Research And Application Of HWMP Protocol Based On The Wireless Mesh Networks

Wireless Mesh network has broad application prospects in many fields, such as family, enterprise and public places, so it has become a hot research topic at home and abroad. It is important and difficult to design a stable wireless link and efficient path selection algorithm. This paper is based on an in-depth study of HWMP protocol in H3C, and to improve the standard HWMP protocol. The main work is as follows:Path selection of wireless Mesh network module is designed. The module includes the path request module, path reply module, path error module and routing information module. In the path request module, a Timer timer is designed for periodically broadcasts a proactive PREQ message. Reply path module includes an intermediate node sent PREP and the destination node reply PREP. Path error module includes next-hop is unreachable, routing information lost and proxy information is not available. In the routing information module, we designed an AVL tree structure used to store path information. The structure defined all the variables of path information.An improved Standard HWMP protocol is presented. It was showed by the standard HWMP protocol routing update algorithm that only one next-hop can be saved by route information. By adding next-hop pointer and the number of the next-hop in the structure body to add multiple next-hop when you update the route. If the multiple optimal paths node exists, and the next-hop is unreachable, path error message is not transmitted. A support for VLAN is added, according to the port of the device to divide different VLAN, so that the communication between devices become easier.Routing module of node model is designed. Due to the OPENET is not supported HWMP protocol and improved HWMP protocol by default, therefore new function modules should be added in node model of the original simulation. In this paper, a new routing module hwmp_routing is added by the node model wlan_station_adv. According to the state transition diagram of routing module, encoding for HWMP route selection can be realized in the hwmp_routing module. Two protocols are simulated under the same simulation scenarios. Finally, through the comparison and analyzed of simulation results, the improved HWMP protocol was turned to be effective in packet delivery ratio, data transmission delay, routing overhead.