HSDPA/HSUPA High speed packet access
March 22nd 2005Salo, Finland
Harri Holma, Principal EngineerAntti Toskala, HSDPA Chief Architect
Nokia, Finland
1 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Agenda
2 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• WCDMA R99 performance today• HSDPA standard • HSDPA performance • HSUPA standard• HSUPA performance
WCDMA Performance in Commercial Networks
3 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
WCDMA Release’99 Terminal Capability – Nokia 6630
• Data rates• WCDMA up to 384 kbps (DL) and 128 kbps (UL) • EDGE 4+2 = 236 kbps (DL) and 118 kbps (UL)
• WCDMA2100, GSM900/1800/1900• Symbian Series 60 platform• Colour display 176 x 208 pixels & 65k colours• Camera 1.3 Mpixel• Stand-by up to 11 days• Talk time up to 3 hours• Weight/volume: 127 g
Downlink 384 kbps Uplink 128 kbpsEDGE included
4 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
WCDMA Coverage – Noise Limited
-115 -110 -105 -100 -95 -90 -85 -800
50
100
150
200
250
300
350
400
CPICH RSCP [dBm]
kbps
WCDMA2100EDGE900
384 kbps
384 kbps can be provided down to approx– 105 dBm if
no other-cell interference
Similar average data rate of approx 200 kbps with
WCDMA2100 and EDGE900
3 parallel users in WCDMA
5 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
WCDMA Coverage – Interference Limited
-100 -95 -90 -85 -80 -75 -700
50
100
150
200
250
300
350
400
CPICH RSCP [dBm]
kbps
WCDMA2100EDGE900
Approx 2 x higher data rate in WCDMA than in EDGE
3 parallel users in WCDMA
Data rate other-cell interference limited at
the cell edge
6 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
WCDMA Round Trip Time (RTT)• Typical round trip time 150-200 ms for small IP packets in today’s networks • R99 round trip time expected to go below 120 ms with 10-ms TTI
7 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
End-to-end Round Trip Time (RTT) 150 – 200 ms
Radio transmission UMTS RAN + core Internet
UE RNC SGSN GGSN ServerBTS
Download of 1st WAP Page Today• 384 kbps DCH is fully used only <1 s out of 10 s• Packet setup times must get (and will get!) shorter to get full benefit from HSDPA
8 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
0.6 s
32kbps
0.9 s0.4
6 8 9 10 12
6 Radio bearer reconfiguration from 0/0 kbps to 16/32 kbps – uplink initiated
8 TCP connection establishment
9 HTTP request in uplink10 Radio bearer reconfiguration to 16/384 kbps – downlink initiated11 Page download starts over 384 kbps. TCP slow start takes about 0.7 s.
= 10 s0.7
11
12
3
0.7 s 2.0 s 1.4 s
1
RB reconfig
TCPHTTP
requestRB reconfig
Rest of the page downloaded with full 384 kbps speed, depends on the page size.
User pushes WAP home page key
RRC PDP
5
5 PDP context activation + signaling radio bearer setup + measurement control
0.4
4
4 Security mode
1
3
1.5 s
RRC connection activation
0.5
7
2 UE internal delay (in Nokia browser in Charlie)
2
384 kbps
7 UE internal delay
0.5
13
13
0.4
UE display rendering
Optimized 1st WAP Page Download• WAP page download time could be reduced from 10 s below 5 s without increasing bit rate• Setup time is reduced from 5.7 to 1.6 s, the rest is application signalling and UE delays
1st WAP Page Download Time
0.0
2.0
4.0
6.0
8.0
10.0
12.0
RAN04 Optimized
s
Display renderingDownload over 384 kbpsTCP slow startDCH upgrade DNS query and HTTP requestTCP connection establishmentUE internal delayRB reconfigurationPDP context activationSecurity modeAuthentication and cipheringRRC connection establishmentUE internal delay
10.3 s
4.7 s
1 UE Symbian delay reduced from 1.5 to 0.5 s
1
2
2 RRC setup on common channels
4
4 Direct RB allocation after PDP context
5
5 UE delay removed
6 Seamless RB upgrade6
= Setup times
3
3 Authentication done with GPRS attach already
9 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Summary of Voice Capacity Tests• Typical voice capacity 60-70 users per cell with AMR 12.2 kbps. Up to 2x more
with lower rate AMR.
AMR 12.2 kbps users with 50% voice activity
0
10
20
30
40
50
60
70
80
Europeanop
Example lastslide
Asia, highresult
Asia, lowresult
Asia,stationary
Asia, drivetest
Voic
e us
ers
per 5
MH
z
10 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Summary of Data Capacity Tests• Typical data capacity 600-1000 kbps per cell
0
100
200
300
400
500
600
700
800
900
1000
Packet throughputuplink
Packet throughputdownlink (64)
Packet throughputdownlink (128)
Packet throughputdownlink (384)
Agg
rega
te c
ell t
hrou
ghpu
t
Measured stationaryMeasured drive test
11 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
WCDMA High Speed Downlink PacketAccess (HSDPA) of Release 5
12 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Reference: WCDMA for UMTS, 3rd edition, Chapter 11
Outline
13 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• HSDPA Introduction• HSPDA Protocol Architecture• New Node B & UE functions• Modulation and coding• HSDPA & Soft Handover• HSDPA vs DCH/DSCH• HSDPA & Iub• Summary
High Speed Downlink Packet Access HSDPA
• Peak data rates increased to significantly higher than 2 Mbps; Theoretically exceeding 10 Mbps
• Packet data throughput increased 50-100% compared to 3GPP release 4
• Reduced delay from retransmissions.• Solutions
• Adaptive modulation and coding QPSK and 16-QAM• Layer 1 hybrid ARQ• Short frame 2 ms
• Schedule in 3GPP• Part of Release 5• First specifications version completed 03/02
14 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA – General Principle
15 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Terminal 1 (UE)
L1 Feedback
L1 Feedback
Data
Data
Downlink fast schedulingdone directly by Node B (BTS) based on knowledge of:
• UE's channel quality• UE's capability• QoS demands• Power and code resource availability• Node B buffer status
Terminal 2Users may be time and/or code multiplexed
Multi-user Diversity (Fast Scheduling)
UE2
Channel quality(CQI, Ack/Nack, TPC)
Channel quality(CQI, Ack/Nack, TPC)
Data
Data
UE1
Multi-user selection diversity(give shared channel to “best” user)
TTI 1 TTI 2 TTI 3 TTI 4
USER 1 Es/N0USER 2 Es/N0
Scheduled user
Node-B scheduling can utilize information on the
instantaneous channel conditions for each user.
16 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Fast Link Adaptation in HSDPA
0 20 40 60 80 100 120 140 160-202468
10121416
Time [number of TTIs]
QPSK1/4
QPSK2/4
QPSK3/4
16QAM2/4
16QAM3/4
Inst
anta
neou
s Es
No
[dB]
C/I received by UE
Link adaptation
mode
C/I varies with fading
BTS adjusts link adaptation mode with a few ms delay based on channel quality
reports from the UE
17 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Release’99 RRM Functional Split
• Admission control on interference and power level• Initial power and SIR setting• Radio resource reservation• Air interface scheduling for common channels• DL code allocation and code three handling• Load and overload control
• Admission control on interference and power level• Initial power and SIR setting• Radio resource reservation• Air interface scheduling for common channels• DL code allocation and code three handling• Load and overload control
• Mapping RAB QoS Parameters into air interface L1/L2 parameters (incl. transport channel selection)• Air interface scheduling (for dedicated channels)• Handover Control• Outer loop power control and power balancing
• Mapping RAB QoS Parameters into air interface L1/L2 parameters (incl. transport channel selection)• Air interface scheduling (for dedicated channels)• Handover Control• Outer loop power control and power balancing
Radio network topology hidden to the CN
Radio network topology hidden to the CN
Node BServing
RNC SGSN
MSCDrift RNC
Iur IuIub
RRC
• Fast power control• Overload control
• Fast power control• Overload control
18 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA Protocol Architecture• New MAC entity, MAC-hs added to the Node B• Layers above, such as RLC, unchanged.
