Lec 3 & 4 GSMNetArchitecture(Revised)

GSM Architecture

Numbering and Routing

GSM Services

GSM Network ArchitectureGSM Network Architecture

Engr. Mian Shahzad IqbalLecturerDepartment of TelecommunicationEngineering

IntroductionIntroductionGlobal System for Mobile Communication (GSM)Global System for Mobile Communication (GSM)

Anybody Anybody –– 500 million users (may 2001)500 million users (may 2001)Anywhere Anywhere –– 168 countries (may 2001)168 countries (may 2001)Any media Any media –– voice, messaging, data, multimediavoice, messaging, data, multimedia

Source: Hillebrand, 1

GSM ArchitectureGSM Architecture

OMC

Home Location Register

AuC

Equipment ID

Network Management Center

BTS

BTS

BTS

ME

ME

ME

Subscriber Identity Module



Base station controller

PSTN

Mobile switching center

Data communication network

BTS = Base Transceiver Station

AuC = Authentication Center

OMC = Operation and Maintenance Center

PSTN = Public Switched Telephone Network

ME = Mobile Equipment

Source: Stallings, 313

Source: Mehrotra, 27

Visitor Location Register

GSM ArchitectureGSM Architecture

F1 F2 F1' F2'Frequency

12345678

45 MHz

BS Transmission Band : 935 – 960 MHZ

MS Transmission Band : 890 – 915 MHZ

Year IntroducedYear Introduced 19901990

Access methodAccess method TDMATDMA

Channel BandwidthChannel Bandwidth 200 kHz200 kHz

Number of duplex Number of duplex channelschannels

125125

Users per channelUsers per channel 88

Speech coding bit Speech coding bit raterate

13 kbps13 kbps

Data coding bit rateData coding bit rate 12 kbps12 kbps

Frame sizeFrame size 4.6 ms4.6 ms

SIM (Subscriber Identity Module)SIM (Subscriber Identity Module)

Billions of Calls

Millions of Subscribers

Thousand of Different Types of Telephones

Hundreds of Countries

Dozens of Manufacturers….

And only one Card: The SIM

Source: Hillebrand, 369

http://ucables.com/products/simcards/

•Administrative data

•Security data

•Subscriber data

•Roaming data

•PLMN (Public Land Mobile Network

Subscriber Identity Module Subscriber Identity Module (SIM)(SIM)

Subscriber Identity ModuleSubscriber Identity ModuleContainsContains

phone number (MSISDN)phone number (MSISDN)international mobile subscriber identity (IMSI)international mobile subscriber identity (IMSI)status of SIMstatus of SIMservice codeservice codeauthentication keyauthentication keyPIN (personal identification code)PIN (personal identification code)PUK (personal unlock code)PUK (personal unlock code)

SIM CardsSIM Cards

SIM cards are embedded with a SIM cards are embedded with a microprocessormicroprocessor

Stores customer identity information and is Stores customer identity information and is made to fit inside the cellular phonemade to fit inside the cellular phone

Memory capacityMemory capacity1K, 3K, 8K, 16K,32K,64K1K, 3K, 8K, 16K,32K,64K

+G S M

Global GSM MobilityCardThe Smart Card to use

SIM Card

+

BatteryHandset

Mobile Station

=

battery

f153454

2Wjmhfodkgdjipj

Mobile StationMobile Station

G S M

Global GSM MobilityCardThe Smart Card to use +

SIM-Card

Subscriber knowsCalled party number = MS-ISDN-PIN

Contains:- IMSI

Handset

= Calling line0609225831

SIMSIM--CardCard and GSM Mobile and GSM Mobile EquipmentEquipment

25 mm

15 mm

Microchip with storeduser information

Credit Card Size

Permanent data:- Unique mobile subscriber identitythrough IMSI number,

- Authentication parameter Ki,- Authentication algorithm A3,- Generating encryption key Kcalgorithm A8.

Removable data:- Temporary Mobile Subscriber Number,- Location Area Identification.

