【導讀】適合長距離大容量傳輸，是首選的長途骨干傳輸介質(zhì)。目前，為了適應不同。的線路和局域網(wǎng)的發(fā)展要求，已經(jīng)制定了一個非分散纖維，低色散斜率光纖，大有效面積光纖，水峰光纖等新型光纖。長波光學研究人員研究認為，傳輸。中繼器可以以不同的速率傳輸光纖放大器，也可以發(fā)送特定波長的光信號。在從模擬信號轉(zhuǎn)換成數(shù)字信號、從低到高比特率比特率的光纖網(wǎng)絡升級中，系統(tǒng)采用光復用技術的擴大，他們都不必改變摻鉺放大器電路和設備。不同的環(huán)境中企業(yè)和住宅客戶提供了多種寬帶接入解決方案。主要完成三大功能：高速傳輸，復用/路由，網(wǎng)絡的擴展。等服務，同時還提供PSTN業(yè)務。目前仍滯留在今后進一步探索實踐的方式最不確定的接入技術。能提供足夠的帶寬，支持所有目前可預見的業(yè)務，但仍存在技術和經(jīng)濟問題，激光，傳感器和調(diào)制解調(diào)器進一步的需要。MEMS是一個微小的固體機械元件，其大小通常小于1毫米。個網(wǎng)絡傳輸?shù)挠脩魧σ粚ζ胀ǖ挠脩簟?

　　

【正文】 basic approach, there is no substantive difference. From the operational point of view, the current volume of business the most, the most pressing user needs is FTTB. Currently, FTTH is still costly, difficult to accept the majority of users. HFC Access (HFC) HFC work is a cable television (CATV) to develop. It can provide CATV services as well as voice, data and other interactive services. HFC work is a kind of analog frequency division multiplexingbased, integrated application of ana 14 log and digital transmission technology, optical fiber and coaxial cable technology, radio frequency technology, highly distributed intelligent broadband subscriber access works, CATV and telephone works are bined product. HFC work coverage up to 100 km, and the transmission signal attenuation, low noise, is ideal for CATV work transmission technology. The typical structure used HFC CATV cable as the trunk transmission work to cable television star as the central frontend or ring distribution, has been extended to the city39。s downtown office district and suburban residents and rural counties, the formation of many of the optical node. Starting from the optical node through traditional coaxial cable to cable TV signal to the end user. Wireless Access Wireless munications technology has the characteristics of flexibility, widely used in various fields of munication works. The following wireless subscriber loop (WLL) are presented. Wireless Subscriber Loop is a basic telephone service to provide digital wireless access system, is currently the most widely used as a wireless access technology. The work side of a standard 2wire analog interface cable access or 2Mbps digital interface, can be directly connected with the local switch。 in the user side and a regular telephone connected to the main features of the transmission medium is wireless technology to provide users with fixed terminal business services . Wireless local loop on the end user or the user is basically a fixed enduser with limited mobility. Wireless Subscriber Loop39。s goal is to provide cable access work with the same types of business and the wider range of services. Wireless local loop consists of three parts, namely, the control center, base stations and user terminals. General, the wireless subscriber loop connected with the PSTN work as a part of it. Wireless local loop access many ways, can be frequency division multiple access (FDMA), time division multiple access (TDMA) or Code Division Multiple Access (CDMA) and other. Ether Developed in recent years were established in five categories based on the Ether cable on the traditional copper and cable access launched a new challenge. This access is through a general work equipment such as switches, hubs and other users within the same building together into a local area work, optical fiber backbone work and then connect with the outside world. Such access methods inherited Inter connection, and architecture of digital systems in the natural basis, and the inevitable trend of future dates triple play IP work closely with a large space for development. However, on the application, the Ether access method is still in the exploratory stage, the coverage is relatively small. Because changing the user39。s terminal equipment may be digital, it may be simulated, not limited to puters, so can not copy the puter access the work connection. 15 4. Access System Access System AnyMedia is a truly global product, which supports all relevant international standards, the system bines for North America TR303/TR08 exchange interfaces as well as international mon egration capacity broadband data and video services can be integrated together as part of the system telephone and broadband or existing work coverage, enabling more convenient services, program design and higher cost performance. AnyMedia access system to the application of fiberoptic work to indepth and in all configurations to simplify operation of the system, it is built on the AIP platform access interface to support traditional copper, twisted pair, fiberto point, fibertoedge . Using ATM passive optical work (PON0) fiber to the home (FTTH), as well as wireless access and other access loop topology. AnyMedia design allows the arbitrary application into an application framework, and a variety of enhanced access with the following features: . Builtin broadband capacity, allowing the system to use ATM technology to support current highspeed data work and the Inter and video access. function, the system can be configured in an existing exchange or other remote access systems, ATMbased broadband capacity of digital subscriber line access multiplexer dedicated (DSLAM). . To diverging performance, users can build flexible and a small work that can acmodate up to 600 units of large works . Voice and data within the separation system will first flow into the ATM business voice and ADSL data separated from the different channels in their routing to reduce work congestion. AnyMedia access system in the face of the future ATMbased broadband services based on the same time, support for lowcost narrowband services, the application provides the user with maximum flexibility. Access Server PathStar access server is AnyMedia access system features and advantages of packet switching technology program requirements developed by the innovative products. PathStar Access Server is built on the AIP platform access interfaces, such as the Inferno operating system and the operating system such as Bell Line Card Lucent39。s Inter access software and technology integration as a whole. PathStar access server to meet the need for integrated voice and data work access needs of users, the traditional circuitswitched functions and features with advanced p