Multi-radio Multi-channel Ad Hoc Networks Channel Assignment Technology Based On CSMA/CA

As a typical wireless network,Wireless Ad hoc networks are widely used in real life because of its advantages such as centerless and self-organizing.In the traditional Ad hoc networks,the radio interface on the node and the channel in the network are both single,which not only limits the expansion of the network,but also generates lots of co-channel interference seriously affecting the network performance.The Multi-Radio Multi-Channel(MRMC)Ad hoc network can solve many problems of traditional Ad hoc networks.The use of multiple channels enriches the channel resources,and the configuration of multiple radio interfaces enables the orthogonal channels to be fully utilized.The MRMC Ad hoc networks can not only reduce the co-channel interference,but also minimize the hidden terminals and exposed terminals.to improve the network performance.The maim content of this paper is the research of MRMC Ad hoc networks.Based on CSMA/CA,we proved that the MRMC network mode can effectively improve channel throughput.And a throughput calculation suitable for MRMC network is derived.Finally,a high-priority minimum interference channel assignment algorithm is designed for MRMC Ad hoc networks,and its effectiveness is proved.The main work and innovations of this paper are as follows:Firstly,combining with the scenarios in which multiple nodes compete for the same channel at the same time according to the basic mode and RTS/CTS mode in CSMA/CA respectively,the single-radio configuration and multi-radio configuration method in the Ad hoc network are both studied.By comparing the simulation results,it is proved that the MRMC configuration can effectively improve the channel throughput in Ad hoc networks.This also illustrates the practical significance of studying the MRMC Ad hoc networks.Secondly,the throughput performance of the MRMC Ad hoc networks is studied based on CSMA/CA.According to the simulation results of channel throughput in the scenario where multiple nodes compete to access the same channel,it is concluded that there is a deterministic relationship between both channel throughput and the number of competing nodes and channel transmission rate.Combined with the network structure of MRMC Ad hoc network,a new method for calculating the throughput of MRMC network is deduced,and this method is applied to evaluate the performance of channel assignment algorithm.Thirdly,a new channel assignment algorithm is designed based on the network connectivity graph and the conflict graph.The algorithm can ensure that effective links are formed between nodes in the communication range of each other.In the channel assignment process,we fully consider the different environment of each node and link,and prioritize nodes and links according to their interference probability.The channel assignment of nodes and links according to the priority order ensures fairness of nodes and links located in different environments,so that they can allocate optimal channels.Simulation experiments show that the proposed algorithm has 69.94%improvement over traditional single-radio single-channel network in reducing the number of network collisions,and 14.12%advantage over the classical channel assignment algorithm.In terms of throughput performance,the simulation results show that the proposed algorithm can significantly improve the throughput performance of the Ad hoc network.Finally,the paper also explores the relationship between MRMC network performance and network scale,and draws effective conclusions to further study the network saturation.