The Technology

 

By the year 2002 the number of satellites providing communications for the world is expected to grow from 150 to 1,700. Current satellites operate in Geosynchronous Earth Orbit (GEO). The main drawback with these satellites is that the height of their orbit generally results in a minimum propagation delay of _ second. Leo’s sit only a few hundred miles above the earth’s surface, which allows them to receive and transmit signals within milliseconds from antennas as small as 60 cm. The limitation of LEO’s is that, because they can only see a small part of the earth’s surface, more of them are needed. Intersatellite links similar to the telephone network must be developed to handle network traffic.

The first group of satellites will handle primarily voice traffic but will also handle data between 2.4 bit/sec and 9.6 bit/sec. Fast Internet service will not be available for approximately 4-5 years. The proposed systems are expected to be able to handle 30,000 and 50,000 simultaneous calls. Large cellular telephones will first search out a terrestrial connection and then look to the heavens if it cannot connect on earth. These phones will be equipped with large antenna’s to accomplish this feat.