Research On Key Techniques Of Space-ground Intergrated Optical Networks

The space-ground integrated optical network combines the satellite optical network with the traditional ground optical network. It implements the global seamless coverage through the space-ground laser link. Also, it has characteristics of flexibility and a strong ability to coordinate information. At the same time, the space-based optical network and ground optical network are backups for each other.When ground optical network is under attack or occurs a failure, the traffic can transmit through the space-based optical network. On the other hand, when the nodes of space-based optical network are disturbed, we can also use ground network for transmission. Thus it further enhances the survivability of the network. The space-ground integrated optical network has become one of the trends of the optical communication. It has attracted worldwide attention and has become a key research and exploitation of every powerful country.Firstly, this paper has introduced and analyzed the main characteristics of satellite optical network, including the dynamic characteristic and the influence of atmospheric on space-ground laser link. It has provided a certain theoretical basis for later study. According to the insufficiencies of the existing simulation platform, this paper has improve the traffic procedures of the platform and added space-based satellite network traffic flow model, LEO/GEO satellite node model, space-ground laser link model and satellite control node model, which would build good simulation environment for subsequent experiments.Secondly, this thesis has studied and simulated the satellite networking technology of the integrated optical network and the dynamic resource management and allocation of the space-ground laser link. It has designed a kind of hybrid constellation communication system based on laser links. This hybrid constellation can avoid heavy satellite routing load and poor anti-destroying ability of the single layer satellite constellation. Meanwhile, it has researched the dynamic characteristics of the laser links between satellites in the hybrid constellation. Furthermore, it has proposed the space-based network dynamic RWA strategy, aimed at disadvantage of the assignment algorithm between static route and wavelength. This strategy has taken into account the time delay, Doppler frequency shift and the effect of load balance on network performance. Finally, it has simulated the influence o on the integrated optical network. In the dynamic resource management and allocation strategy of the space-ground laser link, it has firstly put forwards the elevation weighted load balancing access strategy, which overall considered the effect of link quality and load balance on the space-ground communication system. At the same time, the reserved bandwidth scheme can avoid traffic interruption and reduce the link’s handover failure rate. Finally the performance of the algorithm is verified by simulations.Integrated network which use laser as the carrier of the information is one of the growing trends in the future. This dissertation has provided design foundation and theoretical basis for researches of the integrated optical network in our country. It has also given a useful reference for its practical application.