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早先的技术预测预见到纤维光学在电信应用上的广泛使用。这些预测已经开始变为现实。目前有几个试验的或者传输话务的系统在电话经营公司的干线和环路设备中使用。本文讨论光纤技术在电话网络中的干线和环路应用。在讨论干线应用时,对纤维光学技术的当前状况作了评述,介绍了在各不同传输速率下的目前的和近期的性能水平,给出目前的硬设备的例子,讨论了费用和可靠性分析,并且陈述了今后由长波长传输和波分多路复用带来的性能改善。对于环路应用,讨论了作为例子的一个系统结构,即一个有转换装置的多种服务的系统和与其相关联的费用。本文的结论是,在干线应用方面目前光纤技术对高容量的情况是可行的。对于提供宽带服务的环路应用,在八十年代中期以前纤维光学系统就会是可行的。自从1977年首次使用纤维光学T_1传输系统以来,光纤通信系统在电话网络中的使用进展得非常迅速。自从那时候以来,干线和环路系统都已投入传输实际话务的使用。本文评述有关在电话网络中的干线与环路应用方面的技术状态。先讨论干线应用。在讨论中继间隔,系统可靠性和比较系统费用的同时,评述纤维光学数字传输系统的当前状况。讨论了长波长技术的效果和波分多路复用(WDM)的使用。接着讨论了环路应用。叙述了纤维光学宽带系统的实现可能性,包括在性能方面和费用方面的考虑。结论是纤维光学干线系统目前就是可行的。技术上的进一步改进将会使其生命力更强。光纤环路系统对于实现未来的“有线联络城市”(“wired city”)是一种可行的手段。
Earlier technical predictions foresee the widespread use of fiber optics in telecommunications applications. These forecasts have begun to come true. There are currently several piloted or traffic-carrying systems that are used in the trunk and loop equipment of telephone operators. This article discusses the trunk and loop applications of optical fiber technology in the telephone network. When discussing trunk applications, the current state of fiber optics was reviewed, current and recent performance levels at various transmission rates were introduced, examples of current hardware were presented, cost and reliability analyzes were discussed , And states future performance improvements resulting from long wavelength transmission and wavelength division multiplexing. For loop applications, a system architecture is discussed as an example, a multi-service system with switching devices and the costs associated with it. The conclusion of this paper is that fiber optic technology is currently feasible for high-capacity applications in trunk applications. For loop applications that offer broadband services fiber optic systems were viable until the mid-1980s. Since the fiber optic T_1 transmission system was first used in 1977, optical fiber communication systems have progressed very rapidly in the telephone network. Since then, both trunk and loop systems have been put into practical use for transmitting traffic. This article reviews the state of the art about trunk and loop applications in the telephone network. Discuss trunk applications first. While discussing relay intervals, system reliability, and system costs, comment on the current status of fiber optic digital transmission systems. The effects of long wavelength technology and the use of wavelength division multiplexing (WDM) are discussed. Then discuss the loop application. Described the possibility of fiber optic broadband system implementation, including performance and cost considerations. The conclusion is that fiber optic backbone systems are currently viable. Further technical improvements will make it more viable. Fiber loop systems are a viable means of achieving the “wired city” of the future.