09_ra20209en30gln0_ pcu capacity and dimensioning for packet abis

1 © Nokia Siemens Networks RA20209EN30GLN0

PCU Capacity and Dimensioning for Packet Abis

2 © Nokia Siemens Networks

Nokia Siemens Networks Academy

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Module Objectives

After completing the module, the student will be able to:

• Understand PCU functionalities in the BSC

• Explain RNW capacity for PCU2-E

• Explain RNW capacity for PCU2-D

• Discuss feature dependencies on PCU2

• Understand asymmetrical hardware configuration and depending restrictions

• Know about PCU configuration steps in BSC3i 1000/2000 and Flexi BSC

• Highlight the main differences between Legacy Abis and Packet Abis when referring to the PS U-plane

• Understand main PCU/BSC Dimensioning rules when Packet Abis is in use

Practice:

• PCU2 Dimensioning for Packet Abis

Refer to RG30 Documentation:•Plan and Dimension/ BSC EDGE Dimensioning

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PCU functionalityBSC Location

GPRS network

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GPRS transmission plane protocol stack

PCU functionality

PCU functionality

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PCU functionality

• Packet Control Unit (PCU) is a functional unit located in BSC– it is installed in BCSU unit– it allows to handle PS traffic in BSS

• Controls (E)GPRS radio resources by acting as the key unit in the following procedures– (E)GPRS radio resource allocation and management– (E)GPRS radio connection establishment and management– Data transfer (LLC Layer PDU segmentation / re-segmentation for UL & DL)– Coding scheme selection– PCU Statistics

• supports different methods of transport between BSC and SGSN– Frame Relay and IP as transport alternatives for Gb interface

BTS, BCF:- (E)GPRS cell- (E)GPRS TRX

Packet Abis

Gb interface:- Gb over Frame Relay over E1/T1- Gb over IP over Ethernet

BSC:- PCU

SGSNBTS

BSC

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PCU implementations in BSC3i/Flexi BSC

PCU type

PCU

PCU-S

PCU-T

PCU-B

PCU2-U

PCU2-D

PCU2-E

BSCi type

BSCi, BSC2i

BSCi, BSC2i

BSCi, BSC2i

BSC3i

BSC2i

BSC3i

BSC3i

#logical PCUper PIU

1

1

1

2

1

2

1

#Abis/BTS/TRX/RTSL/Gbper logical PCU

256 / 064 / 128 / 128 / 32

256 / 064 / 128 / 128 / 32

256 / 064 / 128 / 256 / 32

256 / 064 / 128 / 256 / 32

256 / 128 / 256 / 256 / 32

256 / 128 / 256 / 256 / 32

1024 / 384 /1024/1024/ 128

CPU/memory

166MHz / 128MB

200MHz / 128MB

300MHz / 256MB

300MHz / 256MB

450MHz / 256MB

450MHz / 256MB

1.33GHz / 1GB

Packet Abis is only supported by PCU2-D and PCU2-E

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RNW capacity for PCU2-E and PCU2-D

PCU2-E capacity is collected in the table below together with the respective values of PCU2-D for comparison

Parameter PCU2-E PCU2-D

#BTS objects / logical PCU 384 128

#EGPRS cells / logical PCU 256 64

#GPRS/EGPRS TRX / logical PCU 1024 / 720 256 / 192

#Abis channels / logical PCU

#logical PCU 1 2

384 128

#EDAP / logical PCU 60 16

#BCF / logical PCU

1024 256

These 2 limiting factors are irrelevant in case of PCU dimensioning for Packet Abis

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• Max 6 working BCSU’s +1 redundant BCSU

• Max 5 PCU2-E plug-in units per BCSU ( 1 Physical PCU2-E corresponds with 1 Logical PCU)

• Max number of logical PCU’s : 30

• Steps of increase of logical PCU’s– 1: 5

– 2: 10

– 3: 15

– 4: 20

– 5: 25

– 6: 30

1-5 PCU2-E physical PIUs

per BCSU

Flexi BSC cabinet Flexi BSC cabinet

2000 x 900 x 600 cabinet (HxWxD)

PCU2 HW Installation in Flexi BSC

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Max 10 working BSCUs + 1 spare BCSU

Max 5 PCU plug-in units per BCSU (10 logical PCUs per BCSU)

