ELHFR: A graph routing in industrial wireless mesh network

Graph routing is proposed in wireless HART communication foundation, but the implementing of the algorithm is not specified. This paper proposes a graph routing mechanism termed ELHFR (exhenced least-hop first routing) that exploits the mesh topology and application characteristics of wireless HART. ELHFR defines the network topology as a connected graph then generates the sub-graph that includes all the shortest paths from a node to the given destination. ELHFR does not need find the shortest paths of all nodes in the network, but only of the special nodes that are leaves of a breadth first tree. After several sub-graphs of topology graph are generated, the shortest paths to the destination of ever node can be found in them. The routing generating algorithm is presented in detail, as well as the routing updating mechanism. We analyze the ELFHR to provide intuitive understanding of its performance, and simulate it in OMNet++ subsequently. The simulation result shows that significant improvement over AODV routing in aspects of reliability and stability, which are the important requirements of industrial wireless network.