Research And Simulation Of Schedule Algorithm In Time Sensitive Networking

With the rapid development of mobile Internet,mobile data services have grown exponentially.The fifth generation mobile network has greatly increased the transmission rate while increased the distance of fronthaul and improved the delay and jitter requirements of the network transmission.In order to optimize the deployment cost and transmission performance of fronthaul,the industry is trying to introduce the time sensitive network into fronthaul.Combine with the wide application and easy deployment of Ethernet,it simplifies the deployment process and reduces the costs and difficulty of maintenance of fronthaul equipment,while solving the transmission difficulties such as delay,jitter and synchronization in fronthaul.However,when the existing technology is applied to the fronthaul,it will cause a large jitter in transmission which is affected by the factors such as the fluctuation of flow transmission in the network and the error of the clock synchronization.This dissertation explored the time-sensitive networking for fronthaul,researched the schedule algorithms in the time-sensitive networks.Based on the analysis of the existing scheduling algorithms,it has clarified the existing problems when time-sensitive networks were applied to fronthaul.On the basis of the conclusions,it proposesd an asynchronous schedule algorithm which is called Deterministic Transmittable Time Based Asynchronous Scheduler.The DTT-BAS provides a traffic-type and traffic-source classified scheduling based on the deterministic transmittable timestamp mechanism and the queue selection and maintenance algorithms,so as to provide a stable and efficient transmission guarantee for the high-priority flows in the network,solve the influence of jitter which caused by the uncertain transmission and uncertain exchange of streams,and the inaccuracy of clock synchronization between network devices.This dissertation has also proposed a time-sensitive networking simulation platform,elaborate the design and implementation of the simulation platform that supports the time-sensitive networking.Through the realization of simulation platform,it supports the simulation of scheduling algorithm such as frame preemption in time-sensitive network.The simulation results of DTT-BAS show that compared with the existing scheduling algorithms,DTT-BAS can provide a well jitter performance which is significantly better than the existing scheduling solution based on providing a slightly worst delay.In order to analyze the scheduling algorithm,this dissertation has designed and implemented network simulator that supports the simulation of time sensitive networking,which is called TSN-NS.TSN-NS supports the simulation of scheduling algorithm such as frame preemption in time-sensitive network,to make up the gap of time-sensitive network simulation tools and provide a simulation analysis tool for DTT-BAS.The simulation results have shown that DTT-BAS can provide jitter performance that is significantly better than the existing scheduling algorithm based on providing low delay.