• 1-2 PCU-B’s

• 1-5 PCU2-D’s

• 1-3 PCU2-E’s

Max number of logical PCUs : 10010 BCSU x 5 PCU2-D/BCSU x 2 log PCU/PCU2_D

Steps of increase of logical PCUs

• 1: 20

• 2: 40

• 3: 60

• 4: 80

• 5: 100

1-5 PCU2-D physical PIU's per

BCSU

PCU2 HW Installation in BSC3i 1000 / 2000

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Possible configuration of PCU2-E

PCU2-E can be installed in any BSC3i but certain additional limitations exist

PCU2-E can be installed neither in BSCi nor in BSC2i there are 2 constraints that avoids reaching max PCU2-E capacity beyond BSC3i 3000

all PCU slots in BCSU can not host PCU2-E due to limitations of power supply and cooling systems 1024 Abis channels can not be reached due to connectivity and switching capacity limitations

PCU2-E in BSC3i 660/1000/2000 usage of PCU2-E beyond BSC3i 3000 results in PS data capacity reduction compared with PCU2-D (values in brackets) nevertheless for configurations with smaller volume of PS data traffic it is recommended to use PCU2-E (instead of prior PCU

versions) due to expected cost savings

BSC3i type

BSC3i 660

BSC3i 1000

BSC3i 2000

BSC3i 3000

max #PCU2-Eper BCSU

1 (not 2)

3 (not 5)

3 (not 5)

5

#Abis channelsper PCU2-E

512

512

512

1024

#active BCSU per BSC /#logical PCU per BSC

6 / 6

5 / 15

10 / 30

6 / 30

Abis bw controllable(Abis bw in max conf.)

~ 49 Mbps (~ 98 Mbps)

~ 122 Mbps (~204 Mbps)

~ 245 Mbps (~ 409 Mbps)

~ 491 Mbps (~491 Mbps)

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Mixed PCU configuration

different amount of PCUs in different BCSUs of the same BSC or different PCU HW variants in the same slots of different BCSUs

allows coexistence of BSCUs having the same tracks equipped with PCUs and left empty

‘mixed PCU configuration’ is possible however some restrictions exist, i.e. the following mixtures are allowed within the same BCSU track of different BCSU PCU, PCU-S, PCU-T, PCU2-U, empty slot PCU-B, PCU2-D, empty slot PCU2-E, empty slot

mixed PCU configuration in such context is a new functionality that leads to “asymmetrical” PCU configuration

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Symmetrical and Asymmetrical PCU configuration

Asymmetrical PCU configuration is available as a separate S14 feature

Before the feature: each BCSU within one BSC needs to have the same PCU configuration in terms of PCU number and types.

e.g. in order to extend PCU capacity (for instance add second PCU in one BCSU) such PCU extension from 1 to 2 units would need to be done in each and every BCSU the BSC is equipped with (11 extra PCU is needed in case of fully equipped BSC3i 2000 to add 1 PCU in 1 BCSU!!!)

NOTE: even with the feature it is recommended to increase PCU capacity in BCSUs evenly to keep load in BCSUs in balance.

With the feature: PCU can be installed and activated according to actual traffic needs with a

granularity 1 in every BCSU separately each active BCSU can have different number of PCU (depending on actual

traffic requirements), i.e. it may happen that some BCSU have no PCU units while the other ones have some PCU installed

different PCU types can be mixed in the same BSC/BCSU (restrictions concerning the same BCSU track exist -> see previous slide)

The redundancy concept has been changed to a primary spare unit concept The BCSU marked as primary spare must be equipped with the number of

PCU sufficient to replace any of the active BCSU

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Redundancy within Asymmetrical PCU Configuration

BCSU – N SP - EXBCSU – N SP - EX

......

BCSU – 0 WO - EXBCSU – 0 WO - EX


• (SP-EX) Primary spare – three PCU cards configured. Enough PCU cards to replace any of the active BCSU units

• (WO-EX) Active BCSU – three PCU cards configured

• (WO-EX) Active BCSU – two PCU cards configured

WO-EX

WO-EX

SP-EX


......



SE-OU

WO-EX

WO-EX

1. Working BCSU gets faulty, primary spare takes over


......



