Research On Caching Strategy In Content Centric Networking

With the rapid development of the Internet,network data traffic has grown exponentially,and the energy consumption of the Internet has become more and more serious,making the TCP/IP networks based on end-to-end difficult to meet the needs of users.In response to this challenge,researchers have proposed a new architecture named Content-Centric Networking(CCN).Each routing node in CCN can cache content,which can effectively alleviate the load pressure of the backhaul link,improve the transmission efficiency of the content,and reduce network energy consumption.Therefore,designing a reasonable and efficient caching strategy is a key factor affecting system performance and energy efficiency.This paper mainly focuses on two aspects: caching placement strategy and caching replacement strategy.The details are as follows.First of all,this paper proposes a multi-parameter probabilistic caching placement strategy with energy priority.At present,the research on caching strategy in CCN mainly focuses on improving network cache resources,and pays less attention to the energy consumption of the network.Therefore,this paper first builds an energy consumption model for the content transmission process and designs a new judging condition to reduce the total energy consumption in the network and improve the energy efficiency of the system.On this basis,combining the content popularity,the node replacement rate,the number of hops to the content hit node,and the betweenness centrality of the node,four network parameters are comprehensively considered.And then the weighting factor of each parameter is determined by analytical hierarchy process.Lastly,a probabilistic caching strategy for content is designed.The simulation results show that the scheme can improve the cache hit rate and energy saving rate of nodes in the network and reduce the average hops of acquiring contents.Secondly,this paper proposes a caching replacement strategy based on content value.The caching space of each routing node in CCN is limited.When the network reaches a stable state,content replacement is required.The traditional caching replacement algorithms always consider the single factor,which cannot meet the diverse needs of users.The proposed scheme in this paper considers the dynamic popularity of content,the cost of caching,and the time of the most recently requested,builds a more realistic content value function,and designs an effective content storage and replacement scheme based on the content value function.Specifically,when the cache space is insufficient,the existing cache contents are replaced according to the value from small to large.Simulation results show that compared with the traditional replacement algorithms LRU,LFU and FIFO,the proposed scheme effectively improves the content cache hit rate of network nodes and reduces the average hops of users' content acquisition.