GSM has become the standard protocol for mobile phones. Understand the facts about GSM and how it operates throughout the world. Gather information on GSM and discover its features and technical specifications.
Since its inception, GSM has become the de facto standard for mobile communications. Recent estimates put the number of users at 3 billion around the world, or over 80% of the market.
GSM Specifications
The system utilizes the TDMA (Time Division Multiple Access). The basic process involves compressing information and relaying it to the channel. It sends the data with two streams and functions at 900 MHz and 1,800 MHz.
The mobile frequency range is at 925-960; Tx: 880-915. The channel space is 200 KHz; the modulation GMSK is 0.3 (Gaussian filter). The channel bit rate is set at 270.833 Kb.
Second Generation System (2G)
The GSM system utilizes digital technology, which makes it different from the ones that came before it. Because it uses digital technology for speech and signal, it’s more efficient in transmitting data. This is the main reason why the system has become very popular in international roaming.
As a 2G technology, the system offers advantages to both consumers and networks. For the former it allows them to change carriers without changing phones. The system is also preferred by network operators because there are many vendors and companies that implement it.
Short Messaging System (SMS)
Another innovative feature of the GSM is the short messaging system (SMS or text messaging). This feature allows mobile phone users to send short messages using their phone anywhere around the world.
This service has become very popular and is being implemented by other standards. The text services are less expensive that making calls, hence its increasing popularity.
The worldwide emergency number (112) is also part of the system. This feature lets users get in touch with emergency numbers. This is very helpful for travelers who aren’t familiar with local police / hospital numbers.
Cell Sizes
The cell sizes in the network are macro, micro, pico, femto and umbrella. The macro cell refers to the base station antenna set up on a mast and on average roof level. The micro cells are below this level and utilized in urban sites.
The GSM pico cells extend to a few meters. The femto cells are usually used in residential areas and linked via broadband Internet. The umbrella cells are used to cover gaps found in other cells.
Radio Interference
The system’s services can run into conflict with radio signals. Other electronic devices may cause problems. Interference can come in the form of dropped calls or static. There are several devices and gadgets sold that can reduce the interference rate.
Several devices have also been developed to lessen the interference caused when the person is moving or in a vehicle.
Security
The system uses A5/1 and A5/2 for privacy. The A5/1 is more stable and used mostly in the US and Europe. Other security features like USIM and UMTS are now being implemented as well. However, some operators have started utilizing their own security systems.
The innovations in technology are continuing and changing. It’s widely expected that GSM will continue to be a standard in mobile communications in the foreseeable future.