Research On Key Simulation Technologies Of Multilayer Satellite Networks Based On Inter-satellite Links

Multilayer satellite network based on inter-satellite links is the core component of air/space/ground network, which has significant value and also faces serious security threat. Building a satellite network simulation system will provide basic experimental environment for its security issues research. With the target to design a satellite network simulation system, some key technologies of establishing satellite network simulation system are studied under the background of researching security policies of satellite network. The main works of the dissertation are as follows:1. As the antenna model in OPNET is not generally applicable and is complicated in gain computing, an effective and universal model is presented in this thesis, which makes improvement from antenna pattern representation and gain computing. A model of satellite communication link is established through researching on the features of satellite link, including link establishing conditions, communication delay and link quality factors. Simulation experiments indicate that the model is rather reliable.2. The effects of inter-satellite link handover on satellite network topology are studied, and a time-slot division algorithm for dividing the satellite network revolution period is presented. A multilayer satellite network routing protocol (MLSNRP) is designed based on network topology precomputation and link status direct report, whose feasibility and efficiency is verified in this thesis. Model of MLSNRP routing protocol is established based on finite state machine theory.3. A simulation system framework of multilayer satellite network based on inter-satellite links is designed, and key modules of the system are implemented based on the simulation tool OPNET. By conducting simulation experiments of some basic satellite network applications, both correctness of the routing protocol model and fundamental functions of the simulation system are verified. The model of IPsec protocol is built, and its performance is evaluated and analyzed in the simulation system. Experiments show that the simulation system in this thesis can support security protocol simulation effectively.