WCDMA L1
UE
Iub/Iur
SRNCNode B
Uu
MACRLC
NAS
WCDMA L1
MAC-hs
TRANSPORT
FRAMEPROTOCOL
TRANSPORT
FRAMEPROTOCOL
MAC-dRLC
Iu
HSDPA user plane
19 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Release’99 vs HSDPA RetransmissionsRel’99 DCH/DSCH Rel’5 HS-DSCH
20 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Terminal
BTS
RNC
Packet Retransmission
RLC ACK/NACK
Retransmission
L1 ACK/NACK
Packet
HSDPA L1 Retransmissions
21 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• The L1 retransmission procedure (Hybrid ARQ, HARQ) achieves following• L1 signaling to indicate need for retransmission -> fast round trip time facilitated
between UE and BTS• Decoder does not get rid off the received symbols when decoding fails but combines the
new transmisssion with the old one in the buffer.
• There are two ways of operating:• A) Identical retransmission (soft/chase combining): where exactly same bits are
transmitted during each transmission for the packet• B) Non-identical retransmission (incremental redundancy): Channel encoder output is
used so that 1st transmission has systematic bits and less or not parity bits and in case retransmission needed then parity bits (or more of them) form the second transmission.
New Node B functionality for HSDPA
Node BRNC Terminals
PacketsScheduler
& Buffer
ARQ &
Coding
ACK/NACK & Feedback Decoding
Flow Control
New Node B functions:• Scheduler: Terminal scheduling, Coding & Modulation selection (16QAM as
new modulation)• ARQ Retransmissions Handling• Uplink Feedback Decoding • Flow Control towards SRNC
22 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
New terminal functionality for HSDPA
RNC Node B Terminal
23 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
ARQ
Decoding
Soft Buffer
& Combining
ACK/NACK & Feedback
Generation
Packets
Flow Control
New terminal functions:• 16 QAM demodulation• ARQ Retransmissions Handling• Soft buffer & combining• Fast Uplink Feedback Generation & encoding
Adaptive Modulation – QPSK and 16QAM• Release’99 uses QPSK • HSDPA uses both QPSK and 16-QAM• 16-QAM requires also amplitude estimation from CPICH for detection
QPSK 16QAM
24 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA - UE Categories• Theoretical peak bit rate up to 14 Mbps• 1.8 Mbps and 3.6 Mbps capability expected initially
10
9
7/8
5/6
3/4
1/2
12
11
HSDPACategory
-
-
-
3.6 Mbps
1.8 Mbps
1.2 Mbps
1.8 Mbps
0.9 Mbps
5 Codes
--36302QPSK only
--36301QPSK only
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
Modulation
14.0 Mbps
10.1 Mbps
-
-
-
-
15 Codes
-279521
-202511
7.2 Mbps144111
-72981
-72982
-72983
10 CodesTransportBlock sizeInter-TTI
25 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA - UE Categories (cont.)• Inter-TTI interval > 1 means that terminal can not receive data in consecutive TTIs• No indication of actually being used in the market place• Other key issues are:
• 16QAM support (not part of 2 categories)• The key different in the first devices
• Size of the memory: Larger memory per class allows incremental redundancy even with full rate
• Number of HS-DSCH codes supported (5, 10 or 15)
26 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Not permitted for the same user with Inter TTI > 1
HS-DSCH
HSDPA DL Channel Structure• High speed downlink shared channel (HS-DSCH) carries the user data in the
downlink direction, with the peak rate up to 10 Mbps • High speed shared control channel (HS-SCCH) carries the necessary physical layer
control information to enable decoding of the data on HS-DSCH• Only one HS-SCCH needed if only time multiplexing is used• DCH always running in parallel
27 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
2 ms
HS-SCCHs
HS-DSCH
……
Demodulation information
Control dataControl data
User dataUser data
28 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HS-SCCH• The HS-SCCH is fixed data rate channel
with SF 128 (60 kbps)• The content is divided in two parts• First part carries
• Channelisation-code-set info• Modulation info
• Second Part• Transport-block size information• Hybrid-ARQ process information• Redundancy and constellation version• New data indicator
• Additionally UE identify information is used target the information to correct user
• To separate which of the 4 HS-SCCHs UE needs to decode (UE specific masking)
• Decoder matrix to be observed…..
ChannelCoding 1
HS-SCCH
Physicalchannelmapping
Ratematching 1
mux mux
Xccs Xms
Xue
X1X2
Xtbs Xhap
XrvXnd
Y
ChannelCoding 2
Ratematching 2
UEspecificmasking
Z1 Z2
S1
R1 R2
Xue
RVcoding
r s b
UE specificCRC
attachment
HS-DSCH
29 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• The HS-DSCH uses 1 to 15 codes with fixed SF 16
• Specific parts in the channel coding chain are related to HARQ and 16QAM modulation (and some simplifications as there is no DTX, compressed mode etc…)
• Impacted by 16QAM• Interleaving (two identical interleavers
with 16QAM TTIs)• Constellation re-arrangement (same bits
not in same constellation point between retransmissions
CRC attachment
aim1,aim2,aim3,...aimA
Code block segmentation
Channel Coding
Physical channelsegmentation
PhCH#1 PhCH#P
Physical Layer Hybrid-ARQfunctionality
dim1,dim2,dim3,...dimB
oir1,oir2,oir3,...oirK
ci1,ci2,ci3,...ciE
vp,1,vp,2,vp,3,...vp,U
up,1,up,2,up,3,...up,U
w1,w2,w3,...wR
HS-DSCHInterleaving
Physical channel mapping
Constellationre-arrangement
for 16 QAM
rp,1,rp,2,rp,3,...rp,U
Bit Scrambling
bim1,bim2,bim3,...bimB
HSDPA UL Channel Structure• High Speed Dedicated Physical Control Channel (HS-DPCCH) carries the uplink
HSDPA related L1 control information to the BTS• This is parallel to the Uplink DCH• Timing from downlink packet to uplink feedback (ACK/NACK) is fixed thus
network knows for which packet the info is related to
2 ms
HS-SCCHs
HS-DSCH
7.5 slots (approx.)
HS-DPCCH
ACK/NACK Channel Quality Information
2 ms
CRC result
30 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HS-DPCCH• The HS-DPCCH is fixed data rates channel with SF 256 • As this is BPSK channel, this gives 10 bits per slot• 1 slot used for ACK/NACK code word, 2 slots for the CQI info
• For CQI one of the 0 .. 30 values transmitted (one unused value)•(20,5) code used
i Mi,0 Mi,1 Mi,2 Mi,3 Mi,4 0 1 0 0 0 1 1 0 1 0 0 1 2 1 1 0 0 1 3 0 0 1 0 1 4 1 0 1 0 1 5 0 1 1 0 1 6 1 1 1 0 1 7 0 0 0 1 1 8 1 0 0 1 1 9 0 1 0 1 1
10 1 1 0 1 1 11 0 0 1 1 1 12 1 0 1 1 1
message to be transmitted
w0
w1
w2
w3
w4
w5
w6
w7
w8
w9
ACK 1 1 1 1 1 1 1 1 1 1
NACK 0 0 0 0 0 0 0 0 0 0
PRE 0 0 1 0 0 1 0 0 1 0
POST 0 1 0 0 1 0 0 1 0 0
Party omitted …
31 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
PAR Increase due HS-DPCCH• Terminal TX power is allowed to be reduced with low DCH uplink data rates, due
to the added parallel channel -> increased peak to average ratio when channels have close to equal power
Ratio of DPCCH/DPDCH gain factors for all values of
HS-DPCCH gain factor
Power Class 3 Power Class 4
Power(dBm)
Tol(dB)
Power(dBm)
Tol(dB)
1/15 ≤ βc/βd ≤ 12/15 +24 +1/-3 +21 +2/-2
13/15 ≤ βc/βd ≤ 15/8 +23 +2/-3 +20 +3/-2
15/7 ≤ βc/βd ≤ 15/0 +22 +3/-3 +19 +4/-2
32 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
MAC-hs Round-Trip Loop Timing• Minimum retransmission delay 12 ms
33 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HS-SCCH
HS-PDSCH2 slots 3 slots
A = HS-DPCCH L1, MAC-hs,HS-SCCH L1
B = HS-PDSCH L1
Retransmit
Retransmit
A B
18 slots = 12 ms 2 slots
2 x Tprop + 15.5 slots
CQIA/N
Rate Matching
34 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Turbo encoder coding rate = 1/3.• Rate Matching is used to adapt to the
desired coding rate.• Either puncturing or repetition.• In the example, RM punctures into
rate 3/4.• Note: The systematic bits are more
important than parity bits!
