10G EPON中一种基于ALR的节能机制研究

提出了一种适用于10G EPON的ALR节能机制,并详细阐述了其在10G EPON系统中的设计思路.该节能机制采用了基于带宽的单阈值控制策略和双向控制帧信息交换机制,降低了ONU的功率损耗.仿真结果验证了该节能机制的有效性.     

EPON中ONU的自动发现过程和冲突解决方案

在EPON中,所有的ONU只有在得到了OLT的授权后才能发送数据。因此OLT必须周期性地执行自动发现过程,以便发现网络中是否加入了新的ONU。本文主要说明EPON中的ONU的自动发现和注册过程,定义了这个过程中使用的MPCP消息。并简单介绍了当有多个ONU企图在同一时刻注册而发生冲突时的解决方案。     

EPON系统中ONU的自动加入

ONU的注册是EPON系统正常运行的前提．在系统运行中新ONU自动加入或故障ONU重新加入而不影响正常运行的ONU是PON系统可扩展性好、操作维护方便的重要体现．文章分析了对ONU自动加入的基本需求,详细描述了ONU自动加入过程,并对冲突处理方法进行了分析比较。     

EPON MPCP协议一致性测试的研究

随着EPON的部署规模逐渐增大,对EPON系统的测试越发显得重要.多点控制协议(MPCP)是EPON的核心控制协议,MPCP协议一致性验证对EPON设备互通测试和运行维护管理都是必要的.文章针对被动测试下MPCP协议一致性的验证方法展开研究.通过分析比较几种典型状态机模型,确定采用NFSM模型描述MPCP协议,设计并实现了MPCP协议一致性验证的算法.该算法已应用于参与研发的EPON被动测试仪中,能够完成对协议交互的正常过程及典型错误过程的识别.     

以太网无源光网络协议和常见故障简析

阐述了MPCP（多点控制协议）中ONU（光网络单元）注册的详细过程及在此过程中常见的故障,运用总结了在实现EPON（以太网无源光网络）协议分析能力的设计与研发中的经验,提出以EPON协议的解码分析为基础的分析处理方法,为EPON中层出不穷的疑难故障提供一种定位和解决方案.     

基于签密算法的EPON认证方案研究

介绍了签密密码体系和ONU/OLT注册过程,提出了一种适用于EPON安全注册的双向认证方案.分析了该方案在EPON注册认证过程中一逻辑步完成加密和签密的认证效率优势,与两种传统公钥EOPN双向认证方案相比,该方案自定义控制帧的快速封装特性能确保认证信息的机密性.     

利用动态队列缓存技术实现10G EPON ONU的节能设计

结合10G EPON ONU上行通道突发传输的特点,提出了利用动态队列缓存技术实现10G EPON ONU节能设计的方法。在协议分析的基础上,用OMNet++搭建了10G EPON仿真模型,得出了10G EPON ONU上行通道队列缓存实现的量化参考数据,并在FPGA平台上进行了仿真实验。     

10G EPON市场潜力巨大 Cortina推三款新品迎接未来机遇

近日,为应对10G PON市场的快速发展,通信半导体系统提供商Cortina Systems(Cortina,科缔纳)针对客户需求推出了三款产品,包括业界首款4端口10G EPON OLT设备CS8124以及10G EPON ONU设备CS8160,同时针对中国市场的特殊情况也推出了双模EPON/GPON ONU设备CS8232。双模ONU在中国成趋势在国外,运营商主     

百兆EPON系统的FPGA设计

在分析EPON多点控制协议(MPCP)的基础上,对EPON的层次模型以及各项关键技术进行了研究,设计了EPON系统的FPGA实现方案,研制了一套带局端设备(OLT)和用户端设备(ONU)的百兆EPON实验系统。测试结果表明,系统性能达到了EPON技术对丢包率和带宽的要求。     

EPON接入网的关键技术研究

介绍EPON的网络结构、层次模型，探讨多点控制协议(MPCP)的关键问题，包括：系统同步、测距、ONU的自动识别、TDM业务传输、信息安全及以太网管理等关键技术，提出OLT及ONU的软硬件实现方案。     

EPON系统中ONU告警仿真的设计与实现

在EPON系统工程应用中,如何在实验室环境下,用有限的ONU设备,测试大规模工程应用条件下EMS对于ONU告警的处理能力,一直是困扰业界的难题。创新地提出了采用模拟ONU进行告警仿真的思想。经实验验证,该设计完全可以满足需求,降低了EPON系统测试的复杂度,缩短了EMS测试周期,节省了测试成本,对于促进行业的发展有着重要的参考价值。     

EPON中ONU大规模软件升级技术研究与设计

如何快速稳定地对数量众多的ONU进行软件升级是EPON系统面临的一个重要问题,文章提出一种实现ONU软件批量升级、定时升级和自动升级的方法,它由OLT通过OAM协议发启ONU升级事件,然后ONU主动通过FTP(文件传输协议)完成文件下载、数据校验和程序烧写等操作步骤,同时OLT还需监控、维护和管理ONU软件升级的状态.     

