Nokia PS- (e)Gprs Explain

Company Confidential

1 © 2005 Nokia (E)GPRS EXPLAIN

(E)GPRS Explain

FunctionalityBase Station SubsystemNetwork AuditNetwork Dimensioning and PlanningNetwork OptimizationTools



(E)GPRS EXPLAIN - Course objectives

“2G Data EXPLAIN”

• Aimed for radio network planners / optimization engineers

Main topics

• Basic GSM/GPRS/EDGE data network functionality

• Provide information for data network dimensioning and dimensioning process

Concepts

• (E)GPRS = GPRS & EDGE

• EGPRS = EDGE



(E)GPRS Explain - ContentFunctionality

• NE & interfaces

• Protocol stack

• TBF, Session Management, Mobility Management

Network Audit

• HW, SW and Feature audit

• GSM coverage and interference audit

Network Dimensioning and Planning

• Coverage and capacity planning

Network Optimization

Tools

Base Station Subsystem (BSS)

• Modulation (Air interface),

• EDAP and PCU (Resource allocation)

• Gb



SW and HW Releases

This material describes the Nokia (E)GPRS System with the following SW and HW releases:

• BSS SW:• BSS10.5, 11.0 and 11.5

• BSC variants with PCU1:• BSCi, BSC2, BSC2i, BSC3i

• BTS versions:• Talk, PrimeSite, MetroSite, UltraSite

• SGSN• SG5



(E)GPRS Explain




Functionality - Content

Introduction

• Network Architecture and Interfaces

• Mobile Classes

• Network Protocols

• Multiframe and Header Structure

• Air Interface Mapping – Physical and Logical Channel

Procedures

• State and Mobility Management

• GPRS Attach/Detach

• Routing Area

• Session Management (PDP context)

• Temporary Block Flow

•RLC/MAC Header

•TBF Establishment



MSCHLR/AuCEIR

BSCBTSUm

PSTNNetwork

GSM & (E)GPRS Network Architecture

PCU

EDAPGb

Gateway GPRSSupport Node(GGSN)

Charging Gateway (CG) Local

AreaNetwork

Server

Router

Corporate 1

Server

Router

Corporate 2

Datanetwork(Internet)


Billing System

Inter-PLMNnetwork

GPRSINFRASTRUCTURE

BorderGateway (BG)

Lawful InterceptionGateway (LIG)

GPRSbackbo

nenetwork

(IP based)

Serving GPRSSupport Node(SGSN)

SS7Network

PAPU



(E)GPRS Network Elements and Primary Functions

SGSN• Mobility Management• Session Management• MS Authentication• Ciphering• Interaction with

VLR/HLR• Charging and

statistics• GTP tunnelling to

other GSNs

GGSN• GTP tunnelling to

other GSNs • Secure interfaces

to external networks

• Charging & statistics

• IP address management

Charging Gateway

• CDR consolidation

• Forwarding CDR information to billing center

Border Gateway• Interconnects

different GPRS operators' backbones

• Enables GPRS

roaming• Standard Nokia IP

router family

Domain Name Server• Translates IP host names to IP

addresses• Makes IP network configuration

easier• In GPRS backbone SGSN uses

DNS to get GGSN and SGSN IP addresses

• Two DNS servers in the backbone to provide redundancy

Legal Interception Gateway• Enables authorities to intercept

subscriber data and signaling• Chasing criminal activity• Operator personnel has very

limited access to LI functionality• LI is required when launching the

GPRS service



GSM and (E)GPRS Interfaces

Gf

D

Gi

Gn

GbGc

CE

Gp

Gs

Signaling and Data Transfer InterfaceSignaling Interface

MSC/VLR

TE MT BSS TEPDN

R Um

GrA

HLR

Other PLMN

SGSN

GGSN

Gd

SM-SCSMS-GMSCSMS-IWMSC

GGSN

EIR

SGSN

Gn



(E)GPRS Interfaces

Gf

D

Gi

C

E

Gp

Gs

Signaling and Data Transfer InterfaceSignaling Interface

MSC/VLRTE BSS

TEPDN

R Um

Gr

HLR

Other PLMN

GGSN

Gd

SM-SCSMS-GMSCSMS-IWMSC

EIR

GnLAN

SW / IP BB

DNS CG LIG

Gn Gn

Gc

A

Gb

MT

SGSN SGSN GGSN

Gn

Gn Gn

Optional



BSC

BTS

• Class C Packet only (or manually switched between GPRS and speech modes)

• Class B Packet and Speech (not at same time) (Automatically switches between GPRS and speech modes)

• Class A Packet and Speech at the same time(DTM is subset of class A)

(E)GPRS Mobile Terminal Classes



(E)GPRS Multislot ClassesType 1

Multislot Classes 1-12- Max 4 DL or 4 UL TSL (not at same time)- Up to 5 TSL shared between UL and DL- Minimum 1 TSL for F Change- 2-4 TSL F Change used when idle

measurements required

Multislot Classes 19-29- Max 8 downlink or 8 uplink

(not required at same time)- 0-3 TSL F Change

Multislot Classes 30-45 (Rel-5)- Max 5 downlink or 5 uplink (6 shared)- Max 6 downlink or 6 uplink (7 shared)

Type 2

Multislot Classes 13-18- simultaneous receive & transmit- max 8 downlink and 8 uplink (Not available yet, difficult RF design)

DL

UL

DL

UL

1 TSL for F Change

1 TSL for Measurement

DL

UL



GPRS implementation

• GPRS/EGPRS capable terminals are required

• GPRS territory is required in BTS

• Packet Control Units (PCUs) need to be implemented in BSCs

• Gb interface dimensioning

• GPRS packet core network dimensioning

• If CS3&CS4 will be implemented following units/items are required• PCU2 with S11.5 BSC SW

• Dynamic Abis Pool (DAP)

• EDGE capable TRXs

• UltraSite and MetroSite BTS SW support



EGPRS Implementation

• Can be introduced incrementally to the network where the demand is

• EGPRS capable MS

• Network HW readiness/upgrade (BTS and TRX)

• TRS capacity upgrade (Abis and Gb!)

• Dynamic Abis

GMSK coverage

8-PSK coverage

AA-bis

Gb

Gn

BTS

BTS

BSC

SGSNGGSN

MSC

More capacity in interfaces to support higher data usage

EDGE capable TRX, GSM compatible

EDGE capable terminal, GSM compatible

EDGE functionality in the network elements



(E)GPRS Protocol Architecture

L1

L2

IP

UDP

GTP

USERPAYLOAD

GGSN

L1

L2

IP

GPRS Bearer

GGSN

Relay

IP

GPRS IP Backbone

L1

L2

IP

GTP

L1bis

NW sr

BSSGP

SNDCP

LLC UDP

SGSN

Relay

Gn

Internet

L1

L2

IP

TCP/UDP

APP

Gi

User information transferUser information transfer

LLC

SNDCP

IP

TCP/UDP

APP

RLC

MAC

GSM RF

MS

RLC

MAC

GSM RF

BSSGP

NW sr

L1bis

BSS

Ciphering and reliable link

Um Gb

Compression, segmentation

FIXED HOST



SNDCP (Subnetwork Dependent Convergence Protocol) Layer

• Multiplexer/demultiplexer for different network layer entities onto LLC layer

• Compression of protocol control information (e.g. TCP/IP header)

• Compression of data content (if used)

• Segmentation/de-segmentation of data to/from LLC layer

LLC

SNDCP

IP

TCP/UDP

APP

RLC

MAC

GSM RF



Logical Link Control (LLC) Layer

LLC

SNDCP

IP

TCP/UDP

APP

RLC

MAC

GSM RF

•Reliable logical connection between SGSN and MS

•Independent of underlying radio interface protocols

ControlAddress

FCSInformation

LLC Frame

1 1-3 1-1520 3Octets



Radio Link Control (RLC)/ Medium Access Control (MAC) Layers

RLC• Achieves reliable transmission of data across air interface

• Segmentation/de-segmentation of data from/to LLC layer

MAC• Control of MS access to common air-interface medium

• Flagging of PDTCH/PACCH occupancy

LLC

SNDCP

IP

TCP/UDP

APP

RLC

MAC

GSM RF



Downlink RLC Data Block with MAC Header

USF - Uplink State Flag

TFI - Temporary Flow Indicator

BSN - Block Sequence Number

FBI - Final Block Indicator



Uplink RLC Data Block with MAC Header

TFI - Temporary Flow Indicator

= TBF ID.BSN - Block Sequence Number = RLC block ID within TBFTLLI - Temporary Logical Link Identifier = type of mobile ID Countdown value - used to calculate number of RLC blocks remaining



GSM RF Layer

• Modulation/demodulation

• Bit inter-leaving

• TDMA frame formatting

• Cell selection/re-selection

• Tx power control

• Discontinuous reception (DRx)LLC

SNDCP

IP

TCP/UDP

APP

RLC

MAC

GSM RF



(E)GPRS Protocol Architecture – Mapping to RF layer

• LLC frames are segmented into RLC Data Blocks

• In the RLC/MAC layer, a selective ARQ protocol provides retransmission of erroneous RLC Data Blocks

• When a complete LLC frame is successfully transferred across the RLC layer, it is forwarded to the LLC layer.



Bursts on the Air Interface – Mapping RLC blocks

1 TDMA frame = 4.615 ms

= BURST PERIOD

RLC/MAC Blocks

TDMA Bursts

RLC Blocks

4 x TDMA Frames = 4 Bursts = 1 Radio block = 18.46 ms = 1-2 RLC block(s)

Note: Amount of RLC blocks per radio

block depends on used (modulation)

coding scheme (M)CS0 70 70 70 7

12 x RLC/MAC Blocks = 1 x 52 PDCH MultiFrame = 240 ms12 RLC/MAC Blocks / 0.240 s = 50 RLC/MAC Blocks / s

0 1 2 3 4 5 6 7 8 9 10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

B0(0..3)

B1(4..7)

B2 (8..11)

PTCCH

B3(13..16)

B4(17..20)

B5(21..24)

IDLE

B6(26..29)

B7(30..33)

B8(34..37)

PTCCH

B9(39..42)

B10(43..46)

B11(47..50)

IDLE

52 TDMA Frames (240 ms)



GSM and (E)GPRS Multiframe

D O C U M E N T T Y P E

T y p e U n i t O r D e p a r t m e n t H e r eT y p e Y o u r N a m e H e r e T y p e D a t e H e r e

G S M S i g n a l l i n g t i m e s l o t G S M T r a f f i c T S G P R S t r a f f i c T ST D M A f r a m e

T S 0 T S 1 T S 2 T S 3 T S 4 T S 5 T S 6 T S 70 F C C H T C H1 S C H T C H2 B C C H T C H R a d i o B l o c k 03 B C C H T C H4 B C C H T C H5 B C C H T C H6 P C H + A G C H T C H R a d i o b l o c k 17 P C H + A G C H T C H8 P C H + A G C H T C H9 P C H + A G C H T C H

1 0 F C C H T C H R a d i o B l o c k 21 1 S C H T C H1 2 P C H + A G C H S A C C H P T C C H1 3 P C H + A G C H T C H1 4 P C H + A G C H T C H1 5 P C H + A G C H T C H R a d i o B l o c k 31 6 P C H + A G C H T C H1 7 P C H + A G C H T C H1 8 P C H + A G C H T C H1 9 P C H + A G C H T C H R a d i o B l o c k 42 0 F C C H T C H2 1 S C H T C H2 2 P C H + A G C H T C H2 3 P C H + A G C H T C H R a d i o B l o c k 52 4 P C H + A G C H T C H2 5 P C H + A G C H I D L E I D L E2 6 P C H + A G C H2 7 P C H + A G C H2 8 P C H + A G C H R a d i o B l o c k 62 9 P C H + A G C H3 0 F C C H3 1 S C H3 2 P C H + A G C H R a d i o B l o c k 73 3 P C H + A G C H3 4 P C H + A G C H3 5 P C H + A G C H3 6 P C H + A G C H R a d i o B l o c k 83 7 P C H + A G C H3 8 P C H + A G C H P T C C H3 9 P C H + A G C H4 0 F C C H4 1 S C H R a d i o B l o c k 94 2 P C H + A G C H4 3 P C H + A G C H4 4 P C H + A G C H4 5 P C H + A G C H R a d i o B l o c k 1 04 6 P C H + A G C H4 7 P C H + A G C H4 8 P C H + A G C H4 9 P C H + A G C H R a d i o B l o c k 1 15 0 I D L E5 1 I D L E



(E)GPRS Logical Channels

GPRS Air Interface Logical Channels

CCCHCommon Control Channels

DCHDedicated Channels

PCHPaging CH

AGCHAccess Grant CH

RACHRandom Access CH

Existing GSM Channels(Shared with GPRS Signaling in GPRS Release 1)

PACCHPacket Associated

Control CHPDTCH

Packet Data TCH

NEW GPRS Channels



Functionality - Content

Introduction

• Network architecture and Interfaces

• Mobile classes

• Network Protocols

• Multiframe and header structure

• Air interface mapping – physical and logical channel

Procedures

• State and Mobility Management

• GPRS Attach/Detach

• Routing Area

• Session Management (PDP context)

• Temporary Block Flow

•RLC/MAC Header

•TBF Establishment



(E)GPRS Procedures - Content

• Mobility Management and State Management• Mobile States

• GPRS attach

• GPRS detach

• Routing Area

• Session Management• PDP context activation

• Temporary Block Flow• RLC/MAC Header

• TBF establishment



GPRS Mobility Management - Mobile States

MS location not known, subscriber is not reachable by the GPRS nw.

IDLE READY

STANDBY

READY Timer expiry

MOBILE REACHABLE Timer expiry

Packet TX/RX

GPRS Attach/Detac

h

MS location known to Routing Area level. MS is capable to being paged for point-to-point data.

MS location known to cell level. MS is transmitting or has just been transmitting. MS is capable of receiving point-to-point data.



GPRS Mobility Management - Mobile States

• GPRS MM is based on States• State Transition occurs when a pre-defined transaction takes place• GPRS Attach (/Detach)

• MS makes itself known to the network

• The authentication is checked and the mobile location is updated

• Subscriber Information is downloaded from the HLR to the SGSN

• State transition Idle to Ready

• Normal procedure should occur within 5 seconds each

• Mobility Management before Session Management:• GPRS attach needs to happen before PDP context activation

• States controlled by timers• READY Timer• MOBILE REACHABLE Timer• Timer values are configurable with SGSN Parameter Handling



Attach Procedure

• The GPRS Attach procedure establishes a GMM context. This procedure is used for the following two purposes:

• a normal GPRS Attach, performed by the MS to attach the IMSI for GPRS services only

• a combined GPRS Attach, performed by the MS to attach the IMSI for GPRS and non-GPRS services

• Attach procedure description• MS initiates by sending Attach Request

• If network accepts Attach Request it sends Attach Accept• P-TMSI, RAI

• If network does not accept Attach request it sends Attach Rejected

• MS responds for Attach Accept message with Attach Complete (only if P-TMSI changes)



(E)GPRS Attach Process – Combined GPRS/IMSI Attach

1. Attach Request

2. Identification Request

2. Identification Response

3. Identity Request

3. Identity Response

4. Authentication

5. (IMEI Check - optional)

6a. Update Location

6b. Cancel Location

6c. Cancel Location Ack

6d. Insert Subscriber Data

6e. Insert Subscriber Data Ack

MS BSS new SGSN old SGSN GGSN HLR EIR old

MSC/VLR new

MSC/VLR



(E)GPRS Attach Process – Combined GPRS/IMSI Attach

6f. Update Location Ack

7a. Location Update Request

7b. Update Location

7c. Cancel Location

7d. Cancel Loc. Ack

7e. Insert Subscriber Data

7f. Insert Subscriber Data Ack

7g. Update Location Ack 7h. Location Update Accept

9. Attach Complete

8. Attach Accept

10. TMSI Reallocation Complete

MS BSS new SGSN old SGSN GGSN HLR EIR old

MSC/VLR new

MSC/VLR



Detach Process

• GPRS Detach procedure is used for the following two purposes:• a normal GPRS Detach

• a combined GPRS Detach (GPRS/IMSI detach, MS originated)

• MS is detached either explicitly or implicitly:• Explicit detach: The network or the MS explicitly requests detach.

