gsm call flow procedures

GSM CALL FLOW PROCEDURES

Quality of Service Team

Compiled By: Sarmad khalique

GSM Signalling Matrix:

Air

MTP Level 2 & 3

SCCP

TCAP

ISUP TUPMAP

BSSAP

MTP Level 1

DTAPBSSMAP

Databases PSTN

MSC G.703

LAPD

RSM 08.58

MTP Level 2, 3

SCCP

BSSAP

MTP Level 1

BSSMAP

LAPDm

RIL3

Rad Int

DTAP RR

MS G.703 LAPD

RSM 08.58

LAPDm

RIL3

Rad IntBTS BSC

Abis A The fig above gives an overview of GSM Protocol Matrix. The MSC uses ISUP/TUP protocols for PSTN signaling. It has MAP for signaling to database applications like HLR, VLR, EIR, AUC, SMSSC, and GMSC. On the A interface it has GSM specific protocol as BSSAP. The BSSAP comprises of DTAP and BSSMAP. DTAP signaling is direct signaling between mobile and MSC, whereas BSSMAP is mobile related signaling between MSC and BSC. The BSC also uses the BSSAP but only the BSSMAP part of it for MSC. On the BTS side GSM has defined its own set of protocols in 08.58 which have no official name but we term it as RSM (Radio Subsystem Management. The BSC on layer 2 uses Lapd (Link Access Procedures on D - Channel) which is an ISDN protocol and includes functions for error correction and detection and frame delimitation by insertion of flags. The BTS on the mobile has again set of GSM protocols for physical layer which is the Radio Air Interface and uses Lapdm for Layer 2 signaling. This is a modified Lapd protocol with one difference being some Lapd functions like error correction are removed and used at Layer 1, and second major difference being the Lapdm messages cannot be lengthy due limitation of burst length. The BTS on the Mobile user part uses RIL3 which is again a GSM protocol for Radio Resource Management. The Mobile on the other hand in RIL3 has DTAP for MSC signaling and RR for Radio Resource signaling. MAP (Mobile Application Part) Messages:

• MAP messages are between Switching and Database interfaces • MAP messages are not present on the Air Interface • Not much significance related to Drive Testing • Can be useful in analyzing some Protocol failures experienced on the air

interface during drive testing.

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BSSAP (BSS Application Part):

SCCP

BSSAP

MTP

DTAP BSSMAP

Distribution Layer

SCCP

BSSAP

MTP

DTAP BSSMAP

Distribution Layer

MSC BSCBTS

DTAP

BSSMAP

BSSAP is used between BSC and MSC on A interface. It uses the services of MTP and SCCP and hence it is based on C7. BSSAP deals with signaling between MSC and BSC and also MSC and Mobile. BSSAP has two subsets the DTAP and the BSSMAP. DTAP deals with the signaling messages directly between the MSC and Mobile. The BSC and/or BTS just routes theses messages. DTAP messages are all connection oriented messaged. BSSMAP messages are MS related messages but originate and terminate at the BSC, from where BSC modifies the message and send it across in different message (RSM, 08.58 messages). The distribution layer does the function of distribution of message to DTAP and BSSMAP. It does this by identifying certain parameter in the BSSAP message which is explained on next message. BSSAP supports both connectionless and connection-oriented signaling. Messages like paging, reset are sent in CL mode, (Message lists are give further). BSSMAP:

• Between BSC and MSC • Linked to certain messages on the Air Interface • Useful in troubleshooting certain Blocked Calls and Dropped Calls

problems in conjunction with Drive Testing DTAP (Direct Transfer Application Part):

• Transparent Messages between MSC and MS • Further divided into sub-categories ( MM ,CC,SMS,SS)

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BSSMAP Messages: Connectionless MessagesBlock Block Acknowledge Paging Reset Reset Acknowledge Reset Circuit Reset Circuit Acknowledge Resource Indication Resource Request Unblock Unblocking Acknowledge Connection Oriented Messages Assignment Complete Assignment Failure Assignment Request Candidate Response Cipher Mode Command Cipher Mode Complete Classmark Update Complete Layer 3 Information Handover Candidate Enquiry Handover Command Handover Complete Handover Detect Handover Failure Handover Performed Handover Request Handover Request Acknowledge Handover Required Reject Trace Invocation Queuing Indication Types of DTAP Messages:

• CC : Call control and call related SS Messages Related to call setup and activation/deactivation of SS between.

• MM : Mobility Management Messages Location updates, security procedures and connection management.

• SS : Non-Call related Supplementary Messages Like call barring, call forwarding etc.

• SMS : Short Message Service Messages Related of transmission and reception of SMS

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DTAP Messages: MM Message Authentication Request Authentication Response CM Re-Establishment Request CM Service Accept CM Service Reject CM Service Request Identity Request Identity Response IMSI Detach Location Updating Accept Location Updating Reject Location Updating Request TMSI Reallocation Command TMSI Reallocation Complete CC Messages Alerting Call Confirmed Call Proceeding Connect Connect Acknowledge Disconnect Emergency Setup Facility Hold Hold Acknowledge Modify Modify Complete Notify Progress Release Release Complete Retrieve Retrieve Acknowledge Setup SS Messages Hold Hold Acknowledge Hold Reject Retrieve Retrieve Acknowledge Retrieve Reject Facility Register SMS Messages CP-Ack CP-Data

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CP-Error RP-Ack RP-Data RP-Error Note: All types of DTAP messages described above are RIL 3 (Radio Interface layer 3) messages. Air Interface:

LAPDm

RIL3

Rad IntBTS

LAPDm

RIL3

Rad Int

DTAP

RR

MS

04.04 04.04

04.08/ 04.10 04.08/ 04.10

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Radio Interface (Layer 1): Following are the functions of layer 1:

• Mapping of Logical Channels to Physical Channel • Channel Coding • Ciphering • Cell Selection and Reselection • Connection Establishment on Logical Channels • Measurement of serving and neighboring cells signal level • Setting of Timing Advance • Transmit Power Control as commanded by BTS.

