Longer life time is the primary goal of interest in Wireless Sensor Networks (WSNs). Communication dominates the power consumption among all the activities in WSNs. The classical sleep and wake up scheduling scheme at the application layer is believed to be one of the best power saving schemes for dense WSNs. These schemes reduce redundant transmissions, and as a result, prolong the network life time. This chapter analyzes the effect of density on inter cluster and intra cluster communication and evaluates a hybrid cross layer scheduling schemes to enhance the life time of the WSNs. In the conventional scheduling schemes at the application layer, all the nodes whose area are covered by their neighbors are put to sleep in order to prolong the life time of the WSNs. The hybrid cross layer scheme in this chapter suggests that instead of putting the redundant nodes to sleep if they are used for some other energy intensive tasks, for example the use of redundant nodes as relay stations in inter cluster communication, will be more energy efficient compare to the conventional application layer scheduling schemes in WSNs. Performance studies in the chapter indicate that the proposed communication strategy is more energy efficient than the conventional communication strategies that employ the sleep/wake up pattern at application layer.
Cross-Layer Analysis of the End-to-End Delay Distribution in Wireless Sensor Networks
