Research On MAC Protocol Based On Collision Length Control In Ad Hoc Networks

With the advent of the 5G era,the Internet has also entered a period of rapid development,and the civilianization and commercialization of Ad Hoc networks are also increasing.Therefore,whether it is in the military or civilian fields,Ad Hoc networks have great development prospects.The access protocol of the communication channel is the most basic transmission of the network system.Therefore,how to develop or improve the channel access protocol of the Ad Hoc network to improve the throughput and channel utilization of the system and reduce the collision rate and delay of the system under high load conditions are the current research focus of domestic and foreign scholars.However,multiple access communication technology is a hot issue in modern communication research.The traditional carrier-sensing multiple access protocol is used in the transmission control of Ad Hoc network systems and to solve the energy consumption problem.This paper proposes three CSMA protocols with variable collision duration: P-detection CSMA protocol with variable collision duration,and two-dimensional probability detection CSMA protocol with variable collision duration,three-dimensional probability detection CSMA protocol with variable collision duration.The protocol proposed in this paper is mainly aimed at the improvement of the traditional CSMA protocol.Based on the dual-slot model,the concept of collision duration(b)is proposed,which divides the time slot of the system into the duration of successful information packet transmission(1+a),The collision time(b+a)and the time the system is in the idle state(a)of the three-slot model.Through the analysis of the model,the throughput,collision rate,idle rate and delay of the system are obtained.The collision time slot length(b)to reduce the loss of the system.According to different time slot states and the arrival rate of information packets,different sending probabilities are set to achieve the purpose of adaptive sending probabilities.This method effectively reduces the collision probability of information packets under high load conditions,and effectively improves the utilization of channel resources.Compared with the traditional carrier-sensing multiple access protocol,it has been improved.Based on the battery model,the life time(T)of the obtained system node has increased.In addition,according to the multi-service types of users,the multi-priority and multi-channel technologies are divided to realize the multi-user and multi-service type requirements in the Ad Hoc network.Finally,a CSMA hardware system based on programmable logic gate array(FPGA)is designed according to the protocol principle to improve the reliability of Ad Hoc network transmission.The experimental simulation verifies the accuracy of the theoretical derivation.FPGA is a hardware circuit design method.In this paper,combined with FPGA top-down design principles,a CSMA hardware system based on programmable logic gate array(FPGA)is designed according to the protocol principle,and the theoretical mathematical model is reflected the modular hardware circuitis used to improve the reliability of Ad Hoc network transmission.In this paper,Matlab and Quartus II are used as experimental platforms,and the accuracy of theoretical derivation is verified through experimental simulation.