• Implicit detach: The network detaches the MS, without notifying the MS, a configuration-dependent time after the mobile reachable timer expired, or after an irrecoverable radio error causes disconnection of the logical link



(E)GPRS Detach Process

2. Delete PDP Context Request

1. Detach Request

2. Delete PDP Context Response

3. IMSI Detach Indication

5. Detach Accept

MS BSS GGSNSGSN MSC/VLR

4. GPRS Detach Indication



Routing Area

The Routing Area Update procedure is used for the followings:

• a normal Routing Area Update

• a combined Routing Area Update

• a periodic Routing Area Update

• an IMSI Attach for non-GPRS services when the MS is IMSI-attached for GPRS services.

• Routing Area (RA)• Subset of one, and only one Location Area (LA)

• RA is served by only one SGSN

• For simplicity, the LA and RA can be the same

• Too big LA/RA increases the paging traffic, while too small LA/RA increases the signaling for LA/RA Update



Routing Area Location

Area (LA)

Routing Area (RA)

SGSN

MSC/VLR

GS Interface

• Bad LA/RA border design can significantly increase the TRXSIG on LA/RA border cells causing the cell-reselection outage to be longer

• LA/RA border should be moved from those areas where the normal CSW and PSW traffic is very high



Large RA Support – LRAS (SG4)

PAPU 1

PAPU 4

HCPAPU 5

Nokia 2G SGSN

BSC 1

RA 1

BSC 2

BSC 3

RA 2 RA 3

Frame Relay/ IP

PAPU n

PAPU 2

PAPU 3

PAPU group

From SG1 to SG3, only one Packet Processing Unit (PAPU) could serve one specific RA.

The Large RA Support feature now allows more than one PAPU to serve one RA/NSE (Network Service Entity) by making it possible to define PAPU groups with multiple PAPUs.

Together with the High Capacity PAPU, this feature offers the operators a possibility of enhancing capacity within a certain RA or NSE as the number of subscribers increases.

PAPU capacity limited and GPRS subscribers blocked if

more than 20 000 subscribers

With HCPAPU (High Capacity PAPU) max. 60

000 supported subscribers in one RA.

SGSN capacity remains the same with HCPAPU - 320000

subscribers



MS BTS BSC New SGSNMS BTS BSC New SGSNMS BTS BSC New SGSN

LA/RA Update (Intra PAPU)

Routing Area Update Accept

Routing Area Update Accept (PDCCH)Routing Area Update Accept

Location update request (SDDCH)

Routing Area Update complete (PDCH)Routing Area Update complete

First System information message

Location update request

Location Update AcceptLocation Update Accept

Channel Request (RACH)

Immediate Assignment (CCCH)

P_Channel Required

P-Immediate Assignment Cmd

Channel Release (SDCCH)

Routing Area Update RequestRouting Area Update Request (PDTCH) Routing Area Update Request

Location area Update

Routing area Update

Ce

ll r

es

ele

cti

on

d

ata

ou

tag

e

First System information message (BCCH)

SECURITY FUNCTIONS AS SET BY THE OPERATOR

DL TBF ASSIGNMENT



LA/RA Update (Inter PAPU or Inter SGSN) 1/2

MS BTS BSC New SGSN

Routing Area Update Request

Including TLLI for contention resolution Including TLLI for contention resolution

Including TLLI for contention resolution

MS BTS BSC New SGSNMS BTS BSC New SGSN

Routing Area Update Request (PDTCH)

Packet Uplink Ack/Nack (PACCH)





Packet Downlink Ack/Nack (PACCH)

UL TBF ASSIGNMENT, MS ON CCCH 1-ph access

Routing Area Update RequestPacket Uplink Ack/Nack

Packet control ack (PACCH) Packet control ack

SECURITY FUNCTIONS AS SET BY THE OPERATOR

DL TBF ASSIGNMENT


Packet Downlink Ack/Nack

New SGSN sends context req to old SGSN

Old SGSN sends response and starts tunneling data to new SGSN

New SGSN sends ‘Update PDP context request’ to GGSN

New SGSN informs HLR about SGSN change by sending ‘Update location’

HLR sends ‘Cancel location’ to old SGSN.



MS BTS BSC New SGSNMS BTS BSC New SGSNBTS BSC New SGSN

Routing Area Update Complete (PDTCH)Routing Area Update Complete




Packet Uplink Ack/Nack

UL TBF ASSIGNMENT

Routing Area Update Complete

Packet Uplink Ack/Nack (PACCH)

LA/RA Update (Inter PAPU or Inter SGSN) 2/2



•PDP Context (Packet Data Protocol): Network level information which is used to bind a mobile station (MS) to various PDP addresses and to unbind the mobile station from these addresses after use

•PDP Context Activation• Gets an IP address from the network• Initiated by the MS• Contains QoS and routing information enabling data transfer between MS and

GGSN• PDP Context Activation and Deactivation should occur within 2 seconds

Session Management - Establishing a PDP Context

PDP Context Request

155.131.33.55



MSC

PSTNNetwork

GPRSINFRASTRUCTURE

HLR/AuCEIR


Domain Name Server (DNS)

GPRSbackbo

nenetwork

(IP based)

PDP Context Activation - 11. MS sends "Activate PDP Context Request" to SGSN

2. SGSN checks against HLR



Access Point

SS7Network

APN= "Intranet.Ltd.com" 2.


Access Point Name = Reference to an external packet data network the user wants to connect to

BSCBTSUm

1.



MSC

PSTNNetwork

GPRSINFRASTRUCTURE

HLR/AuCEIR

PDP Context Activation - 2Finding the GGSN

3. SGSN gets the GGSN IP address from DNS

4. SGSN sends "Create PDP Context Request" to GGSN



SS7Network

4.


GPRSbackbo

nenetwork

(IP based)

3.



Access Point

BSCBTSUm

DNS (Domain Name System) = mechanism to map logical names to IP addresses



MSC

GPRSINFRASTRUCTURE

HLR/AuCEIR

PSTNNetwork

PDP Context Activation - 3Access Point Selection

Access Point Name refers to the external network the subscriber wants to use


SS7Network


GPRSbackbo

nenetwork

(IP based)



Access Point

APN="Intranet.Ltd.com"


BSCBTSUm



MSC

PSTNNetwork

GPRSINFRASTRUCTURE

HLR/AuCEIR



Access Point

APN="Intranet.Ltd.com"


SS7Network

5.


GPRSbackbo

nenetwork

(IP based)

6.


BSCBTSUm

User (dynamic) IP address allocated

5. GGSN sends "Create PDP Context Response" back to SGSN

6. SGSN sends “Activate PDP Context Accept“ to the MS

PDP Context Activation - 4Context Activated



Temporary Block Flow

Temporary Block Flow (TBF):• Physical connection where multiple mobile stations can share one or more traffic

channels – each MS has own TFI• The traffic channel is dedicated to one mobile station at a time (one mobile station is

transmitting or receiving at a time)• Is a one-way session for packet data transfer between MS and BSC (PCU)• Uses either uplink or downlink but not both (except for associated signaling)• Can use one or more TSLs

Comparison with circuit-switched:• normally one connection uses both the uplink and the downlink timeslot(s) for traffic

In two-way data transfer:• uplink and downlink data are sent in separate TBFs - as below

BSBSCC

Uplink TBF (+ PACCH for downlink TBF)

Downlink TBF (+ PACCH for uplink TBF)

PACCH (Packet Associated Control Channel): Similar to GSM CSW SACCH



TLLI / TBF Concept

TBF (TFI + TSL)

MS SGSN GGSN

Internet or Intranet

GPRS CORE

BSS

TBF (RLC / MAC Flow)

TBF (LLC Flow)

PCUBTS

TLLI (SNDCP Flow)

P-TMSI

HLRVLR

IMSITMSI



TBF Flow

Gb SGSN(LLC) Buffer

PCU(LLC -> RLC/MAC)

Air Interface(RLC/MAC)

MS Re-assembly(RLC/MAC -> LLC)

Application

Gb SGSN(LLC) Buffer

PCU(LLC -> RLC/MAC)

Air Interface(RLC/MAC)

MS Re-assembly(RLC/MAC -> LLC)

Application

Start of TBF“Slow” TBF

“Full Speed”

TBF Ending“Slow down”



Temporary Block Flow

• DL TBF• Network starts and releases TBFs

• FBI (Final Block Indicator) indicates the last block in a DL TBF

• Uplink TBF• Close-ended: limited number of octets

• Open-ended: an arbitrary number of octets

• MS may request either close-ended or open-ended TBF• NW decides the type in PACKET UPLINK ASSIGNMENT

• MS can ask network to give more resources if needed



EGPRS RLC/MAC Header for Data Block

Bit8 7 6 5 4 3 2 1 Octet

TFI RRBP ES/P USF 1BSN1 PR TFI 2

BSN1 3BSN2 BSN1 4

CPS BSN2 5

Bit8 7 6 5 4 3 2 1 Octet

TFI Countdown Value SI R 1BSN1 TFI 2

BSN2 BSN1 3BSN2 4

Spare PI RSB CPS 5Spare 6

Downlink:

Uplink:

Ref: TS 04.60

• Three header types for EGPRS RLC/MAC data block

• Example: Header type 1 (header for MCS-7, MCS-8 and MCS-9)



Establishing a DL TBF and Sending DataPaging

UL TBF forMS location

Packet Control Ack (for TA)

Packet Polling

Packet Downlink Assignment

Data / Signalling

Ack / Nack

Packet Channel Request

Packet Paging Response (LLC Frame)

BTSBTS

RACH

AGCH

PDTCH

PACCH

PACCH

PACCH

PCH

Immediate Assignment for UL TBF

Immediate Assignment for DL TBFAGCH

PDTCH

PACCH

PACCH



Multiple Mobiles and Downlink Transmission

TFI2

TFI5

TFI3

TFI2

MSs

BTS

The TFI included in the Downlink RLC Block header indicates which Mobile will open the RLC Block associated with its TBF

RLC Data Block



Establishing an UL TBF and Sending Data

Packet Channel Request

Immediate Assignment for UL TBF

UL Data

Signaling + Ack/Nack

Final UL Data

Final Ack/Nack

Packet control Ack

RACH

AGCH

PDTCH

PACCH

PDTCH

PACCH

PACCH

BTSBTS



• Several mobiles can share one timeslot

• Maximum of 7 Mobiles are queued in the Uplink

• Mobile transmissions controlled by USF (Uplink State Flag) sent on DL (dynamic allocation)

TS 1

TS 2

TS 3

Uplink State Flag

• Mobile with correct USF will transmit in following Uplink block

• Timeslot selected to give maximum throughput

New MS

Multiple Mobiles and Uplink Transmission



Multiple Mobiles and Uplink Transmission

USF = 1

USF = 2

USF = 3

USF = 3

MSs

BTS

RLC Data Block

The USF included in the Downlink RLC Block header identifies which Mobile will transmit in the following Uplink RLC Block



(E)GPRS Explain




BSS - Content

Air interface - Modulation and Link Adaptation

• GMSK and 8PSK Modulation and bursts

• Power Back-off

• GPRS Coding Schemes (CS)

• EGPRS Modulation and Coding Schemes (MCS)

• GPRS Link Adaptation

• EGPRS Link Adaptation and incremental Redundancy (IR)

• EDAP and PCU (Resource allocation)

• Gb



GMSK & 8-PSK - Phase State Vectors

22,5° offset to avoid zero crossing

GMSK

8PSK(0,0,1)

(1,0,1)

(0,0,0) (0,1,0)

(0,1,1)

(1,1,1)

(1,1,0)

(1,0,0)

Time

Envelope (amplitude)

Time

Envelope (amplitude)



(0,0,1)

(1,0,1)

(d(3k),d(3k+1),d(3k+2))=

(0,0,0) (0,1,0)

(0,1,1)

(1,1,1)

(1,1,0)

(1,0,0)

8-PSK Modulation

EDGE GSM + EDGE Modulation 8-PSK, 3bit/sym GMSK, 1 bit/sym Symbol rate 270.833 ksps 270.833 ksps Bits/burst 348 bits

2*3*58 114 bits 2*57

Gross rate/time slot 69.6 kbps 22.8 kbps

• 8-PSK (Phase Shift Keying) has been selected as the new modulation added in EGPRS

• 3 bits per symbol

• 22.5° offset to avoid origin crossing (called 3/8-8-PSK)

• Symbol rate and burst length identical to those of GMSK

• Non-constant envelope high requirements for linearity of the power amplifier

• Because of amplifier non-linearities, a 2-4 dB power decrease back-off (BO) is typically needed, Nokia guaranteed a BO of 2 DB for BTS

3/8

Phase states transitionsto avoid zero-crossing



GMSK and 8PSK BurstsdB

t

- 6

- 30

+ 4

8 µs 10 µs 10 µs 8 µs

(147 bits)

7056/13 (542.8) µs 10 µs

(*)

10 µs

- 1+ 1

(***)

(**)

10 8 10 10 8 10 t (s)

dB

-30

(*)

-6

+2,4

+4

-20

-2

(***)

(**)

2 2 22

7056/13 (542,8)s

(147 symbols)

0

GMSK Burst

8PSK Burst

Phase state vector diagram•Amplitude is not fixed•Origin is not crossed•Overshooting



8-PSK Modulation – Back-off Value

• Since the amplitude is changing in 8-PSK the transmitter non-linearities can be seen in the transmitted signal

• These non-linearities will cause e.g. errors in reception and bandwidth spreading.

