Research Of Topology Control In Multi-interface Multi-channel Wireless Multi-hop Networks

Multi-interfaces multi-channels wireless mobile networks can improve network capacity and enhance network connectivity.Topological control mechanisms and algorithms are one of the key research issues.Because the centralized topology control method is limited by the scalability of the network scale and the vulnerability of the central control node,the distributed topology control algorithm has gradually become a research hotspot.In this paper,based on the existing MIMC multi-hop network topology control research,the node transmit power and radio station assignment channels are used as topology control methods.Distributed power control algorithms and channel assignment algorithms are designed,and a network topology control algorithm is developed.The software and its experimental system were implemented and analyzed.Firstly,using the power control method,the distributed dynamic power control algorithm that satisfies k-edge connectivity is designed.In the dynamic environment of the mobile network,this algorithm guarantees that the network is still connected after the network(k-1)links are disabled.The algorithm calculates the network connectivity dynamically,which reduces the impact of the network node mobility.Nodes exchange packets to obtain local topology information and calculate the local connectivity k.Each node executes a distributed dynamic power control algorithm to obtain a logical neighbor set that satisfies k-edge connectivity,and adjusts the node power dynamically according to link quality to ensure network k-edge connectivity.Secondly,using the channel allocation method,the robust distributed channel allocation algorithm is designed.There are multiple available interfaces and channels in the node of the wireless multi-hop MIMC network.This algorithm allocates the working channels of the node stations to avoid network segmentation caused by the unavailability of a certain channel.Each node utilizes the local logical topology information generated by the distributed dynamic power control algorithm to run a robust distributed channel allocation algorithm and assigns a radio working channel,which reduces the intra-network interference and enhances the robustness of the network.Finally,based on the Linux system,the network topology control algorithm software and its experimental system were developed.The topology control algorithm program completes functions such as network topology collection,logical topology construction,node power adjustment and radio channel allocation.In the experiment,the computer is used as a network node to build a wireless multi-hop Ad hoc network.Each node runs the distributed topology control algorithm program in the experimental system,and tests the function and performance of the topology control algorithm designed in this paper.The experimental results show that the distributed dynamic power control algorithm changes the topology structure of the network by adjusting the power of the nodes and satisfies the network k-edge connectivity.The robust distributed channel assignment algorithm compared with the interference-aware channel assignment algorithm,ensures network connectivity when a certain channel is unavailable,satisfies the network robustness,and improves network capacity compared with all nodes using the same channels.