一种基于弱实时的加权公平队列调度算法

针对目前的一些实时应用，例如视频传输应用、网络传输延迟和网络资源利用率相矛盾的问题，结合弱实时理 论，提出了基于弱实时约束的广义处理器共享(WGPS)的调度策略以及面向分组模型的基于弱实时约束的加权公平队列 (W2FQ) 调度算法.该算法以加权公平队列(WFQ)调度算法为基本算法，根据丢失率参数和弱实时约束的要求，适当丢失一 些分组，从而可以降低网络传输延迟和减小网络服务带宽.理论分析和仿真结果表明，该算法是一个公平可行的调度算法 ，而且与WFQ算法相比，实时应用能够得到更及时的传输且保证服务质量不受影响.

Weighted fair queuing scheduling algorithm based on weakly hard real-time constraint

In order to weaken the incompatibility between transmission delay and network resource utilization of some real-time applications,such as video transmission application,by integrating weakly hard real-time constraint guarantee,the weak generalized processor sharing(WGPS) scheduling policy based on fluid model and weak weighted fair queuing(W~2FQ) scheduling algorithm based on packet model were proposed.W~2FQ scheduling algorithm improved the weighted fair queuing(WFQ) scheduling algorithm.W~2FQ scheduling algorithm dropped some optional packets according to the miss ratio and weakly hard real-time constraint of real-time applications,therefore,the transmission delay and the network service rate of real-time applications were reduced effectively.Theoretical analysis with network calculus and simulation results show that W~2FQ scheduling algorithm has good performances in fairness and feasibility,and that real-time applications can be transmitted better under W~2FQ than under WFQ.