3G Transmission Dimension Ing Process
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Transcript of 3G Transmission Dimension Ing Process
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1 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
3G Transmission DimensioningProcess
June 2005
Charles Kao
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2 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
TRS Planning Requirement & Dimensioning
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3 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Network Dimensioning Process Flowchart
Input fromcustomer
RFDimensioning
TransmissionDimensioning
IPDimensioning
NetworkDimensioning
done
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Trs Network Dimensioning Process Flowchart
Input from RFIub
dimensioningRNC
dimensioning
Quantity of
E1, STM-1 etcrequired
Iu-CS, Iu-PS, Iur
dimensioningTrs dimensioningassumptions
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5/465 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Network Dimensioning Process
CS/PS Core NetworkDimensioning
The Customer Requirements and/or Nokia assumptions
Node B Dimensioning
RAN Dimensioning
RNC location
Iub traffic
IuCS/PS traffic
3G subscriber growth forecast and distribution per region 3G Packet Data, Circuit Switched Data & Voice traffic/sub
CS Core Traffic Model Coverage Requirements
# of Core sites
QoS requirements
Number &configuration ofNode B
# of sites
configuration of sites
e.g. 1+1+1/SRC/MHA
# of Hardware channels
# andconfigurationof RNC
RAN InerfaceCapacityrequirements
# and configuration of coreelements
user plane/control planerequirements
# & type of Iub & Iu
links # of interface cards
# of AXC
Link Capacity
Transmission Dimensioning
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RAN dimensioning output
Interfaces
Iub Link Capacity (Node B < = > RNC)
Iur Link Capacity (RNC < = > RNC)
Iu Link Capacity
Circuit Switched (RNC < = > MSC)
Packet Switched (RNC < = > SGSN)
Equipment
Number of RNCs
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RAN & Core dimensioning Steps
INPUTS
Traffic
Hypothesis/Assumptions
INTERFACES
Iub_Voice
Iub_PS
Iub_CS_data Total_Iub
RNCIu_CS
Iu_PS
Circuit Core Dimensioning
Iur
Packet Core Dimensioning
3G-MSC
DNS, CG, ....
xGSN
MGW
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RAN Protocol Stacks
IP
AAL5
PHY
UDP
LLC/SNAP
GTP-U
ATM
PHY
ATM
AAL2
FP
PDCP
UDP
IP
Link
Layer
PHY
GTP
IP
AAL5
PHY
UDP
LLC/SNAP
GTP-U
ATM
UDP
IP
Link
Layer
PHY
GTP
AAL2
PHY
ATM
WCDMAL1
FP
WCDMAL1
PDCP
E.g.,IPv4, IPv6
PHY
E.g.,IPv4, IPv6
GnIuIubUuGGSN
3G-RNC
Node B
UEGi
RLC-U
MAC
RLC-U
MAC
Each layer in protocol stack will add additional bits to the original payload and depending of the interface,
different overheads are used. Below there are presented protocol stacks for both CS and PS traffic.In Iu interface there can be distinguished two different types of traffic,IuCS (Iu-Circuit Switched, data and speech) for connections towards MGW/MSC andIu-PS (Iu-Packet Switched) for 3G-SGSN.
AAL2
PHY
ATM
PHY
ATM
AAL2
FP
PHY
AAL2
PHY
ATM
LinkLayer
PHY
AAL2
PHY
ATM
WCDMAL1
FP
WCDMAL1
E.g.,Vocoder
PHY
PSTN/
N-ISDN
AIuIubUu
IWU
RNC
Node B
UE
E
Iu-CS UPIu-CS UP
E.g.,Vocoder
LinkLayer
/lawPCM,UDI,etc.
/lawPCM,UDI,etc.
MSC
RLC-U
MAC
RLC-U
MAC
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9 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Circuit Switched Traffic
Circuit Switched Traffic
Circuit switched traffic can be divided in two types, Voice and Data.
Most cases 12.2 kbps (AMR mode 0) for voice is used. This mode correspondsEnhanced FR in GSM network.
