Dynamic allocation of satellite capacity through packet reservation

If one projects the growth of computer communication networks like the ARPANET to a worldwide situation, satellite communication is attractive for intercommunicating between the widespread geographic areas. For this variable demand, multi-station, data traffic situation, satellites are uniquely qualified in that they are theoretically capable of statistically averaging the load in total at the satellite rather than requiring each station or station-pair to average the traffic independently. However, very little research has been done on techniques which permit direct multi-station demand access to a satellite for data traffic. For voice traffic statistics, COMSAT Laboratories has developed highly efficient techniques; the SPADE system currently installed in the Atlantic permitting the pooled use of 64KB PCM voice channels on a demand basis, and the MAT-1 TDMA (Time Division Multiple-Access) experimental system. Both systems permit flexible demand assignment of the satellite capacity, but on a circuit-switched basis designed to interconnect a full duplex 64KB channel between two stations for minutes rather than deliver small blocks of data here and there. This work forms the technical base for advanced digital satellite communication, and provides a very effective means for moving large quantities of data between two points. However, for short interactive data traffic between many stations, new allocation techniques are desirable.