WO-EX

WO-EX

SP-EX

Faulty BCSU

2. Faulty BCSU is fixed, primary spare is returned to spare state

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Restrictions of Asymmetrical PCU configuration

Reasons for keeping certain restrictions concerning the same BCSU tracks are: PCU HW having two logical PCUs cannot be mixed with HW having one logical PCU

because, in case of failure, the HW having one logical PCU cannot stand in for the one having two logical PCUs,

although PCU2-E has one logical PCU it does not make any sense to mix it with other HW comprising of one logical PCU due huge to differences with achievable capacity (and in consequence none of HW variant, except PCU2-E itself, cannot stand in for PCU2-E in the event of failure)

The restrictions above avoid mixing up PCU2-E with any PCU type in the same BCSU slot

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PCU2 HW and SW Activation

PCU2-D HW

PCU2-D HW

PCU2-D HW

PCU2-D HW

PCU2-D HW

PCU2-D HW

PCU2-D HW

PCU2 BSW

PCU2 BSWPCU2-E HW

PCU2-E HW

PCU2-E HW

PCU2 BSW

PCU2 BSW

PCU2-E HW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

• PCU2-D HW is installed according to number of BCSUs in BSC3i

• Equal amount of PCU2-D HW is required in every BSCU

• PCU2-D SW is activated according traffic requirements

• In maximum two PCU2 BSW licenses per one PCU2-D HW plug-in unit

• One PCU2 BSW license = 256 Abis channels (16 kbit/s)

Example :

• Minimum configuration for 6 BCSUs =>

• 6 + 1 PCU2-D HW units + one PCU2 BSW license

• PCU2-E HW is installed according traffic requirements

• PCU2-E SW is activated according traffic requirements

• In minimum one PCU2-E HW unit + one PCU2-E HW unit for spare BCSU

• In maximum four PCU2 BSW licenses per one PCU2-E HW plug-in unit

• One PCU2 BSW = 256 Abis channels (16 kbit/s)

Example :

• Minimum configuration for 3 BCSUs =>

• 1 + 1 PCU2-E HW units + one PCU2 BSW license

OP

TIO

NA

L –

ac

tiv

ated

ac

co

rdin

g t

raff

ic r

eq

uir

emen

ts

Spare BCSU Spare BCSU

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

PCU2 BSW

OP

TIO

NA

L –

ac

tiv

ated

ac

co

rdin

g t

raff

ic r

eq

uir

emen

ts

OP

TIO

NA

L –

ac

tiva

ted

acc

ord

ing

tr

affi

c re

qu

irem

ents

S12, S13 : E.g. with BSC3i 2000 : S14 : E.g. with Flexi BSC and with Asymmetrical PCU HW Configuration

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BSC Application software requiring PCU2

S11.5 Application features:– GPRS CS3&4

S12 Application features:– High Multislot Classes for Type 1 MS (HMC)– Extended Dynamic Slot Allocation (EDA)– Dual Transfer Mode (DTM)

S13 Application features:– Multipoint Gb-Interface – Packet Control Unit (PCU2) pooling – Packet Data Optimisation package – Extended Cell for GPRS/EDGE

RG10 (S14) Application features:– Downlink Dual Carrier

RG20 (S15) Application features:– Downlink Dual Carrier (DLDC) Territory Procedures– TRX Specific Link Adaptation for DLDC– Inter-BSC NACC– Inter-system NACC– Inter-System NACC for LTE– Co-siting with BS2xx (ex-Siemens BTS)

RG30 (S16) Application features:– Dynamic PCU2 Pooling

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Dynamic PCU2 Pooling [RG30]Feature introduction

Dynamic PCU2 Pooling feature: Extension of the already existing Packet Control Unit (PCU2) Pooling feature.

Reallocates segments automatically between PCUs within a PCU pool based on the load condition of each PCU in the pool.

Balances the load between PCUs within a PCU pool.

Each PCU pool is handled individually.

You have the control on when PCU pool reallocation is to be started and how often it is to be done, for example, once a day and only at night. During reallocation, segments are moved from the PCU with high load condition to the PCU with lower load condition. Disturbance to end users’ services is minimized as segments are moved one by one so that all mobile stations (MSs) connected to a segment can move to the neighboring segments if needed until the segment in question is moved to a new PCU. Other segments are not disturbed during the movement.

