CM

MM

RR

LAPDm

Layer

1

Layer

1

LAPDm

RR

MS

BTS

Um

interface

Address

Control

Information

SAPI

N(S)

N(R)

Abis

BTS

BTSM

LAPD

Layer

1

BSC

i

nterface

Layer

1

LAPD

BTSM

RR

flagAddressControlInformationFCSflag

SAPITEIN(S)N(R)

10-26021

BSC

MTP3

MTP2

Layer1

MSC

A interface

Layer1

MTP2

MTP3

RR

SCCP

SCCP

BSSAP

BSSAP

MM

CM

MSBTSBSC

MSC

CH REQ(1)

CH RQD(2)

CH ACT(3)

IMM ASS(6)

CH ACT ACK(4)

IMM ASS CMD(5)

SABM(7)

UA(10)

EST IND(8)

CM SERV REQ(9)

AUTH REQ(11)

AUTH REQ(12)

AUTH RSP(13)

AUTH RSP(14)

CIPH MODE CMD(16)

CIPH MODE CMP(18)

CIPH MODE CMP(19)

CIPH MODE CMD(17)

CIPH MODE CMD(15)

MSBTSBSC

MSC

TMSI REALL CMD(20)

TMSI REALL CMD(21)

TMSI REALL CMP(22)

TMSI REALL CMP(23)

SETUP(24)

SETUP(25)

CALL PRO(26)

CALL PROCEEDING(27)

ASSIGN REQ(28)

CH ACT(29)

CH ACT ACK(30)

ASSIGNMENT COMMAND(31)

SABM(32)

UA(34)

EST IND(33)

ASSIGNMENT COMPLETE(35)

ASSIGN CMP(36)

RF CH REL(37)

RF CH REL ACK(38)

MSBTS

BSC

MSC

ALERTING(39)

ALERTING(40)

DEACT SACCH(55)

CONNECT ACK(43)

CONNECT ACK(44)

RELEASE(49)

CONNECT(41)

CONNECT(42)

MEAS REPORT(45)

MEAS REPORT(46)

DISCONNECT(47)

DISCONNECT(48)

RELEASE(50)

RELEASE COMPLETE(51)

RELEASE CMP(52)

CLEAR CMD(53)

CHANNEL RELEASE(54)

DISC(56)

UA(57)

REL IND(58)

RF CH REL(59)

RF CH REL ACK(60)

CLEAR CMP(61)

SCCP REL(62)

SCCP REL ACK(63)

MSBTSBSC

MSC

CH REQ(4)

CH RQD(5)

CH ACT(6)

IMM ASS(9)

CH ACT ACK(7)

IMM ASS CMD(8)

SABM(10)

UA(13)

EST IND(11)

PAGE RSP(12)

AUTH REQ(14)

AUTH REQ(15)

AUTH RSP(16)

AUTH RSP(17)

CIPH MODE CMD(19)

CIPH MODE CMP(21)

CIPH MODE CMP(22)

CIPH MODE CMD(20)

CIPH MODE CMD(18)

PAGING CMD(1)

PAGING CMD(2)

PAGING RQT(3)

MSBTSBSC

MSC

TMSI REALL CMD(23)

TMSI REALL CMD(24)

TMSI REALL CMP(25)

TMSI REALL CMP(26)

ASSIGN REQ(31)

CH ACT(32)

CH ACT ACK(33)

ASSIGNMENT COMMAND(34)

SABM(35)

UA(37)

EST IND(36)

ASSIGNMENT COMPLETE(38)

ASSIGN CMP(39)

RF CH REL(40)

RF CH REL ACK(41)

SETUP(27)

SETUP(28)

CALL CONFIRMED(29)

CALL CONF(30)

MSBTS

BSC

MSC

DEACT SACCH(58)

RELEASE(52)

MEAS REPORT(48)

MEAS REPORT(49)

DISCONNECT(50)

DISCONNECT(51)

RELEASE(53)

RELEASE COMPLETE(54)

RELEASE CMP(55)

CLEAR CMD(56)

CHANNEL RELEASE(57)

DISC(59)

UA(60)

REL IND(61)

RF CH REL(62)

RF CH REL ACK(63)

CLEAR CMP(64)

SCCP REL(65)

SCCP REL ACK(66)

ALERTING(42)

ALERTING(43)

CONNECT(44)

CONNECT(45)

CONNECT ACK(46)

CONNECT ACK(47)

MSBTSBSC

MSC

CH REQ(1)

CH RQD(2)

CH ACT(3)

IMM ASS(6)

CH ACT ACK(4)

IMM ASS CMD(5)

SABM(7)

UA(10)

EST IND(8)

LOC UPDATE REQ(9)

AUTH REQ(15)

AUTH REQ(16)

AUTH RSP(17)

AUTH RSP(18)

IDENTITY REQ(11)

IDENTITY REQ(12)

IDENTITY RSP(13)

IDENTITY RSP(14)

CIPH MODE CMD(20)

CIPH MODE CMP(22)

CIPH MODE CMP(23)

CIPH MODE CMD(21)

CIPH MODE CMD(19)

MSBTSBSC

MSC

LOC UPDATE ACC(24)

LOC UPDATE ACCEPT(25)

TMSI REALL CMP(26)

TMSI REALL CMP(27)

DEACT SACCH(30)

CLEAR CMD(28)

CHANNEL RELEASE(29)

DISC(31)

UA(32)

