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Submitted by Yogesh Alwe Tushar Pandav

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GSM (Global System For Mobile communication)

Outline

1. Introduction2. Architecture of GSM3. Features of GSM4. Services of GSM5. GSM Radio subsystem6. Call processing in GSM

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Introduction

In 1982, the European Conference of Postal and Telecommunications Administrations (CEPT) created the GSM to develop a standard for a mobile telephone system that could be used across Europe.

The first GSM network was launched in 1991 by Radiolinja in Finland with joint technical infrastructure maintenance from Ericsson.

outline

1. Introduction2. Architecture of GSM3. Features of GSM4. Services of GSM5. GSM Radio subsystem6. Call processing in GSM

Architecture of GSM

BTS

BTS

BTS

BTS

BTS

BTS

MS

MS

BSS

BSS

MSC

OMC

PSTN

ISDN

DATAN/W

AUCHLR VLR

outline

1. Introduction2. Architecture of GSM3. Features of GSM4. Services of GSM5. GSM Radio subsystem6. Call processing in GSM

Features of GSM

Roaming in European countries. Use of SIM card. Control of transmission power. Frequency hopping. Discontinuous transmission. On air privacy for the user.

outline

1. Introduction2. Architecture of GSM3. Features of GSM4. Services of GSM5. GSM Radio subsystem6. Call processing in GSM

Services by GSM

GSM services are classified into two types:-

Tele-services

Data services

The user services are divided into three categories:-

1. Telephone services.

2. Bearer service or data services.

3. Supplementary ISDN services

outline

1. Introduction2. Architecture of GSM3. Features of GSM4. Services of GSM5. GSM Radio subsystem6. Call processing in GSM

RADIO SUBSYSTEMTS0TS1

TS7

576.92uS

4.615mS1 Frame

Time frame

200KHz

200KHz

890MHz

915MHz935MHz

960MHz

uplink

downlink 124 frames

ARFCN

25MHz

25MHz

outline

1. Introduction2. Architecture of GSM3. Features of GSM4. Services of GSM5. GSM Radio subsystem6. Call processing in GSM

Call processing in GSM

The typical signaling sequences for call flow in GSM are as follows:

Mobile call origination. Mobile call termination. Authentication. Inter-MSC call handoff.

The mobile call origination and the mobile call termination features are discussed:-

1.Mobile call origination procedure:

BTS BSC MSC GMSC

VLR

LE

1 1 34

5

6

7

7

22

77

71

Telephone

MS

2. Mobile Call Termination Procedure:

BTSBTSBTS

BTSBSC MSC GMSC

VLR HLR

LE

PSTN

12

1

2 12

63

7

1211

10

11

10

1011 98

4

5

Paging Area

Telephone

MS