input A: User’s Data
Input B: Spreading Code
Spread Spectrum Signal
XORExclusive-OR
Gate
Originating Site
Destination Site
February, 2008 132 - 8Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Spreading from a Frequency-Domain View
Traditional technologies try to squeeze signal into minimum required bandwidthCDMA uses larger bandwidth but uses resulting processing gain to increase capacity
Spread Spectrum Payoff:Processing Gain
Spread SpectrumTRADITIONAL COMMUNICATIONS SYSTEM
SlowInformation
SentTX
SlowInformationRecovered
RX
NarrowbandSignal
SPREAD-SPECTRUM SYSTEM
FastSpreadingSequence
SlowInformation
SentTX
SlowInformationRecovered
RX
FastSpreadingSequence
WidebandSignal
February, 2008 132 - 9Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The CDMA Spread Spectrum Payoff:Would you like a lump-sum, or monthly payments?
Shannon's work suggests that a certain bit rate of information deserves a certain bandwidthIf one CDMA user is carried alone by a CDMA signal, the processing gain is large - roughly 21 db for an 8k vocoder.
• Each doubling of the number of users consumes 3 db of the processing gain
• Somewhere above 32 users, the signal-to-noise ratio becomes undesirable and the ultimate capacity of the sector is reached
Practical CDMA systems restrict the number of users per sector to ensure processing gain remains at usable levels
# Users Processing Gain1 21 db
2 18 db
4 15 db
8 12 db
16 9 db
32 6 db
64…..Uh, Regis, can I justtake the money I've already
won, and go home now?
CDMA Spreading Gain
Consider a user with a 9600 bps vocoder talking on a
CDMA signal 1,228,800 hzwide. The processing gain is 1,228,800/9600 = 128, which
is 21 db. What happens if additional users are added?
February, 2008 132 - 10Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA Uses Code Channels
A CDMA signal uses many chips to convey just one bit of information Each user has a unique chip pattern, in effect a code channelTo recover a bit, integrate a large number of chips interpreted by the user’s known code patternOther users’ code patterns appear random and integrate in a random self-canceling fashion, don’t disturb the bit decoding decision being made with the proper code pattern
Building aBuilding aCDMA SignalCDMA Signal
Bitsfrom User’s Vocoder
Symbols
Chips
Forward Error Correction
Coding and Spreading
February, 2008 132 - 11Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
How a BTS Sector Serves Multiple Users
Σ
if 1 =if 0 =
1
AnalogSummingUsers
QPSK RF
Σ
DemodulatedReceived
CDMA SignalDespreading Sequence(Locally Generated, =0)
matchesopposite
Decision:
Matches!( = 0 )
TimeIntegration
1
Opposite( =1)
+10
-26
Received energy: Correlation
-16
BTS
This figure illustrates the basic technique of CDMA signal generation and recovery.The actual coding process used in IS-95 CDMA includes a few additional layers, as we’ll see in following slides.
February, 2008 132 - 12Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Spreading: What we do, we can undo
Sender combines data with a fast spreading sequence, transmits spread data streamReceiver intercepts the stream, uses same spreading sequence to extract original data
ORIGINATING SITE DESTINATION
SpreadingSequence
SpreadingSequence
InputData
RecoveredData
Spread Data Stream
February, 2008 132 - 13Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
“Shipping and Receiving” via CDMA
Whether in shipping and receiving, or in CDMA, packaging is extremely important!Cargo is placed inside “nested” containers for protection and to allow addressingThe shipper packs in a certain order, and the receiver unpacks in the reverse orderCDMA “containers” are spreading codes
FedE
x
Data Mailer
FedE
x
DataMailer
Shipping Receiving
February, 2008 132 - 14Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA’s Nested Spreading Sequences
CDMA combines three different spreading sequences to create unique, robust channelsThe sequences are easy to generate on both sending and receivingends of each link“What we do, we can undo”
SpreadingSequence
ASpreadingSequence
BSpreadingSequence
CSpreadingSequence
CSpreadingSequence
BSpreadingSequence
A
InputDataX
RecoveredDataX
X+A X+A+B X+A+B+C X+A+B X+ASpread-Spectrum Chip Streams
ORIGINATING SITE DESTINATION
February, 2008 132 - 15Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
One of the CDMA Spreading Sequences:Walsh Codes
64 “Magic” Sequences, each 64 chips longEach Walsh Code is precisely Orthogonal with respect to all other Walsh Codes
• it’s simple to generate the codes, or• they’re small enough to use from ROM
WALSH CODES# ---------------------------------- 64-Chip Sequence ------------------------------------------0 00000000000000000000000000000000000000000000000000000000000000001 01010101010101010101010101010101010101010101010101010101010101012 00110011001100110011001100110011001100110011001100110011001100113 01100110011001100110011001100110011001100110011001100110011001104 00001111000011110000111100001111000011110000111100001111000011115 01011010010110100101101001011010010110100101101001011010010110106 00111100001111000011110000111100001111000011110000111100001111007 01101001011010010110100101101001011010010110100101101001011010018 00000000111111110000000011111111000000001111111100000000111111119 0101010110101010010101011010101001010101101010100101010110101010
10 001100111100110000110011110011000011001111001100001100111100110011 011001101001100101100110100110010110011010011001011001101001100112 000011111111000000001111111100000000111111110000000011111111000013 010110101010010101011010101001010101101010100101010110101010010114 001111001100001100111100110000110011110011000011001111001100001115 011010011001011001101001100101100110100110010110011010011001011016 000000000000000011111111111111110000000000000000111111111111111117 010101010101010110101010101010100101010101010101101010101010101018 001100110011001111001100110011000011001100110011110011001100110019 011001100110011010011001100110010110011001100110100110011001100120 000011110000111111110000111100000000111100001111111100001111000021 010110100101101010100101101001010101101001011010101001011010010122 001111000011110011000011110000110011110000111100110000111100001123 011010010110100110010110100101100110100101101001100101101001011024 000000001111111111111111000000000000000011111111111111110000000025 010101011010101010101010010101010101010110101010101010100101010126 001100111100110011001100001100110011001111001100110011000011001127 011001101001100110011001011001100110011010011001100110010110011028 000011111111000011110000000011110000111111110000111100000000111129 010110101010010110100101010110100101101010100101101001010101101030 001111001100001111000011001111000011110011000011110000110011110031 011010011001011010010110011010010110100110010110100101100110100132 000000000000000000000000000000001111111111111111111111111111111133 010101010101010101010101010101011010101010101010101010101010101034 001100110011001100110011001100111100110011001100110011001100110035 011001100110011001100110011001101001100110011001100110011001100136 000011110000111100001111000011111111000011110000111100001111000037 010110100101101001011010010110101010010110100101101001011010010138 001111000011110000111100001111001100001111000011110000111100001139 011010010110100101101001011010011001011010010110100101101001011040 000000001111111100000000111111111111111100000000111111110000000041 010101011010101001010101101010101010101001010101101010100101010142 001100111100110000110011110011001100110000110011110011000011001143 011001101001100101100110100110011001100101100110100110010110011044 000011111111000000001111111100001111000000001111111100000000111145 010110101010010101011010101001011010010101011010101001010101101046 001111001100001100111100110000111100001100111100110000110011110047 011010011001011001101001100101101001011001101001100101100110100148 000000000000000011111111111111111111111111111111000000000000000049 010101010101010110101010101010101010101010101010010101010101010150 001100110011001111001100110011001100110011001100001100110011001151 011001100110011010011001100110011001100110011001011001100110011052 000011110000111111110000111100001111000011110000000011110000111153 010110100101101010100101101001011010010110100101010110100101101054 001111000011110011000011110000111100001111000011001111000011110055 011010010110100110010110100101101001011010010110011010010110100156 000000001111111111111111000000001111111100000000000000001111111157 010101011010101010101010010101011010101001010101010101011010101058 001100111100110011001100001100111100110000110011001100111100110059 011001101001100110011001011001101001100101100110011001101001100160 000011111111000011110000000011111111000000001111000011111111000061 010110101010010110100101010110101010010101011010010110101010010162 001111001100001111000011001111001100001100111100001111001100001163 0110100110010110100101100110100110010110011010010110100110010110
EXAMPLE:Correlation of Walsh Code #23 with Walsh Code #59
#23 0110100101101001100101101001011001101001011010011001011010010110#59 0110011010011001100110010110011010011001011001100110011010011001Sum 0000111111110000000011111111000011110000000011111111000000001111
Correlation Results: 32 1’s, 32 0’s: Orthogonal!!
Unique Properties:Mutual Orthogonality
In CDMA2000, user data comes at various speeds, and different lengths of walsh codes can exist.See Course 332 for more details on CDMA2000 1xRTT fast data channels and additional Walsh codes.
February, 2008 132 - 16Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Other Sequences: Generation & Properties
Other CDMA sequences are generated in shift registersPlain shift register: no fun, sequence = length of registerTapped shift register generates a wild, self-mutating sequence 2N-1 chips long (N=register length)
• Such sequences match if compared in step (no-brainer, any sequence matches itself)
• Such sequences appear approximately orthogonal if compared with themselves not exactly matched in time
• false correlation typically <2%
A Tapped, Summing Shift Register
Sequence repeats every 2N-1 chips,where N is number of cells in register
An Ordinary Shift Register
Sequence repeats every N chips,where N is number of cells in register
A Special Characteristic of SequencesGenerated in Tapped Shift Registers
Compared In-Step: Matches Itself
Complete Correlation: All 0’sSum:Self, in sync:
Sequence:
Compared Shifted: Little Correlation
Practically Orthogonal: Half 1’s, Half 0’sSum:Self, Shifted:
Sequence:
February, 2008 132 - 17Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Original IS-95 CDMA PN Scrambling
Short PN Scrambling
New CDMA2000 1x Complex Scrambling
Another CDMA Spreading Sequence:The Short PN Code, used for Scrambling
The short PN code consists of two PN Sequences, I and Q, each 32,768 chips long
• Generated in similar but differently-tapped 15-bit shift registers
• the two sequences scramble the information on the I and Q phase channels
Figures to the right show how one user’s channel is built at the bTS
IQ
32,768 chips long26-2/3 ms.
(75 repetitions in 2 sec.)Σ
RF: cos ωt
RF: sin ωt
user’ssymbols
QPSK-modulated
RFOutput
Same information duplicatedon I and Q
Walsh
I-sequence
Q-sequence
Σ
RF:cos ωt
sin ωtRF
user’ssymbols
QPS
K
Out
put
Walsh
Seria
l to
Para
llel
Σ
Σ
+
DifferentInformationon I and Q
Complex Scrambling
I-sequence
Q-sequence
-+
+
February, 2008 132 - 18Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Generating the PN Long Codeat a desired Timing Offset
Every phone and every BTS channel element has a Long Code generator• Long Code State Register makes long code at system reference timing• A Mask Register holds a user-specific unique pattern of bits
Each clock pulse drives the Long Code State Register to its next state• State register and Mask register contents are added in the Summer• Summer contents are modulo-2 added to produce just a single bit output
The output bits are the Long Code, but shifted to the user’s unique offset
LONG CODE STATE REGISTER dynamic contents, zero timing shift
MASK REGISTER unique steady contents cause unique timing shift
SUMMER holds dynamic modulo-2 sum of LC State and Mask registers
Each clock cycle, all the Summer bits are added into a single-bit modulo-2 sum
The shifted Long Code emerges, chip by chip!
clock
February, 2008 132 - 19Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Different Masks ProduceDifferent Long PN Offsets
Ordinary mobiles use their ESNs and the Public Long Code Mask to produce their unique Long Code PN offsets
• main ingredient: mobile ESNMobiles needing greater privacy use the Private Long Code Mask
• instead of 32-bit ESN, the mask value is produced from SSD Word B in a calculation similar to authentication
Each BTS sector has an Access Channel where mobiles transmit for registration and call setup
• the Access Channel Long Code Mask includes Access Channel #, Paging Channel #, BTS ID, and Pilot PN
• The BTS transmits all of these parameters on the Paging Channel
fixed AC# PC# BASE_ID PILOT PN
LONG CODE STATE REGISTER
SUMMING REGISTER
LONG CODE STATE REGISTER
SUMMING REGISTER
fixed PERMUTED ESN
LONG CODE STATE REGISTER
SUMMING REGISTER
calculated PRIVATE LONG CODE MASK
ACCESS CHANNEL (IDLE MODE)USING THE ACCESS CHANNEL LONG CODE MASK
TRAFFIC CHANNEL – NORMALUSING THE PUBLIC LONG CODE MASK
TRAFFIC CHANNEL – PRIVATEUSING THE PRIVATE LONG CODE MASK
February, 2008 132 - 20Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Section B
IS-95 CDMA Forward and Reverse Channels
IS-95 CDMA Forward and Reverse Channels
February, 2008 132 - 21Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
How a BTS Builds the Forward Code Channels
BSC orAccess Manager
BTS (1 sector)
FECWalsh #1
Sync FECWalsh #32
FECWalsh #0
FECWalsh #12
FECWalsh #27
FECWalsh #44
Pilot
Paging
Vocoder
Vocoder
Vocoder
Vocoder
more more
Short PN CodePN Offset 246
Trans-mitter,
Sector X
Switch
more
a Channel Element
A Forward Channel is identified by:its CDMA RF carrier Frequencythe unique Short Code PN Offset of the sectorthe unique Walsh Code of the user
FECWalsh #23
ΣQ
ΣI
x
x+
cos ωt
sin ωt
I Q
February, 2008 132 - 22Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Functions of the CDMA Forward Channels
PILOT: WALSH CODE 0• The Pilot is a “structural beacon” which
does not contain a character stream. It is a timing source used in system acquisition and as a measurement device during handoffs
SYNC: WALSH CODE 32• This carries a data stream of system
identification and parameter information used by mobiles during system acquisition
PAGING: WALSH CODES 1 up to 7• There can be from one to seven paging
channels as determined by capacity needs. They carry pages, system parameters information, and call setup orders
TRAFFIC: any remaining WALSH codes• The traffic channels are assigned to
individual users to carry call traffic. All remaining Walsh codes are available, subject to overall capacity limited by noise
Pilot Walsh 0
Walsh 19
Paging Walsh 1Walsh 6
Walsh 11
Walsh 20Sync Walsh 32
Walsh 42
Walsh 37Walsh 41
Walsh 56Walsh 60
Walsh 55
February, 2008 132 - 23Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Code Channels in the Reverse DirectionBSC, CBSC,Access
Manager
Switch BTS (1 sector)
Channel Element
Access Channels
Vocoder
Vocoder
Vocoder
Vocoder
more more
Receiver,Sector X
A Reverse Channel is identified by:its CDMA RF carrier Frequencythe unique Long Code PN Offsetof the individual handset
Channel Element
Channel Element
Channel Element
Long Code Gen
Long Code Gen
Long Code Gen
Long Code Gen
more
a Channel Element
LongCodeoffset Long
Codeoffset Long
Codeoffset
LongCodeoffset
LongCodeoffset
LongCodeoffset
Channel Element
Long Code Gen
February, 2008 132 - 24Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
REG
1-800242
4444
BTS
Although a sector can have up to seven paging channels, and each paging channel can have up to 32 access channels, nearly all systems today use only one paging
channel per sector and only one access channel per paging channel.
Functions of the CDMA Reverse ChannelsThere are two types of CDMA Reverse Channels:
TRAFFIC CHANNELS are used by individual users during their actual calls to transmit traffic to the BTS
• a reverse traffic channel is really just a user-specific public or private Long Code mask
• there are as many reverse Traffic Channels as there are CDMA phones in the world!
ACCESS CHANNELS are used by mobiles not yet in a call to transmit registration requests, call setup requests, page responses, order responses, and other signaling information
• an access channel is really just a public long code offset unique to the BTS sector
• Access channels are paired to Paging Channels. Each paging channel can have up to 32 access channels.
February, 2008 132 - 25Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Summing Up Original IS-95 CDMA Channels
Existing IS-95A/JStd-008 CDMA uses the channels above for call setup and traffic channels – all call processing transactions use these channels
• traffic channels are 9600 bps (rate set 1) or 14400 bps (rate set 2)IS-2000 CDMA is backward-compatible with IS-95, but offers additional radio configurations and additional kinds of possible channels
• These additional modes are called Radio Configurations• IS-95 Rate Set 1 and 2 are IS-2000 Radio Configurations 1 & 2
FORWARD CHANNELS
BTS
W0: PILOT
W32: SYNC
W1: PAGING
Wn: TRAFFIC
REVERSE CHANNELS
ACCESS
TRAFFIC
February, 2008 132 - 26Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Channels at Phase One 1xRTT Launch
CDMA2000 1xRTT has a rich variety of traffic channels for voice and fast dateThere are also optional additional control channels for more effective operation
Includes PowerControl Subchannel
Enhanced Access Channel
CommonControl Channel
DedicatedControl Channel
Reverse FundamentalChannel (IS95B comp.)
Reverse Supplemental Channel
Access Channel(IS-95B compatible)
R-TRAFFIC
REVERSE CHANNELS
R-Pilot
R-CCCH
R-DCCH
R-FCH
R-SCH
R-EACH
1
1
0 or 1
0 or 1
0 to 2
R-ACH or
1
BTS
Dedicated Control Channel
Same coding as IS-95B,Backward compatible
Same coding as IS-95B,Backward compatible
Same coding as IS-95B,Backward compatible
Broadcast Channel
Quick Paging Channel
Common Power Control Channel
Common Assignment Channel
Common Control Channels
Forward Traffic Channels
Fundamental Channel
SupplementalChannels IS-95B only
SupplementalChannels RC3,4,5
F-TRAFFIC
FORWARD CHANNELS
F-Pilot
F-Sync
PAGING
F-BCH
F-QPCH
F-CPCCH
F-CACH
F-CCCH
F-DCCH
1
1
1 to 7
0 to 8
0 to 3
0 to 4
0 to 7
0 to 7
0 or 1
F-FCH
F-SCH
F-SCH
1
0 to 7
0 to 2
IS-95B only
Users:Users:0 to many0 to many
How manyPossible:
See Course 332 for more details.
February, 2008 132 - 27Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Spreading Rates & Radio ConfigurationsRadio
Configuration
RC1
RC2
RC3
RC4
RC5
RC6
RC7
RC8
RC9
SpreadingRate
SR11xRTT1 carrier1.2288MCPS
SR33xRTT
Fwd:3 carriers
1.2288MCPSRev:
3.6864MCPS
Forward Link
Required. IS-95B CompatibleNo CDMA2000 coding features
Compatible with IS-95B RS2No CDMA2000 coding features
Quarter-rate convolutional or Turbo Coding, base rate 9600
Half-rate convolutional or Turbo Coding, base rate 9600
Quarter-rate convolutional or Turbo Coding, base rate 14400
1/6 rate convolutionalor Turbo coding, base rate 9600
Required. 1/3 rate convolutionalor Turbo coding, base rate 9600
¼ or 1/3 rate convolutional orTurbo coding, base rate 14400
½ or 1/3 rate convolutional or Turbo encoder, base rate 14400
DataRates
9600
14400
9600153600
9600307200
14400230400
9600307200
9600614400
14400460800
144001036800
Quarter rate convolutional or Turbo coding; Half rate convolutional or Turbo coding;base rate 9600
Quarter rate convolutional or Turbo Coding, base rate 14400
Required. ¼ or 1/3 convolutionalor Turbo coding, base rate 9600
¼ or ½ convolutional or Turboencoding, base rate 14400
Required. IS-95B CompatibleNo CDMA2000 coding features
Compatible with IS-95B RS2No CDMA2000 coding features
RC1
RC2
RC3
RC4
RC5
RC6
9600
14400
9600
153600
307200
14400230400
9600
307200
614400
14400
460800
1036800
Reverse LinkDataRates
RadioConfiguration
February, 2008 132 - 28Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
SR1, RC1 9,600 bps F-FCH (IS-95-Compatible)
Same sym
bols go on both I and Q!
PowerControl
Puncturing
Data Bits
8.6 kbps
+CRC &Tail bits
9.6 kbps
1/2 rateConv Encoder Interleaver
User Long Code Mask
Long CodeGenerator
Long CodeDecimator
Power CtrlDecimator
PCPunc
Pwr CtrlBits
GainGain
19.2 ksps
I Short Code
QShort Code
FIRLPF
FIRLPF
II
OrthogonalSpreading
1228.8 kbps /W
800 bps
800 bps
19.2 ksps
1228.8 kcps
1228.8 kcps
SymbolRepetition Σ
ΣBTS Walsh 64Generator
1228.8 kcps
February, 2008 132 - 29Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
SR1, RC2 14,400 bps F-FCH (IS-95-Compatible)
Same sym
bols go on both I and Q!
PowerControl
Puncturing
Data Bits
13.35 kbps
+CRC &Tail bits
14.4 kbps
1/2 rateConv Encoder Interleaver
User Long Code Mask
Long CodeGenerator
Long CodeDecimator
Power CtrlDecimator
PCPunc
Pwr CtrlBits
GainGain
19.2 ksps
I Short Code
QShort Code
FIRLPF
FIRLPF
II
OrthogonalSpreading
1228.8 kbps /W
800 bps
800 bps
19.2 ksps
1228.8 kcps
1228.8 kcps
SymbolRepetition
SymbolPuncturing
28.8 ksps
2 of 6
Σ
ΣBTS Walsh 64Generator
1228.8 kcps
February, 2008 132 - 30Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
SR1, RC3 F-FCH (9,600 bps)
The stream of symbols is divided into two parts: one on logical I and one on logical Q
Complex scrambling ensures that the
physical I and Q phase planes contain equal
amplitudes at all times. This minimizes the
peak-to-average power levels in the signal.
PowerControl
PuncturingFull RateData Bits8.6 kbps
+CRC &Tail bits
9.6 kbps
1/4 rateConv Encoder Interleaver
User Long Code Mask
Long CodeGenerator
Long CodeDecimator
Power CtrlDecimator
PCPunc
Pwr CtrlBits
GainGain
Serial toParallel
Walsh 64Generator
I
Q
38.4 ksps
I Short Code
QShort Code
FIRLPF
FIRLPF
I
II
Q QQ
OrthogonalSpreading
ComplexScrambling
+
-
+
+Power control informationmay be carried as shown
or on the F-DCCH
1228.8 kbps /W/2
800 bps
800 bps
19.2 ksps
19.2 ksps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
38.4 ksps
Σ
ΣBTS
Doubled power efficiency, but still only 64 walsh codes
February, 2008 132 - 31Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
SR1, RC4 F-FCH (9,600 bps)
Complex scrambling ensures that the
physical I and Q phase planes contain equal
amplitudes at all times. This minimizes the
peak-to-average power levels in the signal.
The stream of symbols is divided into two parts: one on logical I and one on logical Q
PowerControl
PuncturingFull RateData Bits8.6 kbps
+CRC &Tail bits
9.6 kbps
1/2 rateConv Encoder Interleaver
User Long Code Mask
Long CodeGenerator
Long CodeDecimator
Power CtrlDecimator
PCPunc
Pwr CtrlBits
GainGain
Serial toParallel
Walsh 128Generator
I
Q
19.2 ksps
I Short Code
QShort Code
FIRLPF
FIRLPF
I
II
Q QQ
OrthogonalSpreading
ComplexScrambling
+
-
+
+Power control informationmay be carried as shown
or on the F-DCCH
1228.8 kbps /W/2
800 bps
800 bps
9.6 ksps
9.6 ksps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
19.2 ksps
Σ
ΣBTS
Double the walsh codes, but no better power efficiency.
February, 2008 132 - 32Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
SR1, RC3 F-SCH (153,600 bps)
Complex scrambling ensures that the
physical I and Q phase planes contain equal
amplitudes at all times. This minimizes the
peak-to-average power levels in the signal.
The stream of symbols is divided into two parts: one on logical I and one on logical Q
PayloadData Bits
152.4 kbps
+CRC &Tail bits
153.6 kbps
1/4 rateConv Encoder Interleaver
User Long Code Mask
Long CodeGenerator
Long CodeDecimator
GainSerial toParallel
Walsh 4Generator
I
Q
614.4 kspsI
Short Code
QShort Code
FIRLPF
FIRLPF
I
II
Q QQ
OrthogonalSpreading
ComplexScrambling
+
-
+
+
1228.8 kbps /W/2
307.2 ksps
307.2 ksps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
614.4 ksps
614.4 ksps
Σ
ΣBTS
February, 2008 132 - 33Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
SR1, RC4 F-SCH (307,200 bps)
Complex scrambling ensures that the
physical I and Q phase planes contain equal
amplitudes at all times. This minimizes the
peak-to-average power levels in the signal.