Radio Interface (Layer 3) Messages Categories: DTAP Messages: Transparent to BSC, CC, MM, SS, SMS as described earlier. RR Messages: Radio Resource messages specific to BTS and MS. Test Messages: Related to testing procedure (Like Loop back etc). RR Messages: Assignment Command Assignment Complete Assignment Failure Channel Mode Modify Channel Mode Modify Acknowledge Channel Release Channel Request Ciphering Mode Command Ciphering Mode Complete Classmark Change Frequency Redefinition Handover Access Handover Command Handover Complete Handover Failure Immediate Assignment Immediate Assignment Extended Immediate Assignment Reject Measurement Report Paging Request Type 1 Paging Request Type 2 Paging Request Type 3 System Information Type 1 System Information Type 2 System Information Type 3 System Information Type 4 System Information Type 5 System Information Type 6 System Information Type 2bis . etc.

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Mobile Phone Mode:

RR Idle Mode

RR Connection Establishment Mode

RR Connected Mode

MM Connection Establishment Mode

MM Connected Mode

Call Control Process

BCCH & PCH RACH & AGCH SDCCH Initial Message

Initial Message Ack

CC ReleaseMM ReleaseRR Release

Access Procedure (RACH/AGCH)

MM CM Procedure (SDDCH)

MM Common Procedures (SDDCH)

MM Specific Procedures (SDDCH)

Release Procedures (SDDCH)

Access Procedure (RACH/AGCH)

MM CM Procedure (SDDCH)

MM Common Procedures (SDDCH)

CC Procedures (SDDCH)

RR Procedures (TCH) CC Procedures (TCH)

Release Procedures (SDDCH)

Non-call Related Call Related

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Air Interface - Layer 2 Signaling:

LAPDm (Link Access Protocol on Dm):

• LAPDm signaling is done using Frames. • LAPDm frames contain Address, Control and L3 information. • LAPDm has a window size of 1 (every frame sent must be acknowledged

before next is sent, in acknowledge mode) • Lapdm frame supports maximum 23 octets only • Lapdm frame structure has no flags (since blocks channels available). • Lapdm has two SAPI (Service Access Point Identifier). SAPI 0 for RR and

DTAP signaling & SAPI 3 for SMS. The data Link of LAPD is based on HDLC and uses two modes of operations, the Acknowledge mode and Unacknowledged mode. In the acknowledge mode every frame sent must receive acknowledgement whereas for unacknowledged mode no acknowledge is required for the frames sent. There in general 3 types of HDLC and hence LAPD frames U - Frames which set up the acknowledge mode and does unacknowledged mode Information transfer I - Frames which the actual signaling or information data in acknowledge mode S-Frame which maintains the flow of I-frames by acknowledging or requesting retransmission of I-frames.

LAPDm

RIL3

Rad Int BTS

LAPDm

RIL3

Rad Int

DTAP

RR

MS

04.04 04.04

04.08/ 04.1004.08/ 04.10

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LAPD Frames: Unnumbered Frames: SABM (Set Asynchronous Balance mode): This frame is sent to begin acknowledge mode of information transfer (I -frame) Disc (Disconnect Mode): This frame is sent to terminate acknowledge mode of Information Transfer UI (Unnumbered Information): This is used for Unacknowledged Information transfer UA (Unnumbered Acknowledge): This is used to acknowledge the SABM & DISC frames DM (Disconnect Mode): This indicates the disconnection and SABM could be performed These frames don't use sequencing [N(R) & N(S)] Information Frames: These frames are used to transfer Layer 3 Information (RSL, OML, L2M messages) in sequence that is in acknowledged mode. These frames use Sequencing Supervisory Frames: RR (Receive Ready): Positive Acknowledgement. RNR (Receive Not Ready): Stop sending messages (buffer is full). REJ (Reject) : Negative Acknowledgement These Frames uses Sequencing [only N (R)]

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LAPDm Frames Flow:

Layer 2

Layer 2

Layer 3

Layer 2

Layer 3

Layer 2

SABM

UA

I - frame (C)

RR

Disc

I - frame (R)

DM (or UA)

RR

Layer 2

Layer 2

Acknowledge Mode

Call Procedures are explained in great detail in the next section.

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MS Terminated Call Procedure

B MSC PSTNHLR GMSC

D C VLR

MAP_SEND_ROUTING_

INFORMATION

IAI (TUP)

MAP_PROVIDE_ROAMING_

NUMBER

MAP_PROVIDE_ROAMING_

NUMBER ACK

MAP_SEND_ROUTING_

INFORMATION ACK

IAI (TUP)

MAP_SEND_INFO_I/C_CALL

MAP_PAGE

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MS Terminated Call ProcedureContinue 1

MS MSCBTS BSC

(IMSI/TMSI,LAI or CGI)

(IMSI/TMSI,pag group,ch)

Channel Request

Channel Required

Channel Activation

Channel Activation ACK

Immediate Assignment(L2 - UI)

A interfaceAbis interfaceUm interface

BSSMAP

Paging RESP (L2-SABM)

EST IND(Paging Resp)

Paging Resp

CR(COMPL - L3 - INFO)L2 - UA

(CKSN,MS ID,CGI,CLrk2)

CC

RR(SDCCH)

RR(SDCCH)BSSMAP

Paging

Immediate Assign Command

T3113 +

T3113 -

3120 +

3120 -

T3101 +

T3101 -

Paging(UDT)

Paging Command

Paging Request (L2-UI)

RR(PCH)(IMSI/TMSI)

RR(RACH) T

RR(AGCH) T

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MS Terminated Call Procedure

Continue 2

MM(SDCCH)

MM(SDCCH)

RR(SDCCH)

RR(SDCCH)

