Performance assessment of a deterministic access protocol for high performance bus topology LANs

This paper describes the operation of a proposed method of access to bidirectional local area network buses-called timed packet release or TPR. The method is based on a system of time delays in the nodes, reckoned from a timing reference signal and provides collision free deterministic access for queued packets. A comparative evaluation of the performance of TPR with other methods of bidirectional bus access such as token passing and the reservation protocols is provided. Results, obtained using discrete event simulation models, are presented for the various access protocols. Performance is measured in terms of the average delay-throughput characteristics of the networks. The implementation aspects of TPR are reviewed briefly.