Research On Key Techniques Of Near-space Adpative Network

Near-space vehicles have a wider coverage than aircraft under the near-space platform. In the applications of military, near space has become a hot research in various countries’ research. It’s of high research value that near-space MANET can networking efficiently and fast. This thesis is point at the routing protocol of access network and the access protocol of bone network, access network, UAV network in the near-space network.This thesis first deals with the routing protocol based on the link stability. Thinking about the number and the mobility of the nodes, it’s of importance to reduce the overhead and the link breaks. Based on the design of the flooding area, it ensures the overhead and the number of valid path. In the near-space MANET, the mobility of near-space vehicles are unavoidable. Consequently, it’s necessary to establish the mobility model of the near-space vehicles. Considering the task of operations, the near-space vehicles are divided into different groups. Therefore, this thesis chooses Reference Point Group Mobility Model as group mobility model, and Random Waypoint Mobility Model as entity mobility model. According to the mobility model,the near-space vehicles have regularity movements. Through the study of the regularity movements, the sequence of movement state is being derived, and the value of the link stability is based on the sequence’s Markov property. Taking the hop counts into account, the value of the link stability is calculated by the successively multiplication standard. The protocol is simulated to prove that compared with common protocol, the new algorithm has a higher delivery rate and lower number of average breaking under the conditions of different number of nodes and different mobile speeds.Then the thesis investigates the access protocol based on the statistical service priority. Directing against the numerous nodes and various services, it is necessary to think about the channel collisions and the access performance of different services. By means of listening the channel status in the past times, the nodes enable send the messages only when the channel collisions less than the threshold. Simultaneously, the services is divided into different priority based on the time delay sensitivity, the nodes is classified into groups relay on the importance. Through desgin of the back-off algorithm,to ensure high-priority services’ or advanced users’ performance and time delay, theirback-off windows are less than others’.The routing protocol and access protocol are simulated to prove that compared with common protocol, the new algorithm has a higher delivery rate and lower number of average breaking under the conditions of different number of nodes and different mobile speeds, and the high-priority services and advanced users have a higher delivery rate and lower time delay than others under the conditions of different load.