| With the advancement of communication technology and the rapid improvement of the level of social informatization,data transmission services have increased dramatically around the world,and the global data traffic has exploded.The ground transmission network is under enormous pressure,and the need for transmission capacity expansion is very urgent.Satellite networking has become an important direction for the evolution of next-generation networks because of its global indiscriminate coverage and is not easily affected by ground disasters.And satellite laser networking is bound to become a major trend of satellite networking due to its large capacity and low loss characteristics,especially the large-scale satellite laser network with multi-layer satellite collaborative networking will surely become an important part of the future space-earth integrated network.However,with the continuous expansion of satellite network scale,the improvement of satellite network performance is bound to be restricted by the complexity of satellite hardware structure and the dynamics of satellite network topology structure,and the management and control of large-scale satellite network becomes more difficult.In this paper,we mainly study the routing stability problem of large-scale satellite laser network under the constraint of limited load.The main innovations of this paper are as follows:First,in view of the difficulty of large-scale satellite laser networking management and control,a multi-layer hybrid satellite constellation design scheme was proposed,and combined with the characteristics of the constellation,the software-defined networking(SDN)technology was introduced into the satellite optical network,and a centralized and distributed satellite optical network was proposed.A collaborative software-defined satellite optical network(SDSON)architecture.By deploying the master controller and the slave controller on the ground control center and the geosynchronous orbit satellite node respectively,the flexible management and unified configuration of the entire network can be realized.The network architecture complements the multi-layer hybrid satellite constellation,thus providing the basis for better routing stability under limited load constraints.Second,aiming at the problem of limited on-board computing and storage resources,combined with the characteristics of SDSON architecture and multi-layer hybrid constellation collaborative networking,a multi-domain satellite optical network snapshot division method is proposed.On the premise of ensuring the authenticity of satellite topology snapshots,It reduces the occupation of storage resources by on-board snapshot storage,and at the same time,routing computation based on the local topology of a single coverage domain greatly reduces the on-board computing pressure.The simulation results show that,based on the premise that the entire satellite network topology is divided into 6 coverage domains in this paper,the snapshot division method can save about 70%of the on-board storage resources.Third,for the problem of poor routing stability in satellite networks,an adaptive snapshot routing algorithm(TS-ASRA)based on the superposition of space-time dimensions is proposed.,and plan routes for the service based on this topology.In this paper,the route calculation success rate,additional route calculation times and service blocking rate are used to evaluate the routing stability.The simulation results show that compared with the classic snapshot routing algorithm(CSRA),the TS-ASRA algorithm can increase the path calculation success rate by about 33%at most,while the additional calculation times can be reduced by about 65% at most. |