RAN 1 and 1.5 supports the following Voice and Circuit switched service rates whichcorresponds to the following bitrates:
AMR Mode 0 1 2 3 4 5 6 7
Rate (kbps) 12.20 10.20 7.95 7.40 6.70 5.90 5.15 4.75
RAN 1 and RAN 1.5 supports the following service rates for circuit switched data.
Rate kbps Comment
9.6 Base Rate 114.4 Base Rate 2
19.2 2 x 9.6 kbps
28.8 2 x 14.4 kbps
38.4 4 x 9.6 kbps
57.6 4 x 14.4 kbps
64 UDI (Unrestricted Digital Information)
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10 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Packet Switched Traffic
Packet Switched Traffic
RAN 1 and 1.5 supports the following service rates or combination of them for packetswitched data.
Rate 0 1 2 3 4 5 6 7 8
Rate kbps 384 320 256 128 64 32 16 8 0
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11 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
RAN calculation related protocols & overheads, 1
Air Interface Protocols Assumptions (L1, MAC, RLC,PDCP), Re-Transmission & Buffering
L1 OH includes pilot symbols, TFCI field, closed loop PC bits ...etc,this is not used by RNC L1, they are generated inside the BS and so this
overhead is not included.The L1 functions inside the RNC are macro-diversity combining(MDC) & Outer-looppower control
L2 OH includes MAC & RLC. For CS traffic the RLC is transparent. For PS traffic the
RLC takes care of re-transmission in case of errors, and consequently there is a L2OH. The assumption is that L2 re-transmission is 10% (Quality of the radio link, BLER) 15% headroom to avoid infinite buffering.
For PS data this will result 1/0.79 extra overhead :
(1 + 10% L2 reTRX)( 1 + 15% headroom) = 1/0.79 = 26.5% OH.
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RAN calculation related protocols & overheads, 2
Frame ProtocolsFrame protocols are applied to transfer user data and the necessary control informationbetween the Serving RNC (SRNC) and the BS. They are characterized by a frame structureconsisting of the payload, that contains the data (typically one or more MAC PDUs) and aheader/trailer with control information (used for synchronization, power control, CRC bits, etc).Three different Frame Protocols are specified in UTRAN:
Iub CCH FP (3GPP TS 25.435)
RAN: DCH FP (3GPP TS 25.427)
Iur CCH FP (3GPP TS 25.425)
They are independent but have a similar structure and coding of the frames.
For Voice (Active and Silent Mode), FP frames (including OH) are sent every TTI(TransmissionTime Interval) regardless of the activity (Active or Silent) of the user. During theSilent mode, SID (Silence Descriptor) otherwise known as Comfort Noise frames, are sent every8th frame of the FP frames (including OH) thus bits are generated even during the silent mode.
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13 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
RAN calculation related protocols & overheads, 3
Iu-User Plane ProtocolsFrame Protocols are terminated in the RNC and replaced by Iu-UP (User Plane) protocols in the Iu-CS andIu-PS interface. User Plane protocols either operates on Transparentor Support modes. Transparent modesare used for transmission of GTP-PDUs and no headers at the head of the Iu-UP PDU are defined. Supported
modes are applicable during e.g. the AMR based speech connection thus headers are generated on thismode of operation. The percentage of header generated on support mode is comparable to the FP headersthus, traffic calculation in Voice & CS data for Iu-CS interface is similar to Iub calculation.
ATM Protocols
ATM protocols overhead consists of two-layers :
ATM Adaptation Layer 2 (AAL2) - is used to adapt the air-interface protocols into ATM cells.
ATM Layer consists of 5 bytes of overheads that adapts AAL PDUs to ATM cells
PDH/SDH layer ATM cells are then mapped into physical transmission channels implemented usingPDH/SDH technologies.
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14 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
RAN calculation related protocols & overheads, 4
Soft-Handover FactorSoft Hadover Factor is assumed to be 40%.