µ SIM-Card

G S M


The The SIMSIM--CardCard FunctionsFunctions

NatureInternational Mobile Subscriber Identity

Conformity with E212

Mobile Station -Integrated Services Digital Network Nb

Similar to ISDN, Conformity with E164/E213

Nb. digits 3 2 max 10 1 to 3 2 to 4 total max 15

*This code does not identify a geographical areabut an operator

MS - ISDN

Format MCC MNC MSINH1 H2 x x x ......... x x x CC NDC SN

M1 M2 x x x x x x x x

MeaningMobile

CountryCode

MobileNetwork

Code

Mobile SubscriberIdent. Nb

H1 H2 = Identity of HLR within the home PLMN

CountryCode

(wheresubscription

has been made)

NationalDestination

Code *

Mobile Subscriber(national definition)

M1 M2 = nbr of logical HLR

IMSI

National Significant Mobile NumberIdentify a PLMNworldwide

Identify the subscriberof a PLMN

SubscriberSubscriber IdentificationIdentification

Revision level (Phase 1, 2, 2+)

RF power

Encryption algorithm (A5/1,A5/2)

Frequency (900/1800/1900)

Short message

Classmark

Class GSM900

GSM1800

GSM1900

Power classes

1

2

3

4

5

8 W*

5 W

2 W**

0.8 W

1 W**

0.25 W

4 W

1 W**

0.25 W

4 W

* Typical value for car mounted** Typical value for handheld

MS MS ClassmarkClassmark

MS (Mobile Station)

ME (Mobile Equipment)

ADVANTAGES OF GSM

DigitalDigital Global

Open Interfaes Secure

Noise Robust

NETWORK ARCHITECTURE

MS

Mobile StationBSS

Base Station Subsystem

OMS

Operations & Maintenance Subsystem

NSS Network Switching Subsystem

BSS (Base Station Subsystem)

BSS Connectivity

NSS (Network Switching Subsystem)

OMS (Operations & Maintenance Subsystem)

The Network In Reality

GSM Network ElementsGSM Network Elements

HandsetHandsetBTS: BTS: Base Transceiver StationBase Transceiver Station

MSC: MSC: Mobile Switching CenterMobile Switching Center

BSC: BSC: Base Station ControllerBase Station Controller

HLR/VLR:HLR/VLR: Home Location Register/Visiting Home Location Register/Visiting Location RegisterLocation RegisterSIM Card: SIM Card: Subscriber Identity Module CardSubscriber Identity Module Card

Service Centers: Service Centers: USSD, SMS, ...USSD, SMS, ...

Base Transceiver Station (BTS)Base Transceiver Station (BTS)/ Base Station/ Base Station

Responsible for communication to and from Responsible for communication to and from MHsMHs via air interfacevia air interface

MS communicates with the mobile system using a MS communicates with the mobile system using a radio channel to a BTSradio channel to a BTS

BTS comprises radio transmission and BTS comprises radio transmission and reception devicesreception devices

Including the antennae and signaling processing Including the antennae and signaling processing specific to the radio interfacespecific to the radio interface

BTS separates the speech and control BTS separates the speech and control signaling associated with a MS and sends signaling associated with a MS and sends them to the BSC on separate channelsthem to the BSC on separate channels

Mobile services SwitchingMobile services SwitchingCenter (MSC)Center (MSC)

Responsible for all switching functions Responsible for all switching functions related to call processingrelated to call processing

Coordinate the setting up of calls to and from Coordinate the setting up of calls to and from GSM usersGSM users

MSC is the interface between GSM MSC is the interface between GSM network & PSTN (Public Switched network & PSTN (Public Switched Telephone Network)Telephone Network)

Gateway MSC (G-MSC)

• The MSC with an interface to other networks is called GMSC.

• Network operator may equip all there MSCs with gateway function or only few.

• MSC that don’t have gateway function has to route call from GMSC.

• GMSC has some additional tasks like call from outer network enters in GMSC which queries HLR then forwarded the call to MSC where the called party is located.

Base Station Controller (BSC)Base Station Controller (BSC)

Monitor and Control several base stationsMonitor and Control several base stationsFrequency administration, control of Frequency administration, control of BTSsBTSs, , exchange functionsexchange functions

Responsible for all the radio interface Responsible for all the radio interface managementmanagement

Channel allocation and release, handover Channel allocation and release, handover managementmanagement

BSC is the interface between MSC and BSC is the interface between MSC and BTSBTS

BSC is connected on one side to several BSC is connected on one side to several BTSsBTSs and on the other side to the MSCand on the other side to the MSC

Home Location Register (HLR)Home Location Register (HLR)

A database in charge of the management A database in charge of the management of mobile subscribersof mobile subscribersContains information of network Contains information of network subscriberssubscribers

Information on Information on teleservicesteleservices and bearer and bearer services subscription, service restrictions, and services subscription, service restrictions, and supplementary servicessupplementary servicesThe data stored in HLR is of a semi The data stored in HLR is of a semi permanent nature and does not usually permanent nature and does not usually change from call to callchange from call to call

