The Research And Development Of The VANET Solution Based On IEEE802.11p/1609.x

With popularity of vehicles, frequent traffic congestions and accidents, intelligent transportation and vehicle networking technology were born at the right moment. It became a new research hotspot and was widely concerned by academia and industry. Vehicle ad-hoc network (VANET) is based on the IEEE802.11p/1609.x protocol stack. It provides wireless access to the users in a high-speed environment, so that communications between vehicles and roadside units could be smooth. VANET can notice the driver about the real-time traffic information and vehicle status out of the sight range. So the VANET has considerable practical value.This paper studies the relevant provisions of802.11p protocol and1609.x protocol and achieves a protocol-based VANET solution. After studies the differences between IEEE802.11a and IEEE802.11p, modification on the PHY layer parameters was made in the ath5k drivers. It moved the channel frequency to5.9GHz and reduced the channel bandwidth to10MHz. The paper implemented the mandatory functions ruled in IEEE1609.4, including the use of GPS module for time synchronization, channel coordination and fast channel switching.After studying the packet type classification rules in the IEEE1609.3, the paper modified the QoS controlling process, so that the packets could be pushed into different buffer queues according to the type flags before sent out. Then the packets could send out in the right channel intervals. This paper removes the filter of the bssid and the works of scan on other channels in order to avoid disconnect issue. All these would provide a comprehensive support to the IEEE1609protocols.For the verification of the platform’s functionality and performance, the paper presents the test results about throughput, latency and packet loss rate, with the help of our own test tools and other network performance test tools like "iperf’. Finally, introduce some problems and solutions of the transplanting of the platform.