The Design And Implement Of A TDMA Protocol And Acceleration Forwarding In Wireless Ad Hoc Networks

As a non-center network, Wireless Ad hoc Networks is more widely used now. The service transmitted also evolved from low rate message to multimedia applications. The Qo S designed for the Internet isn’t suitable for Ad hoc Network because the network protocols and algorithms should be designed according to specific situations.TDMA protocol has a good throughput performance in a heavy load network; as a result, it has become a hot research direction. In addition, the technique to reduce the transmission delay of multimedia services in a multi-hop Wireless Ad hoc Network is also very important.Based on the hardware platform(ARM + FPGA + n RF24L01), We design a MANETs demo platform which can support the transmission of multimedia services. First of all, this paper briefly describes the research status of MAC Protocol and the Qo S requirement. Some packet scheduling algorithms and their advantages and disadvantages are analyzed. Then, according to the specific problem, the paper designs a TDMA protocol and its implement on FPGA, including frame design, open-loop synchronization, closed-loop synchronization and topology adaptation. Meanwhile, in order to improve the network Qo S capabilities further, we design and implement Ad Hoc Accelerating(AAF) algorithm, greatly reducing the packet forwarding delay.In order to enhance the communication quality of voice and other multimedia services, we design a Qo S guarantee technology based on different services classification. After introduce several indicators concerned in packet scheduling, a WRR scheduling algorithm is used to enhance the performance of multi-hop voice transmission with other services transmitted at the same time. Based on RED, a queue management strategy is designed to avoid a global network synchronization problem. In fact, combined with TCP protocol, the system can avoid congestion.Also, the paper gives a detailed description of hardware platform and makes a lot of test including communication distance, transmission rate, power consumption, voice transmission performance testing and network test(packet loss rate, throughput, etc.).At last, a variety of test data were conducted, and the results illustrated that the new scheme can improve the performance of the system.