Visitor Location Register (VLR)Visitor Location Register (VLR)

Contains the relevant data of all Contains the relevant data of all MSsMSscurrently located in a serving MSCcurrently located in a serving MSC

The permanent data is the same as data in The permanent data is the same as data in the HLRthe HLRThe temporary data includesThe temporary data includes

Temporary Subscriber Identity (TMSI)Temporary Subscriber Identity (TMSI)Location Area Identity (LAI) of an MSLocation Area Identity (LAI) of an MS

VLR allocates mobile subscriber roaming VLR allocates mobile subscriber roaming numbers (MSRNs) for the incoming call numbers (MSRNs) for the incoming call setupsetup

The relation between MSC and VLR

• Sum of MSC areas determine the geographical area of any PLMN.

• Each MSC has its own VLR so PLMN can also be described as the sum of all VLR areas.

• VLR can serve several MSC but one MSC always use only one VLR.

Equipment identity register (EIR)

• The separation of subscriber identity from the identifier of MS also bears a potential pitfall for GSM subscribers.

• It is possible to operate any GSM MS with any valid GSM SIM. An opportunity exists for black market and stolen equipment. •To combat this problem EIR is introduced to identify and track such equipment.

EIR (cont) • Each GSM phone has a unique identifier IMEI which

can not be altered. • Like HLR and VLR, the EIR is also a data base

which maintain three lists.

EIR (cont)

• The processes of mobile equipment fallen dramatically due to great success of GSM consequently the theft rate reduced. So several GSM operators have decided not to install the EIR.

• If the EIR is installed there is no specification when the EIR should be interrogated. The EIR may be interrogated any time during call setup or during location update.

Transcoding rate and adaptation unit. (TRAU)

• One of the most interesting features of GSM is TRAU. Its function is the compress and decompress the speech between TRAU and MS. Possible location are as below.

Geographical Network StructureGeographical Network Structure

Location UnitsLocation UnitsCellCellLocation Area (LA)Location Area (LA)MSC/VLR Service Area MSC/VLR Service Area PLMN (Public Land Mobile Network) Service PLMN (Public Land Mobile Network) Service AreaAreaGSM Service AreaGSM Service Area

Cell PlanningCell Planning

Location Information Location Information ----GSM Service Area HierarchyGSM Service Area Hierarchy

The area The area in which a in which a subscribesubscriber can r can access access the the network.network.

cell

Location Area

MSC/VLR

PLMN Service Area(one per operator)

GSM Service Area

Numbering & RoutingNumbering & Routing

NumberingNumbering

Mobile Subscriber ISDN Number (MSISDN)Mobile Subscriber ISDN Number (MSISDN)Mapping to Mobile Station Roaming Number Mapping to Mobile Station Roaming Number (MSRN) by HLR(MSRN) by HLR

International Mobile Subscriber Identify (IMSI)International Mobile Subscriber Identify (IMSI)Stored in SIM/HLRStored in SIM/HLR

Temporary Mobile Subscriber Identity (TMSI)Temporary Mobile Subscriber Identity (TMSI)Assigned by VLR, Stored in VLRAssigned by VLR, Stored in VLR

International Mobile Equipment Identity (IMEI)International Mobile Equipment Identity (IMEI)Unique ID to handset, used by air interfaceUnique ID to handset, used by air interface

IDID--NumbersNumbersMSISDN = CC + NDC + SNMSISDN = CC + NDC + SN

MSISDN: Mobile Station ISDN NumberMSISDN: Mobile Station ISDN NumberCCCC Country CodeCountry CodeNDCNDC National Destination CodeNational Destination CodeSNSN Subscriber NumberSubscriber Number

IMSI = MCC + MNC + MSINIMSI = MCC + MNC + MSINIMSIIMSI International Mobile Subscriber IdentityInternational Mobile Subscriber IdentityMCCMCC Mobile Country CodeMobile Country CodeMNCMNC Mobile Network CodeMobile Network CodeMSINMSIN Mobile Station Identification NumberMobile Station Identification Number

IDID--Numbers (cont.)Numbers (cont.)IMEI = TAC + FAC + SNR + spareIMEI = TAC + FAC + SNR + spare

