Research On Space Satellites Network Autonomous Management And Its Collaboration Model

Space satellites network is a novel wireless mobile communication network. Comparing with other communication networks, its unique properties increase the difficulties to the network management and current network management technologies can be hardly used in its management. Network autonomous management emphasizes distributed managing network by collaboration and can meet the requirements of real-time managing and anti-destruction ability of space satellites network management system. Focusing on the foundation of information and communication, algorithms of dividing management domains and collaboration model, which are required in the implementation of space satellites network autonomous management, this paper makes following contributions:1. Investigate the management model in space satellites network management, which includes function model, information model, and communication model.Propose the function model which includes fault management, topology management, performance management, resource and mission management. In fault management, diagnosing policy combining satellite nodes diagnosis and payloads diagnosis is proposed; in topology management, the mechanism of topology polling is researched and the effects of delay of network on collecting topology information are analyzed; in performance management, a method of locating bottleneck of communication links is proposed; in resource and mission management, formal description of mission in satellites network is presented by defining the resources of satellites network and the characteristics of mission are analysed. Propose the information model, SN_MIB, in space satellites network management, which using ASN.1 to organise the management information of managed object in hierarchical tree-type according to the managed object identifier. The indexing and locating the management information can be easily performed. And the information model provides the information basis in the implementation of management function. Propose the architecture of communication model, which includes IntraDCP and InterDCP, and the protocol data units of IntraDCP are designed.2. Propose algorithms of dividing management domains in different architectures of satellites networks.Firstly a dividing algorithm of management domains, ABDL, is given based on the delay of communication links between the managed satellites and the sub-managers in multiplex-layers space satellites network. An improved algorithm,δ-ABDL, which can increase the average stable time of management domains, is presented with a dividing factorδbased on the analysis of related simulation results. A dividing algorithm of management domains in simplex-layer satellites network, ADSSNMD, is given based on its characteristics and the algorithm of the managed satellites selecting its sub-manager, ASNSM, is also presented. Related simulation results show that algorithm of ADSSNMD+ASNSM can increase the stable time of the management domains. The uniqueness and the completeness of these algorithms are proven in theory.3. Present a service-based collaboration model of network autonomous management.By defining the service, management goal and collaboration goal, service-based collaboration model is presented. Describe the model with and/or graph and two algorithms of finding collaboration schemes, AFAMCS and AGCBG, are proposed. A service description language, sMSDL, and collaboration inter-communication protocol, CiCP, are designed. Finally research the applications of autonomous management collaboration model in management functions of space satellites network. In fault management, application of collaboration model in nodes diagnosis is researched; in topology management, application of collaboration model in gathering the topology information of entire network is researched; in performance management, application of collaboration model in analyzing the bandwidth performance of the communication links is researched; in resource and mission management, application of collaboration model in applying and releasing resource, gathering status of mission are researched. These researches show that the collaboration model of autonomous management can implement the autonomous management in satellites network.4. Design SSNAMSS, a HLA/RTI-based simulation system of space satellites network autonomous management.In SSNAMSS, satellite nodes, inter-satellites links, satellite orbits, sub-managers, simulation controlling and communication nodes' routing are divided into function-independent federates. This architecture has a good extensibility and it can be used in different satellite constellations while it is adapted to different routing strategies and types of space communication link models. Simulate the nodes fault diagnosis, topology discovery, obtaining the bandwidth of communication links, applying and releasing the resources in resource and mission management. Meanwhile simulate the managing the satellites network by the ground network management center. Related simulation results indicate that autonomous collaboration model can support sub-managers to fulfill the management tasks of the whole network and that autonomous network management can resolve the problem that ground network center can not manage network in real time. Statistics of simulating IntraDCP and SNMP show that IntraDCP is more suitable for satellites network management than SNMP in respect of the responding time and the ratio of using bandwidth. Statistics of data stream generated by the communication of collaboration among sub-managers show that collaboration model can meet the requirements of satellites network management.