Performance Comparison of Media Access Protocols for Packet Oriented Satellite Channels

Satellite systems for mobile communications will start operation in the next few years. They will support circuit switched low bandwidth channels for the transmission of speech. For the transmission of packet oriented data, these channels are not very convenient, due to the long connection set-up and release phases. Hence, a special access protocol for packet oriented data transfer is required.In this paper the analysis of a class of access protocols that combine the advantages of the pure random and reservation access schemes is presented. The analysis method is based on the iterative solution of the corresponding state equations. The results of the analysis, i.e. carried load and transfer delay, are presented for a system with 20 ground stations. The stability of the protocols is investigated and the bandwidth requirements of the combined protocols is compared to Slotted ALOHA.