gsm seminar

31.1.2000-1Vö 1Lehrstuhl für KommunikationsnetzeTechnische Universität MünchenProf. Dr .–Ing. J. Eberspächer

J. Eberspächer; H.-J. Vögel

GSM – Global System for MobileCommunication.Switching, Services and Protocols.

Prof. Dr.-Ing. J. Eberspächer, Hans–Jörg VögelLehrstuhl für Kommunikationsnetze (Institute for Communication Networks)

Technische Universität München (Munich University of Technology), Arcisstr. 21, 80290 München, Germany

http://lkn.ei.tum.de/



Contemporary and future mobile communication systems

Packet Radio

Satellite systemsInmarsat

Analog cellular systemsC-Netz, NMT, AMPS

Private MobileRadio

Analogcordless phone

Cordless public telephone

Paging systems

Digital cellular systemsGSM

Digital cordless systemsCordless PBX, DECT

Paging systemsERMES

Digital trunked radioTETRA

Mobile data networks, mobile IP, WirelessLAN (HIPERLAN, 802.11)

Satellite systemsLEO, MEO

Wireless Local Loop WLLRadio in the Local Loop RTLL

UMTSIMT 2000

Mobile ATM

1st generation 2nd generation 3rd generation



Milestones in the evolution of GSM

Year Event1982 Groupe Spécial Mobile established by the CEPT.1987 Essential elements of wireless transmission are specified, based on

prototype evaluation (1986).Memorandum of Understanding (MoU) Association founded in Septem-ber with 13 members from 12 countries.

1989 GSM becomes an ETSI Technical Committee (TC).1990 The Phase 1 GSM900 specifications (designed 1987 through 1990) are

frozen.Adaption to DCS1800 commences.

1991 First GSM networks launched.The DCS1800 specifications are finalized.

1992 Most European GSM networks turn commercial by offering voice com-munication services. Some 13 networks in 7 countries are “on air” bythe end of the year.

1993 First roaming agreements in effect By the end of 1993, 32 networks in18 countries are operational.



Year Event1994 Data transmission capabilities launched.

The number of networks rises to 69 in 43 different countries by the endof 1994.

1995 MoU counts 156 members from 86 countries.After the GSM standardization Phase 2 including adaptations and modi-fications for the PCS1900 (Personal Communication System) is passed,the first PCS1900 Network is launched in the USA.Facsimile, data and SMS roaming starts.Videosignals are transmitted via GSM for demonstration purposes.An estimated 50 000 GSM base stations are in use all over the world.

1996 January: 120 networks in 71 countries operational.June: 133 networks in 81 countries operational.

1997 July: 200 GSM networks from 109 countries operational, amounting to44 million subscribers worldwide.



Simplified two–path model of radio propagation

h1 h2

L

PE � P04

(4�L��)2��

�

�

2�h1h2

�L��

�

�

2

� P0��

�

�

h1h2

L2��

�

�

2 �E �PE2PE1

��

�

L1L2

��

�

4

�E � 40 log��

�

L1L2

��

�[dB]



Typical signal in a channel with Rayleigh fading

Distance

Rec

eive

d si

gnal

leve

l/dB

heavily impacted undisturbedtime slot

��

typ.30–40 dB



Frequency selectivity of a mobile radio channel

f

Rec

eiv

ed s

igna

l lev

el/d

B narrowband

broadband

narrowband



Frequency and time duplex

transmit

band gap

transmitter

receiver reception

receivetransmitf

Duplexing Unit

transmissionfilter

filter

t

receive

transmit receive

receive

transmit

transmit

receive

frequency duplex

time duplex T

Uplink Downlink Uplink Downlink



Multiple access procedures



FDMA system channels



TDMA channels on multiple carrier frequencies



TDMA with use of frequency hopping technique



Propagation delay and synchronization (TDMA)

time

propagation delay

delay

DownlinkUplink

ÏÏÏÏÏ

ÏÏÏÏÏÏÏÏÏÏÏÏÏ

ÏÏÏÏÏÏÏÏ

ÏÏÏÏÏÏÏÏ

distance

MS 2

DownlinkUplink MS 1

DownlinkUplink BTS

collision without advance

ÏÏÏÏÏÏÏ

ÏÏÏÏÏÏÏ

ÏÏÏÏÏÏÏ

ÏÏÏÏÏ

ÏÏÏÏÏ

ÏÏÏÏÏ

advanceUplink without advanc



Spread spectrum technique for direct sequence CDMA

binary

bipolardata se-quence

bipolarspreadingsequence

0 1 0

+1

–1

+1

–1

+1

–1

spreadsignal

1 bit

1 Chip

signal spectrum



Simplified scheme of code division multiple access (uplink)

modulatord1(t)

c1(t)MS 1

modulatord2(t)

c2(t)MS 2

demodulator d1(t)

c1(t)BTS

d2(t)

c2(t)



Mulitpath signal at an antenna array

��

��

��

antenna elements

��

�

�

��

��

��

��

��

�

�

��

��

��

��

��

��

��

��



Schematic representation of spatial multiple access

demodulation& separation

MS 1

modulator

d1(t)

BTSMS 2

modulator

d1(t)

d2(t)

d2(t)



Model of a cellular network with frequency reuse

2R

D

D

D

MS

cochannel

user signal

interference

D



Frequency reuse and cluster formation

k=3

k=4

k=71 2

3

1 2

3 1 2

3

1 2

31 2

3

1 2

3

1 2

3

1 2

34

5

6 7

1 2

34

5

6 7 1 2

34

5

6 7

1 2

34

5

6 7

1 2

34

5

6 7 1 2

34

5

6 7

1 2

34

5

6 7

1 2

34

1 2

34

1 2

34

1 2

34

1 2

34

1 2

34

1 2

34



Cell structure of a real network

33

35

30

38

38

3135

33

33

33

38

30

27

21 36 32

30

26

31

36

28

31 23

29

2132

36

23 3530 38

21

28

33

22 30 22

32

21



GSM system hierarchy

GSM Network (PLMN)

Cell CellLocation Area

BS Controller

MSC Region

MSC Region

��

��

��BS Controller

MSC Region

Location Area

BS Controller

Location Area



Evolution of a GSM network in Germany

Cells BSC MSCEnd of 1992 approx. 500 7 7Total completion approx. 7000 20 � 50 20 – 50



GSM system architecture with essential components

ISC

GMSC

BTSBSC

PLMN& Internat.

PSTNISDNPDN

OMC

MSCBTS BSC

HLR VLR

EIR AUC

MS

MSBTSMS

BTSBSCMSCGMSCISC

Base Transceiving StationBase Station ControllerMobile Switching CenterGateway MSCInternational Switching Center

HLRVLREIRAUC

Home Location RegisterVisited Location RegisterEquipment Identity RegisterAuthentication Center

OMC Operation and Maintenance Center

MS Mobile Station



Mobile equipment personalization with the SIM



Components of the GSM radio network

ISC

PLMN& Internat.

GMSC

PSTNISDNPDN

OMC

MSC

HLR VLR

EIR AUC

BTS BSC

MSBTSMS

BTSBSCMSCGMSCISC


HLRVLREIRAUC



MS Mobile Station

BSCMS BTS



Components of the GSM mobile switching network

BTSBSC

PLMN& Internat.

PSTNISDNPDN

OMC

BTSBSC

MS

MSBTSMS

GMSC

MSC

EIR

VLRHLR

ISC

AUC

BTSBSCMSCGMSCISC


HLRVLREIRAUC



MS Mobile Station



Components of the GSM OMSS

BTSBSC

ISC

PLMN& internat.

GMSC

PSTNISDNPDN

OMC

MSC

HLRVLR

EIRAUC

BTS BSC

MS

MSBTSMS

BTSBSCMSCGMSCISC


HLRVLREIRAUC



MS Mobile Station



Overview of addresses and pertinent data bases

BTS(BSIC)

EIR

VLR(SPC)

MSC(SPC)

Equipment(IMEI)

Subscriber(IMSI,

MSISDN,TMSI, MSRN)

Cell(CI,LAI)

IMEI

HLR(SPC) AUC

LMSIMSRNIMSI TMSI MSISDNLAI

IMSI MSISDNIMSI RANDSRESKi Kc

MSRN



Mobile subscriber data in the HLR

Subscriber and subscription data Tracking and routing informationInternational Mobile Subscriber Iden-tity IMSI

Mobile Station Roaming NumberMSRN

International Mobile Subscriber ISDNNumber MSISDN

Current VLR address (if available)

Bearer and telesevice subscriptions Current MSC address (if available)Sevice restrictions, e.g. roaming re-strictions

Local Mobile Subscriber Identity LMSI(if available)

Parameters for additional servicesInformation on the subscriber’s equip-ment (if available)Authentication data (subject to imple-mentation)



Mobile subsriber data in the VLR

Subscriber and subscription data Tracking and routing informationInternational Mobile Subscriber Iden-tity IMSI

Mobile Station Roaming NumberMSRN

International Mobile Subscriber ISDNNumber MSISDN

Temporary Mobile Station IdentityTMSI

Parameters for supplementary ser-vices

Local Mobile Subscriber Identity LMSI(if available)

Information on subscriber-used equip-ment (if availiable)

Location Area Identity LAI of LA,where MS was registered (used for

i d ll t )Authentication data (subject to imple-mentation)

paging and call setup)



Signaling and user data transport in a GSM PLMN

GMSC

PSTNISDNPDN

MSC

MSC

VLR

VLRVLR

HLRAUCEIR

HLRAUC

BTS BSC

MSBTSMS user datasignaling data



Interfaces in a GSM PLMN

EIRF MSC

MSC

BTSBSC

HLR

MSBTS

C

E

B

VLR

D

AAbis

Um

MS-SIMG

VLR



Basic configuration of a GSM PLMN

PSTNISDN

GMSC

VLR

MSCMSC

HLR

BTS BSC

MSBTSMS

SPSP

SPSP SP



Configuration of a GSM PLMN with a VLR for each MSC

PSTNISDN

VLRGMSC

MSCMSC

HLR

BTS BSC

MSBTSMS

VLR

SP

SPSP SP

VLR

HLR

SP



Bearer and teleservices

GSM Transit Terminatingnetwork

TE(MS)

PLMN section

Teleservices

InterworkingFunction IWF

TE(MS)

section outside of PLMNBearer services

networknetwork



Phases of implementation and introduction

Class Intro-duction

Services

E1 1991 Basic operation consisting of telephone servicesand some appropriate supplementary services

E2 1994 Extended operation with telephone services , firstnon-speech services (e.g. BS26) and an extendedrange of supplementary services

E3 1996 Enhanced service range with even more telecom-munication and supplementary services



GSM bearer services (excerpt)

Service Structure BS no . Bit rate[bit/s]

Mode Transmission

Data asynch 21 300 T or NT UDI or 3.1 kHz22 1200 T or NT UDI or 3.1 kHz23 1200/75 T or NT UDI or 3.1 kHz24 2400 T or NT UDI or 3.1 kHz25 4800 T or NT UDI or 3.1 kHz26 9600 T or NT UDI or 3.1 kHz

