Abstract:To meet the coverage challenges arising in directional wireless sensor networks, this paper presents twodistributed direction optimizing algorithms and a node scheduling: enhanced greedy algorithm (EGA), equitabledirection optimization (EDO) and neighbors sensing scheduling (NSS) protocol. EGA algorithm optimizes directionmerely according to the amount of uncovered targets. It is used as the baseline for comparison. EDO adjusts thedirections of nodes to cover the critical targets superiorly and allocates sensing resource among nodes fairly tominimize the coverage differences between nodes. The utility function is introduced in EDO to assess the value of adirection contributed to overall networks sensing. The factors which affecting the utility are composed of the targetsin per direction, the coverage of targets and the neighbor’s decision of direction. EDO always selects the directionwith the maximum utility as the working direction. NSS arranges all sensors into multiple cover sets and allows anode to join several cover sets. Through employing local cover set, NSS identifies a redundant node and decideswhether it can sleep while taking residual energy to account. Nodes are activated in turn and the energy is consumedevenly to prolong the network life. The simulation shows that EDO outperforms EGA up to 30% in terms of criticalcoverage, and the combination of EDO and NSS prolongs the lifetime distinctly.