P2P流媒体的数据调度算法

数据驱动型覆盖网络中的数据调度算法是影响P2P流媒体系统性能的重要因素，为了解决当前算法未能有效利用数据块和节点的特性导致流媒体服务质量差的问题，提出了一种基于数据块优先级和节点能力度的数据调度算法。该算法能够根据数据块的稀缺性、紧迫性得到块的优先级大小，根据节点的上行带宽、在线时间、相对距离得到节点能力度的大小，使优先级高的数据块和能力度大的节点优先被请求，减少了数据块的播放等待时间。在OPNET网络仿真实验表明该算法能够有效降低流媒体播放系统的启动延时和服务器的负载。

Data scheduling algorithm of P2P streaming media

The data scheduling algorithm in data-driven overlay network is identified as one of the most influential factors affecting system performance of P2P streaming media.Considering the fact that the current algorithm fails to make use of the data blocks and nodes efficiently,which leads to low-quality streaming media services,a new method for data scheduling algorithm was proposed in this study based on both priority of data blocks and capacity of nodes.This algorithm could get priority value according to the scarcity and urgency of blocks.It also could get the capacity of the nodes according to uplink-bandwidths,time-online and relative distance of the nodes.With the utilization of this algorithm,higher priority blocks and higher capacity nodes were requested,and the waiting time to play was decreased.The simulations in the OPNET network indicate that the algorithm can efficiently reduce start-up delay of streaming media playing system and the server load.