Speech decoding

Channel decoding

De-interleaving

Burst Formatting

De-ciphering

DemodulationModulation

Ciphering

Burst Formatting

Interleaving

Channel Coding

Speech coding

Radio Interface

Speech Speech

13 Kbps

22.8 Kbps

22.8 Kbps

33.6 Kbps

33.6 Kbps

270.83 Kbps

CM

MM

RR

LAPDm

MS

RR

LAP Dm

Um

LAPD

BTSM

LAPD

Abis

RR

BTSM SCCP

MTP3

BS SAP

BTS BSC

MTP2

SCCP

MTP3

BS SAP

MTP2

CM

MM

MSC

A

Trafficchannels

(TCH)

Signalingchannel

TCH/F: Full-rate Traffic Channel

TCH/H: Half-rate Traffic Channel

FCCH: Frequency correction

SCH: Synchronization

BCCH: Broadcast control

PCH: Paging

AGCH: Access grant

RACH: Random accessSDCCH: Stand-alone dedicated control

SACCH: Slow associated control

FACCH: Fast associated control

Two-way

Base-to-mobile

Two-way

Logical Channel List

BCH

CCCH

DCCH

Logical Channels Characteristics

LogicalChannel

Uplink-only

Downlink-only

Both uplink& downlink

Point-to-pint

Broadcast Dedicated shared

BCCHFCCHSCHRACHPCHAGCHSDCCHSACCHFACCHTCH

√

√√√

√√ √

√

√√√√√√√

√√√

√√√√

√√√√√√

√√

Message name Transmitted by

AUTHENTICATION REQUESTAUTHENTICATION RESPONSEAUTHENTICATION REJECTIDENTITY REQUESTIDENTITY RESPONSETSMI REALLOCATION COMMANDLOCATION UPDATING REQUETLOCATION UPDATING ACCEPTLOCATION UPDATING REJECTIMSI DETACH REQUESTCM SERVICE REQUESTCM RE-ESTABLISHMENT REQUESTMM-STATUS

BaseMobileBaseBaseMobileBaseMobileBaseBaseMobileMobileMobileMobile/Base

Mobility Management Messages

Message nameStarting a call

Transmitted by

SETUPEMERGENCY SETUPCALL PROCEEDING

PROGRESSCALL CONFIRMED

ALERTINGCONNECT

Mobile/basemobile

basebase

mobilemobile/basemobile/base

During a callSTART DTMFSTOP DTMF

MODIFYUSER INFORMATION

Mobilemobile

mobile/basemobile/base

Ending a callDISCONNECT

RELEASERELEASE COMPLET

Mobile/basemobile/basemobile/base

Abnormal conditionsSTATUS

STATUS ENQUIRYCONGESTION CONROL

Mobile/basemobile/basemobile/base

Call management messages

Message name Logical channel Transmitted by

SYNC CHANNEL INFORMATIONSYSTEM INFORMATION (TYPE 1,2,3,4,5)SYSTEM INFORMATION (TYPE 6)CHANNEL REQUESTPAGING REQUEST (TYPE 1,2.3)IMMEDIATE ASSIGNMENTIMMEDIATE ASSIGNMENT EXTENDEDIMMEDIATE ASSIGNMENT REJECTASSIGNMENT COMMANDADDITIONAL ASSIGNMENTPAGING RESPONSEMERSUREMENT REPORTHANDOVER COMMANDHANDOVER ACCESSPHYSICAL INFORMATIONHANDOVER COMPLETECIPHERING MODECHANNEL RELEASEPARTIAL RELEASEFREQUENCY REDEFINITION

CLASSMARK CHANGE

CHANNEL MODE MODIFYRR STATUS

SCHBCCHSACCHRACHPCHAGCHAGCHAGCHFACCHFACCHSDCCHSACCHFACCHTCHFACCHFACCHFACCHFACCHFACCHSACCHFACCHSACCHFACCHFACCHFACCHSACCH

BaseBaseBaseMobileBaseBaseBaseBaseBaseBaseMobileMobileBaseMobileBaseMobileBaseBaseBaseBase

Mobile

BaseMobile/base

Radio Resources Management Messages

Mobilestation

Basestation

Category Logical Channel

SYNC CHANNEL INFORMATION

Carrier sine wave

SYSTEM INFORMATION TYPE3

CHANNEL REQUEST

IMMEDIATE ASSIGNMENT

LOCATION UPDATING REQUEST

AUTHENTICATION REQUEST

CIPHERING MODE COMMAND

CIPHERING MODE ACK

LOCATION UPDATING ACCEPT

TMSI ALLOCATION COMPLETE

AUTHENTICATION RESPONSE

CHANNEL RELEASE

RRM

RRM

RRMRRM

MMMMMM

MMMM

RRMRRM

RRM

FCCH

SCH

BCCH

RACHAGCH

SDCCHSDCCHSDCCHSDCCHSDCCH

SDCCHSDCCHSDCCH

Location-Updating Procedure

Mobilestation

Basestation

Category Logical Channel

RRMRRMRRMRRMRRMRRMMMMMRRMRRMCMCMCMCMRRMRRMCM

CMCMCMRRM

FCCHSCHBCCHPCHRACHAGCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCHFACCHTCHTCHFACCHFACCHFACCHFACCH

Carrier sine waveSYNC CHANNEL INFORMATIONSYSTEM INFORMATIONPAGING REQUESTCHANNEL REQUESTIMMEDIATE ASSIGNMENTPAGING RESPONSEAUTHENTICATION REQUESTAUTHENTICATION RESPONSECIPHERING MODECIPHERING MODE ACKSETUPCALL CONFIRMEDALERTINGCONNECTASSIGNMENT COMMANDASSIGNMENT ACKCONNECT ACKconversationconversationconversationDISCONNECTRELEASERELEASE COMPLETECHANNEL RELEASE