The stream of symbols is divided into two parts: one on logical I and one on logical Q
PayloadData Bits
304.8 kbps
+CRC &Tail bits
307.2 kbps
1/2 rateConv Encoder Interleaver
User Long Code Mask
Long CodeGenerator
Long CodeDecimator
GainSerial toParallel
Walsh 4Generator
I
Q
614.4 kspsI
Short Code
QShort Code
FIRLPF
FIRLPF
I
II
Q QQ
OrthogonalSpreading
ComplexScrambling
+
-
+
+
1228.8 kbps /W/2
307.2 ksps
307.2 ksps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
1228.8 kcps
614.4 ksps
614.4 ksps
Σ
ΣBTS
February, 2008 132 - 34Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Famous Walsh Codes from IS-95 Days
64 “Magic” Sequences, each 64 chips longEach Walsh Code is precisely Orthogonal with respect to all other Walsh Codes and their opposites too!
• it’s simple to generate the codes, or• they’re small enough to use from ROM
WALSH CODES# ---------------------------------- 64-Chip Sequence ------------------------------------------0 00000000000000000000000000000000000000000000000000000000000000001 01010101010101010101010101010101010101010101010101010101010101012 00110011001100110011001100110011001100110011001100110011001100113 01100110011001100110011001100110011001100110011001100110011001104 00001111000011110000111100001111000011110000111100001111000011115 01011010010110100101101001011010010110100101101001011010010110106 00111100001111000011110000111100001111000011110000111100001111007 01101001011010010110100101101001011010010110100101101001011010018 00000000111111110000000011111111000000001111111100000000111111119 0101010110101010010101011010101001010101101010100101010110101010
10 001100111100110000110011110011000011001111001100001100111100110011 011001101001100101100110100110010110011010011001011001101001100112 000011111111000000001111111100000000111111110000000011111111000013 010110101010010101011010101001010101101010100101010110101010010114 001111001100001100111100110000110011110011000011001111001100001115 011010011001011001101001100101100110100110010110011010011001011016 000000000000000011111111111111110000000000000000111111111111111117 010101010101010110101010101010100101010101010101101010101010101018 001100110011001111001100110011000011001100110011110011001100110019 011001100110011010011001100110010110011001100110100110011001100120 000011110000111111110000111100000000111100001111111100001111000021 010110100101101010100101101001010101101001011010101001011010010122 001111000011110011000011110000110011110000111100110000111100001123 011010010110100110010110100101100110100101101001100101101001011024 000000001111111111111111000000000000000011111111111111110000000025 010101011010101010101010010101010101010110101010101010100101010126 001100111100110011001100001100110011001111001100110011000011001127 011001101001100110011001011001100110011010011001100110010110011028 000011111111000011110000000011110000111111110000111100000000111129 010110101010010110100101010110100101101010100101101001010101101030 001111001100001111000011001111000011110011000011110000110011110031 011010011001011010010110011010010110100110010110100101100110100132 000000000000000000000000000000001111111111111111111111111111111133 010101010101010101010101010101011010101010101010101010101010101034 001100110011001100110011001100111100110011001100110011001100110035 011001100110011001100110011001101001100110011001100110011001100136 000011110000111100001111000011111111000011110000111100001111000037 010110100101101001011010010110101010010110100101101001011010010138 001111000011110000111100001111001100001111000011110000111100001139 011010010110100101101001011010011001011010010110100101101001011040 000000001111111100000000111111111111111100000000111111110000000041 010101011010101001010101101010101010101001010101101010100101010142 001100111100110000110011110011001100110000110011110011000011001143 011001101001100101100110100110011001100101100110100110010110011044 000011111111000000001111111100001111000000001111111100000000111145 010110101010010101011010101001011010010101011010101001010101101046 001111001100001100111100110000111100001100111100110000110011110047 011010011001011001101001100101101001011001101001100101100110100148 000000000000000011111111111111111111111111111111000000000000000049 010101010101010110101010101010101010101010101010010101010101010150 001100110011001111001100110011001100110011001100001100110011001151 011001100110011010011001100110011001100110011001011001100110011052 000011110000111111110000111100001111000011110000000011110000111153 010110100101101010100101101001011010010110100101010110100101101054 001111000011110011000011110000111100001111000011001111000011110055 011010010110100110010110100101101001011010010110011010010110100156 000000001111111111111111000000001111111100000000000000001111111157 010101011010101010101010010101011010101001010101010101011010101058 001100111100110011001100001100111100110000110011001100111100110059 011001101001100110011001011001101001100101100110011001101001100160 000011111111000011110000000011111111000000001111000011111111000061 010110101010010110100101010110101010010101011010010110101010010162 001111001100001111000011001111001100001100111100001111001100001163 0110100110010110100101100110100110010110011010010110100110010110
EXAMPLE:Correlation of Walsh Code #23 with Walsh Code #59
#23 0110100101101001100101101001011001101001011010011001011010010110#59 0110011010011001100110010110011010011001011001100110011010011001Sum 0000111111110000000011111111000011110000000011111111000000001111
Correlation Results: 32 1’s, 32 0’s: Orthogonal!!
Unique Properties:Mutual Orthogonality
February, 2008 132 - 35Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
IS-95 Busy SectorSnapshot of Walsh Usage
February, 2008 132 - 36Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Walsh Codes in 1xRTT
Data Rates are different, butChip Rates must stay the same!
2G VOICE AND DATAOne Symbol of Information
64 chips of Walsh Code1,228,800 walsh chips/second
19,200 symbols/secondDATA
SYMBOLS
WALSHCODE
3G 153.6 kb/s DATA One Symbol of Fast Data
4 Chips of Walsh Code 1,228,800 walsh chips/second
307,200 symbols/secondDATA
SYMBOLS
WALSHCODE
February, 2008 132 - 37Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Families of the Walsh Codes
All Walsh codes can be built to any size from a single zero by replicating and invertingAll Walsh matrixes are square -- same number of codes and number of chips per code
WALSH CODES# ---------------------------------- 64-Chip Sequence ------------------------------------------0 00000000000000000000000000000000000000000000000000000000000000001 01010101010101010101010101010101010101010101010101010101010101012 00110011001100110011001100110011001100110011001100110011001100113 01100110011001100110011001100110011001100110011001100110011001104 00001111000011110000111100001111000011110000111100001111000011115 01011010010110100101101001011010010110100101101001011010010110106 00111100001111000011110000111100001111000011110000111100001111007 01101001011010010110100101101001011010010110100101101001011010018 00000000111111110000000011111111000000001111111100000000111111119 0101010110101010010101011010101001010101101010100101010110101010
10 001100111100110000110011110011000011001111001100001100111100110011 011001101001100101100110100110010110011010011001011001101001100112 000011111111000000001111111100000000111111110000000011111111000013 010110101010010101011010101001010101101010100101010110101010010114 001111001100001100111100110000110011110011000011001111001100001115 011010011001011001101001100101100110100110010110011010011001011016 000000000000000011111111111111110000000000000000111111111111111117 010101010101010110101010101010100101010101010101101010101010101018 001100110011001111001100110011000011001100110011110011001100110019 011001100110011010011001100110010110011001100110100110011001100120 000011110000111111110000111100000000111100001111111100001111000021 010110100101101010100101101001010101101001011010101001011010010122 001111000011110011000011110000110011110000111100110000111100001123 011010010110100110010110100101100110100101101001100101101001011024 000000001111111111111111000000000000000011111111111111110000000025 010101011010101010101010010101010101010110101010101010100101010126 001100111100110011001100001100110011001111001100110011000011001127 011001101001100110011001011001100110011010011001100110010110011028 000011111111000011110000000011110000111111110000111100000000111129 010110101010010110100101010110100101101010100101101001010101101030 001111001100001111000011001111000011110011000011110000110011110031 011010011001011010010110011010010110100110010110100101100110100132 000000000000000000000000000000001111111111111111111111111111111133 010101010101010101010101010101011010101010101010101010101010101034 001100110011001100110011001100111100110011001100110011001100110035 011001100110011001100110011001101001100110011001100110011001100136 000011110000111100001111000011111111000011110000111100001111000037 010110100101101001011010010110101010010110100101101001011010010138 001111000011110000111100001111001100001111000011110000111100001139 011010010110100101101001011010011001011010010110100101101001011040 000000001111111100000000111111111111111100000000111111110000000041 010101011010101001010101101010101010101001010101101010100101010142 001100111100110000110011110011001100110000110011110011000011001143 011001101001100101100110100110011001100101100110100110010110011044 000011111111000000001111111100001111000000001111111100000000111145 010110101010010101011010101001011010010101011010101001010101101046 001111001100001100111100110000111100001100111100110000110011110047 011010011001011001101001100101101001011001101001100101100110100148 000000000000000011111111111111111111111111111111000000000000000049 010101010101010110101010101010101010101010101010010101010101010150 001100110011001111001100110011001100110011001100001100110011001151 011001100110011010011001100110011001100110011001011001100110011052 000011110000111111110000111100001111000011110000000011110000111153 010110100101101010100101101001011010010110100101010110100101101054 001111000011110011000011110000111100001111000011001111000011110055 011010010110100110010110100101101001011010010110011010010110100156 000000001111111111111111000000001111111100000000000000001111111157 010101011010101010101010010101011010101001010101010101011010101058 001100111100110011001100001100111100110000110011001100111100110059 011001101001100110011001011001101001100101100110011001101001100160 000011111111000011110000000011111111000000001111000011111111000061 010110101010010110100101010110101010010101011010010110101010010162 001111001100001111000011001111001100001100111100001111001100001163 0110100110010110100101100110100110010110011010010110100110010110
WALSH CODES# ----------- 32-Chip Sequence -------------0 000000000000000000000000000000001 010101010101010101010101010101012 001100110011001100110011001100113 011001100110011001100110011001104 000011110000111100001111000011115 010110100101101001011010010110106 001111000011110000111100001111007 011010010110100101101001011010018 000000001111111100000000111111119 01010101101010100101010110101010
10 0011001111001100001100111100110011 0110011010011001011001101001100112 0000111111110000000011111111000013 0101101010100101010110101010010114 0011110011000011001111001100001115 0110100110010110011010011001011016 0000000000000000111111111111111117 0101010101010101101010101010101018 0011001100110011110011001100110019 0110011001100110100110011001100120 0000111100001111111100001111000021 0101101001011010101001011010010122 0011110000111100110000111100001123 0110100101101001100101101001011024 0000000011111111111111110000000025 0101010110101010101010100101010126 0011001111001100110011000011001127 0110011010011001100110010110011028 0000111111110000111100000000111129 0101101010100101101001010101101030 0011110011000011110000110011110031 01101001100101101001011001101001
WALSH# ---- 16-Chips -------0 00000000000000001 01010101010101012 00110011001100113 01100110011001104 00001111000011115 01011010010110106 00111100001111007 01101001011010018 00000000111111119 0101010110101010
10 001100111100110011 011001101001100112 000011111111000013 010110101010010114 001111001100001115 0110100110010110
WALSH# 8-Chips 0 000000001 010101012 001100113 011001104 000011115 010110106 001111007 01101001
WALSH# 4-Chips 0 00001 01012 00113 0110
WALSH# 2-Chips 0 001 01
WALSH# 1-Chip0 0
64x64
32x32
16x16
8x84x42x2
Walsh Level MappingThe Walsh Codes shown here are in logical state values 0 and 1.Walsh Codes also can exist as physical bipolar signals. Logical zero is the signal value +1 and Logical 1 is the signal value -1.Mapping: Logical 0,1 > +1, -1 Physical
Walsh Code NamesW1232 = “Walsh Code #12, 32 chips long.”
February, 2008 132 - 38Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Walsh Code Trees and Interdependencies
Entire Walsh matrices can be built by replicating and inverting -- Individual Walsh codes can also be expanded in the same way.CDMA adds each symbol of information to one complete Walsh codeFaster symbol rates therefore require shorter Walsh codesIf a short Walsh code is chosen to carry a fast data channel, that walsh code and all its replicative descendants are compromised and cannot be reused to carry other signalsTherefore, the supply of available Walsh codes on a sector diminishes greatly while a fast data channel is being transmitted!CDMA2000 Base stations can dip into a supply of quasi-orthogonal codes if needed to permit additional channels during times of heavy loading
0110
1001
0110
0110
0110
0110 0110 0110 0110
0110 0110 1001 1001
10010110 10010110
10010110 1001 011010010110 1001 0110 10010110 1001 0110
10010110 1001 0110 1001 0110 10010110
10010110 10010110
10010110 10010110
10010110 10010110
100101101001 0110
0110 0110 1001 1001
0110 0110 1001 1001 0110 0110 1001 1001
0110 01101001 1001
0110 0110 0110 0110 0110 0110 0110 0110
0110 0110 0110 0110 1001 1001 1001 1001
W34
W38
W78
W716
W1116
W316
W1516
W732
W2332
W1532
W3132
W2732
W1132
W1932
W332 W364
W3564
W1964
W5164
W1164
W4364
W2764
W5964
W764
W3964
W2364
W5564
W1564
W4764
W3164
W6364
February, 2008 132 - 39Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Walsh Code Families and ExclusionsConsider a forward link supplemental channel being transmitted with a data rate of 307,200 symbols/second
• Each symbol will occupy 4 chips at the 1x rate of 1,228,800 c/s.
• A 4-chip walsh code will be used for this channel
If Walsh Code #3 (4 chips) is chosen for this channel:
• Use of W34 will preclude other usage of the following 64-chip walsh codes:
• 3, 35, 19, 51, 11, 43, 27, 59, 7, 39, 23, 55, 15, 47, 31, 63 -- all forbidden!
• 16 codes are tied up since the data is being sent at 16 times the rate of conventional 64-chip walsh codes
The BTS controller managing this sector must track the precluded walsh codes and ensure they aren’t assigned
WALSH CODES# ---------------------------------- 64-Chip Sequence ------------------------------------------0 00000000000000000000000000000000000000000000000000000000000000001 01010101010101010101010101010101010101010101010101010101010101012 00110011001100110011001100110011001100110011001100110011001100113 01100110011001100110011001100110011001100110011001100110011001104 00001111000011110000111100001111000011110000111100001111000011115 01011010010110100101101001011010010110100101101001011010010110106 00111100001111000011110000111100001111000011110000111100001111007 01101001011010010110100101101001011010010110100101101001011010018 00000000111111110000000011111111000000001111111100000000111111119 0101010110101010010101011010101001010101101010100101010110101010
10 001100111100110000110011110011000011001111001100001100111100110011 011001101001100101100110100110010110011010011001011001101001100112 000011111111000000001111111100000000111111110000000011111111000013 010110101010010101011010101001010101101010100101010110101010010114 001111001100001100111100110000110011110011000011001111001100001115 011010011001011001101001100101100110100110010110011010011001011016 000000000000000011111111111111110000000000000000111111111111111117 010101010101010110101010101010100101010101010101101010101010101018 001100110011001111001100110011000011001100110011110011001100110019 011001100110011010011001100110010110011001100110100110011001100120 000011110000111111110000111100000000111100001111111100001111000021 010110100101101010100101101001010101101001011010101001011010010122 001111000011110011000011110000110011110000111100110000111100001123 011010010110100110010110100101100110100101101001100101101001011024 000000001111111111111111000000000000000011111111111111110000000025 010101011010101010101010010101010101010110101010101010100101010126 001100111100110011001100001100110011001111001100110011000011001127 011001101001100110011001011001100110011010011001100110010110011028 000011111111000011110000000011110000111111110000111100000000111129 010110101010010110100101010110100101101010100101101001010101101030 001111001100001111000011001111000011110011000011110000110011110031 011010011001011010010110011010010110100110010110100101100110100132 000000000000000000000000000000001111111111111111111111111111111133 010101010101010101010101010101011010101010101010101010101010101034 001100110011001100110011001100111100110011001100110011001100110035 011001100110011001100110011001101001100110011001100110011001100136 000011110000111100001111000011111111000011110000111100001111000037 010110100101101001011010010110101010010110100101101001011010010138 001111000011110000111100001111001100001111000011110000111100001139 011010010110100101101001011010011001011010010110100101101001011040 000000001111111100000000111111111111111100000000111111110000000041 010101011010101001010101101010101010101001010101101010100101010142 001100111100110000110011110011001100110000110011110011000011001143 011001101001100101100110100110011001100101100110100110010110011044 000011111111000000001111111100001111000000001111111100000000111145 010110101010010101011010101001011010010101011010101001010101101046 001111001100001100111100110000111100001100111100110000110011110047 011010011001011001101001100101101001011001101001100101100110100148 000000000000000011111111111111111111111111111111000000000000000049 010101010101010110101010101010101010101010101010010101010101010150 001100110011001111001100110011001100110011001100001100110011001151 011001100110011010011001100110011001100110011001011001100110011052 000011110000111111110000111100001111000011110000000011110000111153 010110100101101010100101101001011010010110100101010110100101101054 001111000011110011000011110000111100001111000011001111000011110055 011010010110100110010110100101101001011010010110011010010110100156 000000001111111111111111000000001111111100000000000000001111111157 010101011010101010101010010101011010101001010101010101011010101058 001100111100110011001100001100111100110000110011001100111100110059 011001101001100110011001011001101001100101100110011001101001100160 000011111111000011110000000011111111000000001111000011111111000061 010110101010010110100101010110101010010101011010010110101010010162 001111001100001111000011001111001100001100111100001111001100001163 0110100110010110100101100110100110010110011010010110100110010110
0110W34
Which Walsh Codes get tied up by another?Wxxyyties up every YYth Walsh Code starting with #XX.
February, 2008 132 - 40Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Forward Link Walsh Codes in 1xRTT
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
Paging 7
Paging 3
Paging 5
Paging
PCH
6
PCH
2
PCH
4
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
76.8ksps
This way of arranging Walsh codes is called “bit reversal order”. It shows each Walsh code’s parents and children. Remember, we cannot use any Walsh code if
another Walsh code directly above it or below it is in use.
February, 2008 132 - 41Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
IS-95 Today Typical Usage:Pilot, Paging Sync, up to 61 Voice Users
But if the users are highly mobile, forward power may exhaust at typically 30-40 users.In fixed-wireless or “stadium” type applications, all walsh codes may be usable.
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
19.2k19.2kS
yncPilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k ???????Traffic Channels
Voice or Data9.6k/14.4k
76.8ksps
38.4k
February, 2008 132 - 42Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Mixed IS-95 / 1xRTT RC3 Voice Typical Usage: Pilot, Paging Sync, up to 61 Voice Users
FCHs of 1xRTT RC3 users consume less power, so more total users are possible than inIS-95. The BTS will probably have enough forward power to carry calls on all 61 walsh codes!
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
19.2k19.2kS
yncPilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-FCHs mixedRC1,2,3 Voice
76.8ksps
??
February, 2008 132 - 43Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
A Not-too-Desirable 1xRTT RC3 State:1 F-SCH, 27 Voice IS-95/1xRTT RC3 Users, 16 Active Data Users
The data users can rapidly share the one F-SCH for 153 kb/s peak, ~9Kb/s avg. user rates.But so many active data users F-FCHs consume a lot of capacity, reduce number of voice users!
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-SCH 153K RC3
F-FCHs 9.6kRC3 Data
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
76.8kspsWasteful, since many of these users are
not actively sending or receiving data
February, 2008 132 - 44Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
A Better 1xRTT RC3 BTS Dynamic State:1 F-SCH, 39 IS-95/1xRTT RC3 Voice Users, 4 Active+12 Dormant Data Users
But it takes seconds to move various data users from Dormant to Active!Data users will get 153 kb/s peak, ~9 kb/s average, but latency will be high.
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCH
sD
ata
F-SCH 153K RC3
76.8ksps
February, 2008 132 - 45Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Slightly Improved 1xRTT RC3 BTS Dynamic State:1 F-SCH, 37 IS-95/1xRTT RC3 Voice Users, 4 Active+12 Control-Hold Data Users
Instead of sending 16 data users to Dormant State, let them time-share 2 F-DCCH for Control Hold state. Data users will get 153 kb/s peak, ~9 kb/s average, good latency.
Not yet available or implemented.
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCH
sD
ata
F-SCH 153K RC3
F-DC
CH
s76.8ksps
February, 2008 132 - 46Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Heavy Data 1xRTT RC3 BTS Dynamic State:2 F-SCH, 21 IS-95/1xRTT RC3 Voice Users, 4 Active+12 Control-Hold Data Users
16 data users time-share 2 F-DCCH for Control Hold state. Data users get 38.4, 76.4,or 153.6 kb/s peak, ~19 kb/s average, good latency. But only 21 voice users!
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCH
sD
ata
F-SCH 153K RC3
F-DC
CH
s
F-SCH 153K RC3
76.8ksps
February, 2008 132 - 47Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xRTT Busy SectorWalsh Code Usage
February, 2008 132 - 48Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xRTT RC3 BTS with Different User Data Rates:3 F-SCH, 37 IS-95/1xRTT RC3 Voice Users, 4 Active+12 Control-Hold RC3 Data Users
16 data users time-share 2 F-DCCH for Control Hold state. Data users get 38.4, 76.4, or 153.6 kb/s peak, ~9 kb/s average, good latency.
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCH
sD
ataF-SCH
76K RC3F-D
CC
Hs
F-SCH
38K
F-SCH
38K76.8ksps
February, 2008 132 - 49Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xRTT RC4 Voice Only:Pilot, Paging Sync, up to 118 Voice Users
Wow! 118 users! But RC4 users F-FCHs consume as much power as old IS-95 calls.BTS may run out of forward power before the all walsh codes are used.
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6k RC4 Voice???????
76.8ksps
February, 2008 132 - 50Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xRTT RC4 Voice and Data:1 F-SCH, 80 1xRTT RC4 Voice Users, 4 Active+12 Control-Hold RC4 Data Users
16 data users time-share 2 F-DCCH for Control Hold state. Data users will get 38.4,76.4, 153.6 or 307.2 kb/s peak, ~19 kb/s average, good latency. But fwd power may exhaust!
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
Sync
Pilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-SCH 307K RC4
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6k RC4 Voice????
F-FCH
sF-D
CC
Hs
76.8ksps
February, 2008 132 - 51Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Mature 1xRTT Mixed-Mode Voice and Data:1 RC3/RC4 Shared F-SCH, 20 RC3 Voice Users, 38 RC4 Voice Users,
3 Active+12 Control-Hold RC3 and RC4 Data Users16 data users time-share 2 F-DCCH for Control Hold state. Data users will get
38.4, 76.4, 153.6 or 307.2 kb/s peak, ~9 or 19 kb/s average, good latency. Fwd power tight!
9,6004,8002,400sps
307200sps
153,600sps
76,800sps
38,400sps
19,200sps
Code#
Code#
Code#
Code#
Code#
Code#
128 chips4 chips
8 chips16 chips
32 chips64 chips
Code#
Code#
Code#
Code#
Code#
Code#
73516240
3120
1571131359114610212480
311523727111932913215259171301422626101822812204248160
54
12763953111147791511955872310339717123599127107437511115518319993567312561932910945771311753852110137695121578925105417391134981189733651126629430110467814118862210238706122589026106427410114508218983466212460922810844761211652842010036684120568824104407281124880169632640
0 32 16 48 8 40 24 56 4 36 20 52 12 44 28 60 2 34 18 50 10 42 26 58 6 38 22 54 14 46 30 62 1 33 17 49 9 41 25 57 5 37 21 53 13 45 29 61 3 35 19 51 11 43 27 59 7 39 23 55 15 47 31 63
QPC
HQ
PCH
QPC
HTX
Div PIlot
19.2k
19.2k
19.2k
19.2k
Paging
19.2k
19.2k
19.2k
19.2k19.2kS
yncPilot
38.4k
38.4k38.4k
38.4k
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
76.8ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH153.6 ksps
F-SCH307.2 ksps
F-SCH307.2 ksps
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
38.4k
19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k19.2k19.2k19.2k
19.2k19.2k19.2k19.2k
F-SCH 153K RC3or
F-SCH 307K RC4
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6k RC4 Voice
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCHs 9.6kRC3 Voice
F-FCH
sF-D
CC
Hs
Or Combinations
????
76.8ksps
February, 2008 132 - 52Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Section C
Operational DetailsVocoding, Multiplexing, Power Control
Operational DetailsVocoding, Multiplexing, Power Control
February, 2008 132 - 53Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Variable Rate Vocoding & Multiplexing
Vocoders compress speech, reduce bit rate, greatly increasing capacityCDMA uses a superior Variable Rate Vocoder
• full rate during speech• low rates in speech pauses• increased capacity• more natural sound
Voice, signaling, and user secondary data may be mixed in CDMA frames
DSP QCELP VOCODER
Codebook
PitchFilter
FormantFilter
Coded Result Feed-back
20ms Sample
Frame Sizesbits
Full Rate Frame1/2 Rate Frame1/4 Rt.1/824/36
48/7296/144
192/288
Frame Contents: can be a mixture ofPrimaryTraffic(Voice or
data)
Signaling(System
Messaging)
Secondary(On-Air
activation, etc)
February, 2008 132 - 54Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
How Power Control Works
800 Power Control Bits per second!
TX RF Digital
BTSBSC
Eb/NoSetpoint
Bad FER?Raise Setpoint
Stronger thansetpoint?
