A range-free localization algorithm based on the velocity information for mobile sensors

In mobile sensor networks, sensor nodes are often required to move in order to complete various tasks, such as environment exploration and data collection. In these applications, the location-awareness information plays an important role. However, it is too expensive to equip each sensor node with special hardware for locating them from time to time. As a result, a distributed range-free localization scheme is very desirable in mobile sensor networks. Unlike previous work about locating mobile sensor nodes, this paper explores the static constraint set caused by the transmission range of both seed nodes and sensor nodes, and introduces the velocity constraint set caused by node movement. Specially, we have distinguished the transmission range of seed nodes and sensor nodes in order to generate strict boundaries. Once the constraint set is obtained, a numerical method is used to solve such seriously non-linear inequalities. The approach proposed in this paper is distributed and re-localizable, and performs well even when all sensor nodes are moving uncontrollably. Furthermore, we analyze the computation complexity of the proposed approach and discuss the communication protocols for seed nodes and sensor nodes respectively. Finally, we demonstrate by simulations that the proposed algorithm performs much better than existing algorithms.