Vocabulary. available- доступный, в распоряжении carrier- несущая, compatible- совместимый complexity- сложность customer- потребитель field- поле
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The present status of telecommunications is a result of a long revolution through more than a hundred years. It is interesting to note that the old telegraph system used digital transmission. When many years later, telephony was introduced, analogue transmission was used. Telex, on the other hand, worked with a digital technique while video transmission in principle uses analogue transmission. Data communication is digital and a transition is now taking place where all services, voice, text, data and picture- will be integrated in a basic digital network. This digital network will be an ideal carrier of data communications and will promote the growth of such communications. The development of data communications depends, to a great extent, on the development of data processing. So far, all the signs indicate a trend towards remote data processing which means a greater usage of data communications services. Indeed, a `marriage` of telecommunications and data processing will be the result. This `marriage` will hopefully result in a number of useful products. Already a range of specialized services is foreseen- in particular in the text and picture communication field. A number of new text services have been, or will be, introduced shortly: Firstly, a lot of interest has been shown in Teletex which is already being introduced in some countries. Teletex is an international service enabling subscribers to exchange correspondence on an automatic memory to memory basis, via telecommunications networks. As a successor to telex, it will use specially adapted word processors and electronic typewriters and enable a 3- page A4 letter to be sent almost instantaneously from one end of the country to the other. In Britain, estimates vary of when teletex will be forthcoming, but meanwhile, Germany and Sweden already have systems in operation and teletex launches are planned in France, Spain, Belgium and Canada before long. The Telefacsimile service is well established, though faster and more advanced systems will be introduced shortly. This service provides for the transmission and reproduction of still pictures and printed matter. Telefax has its biggest market in Japan where the complexity of Japanese script makes this an ideal medium of transmission. Videotex, called viewdata in the UK, has passed through an experimental and testing stage and is now available in many countries. Videotex is a service enabling a subscriber to obtain information over the public switched telecoms network (PSTN) for presentation in alphanumeric and/ or graphic form on a VDU-usually a specially adapted TV receiver. This service is marketed under different names in different countries. Prestel in the UK, Bildschirmtext in FRD and Telidon in Canada. Videotex subscribers may choose to have an additional service- electronic mailbox enabling them to send messages directly and instantaneously to one another. The UK viewdata system, which is an interactive service, should not be confused with Teletext,a one- way information service which TV companies broadcast. (In the UK two systems are available- Ceefax and Oracle.) Technically it will be possible to integrate various types of telecommunications networks (private and public, data and telephony) to form an Integrated Services Digital Network (ISDN). In Germany the BIGFON experiment has recently been launched. BIGFON is a wideband integrated services local communications system, offering the subscriber the complete spectrum of telecommunications services, including a new video telephone service as well as radio and TV broadcasts, all transmitted via optical fibre cables. Despite this development towards ISDN, a number of specialized networks will have to live side by side for many years to come. From the customer’s point of view, it is therefore essential that networks and services are compatible. It should be possible to use one and the same terminal for different services and to send traffic over different networks. The question is how can this be realized? Could an integrated network be developed?
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