A Novel PF-MAC Protocol For Wireless Sensor Network Based On Prediction And Feedback

The MAC protocols based on competition for Wireless Sensor Network (WSN) are analyzed in the paper, such as S-MAC and its improved protocols. The dominant idea of the design is in exchange for energy savings at the expense of fairness and other network performance. The design requirements of low energy consumption can be realized only in low traffic network environment, but not for high traffic load or burst data traffic network environment. Against the shortcomings and deficiency problems emerged in existing MAC protocols, this paper put forward a new MAC protocol based on S-MAC——PF-MAC (Predict and Feedback MAC).The design idea of PF-MAC mainly includes two aspects:One is the new protocol has proposed a new backoff algorithm mechanism based on prediction and feedback. It is to intercept the channel’s busy or idle status at backoff stage in each backoff slottime by sending sensor nodes. If the channel is idle, the backoff timer will be decreased until to be0; if the channel is busy, the backoff timer will be suspended and the channel occupied counter will be added1, and according them to calculate slot utilization. Then assume the whole network’s congestion level reasonable, thus the sensor node can change contention window adaptively based on update rule equation after send packets to adapt to the current network load conditions.The other is the new protocol adopts traffic adaptive techniques. It is to record the packet amounts in the sending stage by sensor nodes, according it to calculate the packet sending rate and adjust its duty cycle dynamically when synchronization cycle finished.In order to verify the PF-MAC’s efficiency, this paper implements PF-MAC protocol in NS-2compares its performance with S-MAC and IEEE802.11, moreover, by analyzed different MAC protocols which show different performances run in the same simulation network environment to further illustrate the PF-MAC protocol’s feasibility and superiority.The results of simulation shows that compared with other MAC protocols, the PF-MAC protocol can show better adaptability to the traffic load dynamically changes environment, it can improve the whole network performance effectively. In the case of same traffic load, PF-MAC protocol will get higher network throughput and lower transmission delay, which can reduce energy consumption availably and extend the energy constrained WSN’s life time.