BTS

DATA REQ<AUTH>

ENCR CMD

CIPHER MOD CMD

Abis interfaceUm interface

AUTH RESPONSE

DATA IND<AUTH>

CIPHER MOD COM

BSC

AUTH REQUEST (DT1)

(CKSN, RAND)

AUTH RESPONSE (DT1)

A interface

CIPHER MOD CMD(DT1)

(algo nb,key)

(SRES)

DATA IND

<CIPH MOD COM>CIPHER MOD COM(DT1)

BSSMAP

DATA REQ

TMSI REAL CMD

TMSI REAL COMDATA IND

(new TMSI,LAI)<TMSI REAL CMD>

<TMSI REAL COM> TMSI REAL COM (DT1)

TMSI REAL CMD (DT1) DTAP-MM

DTAP-MM

MAP_AUTHENTICATE

MAP_AUTHENTICATE ACK

MAP_SET_CIPHERING_MODE

MAP_FORWARD_NEW_TMSI

MAP_FORWARD_NEW_TMSI ACK

B interface

T3260 +

T3260 -

MAP_PROCESS_ACCESS_REQ

MAP_PROCESS_ACCESS_REQ_ACK

MS MSC VLR

DTAP-MM

AUTH REQUEST

DTAP-MM

BSSMAP

MM(SDCCH)

MM(SDCCH)

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A interface B interface

CC(SDCCH)

CC(SDCCH)

DTAP-CC

DTAP-CC

MS BTSUm interface

CALL CONFIRMED

DATA IND

<SET UP>

<CALL CONF>

Abis interfaceBSC MSC VLR

MAP_COMPLETE_CALL

SET-UP (DT1)T303 +

DATA REQ

SET-UP

CALL CONF (DT1) T303 -T310 +

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MS MSCBTS BSC

(Ch type,CIC,L3 hd)

QUEUING(DT1)Channel ACTIV

DATA REQ


RELEASE REQ

RR(FACCH)

A interfaceAbis interface

BSSMAP

PHYS CTX CONF

(TCH)

<ASSIGN CMD>

RR(SDCCH)

(local end)(L2 - SABM)

EST IND

RR(FACCH)

RR(FACCH)DATA IND

<ASSIGN COM>ASSIGN COM(DT1)

RF CHAN REL

(SDCCH)

BSSMAP

RF CHAN REL ACK

(BS/MS POW,TA)

CC

TNT2 +

TNT2 -

T9103 +

T9103 -

Um interface

ASSIGN REQ(DT1)

PHYS CTX REQ

BSSMAP

ASSIGN CMD

(L2 - UA)

ASSIGN COM

Radio-resourceassignment

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Um interfaceMS MSC

CC(FACCH)

CC(FACCH)

DTAP-CC

DTAP-CC

ALERTING

CONNECT

CONNECT (DT1)

CONNECT ACK (DT1)DTAP-CC

BTS

DATA IND

Abis interface

DATA IND

<ALERT>

<CONNECT>

BSC

ALERTING (DT1)

A interface

DATA REQ<CONNECT ACK>

CONNECT ACK

ACM(TUP)

ACM(TUP)

ANC(TUP)

ANC(TUP)

E interface

T310 -T301 +

T301 -

T313 -

T313 +

GMSC PSTN

CC(FACCH)

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(Mobile Release First)

Um MS

(L2 - UA)

RR(FACCH)

DTAP-CC

DTAP-CC

BSSMAP

BTS

DATA IND

<RELASE COM>

RF CHAN REL ACK

DEACT SACCH

BSC

DISCONNECT(DT1)

RELEASE(DT1)

DATA REQ

DATA INDRELEASE COM(DT1)

CLEAR CMD(DT1)

A Abis

<REL>

DATA REQ

CLEAR COM(DT1)RF CHAN REL

<DISC>

<CHAN REL>

REL IND

<RLSD>

<RLC>

GMSC PSTN

CBK(TUP)

CBK(TUP)

CLF(TUP)

CLF(TUP)

RLG(TUP)

RLG(TUP)

E

DEACT SACCH ACK

T308 +

T308 -

TNT3 +

TNT3 -

T3109 +

T3109 -T3111 +

T3111 -

MSC

DISCONNECTCC(FACCH)

RELEASECC(FACCH)

RELEASE COMCC(FACCH)

DTAP-CC

BSSMAP

CHAN REL

(L2 - DISC)RR(FACCH)

RR(FACCH)

Radio-resourcerelease

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MS MSC

RELEASE COM(DT1)

(L2 - UA)

RR(FACCH)CHAN REL

(L2 - DISC)RR(FACCH)

RR(FACCH)

CLEAR COM(DT1) BSSMAP

BTS

<RELASE COM>

DATA REQ

RF CHAN REL

RF CHAN REL ACK


<DISC>

<CHAN REL>

DEACT SACCH

REL IND

BSC

DISCONNECT(DT1)

RELEASE(DT1)

CLEAR CMD(DT1)

A

<RLSD>

<RLC>

(Mobile Release last)

GMSCCLF(TUP)

CLF(TUP)

RLG(TUP)

RLG(TUP)

DEACT SACCH ACK

T305 +

T305 -

TNT3 +

TNT3 -

T3109 -T3111 +

T3111 -

T3109 +

EAbis UmPSTN

DATA REQ DTAP-CC

DISCONNECTCC(FACCH)

RELEASECC(FACCH)

DATA INDDTAP-CC

<REL>

DTAP-CC

DATA REQ

RELEASE COMCC(FACCH)

BSSMAP

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Mobile - Originating Call Procedure

MS MSCBTS BSC

Channel Required

Channel Activation



Abis interface

CM SERV REQ (L2-SABM)

EST IND<CM SERV REQ>

<CM SERV REQ>CR(COMPL - L3 - INFO)

L2 - UA

(CKSN,MS ID,SER type,CLmk)

