Multi-Tier Multi-Hop Routing in Large-Scale Wireless Sensor Networks for Freight-Train Monitoring
Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Ting Zhou, Wei Wang, Tao Ma · 2010
This paper presents an overview for a multi-hop communication system onboard freight trains based on wireless sensor networks (WSNs). Because a WSN with nodes in each freight car has a linear chain-like topology of significant length, the existing IEEE 802.15.4 communication protocol, assuming a star topology, is unable to provide acceptable service. The end-to-end communication between nodes relies on individual nodes communicating with their respective neighbors to carry the information over multiple hops and deliver it to the desired destination. The routing performance and reliability degrades significantly with the increasing number of hops. The authors propose a practical solution for large-scale multi-hop wireless sensor networks in railroad environments that overcomes this problem. The authors simulation results show that our proposed multi-tier communication approach is a feasible and reliable solution for implementing chain-topology WSNs with a high number of hops onboard freight trains. The protocol, based on the IEEE 802.15.4 network stack, is implemented and tested in ns-2.