QoE-Driven Code Rate Adaptive Gorithm Based On CDN Cache Hit Rate

With the growth of the mobile streaming user base,the content delivery network(CDN)has become an important way to improve network capacity and quality of experience(QoE).It is of great significance to study the impact of CDN cache hit rate on user QoE.Therefore,this thesis proposes to study the optimization strategy based on CDN node cache hit rate.The main work of this thesis is as follows:(1)Propose a QoE model based on CDN cache hit rate.Through in-depth analysis of the relationship between the CDN cache and the initial delay,the client cache change amount,and the rate shear event,the impact of the CDN node cache hit rate on user QoE is studied,and a QoE model based on network parameters and user feedback parameters is established.(2)A code rate control adaptive algorithm based on CDN cache hit rate is proposed.The algorithm combines the parameters of the client and the influence of the network,as well as the change of the cache hit rate in the CDN and the average level of the regional network,so as to achieve the purpose of optimizing the rate control adaptive algorithm.By improving the hit rate of the CDN cache,reducing the flow back to the source,and effectively improving the throughput of the entire system under the condition of ensuring the user QoE.(3)Propose CDN cache replacement strategy based on regional network average.By shunting and controlling the communication between the client and the load-balanced CDN server,the communication strategy between the CDN server node and the node,the CDN server node and the source server is optimized,and the network throughput is improved.