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Launching the age of cheap video conferencing

点击量:   时间:2017-07-05 01:02:10

By Barry Fox THE cost of video conferencing will plummet when an Astra satellite capable of handling huge volumes of data at high speed is launched in 2000. The satellite is currently being built by a French company, Aerospatiale of Toulouse. The satellite will use 16 highly focused aerials to receive ground signals from across Europe. Terminals with 1.2-metre dishes and 2-watt transmitters will be able to send 2 megabits per second into space. This rate of data transfer means that the picture quality of video conferences will rival that of television broadcasts—VHS video needs a data transfer rate only half this level. Initially, all data sent to the satellite from ground terminals will first be transmitted to the satellite control centre at Betzdorf, Luxembourg. The centre will electronically label the data so that only people taking part in a particular video conference will be able to receive the transmissions. The data will then make a second trip to the satellite for transmission back to Earth. Because the signals have to make two return journeys from the Earth to the satellite, the signal is delayed by around a second, adding awkward gaps to a conversation. However, the Société Européenne des Satellites, which operates the Astra satellites, plans to cut the need for two trips by putting a computer server on a future satellite to process and label the data. “The next generation systems will use space processing,” says Romain Bausch, the Société’s director general. Technically, however, people using this system to take part in video conferences count as transmitting stations and require licences in most European countries. Roland Jaeger, Astra’s legal manager, is trying to persuade the European Commission to issue a class licence, like the one that allows anyone with a digital cellphone to use it anywhere in Europe. “It is impractical to seek local licences. We need a single licence at EC level,