Queueing analysis of CSMA-CD LANs with heterogeneous population of buffered users

The performance of CSMA-CD (carrier-sense multiple-access with collision detection) LANs that consist of a finite number of heterogeneous buffered users is investigated, utilizing an approximate analytic technique that is based on the coupling between the channel and the user Markov chains. Expressions are derived for the probability-generating function for queue length, the mean queue length for each user, the mean packet delay for each user, the weighted mean packet delay for the system, the channel throughput, and the condition for system stability. Numerical results from analysis and simulation are presented for a two-node network. They show that performance predictions for CSMA-CD LANs consisting of two heterogeneous users on the basis of the user homogeneity assumption tend to be overly optimistic, especially for medium to heavy network traffic