Data synch 31 1200 T UDI or 3.1 kHz32 2400 T or NT UDI or 3.1 kHz33 4800 T or NT UDI or 3.1 kHz34 9600 T or NT UDI or 3.1 kHz

PAD asynch 41 300 T or NT UDI42 1200 T or NT UDI43 1200/75 T or NT UDI



Service Structure BS no . Bit rate[bit/s]

Mode Transmission

PAD asynch 44 2400 T or NT UDI45 4800 T or NT UDI46 9600 T or NT UDI

Packet synch 51 2400 NT UDI52 4800 NT UDI53 9600 NT UDI

Altern. speech/data

61 13 000 or9600

Speech followedby data

81 13 000 or9600

T, NT = transparent, non transparent UDI = Unrestricted Digital InformationPAD = Packet Assembler/Disassembler asynch, synch = asynchronous,synchronous



GSM teleservices (excerpt)

Category TS no . Service ClassSpeech 11 Telephone E1

12 Emergency call E1Short MessageServices

21 Short Message Mobile Terminated,Point to Point

E3

22 Short Message Mobile Originated,Point to Point

A

23 Short Message Cell Broadcast �

MHS access 31 Access to Message Handling Systems AVideotex access 41 Videotex access profile 1 A

42 Videotex access profile 2 A43 Videotex access profile 3 A

Teletext trans-mission

51 Teletext A

Fax transmission 61 Speech and fax group3 lt ti

T E23 alternating NT A

62 Fax group 3 automa-ti

T �tic NT �



Overview of GSM supplementary services (GSM Phase 1)

Category Abbrev . Service Class

Call Offe-i

CFU Call Forwarding Unconditional E1ring CFB Call Forwarding on Mobile Subscri-

ber BusyE1

CFNRy Call Forwarding on No Reply E1

CFNRc Call Forwarding on Mobile Subscri-ber Not Reachable

E1

CallR t i

BAOC Barring of All Outgoing Calls E1Restric-tion

BOIC Barring of Outgoing InternationalCalls

E1

BAIC Barring of All Incoming Calls E1

BOIC-exHC

Barring of Outgoing InternationalCallsExcept Calls to Home PLMN

A

BIC-Roam

Barring of Incoming Calls when Roa-ming outside the Home PLMN

A



Overview of GSM supplementary services (GSM Phase 2)

Category Abbrev . Service ClassNumberIdentification

CLIP Calling Line Identification Presenta-tion

A

CLIR Calling Line Identification Restric-tion

A

COLP Connected Line Identification Pre-sentation

A

COLR Connected Line Identification Re-striction

A

MCI Malicious Call Identification ACall Offering CT Call Transfer A

MAH Mobile Access Hunting ACommunity of In-terest

CUG Closed User Group A

Charging AoC Advice of Charge E2FPH Freephone Service A



Category Abbrev . Service ClassCharging REVC Reverse Charging AAdd. InformationTransfer

UUS User-to-User Signaling A

CallC l ti

CW Call Waiting E3Completion HOLD Call Hold E2

CCBS Completion of Call to Busy Subscri-ber

A

Multi-Party 3PTY Three-Party Service E2CONF Conference Calling E3



Classification of logical channels in GSM

Traffic Channels Signaling ChannelsBidirectional Unidirectional ,

DownlinkUnidirectional ,

Down- or UplinkBidirectional

Traffic ChannelTCH

BroadcastChannel BCH

Common ControlChannel CCCH

Dedicated ControlChannel DCCH

Full-rate channelBm

Broadcast ControlChannel BCCH

Random AccessChannel RACH

StandaloneDedicated ControlChannel SDCCH

Half-rate channelLm

SynchronizationChannel SCH

Access GrantChannel AGCH

AssociatedControl Channel

ACCHFrequency

Correction ChannelFCH

Paging ChannelPCH

Slow AssociatedControl Channel

SACCHFast AssociatedControl Channel

FACCH



Logical channels of GSM Protocol Layer 1

Channel type Net datathroughput

[kbit/s]

Block length[bit]

Block distance[ms]

TCH (full-rate speech) 13.0 182+78 20TCH (half-rate speech) standardization

in progressstandardization

in progress standardization

in progressTCH (data, 9.6 kbit/s) 12.0 60 5TCH (data, 4.8 kbit/s) 6.0 60 10TCH (data, � 2.4 kbit/s) 3.6 72 20Full-rate FACCH 9.2 184 20Half-rate FACCH 4.6 184 40SDCCH 598/765 184 3060/13SACCH (with TCH) 115/300 168+16 480SACCH (with SDCCH) 299/765 168+16 6120/13BCCH 598/765 184 3060/13AGCH n*598/765 184 3060/13PCH p*598/765 184 3060/13RACH r*27/765 8 3060/13



Channel combinations offered by the base station

Bm Lm Lm FACCH SACCH SDCCH FCCH SCH BCCH CCCHB1B2B3B4B5B6B7



Channel combinations used by the mobile station

Bm Lm Lm FACCH SACCH SDCCH BCCH CCCHM1M2M3M4M5M6M7



Logical channels and signaling

Channel Request

Call Conf.

Paging Response

Auth. Response

MS

Assign Compl.Alert

Connect

BSS/MSC

ImmediateAssignment

Paging Request

Authentic. Req.

Setup

AssignmentCommand

Connect Ack.DataData

Cipher Mode Compl.Cipher Mode Com.

AGCH

SDCCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCHSDCCH

FACCHFACCHFACCHFACCH

PCH

RACH

TCH



Steps of GSM digital modulation

Differentialencoding

Transm.filter

di(t) ai(t) Phase�(t)

modulation

x(t)

d^

i � ( di � di�1 )mod 2; di � (0; 1) �i � 1 � 2d^

i

g(t) � h(t)�

� ��

�

1�T0

h(t) � 12� �T � �

ln 2

2�BT; BT� 0, 3

|t|� T�2

|t|� T�2forfor

rect(t�T)

rect (t�T)

exp�

�

� t2

2�2T2��



Impulse responses for the building blocks of the GMSK filter

T/2–T/2

1/T

t tT–T

12�� T

�(t) � �i

�i �� t�iT

��

g(u) du

x(t) �2Ec

T� cos(2�f0t � �(t) � �0)

rect(t/T) h(t)



Impulse response g(t) of the frequency filter (transmitter filter)

0.0

0.2

0.4

0.6

0.8

1.0

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

BT=0.3BT=0.1BT=0.5BT=1.0

t / T

g(t)



Carrier frequencies, duplexing and TDMA frames

Downlink

935 MHz

960 MHz

200 kHz

124123...

21

...

...

Data burst, 156.25 bit periods = 15/26 ms � 576.9 �s

890 MHz

915 MHz

200 kHz

124123...

21

...

...

Delay

Uplink

1 2 3 4 5 6 7 8

935.2 MHz

959.8 MHz

890.2 MHz

914.8 MHz

1 2 3 4 5 6 7 8



Bursts of the GSM TDMA procedure

Dummy Burst 26 bit trainingsequence

Normal Burst 57 databits

57 databits

26 bit trainingsequence

1 signaling bit(stealing flag)

3 tail bits 8.25 bit guard period

Frequency Cor-rection Burst

142 fixed bits3 3

8.25

SynchronizationBurst

64 bit training se-quence (synchroniza-

tion sequence)3 3 8.25

39 databits

Access Burst 8 68.2541 bit training

sequence36 databits

3 3 8.25

3 3

8.25

39 databits

3



GSM full rate traffic channel with frequency hopping

0 1 2 3 4 5 6 70 1 2 3 4 5 6 7

0 2 3 4 51

0 1 2 3 4 5 6 70 1 2 3 4 5 6 7

0 1 2 3 4 5 6 7

0 2

frequency 1frequency 2frequency 3frequency 4

frequency 1’frequency 2’frequency 3’frequency 4’

Downlink

TDMA frame

Downlinks of

0 1 2 3 4 5 6 7

1

adjacent cellsfrequency 5frequency 6

(mobile

receiving)

delay

station

Uplink(mobile

transmitting)station

(mobile

monitoring)station



Typical power spectrum of a BCCH Carrier

FCCH

67 kHz

940.2 MHz 940.6 MHz939.8 MHz

10 dBm

frequency

spec

tral

pow

er d

ensi

ty



Values T2 and T3 for the calculation of RFN

0

25

T2

T350

51

0

1 (T3 – T2)mod26

51 102

2

FN

FN



Simplified synchronization timers

0

624

0

156

0

7

0

2715647

QN

BN

TN

FN

time

time

time

time



Generation of the GSM frequency hopping sequence

M� (T2� RNTABLE [HSNYes No

MAI� (FN�MAIO) mod N XOR

M � � (M mod 2INT(log2(N)�1))T � � (T3 mod 2INT(log2(N)�1))

M � � N

HSN � 0

Yes NoS � M �S � (M � � T � ) mod N

MAI� (MAIO� S) mod N

((T1 mod 64)� T3)]

RFCHN� MA[MAI]

HSNFN(T1,T2,T3)MAIO



Operation of Timing Advance

time

Downlink

Uplink

propagation

Timing Advance

without timing advance

with timing advance

ÏÏÏ

ÏÏÏ

ÏÏÏ

Collision without timing advance

without timing advance

with timing advance

Downlink

Uplinkdelay



Timing for RACH random multiple access

Time

Downlink

Uplink

Propagation Delay

AB Guard Period

Downlink

Uplink

BTS

MS



GSM frame structures

1 2 25 26

1 2 2048 Hyperframe

1 2 50 51

1 2 25 261 2 50 51

51-frame Multiframe

Superframe

26-frame Multiframe



GSM multiframes

Multiframe with 26 frames ( Traffic, Associated Control ) 120 ms

TDMA frame

1 2 4 5 6 7 8

Multiframe with 51 frames, (3060/13) ms=235.4 ms

1 2 50 51

1 2 12 13 14 25 26

12 13 14

3



Channel organization in a 26 frame multiframe

TC1 TC2 ACTC12 TC13 TC24 IDLE/AC

1 2 12 13 14 25 26

��



Channel organization in a 51–frame multiframe

FS B C FS C C FS D0 D1 FS D2 D3 FS A0 A1 –

FS B C FS C C FS D0 D1 FS D2 D3 FS A2 A3 –

Uplink

Downlink

D3

D3

RR

RR

A2 A3

A0 A1

D2

D2

RR

RR

D0 D1

D0 D1

RRRRRRRRRRRRRRRRRRRRRRR

RRRRRRRRRRRRRRRRRRRRRRR

D0 D1 D2 D3 D4 D5 D6 D7 A0 A1 A2 A3 – – –

D0 D1 D2 D3 D4 D5 D6 D7 A4 A5 A6 A7 – – –

A5 A6 A7 – – – D0 D1 D2 D3 D4 D5 D6 D7 A0

A1 A2 A3 – – – D0 D1 D2 D3 D4 D5 D6 D7 A4Uplink

DownlinkSDCCH+

FS FS FS FS FS –1 10 20 30 40 50

RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRBCCH+

Uplink

Downlink

F: TDMA frame for frequency correction bursts S: TDMA frame for synchronization burstsB: TDMA frame for BCH

C: TDMA frame for CCCH R: TDMA frame for RACH D: TDMA frame for SDCCH A: TDMA frame for SADCH

B C C C C C C C C C

SACCH

BCCH+

SDCCHCCCH+

SDCCH



Mapping of frame number onto BCCH message

TC System information mes-sage

0 Type 11 Type 2

2, 6 Type 33, 7 Type 44, 5 any (optional)



SACCH block format

12345678

bit numberoc

tet n

umbe

r

23

...

