Range-free localization based on hop-count quantization in wireless sensor networks

Localization is an important research issue in Wireless Sensor Networks (WSNs). Recently, hop-count-based localization has been proposed as a cost-effective alternative to range-based localization algorithms. Traditionally, hop-counts between any pair of nodes can only take on integer values regardless of relative positions of nodes in the hop. We show that by partitioning a node´s one-hop neighbor set into three disjoint subsets according to their hop-count values, the integer hop-count can be transformed into a real number. The transformed real number hop-count is a more accurate representation of a node´s relative position than an integer-valued hop-count. The real number hop-count is then used to solve WSNs localization problems based on the MDS (multidimensional scaling) method. Simulation results show that the performance of the MDS algorithm using the real number hop-count outperforms those which use integer hop-count values.