Data link control in the LEO satellite store and forward network

This paper describes the design and analysis of a simplified data link control protocol for a low earth satellite network. The generic HDLC protocol affords a means of peer-to-peer communication. In our case the satellite payload initiates, controls and terminates all communication sequences between the user terminal and the satellite payload. Since resources are severely restricted on a micro satellite, the focus of the study is to assess the efficiency of the service in terms of the effective throughput, and the maximum number of users who can be served. The major change in the adopted protocol is the reduction in number of responses in both the random access and the connected modes. This reduces the handshake time needed, which is of prime importance as round trip delay increases. The inherent unreliability of a satellite (long distance wireless) link have been analysed and handled by reduction in number of types of frames, piggybacking critical information and simplified error handling.