Thomas Richon and Serge Hethuin
Thomson-Csf Communications

An Aloha Channel, without synchronization, is generally limited, in throughput, up to 0.186 of the channel capacity and 0.37 with synchronization between all transmitters. A Spread Aloha channel provides, among other advantages, a better collision probability, but is still limited to the same maximum throughput. This paper proposes an expansion of the capacities of this last protocol, in the form of the Extended Spread Aloha Multiple Access Protocol (ESAMA). It explains why ESAMA could prove a unique and effective solution for Internet via Satellite with a satellite Transmission Control Protocol/Internet Protocol (TCP/IP) return channel.