3

2

1 free

free

power level

timing advance

layer 2 data (21 octets)



Principal operation of the radio subsystem link control

Init

Measuring

BSS_Power_Control start transmitter powercontrol process

start handovercontrol process

Measurement Info (Up–/Downlink, adjacent BCCH)

Calculate mean values:

RXLEV/RXQUAL UL/DLTO BSS_Power_Control

Connection

RXLEV & RXQUAL Up–/DownlinkRXLEV(n) n adjacent cells

BSS_HO_Control

PWR_CTRLWaiting

PWR_CTRL

Measuring

RXLEV/RXQUAL

RXLEV_NCELL,Power OK, TO

_SUCCESSPWR_CTRL

_FAIL

closed

PWR_CTRLWaiting

UL/DL

BSS_HO_Control

RXLEV/RXQUAL

RXLEV_NCELL,Power FAIL,TO

UL/DL

BSS_HO_Control



Measurement range of the received signal level

LevelReceived signal level

LevelFrom To

RXLEV_0 � –110 dBmRXLEV_1 –110 dBm –109 dBm

.

.

.

.

.

.

.

.

.RXLEV_62 –49 dBm –48 dBm

RXLEV_63 –48 dBm –



Measurement range of bit error ratio

LevelBit error ratio

LevelFrom To

RXQUAL_0 – 0.2%RXQUAL_1 0.2% 0.4%

RXQUAL_2 0.4% 0.8%RXQUAL_3 0.8% 1.6%RXQUAL_4 1.6% 3.2%RXQUAL_5 3.2% 6.4%RXQUAL_6 6.4% 12.8%RXQUAL_7 12.8% –



Synchronization with adjacent cells during a call

TCH SACCH IDLETCHTCH

CCCH FCCH SCHCCCHCCCH SCHFCCH

IDLE

Search Frame

261 12 13 14 261 12 13 14

120 ms

BCCHotherBTS

TCHUp/Downlink

MS

261 12 13 14



Principle of FCCH search during the search frame

4131 1261

11 21

1261 261

11 4121 31 1

261 26111 4121 31

26111 21

2614131

26111 21 311

4131261

1

261

261

41

11 21

1

2611 11 21

2614131

261 11 211

26141

31

26111 21 311

26141 1

26111 21

2614131

26111 211 31

51

4131261

1261

11 21 5151

240 ms

1 26



GSM power classes

Power class Max. peak transmission powerMobile station Base station

1 20 W (43 dBm) 320 W2 8 W (39 dBm) 160 W3 5 W (37 dBm) 80 W4 2 W (33 dBm) 40 W5 0.8 W (29 dBm) 20 W6 – 10 W7 – 5 W8 – 2.5 W



Thresholds for transmitter power control

Thresholdparameter

Typicalvalue

Meaning

L_RXLEV_UL_P –103 to –73dBm

Th h ld f i i fL_RXLEV_DL_P –103 to –73dBm

Threshold for raising oftransmission power in uplinkor downlink

L_RXQUAL_UL_P –or downlink

L_RXQUAL_DL_P –U_RXLEV_UL_P –

Th h ld f d i fU_RXLEV_DL_P – Threshold for reducing oftransmission power in uplink

U_RXQUAL_UL_P –transmission ower in u linkor downlink

U_RXQUAL_DL_P –or downlink

31.1.2000-72V

ö72

Lehrstuhl für K

omm

unikationsnetzeTechnische U

niversität München

Prof. D

r.–Ing. J. Eberspächer

J. Eberspächer; H

.-J. Vögel

Schem

atic operation of transm

itter power control

Init

Info Waiting

Mean RXLEV/

2

Yes

MS transm. powermax. ?

RXQUAL UL/DL

1

Power IncreaseTO MS

RXLEV_UL<L_xx_PRXQUAL_UL>L_xx_P

Yes

No

2

Yes

BTS transm. powermax. ?

1

Power IncreaseTO BTS

RXLEV_DL<L_xx_PRXQUAL_DL>L_xxP

Yes

No

No

...

No

31.1.2000-73V

ö73

Lehrstuhl für K

omm

unikationsnetzeTechnische U

niversität München

Prof. D

r.–Ing. J. Eberspächer

J. Eberspächer; H

.-J. Vögel

Schem

atic operation of transm

itter power control (2)

2

Yes

MS transm. powermax. ?

1

Power IncreaseTO MS

RXLEV_UL<U_xx_PRXQUAL_UL>U_xx_P

Yes

No

2

Yes

BTS transm. powermax. ?

1

Power IncreaseTO BTS

RXLEV_DL<U_xx_PRXQUAL_DL>U_xx_P

Yes

No

...

No

1

No



Schematic operation of transmitter power control

2

PWR_CTRL_FAIL

Info Waiting

TO BSS_LINK_CONTROL

1

PWR_CTRL_SUCCESS

Info Waiting

TO BSS_LINK_CONTROL



MS disconnect procedure

Correct SACCH

Radio Link Failure

S <

No

messageNon-decodableSACCH message

Power Control,Timing Advance etc.

RADIO_LINK_

S := S + 2

Yes

S := S – 1

S <= 0Yes

SACCHWaiting

Indication TO MM

No

TIMEOUT

SACCHWaitingStart

S := RADIO_LINK_TIMEOUT

SACCHWaiting



BCCH search in the power density spectrum (schematic)

200 kHzNetwork BCCHRFCHN

Stored BCCH–list



Schematic representation of speech functions (transmitter)

Speech Coder

VADVoice Activity

Detection

Comfort NoiseSynthesizer

DTXDiscontinuousTransmission

Voice, 13 bit8000 samples/s

VoiceFrame

VAD

SIDFrame



Schematic representation of speech functions (receiver)

BFI

Voice Decoder

BadFrame

Replacement

Comfort NoiseSynthesizer

DTXDiscontinuousTransmission

VoiceFrame

SIDFrame

Voice, 13 bit8000 samples/s



Simplified block diagramm of the GSM speech coder

Voice datapreprocessing

Short-termLPC analysis

Short-termanalysis filter

RPE analysisand encoding

RPE decoding

and analysis

Long-termanalysis filter

LTPanalysis

1

2

3

1

2

3

Reflection

RPE parameter

36 bit/20 msLTP parameter

260 bit/20 ms

4�47 bit/20 ms

4�9 bit/20 ms

coefficient



Simplified block diagramm of the GSM speech decoder

Voice data

preprocessing

Short-term

synthesis filter

RPE

decodingand analysis

Long-term

synthesis filter

1

2

3



MOS results of codec hearing tests

CODEC Process Bit rate[kbit/s]

MOS

FM Frequency Modulation – 1.95SBC-ADPCM Subband-CODEC – Adaptive

Delta-PCM15 2.92

SBC-APCM Subband-CODEC – Adaptive PCM 16 3.14MPE-LTP Multi-Pulse Excited LPC-CODEC –

Long Term Prediction16 3.27

RPE-LPC Regular-Pulse ExcitedLPC-CODEC

13 3.54

RPE-LTP Regular Pulse ExcitedLPC-CODEC – Long TermPrediction

13 ≈ 4

ADPCM Adaptive Delta Modulation 32 ≥ 4



Stages of channel coding

Blockcode

Convol.code

Inter-leaving

Deinter-leaving

Convol.decoder

Paritycheck

Internal error protection

External error protection



Error protection coding and interleaving of logical channels

Channel type Abbr . Bit per block Convol .code

Encodedbits per

Inter-leav

Data Parity Tailcode rate

bits perblock

leav.depth

TCH, full-rate TCH/FS 456 8

Voice Class I 182 3 4 1/2 (378)

Voice Class II 78 0 0 – (78)

TCH, full-rate, 9.6kbit/s

TCH/F9.6 4�60 0 4 244/456 456 19


TCH/F4.8 60 0 16 1/3 228 19

TCH, half-rate, 4.8kbit/s

TCH/H4.8 4�60 0 4 244/456 456 19


TCH/F2.4 72 0 4 1/6 456 8

TCH, half-rate, 2.4kbit/s

TCH/H2.4 72 0 4 1/3 228 19

FACCHs FACCH 184 40 4 1/2 456 8



Channel type Abbr . Bit per block Convol .code

Encodedbits per

Inter-leav

Data Parity Tailcode rate

bits perblock

leav.depth

BCCH, AGCH, PCH BCCH,AGCH,PCH

184 40 4 1/2 456 4

RACH RACH 8 6 4 1/2 36 1

SCH SCH 25 10 4 1/2 78 1



Overview of block coding for logical channels

TCH

Voice

FACCH SACCHBCCH, PCH

AGCH, SDCCH

RACH

SCH

TCH

Data2.4 kbit/s Other

CyclicCode + Tail

Fire Code+ Tail

CyclicCode + Tail

260 bit 184 bit 184 bit P0 bit N0 bit

267 bit 228 bit 228 bit P1 bit N1 bit

N0 bit

N1 bit

Tail



Feedback shift register for CRC

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Block formation for data traffic channels

Data channel N0 Tail bits N1TCH/F9.6 4 � 60 4 244TCH/F4.8 2 � 60 2 � 16 2 � 76TCH/F2.4 2 � 36 4 76TCH/H4.8 4 � 60 4 244TCH/H2.4 4 � 36 2 � 4 2 � 76



Block lengths for the RACH and SCH channels

Data channel P0 Redundancybits

Tail bits P1

RACH 8 6 4 18SCH 25 10 4 39



Cyclic codes used for block coding in GSM

Channel PolynomialTCH/FS x 3 + x + 1

DCCH and CCCH(part.)