• In practice it is not possible to transmit 8-PSK signal with the same power as in GMSK due to the signal must remain in the linear part of the power amplifier

Peak to Average of 3,2 dB

Pin

Pout

Back Off= 4 dB

Compression point

Peak to Average of 3,2 dB

Pin

Pout

Back Off= 4 dB

Compression point

• The back-off value is taken into account in link budget separately for UL / DL and bands: 900/850, 1800/1900)

• Too high MCA (8PSK) can lead to unsuccessful TBF establishment, if the MS is on cell border with low signal level (so the back-off is taken into account) and / or low C/I



Burst Structure

• Burst structure is similar with current GMSK burst, but term 'bit' is replaced by 'symbol'

• Training sequence has lower envelope variations

• Seamless switchover between timeslots

• In case of max output power only, back-off applied to 8-PSK

TSL1 TCH

GMSK

TSL2 TCH

GMSK

TSL3 TCH

GMSK

TSL4 TCH

GMSK

TSL5 PD T CH 8 - PSK / GMSK



TSL0 BCCH GMSK

P (dB)

t ( us )



EDGE Signal

1 2 3 4

1. Spectrum of Unfiltered 3pi/8 8psk modulation.

2. Filtered to fit GSM bandwidth.

3. Constellation after filtering: error vectors introduced.

4. Constellation after receiver Edge (equalised) filtering



GPRS Coding Schemes

• GPRS provides four coding schemes: CS-1, CS-2 and with PCU2 CS-3, CS-4

• PCU1 and 16 kbit/s Abis links support CS-1 and CS-2, the Dynamic Abis makes it possible to use CS-3 and CS-4

• Each TBF can use either a fixed coding scheme (CS-1 or CS-2), or Link Adaptation (LA) based on BLER

• Retransmitted RLC data blocks must be sent with the same coding as was used initially



Coding Scheme

Payload (bits)per RLC block

Data Rate (kbit/s)

CS1 181 9.05

CS2 268 13.4

CS3 312 15.6

CS4 428 21.4

More Data =

Less Error Correction

Nokia GPRSPCU1

•CS1 & CS2 – Implemented in all Nokia BTS without HW change

•CS3 & CS4 – S11.5 (with PCU2) and UltraSite BTS SW CX4.1 CD1 (Talk is supporting CS1 and CS2)

Data

Err

or

Corr

ect

ion

GPRS Coding Schemes

Nokia GPRSPCU2



CS-1

CS-2

CS-3

57 57 57 57 57 57 57 57

456 bits

MAC

USF BCS +4

puncturing

rate a/b convolutional coding

CS-1 CS-2 CS-3

RLC/MAC Block Size: 181 268 312

Block Check Sequence: 40 16 16

Precoded USF: 3 6 6

1/2 ~2/3 ~3/4

length: 456 588 676

0 132 220

Data rate (kbit/s): 9.05 13.4 15.6

interleaving

MAC

USF BCS

RLC/MAC Block Size: 428

BCS Size: 16

Precoded USF: 12

Data rate (kbit/s): 21.4

CS-4

20 ms

GPRS Coding Schemes



EGPRS Modulation and Coding Schemes

• EGPRS has nine basic coding schemes, MCS-1...9.

• In general, a higher coding scheme has higher coding rate, and consequently higher peak throughput, but it also tolerates less noise or interference.

• The figure shows throughput vs. C/I of EGPRS coding schemes in TU50iFH, without incremental redundancy.

• The basic unit of transmission is radio block (= 4 bursts = 20 ms on average), which contains one or two RLC blocks.

0

10

20

30

40

50

60

0 5 10 15 20 25 30

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

Frequency Hopping Network

Frequency Hopping Network



EGPRS Modulation and Coding Schemes

EGPRS modulation and coding schemes:

Scheme Code rate Header Code rate

Modulation RLC blocks per Radio

Block (20ms)

Raw Data within one

Radio Block

Family BCS Tail payload

HCS Data rate kb/s

MCS-9 1.0 0.36 2 2x592 A 59.2

MCS-8 0.92 0.36 2 2x544 A 54.4

MCS-7 0.76 0.36 2 2x448 B

2x12 2x6

44.8

MCS-6 0.49 1/3 1 592 544+48

A 29.6 27.2

MCS-5 0.37 1/3

8PSK

1 448 B 22.4

MCS-4 1.0 0.53 1 352 C 17.6

MCS-3 0.80 0.53 1 296 272+24

A 14.8 13.6

MCS-2 0.66 0.53 1 224 B 11.2

MCS-1 0.53 0.53

GMSK

1 176 C

12

6

8

8.8

NOTE: the italic captions indicate the padding.

Ref: TS 03.64



EGPRS Data Treatment Principle in RF Layer

User data

"Additional info" that does not require extra protection

Header part, robust coding for secure transmission

Adding redundancy

Puncturing of the coded info



EGPRS Channel Coding (MCS-9)

• EGPRS channel coding consistsof separate data and headercoding, as shown in the figurefor MCS-9 downlink.

• Coding of data part:• Data part includes user

data, two information from RLCheader, BCS (block check sequence)and tail bits.

• Coded using 1/3 convolutional code.

• Punctured with a selectable puncturing scheme (P1, P2 or P3).

• Two separate data parts for MCS-7...9.

• Header part:• Includes RLC/MAC header information and

information on the coding of the data part (like used puncturing scheme).

• Convolutional coding + puncturing.

USF

encoded USF P2 P3

P1 P2 P3

puncturing puncturing

1st burst2nd burst3rd burst4th burst

1/3 tailbitingconvolutional coding

block coding

P1

header FBI+E

data 2 BCStail

1/3 convolutional coding

mother code

protected

header

4 TDMA bursts = 20 ms

FBI+E data 1

mother code

BCStail

puncturing

1/3 convolutional coding



Interleaving over 2 bursts(header: 4 bursts)

Decreasing redundancy

Adding redundancy

EGPRS Channel Coding (MCS-9)

P2 P3P1 P2

puncturingpuncturing

1836 bits

USF RLC/MACHdr.

36 bits

Rate 1/3 convolutional coding

135 bits

612 bits

612 bits124 bits36 bitsSB = 8

1392 bits

45 bits

Data = 592 bits BCS TB

612 bits

612 bits 612 bits

1836 bits

Rate 1/3 convolutional coding

EFBIData = 592 bits BCS TBEFBI

612 bits 612 bits 612 bits

P3 P1

3 bits

HCS

puncturing

Ref: TS 03.64

1 1 12 6

Data rate:

skbms

/2,5920

5922

Robust coding for header

Normal burst: 2x58x3 bits




BP: 15/26 ms BP: 15/26 ms BP: 15/26 ms BP: 15/26 ms

skbms

/6,6920

1392

20 ms



EGPRS MCS Families

37 octets 37 octets 37 octets37 octets

MCS-3

MCS-6

Family A

MCS-9


MCS-2

MCS-5

MCS-7

Family B

22 octets22 octets

MCS-1

MCS-4

Family C

34+3 octets34+3 octets

MCS-3

MCS-6Family A padding

MCS-8


• The MCSs are divided into different families A, B and C

• Each family has a different basic unit of payload: 37 (and 34), 28 and 22 octets respectively.

• Different code rates within a family are achieved by transmitting a different number of payload units within one Radio Block.

• For families A and B, 1 or 2 or 4 payload units are transmitted, for family C, only 1 or 2 payload units are transmitted

• When 4 payload units are transmitted (MCS 7, MSC-8 and MCS-9), these are splitted into two separate RLC blocks (with separate sequence BSN numbers and BCS, Block Check Sequences)

• The blocks are interleaved over two bursts only, for MCS-8 and MCS-9.

• For MCS-7 the blocks are interleaved over four bursts



GPRS Link Adaptation (with PCU1)

• The Link Adaptation (LA) algorithm selects the optimum channel coding scheme (CS-1/CS-2) for a particular RLC connection to provide the highest throughput and lowest delay available

• In PCU1 the algorithm is based on detecting the occurred RLC block errors and calculating the block error rate (BLER)

• The coding scheme will change based on set BLER thresholds defined in simulations and changing from hopping to non hopping networks

• A new LA algorithm is introduced in BSS11.5 with PCU-2



EGPRS Link Adaptation & Incremental RedundancyLink Adaptation (LA)• The task of the LA algorithm is to select the

optimal MCS for each radio condition to maximize RLC/MAC data rate, so the LA algorithm is used to adapt to situations where signal strength and or C/I level is low and changing slowly with time

• RLC selects the data block and additionally selects the MCS depending on radio link quality and amount of available dynamic Abis channels

• LA is done independently for each UL and DL TBF on RLC/MAC block level, but the LA algorithm is same for uplink and downlink

• The MCS selection is not the same in case of initial transmission and retransmission (IR)

• LA algorithm works differently for acknowledged mode and unacknowledged mode

• RLC control blocks are transmitted with GPRS CS-1 coding

0

10

20

30

40

50

60

0 5 10 15 20 25 30


Link Adaptation



Incremental Redundancy (IR)• IR is a combination of two techniques:

• Automatic Repeat reQuest (ARQ)

• Forward Error Correction (FEC)

• In the ARQ method the receiver detects the errors in a received RLC block and requests and receives a re-transmission of the same RLC block from the transmitter. The process continues until an uncorrupted copy reaches the destination

• The FEC method adds redundant information to the re-transmitted information at the transmitter and the receiver uses the information to correct errors caused by disturbances in the radio channel

• IR needs no information about link quality to in order to protect the transmitted data but can increase the throughput due to automatic adaptation to varying channel conditions and reduced sensitivity to link quality measurements

Data block

P1 P2 P3

One MCS

1. transmission

1st re-transmission upon reception

failure

2nd re-transmission upon reception failure

Transmitter

Receiver

P2 P3P1

P1

P1

P1

P2

P2 P3

Protection level 1

Combination: Protection level x 2

Combination: Protection level x 3

No data recovered

Stored

Stored

No data recovered

Stored

EGPRS Link Adaptation & Incremental Redundancy



• Normally, LA adapts to• path loss

• shadowing

• Incremental Redundancy is better suited to compensate fast fading

• The retransmission process is based on IR

• LA must take into account• if IR combining is performed at the receiver

• the effect of finite IR memory

EGPRS Link Adaptation & Incremental Redundancy



Modulation and Coding Schemes - MCS Selection• The link adaptation algorithm is based on Bit Error Probability (BEP)

measurements performed at the MS (downlink TBF) and the BTS (uplink TBF)

• In acknowledged mode, the algorithm is designed to optimize channel throughput in different radio conditions

• In unacknowledged mode, the algorithm tries to keep below a specified Block Error Rate (BLER) limit

• The MCS selection can be divided in four classes:

• Initial MCS to be used when entering packet transfer mode

• Modulation selection

• MCS selection for initial transmissions of each RLC block in ACK mode

• MCS to be used for re-transmissions



Modulation and Coding Schemes - MCS Selection• In DL case the MCS selection is based on EGPRS Channel Quality Report

received in EGPRS PACKET DOWNLINK ACK/NACK message sent from the MS to network using PACCH to indicate the status of the downlink RLC data blocks received.

• The MCS selection is based on using the BEP (Bit Error Probability) measurement data

• In UL case the MCS selection is based on the respective BEP measurement values which are received within the UL PCU frames



(E)GPRS Resource Allocation - Content

Territory method

• Default and dedicated territory

• Free TSLs

Cell selection and re-selection

• C1, C2, C31/32, NCCR

BTS selection

• MultiBCF and CBCCH

TSL Allocation

• Scheduling with priority based QoS



Territory Method

• Territory method is used to divide the CS and PS resources• Timeslots within a cell are dynamically divided into the CS and (E)GPRS

territories

• Number of consecutive traffic timeslots in (E)GPRS territory are reserved (or initially available) for (E)GPRS traffic, the remaining timeslots are available for GSM voice

• The dynamic variation of the territory boundary are controlled by territory parameters

• The system is able to adapt to different load levels and traffic proportions, offering an optimized performance under a variety of load conditions

• The PS territory can contain dedicated, default and additional capacity• Dedicated capacity: number of timeslots are allocated to (E)GPRS on a permanent

basis i.e. are always configured for (E)GPRS and cannot be used by the circuit switched traffic. This ensures that the (E)GPRS capacity is always available in a cell

• Default capacity: the (E)GPRS territory is an area that always is included in the instantaneous (E)GPRS territory, provided that the current CS traffic levels permit this

• Additional capacity= Additional (E)GPRS capacity means the extra time slots beyond the default capacity which are assigned due to a load demand.



Territory Method

TRX 1

TRX 2

BCCH TS TS TS TS TS TSSDCCHBCCH TS TS TS TS TS TSSDCCHBCCH TS TS TS TS TS TSSDCCH

TS TS TSTS TSTS TS TSTS TSTS TS TS TSTS TS TSTS

TS

TS

= (E)GPRS Territory/Dedicated capacity

= CSW Territory

TS= (E)GPRS Territory/Additional capacity

BCCH= Signaling

TS = Free TSL for CSW

TS= (E)GPRS Territory/ Default capacity

Territory border



Cell Selection / Re-selection

• The network may request measurement reports from the MS and control its cell re-selection

• Depending on the NC (Network Control) mode set by the network, the MS shall behave as follows:

• NC0: Normal MS control; the MS shall perform autonomous cell re-selection

• NC1: MS control with measurement reports; the MS shall send measurement reports to the network and shall perform autonomous cell re-selection

• NC2: Network control; the MS shall send measurement reports to the network

• NC1 and NC2 only apply in MM (Mobility Management) Ready state. In MM Standby state, the MS shall always use NC0 mode independent of the ordered NC mode



Cell Selection / Re-selection - NC0/NC1

• MS cell selection/re-selection is controlled by the following criteria

• Path loss criterion (C1)

• Cell reselection criteria (C2)

• These criteria are used for the cell selection for (E)GPRS in the same way as for CSW in idle mode

• C31/C32 are introduced as a complement to the current GSM cell re-selection criteria

• The activation requires the implementation of PBCCH

• C31: Signal Strength threshold criterion

• C32: Cell ranking

• MS selects the cell with the highest C32 value from those having the highest priority class and fulfilling the C31 criterion (if none fulfills C31, then only C32)

• The priority classes may correspond to different HCS layers



Cell Selection / Re-selection - NCCR (NC2)

• NCCR (Network Controlled Cell Re-selection) (S11.5)• Enables the network to order a cell re-selection instead of the

autonomous selection done by the mobile station

• The network may command the MS to change cell and decides which cell is to be the target cell

• Efficient allocation of EGPRS resources:• The PCU will push EGPRS capable MSs to EGPRS cells and GPRS capable

MSs to non-EGPRS capable cells by power budget

• Cell attractiveness can be defined neighbour cell specifically also taking into account the capabilities of each neighbour cell (e.g. CS-3/CS-4)

• Can be based on the following criteria:• Power budget pushes EGPRS capable MSs to EGPRS cells and non-EGPRS

capable MSs to non-EGPRS capable cells

• Quality control triggers NCCR when the quality of the serving cell transmission drops even if the serving cell signal level is good



Cell Selection / Re-selection - NACC

• NACC (Network Assisted Cell Change) (S11.5)• Reduces service outage time when a Rel-4 capable GPRS MS moves

between GSM cells in packet transfer mode

• Improves both autonomous and network-controlled cell change• In a cell change the MS has to stop data transmission in the serving cell

and has to acquire certain system information from the target cell

• After this the MS has to restart the data transmission in the new cell

• This causes a delay as the MS has to synchronise with the system information broadcast cycle and collect a consistent set of System Information and Packet System Information messages from the target cell

• Outage time is reduced because the network is allowed to assist MSs before and during the cell change by

• sending neighbour cell system information on the packet associated control channel (PACCH) to the MS in packet transfer mode on the serving cell

• introducing the PACKET SI STATUS procedure for the cells that have no packet broadcast control channel (PBCCH)



Cell Selection / Re-selection - NACC

• NACC (Network Assisted Cell Change)• Neighbour cell system information messages sent to the MS contain a

set of SI or PSI messages (with PBCCH) needed in performing packet access in the new cell

• When all required messages are sent to the MS and PACKET SI STATUS is supported by the PCU (no PBCCH allocated) in the new cell, the MS may perform packet access and use PACKET SI STATUS procedures for the acquisition of SI messages

Without PBCCH network will send MS

SI1, SI3 and SI13 of neighbour cells

PACKET NEIGHBOUR CELL DATA (PACCH ).

