Title: GSM: The European Standard for Mobile Telephony
1GSM The European Standard for Mobile Telephony
- Presented by
- Rattan Muradia
- Requirement for course CSI 5171
2Presentation Objective
- No discussion of mobile network concepts already
covered (MSC, BSC, HLR, VLR, registration, call
setup, roaming, handover, OSS etc..) - GSM Architecture
- Focus on features specific to GSM
- Provide basic information required for
presentations on CAMEL, GPRS and UMTS
3Evolution of Digital Mobile Systems
- 1st Generation, Analogue Cellular - AMPS,
ETACS, NMT, C-NET... - 2nd Generation, Digital Cellular - GSM, PDC,
DAMPS, CDMA... - 2nd Generation Cordless - DECT, PHS...
- 2nd Generation Satellite - Iridium, Globalstar..
- 2.5 Generation GPRS...
- 3rd Generation Universal - IMT-2000, UMTS
4Digital Mobile Systems
5GSM Overview
- Developed in Europe
- One of first intelligent networks with
distributed processing - International roaming
- 174 countries, 647 million subscribers
- 67 of world wireless market share
6GSM Network
- Mobile Station (MS)
- Base Station Subsystem (BSS)
- Network and Switching Subsystem (NSS)
- Operation and Support Subsystem (OSS)
7GSM Network Architecture
INTERFACE TO LANDTELEPHONE NETWORKS
STOLEN, BROKEN CELLPHONE LIST
LIST OF ROAMINGVISITORS
ENCRYPTION, AUTHENTICATION
LIST OF SUBSCRIBERS IN THIS AREA
SOURCE UWC
8GSM Reference Model
9GSM Protocol Stack
10GSM Address and Identifiers
- International Mobile Subscriber Identity (IMSI)
- 3 digit Mobile Country Code 2 digit Mobile
Network Code 10 digit Mobile Subscriber
Identification Number - International Mobile Equipment Identity (IMEI)
- 19 digit unique ID, used by air interface, stored
in EIR - Mobile Subscriber ISDN Number (MSISDN)
- upto 3 digit Country Code 2-3 digit national
Destination Code max 10 digit Subscriber Number
- mapped to MSRN by HLR
- Mobile Station Roaming Number (MSRN)
- temporary ISDN number assigned by VLR
11GSM Mobile Station
- Each MS identified by IMEI
- In addition to the physical equipment common to
most MS, GSM equipment includes a SIM. - Subscriber Identity Module (SIM) provides true
mobility. Access to subscribed services - regardless of location of the terminal
- regardless of use of specific terminal
- SIM contains IMSI, secret key for authentication
more information
12GSM Databases
- Equipment Identity Register (EIR)
- contains list of valid mobile equipment (IMEI)
- an IMEI can be marked invalid if MS is stolen,
unauthorized or defective - Authentication Center (AuC)
- protected database that stores authentication and
encryption parameters - used to verify user identity and ensure
confidentiality of each call
13GSM Call Delivery
14GSM Services
- Patterned after ISDN
- Bearer Services
- sync, async data transport, represent layers 1-3
- also used by higher layers to offer teleservices
- Teleservices
- voice, SMS, FAX, Teletext etc..
- Supplementary Services
- modify or supplement teleservices
15GSM Services - Phase 1
Offered by all operators in 1991.
16GSM Services - Phase 2
Introduced in 1996. Major rework of standards.
Backward compatible. More supplementary services.
17GSM Phase 2
- Increased globalization using SIM, multiband
systems and terminals - Phase 2
- increase network capacity via spectral efficiency
- improve voice quality
- group call (party line)
- integration of packet services (on air interface)
and higher data speeds (GPRS) - expand supplementary services (SMS Forwarding,
Multiple Subscriber profile, Call Xfer etc..)
(see GPRS presentation by Miao Lu and Nancy
Samaan on April 5th).
18GSM Phase 2
- No complete revision of standards in Phase 2
- Each subject area treated separate, allowed to
implement and introduce independently - Standardize mechanisms for service introduction,
not complete services - Reduce time-to-market, allow differentiation
- GSM already has similarities with IN (MSCSSP,
HLRSCP, SS7 signaling) - Convergence of GSM and IN - CAMEL
(see CAMEL presentation by Tina Deng and Yinyan
Zhou on April 2th).
19Beyond GSM - 3GRoad to UMTS/IMT2000
- New generation of mobile systems based on IP
- Must support large number of subscribers
- Wide range of voice and data services
- Build on existing GSM infrastructure as much as
possible. - Higher bandwidth for multimedia applications
- new radio interface
- better use of spectrum
(see IMT2000 presentation by Mingdi Zhao and Wei
Lin on April 9th).
20Questions?
21GSM/GPRS/UMTS
Backup slide 1
22GSM Network Architecturebackup slide
Backup slide 2
SOURCE UWC
23GSM Protocol Stack
Backup slide 3