Traffic Information System Based On Wireless MESH Network

With the introduction and implementation of the national new plan,the number of urban motor vehicles has been gradually improved,and the existing traffic lights information system has put forward higher requirements.The traditional traffic light information system has the problem of signal cycle fixed,the decision algorithm is simple,the lack of awareness of road traffic information,these problems restrict the development of traffic lights information system to the intelligent direction.In the country"Internet plus" strategy under the guidance of the application of network technology in traffic information system optimization is an important topic.Based on this,this paper proposes a traffic light information system based on wireless MESH network.Firstly,this paper introduces the principle,key parameters and existing problems of traffic light information system,and then puts forward the traffic light information system based on wireless MESH network.Secondly,the problem of BATMAN routing protocol is studied and the corresponding improvement is made.The MESH network is composed of a wireless controller AC and a traffic light node(MESH node),where in the wireless controller AC controls and manages the traffic light nodes in the MESH network,and they can communicate with each other.When a node failure,the other nodes in the network can automatically find and initiate the establishment of multi hop wireless connection,and continue to carry out information transmission.This paper is to optimize the MESH routing protocol in the BATMAN routing protocol,which is to improve the detection packet structure and content of the neighbor node declaration process.There are two key technology of the improved:one is probed in the Batman protocol packet OGM to add a domain VN,for characterization of the source node local conversion table of changes of the judgment domain VN can be of value to determine whether a change in the source node information;the second is in the update step,setting a detection packet OGM carry only domain of VN value,need to update the node of MAC addresses and routing information.According to the improved scheme,the hardware implementation scheme based on MT7620A is proposed.The wireless router is widely used in the world,wireless router SOC single chip solutions has many advantages,has stable performance,low cost and reliable scheme.In addition,it also can be used for wireless mesh network,and advantage by the market welcome.MTK wireless router single chip with its outstanding performance,stable performance and low price has been received by the market.The wireless router single chip solution scheme and traffic lights control system combined,realize the communication between different junctions,improve the automation and intelligence of the traffic light system,so that the traffic light system is more flexible and reliable.Finally,the test environment is set up to get the test results.The test results show that the performance of the traffic light information system based on wireless MESH network is obviously better than that of the traditional traffic light information system.But there are some areas that need to be improved,with the following:(1)Continue to change the decision-making mechanism,in view of the factors that affect the decision to optimize the particle size of the algorithm to participate in decision-making algorithm,making the operation model more in line with the actual situation.(2)To improve the channel allocation of wireless MESH network,to solve the problem of channel congestion caused by traffic signal lamp node using 2.4G band.(3)Reduce the overhead of OGM message transmission,reduce the traffic signal lamp node maintenance link state information,and maintain the cost of routing information(4)Enhance network security,using block cipher or stream cipher to encrypt the network payload.