Research On Flow Scheduling Strategy Of Wired And Wireless Converged Satellite Time Sensitive Network

With the increasing complexity of space communication tasks and the continuous emergence of time-sensitive services,new demands are put forward for information transmission.On the one hand requires high bandwidth,reliability and real-time of the satellite system;on the other hand,inter-satellite communication through wireless link networking should also have low latency and high reliability.However,there is a big difference between the wired link inside the satellite and wireless link between the satellites.When the business data are transmitted jointly by the cable link within the satellite and the inter-satellite wireless link,it is easy to cause node congestion,and thus cannot guarantee the real-time transmission of the time-sensitive business.In order to ensure the real-time data transmission of time-sensitive service in the spatial information network,this thesis proposes a flow scheduling strategy of wired and wireless converged satellite Time Sensitive Network(TSN).The main research work of this paper is as follows:Firstly,the influence factors of end-to-end delay are modeled and analyzed,and the influence of satellite relative motion on the propagation delay of inter-satellite links is analyzed.The influence of wireless slot allocation based on Time Division Multiple Access(TDMA)on the queuing delay of inter-satellite links,and the influence of IEEE802.1 Qbv scheduling mechanism on the wired side delay within the satellite are analyzed.Then,the wireless TDMA time slot allocation and wired 802.1Qbv fusion scheduling are modeled and analyzed,and the time slot fusion allocation problem is modeled with the minimum average end-to-end delay of the whole network time-sensitive service as the optimization objective,and the time slot allocation scheme is quickly solved based on the enhanced elite reservation genetic algorithm.Finally,by comparing the Pycharm platform with the existing algorithms,the results show that the proposed time slot allocation algorithm can improve the delay performance by 30 % in20 terminal devices.Based on EXata simulation platform,the satellite TSN system with wired and wireless integration is developed,and the flow scheduling scheme in this thesis is designed and implemented.Firstly,in order to ensure the deterministic transmission of intra-satellite time-sensitive service to the satellite output port,a Timer Aware Shaper(TAS)is developed.Secondly,in order to achieve fusion scheduling,the TSN gateway of wired and wireless fusion is developed at the output port of the satellite;Then,each function module of TSN controller is designed and developed for collecting terminal business requirements and distributing time slot results.Finally,a LEO satellite network scenario is built based on EXata to test the flow scheduling scheme in this thesis.The results show that the flow scheduling scheme in this thesis can meet the end-to-end delay requirements of the current typical space task.