Simulation And Optimization Design Of A Large-scale Time-division Multiplexing Wireless Self-organizing Network Protocol

Traditional mobile ad hoc networks are limited by technology and cost,and most of them use single-channel competitive MAC(Media Access Control)protocols.When the network scale or network load becomes large,the network performance drops sharply and it is difficult to provide QoS support.In order to meet the requirements of large-scale node simultaneous communication,maximum network throughput rate of12 Mbps,packet delivery success rate not less than 90%,and QoS support,this paper proposes a multi-channel TDMA self-organizing network protocol.The main research contents are as follows:First,by analyzing the current status of existing ad hoc network routing and MAC technology,a self-organizing network protocol that can meet the needs is proposed.In order to meet the maximum throughput of 12 Mbps,the protocol is designed to have 8frequency hopping channels,of which channel 1 is responsible for the interaction of control information and data information,and channels 2-7 are only responsible for data information interaction.The time axis is divided into time frames,and the time frames are divided into fixed time slots.In the division of the time slot structure,each node has its own service(control)time slot.The occupation of the time slot is completed through channel monitoring,time slot reservation and reservation confirmation.This design effectively limits the control information overhead.Second,in order to meet the simultaneous communication needs of large-scale nodes,a time synchronization scheme needs to be designed.Time synchronization is divided into coarse synchronization before entering the network,fine synchronization and channel period synchronization after entering the network.Since the clock of the real device is not ideal enough,time deviation will occur after running for a long time.Therefore,in the time synchronization time slot,the entire network node performs channel cycle synchronization.Third,a multi-channel time slot resource allocation algorithm is designed.The node constructs the time slot state occupancy table through time slot monitoring,and calculates the channel occupancy rate through the time slot state occupancy table to determine the reserved channel number and time slot number.And by limiting the number of time slots reserved for services of different priorities,QoS support is guaranteed.At the same time,a route application method with collision detection is designed to improve the success rate of packet delivery.This paper uses MATLAB and NS3 to simulate and test the proposed protocol.A simulation model was constructed on MATLAB,and the tests of coarse synchronization of network access,fine synchronization of network access and channel cycle synchronization were completed.A simulation model was built on NS3,and performance analysis was performed on various indicators.The design goal of the network maximum throughput rate is 12 Mbps,and the paper reached 9.2Mbps;under the static state and the network load of 20 nodes sending data at the same time,the packet delivery success rate reached more than 98%,in the mobile state,and 20 nodes at the same time Under the network load of sending data,the packet delivery success rate is over 94%;QoS service support is guaranteed,and the key indicators all meet the design requirements.