一种基于SDN的HAS全局优化策略

摘要

在传统基于HTTP的自适应流媒体(HAS)系统中,当多个用户共享同一瓶颈链路时,客户端存在不公平、不稳定、网络资源利用不充分的问题.为此,提出一种HAS全局优化策略.在软件定义网络控制器上部署全局优化模块实现全局优化,在制定策略时,将用户体验质量的全局优化和路径规划相结合,根据网络状况和用户体验需求,得到客户端的最优请求码率和最佳路径.仿真结果表明,与未经优化的HAS系统相比,该策略能够有效提高用户体验质量,并且使公平性和稳定性得到改善.%In Traditional HTTP Adaptive Streaming (HAS) clients,when multiple users share the same bottleneck link,this may result in unfairness and instability in clients,and may underutilize the network resource.To address this problem,this paper proposes a HAS global optimization strategy.It realizes global optimization by means of deploying a global optimization module on Sofware Defined Network(SDN) controller.When formulating the strategies,it combines the global optimization and path planning of users' Quality of Experience (QoE),and makes decision of the optimal request rate and best path of each client according to the network conditions and different requirements of users.Simulation results validate that compared with raw HAS system,the proposed strategy can effectively improve the users' QoE,and the fairness and stability are improved.