GSM (Global System for Mobile Communication) is a 2G digital cellular network. It was developed to address fragmentation issues in first-generation analog cellular systems and introduce digital technology and networking architectures. GSM specifies services, architecture, and frequencies. It uses a SIM card for user identification and supports voice calls and data services. GSM networks are organized into cells managed by switching centers. As users move between cells, the network performs handovers to maintain connections. GSM was followed by 2.5G, 3G, and 4G networks with increasing data speeds and capabilities.
2. Introductionto WirelessCommunication
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.
7. 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.
8. 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
11. 2nd Generation:-1980
• Data services along with traditional speed service.
• Technology used-TDMA
• Speed-10kbps
2.5G:- HSCSD,GPRS,EDGE
Technology used-circuit Switched technique .
Speed-14.4kbps
GPRS-General packet Radio services
multi user
-email,fax,multiuser network sharing of individual radio
Channels and time slots.
Speed-121.2kbps
13. 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..
14. 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.
15. HISTORY:-
•GSM was first introduced in European market in
1980 by the GSM committee CEPT.
•1992 GSM changed its name under ETSI.
16. GSM SERVICES AND FEATURES
• GSM services follows ISDN guidelines and are classified as either
teleservices or data services.
17. Telephoneservices
including emergency calling and facsimile.
• BEARERSERVICES OR DATASERVICES
• 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 ISDNSERVICES
• 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).
18. 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.
20. 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.
21. GSM CHANNEL TYPE:-
1.)GSMTRAFFICCHANNELS(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.)GSMCONTROLCHANNEL(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.
22. 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