Research Of The Aerospace Integrated Information Network Switching And Networking

The aerospace integrated informatio n network is attracting more and more research interests and several governments supported experimentation and implementation projects are on their way around the globe. By comparing the United States and the European space integrated information network design and R & D programs, and considering the existing technology and objective conditions of our country, we summarize some possibilities and opportunities in the development in this area of our country. Two problems of the core scientific issues in the research of the space integrated information network, the space network switching and the high dynamic MANET, are presented as the main contents of this thesis.In the research of the space network switching, firstly, the architectures of the space switching network is introduced. We analyse and compare the advantages and disadvantages of traditional switching schemes, summarize the char acteristic and applicable conditions of the space switching network. For full use of the existing space platforms hardware devices and meeting the diversity of network data services, the concept of circuit and packet hybrid switching scheme which is based on packet switching is proposed. Combined with the advantages and disadvantages of circuit and packet switching schemes, hybrid switching architecture block diagram which is based on the three-stage C los is provided, and CMSD(Concurrent Master-slave Round-robin Dispatching) algorithm is utilized for packet to apply for matching the switching link. After that, the forwarding process of circuit and packet information is described in detail, and the queuing theory is used to make a simple analysis about the hybrid switching system. Finally, simulation model is set up on OPNET to test the system performance. When the system load increased from 0.3 to 0.7, testing the entire system end to end delay, packet loss and network throughput on the case of circuit and packet traffic ratio is 4: 6, 5: 5 and 6: 4. The results show that the system is able to meet the constant output characteristics of the circuit business, the delay and delay jitter of circuit and packet businesses both can meet the performance specification of space switches, and multiple services can be supported well.As to the high dynamic MANET, on the basis of the traditional mobile ad hoc network,the objectivity and the characteristics of it are pointed out. According to the characteristics of the high dynamic ad hoc network and some analyses of existing technologies, we give a solution to the key problems of the physical layer, MAC layer and the network layer for a specific application scenario. We propose distributed, multi- hop, head competing network, which jointly utilize TDMA and slot random access method to achieve dynamic slot allocation. And as beam switching antena are used in each node of the network, an transmission antenna selection method is proposed. We build simulation models on the OPNET network simulation platform to study the performance of our scheme, and create animation to show the dynamic changes of the real-time link connections between the nodes and to observe network node delay and throughput intuitively. The results show that under a scenario of 5 nodes, the scheme can achieve networking in 1.0375 s, but the packet lost because of frequent connection losts and re-connections can not be ignored, showing the scheme still has much more room to improve.