With PBCCH, network will send MS

PSI TYPE 1, a consistent set of PSI TYPE 2

messages and PSI TYPE 14



NACC for NC0 / NC1 - CCN Mode

• A new mode, Cell Change Notification (CCN), is needed for a MS in NC0 mode in order to make use of NACC feature

• MS in NC0 mode can enter CCN mode

• MS must be in Transfer Mode

• Both NW and the MS must support CCN

• The serving and the target neighbor cell must support CCN mode

• The CCN Activity support info is in: • SI13 , PSI1 and PSI14 for serving cell

• SI2quater , PSI3 and PSI3bis for the neighbor cell

The support for CCN implies also that it is mandatory for the mobile station to support the Packet PSI/SI Status procedures



EDAP, PCU and Gb Functionality - Content

EDAP

• Abis vs. Dynamic Abis

• Channels carried on EDAP

• EDAP limits

• Abis PCM structure

PCU

• PCU procedures

• PCU types and limits

Gb

• Gb protocols

• Gb over FR

• Gb over IP



Abis Basic Concepts – PCM frame (E1)

One 64 kbit/s (8 bits) channel in PCM frame is called timeslot (TSL)One 16 kbit/s (2bits) channel timeslot is Sub-TSLPCM frame has 32 (E1) or 26 (E1) TSLs

One Radio timeslot corresponds one 16 kbit/s Sub-TSL (BCCH, TCH/F etc.) and one TRX takes two TSLs from Abis

0 MCB LCB123456789

101112131415161718 TCH 0 TCH 1 TCH 2 TCH 319 TCH 4 TCH 5 TCH 6 TCH 7202122232425 TRXsig2627 BCFsig28293031 Q1-management

One TRX has dedicated TRXsig of 16, 32 or 64 kbit/s

One BCF has dedicated BCFsig (16 or 64 kbit/s) for O&M

TRX1

Q1-management needed if TRS management under BSC

MCB/LCB required if loop topology is used

AbisBTS BSC



(E)GPRS Dynamic Abis Pool – EDAP Introduction• Fixed resources for signaling and voice• Dynamic Abis pool (DAP) for data

• Predefined size 1-12 PCM TSL per DAP

• DAP can be shared by several TRXs in the same BCF (and same E1/T1)

• Max 20 TRXs per DAP• Max 480 DAPs per BSC• DAP + TRXsig + TCHs have to be

in same PCM• UL and DL EDAP use is

independent• DAP schedule rounds for each

active Radio Block• Different users/RTSLs can use

same EDAP Sub-TSL

0 MCB LCB1234 TCH 0 TCH 1 TCH 2 TCH 35 TCH 4 TCH 5 TCH 6 TCH 76 TCH 0 TCH 1 TCH 2 TCH 37 TCH 4 TCH 5 TCH 6 TCH 78 TCH 0 TCH 1 TCH 2 TCH 39 TCH 4 TCH 5 TCH 6 TCH 7

101112131415 EDAP EDAP EDAP EDAP16 EDAP EDAP EDAP EDAP17 EDAP EDAP EDAP EDAP18 EDAP EDAP EDAP EDAP19 EDAP EDAP EDAP EDAP20 EDAP EDAP EDAP EDAP21 EDAP EDAP EDAP EDAP22 EDAP EDAP EDAP EDAP232425 TRXsig1 TRXsig226 TRXsig327 BCFsig28293031 Q1-management

TRX1

TRX2

TRX3

EGPRS

pool



Dynamic Abis - Master and Slave Channels

Master channel

• Fixed TCH Sub-TSL is called master channel

• Master cannel contains user data and inband signalling for TRX

Slave channel

• Located in EDAP

• Contains user data that does not fit in the master data frame

Dynamic Abis Pointer

Each DL PCU master channel includes a pointer to

•DL slave frames on the same block period

•UL slave frames on the next block period

M M

S S S

S S S S

downlink PCMframes during

one block period

uplink PCMframes during

next block period

EDAP



EDGE and GPRS – Master / Slave Channel Usage

Coding scheme

CS-1CS-2CS-3CS-4


Bit rate (bps)

8,0 12,014,420,0

8,8 11,214,817,622,429,644,854,459,2

Abis PCM allocation (fixed + pool/slave)

GPRSand

EDGE

EDGE

• Higher data rates don’t fit in 16 kbit/s channels

• GPRS CS-2 requires 1 slave when EDGE activated (TRX/BTS)

• 32, 48, 64 or 80 kbit/s Abis links per RTSL needed

Retrans.



Nokia Dynamic Abis Dimensioning - with EGPRS Data Traffic

• Fixed master TSL in Abis for all EGPRS air TSL • Slave TSL’s (64 k) in EDAP pool for each air TSL• TRX and for OMU signaling fixed• TSL 0 and 31 typically used for signaling• EDAP pool dimensioning considerations

• Planned throughput in radio interface

RTSL territory size MS multiclass

• Number of TRXs/BTSs connected to DAP• Total number of PCU Abis Sub-TSLs • Gb link size• GPRS/EDGE traffic ratio

0 MCB LCB1 TCH 0 TCH 1 TCH 2 TCH 32 TCH 4 TCH 5 TCH 6 TCH 73 TCH 0 TCH 1 TCH 2 TCH 34 TCH 4 TCH 5 TCH 6 TCH 75 TCH 0 TCH 1 TCH 2 TCH 36 TCH 4 TCH 5 TCH 6 TCH 77 TCH 0 TCH 1 TCH 2 TCH 38 TCH 4 TCH 5 TCH 6 TCH 79 TCH 0 TCH 1 TCH 2 TCH 310 TCH 4 TCH 5 TCH 6 TCH 711 TCH 0 TCH 1 TCH 2 TCH 312 TCH 4 TCH 5 TCH 6 TCH 7

13 TRXsig 1 TRXsig 214 TRXsig 3 TRXsig 415 TRXsig 5 TRXsig 616 BCFsig171819 EDAP1 EDAP1 EDAP1 EDAP120 EDAP1 EDAP1 EDAP1 EDAP121 EDAP1 EDAP1 EDAP1 EDAP122 EDAP1 EDAP1 EDAP1 EDAP123 EDAP1 EDAP1 EDAP1 EDAP124 EDAP1 EDAP1 EDAP1 EDAP125 EDAP1 EDAP1 EDAP1 EDAP126 EDAP1 EDAP1 EDAP1 EDAP127 EDAP1 EDAP1 EDAP1 EDAP128 EDAP1 EDAP1 EDAP1 EDAP129 EDAP1 EDAP1 EDAP1 EDAP130 EDAP1 EDAP1 EDAP1 EDAP131 Q1-management

TRX 1

TRX 2

TRX 3

TRX 4

TRX 5

TRX 6

EGPRS DAP



Packet Control Unit (PCU) - Introduction

• BSC plug-in unit that controls the (E)GPRS radio resources, receives and transmits TRAU frames to the BTSs and Frame Relay packets to the SGSN

• Implements both the Gb interface and RLC/MAC protocols in the BSS

• Acts as the key unit in the following procedures:• (E)GPRS radio resource allocation and management

• (E)GPRS radio connection establishment and management

• Data transfer

• Coding scheme selection

• PCU statistics

• The first generation PCUs are optimized to meet GPRS requirements, i.e. non real time solutions (QoS classes "Background" and "Interactive“)

• The second generation PCUs (PCU2) supports the real time traffic requirements and enhanced functionality (GERAN) beyond (E)GPRS



Packet Control Unit (PCU) - Variants and Connectivity Limits• PCU types and capacity limits

• The relations between PCU and BSC types as well as the connectivity limits of BTSs, TRXs, TSLs, Abis and Gb TSLs are shown below

PCU TypeBSC Types Network elements BSS10.5BSS10.5 EDBSS11 BSS11.5PCU BSCE, BSC2, BSCi, BSC2i BTS 64 64 64 64

TRX 128 128 128 128Radio TSLs 256 256 256 128Abis 16 kbps channels 256 256 256 256Gb 64 kbps channels 31 31 31 31

PCU-S BSCE, BSC2, BSCi, BSC2i BTS 64 64 64 64TRX 128 128 128 128Radio TSLs 256 256 256 128Abis 16 kbps channels 256 256 256 256Gb 64 kbps channels 31 31 31 31

PCU-T BSCE, BSC2, BSCi, BSC2i BTS 64 64 64 64TRX 128 128 128 128Radio TSLs 256 256 256 256Abis 16 kbps channels 256 256 256 256Gb 64 kbps channels 31 31 31 31

PCU2-U BSCE, BSC2, BSCi, BSC2i BTS N/A N/A N/A 128TRX N/A N/A N/A 256Radio TSLs N/A N/A N/A 256Abis 16 kbps channels N/A N/A N/A 256Gb 64 kbps channels N/A N/A N/A 31

PCU-B BSC3i BTS 2 x 64 2 x 64 2 x 64 2 x 64TRX 2 x 128 2 x 128 2 x 128 2 x 128Radio TSLs 2 x 256 2 x 256 2 x 256 2 x 256Abis 16 kbps channels 2 x 256 2 x 256 2 x 256 2 x 256Gb 64 kbps channels 2 x 31 2 x 31 2 x 31 2 x 31

PCU2-D BSC3i BTS N/A N/A N/A 2 x 128TRX N/A N/A N/A 2 x 256Radio TSLs N/A N/A N/A 2 x 256Abis 16 kbps channels N/A N/A N/A 2 x 256Gb 64 kbps channels N/A N/A N/A 2 x 31



BSC Types

• BSC types and capacity limits

• The 75 % utilization of the connectivity is recommended by Nokia

• The number of BCSUs are limiting the max number of PCUs

BSC2i BSC3i BSC3i BSC3i BSC3i BSC3i

Max BCSUs Working 8 2 3 4 5 6

BCSU_Spare 1 1 1 1 1 1

Max PCUs Working (logical) 16 8 12 16 20 24

PCUs_Spare (logical) 2 4 4 4 4 4

Max_RTLs 4096 2048 3072 4096 5120 6144

TRX_MAX 512 110 220 330 440 660

BTS_MAX 512 110 220 330 440 660

BCF_MAX 248 504 504 504 504 504



Gb Interface - Introduction

• The Gb interface is the interface between the BSS and the Serving GPRS Support Node (SGSN)

• Allows the exchange of signaling information and user data

• The following units can be found in Gb• Packet Control Unit (PCU) at the BSS side

• Packet Processing Unit (PAPU) at the GPRS IP backbone side

• Each PCU has its own separate Gb interface to the SGSN

BSC

PCU

BSS

SGSN

PAPU

GPRS

Gb



Gb Interface

• Allow many users to be multiplexed over the same physical resource

• Resources are given to a user upon activity (sending/receiving)

• GPRS signaling and user data are sent in the same transmission plane and no dedicated physical resources are required to be allocated for signaling purposes

• Access rates per user may vary without restriction from zero data to the maximum possible line rate (e.g., 1 984 kbit/s for the available bit rate of an E1 trunk)

BSC

PCU

BSS

SGSN

PAPU

GPRS

Gb



Gb Interface - Protocols

• The Gb interface can be implemented using the Frame Relay or IP

L1

L2

IP

UDP

GTP

USERPAYLOAD

GGSN

L1

L2

IP

GPRS Bearer

GGSN

Relay

IP

GPRS IP Backbone

L1

L2

IP

GTP

L1bis

NS

BSSGP

SNDCP

LLC UDP

SGSN

Relay

Gn

Internet

L1

L2

IP

TCP/UDP

APP

Gi

User information transferUser information transfer

LLC

SNDCP

IP

TCP/UDP

APP

RLC

MAC

GSM RF

MS

RLC

MAC

GSM RF

BSSGP

NS

L1bis

BSS

Ciphering and reliable link

Um Gb

Compression, segmentation

FIXED HOST



Gb Interface - Protocols

• The protocol stack consists of three layers• Physical layer (L1)

• Network Service (NS) layer

• Base Station System GPRS Protocol (BSSGP)

• L1 is implemented as one or several PCM-E1 lines

• Network Service (NS) layer is divided into frame relay (FR) and network service control

• L1= Physical layer

• NS= Provides the capability for the transmission of signals between user-network interfaces

• BSSGP= Conveys routing information and QoS related information between BSS and SGSN



Gb Interface - FR

• The Gb interface can be implemented using the Frame Relay or IP

• The Frame Relay can be :• Point-to-point (PCU–SGSN)

• spare capacity of Ater and A interfaces

• any transmission network

• Frame relay network between the BSC and SGSN

• In Frame Relay there are different options available:• Voice and data multiplexed

• Voice and data separated in the transcoder

• Channels going through the transcoders and MSC

• Traffic streams concentrated in the FR switch

• Dedicated 2 Mbit/s E1 PCM links

BSC

MSC

TC

SGSN

MUX

Gb

GbGb



Gb Interface - IP

• The increased demand for packet switched traffic transmission cost efficiency can be met by deploying IP in the transmission network

• IP offers an alternative way to configure the subnetwork of the Gb interface:• the subnetwork is IP-based and the physical layer is Ethernet

• The introduction of IP makes it possible to build an efficient transport network for the IP based multimedia services of the future

• Both the IPv6 and IPv4 protocol versions are supported

• IP transport can be used in parallel with FR under the same BSC and BCSU

• Within one BCSU, separate PCUs can use different transmission media



Gb Interface - IP

• Gb over IP is an application software product and requires a valid license in the BSC

• The licensing is based on the number of PCUs to which IP Network Service Entities can be configured

• Requires support from both BSC and SGSN

• In the BSC, the capacity of the Gb interface remains the same, regardless of whether IP or FR is used as the transport technology

SGSN

Gb

IPBTS

BTS

BSC

FR



(E)GPRS Explain

FunctionalityNetwork AuditNetwork Dimensioning and PlanningNetwork OptimizationTools



Network Audit - Content

Hardware Audit

Software, Parameter and Feature Audit

GSM Coverage / Interference Audit



Network Audit - Introduction

• Before (E)GPRS implementation a full network audit is proposed to clarify the network status

• The audit helps to avoid HW, SW and feature interoperability issues

• The audit should preferably contain the following areas:

• BSS HW audit

• BSS SW/ features audit

• Coverage and interference audit



Network Audit - Hardware

• HW audit contains:• BSC types

• PCU and PCU2

• BTS types

• TRX capability (GPRS/EGPRS)

• Abis capability

• Gb interface

• SGSN, PAPU



BSS Network Analysis – Hardware Audit

• BTSs with (E)GPRS (CS1-4) capability• (E)GPRS capability of BTSs (BTS SW support)

• TALK roadmap does not have CS3-4 capability currently

• Baseband unit limits in UltraSite

Base Band Unit and TRX type Functionality

BB2A + TSxA Ok

BB2A + TSxB Not Ok

BB2E + TSxA Ok

BB2E + TSxB Ok

BB2F + TSxA Ok

BB2F + TSxB Ok

Talk InSite PrimeSite MetroSite UltraSiteGSM Ok Ok Ok Ok OkGPRS CS1-2 CS1-2 CS1-2 CS1-2 (* CS1-2 (*EGPRS No No No MCS1-9 MCS1-9(* CS1-4 with PCU2 and BTS SW 4.1 CD1



BSS Network Analysis – Hardware Audit

• TRX capability (mixture of GPRS and EGPRS TRXs)• TALKFAMILY TRXs are GPRS capable only.

