Coverage Aware Buffer Management and Scheduling for Wireless Sensor Networks

Environmental monitoring and surveillance is a popular application of wireless sensor network. In such an application, the data transmitted are tagged with geographic information. A network with better coverage provides better quality-of-service since it will be able to monitor its area of responsibility more effectively. In this work, we study the impact of congestion on coverage of the sensor network. Congestion can negatively impact the performance since it can result in reduced coverage and power wastage. In this paper, we present a buffer management scheme called most redundant drop (MRD) and a scheduling algorithm called coverage transmit (CT) that make use of spatial information in sensor data to improve network coverage. Compared to drop-tail and FIFO, MRD and CT improve coverage by up to 75% when exact sensor location is available. Furthermore, as exact locations may not be available in practice, MRD and CT are evaluated using a modified DV-hop scheme that provides approximate localization. Simulation results show that substantial improvement can also be obtained using only approximated locations