35% of the Mobiles are connected to two or more Base Stations at the same time.
30% of the Mobiles are in two way SHOs5% of the Mobiles are in three way SHOs
This value is coming from the IS-95 experience and from our simulations. There is trade offbetween SHO gain and capacity and this is somehow of our target in order to get some gain
without waste of our capacity.
In other words, if one RNC manages 100 Voice calls, then it must have 140 (100*1.4) physicalchannels (as compared to a GSM BSC managing 100 calls, having 100 time slots).
For transmission networks this factor is only relevant in the Iub interface because the RNC
terminates all connections and selects the connections with the best quality.
For The Customer case, SHO of 30% was adopted
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15 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
RAN calculation related protocols & overheads, 5
Voice Activity Factor
The system uses DTX (Discontinuous Transmission), so when there is no speech, the systemstops transmitting data (on L1). Unless the operator gives the Voice Activity factor, we assumeactivity factor as from 50% to 69%. (67% used in The Customer case)
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RAN calculation related protocols & overheads, 6
Signalling Overheads
Signaling has to be considered for each of the interfaces. Different assumptions are to be defined for Iub, Iur and Iuinterfaces.
In Iub interface this is normally includes
L3 signalling DCH (Dedicated channels) overhead
Mobile signalling overhead in common channel states
CC, MM.
NBAP-C
NBAP-D
AAL2 signalling
Since there is no practical network results available yet, 10% of user-plane traffic can be assumed (based on GSMexperience and modelling) as signalling.
For the Iu interface, signalling overhead is considered as 1% of user-plane traffic.
This is a temporary value as this is also based on GSM experience (the A-interface). This includes AAL2 Signallingand RANAP signaling for Iu-CS and GTP signalling and RANAP signaling for Iu-PS interface.
For Iur interface, 2- 4 % of the user traffic is assumed to be signaling.. This is includes AAL2 signaling and RNSAP.
This is again based on studies made inside Nokia.
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17 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Each different service require different overheadEach different service require different overhead
Overhead vsTraffic Classes?
Voice services Activity Service bit rate L1 bit rate Bit rate incl. FP Bit rate below ATM
kbps kbps kbps 12.76%
RT12.2 (AMR) UL active 12.2 12.2 15.6 18.9
silent 0 0 2.8 4.5
RT12.2 (AMR) DL active 12.2 12.2 14.8 18.0
silent 0 0 0 0.0
RT Services Activity service bit rate L1 bit rate Bit rate incl. FP Bit rate below ATM
kbps kbps kbps 12.76%
RT64 active 64 64 65 78.7
NRT Services service bit rate L1 bit rate Bit rate incl. FP Bit rate below ATM
kbps kbps kbps 12.76%
NRT64 UL/DL 64 67.2 71.2 85.7
NRT128 DL 128 134.4 138.4 166.9
NRT256 DL 256 268.8 272.8 329.3NRT256 DL 320 336 340 410.4
NRT384 DL 384 403.2 407.2 491.6
Different OH for Different Traffic Classes
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18 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
AAL2 OH
Voice services Activity Service bit rate L1 bit rate TTI Data/frame FP OH Total /frame Bit rate incl. FP AAL2 PDU AAL2 OH Bits to ATM Bit rate below AAL2
kbps kbps ms bit octet bit kbps # octet bits kbps
RT12.2 (AMR) UL active 12.2 12.2 20 244 7 312 15.6 1 3 336 16.8
silent 0 0 20 0 7 56 2.8 1 3 80 4.0
RT12.2 (AMR) DL active 12.2 12.2 20 244 5 296 14.8 1 3 320 16.0silent 0 0 20 0 0 0 0 0 3 0 0.0
RT Services Activity service bit rate L1 bit rate Frame period Data/frame FP OH Total /frame Bit rate incl. FP AAL2 PDU AAL2 OH Bits to ATM Bit rate below AAL2
kbps kbps ms bit octet bit kbps # octet bits kbps
RT14.4 active 14.4 14.4 40 576 5 616 15.4 2 3 664 16.6
RT28.8 active 28.8 28.8 40 1152 5 1192 29.8 4 3 1288 32.2
RT32 active 32 32 40 1280 5 1320 33 4 3 1416 35.4