CC

BSSMAP


(SDCCH ID)

T3120 +

T3120 -

T3101 +

T3101 -

T303 +

VLR


B interfaceA interfaceUm interface

Channel RequestRR(RACH)

RR(AGCH)

RR(SDCCH)

RR(SDCCH)

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Continue 1

BTSAbis interfaceUm interface

BSCA interface B interface

MS MSC VLR

MM(SDCCH)

MM(SDCCH)

RR(SDCCH)

RR(SDCCH)

DATA REQ<AUTH>

AUTH REQUEST

ENCR CMD

CIPHER MOD CMD

AUTH RESPONSE

DATA IND<AUTH>

CIPHER MOD COM

AUTH REQUEST (DT1)

(CKSN, RAND)

AUTH RESPONSE (DT1)

CIPHER MOD CMD(DT1)

(algo nb,key)

(SRES)

DATA IND

<CIPH MOD COM> CIPHER MOD COM(DT1)BSSMAP

DATA REQTMSI REAL CMD

TMSI REAL COM

DATA IND



TMSI REAL CMD (DT1)DTAP-MM

DTAP-MM

MM(SDCCH)

MM(SDCCH)

MAP_AUTHENTICATE





T3260 +

T3260 -


DTAP-MM

DTAP-MM

BSSMAP

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Mobile - Originating Call ProcedureContinue2

CC(SDCCH)

CC(SDCCH)

BTSUm interface

CALL PROCEEDING

DATA REQ

BSC

SET-UP (DT1)

CALL PROCEEDING (DT1)

A interface

<SET UP>

<CALL PROC>

T303 -T310 +

MAP_SEND_INFO_FOR_O/G_CALL

VLRB interface

MAP_COMPLETE_CALL

Abis interfaceMS MSC

SET-UP

DATA IND

DTAP-CC

DTAP-CC

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Continue 3

MS MSCBTS BSC

ASSIGN REQ(DT1)

(Ch type,CIC,L3 hd)

QUEUING(DT1)Channel ACTIV

DATA REQ


RELEASE REQ

RR(FACCH)


BSSMAP

PHYS CTX CONF

(TCH)

<ASSIGN CMD>

RR(SDCCH)

(local end)(L2 - SABM)

EST IND(L2 - UA)

RR(FACCH)

RR(FACCH)DATA IND

<ASSIGN COM>ASSIGN COM(DT1)

RF CHAN REL

(SDCCH)

BSSMAP

RF CHAN REL ACK

(BS/MS POW,TA)

Radio-resourceassignment

CC

T9103 +

T9103 -

TNT2 +

TNT2 -

Um interface

PHYS CTX REQ

BSSMAP

ASSIGN CMD

ASSIGN COM

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Mobile - Originating Call ProcedureContinue 4

Um interfaceMS MSC

CC(FACCH)

CC(FACCH)

DTAP-CC

DTAP-CC

ALERTING

CONNECT

CONNECT (DT1)

CONNECT ACK (DT1)

DTAP-CC

BTS

DATA REQ

Abis interface

DATA REQ

<ALERT>

<CONNECT>

BSC

ALERTING (DT1)

A interface

DATA IND

<CONNECT ACK>

CONNECT ACK

ACM(TUP)

ACM(TUP)

ANC(TUP)

IAI(TUP)

IAI(TUP)

ANC(TUP)

E interface

T310 -

T313 +

T313 -

GMSC PSTN

CC(FACCH)

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(Mobile Release First)

MS

RR(FACCH)

RR(FACCH)

RR(FACCH)

RELEASE COM

BTS

DATA IND

<RELASE COM>

BSC

DISCONNECT(DT1)

RELEASE(DT1) DATA REQ


A Abis

<REL>

<DISC>

(L2 - UA)

CHAN REL

(L2 - DISC)

BSSMAP


BSSMAP

RF CHAN REL ACK

DEACT SACCH

CLEAR CMD(DT1)

DATA REQ


<CHAN REL>

REL IND

<RLSD>

<RLC>

E

DEACT SACCH ACK

T305 +

T305 -T308 +

T308 -

TNT3 +

TNT3 -

T3109 +

T3109 -T3111 +

T3111 -

Um GMSC PSTN

CLF(TUP)

RLG(TUP)

MSC

DTAP-CC

DTAP-CC

RELEASECC(FACCH)

DISCONNECTCC(FACCH)

CC(FACCH)

DTAP-CC

CLF(TUP)

RLG(TUP)

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(Mobile Release Last)

MS

RR(FACCH)

DTAP-CC

DTAP-CC

RR(FACCH)

RR(FACCH)

RELEASE COM

DTAP-CC

BTS

DATA REQ

<RELASE COM>

BSC

DISCONNECT(DT1)

RELEASE(DT1) DATA IND


A Abis

<REL>

<DISC>

RLG(TUP)

(L2 - UA)

CHAN REL

(L2 - DISC)

BSSMAP


BSSMAP

RF CHAN REL ACK

DEACT SACCH

CLEAR CMD(DT1)

DATA REQ


<CHAN REL>

REL IND

<RLSD>

<RLC>

CBK(TUP)

CLF(TUP)

E

DEACT SACCH ACK

T3109 +

T305 +

T305 -T308 +

T308 -

TNT3 +

TNT3 -

T3109 -T3111 +

T3111 -

Um GMSC PSTN

CLF(TUP)

RLG(TUP)

CBK(TUP)

MSC

DISCONNECTCC(FACCH)

RELEASECC(FACCH)

CC(FACCH)

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INTRA_VLR LOCATION UPDATINGOR IMSI ATTACH( in old VLR )

MS MSCBTS BSC

Channel Required

Channel Activation



Abis interface

LOC UPDAT REQ

EST IND<LOC UPA REQ>

<LOC UPDAT REQ>CR(COMPL - L3 - INFO)

(CKSN,MS ID,LUT,LAI,CLmk1)BSSMAP


(SDCCH ID)

(L2-SABM)

**

T3120 +

T3120 -

T3101 +

T3101 -

T3210 +

A interfaceUm interface


RR(AGCH)

RR(SDCCH)

L2 - UARR(SDCCH)

CC

** : This message is sent by the MS to the network either to request update of its location (normal updating or periodic updating) or to request IMSI attach .

