Example: XYZ Corp. has 10 identical 24-fiber cables used as an outside
plant backbone running between Building A and Building B. These fibers
follow the same pathway, have the same length (1.5 km), are 9/125 micron
single mode, and have the same number of interconnects (0) and splices (0).
All of these fibers can be included under a single site. A suggested name
for this site could be: XYZ-A-B-BBONE.
These links are to be tested against the TIA-568-A cabling standard. This
standard specifies testing backbone cables at both wavelengths. In the case
of single mode fiber, this would be 1310nm and 1550nm. The standard allows a
maximum of 0.5 dB/km for the fiber (both wavelengths), 0.75 dB per connector
pair, and 0.3 dB per splice. The reference value set prior to testing is –10.12
dBm.
1.5 km x 0.5 dB/km 0.75 dB
0 connector pair x 0.75 dB 0.00 dB
0 splices x 0.3 dB 0.00 dB
Total Allowed Passive Attenuation 0.75 dB
Reference Value -10.12 dBm
Total System Reference Value for Site XYZ-A-B-BBONE -10.87 dBm
During testing, any reading lower than –10.87 would fail, and readings
above –10.87 would pass.
