SATELLITE SYSTEMS FOR PERSONAL COMMUNICATIONS

A number of industrial groups are currently planning to construct sate llite systems to provide personal communications services (typically v oice, data, and fax) to users who will employ small, hand-held, cellul ar-type telephones. Some of these systems (e.g., Iridium and Globalsta r) will be constructed using satellites in low Earth orbit. Two (Odyss ey and ICO) will employ medium Earth orbit (six-hour period), and stil l others (ACeS and Agrani) will operate from geostationary altitude. T he origin and evolution of mobile satellite communications is discusse d first, including the INMARSAT system and several land-based mobile s atellite systems currently in operation. The rival approaches to the p ersonal communications services (PCS) market are then described, and s ome of the technical challenges inherent in each are indicated. The pa per concludes with speculation on the factors influencing the likeliho od of business success for the various PCS systems.