Call Deliver to MH

Mobile-Assisted HandoverMobilestation

Basestation

Logical Channel

TCHTCHSACCHTCHTCHTCHSACCHTCHFACCHnew TCHTCHTCHTCH

FACCHTCHTCHSACCHTCHTCHTCHSACCHTCH

conversationconversation

MEASUREMENT REPORTconversationconversationconversation

MEASUREMENT REPORTconversation

HANDOVER COMMANDHANDOVER ACCESSHANDOVER ACCESSHANDOVER ACCESS

PHYSICAL INFORMATIONHANDOVER COMPLETE

conversationconversation

MEASUREMENT REPORTconversationconversationconversation

MEASUREMENT REPORTconversation

GSM Registration (simplified)• When an MS needs registration (first turned on, found the current cell has a

different ID)1. MS sends Channel Request to BSC2. BSC replies with Activation Response3. MS sends Activation ACK4. BSC assigns a channel to process registration5. MS sends Location Update Request to MSC6. MSC replies with Authentication Request7. MS replies with Authentication Response8. MSC checks the authentication9. MSC assigns TMSI to MS10. MS sends ACK for TMSI11. MSC updates VLR and HLR12. BSC informs the MS to release the channel for registration

Location Registry

Location Registry

• Registration Message Flow– Inter-LA movement• In the same MSC

– Inter-MSC movement• In the same GSM Operator

– Inter-VLR movement

Registration Message Flow-- Inter-LA Movement

1

2

3

4

HLR

MSC2

LA2LA1

MSC1

VLR2VLR1

17

Mobile Switching

Center

VLR

old BSS

1

3

24

5 6

78

GSM: handoff with common MSC

new BSS

1. old BSS informs MSC of impending handoff, provides list of 1+ new BSSs

2. MSC sets up path (allocates resources) to new BSS

3. new BSS allocates radio channel for use by mobile

4. new BSS signals MSC, old BSS: ready 5. old BSS tells mobile: perform handoff to

new BSS6. mobile, new BSS signal to activate new

channel7. mobile signals via new BSS to MSC: handoff

complete. MSC reroutes call8 MSC-old-BSS resources released

Call Setup

MS BSS MSC/VLR HLR PSTN

Channel REQuest

IMMediate ASSignComplete layer 3 Info,

AUThentication REQuest

TMSI REALlocation CoMmanD

SETUP

Mobile-originated call, mobile to land call flow (part 1 of 2)

AUThentication RESponse

Cipher Mode CompleteCipher Mode CMD

Cipher Mode CMDCipher Mode Complete

TMSI REALlocation COMplete

MS BSS MSC/VLR HLR PSTNCALL PROCeeding

Mobile-originated call, mobile to land call flow (part 2 of 2)

Assignment Request

ASSignment CoMmanD

Assignment CompleteAssignment Complete

Initial Address Message (IAM)

Address Complete message (ACM)Alerting

Answer Signal/answer Message(ANM)connect

Connect Acknowledge

PriorMSC

PriorVLR HLR

ServingVLR

ServingMSC

ServingBase

Call setup to a roaming subscriber

Receive callsetup request

LOCATION REQUEST INVOKE

ROUTE REQUEST INVOKE

ROUTE REQUEST INVOKE

ROUTE REQUEST RESULT

ROUTE REQUEST RESULT

LOCATION REQUEST RESULT

Call setup request

(temporary phone number) Page command

PAGE

Delete MIN

conversation VMPS call setup

GMSC

MSC/VLR

BSC

HLR

BTS BTS BTS

MSISDN

MSISDN

MSRN

IMSI

MSISDN-->IMSI-->MSC/VLR Service Area

IMSI<-->MSRN

6.

1.3.

5.

4.

7.

8.

8. 9.

2.

PSTN5.

Call Delivery

MS BSS MSC/VLR HLR PSTN

Mobile-terminated call, land to mobile call flow (part 1 of 2)

Send routing info.Provide roaming numberRoaming number

Routing informationInitial address message

Paging commandPaging request

Channel requestImmediate assign

Complete layer 3 info.Authentication requestAuthentication response

Cipher mode cmdCipher mode cmd

Cipher mode cmdCipher mode complete

Mobile-terminated call, mobile to land call flow (part 2 of 2)

MS BSS MSC/VLR HLR PSTNTMSI reallocation commandTMSI reallocation completeSETUPCall confirmed

Assignment requestAssignment command

Assignment completeAssignment complete

alerting

connect

Connect acknowledge

Address complete message

Answer signal /answer message

Handover

MS BSS MSC VLR HLR VLR

Location Update in new MSC

Authenticate

Authentication Resp,

Start ciphering

Forward new TMSI

Loc.n area up. acc

Send para(authentication)

Authentication Prar.

Update location

Insert subscriber data

Subs. Data Ins. Acc.Loc.n update acc

Cancel location

Loc.n cancellation acc.

Location update call flow

Registration Message Flow-- Inter-MSC Movement

1

2

3

4

5

6

LA2

MSC2

HLR

LA1

MSC1

VLR1VLR2

Inter-MSC handover

BSS1 MSC-A MSC-B BSS2 VLR-B

Handover request

MS

Perform handover Allocate handover numberHandover request

Send handover reportHandover request ack

Radio channel ackInitial address messageAddress complete message

Handover commandHandover command

Handover accessHandover detect physical information

Handover completeHandover complete

Answer signalSend end signal

Clear commandClear complete End signal

Remove handover report

HLR

VLR

GMSC

MSC

MSISDN

MSISDN

MSRN

MSRNIMSI

IMSI

MSRN

MSRN

1

2

3 45

6

The Use of MSRN

PSTN