ABSTRACT
The launch of commercial communications satellite services in the early 1960s ushered in a new era in international telecommunications that has affected every facet of human endeavor. Although communications satellite systems were first conceived to provide reliable telephone and facsimile services among nations around the globe, today satellites provide worldwide TV channels (24 h a day), global messaging services, positioning information, communications from ships and aircraft, communications to remote areas, disaster relief and emergency services on land and sea, personal communications, and high-speed data services including Internet access. The percentage of voice traffic being carried over satellites-which stood at approximately 70% in the 1980s-has been rapidly declining [1] as new video, data and IP services are added over existing satellite networks.
