Research And Implemention Of WMN MAC Sublayer

Unlike the tranditional wireless network, Wireless Mesh Network (WMN) is a centerless, self-organizing, distributed wireless network. At the begining, the technology of WMN is used to solve the problem of "Last-mile", but because of the advantages of multi-hop, flexible structure, low cost and so on, the technology of WMN has been used in the future mobile communication network system, such as LTE. Based on the research of MAC sublayer, the paper designd a set of MAC sublayer protocol in "Special carrying TD-LTE access gateway", and realizes it with the software defined radio baseband chip SB3500.Firstly, the paper introduces WMN from four aspects:the background and research status of WMN, the architecture and definition of WMN, characteristics of WMN and the application scenarios of WMN. Secondly, the paper does research on the MAC protocol of WMN and Ad hoc, and introduces the superframe, MAC frame, the prioritized contention access (PCA) and the distributed reservation protocol (DRP). Then, the paper analyzes some mechanisms of MAC sublayer in detail, containing the RTS/CTS handshake mechanism, ACK mechanism, synchronization mechanism, PCA mechanism and so on.Based on the analysis of MAC sublayer, WMN MAC sublayer protocol is implemented with the software defined radio baseband chip SB3500. The MAC sublayer protocol is designed for seven modulars, which are the MAC scheduler, the management module, the beacon/command frame processing module, the control frame processing module, the frame processing module of the interface between MAC layer and PHY layer (MPI), the interface between the MAC upper and the lower layer, and the interface of the MPI. After the realization of MAC sublayer, combined with MAC upper layer and PHY layer, realizes the WMN module, and shows the result.Finally, in view of the requirement of the energy consumption in WMN, this paper puts forward a energy-saving nodes election algorithm adapting to the WMN module. Under the consideration of the energy-saving parameters, referring to some achievements of graph theory, the algorithm selects the backbone node as the agent of the network, and the energy-saving nodes can be dormant, which can reduce the energy consumption of the whole network. Taking the methods of NS2+MATLAB, the energy saving algorithm is realized and it has good energy saving effect in WMN module, well prepared for the energy saving implementation in WMN module.