Research On MAC Protocol And Clustering Algorithm For Polling Multiple Access And Random Multiple Access Hybrid In WSN

As the core technology of the Internet of Things,Wireless Sensor Network(WSN)is widely used in various fields due to its low cost,low power consumption and self-organization.However,due to its cost constraints,processing and computing power is weak and energy is limited,how to improve the network packet transmission success rate and extend the network life cycle of wireless sensor networks with limited energy is a problem that must be considered when designing the media access control(MAC)protocol.The MAC controls the allocation of the wireless channel.A good MAC protocol can improve the throughput of the network,reduce energy consumption,and have lower latency.This paper first analyzes the polling multiple access and random multiple access protocols.By transforming the Z-Stack protocol stack,the threshold service,the full service system and the random multiple access protocol are simulated on the CC2530.The results show that the method is feasible and the protocol performance index is in line with the theoretical value.Then,a hybrid MAC protocol is designed for the hierarchical network structure,combined with the polling mechanism and CSMA mechanism.The protocol uses a clustering algorithm to divide the WSN into two layers.The cluster head establishes a polling table according to the information of the members,and polls the member nodes in the order of the list to obtain channel usage rights for data transmission.The cluster head uses the CSMA mechanism to contend for the channel to transmit data to the base station.Finally,the hardware simulation of the designed hybrid MAC protocol is carried out in the WSN built by CC2530.The results show that the protocol can operate correctly and the key performance indicators are consistent with the theoretical values.Finally,in order to solve the problem of WSN energy imbalance,short working time and low throughput,a WSN clustering algorithm based on genetic clustering and hybrid MAC mechanism is proposed.When the network is initialized,all nodes report their own position coordinates to the base station,and the base station forms a cluster using the FCM optimized by the genetic algorithm(GA).In the first round,the node closest to the cluster core is selected as the cluster head.Starting from the second round,the election process refers to the remaining energy of the node,the distance from the base station,and the distance from other nodes in the cluster,and adjusts the weights of the three factors in real time according to the network status.In the data transfer phase,a hybrid MAC mechanism is used.The simulation results show that compared with LEACH and K-Means-based uniform clustering routing algorithm(KUCR)in the same network environment,the algorithm clusters more evenly,prolongs the network life cycle,and has good energy balance and higher.Throughput.