Views: 0 Author: Site Editor Publish Time: 2023-07-03 Origin: Site
With the development of communication, the information required to be transmitted is not only voice, but also text, data, images, and videos. In addition to the development of digital communication and computer technology, from the 1970s to the 1980s, T1 (DS1)/E1 carrier system (1.544/2.048 Mbps), X.25 Frame Relay, ISDN (Integrated Services Digital Network) and FDDI (Fiber Distributed Data Interface) and other network technologies emerged in succession. With the advent of the information society, people hope that modern information transmission networks can quickly, economically, and effectively provide various circuits and services. However, due to the monotony of their services, the complexity of expansion, and the limitations of bandwidth, modifying or improving the aforementioned network technologies within the original framework is no longer effective. SDH developed in this context. Among various broadband fiber optic access network technologies, SDH technology is the most commonly used access network system. The birth of SDH has solved the problem of "bottleneck" of access between users and the core network due to the Bandwidth throttling of the incoming media, which can not keep up with the development of Backbone network network and users' business needs. At the same time, it has improved the utilization rate of a large amount of bandwidth on the transmission network. SDH technology has been a mature and standard technology since it was introduced in the 1990s. It is widely used in the Backbone network, and its price is getting lower and lower. The application of SDH technology in the access network can bring the huge bandwidth advantages and technical advantages in the core network into the access network field, and make full use of SDH synchronous multiplexing, standardized optical interfaces, strong network management capabilities, flexible network topology capabilities and high reliability to bring benefits, Long term benefits in the construction and development of access networks.