A Novel Proximity-Based Range-Free Positioning Algorithm for Wireless Sensor Network Nodes

This paper aims to reduce the estimated distance error (EDE) and location error (LE) of hop-based range-free node positioning algorithms. For this purpose, a novel range free positioning algorithm was proposed based on proximity, denoted as PNN-MAP. First, the proximity was introduced to express the distance between neighbouring nodes and the proximity expression was derived based on the geometric relationship between these nodes. Then, the estimated distance was calculated by the proximity expression and relevant information of anchor nodes, and the unknown node positions were estimated by the MDS-MAP to reduce the LE. Later, the PNN-MAP algorithm was simulated and compared to three other node positioning algorithms. The results show that the proposed algorithm achieved the smallest EDE and LE at different communication radiuses or different number of anchor nodes. In terms of energy consumption, the PNN-MAP had a relatively high traffic volume. However, there is no requirement on the calculation ability of network nodes, and the estimated node positions can be displayed directly on the server after the positioning. In general, the PNN-MAP enjoys a strong practicality and universality. This research promotes the application of wireless sensor networks (WSNs).