RT33.6 active 33.6 33.6 40 1344 5 1384 34.6 4 3 1480 37.0RT56.7 active 56.7 56.7 40 2268 5 2308 57.7 7 3 2476 61.9
RT64 active 64 64 40 2560 5 2600 65 8 3 2792 69.8
NRT Services service bit rate L1 bit rate Frame period Data/frame FP OH Total /frame Bit rate incl. FP AAL2 PDU AAL2 OH Bits to ATM Bit rate below AAL2
kbps kbps ms bit octet bit kbps # octet bits kbps
NRT8 UL/DL 8 9.6 10 96 5 136 13.6 1 3 160 16.0
NRT16 UL/DL 16 17.6 10 176 5 216 21.6 1 3 240 24.0NRT32 UL/DL 32 33.6 10 336 5 376 37.6 2 3 424 42.4
NRT64 UL/DL 64 67.2 10 672 5 712 71.2 2 3 760 76.0
NRT128 DL 128 134.4 10 1344 5 1384 138.4 4 3 1480 148.0
NRT256 DL 256 268.8 10 2688 5 2728 272.8 8 3 2920 292.0
NRT256 DL 320 336 10 3360 5 3400 340 10 3 3640 364.0
NRT384 DL 384 403.2 10 4032 5 4072 407.2 12 3 4360 436.0
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19 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
RAN Dimensioning Inputs
In general, the following inputs are required for dimensioning:
Total number of Subscribers (Subs)
Number of Subscribers for Voice
Number of Subscribers for CSD/ Service class Number of Subscribers for PSD/ Service class
Number of Base Stations
Average Voice traffic / busy hour Average CSD traffic / busy hour
Average PSD traffic / busy hour
Uu interface blocking
Voice Activity Factor for Voice (VAF=50-69%)
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20 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Iub Interface Dimensioning
Iub
BS
BS
BS
Iur
Iub
Iub
RNC
RNC
Iub is the interface between Base Station and Radio Network Controller
Iub Traffic is the total of both Circuit Switched (Voice & data) and Packet Switched data
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I b Dimensioning CS Traffic
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22 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Iub Dimensioning, CS Traffic
Input information
10 mErl/sub (Voice) 5 mErl/sub (CS data) Service rate 64kbit/s 500 subs/BTS SHO = 40%
VAF = 65% Iub sig. = 10%
7,5 Erl /BTS
14 ch's/BTS
SHO = 40%
Erlang B table (Traffic with 2% blocking)
20 ch's/BTS
Voice channels/BTS
10 mErl15 mErl
x 20 ch's = 14 ch's5 mErl
15 mErlx 20 ch's = 7 ch's
CS data channels/BTS
Iub Dimensioning CS Voice
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23 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Iub Dimensioning, CS Voice
VAF = 65%
Average voice rate in ATM:18,9 kbit/s x 65 % + (4,5 kbit/s x 35%) = 13,86 kbit/s
Voice channel in Uu = 12,2 kbit/s
Voice channel, Active = 18,9 kbit/s Voice channel, Silent = 4,5 kbit/s
Voice in the ATM
VAF of 67% is used in The Customer case
Iub Dimensioning CS Traffic
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24 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Iub Dimensioning, CS Traffic
14 ch's/BTS x 13,86 kbit/s/ch = 194,04 kbit/s/BTS 7 ch's/BTS x 64 kbit/s/ch = 448 kbit/s/BTS
Voice CS Data
ATM OH = 23%
551 kbit/s
Total CS traffic in Iub/BTS = (194,04 kbit/s + 551 kbit/s) + 10 % Iub sig. = 819,5 kbit/s
Iub Dimensioning (3/3) PS Data
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25 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Iub Dimensioning (3/3), PS Data
Input : Traffic ( kbits) / cell / region
BS Config / region
Method : Bit rate (kbps) / BS
Output : PS Iub Bit rate (kbps) / BS
@ BH@ BH
Activity Factor 100%SHO factor 30%ATM OH (64k +33%, 128k +30%, 384k +28%)
L1 BufDelay OH 26.5%
For each service
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26 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Iur Dimensioning
Iur interface is the traffic between two different RNCs. Eg for Soft Handover
Iub
RNC
RNC
RNC
Iur
Iur
I t d ti t I I t f
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27 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Introduction to Iur Interface
MSC
IurRNC
BSBS
Iub
BS
RNC
BSBS BS
RNC
BSBS BS
Iu
Iur
MSCSGSN
IuIu
Iub Iub
Iur interface is needed for :
Transmitting and receiving the MS signal via two different BS which belong to twodifferent RNCs.
