Design And Implementation Of Channel Optimization Scheme In Vehicular Network

With the number of cars increasing every year,the traffic congestion problem is increasingly serious.The social efficiency of cities is challenged by frequent traffic accidents,noise and air pollution.In fact,most of the traffic accidents are due to the range of visibility,and it has been too late to dodge when they realize it.The misjudgment of the state of roads and bad driving habits are also the main cause of traffic accidents.V2X technology adopts IEEE 802.1lp standard as the basis of communication and IEEE 1609 standards as the basis of network services to form VANET,according to the characteristics of vehicular network.And both standards is defined particularly for vehicular network.V2X technology would provide tips about safety and driving through data collection and processing of direction,speed and location of a vehicle.V2X technology can solve most of traffic accidents,and can provide driving advice for drivers to improve the efficiency of driving.In this paper,the message communication part of the application layer is realized,using the information collected from GPS as safety message,considering the practical application and basic requirements of vehicle network.According to IEEE 802.11p/1609 standards and the specific function of the network hardware,the data transmission part and implementation structure of this network has been studied.And according to the channel coordination defined in IEEE 1609 standards,the real-time feedback interfaces of channel state information are realized,and used to get channel state information,so that the dynamic assignment of channel can be realized.Also the transmission interfaces of VSA frames are realized,and used to transmit channel switching information in order to realize the switching decisions of SCH.Furthermore,priority value is assigned to each packet according to its data type and the priority queue of transmission is also realized.And the priority can be changed according to the state of transmission and the real-time feedback from the underlying hardware.In the end,the implementations involved in this paper are tested,including the communication part,transmission interfaces,channel assignment and priority queue.And the results are relatively satisfactory.The throughput of WSMP packets is raised using the dynamic channel assignment.The priority queue has a better transmission performance for high-priority packets.The dynamic adjustments of priority guarantee the transmission performance of IPv6 packets.