Multi-token based MAC protocol in heterogeneous networks and time performance analysis

With the application and development of wireless network in industrial fields, Wireless network technology can be applied to control network systems at field device layer and control layer, which achieves an open hybrid wired/wireless field measure and control networks with industrial-grade reliability and real-time performance. This paper focuses on the integration architecture and performance evaluation of the industrial wired/wireless hybrid networks, and proposes synchronized optimization methods for hybrid integration by real-time gateway based on the models. Firstly, it is introduced that the conventional wireless MAC protocols cannot be directly adopted to meet the special requirements of wireless industrial control network, which is to be integrated with the existing wired system to form a hybrid industrial control networks. Then a universal conversion structure with DCM module was designed upon the OSI model. In order to assure the real time performance in the data transform between WICN and CCIN segments, Token-MAC was designed and the logical ring establishment, token recovery mechanism and the joining and exiting of ring, the frame-structure of the token were studied respectively. At last, a limit of the token-rotation time is given to provide a dynamic QoS and reduce the average response time.