Signalling between the individual RNCs, (e.g. for HO establishments).
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RNC Dimensioning
Based on Nokia ATM Platform
Nokia RNC Dimensioning
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Nokia RNC Dimensioning
What need to be checked ?
Iub throughtput
Number of carriers
Number of BTS's
Nokia Radio Network Controller
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30 NOKIA TRS_Presentation_Smart / 01-07-2005/OSP-Manila Company Confidential
Nokia Radio Network Controller
Rel. 1.5 & 2: 48-196 Mbit/s Dynamic Traffic Capacity
1 2
3
4
5
RNC release 1.5 & 2Config.
Iub Mbit/s BTSs Carriers STM-1 E1
1 48 128 384 4*4 6*16
2 85 192 576 4*4 8*16
3 122 256 768 4*4 10*16
4 159 320 960 4*4 12*16
5 196 384 1152 4*4 14*16
Iub traffic capacity Interfaces
Nokia RNC Dimensioning
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Nokia RNC Dimensioning
Limitations:
Inputs:
RNC fill rate 90%
Circuit Switched Voice
Circuit Switched Data
Packet Switched Data
Iub Data Throughput Number of Carriers Number of Node Bs
Release 1.5
196 Mbps 1152 carriers 384 Node Bs
Voice Channels 16Kbps in RNC
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Voice Channels, 16Kbps in RNC
MGW
Voice Channel at 12.2 kbps or lesser
Voice Channel at 16 kbps
12.2 or lesser
Even lower bitrates requires as much processing capacity (user and control plane)Within RNC as a 16kbps channels.
In the Transmission it is taken as original bit rates.
ATM Overhead in RNC
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ATM Overhead in RNC
RNCNode B
ATM Transmission Medium
ATM OH added atNIU
ATM OH stripped offat the Interface unit
of RNC
ATM Overhead is considered only on the Transmission
The ATM OH is stripped off at the NIU of RNC
Hence traffic to RNC will not include ATM overhead.
Nokia RNC Dimensioning Principle
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Nokia RNC Dimensioning Principle
Check the number of carriers per RNC
Check the number of Node B per RNC
RNC nominal traffic capacity
Carriers to be connectedCarriers connectivity per RNC * Fillrate
Node B to be connectedNode B connectivity capacity per RNC * Fillrate
Total user traffic in the area
Voice erlangs* 16kbit/s
CS-data erlangs* data rate
PS-data volume(busy hour)
* SHO overhead * SHO overhead * SHO overhead
1)
Capacity Almost Independent of the Traffic Mix
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Iu Interface Dimensioning
RNC
MGW SGSN
CS
PS
Iu interface
Iu Dimensioning Flow
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Iu Dimensioning Flow
Voice ActivityFactor
(VAF=67%)
Voice CS Traffic@ 12.2 kbit.sData CS Traffic @ X kbit/s Data PS Traffic @ X kbit/s
ATM overhead (ATMOH)
@ X kbit/s
ATM overhead (ATMOH)
@ X kbit/s
ATM overhead(ATMOH) @
12.2 kbit/s
Iu-CS Capacity needed
Iu signalling (SigOH%) 1% Iu signalling (SigOH%) 1%
Iu-PS Capacity needed
Iu-CS Protocol Overheads
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Iu CS Protocol Overheads
The transmission overheads between RNC and MSC are similar to theoverheads of Voice and Circuit Switched traffic in Iub. Therefore thecalculation of Iu traffic from RNC to MGW/MSC is similar to Iub trafficcalculation. The only difference is that all subscribers under one RNC are
pooled together and the calculations are based on that.
