RFS INSTALLATION GUIDELINES
HYBRIFLEX
®
CABLE|603400210500|September 2020
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Mobile operator specific optical testing
Note:
OTDR unidirectional measurements lead to inaccuracies when fibers with different Mode Field
Diameters (MFD) are connected. The inaccuracies usually are in the form of “gainers” or “exaggerated losses”.
At MFD mismatched connection OTDR backscattered light is greater or smaller, depending on the direction.
Specifically, the capture fraction in an optical fiber is inversely proportional to the mode-field diameter
squared. Thus, when two fibers of dissimilar mode field diameter are connected, measurable differences in
back reflected signal will occur that will add additional 0.1 to 0.5dB per IL connection. This is an OTDR testing
issue only and does not affect cable performance and actual optical loss. To avoid this issue, OTDR testing
must be done bi-directionally per FOTP-61.
Certain Mobile Operators require that all cables be tested using Loopback loss method:
•
Use only mobile operator approved test equipment and loopback patch cords
•
Perform only recommended tests
•
Keep all cleaners, adapters and calibration items clean and free of any contamination
•
Replace any old, worn adapters and test cables
•
Test all individual components before mating
•
Used only single-mode fiber accessories. Do not mix-match adapter or loopback devices.
Mobile Operator system insertion loss table (using power meter only to measure insertion loss)
Fiber characteristic
Single-mode
Light propagation mode
1310 and 1550 nm
IL per connector one way
0.25 dB
Reflectance
Min 50 dB
Max system fiber loss allowed
4 dB (2 dB up and 2 dB down)
Field Jumpers testing
Connect the HYBRIFLEX® jumper cable to the ODC plug test lead as shown below and follow test equipment
instructions. Refer to the system insertion loss table for pass/fail criteria when recording results.
Note
: ODC plug and socket may be mated securely by hand, but if need be, use approved torque wrench with
the applicable torque of 1 N-m to firmly secure the connection. Test equipment and reference cables should
be reset prior to each measurement.