Analysis Of IEEE802.16 MAC Layer Protocol And Design Of Bandwidth Request Algorithm In Mesh Mode

In the 1990s, the technology of BWA develops rapidly, because of the absence of global uniform standard, related market has not been extended. Under this circumsrance, WMAN is proposed which meets the increasing demand of BWA market. Meanwhile, the established IEEE802.16 workgroup draws the global uniform standard in order to resolve "the last kilometer" access problem in WMAN. The distinguished characteristics of wireless mesh network, such as self-organize, mobile and multi-hop routing bring a prominent future of its broad application in civil and army. In mesh network, because no central control entity manages and distributes the global resource, a distributed mechanism to correspond the node accessing is proposed. IEEE802.16 standard defines the MAC layer basic access control protocol in both PMP and mesh mode, but the bandwidth request and distribute algorithm in mesh mode is half-baked, which brings wider research space.First, this paper briefly introduces the background of IEEE802.16 standard, standard course and the meaning of MAC layer research in mesh mode. Then from the point of its function and defined protocol framework of IEEE802.16, the basic function of each sublayer is introduced, including the PUD formation and transmission, scheduling mechanism and contention resolved mechanism in PMP mode of common part sublayer. Second, this paper introduces network access process in mesh mode in detail, analyzes multi-point access methods at present, and points out the advantages of multi-point access in mesh mode. Finally, research scheduling and bandwidth preserved algorithm in mesh mode, design the scheme of scheduling resolved in mesh mode. It has advantages in priority of real-time service and fairness between each class of service.