bsnl gsm training presentation
TRANSCRIPT
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GSMOperations & Maintenance
BSNL, Lucknow
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BSNL - History
On October 1st, 2000, the Department of Telecom Operations,
Government of India became a corporation and was christened
Bharat Sanchar Nigam Limited (BSNL).
It is the largest public sector undertaking of India in telecom. Its99.9% exchanges are digital.
In order to manage efficiently and better way U.P. Telecom Circle
was bifurcated into two separate Circles viz., U.P. (East) TelecomCircle with Headquarters at Lucknow and U.P. (West) Telecom
Circle with Headquarters at Meerut.
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GSM - Introduction
Global System for Mobile (GSM) is
a second generation cellularstandard developed to cater voice
services and data delivery using
digital modulation.
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GSM - History
Developed by Group Spciale Mobile (founded 1982) which wasan initiative of CEPT ( Conference of European Post and
Telecommunication)
Aim : to replace the incompatible analog system
Presently the responsibility of GSM standardization resides withspecial mobile group under ETSI ( European telecommunication
Standards Institute )
Full set of specifications phase-I became available in 1990
Under ETSI, GSM is named as Global System for Mobile
communication
Today many providers all over the world use GSM (more than 135
countries in Asia, Africa, Europe, Australia, America)
More than 1300 million subscribers in world and 45 million
subscriber in India.
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GSM Network Architecture
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GSM System Architecture
Mobile Station (MS)Mobile Equipment (ME)
Subscriber Identity Module (SIM)
Base Station Subsystem (BSS)Base Transceiver Station (BTS)
Base Station Controller (BSC)
Network Switching Subsystem(NSS)Mobile Switching Center (MSC)
Home Location Register (HLR)
Visitor Location Register (VLR)
Authentication Center (AUC)
Equipment Identity Register (EIR)
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GSM System Architecture
contMobile Station (MS)
The Mobile Station is made up of two entities:
1.Mobile Equipment (ME)
2. Subscriber Identity Module (SIM)
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GSM System Architecture
contMobile Station - SIM
Subscriber Identity Module (SIM)
Smart card contains the International Mobile Subscriber Identity
(IMSI) Allows user to send and receive calls and receive other subscribed
services
Encoded network identification details
- Key Ki,Kc and A3,A5 and A8 algorithms
Protected by a password or PIN
Can be moved from phone to phone contains key information toactivate the phone
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GSM System Architecture
contBase Station Subsystem
BSS is composed of two parts that communicate across the
standardized Abis interface allowing operation between components
made by different suppliers
1.Base Transceiver Station (BTS)
2.Base Station Controller (BSC)
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GSM System Architecture
contBase Transceiver Station (BTS):
Encodes, encrypts, multiplexes,modulates and feeds the RF
signals to the antenna.
Frequency hopping
Communicates with Mobile station and BSC
Consists of Transceivers (TRX) units
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GSM System Architecture
contBase Station Controller (BSC)
Manages Radio resources for BTS
Assigns Frequency and time slots for all MSs in its area
Handles call set up Transcoding and rate adaptation functionality
Handover for each MS
Radio Power control
It communicates with MSC and BTS
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GSM System Architecture
contMobile Switching Center (MSC)
Heart of the network Manages communication between GSM and other
networks Call setup function and basic switching Call routing Billing information and collection Mobility management
- Registration
- Location Updating- Inter BSS and inter MSC call handoff
MSC does gateway function while its customer roams toother network by using HLR/VLR.
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GSM System Architecture
cont Home Location Registers (HLR)
- permanent database about mobile subscribers in a largeservice area(generally one per GSM network operator)
- database contains IMSI,MSISDN,prepaid/postpaid,roaming
restrictions,supplementary services.
Visitor Location Registers (VLR)
- Temporary database which updates whenever new MS enters
its area, by HLR database- Controls those mobiles roaming in its area
- Reduces number of queries to HLR
- Database contains IMSI,TMSI,MSISDN,MSRN,LocationArea,authentication key
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GSM System Architecture
cont Authentication Center (AUC)
- Protects against intruders in air interface
- Maintains authentication keys and algorithms and providessecurity triplets ( RAND,SRES,Kc)
- Generally associated with HLR
Equipment Identity Register (EIR)- Database that is used to track handsets using the IMEI
(International Mobile Equipment Identity)
- Made up of three sub-classes: The White List, The Black List andthe Gray List
- Only one EIR per PLMN
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GSM - Operation
Speech decoding
Channel decoding
De-interleaving
Burst Formatting
De-ciphering
DemodulationModulation
Ciphering
Burst Formatting
Interleaving
Channel Coding
Speech coding
Radio Interface
Speech Speech
13 Kbps
22.8 Kbps
22.8 Kbps
33.6 Kbps
33.6 Kbps
270.83 Kbps
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Core Technologies
2G - Second generation telephone technology is based on. Secondgeneration was launched in Finland in the year 1991.
2G networks are fully digital while their predecessors were
analog.
Three primary benefits
Improved voice quality (less noise)
Longer battery life
Encryption
2.5G
Second and a Half generation telephone technology was thestepping stone between 2G and 3G cellular wireless technology.
It can provide some of the benefits of 3G and can use some of the
existing 2G infrastructure in GSM and CDMA.
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Core Technologies cont
3G Third Generation telephone technology is the superseding
technology to 2G and preceding 4G.
The International Telecommunications Union (ITU) defined the
third generation (3G) of mobile telephony standards IMT-2000 tofacilitate growth, increase bandwidth, and support more diverse
applications.
Service includes wide area wireless voice telephony , video calls,
and broadband wireless data, all in a mobile environment.
It incorporates high speed Internet access.
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Future of 3G
3G evolution (pre-4G)
The standardization of 3G evolution is progressing in both 3GPP and
3GPP2.
The corresponding specifications of 3GPP and 3GPP2 evolutions arenamed as LTE and UMB, respectively. 3G evolution uses partly beyond 3G
technologies to enhance the performance and to make a smooth
migration path.
A 4g network is in the pipe line, capable of speeds of 100Mbit/s whilemoving and 1Gbit/s stationary. This however will take some time.
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Thank you!