Data
Turbo Encoder
SystematicParity 1Parity 2
Rate Matching (Puncturing)
SystematicParity 1Parity 2
Hybrid ARQ (HARQ): Chase CombiningTurbo Encoder
SystematicParity 1Parity 2
Rate Matching (Puncturing)
Original transmission Retransmission
35 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
SystematicParity 1Parity 2
Chase Combining (at Receiver)
SystematicParity 1Parity 2
Hybrid ARQ (HARQ): Incremental RedundancyTurbo Encoder
SystematicParity 1Parity 2
Rate Matching (Puncturing)
36 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Original transmission RetransmissionSystematicParity 1Parity 2
Incremental Redundancy Combining
SystematicParity 1Parity 2
HSDPA Channel Quality Feedback• This will depend on the location in the cell, expected BTS TX power for HSDPA
(parameter), channel condition & receiver etc. details
High CQI reported (close to BTS, high HSDPA power)
Low CQI reported (far from BTS, low HSDPA power)
37 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
-14 -12 -10 -8 -6 -4 -2 0Tx Ec/Ior (dB)
Thr
ough
put (
kbps
)
High Throughput
Low ThroughputGeometry=0dB Geometry=5dB Geometry=10dB
Example CQI Mapping Table
• BTS can map the received CQI value for the data rate to be used in the link adaptation
• Necessary conversion to be done depending on BTS power availability
• Reference power adjustment used when quality would allow higher rate than UE capability
CQI value Transport Block Size
Number of HS-PDSCH Modulation
Reference power adjustment ∆
NIR XRV
0 N/A Out of range
1 137 1 QPSK 0
2 173 1 QPSK 0
3 233 1 QPSK 0
4 317 1 QPSK 0
5 377 1 QPSK 0
6 461 1 QPSK 0
7 650 2 QPSK 0
8 792 2 QPSK 0
9 931 2 QPSK 0
10 1262 3 QPSK 0
11 1483 3 QPSK 0
12 1742 3 QPSK 0
13 2279 4 QPSK 0
14 2583 4 QPSK 0
15 3319 5 QPSK 0
16 3565 5 16-QAM 0
17 4189 5 16-QAM 0
9600 0
(continues until 31…)38 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA & Soft Handover• In case of DCH all data is sent from all active set BTSs• In case of HSDPA, HS-DSCH sent from one BTS only, associated DCH (can be
low rate if only signaling) from all cells
39 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Iub
RNC
Node B
Iub
Node B
Node B
RNC
DCH +HS-DSCH
DCH
DCH
DCH
Node B
HSDPA & Soft Handover (cont.)• The intra-frequency measurement event ID is modified• Now a measurement report will be initiated when the best serving cell changed
(parameters to have some hysteresis)• This is needed to initiate the HS-DSCH serving cell change even when active set is
unchanged• In case serving cell change, RLC layer (in the RNC) will handle unfinished ARQ
processes when Node B memory is flushed.
40 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
IubRNC
Node B
DCH +HS-DSCH
DCH
Node B
HS-DSCH vs. DSCH• DSCH of Release’99 uses variable spreading factor and fast power control
(otherwise like DCH)• Principle agreement also to remove DSCH from Release 5 and onwards
from 3GPP specifications as part of feature clean-up (CRs for 06/05 specs)• HS-DSCH of Release 5 uses adaptive modulation and coding and L1 Hybrid
ARQ
Feature
Variable spreading factor
Fast power control
Adaptive modulation and coding
Fast L1 HARQ
DSCH
Yes
Yes
No
No
HS-DSCH
No
No
Yes
Yes
41 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA & DCH Resource Sharing
42 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Common channels
DCH RT
DCH NRT
HSDPA NRT
PtxTarget
Max power
Power control head-room
Non-controllable power
Controllable power
Total transmittedcarrier power
NEW non-HSDPApower measurements
Power measurementsfrom the Node-B to
the RNC
Node-B Tx power
In addition to power also code resource
shared!
HSDPA vs DCH Code Space Usage• With Downlink DCH Time multiplexed DPCCH and DPDCH• Variable rate with DTX -> Code space not released due inactivity• Problematic for high bit rates -> Current highest DL rate 384 kbps
FULL RATE
Data TPC
43 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
PilotData
Slot 0.667 ms = 2/3 ms
TPC
DPDCH DPDCH
Data
DPCCH DPCCH
TFCI
PilotDataTFCI
Slot 0.667 ms = 2/3 msDPDCH DPCCH DPDCH DPCCH
HALF RATE
DTX
HSDPA vs DCH code space usage (cont.)• With HSDPA code resource (except what is needed for DCH) shared with 2 ms
resolution -> Optimum code resource use• Also no soft handover related extra code use
44 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
C0(0) = [ 1 ]
C1(0) = [ 1 1 ]
C1(1) = [ 1 0 ]
C2(0) = [ 1 1 1 1 ]
C2(1) = [ 1 1 0 0 ]
C2(2) = [ 1 0 1 0 ]
C2(3) = [ 1 0 0 1 ]
C3(0) = [ 1 1 1 1 1 1 1 1 ]
C3(1) = [ 1 1 1 1 0 0 0 0 ]
. . .
. . .
Spreading factor:
SF = 1 SF = 2 SF = 4 SF = 8
C3(2) = [ 1 1 0 0 1 1 0 0 ]
C3(3) = [ 1 1 0 0 0 0 1 1]
. . .
. . .
C3(4) = [ 1 0 1 0 1 0 1 0 ]
C3(5) = [ 1 0 1 0 0 1 0 1 ]
. . .
. . .
C3(6) = [ 1 0 0 1 1 0 0 1 ]
C3(7) = [ 1 0 0 1 0 1 1 0 ]
. . .
. . .
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
= Allocated code
= Code which cannotbe allocated at the sametime as C3(1)
= Code which canbe allocated at the sametime as C3(1)
These codes cannot be used at the same
time as C3(1)
HSDPA & Iub• HSDPA improves Iub efficiency compared to Release’99 packet data since HSDPA is
a time shared channel with a flow control in Iub• Release’99 requires dedicated resources from RNC to UE. Those resources are not
fully utilized during TCP slow start, during data rate variations or during inactivity timer
• Additionally, HSDPA does not use soft handover ⇒ no need for soft handover overhead in Iub
45 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
= User 1= User 2= User 3
Iub link 1
Iub link 2
1 2 HSDPA Iubcapacity
Iub efficiently utilized by HSDPA
1 2
= TCP slow start1= Inactivity timer2
HSDPA & Iub (Cont.)• The needed Iub capacity is NOT
equal to air interface peak rate (e.g. 1.8 or 7.2 Mbps)
• The momentary data rate over 2 ms can be higher than the Iub capacity available, as BTS has buffers and is scheduling to multiple users
• Iub loading thus more related to the actual air interface capacity
0.01 0.1 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
180% power and 15 codes allocated to HSDPA service
Instantaneous (per 2 ms) user throughput [Mbps]
Cum
ulat
ive
distr
ibut
ion
func
tion
[-]
Macrocell/Veh A/3kmph
Microcell/Ped A/3kmph
Average data rate avaible
46 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA - Summary
47 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Multi-code operation combined with lower coding rates and fast HARQ improves link performance at cell edge (low SIR)
• Multi-code operation combined with increased coding rates (e.g. 3/4) fully utilize favorable radio environments (high SIR) without running into code shortage.
• HSDPA is backwards compatible and can be introduced gradually in the network.
• Retransmission and scheduling into Node B• -> reduces (re-)transmission delays; Improves QoS control.
