Overview of IRIDIUM satellite network

The IRIDIUM system is a satellite-based, wireless personal communications network designed to permit a wide range of telephone services-voice data, fax, paging-to connect to destinations virtually anywhere on earth. The 66 satellite interlinked constellation system will track the location of the telephone handset, determine routings through a network of ground gateways, establish the path of the telephone call, initiate connections, and terminate the telephone call with appropriate revenue tracking. This activity provides global communication even if the subscriber´s location is unknown to the caller. The global communications network will provide revenue to all parties of each telephone call, including the country of origin or termination. There will be no bypass of sovereign territory due to the licensing agreements around the globe. The phones of the IRIDIUM system use L-band frequencies, with Frequency Division Multiple Access and Time Division Multiple Access (FDMA/TDMA) multiplexing to make the most efficient use of a limited spectrum