Call management

8/12/2019 Call management

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Course Outlines• 1-basic communication concepts

• 2-GSM introduction

• 3-GSM system architecture

• 4-GSM system interface

• 5-GSM radio Link

• 6-Mobility Management

• 7-call management

• 8-Radio Resource Management

• 9-GSM system Services



CALL MANAGEMENT

Objectives:1-Mobile-to-land call scenario

2-Land-to-Mobile call scenario

3-Mobile-to-Mobile call scenario



1-Mobile to Land

• Phases:

• 1-Request for service

• 2-Authentication

• 3-Ciphering

• 4-Equipment Validation

• 5-Call Setup

• 6-Handover • 7-Call release



Mobile to Land (cont.)

• Phase 1: REQUEST FOR SERVICE

MS BSS MSC/VLRUm A

1Channel Request

RACH

2

3

SDCCH AssignmentAGCH

SDCCHService Request



2-Authentication Phase

MS BSS

MSC/VLR

HLR

Um A

2

Get Authentication parameters(IMSI)

1

4

Authentication parameters

(SRES,Kc,RAND)Authenticate MS

(RAND)

3SDCCH

SDCCH

Authentication Response

(SRES)



3-Ciphering Phase

MS BSS

MSC/VLR

Um A

2

1

4

Cipher-Uplink-channel

3

SDCCHUplink-channel-Ciphered

SDCCH

Cipher-radio-channel (Kc)

Ciphering Complete



4-Equipment Validation Phase

MS BSS

MSC/VLR

EIR

Um A

2

1

4

3

IMEI Response (IMEI)

SDCCH

IMEI Request

IMEI Check Result

SDCCH

Check IMEI




• Phase 5: Call Setup Phase

MS BSS MSC/VLRUm A

1Call Setup Request

SDCCH

2 Call proceeding

SDCCH




• Phase 5: Voice Path Establishment {with MS-MSC}

MS BSS MSC/VLRUm A

1

Assign Trunk&Radio

2Assign TCH

SDCCH

3Radio Assignment Complete

SDCCH Trunk & Radio Channel

Assignment Complete4




• Phase 5: Voice Path Establishment {with MSC-PSTN}

MS MSC

/VLR

Um ABSS PSTN

1 Network Setup (DD)

2 Network Alerting

3FACCH

Alerting

4Connect (answer)

Start Billing5

ConnectFACCH

6

Connect Aknowledge

FACCH




• Phase 7: Call Release

MS MSC

/VLR

Um ABSS PSTN

2 Network Release

3 FACCH

Releasestop Billing

1Disconnect

FACCH

4

Release Complete

FACCH

Clear Command5

Channel ReleaseFACCH6

7Clear Complete



2- Land to Mobile

• Phases:• 1-Routing Analysis

• 2-Paging

•

3-Authentictaion• 4-Ciphering

• 5-Equipment Validation

•

6-Call Setup• 7-Handover • 8-Call release



Land to Mobile (cont.)

• Phase 1: Routing Analysis

MSC

/VLR

GMSC

HLR PSTN

Incoming Call (MSISDN)

Get Rout (MSISDN)

Get Rout (IMSI)

Routing info (MSRN)

Routing info (MSRN)

Incoming Call (MSISDN)

1

2

3

5

4




• Phase 2: Paging Phase

MS BSS MSC/VLRUm A

1

Channel Request

RACH

2

3

SDCCH Assignment

AGCH

SDCCH

Page Response (TMSI,LAI)

Perform Page (TMSI)Page

PCH

4

5

Page Response

6



3-Authentication Phase

MS BSS

MSC/VLR

HLR Um A

2

Get Authentication parameters(IMSI)

1

4

Authentication parameters

(SRES,Kc,RAND)Authenticate MS

(RAND)

3

SDCCH

SDCCH

Authentication Response

(SRES)



4-Ciphering Phase

MS BSS

MSC/VLR

Um A

2

1

4

Cipher-Uplink-channel

3

SDCCHUplink-channel-Ciphered

SDCCH

Cipher-radio-channel (Kc)

Ciphering Complete



5-Equipment Validation Phase

MS BSS

MSC/VLR

EIR

Um A

2

1

4

3

IMEI Response (IMEI)SDCCH

IMEI Request

IMEI Check Result

SDCCH

Check IMEI




• Phase 6: Call Setup Phase

MS BSS MSC/VLRUm A

1 Call Setup Request

SDCCH

2 Call Setup confirmation

SDCCH




• Phase 6: Voice Path Establishment {with MS-MSC}

MS BSS MSC/VLRUm A

1

Assign Trunk&Radio

2Assign TCH

SDCCH

3

Radio Assignment Complete

SDCCH Trunk & Radio Channel

Assignment Complete4




• Phase 6: Land Network

MS MSC

/VLR

Um ABSS PSTN

1Mobile Alerting

2 Network Alerting

3FACCH

4

Connect

Connect-off Hook

5Connect Acknowledge

FACCH

FACCH

GMSC




• Phase 8: Call Release

MS MSC

/VLR

Um ABSS PSTN

1 Network Release

3 FACCHRelease

2Disconnect

FACCH

4

Release Complete

FACCH

Clear Command5

Channel ReleaseFACCH6

7Clear Complete

GMSC

HLR



3-Mobile To Mobile Call scenario

• The Mobile-to-Mobile call is established

using the same phases as seen earlier.

• It can be subdivided in two parts:

• 1-Originating Mobile

• 2-Terminating Mobile



Course Outlines• 1-basic communication concepts

• 2-GSM introduction

• 3-GSM system architecture

• 4-GSM system interface

• 5-GSM radio Link

• 6-Mobility Management

• 7-call management

• 8-Radio Resource Management

• 9-GSM system Services

Documents

Call management