(x 23 + 1) (x 17 + x 3 + 1)

RACH x 6 + x 5 + x 3 + x 2 + x + 1SCH x 10 + x 8 + x 6 + x 5 + x 4 + x 2 + x + 1



Principle of a convolutional coder

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1 2 3 4 K=5 ��

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Overview of convolutional coding for logical channels

TCH

Voice

FACCH SACCHBCCH, PCH

AGCH, SDCCH

RACH

SCH

TCH

Data2.4 kbit/s other

Convol. codeK=5, 2 classes

456 bit 456 bit 456 bit 456 bit456 bit

267 bit 228 bit 228 bit P1 bit N1 bitN1 bit

Convol. codeK=5, rate=0.5

Convol. codeK=5, rate=r

2 � P1bit



Generating polynomials for convolutional codes

Type PolynomialG0 1 + d 3 + d 4

G1 1 + d + d 3 + d 4

G2 1 + d 2 + d 4

G3 1 + d + d 2 + d 3 + d 4



Usage of generating polynomials

Channel type Generating polynomialG0 G1 G2 G3

TCH, full-rateVoice Class IVoice Class II

TCH, full-rate, 9.6 kbit/sTCH, full-rate, 4.8 kbit/s

TCH, half-rate, 4.8 kbit/sTCH, full-rate, 2.4 kbit/sTCH, half-rate, 2.4 kbit/sFACCHsSDCCHs, SACCHsBCCH, AGCH, PCHRACH

SCH



Interleaving, spreading and merging

Spreading

Merging



Distributing bit errors through deinterleaving

Interleaving

Signal

DespreadedSignal



Principle of block interleaving

Write

Read

InterleavingMatrix



Transmission delay caused by interleaving

Channel type Interleav.depth

Transmissiondelay [ms]

TCH, full-rate, voice 8 38TCH, full-rate, 9.6 kbit/s 22 (19) 93TCH, full-rate, 4.8 kbit/s 22 (19) 93TCH, half-rate, 4.8 kbit/s 22 (19) 185TCH, full-rate, 2.4 kbit/s 8 38TCH, half-rate, 2.4 kbit/s 22 (19) 185FACCH, full-rate 8 38

FACCH, half-rate 8 74SDCCH 4 14SACCH/TCH 4 360SACCH/SDCCH 4 14BCCH, AGCH, PCH 4 14



Overview: interleaving of logical channels

TCHVoice

FACCHSACCHBCCH, PCH

AGCH, SDCCH

RACHSCH

Bit sorting, partitioning& stealing flags

8 subblocks, 57 bits each Subblocks

Diagonal interleaving& stealing flags

456 bit 456 bit 456 bit 456 bit 456 bit

TCHData

2.4 kbit/s Other

Diagonal interleavingof subblocks

Block interleavingof subblocks

Intraburstinterleaving

pairs of subblocks

pairs of 57-bit subblocks

2 � P1 bit



Interleaving TCH/FS: block mapping

Data block n

B B+1

Interleaving

B+2 B+3 B+4 B+5 B+6 B+7

Data block n+1

Even OddBit positions

block



Mapping of data block n onto interleaving block B

98867258443016 4228 70 8456142

0 8 16 24 32 40 48 56 64 448

0 100 112

432 440416408 424400392



Mapping onto a burst

Interleaving block b

hu(b)hl(b)

57 data bits 57 data bits26 bit trainingsequence

3 3 8.25

Normal burst



Insertion of a FACCH message into the TCH/FS data stream

TCH/FS Data block n

B B+1 B+2 B+3 B+4 B+5 B+6 B+7

Data block n+1Data block n–1

FACCH message

hu=1 hu=1 hu=1 hu=1hl=0 hl=0 hl=0 hl=0

hu=0hl=1

hu=0hl=1

hu=0hl=1

hu=0hl=1



Encrypted transmission of the temporary subscriber identity

MS BS/MSC/VLRLAIold, TMSIold

Ciphered(TMSInew)

Resource setup and ciphering commencement

AssignTMSInew

Ack.



Clear text transmission of the IMSI when the TMSI is unknown

MS BS/MSC/VLRLAIold, TMSIold

Ciphered(TMSInew)

Resource setup and ciphering commencement

Ack.

TMSIoldunknown

Request ID

IMSI

AssignTMSInew



Principle of subscriber authentification

MS Network

A3 A3

RAND

IMSI

KiKi

=SRES

SRES



Generation of a set of security data for the HLR

Authentication Information Request

(IMSI)

Authentication Information(IMSI,Kc,RAND,SRES)

HLR AUC

Ki RAND

Kc SRES

A3 & A8



Highly secure authentication (no transmission of Ki)

BS/MSC/VLR

Authentication Information Request

Authentication Vector Response

HLR/AUC

IMSI

Ki

(RAND[n],SRES[n])

RAND[n] gene-ration

A3



Weakly secure authentication (transmission of Ki to VLR)

MS VLR

A3 A3

RAND

IMSI

KiKi

=SRES

SRES



Encryption of payload data in the GSM transport chain

Block codeConvol. codeInterleaving

User dataencryption

Burstbuilding

Differentialcoding andmodulation

ceiverTrans–



Generation of the cipher key Kc

MS Network

A8

RAND

IMSI

KiKi

Kc Kc

A8



Principle of symmetric encryption of user data

MS BTS

KcData

Kc(Data)

Kc Data

A5 A5



Combining payload data stream and ciphering stream

A5Kc

1 0 1 1 0 0 1

0 1 1 0 0 1 0

User data flow

Key flowA5

Kc

1 0 1 1 0 0 1

0110010FN

User data flow

Key flow

FN

Ciphering Deciphering

Synchronization



Synchronized start of the ciphering process

MS BS/MSC/VLR

Start ofdeciphering

Correctly decipherable message

“Start ciphering”

Start of ciphering anddeciphering

Start ofciphering



Logical channels at the air interface (ISDN reference model)



User data and control at the air interface

SA

CC

H

SD

CC

H

Multiplex

Layer 3

Layer 2

Layer 1

s

TC

H

Signalling User Data User Data

Dm Bm

(SMS)

p



Connection elements

Radio Interface

Connection Element

A Interface

Connection Element

GSM-specific

signaling

ISDN-specific

signaling

MSCBSSMS



Speech transmission in GSM

Radio Interface BSS – MSCInterface

BSS MSCMS (MT0)

Voice

GSCITU-T A-Law

FEC MPXFEC MPX

GSC A-Law

TRAU



BTS architecture variations and TRAU placement

BSC

TRXBCF

TRX

BCF Base Control FunctionTransceiverTRX

MSCTRAU

TRXBCF

TRX

Inband remote controlTRAU Transcoding and Rate

Adaptation Unit

TRXBCF

TRXTRAU

TRXBCF

TRAU

TRAU

BTS 1

BTS 2

BTS 3

BTS 4

TRAU



GSM protocol architecture for speech (TRAU at BTS site)

Um AAbis

MS BTS BSC MSC

G.703G.705G.732

FECG.703G.705G.732

G.703G.705G.732

GSMVoice

ISDNVoice

GSMVoice

CipherTDMAFDMA

FECCipherTDMAFDMA



GSM protocol architecture for speech

Um

MS BTS

G.703G.705G.732

GSMVoice

A

BSC MSC

G.703G.705G.732

G.703G.705G.732

Abis

Um A

LocalInterface

ISDNVoice

GSMVoice

Sub-Ch.

TRAUInbandSign.

G.703G.705G.732

Sub-channel multiplex& Inband–TRAU–Sign.

Abis

G.703G.705G.732

TRAU atBSC site

TRAU atMSC site

BSC–MSC–Link

BSC–MSC–Link

FECCipherTDMAFDMA

FECCipherTDMAFDMA

FECCipherTDMAFDMA

G.703G.705G.732

G.703G.705G.732

G.703G.705G.732

FECCipherTDMAFDMA

GSMVoice

TRAUInbandSign.

GSMVoice

Sub-Ch.

ISDNVoice



GSM protocol architecture for transparent data

Um A

G.703

Abis

MS BTS BSC MSC/IWF

G.705G.732

G.703G.705G.732

G.703G.705G.732

L1

TE

L1G.703G.705G.732

each one with bit rate adaptation

FECCipherTDMAFDMA

FECCipherTDMAFDMA

IWF

e.g.X.21X.25V.24

User data



GSM protocol architecture for nontransparent data

Um A

TDMAFDMA

G.703

Abis

MS BTS BSC MSC/IWF

G.705G.732

G.703G.705G.732

G.703G.705G.732

TDMAFDMA

RLP

IFP

User

Layer 2 Relay L2Reach one with bit rate adaptation

e.g.X.21X.25V.24

G.703G.705G.732

RLP

IWF

IFP

NTP NTP



Frame structure of the RLP protocol

Bit number

N(S)

Header16 bit

User data200 bit

Check sum FCS24 bit

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

N(R)

N(R)

C/R – – 1 1 1 1 1 1 P/F M1 M2 M3 M4 M5 –

C/R S1 S2

C/R S1 S2 0 1 1 1 1 1 P/F

P/FInformation

frame

Controlframe

1

2



GSM protocol architecture for signaling

Layer 2

Layer 1

CM

MM

RR

CM

MM

MTP’ MTP

SCCP

TCAP

MAPISDNUP

Um A

MTP’ MTP’

BTSM

LAPDLAPD

RR

SCCP SCCPBTSM

Abis

Layer 3

MS BTS BSC MSC

BS

SM

AP

DTA

P

G.703G.705G.732

LAPDm LAPDm

TDMAFDMA

TDMAFDMA

B,C,E

RR’

BS

SM

AP

DTA

P

G.703G.705G.732

CMMMRRLAPDm

Connection ManagementMobility ManagementRadio Resource ManagementLink Protocol (specially adaptet for air interface Um)

BTSM Base Transceiving Station ManagementBSSMAP

DTAP

TCAPMTP

SCCP

MAPUPBase Station System Management Application Part

Direct Transfer Application Part

Transaction Capabilities Application PaMessage Transfer Part

Signaling Connection Control Part

Mobile Application PartUser Part



Layer 3 protocol architecture at the MS side

BC

CH

AG

CH

SD

CC

HFA

CC

HS

AC

CH

RA

CH

SD

CC

HS

AC

CH

RR

MM

CC SS SMS

Laye

r 3

Sig

nalin

g

SAPI 0 SAPI 3

RR-SAP

MMREG-SAPMMCC/SS

MNCC-SAP MNSS-SAP MNSMS-SAP

�De–)

+R

CH

SMS/SAP

Multiplexing



Distribution of functions between BTS, BSC and MSC

BTS BSC MSC

Terrestrial Channel Management

MSC-BSC-Channels

Channel allocation X

Blocking indication X

BSC-BTS-Channels


Blocking indication X

Mobility Management

Authentication X

Location Updating X

Call Control X

Radio Channel Management

Channel Coding/Decoding X

Transcoding/Rate Adaptation X

Interworking Function X



BTS BSC MSC

Measurements

Uplink measuring X X

Processing of re-ports from MS/TRX

X X X

Traffic measure-ments

X

Handover

BSC internal, intra-cell

X

BSC internal, inter-cell

X

BSC external X

Recognition, deci-sion, execution

X

HO access detec-tion

X



BTS BSC MSC

Paging

Initiation X

Execution X

Radio Channel Management

Channel Configuration Management X

Frequency Hopping

Management X

Execution X

TCH Management


Link supervision X

Channel release X X

Idle channel obser-vation

X

Power control de-termination

X X



BTS BSC MSC

SDCCH Management

SDCCH allocation X

Link supervision X

Channel release X X

Power control de-termination

X X

BCCH/CCCH Management

Message schedu-ling management

X

Message schedu-ling execution

X

Random accessdetection

X

Immediate assign X

Timing Advance

Calculation X

Signalling to MS atrandom access

X



BTS BSC MSC

Timing Advance

Signalling to MS athandover/duringcall

X

Radio Resource Indication

Report status ofidle channels

X

LAPDm Functions X

Encryption

Management X

Execution X



Protocol interfaces in the mobile network

TCAPMTPSCCPMAPISUP

Transaction Capabilities Application PartMessage Transfer PartMobile Application PartISDN User Part

