Performance analysis of multiple-packet messages in uni-directional bus networks

A slotted p_i-persistent protocol and the effects of random message length are considered. Since the length of messages is not fixed, a message is divided into a number of equal-size packets such that a packet can fit into one slot. The utilization of the network degrades because of the increasing transmission overhead owing to excess packet headers and a possible empty portion in the last packet of any message. Furthermore, the increasing ratio of message-to-packet length increases the interdependence among the nodes and thus affects the bus access probabilities. An analytical model is presented to determine the upper and lower bounds to the access probabilities. Due to the complexity of this problem, only two nodes are considered. Simulation results showing average queue length performance versus different message statistics are also presented