Directed position estimation: a recursive localization approach for wireless sensor networks

The establishment of a localization system is an important task in wireless sensor networks. Due to the geographical correlation of the sensed data, location information is commonly used to name the gathered data and address nodes and regions in data dissemination protocols. In general, to estimate its location, a node needs the position information of, at least, three reference points (neighbors that know their positions). In this work, we propose a different scheme in which only two reference points are required to estimate a position. To choose between the two possible solutions of an estimate, we use the known direction of the recursion. This approach leads to a recursive localization system that works with low density networks (increasing in 40% the number of nodes with estimates in some cases), reduces the position error in almost 30%, requires 37% less processor resources to estimate a position, uses less beacon nodes, and also indicates the node position error based on its distance to the recursion origin. No GPS-enabled node is required, as the recursion origin can be used as the relative coordinate system.