The cellular-like wireless communication network do not provide an economically viable solution when the coverage area is extended beyond national boundaries or connectivity is to be provided in the remote areas. In thes cases, satellites communications services could fill the gap; allowing complete global coverage. GEOS systems for public use include INMARST-M, MSAT,ACTS. LEOS system include Iridium ( 66 satellites at roughly 770 Km), and Teledesic (840 Satellites at about 700 Km). Odyssey is a MEOS proposal with 12 satellites at about 10,600 Km. Satellites operate along two main frequency: the lower-frequency C band ( 4 and 6 gigahertz) and higher frequency ( 11 and 14 gigahertz) Ku band, which is digital. Satellites communication systems can be categorized on the basis of there orbital altitudes: