EPON系统中的MPCP协议研究

在对近几年提出的EPON系统进行深入研究的基础上．针对EPON系统点到多点的特殊拓扑结构、详细介绍了用于EPON系统控制管理的多点控制协议(MPCP)．包括5个控制帧的结构、各个字段的含义等，并阐述了用MPCP协议如何实现点到多点的控制功能．即实现启动注册、测距和时延补偿、时隙分配的原理，对推动EPON系统的研究发展具有一定的价值，为同行提供了有益的参考。     

一种半双工EPON系统的性能分析

提出了改进的上行光环回技术和冲突检测技术以解决现有全双工CSMA/CD EPON方案中上行环回光功率损耗过大和冲突检测实现困难等问题.提出了一种半双工CSMA/CD EPON方案.通过理论推导和仿真验证,说明了虽然接入网系统中上/下行业务量往往是高度不对称的,该半双工CSMA/CD EPON的吞吐量性能与现有的半双工以太局域网的吞吐量性能相当.     

SMUX协议及其在EPON中的应用

着重介绍了SMUX协议的内容及工作原理,并讨论了SMUX协议作为SNMP代理的扩充的实现方法,给出了在EPON系统中利用SMUX协议实现分布式网络结构的具体方案。     

BEPC-Ⅱ同步光光学诊断系统研究

提出了用同步光进行BEPC-Ⅱ束流测量.分析了用同步光进行BEPC-Ⅱ光学诊断的可行性,并详细讨论了BEPC-Ⅱ同步光光学诊断系统实现方案.     

网页提交时的日期过滤

本文给出了一个用JavaScript实现日期过滤函数的网页示例，并对其作了详细解释。     

光通信 光纤通信

TN914 2005032181 RMON的功能及其在EPON系统中的优化设计=Func- tion of remote monitoring and its design in EPON[刊,中]／ 江国舟(华中科技大学光电子工程系．湖北,武汉 (430074)),刘海…∥光通信研究．-2004(4)．-26-28 在交换式局域网中,RMON代理可以监视一个网段的 所有流量,最适合放置RMON代理的位置就是交换机内 部。介绍了RMON的功能,然后讨论了影响RMON代理     

用WinDriver和DirectDraw快速开发图像采集卡检测程序

为了快速检测实验室新开发的图像采集卡,介绍了用WinDriver编写采集卡驱动程序的原理,详细地说明了几个主要函数的使用方法,可以方便地在用户态下实现读写寄存器、中断使能和DMA传输等功能。简述了Direct Draw的工作原理和优点,说明了图面切换、图面拷贝等操作以及相应函数的使用。详细地说明了检测程序的实现思路。该方法可以扩展到对其它类型采集设备的检测。     

基于单原子的量子计算机

介绍了量子计算机的最新发展状况。对实现量子计算机的各种实验方法作了简介和比较。特别是详细介绍了最近Ｋａｎｅ提出的一种方案，并提出了一种新的用扫描隧道显微镜实现基于单原子的量子计算机方案。     

原子束计算全息技术的原理与实现

提出用计算全息技术来实现原子束全息成像，降低了原子束全息的实现难度.首先论述了原子束的波动性质以及如何形成相干性能良好的准单色原子波包，然后讨论了原子束计算全息片的设计步骤，并给出了制作完成的SiN薄膜计算全息片，最后详细介绍了原子束全息的实现方案.     

光纤传感器在线检测耐火砖厚度的研究

本文详细论述了光纤在线砖厚传感器的原理,阐述了砖厚偏差量的光纤测量方法以及光纤砖厚传感器的研制。并讨论了用V/F转换器实现A/D转换和单片机智能系统的设计特点。     

Variable disparity estimation based intermediate view reconstruction in dynamic flow allocation over EPON-based access networks

In this paper, a variable disparity estimation (VDE)-based intermediate view reconstruction (IVR) in dynamic flow allocation (DFA) over an Ethernet passive optical network (EPON)-based access network is proposed. In the proposed system, the stereoscopic images are estimated by a variable block-matching algorithm (VBMA), and they are transmitted to the receiver through DFA over EPON. This scheme improves a priority-based access network by converting it to a flow-based access network with a new access mechanism and scheduling algorithm, and then 16-view images are synthesized by the IVR using VDE. Some experimental results indicate that the proposed system improves the peak-signal-to-noise ratio (PSNR) to as high as 4.86 dB and reduces the processing time to 3.52 s. Additionally, the network service provider can provide upper limits of transmission delays by the flow. The modeling and simulation results, including mathematical analyses, from this scheme are also provided.     