Can be used only on PCU2 and PCUM units where Packet Abis is in use (dynamic PCU2 Pooling cannot be used with Legacy Abis).

Benefits: Improvement in BSC PCU utilization factor.

Reduction in CAPEX investments.

Increase in revenue due to decreased PS call drops caused by a single PCU capacity limitation.

OPEX saving as radio network resource allocation is done automatically.

More accurate PCU pool analysis in the PCU selection algorithm.

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Dynamic PCU2 Pooling [RG30]Example

1. PCU-1 is running at high load. Hence, the PCU selection algorithm of Dynamic PCU2 Pooling selects segment-2 to be moved to PCU-2. (E)GPRS is downgraded from segment-2 and the MSs are changed to neighboring segments (segment-1, segment-7, or segment-9) based on the received signal strength.

2. In this case, the MS context is changed to segment-1 within the same PCU. If the MS communication is changed to segment-7, the MS context is moved to another PCU which is connected to the same ETP. The MS can also change its communication to segment-9, in which case the MS context is moved to another PCU in the pool which is connected to another ETP.

3. When (E)GPRS is disabled at segment-2, PCU selection algorithm of Dynamic PCU2 Pooling feature moves segment-2 to PCU-2 which is running at a lower load. A segment can be moved from one PCU to another one only if both the PCUs are connected to the same ETP. Once the move is complete, (E)GPRS is enabled again in segment-2.

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Dynamic PCU2 Pooling [RG30]Reallocation scheduling

Can be defined:

Days of the week when Dynamic PCU2 Pool reallocation is done with the PCU pool reallocation day parameter.

The initial clock time when Dynamic PCU2 Pool reallocation starts with the PCU pool reallocation start time parameter.

Periods how often Dynamic PCU2 Pool reallocation is done per day with the PCU pool reallocation period parameter.

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Dynamic PCU2 Pooling [RG30]Example of PS traffic load when Dynamic PCU2 Pooling feature is enabled

PCU reported PS traffic load

PCU2-D/U PCU2-E PCU2-E* PCUM-A PCUM-B

1 0.4 0.1 0.1 0.1 0.04

10 4 1 1 1 0.4

100 40 10 10 10 4

1000 400 100 100 100 40

4000 - 400 400 400 160

10000 - - - - 400

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Gb interface capacity for PCU2-E and PCU2-D

Overall, applicable for both PCU2-E / PCU2-D max Gb throughput can be reached with more than 1 Frame Relay Link Gb over FR: capacity of the transport links may limit the throughput Gb over IP: PCU capacity is the limiting factor

Parameter PCU2-E PCU2-D

capacity per FR link 1…31 TSL (1984 kbps) 1…31 TSL (1984 kbps)

Total rate of FRLs / logical PCU 128 x 64 kbps 32 x 64 kbps

# of bearer channels per logical PCU

# max Gb throughput per logical PCU )* 8 Mbps (128 TSL x 64 kbps) 2 Mbps (32 TSL x 64 kbps)

16 FRL/NS-VC 4 FRL/NS-VC

*) incl. both user traffic and overheads

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Implementation of Packet Abis Overview on PS U-plane

PS U-plane: mapping of radio blocks to legacy Abis interface radio interface:

– 4 subsequent TDMA frames contribute to a single RLC/MAC block– GMSK: 1 bit/symbol => 114 bits per TDMA frame => 1456 bits of gross rate per RLC/MAC block

– 8-PSK: 3 bit/symbol => 348 bits per TDMA frame => 1392 bits of gross rate per RLC/MAC block

Legacy Abis:

– RLC/MAC blocks are transmitted in PCU frames

– PCU frame has similar structure as TRAU frame– 320 bits per 20 msec for header, payload (i.e. RLC/MAC block) and dummy bits (cf. Slide28)

– concatenated PCU frames are needed to preserve high throughput rates on Abis (for CS2-4 and MCS2-9 in case of EDGE)– large RLC/MAC blocks are split into up to 5 PCU frames depending on (M)CS

– PCU frames can act either as PCU master data frames or PCU slave data frames

– each RTSL gets one PCU master data frame and up to 4 PCU slave data frames depending on transmitted (M)CS (e.g. MCS1 does not need any slave frames while MCS9 needs 4 ones)

