Detailed Installation Guide; Technical Check Of A Link By Reflectometry: A Pre- And Post-Installation Analysis Tool; Reflectometry Measurement Setup (Otdr) - Cailabs Aroona Star Instruction Manual

4. Detailed installation guide

1. Technical check of a link by reflectometry: a pre- and
post-installation analysis tool
Prior to installing any AROONA-STAR equipment, it is necessary
to carry out a "technical check" of the optical links that you wish
to upgrade. It is therefore essential to perform reflectometry
measurement on the multi-mode fibers in question. The analysis
may result in having to perform certain actions on the link to
make it consistent it with an AROONA upgrade.
Note: apart from the technical aspect, it is recommended
to carry out this OTDR measurement on the link to be
A. Reflectometry measurement setup (OTDR)
A reflectometry
recommendations is recommended before installation and
essential after installation to be able to certify the link.
Measurements must be carried out under the following
conditions:
• Use of a single mode OTDR, at a wavelength of 1310 nm
• Measurement in short pulses (5 or 10 ns)
• Minimum one minute measurement time (≥1 min)
Use of a single-mode launch fiber (100 m to 1000 m) (1)
•
• Distance range best suited to the total length of the link
measured (fiber measured + launch fiber)
Perform the measurement in both directions (2)
•
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measurement according
upgraded in order to have a "picture" of the state of the
customer's fibers before any intervention by the installer.
After installation, OTDR measurements also qualify the link for
high bit rates transmission over upgraded multimode fibers.
OTDR parameterization and analysis conditions are listed be-
low, thus providing a framework for optimal conditions for the
proper functioning of the AROONA-STAR solution.
to Cailabs (1) Using the receiving fiber allows you to assess the quality
of the end-of-line element and thus correctly measure the
loss and reflection levels of the end-of-line connector or the
end-of-line AROONA -STAR extension unit.
(2) The OTDR measurement on a fiber in both directions
allows precise quantification of each event. In the case of a
one-way measurement, the loss of an event can be overestimated
or underestimated (up to 1 dB of error) and therefore distort
the evaluation of a link before and after installation.
It is recommended
measurements independently on each fiber. However, depending
on the field constraints, it is possible to perform a physical
loopback at the end of the line (with a > 10 m single-mode fiber)
to facilitate taking measurements as shown in the diagram
below. In these loopback cases, pulses of 5 ns or 10 ns may be
insufficient in terms of power to maintain a good signal-to-
noise ratio of the measurement. It will then be necessary to
carry out another measurement with longer pulses (20, 50 or
100 ns) in order to guarantee an OTDR trace end at least 10 dB
above the noise level.
to carry out these reflectometry