A SDP Approach for Range-Free Localization in Wireless Sensor Networks

Location awareness is of great importance for many wireless sensor network applications. However, it is too expensive to equip all nodes with GPS receivers or configure the location for each node manually. Consequently, many localization methods have been proposed. While most of them are range-based, we propose a range-free localization method, which is based on semidefinite programming. The method can be not only used for relative localization but also for absolute localization. Extensive simulations have been conducted. The results show that 1) the method performs better with fewer anchors, especially for relatively uniform networks of high connectivity level, and 2) the method is more robust to anchor placement, as compared to the popular MDS-MAP method which is based on multidimensional scaling(MDS) technique. Moreover, the method can intrinsically keep the proximity of neighbor nodes, whether the network is regular or not.