Performance evaluation of multi-traffic on wireless sensor networks using a novel Diffserv mechanism

In this paper, we propose a novel DiffServ mechanism for multi-traffic Wireless Sensor Networks (M-WSNs) supporting real-time traffic and non-real-time traffic simultaneously. This mechanism will reduce the average transmission time of the real-time traffic and improve the transmission reliability of the non-real-time traffic when one cluster transmits its packets to the next cluster. The packets of the non-real-time traffic will be queueing at a finite buffer of the cluster to be transmitted following a First-Come First-Serve (FCFS) strategy. The packets of the real-time traffic will immediately occupy the channel between two adjacent clusters preemptively and will be transmitted without queueing if there is no other packet of realtime traffic being transmitted. A discrete-time queueing model with two classes of traffic is built with a finite cluster capacity in order to describe the working principle of the novel DiffServ mechanism. By using the method of a two-dimensional Markov chain, the formulas for the performance measures in terms of drop rate, average response time, system throughput and energy saving ratio are given. Finally, numerical results are given to demonstrate the influence of the system parameters on the system performance.