OpenLoop Closed
LoopReverse Link
REVERSE LINK POWER ADJUSTMENT
RX RF Digital
IS-95, 1xRTTALL SAME METHOD
TXPO = -(RXdbm) -C + TXGA
MOBILE
FEI Bits Mark Bad Frames Received
BSCSyncPilot
Paging
Short PN
Trans-mitter,
Sector XΣ I QUser 1User 2User 3
Voc-oder
BTS (1 sector)
Forward Link
FORWARD LINK POWER ADJUSTMENT
Selec-tor
MOBILE
Eb/NoSetpoint
FEI Bits
Bad FrameCounterPMRM POWER MEAS. REPORT MSG “2 bad in last 4, Help!!”
POWER CONTROL BITSTREAM RIDING ON MOBILE PILOT
DGU
IS-95 RS1Method
IS-95 RS2Method1xRTTMethod
February, 2008 132 - 55Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Details of Reverse Link Power Control
TXPO Handset Transmit Power• Actual RF power output of the
handset transmitter, including combined effects of open loop power control from receiver AGC and closed loop power control by BTS
• can’t exceed handset’s maximum (typ. +23 dBm)
TXGA Transmit Gain Adjust• Sum of all closed-loop
power control commands from the BTS since the beginning of this call
TXPODUP x ≈ IF
LNA
Subscriber Handset
R
R
R
S
Rake
Σ ViterbiDecoder
Vocoder
∼
FECOrthMod
Long PN
xx
xIF Mod
I
Q
x ~LO Open Loop
LO
Closed Loop Pwr Ctrl
IF
Receiver>>
<<Transmitter
PA
BTS
Typical TXPO:+23 dBm in a coverage hole0 dBm near middle of cell-50 dBm up close to BTS
0 dB
-10 dB
-20 dB
Typical Transmit Gain Adjust
Time, Seconds
TXPO = -(RXdbm) -C + TXGAC = +73 for 800 MHz. systems= +76 for 1900 MHz. systems
February, 2008 132 - 56Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA Network ArchitectureCDMA Network Architecture
February, 2008 132 - 57Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
BASE STATIONCONTROLLER
SUPPORTFUNCTIONS
BASE STATIONS
Mobile TelephoneSwitching Office
PSTNLocal CarriersLong Distance
CarriersATM Link
to other CDMANetworks(Future)
Structure of a Typical CDMA System
Voice Mail System SWITCH
HLR Home Location Register(subscriber database)
February, 2008 132 - 58Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Voice Call Path through the CDMA Network
BSC-BSMMTX BTS
Ch. Card ACC
Σα
Σβ
Σχ
TFU1
GPSRBSM
CDSU
CDSU
SBSVocodersSelectors
CDSU
CDSU
CDSU
CDSU
CDSU
CMSLM
LPP LPPENET
DTCs
DMS-BUS
TxcvrA
TxcvrB
TxcvrC
RFFEA
RFFEB
RFFEC
TFU
GPSR
GPS GPS
IOC
PSTN
CDSU DISCOCDSU
DISCO 1
DISCO 2
DS0 in T1Packets
ChipsRFChannel
ElementVocoder,Selector
February, 2008 132 - 59Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1x Data Call Path through the CDMA Network
BSC-BSMMTX BTS
Ch. Card ACC
Σα
Σβ
Σχ
TFU1
GPSRBSM
CDSU
CDSU
SBSVocodersSelectors
CDSU
CDSU
CDSU
CDSU
CDSU
CMSLM
LPP LPPENET
DTCs
DMS-BUS
TxcvrA
TxcvrB
TxcvrC
RFFEA
RFFEB
RFFEC
TFU
GPSR
GPS GPS
IOC
PSTN
CDSU DISCOCDSU
DISCO 1
DISCO 2Packets
ChipsRFChannel
Elements(FCH, SCH)
Selector
PDSNInternetVPNs
R-PInterface
February, 2008 132 - 60Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Section D
CDMA Messages and Call ProcessingCDMA Messages and Call Processing
February, 2008 132 - 61Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Messages in CDMA
In CDMA, most call processing events are driven by messagesSome CDMA channels exist for the sole purpose of carrying messages; they never carry user’s voice traffic
• Sync Channel (a forward channel)• Paging Channel (a forward channel)• Access Channel (a reverse channel)• On these channels, there are only messages, continuously all
of the timeSome CDMA channels exist just to carry user traffic
• Forward Traffic Channel• Reverse Traffic Channel• On these channels, most of the time is filled with traffic and
messages are sent only when there is something to doAll CDMA messages have very similar structure, regardless of thechannel on which they are sent
February, 2008 132 - 62Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
How CDMA Messages are Sent
CDMA messages on both forward and reverse traffic channels are normally sent via dim-and-burstMessages include many fields of binary dataThe first byte of each message identifies message type: this allows the recipient to parse the contentsTo ensure no messages are missed, all CDMA messages bear serial numbers and important messages contain a bit requesting acknowledgmentMessages not promptly acknowledged are retransmitted several times. If not acknowledged, the sender may release the callField data processing tools capture and display the messages for study
MSG_TYPE (‘00000110’)
ACK_SEQ
MSG_SEQ
ACK_REQ
ENCRYPTION
ERRORS_DETECTED
POWER_MEAS_FRAMES
LAST_HDM_SEQ
NUM_PILOTS
PILOT_STRENGTH
RESERVED (‘0’s)
8
3
3
1
2
5
10
2
4
6
0-7
NUM_PILOTS occurrences of this field:
Field Length (in bits)
EXAMPLE: A POWER MEASUREMENT
REPORT MESSAGE
t
February, 2008 132 - 63Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Message Vocabulary: Acquisition & Idle StatesSync Channel
Sync Channel Msg
Pilot Channel
No Messages
Paging Channel
Access Parameters Msg
System Parameters Msg
CDMA Channel List Msg
Extended SystemParameters Msg
Extended NeighborList Msg
Global ServiceRedirection Msg
Order Msg•Base Station Acknowledgment
•Lock until Power-Cycled• Maintenance required
many others…..
AuthenticationChallenge Msg
Status Request Msg
Feature Notification Msg
TMSI Assignment Msg
Channel AssignmentMsg
SSD Update Msg
Service Redirection Msg
General Page Msg
Null Msg Data Burst Msg
Access Channel
Registration Msg
Order Msg• Mobile Station Acknowldgment• Long Code Transition Request
• SSD Update Confirmationmany others…..
Origination Msg
Page Response Msg
Authentication ChallengeResponse Msg
Status Response Msg
TMSI AssignmentCompletion Message
Data Burst Msg
BTS
February, 2008 132 - 64Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Message Vocabulary: Conversation State
Reverse Traffic Channel
Order Message• Mobile Sta. Acknowledgment
•Long Code Transition Request
• SSD Update Confirmation• Connect
Authentication ChallengeResponse Msg
Flash WithInformation Msg
Data Burst Message
Pilot StrengthMeasurement Msg
Power MeasurementReport Msg
Send Burst DTMF Msg
OriginationContinuation Msg
Handoff Completion Msg
Parameters ResponseMessage
Service Request Msg
Service Response Msg
Service ConnectCompletion Message
Service Option ControlMessage
Status Response Msg
TMSI AssignmentCompletion Message
Forward Traffic ChannelOrder Msg
• Base Station Acknowledgment • Base Station Challenge
Confirmation• Message Encryption Mode
AuthenticationChallenge Msg
Alert WithInformation Msg
Data Burst Msg
Analog HandoffDirection Msg
In-Traffic SystemParameters Msg
Neighbor ListUpdate Msg
Send Burst DTMF Msg
Power ControlParameters Msg.
Retrieve Parameters Msg
Set Parameters Msg
SSD Update Msg
Flash WithInformation Msg
Mobile StationRegistered Msg
Status Request Msg
Extended HandoffDirection Msg
Service Request Msg
Service Response Msg
Service Connect Msg
Service OptionControl Msg
TMSI Assignment Msg
February, 2008 132 - 65Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Section E
CDMA Handset ArchitectureCDMA Handoffs
CDMA Handset ArchitectureCDMA Handoffs
February, 2008 132 - 66Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
What’s In a Handset? How does it work?
ReceiverRF SectionIF, Detector
TransmitterRF Section
Vocoder
Digital Rake Receiver
Traffic CorrelatorPN xxx Walsh xx ΣTraffic CorrelatorPN xxx Walsh xxTraffic CorrelatorPN xxx Walsh xx
Pilot SearcherPN xxx Walsh 0
Viterbi Decoder,Convl. Decoder,Demultiplexer
CPUDuplexer
TransmitterDigital Section
Long Code Gen.
Open Loop Transmit Gain Adjust
Messages
Messages
Audio
Audio
Packets
Symbols
SymbolsChips
RF
RF
AGC
time-
alig
ned
su
mm
ing
pow
er
Traffic CorrelatorPN xxx Walsh xx
Δtcont
rol
bits
February, 2008 132 - 67Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Rake Receiver
Every frame, handset uses combined outputs of the three traffic correlators (“rake fingers”)Each finger can independently recover a particular PN offset andWalsh codeFingers can be targeted on delayed multipath reflections, or even on different BTSsSearcher continuously checks pilots
Handset Rake Receiver
RF
PN Walsh
PN Walsh
PN Walsh
SearcherPN W=0
ΣVoice,Data,
Messages
Pilot Ec/Io
BTS
BTS
February, 2008 132 - 68Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA Soft Handoff Mechanics
CDMA soft handoff is driven by the handset• Handset continuously checks available pilots• Handset tells system pilots it currently sees• System assigns sectors (up to 6 max.), tells handset• Handset assigns its fingers accordingly• All messages sent by dim-and-burst, no muting!
Each end of the link chooses what works best, on a frame-by-frame basis!
• Users are totally unaware of handoff
Handset Rake Receiver
RFPN Walsh
PN Walsh
PN Walsh
SearcherPN W=0
ΣVoice,Data,
Messages
Pilot Ec/Io
BTS
BSCSwitch
BTS
Sel.
February, 2008 132 - 69Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Complete Rules of Soft Handoff
The Handset considers pilots in sets• Active: pilots of sectors actually in use• Candidates: pilots mobile requested, but
not yet set up & transmitting by system• Neighbors: pilots told to mobile by system,
as nearby sectors to check• Remaining: any pilots used by system but
not already in the other sets (div. by PILOT_INC)
Handset sends Pilot Strength Measurement Message to the system whenever:
• It notices a pilot in neighbor or remaining set exceeds T_ADD
• An active set pilot drops below T_DROP for T_TDROP time
• A candidate pilot exceeds an active by T_COMP
The System may set up all requested handoffs, or it may apply special manufacturer-specific screening criteria and only authorize some
65
Remaining
ActiveCandidateNeighbor 20
PILOT SETS
Min. M
embers
Req’d. B
y Std.
T_COMPT_ADD T_DROPT_TDROP
HANDOFF PARAMETERS
Exercise: How does a pilot in one set migrate into another set, for all cases? Identify the trigger, and the messages involved.
February, 2008 132 - 70Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Softer Handoff
Each BTS sector has unique PN offset & pilot Handset will ask for whatever pilots it wantsIf multiple sectors of one BTS simultaneously serve a handset, this is called Softer HandoffHandset can’t tell the difference, but softer handoff occurs in BTS in a single channel elementHandset can even use combination soft-softer handoff on multiple BTS & sectors
Handset Rake Receiver
RFPN Walsh
PN Walsh
PN Walsh
SearcherPN W=0
ΣVoice,Data,
Messages
Pilot Ec/Io
BTS
BSCSwitchSel.
February, 2008 132 - 71Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
What is Ec/Io?
Ec/Io is the measurement mobiles use to gauge strengths of the various nearby sectors they encounter
• Ec means the energy per chip of the pilot of the observed sector
• Io means the total power currently being picked up by the mobile
≈ x
LO
≈
RX Level(from AGC)
IFLNA
BW~30
MHz.
BW1.25MHz.
Handset Receiver
R
R
R
S
Rake
Why can’t the mobile just measure the signal strength of a sector directly with its receiver?
• all sectors are on the same frequency• the measurable signal strength on that frequency is just the
sum of all the individual signal powers• to distinguish them individually CDMA decoding must be used
Each sector dedicates 10-15% of its power to a steady test signal called the “pilot”. Mobiles can easily measure the pilot of a sector, determining its strength as a percentage of total received power
February, 2008 132 - 72Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Light Traffic Loading
Heavily Loaded
How Ec/Io Varies with Traffic Loading
Each sector transmits a certain amount of power, the sum of:
• pilot, sync, and paging• any traffic channels in use
at that momentEc/Io is the ratio of pilot power to total power
• On a sector with nobody talking, Ec/Io is typically about 50%, which is -3 db
• On a sector with maximum traffic, Ec/Io is typically about 20%, which is -7 db.
Ec/Io = (2/4)= 50%
= -3 db.
Ec/Io = (2/10)= 20%
= -7 db.
2w
1.5w
Pilot
PagingSync
I0
EC
Traffic Channels
6w
0.5w
2w
1.5w
Pilot
PagingSync I0EC
0.5w
February, 2008 132 - 73Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Many Sectors, Nobody Dominant
One Sector Dominant
How Ec/Io varies with RF Environment
In a “clean situation”, one sector is dominant and the mobile enjoys an Ec/Io just as good as it was when transmittedIn “pilot pollution”, too many sectors overlap and the mobile hears a “soup” made up of all their signals
• Io is the power sum of all the signals reaching the mobile
• Ec is the energy of a single sector’s pilot
• The large Io overrides the weak Ec; Ec/Io is low!
Io = -90 dbmEc = -96 dbmEc/Io = -6 db
Io = 10 signalseach -90 dbm
= -80 dbmEc of any onesector = -96
Ec/Io = -16 db
2w
1.5w
Pilot
PagingSync
I0
ECTraffic
Channels
4w
0.5w
BTS1
I0
EC
BTS2
BTS3
BTS4
BTS5
BTS6
BTS7
BTS8
BTS9
BTS10
PilotSync & Paging
TrafficPilot
Sync & PagingTraffic
PilotSync & Paging
TrafficPilot
Sync & PagingTraffic
PilotSync & Paging
TrafficPilot
Sync & PagingTraffic
PilotSync & Paging
TrafficPilot
Sync & PagingTraffic
PilotSync & Paging
TrafficPilot
Sync & PagingTraffic
February, 2008 132 - 74Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA Call ProcessingCDMA Call Processing
Section F
February, 2008 132 - 75Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s Acquire the System!Let’s Acquire the System!
Example 1
February, 2008 132 - 76Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Find a Frequency with a CDMA RF Signal
Mobile scans forward link frequencies:(Cellular or PCS, depending on model)
History ListPreferred Roaming List
until a CDMA signal is found.NO CDMA?! Go to AMPS,
or to a power-saving standby mode
HISTORYLIST/MRU
Last-used:FreqFreqFreqFreqFreqetc.
FREQUENCY LISTS:PREFERREDROAMINGLIST/PRL
System1System2System3System4System5etc.
Forward Link Frequencies(Base Station Transmit)
A D B E F C unlic.data
unlic.voice A D B E F C
1850MHz. 1910MHz. 1990 MHz.1930MHz.
1900 MHz. PCS Spectrum
824 MHz. 835 845 870 880 894
869
849
846.5825
890
891.5
Paging, ESMR, etc.A B A B
800 MHz. Cellular Spectrum
Reverse Link Frequencies(Mobile Transmit)
February, 2008 132 - 77Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
How Idle Mobiles Choose CDMA CarriersAt turnon, Idle mobiles use proprietary algorithms to find the initial CDMA carrier intended for them to useWithin that CDMA signal, two types of paging channel messages could cause the idle mobile to choose another frequency: CDMA Channel List Message and GSRM
Go to last frequency from MRU
Strongest PN, read
SyncIs SID
permitted?
No Signal
Preferred Only Bit 0
Denied SIDRead
Paging Channel
CDMA Ch List Message
Global Svc Redir Msg
HASH using IMSI
my ACCOLC? redirect
Is better SID
available?
PRLMRU Acq IdxYes
NoF1F2F3
to Analog
to another CDMA frequency or system
ConfigMessages:
remain
Steps from the CDMA standards
Steps from proprietary
SDAs
Proprietary SDA
databases
Start
LegendTypical MobileSystem Determination Algorithm
February, 2008 132 - 78Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Find Strongest Pilot, Read Sync Channel
Rake Fingers
Reference PN
Active Pilot
Ec/
Io
00
32K512
ChipsPN
1. Pilot Searcher Scans the Entire Range of PNs
All PN Offsets0
-20
98/05/24 23:14:09.817 [SCH] MSG_LENGTH = 208 bitsMSG_TYPE = Sync Channel MessageP_REV = 3MIN_P_REV = 2SID = 179NID = 0PILOT_PN = 168Offset IndexLC_STATE = 0x0348D60E013SYS_TIME = 98/05/24 23:14:10.160LP_SEC = 12LTM_OFF = -300 minutesDAYLT = 0PRAT = 9600 bpsRESERVED = 1
2. Put Rake finger(s) on strongest available PN, decode Walsh 32, and read Sync Channel Message
SYNC CHANNEL MESSAGE
Handset Rake Receiver
RF≈ x ≈
LO Srch PN??? W0
F1 PN168 W32F2 PN168 W32F3 PN168 W32
February, 2008 132 - 79Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Configuration Messages
After reading the Sync Channel, the mobile is now capable of reading the Paging Channel, which it now monitors constantlyBefore it is allowed to transmit or operate on this system, the mobile must collect a complete set of configuration messages Collection is a short process -- all configuration messages are repeated on the paging channel every 1.28 secondsThe configuration messages contain sequence numbers so the mobile can recognize if any of the messages have been freshly updated as it continues to monitor the paging channel
• Access parameters message sequence number• Configuration message sequence number• If a mobile notices a changed sequence number, or if 600
seconds passes since the last time these messages were read, the mobile reads all of them again
February, 2008 132 - 80Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Go to Paging Channel, Get Configured
Rake Fingers
Reference PN
Active Pilot
Ec/
Io
00
32K512
ChipsPN
All PN Offsets0
-20
Keep Rake finger(s) on strongest available PN, decode Walsh 1,
and monitor the Paging Channel
Read the Configuration Messages
Access Parameters Msg
System Parameters Msg
CDMA Channel List Msg
Extended SystemParameters Msg (*opt.)
(Extended*) NeighborList Msg
Global ServiceRedirection Msg (*opt.)
Now we’re ready to operate!!
Handset Rake Receiver
RF≈ x ≈
LO Srch PN??? W0
F1 PN168 W01F2 PN168 W01F3 PN168 W01
February, 2008 132 - 81Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Two Very Important Configuration Messages
98/05/24 23:14:10.427 [PCH] MSG_LENGTH = 184 bitsMSG_TYPE = Access Parameters MessagePILOT_PN = 168 Offset IndexACC_MSG_SEQ = 27ACC_CHAN = 1 channelNOM_PWR = 0 dB INIT_PWR = 0 dB PWR_STEP = 4 dBNUM_STEP = 5 Access Probes MaximumMAX_CAP_SZ = 4 Access Channel Frames MaximumPAM_SZ = 3 Access Channel FramesPersist Val for Acc Overload Classes 0-9 = 0Persist Val for Acc Overload Class 10 = 0Persist Val for Acc Overload Class 11 = 0Persist Val for Acc Overload Class 12 = 0Persist Val for Acc Overload Class 13 = 0Persist Val for Acc Overload Class 14 = 0Persist Val for Acc Overload Class 15 = 0Persistance Modifier for Msg Tx = 1 Persistance Modifier for Reg = 1 Probe Randomization = 15 PN chipsAcknowledgement Timeout = 320 msProbe Backoff Range = 4 Slots MaximumProbe Sequence Backoff Range = 4 Slots Max.Max # Probe Seq for Requests = 2 SequencesMax # Probe Seq for Responses = 2 SequencesAuthentication Mode = 1Random Challenge Value = Field OmittedReserved Bits = 99
ACCESS PARAMETERS MESSAGE98/05/24 23:14:11.126 [PCH] MSG_LENGTH = 264 bitsMSG_TYPE = System Parameters MessagePILOT_PN = 168 Offset IndexCONFIG_MSG_SEQ = 0SID = 179 NID = 0REG_ZONE = 0 TOTAL_ZONES = 0 ZONE_TIMER = 60 minMULT_SIDS = 0 MULT_NID = 0 BASE_ID = 8710BASE_CLASS = Public MacrocellularPAGE_CHAN = 1 channelMAX_SLOT_CYCLE_INDEX = 0HOME_REG = 0 FOR_SID_REG = 0 FOR_NID_REG = 1POWER_UP_REG = 0 POWER_DOWN_REG = 0PARAMETER_REG = 1 REG_PRD = 0.08 secBASE_LAT = 00D00'00.00N BASE_LONG = 000D00'00.00EREG_DIST = 0SRCH_WIN_A = 40 PN chipsSRCH_WIN_N = 80 PN chipsSRCH_WIN_R = 4 PN chipsNGHBR_MAX_AGE = 0PWR_REP_THRESH = 2 framesPWR_REP_FRAMES = 56 framesPWR_THRESH_ENABLE = 1PWR_PERIOD_ENABLE = 0PWR_REP_DELAY = 20 framesRESCAN = 0T_ADD = -13.0 Db T_DROP = -15.0 dB T_COMP = 2.5 dBT_TDROP = 4 secEXT_SYS_PARAMETER = 1RESERVED = 0GLOBAL_REDIRECT = 0
SYSTEM PARAMETERS MESSAGE
February, 2008 132 - 82Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Four Additional Configuration Messages
98/05/24 23:14:10.946 [PCH] MSG_LENGTH = 104 bitsMSG_TYPE = Extended System Parameters MessagePILOT_PN = 168 Offset IndexCONFIG_MSG_SEQ = 0 RESERVED = 0PREF_MSID_TYPE = IMSI and ESNMCC = 000 IMSI_11_12 = 00 RESERVED_LEN = 8 bitsRESERVED_OCTETS = 0x00 BCAST_INDEX = 0RESERVED = 0
EXTENDED SYSTEM PARAMETERS
98/05/17 24:21.566 Paging Channel: Global Service RedirectionPILOT_PN: 168, MSG_TYPE: 96, CONFIG_MSG_SEQ: 0Redirected access overload classes: { 0, 1 }, RETURN_IF_FAIL: 0, DELETE_TMSI: 0, Redirection to an analog system: EXPECTED_SID = 0 Do not ignore CDMA Available indicator on the redirected analog systemAttempt service on either System A or B with the custom system selection process
GLOBAL SERVICE REDIRECTION
98/05/24 23:14:11.486 [PCH]MSG_LENGTH = 216 bitsMSG_TYPE = Neighbor List MessagePILOT_PN = 168 Offset IndexCONFIG_MSG_SEQ = 0PILOT_INC = 4 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 220 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 52 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 500 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 8 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 176 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 304 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 136 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 384 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 216 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 68 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 328 Offset IndexNGHBR_CONFIG = 0 NGHBR_PN = 112 Offset IndexRESERVED = 0
NEIGHBOR LIST
98/05/24 23:14:10.786 [PCH]MSG_LENGTH = 72 bitsMSG_TYPE = CDMA Channel List MessagePILOT_PN = 168 Offset IndexCONFIG_MSG_SEQ = 0CDMA_FREQ = 283RESERVED = Field Omitted
CDMA CHANNEL LIST MESSAGE
February, 2008 132 - 83Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s do an Idle Mode Handoff!
Let’s do an Idle Mode Handoff!
Example 2
February, 2008 132 - 84Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Idle Mode Handoff
An idle mobile always demodulates the best available signal• In idle mode, it isn’t possible to do soft handoff and listen to
multiple sectors or base stations at the same time -- the paging channel information stream is different on each sector, not synchronous -- just like ABC, NBC, CBS, and CNN TV news programs aren’t in word-sync for simultaneous viewing
• Since a mobile can’t combine signals, the mobile must switch quickly, always enjoying the best available signal
The mobile’s pilot searcher is constantly checking neighbor pilotsIf the searcher notices a better signal, the mobile continues on the current paging channel until the end of the current superframe, then instantly switches to the paging channel of the new signal
• The system doesn’t know the mobile did this! (Does NBC’s Tom Brokaw know you just switched your TV to CNN?)
On the new paging channel, if the mobile learns that registration is required, it re-registers on the new sector
February, 2008 132 - 85Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Idle Mode on the Paging Channel: Meet the Neighbors, track the Strongest Pilot
Ec/
IoAll PN Offsets
00
32K512
ChipsPN
0
-20
Neighbor Set
The phone’s pilot searcher constantly checks the pilots listed in the Neighbor List Message
If the searcher ever notices a neighbor pilot substantially stronger than the current reference pilot, it becomes the new reference pilot
and the phone switches over to its paging channel on the next superframe.This is called an idle mode handoff.
