Research On Partially Overlapped Channels Assignment And Routing Metric Algorithm In Multicast Wireless Mesh Network

Wireless Mesh Networks(WMN),as one of the evolution directions of the next-generation wireless communication network,has attracted wide attention from the industry.Multicast communication is one of the key components of WMN.It can save network bandwidth,provide services for many real-time applications,and maximize the number of users of WMN services.In the research process of multicast technology,channel allocation for multicast and routing metrics are two important research parts.Through reasonable channel allocation,network capacity can be effectively improved,co-channel interference can be reduced,and network delay and packet loss rate can be reduced.Relay nodes can be reasonably selected through a routing metrics strategy to construct a multicast tree,which can further reduce links interference,maximize the number of clients accessing the WMN,and improve network quality of service.Therefore,the system capacity of the WMN network can be improved and the network interference can be reduced by designing a reasonable channel allocation strategy and constructing an effective multicast tree.This research also has certain guiding significance for the development of the next-generation wireless communication network.WMN mostly adopts IEEE 802.11b/g standard protocol.However,IEEE 802.11b/g only provides up to three Orthogonal Channels(OCs),the number of channels is difficult to meet the needs of Mesh nodes.Therefore,this paper uses Partially Overlapped Channels(POCs)to design a channel allocation strategy to further improve network performance and reduce network interference.Aiming at the problem that the current channel allocation algorithms only consider single factor to conduct channel assignment,this paper proposes the concept of local multicast,and designs a POCs channel allocation algorithm considering local multicast and forwarding weights(LMFW)comprehensively.The LMFW algorithm calculates the interference of local multicast and forwarding weight of each node,designs the weight interference function,arranges all the nodes in descending order according to interference status,and uses the heuristic algorithm to allocate POCs to nodes with larger interference.Simulation results show that the LMFW algorithm can improve network performance and reduce network interference.Traditional routing metrics are often applied to unicast communications,which ignore the impact of link load and link quality on the network.Therefore,this paper considers the two important factors and proposes a link load and link quality(LLLQ)multicast routing algorithm.The LLLQ algorithm uses the criterion of product of link load and link quality to select routing,and chooses the link with larger link load and a higher link quality to construct a multicast tree in order to maximize the number of clients,improve the overall network quality of service,reduce the number of retransmissions of data packets and improve the average network throughput.This paper extends NS-3 software to a simulation platform that supports multiple channels and multiple interfaces.Based on extended NS-3,this paper completes the performance verification of LMFW and LLLQ algorithms.Simulation results show that the proposed POCs channel allocation and routing algorithms can improve the WMN network capacity,reduce network interference and average packet loss ratio,and improve network performance.The research in this paper provides a theoretical basis for improving the WMN performance.