Hybrid multiplexed OFDM-DWDM-EPON access network

For bottleneck problem of the broadband access networks, Ethernet-PON comes out as a striking and promising solution. Even though, EPON nodes necessitate a cost-effective up-gradation, WDM based topology proves to be a vigilant up-grading approach that deals with the deployment of multiple wavelengths in the upstream/downstream directions. Furthermore, only EPON nodes with privileged traffic can be WDM-upgraded. Accordingly, we propose and demonstrate a hybrid multiplexed OFDM/DWDM-EPON access network employing OSSB modulation scheme. Case A demonstrates a single channel OFDM-OSSB-EPON system and achieves a fiber link of 27 km with split ratio of 16. Afterwards, a contrast between OFDM-EPON and conventional EPON (C-EPON) after a fiber link of 20 km with split ratio of 16 is carried out. Case B targets the transmission of two channels with channel spacing of 0.1 nm to realize OFDM-DWDM-OSSB-EPON system and achieves a fiber link of 20 km with split ratio of 32.     

Bandwidth Allocation Method by Service for WDM EPON

A WDM(Wavelength Division Multiplexing) EPON(Ethernet Passive Optical Network) is an economical and efficient access network that has attracted significant research attention in recent years. A MAC(Media Access Control) Protocol of PON is based on TDMA(Time Division Multiple Access) basically, we can classify this protocol into a fixed length slot assignment method suitable for leased line supporting Qos(Quality of Service) and a variable length slot assignment method suitable for LAN/MAN with the best efforts. In this paper, we present bandwidth allocation method by service for WDM EPON and verify this method by simulation results.     

Variable TDMA MAC Protocol For WDM EPON

A MAC(Media Access Control) protocol, one of the most important technologies for an EPON(Ethernet Passive Optical Network), contains a scheduling algorithm to avoid collisions in shared links and assigns an effective bandwidth when ONUs (Optical Network Units) transfer signals upward. The current paper proposes a MAC Protocol that operates a TDMA(Time method with a variable slot assignment to overcome short of bandwidth using by the number of n wavelength., the next generation access network. To verify the above, the current study also implements an EPON model using OPNET as the simulation tool.     

Analysis and testing of total ionizing dose effect on several commercial optical transceivers via gamma-ray radiation

In our Letter, we selected several commercial optical transceivers, which consist of single-channel transceiver modules, parallel transmitting and receiving modules, and Ethernet passive optical network(EPON) optical line terminal(OLT) and optical network unit(ONU) modules, to do the total ionizing dose(TID) testing via the gamma-ray radiation method. The changing of current and receiver sensitivity of optical transceivers is discussed and analyzed. Based on the TID testing exposed to a TID of 50 krad(Si) at a dose rate of about 0.1 rad(Si)/s,the performance of single-channel transceivers and parallel receiving modules has not changed after 50 krad(Si)exposure, the parallel transmitting and EPON ONU modules have not worked after 40 krad(Si) and 47 krad(Si)exposure, the EPON OLT module has bit error in the process of irradiation, and it can work well after annealing;the reason for the error of OLT is analyzed. Finally, based on the theoretical analysis and testing results, this Letter provides several design suggestions to improve the reliability for optical transceivers, which can be referenced by satellite system designation for various space missions.     

Performance Comparison Between Full-Duplex and Half-Duplex CSMA/CD EPON

In this paper, we compare the throughput and delay performance between the full-duplex and half-duplex CSMA/CD EPON systems by theoretical derivation and simulation. We conclude that it's preferable to implement the full-duplex system.     

An Improved Dynamic Bandwidth Allocation Algorithm for Ethernet PON

This paper proposes an improved Dynamic Bandwidth Allocation (DBA) algorithm for EPON, which combines static and traditional dynamic allocation schemes. Simulation result shows that the proposed algorithm may effectively improve the performance of packet delay.     

On WDM RoF–EPON link using OSSB transmission with and without DCF + FBG

A system is presented which uses optical SSB transmission on WDM RoF–EPON link to compensate dispersion and FWM with DCF and FBG. Performance of the system is improved by 8.91% with the use of DCF and FBG for equal spacing between the channels and it is further increased by 9.51% by keeping unequal spacing between the channels. Results are compared for equal and unequal spacing with and without DCF and FBG. BER, Q factor and eye diagrams have been analyzed for evaluating the performance of the system.