Routing Graph Management for Mobility Support in Industrial Wireless Sensor Networks

The Industrial Wireless Sensor Networks (IWSNs) have been exploited in various industrial applications in order to improve the productivity and reduce the cost. Recently, today’s diverse industrial fields such as manufacturing, automotive and logistics demand the cooperation of both the static nodes and mobile nodes in order to foster better efficient industrial environment. However, the existing industrial wireless sensor networks standards have been focused on the network where consist of the static nodes only. Thus, the performance of the current standards would be reduced in the environments with mobile nodes. The movement of the mobile node causes the network changes and a path related to the mobile node would be disconnected until the network adapts to the changes. This phenomenon leads to loss of the data and the command, finally, it brings about a critical problem in the industrial environment where requires high-reliability and high-exactitude. To solve the problem, we propose the routing graph construction for minimizing of the network changes from the mobile nodes. The proposed method constructs the graph by distinguishing between the static node and the mobile node. To construct the graph, a skeleton graph constructed consists of the static nodes, and the mobile nodes are grafted on the graph. This is achieved that minimizing the effect of the network change and reduce the number of the disconnected path. The proposed method could be adapted to the various standards which exploit the graph for the routing. In this paper, we adapt the proposed method to the WirelessHART standard. Through the simulation result, we verify that the proposed method would reduce the damage of the network changes from the mobile node rather than the current WirelessHART standard.