A Token-based MAC oriented Wireless Industrial Control Networks

After introducing the features and requirements in an industrial control networks, the properties of several wireless media access control protocols such as MACA, MACAW, IEEE802.il and WTRP are analyzed. An innovative MAC protocol based on token control is proposed to suit the requirements of WICN (Wireless Industrial Control Network). Logical ring under wireless link is defined; mechanisms of token resuming, joining and exiting of stations are introduced respectively. Then a simulation model has been made to compare the protocol with 802.11 upon OMNeT++ concrete event simulation platform. The results demonstrate that the throughput in the proposed protocol is ca.50% higher than CSMA/CA and has a smaller transmission delay. The protocol ensures the impartiality of channel medium access; reduces the transmitting delay of data and meets the time requirement of WICN.