Bridging electrical power and entropy of ONU in EPON

This letter deliberates bridging of overall electricity power requirements of the optical network unit(ONU) with the entropy noted through the ONU state transition models considered in ethernet passive optical network(EPON). The entropy depends on the steady state and transition probabilities of data. On the other hand, the power requirements(consumption) of ONUs depend on the steady sate probability of ONUs. The potential relation derived between the entropy and electrical power reveals that they related exponentially but for their logarithmic reliance. Also, the relation is validated through the numerical simulation. The deduced relation has its importance to understand the nuances of one entity given the other.     

EPON系统中ONU应用场景的探讨

以太网无源光网络(EPON)是一种新型的光纤接入技术,它采用点到多点的网络拓扑结构、无源光纤传输。探讨了在实际中根据各种应用场景的不同,系统中的光网络单元(ONU)可以分为单住户单元(SFU)、家庭网关单元(HGU)、单商户单元(SBU)、多住户单元(MDU)和多商户单元(MTU)。指出不同类型的ONU所面向的用户是不同的,所支持的端口类型、端口数目和功能也各不相同。     

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承载IPTV组播业务的设计

提出一种在EPON系统上实现IPTV组播业务的方案,该方案通过重新定义逻辑链路标识(LLID)作为VLAN的标志,把具有相同节目频道业务的ONU划分到同一个VLAN上,实现组播功能。并在OLT和ONU分别执行因特网组管理协议代理(IGMP Proxy)和监听(IGMP Snooping)机制对组播成员进行管理,大大减少了组播控制报文的开销。最后用现场可编程门阵列(FPGA)设计实现该方案的主要功能模块,通过仿真验证该方案的可行性。     

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.     

高效公平的EPON TCP性能调节机制

 提出了一个基于效用的EPON公平性指标算法.通过建立一个基于ACK特征包的ACK压缩和解压缩机制,消除了上游ONU的ACK对下游ONU下行数据流的影响,在保证ONU之间的公平性的同时,提高了带宽的使用效率.通过建立一个效用分类器,在维护了优先级机制扩展性的前提下,提高了并发的同业务类业务流之间的公平性.通过建立一个时延公平调度机制,在保证带宽的使用率前提下,保证了ONU的业务类之间的时延公平性.仿真结果很好验证了本机制的优点.     

Energy-saving scheme based on downstream packet scheduling in ethernet passive optical networks

With increasing network sizes, the energy consumption of Passive Optical Networks (PONs) has grown significantly. Therefore, it is important to design effective energy-saving schemes in PONs. Generally, energy-saving schemes have focused on sleeping the low-loaded Optical Network Units (ONUs), which tends to bring large packet delays. Further, the traditional ONU sleep modes are not capable of sleeping the transmitter and receiver independently, though they are not required to transmit or receive packets. Clearly, this approach contributes to wasted energy. Thus, in this paper, we propose an Energy-Saving scheme that is based on downstream Packet Scheduling (ESPS) in Ethernet PON (EPON). First, we design both an algorithm and a rule for downstream packet scheduling at the inter- and intra-ONU levels, respectively, to reduce the downstream packet delay. After that, we propose a hybrid sleep mode that contains not only ONU deep sleep mode but also independent sleep modes for the transmitter and the receiver. This ensures that the energy consumed by the ONUs is minimal. To realize the hybrid sleep mode, a modified GATE control message is designed that involves 10 time points for sleep processes. In ESPS, the 10 time points are calculated according to the allocated bandwidths in both the upstream and the downstream. The simulation results show that ESPS outperforms traditional Upstream Centric Scheduling (UCS) scheme in terms of energy consumption and the average delay for both real-time and non-real-time packets downstream. The simulation results also show that the average energy consumption of each ONU in larger-sized networks is less than that in smaller-sized networks; hence, our ESPS is better suited for larger-sized networks.     

High‐reliability grid architecture supporting discretionary and efficient communication between ONUs in metro‐access optical network

Direct communication of optical network units (ONUs) is an important function in metro‐access optical network. In this paper, a grid architecture supporting discretionary and efficient communication between ONUs is proposed. The grid architecture is built by using two interconnecting fibers to connect every two ONUs; this can give protection to every ONU by four ONUs. Additionally, the network reliability can be improved greatly. Grid topology of ONUs leads to their discretionary direct communication. In this topology, direct communication signal can be transmitted from one ONU to another ONU directly, rather than being returned to remote node central office. Also, the efficiency of direct communication can be improved remarkably with the proposed architecture. Finally, the performance analyses and the simulation results verify the feasibility of the proposed architecture. When the n reaches to 10, the reliability of downstream and direct communication signals is all larger than 99.993%.