Improving the priority service provided in a token ring with the new ring/bus protocol

The authors propose a novel ring/bus protocol which may be implemented normally with a substantially lower average nodal delay than the IEEE 802.5 token ring. In this scheme, the nodal delay is usually zero except under special loading/access conditions. This also allows service to multiple priority classes of users but does not require a priority reservation approach. The authors present a brief description and analysis of the multi-priority ring/bus protocol and compare its performance with that of the IEEE 802.5 token ring for service to multiple priority classes of users. The performance of the new system has been shown to be significantly better in terms of lower average packet delays and a better priority service. The proposed system does show an unfairness problem for very asymmetrically loaded systems