Performance Analysis of Multi-User Communication Systems: Access Methods and Protocols

Abstract

In a multi-user communication facility a set of processes (term which we use here in the sense of computer science, i.e. a “program” in execution) exchange information via a communication “channel”. Various examples of such a system can be imagined : micro-processors exchanging data via a communication bus, transceivers using a common satellite channel, several programs exchanging messages through a packet switching network, etc. The rules imposed to the processes for their use of the communication medium have a fundamental influence on the usual performance measures (throughput, response time, reliability, etc.) of interest. However, the “second level” rules which the processes apply to their dialogue are also extremely important. These second level rules, usually called protocols, are designed to insure reliable communication of processes through an imperfect communication channel, and concern essentially the communicating processes, whereas the access rules define the relationship between the processes and the physical channel.