Rake Fingers
Reference PN
Active Pilot
SRCH_WIN_A
SRCH_WIN_N
Mobile Rake RX
Srch PN??? W0
F1 PN168 W01F2 PN168 W01F3 PN168 W01
February, 2008 132 - 86Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Phone Operation on the Access Channel
A sector’s Paging Channel announces 1 (typ) to 32 (max) Access Channels: PN Long Code offsets for mobiles to use if accessing the system.
• For mobiles sending Registration, Origination, Page Responses
• Base Station always listening!On the access channel, phones are not yet under BTS closed-loop power control!Phones access the BTS by “probing” at power levels determined by receive power and an open loop formula
• If “probe” not acknowledged by BTS within ACC_TMO (~400 mS.), phone will wait a random time (~200 mS) then probe again, stronger by PI db.
• There can be 15 max. (typ. 5) probes in a sequence and 15 max. (typ. 2) sequences in an access attempt
• most attempts succeed on first probe!The Access Parameters message on the paging channel announces values of all related parameters
ACCESS
RV TFC
BTS
Channel Assnmt. Msg.
Origination Msg
Base Sta. Acknlgmt. Order
TFC frames of 000s
TFC preamble of 000s
Base Sta. Acknlgmt. Order
Mobile Sta. Ackngmt. Order
Service Connect Msg.
Svc. Connect Complete Msg
Base Sta. Acknlgmt. Order
Call is Established!
MSProbing
PAGING
FW TFC
PAGING
RV TFC
FW FC
RV TFC
FW TFC
FW TFC
A Successful Access Attempt
a Probe Sequencean Access Attempt
Success!
an Access Probe
February, 2008 132 - 87Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s Register!Let’s Register!
Example 3
February, 2008 132 - 88Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Registration
Registration is the process by which an idle mobile lets the system know it’s awake and available for incoming calls
• this allows the system to inform the mobile’s home switch of the mobile’s current location, so that incoming calls can be delivered
• registration also allows the system to intelligently page the mobile only in the area where the mobile is currently located, thereby eliminating useless congestion on the paging channels in other areas of the system
There are many different conditions that could trigger an obligation for the mobile to register
• there are flags in the System Parameters Message which tell the mobile when it must register on the current system
February, 2008 132 - 89Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
An Actual Registration
16:18:27.144 Access Channel: Registration ACK_SEQ: 7 MSG_SEQ: 1 ACK_REQ: 1 VALID_ACK: 0ACK_TYPE: 0MSID_TYPE: 3, ESN: [0x 01 99 0d fc]MFR 1, Reserved 38, Serial Number 69116,IMSI: (Class: 0, Class_0_type: 1) [0x 01 8d 31 74 29 36]00-416-575-0421AUTH_MODE: 0REG_TYPE: Timer-basedSLOT_CYCLE_INDEX: 2MOB_P_REV: 1EXT_SCM: 1SLOTTED_MODE: 1MOB_TERM: 1
REGISTRATION MESSAGE
18:26.826 [PCH] System Parameters Message Pilot_PN: 32CONFIG_MSG_SEQ: 14 SID: 16420 NID: 0,REG_ZONE: 0 TOTAL_ZONES: 0 Zone timer length (min): 1MULT_SIDS: 0 MULT_NIDS: 0 BASE_ID: 1618 BASE_CLASS: ReservedPAG_CHAN: 1 MAX_SLOT_CYCLE_INDEX: 2 HOME_REG: 1 FOR_SID_REG: 1 FOR_NID_REG: 1, POWER_UP_REG: 1 POWER_DOWN_REG: 1 PARAMETER_REG: 1 Registration period (sec): 54 Base station 0°00´00.00¨ Lon., 0°00´00.00° Lat. REG_DIST: 0SRCH_WIN_A (PN chips): 28 SRCH_WIN_N (PN chips): 100, SRCH_WIN_R (PN chips): 130 NGHBR_MAX_AGE: 2PWR_REP_THRESH: 2 PWR_REP_FRAMES (frames): 15PWR_THRESH_ENABLE: 1 PWR_PERIOD_ENABLE: 0, PWR_REP_DELAY: 1 (4 frames) RESCAN: 0, T_ADD: -14.0dB T_DROP: -16.0dB T_COMP: 2.5dB, T_TDROP: 4s EXT_SYS_PARAMETER: 1 EXT_NGHBR_LIST: 1 GLOBAL_REDIRECT: 0
SYSTEM PARAMETERS MESSAGE
16:18:27.506 Paging Channel: Order ACK_SEQ: 1 MSG_SEQ: 0 ACK_REQ: 0 VALID_ACK: 1 MSID_TYPE: 2 IMSI: (Class: 0, Class_0_type: 3) [0x 02 47 8d 31 74 29 36] (302) 00-416-575-0421Order type: Base Station Acknowledgement Order
BASE STATION ACKNOWLEDGMENT
The System Parameters Message tells all mobiles when they should register.
This mobile notices that it is obligated to register, so it transmits a Registration
Message.
The base station confirms that the mobile’s registration message was received. We’re officially registered!
February, 2008 132 - 90Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s Receive an incoming Call!
Let’s Receive an incoming Call!
Example 4
February, 2008 132 - 91Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Receiving an Incoming Call
All idle mobiles monitor the paging channel to receive incoming calls.When an incoming call appears, the paging channel notifies the mobile in a General Page Message.A mobile which has been paged sends a Page Response Message on the access channel.The system sets up a traffic channel for the call, then notifies the mobile to use it with a Channel Assignment Message.The mobile and the base station notice each other’s traffic channel signals and confirm their presence by exchanging acknowledgment messages.The base station and the mobile negotiate what type of call this will be -- I.e., 13k voice, etc.The mobile is told to ring and given a “calling line ID” to display.When the human user presses the send button, the audio path is completed and the call proceeds.
February, 2008 132 - 92Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
An Actual Page and Page Response
98/05/24 23:14:46.425 [ACH] Page Response MessageMSG_LENGTH = 216 bitsMSG_TYPE = Page Response MessageACK_SEQ = 1 MSG_SEQ = 2 ACK_REQ = 1VALID_ACK = 1 ACK_TYPE = 2MSID_TYPE = IMSI and ESN MSID_LEN = 9 octetsESN = 0xD30E415C IMSI_CLASS = 0IMSI_CLASS_0_TYPE = 0 RESERVED = 0IMSI_S = 6153300644AUTH_MODE = 1AUTHR = 0x307B5 RANDC = 0xC6 COUNT = 0MOB_TERM = 1 SLOT_CYCLE_INDEX = 0MOB_P_REV = 3 SCM = 106REQUEST_MODE = Either Wide Analog or CDMA OnlySERVICE_OPTION = 32768 PM = 0NAR_AN_CAP = 0 RESERVED = 0
PAGE RESPONSE MESSAGE
98/05/24 23:14:46.127 [PCH] General Page MessageMSG_LENGTH = 128 bits MSG_TYPE = General Page MessageCONFIG_MSG_SEQ = 1 ACC_MSG_SEQ = 20CLASS_0_DONE = 1CLASS_1_DONE = 1 RESERVED = 0BROADCAST_DONE = 1 RESERVED = 0ADD_LENGTH = 0 bits ADD_PFIELD = Field OmittedPAGE_CLASS = 0 PAGE_SUBCLASS = 0MSG_SEQ = 1 IMSI_S = 6153300644SPECIAL_SERVICE = 1SERVICE_OPTION = 32768RESERVED = Field Omitted
GENERAL PAGE MESSAGE
98/05/24 23:14:46.768 [PCH] Order MessageMSG_LENGTH = 112 bitsMSG_TYPE = Order MessageACK_SEQ = 2 MSG_SEQ = 0 ACK_REQ = 0VALID_ACK = 1 ADDR_TYPE = IMSI ADDR_LEN = 40 bitsIMSI_CLASS = 0 IMSI_CLASS_0_TYPE = 0 RESERVED = 0 IMSI_S = 6153300644ORDER = Base Station Acknowledgement OrderADD_RECORD_LEN = 0 bitsOrder-Specific Fields = Field Omitted RESERVED = 0
BASE STATION ACKNOWLEDGMENT
The system pages the mobile, 615-330-0644.
The base station confirms that the mobile’s page response was received. Now the
mobile is waiting for channel assignment,expecting a response within 12 seconds.
The mobile responds to the page.
February, 2008 132 - 93Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Channel Assignment and Traffic Channel Confirmation
18:14:47.598 Reverse Traffic Channel: Order ACK_SEQ: 0 MSG_SEQ: 0 ACK_REQ: 0 ENCRYPTION: 0Mobile Station Acknowledgement Order
MOBILE STATION ACKNOWLEDGMENT
18:14:47.027 Paging Channel: Channel Assignment ACK_SEQ: 2 MSG_SEQ: 1 ACK_REQ: 0 VALID_ACK: 1MSID_TYPE: 2 IMSI: (Class: 0, Class_0_type: 0) [0x 01 f8 39 6a 15] 615-330-0644 ASSIGN_MODE: Traffic Channel AssignmentADD_RECORD_LEN: 5 FREQ_INCL: 1 GRANTED_MODE: 2CODE_CHAN: 43 FRAME_OFFSET: 2ENCRYPT_MODE: Encryption disabledBAND_CLASS: 800 MHz cellular bandCDMA_FREQ: 283
CHANNEL ASSIGNMENT MESSAGE
18:14:47.581 Forward Traffic Channel: Order ACK_SEQ: 7 MSG_SEQ: 0 ACK_REQ: 1 ENCRYPTION: 0 USE_TIME: 0 ACTION_TIME: 0Base Station Acknowledgement Order
BASE STATION ACKNOWLEDGMENT
Only about 400 ms. after the base station acknowledgment order, the mobile receives
the channel assignment message.
The base station is already sending blank frames on
the forward channel,using the assigned Walsh code.
The mobile sees at least two good blank frames in a row on
the forward channel, and concludes this is the right traffic channel. It sends a preamble of two blank frames of its own on the reverse traffic channel.
The base station acknowledges receiving the mobile’s preamble.
The mobile station acknowledges the base station’s acknowledgment.
Everybody is ready!
February, 2008 132 - 94Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Service Negotiation and Mobile Alert
18:14:47.835 Reverse Traffic Channel: Service Connect Completion ACK_SEQ: 1 MSG_SEQ: 3 ACK_REQ: 1 ENCRYPTION: 0 SERV_CON_SEQ: 0
SERVICE CONNECT COMPLETE MSG.
18:14:47.760 Forward Traffic Channel: Service Connect ACK_SEQ: 0 MSG_SEQ: 1 ACK_REQ: 0 ENCRYPTION: 0USE_TIME: 0 ACTION_TIME: 0 SERV_CON_SEQ: 0Service Configuration: supported Transmission: Forward Traffic Channel Rate (Set 2): 14400, 7200, 3600, 1800 bps Reverse Traffic Channel Rate (Set 2): 14400, 7200, 3600, 1800 bps Service option: (6) Voice (13k) (0x8000) Forward Traffic Channel: Primary Traffic Reverse Traffic Channel: Primary Traffic
SERVICE CONNECT MESSAGENow that both sides have arrived on the
traffic channel, the base station proposes that the requested call
actually begin.
The mobile agrees and says its ready to play.
18:14:47.961 Forward Traffic Channel: Alert With Information ACK_SEQ: 3 MSG_SEQ: 1 ACK_REQ: 1 ENCRYPTION: 0SIGNAL_TYPE = IS-54B Alerting ALERT_PITCH = Medium Pitch (Standard Alert)SIGNAL = Long RESERVED = 0RECORD_TYPE = Calling Party NumberRECORD_LEN = 96 bitsNUMBER_TYPE = National NumberNUMBER_PLAN = ISDN/Telephony Numbering PlanPI = Presentation Allowed SI = Network ProvidedCHARi = 6153000124 RESERVED = 0 RESERVED = 0
ALERT WITH INFORMATION MESSAGE
The base station orders the mobile to ring, and gives it the calling party’s number to display.
18:14:48.018 Reverse Traffic Channel: Order ACK_SEQ: 1 MSG_SEQ: 4 ACK_REQ: 0ENCRYPTION: 0 Mobile Station Acknowledgement Order
The mobile says it’s ringing.
SERVICE CONNECT COMPLETE is a major milestone in call processing. Up until now, this was an access attempt.
Now it is officially a call.
February, 2008 132 - 95Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Human Answers! Connect Order
The mobile has been ringing for several seconds. The human user finally comes over and presses the send
button to answer the call.
Now the switch completes the audio circuit and the two callers can talk!
18:14:54.920 Forward Traffic Channel: Order ACK_SEQ: 0 MSG_SEQ: 1 ACK_REQ: 0 ENCRYPTION: 0 USE_TIME: 0 ACTION_TIME: 0 Base Station Acknowledgement Order
BASE STATION ACKNOWLEDGMENT
18:14:54.758 Reverse Traffic Channel: Order ACK_SEQ: 6 MSG_SEQ: 0 ACK_REQ: 1 ENCRYPTION: 0 Connect Order
CONNECT ORDER
February, 2008 132 - 96Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s make an Outgoing Call!Let’s make an Outgoing Call!
Example 5
February, 2008 132 - 97Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Placing an Outgoing Call
The mobile user dials the desired digits, and presses SEND.Mobile transmits an Origination Message on the access channel.The system acknowledges receiving the origination by sending a base station acknowledgement on the paging channel.The system arranges the resources for the call and starts transmitting on the traffic channel.The system notifies the mobile in a Channel Assignment Message on the paging channel.The mobile arrives on the traffic channel.The mobile and the base station notice each other’s traffic channel signals and confirm their presence by exchanging acknowledgment messages.The base station and the mobile negotiate what type of call this will be -- I.e., 13k voice, etc.The audio circuit is completed and the mobile caller hears ringing.
February, 2008 132 - 98Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Origination17:48:53.144 Access Channel: Origination ACK_SEQ: 7 MSG_SEQ: 6 ACK_REQ: 1 VALID_ACK: 0 ACK_TYPE: 0 MSID_TYPE: 3 ESN: [0x 00 06 98 24] MFR 0 Reserved 1 Serial Number 170020 IMSI: (Class: 0, Class_0_type: 0) [0x 03 5d b8 97 c2] 972-849-5073AUTH_MODE: 0 MOB_TERM: 1SLOT_CYCLE_INDEX: 2 MOB_P_REV: 1 EXT_SCM: 1DualMode: 0 SLOTTED_MODE: 1 PowerClass: 0REQUEST_MODE: CDMA only SPECIAL_SERVICE: 1 Service option: (6) Voice (13k) (0x8000) PM: 0 DIGIT_MODE: 0 MORE_FIELDS: 0 NUM_FIELDS: 11Chari: 18008900829 NAR_AN_CAP: 0
ORIGINATION MESSAGE
17:48:53.487 Paging Channel: Order ACK_SEQ: 6 MSG_SEQ: 0 ACK_REQ: 0 VALID_ACK: 1 MSID_TYPE: 2IMSI: (Class: 0, Class_0_type: 0) [0x 03 5d b8 97 c2] 972-849-5073 Base Station Acknowledgment Order
BASE STATION ACKNOWLEDGMENT
The mobile sends an origination message
on the access channel.
The base station confirms that the origination message
was received.17:48:54.367 Paging Channel: Channel Assignment ACK_SEQ: 6 MSG_SEQ: 1 ACK_REQ: 0 VALID_ACK: 1MSID_TYPE: 2 IMSI: (Class: 0, Class_0_type: 0) [0x 03 5d b8 97 c2] 972-849-5073 ASSIGN_MODE: Traffic Channel Assignment, ADD_RECORD_LEN: 5 FREQ_INCL: 1 GRANTED_MODE: 2CODE_CHAN: 12 FRAME_OFFSET: 0 ENCRYPT_MODE: Encryption disabled BAND_CLASS: 1.8 to 2.0 GHz PCS band CDMA_FREQ: 425
CHANNEL ASSIGNMENT MESSAGE
The base station sends a Channel Assignment
Message and the mobile goes to the traffic channel.
February, 2008 132 - 99Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Traffic Channel Confirmation
17:48:54.835 Reverse Traffic Channel: Order ACK_SEQ: 0 MSG_SEQ: 0 ACK_REQ: 0 ENCRYPTION: 0 Mobile Station Acknowledgment Order
MOBILE STATION ACKNOWLEDGMENT17:48:54.757 Forward Traffic Channel: Order ACK_SEQ: 7 MSG_SEQ: 0 ACK_REQ: 1 ENCRYPTION: 0USE_TIME: 0 ACTION_TIME: 0 Base Station Acknowledgment Order
BASE STATION ACKNOWLEDGMENT
The base station is already sending blank frames on
the forward channel,using the assigned Walsh code.
The mobile sees at least two good blank frames in a row on
the forward channel, and concludes this is the right traffic channel. It sends a preamble of two blank frames of its own on the reverse traffic channel.
The base station acknowledges receiving the mobile’s preamble.
The mobile station acknowledges the base station’s acknowledgment.
Everybody is ready!
February, 2008 132 - 100Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Service Negotiation and Connect Complete
17:48:55.137 Reverse Traffic Channel: Service Connect Completion ACK_SEQ: 1, MSG_SEQ: 0, ACK_REQ: 1, ENCRYPTION: 0, SERV_CON_SEQ: 0
SERVICE CONNECT COMPLETE MSG.
17:48:55.098 Forward Traffic Channel: Service Connect ACK_SEQ: 7 MSG_SEQ: 1 ACK_REQ: 1 ENCRYPTION: 0USE_TIME: 0 ACTION_TIME: 0 SERV_CON_SEQ: 0 Service Configuration Supported Transmission: Forward Traffic Channel Rate (Set 2): 14400, 7200, 3600, 1800 bpsReverse Traffic Channel Rate (Set 2): 14400, 7200, 3600, 1800 bpsService option: (6) Voice (13k) (0x8000) Forward Traffic Channel: Primary TrafficReverse Traffic Channel: Primary Traffic
SERVICE CONNECT MESSAGENow that the traffic channel is working
in both directions, the base station proposes that the requested call
actually begin.
The mobile agrees and says its ready to play.
17:48:55.779 Forward Traffic Channel: Order ACK_SEQ: 0 MSG_SEQ: 0 ACK_REQ: 0 ENCRYPTION: 0USE_TIME: 0 ACTION_TIME: 0 Base Station Acknowledgment Order
BASE STATION ACKNOWLEDGMENT
The base station agrees. SERVICE CONNECT COMPLETE is a major milestone in call processing. Up until now, this was an access attempt.
Now it is officially a call.
Now the switch completes the audio circuit and the two callers can talk!
February, 2008 132 - 101Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s End a Call!Let’s End a Call!
Example 6
February, 2008 132 - 102Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Ending A Call
A normal call continues until one of the parties hangs up. Thataction sends a Release Order, “normal release”. The other side of the call sends a Release Order, “no reason given”.
• If a normal release is visible, the call ended normally.At the conclusion of the call, the mobile reacquires the system.
• Searches for the best pilot on the present CDMA frequency• Reads the Sync Channel Message• Monitors the Paging Channel steadily
Several different conditions can cause a call to end abnormally:• the forward link is lost at the mobile, and a fade timer acts• the reverse link is lost at the base station, and a fade timer acts• a number of forward link messages aren’t acknowledged, and the
base station acts to tear down the link• a number of reverse link messages aren’t acknowledged, and the
mobile station acts to tear down the link
February, 2008 132 - 103Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
A Beautiful End to a Normal Call
17:49:21.715 Reverse Traffic Channel: Order ACK_SEQ: 1 MSG_SEQ: 1 ACK_REQ: 1 ENCRYPTION: 0 Release Order (normal release)
MOBILE RELEASE ORDER
BASE STATION ACKNOWLEDGMENT17:49:21.936 Forward Traffic Channel: Order ACK_SEQ: 1 MSG_SEQ: 2 ACK_REQ: 0 ENCRYPTION: 0, USE_TIME: 0 ACTION_TIME: 0 Base Station Acknowledgement Order
At the end of a normal call, this mobile user pressed end.
The mobile left the traffic channel, scanned to find the best pilot, and read
the Sync Channel Message.
BASE STATION RELEASE ORDER17:49:21.997 Forward Traffic Channel: Order ACK_SEQ: 1 MSG_SEQ: 3 ACK_REQ: 0 ENCRYPTION: 0USE_TIME: 0 ACTION_TIME: 0 Release Order (no reason given)
17:49:22.517 Sync Channel MSG_TYPE: 1 Sync Channel MessageP_REV: 1 MIN_P_REV: 1SID: 4112 NID: 2 Pilot_PN: 183 LC_STATE: 0x318fe5d84a5 SYS_TIME: 0x1ae9683dcLP_SEC: 9 LTM_OFF: -10 DAYLT: 1 Paging Channel Data Rate: 9600 CDMA_FREQ: 425
SYNC CHANNEL MESSAGE
The base station acknowledged receiving the message, then sent
a release message of its own.
February, 2008 132 - 104Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s receive Notificationof a Voice Message!
Let’s receive Notificationof a Voice Message!
Example 7
February, 2008 132 - 105Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Feature Notification
98/06/30 21:16:44.368 [PCH] Feature Notification MessageMSG_LENGTH = 144 bitsMSG_TYPE = Feature Notification MessageACK_SEQ = 0MSG_SEQ = 0ACK_REQ = 1VALID_ACK = 0ADDR_TYPE = IMSIADDR_LEN = 56 bitsIMSI_CLASS = 0IMSI_CLASS_0_TYPE = 3RESERVED = 0MCC = 302IMSI_11_12 = 00IMSI_S = 9055170325RELEASE = 0RECORD_TYPE = Message WaitingRECORD_LEN = 8 bitsMSG_COUNT = 1RESERVED = 0
FEATURE NOTIFICATION MESSAGE
The Feature Notification Message on the Paging Channel tells a specific mobile it has voice messages waiting.
There are other record types to notify the mobile of other features.
The mobile confirms it has received the notification by sending a Mobile Station Acknowledgment Order on the access
channel.
MOBILE STATION ACKNOWLEDGMENT
February, 2008 132 - 106Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Let’s do a Handoff!Let’s do a Handoff!
Example 8
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0107
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SYSTEM ACQUISITIONAt turn-on, and after the end of every call, a mobile
makes a fresh attempt to acquire the system. It scans all the PN offsets in tiny steps to be sure no pilot signal is missed. After the scan is complete, the mobile locks to the strongest pilot it has found.
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E C/I O
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Strongest
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0108
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IDLE MODE The strongest pilot is now the only Active pilot.
The mobile puts its rake fingers on this PN and decodes Walsh Code 32, the Sync channel.The Sync channel announces the system (SID) and network (NID); how to make the long code properly synchronized (Long Code State); and when the 20 ms. frames begin on the Paging and traffic channels.Now the mobile knows how to receive the paging channel!
It begins continuously listening to the paging channel. Soon it receives the neighbor list message.
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E C/I O
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0109
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3 Db, 5 sec.
IDLE MODE HANDOFF
In idle mode, listening to the paging channel, the mobile can have only one active pilot at a time. Soft handoff is not possible during idle mode, since the messages on one sector’s paging channel do not match the messages on another sector’s paging channel.
The mobile’s pilot searcher is continuously checking both the active pilot (to keep the rake fingers aligned on the best multipath signals) and the neighbor pilots. If a neighbor pilot is noticed at least 3 db stronger than the current active pilot, and it remains so for 5 seconds, the mobile just stops listening to the old active and the stronger neighbor becomes the new active pilot. If the current active pilot should fade and the mobile loses the paging channel, it is allowed to switch to another stronger sector immediately without waiting 5 seconds.
The system does not even know the mobile has done an idle mode handoff, since no messages are exchanged. The mobile just starts listening to a different sector!Of course, if the mobile notices that the new sector has a different SID or NID from the old sector, it will register to let the new system know it has arrived.
(Settable parameters)
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E C/I O
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0110
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T_ADD
T_DROP
IN CALL
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When a mobile begins a call, it has only one active pilot – the same sector it was listening to in idle mode. It remembers the same neighbor list from its idle time.During a call, the mobile’s pilot searcher is scanning alternately the active pilot and each pilot on the neighbor list.If the mobile notices any pilots with EC/IO above T_Add, it will immediately send a PSMM to the system, asking for handoff with them.
E C/I O
db.
PSMM: PN248, -5, keep; PN134, -10, keep; PN102, -11.5, keep BTS
SEE ADDITIONAL PILOTS >T_ADD,
SEND PSMM!!
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0111
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IN CALL
T_ADD
T_DROP
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After the mobile has sent the PSMM, the newly-requested pilots are considered “Candidates”. The mobile cannot begin listening to them yet, because they do not have channel elements set up yet to simulcast the traffic channel, and the mobile must also be told which walsh codes have been assigned for it to listen to.The mobile patiently waits for the Extended Handoff Direction Message.
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WAITfor EHDM
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0112
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T_ADD
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EHDM: PN248, W14; PN134, W08; PN102, W52 BTS
IN CALL With approximately 500 ms after sending the PSMM, the mobile receives the Extended Handoff Direction Message (EHDM). The base station has authorized the handoff on all the requested sectors, and included the walsh codes the mobile must know in order to hear the sectors.After beginning to use the new pilots, the mobile confirms by sending a Handoff Completion Message. Then the system sends the mobile a new Neighbor List Update message.