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Continue 1Abis interface A interface B interfaceUm interface

MM(SDCCH)

MM(SDCCH)

RR(SDCCH)

RR(SDCCH)

CIPHER MOD CMD

CIPHER MOD COM

AUTH REQUEST (DT1)

(CKSN, RAND)

AUTH RESPONSE (DT1)

CIPHER MOD CMD(DT1)

(algo nb,key)

(SRES)

DATA IND

CIPHER MOD COM(DT1)BSSMAP

(new TMSI,LAI)

TMSI REAL COM (DT1)


DTAP-MM

MM(SDCCH)

MAP_AUTHENTICATE



T3260 +

T3260 -

MAP_UPDATE_

LOCATION_AREA



MAP_UPDATE_LOCATION_AREA ACK

MS BTS BSC MSC VLR

DTAP-MMDATA REQ<AUTH>

AUTH REQUEST

AUTH RESPONSE

DATA IND<AUTH>

DTAP-MM

BSSMAPENCR CMD

<CIPH MOD COM>

DATA REQ<TMSI REAL CMD>TMSI REAL CMD

MM(SDCCH)


<TMSI REAL COM>

27 of 53


Continue 2

Um Abis A MS BTS BSC MSC

RR(SDCCH)

RR(SDCCH)

RR(SDCCH) (L2 - UA)

CHAN REL

(L2 - DISC)

BSSMAP


BSSMAP

RF CHAN REL ACK

DEACT SACCH

CLEAR CMD(DT1)

DATA REQ


<CHAN REL>

REL IND

<RLSD>

<RLC>

DEACT SACCH ACK

TNT3 +

TNT3 -

T3109 +

T3109 -

MM(SDCCH)

DTAP-MMLoc Updat Acc(DT1)

DATA REQ

<Loc Upd Acc>

Loc Upd AccT3210 -

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INTER_VLR LOCATION UPDATING (MS Send IMSI)OR IMSI ATTACH( not in old VLR )

MS MSCBTS BSC

Channel Required

Channel Activation



Abis interface

LOC UPDAT REQ **



L2 - UA

(CKSN,IMSI,LUT,LAI,CLmk1)

CC

BSSMAP


(SDCCH ID)

(L2-SABM)

T3120 +

T3120 -

T3101 +

T3101 -

T3210 +



RR(AGCH)

RR(SDCCH)

RR(SDCCH)

** : This message is sent by the MS to the network either to request update of its location (normal updating or periodic updating) or to request IMSI attach .

29 of 53


Continue 1

MM(SDCCH)

MM(SDCCH)

RR(SDCCH)

DTAP-MM

RR(SDCCH)

DTAP-MM

BSSMAP

MS BTS

DATA REQ<AUTH>AUTH REQUEST

ENCR CMDCIPHER MOD CMD

AUTH RESPONSE

DATA IND<AUTH>

CIPHER MOD COM

MSCBSC

AUTH REQUEST (DT1)

(CKSN, RAND)

AUTH RESPONSE (DT1)

A

CIPHER MOD CMD(DT1)

(algo nb,key)

(SRES)

DATA IND

<CIPH MOD COM>CIPHER MOD COM(DT1)

BSSMAP

DATA REQ

TMSI REAL CMD





DTAP-MM

MM(SDCCH)

MM(SDCCH)

VLR

MAP_AUTHENTICATE



T3260 +

T3260 -

MAP_UPDATE_

LOCATION_AREA



MAP_UPDATE_

LOCATION_AREA ACK

HLR

MAP_INSERT_SUBSCRIBER_DATA

MAP_INSERT_SUBSCRIBER_DATA ACK

MAP_UPDATE_LOCATION ACK

MAP_UPDATE_LOCATION

PVLRDAbisUm B

D

MAP_CANCEL_

LOCATION

MAP_CANCEL_

LOCATION ACK

30 of 53


Continue 2


RR(SDCCH)

RR(SDCCH)

RR(SDCCH) (L2 - UA)

CHAN REL

(L2 - DISC)

BSSMAP


BSSMAP

RF CHAN REL ACK

DEACT SACCH

CLEAR CMD(DT1)

DATA REQ


<CHAN REL>

REL IND

<RLSD>

<RLC>

DEACT SACCH ACK

TNT3 +

TNT3 -

T3109 +

T3109 -

MM(SDCCH)


DATA REQ

<Loc Upd Acc>

Loc Upd AccT3210 -

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INTER_VLR LOCATION UPDATING (MS Send TMSI)

OR IMSI ATTACH( not in old VLR )

MS MSCBTS BSC

Channel Required

Channel Activation



Abis interface

LOC UPDAT REQ



(CKSN,TMSI,LUT,LAI,CLmk1)

CC

BSSMAP


(SDCCH ID)

(L2-SABM)

T3120 +

T3120 -

T3101 +

T3101 -

T3210 +



RR(AGCH)

RR(SDCCH)

L2 - UARR(SDCCH)

32 of 53

INTER_VLR LOCATION UPDATING (MS Send TMSI)OR IMSI ATTACH( not in old VLR )

Continue 1

MM(SDCCH)

MM(SDCCH)

RR(SDCCH)

DTAP-MM

RR(SDCCH)

DTAP-MM

BSSMAP

MS BTS

DATA REQ<AUTH>AUTH REQUEST

ENCR CMDCIPHER MOD CMD

AUTH RESPONSEDATA IND<AUTH>

CIPHER MOD COM

MSCBSC

AUTH REQUEST (DT1)

