Based On Petri Net Wireless Chain Network Mac Protocols And Routing Algorithms

As the highly development of freight train, the greater demands of safety-work are requested. In this thesis, a new network named wireless chain is proposed to monitor the real-time state of overload freight train. Due to the particularity of wireless chain network, the communication protocols of wireless sensor network on which many research had been done are inappreciative for it.After a fairly study on the achievements and applications of wireless sensor network, and combined with the national 863 topic, the thesis aims at a fully design of new protocols about the MAC protocol combined with route infomation and Route protocol related, considering the design feature and multi-hop of wireless chain neiwork. The main works are as follows:First, a multi-channel MAC protocol based on the IEEE 802.11 is proposed to solve the problem of the lack of channel capacity, which united the information of MAC layer and network layer. And we make CPNtools as a tool to build the model of multi-channel MAC protocol and perform the simulation using the theory of colored petri net. Then, two methods-reachability tree and matrix equations-fully verify the CPN model.Second, considering the topology of WCN and making OLSR protocol as the basic protocol, we do two mainly changes on OLSR: modifying the format of HELLO and TC message to assign channels for MC-MAC protocol more effectively; enhancing the MPR selection to choose the suitable route rather than optimum route. We name the new route protocol EOLSR.Last, to compare the performance of MC-MAC with IEEE802.11 and EOLSR with OLSR, NS2 is used to perform the simulation of mentioned-protocol above. The result shows that MC-MAC gives a better performance than IEEE802.11, and EOLSR also turns out a higher behavior than OLSR.