GSM is a digital mobile communication standard that is one of the most widespread in the world today. It is supported by a large number of operators and implements the transmission of radio frequencies in a specific range, allowing voice calls to be made over long distances.
History and use
The standard got its name in honor of the group of companies that developed the Groupe Special Mobile standard. Subsequently, this group was renamed Global System for Mobile Communications. Development of the standard began in 1982, when several European telephone companies teamed up to create a single cellular system that would make it possible to make calls on a specific frequency of 900 MHz throughout Europe. After the accomplishment of this task, the standard was certified in 1991 and spread throughout the world.
Today GSM supports not only voice communication services, but also packet data (GPRS) services on the Internet. The exchange of short text messages (SMS) and facsimile data is also implemented on the basis of GSM.
GSM allows you to determine the calling number, forwarding to another subscriber, conference calls (3 or more subscribers) and voice mail.
Advantages and disadvantages of the standard
GSM enables the creation of compact radio modules that are significantly lighter and smaller than most analogue networks. The implementation of this approach is achieved due to the structure of the implementation of data transmission at the expense of radio towers, i.e. base stations analyzing signals from subscribers.
The network also provides a sufficiently high quality of communication within the coverage radius of GSM towers. The network is more capacious, which ensures the simultaneous use of the network by a large number of subscribers. This achieves a relatively small amount of interference to the radio signal.
GSM has good protection against eavesdropping through signal encryption algorithms. A great advantage is the possibility of roaming, which allows the subscriber to move around the world without changing the operator or phone number.
There are also some drawbacks to the network. First, GSM is prone to speech distortion due to digital processing and signal transmission to an intermediate station. Secondly, there is a limited coverage of one tower, which is no more than 120 km when using amplifiers and separate directional antennas.
Networking requires more transmitters and technology than other standards (eg AMPS) networks.
In most countries, GSM is being replaced by the CDMA standard, which has some advantages over GSM. For example, with the help of CDMA, it is possible to achieve faster data transmission, which improves the quality of communication and allows you to work faster on the Internet due to a larger and more powerful channel.
