The amount of bandwidth that can be processed by a satellite broadband provider can be measured in terms of megabits per second (or one million bits of data per second). There are approximately 300 communications satellites stationed in the geosynchronous orbits, lying directly above the equator 2-3 degrees apart. Geostationary satellites circle Earth at the same speed without changing its fixed location relative to Earth’s equator.
In evaluating satellite broadband, the following factors should be considered seriously: transponder bandwidth (MHz), uplink G/T (dBK), downlink EIRP power (dBW), and sensitivity (dBW/^m2), which is bought by satellite Internet operators.
The conversion of bandwidth (MHz) to information data rate varies depending on the following factors:
modulation method (e.g 8-QAM , 16-QAM, BPSK, QPSK )
the type of FEC (e.g. Low Density Parity Check, Turbo Code, Viterbi, Reed Soloman or combination of these)
Forward error correction code
A geostationary satellite can cover as much as one-third of the globe. The coverage areas of a communication satellite stationed at the orbit just above India’s equator include Europe, Australia, South Africa and Japan. Spot beams are directed at certain regions to support small dish operations.
Satellite broadband signals can be sent and received by a small dish 60cm to 3.7m in diameter, provided that there are transmit module and receiver module. For residential users, there is an indoor device provided to process and prepare signals for transmission in TDMA bursts.
Satellite Internet providers usually charge customers per bit rate usage. Under a satellite broadband plan with 512k download /64k upload speed and 20:1 user-host ration, the monthly fee can be as much as $202. Such broadband plan is good for two computer terminals per site. Like traditional ISPs, VSAT operators implement fair usage policy. Customers who fail to limit their bandwidth consumption can be penalized either through reduced speed or higher limit in bandwidth consumption.
Upload and download satellite broadband speeds are normally sufficient to perform common computer tasks like web browsing, computer games and video download.
Satellite broadband is the ideal backup wireless solution for businesses. It may not be the fastest, but satellite Internet is often the only option for travellers stuck in countrysides with no telecommunication facilities.
Various industries like airlines, shipping, airlines and banks can enjoy continuous wireless connectivity through satellite broadband. Although latency and other technical issues remain a problem, satellite broadband services are continuously improving, thus reducing cost and signal delays.