Temporary Provisions for the Engineering Design of Long-distance Fiber Optic Transmission Networks Based on Synchronous Digital Hierarchy (SDH)

Author: Beijing University of Posts and Telecommunications Press
Publisher:
Publish Date: 1998-08-01
Features:
Fragment: 3.2 Optical Interface
3.2.1 The classification of optical interfaces for SDH long-distance optical cable transmission projects shall comply with the specifications in Table 3.2.1. The letter "S" in the table indicates short-distance inter-office transmission, and "L" indicates long-distance inter-office transmission. The digit(s) following the letter represent the STN-N grade. The second digit "1" indicates a nominal operating wavelength of 1310nm and the use of G.652-type fiber, "2" indicates a nominal operating wavelength of 1550nm and the use of G.652-type fiber, and "3" indicates a nominal operating wavelength of 1550nm and the use of G.653-type fiber.
3.2.2 The location of optical interfaces for SDH long-distance optical cable transmission projects shall comply with the specifications in Figure 3.2.2. In the figure, "S" is a reference point on the fiber immediately after the active connector (Ctx) of TX, and "R" is a reference point on the fiber immediately before the active connector (CRx) of RX.
3.2.3 The optical interface parameters for STM-1, STM-4, and STM-16 in SDH long-distance optical cable transmission projects shall respectively comply with the specifications in Appendix A, Appendix B, and Appendix C. The specification for STM-64 optical interface parameters is pending.
3.2.4 The optical interface parameters for SDH long-distance optical cable transmission projects shall be reasonably selected based on the specific conditions of the engineering project.
3.3 Electrical Interface
3.3.1 The electrical interfaces for SDH long-distance optical cable transmission networks shall comply with the following specifications:
a) 155520kbit/s Electrical Interface:
1) Basic Requirements: Nominal bit rate: 155520kbit/s; Bit rate tolerance: ±15×10??; Code type: CMI; Overvoltage protection of the interface: The input and output ports must be able to withstand 10 consecutive standard lightning pulses (5 positive and 5 negative) without damaging the equipment. The pulse rise time is 1.2μs, the pulse width is 50μs, and the voltage amplitude is 20V.
2) The specifications of the output port shall comply with the requirements in Table 3.3.1-1.