Research On Traffic Shaping Policy In Hybrid Optical-wireless Broadband Access Networks

Hybrid optical-wireless broadband access networks combines the advantages of optical access network and wireless access network to provide high capacity,low loss,high reliability,flexible networking,Low cost and other characteristics,has become to meet the needs of the best next-generation access network technology.As the optical wireless hybrid broadband access network and the traditional access network structure is different,making the traditional traffic shaping strategy is no longer applicable.Therefore,it is necessary to design a highly efficient and reasonable traffic shaping strategy to solve the problem that the quality of service is degraded by the difference of the transmission capability between the front-end and the back-end network in the hybrid network.First of all,this thesis summarizes the research background of hybrid optical wireless broadband access networks and introduces the related key technologies.Then the traffic shaping strategy is analyzed,and the key problems and basic principles of traffic shaping in traditional network are expounded.Two commonly used traffic shaping algorithms are introduced in detail,and analyzes the correctness of self-similar mathematical model as network traffic model.Secondly,this thesis proposes an adaptive token bucket traffic shaping strategy suitable for hybrid optical-wireless broadband access networks.According to the self-similar model,a network traffic model is established.Based on the token bucket algorithm,combined with the proposed hierarchical scheduling strategy and the triple quality of service mapping rules,consider the relative priority of the service and select the reasonable token bucket parameters to obtain the high quality shaping effect.In addition,using the adaptive cache management strategy,dynamic adjustment of the token bucket parameters to improve the QoS of the entire network business.Then the simulation results show that the proposed strategy can effectively improve the using efficiency of the whole hybrid network and reduce the running pressure of the core equipment in the hybrid network.Thirdly,this thesis proposes a traffic shaping strategy driven by user quality of experience for HTTP adaptive video streaming in hybrid optical-wireless broadband access networks.Based on the traffic shaping of the gateway,a reasonable QoE evaluation model is established based on the user's preference for the video quality level stability,the fidelity of the optimal quality level and convergence speed rate.Then the video rate under the best QoE evaluation and the proposed adaptive token bucket algorithm are combined to make a reasonable traffic shaping of the HAS service.The simulation results show that the proposed strategy can effectively improve the user experience of video users.Finally,the work of this thesis is summarized and the future research work is expected.