Anna University Chennai 2006 B.E HS 1101 _ ENGLISH - Question Paper

two and 4 hours.
The most important kind of satellite for telecommunications is the
geosynchronous or geostationary satellite positioned over the Equator at a
-height
of 35,800 kilometers. Its rotation period is 24 hours, the identical as the
Earth's, and consequently, seen from the Earth, this kind of sateilite appears to
remain motionless in the sky. It is within line of sight of an earth station for its
entire life.

A communication satellite is, in essence of microwave relay station which
receives signals in a provided frequency band and?'elrahsmits them at a various
frequency to avoid issues of interference ranging from the weak incoming signal
and the powerful retransmitted signal. The equipment which receives a signal,
ampiifies 1t, modifications its frequency and then retransmits it, is calied a
transponder. A satellite can handle large amounts of traffic which it can send
o-ver vast areas of the Earth. It therefore represents a relatively cheap way of
transmitting info over long distances. For countries which do not
already have sophisticated cable or microwave networks the use of a satellite
can be extremely beneficial as it can be used in their place.
The 1st satellite were seen as a way of communicating with people who lived
in isolated areas of the world. As a result,'earth s-tations began to appear in the
remotest parts of the globe. The cost of sateilite communication began to fali
steadily and, consequently, satellites have to compete with submarine cables
as a riiay of linking continents cheaply. With the arrival of optical undersea
cables, however, a more balanced intercontinental bircuits ranging from the 2 are
likely. Satellites were soon used to broadcast TV programmes 'live' from one
side of the Earth to the other, aird then to linJ< up computer terminal,q in
various parts of the world. The use of digital transmission and multiplexing
techniques has led to an enormous increase in the capacity of satellites.
The international organization INTELSAT u'as created in 1964 to give
international communication services by satellite. In 1983 it operated and
owned L6_5pgce crafts in gggqfnqb{engus orbit representing an investment
o-yep_llqggb illi_ol_U$ dollars-. In 1,983i t handled 2 thirds of ail international
telephone and data communications and transmitted virtually all 'live'
international television broadcasts. 109 nations are members of INTELSAT.
ranging from 1979 and 1983 INTELSAT's iraffrc doubied, yet its communications

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