Freely configurable transmissionHSDPA is a natural capacity evolution to WCDMAand an enabler for higher speed data services
HSDPA Release 6 improvements
48 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• The following items are added in Release 6 specifications• Fractional DPCH
• To avoid need for full DCH in downlink when only PS data (SRB in HS-DSCH), shared DL channel to provide uplink TPC commands
• Pre/Post scheme• To avoid DTX detection in BTS for ACK/NACK
commands -> smaller power offsets for the ACK/NACK –> better uplink range
• RX diversity and improved receiver performance• Latter still on-going
• L2/L3 Signaling improvements on-going as well…. • Proposed e.g. combined active set update and HS-DSCH
serving cell change
• Mandatory for a HSDPA capable Release 6 UE, RX diversity and improved receiver optional from the spec …
HSDPA Performance
49 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA RLC Layer Data Rates• Max RLC layer throughput shown below• Max application layer throughput can be very close to RLC throughput
• Difference <5% mainly due to IP headers
5 codes QPSK 10 x 320 3440 1.6 Mbps
# of codes Modulation RLC blocks per 2 ms TTI1
Transport block1
Max RLC data rate
5 codes 16-QAM 21 x 320 7168 3.36 Mbps
10 codes 16-QAM 42 x 320 14155 6.72 Mbps
15 codes 16-QAM 60 x 320 20251 9.6 Mbps
15 codes 16-QAM 83 x 320 27952 13.3 Mbps
12
UE category
5/6
7/8
9
10
1RLC block size of 320 bits assumed2Includes user plane + RLC headers + MAC headers + padding
50 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Nokia HSDPA RAN Measurements
51 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Nokia HSDPA RAN Throughput [kbps]• Application throughput matches with the theoretical calculation • >1.5 Mbps measured with FTP download
Throughput [kbps]
0200400600800
100012001400160018002000
L1 throughput(theory)
RLC throughput(theory)
Applicationthroughput
(theory)
Applicationthroughput(measured)
1.8 Mbps5-code QPSK
1.6 Mbps 1.53 Mbps
52 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Nokia HSDPA RAN Latency [ms]• Measured round trip time 94 ms with 20-ms uplink TTI• Approx 20 ms faster expected with 10-ms uplink TTI
53 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
020406080
100120140160180200
RAN1.5ED2 RAN04 (20-ms UL+DL)
RAN04 (20-ms UL 10-ms
DL)
RAN04 (10-ms UL+DL)
3GPP R5HSDPA (20-ms UL 2-ms
DL)
3GPP R5HSDPA (10-ms UL 2-ms
DL)
3GPP R6HSUPA (2-ms UL+DL)
ms
CalculatedMeasured
94 ms measured with 20-ms uplink
Measured with Ubinetics
System Control Algorithms
54 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Link Adaptation and Power Control
55 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• HS-DSCH link adaptation has typically two loops• A) Inner loop based on CQI reports from UE• B) Outer loop in Node-B to control the BLER of the inner loop
• HS-SCCH power control has typically two loops as well• A) Inner loop based on the fast power control commands from UE• B) Outer loop in Node-B to control the BLER of the inner loop
• These algorithms are not standardized
HS-DSCH link adaptation
HS-SCCH power control
Link Adaptation
56 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
A Two-Step HS-DSCH Link Adaptation (1)
57 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Inner loop algorithms• LA estimates based on UE feedback information, i.e. CQI reports.• LA estimates based on Node-B measurements = UE power control commands• Hybrid schemes using both UE/Node-B measurements.
• Outer loop algorithms• The goal is to compensate for any bias introduced by the inner loop algorithm.• Bias might be introduced due to offsets in relative UE performance caused by improved
receiver architecture, etc.• The outer loop is based on Ack/Nack.• The outer loop controls the residual BLER after 1st retransmissions (=2nd transmission) • The 1st retransmission is used to take into account the gain from HARQ.
A Two-Step HS-DSCH Link Adaptation (2)
RNC Node-B
HS-DSCH
CQI PDCHUL HS-DPCCHdetection
Inner loopLA algorithm
Outer loopLA algorithm
Handovercontrol
CQIsettings
58 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
CQI Based Inner Loop Procedure
59 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Step 1: CQI offset compensation• Compensate for HS-PDSCH transmit power mismatch, if the CQI report at the UE is
derived for a different power level than the one used at the Node-B.
• Step 2: Mapping of CQI report to feasible LA estimate• The offset compensated CQI report may not correspond to a feasible LA estimate, if for
instance the number of suggested multi-codes exceeds the number of HS-PDSCH multi-codes available at the Node-B.
• Step 3: Transport block size adjustment• Adjust the transport block size for the feasible LA estimate according to the number of
available bits to be transmitted to the UE, i.e., perform a simple “rounding” operation.
Outerloop Algorithm Based on Ack/Nack's
60 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Start
Set A equal to the predefined initial value
Ackreceived from re-transmission of
block ?
first
Ackreceived from
transmission ofblock ?
first
Decrease Aby "AStepDown" [dB]
Increase Aby "AStepUp" [dB]
Yes
Yes
No
No
Increase set-point if:
Nack on 2nd trans.
Decrease set-point if:
Ack on 1st or 2nd trans.
Ratio between up/down step determines the residual BLER, I.e. similar as conventional outerloop power control.
HS-SCCH Power Control
61 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HS-SCCH PC Summary
RNC Node-B
HS-SCCH transmit power
CQI PDCHUL HS-DPCCHdetection
SHO: On\Off
HS-SCCH power offset Inner loop
PC algorithmOuter loop
PC algorithm
Handovercontrol
HSDPAoffset
P /0 Por
1
β
Inner loop based on CQI
62 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Outer Loop PC for the HS-SCCH
63 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• The outer loop for HS-SCCH is similar to the standard outer loop PC algorithm for dedicated channels.
• Uplink detection of DTX on the HS-DPCCH (when expecting an Ack/Nack) is assumed to indicate that the HS-SCCH has been erroneously decoded.
• Algorithm• DTX received : Increase target with Pup decibels• Otherwise : Decrease target with Pdown decibels
• The outer loop algorithm is UE specific• Given this approach, the HS-SCCH average BLER converges to
1
1
+=
down
up
PPBLER
System Performance and Simulations
64 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA Performance
Link performanceLink performance How far from Shannon limit?
65 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Macro cell performance – single
user per cell
Macro cell performance – single
user per cellWhat can be achieved in macro cells if all resources given to single user?
Scheduler performance –
multiple users per cell
Scheduler performance –
multiple users per cellHow cell resources can be shared between simultaneous users?
Application performance – end
user view
Application performance – end
user viewWhat is e2e application performance over HSDPA?
HSDPA Link Performance with Turbo Coding Approaches Shannon Limit
Higher bit rates can be obtained only with more antennas (MIMO) and/or wider bandwidth.
Sup
porte
d ef
fect
ive
data
rate
[Mbp
s]
0.1
1.0
10.0
-15 -10 -5 0 5 10 15 20
16QAM
0.01
Instantaneous HS-DSCH C/I before processing gain [dB]
QPSK
HSDPA linkadaptation curve
Shannon limit:3.84MHz*log (1+C/I)2
15 HS-PDSCH allocation(Rake, Pedestrian-A, 3km/h)
66 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA Bit Rates
0.01 0.1 1 100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
180% power and 15 codes allocated to HSDPA service
Instantaneous (per 2 ms) user throughput [Mbps]
Cum
ulat
ive
distr
ibut
ion
func
tion
[-]
Macrocell/Veh A/3kmph
Microcell/Ped A/3kmph
Mean bit rate1.5 Mbps in macro cells
Mean bit rate>5 Mbps in micro cells
67 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Bit Rate Coverage – Interference Limited Case
-100 -98 -96 -94 -92 -90 -88 -86 -84 -82 -800
200
400
600
800
1000
1200
1400
1600
1800
2000
CPICH RSCP [dBm]
kbps
HSDPA2100WCDMA2100EDGE900
3 parallel users in WCDMA and in HSDPA
EDGE900
Average data ratesHSDPA2100 1920 kbps (1 user)HSDPA2100 640 kbps (3 users)WCDMA2100 250 kbps (3 users)EDGE900 140 kbps
Average data ratesHSDPA2100 1920 kbps (1 user)HSDPA2100 640 kbps (3 users)WCDMA2100 250 kbps (3 users)EDGE900 140 kbps
HSDPA2100 (3 users)
WCDMA2100 (3 users)
68 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA Coverage – Interference Limited
69 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
0
1000
2000
3000
4000
5000
6000
7000
8000 Single user assumed on HS-DSCH
7.2 Mbps 2-rx equalizer other
cells fully loaded
3.6 Mbps 1-rx Rake with other cells fully loaded
Average data rate 1-3 Mbps
kbps
Base station Cell edge
7.2 Mbps 2-rx equalizer other cells low loaded
Advanced terminals push
data rates higher
Average user data rate
0
500
1000
1500
2000
2500
3000
2 4 6 8 10 12
HS-DSCH power [W] out of 16-W BTS power
kbps
10-code, 2-eq
10-code, 1-eq
5-code Rake
Average HSDPA Bit Rates with Shared R99 Carrier
0.5-1.5 Mbps in macro cells if carrier
shared with R99
Single user assumed on HS-DSCH
70 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Packet Scheduling Strategies
Fair Throughput
Fair timeC/I based
Operator adjustable slopes for different service and user classes
Min
. tar
get T
hrou
ghpu
t
Tradeoff between cellthroughput, coverage
and user fairnessSpectral Efficiency
71 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Throughput coverage of C/I based scheduling
Throughput coverage of fair throughput scheduling
Throughput
high
low
Low coverage of high data rates
Packet Scheduling Strategies
PS Method
Fair throughput(FT)
*) Note that actual resource allocation will be heavily influenced by QoS/delay requirements and user prioritization schemes!