• UltraSite and MetroSite TRX capability

Frequency band TSxA TSxB

GSM 900 TSGA N/A

GSM 1800 TSDA N/A

GSM 1900 TSPA N/A

GSM/EDGE 800 N/A TSTB

GSM/EDGE 900 N/A TSGB

GSM/EDGE 1800 N/A TSDB

GSM/EDGE 1900 N/A TSPB

Output power Frequency band Unit type Notes

5 W GSM 900 HVTG Standard filter

5 W GSM 900 HVTJ Customer specific filter J

5 W GSM 900 HVTH Customer specific filter H

5 W GSM 1800 HVTD Standard filter

5 W GSM 1900 HVTP Standard filter

5 W GSM/EDGE 800 WTFA Standard filter

10 W GSM/EDGE 900 CTGA Standard filter

10 W GSM/EDGE 900 CTGJ Customer specific filter J

10 W GSM/EDGE 900 CTGH Customer specific filter H

10 W GSM/EDGE 1800 CTDA Standard filter

5 W GSM/EDGE 1900 WTPA Standard filter

- - VTSA Transceiver shield unit



Network Audit – Software and Feature

• BSS SW/feature audit contains:

• MultiBCF and Common BCCH

• FR/DR/HR

• AMR

• RF and BB Hopping

• IUO/IFH

• Extended Cell

• BSS SW/feature considerations:• PBCCH (Packet BCCH)

• NMO (Network Mode of Operation I or II)

• EPCR (EGPRS Packet Channel Request)

• NACC (Network Assisted Cell Change)

• NCCR (Network Controlled Cell Re-selection)

• DFCA

• QoS

• CS3-4



GSM Network Audit– Coverage & Interference

• The coverage and interference must be analyzed because the TSL data rate is defined by coverage and interference as well

• The average signal level of a cell/segment must be estimated for calculating the TSL data rate based on sensitivity

• The following methods can be used in the analysis:• Planning tool plots

• Drive test measurements

• Network measurements

RLC/MAC Data Rate (FTP Download on 2 TSLs)

0

20

40

60

80

100

120

-65 -70 -75 -80 -85 -90 -95 -100 -105

Signal level (dBm)

kbp

s

No Interference

C/I 25 dB

C/I 20 dB

C/I 15 dB



(E)GPRS Explain




Network Dimensioning and Planning - Content

Coverage and Interference Planning

Capacity Planning (Deployment, TSL Data Rate and BSS connectivity)

Dimensioning Example

Mobility Planning



Coverage and Interference Planning

Coverage Planning with Link Budget

Frequency Planning



(E)GPRS Coverage Planning and Link Budget

• The (E)GPRS coverage area depends on the GSM service area

• The coverage planning aspects concern the provision of sufficient C/N ratios across the coverage area to allow for successful data transmission (UL/DL)

• Each coding scheme is suited to a particular range of C/N (or Eb/No) for a given block error rate (BLER)

• The higher the level of error protection, the lower required C/N

• Due to the different C/N requirements the relative coverage area of the coding schemes is different:

• The MCS-5 coverage is approx 50% of MCS-1, while MCS-8 coverage is approx 40% of MCS-5

• In urban areas coverage is not usually the limiting factor but the interference caused by reused frequencies -> C/I requirements



(E)GPRS Coverage Planning and Link Budget

(E)GPRS Coverage Relative to MCS-5 (Noise limited)2.5

2

1.5

1

0.5

0

Rela

tive R

an

ge

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



Link Budget Calculation – Voice/ (E)GPRS

Receiving End• Sensitivity

• Additional fast fading margin

• Connector, cable and body loss

• Antenna gain

• MHA and diversity (space, IUD, IDD) gain

Transmitting End• Output power

• Back-off

• Isolator, combiner and filter loss

• Connector, cable and body loss

• Tx Antenna gain

Cell Range• BS and MS antenna

height

• Standard deviation

• Building penetration loss (BPL)

• BPL deviation

• Area Type correction factor

• Location probability

BTS Area• k*R²



(E)GPRS Link Budget – Receiving and Transmitting End

RADIO LINK POWER BUDGETMacro MacroCityTalk UltraSiteUrban Urban

MS CLASS 4 EDGE

SYSTEM MHz 2 GSM 900 GSM 900

* Z = 77.2 + 20*log(freq[MHz]) 136,28485 136,285RECEIVING END: BS MS BS MS

RX RF-input sensitivity (as GSM05.05) for speech dBm -109,0 -102,00 -108.5 -102,00

TP TPIRThroghput kbit/s 20,16 20,30

Eb/No Eb/No Es/No BLER w/oIR

Es/No,Eb/No [dB] | BLER [%] w/o IR 6,00 6,00 15,76 10,00Required signal power (sensitivity) S = BTS noise Power + Es/No dBm -109 -102 -100,31 -93,91

Addit fast fading marg (voice+CSdata) dB 2,00 2,00Cable loss + connector dB 2,00 0,00 2,00 0,00Body loss dB 0,00 0,00 0,00 0,00Rx antenna gain dBi 18,00 0,00 15,00 2,00MHA Gain dB 0,00 0,00Diversity gain dB 4,00 0,00 4,00 1,00Isotropic power dBm -127,0 -100,0 -117,3 -97,9Field strength dBµV/m 9,28 36,28 18,97 38,37

TRANSMITTING END: MS BS MS BS

TX RF output peak power (GMSK) W 1,00 28,18 2,00 28,18(mean power over RF cycle) dBm 30,00 44,50 33,00 44,50Backoff for 8-PSK 0,00 0,00 6,00 2,00Isolator + combiner + filter dB 0,00 3,80 0,00 2,00RF-peak power, combiner output dBm 30,0 40,7 27,0 38,8

Cable loss + connector dB 0,00 2,00 0,00 2,00Body Loss 0,00 0,00 0,00 0,00IDD 1,00TX-antenna gain dBi 0,00 18,00 2,00 15,00Peak EIRP W 1,00 467,74 0,79 302,00(EIRP = ERP + 2dB) dBm 30,00 56,70 29,00 54,80Isotropic Path Loss Uplink / Downlink 157,00 156,70 146,31 152,71Isotropic path loss dB 156,7 152,7

EPR 295,12092 190,54607

900

2:1 WBC

ON

URBAN



(E)GPRS Link Budget - Cell Range For Indoor and Outdoor

CELL SIZESCOMMON INFO Macro

MS antenna height (m): 1.5

BS antenna height (m): 25.0

Standard Deviation (dB): 7.0

BPL Average (dB): 15.0

BPL Deviation (dB): 10.0OKUMURA-HATA (OH)

Area Type Correction (dB) 4.0

INDOOR COVERAGE Macro

Propagation Model OH

Slow Fading Margin + BPL (dB): 26.7Coverage Threshold (dBµV/m): 63.0Coverage Threshold (dBm): -73.3Location Probability over Cell Area(L%): 95%

Cell Range (km): 0.91

OUTDOOR COVERAGE Macro

Propagation Model OH

Slow Fading Margin (dB): 7.4

Coverage Threshold (dBµV/m): 43.6Coverage Threshold (dBm): -92.6Location Probability over Cell Area(L%): 95%

Cell Range (km): 3.16

Cell Area (km2)

3-sector (K=1.95) 19.442-sector (K=1.3) 12.96Omni (K=2.6) 25.92



EGPRS and GPRS Coverage – Comparison

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9 10 11

Pathloss distance [km]

DL

Thro

ughp

ut p

er T

SL

[Kbp

s]

EGPRS

GPRS CS1-2

GPRS CS1-4

Path loss [dB]120.8 132.1 138.8 143.5 147.1 150.1 152.6 154.8 156.7 158.4 160.0

Average

gain: 3.6

Average

gain: 2.3

Es/No=8.3 dB

Es/No=42.3 dB



Frequency Planning

•The TSL data rate is C/I dependent

•Lower C/I can reduce the TSL data rate significantly

•The figure shows that the TSL data rate is around 25 kbps if the C/I is 15 dB.

•The proper frequency plan of GSM network is very important to maximize TSL data rate

C/I

Th

rou

gh

pu

t

With Impairments



Frequency Planning

Combined interference and noise estimations needed for (E)GPRS link budget

Frequency allocation and C/I level• The existing frequency allocation has high impact on EGPRS performance• Loose re-use patterns will provide better performance for all MCSs

Data rate and network capacity• EGPRS highest data rates require high C/I, typ > 20dB for MCS-7, 8 & 9• Possibly no extra spectrum for EDGE so efficient use of the existing spectrum is very

important• EGPRS traffic suited to BCCH use - typically the layer with highest C/I. But limited no. of TSLs

available on BCCH; may need to use TCH layer too

Sensitivity in tighter reuse and higher load• EDGE can utilize tighter reuse schemes and this is beneficial when planning for high load with

limited frequency resources• For systems with stringent spectrum constraints, EGPRS can offer good performance even

with tight re-use patterns (1/3 or 3/9). Load dependent



Data rate vs. CIR in Time (Field Measurement)

0

20

40

60

80

100

120

140

0 10 20 30 40

Time (s)

Th

rou

gh

pu

t (k

bp

s)

0

5

10

15

20

25

CIR

(dB

)

Data ThroughputApplication Throughput

TEMS-C/I-GMSKPoly. (TEMS-C/I-GMSK)

Good quality environment




0

20

40

60

80

100

120

0 10 20 30 40 50 60 70

Time (s)

Th

rou

gh

pu

t (k

bp

s)

0

5

10

15

20

25

CIR

(dB

)



Average quality environment




0

10

20

30

40

50

60

70

80

0 50 100 150

Time (s)

Th

rou

gh

pu

t (k

bp

s)

0

2

4

6

8

10

12

14

16

18

20

CIR

(dB

)



Worse quality environment



Capacity Planning

Deployment Scenarios

Air Interface Capacity

Connectivity Planning



• The aim behind the preparation of deployment plan• Adapt the existing network configuration for (E)GPRS

• Maximize the TSL data rate (RLC/MAC) and multislot usage

• Minimize the impact of PSW services on CSW services (and vice versa)

• Take all the hardware and software considerations into account

• Controlled investment

• Most of the networks can be described by few cell/segment options

• The analysis of the different options can give exact picture about the network based on:

• Hardware types, software releases

• Features, parameters

• Current network structure and functionality

• Coverage, quality and capacity characteristics of BSS

Deployment Planning



Deployment Plan - Cell / Segment Option Creation

Cell / Segment option examplesLayer strategy BTSs TRXs TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7 PSW terr.

TRX1 BCCH TCH/D TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX2 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTRX3 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F Default Default (E)GPRS

Layer strategy BTSs TRXs TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7TRX1 CBCCH SDCCH TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX2 TCH/F TCH/F TCH/F TCH/F Default Default Default Dedicated (E)GPRS

Layer2 CSW only BTS2 TRX3 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F

Layer strategy BTSs TRXs TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7TRX1 CBCCH SDCCH TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX2 TCH/F TCH/F TCH/F TCH/F TCH/F Default Default Dedicated GPRS

Layer2 CSW, EGPRS BTS2 TRX3 TCH/F TCH/F TCH/F TCH/F Default Default Default Dedicated EGPRS

Layer strategy BTSs TRXs TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7 TSL8 PSW terr.TRX1 CBCCH SDCCH TCH/F TCH/F Default Default Default Dedicated EGPRSTRX2 TCH/D TCH/D TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX3 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTRX4 TCH/F TCH/F TCH/F TCH/F Default Default Default Dedicated GPRS

Cell / Segment option 2

BTS1CSW, GPRS, EGPRSLayer1Cell / Segment option 1

BTS1

BTS1Cell / Segment option 4

CSW, EGPRS

Cell / Segment option 3

Layer1

Layer1 CSW, GPRS

CSW, GPRSLayer2 BTS2

Layer1 CSW, (E)GPRS BTS1

• The options can cover most of the cell/segment configurations of the network

• These options can be analyzed in details, so the time consuming cell/segment based analysis is not needed

• All the options are examples and can have different channel configuration



Deployment Plan - Cell / Segment Option 1 Analysis• Layer strategy

• No multiBCF/CBCCH

• GPRS and EGPRS have the same territory – data rate degradation due to multiplexing

• There is not any dedicated territory (CDED) – The implementation of NMO1 is not recommended, because the MS cannot paged if there is not any GPRS territory

• GPRS Enabled is a must for all the cells with NMO1

• Signaling strategy

• Combined signaling structure – load check is needed

• TCH usage (CSW)

• TRX1 has TCH/D TSLs - which can lead to heavy signaling.

• The CSW calls will be allocated to FR firstly.

• AMR packing – more capacity for PSW traffic

• TCH usage (PSW)

• CDEF is 2 TSLs only - the 4 TSL DL capable terminals require territory upgrade, which takes time




• The Cell / Segment Option 2 has segment configuration. • GPRS and EGPRS have the same territory possibility for GPRS-EGPRS multiplexing• The PSW territory has 4 TSLs for 4 TSL DL capable terminals.• Dedicated territory for providing PSW services even when CSW traffic high • NMO1 well supported• Layer 2 is used for CSW traffic only with as high utilization as possible (GENA = N).

• Signaling• SDCCH has enough capacity for RA/LA cell-reselection (used only if NMO1 is not

implemented)• The SDCCH TSL is reducing the available capacity for user traffic.

• TCH (CSW)• TRX1 has TCH/D TSLs, which can lead to heavy signaling – TRXsig size• AMR packing

• More time slots available for (E)GPRS traffic without more hardware • Bad C/I - AMR HR quality might suffer

• TCH (PSW)• GPRS and EGPRS multiplexing likely – impact depends on the penetration of GPRS and

EGPRS users and CSW traffic• There is dedicated territory provides minimum PSW capacity for cell




• The Cell / Segment Option 3 has segment configuration. • GPRS and EGPRS have separated territory GPRS-EGPRS multiplexing less likely• EGPRS has 4 TSLs territory for 4 TSL DL capable terminals.• There is dedicated territory for providing PSW services even in high CSW traffic, too.• NMO1 well supported

• Signaling• SDCCH/8 SDCCH has probably enough capacity for RA/LA cell-reselection (if NMO1 is

not implemented)• The SDCCH TSL is reducing the available capacity for user traffic.

• TCH (CSW)• TRX1 has TCH/D TSLs, which can lead to heavy signaling – TRXsig size• AMR packing


• TCH (PSW)• Layer1 has GPRS territory only (EGENA = N) with three TSLs. • Layer2 has the EGPRS territory with 4 TSLs, support for 4 RTSL MSs• Less GPRS - EGPRS multiplexing• Both layers have dedicated territory for minimum PSW capacity




• The Cell / Segment Option 3 has segment configuration. • GPRS and EGPRS have separated territory GPRS-EGPRS multiplexing less likely• Both layers have 4 TSLs territory for 4 TSL DL capable terminals.• There is dedicated territory for providing PSW services even in high CSW traffic, too.• NMO1 well supported• EGPRS territory is allocated to TRX1. It is useful if BCCH frequency has good C/I

• Signaling• The SDCCH has enough capacity for RA/LA cell-reselection if NMO1 is not implemented.• The CSW traffic should be moved from TRX1, because the limited resources for CSW. • AMR packing


• TCH (CSW)• TRX1 has only two TCH/F TSLs.

• TCH (PSW)• Layer1 has EGPRS territory (EGENA = Y) with 4 TSLs. • Layer2 has GPRS territory with 4 TSLs support for 4 RTSL MS• Multiplexing is still possible in case of high PSW and CSW traffic, but the possibility is

reduced.• Both layers have dedicated territory for minimum PSW capacity



After the network audit the following need to be completed:

• Air Interface Capacity Calculations• TSL data rate

• Multislot usage

• Available / required capacity calculation

• BSS Connectivity Calculations• PCU calculation

• Gb link calculation

• PAPU and SGSN calculation

Capacity Calculations



Capacity Planning – Introduction

• The accuracy of BTS dimensioning depends on the accuracy of the input values

• The capacity of the radio interface has a significant role in defining the capacity of the rest of the network elements (BSC, SGSN and transmission interfaces between the different network elements)

• Changes in the BTS configurations have direct impact on the BSC and SGSN configuration

• The BSC can handle a limited number of BTSs, TRXs and timeslots and the PCUs have maximum data traffic limitations and restrictions for the number of PAPU units in the SGSN



Capacity Planning – InputsThe following information should be available to define the available/required capacity:

BSC

• BSC variant

• PCU variant

• Restrictions (EDAPs, pools,

DSPs)

• BTS

• Segment

• TRX

• SW version

• Half rate

• DFCA

• DTM/ HMC/ EDA

• PBCCH/ PCCCH

BTS

• TRXs

• Time slots (Territory)

• Voice traffic load

• TRX configuration

• Signaling channels

• Free timeslots (Guard TSL)

• GPRS Territory (DED/DEF/ADD.)

