实现三网融合的FTTH工程设计

光纤到户作为一种能够高效承载语音、数据、视频等多业务、具有超高带宽的网络解决方案,引起人们越来越多的兴趣,被公认为是接入网发展的最终目标.文章给出了基于GPON技术实现FTTH的基本设计方案,施工方式和测试验收标准,基于该方案实现了"三网融合"和全业务高速接入.     

有线宽带网络事业发展的福音：1550＋GEPON技术方案

本文论述了下一代宽带网络运营格局,基于IEEE802．3ah标准而提出了适合中国国情的1550 GEPON的技术及未来十年发展到FTTH的平滑升级方案。广电运营商若在技术方案上借助1550 GEPON架构极具竞争力的光接入网,则可领先其他运营商快速抢占未来的居民市场。从长远看,1550 GEPON将是一项可使有线电视网络运营商在未来用户市场上,领先传统电信TDM业务运营商的制胜关键技术。     

氨水存放试剂瓶颜色的选择

氨水见光不分解,所以理论上氨水不需要放在棕色瓶中,而生产厂家和实验室却都在用棕色瓶存放氨水,针对此问题,通过数字化实验来探究氨水存放在哪种颜色的试剂瓶中更为合适。实验结果表明氨水存放在无色试剂瓶中更合适。     

Synthesis,characterization, and properties of colorless rigid-rod poly(benzobisthiazole) derived from bicyclo[2.2.2]octane

Polycondensation in polyphosphoric acid of 2,5-diamino-1,4-benzene dithiol dihydrochloride with bicyclo[2.2.2]octane-1,4-dicarboxylic acid, as well as the corresponding dimethyl ester or diacid chloride, led to rigid-rod benzobisthiazole polymers. Colorless and soluble polymers with intrinsic viscosities as high as 30.6 dL/g (methanesulfonic acid, 30°C) were obtained. The ultraviolet-visible spectrum of a polymer film cast from methanesulfonic acid under reduced pressure displayed no absorptions in the visible range (400–900 °m). The polymer was thermooxidatively stable up to 420°C in air as determined by thermogravimetric analysis. Fibers spun from a lyotropic polyphosphoric acid solution exhibited a tensile strength of 300–450 Ksi, a modulus of 26 Msi, and a compressive strength of 53 Ksi. Wide-angle X-ray scattering patterns of polymer fibers indicated a 3-dimensional crystal structure rather than a nematic liquid crystal structure. © 1994 John Wiley & Sons, Inc.     

A Transparent,Smooth, Thermally Robust,Conductive Polyimide for Flexible Electronics

In this work, a thermally and mechanically robust, smooth transparent conductor composed of silver nanowires embedded in a colorless polyimide substrate is introduced. The polyimide is exceptionally chemically, mechanically, and thermally stable. While silver nanowire networks tend not to be thermally stable to high temperatures, the addition of a titania coating on the nano­wires dramatically increases their thermal stability. This allows for the polyimide to be thermally imidized at 360 °C with the silver nanowires in place, creating a smooth (<1 nm root mean square roughness), conductive surface. These transparent conducting substrate‐cum‐electrodes exhibit a conductivity ratio figure of merit of 272, significantly outperforming commercially available indium‐tin‐oxide (ITO)‐coated plastics. The conductive polymide is subjected to various mechanical tests and is used as a substrate for a thermally deposited, flexible, organic light‐emitting diode, which shows improved device performance compared to a control device made on ITO coated glass.     

Performance evaluation of bi-directional passive optical networks in the scenario of triple play service

In this paper, the performance of bi-directional passive optical network (BPON) has been evaluated and compared at different bit rates in the scenario of triple play service. The triple-play service is realized as a combination of data, voice and video signals. This architecture is investigated for symmetrical data traffic for uplink and downlink transmission and its performance is also evaluated in terms of Q-factor and eye height at different transmission distance. The Q-factor results show the acceptable performance at 10 Gbps data rate for downstream and upstream transmission, as it accommodates 128 optical network units (ONUs). Further the proposed system's performance is compared with the current state-of-the-art PON architectures.     

EPON系统中PCS层方案的设计

由于物理编码子层(PCS)处于EPON系统物理层的最高层,它的功能实现对于上层而言起着重要的作用.详细介绍了PCS层的功能,并根据功能对基于光网络单元(ONU)端的发送模块和接收模块的设计进行阐述,并在此基础上介绍了PCS层消息的处理流程.     

PON在陕西移动的应用策略

简要介绍了PON基本概念;对GPON和OEPON模式进行了比较;对GPON模式进行了重点分析;根据陕西移动全业务运营下的固定宽带接入要求,结合实际案例提出了GPON建设方案。     

海门城区有线电视EPON网络规划设计方案

随着三网融合时代的到来,有线电视从模拟向数字全面转换,对有线电视网络进行双向化改造也变得更加迫切。EPON方案作为一个无源光网络非常适合广电网络的双向化改造,该方案在技术上有前瞻性,在网络功能上有扩展性,介绍海门城区有线电视双向网络改造思路和规划方案,为双向化网络改造提供参考。     

基于ONU和OLT休眠-唤醒模式的WDM-PON绿色接入网

提出了基于ONU和OLT休眠-唤醒节能工作模式的WDM-PON绿色接入网设计.介绍了WDM-PON的节能原理及0LT、ONU的休眠模式和唤醒模式.当休眠模式时间和唤醒模式时间分别设置为20ms和2ms时,每个OLT PON线路卡和ONU家庭路由器可以有效减少约70％的功率消耗.