PDH信号载入SDH系统（Ⅰ）

针对ＰＤＨ与ＳＤＨ的兼容问题，简述了ＳＤＨ的信息结构，并分别介绍了１４０Ｍｂｉｔ／ｓ、３４Ｍｂｉｔ／ｓ、２Ｍｂｉｔ／ｓ信号载入ＳＤＨ系统的过程。     

PDH信号载入SDH系统（Ⅱ）

针对ＰＤＨ与ＳＤＨ的兼容问题，简述了ＳＤＨ的信息结构，并分别介绍了１４０Ｍｂｉｔ／ｓ、３４Ｍｂｉｔ／ｓ、２Ｍｂｉｔ／ｓ信号载入ＳＤＨ系统的过程     

2Mbit／s信号向STM—1的异步映射和复用

根据ＣＣＩＴＴ关于ＳＤＨ技术体制的建议，本文讨论了２Ｍｂｉｔ／ｓ信号向ＳＴＭ－１的异步映射和复用的原理，并提出了映射和复用较易实现的方案。     

浅谈SDH和WDM在通信工程中的应用

一、 ＳＤＨ和ＷＤＭ在技术原理上的异同 ＳＤＨ（同步数字系列）是取代ＰＤＨ（准同步数字系列）的新数字传输网体制,主要针对光纤传输,是在ＳＯＮＥＴ（同步光网络）标准基础上形成的。它把信号固定在帧结构中,复用后以一定的速率在光纤上传送。 ＳＤＨ在电路层上对信号进行复用和上下。当带着信号的光纤通过 ＯＤＦ（光纤分配架）进入 ＡＤＭ分插复用器或上下复用器）时,信号必须通过Ｏ／Ｅ（光／电）转换和设备上的支路卡才能变成２Ｍｂｉｔ／ｓ的基本电信号,并经过通信电缆和ＤＤＦ（数字配线架）接到用户接口或基站的ＢＴＳ（基…     

SDH的映射和同步复用原理（四）

ＳＤＨ的映射和同步复用原理（四）陈朝枢ＭａｐｐｉｎｇａｎｄＭｕｌｉｔｉｐｌｅｘｉｎｇＰｒｉｎｃｉｐｌｅｏｆＳＤＨ￥ＣｈｅｎＣｈａｏｓｈｕ三、用２．０４８Ｍｂ／ｓ信号组成ＳＴＭ－１按照我国《光同步传输网技术体制》规定，用２．０４８Ｍｂ／Ｓ信号１成ＳＴＭ...     

数字视频压缩信号在SDH网上的传送

文章通过在国内一条速率为２．５Ｇｂｉｔ／ｓ长达３０００ｋｍ的长途光干线ＳＤＨ网上进行８Ｍｂｉｔ／ｓＭＰＥＧ２信号传送的试验，讨论了利用ＳＤＨ网传送数字视频信号时，由于网中指针的调整将引起可见的图像质量下降的问题。试验还检验了国外最新ＳＤＨ和视频测量仪表的功能。在对试验结果进行了分析后，提出了为保证数字视频压缩信号在ＳＤＨ网上高质量地传送，需对视频解码器的定时和同步性能及新一代视频测量仪表有新的要求。     

用于网络单元时钟的压控石英振荡器

介绍了１５５．５２Ｍｂｉｔ／ｓ、６２２．０８Ｍｂｉｔ／ｓ、２４８８．３２Ｍｂｉｔ／ｓ、１０Ｇｂｉｔ／ｓＳＤＨ系统上的时钟频率源的基本原理，针对ＳＤ我同步对网络单元时钟要求的３８．８８ＭＨｚ压控振荡顺频率源进行了设计，当环境温度在０℃到７０℃范围内变化时，压控振荡器的频率漂移优于±１×１０＾－６，瞬时频率稳定定优于１．２５×１０＾－９。     

光通信技术的最新发展动态

本文在报告了美国光通信市场格局之后,介绍了未来高速大容量数据传输系统ＤＷＤＭ的发展状况,并预测ＤＷＤＭ的市场规模将从１９９９年的４０亿美元扩大到５年后的２１５亿美元。在文章第二部分介绍了新型光通信元件,凶手对应波长１４５０ｎｍ～１６５０ｎｍ的宽带光通信单向波导管、无需温控的２．５Ｇｂｉｔ／ｓ半导体激光元件、１０Ｇｂｉｔ／ｓ光信号传输器和５００Ｍｂｉｔ／ｓ光收发信器。     

传输系统在线误码监测系统

１系统功能传输系统自动在线误码监测、质量分析、故障定位系统具有如下功能：（１）本系统分为监测设备和管理系统两部分。监测设备能适应ＳＤＨ和ＰＤＨ两种制式要求，能反映光通信和微波通信两种传输媒介的传输质量；管理系统能进行性能分析、故障定位。（２）监测设备具有可扩充性，管理系统具备兼容性。硬件可扩容，软件可升级。（３）质量监测在２Ｍｂｉｔ／ｓ、３４Ｍｂｉｔ／ｓ、１４０Ｍｂｉｔ／ｓ接口进行，监测对象覆盖ＤＤＦ架和传输设备。２Ｍｂｉｔ／ｓ、３４Ｍｂｉｔ／ｓ、１４０Ｍｂｉｔ／ｓ采用帧同步检测，并采用高阻输入…     