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RECEIVEEHDM
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0113
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T_ADD
T_DROP
IN CALL
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One of the active pilots, PN134, has faded below T_Drop.The mobile puts PN134 on a “probation watch” – waiting to see if it remains below T_Drop for T_TDrop seconds .
E C/I O
db.
AN ACTIVE PILOTFALLS BELOW
T_DROP
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T_TDrop
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0114
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T_ADD
T_DROP
IN CALL
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If PN134 recovers, becoming stronger than T_Drop before the T_TDroptime has passed, the mobile “forgives” its earlier weakness and will not send a PSMM to request any change.
E C/I O
db.
PILOT RECOVERS,REMAINS ACTIVE
Act
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0115
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T_DROP
IN CALL
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PN134 has faded below T_Drop again.The mobile puts PN134 on a “probation watch” – waiting to see if it remains below T_Drop for T_TDrop seconds .
E C/I O
db.
AN ACTIVE PILOTFALLS BELOW
T_DROPAGAIN
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T_TDrop
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0116
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T_ADD
T_DROP
IN CALL
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If PN134 remains below T_Drop for T_TDrop seconds, the mobile sends a PSMM requesting to drop it from the handoff.
E C/I O
db.
PSMM: PN248, -5, keep; PN134, -16, drop;PN102, -11.5, keep BTS
PILOT REMAINSBELOW T_DROPFOR T_TDROP
SECONDS.SEND PSMMTO REMOVE!
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>T_TDrop
!
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0117
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T_ADD
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IN CALL
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The mobile waits for an Extended Handoff Direction Message (EHDM), giving permission to drop the pilot from the Active set.
E C/I O
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WAIT FOREHDM
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0118
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T_ADD
T_DROP
IN CALL
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PN134 is now dropped from the Active set, and becomes a neighbor. The mobile continues with Active pilots PN102 and PN248.
E C/I O
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ReceiveEHDM,DropPilot EHDM: PN248, W14;
PN102, W52BTS
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0119
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IN CALLSEE ADDITIONAL PILOTS >T_ADD,
SEND PSMM!!
The mobile has just noticed several neighbor pilots have risen above T_ADD. It will immediately send a PSMM requesting to add them in handoff. It quickly sends a PSMM requesting handoff with them.
PSMM: PN248, -5, keep; PN300, -3.5, keep;PN134, -10.5, keep; PN488, -10.5, keep;PN102, -11.5, keep; PN328, -11.5, keep;PN200, -12, keep; PN396, -12.5, keep;PN420, -12, keep; PN504, -12, keep BTS
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0120
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IN CALL
WAITfor EHDM
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After the mobile has sent the PSMM, the newly-requested pilots are considered “Candidates”. The mobile cannot begin listening to them yet, because they do not have channel elements set up yet to simulcast the traffic channel, and the mobile must also be told which walsh codes have been assigned for it to listen to.The mobile patiently waits for the Extended Handoff Direction Message.
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0121
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RECEIVEEHDM
T_ADD
T_DROP
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EHDM: PN300, W31; PN248, W14;PN134, W08; PN488, W10;PN328, W27; PN102, W52 BTS
IN CALL
The mobile receives the Extended Handoff Direction Message, and implements the handoff with the pilots listed in the message. The BSC has chosen the strongest six pilots requested in the previous PSMM. Only the strongest 6 signals requested by the mobile are chosen to be active.PN 200, PN396, PN420 and PN504 are Unassigned Candidates.
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0122
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T_DROP
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IN CALL PSMM: PN248, -5, keep; PN300, -3.5, keep;PN134, -10.5, keep; PN488, -10.5, keep;PN102, -11.5, keep; PN328, -11.5, keep;PN200, -12, keep; PN396, -12.5, keep;PN416, -10.5, keep; PN420, -12, keep; PN504, -12, keep
BTS
The mobile notices that PN416 has just grown stronger, and is now above T_Add. It sends a PSMM requesting handoff with it and the other 10 signals above T_Add.
SEE ADDITIONAL PILOTS >T_ADD,
SEND PSMM!!
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0123
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IN CALL
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After the mobile has sent the PSMM, the newly-requested pilots are considered “Candidates”. The mobile cannot begin listening to them yet, because they do not have channel elements set up yet to simulcast the traffic channel, and the mobile must also be told which walsh codes have been assigned for it to listen to.The mobile patiently waits for the Extended Handoff Direction Message.
WAITfor EHDM
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0124
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T_ADD
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IN CALL
The mobile receives the Extended Handoff Direction Message, and implements the handoff with the pilots listed in the message. The BSC has chosen the strongest six pilots requested in the previous PSMM. Only the strongest 6 signals requested by the mobile are chosen to be active.Notice that PN416 replaces PN102. PN102, PN200, PN396, PN420 and PN504 are Unassigned Candidates.
RECEIVEEHDM
EHDM: PN300, W31; PN248, W14;PN134, W08; PN488, W10;PN416, W52; PN396, W34 BTS
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February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0125
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T_ADD
T_DROP
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IN CALL
Suppose T_COMP = 4 db. The mobile notices that the strongest candidate, PN396, has grown T_COMP db stronger than the weakest active pilot, PN328.This triggers the mobile to send a new PSMM including all the pilots above T_ADD. All of them were already either actives or candidates, but the new PSMM includes the new current strength of each pilot.
Notice T_COMPtrigger, send
EHDM
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PSMM: PN248, -5, keep; PN300, -3.5, keep;PN134, -10.5, keep; PN488, -10.5, keep;PN102, -11.5, keep; PN328, -14, keep;PN200, -12, keep; PN396, -10, keep;PN416, -10.5, keep; PN420, -12, keep; PN504, -12, keep
BTS
T_COMP
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0126
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IN CALLWAIT
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Both before and after the mobile sends the PSMM, the active pilots are the same and the candidate pilots are the same. The mobile patiently waits for the Extended Handoff Direction Message, which may cause some of the pilots to change sets.
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0127
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IN CALL
Notice that PN396 has become Active, replacing PN328.
RECEIVEEHDM
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EHDM: PN300, W31; PN248, W14;PN134, W08; PN488, W10;PN416, W52; PN328, W27 BTS
February, 2008 132 - 128Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Messages from a HandoffMessages from a Handoff
February, 2008 132 - 129Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Call is Already Established. What Next?E
c/Io
All PN Offsets
0
032K
512Chips
PN
0
-20
Neighbor Set
The call is already in progress. PN 168 is the only active signal,and also is our timing reference.
Continue checking the neighbors.
If we ever notice a neighbor with Ec/Io above T_ADD,ask to use it! Send a Pilot Strength Measurement Message!
T_ADD
Rake Fingers
Reference PN
Active Pilot
10752
16832002
50014080
220
! !
Mobile Rake RX
Srch PN??? W0
F1 PN168 W61F2 PN168 W61F3 PN168 W61
February, 2008 132 - 130Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Mobile Requests the Handoff!
98/05/24 23:14:02.205 [RTC] Pilot Strength Measurement MessageMSG_LENGTH = 128 bitsMSG_TYPE = Pilot Strength Measurement MessageACK_SEQ = 5 MSG_SEQ = 0 ACK_REQ = 1ENCRYPTION = Encryption Mode DisabledREF_PN = 168 Offset Index (the Reference PN)PILOT_STRENGTH = -6.0 dBKEEP = 1PILOT_PN_PHASE = 14080 chips (PN220+0chips)PILOT_STRENGTH = -12.5 dBKEEP = 1PILOT_PN_PHASE = 32002 chips (PN500 + 2 chips)PILOT_STRENGTH = -11.0 dBKEEP = 1RESERVED = 0
PILOT STRENGTH MEASUREMENT MESSAGE
98/05/24 23:14:02.386 [FTC] Order MessageMSG_LENGTH = 64 bitsMSG_TYPE = Order MessageACK_SEQ = 0 MSG_SEQ = 0 ACK_REQ = 0ENCRYPTION = Encryption Mode DisabledUSE_TIME = 0 ACTION_TIME = 0ORDER = Base Station Acknowledgment OrderADD_RECORD_LEN = 0 bitsOrder-Specific Fields = Field Omitted RESERVED = 0
BASE STATION ACKNOWLEDGMENT
Just prior to this message, this particular mobile already was in handoff with PN 168 and 220. This pilot strength measurement message reports PN 500 has increased above T_Add, and the mobile wants to use it too.
The base station acknowledges receiving the Pilot Strength Measurement Message.
February, 2008 132 - 131Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
System Authorizes the Handoff!
98/05/24 23:14:02.926 [FTC] Extended Handoff Direction MessageMSG_LENGTH = 136 bitsMSG_TYPE = Extended Handoff Direction MessageACK_SEQ = 0 MSG_SEQ = 6 ACK_REQ = 1ENCRYPTION = Encryption Mode DisabledUSE_TIME = 0 ACTION_TIME = 0 HDM_SEQ = 0SEARCH_INCLUDED = 1 SRCH_WIN_A = 40 PN chipsT_ADD = -13.0 dB T_DROP = -15.0 dB T_COMP = 2.5 dBT_TDROP = 4 secHARD_INCLUDED = 0 FRAME_OFFSET = Field OmittedPRIVATE_LCM = Field Omitted RESET_L2 = Field OmittedRESET_FPC = Field Omitted RESERVED = Field OmittedENCRYPT_MODE = Field Omitted RESERVED = Field OmittedNOM_PWR = Field Omitted NUM_PREAMBLE = Field OmittedBAND_CLASS = Field Omitted CDMA_FREQ = Field OmittedADD_LENGTH = 0PILOT_PN = 168 PWR_COMB_IND = 0 CODE_CHAN = 61PILOT_PN = 220 PWR_COMB_IND = 1 CODE_CHAN = 20PILOT_PN = 500 PWR_COMB_IND = 0 CODE_CHAN = 50RESERVED = 0
HANDOFF DIRECTION MESSAGEThe base station sends a HandofDirection Message authorizing the mobile to begin soft handoff with all three requested PNs. The pre-existing link on PN 168 will continue to use Walsh code 61, the new link on PN220 will use Walsh Code 20, and the new link on PN500 will use Walsh code 50.
The mobile acknowledges it has received the Handoff Direction Message.
98/05/24 23:14:02.945 [RTC] Order MessageMSG_LENGTH = 56 bits MSG_TYPE = Order MessageACK_SEQ = 6 MSG_SEQ = 6 ACK_REQ = 0ENCRYPTION = Encryption Mode DisabledORDER = Mobile Station Acknowledgment OrderADD_RECORD_LEN = 0 bitsOrder-Specific Fields = Field Omitted RESERVED = 0
MOBILE STATION ACKNOWLEDGMENT
February, 2008 132 - 132Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Mobile Implements the Handoff!
The mobile searcher quickly re-checks all three PNs. It still hears their pilots!
The mobile sends a Handoff Completion Message, confirming it still wants to go
ahead with the handoff.
BASE STATION ACKNOWLEDGMENT
98/05/24 23:14:02.985 [RTC] Handoff Completion MessageMSG_LENGTH = 72 bits MSG_TYPE = Handoff Completion MessageACK_SEQ = 6 MSG_SEQ = 1 ACK_REQ = 1ENCRYPTION = Encryption Mode DisabledLAST_HDM_SEQ = 0PILOT_PN = 168 Offset IndexPILOT_PN = 220 Offset IndexPILOT_PN = 500 Offset IndexRESERVED = 0
HANDOFF COMPLETION MESSAGE
The base station confirms it has received the mobile’s Handoff Completion message, and will continue with all of the links active.
98/05/24 23:14:03.085 [FTC] Forward Traffic Channel: Order ACK_SEQ: 0 MSG_SEQ: 1 ACK_REQ: 0 ENCRYPTION: 0 USE_TIME: 0 ACTION_TIME: 0 Base Station Acknowledgement Order
February, 2008 132 - 133Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Neighbor List Updated, Handoff is Complete!
98/05/24 23:14:03.245 [RTC] Order MessageMSG_LENGTH = 56 bits MSG_TYPE = Order MessageACK_SEQ = 7 MSG_SEQ = 7 ACK_REQ = 0ENCRYPTION = Encryption Mode DisabledORDER = Mobile Station Acknowledgement OrderADD_RECORD_LEN = 0 bitsOrder-Specific Fields = Field OmittedRESERVED = 0
MOBILE STATION ACKNOWLEDGMENT
98/05/24 23:14:03.166 [FTC] Neighbor List Update MessageMSG_LENGTH = 192 bitsMSG_TYPE = Neighbor List Update MessageACK_SEQ = 1 MSG_SEQ = 7 ACK_REQ = 1ENCRYPTION = Encryption Mode DisabledPILOT_INC = 4 Offset IndexNGHBR_PN = 164 Offset IndexNGHBR_PN = 68 Offset IndexNGHBR_PN = 52 Offset IndexNGHBR_PN = 176 Offset IndexNGHBR_PN = 304 Offset IndexNGHBR_PN = 136 Offset IndexNGHBR_PN = 112 Offset IndexNGHBR_PN = 372 Offset IndexNGHBR_PN = 36 Offset IndexNGHBR_PN = 8 Offset IndexNGHBR_PN = 384 Offset IndexNGHBR_PN = 216 Offset IndexNGHBR_PN = 328 Offset IndexNGHBR_PN = 332 Offset IndexNGHBR_PN = 400 Offset IndexNGHBR_PN = 96 Offset IndexRESERVED = 0
NEIGHBOR LIST UPDATE MESSAGE
In response to the mobile’s Handoff Completion Message, the base station assembles a new composite neighbor list including all the neighbors of each of the three active pilots.This is necessary since the mobile could be traveling toward any one of these pilots and may need to request soft handoff with any of them soon.
The mobile confirms receiving the Neighbor List Update Message. It is
already checking the neighbor list and will do so continuously from now on.
The handoff is fully established.
February, 2008 132 - 134Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Handoff Now In Effect, but still check Pilots!E
c/Io
All PN Offsets
0
032K
512Chips
PN
0
-20
Neighbor Set
Continue checking each ACTIVE pilot. If any are less than T_DROP and remain so for T_TDROP time, send Pilot Strength Measurement Message, DROP IT!!
Continue looking at each NEIGHBOR pilot. If any ever rises above T_ADD, send Pilot Strength Measurement Message, ADD IT!
T_ADD
Rake Fingers
Reference PN
Active Set
10752
16832002
50014080
220
T_DROP
Mobile Rake RX
Srch PN??? W0
F1 PN168 W61F2 PN500 W50F3 PN220 W20
February, 2008 132 - 135Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Complete Picture of Handoff & Pilot Sets
T_ADD
Ec/
IoAll PN Offsets
00
32K512
ChipsPN
0
-20
Neighbor Set
SRCH_WIN_N
Active Set
Candidate SetT_DROP
SRCH_WIN_A
Remaining SetT_ADD
SRCH_WIN_R
SRCH_WIN_A
T_DROP
Rake Fingers
Reference PN
Pilots of sectors now used for communication
Pilots requested by mobile but not set up by system
Pilots suggested by system for more checking
All other pilots divisible by PILOT_INC but not presently in Active, Candidate, or Neighbor sets
Mobile Rake RX
Srch PN??? W0
F1 PN168 W61F2 PN500 W50F3 PN220 W20
February, 2008 132 - 136Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Deeper Handoff Details:Search Windows & TimingDeeper Handoff Details:
Search Windows & Timing
Section G
February, 2008 132 - 137Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Pilot Searcher’s Measurement Process
The searcher checks pilots in nested loops, much like meshed gears. Actives and candidatesoccupy the fastest-spinning wheel. Neighbors are next, advancingone pilot for each Act+Cand. revolution.Remaining is slowest, advancing one pilot each time the Neighbors revolve.
CURRENT PILOT SET CONTENTSA A A
C
N N N N N N N N N N N N
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R R R R R R R R R
R R R R
31
12112
PILOT SEARCHER VIEWED IN SEQUENCE: Typical Elapsed Time = 4 secondsA A A C N
R
A A A C A A A C A A A C A A A C A A A C A A A CN N N N N N
A A A C N A A A C A A A C A A A C A A A C A A A C A A A CN N N N N
A A A CN A A A C A A A C A A A C A A A C A A A C A A A CN N N N N N
N A A A C A A A C A A A CN N N R A A A C N A A A C A A A C A A AN N
C A A A C A A A CN N N
R
A A A C N A A A C A A A C A A AN N C A A AN
C A A A CN N Only 3 of 112 remaining set pilots have been checked thus far!
A
N
R
R
R
R
R
R
R
NN
N
N
NN N N
AA
February, 2008 132 - 138Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
A Quick Primer on Pilot Search WindowsThe phone chooses one strong sector and “locks” to it, accepting its offset at “face value”and interpreting all other offsets by comparison to itIn messages, system gives to handset a neighbor list of nearby sectors’ PNsPropagation delay “skews” the apparent PN offsets of all other sectors, making them seem earlier or later than expectedTo overcome skew, when the phone searches for a particular pilot, it scans an extra wide “delta” of chips centered on the expected offset (called a “search window”) Search window values can be datafilledindividually for each Pilot set:There are pitfalls if the window sizes are improperly set
• too small: overlook pilots from far away• too large: search time increases• too large: might misinterpret identity of a
distant BTS’ signal One chip is 801 feet or 244.14 m
1 mile=6.6 chips; 1 km.= 4.1 chips
PROPAGATION DELAYSKEWS APPARENT PN OFFSETS
BTSBTSA
B
33Chips
4 Chips
If the phone is locked to BTS A, thesignal from BTS B will seem 29 chipsearlier than expected.If the phone is locked to BTS B, thesignal from BTS A will seem 29 chipslater than expected.
February, 2008 132 - 139Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Setting Pilot Search Window SizesWhen the handset first powers up, it does an exhaustive search for the best pilot. No windows are used in this process.On the paging channel, the handset learns the window sizes SRCH_WIN_A, N, R and uses them when looking for neighbors both in idle mode and during calls.When a strong neighbor is requested in a PSMM, the former neighbor pilot is now a candidate. Its offset is precisely remembered and frequently rechecked and tracked by the phone.Window size for actives and candidates can be small, since their exact position is known. Only search wide enough to include multipath energy!
• This greatly speeds up overall searching!Most post-processing tools deliver statistics on the spread (in chips) between fingers locked to the same pilot. These statistics literally show us how wide the SRCH_WIN_A should be set.Neighbor and Remaining search windows should be set to accommodate the maximum intercelldistances which a mobile might experience
SEARCH WINDOW SETTINGSAND PROPAGATION DISTANCES
Window Size (Chips)
14 (±7)
DatafillValue
N,R Delta Distance
4 1.0620 (±10)
40 (±20)28 (±14)
Miles KM.
56789101112131415
60 (±30)80 (±40)
100 (±50)130 (±65)160 (±80)226 (±113)320 (±160)452 (±226)
1.711.52 2.442.12 3.423.03 4.884.55 7.326.07 9.777.59 12.29.86 15.912.1 19.517.1 27.624.3 39.134.3 55.2
February, 2008 132 - 140Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Handoff Problems: “Window” Dropped Calls
Calls often drop when strong neighbors suddenly appear outside the neighbor search window and cannot be used to establish soft handoff.Neighbor Search Window SRCH_WIN_N should be set to a width at least twice the propagation delay between any site and its most distant neighbor site Remaining Search Window SRCH_WIN_R should be set to a width at least twice the propagation delay between any site and another site which might deliver occasional RF into the service area
A
B
1 mi.7 Chips
BTS
BTS
SITUATION 1 Locked to distant site, can’t see
one nearby12 miles80 ChipsSRCH_WIN_N = 130BTS A is reference.BTS B appears (7-80) chipsearly due to its closer distance.This is outside the 65-chip window.Mobile can’t see BTS B’s pilot, but its strong signal blinds us and the call drops.
Travel
mountains
A
B
1 mi.7 Chips
BTS
BTS
SITUATION 2Locked to nearby
site, can’t see distant one12 miles80 Chips
Travel
SRCH_WIN_N = 130BTS B is reference.BTS A appears (80-7) chipslate due to its farther distance.This is outside the 65-chip window.Mobile can’t see BTS A’s pilot.
mountains
February, 2008 132 - 141Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Overall Handoff Perspective
Soft & Softer Handoffs are preferred, but not always possible• a handset can receive BTS/sectors simultaneously only on one
frequency • all involved BTS/sectors must connect to a networked BSCs.
Some manufacturers do not presently support this, and so are unable to do soft-handoff at boundaries between BSCs.
• frame timing must be same on all BTS/sectorsIf any of the above are not possible, handoff still can occur but can only be “hard” break-make protocol like AMPS/TDMA/GSM
• intersystem handoff: hard• change-of-frequency handoff: hard• CDMA-to-AMPS handoff: hard, no handback
– auxiliary trigger mechanisms available (RTD)
February, 2008 132 - 142Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Section I
Introduction to OptimizationIntroduction to Optimization
February, 2008 132 - 143Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
What is Performance Optimization?
The words “performance optimization” mean different things to different people, viewed from the perspective of their own jobsSystem Performance Optimization includes many different smaller processes at many points during a system’s life
• recognizing and resolving system-design-related issues (can’t build a crucial site, too much overlap/soft handoff, coverage holes, etc.)
• “cluster testing” and “cell integration” to ensure that new base station hardware works and that call processing is normal
• “fine-tuning” system parameters to wring out the best possible call performance
• identifying causes of specific problems and customer complaints, and fixing them
• carefully watching system traffic growth and the problems it causes - implementing short-term fixes to ease “hot spots”, and recognizing problems before they become critical
February, 2008 132 - 144Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Performance Optimization Phases/Activities
hello
RF Design and Cell Planning
New Cluster Testing and
Cell Integration
Solve SpecificPerformance
Problems
Well-System Performance Management
Capacity Optimization
Growth Management:
Optimizing both Performance and Capital
Effectiveness
Cover desired area; have capacity for anticipated traffic
Ensure cells properly constructed and
configured to give normal performance
Identify problems from complaints or statistics; fix them!
Ensure present ‘plant’is giving best possible
performance
Manage congested areas for most
effective performance
Overall traffic increases and congestion;
competition for capital during tight times
Phase Drivers/Objectives Activities Main Tools Success Indicators
Plan cells to effectively cover as needed and divide traffic
load appropriately
Drive-test: coverage, all handoff boundaries, all call
events and scenarios
Detect, Investigate, Resolve performance problems
Watch stats: Drops, Blocks, Access Failures; identify/fix hot
spots
Watch capacity indicators; identify problem areas, tune parameters & configuration
Predict sector and area exhaustion: plan and validate effective growth plan, avoid
integration impact
Prop. Models,Test Transmitters,
planning tools Model results
Drive-test tools;cell diagnostics and
hardware test
All handoffs occur; all test cases
verified
Drive-test tools, system stats,
customer reports
Identified problems are
resolved
System statisticsAcceptable levels and good trends for all indicators
Smart optimization of parameters;
system statistics
Stats-Derived indicators; carried
traffic levels
Traffic analysis and trending tools;
prop. models for cell spliiting; carrier
additions
Sectors are expanded soon
after first signs of congestion;
capital budget remains within
comfortable bounds
February, 2008 132 - 145Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Good Performance is so Simple!!
One, Two, or Three good signals in handoff• Composite Ec/Io > -10 db
Enough capacity• No resource problems – I’ve got what I
need
BTS BTS
BTS
Pilot
Paging
TrafficChannels
In use
availablepower
Sync
BTS
A
BTS
B
BTS
C
Ec/Io -10
FORWARDLINK
February, 2008 132 - 146Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Bad Performance Has Many CausesWeak Signal / Coverage HolePilot Pollution
• Excessive Soft HandoffHandoff Failures, “Rogue” mobiles
• Missing Neighbors• Search Windows Too Small• BTS Resource Overload / No Resources
– No Forward Power, Channel Elements
– No available Walsh Codes– No space in Packet Pipes
Pilot “Surprise” ambush; Slow HandoffsPN Plan errorsSlow Data Problems: RF or IP congestionImproper cell or reradiator configurationHardware and software failuresBut on analysis, all of these problems’ bad effects happen because the simple few-signal ideal CDMA environment isn’t possible.
360
+41
+8
360+33cA
BBTS
BTS
BTS BPN 99
BTS APN 100
1 mile 11 miles
ACTIVE SEARCH WINDOW
xPilot
PagingSync
TrafficChannels
In Use
NoAvailablePower!B
TS Sector Transmitter
CEsVocodersSelectors
BTS Rx PwrOverload
February, 2008 132 - 147Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Aeronautical Analogy: Tools for Problem Investigation
To study the cause of an aeronautical accident, we try to recover the Flight Data Recorder and the Cockpit Voice Recorder.
To study the cause of a CDMA call processing accident, we review data from the Temporal Analyzer and the Layer 3 Message Files -- for the same reasons.
