Lucent Technologies Release 6 manual When to Use Single-Mode Fiber Attenuators

DEFINITY Enterprise Communications Server Release 6	Issue 5
Installation and Test for Multi-Carrier Cabinets 555-230-112	May 1998
A Connecting Fiber Optic Cables
Optical Cross-Connect Hardware	Page A-7

When to Use Single-Mode Fiber Attenuators

For 300A operation, single-mode fiber loss must be between 10dB and 17dB (at 1300 to 1310 nm). Since saturation may occur if distances are short, attenuators may be required if the total loss on the fiber link is less than 10dB. Perform an OTDR or Optical Power Meter test to determine specific requirements. Typically, fiber distances of 9 miles (14 km) or less require an in-line attenuator.

Using Figure A-1, find the line that most closely matches the customer’s fiber plant, or overlay your own load line. Using the measured loss of 0.33dB/km as an example, install a 10dB attenuator if the distance is about 9 miles (14 km) or less. Use a 5dB attenuator if the distance is from 9 to 18 miles (14.4 to 30 km).

Figure A-1. Single-Mode Attenuator Requirements