Query Slipping Prevention for Trajectory-Based Matchmaking Service in Wireless Sensor Networks

초록

In this paper, we consider the query slipping and its prevention in wireless sensor networks. The problem happens when a query propagating along a subscribe trajectory moves through a publish trajectory without obtaining desired information, even though two trajectories intersect geometrically. There follows resubmission of the query or initiation of another subscribe trajectory. Thus, query slipping results in considerable time delay and in the worst, looping in the trajectory or query flooding the network. We address the problem formally and suggest a solution. First, the area where nodes are distributed is logically partitioned into smaller grids, and a grid-based next-hop selection algorithm is proposed. Thealgorithm not only attempts to make the trajectory straight but also considers the nodal density of recipient nodes and the seamless grid-by-grid multicast. We show that the publishing and subscribing using the algorithm eventually eliminate the possibility of the slipping. It turns out that our approach dissipates less power of neighbor nodes, compared to the non grid-based method, as greedy forwarding.