GSM Vs CDMA - A Comparative Study

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History of GSM

During the early 1980s, there was rapid growth in the number of analog cellular telephone systems10 in most European countries, particularly in the United Kingdom, France, Germany and the Scandinavian countries. Unfortunately, every country in Europe had its own system, which was incompatible with the equipment and operations of the other systems. This was an undesirable situation since it limited mobile equipment to national boundaries. Consequently, there was a very limited market for each type of equipment. To address this problem, in 1982, the Conference of European Posts and Telegraphs (CEPT) formed a group called the Groupe Special Mobile (GSM) to study a public land mobile system. The group developed a land mobile system which provided several features such as good speech quality, ability to support handheld services, support for a range of new services and facilities, spectral efficiency and ISDN11 capability. This system also had a low service cost.

In 1989, the responsibility for the further growth of GSM was taken up by the European Telecommunication Standards Institute (ETSI),¹² and the first GSM specifications were published in 1990. The commercial service of GSM started in mid-1991. By 1993 there were 36 GSM networks¹³ in 22 countries. Though GSM was standardized in Europe, it was not restricted to Europe alone. At the beginning of 1994, GSM had 1.3 million subscribers worldwide; this number increased to more than 55 million by October 1997. By the end of 2002, there were more than 200 GSM networks operating in 110 countries around the world. The acronym GSM now aptly stands for Global System for Mobile communications.

The developers of GSM believed that advancements in compression algorithms¹⁴ and digital signal processors¹⁵ would support the use of the GSM digital system and bring about a continuous improvement in quality and reduction in cost. By 2002, ETSI had brought out more than 8000 pages of GSM recommendations, which provided functional and interface descriptions of all the components used in the system. The recommendations provide standards that ensure the proper working of the different components in the system.

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10] Invented by Bell laboratories, it is also called AMPS (Advanced Mobile Phone Systems). The entire frequency range, from 800-900MHz, is allocated to the service providers, who use half the range for receiving from cellular phones and the other half for transmitting to cellular phones.
11] Integrated Service Digital Network provides a single physical outlet and transport mechanism for transmission of all types of information including data, video and voice.
12] A standards setting body in Europe.
13] Operators providing GSM technology.
14] Developed to transmit data in a format that saves storage space. Converts data from the original format to one optimised for compactness.
15] A modern digital technique for processing signals. It allows complex operations to be performed cost efficiently.

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