Fair resource(FR)
C/I based(CI)
Serve order Allocation method
Round robin in random order
Resources according to samethroughput (up to max. alloc. time)
Round robin in random order
Same resources (time/power/codes) per allocation time
Served according to highest slow-averaged channel
quality
Same resources (time/power/codes) per allocation time
Scheduling rate
Slow(avg. over 20-100ms)
Slow(avg. over 20-100ms)
Slow(avg. over 20-100ms)
*) Note that actual resource allocation will be heavily influenced by QoS/delay requirements and user prioritization schemes!
Max C/I based(M-CI)
Served according to highest instantaneous channel
quality
Same resources (time/power/codes) per allocation time
Fast(Per-TTI basis)
Proportional Fair throughput (P-FT)
Proportional Fair resource (P-FR)
Served according to highest relative instantaneous channel quality (RICQ)
Resources according to samethroughput (up to max. alloc. time)
Served according to highest relative instantaneous channel quality (RICQ)
Same resources (time/power/codes) per allocation time
Fast(Per-TTI basis)
Fast(Per-TTI basis)
72 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Multi-user Diversity (Fast Scheduling)
UE2
Channel quality(CQI, Ack/Nack, TPC)
Channel quality(CQI, Ack/Nack, TPC)
Data
Data
UE1
Multi-user selection diversity(give shared channel to “best” user)
TTI 1 TTI 2 TTI 3 TTI 4
USER 1 Es/N0USER 2 Es/N0
Scheduled user
Node-B scheduling can utilize information on the
instantaneous channel conditions for each user.
73 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Proportional Fair Algorithm• Principle is to schedule the user who currently has the highest ratio of instantaneous
throughput to average throughput. The averaging time is typically a few 100 ms.• The user with the highest selection metric at a given time is selected for scheduling
in the following TTI
74 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
[ ][ ]nTnRM
k
kk ≡ Rk = instantaneous supported data rate for user k
Tk = average throughput for user k
Proportional Fair Scheduling as a Function of Number of Users
75 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Avg.
cel
l cap
acity
gai
nof
PF
PS
ove
r FR
PS
[dB
]
User diversity order, UDO [-]0 5 10 15 20 25 30
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
Macrocell/Ped-A (3km/h), PCDE=-36dBMacrocell/Veh-A (30km/h), PCDE=-36dBMicrocell/Ped-A (3km/h), PCDE=-36dB
• Significant gain from proportional fair scheduling if at least 3-5 simultaneous users.
HSDPA Cell ThroughputDynamic System Simulation Macro Cells Vehicular A Channel
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Rake 1-ant Equalizer 1-ant Rake 2-ant Equalizer 2-ant
kbps
Round robin 5 codesRound robin 10 codesProportional fair 5 codesProportional fair 10 codesProportional fair 15 codes
1 Mbps
2 Mbps
4 Mbps
• 5-code BTS and single antenna UE Rake provides 1 Mbps• 10-code BTS and single antenna UE provides 2 Mbps• 15-code BTS and dual antenna UE provides 4 Mbps
76 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Transport Block Size Selection Statistics
Break point for16QAM selection
10 HS-PDSCH codes 16-QAM selection probability <5%
in macro cells
16-QAM selection probability 25%
in micro cells
77 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Co-Existence of R99 and HSDPA
78 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Co-existence of R99 and HSDPA= R5 HSDPA • HSDPA can be introduced to the network with shared or
with dedicated frequency = R99 DCH
f1f1• Carrier shared between HSDPA and R99• Operator definable or dynamic resource sharing between
HSDPA and R99
79 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
f1f1
f2f2 • Dedicated HSDPA carrier• HSDPA UE directed to HSDPA carrier
f1f1
f2f2 • HSDPA carrier, which can also be used for R99 traffic in case of R99 high load
• UE moved by RRC connection setup or by handovers
HSDPA and Iub Capacity
80 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA Improves Iub Efficiency by 50-100%• In total, HSDPA improves Iub efficiency 50-100% compared to Release’99• HSDPA requires more E1 lines? Yes, if we want to show higher peak rates. 2 x E1
is required to provide peak rate of 2 Mbps and 3 x E1 for 3.6 Mbps.• HSDPA can be operated with 1 x E1? Yes, and it even improves Iub efficiency but
the peak data rate will be approx 1 Mbps. Also, the operator may want to provide a minimum HSDPA throughput and single E1 is not enough in that case.
81 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
InactivityInactivity
Soft HOSoft HOHSDPA
user dataHSDPA
user dataRelease’99user data
Release’99user data
Common ch
DCH HSDPA
Common ch Common chCommon ch
E1 capacityIub capacity requirement
HSDPA RF vs Iub efficiency
60%
65%
70%
75%
80%
85%
90%
95%
100%
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8Iub capacity for 1+1+1 site [Mbps]
RF utilization [%]Iub utilization [%]
Trade-off Between HSDPA RF and IubCapacity
High Iub efficiency (95%) requires some overhead (15%) in air
interface dimensioning
High RF efficiency (95%) requires some
overhead (25%) in Iub dimensioning
82 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
End User Capacity and Cost
83 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA Enables Mass Market >1 GB/Sub/Month
0.0
0.5
1.0
1.5
2.0
2.5
300 400 500 600 700 800 900 1000Subscribers per site
GB
/sub
/mon
th
HSDPA 2-rx UE
HSDPA 1-rx UE
HSDPA with 1rx UE 2.0 Mbps/cellHSDPA with 2rx UE 3.6 Mbps/cellBusy hour share 20%Busy hour utilization 80%Spectrum 2 x 5 MHz = 1 carrier dedicated for HSDPA
1 GB/month for 300-600 subs
1-carrier HSDPA assumed
84 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Cost of Data Delivery (Network Capex)
Delivery cost of downloaded GB
0.00.51.01.52.02.53.03.54.04.55.0
14 16 18 20 22 24 26 28 30 32 34 36 38 40
Price per TRX [k€]
[EU
RO
€/G
B]
<4 €/GB data
Depreciation over 6 yearsOther assumptions from previous slide
85 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
VoIP over HSPA
86 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
VoIP Usage Growing Fast in Fixed Internet
• Close to 100 Mdownloads and counting...
• Also Pocket PCversion, ca. 2 MB
87 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
VoIP Drivers and Challenges in Cellular
88 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Drivers1. Enterprise VoIP extension to wide area2. Rich call interworking3. Plain vanilla VoIP for network simplicity
• Challenges1. End-to-end delay capability2. Bandwidth and delay during high load3. Efficiency in the air interface and Iub
RNC SGSN/GGSNBTS
Potential VoIP Capacity on HSDPA• HSDPA VoIP can increase voice capacity – but at the expense of end-to-end delay• 80-150 ms was allowed for queuing and transmission in the results below, which
causes >250 ms worst case mobile-to-mobile delay• At maximum load HSDPA VoIP delay was about 100 ms more than in CS voice.
