The Design And Implementation Of A Mesh Network MAC Protocol Based On FPGA

Wireless Mesh Network is a new type of wireless network technology, which is completely different from traditional wireless network. Wireless Mesh Network has the advantages of high speed and high frequency spectrum efficiency, which is based on mutual cooperation and coordination of numerous access point that show network distribution. It has been widely used in the construction of the wireless city, the military and the campus network. MAC of Wireless Mesh Network is mainly responsible for network access, resource scheduling and business data processing and so on.The content of this thesis come from the research of the “The Design of Surface Broadband Mesh Mobile Communication Network and the Development of the Demonstration System”, which is cooperative project of the laboratory and some research institute. The aim of the project is to design and implement a wireless mesh network demonstration system based on the theory of mesh network. Relatively stable sea surface environment, the project is to carry out a large number of business data transmission with fast and stable time slot scheduling.According to the requirements of the subject, the protocol of IEEE802.16 Mesh networks MAC layer is researched and analyzed, including protocol stack architecture, frame structure, time slot scheduling mechanism, network access and synchronization process and MAC PDU in depth. On this basis, the design of scheduling was improved according to requirement of stable delay. At the same time, with the change of the scheduling algorithm, the frame structure is changed correspondingly. Join the redesign of the algorithm in the network and synchronization process. The design of MAC Protocol Data Unit format is based on the business type of the system. Based on Micro Blaze of Xilinx FPGA, this thesis achieved specific protocol according to the protocol scheme. This thesisr introduced the overall system architecture of MAC protocol. At the same time, the hardware circuit diagram of the MAC layer protocol system and the list of the IP core resource used by the underlying hardware platform are presented. Then, the public variable are described for recording the running status of the nodes and the connectivity of the whole network nodes.The data storage area is described. Next, according to the idea of modular, the whole system is divided into seven functional subsystems, including data processing subsystem, and the host computer interaction subsystem, network and synchronization subsystem, routing and forwarding subsystem, resource scheduling system, time-based maintenance subsystem and list update subsystem. Each function subsystem is described in detail. On the basis of the entire mesh network protocol, MAC layer transfers data to application layer. Application layer at the PC end prints data, with the help of Mesh network application layer software display interface. Verification and analysis of the MAC function is completed. Some information is transmitted to the application layer and is printed. The MAC layer function is analyzed with the printed results. After analysis, it is proved that the system is running well and can realize the network nodes access and synchronization and slot scheduling and service data transmission function.Scheduling strategy is an important measure to guarantee the quality of service. Then we can study and implement the part of the system, which is measure to improve the performance of the system.