AN IMPROVED EPON UPSTREAM TRANSMISSION SCHEME WITH ZERO INTER-PERIOD IDLE LOSS

Existing Ethernet Passive Optical Network (EPON) Dynamic Bandwidth Allocation (DBA) algorithms suffer from the disadvantage of idle time loss,which lower the upstream bandwidth utilization.This letter ...     

Packet Delay Analysis of Symmetric Gated Polling System for DBA Scheme in an EPON

In this paper, we analyze the mean packet delay of a dynamic bandwidth allocation (DBA) scheme in an Ethernet passive optical network (EPON). We propose the interleaved polling system with a gated service discipline and a two-stage queue in order to investigate the delay performance of DBA scheme in an EPON. We assume that input packets arrive at an optical network unit (ONU) according to a Poisson process from several types of users. We use a continuous time queueing model in order to find the mean packet delay and the mean cycle time of an arbitrary packet. We obtain the closed form solution for the mean packet delay of the proposed gated polling system with a two-stage queue. We obtain another result on the mean packet delay by solving a system of linear equations derived from the moments of the queue length distribution. We give some numerical results to investigate the delay performances for the symmetric polling system with statistically identical stations. In addition, we compare numerical results on the closed form solution with numerical results on a system of linear equations.     

GPON的MAC协议设计

参照ITU T建议草案:吉比特无源光网络传输汇聚层规范(G.GPON.gtc),提出了一种支持分组业务接入的媒质接入控制(MAC)协议.通过仿真建模对该协议的性能进行了分析.     

光无线混合宽带接入网QoS感知DBA算法

针对光无线混合宽带接入网的特点,提出一种考虑公平性的Qo S感知DBA算法(QDBA)。仿真结果表明:与已有算法相比,QDBA具有较高的吞吐量和较低的平均时延,同时具有更好的公平性和Qo S保障。     

基于OPNET对SSA的EPON系统性能分析

对采用静态时隙结构的EPON系统如何与高度突发数据业务相结合进行了研究。并用OPNET创建了一个采用静态时隙分配(SSA)的上行系统,且确定合适的参数进行了EPON系统性能的仿真分析。仿真结果表明:基于SSA的EPON显然不适合高突发与高负载的业务流,但在负载小于0.47时,该系统性能良好。在长距离的情况下,基于动态带宽分配(DBA)的EPON轮询周期较长,使得系统效率降低,因而在长距离情况下建议采用静态带宽分配(SBA)算法。     

基于国际标准的新型EPON动态带宽分配方案

提出一种新的基于国际标准和区分服务(Differentiated Service)的以太无源光网络(EPON)动态带宽分配(dynamic bandwidth allocation,DBA)方案,该方案不仅能够在上行方向为多个光网络单元(Optical Network Unit,ONU)高效并公平地分配有限的带宽,而且能够最大限度地保证不同ONU间及不同通信等级间的公平性以及高等级通信的服务质量(QoS)要求.仿真结果证明,与现有算法相比,本算法在延时和利用率方面均有改进,在重负荷情况下改进更明显.     

一种新的EPON动态带宽分配方法的研究

传统的EPON系统的上行带宽分配方案是类似于IPACT的基于时隙长度分配的,这样虽然使上行信道得到了充分的利用,但是由于包延迟变化较大,不适合实时业务的传送.介绍了一种混合时隙长度/速率DBA方案,它可以为不同业务提供不同的QoS,既满足了实时业务的需要,又在一定程度上提升了网络的利用率.     

一种WDM-EPON的DBA算法及其改进

介绍了一种WDM-EPON的DBA算法并对其进行改进,改进的算法能根据ONU端不同的业务类型情况对波长和带宽进行分配,以支持多业务接入的QoS,从而使整个网络带宽的得到更公平有效地分配,最后用OPNET进行仿真,结果表明改进的算法能为不同等级的业务流提供相应的带宽,时延等QoS保证.     

Technology for extending transmission distance of EPON system

At present, the maximal transmission distance between the optical line terminal (OLT) and opticalnetwork unit (ONU) of an Ethemet passive optical network (EPON) system is 20 km.However, this distance should be extended to 50 km or even longer in some applications such as fiber to the village (FTTV).A method for extending the transmission distance of an EPON system is proposed in this paper, in which the optical power amplifier and the adjustment of dynamic bandwidth allocation (DBA) are the key technologies.     

Ms-EPON系统中的弹性保护倒换技术

创新地提出了一种应用于多业务EPON系统的保护倒换技术--弹性保护倒换技术。阐述了弹性保护倒换Ms-EPON系统的网络拓扑结构,论述了设计实现方案,分析了弹性保护倒换技术的特点。