The document presents information on Global System for Mobile Communication (GSM). It discusses that GSM is a second generation cellular standard developed in Europe to provide digital voice services and data delivery. The key features of GSM include spectral efficiency, good speech quality, international roaming, low terminal and service costs, and support for new services. The document outlines the GSM specification including modulation, frequency bands, channel spacing and access methods. It also describes the architecture of a GSM network and its interfaces. Finally, it notes that GSM handles both voice and data traffic through circuit switched and packet switched modes.

1. Presentation on
Global System for Mobile Communication
(GSM)
Prepared by,
Syed Mainul Islam
Department of ETE,IIUC.

2. CONTENTS
• Introduction
• What is GSM?
• Features of GSM
• GSM Specification
• GSM Architecture
• GSM Interfaces
• GSM Data services
• Conclusion

3. INTRODUCTION
• In the early 1980’s, many countries in Europe witnessed a rapid expansion of analog
cellular telephone systems. However, each country developed it’s own system and
interoperability across borders became a limiting factor.
• In 1982, the Conference of European Post and Telecommunication (CEPT) established
a working group to develop a new public land mobile system to span the continent.
Because their working language was French, the group was called “Groupe
Speciale Mobile”(GSM). When the official language changed to English, GSM was
changed to “Global System for Mobile Communication”.

4. WHAT IS GSM?
• GSM (Global System for Mobile) is a second generation cellular standard developed
to provide voice services and data delivery using Digital Modulation.
• The European TDMA Digital cellular standard.
• GSM is the most widely accepted standard in telecommunications which is
implemented globally.

5. FEATURES OF GSM
• Spectral efficiency
• Good speech quality
• International Roaming
• Low cost for terminal and services
• Support for introduction new services
• Compatibility with Integrated Digital Service Network(ISDN)

6. GSM SPECIFICATION
#Modulation:
Gaussian Minimum Shift Keying (GMSK)
#Frequency Bands:
• 450 MHz (Upgrade of older analog cellular system)
• 900 MHz (Original band used everywhere except North
America and most of South America)
• 1800 MHz (New band to increase capacity used everywhere
except North America and most of South America)
• 1900 MHz (personal communication band used in North
America and most of South America)
#Channel Spacing:
The spacing between adjacent carrier frequencies (200KHz)
#Access Methods:
• GSM uses a combination of both the TDMA & FDMA.
• The FDMA part divides the frequency of the total 25
MHz bandwidth into 124 carrier frequencies of 200
KHz bandwidth.
• Each of this frequency is divided into eight timeslots
using TDMA scheme.

7. GSM ARCHITECTURE
A GSM network consists of the following network components:
• Mobile Station (MS)
• Base Station Subsystem (BSS)
• Network Switching Subsystem (NSS)
• Operation Support Subsystem (OSS)

8. GSM ARCHITECTURE...

9. GSM INTERFACES
Fig: GSM Interfaces

10. GSM DATA SERVICES
GSM networks handle both voice and data traffic requirements of the mobile
communication by providing two modes of operation:
• Circuit switched (high speed circuit switched data)
• Packet switched (GPRS)

11. CONCLUSION
• GSM makes a tremendous shift in traffic volume from fixed networks to mobile
networks.
• GSM is the most widely used in the whole world (70% of phones).
• GSM uses TDMA & FDMA which is replaced by CDMA in next feature.

12. WHAT
NEXT??

13. Thank You