During low load e2e delay with HSDPA VoIP is slightly less than with CS voiceAMR 12.2 kbps voice users per cell
0
20
40
60
80
100
120
R99 CS voice HSDPA VoIP withround robin
HSDPA VoIP withproportional fair
Voi
ce u
sers
150 ms delay80 ms delay
Queuing + transmission
delay in downlink
89 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Radio Technology Evolution
90 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Round trip time [ms]400 300 200
End user bit rate [kbps]
GPRS500-700ms40kbps
EGPRS, Rel. 4 100-200kbps200-500ms
EGPRS, Rel. 99 100-200kbps500-700ms
HSPA1-2 Mbps50-100ms
WCDMA, R99 200-300kbps150-200ms
EVDO Rev 0400 kbps200-300 ms
ADSL1-2 Mbps<50ms
VoIP feasible from e2e performance point of view
3Mbps
1Mbps
300 kbps
100 kbps
30 kbps
100 0600 500
Conclusions on HSDPA Performance
91 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• End user capabilities• Peak data rate 3.6 – 14.4 Mbps• Macro cell data rates 1.0-2.5 Mbps with dedicated carrier and 0.5-1.5 Mbps when shared
carrier with R99• Latency <100 ms• Simultaneous CS voice + PS data on the same connection
• Capacity and cost• Cell throughput 2 Mbps/carrier • User capacity 1 GB/month/subscriber for 300-600 subs/site• Delivery cost <4 €/GB for network capex
• Integration with WCDMA• HSDPA can co-exist on the same carrier as WCDMA• WCDMA integrates efficient voice network to the low latency high bit rate HSDPA
network
Mobile Broadband Access Landscape
Mobile broadband wireless access
CellularFixed broadband wireless 802.16
Wireless DSLFlat rate
Mobile premiumValue added services
EDGE, WCDMA, cdma
EV-DOHSDPA
802.16e
LAN
802.11 WiFi
Proprietary extensionsFlarion
Proprietary
92 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
93 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Technology Positioning - Use Cases1 Fixed BWA “Wireless DSL”
• User uses wireless broadband service from fixed location, home or office, in similar way as DSL or cable modem access
• Usually requires non-movable, outdoor antenna for coverage
2 Portable BWA “Laptop/PDA access from park”• User uses wireless broadband service from any location within coverage
area• Mobility of the user between cells is not supported (no handovers)• Use case is very similar to that of hot spot WLAN access
3 Mobile BWA “Smart phone access from car”
• User uses wireless broadband service from any location within coverage area including the mobility of the user (e.g. up to 250 km/h)
• Use case is very similar to that of 3G cellular data
Spectrum
..
850
1800
19002.1 GHz
2.6 GHz3.4 GHz5 GHz
2x60 MHz
New 3G band in Europe by 2008190 MHz
Unlicenced
Mainstream WCDMA
1700 2x45 MHz New USA 3G band by 2006
Fixed wirelss access band in Europe
= WCDMA/HSPA band with products today= WCDMA/HSPA band - future
2x75 MHz
2x60 MHz
900 2x35 MHz
= Expected bands for 802.16
Europe and Asia
2.5 GHz MMDS in USA190 MHz
US PCS band
Americas, Japan, Asia2x25 MHz
Europe and Asia
Smallest coverage
Best coverage
94 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSDPA and EV-DO
95 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• HSDPA and EV-DO have similar technical solutions, which is leads to similar spectral efficiency for best effort data
• Fast retransmissions• Hybrid ARQ• Adaptive modulation and coding
• HSDPA allows simultaneous voice and packet data• Simultaneous CS voice + PS video possible in HSDPA• EV-DO Rev.A must use VoIP to carry voice
• HSDPA has higher bandwidth, which brings high user bit rates• EV-DO downlink typical bit rate during low loading 300-500 kbps• HSDPA downlink typical bit rate during low loading 1-2 Mbps
WCDMA High Speed Uplink Packet Access (HSUPA) of Release 6
96 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Reference: WCDMA for UMTS, 3rd edition, Chapter 11
Outline
97 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• HSUPA Introduction• HSUDA Protocol Architecture• HSUPA Retransmissions• HSUPA Peak Bit Rates• HSUPA UE Capabilites• HSUPA Channel Stuctures Uplink and Downlink• Summary
High Speed Uplink Packet Access HSUPA
• Peak data rates increased to significantly higher than 2 Mbps; Theoretically reaching 5.8 Mbps
• Packet data throughput increased, though not quite high numbers expected as with HSDPA
• Reduced delay from retransmissions.• Solutions
• Layer 1 hybrid ARQ• Node B based scheduling for uplink• Frame sizes 2ms & 10 ms
• Schedule in 3GPP• Part of Release 6• First specifications version completed 12/04• In 3GPP specs with the name Enhanced uplink DCH (E-DCH)
98 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA Status in 3GPP• Study item for 3GPP Release 6 completed 03/04• First versions of HSUPA specs published 12/04• Work item completion date 03/05• Remaining open issues closed 06-09/05
99 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
2003 2004 2005 2006 2007
3GPP study item
Study item completed
1st version in 3GPP spec
Official work item completion date
HSUPA Protocol Architecture• New MAC entity, MAC-e added to the Node B• In RNC MAC-es handling packet in-sequence delivery & soft handover combining• Layers above, such as RLC, unchanged -> this required MAC-es to perform
reordering for packets
RLC
WCDMA L1
UE
Iub/Iur
SRNCNode B
Uu
MAC
NAS
HSUPA user plane
WCDMA L1
MAC-e
TRANSPORT
FRAMEPROTOCOL
TRANSPORT
FRAMEPROTOCOL
MAC-esMAC-d
IuRLC
MAC-es/e
RLC
100 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Node B Controlled HSUPA Scheduling
Data packet
+ possible retransmissions
+ control for scheduling
ACK/NAK
+ control
Node B RNCUE
Mac-es
Iub
Mac-e
New Node B functions:Uplink packet data schedulingHARQ control: ACK/NAKs
New Iub signalling
New L1 signalling
• Target is to shorten the packet scheduling period ⇒ packet scheduler is able to track burstiness of source application
101 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Fast Scheduling Reduces Noise Variance
0 1 2 3 4 5 6 7 8 9 100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
NR [dB]
PDF of the NR per BTS
Mean: 4.1 (dB) StD: 1.2 (dB)
Mean: 5 (dB) StD: 0.72 (dB)
RNC sheduling Node B scheduling
• Faster scheduling reduces noise rise variations
⇒ Less headroom needed⇒ Cell capacity and user data
rates are increased• With low loaded uplink, the
users may get significantly higher data rates as much more aggressive data rates can be granted to UEs
Operation point can be increased because variance is reduced.
102 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
DCH vs E-DCH RetransmissionsDCH E-DCH
103 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
RNC
Terminal
BTS
Packet Retransmission
RLC ACK/NACK
Combining of packet and
retransmission
Packet (1st TX) Retransmission
L1 ACK/NACK
Fast Hybrid-ARQ between UE and BTS• Fast ACK/NAK from BTS• N-process Stop-And-Wait (SAW) HARQ (similar to HSDPA)• short round trip delay => lower total delay• Chase combining or Incremental Redundancy, soft buffering in BTS• In SHO, each BTS sends ACK, retransmission if no ACKs
104 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
UEBTSRNC Correctly received packet
HARQ control and soft combining
ACK/NAK
ACK/NAK
E-DCH data
E-DCH data
105 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Feedback from UE to BTS/RNC• For the RNC UE provides the following information (MAC layer)
• UE buffer occupancy: how much data buffers • Available transmission power resource
• For the BTS, the following is provided on E-DPCCH (L1)• Information of the data rate for the frame (E-TFI)• Information of the redundancy version for the packet
• Timing is known thus BTS knows which ARQ channel to expect
• Happy bit: Is the current data rate satisfactory• UE would not be happy of the data rate if it could transmit
with higher rate due:– Transmission power left– Data left in the buffers (for more than X TTIs, X as
parameter)
BTS
RNC
E-DPCCH
MAC-PDU
Adaptive Modulation – Why not with HSUPA?
106 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• In the downlink direction, BTS has limited power control dynamics, in the order of 10-20 dB
• However in the uplink received power level is kept constant with fast closed loop power control with more than 70 dB dynamic range
• Thus there are no times when there would be “free lunch” to use higher order modulation
• Other reasons why higher order modulation sounds interesting*…• A) To get more bits per given bandwidth - > range problem• B) To reduce the terminal peak to average ratio as having multicodes in use later ->
This would have resulted to higher average power even if the PAR would have been smallel -> less capacity
* When searching from the web HSUPA info, often one sees adaptive modulationas part of the story. This is based on the outdated stuff from the study item phase
HSUPA - UE Categories• HSUPA uses BPSK modulation with multicode transmission to achieve high data
rates, 6 different UE categories defined, key element number of codes supported and whether 2 ms TTI is supported or not
• Theoretical peak bit rate up to 5.76 Mbps• 1.46 Mbps capability expected initially
11520
20000
20000
5837
20000
14592
2919
14592
7296
Transport Block size
2 Mbps102 x SF24
2.9 Mbps22 x SF24
1.46 Mbps102 x SF42
1.46 Mbps22 x SF42
2 Mbps102xSF2 + 2xSF46
6
5
3
1
HSUPACategory
2
10
10
10
TTI
2xSF2 + 2xSF4
2 x SF2
2 x SF4
1 x SF4
Codes x Spreading
5.76 Mbps
2 Mbps
1.46 Mbps
0.73 Mbps
Data rate
107 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA Channel Structure - Uplink• E-DPDCH, (E-DCH Dedicated Physical
Data Channel) - carries the user data in the uplink
direction, with the peak rate reaching up to 5.76 Mbps
- codes are not shared with HSUPA (no code shortage in the uplink)
• E-DPCCH (E-DCH Dedicated Physical Control Channel )
- Parallel physical layer control channel - carrying e.g. ARQ information needed
for the BTS decoding process + UE txbuffer status
- Normal DCH operated in parallel (DPCCH always and DPDCH if there is data)
Σ I+jQ
Se-dpch
ced,1 βed,1
E-DPDCH1
iqed,1
ced,k βed,k
E-DPDCHk
iqed,k
ced,K βed,K
E-DPDCHK
iqed,K
cec βec
E-DPCCH
iqec
.
