Research On MAC Protocol For ITS Wireless Mesh Network Based On Smart Antenna

The Intelligent Transportation System (ITS) is the future trend of transportation modernization. The service of ITS requires wireless network equipped with high real-time performance and Quality of Service (QoS) guarantee capability. Wireless Mesh Network (WMN) becomes a support network technology which effectively meets the demand of service in ITS, with the advantages of not relying on the cable network, all-wireless, multi-hop transmission, broad coverage, easy to maintain and destruction resistance. Bandwidth is the bottleneck of the Wireless Mesh Network. The space-time signal processing based on smart antenna has become a key technology of communication system. Introducing smart antenna in the Wireless Mesh Network can largely improve the bandwidth utilization and the network’s performance.According to the demand of service in the background and the bottleneck of the network, a specific research of MAC (Media Access Control, MAC) based on the smart antenna is carried out. A comprehensive analysis in the existing wireless mesh network which based on smart antenna with Media Access Control technology is studied. Combined with the demand of QoS in the target network, the QoS guarantee mechanism of IEEE802.1 le is analyzed. In addition, paper also focused on the Head of Line Blocking problem and its solution. With the existing research results, a new optimization method based on smart antenna called HOL_DMAC is presented, by combining the DMAC and EDCA and adjusting the queue scheduling. This method increases the bandwidth utilization, solves the problem of Head of Line Blocking and guarantees the demand of QoS. At last, through the model building and simulation analysis in network simulation platform, the simulation results show that the new method is practical and worth studying.