GSM: The European Standard GSM: The European Standard for Mobile Telephonyfor Mobile Telephony

GSM: The European Standard GSM: The European Standard for Mobile Telephonyfor Mobile Telephony

Presented byPresented by

Rattan MuradiaRattan Muradia

Requirement for course CSI 5171Requirement for course CSI 5171

Presented byPresented by

Rattan MuradiaRattan Muradia

Requirement for course CSI 5171Requirement for course CSI 5171

Presentation ObjectivePresentation ObjectivePresentation ObjectivePresentation Objective

No discussion of mobile network concepts No discussion of mobile network concepts already covered (MSC, BSC, HLR, VLR, already covered (MSC, BSC, HLR, VLR, registration, call setup, roaming, handover, registration, call setup, roaming, handover, OSS etc..)OSS etc..)

GSM ArchitectureGSM Architecture Focus on features specific to GSMFocus on features specific to GSM Provide basic information required for Provide basic information required for

presentations on CAMEL, GPRS and UMTSpresentations on CAMEL, GPRS and UMTS

Evolution of Digital Mobile Evolution of Digital Mobile SystemsSystems

Evolution of Digital Mobile Evolution of Digital Mobile SystemsSystems

1st Generation, Analogue Cellular - 1st Generation, Analogue Cellular - AMPS, ETACS, NMT, C-NET...AMPS, ETACS, NMT, C-NET...

2nd Generation, Digital Cellular - 2nd Generation, Digital Cellular - GSM, PDC, DAMPS, CDMA...GSM, PDC, DAMPS, CDMA...

2nd Generation Cordless - DECT, PHS...2nd Generation Cordless - DECT, PHS... 2nd Generation Satellite2nd Generation Satellite - Iridium, Globalstar.. - Iridium, Globalstar..

2.5 Generation GPRS...2.5 Generation GPRS... 3rd Generation Universal 3rd Generation Universal - IMT-2000, UMTS- IMT-2000, UMTS

Digital Mobile SystemsDigital Mobile SystemsDigital Mobile SystemsDigital Mobile SystemsAmericas CTACOperating Manual

Standard PDC D-AMPS GSM 900

Frequency bandUplink

940-956 MHz1429-1441 MHz1453-1465 MHz

824-849 MHz 890-915 MHz

Frequency bandDownlink

810-826 MHz1477-1489 MHz1501-1513 MHz

869-894 MHz 935-960 MHz

Channel separation 25 kHz 30 kHz 200 kHz

Multiplexing 3 (6) channel TDMA 8 (16) ch TDMA

BearerBits/frequencychannel

42 kbit/s 46.6 kbit/s 270 kbit/s

GSM OverviewGSM OverviewGSM OverviewGSM Overview

Developed in EuropeDeveloped in Europe One of first ‘intelligent’ networks with One of first ‘intelligent’ networks with

distributed processingdistributed processing International roamingInternational roaming 174 countries, 647 million subscribers174 countries, 647 million subscribers 67% of world wireless market share67% of world wireless market share

GSM NetworkGSM NetworkGSM NetworkGSM Network

Mobile Station (MS)Mobile Station (MS) Base Station Subsystem (BSS)Base Station Subsystem (BSS) Network and Switching Subsystem (NSS)Network and Switching Subsystem (NSS) Operation and Support Subsystem (OSS)Operation and Support Subsystem (OSS)

GSM Network ArchitectureGSM Network ArchitectureGSM Network ArchitectureGSM Network Architecture

SOURCE: UWC

INTERFACE TO LANDTELEPHONE NETWORKS

HIERARCHYOF CELLS

CELL TRANSMITTER& RECEIVER

PHONE

SIM:IDENTIFIES ASUBSCRIBER

LIST OFROAMINGVISITORS

LIST OF SUBSCRIBERSIN THIS AREA

STOLEN, BROKENCELLPHONE LIST

ENCRYPTION,AUTHENTICATION

GSM Reference ModelGSM Reference ModelGSM Reference ModelGSM Reference Model

GSM Protocol StackGSM Protocol StackGSM Protocol StackGSM Protocol Stack

GSM Address and IdentifiersGSM Address and IdentifiersGSM Address and IdentifiersGSM Address and Identifiers

International Mobile Subscriber Identity International Mobile Subscriber Identity (IMSI)(IMSI)– 3 digit Mobile Country Code + 2 digit Mobile Network Code 3 digit Mobile Country Code + 2 digit Mobile Network Code

+ 10 digit Mobile Subscriber Identification Number+ 10 digit Mobile Subscriber Identification Number

International Mobile Equipment Identity International Mobile Equipment Identity (IMEI)(IMEI)– 19 digit unique ID, used by air interface, stored in EIR19 digit unique ID, used by air interface, stored in EIR

Mobile Subscriber ISDN Number Mobile Subscriber ISDN Number (MSISDN)(MSISDN)– upto 3 digit Country Code + 2-3 digit national Destination upto 3 digit Country Code + 2-3 digit national Destination

Code + max 10 digit Subscriber Number Code + max 10 digit Subscriber Number

– mapped to MSRN by HLR mapped to MSRN by HLR

Mobile Station Roaming Number Mobile Station Roaming Number (MSRN)(MSRN)– temporary ISDN number assigned by VLRtemporary ISDN number assigned by VLR