REL IND(33)

RF CH REL(34)

RF CH REL ACK(35)

CLEAR CMP(36)

SCCP REL(37)

SCCP REL ACK(38)

MSBTSBSC

MSC

MEASURE REPORT(1)

MEASURE REPORT(2)

CH ACT(3)

CH ACT ACK(4)

SABM(6)

UA(8)

EST IND(7)

RECEIVE READY(10)

ASSIGNMENT COMMAND(5)

ASSIGNMENT COMPLETE(9)

HO PERFORMED(11)

RF CH REL ACK(13)

RF CH REL(12)

MSBTS1BSC

MSC

MEAS REPORT(1)

MEAS REPORT(2)

CH ACT ACK(4)

CH ACT(3)

PHYSICAL IN

FO(9)

HO ACCESS(7)

HO PERFORMED(16)

HO CMP(15

BTS2

HO CMD(5)

HO CMD(6)

HO DETECT(8)

SABM(10)

EST IND(11)

UA(12)

HO CMP(13)

RECEIVER

READY(14)

RF CH REL ACK(18)

RF CH REL(17)

MSBTS1

BSC1

BSC2

MEAS

REPORT(1)

MEAS REPORT(2)

CH ACT(5)

CH ACT ACK(6)

HO CMD(8)

HO REQUIRED(3)

BTS2

HO REQ

(4)

HO CMD(9)

HO ACCESS(10)

MSC

HO REQ ACK(7)

HO DETECT(11)

HO DETECT(12)

PHYSICAL INFO(13)

SABM(14)

EST IND(15)

UA(16)

HO CMP(17)

RECEIVER READY(18)

HO CMP(19)

HO CMP(20)

CLEAR COMMAND(21)

RF

CH REL(22)

RF CH REL ACK(23)

CLEAR COMPLETE(24)

MSBTSBSC

MSC

CONN FAIL IND(1)

CLEAR CMD(3)

CLEAR REQ(2)

CHANNEL REQ(5)

CM RE-EST REQ(6)

CIPH MODE CMD(7)

CIPH MODE CMP(8)

STATUS(12)

STATUS ENQUIRY(11)

CLEAR CMP(4)

ASS REQ(9)

ASS CMP(10)

MSBTS1

BSC

MSC

BTS2

MS

CH REQ(1)

CH RQD(2)

CH ACT(3)

CH ACT ACK(4)

IMM ASS CMD(5)

SABM(6)

UA(7)

EST IND(8)

CR(9)

CC(10)

CM SERVICE ACCEPTED(11)

SETUP(12)

CALL PROCEEDING(13)

ASS REQ(14)

CHANNEL ACT(15)

CHANNEL ACT ACK(16)

HANDOVER COMMAND(17)HO ACCESS(18)

HO DETECT(19)

PHY INFO(20)

SABM(21)

UA(23)

EST IND(22)

HO CMP(24)

ASS CMP(25)

MSBTSBSC

MSC

CH REQ(1)

CH RQD(2)

CH ACT(3)

CH ACT ACK(4)

IMM ASS

CMD(5)

SABM(6)

UA(7)

EST IND(8)

CM SERV REQ(9)

AUTH REQ(11)

AUTH RSP(12)

CC(10)

SABM(SAPI3)(13)

UA(14)

EST IND(SAPI3)(15)

CIPH MODE CMD(16)

CIPH MODE CMP(17)

CP DATA(18)

CP ACK(19)

MSBTSBSC

MSC

CP DATA(20)

CP ACK(

21)

DEACT SACCH(24)

CLEAR CMD(22)

CHANNEL RELEASE(23)

DISC(25)

UA(26)

REL IND(27)

RF CH REL(28)

RF CH REL ACK(29)

CLEAR CMP(30)

SCCP REL(31)

SCCP REL ACK(32)

MSBTSBSC

MSC

CH REQ(3)

CH RQD(4)

CH ACT(5)

CH ACT ACK(6)

IMM A

SS CMD(7)

SABM(8)

UA(10)

EST IND(9)

CM SERV REQ(11)

AUTH REQ(13)

AUTH RSP(14)

CC(12)

CIPH MODE CMD(15)

CIPH M

ODE CMP(16)

PAGING CMD(1)

PAGING CMD(2)

CP DATA(17)

EST REQ(SAPI3)(18)

SABM(19)

UA(20)

EST CMP(SAPI3)(21)

CP DATA(22)

CP ACK(23)

DEACT SACCH(28)

CLEAR CMD(26)

CHANNEL RELEASE(27)

DISC(29)

UA(31)

REL IND(30)

RF CH REL(32)

RF CH REL ACK(33)

CLEAR CMP(34)

SCCP REL(35)

SCCP REL ACK(36)

CP DATA(24)

CP ACK(25)

MSBTSBSC

MSC

MSBTSBSC

MSC

CM SERVICE REQ1

CM SERVICE ACC(2)

SABM(SAPI3)(3)

UA(4)

EST IND(SAPI3)(5)

CP D

ATA(6)

CP ACK(7)

CP DATA(8)

CP ACK(9)

ACTIVE CALL

ACTIVE CALL

MSBTSBSC

MSC

SABM(3)

UA(4)

EST CNF(SAPI3)(5)

CP DATA(8)

CP ACK(9)

CP DATA(6)

CP ACK(7)

ACTIVE CALL

ACTIVE CALL

CP DATA(1)

EST REQ(SAPI3)(2)