.
.
.
.
.
.
.
108 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA Channel Structure – Uplink (cont)
109 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• With E-DPDCH, there are two transmission time intervals (TTIs):a) 10 ms TTI (DCH has 10, 20, 40 and 80 ms)
- Best for range point of view, typically better capacity than 2 ms b) 2 ms TTI
- Suffers in range, thus with larger cells not usable close to cell edge- Can be used to delay reduction
• E-DPDCH uses multicode transmission • Up to 4 parallel codes (see next slide)
DataNdata bits
E -DPDCH
1 radio frame: T = 10 ms
Slot #0 Slot #1 Slot #i Slot #14Slot #2
1 subframe = 2 ms
Tslot
= 2560 chips, Ndata
= 1 0*2 k+2 bits (k=0...5)
HSUPA Channel Structure – Uplink (cont)• The smallest data rate with single SF 4 code
• Then two SF 4 codes• Then two SF 2 codes• And highest data rate with 2 times SF 2 & 2 times SF 4 (Highest PAR)
• Compare to Release’99 where after reaching SF 4 (e.g. 384 kbps), higher data rates would be by adding more SF 4 codes (up to 6)
Slot Format #i
Channel Bit Rate (kbps)
SF Bits/ Frame
Bits/ Subframe
Bits/SlotNdata
0 60 64 600 120 40
1 120 32 1200 240 80
2 240 16 2400 480 160
3 480 8 4800 960 320
4 960 4 9600 1920 640
5 1920 2 19200 3840 1280
Slot Format #i
Channel Bit Rate (kbps)
SF Bits/ Frame
Bits/ Subframe
Bits/SlotNdata
0 60 64 600 120 40
1 120 32 1200 240 80
2 240 16 2400 480 160
3 480 8 4800 960 320
4 960 4 9600 1920 640
5 1920 2 19200 3840 1280
Slot Format #i
Slot Format #i
Channel Bit Rate (kbps)
Channel Bit Rate (kbps)
SFSF Bits/ FrameBits/
FrameBits/
SubframeBits/
SubframeBits/Slot
Ndata
Bits/SlotNdata
00 6060 6464 600600 120120 4040
11 120120 3232 12001200 240240 8080
22 240240 1616 24002400 480480 160160
33 480480 88 48004800 960960 320320
44 960960 44 96009600 19201920 640640
55 19201920 22 1920019200 38403840 12801280
E-DPDCH slot formats
110 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
E-DCH Coding
111 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• One transport block once per TTI• CRC attachment: 24 bit CRC • Code block segmentation similar to the rel’99/4/5
DCHs, the value of maximum code block size is 5114 for turbo coding
• Channel coding: rate 1/3 turbo coding (as rel’99)• Physical layer HARQ functionality and rate
matching: SF and number of needed E-DPDCHsare determined (similar to rel’99/4/5, but different parameters) and the physical layer HARQ functionality (see next slide)
• Physical Channel Segmentation: similar to the rel’99/4/5 DCHs, when more than one E-DPDCH is used, physical channel segmentation distributes the bits among the different physical channels
• Interleaving and physical channel mapping: similar to the rel’99/4/5 DCHs, rate matching output bits are interleaved and mapped to the allocated E-DPDCH(s)
Transport channel processing for E-DCH
CRC attachment
aim1,aim2,aim3,...,aimA
Code block segmentation
Channel Coding
Physical ChannelSegmentation
Physical channel(s)
Physical Layer Hybrid-ARQ
functionality/Rate matching
oir1,oir2,oir3,...,oirK
ci1,ci2,ci3,...,ciE
up,1,up,2,up,3,...,up,U(p)
s 1,s 2,s 3,...,s R
bim1,bim2,bim3,...,bimB
Interleaving &
Physical channel mapping
E-DCH Channel Coding (cont.)
• Bit separation (similar to rel’99/4/5 turbo coded DCHs)• Rate matching (similar to rel’99/4/5 DCHs)
• PLmax is equal to 0.44 for all E-DCH UE categories except the highest E-DCH UE category, for which PLmax is equal to 0.33
• Parameters depend on the redundancy version (RV) parameters s and r similar to HS-DSCH HARQ second rate matching stage
• Higher layers (RNC) configure, if only RV=0 is used or if RV can be 0, 1, 2 or 3• Bit collection, similar to HS-DSCH HARQ
Systematicbits
Parity 1bits
Parity2bits
RM_P1_2
RM_P2_2
RM_S
Rate Matching
Nsys
Np1
Np2
Nt,sys
Nt,p1
Nt,p2
bitseparation
Ne,j bit
collection
Ne,data,j
E-DCH hybrid ARQ functionality112 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
E-DPCCH Coding
E-DPCCH
Physicalchannelmapping
Multiplexing
xh,1 xrsn,1, xrsn,2
ChannelCoding
xtfci,1, xtfci,2,..., xtfci,7
x1, x2,..., x10
z0, z1,..., z29
113 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Control information on E-DPCCH is multiplexed: •E-TFCI information (7 bits)•Retransmission sequence number (RSN, 2 bits)•‘Happy bit’ (Rate Request, 1 bit)
• Channel Coding: a sub-code of the second order Reed-Muller Code (similar to rel’99/4/5 TFCI coding)
• Physical Channel Mapping: similar to rel’99/4/5, channel coding output bits are mapped to the allocated E-DPCCH
Coding chain for E-DPCCH
HSUPA Channel Structure - Downlink
114 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• The following downlink control channels are defined• E-RGCH (E-DCH Relative Grant Channel)
• Relative grants, to set data rate up/down or hold constant• E-AGCH (E-DCH Absolute Grant Channel)
• Absolute grants, not only up/down• E-HICH (E-DCH HARQ Acknowledgement Indicator Channel)
• Information on the packet transmission station (ACK/NACK)• Shares the same code with E-RGCH
• E-RGCH and E-HICH share the same SF 128 code• For one UE only one is relevant but single code can serve serveral UEs
Slot #14
Tslot = 2560 chip
bi,39bi,1bi,0
Slot #0 Slot #1 Slot #2 Slot #i
1 radio frame, T f = 10 ms
1 subframe = 2 ms
E-HICH (E-DCH Hybrid ARQ Indicator Channel)
• E-DCH hybrid ARQ acknowledgement indicator a is mapped on E-HICH:• ACK: +1• NACK: –1 in cells belonging to the same Radio Link Set (RLS) as the E-DCH
serving cell and 0 in other cells (DTX)
• When Node B has not detected E-DPCCH in uplink, no ACK/NACK is transmitted in the downlink
• ACK/NACK is transmitted using 3 (for 2ms E-DCH TTI) or 12 (for 10ms E-DCH TTI) consecutive slots
Slot #14
Tslot = 2560 chip
bi,39bi,1 bi,0
Slot #0 Slot #1 Slot #2 Slot #i
1 radio frame, Tf = 10 ms
1 subframe = 2 ms
115 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
E-RGCH (E-DCH Relative Grant Channel)
116 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• The E-DCH relative grant (RG) a is mapped on E-RGCH:• UP: +1 (possible only in serving E-DCH RLS) • HOLD: 0 (Note: 0 means DTX, i.e, that HOLD is not transmitted)• DOWN: –1
• An orthogonal signature sequence Css,40,m(i),j is assigned to the E-RGCH by higher layers• One slot long orthogonal signature sequence is different in each slot of a 2ms sub-frame
• Higher layers define the sequence pattern• The orthogonal signature sequence is used to identify the E-RGCH from the other E-RGCHs and E-HICHs
(to different UEs) transmitted on the same SF=128 channelisation code channel (there can be at maximum 40 different E-HICHs/E-RGCHs transmitted on the same SF=128 channelisation code channel )
• RG is transmitted using 3 (for 2ms E-DCH TTI from serving E-DCH cell), 12 (for 10ms E-DCH TTI from serving E-DCH cell) or 15 (from non-serving E-DCH cells) consecutive slots
• in each slot is transmitted a sequence bi,0, bi,1, …, bi,39 : bi,j = a Css,40,m(i),j
• Note, that the E-RGCH is a dedicated channel, defined by a channelisation code and a signature sequence, and each E-HICH and E-RGCH transmitted on the same SF=128 channelisation code
• The channel can be independently power controlled by the Node B (vendor specific)
E-AGCH (E-DCH Absolute Grant Channel)
• The E-DCH absolute grant (AG) is mapped on E-AGCH• content of AG and the number of AG bits are FFS• E-AGCH is a shared channel, where only one AG is
transmitted at a time on one SF=256 channelisation code channel
• CRC attachment: 16 bit CRC, masked with the UE identity (E-DCH Radio Network Identifier, E-RNTI, defined by higher layers), is attached to the AG
• Channel coding: rate 1/3 convolutional coding• Rate matching: the number of channel coding output bits is
matched to the number of E-AGCH bits within 2ms• Physical channel mapping: rate matching output bits are
mapped to allocated E-AGCH• E-AGCH has a 2ms sub-frame structure• Note that some simplifications under discussion in 3GPP!