MSC


HLR/VLR

MTP

SCCP

MAP

TCAP

MTP

SCCP

MAP

TCAP

ISUP

MSC

MTP

SCCP

MAP

TCAPISUP

MAP

ISUP

Interface E Interface B, C

Signaling

Signaling

MAPSignaling

HLR/VLR

MTP

SCCP

MAP

TCAP

Interface D,G



International signaling relations via ISDN

TCAPMTPSCCPMAPISUP

Transaction Capabilities Application PartMessage Transfer PartMobile Application PartISDN User Part


GMSC GMSCInterTransitExchange NetworkISCISC

Foreign Countries ISDN PLMN

ISUP

MTPMTP

SCCP

ISUP

MTP

SCCP

ISUP

MAP

TCAPISUP

MTPMTP

SCCP

ISUP

MAP

TCAP

MTP

SCCP

ISUP

MAP Signaling relationsExchange



Protocol architecture for SMS transfer

SM–CP

SM–RP

MS MSC

SM–RP

SM–TP

(CM: SMS)SM–CP

(CM: SMS)

MAP

SMS-GMSC

MAP

SMS-IWMSCSMS-SC

SM–TP

SMS–IWF

GSM MM Connection SS#7 Connection e.g. X.25 Connection



Layer 1 service interfaces

Radio Resource Management(Layer 3)

Data Link Layer(Layer 2)

Signaling Plane User Data Plane

Physical Layer(Layer 1)

Traffic Channel TCH

SA

CC

H

AG

CH

+P

CH

SD

CC

H

FAC

CH

BC

CH

RA

CH



State diagram of a mobile station’ s physical layer

Dedicated Mode

Idle Mode

NULL

TuningDCH

DCH

BCH Search.BCH



Format of a SACCH block

12345678

Bit numberO

ctet

num

ber

23

...

2

1 free

free

Power level

Timing Advance

Layer 2 data (21 octets)



Logical channels, operational modes and Layer 2 SAPIs

Logical Channel SAPI=0 SAPI=3BCCH Unacknowledged –CCCH Unacknowledged –

SDCCH Unacknowledgedand Acknowledged

Unacknowledgedand Acknowledged

SACCHassoc. with

SDCCHUnacknowledged –

SACCHassoc. with

TCHUnacknowledged Unacknowledged

and Acknowledged

FACCH Unacknowledgedand Acknowledged –



Sample configuration of the MS data link layer

SA

CC

H

AG

CH

+P

CH

SD

CC

H

FAC

CH

BC

CH

RA

CH

DLPRA

DLP(UI)

DLP(UI+I)

DLP(UI)

DLP(UI+I)

DLP(UI+I)

DLP(UI+I)

Data LinkDistribution Proc.

Layer 3

Layer 2

Layer 1

DLP Data Link ProcedureRA Random Access Procedure

(Un)acknowledged OperationUI/I

SAPI 0 SAPI 3



LAPDm frame formats

12345678Bit number

Oct

et n

umbe

r

k

1Address

k+1

Length Indicatork+2

n

Fill Bitsn+1

N201+n

Oct

et n

umbe

r

k

1Address

k+1

Length Indicatork+2

n

Informationn+1

N201+nFill Bits

NN+1

12345678Bit number

Type A Type B

12345678Bit number

Oct

et n

umbe

r

1Length Indicator

m

Fill Bitsm+1

N201+m

Type Abis

Oct

et n

umbe

r 1Length Indicator

m

Informationm+1

N201+mFill Bits

NN+1

12345678Bit number

Type Bbis

Control



Logical channels and LAPDm information field max. length

Logical channel N201SACCH 18 octets

SDCCH, FACCH 20 octetsBCCH, AGCH, PCH 22 octets



Format of a Um signaling message (Layer 3)

12345678

Bit number

Oct

et n

umbe

r

k

1

Information Element ID

Message Type

k+1

Transaction ID

IE Content

Length Indicator

n

n+1


xxxx 0

0011

0

1100

1

0101

1

1011

Call Control and call-

Radio Resource M.SMS messagesNon-call-related

12345678

Bit number

2 0

Protocol Discrim.

suppl. services

Mobility Managementrelated suppl. services



RR messages

Category Message Logicalchannel

Direction MT-Code

Channel Additional Assignment DCCH N -> MS 00111011Establishment Immediate Assignment CCCH N -> MS 00111111

Immediate Assignment Extended CCCH N -> MS 00111001

Immediate Assignment Rejected CCCH N -> MS 00111010

Ciphering Ciphering Mode Command DCCH N -> MS 00110101

Ciphering Mode Complete DCCH MS -> N 00110010

Handover Assignment Command DCCH N -> MS 00101110

Assignment Complete DCCH MS -> N 00101001

Assignment Failure DCCH MS -> N 00101111

Handover Access DCCH MS -> N –

Handover Command DCCH N -> MS 00101011

Handover Complete DCCH MS -> N 00101100

Handover Failure DCCH MS -> N 00101000

Physical Information DCCH N -> MS 00101101



Category Message Logicalchannel

Direction MT-Code

Channel Channel Release DCCH N -> MS 00001101 Release Partial Release DCCH N -> MS 00001010

Partial Release Complete DCCH MS -> N 00001111

Paging Paging Request, Type 1/2/3 PCH N -> MS 00100xxx

Paging Response DCCH MS -> N 00100111

System System Information Type 1/2/3/4 BCCH N -> MS 00011xxx Information System Information Type 5/6 SACCH N -> MS 00011xxx

Miscellaneous Channel Mode Modify DCCH N -> MS 00010000

Channel Mode Modify Acknowledge DCCH MS -> N 00010111

Channel Request RACH MS -> N –

Classmark Change DCCH MS -> N 00010110

Frequency Redefinition DCCH N -> MS 00010100

Measurement Report SACCH MS -> N 00010101

Synchronization Channel Information SCH N -> MS –

RR-Status DCCH MS <-> N 00010010



RR connection setup and takedown

MS

Immediate Assignment

BSS

RR connection setup

Channel Request

Channel Request

Channel Request

(MS initiated)

MS


BSS

RR connection setup

Channel Request

(Network initiated)

Paging Request

Paging Response

LAPDm Connection Setup

MS BSS

RR connection takedown

Channel Release

Return to idle state



Measurement result (information element)

IEI: 01110001

RXLEV Serving Cell

RXQUAL Serving Cell

RXLEV Serving Cell

RXLEV Neighb. Cell 1

BCCH–Freq. NCELL 1 BSIC

NCELL 1 RXLEV NCELL

BCCH–Freq. NCELL 2

BSIC NCELL 6

BCCH–Freq.

NCELL6

LEV NCELL 6

RX

2Oct

et n

umbe

r

n

n+1

n+16



Channel change, encryption and handover

Handover Access

Assignment Command

MS BSS

Assignment Complete

Handover CommandMS BSS

Handover Access

Dedicated Channel

Handover (nonsynchronous)

Handover Complete

Handover Access

Handover Access

Handover CommandMS BSS

Handover Access

Handover (synchronous)

Handover Access

Handover Complete

Physical Information

Cipher Mode Command

MS BSS

Cipher Mode Complete

Ciphering ActivationAssignment



MM messages

Category Message Direction MTRegistration IMSI Detach Indication MS -> N 0x000001

Location Updating Accept N -> MS 0x000010Location Updating Reject N -> MS 0x000100Location Updating Request MS -> N 0x001000

Security Authentication Reject N -> MS 0x010001Authentication Request N -> MS 0x010010Authentication Response MS -> N 0x010100Identity Request N -> MS 0x001000Identity Response MS -> N 0x001001TMSI Reallocation Command N -> MS 0x001010TMSI Reallocation Complete MS -> N 0x001011

Connection M t

CM Service Accept MS <-> N 0x100001Management CM Service Reject N -> MS 0x100010

CM Service Request MS -> N 0x100100CM Reestablishment Request MS -> N 0x101000

Miscellaneous MM-Status MS <-> N 0x110001



MM signaling procedure of category Common

IMSI Detach Indication

TMSI Reallocation Command

MS MSC

TMSI Reallocation Complete

TMSI Reallocation

Authentication Request

MS MSC

Authentication Response

Authentication

Identity Request

MS MSC

Identity Response

Identification

MS MSC

IMSI Detach



MM signaling procedure of category Specific

Location Updating Request

Location Updating Accept

MS MSC

Location Update

TMSI Reallocation Complete

Identification

Authentication

Cipher Mode Activation



MM sign. procedure of category MM connection management

CM-Service Request

CM-Service Accept

MS MSC

MM Connection Establishment

Identification

Authentication

Cipher Mode Activation



CC messages for circuit-switched connections

Category Message Direction MTCallE t bli h t

Alerting N -> MS 0x000001Establishment Call Confirmed MS -> N 0x001000

Call Proceeding N -> MS 0x000010Connect N <-> MS 0x000111Connect Acknowledge N <-> MS 0x001111Emergency Setup MS -> N 0x001110Progress N -> MS 0x000011Setup N <-> MS 0x000101

CallI f ti

Modify N <-> MS 0x010111InformationPhase

Modify Complete N <-> MS 0x011111Phase

Modify Reject N <-> MS 0x010011User Information N <-> MS 0x010000

CallCl i

Disconnect N <-> MS 0x100101Clearing Release N <-> MS 0x101101



Category Message Direction MTCallClearing

Release Complete N <-> MS 0x101010

Miscellaneous Congestion Control N <-> MS 0x111001Notify N <-> MS 0x111110Start DTMF MS -> N 0x110101Start DTMF Acknowledge N -> MS 0x110010Start DTMF Reject N -> MS 0x110111Status N <-> MS 0x111101Status Enquiry N <-> MS 0x110100Stop DTMF MS -> N 0x110001Stop DTMF Acknowledge N -> MS 0x110010



Call setup (mobile station): mobile originating

U1Call Initiated

CALL PRO-CEEDING

RELEASECOMPLETE

U3Mobile orig.Call Proc.

U4Call Delivered

For FurtherStudy

For FurtherStudy

2

CONNECTACKNOWLEDGE

U10Active

U0NULL

Mobile Originating

U0.1MM–Connect.

Pending

Start

U0

Connection Re-quest FROM MMI

NULL

MMCC Est. Req.

SETUP

U1Call Initiated

TO MM

MMCC Est. Conf.FROM MM

SETUP

1

ALERT-ING

CON-NECT

ALERT-ING

CON-NECT

CON-NECT

2

2



Call setup (mobile station): mobile terminating

CompatibilityNot OK

OK

1

RELEASECOMPLETE

CALLCONFIRMED

U9Mobile Term.