SHO is not included because all connections are terminated at the RNC.
Iu-CS Interface Dimensioning
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Iu CS Interface Dimensioning
Input :
Method :
Output :
For each service (voice, CS 64kbps)
@ BH@ BH
Total Traffic (Erl) / RNC area
Erlang B (GOS- 0.1%)
# TCh / RNC area
Line rate (12.2kbps, 64kbps )Activity Factor for voice: 67%ATM OH (as in Iub)
Signalling overhead + 1%
Traffic ( Erl) / BS / region# BSs & Config / region
Bit rate (kbps) / clutter
Iu-PS Protocol Overheads
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Iu PS Protocol Overheads
Between RNC and 3G-SGSN transmission overheads are unique and their relative sizedepends strongly on the packet size that needs to be transmitted from RNC to 3G-SGSN.
The traffic comes from the mobile station to the RNC, then it is tunnelled through the3G-SGSN to destination (Internet, Intranet). This tunnelling requires GTP plus UDP
and IP (encapsulated) running on AAL5 ATM transmission media.
ATM AAL5 Encap IPv4 UDP GTP Data
User Data = 512 Bytes (TCP session)
AAL5 PDU = (512 + 8 Encap+20 IP+ 8 UDP+ 12 GTP)= 560 bytes
AAL5 PDU + trailer =(560+8) = 568AAL5 PDU + trailer + padding = Roundup (568/48) x 48
12 cells needed, 8 bytes of padding
Including ATM headers = Roundup (568/48) x 53 = 636
Total OH required = (636-512)/512= 24% OH
8 20 8 12 (Packet Length)
PHY
AAL5
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Max. 65535 Octets
Padding 0-47 octets
Trailer 8 octetsAAL 5 layer
ATM layer
48 Octets
ATM header 5 octets
PDU
Iu-PS Interface Dimensioning
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g
Input : Traffic ( kbits) / BS / region
# BSs & Config / region
Method :
Output : Bit rate (Mbps) / region
@ BH@ BH
ATM, AAL5, IP, UDP, GTP OH +24%
Signalling overhead +1%
Bit rate (kbps) / region
For packet sizeOf 512 bytes
Via ATM/AAL5
RNC --> SGSN
Transmission Lines Calculation in RAN
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When a needed amount of the physical connections (for example E1's or STM1s)are calculated it should be always noticed that only available payload part of theconnection can be used. It was specified in ATM Forum that TS 0 & TS 16 arenot to be used for ATM traffic. Thus
Table 1: SONET Multiplexing Hierarchy
ElectricalSignal
OpticalSignal
GrossRate
(Mbps)
User Rate(Mbps)
STS-1 OC-1 51.84 49.536
STS-3 OC-3 155.52 149.46
STS-12 OC-12 622.08 594.432
STS-48 OC-48 2488.32 2377.728
Possibility of Introducing AXCs
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50 Node B- DU
50 X 0.33 E1
50 Node B- DU
50 X 0.33 E1
80 Node B- U
80 Node B- U
80 X 0.44 E1
80 X 0.44 E1
RNC
AXC
AXC
AXC
AXC
1 X STM1
1 X STM1
1 X STM1
Config.
Iub Mbit/s BTS Carriers STM-1 E11 48 128 384 4*4 642 85 192 576 4*4 963 122 256 768 4*4 1284 159 320 960 4*4 1605 196 384 1152 4*4 192
Iub traffic capacity InterfacesMax. capacity in different configurations
Detailed Transmission requirement, NetAct Planner
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