Implementation And Optimization Of Routing And Communication Scheduling For Indus-trial Wireless Networks

Industrial wireless networks (IWN) have been widely used in the field of industrial automation monitoring and process control due to the advantages in low allocation cost and easy-maintainance. The thesis analyzes the practical requirements of IWN and studies critical technologies of routing management and communication scheduling based on WirelessHART protocol. Network route managing and scheduling methods are proposed seperately and then demonstrated by both simulation analysis and experimental tests. The main contributions of this thesis are as follow:A multi-path graph routing method based on network status is designed in accordance with the need of reliable transmissions in IWN. Two routing algorithms are adopted depending on the status of network. The first algorithm is a local adjusting algorithm for continuous network topology changes, which responds to adjustment of related links and avoids overall changes. The second algorithm is a load-balancing routing algorithm for stable network topologies. The (?)lation results show that our method could achieve the goal of both reliability transmission and load balance.Further, a communication scheduling method based on channel-first searching is designed (?) meet the practical demands of industrial wireless network. A slot-reserved scheduling strategy is designed for links of high priorities, which can avoid the scheduling delay caused by data transmissions of lower priorities occupying continuous slots. A superframe stiching strategy is designed to deal with the compatibility problem of different data refresh rates by using fixed length superframes. Simulation analysis shows that the designed slot-reserved scheduling strategy can be used to guarantee the realtime performance of important links. Besides, the designed scheduling method is implemented on embedded platform, and related communication scheduling services are verified to demonstrate the viability of the designed method.Finally, Extremal Dynamics Optimization is applied to solve joint routing and link scheduling problem. An integer linear programming (ILP) problem is presented which meets the characteristics and needs of network by taking real-time performance and lifetime as objectives. The thesis proposes and uses a technique based on extermal optimization by designing the fitness assignment strategy, mutation rules and operating process. Numerical results show that our method provides optimal objectives quickly and efficiently which are extending the network lifetime and reducing data latency. In addition, the trade-off between energy consumption and delay is presented and the networks can be flexibly configured according to the specific performance needs.