Research On Anti-destruction Routing Strategy For GEO/LEO Double-layer Satellite Network

Satellite networks will not be restricted by the geographic environment to provide long distance communication service for the users around the world.Therefore,the researchers from the whole world are focusing on this topic.And because of the rapid development of space and communication technology,satellite networks have become the key communication infrastructure.With the gradual commercialization of satellite networks,there is a growing demand for the high efficacy and practicality of satellite communications.In order to meet these requirements,it becomes necessary to study the satellite network routing strategies.Because of the difficulties to repair the failures of satellites launched and the high dynamic topology of satellite networks,the terrestrial network anti-bypass routing strategy is no longer applicable.There is no doubt that the satellite network anti-destruction routing has become the research focus of scholars over the world.There are two factors affecting its survivability in current satellite networks:one is that the satellite link congestion will lead to satellite route failures or even the satellite network failures;the other is that the satellite's complex environment will bring satellite link parameters uncertainty leading to satellite route failure.Therefore,this paper studies the anti-destruction routing strategy for GEO/LEO double-layer satellite network from two aspects of congestion control and uncertainty.The main work is as follows:(1)A two-layer satellite network model based on virtual node is proposed.Firstly,the model adopts the Geo/leo Double-layer satellite network,which is designed with redundancy,avoids single point fault and improves the damage resistance.Then,the model of virtual node is used to reduce the complexity of routing calculation and to simplify the design of the anti destruction routing.(2)As for the problem of satellite link congestion,this paper proposes a congestion control based satellite network anti-destruction routing strategy.In this strategy,a new link state evaluation function and a rerouting triggering mechanism are designed to control the satellite network congestion so as to enhance its invulnerability.At the same time,a routing calculation method based on the Floyd algorithm is used to reduce the number of GEO satellites Routing calculation burden;and in the distribution of the new routing table,a partial incremental update way is used to reduce the signaling costs.The simulation results show that this strategy can reduce the times of rerouting,failure recovery time and the number of satellites waiting for updating in routing table without increasing the average delay and delay jitter.(3)As for the uncertainty of the satellite link parameters caused by the complex environment of the satellites,a strategy based on the uncertainty theory for satellite network anti-destruction routing is proposed.Firstly,the satellite link parameters based on triangular fuzzy numbers are determined.Then the satellite routing model based on uncertainty theory is constructed and the uncertain routing model is solved by genetic algorithm.Finally,in order to satisfy the reliability of transmission,multipath transfer data packets are used.The simulation results show that this strategy can accomplish the anti-destruction routing strategy of satellite networks in complex environment and also has good performance on throughput,average delay and packet loss rate.