GSM: An Overview

GSM is an acronym for the Global System for Mobile Communication. It was developed by the European Telecommunication Standards Institute (ETSI) as a set of standards for 2G cellular networks, replacing the 1G networks.

Today, GSM is a widely used digital cellular radio network, operating in almost all countries globally. It's not only used for voice calls but also for transmitting data and text messages.

Key Features of GSM

• GSM uses Narrowband Time Division Multiple Access (TDMA) for signal transmission.
• It is a circuit-switched system that splits each 200 kHz channel into eight 25 kHz time-slots.
• GSM primarily operates on the 900 MHz and 1800 MHz frequency bands for mobile communication in most parts of the world.

Components of the GSM Network

A GSM network comprises four main parts that function cohesively to ensure its operation.

1. The mobile phone.
2. NSS – The Network Switching Subsystem.
3. BSS – The Base Station Subsystem.
4. OSS – The Operation and Support Subsystem.

The GSM system primarily operates on three frequencies .

• 900 MHz – Used for the original GSM system.
• 1800 MHz – Introduced to support increased subscriber capacity.
• 1900 MHz – Primarily used in the USA.

Benefits of Using GSM

• High security due to the difficulty in duplicating services since the data is stored on a SIM card.
• Compatibility with a wide range of applications.
• Facilitates concurrent use of voice calls and data, an advantage over CDMA Technologies.
• Superior voice service clarity.

Drawbacks of GSM

• Bandwidth sharing can lead to transmission interference.
• More recent cellular networks like 3G use CDMA technology.
• GSM's pulse transmission technology can interfere with electronic devices. Hence, it's advised to switch mobile phones to airplane mode in hospitals and on aircraft.
• The complexity of the GSM system can be a disadvantage.