The Development Of Mobile Telephony Essay Research

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The Development Of Mobile Telephony Essay, Research Paper Since the first cellular mobile telephone networks opened for business in the early 1980’s, growth in numbers of subscribers has consistently exceeded even the most optimistic forecasts. Even in the most advanced markets, this growth shows little sign of abating, and meanwhile, new markets are accelerating rapidly. So why is mobile telephony such a success story? And what are it’s scopes for the future? Cellular telephony was developed by AT&T (American Telephone and Telegraph), in it’s Bell laboratories. It operates by allocating a spectrum of radio channel frequencies to telecommunications systems. The radio channel frequencies are subdivided and assigned to a network of radio base stations each responsible

for the coverage of a particular geographical area known as a cell (hence the name cellular telephony). Each cell has a radius of approximately 1.5 to 2.4km, and because cells operate on different frequencies, network operators are able to maximise their coverage by re-using these channels effectively. (Encarta 1996). Each cell is linked to a mobile communications telephone exchange, which in turn communicates with other cells, other networks or the national and international telephone systems. These mobile exchanges are more commonly referred to as either Mobile Telephone Exchanges or Electronic Telephone Exchanges. These exchanges are central to the operation of a mobile telephone network. Cellular base stations emit control channels which recognise the Electronic Serial Number

(ESN), of a mobile phone’s whereabouts. Ultimately the call is delivered to it’s destination as the phone moves around the coverage area. Continuing call clarity is maintained by way of a process named “hand-off”. This involves the network automatically re-allocating the call to the channel with the strongest signal in the designated geographical area. The first mobile cellular network operators in the UK, (Cellnet and Vodaphone), began using analogue technology for their first networks because it was the only available and prevailing technology of that time. Analogue technology is based upon the transmission of sound by way of radio waves through an Analogue Mobile Phone System (AMPS), and conforms to the relevant Total Access Communication System (TACS), standards of

operation in countries such as Italy, Spain, Austria and Eire. Unfortunately, analogue networks are limited, in that they suffer from severe capacity constraints. There are reception and interference problems, they are also less secure to prying ears and most importantly from a user point of view, coverage is restricted to the UK. Along with the expansion of customers there was also a concern about the availability of bandwidth as the radio frequency became overcrowded. Such inefficiencies obviously led to the demand for a new and improved alternative, so along came digital technology. The new digital networks use their allotted radio frequency’s more efficiently than analogue and sound is transmitted by computer code rather than by waves. This enables the network to carry a

higher capacity of calls of a higher reception quality and enables the user access to a wider number of advanced features, such as Personal Digital Assistants, (PDA’s), mobile faxing and wireless e-mail. A new technology called signal compression has since been developed which dramatically cuts the amount of information that needs to be transmitted in order to get a message across. It was a combination of these new technologies that meant that mobile telephony could expand and two technological options then presented themselves. Time Division Multiple Access, (TDMA), technology has 3-7 times the capacity of analogue technology. It has been adopted by Europe since 1982 and the GSM (Global Systems for Mobiles) has also been developed. A number of American firms also developed