IMEIIMEI Internal Mobile Equipment IdentityInternal Mobile Equipment IdentityTACTAC Type Approval Code, determined by a Type Approval Code, determined by a central central GSM/PCS bodyGSM/PCS bodyFACFAC Final Assembly Code, identifies the Final Assembly Code, identifies the

manufacturermanufacturerSNRSNR Serial Number, uniquely identifies all Serial Number, uniquely identifies all

equipment within each TAC and FACequipment within each TAC and FACIMEISV = TAC + FAC + SNR + SVNIMEISV = TAC + FAC + SNR + SVN

IMEISVIMEISV International Mobile Equipment Identity International Mobile Equipment Identity and and Software Version NumberSoftware Version NumberSVNSVN Software Version NumberSoftware Version Number

IDID--Numbers (cont.)Numbers (cont.)MSRN = CC + NDC + SNMSRN = CC + NDC + SN

MSRNMSRN Mobile Station Roaming NumberMobile Station Roaming NumberCCCC Country CodeCountry CodeNDCNDC National Destination CodeNational Destination CodeSNSN Subscriber Number. In this case, the Subscriber Number. In this case, the address to address to the serving MSCthe serving MSC

LAI = MCC + MNC + LACLAI = MCC + MNC + LACMCCMCC Mobile Country CodeMobile Country CodeMNCMNC Mobile Network CodeMobile Network CodeLACLAC Location Area CodeLocation Area Code

IDID--Numbers (cont.)Numbers (cont.)CGI = MCC + MNC + LAC + CICGI = MCC + MNC + LAC + CI

CGICGI Cell Global IdentityCell Global IdentityCICI Cell IdentityCell Identity

BSIC = NCC + BCCBSIC = NCC + BCCBSICBSIC Base Station Identity CodeBase Station Identity CodeNCCNCC Network Color Code (3bits)Network Color Code (3bits)BCCBCC Base Station Color Code (3bits)Base Station Color Code (3bits)

LN = CC + NCD + LSPLN = CC + NCD + LSPLNLN Location NumberLocation NumberCCCC Country CodeCountry CodeNCDNCD National Destination CodeNational Destination CodeLSPLSP Locally Significant PartLocally Significant Part

ID ID --Numbers (cont.)Numbers (cont.)LN = CC + NCD + LSPLN = CC + NCD + LSP

LNLN Location NumberLocation NumberCCCC Country CodeCountry CodeNCDNCD National Destination CodeNational Destination CodeLSPLSP Locally Significant PartLocally Significant Part

RSZI = CC + NDC + ZCRSZI = CC + NDC + ZCRSZIRSZI Regional Subscription Zone IdentityRegional Subscription Zone IdentityCCCC Country CodeCountry CodeNDCNDC National Destination CodeNational Destination CodeZCZC length of the Zone code (2 octets)length of the Zone code (2 octets)

RoutingRouting

Information resident in MS & SIMInformation resident in MS & SIMIMSI, TMSI, IMEI, and misc. informationIMSI, TMSI, IMEI, and misc. information

Routing Information used by NetworkRouting Information used by NetworkMSISDN, MSRNMSISDN, MSRN

GSM Services and FeaturesGSM Services and Features

1.1. Tele ServicesTele Services

2.2. Bearer Services or Data Bearer Services or Data ServicesServices

3.3. Supplementary ServicesSupplementary Services

Hello

1

Speaking

Speaking

1

Originatedcall

Terminatedcall

Hello

TeleservicesTeleservices

1 1 -- TelephonyTelephony

G S M


Do not require a SIM-Cardwhile "112" is invoked

Emergency112


2 2 -- Emergency CallEmergency Call

GSM Network

message B

message B

message B

message B

message A

message A

message A

message A

InformationProvider B

InformationProvider A


3 3 -- Short Message Short Message CellCell BroadcastBroadcast

SMS-MO/ PPRadioPLMN

SMS-MT/ PP

RadioPLMN

Copyright © 1996 Northern Telecom


4 4 -- Short Message ServiceShort Message Service

SMS-SC

Alternate Speech and Fax:

Automaticfax:


5 5 -- FaxFax

Teleservicesvoice

TeleservicesFax G3, SMS

Cable thatbears data

Embodiedbearer

treatments forradio transmission

Data / Faxkit adaptation


6 6 -- User's Data Call FeaturesUser's Data Call Features

Voicemessage

server

Please leavea message

after the tone

GSM network

1

Busy

Voice mailbox

Forwardto voicemail box

Warming up...

You have3 voices

messages...