(CKSN, RAND)

AUTH RESPONSE (DT1)

A

CIPHER MOD CMD(DT1)

(algo nb,key)

(SRES)

DATA IND<CIPH MOD COM>

CIPHER MOD COM(DT1)BSSMAP

DATA REQTMSI REAL CMD



<TMSI REAL COM>TMSI REAL COM (DT1)

TMSI REAL CMD (DT1) DTAP-MM

DTAP-MM

MM(SDCCH)

MM(SDCCH)

VLR

MAP_AUTHENTICATE



T3260 +

T3260 -

MAP_UPDATE_

LOCATION_AREA



MAP_UPDATE_

LOCATION_AREA ACK

HLR

MAP_INSERT_SUBSCRIBER_DATA

MAP_INSERT_SUBSCRIBER_DATA ACK

MAP_UPDATE_LOCATION ACK

MAP_UPDATE_LOCATION

PVLRDAbisUm B

D

MAP_CANCEL_

LOCATION

MAP_CANCEL_

LOCATION ACK

MAP_SEND_IDENTIFICATION

MAP_SEND_

IDENTIFICATION ACK

MAP_PROVIDE_IMSI

MAP_PROVIDE_IMSI ACK

Identity Request

Identity Response

In case of IMSI can

not be retrievefrom PVLR

33 of 53

INTER_VLR LOCATION UPDATING (MS Send TMSI)OR IMSI ATTACH( not in old VLR )

Continue 2


RR(SDCCH)

RR(SDCCH)

RR(SDCCH) (L2 - UA)

CHAN REL

(L2 - DISC)

BSSMAP


BSSMAP

RF CHAN REL ACK

DEACT SACCH

CLEAR CMD(DT1)

DATA REQ


<CHAN REL>

REL IND

<RLSD>

<RLC>

DEACT SACCH ACK

TNT3 +

TNT3 -

T3109 +

T3109 -

MM(SDCCH)


DATA REQ

<Loc Upd Acc>

Loc Upd AccT3210 -

34 of 53

Intra_Cell HandOver

A A-bis Um

MSC BTSBSC MS

L2-SABM

ASSIGN COM

Old channel local end release

RR(FACCH)

RR(FACCH)

T3107 +

T3107 -

<L2-UI>MEAS REP

RR(SACCH)MEAS REP

CHAN ACTIV

(ch typ,Ciph K)(HO Ref)

CHAN ACT ACK

DATA REQ

<ASSIGN CMD>

ASSIGN CMDRR(FACCH)

RR(New FACCH)EST IND

L2-UI

DATA IND

<ASSIGN COM>

HO PERFOMED(DT1)

BSSMAP(Cause: intra_cell)

RF CHA REL

(old TCH)

RF CHA REL ACK

35 of 53

Intra-BSS Handover

A

MSC BTS2BTS1 BSC

A-bis

<HO COMPL>

HO ACCESS

RR(SACCH)

HO ACCESS

PHYS INFO

PHYS INFO

RR(FACCH)

L2-SABM

L2-UI

RR(New FACCH)

HO COMPLET

A-bis

<L2-UI>MEAS REP

MEAS REP

CHAN ACTIV

(ch typ,Ciph K)(HO Ref)

CHAN ACT ACK

DATA REQ

<HO CMD>

HO COMMAND

HO DETECT

ESTA IND

DATA IND

RF CHA REL

(old TCH)

RF CHA REL ACK

RR(FACCH)

BSSMAP

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

T3103 +

T3103 -

T3124 +

T3124 -

Um

MS

HO PERFOMED(DT1)BSSMAP

(Cause)

36 of 53

Intra-MSC Handover

CHAN ACTIV

BTS1

A-bis

BSC2

CC

MSC

HO REQUEST(DT1)

CHA ACT ACK

A-bis

Target BSS <L2-UI>

RR(SACCH)

Cell Id lst,CauseBSSMAP

CR(Ch typ,Clmk)(Cell, Ciph K)

BSSMAP

HO REQ ACK(DT1)

(Cell,Ch Inf,Ho Ref)

BSSMAP

BSSMAP

RR(FACCH)

T7 +

T7 -

T8 +

T101 +

T101 -

T102 +

T9113 +

A A Um

BSC1 BTS2 MS

Serving BSSMEAS REP

MEAS RES

HO REQU(DT1)

HO CMD(DT1)

DATA REQ

<HO CMD>HO COMMAND

BSSMAP

37 of 53

Intra-MSC HandoverContinue 1

HO DETECT

BTS1

A-bis

BSC2MSC

A-bis

Target BSS

RR(new

FACCH)

HO COMPLET(DT1)

BSSMAP

BSSMAP

HO ACCESSRR(FACCH)

PHYS INFO

PHYS INFO

L2-SABM

L2-UI

ESTA IND

HO COMPLET

DATA IND

<HO COMPL>

CLEAR CMP(DT1)BSSMAP

<RLSD>

<RLC>

RF CHAN RELACK

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

T3124 +

T3124 -

T9113 -T102 -

T8 - TNT3 +

TNT3 -

A A Um

BSC1 BTS2 MS

Serving BSS

HO ACCESS

CLEAR CMD(DT1)RF CHAN REL

(old TCH)

38 of 53

Inter-MSC Handover

B E A A-bis Um

VLRB MSCB MSCA BSCA BTSA MS<L2-UI>

MAP_PREPARE_HANDOVER ACK

BSSMAP

BSSMAP

BSSMAPHO REQ(DT1)

CC


HO REQ ACK(DT1)BSSMAP

BSCA

CLEAR CMD(DT1)

BSSMAPCLEAR CMP(DT1)

BSSMAP

<HO Request>

<HO Request ACK>

T201 +

T201 -

T210 +

TNT3 +

TNT3 -

T103 +

T204 +

T210 -

RR(SACCH)

