Performance analysis and parameter region for real time environment in IEEE 802.4 token bus network

The priority option of the 802.4 standard supports multiple classes of traffic by using a set of timers to control information exchange. This paper derives upper and lower bounds of the mean cycle time and the mean service time of the class 6 and 4, within which the minimum utilization constraint of the class 4 is guaranteed. Also, derived are conditions under which the token bus network is stable or unstable. This paper suggests a parameter tuning algorithm in a partially symmetric token bus network with two classes, which maximizes the token rotation time for a suitable high priority token hold time and still meets the stability condition of the network, the real time constraint and the minimum utilization constraint of the class 4.<>