Maximal Coverage Scheduling in Randomly Deployed Directional Sensor Networks
Unlike traditional omni-directional sensors that always have an omni-angle of sensing range, directional sensors may be able to switch to several directions and each direction has a limited angle of sensing range. Area coverage is still an essential issue in a directional sensor network which consists of a number of directional sensors. In this paper, we study a novel "area coverage by directional sensors" problem. We propose the maximum directional area coverage (MDAC) problem to maximize covered area by scheduling the working directions of the sensors in the network. We prove the MDAC to be NP-complete and propose one distributed scheduling algorithm for the MDAC. Simulation results are also presented to demonstrate the performance of the proposed algorithm.
This paper develops necessary and sufficient conditions for analyzing the schedulability of fixed priority algorithms on resources with limited priority levels. We introduce the degree of schedulable saturation (S/sub max/) as an objective function. A multimedia task set is used to demonstrate how S/sub max/ can be used to optimize the grouping of tasks to priority levels. >