RR(FACCH)

MEAS REP

MEAS REP

HO REQU(DT1)Cell Id lst,Cause

MAP_PREPARE_HANDOVERMAP_ALLOCATE

_HO_NUMBER

MAP_SEND_

HO_REPORT BSCB BTSBMAP_SEND_

HO_REPORT ACK

IAM(TUP)

ACM(TUP)

HO CMD(DT1)

(Cell,Ch Inf,Ho Ref) DATA REQ

<HO CMD>HO COMMAND

CHAN ACTIV

CHA ACT ACK

BTSA

After HO Succeed

RF CHA REL

(old TCH)

RF CHA REL ACK

39 of 53

Inter-MSC HandoverContinue 1

B E A A-bis Um

VLRB MSCA MSCB BSCB BTSB MS

BSSMAP

ANC(TUP)

MAP_PROCESS_ACCESS

_SIGNALLING

HO DETECT(DT1)BSSMAP

<HO Detect>

<HO Complete>

T204 -

T103 -

RR(New

FACCH)HO ACCESS

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

HO ACCESS

HO DETECTION

PHYS INFO

PHYS INFO

L2-SABM

ESTA IND

L2-UI

HO COMPLET

DATA IND

<HO COMPL>HO COMMPLETE(DT1)

(Cause)MAP_SEND_END_SIGNAL

40 of 53

Subsequent Inter-MSC Handover

MSCB

RR(SACCH)

MEAS REP

MSCA

MAP_PREPARE_HANDOVER

IAM(TUP)

ACM(TUP)

HO CMD(DT1)DATA REQ

HO COMMAND RR(FACCH)

BSSMAP

BSSMAP

RF CHA REL ACK

After HO Succeed

BSCC

BSSMAP

HO REQ(DT1)

CHAN ACTIV

CC

CHA ACT ACK



BTSC

BTSBBSCB

CLEAR CMD(DT1)


BSSMAP

<HO Request>

<HO Request ACK>

MAP_PREPARE_

Subs_HANDOVER

MSCC

<HO Request>

MAP_PREPARE_

Subs_HANDOVER ACK

E

T201 +

T201 -

T210 +

TNT3 +

TNT3 -

T210 -

T204 +

T103 +

B E A A-bis Um

VLRC BSCB BTSB MS<L2-UI>

MEAS REPHO REQU(DT1)

Cell Id lst,Cause

MAP_ALLOCATE_HO_NUMBER

MAP_SEND_

HO_REPORT

MAP_SEND_

HO_REPORT ACK

MAP_PREPARE_HANDOVER ACK

(Cell,Ch Inf,Ho Ref)<HO CMD>

RF CHA REL

(old TCH)

41 of 53

Continue 1Subsequent Inter-MSC Handover

B E A A-bis Um

MSCB MSCA MSCC BSCC BTSC MS

BSSMAP

ANC(TUP)

MAP_SEND_END_SIGNAL

MAP_PROCESS_ACCESS

_SIGNALLING

HO DETECT(DT1)BSSMAP

<HO Detect>

<HO Complete>

MAP_SEND_END_SIGNAL ACK

REL(TUP)

RLC(TUP)

T204 -

T103 -

RR(New

FACCH)HO ACCESS

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

HO ACCESS

HO DETECTION

PHYS INFO

PHYS INFO

L2-SABM

ESTA IND

L2-UI

HO COMPLET

DATA IND


(Cause)

42 of 53

Subsequent Inter-MSC Handback

B E A A-bis Um

VLRA MSCA MSCB BSCB BTSB MS<L2-UI>

MAP_PREPARE_Subs_HANDOVER ACK

BSSMAP

BSSMAP

BSSMAPHO REQ(DT1)

CC



BSCB

CLEAR CMD(DT1)


BSSMAP

<HO Request>

<HO Request ACK>T104 +

RR(SACCH)

RR(FACCH)

MEAS REP

MEAS REP

HO REQU(DT1)Cell Id lst,CauseMAP_PREPARE_

Subs_HANDOVERMAP_ALLOCATE_HO_NUMBER

MAP_SEND_

HO_REPORT BSCA BTSAMAP_SEND_

HO_REPORT ACK

HO CMD(DT1)

(Cell,Ch Inf,Ho Ref) DATA REQ

<HO CMD>HO COMMAND

CHAN ACTIV

CHA ACT ACK

BTSB

After HO Succeed

RF CHA REL

(old TCH)

RF CHA REL ACK

43 of 53

Continue 1Subsequent Inter-MSC Handback

E A A-bis Um

MSCB MSCA BSCA BTSA MS

MAP_SEND_END_SIGNAL ACK

<HO Complete>

RLC(TUP)

T104 -

RR(New

FACCH)HO ACCESS

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

RR(FACCH)

HO ACCESS

HO DETECTION

PHYS INFO

PHYS INFO

L2-SABM

ESTA IND

L2-UI

HO COMPLET

DATA IND


BSSMAP(Cause)

REL(TUP)

44 of 53

IMSI DETACH

MS MSCBTS BSC

Channel Request

Channel Required

Channel Activation


<IMM ASSIGNMENT>


EST IND

<IMSI DETACH IND>CR(COMPL - L3 - INFO)

(MS ID)BSSMAP

UNIT DATA REQ

B interface

<IMSI DETACH IND>

MAP_DETACH_IMSI

Um interfaceVLR

**

RR(RACH)


RR(AGCH) (SDCCH ID)

IMSI DETACH INDRR(SDCCH)(L2-SABM)

L2 - UARR(SDCCH)

** : If no RR connection exists, the MM sublayer within the mobile station will request the RR sublayer to establish a RR connection. If establishment of the RR connection is not possible because a suitable cell is not (or not yet) available then, the mobile station shall try for a period of at least 5 seconds and for not more than a period of 20 seconds to find a suitable cell. If a suitable cell is found during this time then, the mobile station shall request the RR sublayer to establish an RR connection, otherwise the IMSI detach is aborted.

