CAMS: Consensus-Based Anchor-Node Management Scheme for Train Localisation

Train localisation is important to railway safety. Using Wireless Sensor Networks WSNs in train localisation is a robust and cost effective way. A WSN-based train localisation system contains anchor nodes that are deployed along railway tracks and have known geographic coordinates. However, anchor nodes along the railway tracks are prone to hardware and software deterioration such as battery outage, thermal effects, and dislocation. Such problems have negative impacts on the accuracy of WSN-based localisation systems. In order to reduce these negative impacts, this paper proposes a novel Consensus-based Anchor-node Management Scheme CAMS for WSN-based localisation systems. CAMS can assist WSN-based localisation systems to exclude the input from the faulty anchor nodes and eliminate them from the system. The nodes update each other about their opinions on other neighbours. Each node uses the opinions to develop consensus and mark faulty nodes. It can also report the system information such as signal path loss. Moreover, in CAMS, anchor nodes can be re-calibrated to verify their geographic coordinates. In summary, CAMS plays a vital role in the life of the WSN-based localisation systems and in their ability to accurately estimate the train location. We have evaluated CAMS with simulations and analysed its performance based on real data collected from field experiments. To the best of our knowledge, CAMS is the first protocol that uses consensus-based approach to manage anchor nodes in train localisation.