2.5Gbit／s SDH系统用光接收模块研究

介绍了２．５Ｇｂｉｔ／ｓＳＤＨ光接收机设计原理，并研制出实用化的高灵敏度，大动态范围的２．５Ｇｂｉｔ／ｓＳＤＨ系统用光接收模块，光接口符合ＩＴＵ－Ｔ建议，Ｇ．９５７规范的要求，该模块已用于武汉邮电科学研究辽研制的２．５Ｇｂｉｔ／ｓＳＤＨ光传输系统中。     

同步数字体系中155Mbit/s净荷的误码测试

本文基于光纤传输同步数字体系(S D H)系统的开发背景,较为详细地总结了155Mbit/s速率下的净荷误码测试机理.最后给出了净荷的误码测试方法以及误码测试系统的信号流程.     

SDH传输设备155Mbit/s电路互通时故障的分析判断

通过对日本富士通公司与上海朗讯公司SDH传输设备在155Mbit/s口互通时出现的2Mbit/s滑码故障分析判断，指出了VC－12POH V5字节中Label比特不适配是该故障的直接原因。     

2488Mbit／s SDH系统与设备

由我国自行研制和开发的２４８８Ｍｂｉｔ／ｓ ＳＤＨ复接传输设备和再生中断设备已经成功地应用于从海口市至三亚市长途大容量光缆传输系统。其中还配有若干个１５５Ｍｂｉｔ／ｓ复用设备。本文将简要地介绍该系统的构成及设备特征等情况。     

Bit-interleaved Hamming code for linearly repeatered terrestrialSDH transmission systems

A bit-interleaved SEC shortened Hamming code is proposed for all SDH levels. The error caused by ASE noise in a 156 Mbit/s optical preamplifier is successfully corrected     

1 Gbit/s high-speed bit-synchronisation LSI for B-ISDN

The CCITT recommended that the bit rates for synchronous digital hierarchy (SDH) should be multiples of 155.52 Mbit/s. In handling high-speed data (such as 622.08 Mbit/s) in B-ISDN switching systems, there are problems associated with waveform degradation caused by impedance mismatching and amplitude attenuation. A countermeasure is the regeneration of the distorted waveforms using the system clock in each board. A bit-synchronisation circuit allows distorted waveforms to be regenerated and simplifies the design of timing between boards. The author have developed a high-speed bit-synchronisation LSI with excellent jitter tolerance in the 600 Mbit/s region and which has a simple circuit structure. The LSI features a circuit structure based on an elastic store, Si-bipolar super self-aligned process technology (SST),/sup 1/ and careful timing design. It can handle three different bit-rates (622.08, 155.52, and 51.84 Mbit/s) and has a maximum bit rate of 1 Gbit/s.<>     

622.08Mbit／s SDH设备CID不敏感性测量仪的原理及研制

介绍了６２２．０８Ｍｂｉｔ／ｓ ＳＤＨ设备连续相同数字（ＣＩＤ）不敏感性测量仪的原理及研制情况，对高速伪随机码的产生方法、相位以及同步方法进行了探讨，给出屯电路模拟和实验的结果。     

SDH环网在线扩容的实现

随着传输网的发展 ,原有的SDH网络有可能需要在线扩容 ,增加新的节点。如何保证在业务不中断的情况下实现网络的在线扩容是个新的问题。文中介绍了南京电信局富士通SDH 2 5Gbit/s和 6 2 2Mbit/s环网传输设备在线扩容增加新节点设备的方法 ,讨论了系统扩容前的检查 ,扩容的操作步骤以及对异常情况的处理。     

Carriage of SDH over satellite systems

This paper examines the potential of satellite systems to carry synchronous digital hierarchy (SDH) transmissions and proposes a possible earth-station architecture capitalizing on the benefits that SDH equipment offers. It is shown that a range of SDH multiplexing rates are viable over satellite and that multi-destination operation of satellite systems is facilitated by using the inherent features of the SDH. The use of STM-1 (155 Mbit/s) and sub-STM-1 transmission rates as transmission sections along with appropriate integration of the multiplexing and modem equipment would:. (a) enable SDH path continuity between earth-stations, allowing the satellite network to be integrated with managed terrestrial networks to form global managed transmission platforms. (b) provide bandwidth and equipment savings at earth-stations. Several technical issues relating to SDH operation over satellite systems are considered and SDH pointer corruption is examined in some detail.     

Implementing a flexible synchronous network

The SYNET project, undertaken by Deutsche Telekom to modernize its transmission network, is discussed. The SYNET technology is based on the synchronous digital hierarchy (SDH), which uses synchronous transport modules of 155 Mbit/s (STM-1). The latter include a maximum usable bit rate of about 50 Mbit/s as well as a variety of additional information intended for network management. Since the transmission network is divided into several network levels characterized by different traffic loads and structures, a range of synchronous components geared to the requirements of the different network levels have been developed. The major differences between the trunk network and the local networks are described. The implementation of SYNET is reviewed