Architecture of GSM for e2 to e3.ppt

8/10/2019 Architecture of GSM for e2 to e3.ppt

1/29

GSM Architecture

BSS Rao

GSM Faculty


2/29

GSM Architecture

1. What is GSM?

2.History of GSm

3.NE s in GSM

4.Physical connectivity

5.Interfaces


3/29

GSM

Global Mobile System

A digital mobile system enabled for more

sophisticated services


4/29

History of GSM

GSM began in 1982

GSM was a European wide project from

beginning

GSM used in more than 130 countries

Originated from 1G ->2G->2.5G->3G

3G version is named as UMTS 3G Network provide higher capacity than

the older generations


5/29

Subsystems in GSM

BSS Base Station Subsystem

NSS Network Switching Subsystem

NMS Network Management Subsystem


6/29

BSS

BTS (Base Tranceiver Station)

BSC (Base Station Controller)

TC (Transcoder )


7/29

NSS

GMSC(Gateway Mobile services switching

Centre)

MSC (Mobile Services switching centre)

VLR (Visitor Location Register)

HLR (Home Location Register)

AC (Authentication centre) EIR (Equipment Identity Register)


8/29

NMS

OMC R( R for Radio)

OMC S( S for Switch)


9/29

Functions of BSS

Managing Radio Network

Radio Path control

Synchronization Mobility management

Speech transcoding


10/29

Functions of NSS

Call control

Charging

Signaling Subscriber data handling

Mobility management


11/29

Functions of NMS

Monitoring network

gives info. in the form of reports


12/29

Mobile Station

Mobile Phone is called MS

ME + SIM= MS


13/29

MS

Operator issues SIM card when user joins

Serial no. of the mobile Instrument is IMEI

(International Mobile equipment identity)

IMEI is unique number in universe


14/29

SIM

SIM means Subscriber Identity Module

Data contained in the SIM Card is

1. IMSI of the subscriber

2. Location area identity of the subscriber

3. List of missed calls , Received calls and

List of SMSs etc.

4. List of operators available in the locationarea of the subscriber


15/29

BTS Functions

Synchronization of signals of transmission

Radio resources management


16/29

BSC Functions

Control BTSs connected to it

Performs Inter BTS Handovers


17/29

TC Function

Conversion of 64kbps to 16kbps and vice

versa

Used to compact the signals.

Also used to reduce the data rate at which

traffic is transmitted over air interface


18/29

Necessity of TC

The 64kbps information if transmitted on

the air interface without modification would

occupy an excessive amount of

bandwidth.

Therefore the required bandwidth is

reduced to 16Kbps.


19/29

MSC Functions

Call Control

Routing of call

Billing


20/29

VLR

Maintains subscriber information who are

currently in its service area.

Gives current location of the subscriber

Temporary Database


21/29

HLR

Permanent Register of the subscribers

maintains facilities given to subscriber


22/29

AC

Verifies SIM cards

Authentication of SIM is done using

authentication triplets


23/29

EIR

Used for security purposes

Checks IMEI

Contains 3 Lists ( White LISTGREY LIST

Black LIST )


24/29

Black List

List consisting of Stolen mobile

Instruments Serial nos ie., IMEIs


25/2914

BSNL Network Architecture

B

T

S

MSC VLR

HLR

PSTNISDN

Data

Networks

Air interface

OSS

B

T

S

B

T

S

MSC VLR

BSCBSC

1 MSC=16 BSC

1 BSC=1024 TRU

A Interface

A-bis interface

TC TC


26/29

GMSC

GMSC:Call connections between PLMNs ,

routed to a GMSC.The GMSC contains the

Inter working functions to make these

connections


27/29


28/29

Interfaces

MSC to other MSC ( E interface)

MSC to EIR ( F Interface)

VLR to other VLR ( G Interface)

THE GEOGRAPHICAL AREAS


29/29

THE GEOGRAPHICAL AREASOF THE GSM NETWORK

Architecture of GSM for e2 to e3.ppt

Documents