GSM

Mohammad AL-adwan

Introduction

GSM (Global System for Mobile Communications, originally Groupe Spécial Mobile), is a standard developed by (ETSI) to describe protocols for second generation (2G) digital cellular networks used by mobile phones.

1st Generation

• First use in Tokyo in 1979• Analog System• FDMA • Bw = 40 MHz between 800-900 MHz• 832 channels• 10 kbps• Voice Only

2nd Generation

• First use at end of 1980s• Digital System• TDMA / CDMA• 384 kbps• Voice and Data

3rd Generation

• First use in 2001• Digital System• WCDMA• Downlink : 14.4 Mbps || Uplink : 5.8 Mbps• Voice and Data

4th Generation

• Started in 2010 but used in 2013• Digital System• WCDMA• Downlink : 1 Gbps || Uplink : 0.5 Gbps• Voice and Data

1st Look

MSC

BS

BS

MS

MS

MSBS

1st Look

MSC

Mobile Switching Center is the head of the cellular communications process .

Any provider must have one MSC at least .

1st Look

MSC

BS

BS

MS

MS

MSBS

1st Look

BSBase Stations function is to propagate and receive EM waves .GSM is a cellular network, which means that cell phones connect to it by searching for cells in the immediate vicinity. There are five different cell sizes in a GSM network—macro, micro, pico , femto , and umbrella cells.

1st Look

BS

Some more base station equipment

Typical macro cellTypical micro cell

1st Look

MSC

BS

BS

MS

MS

MSBS

1st Look

MS

Mobile Stations are the mobile phones .In general any device have a GSM module and SIM card (Subscriber Identity Module) .

Call Flow [ 2 MS’s in the same cell ]

Call Flow [ 2 MS’s in different cells ]MSC

Challenges of GSM

1. Co-Channel Interference2. Adjacent Channel Interference

Co-Channel Interference

• Frequency Reuse

Co-Channel Interference

Adjacent Channel Interference

Frequency Bands In Jordan

Any Question ??

Thank You