Prospects of Satellite Communications for Mobiles: Towards a Global Mobile Space Segment

摘要

Terrestrial, maritime, and air transportation applications of communications satellites are considered. Communicating with long distance trucks can be achieved by text transmission which is cheaper than voice links, avoids access problems, and uses the frequency spectrum more efficiently. The need to accept fast and slow air traffic in the same air space, especially near airports, creates safety problems that can be overcome by equipping aircraft with a satellite controlled display device, showing traffic in the vicinity. The maritime satellite service is characterized by low market penetration that can be improved by cutting equipment costs, e.g., by decreasing ship antenna performance and using high gain satellite antennas, producing narrow beams.