Call Conf.

U0NULL

Mobile Terminating

U6Call Present

3

3

ALERTING CONNECT

U7Call Received

CONNECT

4

4

4

CONNECTACKNOWLEDGE

U10Active

U8Connect Req.

Check



Call termination at MS: mobile-initiated and network-initiated

5

U10Active

U0NULL

Mobile InitiatedNetwork Initiated

DISCONNECT DISCONNECT

U11Disconnect

Request

RELEASE

RELEASECOMPLETE

5

5

RELEASE

U19ReleaseRequest

U0NULL

RELEASECOMPLETE

DISCONNECT



DTMF signaling and service charge

Modify Reject

Modify

Start DTMF

Start DTMF Acknowledge

MS MSC

DTMF Signaling

Stop DTMF

Stop DTMF Acknowledge

Start DTMF

Start DTMF Acknowledge

Tpress�Tpress_min

Trelease�Trelease_min

MS MSC

Incall Modification

Modify Complete

Modify

Modify Complete

(network initiated)

Incall Modification(mobile initiated)

Channel assignment/mode change

Channel assignment/mode change



Mobile-initiated call setup with OACSU ( late assignment )

CM-Service Request

Phase 5:Call acknowledgePhase 5:Channel

Setup

Channel Request

Auth. Response

MS

assign compl.

BSS

Authentic. Req.

Connect Ack.

DataData

Cipher Mode Compl.Cipher Mode Com.

MSC

Alert

Connect

Phase 1:RR-Connectionsetup

Phase 3:AuthenticationPhase 4:Start of

Phase 5:Call initiation

Phase 2:Service request

assignmentPhase 5:Call acceptance,switch-through

ciphering

Call Proceeding

ImmediateAssignment

assign command

SDCCHSDCCH

AGCH

SDCCH

FACCHFACCHFACCH

TCH

SDCCHSDCCH

RACH

SDCCHSDCCHSDCCHSDCCH



In-call modification and call release

Channel RequestMS BSS

Connect Ack.

MSC

Connect

Phase 1:RR–Connectionsetup

Phase 5:Call acceptanceswitch-through


ModifyPhase 5:Service change(Voice - Data)

Channel Mode ModifyChannel Mode Modify Ack.

Modify Complete

Phase 5:Mode change(e.g. bit rate)

Channel Mode ModifyChannel Mode Modify Ack.

Phase 6:Connectionrelease

DisconnectRelease

Release CompleteChannel Release

AGCH

FACCHFACCH


FACCHFACCH


RACH



CC messages for supplementary services

Category Message Direction MTCall I f ti

Hold N <-> MS 0x011000InformationPhase

Hold Acknowledge N <-> MS 0x011001Phase

Hold Reject N <-> MS 0x011010Retrieve N <-> MS 0x011100Retrieve Acknowledge N <-> MS 0x011101Retrieve Reject N <-> MS 0x011110

Miscellaneous Facility N <-> MS 0x111010Register N <-> MS 0x111011



Call holding and associated procedures

MS MSC

Holding, Consulting

Setupcalling

SetupMS 1called

MS 2called

CR: 1 (Active, Idle)

Hold Ack.

Hold

CR: 1 (Active, Call Held)

Hold Ack.

Hold

Hold Ack.

Hold

CR: 2(Active, Call Held)

Retrieve Ack.

Retrieve

Retrieve Ack.

Retrieve


CR: 1 (Active, Hold Req.)

CR: 1 (Active, Retrieve Req.)


Hold Ack.

Hold

Setup

and Brokering

CR: 2 (Active, Hold Req.)

Setup



Barring and forwarding of calls

MSC

Barring of OutgoingCalls (BAOC)

Release Complete

Setup

(Facility: BAOC)

MScalling

MSC

Barring of IncomingCalls (BAIC)

Release Complete

Setup

(Facility: BAIC)

MScalling

MS MSC

Call ForwardingUnconditional (CFU)

Facility

Setup

(Facility: CFU)

calling

Setup(Facility: CFU)

MSDestination

Connect Ack.

ConnectConnect Ack.

Connect

MScalled

Connection with Call Forwarding destination

of forw.



Short message transfer between SMR entities

MSC

RP–ACK

RP–DATA(SMS–SUBMIT)

MS

SMS–SUBMIT

SMS–IWF

SM–RL Report Request

SM–RL Data Indic. (RP–DATA)

Mobile-terminated SM–RL transfer

RP–ACKSMS–DELIVERSM–RL Report Indication

SM–RL Data Req. (RP–DATA)

Mobile initiated SM–RL transfer

RP–DATA(SMS–DELIVER)

REPORT

SM–RL SM–RL



Short message transfer on the CM plane between MS and MSC

MSCMSSM–CL SM–CL

MSSM–RL

MNSMS–Est.–Req.

(RP–DATA)

MSMM

MMSM–Est.–Req.

MSCMM

MNSMS–Est.–Ind.(RP–DATA)

MSCSM–RL

MMSM–Est.–Conf.

CP–ACK

CP–DATAMMSM–Est.–Ind.

CP–ACK

CP–DATA

MNSMS–Est.–Req.(RP–ACK)

MNSMS–SSP–Req.MMSM–Rel.–Req.MMSM–Rel.Ind.

MMSM–Est.–Req.MMSM–Est.–Conf.MMSM–Est.–Ind.

MNSMS–Data–Ind.(RP–ACK)

MNSMS–Rel.–Req.MMSM–Rel.–Req.

MNSMS–Rel.–Req.MMSM–Rel.Req.



Protocols at the A interface between MSC and BSS

A

BS

SM

AP

DTA

P

SCCP SCCP

BSC MSC

BS

SM

AP

DTA

P

BS

SO

MA

P

BS

SO

MA

P

MTP � MTP �



Examples of dedicated BSSMAP procedures

Clear Command

Clear Complete

MS

Assignment

BSS

Assignment

MSC

Channel Assignment

RequestCommand

Assignment

CompleteAssignment

Complete

MS BSS MSC

Channel Release

MS

CIPH MOD

BSS

Cipher Mode

MSC

CIPH MODCipher Mode

Command

Cyphering Control

COM

CMD



Dedicated BSSMAP procedures for internal handovers

Handover

Required

Handover

Command

MS BSS 1 MSC

Handover request

Handover

Command

BSS 2

Handover

Request

Handover

Request Ack.

Resource reservation

Handover execution

Handover

Complete Handover

Complete



Examples of global BSSMAP procedures

MS BSSBlock

MSC

Block Ack.

MS

Paging Request

BSS

Paging

MSC

Paging

Unblock

Unblock Ack.

Channel barring/release

MS BSS MSCOverload

Overload

Flow control

Overload

Overload

PagingPaging Request



Logical connections at Layer 2 of the Abis interface

BSC

BCF

TRX

BTS

OMLL2ML

RSL

TRXOMLL2ML

RSL

OMLL2ML

TEI 1

TEI 2

TEI 3



Protocol Layer 3 of the BTS at the Abis interface (BTSM)

SAPI 0 Layer 3

Layer 2

SAPI 63SAPI 62

Distribution

RSL OML L2ML

Transp.messages

Nontransp.messages

NetworkManagement

Layer 2Management

Protocol instancesinside the BTS

TrafficManagement

To MS(Radio interface)



Transfer of transparent signaling messages

MS

LAPDm

BTS

Data Request

BSC MS BTS BSC

Data Indication

I/UI frame

LAPDmI/UI frame



Examples of nontransparent signaling between BTS and BSC

MS

SACCH header(Layer 1)

BTSMS Power Control

BSC

MSChannel Request

BTS BSC

Channel Required

MS

Paging Request

BTSPaging Command

BSC

MS

CIPH MOD CMD

BTSEncrypt. Command

BSC

CorrectLAPDm frame

CIPH MOD COM

Startdeciphering

Startciphering

MS

immediateassign message

BTSIMM ASS CMD

BSC

MSHandover Access

BTS BSC

HandoverDetectionPhysical Info

(Timing Adv.)

CIPH MOD COM



Format of BTSM-RSL protocol messages

12345678

Bit number

Oct

et n

umbe

r

k

1


Message Type

k+1

Message Discrimantor

IE Content

Length Indicator

n

n+1


Txxxx00000001

00110

00010

01000

reservedRadio Link LayerDedicated ChannelCommon ChannelTRX Management

transparent: yes/no

12345678

Bit number



Input format of some MMI commands

Function MMIprocedure

Activate * nn(n)*Si#Deactivate #nn(n)*Si#Status enquiry *#nn(n)*Si#Registration **nn(n)*Si#Delete ##nn(n)*Si#



Some basic MMI commands

Function MMI-ProcedureMobile phone IMEIenquiry

*#06#

Change password forcall barring

**03*330*old_PWD*new_PWD*new_PWD#

Change PIN in SIM **04*old_PIN*new_PIN*new_PIN#Select SIM numberstorage

n(n)(n)#



MMI service codes for supplementary services

Abbr . Service MMIcode

Sia Sib

All Call Forwarding, only for (de)activation 002 – –All conditional Call Forwarding (not CFU),only for (de-)activation

004 – –

CFU Call Forwarding Unconditional 21 DN BSCFB Call Forwarding on Mobile Subscriber

Busy67 DN BS

CFNRy Call Forwarding on No Reply 61 DN BS

CFNRc Call Forwarding on Mobile Subscriber NotReachable

62 DN BS

All Call Barring (only for deactivation) 330 PW BS

BAOC Barring of All Outgoing Calls 33 PW BSBOIC Barring of Outgoing International Calls 331 PW BSBOIC-exHC

Barring of Outgoing International CallsExcept those to Home PLMN

332 PW BS



Abbr . Service MMIcode

Sia Sib

BAIC Barring of All Incoming Calls 35 PW BSBIC-Roam

Barring of Incoming Calls when RoamingOutside the Home PLMN

351 PW BS

CLIP Calling Line Identification Presentation 30 – BSCLIR Calling Line Identification Restriction 31 – BSCW Call Waiting 43 – BSCOLP Connected Line Identification Presentation 76 – BSCOLR Connected Line Identification Restriction 77 – BS

BS=Basic Service (see NO TAG)DN=Destination Number PW=Password



MMI codes for basic services

Category Service MMI codeBS

Telematic service All telematic services 10Telephone 11All data services 12Facsimile 13Videotex 14Teletext 15Short Message Service (SMS) 16

All data services except SMS 18All telematic services except SMS 19

Bearer service All bearer services 20All asynchronous services 21All synchronous services 22



Category Service MMI codeBS

Bearer service All connection-oriented synchronousdata services

24

All connection-oriented asynchronousdata services

25

All packet-oriented synchronous dataservices

26

All PAD-access services 27



Overview of the location registration procedure

Loc. Upd. Req.(IMSI, LAI)

Update Loc. Area(IMSI, LAI)

Auth. Para. Req.(IMSI)

Auth. Info(IMSI,Kc,RAND,SRES)

Authenticate(RAND)

Authentic. Req.(RAND)

MS BSS/MSC VLR HLR AU C

Authentic. Resp.(SRES)

Authentic. Resp.(SRES)

Forward new TMSI(TMSI)

Start Ciphering(Kc)

Ciph. Mode. Com.Kc Message M

Kc(M)A5

Ki RAND

Kc SRESA3 & A8

Ciph. ModeKc(M) Kc Kc(M)

MA5

Loc. Upd. Accept

Loc. Upd. Accept

TMSI Realloc Ack. TMSI Ack.

