MOBILE COMMUNICATION G.S.M. & G.P.R.S.

Evolution of mobile telephone systems Cellular subscriber growth worldwide Currently more than 45 million cellular subscriber worldwide Currently more than 45 million cellular subscriber worldwide Nearly 50 percent in the U.S. Nearly 50 percent in the U.S. More than 100 million subscribers by More than 100 million subscribers by 2005.

Groupe Speciale Mobile Global system for mobile communication (GSM) is a globally accepted standard for digital cellular communication. GSM is the name of a standardization group established in 1982 to create a common European mobile telephone standard that would formulate specifications for a pan-European mobile cellular radio system operating at 900 MHz. It is estimated that many countries outside of Europe will join the GSM partnership.

GSM Milestones YearMilestone 1982 GSM formed 1986 Field test 1987 TDMA chosen as access method 1988 Memorandum of understanding signed 1989 Validation of GSM system 1990 Preoperational system 1991 Commercial system start-up 1992 Coverage of larger cities/airports 1993 Coverage of main roads 1995 Coverage of rural areas

G.S.M System Architecture

GSM Network Areas

GSM Specifications Frequency band—1,850 to 1,990 MHz (mobile station to base station). Frequency band—1,850 to 1,990 MHz (mobile station to base station). Duplex distance— 80 MHz. A channel has two frequencies, 80 MHz apart. Duplex distance— 80 MHz. A channel has two frequencies, 80 MHz apart. Channel separation—The separation between adjacent carrier frequencies is 200 kHz. Channel separation—The separation between adjacent carrier frequencies is 200 kHz. Transmission rate—GSM is a digital system with an over-the-air bit rate of 270 kbps. Transmission rate—GSM is a digital system with an over-the-air bit rate of 270 kbps. Access method—GSM utilizes the time division multiple access (TDMA) concept. Each call is assigned a particular time slot. Access method—GSM utilizes the time division multiple access (TDMA) concept. Each call is assigned a particular time slot.

GSM Addresses and Identifiers International mobile station equipment identity (IMEI) allocated by manufacturer and registered by operator in EIR International mobile station equipment identity (IMEI) allocated by manufacturer and registered by operator in EIR Each registered user uniquely identified by its international mobile subscriber identity stored in subscriber identity module (SIM). Each registered user uniquely identified by its international mobile subscriber identity stored in subscriber identity module (SIM). Mobile subscriber ISDN no. (MSISDN) assigned to each subscriber,serving as the real telephone no. Mobile subscriber ISDN no. (MSISDN) assigned to each subscriber,serving as the real telephone no.

Roaming to a country that uses a different frequency: SIM roaming GSM 1900 (also called PCS-1900, or DCS- 1900) - the only frequency used in North America for GSM. GSM 1900 (also called PCS-1900, or DCS- 1900) - the only frequency used in North America for GSM. GSM 900 (also called GSM) - operates in the 900 MHz frequency range and is the most common in Europe and the world. GSM 900 (also called GSM) - operates in the 900 MHz frequency range and is the most common in Europe and the world. GSM 1800 (also called PCN or DCS-1800) - operates in the 1800 MHz frequency range, and is found in a rapidly increasing number of countries including France, Germany, Switzerland, the UK, and Russia. GSM 1800 (also called PCN or DCS-1800) - operates in the 1800 MHz frequency range, and is found in a rapidly increasing number of countries including France, Germany, Switzerland, the UK, and Russia.

G.S.M Phase 2+ : General Packet Radio Service

G.P.R.S – Introduction a new bearer service for GSM a new bearer service for GSM greatly improves and simplifies wireless access to packet data networks greatly improves and simplifies wireless access to packet data networks applies a packet radio principle to transfer user data packets in an efficient way between mobile stations and external packet data networks. applies a packet radio principle to transfer user data packets in an efficient way between mobile stations and external packet data networks. Networks based on the Internet Protocol (IP) and X.25 networks are supported in the current version of GPRS. Networks based on the Internet Protocol (IP) and X.25 networks are supported in the current version of GPRS.

G.P.R.S System Architecture

Two Intra-PLMN backbone networks of different PLMNs

Key User Features Of GPRS Speed Speed Immediacy GPRS –”always connected” Immediacy GPRS –”always connected” New applications,Better applications over Circuit Switched Data Transmission. New applications,Better applications over Circuit Switched Data Transmission.

LOGICAL CHANNELS

Applications for GPRS Bearer Services Point to Point (PTP) Point to Point (PTP) Point to Multipoint (PTM) Point to Multipoint (PTM) Supplementary Services Call Forwarding Unconditional Call Forwarding Unconditional Closed User Groups. Closed User Groups. Other Applications.

Limitations Of GPRS Limited cell capacity for all Users. Limited cell capacity for all Users. Speed much lower in reality. Speed much lower in reality. Transit Delays. Transit Delays. No store and forward. No store and forward.