WDM EPON中的动态波长带宽分配算法

基于WDM EPON系统结构和已有波长带宽分配算法(DWBA)的不足,提出了一种结合流量预测与预分配机制的动态波长带宽分配算法--DWBPA.仿真表明在不同网络负载情况下,该算法不仅保证了波长带宽分配的公平性,而且能够满足高优先级业务的延时要求.     

混合TDM/WDM EPON中动态带宽分配算法

针对TDM EPON向WDM EPON升级过程中各个光网络单元(ONU)支持波长数不尽相同的特点,提出一种基于波长间负载均衡的动态带宽分配算法(LB-DBA).该算法在分配带宽时考虑波长信道的带宽约束,同时分两步确定授权给ONU的发送波长和发送时间,有利于波长信道间的负载均衡.仿真结果表明,LB-DBA可以避免已有算法在混合TDM/WDM EPON中可能出现的授权周期长度增加和资源利用率低等问题,有效改善网络性能.     

EPON动态带宽分配算法研究

文章针对EPON上行多路访问机制,提出了一种新的动态带宽分配算法:动态最大访问窗口(DMTW)算法.给出了模型和仿真结果,证明了这种算法的正确性和优势.     

支持多业务预测机制的EPON动态带宽分配算法

针对IPACT算法中存在较严重的轻载惩罚现象,提出了一种支持多业务预测机制的动态带宽分配算法(eIPACT算法).通过估计两个连续轮询之间的不同业务分组的到达量,并给ONU授权额外的带宽,减少了ONU分组中的等待时间和缓存占用.采用多业务优先级调度策略,不仅能避免轻载惩罚还可以保证系统的服务质量.结果表明,该算法既极大...     

支持多业务的EPON动态带宽分配算法

EPON的关键技术之一是动态带宽分配(DBA)问题。为了支持语音、视频、数据等多业务和保证不同的服务质量(Qo S)和有效克服轻载惩罚问题,本文提出了一种支持多业务的EPON动态带宽分配算法。通过对ONU侧的业务按照优先级进行区分,对到来的业务按照严格的优先级排队,以此保证高优先级业务的时延要求;引入预测避免出现了轻载惩罚,在OLT侧预测高优先级业务的到来情况,为ONU多分配预测的带宽大小。实验表明,本文算法提高了网络的服务质量。     

EPON上行信道中的动态带宽分配算法研究

传统的EPON系统的上行动态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.文章提出了一种多级授权分离发送动态带宽分配算法,它可以为不同业务提供不同的服务质量,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.通过仿真测试,发现这种算法均有良好的时延特性和较稳定的队列尺度,能较好地支持多业务优先级的EPON系统.     

EPON中保证QoS的动态带宽分配算法

作为一种新技术，EPON系统采取在下行信道使用广播方式而在上行信道使用时分多址(TDMA)方式，为用户提供共享传输介质的接入方式，因此就需要一种接入控制机制来为用户分配带宽。为了使EPON系统更好地支持QoS并且进一步提高带宽利用率，提出了一种新的固定周期轮询动态带宽分配算法，针对不同时延特性业务采用不同的授权分配算法。算法包括两部分：OLT时ONU的调度以及ONU内部不同优先级的队列之间的调度。最后讨论了包时延、系统吞吐量等仿真结果和性能分析。     

一种改进的EPON动态带宽分配算法

对现有的EPON上行链路动态带宽分配算法进行了改进,有效地提高了带宽利用率和时延抖动两个指标.同时利用OPNET构建了EPON系统仿真模型,仿真结果表明:改进后的算法具有较高的带宽利用率和较低EF业务时延抖动.为制定多业务QoS的EPON上行接入带宽分配标准提供参考.     

基于QoS的EPON系统动态带宽分配机制

通过阐述以太网无源光网络（EPON）系统信道传输数据方式以及动态带宽分配的工作原理,进一步研究了动态带宽分配算法（DBA）在EPON系统中的应用。提出一种基于服务质量（QoS）的EPON系统动态带宽分配机制,该机制根据不同业务的优先级和动态带宽分配算法,灵活地分配上行带宽,提高了带宽利用率,改善了服务质量。     

EPON动态带宽分配算法及仿真

对当前EPON(Ethernet Passive Optical Network)系统中比较经典的动态带宽分配算法进行简要分析,提出了一种支持QoS(Quality of Service)的动态带宽分配算法.算法动态确定轮询周期,充分保证了高优先级业务所需的带宽,同时考虑到了剩余带宽的再分配.仿真结果表明,该算法提高了系统的带宽利用率,提供了更加稳定的QoS.     

Energy-efficient dynamic wavelength and bandwidth allocation algorithm with delay constraint for time and wavelength division multiplexed passive optical networks

Based on offline scheduling and node modular design,an energy-efficient dynamic wavelength and bandwidth allocation algorithm with the delay constraint (EE-DWBA-DC) was proposed.Optical line terminal (OLT) and optical network units (ONU) were considered to save energy.Under the constraint of packet delay,the number of active wavelengths could be reduced as much as possible and the length of polling cycle was increased.At the same time,the uplink and downlink transmission time of OLT and ONU were concentrated to reduce the state conversion times and extend its low-power duration.In addition,the high energy consumption voids of channels were attempted to be minimized.The simulation results verify that the proposed algorithm can reduce the energy consumption of OLT and ONU and the total energy consumption of the whole network under the premise of guaranteeing packet delay constraints.     

