Research On Satellite Internet Of Things Based On Content Center Network

With its broad coverage advantages,the satellite Internet of Things can realize the "Internet of Everything" in the true sense,and has gradually become the focus of research by scholars at home and abroad.Content Centric Network(CCN)is a new type of network architecture.Its idea of focusing on data acquisition coincides with the satellite Internet of Things.Scholars at home and abroad have done some research on the integration of CCN and satellite Internet of Things.However,there are still many challenges in the integration of CCN and satellite Io T: on the one hand,the routing and forwarding mechanism of CCN is not suitable for the scenario of satellite Io T,and there are problems of interest loopback and reverse path interruption;on the other hand,using satellite The downlink directly caches the ground nodes,and there are problems such as cache redundancy among the ground nodes and a low overall cache hit rate.In order to solve the above problems,this paper studies the CCN-based satellite Io T architecture,routing and caching mechanism.The specific research contents are as follows:(1)A CCN-based Satellite Io T(CCNSI)architecture is proposed.CCNSI consists of four parts: controller,forwarding satellite,ground CCN network and user.It optimizes the packet structure and table structure in CCN,and improves the content retrieval and naming mechanism to make it more suitable for the scenario of satellite Internet of Things.Chapters 3 and 4 provide the theoretical foundation.(2)Aiming at the problem that the route forwarding mechanism in CCN is prone to interest loopback and reverse path interruption in the inter-satellite link,an interest loop detection algorithm(Interest Loop Detection,ILD)and a reverse path maintenance algorithm(Reversing Path)are proposed.Maintaining Based CCN,RPM).Under the premise of not increasing the computing load of satellite nodes,the ILD algorithm introduces tuples and hops from the content prefix into the Pending Interest Table(PIT)and Pending Interest Table(PIT).According to the proposed The interest loopback detection rule based on the system realizes the correct forwarding of interest packets on the inter-satellite link,reduces the storage pressure of satellite nodes,improves the content delivery rate,and reduces the average delivery delay.The RPM algorithm maintains the reliability of the reverse path of the data packet by introducing the conversion between the virtual interface and the actual interface.(3)Aiming at the problems of cache redundancy among ground nodes and low overall cache hit rate when using satellites to cache ground CCN nodes at present,a CCNbased satellite Io T cache placement algorithm is proposed.The algorithm divides the cache community of the ground network according to the cache similarity between ground nodes,so that the ground forms a small cache community with similar cache requirements,and designs a genetic-based satellite-terrestrial network cache placement algorithm(Genetic-based Satellite-terrestrial Network).Cache Placement,GSNCP),which places high popularity data on the nodes needed by users in a targeted manner.The GSNCP algorithm increases the cache hit rate and has good performance in terms of average routing hops and regional network revenue.