Views: 0 Author: Site Editor Publish Time: 2023-07-03 Origin: Site
(1) The SDH transmission system has a unified frame structure, digital transmission standard rate, and standard optical interface internationally, which enables network management systems to be interconnected. Therefore, it has good horizontal compatibility. It can be fully compatible with existing PDH and accommodate various new business signals, forming a globally unified digital transmission system standard, improving the reliability of the network.
(2) The arrangement of different levels of code streams in the frame structure payload area of the SDH access system is very regular, and the payload is synchronized with the network. It utilizes software to directly insert high-speed signals into low-speed branch signals at once, achieving the characteristic of one-time multiplexing. It overcomes the process of PDH quasi synchronous multiplexing to decompose all high-speed signals step by step and then regenerate and reuse them, greatly simplifying DXC, Reduced back-to-back interface reuse devices and improved the transparency of network service delivery.
(3) Due to the use of advanced Add-Drop Multiplexers (ADM), Digital Cross Connect (DXC), network self-healing and restructuring functions, it appears very powerful and has a strong survival rate. Due to the arrangement of 5% overhead bits of the signal in the SDH frame structure, its network management function appears particularly powerful and can form a unified network management system, playing a positive role in the automation, intelligence, channel utilization, and reducing network maintenance costs and survivability.
(4) Due to the various network topologies of SDH, its network is very flexible. It can enhance network monitoring, operation management, and automatic configuration functions, optimize network performance, and also make network operation flexible, secure, and reliable, making the network's functions very complete and diverse.
(5) SDH has the performance of transmission and exchange. The composition of its series of devices can be freely combined through functional blocks, achieving networks of different levels and topologies, which is very flexible.
(6) SDH is not a specific transmission medium, it can be used for twisted pair and coaxial cables, but for high data rate transmission, optical fiber is required. This feature indicates that SDH is suitable for both trunk and branch channels. For example, China's national and provincial cable television backbone networks use SDH, and it is also compatible with fiber optic cable hybrid networks (HFC).
