摘要
EPON系统的动态带宽分配算法应当达到较高的信道利用率,同时保证业务的服务质量及公平性。分析了影响信道利用率的各种因素,提出将ONU分批交织以消除信道闲置,授权基于以太帧边界以消除授权时隙末的空闲,采用尽量大的轮询周期等三项措施,提高信道利用率。提出三种层次的公平性,主张保证用户间的公平性。提出为用户的各优先级业务分别授权、按SLA协议带宽比例授权,支持QoS的同时实现用户之间和优先级业务之间的公平性。遵照这些原则设计的算法可实现信道利用率的最大化,同时保证各种用户的服务质量。
A good dynamic bandwidth allocation scheme is expected to support QoS and to be efficient and fair. All factors concerning link utilization are studied, thus three principles are proposed to boost link utilization, which areavoiding idle stage of uplink during the DBA running, removing unused slot remainder and keeping the cycle length as long as possible. Practical methods complying with these principles are also proposed, such as interleaved transmission, granting based on frame-boundary-report. Three kind of fairness are presented. Among them, inter-user fairness is significant. To support QoS, DiffServ model should be adopted. A feasible way to guarantee both inter-user fairness and inter-class fairness is to hierarchically grant to each class of every subscriber in proportion to subscriber＇s agreement bandwidth.
出处
《微计算机信息》
2009年第18期158-160,共3页
Control & Automation