Control & Parameters Messaging
BTS
1150011500
114.50118.25125.75
AeronauticalInvestigations
CDMAInvestigations
Flight Data Recorder Cockpit Voice Recorder
Temporal Analyzer Data Layer 3 Message Files
February, 2008 132 - 148Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Starting Optimization on a New SystemRF Coverage Control
• try to contain each sector’s coverage, avoiding gross spillover into other sectors
• tools: PN Plots, Handoff State Plots, Mobile TX plotsSearch Window Settings
• find best settings for SRCH_WIN_A, _N, _R• especially optimize SRCH_WIN_A per sector using collected
finger separation data; has major impact on pilot search speedNeighbor List Tuning
• try to groom each sector’s neighbors to only those necessary but be alert to special needs due to topography and traffic
• tools: diagnostic data, system logsAccess Failures, Dropped Call Analysis
• finally, iterative corrections until within numerical goals
Getting these items into shape provides a solid baseline and foundation from which future performance issues can be addressed.
February, 2008 132 - 149Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Solving Problems on Existing Systems
CDMA optimization is very different from optimization in analog technologies such as AMPS
AMPS: a skilled engineer with a handset or simple equipment can hear, diagnose, and correct many common problems
• co-channel, adjacent channel, external interferences• dragged handoffs, frequency plan problems
CDMA impairments have one audible symptom: Dropped Call• voice quality remains excellent with perhaps just a hint of garbling
even as the call approaches dropping in a hostile RF environment
Successful CDMA Optimization requires:• recognition and understanding of common reasons for call failure• capture of RF and digital parameters of the call prior to drop• analysis of call flow, checking messages on both forward and reverse
links to establish “what happened”, where, and why
February, 2008 132 - 150Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA Problems Attacked in Optimization
Excessive Access Failures• typical objectives: <2% (IS-95B will bring improvements)
Excessive Dropped Calls• typical objective: ~1%, <2%
Forward Link Interference• typical objective: eliminate situations which prevent handoff!
Slow Handoff• typical objective: eliminate situations which delay handoff!
Handoff Pilot Search Window Issues• avoid handoff drops!
Excessive Soft Handoff• control coverage, not T_Add/T_Drop, to manage soft handoff levels (~<50%)
Grooming Neighbor Lists• “if you need it, use it!”
Software Bugs, Protocol Violations• Neither system software, nor mobile software, nor the CDMA standard is
perfect. Don’t humbly accept problems -- dig in and find out what’s happening!
February, 2008 132 - 151Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Sources of CDMA Data and Tools for Processing
CDMA optimization data flows from three places:• Switch• CDMA peripherals (CBSC & BTS)• Handset
Each stream of data has a family of software and hardware tools for collection and analysis
CBSCSwitch BTS
CDSU DISCO
Ch. Card ACC
ΣαΣβΣχ
TFU1GPSR
CDSUCDSU
DISCO 1DISCO 2
SBSVocodersSelectors
CDSUCDSUCDSUCDSUCDSUCDSU
CMSLM
LPP LPPENET
DTCs
DMS-BUS
Txcvr ATxcvr BTxcvr C
RFFE ARFFE BRFFE C
TFU1GPSR
IOC
BSM
Data AnalysisPost-Processing
Tools
IS-95/J-STD-008 Messages
IS-95/J-STD-8 Messages
Switch Datapegs, logs
Mobile DataPost-Processing
Tools
Mobile Data Capture Tools
HandsetMessages
ExternalAnalysis
Tools
PC-based
PC-based
Unix-based,PC-basedVarious
CDMA NETWORK EQUIPMENT HANDSET
System Internal Messages
February, 2008 132 - 152Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Department Store Analogy: Tops-Down, Bottoms-Up
Some things are easier to measure from the customer side!
Complex!!! Simpler
System Phone
Neighbor ListsData Analysis
SoftwareTrans-
mission
Configuration
Provisioning
PSTN Trunking
Dropped Calls
CoverageAccess Failures
Switch
BTS
CBSC
InterferenceAdministration
Data CaptureField Tools
Profits
Complex!!! Simpler
Management Test Shopper
Labor Relations
Cost
sTaxe
s Insurance
Suppliers
Leases
Capital
Stocking
Distribution
Loss
esAdvertis
ing
Selection
ConveniencePrice
Service
February, 2008 132 - 153Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Aeronautical Analogy: Tools for Problem Investigation
To study the cause of an aeronautical accident, we try to recover the Flight Data Recorder and the Cockpit Voice Recorder.
To study the cause of a CDMA call processing accident, we review data from the Temporal Analyzer and the Layer 3 Message Files -- for the same reasons.
Control & Parameters Messaging
BTS
1150011500
114.50118.25130.75
AeronauticalCase
CDMA Case
Flight Data Recorder Cockpit Voice Recorder
Temporal Analyzer Data Layer 3 Message Files
February, 2008 132 - 154Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
So S L O W ! ! Where’s My Data?!!
Some sessions are tormented by long latency and slow throughputWhere is the problem? Anywhere between user and distant host:
• Is the mobile user’s data device mis-configured and/or congested?• Is the BTS congested, with no power available to produce an SCH?• Poor RF environment, causing low rates and packet retransmission?• Congestion in the local IP network (PCU, R-P, PDSN FA)?• Congestion in the wireless operator’s backbone (‘OSSN’) network?• Congestion in the PDSN HA?• Congestion in the outside-world internet or Private IP network?• Is the distant host congested, with long response times?
IP D
ata
Envir
onm
entCDMA RF Environment
CDMA IOS PPPTraditional Telephony
IP Data Environment
t1t1 v CESEL
t1
R-P Interface
PDSN/Foreign Agent
PDSNHome Agent
BackboneNetworkInternet
VPNs
PSTN
T TSECURE TUNNELS
AuthenticationAuthorization
AccountingAAA
BTS
(C)BSC/Access ManagerSwitch WirelessMobile Device
•Coverage Holes•Pilot Pollution•Missing Neighbors•Fwd Pwr Ovld•Rev Pwr Ovld•Search Windows•Island Cells•Slow Handoff
February, 2008 132 - 155Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Finding Causes of Latency and Low Throughput
IP network performance can be measured using test serversProblems between mobile a local test server? The problem is local
• check RF conditions, stats: poor environment, SCH blocking?• if the RF is clean, investigate BSC/PCU/R-P/PDSN-FA
Local results OK, problems accessing test server at PDSN-HA?• problem is narrowed to backbone network, or PDSN-HA
Results OK even through test server at PDSN-HA• then the problem is in the public layers beyond.
IP D
ata
Envir
onm
entCDMA RF Environment
CDMA IOS PPPTraditional Telephony
IP Data Environment
t1t1 v CESEL
t1
R-P Interface
PDSN/Foreign Agent
PDSNHome Agent
BackboneNetworkInternet
VPNs
PSTN
T TSECURE TUNNELS
AuthenticationAuthorization
AccountingAAA
BTS
(C)BSC/Access ManagerSwitch WirelessMobile Device
•Coverage Holes•Pilot Pollution•Missing Neighbors•Fwd Pwr Ovld•Rev Pwr Ovld•Search Windows•Island Cells•Slow Handoff
TestServer
TestServer
TestServer
February, 2008 132 - 156Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Autonomous Data CollectionBy Subscriber Handsets
Autonomous Data CollectionBy Subscriber Handsets
February, 2008 132 - 157Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Using Autonomous Collection
A Server downloads software to a large population of subscriber mobilesMobiles collect on custom profiles
• all or groups of mobiles can be enabled/disabled• new triggers can be rapidly developed and downloaded when desired
Mobiles upload compacted packets to server driven by custom triggers• may be immediately if needed, or at low-traffic pre-programmed times• collected data can include location/GPS/call event/L3
messaging/timestamps/etc.Server manages data, provides filtering and reportingPerformance optimizers use terminals and post-processing software
t1t1 vSELt1
R-P Interface
PDSN/Foreign Agent
PDSNHome Agent
BackboneNetworkInternet
VPNs
PSTN
T TSECURE TUNNELSAuthentication
AuthorizationAccounting
AAABTS
(C)BSC/Access ManagerSwitch
Collection Server•software download•collected data upload•data management, analysis
BTS
BTS
BTS
February, 2008 132 - 158Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Conventional Field ToolsConventional Field Tools
February, 2008 132 - 159Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA Field Test ToolsField Collection Tools using Handset Data
There are many commercial CDMA field test toolsCharacteristics of many test tools:
• capture data from data ports on commercial handsets• log data onto PCs using proprietary software• can display call parameters, messaging, graphs, and maps• store data in formats readable for post-processing analysis• small and portable, easy to use in vehicles or even on foot
A few considerations when selecting test tools:• does it allow integration of network and mobile data?• Cost, features, convenience, availability, and support• new tools are introduced every few months - investigate!
QualcommMDM, CAIT
Grayson
Comarco
Willtech
EricssonTEMS
Motorola
PN Scanners
Agilent(HP + SAFCO)
Agilent(HP + SAFCO)
BerkeleyVaritronics
Grayson Qualcomm
DTI Willtech
February, 2008 132 - 160Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Qualcomm’s MDM: Mobile Diagnostic Monitor
The Qualcomm Mobile Diagnostic Monitor was the industry’s first field diagnostic tool
• used industry-wide in the early deployment of CDMA
• pictures at right from Sprint’s first 1996-7 CDMA trials in Kansas City
Qualcomm’s Mobile Diagnostic Monitor • CDMA handset (customer provided)• Proprietary connecting cable• PC software for collection and field pre-
analysis– Temporal analyzer display mode– Messaging
February, 2008 132 - 161Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Grayson’s Invex3G Tool
100 MB ethernet connection to PCthe eight card slots can hold receivers or dual-phone cardsthere’s also room for two internal PN scannersMultiple Invex units can be cascaded for multi-phone load-test applicationsCards are field-swappable -Users can reconfigure the unit in the field for different tasks without factory assistance
February, 2008 132 - 162Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
This mobile is in a 2-way soft handoff (two green FCH walsh codes assigned) in the middle of a downlink SCH burst. Notice walsh code #3, 4 chips long, is assigned as an SCH but only on one sector, and the downlink data speed is 153.6kb/s.
153.6kb/s
Grayson Invex 1x Data Example
February, 2008Technical Introduction to CDMA v6 (c) 2008 Scott BaxterTechnical Introduction to Wireless -- ©1997 Scott Baxter - V0.0163
F-SCH rates 153.6 kbps; R-SCH 76.8kbps
PN Scanner Data
Grayson Invex 1xData Example
Current Data Task StatusLayer-3 Messages
CDMA Status
February, 2008 132 - 164Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
WillTech Tools
Blue Rose platform can manage multiple phones and collect data
• Internal processor manages test operations independently for stand-alone operation
• Internal PCMCIA flash card provides storage
• An external PC can display collected data during or after data collection
February, 2008 132 - 165Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Agilent Drive-Test Tools
Agilent offers Drive-Test tools• Serial interfaces for up to four
CDMA phones• A very flexible digital receiver
with several modesPN Scanner
• Fast, GPS-locked, can scan two carrier frequencies
Spectrum Analyzer• Can scan entire 800 or 1900
mHz. BandsBase-Station Over-Air Tester (BOAT)
• Can display all walsh channel activity on a specific sector
• Useful for identifying hardware problems, monitoring instantaneous traffic levels, etc.
Post-Processing tool: OPAS32
February, 2008 132 - 166Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
IS-95 Busy SectorSnapshot of Walsh Usage
February, 2008 132 - 167Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xRTT Busy SectorWalsh Code Usage
February, 2008 132 - 168Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
PN Scanners
Why PN scanners? Because phones can’t scan remaining set fast enough, miss transient interfering signalsBerkeley Varitronics
• high-resolution, GPS-locked– full-PN scan speed 26-2/3 ms.
• 2048 parallel processors for very fast detection of transient interferors
Agilent (formerly Hewlett-Packard)• high resolution, GPS-locked
– full-PN scan speed 1.2 sec.• Integrated with spectrum analyzer and
phone call-processing toolGrayson Wireless
• New digital receiver provides CDMA PN searcher and and sector walsh domain displays
February, 2008 132 - 169Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Post-Processing Tools
Post-Processing tools display drive-test files for detailed analysis - Faster, more effective than studying data playback with collection tools aloneActix Analyzer
• Imports/analyzes data from almost every brand of drive-test collection tool
Andrew (formerly Grayson) Interpreter• Imports/analyzes data from Andrew Invex3G
Nortel RF Optimizer• Can merge/analyze drive-test and Nortel CDMA
system dataXceed Technologies Windcatcher
• Imports/analyzes data from almost every brand of drive-test device
Xceed Technologies Vortex• Provides automated analysis of data from manual,
autonomous, and stand-alone sourcesVerizon/Airtouch internal tool “DataPro”
Analyzer Interpreter
Windcatcher
Vortex
February, 2008 132 - 170Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Maintenance Features of CDMA Handsets
Maintenance Features of CDMA Handsets
Drive-Tests: Phones
February, 2008 132 - 171Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Handsets as Tools: Simple but always Available!
Most CDMA handsets provide some form of maintenance display (“Debug Mode”) as well as instrumentation access
• all CDMA drive-test tools use handsets as their “front-ends”Using the handset as a manual tool without Commercial Test Tools:
Enter the maintenance mode by special sequence of keystrokesDisplayed Parameters
• PN Offset, Handset Mode, Received RF Level , Transmit Gain AdjustMaintenance Display Applications
• best serving cell/sector• simple call debugging (symptoms of weak RF, forward link
interference, etc.)Handset Limitations during manual observation
• no memory: real-time observations only; no access to messages or call details; serving PN offset not updated during voice calls
February, 2008 132 - 172Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Interpreting Samsung Maintenance Display:Acquisition, Idle, and Access States
Debug ScreenS04274 SI2 2T-56 D070-04P0060 CH0350PR6 RC0 0Z11
V206T144L:02
Reference PN Offset
0 - Pilot Channel Acquisition Substate1 - Sync Channel Acquisition Substate2 - MS Idle State3 - System Access State4 - Traffic Channel State5,6,7 - various call service options
Processing StateReceive Power,
dbm
Transmit Gain Adjust,
db
Display toggles between:System Identifier (SID)Network Identifier (NID)
Carrier Freq.(Channel #)
Ec/Io, db(primary PN only)
Slot Cycle Index
System ProtocolRevision Level
Packet Zone IDRadio Configuration(Idle mode = 0, 0)
February, 2008 132 - 173Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Interpreting Samsung Maintenance Display:Traffic Channel State
Debug ScreenTE8 RE8 40 6T-10 D070-04P0060 CH0350PR6 RC33 Z11SO00003 G207F001.54%L:02
PN Offset
0 - Pilot Channel Acquisition Substate1 - Sync Channel Acquisition Substate2 - MS Idle State3 - System Access State4 - Traffic Channel State5,6,7 - various call service options
Processing StateReceive Power,
dbm
Transmit Gain Adjust,
db
Carrier Freq.(Channel #)
Ec/Io, db(primary PN only)
FCH Walsh Code
System ProtocolRevision Level
Packet Zone ID
Transmit (RL)Vocoder Rate
1 = 1/82 = 1/44 = 1/28 = Full
Receive (FL)Vocoder Rate
Radio Configuration(RC3, RC3 common)
Live CumulativeFER
Service Option
February, 2008 132 - 174Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Denso Maintenance Display
CBV: 3957ABV: 3954 ABT: 031ARF: 0000 CCL: 01SID: 04157NID: 00001CH: 0100 RSSI: 093DPN: 084 TX:-46BFRM:0000000968TFRM:0000135712FER:% 000.71LT: 036:06:36LG: -086:45:36EC: -16 -63 -63PN: 084 084 084FNGLK: Y Y NWLSH: 01 01 01ACT: 084 484 096-01 -01 200CND: 220 332 200200 332 NGH: 076080 340 068 196O56 320 220 316344 488 196 200392 124 128 084224 008 084
DCharging Battery Voltage
Average Battery Voltage Average Battery Temperature
System IDNetwork ID
RF Channel FrequencyDigital PN Offset
Received Signal StrengthEstimated Transmitter
Power OutputNumber of Bad Frames
Number of Good Frames Frame Erasure Rate, PercentBase Station coordinates
Current status of Rake Fingers
Active Pilot Set
Candidate Pilot SetNeighbor Pilot Set
February, 2008 132 - 175Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Sanyo SPC-4500 Maintenance Display
Choose the following:DISPLAYOK0OKEnter Code: 0 0 0 0 0 0Debug MenuSCREENOK
February, 2008 132 - 176Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Sanyo SPC-4900 Maintenance Display
##040793select MENU/OK buttonscroll to save Phone #select
PN offset
Call Proc. StateReceivePower
Io
ChannelFrequency
February, 2008 132 - 177Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Entering Maintenance Mode: Motorola StarTacContact your service provider to obtain your phone’s Master
Subscriber entity Lock (MSL). Then enter the following:FCN 000000 000000 0 RCL You'll be prompted for your MSL, enter it and press STO.
• New prompts will appear, Press STO in response to each prompt until no more appear. Don’t delay -continue quickly and enter:
FCN 0 0 * * T E S T M O D E STO • The display will briefly show US then just '.
Press 55#.• Step 1 will appear with its current setting displayed.
Press * to accept and move on to the next step. Repeat for steps 2-8.
Step 9 (Option byte 2) is the only step requiring manual changes. Enter 1 0 0 0 0 0 0 0 (The leftmost bit now set to '1' is what enables test mode.)Now press STO to accept the entry and exit back to the ' prompt.Power off and back on.You should now be in test mode!
February, 2008 132 - 178Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
February, 2008 132 - 179Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
RX Power BatteryCondition
N5 N5M failureBS BS Ack failureWO L3 WFO State TimeoutMP Max Probe FailurePC Paging Channel lossRR Reorder or Release on PCH?? Unknown Condition
ChannelNumber
#Neighbors
Local Time#
ActivesStrongest Active
PN Ec/IoStrongest NeighborPN Ec/Io
# Cand-idates Call Proc
StateLast Call
Exit Reason# Drops
# CallsLast Call FER%
NIDSIDRx Powerdbm (Io)
Tx Powerdbm
CurrentService Option
Last Call IndicatorNI No Indication yetMR Mobile ReleaseBR Base Sta. ReleaseTC Traffic Channel LostL2 Layer 2 Ack FailNC No Channel Assn Msg
Current Service Option8V 8K voice originalIL 8K loopback8EV 8K EVRC8S 8K SMS13L 13K loopback
13S 13K SMS8MO 8K Markov OldDAT Data8M 8K Markov New13M 13K Markov New13V 13K Voice
Call Processing StatesCP CP ExitRST CP RestartRTC RestrictedPLT Pilot AcquisitionSYN Sync AcquisitionTIM Timing ChangeBKS Background SchIDL IdleOVD OverheadPAG Paging
ORG Call OriginationSMS Short Message SvcORD Order ResponseREG RegistrationTCI Tfc Ch InitializationWFO Waiting for OrderWFA Waiting for AnswerCON Conversation stateREL ReleaseNON No State
February, 2008 132 - 180Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Motorola V120C Series
MENU 073887* Enter 000000 for security code. Scroll down to Test Mode. Enter subscriber entity lock code if required by your phone
Same maintenance display as shown for Startac
February, 2008 132 - 181Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Motorola V60C
MENU 073887* Enter 000000 for security code. Scroll down to Test Mode. Enter subscriber entity lock code if required by your phone
Same maintenance display as shown for Startac
February, 2008 132 - 182Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Nokia 6185 Maintenance Display
Enter *3001#12345# MENUScroll down to Field testPress SelectScroll up to EnabledPress OKPower the phone off and onYou should now be in Field test mode
February, 2008 132 - 183Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Novatel Merlin C201 1xRTT Data Card
Enter # # D E B U G to enter maintenance mode.To exit, just click “OK” box in the Debug window.
February, 2008 132 - 184Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Audiovox Thera Maintenance Mode Screens
How to enterDebug Mode:
[ctrl] [D] [enter]
Advanced Usr Pwd:##DEBUG [enter]
Protocol Statistics
February, 2008 132 - 185Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Sierra 580 1xEV-DO Rev 0 Aircard
To enter the maintenance display, hover your cursor over the Connection Manager main indicator window or the Start button and type “##debug”.
The Network, Network 2, and HDR tabs provide the most useful information on the air interface. The other tabs provide details of the packet operations and error counters.
February, 2008 132 - 186Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
What’s New in CDMA2000?What’s New in CDMA2000?
The Future is Here! CDMA2000
February, 2008 132 - 187Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
A Quick Survey of Wireless Data Technologies
This summary is a work-in-progress, tracking latest experiences and reports from all the high-tier (provider-network-oriented) 2G and 3G wireless data technologiesHave actual experiences to share, latest announced details, or corrections to the above? Email to [email protected]. Thanks for your comments!
AMPS Cellular9.6 – 4.8 kb/s
w/modem
IS-136 TDMA19.2 – 9.6 kb/s
GSM CSD9.6 – 4.8 kb/s
GSM HSCSD32 – 19.2 kb/s
IDEN19.2 – 19.2 kb/s
IS-9514.4 – 9.6 kb/s
IS-95B64 -32 kb/s
CDPD19.2 – 4.8 kb/sdiscontinued
GPRS40 – 30 kb/s DL
15 kb/s UL
EDGE200 - 90 kb/s DL
45 kb/s UL
1xRTT RC3153.6 – 80 kb/s
1xRTT RC4307.2 – 160 kb/s
1xEV-DO 02400 – 600 DL153.6 – 76 UL
1xEV-DO A3100 – 800 DL1800 – 600 UL
WCDMA 0384 – 250 kb/s
WCDMA 12000 - 800 kb/s
WCDMA HSDPA12000 – 6000 kb/s
Flarion OFDM1500 – 900 kb/s
TD-SCDMAIn Development
Mobitex9.6 – 4.8 kb/s
obsolete
WI-MAX
US CDMA ETSI/GSM
CELLULAR
PAGING
MISC/NEW1xEV-DV
5000 - 1200 DL307 - 153 UL
February, 2008 132 - 188Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Modulation Techniques of 1xEV Technologies
1xEV, “1x Evolution”, is a family of alternative fast-data schemes that can be implemented on a 1x CDMA carrier.1xEV DO means “1x Evolution, Data Only”, originally proposed by Qualcomm as “High Data Rates” (HDR).
• Up to 2.4576 Mbps forward, 153.6 kbps reverse
• A 1xEV DO carrier holds only packet data, and does not support circuit-switched voice
• Commercially available in 20031xEV DV means “1x Evolution, Data and Voice”.
• Max throughput of 5 Mbps forward, 307.2k reverse
• Backward compatible with IS-95/1xRTT voice calls on the same carrier as the data
• Not yet commercially available; work continues
All versions of 1xEV use advanced modulation techniques to achieve high throughputs.
QPSKCDMA IS-95,
IS-2000 1xRTT,and lower ratesof 1xEV-DO, DV
16QAM1xEV-DOat highest
rates
64QAM1xEV-DVat highest
rates
February, 2008 132 - 189Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
DATA BURSTACTUALLY OCCURS
NOW
DA
TA R
ATE
DEC
ISIO
N
Fixed Rate!
1xRTT Data Burst Control Lags RF Conditions
BTS
MO
BIL
E
Tseconds
F-SCH
F-FCH
R-FCH
R-SCH
0 0.50.1 0.2 0.3 0.4
SCH-Assignment Msg.
F-SCH Burst
Setup Time
Path
Los
s, re
lativ
e dB
Eb/N
t, dB
Path Loss, db
GOOD CONDITIONS
BAD CONDITIONS
+6
+4
+2
+0
-2
0 0.1 0.2 0.3 0.4 0.5Time, Seconds
February, 2008 132 - 190Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO vs. 1xRTT at the Same Time-Scale
T0 0.50.1 0.2 0.3 0.4
Time, Seconds
AP
Traffic
DRCSetup time can be less than 10 ms., depending on traffic loading. AT
1xEV-DO Thoughput: 2.4 Mb/s max, 0.6 Mb/s typ.
BTS
MO
BIL
E
F-SCH
F-FCH
R-FCH
R-SCHSCH-Request Msg.
SCH-Assignment Msg.
F-SCH Burst
Setup Time Fixed Rate!1xRTT
Thoughput: 0.15 or 0.31 Mb/s max, 0.06 Mb/s typ.
February, 2008 132 - 191Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Channel Structure of 1xEV-DO vs. 1xRTTCHANNEL STRUCTURE
IS-95 and 1xRTT• many simultaneous users, each
with steady forward and reverse traffic channels
• transmissions arranged, requested, confirmed by layer-3 messages – with some delay……
1xEV-DO -- Very Different:• Forward Link goes to one user at a
time – like TDMA!• users are rapidly time-multiplexed,
each receives fair share of available sector time
• instant preference given to user with ideal receiving conditions, to maximize average throughput
• transmissions arranged and requested via steady MAC-layer walsh streams – very immediate!
