The Research And Optimization Of Time Synchronization Based On Mobile Communication Network

Time synchronization technology refers to a technology that a network node or a terminal device can get the standard time through the network variously,and then the local time of the node or the terminal device is synchronized with the precision standard time.The time synchronization technology based on mobile communication network is attracted the attention of global peers.It becomes a hotspot because it is a supplement and filling of the existing Global Navigation Satellite System.Compared with the Global Navigation Satellite System,the time synchronization technology based on mobile communication network can provide service in some,areas with high speed and low cost and it can reach the millisecond level.Meanwhile,the Internet of Vehicles,Virtual Reality and industrial Internet of Things require high-precision time and they are mostly developed with the dependency of mobile networks.Therefore,this article separately improves the synchronization accuracy of user equipments from the aspects of IEEE 1588 the precision time protocol(PTP)and the use of the time signal in the New Radio(NR).This paper proposed an algorithm based on queuing network to improve the accuracy of time synchronization of PTP protocol in the scenario of mobile network.Firstly,the prior data is collected through different network traffic and then the Poisson distribution property,Bayes formula and other Probability theory are used to classify the network traffic into the different prior data.Moreover,the Poisson estimator calculates the highest probability of the combination of two path delays of both upstream and downstream links.Finally,the PTP slave clock can finish the communication of PTP protocol and complete the time compensation.The simulation results show that compared with Kalman filter,PTP linear processor and optimal minimax estimator,the Poisson estimator decrease the error of clock phase and ensure the stability of clock frequency significantly.This paper proposes an algorithm based on the existing NR physical signals and geographical position measurement in the scenario of radio access network.When the user equipment is synchronized with base station,the time is divided into two parts:absolute time and path delay.For absolute time,the base station sends the System Information Block Type 16 signal to the UE with absolute standard time periodically.Meanwhile,for the path delay,Timing Advance measurement and geographical position measurement are considered.The simulation results show that the proposed algorithm about calculating the path delay and the synchronization mechanism can improve the time accuracy of user equipment effectively.