• Deployment

• Coverage

• Interference

• Throughput/TSL

• GPRS/EDGE

• Data volume

• Traffic mix – Voice/Data

Abis

• Available time slots

• EDAP

• EDAP sharing probability

• TRX/PCM

• PCM usage

• TRX signaling

• Link management

• E1/T1 links



Air Interface Capacity Calculations

The capacity planning is based on calculations for:

• Available capacity:• Calculation determines how much traffic is available through the current system

• The calculation input is a pre-defined system configuration

• The calculation output is the available traffic capacity with a defined performance level

• Alternatively, the available capacities for different alternative configurations can be calculated

• Required capacity:• It is calculated to design a network that supports the defined amount of traffic

and targeted performance level

• The inputs are additional traffic volume, type, and performance requirements

• The output is the needed amount of traffic dependent hardware and associated software configurations



Air interface Capacity Calculations – Available Capacity• The air interface capacity planning is based on deployment scenarios

(PCU-1)

• All the HW, SW and feature interworking are audited by the different cell/segment options

• The next step is to calculate the capacity of the air interface related to the different cell / segment options analyzed above

• The air interface capacity calculation contains the following items:• TSL data rate estimation

• PSW Multislot usage (with CSW traffic volume and free TSLs)

• The TSL data rate calculations and the territory figures together for all the cells/segments can give the calculation results of available air interface capacity



Air Interface Capacity Planning – Required Capacity• The needed capacity is usually estimated based on assumptions on the

number of data users and on the average user traffic during busy hour considering also different types of user profiles

• Voice traffic capacity:• Half/dual rate usage

• maximum allowed blocking

• Data volume per cell can be calculated/estimated as the total data volume per cell (MB/BH/Cell, avg throughput/TSL)

• Using subscriber information is more complicated, data user penetration must be known and user data amount per busy hour must be estimated

• The required capacity can be defined with dedicated time slots (Guaranteed Bit Rate) when the data volume has been calculated



Air Interface Capacity Planning – Required Capacity

The required capacity calculation is the calculation of number of TSLs needed for both circuit switched traffic and packet switched traffic in each cell in order to achieve a given blocking probability for circuit switched traffic and required throughput for packet switched traffic.

• User profile for BH (example)• PSW BH traffic in kbps and in MB

• CSW BH traffic in Erlang

• Service Mix: e.g. 45 % Voice, 10 % Video Streaming, 20 % PoC, etc

• Traffic distribution• # of users phase by phase

• Traffic density

• GPRS/EGPRS multiplexing

32kbps0.45 /2.81(UL)/32 (DL) kbpsVideo (Streaming) GBR

8kbps1.8 /1.88 (UL)/8 (DL) kbpsPoCTHP=ARP=1 NBR

0.1(UL)/0.1(DL) kbps

0.25(UL)/1(DL) kbps

0.5 (UL)/3(DL) kbps

12 mErl

BH Traffic

0.045/0.045

0.1125/0.45

0.225/1.35

Voice

BH Traffic in MB

NRTMMS (Background) NBR

NRTEmail (Background) NBR

NRTBrowsing (Interactive) NBR

Voice channelVoice

BearerApplication

32kbps0.45 /2.81(UL)/32 (DL) kbpsVideo (Streaming) GBR

8kbps1.8 /1.88 (UL)/8 (DL) kbpsPoCTHP=ARP=1 NBR

0.1(UL)/0.1(DL) kbps

0.25(UL)/1(DL) kbps

0.5 (UL)/3(DL) kbps

12 mErl

BH Traffic

0.045/0.045

0.1125/0.45

0.225/1.35

Voice

BH Traffic in MB

NRTMMS (Background) NBR

NRTEmail (Background) NBR

NRTBrowsing (Interactive) NBR

Voice channelVoice

BearerApplication



Connectivity Capacity Planning (MS-Gb)

• The aim of connectivity capacity planning is to calculate the amount of required PCUs and allocate the sites (BCFs) among these PCUs (BSCs) for avoiding connectivity limits and maximizing QoS

• The view here is on the chain between MS and Gb, so all the network elements and interfaces are planned for enough connectivity capacity

• The number of required PCUs are CDEF and DAP size dependent from physical layer point of view, while the amount of Gb links used by PCUs is PAPU limiting factor (or the limited number of PAPUs can limit the number of PCUs, because of Gb link limits in PAPU).



PCU Type BSC Types Network elements BSS10.5BSS10.5 ED BSS11 BSS11.5PCU BSCE, BSC2, BSCi, BSC2i BTS 64 64 64 64

TRX 128 128 128 128

Radio TSLs 256 256 256 128

Abis 16 kbps channels 256 256 256 256

Gb 64 kbps channels 31 31 31 31

PCU-S BSCE, BSC2, BSCi, BSC2i BTS 64 64 64 64

TRX 128 128 128 128

Radio TSLs 256 256 256 128



PCU-T BSCE, BSC2, BSCi, BSC2i BTS 64 64 64 64

TRX 128 128 128 128

Radio TSLs 256 256 256 256



PCU2-U BSCE, BSC2, BSCi, BSC2i BTS N/A N/A N/A 128

TRX N/A N/A N/A 256

Radio TSLs N/A N/A N/A 256

Abis 16 kbps channels N/A N/A N/A 256

Gb 64 kbps channels N/A N/A N/A 31

PCU-B BSC3i BTS 2 x 64 2 x 64 2 x 64 2 x 64

TRX 2 x 128 2 x 128 2 x 128 2 x 128

Radio TSLs 2 x 256 2 x 256 2 x 256 2 x 256

Abis 16 kbps channels 2 x 256 2 x 256 2 x 256 2 x 256

Gb 64 kbps channels 2 x 31 2 x 31 2 x 31 2 x 31

PCU2-D BSC3i BTS N/A N/A N/A 2 x 128

TRX N/A N/A N/A 2 x 256

Radio TSLs N/A N/A N/A 2 x 256

Abis 16 kbps channels N/A N/A N/A 2 x 256

Gb 64 kbps channels N/A N/A N/A 2 x 31

Connectivity in PCU



Connectivity Planning

• The connectivity planning for maximum capacity is based on the proper set of CDEF and DAP size • To provide enough capacity for territory upgrade the 75 % utilization in the connectivity limits is recommended

by Nokia

(*PCU & PCU-S only handle 128 radio TSLs with S11.5, PBCCH not implemented)

• The CDEF is allocated to the cells (BTSs in segment), so the too big CDEF territory will need more PCUs.• The Dynamic Abis Pool (DAP) is allocated to the sites (BCFs). Higher DAP size provides more MCS9 capable TSLs

on air interfaces, but on the other side, higher DAP size needs more capacity on E1s and more PCUs as well. • So the proper value of CDEF on cell (BTS) level and DAP on BCF level can help to be below the 192

(96*) radio TSL limit with 75 % utilization to avoid connectivity bottlenecks even in case of territory upgrades

*It is important to know that the PCU and PCU-S have 128 radio TSL limit with S11.5, which can cause limitations in GPRS only networks.

**Recommended number of EDAPs per PCU1 is 1,2,4 or 8

Outputs Max Limit*

Utilization

Limit

Unit

Abis Channels (Radio and EDAP slave TSLs)*

256 75% 192 TSLs

EDAPs* 16 100% 16 Pcs

BTS (cell, segment) 64 100% 64 Pcs

TRXs 128 100% 128 Pcs



Connectivity Limits in SGSN (SG5)

The following limits must be taken into account:• 1024 PCUs can be connected to SGSN (with 16 PAPU)

• 64 PCUs can be connected to PAPU

• 3072 Gb links can be connected to SGSN (with 16 PAPU)

• 192 Gb links can be connected to PAPU

• 120 E1s can be connected to SGSN (with 16 PAPU)



BSS Dimensioning Example

Dimensioning Inputs

Air Interface Capacity

Connectivity Capacity



Dimensioning Inputs

Network/BSC with 40 BCFsEDGE/GPRS implementation on top of existing CS voice• 3 BTSs per BCF• Site configurations & amounts

• 4+4+4 – 15 BCFs – “central area”• 2+2+2 – 25 BCFs – “surrounding area”

• BCF voice traffic• 2+2+2 site on average has traffic of 8 Erl per BTS• 4+4+4 site on average has traffic of 18 Erl per BTS• Blocking criteria 2%

• Data trafficStreaming user support requirement per BTS ~ 50 kbit/s

Average data throughput per BTS (by operator)• “Central area” - 200 kbit/s• “Surrounding area” – 100 kbit/s

• Other considerations• All BTSs and TRXs EDGE capable• Gb implementation planned as Frame Relay



Dimensioning Inputs

TRX and Abis Configurations before EDGE Implementation

• TRX configurations• No DR/HR implementation

• Abis configurations • Each BCF has own E1

• 2+2+2 configuration


2+2+2 4+4+4

TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7BCCH MBCCH SDCCH TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTCH TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F

TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7BCCH MBCCH SDCCH TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTCH TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTCH SDCCH TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTCH TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F

0 01 TCH0 TCH1 TCH2 TCH3 1 TCH0 TCH1 TCH2 TCH32 TCH4 TCH5 TCH6 TCH7 2 TCH4 TCH5 TCH6 TCH73 TCH0 TCH1 TCH2 TCH3 3 TCH0 TCH1 TCH2 TCH34 TCH4 TCH5 TCH6 TCH7 4 TCH4 TCH5 TCH6 TCH75 TCH0 TCH1 TCH2 TCH3 5 TCH0 TCH1 TCH2 TCH36 TCH4 TCH5 TCH6 TCH7 6 TCH4 TCH5 TCH6 TCH77 TCH0 TCH1 TCH2 TCH3 7 TCH0 TCH1 TCH2 TCH38 TCH4 TCH5 TCH6 TCH7 8 TCH4 TCH5 TCH6 TCH79 TCH0 TCH1 TCH2 TCH3 9 TCH0 TCH1 TCH2 TCH3

10 TCH4 TCH5 TCH6 TCH7 10 TCH4 TCH5 TCH6 TCH711 TCH0 TCH1 TCH2 TCH3 11 TCH0 TCH1 TCH2 TCH312 TCH4 TCH5 TCH6 TCH7 12 TCH4 TCH5 TCH6 TCH713 TRXSIG1 TRXSIG2 13 TCH0 TCH1 TCH2 TCH314 TRXSIG3 TRXSIG4 14 TCH4 TCH5 TCH6 TCH715 TRXSIG5 TRXSIG6 15 TCH0 TCH1 TCH2 TCH316 BCFSIG 16 TCH4 TCH5 TCH6 TCH717 17 TCH0 TCH1 TCH2 TCH318 18 TCH4 TCH5 TCH6 TCH719 19 TCH0 TCH1 TCH2 TCH320 20 TCH4 TCH5 TCH6 TCH721 21 TCH0 TCH1 TCH2 TCH322 22 TCH4 TCH5 TCH6 TCH723 23 TCH0 TCH1 TCH2 TCH324 24 TCH4 TCH5 TCH6 TCH725 2526 2627 27 TRXSIG1 TRXSIG2 TRXSIG3 TRXSIG428 28 TRXSIG5 TRXSIG6 TRXSIG7 TRXSIG829 29 TRXSIG9 TRXSIG10 TRXSIG11 TRXSIG1230 30 BCFSIG31 31Q1-management Q1-management



Dimensioning Inputs – Deployment Scenarios

• TRX configurations• No DR/HR implementation• GTRX = Y

• BTS configuration• GENA = Y, EGENA = Y, CMAX = 100

%• Abis configurations

• Each BCF has own E1

• Rf-environment• Average C/I = 16 dB (BCCH-layer)• Average RxLevel = -85 dBm

Average RLC/MAC throughput for EDGE

35 kbit/s (BCCH layer)

• Typically best C/I TRX preferred for maximum throughput

• Depending on frequency plan this can be either BCCH or TCH TRX

• Features impacting location selection:

• DR RTSL location needs to be considered with 2+2+2 configuration

• DR RTSLs should not be allocated close to GPRS territory boundary.



Dimensioning Inputs – Free timeslots on Air IF

• Free RTSLs between CS and PS territory required in order to serve incoming CS calls without blocking

• Table above gives free RTSLs with default parameters • CS downgrade – if less RTSLs free in CS territory, PS territory downgrade triggered• CS upgrade – PS territory upgrade can be triggered if at least that amount of RTSLs

free• Free TSLs for up and downgrade can be controlled by BSC parameters

• free TSL for CS downgrade• free TSL for CS upgrade

• Mean free RTSLs for 2 TRXs: 1.5; Mean free RTSLs for 4 TRXs: 2.5

TRX 1

TRX 2



TS

TS

= CDED

= CSW Territory

TS = (E)GPRS Territory/Additional capacity

BCCH = Signaling


TS = CDEF

Territory border

GTRX

GTRX

GENA

EGENA

CMAX

TRX 1

TRX 2



TS

TS

= CDED

= CSW Territory


BCCH = Signaling


TS = CDEF

Territory border

TRX 1

TRX 2



TRX 1

TRX 2

BCCH TS TS TS TS TS TSSDCCHBCCH TS TS TS TS TS TSSDCCHBCCH TS TS TS TS TS TSSDCCHBCCH TS TS TS TS TS TSSDCCHBCCH TS TS TS TS TS TSSDCCHBCCH TS TS TS TS TS TSSDCCH

TS TS TSTS TSTS TS TSTS TSTS TS TS TSTS TS TSTSTS TS TSTS TSTS TS TSTS TSTS TS TS TSTS TS TSTS

TS

TS

= CDED

= CSW Territory


BCCH = Signaling


TS = CDEF TS

TS

= CDED

= CSW Territory


TS

TS

= CDED

= CSW Territory


BCCH = Signaling


TS = CDEF

BCCH = Signaling


TS = CDEF

Territory border

GTRX

GTRX

GENA

EGENA

CMAX

TSL number after CS downgrade

TRX number 1 2 3 4 5

70 0 0 0 1 1

95 1 1 1 2 2

99 1 1 2 2 3

TSL number after CS upgradeTRX number 1 2 3 4 5

1 0 1 1 1 2

4 1 2 2 3 4

7 1 2 3 4 5

10 2 3 4 5 6

free TSL for CS downgrade (%) (CSD)

free TSL for CS upgrade (sec) (CSU)



Air Interface – Available Capacity

2+2+2 configuration

• 2 TRXs, 16 RTSLs• 2 RTSLs for signaling• 14 RTSLs for CS traffic

• CS BH traffic 8 Erl per BTS – all BTSs have same BH traffic

• Erlang B table – 1.7% CS blocking @ BH• Mean free RTSLs = 1.5

• Average available for PS traffic @ CS BHAmount_of_TRXs*8 - signaling_RTSLs – CS_BH_traffic-free_RTSLs =2*8-2-8-1.5 =4.5 RTSLs

• Average PS traffic @ CS BH4.5*35 kbit/s = 157.5 kbit/s (> 100 kbit/s)