BTS
IS-95 AND 1xRTTMany users’ simultaneous forward
and reverse traffic channelsW0W32W1W17W25W41
W3
W53
PILOTSYNC
PAGINGF-FCH1F-FCH2F-FCH3
F-SCH
F-FCH4
AP
1xEV-DO AP (Access Point)
ATs (Access Terminals)
1xEV-DO Forward Link
February, 2008 132 - 192Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Power Management of 1xEV-DO vs. 1xRTT
POWER MANAGEMENTIS-95 and 1xRTT:
• sectors adjust each user’s channel power to maintain a preset target FER
1xEV-DO IS-856:• sectors always operate at
maximum power• sector output is time-
multiplexed, with only one user served at any instant
• The transmission data rate is set to the maximum speed the user can receive at that moment
PILOT
PAGINGSYNC
Maximum Sector Transmit Power
User 123
45 5 5678
time
pow
er
IS-95: VARIABLE POWER TO MAINTAIN USER FER
time
pow
er
1xEV-DO: MAX POWER ALWAYS,DATA RATE OPTIMIZED
February, 2008 132 - 193Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Some EV-DO Terminology
Phone, Mobile,
Handset, or Subscriber Terminal
ATAccess
Terminal
Base Station,BTS,
Cell Site
APAccess Point
IS-95, IS-2000, 1xRTT EV-DO
February, 2008 132 - 194Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO Technical DetailsData Flow and Channels
1xEV-DO Technical DetailsData Flow and Channels
February, 2008 132 - 195Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO Transmission TimingForward Link
All members of the CDMA family - IS-95, IS-95B, 1xRTT, 1xEV-DO and 1xEV-DV transmit “Frames”
• IS-95, IS-95B, 1xRTT frames are usually 20 ms. long
• 1xEV-DO frames are 26-2/3 ms. long– same length as the short PN code– each 1xEV-DO frame is divided into
1/16ths, called “slots”The Slot is the basic timing unit of 1xEV-DO forward link transmission
• Each slot is directed toward somebody and holds a subpacket of information for them
• Some slots are used to carry the control channel for everyone to hear; most slots are intended for individual users or private groups
Users don’t “own” long continuing series of slots like in TDMA or GSM; instead, each slot or small string of slots is dynamically addressed to whoever needs it at the moment
One 1xEV-DO Frame
One Slot
One Cycle of PN Short Code
February, 2008 132 - 196Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
What’s In a Slot?
The main “cargo” in a slot is the DATA being sent to a userBut all users need to get continuous timing and administrative information, even when all the slots are going to somebody elseTwice in every slot there is regularly-scheduled burst of timing and administrative information for everyone to use
• MAC (Media Access Control) information such as power control bits
• a burst of pure Pilot– allows new mobiles to acquire the cell and decide to use it– keeps existing user mobiles exactly on sector time– mobiles use it to decide which sector should send them
their next forward link packet
SLOT DATA
MA
CPI
LOT
MA
C
DATA DATA
MA
CPI
LOT
MA
C
DATA
400 chips 64 96 64 400 chips 400 chips 64 96 64 400 chips
½ Slot – 1024 chips ½ Slot – 1024 chips
February, 2008 132 - 197Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
empty empty empty empty
What if there’s No Data to Send?
Sometimes there may be no data waiting to be sent on a sector’s forward link
• When there’s no data to transmit on a slot, transmitting can be suspended during the data portions of that slot
• But---the MAC and PILOT must be transmitted!!• New and existing mobiles on this sector and surrounding
sectors need to monitor the relative strength of all the sectorsand decide which one to use next, so they need the pilot
• Mobiles TRANSMITTING data to the sector on the reverse link need power control bits
• So MAC and PILOT are always transmitted, even in an empty slot
SLOT
MA
CPI
LOT
MA
C
MA
CPI
LOT
MA
C
400 chips 64 96 64 400 chips 400 chips 64 96 64 400 chips
½ Slot – 1024 chips ½ Slot – 1024 chips
February, 2008 132 - 198Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Forward Link Frame and Slot Structure:“Big Picture” Summary
Slots make Frames and Frames make Control Channel Cycles!
SLOT
FRAME1 Frame = 16 slots – 32k chips – 26-2/3 ms
16 Frames – 524k chips – 426-2/3 ms
CONTROLCHANNEL USER(S) DATA CHANNEL
16-FRAMECONTROL CHANNEL
CYCLE
DATA
MA
CPI
LOT
MA
C
DATA DATA
MA
CPI
LOT
MA
C
DATA
400 chips 64 96 64 400 chips 400 chips 64 96 64 400 chips
½ Slot – 1024 chips ½ Slot – 1024 chips
February, 2008 132 - 199Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
EV-DO Rev. A Channels
The channels are not continuous like ordinary 1xRTT CDMANotice the differences between the MAC channels and the Rev. 0 MAC channels – these are the heart of the Rev. 0/A differences
IN THE WORLD OF CODES
Sect
or h
as a
Sho
rt P
N O
ffset
just
like
IS-9
5A
ccessLong PN
offsetPublic or Private
Long PN offset
ACCESS
FORWARD CHANNELS
AccessPoint(AP)
REVERSE CHANNELS
TRAFFIC
Pilot
Data
Primary Pilot
DataACK
Pilot
Control
Traffic
MAC
MAC
FORWARD
Rev ActivityDRCLockRPC
RRI
W 64
W264
W064
Wx16
Wx16
W1232
W12
W416
W016
W24
W016
MA
C
AccessTerminal
(UserTerminal)
Walshcode
Walshcode
Access Channelfor session setup
from Idle Mode
Traffic Channelas used duringa data session
ARQ Auxiliary Pilot
DRCDSC
W2832
W816
W1232
February, 2008 132 - 200Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Sect
or h
as a
Sho
rt P
N O
ffset
just
like
IS-9
5
FORWARDCHANNELS
AccessPoint(AP)
Pilot
Control
Traffic
MAC
Rev ActivityDRCLockRPCW 64
W264
W064
Wx16
Wx16
MA
C
Walshcode
ARQ
Functions of Rev. A Forward Channels
•Access terminals watch the Pilot to select the strongest sector and choose burst speeds
•The Reverse Activity Channel tells ATs If the reverse link loading is too high, requiring rate reduction
Each connected AT has MAC channel:• DRCLock indication if sector busy• RPC (Reverse Power Control) • ARQ to halt reverse link subpackets as soon as complete packet is recovered
•The Control channel carries overhead messages for idle ATs but can also carry user traffic
•Traffic channels carry user data to one user at a time
DATA
MA
CPI
LOT
MA
C
DATA DATA
MA
CPI
LOT
MA
C
DATA
400 chips 64 96 64 400 chips 400 chips 64 96 64 400 chips½ Slot – 1024 chips ½ Slot – 1024 chips
Forward Link Slot Structure (16 slots in a 26-2/3 ms. frame)
AP
February, 2008 132 - 201Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
• Auxiliary Pilot on traffic channel allows synchronous detection during high data rates
Access
Long PN offset
Public or PrivateLong PN
offsetACCESS
REVERSE CHANNELS
TRAFFIC
Pilot
Data
Primary Pilot
DataACK
MAC RRI
W24
W016
AccessTerminal
(UserTerminal)
Walshcode
Access Channelfor session setup
from Idle Mode
Traffic Channelas used duringa data session
Auxiliary Pilot
DRCDSC
Functions of Rev. A Reverse Channels•The Pilot is used as a preamble during access probes
•Data channel during access carries mobile requests
• Primary Pilot on traffic channel allows synchronous detection and also carries the RRI channel
•RRI reverse rate indicator tells AP what rate is being sent by AT
•DRC Data Rate Control channel tells desired downlink speed
•ACK channel allows AT to signal successful reception of a packet
•DATA channel during traffic carries the AT’s traffic bits
•DSC Data Source Control channel tells which sector will send burst
W1232
W12
W416
W016
W2832
W816
W1232
February, 2008 132 - 202Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Reverse Link Frame and Slot Structure:“Big Picture” Summary
Reverse Link frames are the same length as forward link framesThe mobile does not include separate MAC and Pilot bursts
• Its MAC and pilot functions are carried inside its signal by simultaneous walsh codes
There is no need for slots for dedicated control purposes since the mobile can transmit on the access channel whenever it needs
SLOT
FRAME1 Frame = 16 slots – 32k chips – 26-2/3 ms
DATA
½ Slot – 1024 chips ½ Slot – 1024 chips
1 Subframeholds
1 SubpacketSubframe Subframe Subframe
February, 2008 132 - 203Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Rev. A Reverse Channel Sub-Frame Structure
The mobile transmits sub-packets occupying four reverse link slots, called a reverse link “sub-frame”.If multiple subpackets are required to deliver a packet, the additional subpackets are spaced in every third subframe until done
RRI
ACK DSC ACK DSC ACK DSC ACK DSC
DATA CHANNEL
DRC CHANNEL
AUXILIARY PILOT CHANNELPILOT CHANNEL
1 Sub-Frame
1 Slot 1 Slot 1 Slot 1 Slot
February, 2008 132 - 204Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Information Flow Over 1xEV-DO
The system notifies a mobile when data for it is waiting to be sentThe mobile chooses which sector it hears best at that instant, and requests the sector to send it a packetthere are 16 possible transmission formats the mobile may request, called “DRC Indices”. Each DRC Index value is really a combined specification including specific values for:
• what data speed will be transmitted• how big a “chunk” of waiting data will be sent (that amount of data will be
cut of the front of the waiting data stream and will be the “Packet”transmitted)
• what kind of encoding will be done to protect the data (3x Turbo, 5x Turbo, etc.) and the symbol repetition, if any
• after the symbols are formed, how many SUBpackets they will be divided into
Then, the sector starts transmitting the SUBpackets in SLOTS on the forward linkThe first slot will begin with a header that the mobile will recognize so it can begin the receiving process
AP
Data Ready
DRC: 5
Data from PDSN for the Mobile
MP3, web page, or other content
February, 2008 132 - 205Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Transmission of a Packet over EV-DO
AP
Data Ready
A user has initiated a1xEV-DO data session on their AT, accessing a favorite website.The requested page has just been received by the PDSN.The PDSN and Radio Network Controller send a “Data Ready” message to let the AT know it has data waiting.
The AT quickly determines which of its active sectors is the strongest. On the AT’s DRC channel it asks that sector to send it a packet at speed “DRC Index 5”.
The mobile’s choice, DRC Index 5, determines everything:The raw bit speed is 307.2 kb/s.The packet will have 2048 bits.There will be 4 subpackets (in slots 4 apart).The first subpacket will begin with a 128 chip preamble.
DRC: 5
DRCIndex Slots Preamble
ChipsPayload
BitsRawkb/s
0x0 n/a n/a 0 null rate0x1 16 1024 1024 38.40x2 8 512 1024 76.80x3 4 256 1024 153.60x4 2 128 1024 307.20x5 4 128 2048 307.20x6 1 64 1024 614.40x7 2 64 2048 614.40x8 2 64 3072 921.60x9 1 64 2048 1,228.80xa 2 64 4096 1,228.80xb 1 64 3072 1,843.20xc 1 64 4096 2,457.60xd 2 64 5120 1,536.00xe 1 64 5120 3,072.0
C/Idbn/a
-11.5-9.2-6.5-3.5-3.5-0.6-0.5+2.2+3.9+4.0+8.0+10.3
in Rev. Ain Rev. A
Modu-lationQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSK
16QAM8PSK
16QAM16QAM16QAM
Data from PDSN for the Mobile
MP3, web page, or other content
February, 2008 132 - 206Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Transmission of a Packet over EV-DOData from PDSN for the Mobile
MP3, web page, or other content AP
Data Ready
DRC: 5
2048 bits
Interleaver
+ D+
+D D
++ +
+
+ D+
+D D
++ +
+
Turbo Coder
PACKET
Symbols
Using the specifications for the mobile’s requested DRC index, the correct-size packet of bits is fed into the turbo coder and the right number of symbols are created.
DRCIndex Slots Preamble
ChipsPayload
BitsRawkb/s
0x0 n/a n/a 0 null rate0x1 16 1024 1024 38.40x2 8 512 1024 76.80x3 4 256 1024 153.60x4 2 128 1024 307.20x5 4 128 2048 307.20x6 1 64 1024 614.40x7 2 64 2048 614.40x8 2 64 3072 921.60x9 1 64 2048 1,228.80xa 2 64 4096 1,228.80xb 1 64 3072 1,843.20xc 1 64 4096 2,457.60xd 2 64 5120 1,536.00xe 1 64 5120 3,072.0
C/Idbn/a
-11.5-9.2-6.5-3.5-3.5-0.6-0.5+2.2+3.9+4.0+8.0+10.3
in Rev. Ain Rev. A
Modu-lationQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSK
16QAM8PSK
16QAM16QAM16QAM
February, 2008 132 - 207Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Transmission of a Packet over EV-DOData from PDSN for the Mobile
MP3, web page, or other content AP
Data Ready
DRC: 5
2048 bits
Interleaver
+ D+
+D D
++ +
+
+ D+
+D D
++ +
+
Turbo Coder
Block Interleaver
PACKET
Symbols
Using the specifications for the mobile’s requested DRC index, the correct-size packet of bits is fed into the turbo coder and the right number of symbols are created.
To guard against bursty errors in transmission, the symbols are completely “stirred up” in a block interleaver.
DRCIndex Slots Preamble
ChipsPayload
BitsRawkb/s
0x0 n/a n/a 0 null rate0x1 16 1024 1024 38.40x2 8 512 1024 76.80x3 4 256 1024 153.60x4 2 128 1024 307.20x5 4 128 2048 307.20x6 1 64 1024 614.40x7 2 64 2048 614.40x8 2 64 3072 921.60x9 1 64 2048 1,228.80xa 2 64 4096 1,228.80xb 1 64 3072 1,843.20xc 1 64 4096 2,457.60xd 2 64 5120 1,536.00xe 1 64 5120 3,072.0
C/Idbn/a
-11.5-9.2-6.5-3.5-3.5-0.6-0.5+2.2+3.9+4.0+8.0+10.3
in Rev. Ain Rev. A
Modu-lationQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSK
16QAM8PSK
16QAM16QAM16QAM
February, 2008 132 - 208Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Transmission of a Packet over EV-DOData from PDSN for the Mobile
MP3, web page, or other content AP
Data Ready
DRC: 5
2048 bits
Interleaver
+ D+
+D D
++ +
+
+ D+
+D D
++ +
+
Turbo Coder
Block Interleaver
PACKET
Symbols
Interleaved Symbols
Using the specifications for the mobile’s requested DRC index, the correct-size packet of bits is fed into the turbo coder and the right number of symbols are created.
To guard against bursty errors in transmission, the symbols are completely “stirred up” in a block interleaver.
The re-ordered stream of symbols is now ready to transmit.
DRCIndex Slots Preamble
ChipsPayload
BitsRawkb/s
0x0 n/a n/a 0 null rate0x1 16 1024 1024 38.40x2 8 512 1024 76.80x3 4 256 1024 153.60x4 2 128 1024 307.20x5 4 128 2048 307.20x6 1 64 1024 614.40x7 2 64 2048 614.40x8 2 64 3072 921.60x9 1 64 2048 1,228.80xa 2 64 4096 1,228.80xb 1 64 3072 1,843.20xc 1 64 4096 2,457.60xd 2 64 5120 1,536.00xe 1 64 5120 3,072.0
C/Idbn/a
-11.5-9.2-6.5-3.5-3.5-0.6-0.5+2.2+3.9+4.0+8.0+10.3
in Rev. Ain Rev. A
Modu-lationQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSK
16QAM8PSK
16QAM16QAM16QAM
February, 2008 132 - 209Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Transmission of a Packet over EV-DOData from PDSN for the Mobile
MP3, web page, or other content AP
Data Ready
DRC: 5
2048 bits
1 2 3 4
Interleaver
+ D+
+D D
++ +
+
+ D+
+D D
++ +
+
Turbo Coder
Block Interleaver
PACKET
SLOTS
Symbols
Interleaved Symbols
When the AP is ready, the first subpacket is actually transmitted in a slot.
The first subpacket begins with a preamble carrying the user’s MAC index, so the user knows this is the start of its sequence of subpackets, and how many subpackets are in the sequence..
The user keeps collecting subpackets until either:
1) it has been able to reverse-turbo decode the packet contents early, or
2) the whole schedule of subpackets has been transmitted.
Subpackets
DRCIndex Slots Preamble
ChipsPayload
BitsRawkb/s
0x0 n/a n/a 0 null rate0x1 16 1024 1024 38.40x2 8 512 1024 76.80x3 4 256 1024 153.60x4 2 128 1024 307.20x5 4 128 2048 307.20x6 1 64 1024 614.40x7 2 64 2048 614.40x8 2 64 3072 921.60x9 1 64 2048 1,228.80xa 2 64 4096 1,228.80xb 1 64 3072 1,843.20xc 1 64 4096 2,457.60xd 2 64 5120 1,536.00xe 1 64 5120 3,072.0
C/Idbn/a
-11.5-9.2-6.5-3.5-3.5-0.6-0.5+2.2+3.9+4.0+8.0+10.3
in Rev. Ain Rev. A
Modu-lationQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSK
16QAM8PSK
16QAM16QAM16QAM
February, 2008 132 - 210Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
DATA MAC
PILO
T
MAC DATA DATA MAC
PILO
T
MAC DATA
336 chips 64 96 64 400 chips 400 chips 64 96 64 400 chips½ Slot – 1024 chips ½ Slot – 1024 chips
PRBL
64
Example Subpacket: 1536 Data Modulation Symbols (1 slot, 614.4 Kb/s)
1/3 or 1/5encoder
scrambler
ChannelInterleaver
QPSK/8PSK16QAM
Modulator
SequenceRepetition,
SignalPuncturing
SymbolDEMUX1 to 16
16-aryWalshCovers
WalshChannel
Gain
WalshChip LevelSummer
Data(modulation
symbols)SequenceRepetition 0
I
Q
I
Q
32-symbol bi-OrthogonalMAC cover
SignalPoint
Mapping
SequenceRepetition(factor=4)
I
Q
WalshChip LevelSummer Q
RAchannel
gain
SignalPoint
Mapping
BitRepetition(xRAB len)
MAC channelRA bits
DRC LockChannel
Gain
RPCChannel
Gain
SignalPoint
Mapping
SignalPoint
Mapping
BitRepetition(xDRCLlen)
Walsh Cover W264
MAC Index Walsh CoverMAC RPC bits A
MAC channelDRC Lock symbols
0
I
Q
Walsh Cover 0
SignalPoint
MappingPilot Channel (all 0s)
TDM
Time D
ivision Multiplexer
To Quadrature Spreading and M
odulationI W
alsh Channels
Q W
alsh Channels
I
Preamble
One Slot on the Forward Traffic Channel
February, 2008 132 - 211Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The MAC Index
Each active user on a sector is assigned a unique 7-bit MAC index (64 MACs possible)Each data packet begins with a preamble, using the MAC index of the intended recipientFive values of MAC indices are reserved for “multi-user” packets
• packets intended for reception by a group– for example, control channels
• mobiles may have individual MAC indices AND be simultaneously in various groups
• this “trick” keeps payload size low even for transmissions to groups
MAC Channel Use Preamble UseNot Used Not UsedNot Used 76.8 kbps CCHNot Used 38.4 kbps CCH
RA Channel Not UsedAvailable for RPC
and DRCLockChannel
Transmissions
Available forForward
Traffic ChannelTransmissions
MACIndex0 and 1
234
5-63
MA
CIn
dex
Wal
sh C
ode
Phas
e
32 16 I
MA
CIn
dex
Wal
sh C
ode
Phas
e
1 32 Q34 17 I 3 33 Q36 18 I 5 34 Q38 19 I 7 35 Q40 20 I 9 36 Q42 21 I 11 37 Q44 22 I 13 38 Q46 23 I 15 39 Q48 24 I 17 40 Q50 25 I 19 41 Q52 26 I 21 42 Q54 27 I 23 43 Q56 28 I 25 44 Q58 29 I 27 45 Q60 30 I 29 46 Q62 31 I 31 47 Q
MA
CIn
dex
Wal
sh C
ode
Phas
e
0 0 I2 1 I4 2 I6 3 I8 4 I
10 5 I12 6 I14 7 I16 8 I18 9 I20 10 I22 11 I24 12 I26 13 I28 14 I30 15 I
MA
CIn
dex
Wal
sh C
ode
Phas
e
33 48 Q35 49 Q37 50 Q39 51 Q41 52 Q43 53 Q45 54 Q47 55 Q49 56 Q51 57 Q53 58 Q55 59 Q57 60 Q59 61 Q61 62 Q63 63 Q
AP
February, 2008 132 - 212Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Rev. A MAC Index Values and Their Uses
114 MAC indices are available for regular single-user packets3 MAC indices are earmarked for control channel packets5 MAC indices are reserved for mult-user packets1 MAC index is reserved for broadcast packets, or single-users4 MAC indices are not used due to conflicts with multiplexing patterns
February, 2008 132 - 213Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Rev. A MAC Index and I/Q Channel Contents
February, 2008 132 - 214Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Link Rates and Packet/Subpacket Formats
The 1xEV-DO Rev. A reverse link has seven available modes offering higher speeds than available in Rev. 0
• Modulation formats are hybrids defined in the standardThe 1xEV-DO Rev. A forward has two available modes offering higher speeds than available in Rev. 0.
FORWARD LINK REVERSE LINKDRCIndex Slots Preamble
ChipsPayload
BitsRawkb/s
0x0 n/a n/a 0 null rate0x1 16 1024 1024 38.40x2 8 512 1024 76.80x3 4 256 1024 153.60x4 2 128 1024 307.20x5 4 128 2048 307.20x6 1 64 1024 614.40x7 2 64 2048 614.40x8 2 64 3072 921.60x9 1 64 2048 1,228.80xa 2 64 4096 1,228.80xb 1 64 3072 1,843.20xc 1 64 4096 2,457.60xd 2 64 5120 1,536.00xe 1 64 5120 3,072.0
C/Idbn/a
-11.5-9.2-6.5-3.5-3.5-0.6-0.5+2.2+3.9+4.0+8.0+10.3+8.3+11.3
Modu-lationQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSK
16QAM8PSK
16QAM16QAM16QAM
PayloadBits128256512768102415362048307240966144819212288
Modu-lation
B4B4B4B4B4Q4Q4Q2Q2
Q4Q2Q4Q2E4E2
Effective Rate kbps after:4 slots
184312289216144613072301531157638
19.28 slots
92161446130723015311576.857.638.419.29.6
12 slots
614409307
204.8153.6102.476.851.238.425.612.86.4
16 slots
460.8307.2230.4153.6115.276.857.638.428.819.29.64.8
Code Rate (repetition) after4 slots 8 slots 12 slots16 slots
1/5 1/5 1/5 1/51/5 1/5 1/5 1/51/4 1/5 1/5 1/53/8 1/5 1/5 1/51/2 1/4 1/5 1/53/8 1/5 1/5 1/51/2 1/4 1/5 1/53/8 1/5 1/5 1/51/2 1/4 1/5 1/51/2 1/4 1/5 1/52/3 1/3 2/9 1/52/3 1/3 1/3 1/3
February, 2008 132 - 215Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Hybrid ARQ Process
In 1xRTT, retransmission protocols typically work at the link layer
• Radio Link Protocol (RLP)– communicates using
signaling packets– lost data packets aren’t
recognized and are discarded at the decoder
This method is slow and wasteful!
SYSTEM
MAClayer
Physicallayer
RLP RadioLink Protocol
Application layer
LAC layer
MAClayer
Physicallayer
RLP RadioLink Protocol
CDMA2000 1xRTT
F-FCHR-FCH
Application layer
LAC layer
Application layer
Stream layer
Session layer
Connection layer
Security layer
MAC layer
Physicallayer
HARQprotocol
AP Access Point AT Access TerminalCDMA2000 1xEV-DO
Physicallayer
HARQprotocol
R-ACK
Application layer
Stream layer
Session layer
Connection layer
Security layer
MAC layer
F-TFC repeats
In 1xEV-DO, RLP functions are replicated at the physical layer
• HARQ Hybrid Repeat Request Protocol– fast physical layer ACK bits– Chase Combining of multiple
repeats– unneeded repeats pre-empted
by positive ACKThis method is fast and efficient!
February, 2008 132 - 216Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
The Hybrid ARQ Process
Each physical layer data packet is encoded into subpackets• as long as the receiver does not send back an
acknowledgment, the transmitter keeps sending more subpackets, up to the maximum of the current configuration
• The identity of the subpackets is known by the receiver, so it can combine the subpackets for better decoding
each additional subpacket in essence contributes additional signal power to aid in the detection of its parent packet
• it’s hard to predict the exact power necessary for successful decoding in systems without HARQ
– the channel changes rapidly during transmission– various estimation errors (noise, bias, etc.)– exact needed SNR is stochastic, even on a static channel!