Auth. Info. Req.(IMSI)


Update Location(IMSI,MSRN)

Loc. Upd. Accept(IMSI)

Generate TMSI

IMSI, Ki

Insert Subscriber Data(IMSI)

Subscr. Data Insert. Ack.

TMSI Realloc. Cmd.

SRES

=



Overview of the location updating procedure

Loc. Upd. Req.(TMSI,LAI)

Update Loc. Area(TMSI,LAI)

MS BSS/MSC VLR HLR


Start Ciphering(Kc)

Loc. Upd. Accept

Loc. Upd. Accept

TMSI ReallocationComplete TMSI Ack.



IMSI, TMSIKi, Kc, LAI



Auth. Info. Req.(IMSI)


AUC

Generate TMSI

AuthenticationSRES =

SRES

Startciphering



TMSI Realloc. Cmd.



Location update after changing the VLR area

Loc. Upd. Req.(TMSI,LAI)

Update Loc. Area(TMSI,LAI)

MS BSS/MSC VLR new HLR



IMSI, TMSIKi, Kc, LAI

Cancel Location(IMSI)

Cancel Location Ack.(IMSI)

VLR old

GenerateTMSI


SRES

Send Parameters from VLR1(TMSI, LAI)

IMSI Response(IMSI, RAND, SRES, Kc)




Start Ciphering(Kc)



Principle of routing calls to mobile subscribers

GMSC

BTSBSC

HLRVLR

EIRAUC

MS

MSC

BTS BSC

MS

BTS

4

5

7

8 6

2

7

7

MSISDN

MSRN

MSRNTMSI

TMSITMSI

TMSITMSI

1MSISDN

3

MSRN

LA 1

LA 2



Routing variants for national MSISDN

ISDN

PLMNHLR

MSC

ISDN

HLR

MSC

a

bISDN

PLMN

HLR

MSC

c

GMSC

TE

LE Local ExchangeTE Transit Ex-change

LE LE

LE

PLMN



Routing for international MSISDN (HLR interrogation from ISC)

LE Local ExchangeISC International

ISDNH-PLMN

HLRISC

ISDN

ISDN

V-PLMN

ISCISC

MSC

LE



Routing through GMSC for international MSISDN

ISDN ISDN

H-PLMN

HLRISCISDN

V-PLMN

MSC

GMSC

ISC

GMSC

ISC

ISC

LE

LE Local ExchangeISCInternational Switching Center



Overview of connection setup (outgoing)

Setup Indication(TMSI,LAI) Process Acc. Req.

(TMSI,LAI)

MS BSS/MSC VLR HLRIMSI, TMSIKi, Kc, LAI



SS#7 Networ k

Setup Send info for setupInfo ack. for setupCall Proc.

assign comnd.assign compl. IAM

ACMANS

AlertConnect

Connect Ack.

Start of ciphering procedure


SRES

Access Req.Accepted

CM-ServiceAccept



Interrogation of routing information for incoming call

HLR VLRSS#7 Networ k

IAM

Routing Information

GMSC MSC

IAM

HLR VLR

IAM

GMSC MSC

IAM

Routing information (MSRN) in the HLR

Routing information (MSRN) from the VLR

Provide RoamingNumber

Roaming NumberRouting Information

Send RoutingInformation

Send RoutingInformation



Overview of incoming call setup

MS VLR HLRIMSI, TMSIKi, Kc, LAI



SS#7 Ne

Setup

Send info for setup

Call Confassign comnd.assign compl.

ACM

IAM

AlertConnect

Connect Ack.

Page MS(TMSI, LAI)

Paging Request(TMSI)

Paging Response(TMSI)

Complete Call

ANS

BSS/MSC

Authentication


Optional TMSI Reallocation

ProcessAccess Request

Access Req.Accepted



Mobile-initiated call termination and storing of charging inform.

Release Complete

MS HLR

Disconnect

Release

BSS/MSC

Register Charging Information

Charging Information Ack.Channel Release

SS#7 Networ k

REL

RLC



Forwarding short messages in a PLMN

VLR

MS

Send info for setup

Forward Short Message

SMS-GMSC HLSend Routing Information

for Short MessageShort Message

Routing Information

MSC

Forward Acknowledge /

Forward Short Message

Forward Acknowledge/

(a)

(b)

Page MS(TMSI, LAI)

Paging Request(TMSI)

Paging Response(TMSI)

Authentication


Optional TMSI reallocation

ProcessAccess Request

Access Req.Accepted

Error Indication

Error Indication

RP-DataRP-Data



Intracell and intercell handover

BTSMSC

BSC

MSBTS

MS

MS

Intracell Handover

Intercell Handover



Internal and external handover

MSC-B

BTS 1 MSC-A

BSC

MSBTS 2MS

Internal Handover

BSC

BTS 3

MS

External Handover

Connection route



Principal signaling sequence for an intra-MSC handover

MS BSS 1 MSC MS

Handover Req. Ack.

Handover Required

HandoverCommand

BSS 2Measurement Info

Handover Request

HandoverCommand

Measurement Info

Measurement Info

Measurement Info

Handover CompleteHandover Complete

Clear Command

Clear CompleteMeasurement Info

Measurement Info

Handover AccessHandover Detection

Physical Information



Decision steps in a GSM handover

BSS measurement prepro-cessing and threshold analysis

BSS handoverdecision algorithm

MSC destinationselection algorithm

MS measurement values BS measurement values(RXLEV, RXQUAL,RXLEV adjacent BCCH)

(RXLEV, RXQUAL, distance,interference in unoccupied time slots)

Downlink Uplink



Threshold values for the GSM handover

Threshold value Typ . value MeaningL_RXLEV_UL_H –103 to –73 dBm Upper handover threshold of received

signal level in uplinkL_RXLEV_DL_H –103 to –73 dBm Upper handover threshold of received

signal level in downlinkL_RXLEV_UL_IH –85 to –40 dBm Lower(!) received signal level threshold

in uplink for internal handoverL_RXLEV_DL_IH –85 to –40 dBm Lower(!) received signal level threshold

in downlink for internal handoverRXLEV_MIN(n) approx. –85 dBm Minimum required RXLEV of BCCH of

cell n to perform a handover to this cellL_RXQUAL_UL_H – Lower handover threshold of bit error

ratio in uplinkL_RXQUAL_DL_H – Lower handover threshold of bit error

ratio in downlinkMS_RANGE_MAX 2 to 35 km Maximum distance between mobile and

base stationHO_MARGIN(n) 0 to 24 dB Hysteresis to avoid multiple handovers

between two cells



Handover causes

Handover Cause MeaningUL_RXLEV Uplink received signal level too

lowDL_RXLEV Downlink received signal level too

lowUL_RXQUAL Uplink bit error ratio too highDL_RXQUAL Downlink bit error ratio too highPWR_CTRL_FAIL Power control range exceededDISTANCE MS to BTS distance too highPBGT(n) Lower value of path loss to BTS n



Detection of mandatory handover (abbreviated)

Init

Info Waiting

CalculatePower Budget PBGT(n)

for all n

1

HO_CAUSE :=PWR_CTRL_FAIL

FROM BSS_Link_Control

RXLEV/RXQUAL UL/DL,RXLEV(n), Power FAIL

RXLEV/RXQUAL UL/DL,RXLEV(n), Power OK

CalculatePower Budget PBGT(n)

for all n...



Detection of mandatory handover (2)

RXLEV_DL/UL< L_RXLEV_xx_H

No

Yes

Yes

No

Yes

No

1

Yes

HO_CAUSE :=UL/DL_RXLEV

HO_CAUSE :=DISTANCE

3

HO_CAUSE :=PBGT(n)

2

1

No

Info Waiting

Yes

No

1

RXQUAL DL/UL< L_RXQUAL_xx_H

Distance>MAX_MS_RANGE

PGBT(n)>HO_MARGIN(n)

RXLEV_DL/UL>L_RXLEV_xx_H

HO_CAUSE :=UL/DL_RXQUAL

...



Completion of handover decision in the BSS

1

Info Waiting

2Inter-cell Handover,mandatory

Intra-cell Handover,mandatory (Interfe-rence)

3

Generate PreferredTarget Cell List withRXLEV_NCELL(n)

Handover Required

Preferred Target Cell List)TO MSC

Internal

(HO_CAUSE)TO BSC

(HO_CAUSE,Handover Required

Preferred Target Cell List)TO MSC

(HO_CAUSE,Handover

> Threshold

Generate PreferredTarget Cell List withRXLEV_NCELL(n)

> Threshold

Generate PreferredTarget Cell List withRXLEV_NCELL(n)> Threshold, AND

PGBT(n) > MARGIN(n)



Handover criteria for exhausted transmitter power control

RXLEV_DL RXLEV_NCELL(B)

RXLEV_MIN(B)

MS_TXPWR_MAX–RXLEV_DL MS_TXPWR_MAX(B)–RXLEV_NCELL(

HO_MARGIN(B)

Handover

Cell A Cell B

MS_TXPWR_MAXMS_TXPWR_MAX



Principal operation of a basic handover

MS/BSS 1 MSC-A MSC-B

MS/BSS 2

VLR-B

Radio Channel Ack.

Handover RequiredPerform Handover

IAMACMHA Indication HB Indication

HB ConfirmSend End Signal

ANS

REL

End Signal

End of Call

Handover Report

Allocate Handover Number

Send Handover Report

RLC



Principle of subsequent handover from MSC-B to MSC-A

MS/BSS 1MSC-A MSC-B

MS/BSS 2

VLR-B

Perform Subsequent

Handover

HB Indication HA Indication

REL

End SignalHandover Report

HA Required

Subseq. HandoverAcknowledge

HB Confirm

RLC



Principle of subsequent handover from MSC-B to MSC-B’

MSC-B′

MSC–A MSC–B MS

Perform SubsequentHandover

HA Indication

RELEnd Signal

Handover Report

HA Request

Subseq. HandoverAcknowledge

Perform Handover

Radio Channel Ack.

