Research On Topology Abstraction For Large-Scale Satellite Optical Networks

The wave of space research has swept the world.With the rapid development of terrestrial Internet,more huge service demands have emerged as the times require.Satellite Internet has become an inevitable trend in the development of communications.The industrialization of satellite manufacturing and the maturity of microsatellite technology have paved the way for large-scale on-board networking,and the launch capability of "multiple satellites with one rocket" provides a strong guarantee for large-scale deployment onboard.Large-scale low-orbit small satellite laser networking will reduce the capability requirements and construction costs of a single satellite with the help of the increase in satellite scale,and create a seamless network service with low latency,high bandwidth,and large space-time in the inter-satellite Internet mode.The important mode of the integration of space and earth has become the research focus of competition and games in the space field of various countries.This paper takes the routing technology of large-scale satellite laser networking as the core,and adopts "topological abstraction" as the main solution to the pain point of "difficult convergence and high computation"in large-scale networking.Focusing on the problems of "constellation coverage performance,topology dynamic characteristics,and route calculation time cost" faced in the abstraction process,the research is carried out from three perspectives of "constellation coverage design,topology model abstraction,and routing mechanism implementation",and mainly completed the "multiple coverage".The three research innovations of satellite constellation design method,abstract model of large-scale high-dynamic satellite topology,and adaptive routing algorithm to compensate for abstract distortion provide ideas and support for large-scale satellite network routing research.The main research contents and innovations of this paper are as follows:First,based on the research perspective of "constellation design",in view of the current research status of the relatively lack of the multicoverage satellite constellation design process for fixed satellite scale,this paper designs a set of constellation design processes to deal with this scenario,focusing on the single satellite constellation design process.The analysis and research of coverage and multiple coverage theory,combined with the configuration characteristics of the global coverage satellite constellation,improved the design process,and carried out the verification of the parameter influence degree oriented to the coverage multiple,to some extent,made up for the multiple coverage constellation under the fixed satellite scale.Inadequate design process.Second,based on the research perspective of "network topology",a space discretization-based two-layer nested spherical grid is proposed for the polar orbit constellation scene,aiming at the research problems of the continuous expansion of the satellite network scale and the high dynamics of the topology itself.Topological abstraction model.This model mainly adopts the main idea of virtual topology to divide abstract grid,and utilizes the absolute stillness of space segment grid abstraction layer and ground segment grid abstraction layer in the structure of double-layer sphere,which effectively shields the topology caused by satellite operation and earth rotation.Frequent changes,and topology abstraction directly reduces the upper limit of routing time complexity,which greatly improves the problem of increased routing computing costs caused by node scale expansion.The simulation results verify that the model saves 30%-45%of the computing time cost in business route calculation.Third,based on the research point of "network routing",aiming at the objective problem of distortion of real information caused by topology abstract model,a routing algorithm based on double-layer sphere abstract model(TA-LBRA)is proposed.The algorithm focuses on reducing the situation of high traffic congestion caused by topology information loss,and designs a satellite-to-ground road construction mechanism and an abstract grid load evaluation mechanism for the model,which greatly reduces the situation of service congestion caused by information loss caused by topology abstraction.Compared with the comparison algorithm that does not use the load evaluation mechanism,the service routing success rate is increased by 10%.Compared with the model benchmark routing comparison algorithm without abstraction,it only loses less than 5%of the service transmission success rate in exchange for the route calculation time of 30%-45%optimization.