GSM Mobile StationGSM Mobile StationGSM Mobile StationGSM Mobile Station

Each MS identified by IMEIEach MS identified by IMEI In addition to the physical equipment common In addition to the physical equipment common

to most MS, GSM equipment includes a SIM.to most MS, GSM equipment includes a SIM. Subscriber Identity Module (SIM) provides Subscriber Identity Module (SIM) provides

true mobility. Access to subscribed services:true mobility. Access to subscribed services:– regardless of location of the terminalregardless of location of the terminal

– regardless of use of specific terminal regardless of use of specific terminal SIM contains IMSI, secret key for SIM contains IMSI, secret key for

authentication + more informationauthentication + more information

GSM DatabasesGSM DatabasesGSM DatabasesGSM Databases

Equipment Identity Register (EIR) Equipment Identity Register (EIR) – contains list of valid mobile equipment (IMEI)contains list of valid mobile equipment (IMEI)

– an IMEI can be marked invalid if MS is stolen, an IMEI can be marked invalid if MS is stolen, unauthorized or defectiveunauthorized or defective

Authentication Center (AuC)Authentication Center (AuC)– protected database that stores authentication and protected database that stores authentication and

encryption parametersencryption parameters

– used to verify user identity and ensure used to verify user identity and ensure confidentiality of each call confidentiality of each call

GSM Call DeliveryGSM Call DeliveryGSM Call DeliveryGSM Call Delivery

GSM ServicesGSM ServicesGSM ServicesGSM Services

Patterned after ISDNPatterned after ISDN Bearer ServicesBearer Services

– sync, async data transport, represent layers 1-3sync, async data transport, represent layers 1-3

– also used by higher layers to offer teleservicesalso used by higher layers to offer teleservices TeleservicesTeleservices

– voice, SMS, FAX, Teletext etc..voice, SMS, FAX, Teletext etc.. Supplementary ServicesSupplementary Services

– modify or supplement teleservicesmodify or supplement teleservices

GSM Services - Phase 1GSM Services - Phase 1GSM Services - Phase 1GSM Services - Phase 1

Offered by all operators in 1991.

GSM Services - Phase 2GSM Services - Phase 2GSM Services - Phase 2GSM Services - Phase 2

Introduced in 1996. Major rework of standards. Backward compatible.More supplementary services.

GSM Phase 2+GSM Phase 2+GSM Phase 2+GSM Phase 2+

Increased globalization using SIM, multiband Increased globalization using SIM, multiband systems and terminalssystems and terminals

Phase 2+Phase 2+– increase network capacity via spectral efficiencyincrease network capacity via spectral efficiency

– improve voice qualityimprove voice quality

– group call (party line)group call (party line)

– integration of packet services (on air interface) and integration of packet services (on air interface) and higher data speeds (GPRS)higher data speeds (GPRS)

– expand supplementary services (SMS Forwarding, expand supplementary services (SMS Forwarding, Multiple Subscriber profile, Call Xfer etc..)Multiple Subscriber profile, Call Xfer etc..)

(see GPRS presentation by Miao Lu and Nancy Samaan on April 5th).

GSM Phase 2+GSM Phase 2+GSM Phase 2+GSM Phase 2+

No complete revision of standards in Phase 2+No complete revision of standards in Phase 2+ Each subject area treated separate, allowed to Each subject area treated separate, allowed to

implement and introduce independentlyimplement and introduce independently Standardize Standardize mechanismsmechanisms for service for service

introduction, not complete servicesintroduction, not complete services Reduce time-to-market, allow differentiationReduce time-to-market, allow differentiation GSM already has similarities with IN GSM already has similarities with IN

(MSC=SSP, HLR=SCP, SS7 signaling)(MSC=SSP, HLR=SCP, SS7 signaling) Convergence of GSM and IN - CAMELConvergence of GSM and IN - CAMEL

(see CAMEL presentation by Tina Deng and Yinyan Zhou on April 2th).

Beyond GSM - 3GBeyond GSM - 3GRoad to UMTS/IMT2000Road to UMTS/IMT2000

Beyond GSM - 3GBeyond GSM - 3GRoad to UMTS/IMT2000Road to UMTS/IMT2000

New generation of mobile systems based on IPNew generation of mobile systems based on IP Must support large number of subscribersMust support large number of subscribers Wide range of voice and data servicesWide range of voice and data services Build on existing GSM infrastructure as much Build on existing GSM infrastructure as much

as possible.as possible. Higher bandwidth for multimedia applicationsHigher bandwidth for multimedia applications

– new radio interfacenew radio interface

– better use of spectrumbetter use of spectrum

(see IMT2000 presentation by Mingdi Zhao and Wei Lin on April 9th).

Questions?Questions?Questions?Questions?

GSM/GPRS/UMTSGSM/GPRS/UMTSGSM/GPRS/UMTSGSM/GPRS/UMTS

Backup slide 1Backup slide 1

GSM Network ArchitectureGSM Network Architecturebackup slidebackup slide

GSM Network ArchitectureGSM Network Architecturebackup slidebackup slide

SOURCE: UWCBackup slide 2Backup slide 2

GSM Protocol StackGSM Protocol StackGSM Protocol StackGSM Protocol StackBackup slide 3Backup slide 3