– PCU slave data frames are allocated on Abis sub-channels belonging to EDAP

MACheader

RLCheader

RLC data (related to a single RTSL)

payload of PCU frame: user data as well as RLC/MAC headers

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25 © Nokia Siemens Networks RA20209EN30GLN0

Implementation of Packet Abis Format of packet (PS U-plane)

PS U-plane: format of IP packet with PS U-plane in Packet Abis (1/2) The structure of PS U-plane packet in Packet Abis is identical to that carrying CS U-plane

– payload size is variable as it depends on codec in radio

– header size depends on realization of physical layer Payload structure:

– The entire RLC/MAC block is put in to a single packet – length of PCU frame in Packet Abis is not determined by PCM time structure (i.e. it is no longer limited to

320 bits per 20 msec)

– thus RLC/MAC blocks are not split between master and slave frames

– payload size is determined by (M)CS codec used on radio interface

payload header

0

200

400

600

800

1000

1200

1400

CS-1 CS-2 CS-3 CS-4 MCS-1 MCS-2 MCS-3 MCS-4 MCS-5 MCS-6 MCS-7 MCS-8 MCS-9

PS codecs

data

bit

s p

er

PC

U f

ram

e

user bits RLC/MAC header spare bits and byte alignment bits


Implementation of Packet Abis Format of packet (PS U-plane)

PS U-plane: format of IP packet with PS U-plane in Packet Abis (2/2) Payload structure (continuation from the previous slide):

– due to lack of fragmentation of RLC/MAC block, the distinction between master and slave PCU frames is not needed and EDAP concept is removed (in both physical realizations of Packet Abis)

– removal of EDAP modifies handling of PS traffic by PCU

– No PS multiplexing in RG30

– PS multiplexing in Packet Abis is understood as capability to bundle content of several RTSL within the same packet (analogously to CS multiplexing)

– lack of PS multiplexing does not affect a basic EGPRS feature which allows multiplexing of several users in a single RTSL (which is certainly supported regardless of Abis implementation)

– PS multiplexing is a candidate for future releases

Header structure:

– the same like for CS U-plane in terms of length and handling

– header compression is supported for TDM transport and does not for PSN transport

– For further details, please refer to the Chapter Appendix

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Implementation of Packet Abis PCU aspects (PS U-plane)

PCU aspects: overview interdependencies between ETP and PCU: introduction of ETP does not modify PCU tasks

– from PCU perspective, the role of ETP is identical like any other Exchange Terminal (i.e. ET16, ETS2, ETIP): it terminates PCU frames and relies them to PCU for further processing

– in that sense Abis implementation does not matter for PCU (as ETP handles relevant protocols) PCU2-D or PCU2-E are required for Packet Abis. Neither PCU1 nor PCU2-U are supported. PCU2-D and PCU2-E support either Packet Abis or Dynamic Abis (Legacy Abis), but not both simultaneously

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PCU dimensioning for Packet Abis

• In Packet Abis concept of EDAP is removed thus formula that has been used so far for PCU dimensioning must be appropriately changed. • Introduction of new transport concept for Abis interface have direct impact on PCU and for this Abis realization dimensioning is much simpler than before.• Following changes has been done:

– # of EDAPs and # of AbisChannels bave been removed as they are irrelevant

– PCU connectivity target is understood as sum of RTSLs in default territory (CDEF)

– Utilization in radio timeslot criteria is recommended to set 50% not 70% like in Dynamic Abis

parameter (*) PCU2-E PCU2-D

max RTSL 1024 256

max BTS 384 128

max SEG 256 64

max TRX 1024 256

max Gb throughput 8 Mbps 2 Mbps

#DSP 6 8

#bw/DSP 6880 B 1280 B

#logical PCU/PIU 1 2

For RTSL Utilization = 50% which is recommended value (to leave enough capacity for territory upgrade and higher coding scheme/modulation)i.e.:PCU2-E which support up to 1024 RTSL, 512 RTSLs is available for cell.

(*) per logical PCU

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PCU dimensioning for Packet AbisNumber of cells per PCU

Number of cells that can be handled by one PCU is calculated based on the following formula:

CDEF

NN

RTSLCells

With this number of RTSLs one PCU2-E unit can support e.g.:– 256 cells (and this is maximum number of cells that can be served by PCU2-E) with CDEF=2, which in sum gives 512 RTSL. This “extra small” configuration, in terms of default territory can be used to provide connectivity to very high number of cells.