Allocate Handover Number

Send Handover Report

IAMACM

Send End SignalANS

MSC-BHB Indication

HB Confirm

MSC-B VLR-B

RLC

VLR-B′

MSC-B′



GSM reference configuration

Mobile Station ( MS )

MT 1TE 1

R

S

Um

2

1

MT 03

MT 1TATE 2

3

MT 2TE 23

e.g. mobile dataterminal orvoice MS only

e.g. mobile voice anddata terminal

e.g. DTE ofITU-T V. or X.series with mobileterminal adaptere.g. DTE ofITU-T V. orX. series

3

MT: Mobile TerminationTE1: Terminal Equipment, ISDN InterfaceTE2: Terminal Equipment, no ISDN Interface (V,X)

TA: Terminal AdapterUm: Reference Point Radio Interface

R/S: Reference Points ISDN / non-ISDN



Bearer services, interworking and teleservices

BSS

GMSC/MSC

IWF

Modem

Bit rateadaptation

RLP and L2R

(nontransparent bearer services)TE

MTBit rate

and FEC

Support of

telematic services

Analog fixed

network (PSTN)

Digital fixed

network (ISDN)

End-to-end

data and telematic services

adaption



Interworking scenarion PLMN-PSTN for transp. data services

PLMN MSC PSTN

TE MTModem

TEVoice

Data

Voice

Data

In the PSTN:fully transparent ana-

log connection forvoice or data

In the PLMN:switching betweenvoice and data co-

decModemBit rate

IWF

GMSC

Internetworkswitching unit

adaption



Data rates for GSM bit rate adaption

Interface User Intermediate Radio S-InterfaceReference point R – Um S

RA1 ≤ 2.4 kbit/s 8 kbit/sRA1 4.8 kbit/s 8 kbit/sRA1 9.6 kbit/s 16 kbit/sRA2 8 kbit/s 64 kbit/sRA2 16 kbit/s 64 kbit/s

RA1/RA1 ′ 8 kbit/s 3.6 kbit/s

RA1/RA1 ′ 8 kbit/s 6 kbit/s

RA1/RA1 ′ 16 kbit/s 12 kbit/s



V.110 80-bit adaption frame for the RA1 stage

Data0 0 0 0 0 0 0 0

Data

Data

Data

Signaling

Data

Data

Data

Data

1

1

1

1

1

1

1

1

1

Sig

nalin

g

1 2 3 4 5 6 7 8

01

2

3

4

5

6

7

8

9

Bit numberO

ctet

num

ber



Modified V.110 adaption frame for the RA1’ stage

Data

Data

Data

Data

Signaling

Data

Data

DataS

igna

ling

1 2 3 4 5 6 7Bit number

Data

Data

Data

Data Sig

nalin

g

Data

Data

Signaling

Sig

nalin

g

3 4 5 6Bit number

Data

Data

Data

Sig

nalin

g

1 2 7 8

Data

60-bit adaptation frame

36-bit adaptation frame

transparent data 9.6 kbit/s and 4.8 kbit/s)

(transparent data 2.4 kbit/s)

Data

Data

Octet

Data



Transparent transmission of asynchronous data in GSM

Radio Interface BSS-MSC interface

RA 2 RA 2 FEC FEC RA 2

S Interface

TE 1 or TA MT 1BSS MSCMS

RA 2

data transparent, asynchronous data

RA 0

RA 1 RA 1′ RA 1RA 1′RA 1



Transp. transmission of asynchr . data across the R interface

RA 0

FEC FEC

MT 2

RA 1′

D

S

Radio Interface BSS-MSCInterface

RA 2

R Interface

TE 2

BSS MSCMS

RA 2

data transparent, asynchronous data

RA 1′ RA 1

I/FcctI/Fcct



Principle of transparent asynchronous data transfer (modem)

MSCTA MT

Modem TE

RA1 ModemRA2 RA0

IWF

TE

V.24R

V.24

TA′ TE

V.24

PSPDN

MTTE

S

NT Modem

GMSC and inter networkswitching unit

Modem PAD

ISDN

PLMN PSTN



Transparent data transfer to an ISDN (unrestricted digital)

TA MTTE

V.24R

MTTE

S

GMSC and network transitswitching unit

MSC

V.110

IWF

TA′ TE

V.24R

NT Modem

TE

S

NTPLMN ISDN



Weighted distribution of a transparent GSM bearer service

m

P(m,1024)

1e-05

1e-04

1e-03

1e-02

1e-01

1e+00

1e+00 1e+01 1e+02 1e+03

stationaermobil



Nontransparent data transmission in GSM

RA 0


RA 2 RA 2 FECFECS Interface

MT 1BSS MSCMS

Radio Link Protocol

Layer 2 RelayCharacter Oriented Protocol

TE 1

L2R

RA 0

RA 2 RA 2

L2RAsynchro-

nousData

StatusData

StatusRA 1′ RA 1RA 1′RA 1 RA 1RA 1

L2RData

I/Fcct I/FcctR Interface

MT 2

MS

TE 2

Asynchronous

characters

Asynchronouscharacters

characters



Principle of nontransparent data transfer

MSCTA MT

Modem TE

IWF

TE

TA′ TE

R

Modem

MTTE

S

NT Modem

GMSC and internetworkswitching unit

RLP

R

PSPDN

RA1 RA2RA0 NT TE

S

RA1RA2 Modem

PAD

PLMN

ISDN

PSTN



Dedicated PAD access through asynchr . GSM data services

MSC PSPDN

P-IWMSC

RF

TA MTDEE

X.3/X.28/X.29V.24X.21

X.25

DEE

X.25X.29

PAD Packet Assembler/Disas-semblerP-IWMSCPacket Interworking

IWF

RLP

RA1 RA2RA0RA1RA2

V.110

MSC

PAD

PLMN



X.25 access at the ISDN S interface


S InterfaceMT 1

BSS MSC/IWFMS

Radio Link Protocol

Layer 2 RelayBit Oriented Protocol

TE 1

LAPB

X.25 Packet Layer Protocol

RA 2 RA 2 FEC FEC

RA 1′ RA 1RA 1′ RA 1

L2R

RA 2 RA 2

L2R

RA 1

Status

LAPB

L 3

L 2

RA 1



Dedicated packet mode with packet handler in GSM

MSC PSPDNP-

IWMSC PHMTDEE

X.25S

X.75

DEE

X.25X.29

P-IWMSC Packet Interworking MSCPHI Packet Handler InterfacePH Packet Handler

IWF

RLP

RA1 RA2RA0RA1RA2

PHI

PLMN



Fax adapter in GSM

GSMFax MT

G3Fax

MSC

Modem TE

V.24

G3Fax

a/b

GMSC and internetworkswitching unit

Fax

MT

Fax protocolFax adapter protocol

FA

protocol

FA IWF

R

PSTNPLMN



Overview of GSM procedure for fax service

MSC

Modem TE

V.24

G3Fax

a/bFA

GMSC andinternetwork

switching unitIWF with Fax Adapter

RLP

RA1RA2 Fax

Ada

pter

Pro

toco

l

Fax Adapter

V.21

V.27ter

V.29

Tone Handl.F

ax A

dapt

erP

roto

col

G3Fax

V.21

V.27ter

V.29

Tone Handl.

MT

PLMN

PSTN



Transparent fax procedure in GSM

Radio Interface BSS-MSCInterfaceR Interface

Fax adapter protocol

I/Fcct FEC FEC

RA 1

RA 2 RA 2

FA

I/Fcct

FAT.30G3

Fax

RA 1RA 1′RA 1′



Nontransparent fax procedure in GSM

Radio Interface BSS-MSCInterfaceR Interface

Radio Link Protocol

L2RBOP

LAPB Fax adapter protocol

I/Fcct FEC FEC

RA 1RA 1

L2R

RA 2 RA 2

L2R

RA 1

LAPB

FA

G3Fax FA

RA 1′ RA 1′

I/Fcct



Functional areas of TMN systems

Management



TMN architecture (schematically , according to M. 3010)

FQ3

Q3

F,Q3,XQ3

Q3

X Data Communicationnetwork DCN

LocalCommunication

NetworkElement NE

Q3

Qx

Qx

Q3

F,Q3,X

F

F

F

F

Interface

Qx

OtherTMN Systems

TMN SystemWorkstation

WS

Network LCN

WorkstationWS

WorkstationWS

WorkstationWS

WorkstationWS

Q AdapterQA Q Adapter

QANetwork

Element NE

MediationDevice MD

OperationSystems OS

OperationSystem OS

OperationSystem OS



Logical layered architecture of a TMN system

Business Management Layer BML

Service Management Layer SML

Network Management Layer NML

Element Management Layer EML

Network Element Layer



A simple TMN architecture of a GSM system

Q3

Q3

Qx

OS

OSF

NE: BTS

NEF

NE: MSC/VLR

NE: BSC

MF

NEF

NEF

OSFOperating System FunctionNEFNetwork Element Function

Mediation FunctionMF



Potential signaling interfaces in a GSM TMN

VLR

AUC

HLR

PSTNISDN

GMSC

VLRMSC

BTS BSC

BTS

OMC

SP

SP

SP

SP

SP

SP

SP

MNAP

GSM SS#7 routePublic X.25 routeGSM PLMN internal X.25 route (through MSCGSM Abis interface

SP SS#7 Signalling PointManagement Network Access PointMNAP

MNAP

MNAP

MNAP

MNAP

MNAP MNAP

MNAP



GSM network management protocols at the Q3-interface

CMISE, ISO 9596OMAP ASEsCCITT Q.795

Common Management Information Service Element

MTP–3, Q.701–Q.707

CMISEOMAP FTAMOperation, Maintenance and Administration Part File Transfer Access and Managemen

Transport Protocol, CCITT X.224/ISO 8073 (class 2)

CCITT X.25SCCP

MTP–2, Q.701–Q.707

MTP–1, Q.701–Q.707

CCITT X.25 LAPB

X.21/X.21bis CCITT G.703

Session Protocol, CCITT X.225/ISO 8327 (version 2)

Presentation Protocol, CCITT X.226/ISO 8650

ACSE, CCITT X.227/ISO 8650TCAP, CCITT Q.771/Q.775

ROSE, X.229/ISO 9072 FTAM, ISO 8571

SS#7 dedicated GSM SMAP(System Management Application Process)SMAP

ROSE Remote Operation Service Element

ACSE A i i C l S i El



Operation and maintenance of the BSS

A

MTP MTP

BS

SA

P

SCCP SCCP

BSC MSC

BS

SA

P

BS

SO

MA

P

BS

SO

MA

P



Hierarchical organization of network management in Germany

NMC

OMC

OMC

OMC

OMC

OMC OMCOMC

OMCOMC

OMC

OMC

OMC

OMC

OMC



Through-transport of GSM coded speech in phase 2+

MSC

GSM

GSM

MS BSCBTS

BSCTrans–codingBTSMS

MSC

GSM

GSM

MS BSCBTS Trans–coding

BSCTrans–codingBTSMS

GSM

GSM

Trans–coding ISDN

A-Law

ISDNA-Law



Groupcall scenarios

1

2

3

45

6

...

11

1

2

3

45

6

...

11

1

2

3

45

6

...

11



Functional architecture for CAMEL

HLR gsmSCF

gsmSSF

GMSC

gsmSSF

MSCVLR

MAP

CAP MAPMAP CAP

Interrogating Network Visited Network

gsm seminar

Documents

networks in18 countries

countries operational

european gsm networks

number of networks

different countries

gsm standardization

gsm base stations

mobile ip