Study on the telecommunication technology based on the distributed satellite constellation networks

By the motive of the application in the commercial and military regions, the telecommunication technologies have been developed further more in recent years, for the purpose of better performance. Compared with the terrestrial networks, the satellite constellation networks could provide higher communication coverage, faster data transmission rate and more reliable data transmission service under the given quality of service requirements, which would be widely used in the regions of distance education, tele-commanding, telemedicine, etc. In this paper, firstly we introduce the characteristics and structures of the distributed satellite networks (DSN), which are composed by the LEO satellites, GEO satellites, and the ground terminals. The GEO satellites are responsible for the operation and management of the DSN network, the LEO satellites are responsible for providing the telecommunication services for the ground terminals, including the source users and the destination users. Then, in order to provide the more reliable and faster telecommunication services, we suggest a new distributed dynamic source routing (DSR) algorithm based on the thought of flood-routing. The dynamic source routing algorithm in the distributed satellite constellation network (DSN-DSR) is one on-demand routing algorithm utilizing the source routing method between the satellite nodes but not the hop-by-hop routing method. The algorithm is composed of two main mechanisms of Route Discovery and Route Maintenance, which work together to allow source nodes to discover and maintain the source routes to any destination nodes in the distributed satellite constellation networks. While, compared with the earth nodes, satellite nodes are limited by the on-board processing, storage, and so on. In this paper, we suggest other two mechanisms to solve the problem: one is the Route Cache, and the other is the GEO Agency, which could reduce the size of memory on-board and improve the system performance potent- ally. Finally, in order to insure the security and credibility during the telecommunication procedure in the satellite constellation networks, the mechanism of information security and credibility based on the concept of autonomous domain with perceptive interaction is developed, which could be called the multi-level and active security protection mechanism, the key points of our research on the security and credibility include three aspects: first, the "inner-edge" security and credibility system of the autonomous domain; second, the active defense with multifarious techniques; third, the multi-level defending based on the safety grade evaluation. In order to verify the new telecommunication architecture and data transmission approaches, we have done some theoretical works to prove its availability in the distributed satellite constellation networks, and make use of the simulation tools to build the simulation platform of the "terminals + LEOs + GEOs" telecommunication situation. The theoretical analysis and the simulation results shows that, compared with other architectures and algorithms such as the only LEO satellites or only GEO satellites constellation networks, standard Dijkstra algorithm, and so on, our new telecommunication architecture and data transmission approaches could decrease the data transmission time-delay and make the network status more stable, and remarkably improve the telecommunication performance in the distributed satellite constellation networks.