Communication Satellites
History


LEO
MEO
GEO

Bands

Routing

ITU

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G
E
O
LEO MEO GEO
Height (miles) 500 to 1500 6250 to 1300 22,282
Latency (seconds) 20 to 40 msecs 50 to 150 msecs O.24 sec

Geostationary Earth Orbit

Geostationary earth orbit(GEO) is 22,282 miles above the equator. The orbit is important because it allows a satellite to orbit the earth at a fixed location in relation to the earth. From GEO, three satellites can cover all but the polar regions and transmissions can be received through fixed antennas. Traditionally satellites have been given two degrees of separation, which means only 180 satellites could be parked in the orbit.

In 1967, the United Outer Space Treaty declared the orbit to be the "common heritage of mankind." The treaty decided that space in the orbit would be distributed on a first come first serve basis. The treaty allowed the more technologically advanced countries to dominate the orbit and specifically the prime satellite areas over the Pacific, Atlantic, and Indian Oceans. Two World Administrative Radio Conferences have been held and dealt with the possibility of changing the allocation of GEO space from 'first come, first serve' to a priori.

The International Telecommunications Union (ITU) regulates GEO usage. Although a monopoly or oligopoly should not be possible with a common property resource, technology gaps have given certain nations domination over the GEO.

With greater control over the spectrum and signals, satellites can now park closer to each other in the orbit. No country has paid to purchase any segment in space, but many countries are using it to station their satellites for which they have made huge investments in construction and station keeping costs.

Bibliography

Email at
djcoffey@ufl.edu
Electronic
publishing
final project
Dec. 7, 1999