一种公平的EPON动态带宽分配算法

提出一种EPON上行链路动态带宽分配算法一周期比例DBA。ONU基于多门限周期地上报带宽请求，OLT根据ONU的带宽请求及其合约带宽进行动态带宽分配。当多个ONU竞争系统带宽时，OLT按照ONU合约带宽的比例进行带宽分配。仿真结果表明：周期比例DBA算法在实现高带宽利用率的同时又具有良好的公平性。     

Experimental demonstration of an improved EPON architecture using OFDMA for bandwidth scalable LAN emulation

We propose and demonstrate an improved Ethernet passive optical network (EPON) architecture supporting bandwidth-scalable physical layer local area network (LAN) emulation. Due to the use of orthogonal frequency division multiple access (OFDMA) technology for the LAN traffic transmission, there is no need to change the existing EPON architecture. Only one receiver at each optical network unit (ONU) is required to detect both LAN traffic and EPON downstream traffic, which makes the proposed system simple and cost-effective. Moreover, flexible assignment of LAN traffic bandwidth is realized by allocating different number of subcarriers or using different modulation formats. The 250 Mb/s 4-quadrature amplitude modulation (4-QAM) and 500 Mb/s 16-QAM OFDM LAN traffic are successfully emulated with the EPON traffic in our experiment.     

一种保证QoS的EPON上行动态带宽分配算法

文章提出了一种新的保证服务质量(QoS)的EPON上行动态带宽分配算法,该算法根据区分服务(Diffserv)模型和服务等级协定(SLA)确定光网络单元(ONU)的带宽分配权重,根据数据QoS的不同分配不同的优先权,这样不但确保了各个ONU的带宽分配和QoS,而且可以满足一些高优先级业务的要求.同时,文章还提出了相应的多点控制协议(MPCP)控制消息格式.     

EPON中节能动态带宽分配算法

结合光网络单元(ONU)休眠控制和动态带宽分配机制,提出一种节能的双向DBA算法。该算法根据上/下行业务量为每个ONU分配合适的上/下行授权带宽,保证每个ONU在上/下行方向都具有较低的传输时延,同时尽可能增加ONU的休眠时间来降低网络能耗。仿真结果表明,与已有算法相比,该算法具有较低的上/下行平均时延,并能减少ONU的能耗。     

EPON中一种动态带宽分配算法

以太无源光网络(EPON)被认为是下一代宽带接入的最有效的解决方案。文章提出了一种新的基于EOPN提供多种服务的动态带宽分配算法。为了能够应用这种算法还给出了协助带宽分配多点控制协议(MPCP)的控制消息的格式。     

一种改进的GPON动态带宽分配策略

利用小波变换将自相似性网络流量的长相关性转化为短相关性,并预测流量的方法,对GPON系统物理媒质控制(MAC)层的关键技术--动态带宽分配(DBA)进行研究.在理论上对一种已有的DBA策略提出合理改进.     

Design and evaluation of scheduling algorithms for TDM/WDM PON based on RSOA

This paper presents a scalable and costeffective hybrid time division multiplexing (TDM)/wavelength division multiplexing (WDM) passive optical network (PON), in which reflective semiconductor optical amplifiers (RSOAs) are used as optical network units (ONUs) and a shared tunable laser and photoreceiver stack locate at the optical line terminal (OLT). Especially,tunable transmitters are not only shared by all ONUs, but also used for both upstream and downstream transmissions. To solve resource contention problem and provide and the ONUs, two novel algorithms are proposed to manipulate the wavelength accessibility and the burst scheduling. The performance of both algorithms in terms of the average packet end-to-end delay and throughput were simulated and evaluated.     

Review on Dynamic Bandwidth Allocation of GPON and EPON

The passive optical network (PON) technology has been drastically improved in recent years. In spite of using the optical technology, the utilization of the entire bandwidth is a very challenging task. The main categories of PON are the Ethernet passive optical network (EPON) and gigabit passive optical network (GPON). These two networks use the dynamic bandwidth allocation (DBA) algorithm to attain the maximum usage of bandwidth, which is provided in the network dynamically according to the need of the customers with the support of the service level agreement (SLA). This paper will provide a clear review about the DBA algorithm of both technologies as well as the comparison.     

MRMC:一种高效的EPON动态带宽分配方案

提出一种高效的EPON动态带宽分配方案,即多标准带宽请求动态带宽分配方案(MRMC).MRMC采用分步请求/集中授权的轮询机制,ONU向OLT提出多个基于不同标准的带宽请求,OLT权衡选择授权带宽.该分配方案既考虑了ONU适时队列负载情况,又解决了阻塞帧问题,同时兼顾了公平性原则,进一步提高了EPON的工作效率.