Ordinal MDS-based localisation for wireless sensor networks

There are various applications in wireless sensor networks which require knowing the relative or actual position of the sensor nodes. Over the past few years, there have been different localisation algorithms proposed in the literature. The algorithms based on classical Multi-Dimensional Scaling (MDS) only require 3 or 4 anchor nodes and can provide higher accuracy than some other schemes. In this paper, we propose and analyse another type of MDS (called ordinal MDS) for localisation in wireless sensor networks. Ordinal MDS differs from classical MDS in that it only requires a monotonicity constraint between the shortest path distance and the Euclidean distance for each pair of nodes. We conduct simulation studies under square and C-shaped topologies with different connectivity levels and number of anchors. Results show that ordinal MDS provides a lower position estimation error than classical MDS in both hop-based and range-based scenarios.