In effect, HARQ sends progressively more energy until there is just enough and the packet is successfully decoded
February, 2008 132 - 217Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Packet 0Subpackets
Multiple ARQ Instances
Definition: Number of ARQ Instances• the maximum number of packets that may be in transit simultaneously• sometimes also called “the number of ARQ channels”
This figure and the preceding page appear to show 4 ARQ instancesPackets in the different ARQ instances
• may be for the same user (the most common situation)• may be for different users (determined by QOS and scheduling)
Destination mobile knows its packets by their preamble
0 1 2 3Data
PacketsEncoding
andScrambling
Inter-leaving
bits symbols
PacketSubpacket
00
1.0
01
02
03
2.0
3.0
1.1
2.1
3.1
1.2
2.2
3.2
1.3
2.3
3.3
One Slot
Forward
ChannelTraffic
A
February, 2008 132 - 218Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Packet 0Subpackets
Multiple ARQ Instances
Definition: Number of ARQ Instances• the maximum number of packets that may be in transit simultaneously• sometimes also called “the number of ARQ channels”
This figure and the preceding page appear to show 4 ARQ instancesPackets in the different ARQ instances
• may be for the same user (the most common situation)• may be for different users (determined by QOS and scheduling)
Destination mobile knows its packets by their preamble
0 1 2 3Data
PacketsEncoding
andScrambling
Inter-leaving
bits symbols
PacketSubpacket
00
1.0
01
02
03
2.0
3.0
1.1
2.1
3.1
1.2
2.2
3.2
1.3
2.3
3.3
One Slot
Forward
ChannelTraffic
Packet 1Subpackets
0 1 2 3
A
February, 2008 132 - 219Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Packet 0Subpackets
Multiple ARQ Instances
Definition: Number of ARQ Instances• the maximum number of packets that may be in transit simultaneously• sometimes also called “the number of ARQ channels”
This figure and the preceding page appear to show 4 ARQ instancesPackets in the different ARQ instances
• may be for the same user (the most common situation)• may be for different users (determined by QOS and scheduling)
Destination mobile knows its packets by their preamble
0 1 2 3Data
PacketsEncoding
andScrambling
Inter-leaving
bits symbols
PacketSubpacket
00
1.0
01
02
03
2.0
3.0
1.1
2.1
3.1
1.2
2.2
3.2
1.3
2.3
3.3
One Slot
Forward
ChannelTraffic
Packet 1Subpackets
0 1 2 3
Packet 2Subpackets
0 1 2 3
A
February, 2008 132 - 220Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Packet 0Subpackets
Multiple ARQ Instances
Definition: Number of ARQ Instances• the maximum number of packets that may be in transit simultaneously• sometimes also called “the number of ARQ channels”
This figure and the preceding page appear to show 4 ARQ instancesPackets in the different ARQ instances
• may be for the same user (the most common situation)• may be for different users (determined by QOS and scheduling)
Destination mobile knows its packets by their preamble
0 1 2 3Data
PacketsEncoding
andScrambling
Inter-leaving
bits symbols
PacketSubpacket
00
1.0
01
02
03
2.0
3.0
1.1
2.1
3.1
1.2
2.2
3.2
1.3
2.3
3.3
One Slot
Forward
ChannelTraffic
Packet 1Subpackets
0 1 2 3
Packet 2Subpackets
0 1 2 3
Packet 3Subpackets
0 1 2 3
February, 2008 132 - 221Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO Rev. A1xEV-DO Rev. A
February, 2008 132 - 222Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO Rev. A Design Objectives
To enable multimedia services• high-speed upload of multimedia files and attachments • interactive gaming• IP-based services such as Voice over Internet Protocol (VoIP).
To allow real-time conversational services• push to talk, • video telephony • instant multimedia -- an extension of push to talk that combines
immediate voice with simultaneous delivery of video and pictures. multimedia multicasting using QUALCOMM's “Platinum Multicast”
• enables high-quality video/audio to many users simultaneously.Peak forward link data rates of 3.1 Mbps Peak reverse link data rates of 1.8 Mbps Optimized packet data service
• one of lowest costs per bit compared to other wireless technologies.
February, 2008 132 - 223Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Forward Link Enhancements in 1xEV-DO Rev. A
Forward Link Enhancements• Peak rates increased from 2.4 Mbps to 3.1 Mbps• Multi-user packet support• Small payload sizes (128, 256, 512 bits) improve frame fill efficiency• The DRC channel functions are broken out into two channels
– DRC retains rate control indication– new Data Source Control (DSC) Channel shows desired serving cell
• Minimizes interruptions due to server switching on FL
February, 2008 132 - 224Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Reverse Link Enhancements in 1xEV-DO Rev. A
Reverse Link Enhancements• Higher data rates and finer quantization
• Data rates from 4.8 kbps to 1.8 Mbps with 48 payload sizes• 4 slots/sub-packets regardless of payload size (6.66 ms)• Modulation:
– Low rates: 1 walsh channel, BPSK modulation– Medium rates: 1 walsh channel, QPSK modulation– High Rates: 2 walsh channels, QPSK modulation– Highest Rate: 2 walsh channels, 8PSK modulation
• Hybrid ARQ using fast re-transmission (re-tx) and early termination• Flexible rate allocation: each AT has autonomous and scheduled mode• Efficient VOIP support• 3-channel synchronous stop-and-wait protocol• The mobile can use higher power and finish earlier when transmitting
packets of applications requiring minimum latency
February, 2008 132 - 225Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Available Link Rates in 1xEV-DO Rev. A
The 1xEV-DO Rev. A reverse link has seven available modes offering higher speeds than available in Rev. 0
• Modulation formats are hybrids defined in the standardThe 1xEV-DO Rev. A forward has two available modes offering higher speeds than available in Rev. 0.
FORWARD LINK REVERSE LINKDRCIndex Slots Preamble
ChipsPayload
BitsRawkb/s
0x0 n/a n/a 0 null rate0x1 16 1024 1024 38.40x2 8 512 1024 76.80x3 4 256 1024 153.60x4 2 128 1024 307.20x5 4 128 2048 307.20x6 1 64 1024 614.40x7 2 64 2048 614.40x8 2 64 3072 921.60x9 1 64 2048 1,228.80xa 2 64 4096 1,228.80xb 1 64 3072 1,843.20xc 1 64 4096 2,457.60xd 2 64 5120 1,536.00xe 1 64 5120 3,072.0
C/Idbn/a
-11.5-9.2-6.5-3.5-3.5-0.6-0.5+2.2+3.9+4.0+8.0+10.3+8.3+11.3
Modu-lationQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSKQPSK
16QAM8PSK
16QAM16QAM16QAM
PayloadBits128256512768102415362048307240966144819212288
Modu-lation
B4B4B4B4B4Q4Q4Q2Q2
Q4Q2Q4Q2E4E2
Effective Rate kbps after:4 slots
184312289216144613072301531157638
19.28 slots
92161446130723015311576.857.638.419.29.6
12 slots
614409307
204.8153.6102.476.851.238.425.612.86.4
16 slots
460.8307.2230.4153.6115.276.857.638.428.819.29.64.8
Code Rate (repetition) after4 slots 8 slots 12 slots16 slots
1/5 1/5 1/5 1/51/5 1/5 1/5 1/51/4 1/5 1/5 1/53/8 1/5 1/5 1/51/2 1/4 1/5 1/53/8 1/5 1/5 1/51/2 1/4 1/5 1/53/8 1/5 1/5 1/51/2 1/4 1/5 1/51/2 1/4 1/5 1/52/3 1/3 2/9 1/52/3 1/3 1/3 1/3
February, 2008 132 - 226Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
What’s Next? 1xEV-DO Rev. B
CDG says 1Q06 for Rev. BTelecoms.com News17 November 2005Rufus Jay, [email protected]
The CDMA Development Group (CDG) has announced that the EV-DO Revision B standard is pencilled in for release in 1Q06. Rev. B increases data throughput to 73.5Mbps in the forward linkand 27Mbps in the reverse link. As well as supporting mobile broadband data and OFDM based multicasting, Rev. B's lower latency rates will improve the performance of VoIP, push to talk over cellular, video calling, concurrent voice and multimedia and multiplayer online gaming. The CDG also plans to expand cdma2000 by improved roaming and a sub US$40 handset push, similar to the GSMA's emerging markets initiative.
February, 2008 132 - 227Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO Network Architecture1xEV-DO Network Architecture
February, 2008 132 - 228Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA Network for Circuit-Switched Voice Calls
The first commercial IS-95 CDMA systems provided only circuit-switched voice calls
t1t1 v CESEL
t1PSTN
BTS
(C)BSC/Access ManagerSwitch
February, 2008 132 - 229Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
CDMA 1xRTT Voice and Data Network
CDMA2000 1xRTT networks added two new capabilities:• channel elements able to generate and carry independent streams of
symbols on the I and Q channels of the QPSK RF signal– this roughly doubles capacity compared to IS-95
• a separate IP network implementing packet connections from the mobile through to the outside internet
– including Packet Data Serving Nodes (PDSNs) and a dedicated direct data connection (the Packet-Radio Interface) to the heart of the BSC
The overall connection speed was still limited by the 1xRTT air interface
t1t1 v CESEL
t1
PDSNForeign Agent
PDSNHome Agent
BackboneNetworkInternet
VPNs
PSTN
AuthenticationAuthorization
AccountingAAA
BTS
(C)BSC/Access ManagerSwitch
February, 2008 132 - 230Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO Overlaid On Existing 1xRTT Network
1xEV-DO requires faster resource management than 1x BSCs can give• this is provided by the new Data Only Radio Network Controller (DO-RNC)
A new controller and packet controller software are needed in the BTS to manage the radio resources for EV sessions
• in some cases dedicated channel elements and even dedicated backhaul is used for the EV-DO traffic
The new DO-OMC administers the DO-RNC and BTS PCF additionExisting PDSNs and backbone network are used with minor upgradingThe following sections show Lucent, Motorola, and Nortel’s specific solutions
t1t1 v CESEL
t1
PDSNForeign Agent
PDSNHome Agent
BackboneNetworkInternet
VPNs
PSTN
AuthenticationAuthorization
AccountingAAA
BTS
(C)BSC/Access ManagerSwitch CE
DORadio
NetworkController
DO-OMC
February, 2008 132 - 231Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Lucent 1xEV-DO ArchitectureLucent 1xEV-DO Architecture
February, 2008 132 - 232Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Lucent 1xEV-DO Radio Access Network (RAN)
A Lucent 1xEV-DO Radio Access Network (RAN) includes• 1xEV-DO base stations and the• 1xEV-DO Flexent® Mobility Server (FMS).
The 1xEV-DO equipment may be collocated with IS-95 and/or 1xRTT equipment, creating 1xEV-DO/IS-95 and 1xEVDO/3G-1X combination base stations.
T-1/E-1Ethernet
RF
Internet
AAAServer
AP
OMP FXElement Management
System
Router
FlexentMobilityServer
DownlinkInput
Router
DownlinkInput
Router
UplinkInput
Router
UplinkInput
Router
FlexentMobilityServer
PacketData
ServingNode
(PDSN)
User ATs(Access Terminals)
RFAP
AP
AP
February, 2008 132 - 233Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO in Lucent Flexent Mod Cell Cabinets
Lucent Mod Cell cabinets can support up to three IS-95 or 1xRTT carriers on three sectors1xEV-DO CDMA Digital Modules (CDM) can be mixed with conventional CDMs in the same cabinetthe same RF hardware (filters, amplifiers, other RF components) can be used for IS-95, 1xRTT, and 1xEV-DO
February, 2008 132 - 234Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Lucent CDMA Digital Module (CDM) Configurations
At upper left is a CDM for conventional IS-95 / 1xRTT service. It includes
• CRC CDMA Radio controller• up to 6 CCU CDMA Channel Units• PCU power converter module• CBR CDMA Baseband Radio
At lower left is a CDM for 1xEV-DO• it must be occupy the leftmost slot• all CCU packs are removed and
replaced by a single 1xEV-DO modem (EVM) occupying 2 slots
• the CRC must be 44WW13D or later
February, 2008 132 - 235Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO in Lucent Mod Cell 4.0 CabinetsThe Mod Cell 4 cabinet comes in many variationsInstead of per-carrier dedicated CDMs, resources are pooledURCs (Universal Radio Controllers) are used to steer data for each carrier to EVMs for EVDO or CMUs for IS-95/1xRTT.
• in a mixed-mode system, a URC is required for EVDO and a URC for IS-95/1xRTT
The modulated signal from a 4.0 EVM or CMU is upconverted to the RF carrier frequency by the UCR
• each UCR (Universal CDMA Radio) can handle up to three carriers
UniversalRadio
Controller(URC) Evolution
Modem(4.0 EVM) Universal
CDMARadio(UCR)CDMA
ModemUnit
(CMU)Universal
RadioController
(URC)ECP
FMS
Antenna
Carr1
Carr2, 3
Digital Shelf Flow
February, 2008 132 - 236Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Lucent 1xEV-DO Flexent Mobility Server (FMS)
The Flexent Mobility Server is the heart of the Radio Access NetworkIt provides four processors running the 1xEV-DO Application Processor (DO-AP), which provides the Packet Controller Function (PCF)The PCF provides air link and radio resource management to implement 1xEV-DO user sessions, including the dormant state and other DO-specific features
February, 2008 132 - 237Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Motorola 1xEV-DO ArchitectureMotorola 1xEV-DO Architecture
February, 2008 132 - 238Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Motorola 1xEV-DO System Architecture
New 1xEV-DO carrier appears as a standard carrier addition to existing network elements
• new MCC-DO cards and OMC-R database revisions needed• AAA and PDSN need software upgrades
MSC
MM/SDU
OMC-IP
OMC-R 1x-AN
1x-BTS
OMC-DO
BSC-DO
AN-DO
MCC-DO
AAAAN-AAA
PDSNs
HAsPacket CoreNetwork
VPU
1xEV-DOIS-95/1xShared 1x/DO
ConnectionsElementsExisting IS-95New 1xEV-DOShared IS-95/DO
February, 2008 132 - 239Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
New Motorola 1xEV-DO Network Elements
MCC-DO (Multi-Channel Controller - Data Only)AN-DO (Access Node - Data only)
• CR (Consolidation Router) Similar in function to the 1x-AN MGX • LSW (Layer 3 Switch) Similar in function to the 1x-AN CATs
BSC-DO (Base Station Controller-Data Only)• Mobility functions like 1x MM - Packet Control & Selection – like SDU
OMC-DO (Operations & Maintenance Center - Data Only)LMT (Local Maintenance Terminal)
MSC
MM/SDU
OMC-IP
OMC-R 1x-AN
1x-BTS
OMC-DO
BSC-DO
AN-DO
MCC-DO
AAAAN-AAA
PDSNs
HAsPacket CoreNetwork
VPU
1xEV-DOIS-95/1xShared 1x/DO
ConnectionsElementsExisting IS-95New 1xEV-DOShared IS-95/DO
February, 2008 132 - 240Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Motorola 1xEV-DO Block Diagramand Network Upgrade Summary
IS-2000 1xEV-DOTool LMF LMT
MCC-1XGLI (Traffic)
AN (MGX8800) CRAN (Catalyst 6509) LSW
BSC CBSC BSC-DOOMC-R
UNOIP Network
Telephone Network MSC/HLR Not RequiredData Network Not Required AAA
BTS frame & CCP shelf
BTS
PDSN (Note 1)
GLI (Control)
MCC-DO
OMC-DO
AN
O&M
LPABBX-1X
CR
BSC-DO
PDSN
OMC-DO
LSW
BTS
RF
Fron
t End
1x Modems
DO BBX
1x BBX
MCC-DO
AN-AAA
BTSR
F Fr
ont E
nd
1x Modems
DO BBX
1x BBX
MCC-DO
T1 or E1
AN-DO
February, 2008 132 - 241Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Motorola MCC-DO Functions
1xEV-DO Modem• 1 carrier, 3 sectors per
MCC-DO card• Supports 59 channels per
sectorSpan Interface
• Up to 3 Active Span lines per MCC-DO
• Most operators will generally deploy with 2 spans per BTS
BTS provides control:• SCAP messaging• Redundant BBX Selection• Enhanced BBX interface
CR
BSC-DO
PDSN
OMC-DO
LSW
BTSR
F Fr
ont E
nd
1x Modems
DO BBX
1x BBX
MCC-DO
AN-AAA
BTS
RF
Fron
t End
1x Modems
DO BBX
1x BBX
MCC-DO
T1 or E1
AN-DO
MCC- DO
February, 2008 132 - 242Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Nortel 1xEV-DO ArchitectureNortel 1xEV-DO Architecture
February, 2008 132 - 243Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
A Typical Nortel CDMA2000 SystemProviding 1xRTT Voice, Data, and 1xEV-DO
February, 2008 132 - 244Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Nortel Multiple Backhaul and Configuration Possibilities
February, 2008 132 - 245Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Nortel Univity® Indoor Metrocell
Univity® Metro Cell can support:
• up to six CDMA 1.25 MHz carrier frequencies
• up to three sectors. High Power Amplifiers and Low Noise Amplifiers are housed in an external unit
• the Multi-Carrier Flexible Radio Module (MFRM)
• MFRM may be mast mounted to improve AP RF link budget
Univity® CDMA Metro Cell Indoor Base Transceiver System (AP)
February, 2008 132 - 246Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Nortel DOM: Data-Only Module
The Data Only Module (DOM) adds 1xEV-DO capability to a MetroCell AP CEM shelf
• transmits/receives baseband data to/from the digital control group (DCG) in the CORE module
• CORE switches baseband to proper carrier on the MFRM for transmission
• the DOM performs all encoding/decoding of IP packets for transport on data-only network to the Data-Only Radio Network Controller (DO-RNC)
• One DOM supports up to a three-sector, one-carrier MetroCell AP
• Additional DOMs support additional carriers
February, 2008 132 - 247Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Nortel’s DO-RNCThe Data-Only Radio Network Controller
DO-RNC is the heart of a 1xEV-DO network, located at the central office (CO) with the BSC and/or BSS Manager (BSSM)DO-RNC is a stand-alone node supporting 1xEV-DO. It manages:
• DOMs at multiple APs (even on different band classes) over IP-based backhaul network
• access terminal state, both idle and connected
• handoffs of ATs between cells and carrier frequencies (reverse); sector selection (fwd).
• connections from airlink to PDSN over standard A10-A11 interfaces
• connects to MetroCell AP via dedicated IP backhaul network
DO-RNC is the peer of the access terminal for most over-the-air signaling protocols, including session and connection layers
Nortel DO-RNCData-Only
Radio Network Controller
February, 2008 132 - 248Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
An EV-DO Connection
CONTROL
MAC
PILOT
TRAFFIC
AccessPoint(AP)
ACCESS
TRA
FFIC
PILOTRRIDRCACK
DATA
AccessTerminal
(AT)
Rake Receiver#1 PN168+0 W23
#2 PN168+2 W23
#3 PN168+9 W23
#4 PN168+5 W23
Pilot Searcher
CONNECTION REQUESTCONNECTION ROUTE UPDATE
MAC ACKTRAFFIC CHANNEL ASSIGNMENT
MAC RTC ACKTRAFFIC CHANNEL COMPLETE
XON REQUEST
NEIGHBOR LISTXON RESPONSE
ROUTE UPDATE
TRANSITION TO DORMANT
NULL MESSAGE
NULL MESSAGETRAFFIC CHANNEL ASSIGNMENT
TRAFFIC CHANNEL COMPLETENEIGHBOR LIST
February, 2008 132 - 249Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Backhaul and Related Considerations
Backhaul and Related Considerations
February, 2008 132 - 250Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Rate Limitations from Backhaul
Wireless sites are commonly connected using T-1s or E-1s, depending on local availability
• In the case of T-1s, the raw rate is 1.544 megabits/second.– Accounting for overhead, this translates into a maximum
steady throughput of roughly 400 to 450 kb/s per sector on a 3-sector, 1-carrier EV-DO site.
– If one sector is busy while the other two are only lightly loaded, throughput of roughly 1 mb/s can be obtained on one sector
– However, early 1xEV-DO cards without support for multiple ARQ instances can only achieve about 400 kb/s throughput even without backhaul limitations
Solutions under study to relieve backhaul congestion include fiber-based ATM to the sites; multiple-T1s; sites linked by Cable Modems, and other methods
February, 2008 132 - 251Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Speed of Individual Data Bursts
The average data rate received depends on:
• “dilution” of sector capacity by multiple users
• Reduction of speed due to poor RF channel conditions
The distribution of packet rates of one user show the effects of RF impairments only
February, 2008 132 - 252Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO / 1xRTT Interoperability
1xEV-DO / 1xRTT Interoperability
February, 2008 132 - 253Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xEV-DO/1xRTT Interoperability
The CDMA2000 1xEV-DO Standard IS-856 makes no provision for any kind of handoff to or from any other technologyDriven by Operator interest, a “Hybrid” mode has been developed to provide some types of handoff functions to the best extent possibleHybrid Mode
• is a mobile only function – neither the EV nor 1xRTT network knows anything about it
• is a proprietary feature with vendor-specific implementation• has no standard-defined RF “triggers”; no “hooks”
In the 1xEV rev. A standard, some new features will be provided• the 1xEV control channel will be able to carry 1xRTT pages too• this and other changes may make the “hybrid” mode
unnecessary and obsolete
February, 2008 132 - 254Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
What Handoffs are Possible in Hybrid Mode?
All switching between systems occurs in Idle Mode• there are no “handoffs” in active traffic state in either mode
Sessions can be transferred from one system to the other, but NOT in active traffic state
• If there is a connection, it can be closed and then re-originated on the other system
• In some cases this can be accomplished automatically without the end-user’s awareness – in other cases, this is not possible
February, 2008 132 - 255Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xRTT / 1xEV-DO Hybrid Idle Mode
1xRTT/1xEV-DO Hybrid Mode• depends on being able to hear pages on both
systems – 1xRTT and 1xEV-DO• is possible because of slotted mode paging• 1xRTT and 1xEV-DO paging slots do not occur
simultaneously• mobile can monitor both
During 1xEV-DO traffic operation, the hybrid-aware mobile can still keep monitoring 1xRTT paging channelDuring 1xRTT traffic operation, the hybrid-aware mobile is unable to break away; 1xRTT traffic operation is continuous
• no opportunity to see 1xEV-DO signalThis hybrid Idle mode capability is the foundation for all 1xRTT/1xEV mode transfers
• the network does not trigger any transfers
1xR
TT
Act
ive
1xR
TT
Idle
1xEV
-DO
Idle
1xEV
-DO
A
ctiv
e
IdleMode
IdleMode
HybridMode
February, 2008 132 - 256Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
Hybrid Dual-Mode Idle Operation1xRTT / 1xEV-DO Paging Interoperability
A dual-mode 1xRTT/1xEV-DO mobile using slotted-mode paging can effectively watch the paging channels of both 1xRTT and 1xEV-DO at the same timeHow is it possible for the mobile to monitor both at the same time?
• The paging timeslots of the two technologies are staggeredThree of the 16 timeslots in 1xRTT conflict with the control channel slots of 1xEV-DO
• However, conflicts can be avoided by page repetition, a standardfeature in systems of both technologies
16-frame Control Channel Cycle16 slots of 26-2/3 ms = 426-2/3 ms
1xRTT Minimum Slot Cycle Index: 16 slots of 80 ms each = 48 26-2./3 ms frames1xRTT Minimum Slot Cycle Index: 16 slots of 80 ms each = 48 26-2./3 ms frames
16-frame Control Channel Cycle16 slots of 26-2/3 ms = 426-2/3 ms
LONGEST POSSIBLEPACKET
DRC 16 Subpackets
February, 2008 132 - 257Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xR
TT
Act
ive
1xR
TT
Idle
1xEV
-DO
Idle
1xEV
-DO
A
ctiv
eInitial System Acquisition by Hybrid Mobile
IdleMode
Acquire1xRTTSystem
driven byPRL
Registerwith
1xRTTNetwork
Acquire1xEV-DOSystem
driven byPRL
Classical 1xRTTIdle Mode
no, can’t see EV
VoicePage!
1xRTTVoiceCall
IdleMode
Release
when 1xEV-DO is NOT Available
After entering this state, the mobile will not search for
1xEV service again
February, 2008 132 - 258Technical Introduction to CDMA v6 (c) 2008 Scott Baxter
1xR
TT
Act
ive
1xR
TT
Idle
1xEV
-DO
Idle
1xEV
-DO
A
ctiv
eInitial System Acquisition by Hybrid Mobile
IdleMode
Acquire1xRTTSystem
driven byPRL
Registerwith
1xRTTNetwork
Acquire1xEV-DOSystem
driven byPRL
Set Up orRe-establish
1xEVDOData
Session
yes, found EV
IdleMode
IdleMode
HybridMode
1xEVTraffic
AT DataReady!
AN DataPage!
DataConnectionClosed
VoicePage!
1xEVTraffic
1xRTTVoiceCall
IdleMode
HybridMode
IdleMode
IdleMode
HybridMode
Release
when 1xEV-DO is Available
interruptedduring1xRTT
voice call
Triggers: