Research And Implementation Of Cooperative & Shared Caching In Wireless Network

With the development and popularization of network technology and hardware, the demand for the network is growing, which is mainly reflected in the transmission rate, data volume, and convenience. People now exchange data through the network more frequently, however the file uploaders and downloaders all need to interact with web server. To interact with the network server, on the one hand, will increase the efficiency of data access, on the other hand, the server construction and maintenance need to spend effort and financial resources. To cache file resources to local client, accessing to the required resources directly through users interacting, reflects the characteristics of rapid, efficient and convenient. Especially for the wireless network, can well satisfy the demand of users. As a result, the local file caching and shared becomes a developing trend, which is an important way to improve the performance of the network.First,in order to reduce the average data access latency, this paper proposes NC(Neighbor Nodes Neighbor Clusters Cooperative Caching) strategy which is based on adjacent clusters convergence cooperative caching. The NC strategy divides the network into clusters and provides more cache information of neighbor nodes, through the collection and record of the neighbor nodes' and the adjacent clusters' cache information, make the cache hit neighbor nodes and catch lower access delay. Through the analysis of the NC strategy cache hit process, calculate access delay of requester in multiple cases, NC strategy has better performance than adjacent clusters convergence cooperative caching strategy. Then simulation results verify the correctness of the theoretical analysis of NC, and compared with the direct search strategy, the performance of NC is better than the direct search strategy.Secondly, in order to implement the NC strategy and local cache shared, this paper designs an application protocol. Using Gate Server, Client Server and Client Client three modules as well as custom messages to achieve local cache cooperation and sharing. Getting HTTP(Hyper Text Transfer Protocol) protocol and HTTPs(Hyper Text Transfer Protocol over Secure Socket Layer) protocol into the application protocol makes the browser into the implementation process, then Client Client and Gate Server complete file requests and acquisition of local cache files transparently, network file will eventually be rendered in the browser.Finally, in order to verify the NC strategy and the design of the application protocol, test the achievement. According to the test result, when there is no request file in the intranet, browser request data from extranet normally and when the request file is matched in the intranet, browser obtained data from nodes in the internal network directly, achieving cooperative and shared caching. Using the NC strategy node can hit the cache file in neighbor nodes, and the transmission rate is improved. At last, the multiple simultaneous transmission is tested. Through the test and analysis of the different situations, we can see that the use of multiple simultaneous transmission can improve the performance of the network, which provides a direction for future research.