Research On Fault Detection And Diagnosis Algorithm In The Space Information Network

The Space Information Network is composed by spacecraft and ground-station which have space communication ability. The Space Information Network has lots of advantages, such as with broad coverage, flexible networking capability, and without geographical restrictions. It provides integrated communication services for various space missions. It also play an important role in the following aspects:Reconnaissance and surveillance, communications security, navigation and positioning, etc. Because of the dynamic characteristics of the Space Information Network and some existing vulnerability in wireless communication,the nodes in the network are usually interfered and damaged, and thus its quality of service declines. So fault detection and diagnosis algorithm for the netrwork has important significance in enabling the network to operate safely, reliably and stably.Considering characteristics of the space information network, system-level diagnosis algorithm and based-on-CBCD fault detection are introduced into the network. Algorithm is divided into three parts:The part of detection-nodes election and division of detection zone uses the Minimum-weights method to elect some nodes as the detection-nodes which take use of the distributed and cooperatedly way to detect the fault of the network, optimize the network resources. The part of state assessment analyze the importance of the link and the node in the network which is achieved by evaluation of node and link importance. So the algorithm can increase the attention for the links and nodes whick are more important in the network, prevent the more damage owing to the fault in the links and the nodes. The elected nodes use the system-level diagnosis algorithm to detect, trace and locate the fault between them, use based-on-CBCD algorithm to diagonose the fault in the coverage of the detection-nodes.The network simulation software NS2is adopted to evaluate the proposed fault diagnosis algorithm for the Space Information Network. The simulation results demonstrate that outputs of fault level assessment module are more reasonable comparing to the true results in real multi-application environment, which guides network to make a good choice of increasing the attention to the more important nodes or links, reduce the harm to the network. Furthermore, the fault diagosis algorithm which has a elected detection-nodes and based on the System and CBCD diagosis can achieve high accurate judge rate, the full rate of diagonosis and electively detect and localizate the fault, to guarantee performance and QoS, improve the reliability and effectiveness of the network.