Propagation effects on interference in wireless communication services

As a result of the congestion of the frequency spectrum, the geostationary orbit, and soon to be also low earth orbits, and the related widespread use of frequency sharing, consideration of interference has assumed an important role in earth-station siting and other aspects of telecommunication system design. Interference may arise between terrestrial systems, between terrestrial and space systems, and between space systems. Attention is given here to interference involving space systems, whether between space systems or between space and terrestrial systems. Space-system earth stations, which commonly transmit high power and have sensitive receivers, may cause interference to terrestrial systems when transmitting and may be interfered with by terrestrial systems when receiving. In addition, one earth station may interfere with another. Also, earth stations may receive interfering, unwanted transmissions, as well as wanted signals, from satellites. Likewise satellites may receive interfering transmissions from other than the intended earth station, and terrestrial systems may receive interference from space stations