– 128 cells with default territory = 4, and this configuration is recommended Connectivity Cell configuration as it is placed between extra small and medium configuration. For both Connectivity Cells configurations recommended CMAX value is 6 (two TRXs) to leave more capacity for Throughput Cell.

– Up to 42 cells with CDEF equal to 12 RTSLs. This configuration is example of a Throughput Cell in which higher throughput rate is offered per cell. For this configuration recommended EGPRS TRXs is 4 or 5 per cell.

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PCU dimensioning for Packet AbisFormula

Notes: #PCU correspond with the number of logical PCU (only relevant fopr PCU2D)Recommended U value is 50%Utilization for Gb throughput ( P value in the formula) is recommended to be set to 70% to leave safety margin in case of peak in several BTSs in the same time.

PGbThr

GbThr

TRX

TRX

SEG

SEG

BTS

BTS

URTSL

RTSLPCU

max;

max

#;

max

#;

max

#;

max

#max#

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Exercise

For Packet Abis the following figures are used:RTSLs = 570 RTSLsBTSobjs = 120 BTSsSEGs is not usedTRXs = 240 TRXsBHGbThroughput = 6 Mbit/sIn calculation PCU2-E is used.

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Appendix

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Implementation of Packet Abis Overview on protocol stack

various protocol stacks are used for different planes and for different realization of physical layer

Notes:

– these are simplified pictures just for overview needed for network planning

– introduction of IPSec brings in additional headers

p-RTPp-RTP

UDPUDPIUAIUA

SCTPSCTP

IPIP

MC ML PPP / HDLCMC ML PPP / HDLC

TDMTDM

CS/PSU-plane

C/M-plane

p-RTPp-RTP

UDPUDPIUAIUA

SCTPSCTP

IPIP

Ethernet (L2) / VLANEthernet (L2) / VLAN

Ethernet (L1)Ethernet (L1)

CS/PSU-plane

C/M-plane

Packet Abis over TDM Packet Abis over PSN

SCTP: Stream Control Transmission Protocol

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Implementation of Packet Abis Header compression (2/4)

Header compression: basic principles– allows compression of some protocol headers before sending packets over a link

and decompression to their original state upon reception at the far end of the link– is possible due to the redundancy in header fields of given packet stream (many

fields being constant or changing hardly ever in consecutive packets: these can be recognized and replaced with the smallest representation)

– is hop-to-hop process, so it is necessary to decompress the header upon reception at each node to manage the incoming packet (e.g. to perform routing or apply QoS mechanisms), i.e. all interconnecting elements must support header compression

– the functionality is supported (optionally) for Packet Abis over TDM (where bandwidth efficiency is crucial) and is not for Packet Abis over PSN (lack of relevant standard)

Header compression is controlled by means of parameters: Next two slides give overview on header lengths used for network planning;

note that:– header length depends on plane (e.g. C-plane has different headers than U-plane)– header length depends on physical realization of Packet Abis (i.e. TDM vs. Ethernet)– header length depends on whether header compression is enabled or not

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Header compression: compression gain for Packet Abis over TDM

CS/PS U-plane

3 7 20 8 7

HDLC MC/ML-PPP UDP p-RTPIP

3 74 4

PPP headercompression

IP headercompression

UDP headercompression: 0 octets

45 octets without compression

18 octets with header compression

C/M-plane

3 7 20 12 28

HDLC MC/ML-PPP SCTP IUAIP

3 4 4

PPP headercompression

IP headercompression

12 28


51 octets with header compression

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Header compression: overview on headers’ lengths for Packet Abis over PSN– header compression is not supported in case of Packet Abis over PSN

– Note: introduction of IPSec brings in ~40 octets regardless of plane

CS/PS U-plane

4 38 20 8 7

VLAN Ethernet (802.3) incl. IFG UDP p-RTPIP


C/M-plane

4 38 12 28

VLAN Ethernet (802.3) incl. IFG SCTP IUAIP

20……


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09_ra20209en30gln0_ pcu capacity and dimensioning for packet abis

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