Design And Simulated Implementation Of Energy-aware Multi-path Routing Mechanism For Industrial Wireless Networks

Wireless technologies can bring many benefits to industrial control and measure system as compared to traditional solutions. In the wireless industrial networks, due to the adverse properties of the radio channel and the constrained resources of wireless node, the existing routing mechanisms in wireless networks can not satisfy the stringent requirement of industrial applications on reliability, timing and energy-efficiency. Therefore, routing mechanism oriented to industrial wireless networks has been identified as a promising and interesting research topic.In this thesis, an energy-aware multi-path routing mechanism for industrial wireless networks is designed. The energy-aware scheme is a joint consideration of energy-balance and energy-efficiency, and the multi-path scheme is designed to achieve timely and reliable transmission of data packet. Further more, the quality of the error-prone channel in industrial environments can be measured through online link quality estimator, which provides realtime and accurate information for data forwarding process. In addition, the transmission power can be adjusted adaptively according to the link quality, while low transmission power means low energy consumption. Not the exactly hop count but the expected transmission count is adopted as the routing metric, which leads to reliable transmission. The data forwarding process also takes the residual energy of a node into account, which improves the energy-balance. All of the metrics mentioned above, including the link quality, the transmission power, the expected transmission count and the residual energy of a node, are stored in the routing table, which will be make use of by the routing process. The multi-path forwarding process for data packet treats the realtime packet and the non-realtime packet differently. For realtime packet, the parallel multi-path forwarding strategy is adopted. In order to guarantee the reliable transmission and reduce energy consumption at the same time, the obtained multiple paths include only one major path and other minor paths. Non-realtime packet is forwarded in the backup multi-path way, in which reliability and energy-efficiency can be achieved simultaneously.The routing mechanism described above is implemented and the performance is evaluated with OMNeT++simulator. Compared with the existing routing mechanisms, the designed mechanism in this thesis can not only achieve reliable data transmission with low energy consumption and low latency but also prolong the network lifetime.