Retrieving the voicemessages


7 7 -- VoiceVoice MessagingMessaging

Bearer ServicesBearer Services

Limited to 1,2 and 3 OSI layerLimited to 1,2 and 3 OSI layer

Packet Switched ProtocolsPacket Switched Protocols

Data Rates from 300bps to 9.6kbpsData Rates from 300bps to 9.6kbps

Calling line0609225831

Cnted line0609173957

Calling Line Identification

presentation (CLIP)

restriction (CLIR)

Connected Line Identification

presentation (CoLP)

restriction (CoLR)

Calling Name Presentation(CNAP)

Calling PartyCoLPCLIR

Called PartyCLIP CoLR

SupplementarySupplementary ServicesServices

1 1 -- Line IdentificationLine Identification

unconditional (CFU)

on busy (CFB)

on no reply (CFNRy)

on not reachable (CFNRc)1 2


2 2 -- Call Call TransferTransfer andand Call Call ForwardingForwarding

1 2

HOLD

1 2

WAIT

1

2

Multi Party:1

2

Max = 5 persons

Waiting / Hold:

SupplementarySupplementary ServicesServices3 3 -- WaitingWaiting / / HoldHold andand Multi Multi PartyParty

Outgoing (BAOC)

Outgoing international (BOIC)

Outgoing international except home PLMN country (BOIC-exHC)

Incoming (BAIC)

Incoming when roaming outside(BIC-Roam)


4 4 -- Call Call BarringBarring

2

Speaking

1

1

HELLO

Unable to placea call.

Reinitiatethe call

SPEAKING

BUSY...

Speaking

Call isestablished

1

This call in state

Idle

Ring ! Ring !

NEW!

SupplementarySupplementary ServicesServices5 5 -- Call Call CompletionCompletion (CCBS)(CCBS)

information on progressof the cost of the call

Completion of callneed charging

Insert aSIM credit Card

Advice of Charge Information (AoCI)

Advice of Charge Charging (AoCC)


6 6 -- AdviceAdvice of Chargeof Charge

The aim of the CAMEL (Customized Application for Mobile network Enhanced Logic) is to provide GSM network operators with the ability to create specific services in their home network, and export these services to their subscribers when roaming outside the home network.CAMEL introduces the ability to provide location dependent IN type ofservices to mobiles subscribers.

Intelligent Network ServicesIntelligent Network Services

IN IN andand CAMELCAMELMain IN Services:Personal NumberVirtual Private Network (VPN) Sponsored Cell & Call Prepaid CallingLocation InquiryGeo Zone

IN Services: IN Services: VirtualVirtual PrivatePrivateNetworkNetwork

Copyright ©

1996 Northern Telecom


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#* 0

3 DEF

4 GHI5 JKL6 MNO

7 PRS8 TUV9 WXY

4446

c1 2 34 5 67 8 9

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44465696

4197

4197

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XX

LondonBristol



Copyright ©

1996 Northern Telecom

Corporate Numbering Plan

Lower rate for on-net calls

Closed User Group

Wireline Access

Speed DialingLocation & Timedependant routing

Location & Timedependant screening

50 c/min

25 c/min

25 c/min

25 c/min

924 63256

IN Services: IN Services: PrepaidPrepaid CallingCalling

Account statusenquiry andnotification

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Your accountbalance is $ 24.50

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Last call costs $ 0.50New balance is$ 24.50

Flexible features for easyservice packaging

Multiple Tariff Plans

Tariffs using fixed charge, CC, NC, distance, time & day, roaming charges...

Possible language selection by subscriber

Bulk account loading for easy provisioning

Multiple recharging options


RANK1ONE5542 1139 1464 228 99494

6/91 6/99VALID DATES

SCOOBY DOO

PromotionalInformations:

call #15

IN Services: Location IN Services: Location InquiryInquiryC

opyright © 1996 N

orthern Telecom

Possible customization of announcement directly by the advertiser

Today’s special atThe Anchor is Maine lobster soup

Be the first ten caller and get a free cocktail !

The closest restaurants are:

The Wind Jammeron 132 Flinton StreetSea foodPhone 55 1968 press 1 to connect

The Palace on 11 Bourke StreetChinese foodPhone 55 0407 press 2 to connect

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Cell dependent information

Direct connection to advertisers

The closest restaurants are: The Tower, Tower Hill, Phone 56 4589, Press 1 to connectThe AnchorSt Catherine DockPhonce 56 2548Press 2 to connect

Q & A ?Q & A ?

Lec 3 & 4 GSMNetArchitecture(Revised)

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