Saturation Performance of Predictive p-CSMA without Collision Detection

摘要

The approach presented in the paper deals with the analytical evaluation of the performance of predictive p-CSMA with no collision detection under saturation conditions, when all the nodes have always packets to send. Predictive p-CSM4 employed in the MAC sublayer of LonTalk/EIA 709.1 protocol is the heart of communication capability of LonWorks networks. It is displayed that the behavior of the protocol with no collision detection is quite different from that if the collision detection is enabled. We present the analytical study of evaluation of the saturation window using a Markov model. It is shown that the saturation window does not depend on the number of nodes, but on the structure of the traffic broadcasted to the network. The stationary distribution of backlog stages is exponential and asymmetric with respect to the backlog mean value.