GSM(GLOBAL SYSTEM FOR MOBILE COMMUNICATION)

Introduction to Wireless Communication

Wireless communication is the transfer of information and power between two or more points that are not connected by an electrical conductor. The most common wireless technologies use radio.Cellular concept was a major breakthrough in solving the problem spectral congestion and user capacity.

NORMAL CELLULAR STRUCTURE

SOME PARAMETERS RELATED TO WIRELESS COMMUNICATION

CELL:-

•The network is distributed over land areas called cells.

Clusters•A cluster is a group of cells

A seven Cell Cluster

Handoff:-• A handoff refers to the process of transferring an active call or data session from one cell in a cellular network to another or from one channel in a cell to another. 

Handover:-• In cellular telecommunications, the terms handover or handoff refer

to the process of transferring an ongoing call or data session from one channel connected to the core network to another channel

OVERVIEW OF TELECOM NETWORK AND EXCESS TECHNOLOGY

1st Generation:-1979• Band with used-40hz• Technology used-FM technology(FDMA)

2nd Generation:-1980• Data services along with traditional speed service.• Technology used-TDMA• Speed-10kbps2.5G:- HSCSD,GPRS,EDGETechnology used-circuit Switched technique .Speed-14.4kbpsGPRS-General packet Radio servicesmulti user-email,fax,multiuser network sharing of individual radioChannels and time slots.Speed-121.2kbps

EDGE:-Enhanced Data Rates for GSM Evolution• SPEED-547.2KBPS• GMSK,8-PSK

3rd Generation-3GHSPA—HIGH SPEED PACKET ACCESSSPEED-1404 MBPS.TECHNOLOGY USED-CDMA

4th GENERATION• 4G is the fourth generation of wireless mobile telecommunications

technology, succeeding 3G.• Wi-fi,bluetooth• Multi services

• Three times greater speed than 3g..

GSM(GLOBAL SYSTEM FOR MOBILE COMMUNICATION)• GSM is a second generation cellular system standard that was

developed to solve the fragmentation problems of the first cellular systems in Europe.• GSM was the first cellular system to specify digital modulation and

network level architectures and services and is the world most popular 2G technology.

HISTORY:-•GSM was first introduced in European market in 1980 by the GSM committee CEPT.•1992 GSM changed its name under ETSI.

GSM SERVICES AND FEATURES

• GSM services follows ISDN guidelines and are classified as either teleservices or data services.

Telephone services including emergency calling and facsimile.• BEARER SERVICES OR DATA SERVICES• limited to layer 1,2 and 3 of the open system interconnection (OSI)

reference model.• Supported services include packet switched protocols and data rates

from 300 bps to 9.6kbps.• SUPPLEMENTARY ISDN SERVICES • digital in nature and include call diversion closed user groups and

caller identification , and are not available in analog mobile network. It also include the short messing service(SMS).

Features:-• GSM is the subscriber Identity Module (SIM),which is a memory 

device that stores information such as the subscriber’s identification number the network and countries.• A subscriber uses the SIM with a four-digit personal ID number to 

activate service from any GSM phone. • Without  a SIM installed all GSM mobiles are identical and 

nonoperational .It is the SIM that gives GSM subscriber units their identity.• GSM is the on-the-air privacy which is provided by the system. 

GSM ARCHITECTURE:-

GSM SPECTRUM:-• For GSM, the spectrum allocation at 900 MHz is categorized into the

primary GSM band.• The primary GSM band runs from 890 MHz to 915 MHz on the up

link and 935 MHz to 960 MHz as the down link.

GSM CHANNEL TYPE:-1.)GSM TRAFFIC CHANNELS(TCHs)-It may be either full-rate and may carry either digitized speech or user data. when transmitted as full –rate user data is contained within one TS per frame.

2.)GSM CONTROL CHANNEL(CCH)-These are the broad cast channel , the common control channel(CCCH), and the dedicated control channel(DCCH).Each control channel consist of several logical channels which are distributed in time to provide the necessary GSM control Functions.

SIGNALS AND PROTOCOLS• STANDART MESSAGES• SENDER WANTS TO SERVICE• OPERATOR ASK THAT YOU WANTS TO TALK ,BUT

WHICH USER• OPERATOR CONNECT TO RECEIVER• WHEN THE RECEIVER REPLIES TO CALL ,THE CALL

STARTS• WHEN THE RECEIVER OR SENDER CLOSE THE PHONE ,

THE OPERATOR FINISH CONNECTION TO EACH OTHER

PROCEDURE OF CALL SET UP

CONCLUSSION

THANK YOU

•BY:-- PIYUSH KUMAR AND ARUNDHATI CHATTOPADHYAY