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

The authors derive the upper and the lower bounds for the mean cycle time and the mean message transmission time of class six and class four in the IEEE 802.4 token bus network, within which the minimum utilization constraint of class four is guaranteed. They also derive stability conditions for the token bus network. These bounds and stability conditions are represented in terms of the high priority token hold time, the token rotation time, the arrival rate, the total station number, etc. A parameter tuning algorithm is proposed in a partially symmetric token bus network with two classes. This algorithm maximizes the utilization of class four for a given high priority token hold time and at the same time meets the constraints of the stability condition of the network, the real time constraint, and the minimum utilization of class four