Decomposition approach to evaluate CSMA/CD protocol performance with asymmetric workload

A model is proposed for the analysis of a p-persistent, slotted CSMA/CD protocol on a local area network consisting of a finite population of buffered stations with different workloads. The analysis of the protocol is performed using a decomposition strategy, and considering each station as an M/G/1 queueing system. Since stations interact with each other in channel contention, the interference is modelled through the service time probability-density-function L-Transform of the queueing system. The average packet delay characteristics and the stability station behaviour are obtained; to prove the model accuracy, numerical results from both analysis and simulation are given. The influence of scheduling probability p on system stability and average packet delay are analysed. Furthermore, an assignment strategy for probability p is proposed to improve system performance with asymmetric workloads. Finally, the analysis is extended to the transmission of packet bursts on the channel.