Global system for mobile communications technology
Global system for mobile communications technology (popularly known as GSM), is an open and digital cellular technology primarily used for the transmission of mobile voice and, most recently, data services. Unlike the case of first generation wireless systems, GSM utilizes time-division multiple access transmission methods and digital technology. Using a circuit-switched system, GSM divides a 200-kHz channel data into 8 packets of 25 kHz time-slots. GSM works on the 900 and 1800 MHz (or 1. 8 GHz) bands in the European region and the 850 MHz and 1. 9 GHz bands in the United States.
GSM and 3GSM in Canada, Australia, and many South American countries also operate on the 850 MHz band. GSM is capable of data transfer speeds of up to approximately 9. 6 kbps, which allows basic data transmission services such as Short Message Service, (SMS or text messages). One of the major benefits of this technology is its capability for international roaming services. This allows users to have the same services that they enjoyed at home even when traveling abroad — giving consumers and clients same number and seamless connectivity in more than 200 countries worldwide.
GSM satellite roaming recently extended this technology’s service capability even to areas where usual terrestrial coverage is not available (GSM World, 2007). History and technical details of GSM During early 1980s, analog cellular phone facilities or systems were heading to significant improvement in the European region, particularly in the countries of Scandinavia, United Kingdom, as well as in France and Germany. These countries have their own systems for their technologies, which are incompatible with everyone else’s operation and equipment.
Needless to say, this situation is undesirable for a couple of significant reasons: (1) the mobile equipment’s operation is limited only within national borders, and (b) limitation in market for these mobile equipment making economies of scale unrealizable. These two situations are not suitable for the growing integration of the European region (European Union). The Europeans realized this and by 1982, a study group was formed by the Conference of European Posts and Telegraphs (CEPT). This was called the Groupe Special Mobile (GSM) and was tasked to study and develop a public land mobile system across Europe.
This proposed public system had to meet certain ore-defined criteria (Scourias, 2007): Low terminal and service cost Good subjective speech quality Ability to support handheld terminals Support for international roaming ISDN compatibility Spectral efficiency Support for range of new services and facilities By late 1980s, GSM responsibility (the study group) was transferred to the European Telecommunication Standards Institute (ETSI). It was also around this time, 1990, that phase I of the specifications of the proposed system were published.
Commercial service did not start until before mid-1991. Two years later, 36 GSM networks in 22 countries are already in operation (Dechaux and Scheller, 2003). GSM started and was developed in Europe but this does not mean that the technology is only operational in that region. There are more than 200 GSM networks (DCS1800 and PCS1900 included) that are operational in more than 100 countries all over the world. Early 1990s witnessed only 1. 3 million subscribers worldwide (Nilsson, 2007), but this has grown to over 55 million by October 1997.
As of second quarter of 2007, there are more than 2 billion subscriber already (Wireless Intelligence, 2007). North America made a delayed entry into this GSM technology with a derivative of GSM known as PCS1900. By that time, GSM technology exists on all continent, and GSM which formerly is an acronym for Groupe Special Mobile now aptly stands for Global System for Mobile communications. GSM developers opted to use an unproven (at least at the time) digital system, as compared to the standard being used then which is the analog cellular systems like TACS in the United Kingdom and AMPS in the United States.
They believe that the improvement and advancements in algorithms and signal processors would permit the fulfillment and achievement of the criteria set forth originally. They also had faith that this would have a continued improvement in system in terms of cost, and, more importantly, quality. The recommendation contains more than 8,000 pages allowing flexibility in competitive innovations among potential suppliers or developers. It should be noted that these recommendations contain or mandates enough standardization to ensure proper interworking between different components of the system.
This is done by athe establishment and privision of interface and functional descriptions for each of the entities contained in the system. Other Services provided by GSM The planners of GSM aimed for ISDN compatibility ever since they started in terms of the services that they wanted to offer as well as the control signalling to be used. However, radio transmission limitations prevented them from achieving this Telecommunication services, as per ITU-T definitions, can be classified into, teleservices, bearer services, and supplementary services. Telephone is the most basic teleservice that can be supported by GSM.
Similar to other communications, what happens here is that speech is encoded digitally and then transmitted through the GSM system provider as a digital stream. An emergency service, where an emergency-service provider nearest to the subscriber can be notified by simply dialing a three-digit number (this is similar to 911), is also available in the GSM network. Other data services are being offered. GSM subscribers can send and receive data to users on Plain Old Telephone Service (POTS), Packet Switched Public Data Networks, ISDN, and Circuit Switched Public Data Networks by utilizing a number of access methods and protocols.
Because GSM is a digital network, there us no need for a modem between the user and GSM network. An audio modem, however, is required within the GSM network for it to interwork with POTS (Balston, 1993). A very unique and practical feature of GSM, which is not available in earlier analog systems, is the accessibility to Short Message Service (SMS or text messaging). This is a bidirectional service between and among subscribers for short alphanumeric messages (up to 160 bytes). Messages are sent through a store-and-forward fashion.
In the case of point-to-point SMS, messages/data can be sent to a subscriber, wherein an acknowledgement of receipt of data or messages is sent back to the sender. SMS can also be utilized in a broadcast mode for sending broadcasts such as news or traffic updates. Messages Subscriber has the option to stored messages in the SIM card for later retrieval (Balston, 1993).
Works cited: Balston, D. M. “The pan-European system: GSM. ” In Balston, D. M. , and Macario, R. C. V. (eds. ), Cellular Radio Systems. Boston: Artech House, 1993. Dechaux, C. , and Scheller, R. “What are GSM and DCS? ” Electrical Communication, 2nd Quarter 2003. GSM World.
“What is GSM? ” GSM World – the world wide web site of the GSM Association. Date accessed: November 23, 2007 (http://www. gsmworld. com/technology/what. shtml). Nilsson, Torbjorn. “Toward a new era in mobile communications. ” Ericsson WWW server. Accessed November 23, 2007 (http://193. 78. 100. 33/). Scourias, J. Overview of the Global System for Mobile Communications. Date accessed: November 23, 2007 (https://styx. uwaterloo. ca/~jscouria/GSM/gsmreport. html). Wireless Intelligence. “Number of GSM connections. ” Wireless Intelligence Website. Date accessed: November 23, 2007 (https://www. wirelessintelligence. com/Index. aspx).Sample Essay of Masterpapers.com