Channel coding
xag,1, xag,2,..., xag,w
Rate matching
ID specific CRC attachment
Physical channel mapping
y1, y2,..., yw+16
z1, z2,..., z3x(w+24)
E-AGCH
r1, r2,..., r60
Coding for E-AGCH
117 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA and DCH co-existance• For an existing user, E-DCH users will only show as part
of the interference variations (at BTS receiver)• -> Thus mixing DCH & E-DCH users is not a problem• The load variation caused by DCH users are not under BTS
control (but under slower RNC based method)
• Depending on the allocation, there can be allocated both E-DCH and DCH for the same terminal
• E.g. with AMR speech call active while having packet data connection on-going
• This allows smooth introduction for the network as separate carrier is not needed until single carrier capacity fully utilised
118 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
E-DCH vs. DCH• DCH does not use BTS based retransmission handling or BTS based scheduling• Both the variable spreading factor principle as well as fast power control
unchanged from DCH to E-DCH• Both support multicode use, though more practical with E-DCH
Feature
Variable spreading factor
Fast power control
Adaptive modulation
BTS based scheduling
DCH
Yes
Yes
No
No
E-DCH
Yes
Yes
No
Yes
Fast L1 HARQ No Yes119 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA - Summary• Node B based uplink scheduling and HARQ for improved performance• Adaptive modulation not part of HSUPA as power control maintained• HSUPA is backwards compatible and can be introduced gradually in the
network.
120 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA Capacity
121 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA Capacity Gain
Uplink cell throughput [kbps]
0200400600800
10001200140016001800
R99 RNC schedulingBLER=1%
HSUPA round robin HSUPA proportionalfair
kbps
Node-B scheduling + faster retransmissions
Release’99
HSUPA
Advanced scheduling
HSUPA
122 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Coverage of high data-rate
Coverage gain 0.5 – 1.0 dB
UE capabilitybeyond 384 kbps
Uplink data rate gain from 384 kbits
(Rel99) to 1-5 Mbits (Rel6)
Capacity gain 20-
50%
Cell throughput
gain
Latency gain<50 ms
Quality of end user
experience
HSUPAHSUPA
Lower costs in transport
Iub capacity gain
Higher add-onPS Traffic
Savings in BB capacity costs
Saves BTS sites (~10%) and adds PS traffic
Savings in transport – in Dedicated VCCsolution max 25%
Higher add-onPS traffic
HSUPA Performance Gains
123 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
HSUPA – 3GPP Open Issues
124 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
Most of these for WG1, WG2 and WG3 should be closed for the June 2005 spec versions.
For the ASN.1 backwards compatibility not likely to start beforeend 2005 (est.)
3GPP open issues, WG1 (physical layer)
125 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Compressed mode with 10 ms TTI• Need for new UTRAN/UE measurements or modifications to the existing ones.• Possibility to do slot-by-slot power scaling of E-DPDCH only in case the UE runs
out of transmission power within a TTI.• The exact contents of E-AGCH are not yet defined
• 5 bits for DPCCH to E-DPDCH power ratio is agreed• Total # of bits open, inclusion of time duration, per process flag, etc.• The exact number of bits may also have an impact to the E-AGCH coding and spreading
factor
• E-DPxCH gain factor quantisation.
3GPP open issues, WG2 (MAC, RRC, Stage 2)
126 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Scheduling behaviour simplifications being discussed• Two schemes are well defined in general but there are some details that still need some
work. • Trying to merge the two schemes as only one
• Details of E-TFC selection and restriction• Priority based scheduling:
• In addition to UE and HARQ based scheduling, Ericsson and NEC are now proposing to have some kind of priority based scheduling where the grants would be applicable up to a given priority only.
• Content of the uplink MAC-signalling scheduling information: • How many bits needed for the buffer occupancy report.
• Transport block sizes: • Agreed to have 4 tables, but now we need to agree on the tables.
• Serving cell change: • L2 based cell selection for faster cell change Nortel and Panasonic propose to have UE
based cell change. Benefits questionable
• Minimum bit rate for 2ms TTI: • One PDU gives already quite a high minimum bit rate (320-bit PDU: 160 kbps)• Potentially too high and something may have to be done to lower it.
3GPP open issues, WG3 (NBAP, FP)
127 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• HARQ Failure indication signalling principles were agreed. • No CR yet implementing the agreement.
• Iub congestion detection was agreed in principle. • No agreement on the exact nature of loss detection. Whether we will use Frame
Sequence Number or Octet sequence number is FFS.
• The big open issue in Congestion notification is the NodeB action to it.
• Agreed to signal Node B a three level congestion notification; no/mild/severe congestion. Will be conveyed in its dedicated control frame.
• Support of 2ms TTI bundling is already there in the frame structure.• Bundling: Bundle five 2 ms AIF packets to one 10 ms FP packet• However, the support is still missing from NBAP and RNSAP.• FFS how / by whom to decide the bundling in case of SHO. Can different branches have
different approach (bundling, no bundling) <-> RNSAP, NBAP
• FP Frame structure, a lot of things done• The needed header CRC length is FFS. Header is getting longer and more CRC bits may
be needed.
3GPP open issues, WG4 (Performance)
128 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• All the performance requirements are still open• Beta factors for requirements and testing on E-DPDCH and E-DPCCH• RAN4 assumptions on FRC, RV index sequence, Switching between different TTI, and
Number of HARQ processes needs to be revisited after RAN1/RAN2 decision• Working points per FRC• Requirements and testcases for E-RGCH and E-AGCH• False alarm rate for E-RGCH• False alarm rate and miss-detection for E-DPCCH• E-HICH, False alarm ACK rate for serving and non-serving cell • Requirements and tests for E-RGCH/E-AGCH• PAR/CM • E-TFC• Active Set Size• Implementation Margin• Finalize ideal simulation results for all channels (DL & UL)• How accurate can the scheduler follow the targets set by the RNC in x% of the time
UTRAN Long Term Evolution
129 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
General Requirements for UTRAN Evolution
130 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Feasibility study started in 3GPP for UTRAN Long Term Evolution with the following requirements
• Packet switched domain optimized• Server UE round trip time below 30 ms and access delay below 300 ms• Peak rates uplink/downlink 50/100 Mbps• Ensure good level of mobility and security• Improve terminal power efficiency • Frequency allocation flexibility with 1.25/2.5, 5, 10, 15 and 20 MHz
allocations, possibility to deploy adjacent to WCDMA• WCDMA evolution work on-going to continue with full speed
• Technologies under consideration include also new radio access technologies as well as new network architecture possibilities
UTRAN Evolution
3.5G HSDPA/HSUPA3GPP Rel.6
3.5G HSDPA/HSUPA3GPP Rel.6
131 © NOKIA HSDPA/HSUPA.PPT / 22-03-2005 / HH+AT
• Best CS + PS combined radio• Current RAN architecture• Spectrum shared with current 3G• Reduced latency• Full service continuity with 2G and
3G
HSPA evolutionHSPA evolution 3.9G new radio access3.9G new radio access
• Optimized for PS only• New architecture• New modulation• Spectrum and bandwidth flexibility• Further reduced latency • Interworking with 3.5G evolution