A Distributed Location Algorithm In Wireless Sensor Network

In this paper we present a scalable, distributed and range-free algorithm to the problem of localization in wireless sensor network. Accurate and distributed localization algorithms are needed for a wide variety of wireless sensor network applications, but it is too expensive to include a GPS satellite navigation system on each node in wireless sensor network. Several localization algorithms based on range measurement have been proposed, but they are not accurate enough because accurate range measurements are unavailable yet. Our localization algorithm, named RSSI Similarity Localization (RSL), computes the location in a different way. Each sensor node of unknown location estimates its location locally without the range information. First, it computes the RSSI similarity to each neighbor base sensor nodes based on the received signal-strength indication (RSSI). The similarity can be computed by the similarity function. Then each sensor node sorts the neighbor base node according to the similarity, and selects the first Kth neighbor base sensor nodes to estimate location by the weighted-center functioa The time complexity is n^2(n is the number of the neighbor base sensor node). We also provide an evaluation of our algorithm on a simulated sensor network.