Resource Estimation And Virtual Topology Construction For Content Service Network

With the diversified development of online video-on-demand,streaming media and other services,repetitive content occupies a large amount of traditional network resources in the process of transmission and storage.In order to solve the above problems totally,CCN(Content Centric Network)has attracted widespread attention in the industry due to its advantages of universal cache in the network.The cache node can store and respond to users with the popular content,reducing the transmission of duplicate resources in the link.The proposal of CCN promotes the development of future network architecture,at the same time it brings more interesting challenges.Estimating the cache capacity to quantify the service ability according to the demand target is one of the main focuses for network operators.This dissertation focuses on the problem of cache resource estimation and virtual topology construction in CCN.The main work is as follows:1.In the resource estimation problem,in order to estimate the cache capacity of the node theoretically,first of all,the model analyzes the cache modeling method in CCN and Web field and introduces the current research on resource allocation in CCN.Then,it proposes a cache resource estimation model of a small-scale tree topology for access networks based on the "Che approximation" hierarchical cache modeling theory and its extended research.The model quantified the relationship between average system cache hit rate and cache capacity of nodes.At the same time,it estimates the cache capacity according to the hit rate target.The cache resource estimation model also reflects the changing trend of the first and second tier cache capacity in the tree topology,which can help us to have a better understanding of the conversion from system performance to cache capacity.In experimental simulation part,the dissertation analyses the influence of different parameters on the estimating error of the cache estimation model and discusses its usability in actual scenarios.2.This dissertation also proposes a virtual topology construction algorithm for CCN networks based on the expansion of the above cache estimation model.It is applied to the calculation of cache resources in the topology construction process.The virtual topology construction algorithm is different from the research in traditional virtual backbone network and virtual wireless microwave network areas.Essentially,it is a trade-off and consideration of cache resources and node computing resources in CCN.The concept of node service ability,which represents the maximum linear processing ability of user requests is proposed in the topology construction algorithm.The cache capacity of the node is estimated according to the target of its hit rate,and the rate of missing content requests forwarded to the upper topology is calculated at the same time.According to the converged requests and the service capacity of nodes,the number of upper-layer nodes can be calculated-By optimizing the objective function,the virtual topology construction algorithm finally generates a topology configuration which determines the topology structure and cache capacity.It also minimizes the cost of cache capacity within the range of the algorithm accuracy and achieves the goal of the system hit rates.This dissertation proposes a cache resource estimation model and a virtual topology construction algorithm for CCN,quantifying the relationship between system performance and required resources.It has a certain significance for network operators to deploy CCN in the future.