Method and apparatus for range based localization with adaptive neighborhood selection in wireless sensor networks

A location recognition method selectively using a neighbor node having fewer fault factors and a node apparatus using the same are provided to exactly recognize the location of a node by selectively using a node having less fault factors for triangulation in a sensor network. If a target node for location recognition is selected(S1001), the target node selects an anchor node having the nearest estimation distance as the initial reference node(S1002). Then the target node selects a node having the nearest estimation distance, next to the initial reference node, as a test node(S1003). Then the target node selects a representative reference node to judge whether the test node can be added as a reference node(S1004). The representative reference node estimates the distance(Rij) from the test node using RSS(Received Signal Strength) or ToA(Time of Arrival), and acquires the actual distance(Lij) from the test node using its own coordinates and the coordinates of the test node(S1005). The representative reference node obtains the absolute of "Rij - Lij" using the acquired distance information and judges whether the obtained value is within the range of an allowable error(S1006). In case the obtained value is within the range of the allowable error, the representative reference node notifies the target node of it, and also transmits the actual distance information(Lij). The target node estimates the distances(Ri) from the representative reference node and the distance(Rj) from the test node using RSS or ToA(S1008). Then the target node obtains the absolute of "Ri + Rj - Lij" and judges whether the obtained value meets a threshold(S1009). If so, the target node adds the test node as a reference node(S1010). If searching is completed for all the neighbor anchors, the target node acquires exact location information by executing triangulation using selected reference nodes(S1012).