Analyzing the impact of the N-policy on Quality of Service in wireless sensor networks

Energy conservation in wireless sensor networks (WSN) has gained the attention of several research efforts. Several techniques have been proposed to optimize power consumption, and hence increasing network life time, by focusing on different aspects of the functions of a single wireless sensor node such as data aggregation, efficient routing, sleep/wake scheduling, and buffer management. One of the techniques proposed to optimize power consumption in wireless sensor nodes is based on the N-policy which reduces the number of times the radio channel transitions from the off to the on state. Although the impact of the N-policy on power conservation in wireless sensor networks has been verified by several research efforts, the impact of this policy on the Quality of Service (QoS) was never investigated thoroughly especially for applications where end-to-end delay is crucial to the overall performance of the application. In this paper, we analyze the impact of the N-policy on the queuing delay for wireless sensor networks applications that are sensitive to delay. We investigate if there exists an optimal queue length N that can minimize power consumption as well as satisfy the required delay at the same time.