Position estimation for wireless sensor networks

In wireless sensor networks, estimating nodal positions is important for routing efficiency and location-based services. Traditional techniques based on precise measurements are often expensive and power-inefficient, while approaches based on landmarks often require bandwidth-inefficient flooding and hence are not scalable for large networks. In this paper, we propose and investigate a cost-effective and distributed algorithm to accurately estimate nodal positions for wireless sensor networks. In our algorithm, a node only needs to identify and exchange information with a certain number of neighbors (around 30) in its proximity in order to estimate its relative nodal position accurately. For location-identification, only a small number of nodes (around 10) are needed to have additional GPS capabilities to accurately estimate the absolute position of every node in the network. Our algorithm is shown to have fast convergence with low estimation error, even for large networks.