In a further step towards circling the globe with high-quality digital telecommunications, AT&T Co, France Telecom and British Telecommunications Plc have formally inaugurated the first transatlantic optical fibre cable, TAT-8, for data, voice and video communications. TAT-8 stretches 4,200 miles across the Atlantic, leaving Tuckerton, New Jersey, before branching off 200 miles from the European coast to reach Widemouth, on the North Cornwall coast, and Penmarche in Britanny. AT&T owns 34.1% of TAT-8, British Telecom 15.5%, and France Telecom 9.8%; the remainder is held by 26 telecommunications operators throughout the world. Pricing will be governed by the carrier in users’ respective country, and British Telecom maintains that customers will have complete discretion as to the choice of provider between the US and the UK. STC Submarine Systems completed the UK section of the cable, which cost UKP220m to install and should have a lifespan of 25 years. TAT-8 is capable of carrying 40,000 telephone connections simultaneously, four times the capacity of the previous trans-Atlantic cable installed in 1983; it consists of six strands of glass, two pairs to carry messages, a third pair for back-up, and repeaters placed at 25 mile intervals. The cable is buried three feet below the sea bed until the ocean is 3,000 feet deep, and sharks intent on sabotaging the project will have to venture down 8,500 feet, where the protective coating against their bites ends. It has a line rate of 295.6Mbps, and a system interface rate of 140Mbps. For British Telecom, the introduction of TAT-8 will have implications for the future of satellite services, which will now tend to serve specialised applications, with the cable picking up more general services around 20% of British Telecom’s transatlantic telephony services will use TAT-8 by 1991. AT&T, British Telecom and France Telecom all announced customers at the three-way conference between New York, London and Paris that marked TAT-8’s launch, with American Express, British Airways and Bull respectively saying they intend to lease capacity on the new optical cable; during the launch, mildly eccentric futurist author Isaac Asimov was given the honour of saying the first words over the new line. And another fibre optic cable – being installed across the Pacific by AT&T and Japanese long-distance carrier Kokusai Denshin Denwa Co to service the section of the Pacific link from west Hawaii to Guam and Japan – will be ready for service next spring. A second optical transatlantic cable, TAT-9, is planned by AT&T for 1991, and Cable & Wireless Plc and partners are also laying private optical cables across both oceans.
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