4+4+4 configuration

• 4 TRXs, RTSLs• 3 RTSLs for signaling• 29 RTSLs for CS traffic

• CS BH traffic 18 Erl per BTS – all BTSs have same BH traffic

• Erlang B table – 0.4% CS blocking @ BH• Mean free RTSLs = 2.5

• Average available for PS traffic @ CS BHAmount_of_TRXs*8 - signaling_RTSLs – CS_BH_traffic-free_RTSLs =4*8-3-18-2.5 = 8.5 RTSLs

• Average PS traffic @ CS BH8.5*35 kbit/s = 297.5 kbit/s (> 200 kbit/s)



Air Interface – Available Capacity (Default Territory Size) 2+2+2 – territory considerations

• MS multislot capability (4 RTSLs)• Data throughput 100 kbit/s• Air interface – 35 kbit/RTSL

=> RTSLs to support 100 kbit/s100/35 = 2.9 TSLs ~ 3 RTSLs

Default territory sizeMax(MS_multislot, traffic) = 4 RTSLs

4+4+4 – territory considerations

• MS multislot capability (4 RTSLs)• Data throughput 200 kbit/s• Air interface – 35 kbit/RTSL

=> RTSLs to support 200 kbit/s200/35 = 5.7 TSLs ~ 6 RTSLs

Default territory sizeMax(MS_multislot, traffic) = 6 RTSLs



Air Interface – Required Capacity (Dedicated Territory Size)

2+2+2 configuration

• Available RTSLs for CS traffic per BTS14 – 2 (CDED) = 12 RTSLs• Traffic per BTS = 8 ErlErlang B (8Erl, 12 TSLs) = 5.1% CS blocking

5.1% > 2% - NOKNeeded channels for 2% CS blockingErlang B (8Erl,2%) = 14 channels

Either 2 more RTSLs (DR/HR) are needed or one new TRX

Capacity increase done with DR RTSLs

•Streaming user support required per BTS (one streaming user)

•Streaming requires 50 kbit/s

=> (50kbit/s)/(35 kbit/s/RTSL) = 2 RTSLs needs to be dedicated (CDED) per BTS in order to support streaming

4+4+4 configuration

Available RTSLs for CS traffic per BTS

29-2 (CDED) = 27 RTSLs

Traffic per BTS = 18 Erl

Erlang B (18Erl, 27 TSLs) = 1.1% CS blocking

1.1% < 2% - OK



Air Interface Calculations – Summary

• 2+2+2 configurations

• Territory located in BCCH TRX

• 2 RTSL dedicated territory to support streaming

• 4 RTSL default territory for 2+2+2 configuration

• 2 additional DR RTSLs needed to get blocking less than 2%

• 4+4+4 configurations

• Territory located in BCCH TRX

• 2 RTSL dedicated territory per BTS for streaming support

• 6 RTSL default territory for 4+4+4 configuration

• No additional DR RTSLs or TRXs needed



Connectivity Capacity - CDEF

2+2+2 configuration

• CDEF is given by Max(MS_multislot, traffic)

• Max(4, 2.9) => 4

• The CDEF parameter set is 4 RTSLs

4+4+4 configuration

• CDEF is given by Max(MS_multislot, traffic)

• Max(4, 5.7) => 6

• The CDEF parameter set is 6 RTSLs

The results of default territory size calculations (refer to slide 8) determines the CDEF parameter value.



Connectivity Capacity - EDAP Size

General EDAP size considerations:• If support for MCS-9 at least with one MS in

one BTS of BCF is required. (Needed if MS multislot capability not taken into account with default territory calculations)

Min_EDAP_1 = MS_Multislot capability (= 4 TSLs)

• If support for MCS-9 in all GPRS territory timeslots of BTSs is required

Min_EDAP_2 = Max_Default_Territory_size_of one_BTS

• Minimum EDAP size can be calculated from above input

Min_EDAP_size = Max(Min_EDAP_1, Min_EDAP_2)

• If EDAP has more than one BTS attached, BTS multiplexing factor can be taken into account if

• EDAP peak load is estimated to exceed one BTSs territory size

• BTS multiplexing factor can be estimated e.g. by

k = 2/(1+1/x), where

x= amount of BTSs in one EDAP

• EDAP size can be estimated by

EDAP_size = k * Min_EDAP_size

# of BTSs k1 1.02 1.33 1.5



Connectivity Capacity - EDAP Size Considerations

EDAP sizes with different configurations

2+2+2 configuration• MS Multislot capability = 4 RTSLs• Default territory size per BTS = 4

RTSLs=> Min_EDAP_size = Max(4,4)

= 4

4+4+4 configuration• MS Multislot capability = 4 RTSLs• Default territory size per BTS = 6

RTSLs=> Min_EDAP_size = Max(4,6)

= 6# of BTSs k 2+2+2 4+4+41 1.0 4.0 6.02 1.3 5.3 8.03 1.5 6.0 9.0

• Capacity for EDAPs in E1 for 2+2+2 is 16 and for 4+4+4 configuration 2 TSLs2+2+2 configuration fits easily into existing E14+4+4 configuration does not fit into existing E1

• Abis TSL allocation of 4+4+4 configuration needs redesign



Connectivity Capacity - EDAP Size Considerations• Two options for Abis TSL allocation

• TRXs are grouped by function so that all EDGE TRXs and EDAP are allocated to one E1 while the non-EDGE resources are mapped to other E1 frame. One EDAP is enough to serve all cells (BTS objects)

• TRXs are grouped by cell so that two cells are allocated to one E1 and the third one to the second E1. In this case EDAP is created for both groups.

• Pros and cons.• TRXs grouped by function (the 1st E1: 2+2+2 & EDAP, the 2nd E1 2+2+2 non-EDGE)

• + maximum trunking gain of the EDAP can be achieved less total Abis capacity is required (#TSLs for EDAP = 9)

• + smaller number of EDAPs saves PCU resources• - Special care needed to maintain and upgrade the configuration to keep the original slit.

• TRXs grouped by cell (the 1st E1: 4+4 & EDAP1, the 2nd E1 4 & EDAP2)• + Straightforward to maintain and upgrade • - trunking gain of the EDAPs is smaller or non more total Abis capacity is required

(#TSLs for EDAP = 8+6 = 14)• - bigger number of EDAPs eats more PCU resources



Connectivity Capacity - EDAP Size Considerations

TRXs grouped by cells

Two EDAPs 8 TSL and 6 TSL

TRXs grouped by function

One EDAP 9TSL

Cell A

EGDE resources Non-EGDE resources Cell A & B resources Cell C resources

0 01 TCH0 TCH1 TCH2 TCH3 1 TCH0 TCH1 TCH2 TCH32 TCH4 TCH5 TCH6 TCH7 2 TCH4 TCH5 TCH6 TCH73 TCH0 TCH1 TCH2 TCH3 3 TCH0 TCH1 TCH2 TCH34 TCH4 TCH5 TCH6 TCH7 4 TCH4 TCH5 TCH6 TCH75 TCH0 TCH1 TCH2 TCH3 5 TCH0 TCH1 TCH2 TCH36 TCH4 TCH5 TCH6 TCH7 6 TCH4 TCH5 TCH6 TCH77 TCH0 TCH1 TCH2 TCH3 7 TCH0 TCH1 TCH2 TCH38 TCH4 TCH5 TCH6 TCH7 8 TCH4 TCH5 TCH6 TCH79 TCH0 TCH1 TCH2 TCH3 9 TCH0 TCH1 TCH2 TCH3

10 TCH4 TCH5 TCH6 TCH7 10 TCH4 TCH5 TCH6 TCH711 TCH0 TCH1 TCH2 TCH3 11 TCH0 TCH1 TCH2 TCH312 TCH4 TCH5 TCH6 TCH7 12 TCH4 TCH5 TCH6 TCH713 1314 1415 1516 1617 1718 1819 1920 2021 2122 2223 2324 2425 2526 2627 2728 TRXSIG1 TRXSIG2 TRXSIG3 TRXSIG4 2829 TRXSIG5 TRXSIG6 29 TRXSIG7 TRXSIG830 BCFSIG 30 TRXSIG9 TRXSIG10 TRXSIG11 TRXSIG1231 31Q1-management Q1-management

0 01 TCH0 TCH1 TCH2 TCH3 1 TCH0 TCH1 TCH2 TCH32 TCH4 TCH5 TCH6 TCH7 2 TCH4 TCH5 TCH6 TCH73 TCH0 TCH1 TCH2 TCH3 3 TCH0 TCH1 TCH2 TCH34 TCH4 TCH5 TCH6 TCH7 4 TCH4 TCH5 TCH6 TCH75 TCH0 TCH1 TCH2 TCH3 5 TCH0 TCH1 TCH2 TCH36 TCH4 TCH5 TCH6 TCH7 6 TCH4 TCH5 TCH6 TCH77 TCH0 TCH1 TCH2 TCH3 7 TCH0 TCH1 TCH2 TCH38 TCH4 TCH5 TCH6 TCH7 8 TCH4 TCH5 TCH6 TCH79 TCH0 TCH1 TCH2 TCH3 9

10 TCH4 TCH5 TCH6 TCH7 1011 TCH0 TCH1 TCH2 TCH3 1112 TCH4 TCH5 TCH6 TCH7 1213 TCH0 TCH1 TCH2 TCH3 1314 TCH4 TCH5 TCH6 TCH7 1415 TCH0 TCH1 TCH2 TCH3 1516 TCH4 TCH5 TCH6 TCH7 1617 1718 1819 1920 2021 2122 2223 2324 2425 2526 2627 2728 TRXSIG1 TRXSIG2 TRXSIG3 TRXSIG4 2829 TRXSIG5 TRXSIG6 TRXSIG7 TRXSIG8 2930 BCFSIG 30 TRXSIG9 TRXSIG10 TRXSIG11 TRXSIG1231 31Q1-management Q1-management



Connectivity Capacity - EDAP Summary


• EDAP size 6 TSLs

• EDAP fits in existing E1


• EDAP size 9 TSLs

• EDGE TRXs grouped for same E1

• A new E1 needed for each 4+4+4 BCF -> need for 15 new E1s



Connectivity Capacity - PCU Planning ConsiderationsTarget is to calculate the optimal number of PCUs to serve the given

network.

• PCU utilization 75% (25% connectivity for territory upgrdaes)

• Recommended number of EDAPs per PCU is 1,2,4 or 8

• The optimal number of EDAPs and associated default RTSL is calculated for each PCU configuration.

• E.g. up to 5 EDAPs of size 6 TSL serving three cells each having default territory size 4 RTSL can be allocated to PCU without exceeding the 75%.

• To full fill the 1,2,4 and 8 recommendation the number of EDAPs would be 4 #EDAPs 5 6 4 3

EDAP size 6 6 8 9#RTSL in territory 4 6 6 6#cells (territories) per EDAP 3 1 2 3

#EDAP TSLs 30 36 32 27#RTSLs 60 36 48 54PCU Utilization 70% 70% 69% 63%



Connectivity Capacity - PCU Configurations and Requirements• Table below lists possible PCU combinations

• 4+4+4 configurations -> 3 sites per PCU has too low load, 4 too low• 2+2+2 configuration -> 5 sites per PCU provides reasonable load

• When considering total network, 15 (4+4+4) and 25 (2+2+2) configurations one possibility is to have

• 5 PCUs with 1 (2+2+2) and 3 (4+4+4) configurations• 4 PCUs with 5 (2+2+2) configurations

BTS configuration EDAP size2+2+2 (12) 6 0 0 1 3 2 4 3 5 44+4+4 (18) 9 4 3 3 2 2 1 1 0 0

4 3 4 5 4 5 4 5 4total PCU Abis load 216 162 198 216 180 198 162 180 144PCU load% 84% 63% 77% 84% 70% 77% 63% 70% 56%



Connectivity Capacity - Gb Link Size RequirementsGb over FR

• Gb link size can be calculated from maximum EDAP size of PCU

Gb_link_size=5/4*Max_EDAP_size as minimum

• Inputs from PCU planning• 5 PCUs with 1 EDAP of 6 TSLs and 3 EDAPs of 9 TSLs

• 4 PCUs with EDAP of 6 TSLs

• Gb link sizes / PCU• Gb_link1 = 5/4*9 = 11.25 TSLs ~ 11 TSLs

• Gb_link2 = 5/4*6 = 7.5 TSLs ~ 8 TSLs



Connectivity Capacity - Gb Links

• When Gb links are combined into E1s maximum 31 TSLs can be used

• Table above shows that 1 E1 can fit well either• 2 Gb links of 11 TSLs and one link of 8 TSL

• 1 Gb link of 11 TSL and two links of 8 TSLs

• 9 PCUs can therefore be fitted into 3 E1 links

#PCUGb links

5 11 3 2 2 1 24 8 0 0 1 2 2

33 22 30 27 38



Connectivity Capacity - Summary

DR RTSLs 150PCUs 9E1s for Abis 15E1s for Gb 3

Configuration CDED CDEF EDAP2+2+2 2 4 64+4+4 2 6 9

# of PCUs BTS Configurations Abis util. Gb Link5 3*(4+4+4) 1*(2+2+2) 77% 114 5*(2+2+2) 70% 8



Mobility Planning

Cell outage

PCU allocation Planning

LA/RA Design



Mobility Planning

• The aim of mobility planning is to reduce the cell outage time during cell re-selection.

• Cell outage can be reduced by• Providing enough signaling capacity for cell re-selection (the RACH, PCH,

AGCH and SDCCH channel are not limiting the signaling flow)

• Allocating BCFs to PCUs properly (the important neighbors are allocated to the same PCU)

• Allocating LA/RA borders properly

• Using Network Assisted Cell Change (NACC) feature



Event name Time Channel MessageRLC/MAC Uplink 20:42.0 PACCH "EGPRS_PACKET_DOWNLINK_ACK/NACK"Layer 3 Downlink 20:42.0 BCCH "SYSTEM_INFORMATION_TYPE_1"Layer 3 Downlink 20:42.0 BCCH "SYSTEM_INFORMATION_TYPE_2"Layer 3 Downlink 20:42.0 BCCH "SYSTEM_INFORMATION_TYPE_3"Layer 3 Downlink 20:42.0 BCCH "SYSTEM_INFORMATION_TYPE_4"… … … …

Layer 3 Downlink 20:42.6 BCCH "SYSTEM_INFORMATION_TYPE_4"Cell Reselection 20:42.8 from CI 5032 to CI 5033Layer 3 Downlink 20:42.8 BCCH "SYSTEM_INFORMATION_TYPE_2"… … … …

Layer 3 Downlink 20:43.1 BCCH "SYSTEM_INFORMATION_TYPE_13"Layer 3 Uplink 20:43.1 RACH "CHANNEL_REQUEST"Layer 3 Downlink 20:43.2 CCCH "IMMEDIATE_ASSIGNMENT"Layer 3 Downlink 20:43.2 CCCH "PAGING_REQUEST_TYPE_1"Layer 3 Downlink 20:43.2 CCCH "PAGING_REQUEST_TYPE_1"Layer 3 Downlink 20:43.3 CCCH "PAGING_REQUEST_TYPE_1"Layer 3 Downlink 20:43.3 BCCH "SYSTEM_INFORMATION_TYPE_2"… … … …

Layer 3 Downlink 20:43.8 BCCH "SYSTEM_INFORMATION_TYPE_13"RLC/MAC Uplink 20:43.8 PACCH "PACKET_RESOURCE_REQUEST"RLC/MAC Downlink 20:44.0 PACCH "PACKET_UPLINK_ASSIGNMENT"RLC/MAC Downlink 20:44.0 PACCH "PACKET_DOWNLINK_DUMMY_CONTROL_BLOCK"RLC/MAC Downlink 20:44.0 PACCH "PACKET_DOWNLINK_DUMMY_CONTROL_BLOCK"… … … …

