| With the rapid development of the industrial Internet,wireless communication technology is increasingly needed by massive sensors,AGVs and other terminal equipment to realize more flexible and complex information interconnection.5G technology is considered as a key technical means to meet the above needs due to its efficient and flexible wireless transmission capability.In the future,some core production control services of the industrial Internet of things,such as smart factories and smart cars,not only need 5G network to provide the communication capability of URLLC scene,but also need to complete the timing service through the clock timing information provided by 5G radio access to achieve 5G-TSN time synchronization,which puts forward higher requirements for the deterministic communication capability of wireless network.It is an urgent problem to evaluate the certainty of time delay in the uncertain wireless link environment to further ensure the accuracy of clock synchronization as a support for resource scheduling.However,the current research has not considered the upper and lower boundedness of transmission delay,which cannot meet the communication requirements of high-precision clock synchronization service of the industrial Internet of Things.In addition,most of the existing research on clock synchronization is based on the complete observation of clock state variables under reliable networks.Even if there is research on the accuracy of clock synchronization under incomplete observation of state variables,the balance between the deterministic boundary guarantee of time delay and the time resource cost of 5G wireless communication is not considered.Meanwhile,in the scenario of massive Internet of Things terminal communication,the 5G-TSN network must meet the clock synchronization accuracy requirements of each terminal in the network.However,the point-to-point time service transmission of a single link for each user consumes a large amount of communication resources,resulting in a large amount of costs,which affects the transmission of other services.To solve this problem,most of the existing researches use the multicast communication mechanism of 5G network to divide users into multiple multicast subgroups,and use multicast technology to transmit service data,so as to realize flexible allocation and reuse of resources and improve resource utilization.However,it is mainly studied for the grouping mechanism of data transmission service,and it does not apply to the timing service with delay deterministic requirements.Aiming at the problem of wireless resource optimization of 5G-TSN single-link clock synchronization,this paper studies the relationship between delay determinacy and clock synchronization accuracy,and proposes a wireless resource optimization method for 5G-TSN single-link high-precision clock synchronization.Based on the deterministic delay evaluation model,the overhead of time interval protection band is effectively adjusted,and the joint optimization of system average throughput and clock synchronization accuracy is realized.Aiming at the wireless resource optimization problem of ensuring clock synchronization accuracy in 5G-TSN multiuser networks,based on the previously described clock synchronization model and the deterministic evaluation method of delay,the multicast user grouping mechanism adapted to the deterministic communication scenario of multicast networks is studied,the wireless resource optimization algorithm to ensure clock synchronization in multicast networks is designed,and the wireless resource optimization method for high-precision clock synchronization in 5G-TSN multicast networks is proposed,The joint optimization of system throughput and clock synchronization accuracy of the whole network is realized.To sum up,with the deepening and application of 5 G-TSN network in the industrial Internet,the research on resource allocation and optimization of wireless network under the constraint of clock synchronization accuracy in this paper is of great significance to fully save network resource overhead,maximize wireless resource utilization,and further improve network performance. |
