Gsm Global System For Mobile Comm[1]. Really Nice
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Transcript of Gsm Global System For Mobile Comm[1]. Really Nice
INTRODUCTION TO CELLULAR TECHNOLOGY
GSM-GLOBAL SYSTEM FOR MOBILE COMMUNICATION
RAHUL GUPTA
Computer Engineering M.N.I.T Jaipur
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TRAINING CARRIED AT
Computer Engineering M.N.I.T Jaipur
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MOBILTY THE MAGIC WORD
IN THIS DAY & AGE ,MANY FOLKS NEED TO BE ACCESSIBLE EVERYWHERE ,WHETHER THEY’RE AT WORK OR PLAY,IN THE OFFICE OR AT HOME .
•WHAT IS NEEDED FOR MEETING THIS DEMAND?
Computer Engineering M.N.I.T Jaipur
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GSM: GLOBAL SYSTEM FOR MOBILE COMMUNICATION
DEFINITIONGlobal 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.
Computer Engineering M.N.I.T Jaipur
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EVOLUTION OF MOBILE TELEPHONE SYSTEMS
CELLULAR SUBSCRIBER GROWTH WORLDWIDE
0
20
40
60
80
100
1991 1993 1995 2005
YEAR
MILLIONS OF SUBSCRIBER
Series1
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YEAR MOBILE SYSTEM1981 Nordic mobile telephone
1983 American mobile telephone system
1985 Total access communication system
1986 Nordic mobile technology
1991 American digital cellular
1991 GSM
1992 Digital cellular system
1994 Personal digital cellular
1995 PCS-1900
1995 CDMA
1996 PCS-United States
2003 GPRS
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GSM-NETWORK ARCHITECTURE
Mobile station
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Mobile station
Handset /mobile/portable terminal/mobile equipment
Includes– Subscriber identification module (SIM)
– IMSI
(INTERNATIONAL MOBILE SUBSCRIBER IDENTITY)
– MSISDN
– International mobile equipment identity (IMEI)
Computer Engineering M.N.I.T Jaipur
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Base station subsystem(BSS)
Includes– Base transceiver station(BTS)
– Connect mobile to cellular network
– Channel coding\decoding
– Encryption\decryption
– Radio transmitters\receivers
– antennas
– Base station controller(BSC)– Group of BTS’s are connected to a BSC
– Call maintenance
– Report every 480 ms by MS
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Network & switching subsystem(SS)
Includes– Mobile switching center(MSC)
– Act like a fixed exchange
– Provide all functionality for mobile subscriber
– Registration
– Location updating
– Handovers\call routing
– GMSC
– Home location register(HLR)– IMSI
– MSISDN
– Current VLR address
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- Visitor location register(VLR)– Current location of the mobile station
– Connected to one MSC
– Integrated into MSC’s hardware
– Authentication center(AuC)– Hold secret key
– Located close to each HLR
– Equipment identity register(EIR)– List of valid mobile station(IMEI)
– Three databases
– White list
– Black list
– Grey list
Computer Engineering M.N.I.T Jaipur
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INTERFACES & PROTOCOLS
OSI layer structurePHYSICAL LAYER
– Enable physical transmission– Assessment of channel quality
DATA LINK LAYER– Multiplexing of the signal channels– Error detection– Flow control– Routing
NETWORK LAYER– Connection management– Management of location data– Subscriber identification
Computer Engineering M.N.I.T Jaipur
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OSI ARCHITECTURE
PSTNPSPDNISDN
MS BTS BSC MSC
Um Abis A
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The air interface Um
ITU (international telecommunication union) has allocated
following bands:
GSM 900:
uplink : 890-915 MHz
downlink:935-960 MHz
GSM 1800:
uplink : 1710-1785 MHz
downlink:1805-1880 MHz
* TDMA\FDMA scheme
* BURST – fundamental unit in the TDMA scheme
Computer Engineering M.N.I.T Jaipur
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Protocols on the air interfaceLayer 1: Um interface
Layer 2: LAP-Dm protocol
Layer 3: Radio Resource Management (RR): to establish and release stable connection between mobile stations (MS) and MSC for the duration of a call
-Cell selection, -Handover, -Monitoring and forwarding of radio connections, -Introduction of encryption, Mobility management (MM) handles control functions for mobility -Authentication, -Assignment of TMSI, -Management of subscriber location. Connection management (CM)set up, maintain calls- connections
-Call control (CC): Manages call connections, -Supplementary service support (SS): special services, -Short message service support (SMS): Transfers brief texts.
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System features
Cell architectureHandoverSecurity
– Users identity& authentication– Mobile security
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CELL ARCHITECTURE
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Handover
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User identity & authentication
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GSM-subscriber services
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GSM –SUBSCRIBER SERVICES
Telephony services(teleservices)
These are mainly voice services that provide subscriber with the complete capability(including necessary terminal equipment) to communicate with other subscribers.
Data services(bearer services)
These provides the capacity necessary to transmit appropriate data signals between two access points creating an interface to the network .
Subscriber services
-Facsimile group
-SMS-Cell broadcast-Voice mail-Fax mail
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Supplementry services
-Call forwarding
-Baring of outgoing calls
-Baring of incoming calls
-Call hold
-Call waiting
-Calling line identification presentation
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GSM V/S CDMA
PARAMETERS GSM CDMATECHNOLOGY USED
FDMA\ TDMA SPREAD SPECTRUM TECHNOLOGY
HANDOVER HARD
BREAK BEFORE MAKE
SOFT
MAKE BEFORE BREAK
DATA RATE 56 kbps 64-140kbps
INTERNATIONAL ROAMING
456 MILLION USERS
127 MILLION USERS
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THE ONLY WAY TO KNOW AN ANSWER IS TO QUESTION FIRST
?
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THANK YOU