RLC/MAC Downlink 20:44.2 PACCH "PACKET_DOWNLINK_DUMMY_CONTROL_BLOCK"RLC/MAC Downlink 20:44.2 PACCH "PACKET_DOWNLINK_ASSIGNMENT"RLC/MAC Uplink 20:44.3 PACCH "EGPRS_PACKET_DOWNLINK_ACK/NACK"

Diff. Between BSS andtill Packet Uplink Assign. (ms) till Packet Downlink Assign. (ms) full cell-outage (ms)

2.07 2.341 0.273.07 3.349 0.282.09 2.354 0.262.10 2.358 0.262.09 2.375 0.282.11 2.393 0.282.10 2.658 0.562.09 2.355 0.262.11 2.395 0.282.10 2.38 0.286.00 6.254 0.262.12 2.379 0.262.094 2.629 0.542.09 2.631 0.542.14 2.7 0.562.07 4.011 1.942.10 2.379 0.282.10 2.385 0.282.37 2.80 0.43

From EGPRS PACKET DOWNLINK ACK/NACK

Cell Outage Time with intra/inter PCU

Outage measurements• Cell Outage (MS - PCU) is measured

between the first BCCH observation and Packet Uplink Assignment

• Data Outage (MS - SGSN) is measured between the first BCCH observation and Packet Downlink Assignment

Test cases

• Intra PCU cell-reselection outage

• Inter PCU cell-reselection outage



Cell Outage Time with LAU/RAU

Outage measurements

• Cell Outage (MS - PCU) is measured between the first BCCH observation and Packet Uplink Assignment with LA and RA Update procedure

• Data Outage (MS - SGSN) is measured between the first BCCH observation and Packet Downlink Assignment after Routing Area Update Complete

… … … …

Layer 3 Downlink 8:44:05.801 BCCH "SYSTEM_INFORMATION_TYPE_1"… … … …

Layer 3 Downlink 8:44:10.797 BCCH "SYSTEM_INFORMATION_TYPE_13"Cell Reselection 8:44:10.906 from 5691 to 5753Layer 3 Downlink 8:44:11.018 BCCH "SYSTEM_INFORMATION_TYPE_2"… … … …

Layer 3 Uplink 8:44:11.997 RACH "CHANNEL_REQUEST"Layer 3 Downlink 8:44:12.101 CCCH "IMMEDIATE_ASSIGNMENT"Layer 3 Uplink 8:44:12.313 SDCCH "LOCATION_UPDATING_REQUEST"Layer 3 Downlink 8:44:12.353 SACCH "SYSTEM_INFORMATION_TYPE_6"Layer 3 Uplink 8:44:12.388 SACCH "MEASUREMENT_REPORT"Layer 3 Uplink 8:44:12.548 SDCCH "CLASSMARK_CHANGE"Layer 3 Downlink 8:44:12.764 SDCCH "CIPHERING_MODE_COMMAND"Layer 3 Uplink 8:44:12.784 SDCCH "GPRS_SUSPENSION_REQUEST"Layer 3 Uplink 8:44:13.020 SDCCH "CIPHERING_MODE_COMPLETE"Layer 3 Downlink 8:44:13.224 SDCCH "IDENTITY_REQUEST"Layer 3 Uplink 8:44:13.350 SACCH "MEASUREMENT_REPORT"Layer 3 Uplink 8:44:13.490 SDCCH "IDENTITY_RESPONSE"Layer 3 Downlink 8:44:13.697 SDCCH "LOCATION_UPDATING_ACCEPT"Layer 3 Uplink 8:44:13.799 SACCH "MEASUREMENT_REPORT"Layer 3 Downlink 8:44:14.168 SDCCH "MM_INFORMATION"Layer 3 Uplink 8:44:14.284 SACCH "MEASUREMENT_REPORT"Layer 3 Downlink 8:44:14.399 SDCCH "CHANNEL_RELEASE"… … … …

Layer 3 Uplink 8:44:16.258 PDTCH "ROUTING_AREA_UPDATE_REQUEST"… … … …

Layer 3 Uplink 8:44:16.752 RACH "CHANNEL_REQUEST"Layer 3 Downlink 8:44:16.829 CCCH "IMMEDIATE_ASSIGNMENT"… … … …

Layer 3 Uplink 8:44:16.258 PDTCH "ROUTING_AREA_UPDATE_REQUEST"RLC/MAC Uplink 8:44:17.401 PACCH "PACKET_RESOURCE_REQUEST"RLC/MAC Downlink 8:44:17.607 PACCH "PACKET_UPLINK_ASSIGNMENT"… … … …

RLC/MAC Downlink 8:44:17.886 PACCH "PACKET_DOWNLINK_ASSIGNMENT"… … … …

Layer 3 Downlink 8:44:18.950 PDTCH "ROUTING_AREA_UPDATE_ACCEPT"Layer 3 Uplink 8:44:18.964 PDTCH "ROUTING_AREA_UPDATE_COMPLETE"RLC/MAC Uplink 8:44:19.119 PACCH "EGPRS_PACKET_DOWNLINK_ACK/NACK"… … … …

Event name Time Channel Message



PCU Allocation Plan

• The proper allocation of the cells among PCUs can help to maximize the number of intra PCU cell re-selections, which is the most stable cell re-selection event.

• RLC/MAC layer: The intra PCU cell re-selection takes less time compared with inter PCU cell reselection

• LLC layer: In case of intra PCU cell re-selection the untransferred data is moved to new cell (BVCI) and the transfer can be continued on new cell without packet loss on higher layer, while in case of inter PCU cell re-selection the untransferred data is not moved to new cell (BVCI).

• The following rules can be followed:• The cells of a BCF should be connected to the same PCU• The neighbor relations with high re-selection traffic should be connected to the same

PCU• The neighbor relations in very bad signal and quality environment should be

connected to the same PCU

• NACC and NCCR can be used if there is not any possibility to connect the neighbor cells to the same PCU (NACC is working inside BSCs only)



LA/RA Design – Radio Aspects

• Important to avoid LA/RA border allocation between cell with high neighboring traffic

• Usage of NMO I, where the combined RA reduces the cell re-selection time

Radio Aspect of LA/RA Design• The too big LA/RA will increase the paging, while the too small LA/RA will increase the

LA/RA Update. So the balance should be found between too big and too small LA/RAs.

• The not so appropriate LA/RA border design can significantly increase the signaling on air interface signaling channels and TRXSIG on LA/RA border cells, so the cell-reselection outage can be longer in this case because of congestion on signaling.

• The LA/RA border should be moved from those areas where the normal CSW and PSW traffic is very high.

• The combined RAU (NMO I with Gs) is shorter compared to NMO II

• In S11 backwards the GPRS resume always can cause a lot of RAs if GPRS MS has high CS call activity, but this behavior cannot be avoided by proper LA/RA design

• In S11.5 the Resume is working without LA/RA update



(E)GPRS Explain




(E)GPRS BSS Network Optimization - Structure

• GSM Network Optimization• Coverage maximization

• Interference reduction

• Capacity optimization (air interface and connectivity)

• (E)GPRS Network Optimization• Signaling capacity & resource allocation improvement

• Data Rate• Connectivity Capacity (MS-SGSN)

• TSL data rate improvement and multislot usage maximization (BSS)

• E2E data rate (applications)

• Mobility improvement



GSM Network Optimization

The optimal GSM network from PSW services point of view has: • As high signal level as possible

• It means that even the indoor signal level should be high enough to have MCS9 for getting the highest data rate on RLC/MAC layer.

• As low interference as possible • The aim of having high C/I is to avoid throughput reduction based on interference.

• Enough capacity• Enough BSS hardware capacity (interface and connectivity) is needed to provide the required

capacity for PSW services in time. Both CSW and PSW traffic management should be harmonized with the layer structure and long term plans.

• As few cell-reselection as possible• The dominant cell coverage is important to avoid unnecessary cell-reselections in mobility. The

prudent PCU allocation can help to reduce the inter PCU cell reselections. • Dominant cell structure can help to maximize the signal level and reduce the interference, too.

• Features• All the features should be used which can improve the PSW service coverage, capacity and

quality in general.

Before any (E)GPRS optimization related activities the GSM network should be optimized!!!



(E)GPRS Network Optimization - Structure

Signaling Capacity & Resource Allocation improvement• Signaling

• RF, TRXSIG, BCSU, PCU, MM and SM signaling• Resource Allocation

• Cell (re)-selection, BTS selection, scheduling

Data Rate• Connectivity Capacity (MS-SGSN)

• CDEF size, DAP size, # of PCUs and BCF allocation among PCUs, Gb size and PAPU (SGSN)• TSL data rate improvement and multi-slot usage maximization (BSS)

• TSL utilization, TBF release delay and BS_CV_MAX, LA, UL PC, multiplexing, multislot usage • E2E data rate (applications)

• Flow control, SGSN, TCP/IP, applications

Mobility improvement (outage reduction)• PCU rebalancing• LA/RA design• NACC



E2E Data Rate Optimization - Structure

• Connectivity Capacity Optimization (MS-SGSN)• CDEF, DAP and PCU (BSC)• PCU (BSC) and Gb, PAPU (SGSN)• PCU Rebalancing and Allocation

• TSL data rate improvement and multislot usage maximization (BSS)• TSL utilization• Delayed TBF release and BS_CV_MAX• Link Adaptation• Multiplexing• UL Power control• Multislot usage

• E2E Data Rate Optimization (applications)



TSL Data Rate and Multislot Usage Improvement – Structure• TSL Utilization

• Acknowledgement Request, Pre-emptive transmission, One Phase Access with EPCR

• Delayed TBF Release (TBF Release Delay, TBF Release Delay Extended)

• BS_CV_MAX

• Link Adaptation (GPRS, GPRS (CS1-4), EGPRS)

• Multiplexing

• UL Power Control

• Multislot Usage



(E)GPRS Explain




Tools for (E)GPRS Planning

NetAct Planner




• NetAct MultiRadio Planner• Data service area and throughput analysis

• Coverage analysis for both GMSK and 8-PSK modulations

• The service area analyses are based on the interference levels in the network and on the selected coding scheme

• C/I is calculated as an average interference in the network

• Data rate/TSL depends on the interference ratio and it is shown in each pixel

• Link Adaptation and Incremental Redundancy included

• Frequency Hopping utilization

• User-editable C/I vs. throughput dependency table

• User editable Coding Schemes

• GPRS (4), EDGE (9)




• NetAct radio planning capacity definition process:

Configuration

Output

Input

Iteration based on the input

Analysis of the existing configuration (and data

rate/TSL)

CS/PS traffic load estimation (GoS,QoS)

• Traffic carried by different coding schemes




• NetAct Transmission Planner:• Access Transmission & Core

Network Planning

• Capacity planning

• Configuration planning

• ATM/IP

• PDH/SDH

• Multi-layer network modeling and routing

• Link planning

Output

Input

Traffic planning, TSL allocation plan, TRS management plan, connectivity

plan

Capacity & equipment plan

Configuration

ATM Plan (delay calc., AAL2, VPC/VCC)

IP Plan (addressing, routing)

TRS Planning Process:




• NetAct Quality Planner (Drive test analysis tool)• Measurement replay

• Call success rate analysis

• Signal level and quality analysis

• Statistical analysis (KPI)

• Handover analysis

• Neighbor analysis

• Probe

• Site database

GSM data formats supported• NEMO - v1.70 -1.73

• TEMS 3.x – 5.x(fmt files generated via Quality Planner specific export plan)

• AGILENT - SD5 (nitro 7)

• NEPTUNE - all versions

To be supported (parser/loader)• R&S equipment• SwissQual

• DTI and Clarify equipment

• Anritsu equipment



Tools for (E)GPRS Planning • GPRS data analysis

• Average DL/UL throughput

• Average RXLev

• Average UL/DL TS in use

• % data using CS1 and CS2

• Total UL/DL volume for RLC and LLC in bytes

• Total number of RLC and LLC retransmissions in bytes

• Total throughput of RLC and LLC in bytes

• Efficiency of RLC and LLC in %

• Number of cell reselections

• Routing area ID’s

• GPRS cell statistics

• NetAct Quality Planner




• Drive Test/Analysis Tools with (E)GPRS support

<Nemo picture here>




• NetAct Reporter• Reporter supports viewing and analysing the network

performance, fault and configuration data coming from different sources

• Based on numerous counters which enables full support to (E)PRS performance analysis

• Report Builder• central application

• administer the reporting environment • create and manage KPIs

• create and manage reports

• manage the permissions to access data

• run reports

• easy-to-use graphical user interface

• regional/global level




• Report Browser & KPI Browser• Access to reports

• Web interface

• Drill down• KPI details

• regional/global level

• Optional, e.g.• Global Reporter

• PM Database

• Reporting Suite• Ready-made on-demand reports

• ~200 reports/1000 KPIs

• Network Doctor• Ready-made textual reports (CM/FM/PM)

• On-the-field developed reports focusing on network planning and O&M



(E)GPRS Explain - Appendix

Implementing and enabling (E)GPRS



Overview of implementing EGPRS• The required steps depend on whether the GPRS is already integrated

or not

• You can activate EDGE in the network using NetAct

Prerequisites• Node Managers (Remote BTS manager, UltraSite BTS Hub Manager)

must be integrated to NetAct

• OSS3.1ED2 software (for RNW Planning e.g. Plan Manager)

Implementing (E)GPRS



The process of integrating a new EDGE BSS to the radio network (no GPRS BSS)


Create Gb interface *)

Create Routing area and OMU/TRX links

Activate BCF software

Commission Base Station

Unlock radio network objects

Create Dynamic Abis pool and radio network objects *)

*) EDAP and Gb interfaces are described later



The process of implementing EDGE in an integrated GPRS BSS


Activate BCF software

Activate EDGE in BTS already integrated in the network

Enable EGPRS in BSC



Create a BCF

Create a BTS

Attach BTS to RAC

Enable EGPRS (EGENA/Y)

Define GPRS and EGPRS parameters

Enable GPRS (GENA/Y)

Create a TRX with DAP connection

Create handover and power control parameters

The steps to create radio network objects

Enabling (E)GPRS

RAC= Routing Area code



Create the dynamic Abis pool

Disable the GPRS in the cell

Lock the TRX

Delete the TRX to be connected to Dynamic Abis pool

Create a TRX which uses the dynamic Abis pool

All the TRXs that will be using EGPRS in the BTS must be attached to a dynamic Abis pool

Unlock the TRX

Enable EGPRS in the BTS (EGENA/Y)

Enable GPRS in the cell (GENA/Y)

Unlock the BTS

Lock the BTS

The steps to enable the (E)GPRS in BSC

Enabling (E)GPRS



To be considered:• When the TRX has been created with EDAP defined at BSC and EGPRS feature is enabled,

the TRX must be attached to EDAP on the BTS side also not to fail the configuration of BCF

• EDAP in BSC must be inside the TSL boundaries defined in the BTS side• When modifying EDAP the size of EDAP in the BTS has to be the same as the size of EDAP in the

BSC

• Creating, modifying or deleting of EDAP in the BSC will cause a territory downgrade/upgrade procedure to all territories served by the PCU in question

• The ongoing EGPRS/GPRS connections will pause and resume immediately

• The maximum EDAP size is 12 timeslots

• EDAP must be located on the same ET-PCM line as TRX signaling and traffic channels

• There are no specific commissioning tests concerning EDAP

• EDAP must be located on the same BCSU as Gb interface

Enabling (E)GPRS

Date post:	27-Nov-2015
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Nokia PS- (e)Gprs Explain

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