Просмотр полной версии : Japan launches high-speed Internet satellite

27.02.2008, 00:31
Japan has launched a satellite that is able to provide high-speed Internet connections to homes and offices at speeds rivaling those of today's fiber-optic connections.
The satellite launched Saturday, called Kizuna, is part of the government's e-Japan project, and its modest aim is the creation of the world's most advanced information and telecommunications network.
It will be able to provide broadband Internet connections to homes with download speeds of up to 155Mbit/sec. and upload speeds of 6Mbit/sec. The services will be delivered via 45-centimeter dish antennas, which are about the same size as those used for digital direct-to-home (DTH) satellite TV services in many countries.
Even faster connections at download speeds of around 1.2Gbit/sec. will be offered to commercial users via 5-meter antennas.
There are two antennas on the satellite, one serving Japan and one aimed at the Asia-Pacific region as a whole. These multibeam antennas efficiently divide up the satellite's signal into multiple beams so the limited frequencies available can be reused in many different areas, according to the Japanese government.
To help route signals between beams, the satellite carries an Asynchronous Transfer Mode switch.
The domestic Internet services will be primarily aimed at rural areas that are not served by fiber-optic Internet services.
Fiber Internet connections are pervasive in built-up areas of Japan, and a 100Mbit/sec. connection costs around $40 per month, but in rural areas, slower Digital Subscriber Line connections are typically as fast as the Internet gets.
The satellite will also serve as an Internet backup network should terrestrial communications be disrupted by a major earthquake.
The satellite's Asian beam will be used to provide high-speed Internet connections between Japan and other nations in the region, the Japan Aerospace Exploration Agency and the National Institute of Information and Communications Technology said in a joint statement.
The launch from Japan's Tanegashima Space Center, delayed from earlier in February, took place at 5:55 p.m. local time (8:55 a.m. GMT) on Saturday.
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