Research On Routing Based On Virtual Coordinates And Caching In Information Center Internet Of Things

As Internet traffic shifts from host-centric to content-centric,information center networks are rapidly evolving as a new network architecture with a communication model that is fundamentally different from the traditional IP address-centric model.Io T aims to interconnect devices,all of which can be accessed at any time,from any location and by any path.However,when billions or even hundreds of billions of devices are connected to the Io T,a huge amount of data will be generated.Efficient data transfer in the information center network is guaranteed through name-based routing and forwarding mechanisms and content caching at intermediate nodes,making it highly promising in the Io T environment.Therefore,how to route requests from devices to the nearest node that stores that content and improving the cache hit rate of intermediate routing nodes are two key issues facing the Io T in information centers.In order to reduce the latency of content retrieval in the information center Io T,an routing strategy based on virtual coordinates is proposed in this dissertation.First,a clustering algorithm based on node similarity to cluster the network is designed in this dissertation.Then,a prefix tree embedding algorithm is designed to use the same prefix of devices in each cluster network as the cluster prefix,using the cluster prefix as the virtual coordinates of the clustered network.Secondly,considering the problems of information center network caching and Io T mobility,a hyperbolic embedding algorithm is designed in this dissertation to assign virtual coordinates to nodes within each cluster by combining the prevalence of content and the similarity of nodes as important metrics for coordinate assignment.Then,an routing forwarding strategy is designed based on inter-cluster and intra-cluster virtual coordinates to forward requests for resources to nodes with high prevalence and similarity to achieve fast response to device resource requests.The experimental results show that the routing scheme based on virtual coordinates can reduce the delay and hop count,and achieve a high routing success rate compared to the existing routing strategies.To improve the cache hit rate in Io T for information center network,a probabilitybased heuristic caching strategy is proposed in this dissertation.Taking into account the mobility of user nodes and the popularity of requested contents,a cache optimization model is established with the goal of improving the cache hit rate,the node cache capacity,and the link capacity as constraints,and the Lagrangian relaxation method is used to solve the problem.Since solving the model needs much computational and communication resources,it will impose a huge computational and communication burden on the resource-constrained Io T devices.Thus,a probabilitybased heuristic caching strategy is used.When content arrives,the routing node calculates the storage probability of the content by a comprehensive analysis of the content popularity,the requester mobility,its own remaining capacity,the size of the content,and the requests satisfaction rate for the content to decide whether to cache the newly arrived content.The experimental results show that the probability-based heuristic caching strategy improves the cache hit rate while reducing the transmission delay and the routing hop count.