Research And Implementation Of Key Technologies Of Deterministic Networks For Distributed Platforms

With the progress and development of deterministic network,its application scenarios are no longer limited to fixed network systems,and continue to extend to the field of dynamic collaborative network.For example,build a distributed cooperative system between satellite nodes,and use deterministic network to transmit real-time information on high-speed intersatellite links.The typical deterministic network technology standard,TSN(Time Sensitive Networking),is not suitable for new link scenarios,due to the constantly changing positions of satellites and the susceptibility to interference from external factors.Therefore,and we combine the characteristics of the actual satellite link and the key TSN scheduling technology to propose and design the TSN scheduling system for the moving platform,during which we study and implement the dynamic scheduling algorithm suitable for the satellite link.In the thesis,we firstly,introduces the key technologies in the TSN briefly,focusing on the analysis of the CBS(Credit Based Shaper)algorithm in the Qav protocol and the gated scheduling algorithm in the Qbv protocol,determining the research feasibility of TSN technology combined with different satellite orbit types and delay loss for the moving platform.On the basis,the TSN dynamic platform prototype system is proposed and then designed,and the modules such as switching,Priority frame classification,and traffic scheduling are designed and explained in detail.Afterwards,the moving platform model was established according to the characteristics of the satellite dynamic network,and two schemes were designed according to different FPGA(Field-Programmable Gate Array)resources occupancy to simulate satellite transmission data,including data source generator,delay control and other functional modules.Simulation and Circuit testing show that the model conforms to the expected design.We focus on the implementation of CBS algorithm and gated scheduling algorithm under the satellite quasi-dynamic link.Based on the traditional CBS algorithm model,dynamic change scenarios are introduced,and the delay changes of CBS under dynamic bandwidth are qualitatively analyzed.Combined with the established CBS network model,it is further concluded that the bandwidth ratio plays a decisive role for different levels of links.Then according to the dynamic CBS theory,the bandwidth adjustment scheme is designed,the CBS algorithm is improved,and the switching protection mechanism is proposed to avoid data loss during the switching process.Regarding the deterministic delay under gated scheduling,we propose two solutions,using guard band to absorb random jitter delay and controlling the gate open time to buffer the delay of link distance,combined with the gated period to determine the postponement time.Finally,the two dynamic algorithms are tested respectively.The results show that the dynamic scheme proposed in this paper is not only suitable for the deterministic scheduling of satellite networks,but also capable of allocating bandwidth flexibly according to the delay requirements of different data frames,establishing a new deterministic traffic,utilizing fully the advantages of deterministic Ethernet technology and achieving the expected results.