基于时槽预定的加权公平调度策略  

Timeslot-Reservation Based Weighted Fair Scheduling

作　　者：李季[1] 曾华燊[1] 郭子荣[1] 

机构地区：[1]西南交通大学信息科学与技术学院,四川成都610031

出　　处：《软件学报》2007年第10期2605-2612,共8页Journal of Software

基　　金：Supported by the National Natural Science Foundation of China under Grand No.60372065 (国家自然科学基金)

摘　　要：面向以太网的物理帧时槽交换(Ethernet-oriented physical frame timeslot switching,简称EPFTS)技术以用户域内使用最为广泛的以太网MAC(media access control)帧为运载对象、以定长物理层帧EPF(Ethernet-oriented physical frame)的传输时间为时槽,作为数据传输与交换的基础.针对EPFTS交换技术的特点,提出了一类新的调度策略——时槽加权的公平调度原则(timeslot-reservation based weighted fair scheduling,简称TRWFS),以解决EPFTS交换机中的业务数据调度问题.TRWFS以连接建立阶段各业务流预定的时槽数为基础,控制交换矩阵仲裁过程中各输入端向输出端请求转发信元的时刻,借用一般轮询算法的二相迭代机制来解决端口冲突问题.还给出了TRWFS的3种实现算法,表明TRWFS的实现复杂度可与一般Round-Robin调度算法相当.仿真实验结果进一步表明,即使在重负载条件下,TRWFS仍可有效保障EPFTS交换机各端口对上的预定时槽数,并在平均传输时延和吞吐率保障方面优于其他经典调度算法.EPFTS （Ethernet-oriented physical frame timeslot switching） is designed to carry the most popular data link frames, i.e., Ethernet MAC （media access control） frames, and the transmission time for an Ethernet-oriented physical frame （EPF） is defined as a timeslot for transmission and switching the physical layer frames. To resolve the data scheduling problem in EPFTS switches, this paper proposes a new type of scheduling mechanism called TRWFS （timeslot-reservation based weighted fair scheduling） based on the characteristics of EPFTS. The principle of TRWFS is to control the request time of inputs to outputs according to the number of reserved timeslots of each traffic flow and utilize a two-phase iteration mechanism to resolve request conflicts problem. This paper also puts forward three algorithms of TRWFS to show that the implementation complexity of TRWFS is about the same as round-robin based scheduling algorithms. Further simulation results show that even under heavy load conditions, TRWFS algorithms can better guarantee reserved timeslots of each I/O pairs and get better delay and throughput performance compared with other typical algorithms.

关 键 词：单物理层用户数据传输平台网络 面向以太网的物理帧时槽交换 输入排队 时槽预定 公平调度 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]