摘要
介质访问控制(MAC)是以太无源光网络(EPON)中最重要的因素之一。为了防止上行方向数据冲突,必须设计一个好的MAC机制,使光网络单元(ONU)能有效地共享上行信道。现提出了一种MAC调度算法——最早包优先(EPF)算法,就是根据每个ONU队列的首包到达的时间进行排序,每次轮询首包最早到达的ONU。通过模拟结果与最常用RR(Round-Robin)算法包延时进行比较,发现这种算法可以大大改善网络的性能。
MAC is one ot the most important factors in Ethernet passive optical networks （EPON）. In order to prevent the data from collision in upstream direction, an EPON system must employ a good MAC mechanism to arbitrate the access to the shared upstream channel and at the same time to effectively share the bandwidth of the upstream channel among all optical network units （ONUs）. An adaptive scheduling algorithm for MAC in an El＇ON system is presented. It is called earliest-packet-first （EPF） algorithm, which adaptively schedules the transmission order based on the arrival time of the first packet waiting in each ONU queue and polls the ONU with the first packet earliest arrived. Through comparing the simulation results of the proposed scheduling algorithm with the most common-used round-robin scheduling algorithm in terms of packet delay, it is shown that the present algorithm can effectively improve the network performance.
出处
《光纤与电缆及其应用技术》
2007年第4期43-46,共4页
Optical Fiber & Electric Cable and Their Applications