If a RR connection exists, the MM sublayer will release locally any ongoing MM connections before the IMSI DETACH IND message is sent.

45 of 53

IMSI DETACHContinue 1


RR(SDCCH)

RR(SDCCH)

RR(SDCCH) (L2 - UA)

CHAN REL

(L2 - DISC)

BSSMAP


BSSMAP

RF CHAN REL ACK

DEACT SACCH

CLEAR CMD(DT1)

DATA REQ


<CHAN REL>

REL IND

<RLSD>

<RLC>

DEACT SACCH ACK

46 of 53

Mobile - Originating SMS Procedure

MS MSCBTS

Channel Required

Channel Activation


AAbis

CM SERV REQ (L2-SABM)

EST IND<CM SERV REQ>

<CM SERV REQ>CR(COMPL - L3 - INFO)

L2 - UA


CC

BSSMAP


(SDCCH ID)


VLRUm interface

BSC



RR(AGCH)

RR(SDCCH)

RR(SDCCH)

47 of 53


Continue 1

MM(SDCCH)

MM(SDCCH)

RR(SDCCH)

RR(SDCCH)

BTS

DATA REQ<AUTH>

AUTH REQUEST

ENCR CMD

CIPHER MOD CMD


AUTH RESPONSE

DATA IND<AUTH>

CIPHER MOD COM

BSC

AUTH REQUEST (DT1)

(CKSN, RAND)

AUTH RESPONSE (DT1)

A interface

CIPHER MOD CMD(DT1)

(algo nb,key)

(SRES)

DATA IND


UA (SAPI=3)

EST IND (SAPI=3)

RR(SDCCH)

MAP_AUTHENTICATE



B interface

T3260 +

T3260 -

RR(SDCCH)SABM (SAPI=3)


MS MSC VLR

DTAP-MM

DTAP-MM

BSSMAP

48 of 53


Continue 2

Abis AUmMS BTS BSC MSC VLR SMS_GMSC SC

SMS(SDCCH)CP-DATA(RP-DATA)

SMS(SDCCH)

DEACT SACCH ACK

RF CHAN REL ACK

<RLSD>

<RLC>

MAP_SEND_INFO_MO_SMS

MAP_COMPLETE_CALL

MAP_MO_FORWARD_SMS

MAP_MO_FORWARD_SMS_ACK

SMS(SDCCH)

SMS(SDCCH)

CP-DATA(RP-ACK)

CP-ACK

SM-RL Data Req

SM-RL Req Ind.

CP-ACK

CLEAR CMD(DT1)BSSMAP

DATA REQ

<CHAN REL>

CHAN RELRR(SDCCH) DEACT SACCH

DISC (SAPI=0)

RR(SDCCH)

REL IND UA (SAPI=0)

RR(SDCCH)

RF CHAN REL

CLEAR COM(DT1)BSSMAP

49 of 53

Mobile - Terminated SMS Procedure

C interface C interface B interface

SC SMS_GMSC HLR MSC VLR MS

RS-MT-DATA.REQ

MAP_SEND_ROUTING_INFO_FOR_SM

MAP_SEND_ROUTING_INFO_FOR_SM_ACK

MAP_MT_FORWARD_SM

MAP_SEND_INFO_FOR_MT_SMS

MAP_PAGE

50 of 53

Mobile - Terminated SMS ProcedureContinue 1

MS MSCBTS BSC

Channel Required

Channel Activation


Abis interface

Paging RESP (L2-SABM)

EST IND<Paging Resp>

<Paging Resp>CR(COMPL - L3 - INFO)

L2 - UA


CC

BSSMAP


(SDCCH ID)

Paging(UDT)

Paging Command

Paging Request (L2-UI)


RR(PCH)


(L2 - UI)Immediate Assignment

RR(AGCH)

RR(SDCCH)

RR(SDCCH)

51 of 53


Continue 2

MM(SDCCH)

MM(SDCCH)

RR(SDCCH)

RR(SDCCH)

BTS

DATA REQ<AUTH>

AUTH REQUEST

ENCR CMD

CIPHER MOD CMD


AUTH RESPONSE

DATA IND<AUTH>

CIPHER MOD COM

BSC

AUTH REQUEST (DT1)

(CKSN, RAND)

AUTH RESPONSE (DT1)

A interface

CIPHER MOD CMD(DT1)

(algo nb,key)

(SRES)

DATA IND


MAP_AUTHENTICATE



B interface

T3260 +

T3260 -



MAP_COMPLETE_CALL

MS MSC VLR

DTAP-MM

DTAP-MM

BSSMAP

52 of 53


Continue 3

Um Abis A EMS BTS BSC MSC SMS_GMSC SC

RR(SDCCH)

RR(SDCCH)

BSSMAPCLEAR CMD(DT1)

BSSMAP

<RLC>

SMS(SDCCH)

SMS(SDCCH)SABM (SAPI=3)

MAP_MT_FORWARD_SM_ACK

RS-Report Ind.

MAP_REPORT_SM_DELIVERY_STATUS

HLR

SMS(SDCCH)

SMS(SDCCH)

CP-DATA(RP-ACK)

CP-ACK

CP-DATA(RP-DATA)EST REQ (SAPI=3)

UA (SAPI=3)

EST CONF (SAPI=3)CP-ACK

DATA REQ

CHAN REL <CHAN REL>

DEACT SACCHDISC (SAPI=0)

RR(SDCCH)DEACT SACCH ACK

REL IND UA (SAPI=0)

RF CHAN REL

RF CHAN REL ACK

CLEAR COM(DT1)

<RLSD>

53 of 53

gsm call flow procedures

Documents

loc updat

cha act ack

rf cha rel

mm cm procedure

intervlr location

intravlr location

rad int ms

cm serv req