Why is the inspection and cleaning of optical fibre connector end faces important?
The light travelling down fibres does so in extremely small diameter cores (9um in single mode). A small speck of dirt that is
almost invisible to the naked eye could be enough to cause the signal to be attenuated or blocked resulting in signal interference or
even loss of transmission. This could be as simple as a finger print on the end of fibre optic connectors. All optic connectors should
be inspected during installation with a quality microscope and if required cleaned with an approved cleaning technique.
What is OM4 Cable?
OM4 is the next generation multimode fibre to support existing 1 and 10Gb/s applications as well as future 40 and 100Gb/s systems.
It allows for extended distance of 550 metres at 10Gb/s.
What fibre optic cable should be used for underground installation?
Loose tube fibre cable of gel-filled or dry-core construction should be used whether the cable is direct buried or installed within
underground conduit. There is no guarantee against water filling a conduit or the cable becoming exposed to sunlight at some point
in the run so an underground rated cable with UV-resistant jacket is recommended in Australia.
What is the difference between multimode and singlemode fibre?
Multimode fibre has a relatively large light carrying core usually 50 or 62.5 microns in a diameter. It is normally used for short
distance transmissions with LED based optical equipment and has limitations in regards to bandwidth capacity and distance. Singlemode
will have a smaller light carrying core of 8 to 10 microns in diameter. It is used for large bandwidth transmissions over longer
distances with laser diode based optical fibre transmission equipment.
When should I use OM3 over OM1?
OM3 fibre must be used where the fibre optic cable run distance exceeds 220 metres @ 1000mbp/s (1Gb/s) speed on a typical multimode
network. OM3 will extend the distance up to 550 metres @ 1Gb/s speed. OM# can also handle 10GbE (10,000mbp/s) at a distance of up to
300 metres. OM3 should be installed to help future-proof your multimode installation.
What style of fibre cable are commonly used?
Gel filled loose tube for underground direct bury applications with options of termite and rodent protection via nylon jacket and/or
armoring. Indoor/Outdoor tight buffered fibre optic cable can be used for internal or external fibre cable runs but should not be
installed underground even if within conduit.
What is an OTDR dead zone?
Dead zones originate from reflective events (fusion splices, optic connectors pressure points, etc) along the link and can affect
the OTDR's ability to accurately measure attenuation on shorter links and differentiate closely spaced events. The OTDR will become
temporarily blinded by the first event it picks up and will not see upcoming events close to each other and will instead pick them up
as one event. Dead zones can extend hundreds or metres from the OTDR unit but can be reduced (but never eliminated) by adjusting the
pulse width in accordance with the length of the fibre.
Can I convert Multimode to Singlemode and vice versa?
Yes a multimode to singlemode fibre media converter can be used. These products are available in both 10?100Base and Gigabit units
with a range of distances available for the singlemode transmission side.
What are some typical fibre to the home products (FTTH products) used in a residential cabling network?
A FTTH cabling network would usually consist of the Head End equipment (HE), optic cable backbone or Feeder cable to a Local
Convergence Point (LCP) for splitting, distribution cable to a Network Access Point (NAP), and then drop cables to a termination
point on the individual dwellings (ONT).
What is a fusion splicer?
A fusion splice is the technique of joining two fibre optic cores by melting the ends together using an electric arc. A fusion
splicer is used because an extremely high degree of accuracy is required due to the small diameter of fibre optic cable and tight
tolerances. The fusion splicer first aligns the cores and then applies the exact amount of heat needed to melt the ends before
pressing them together and fusing the fibre to form a very low loss joint.
What is a fibre enclosure?
A fibre enclosure or FOBOT as it is also known is a tray, box or dome designed for breaking out and terminating fibre optic cable.
FOBOTs usually are fitted out with splice trays and thru-adaptors and allow a point in the network for mass termination, splicing
and patching of cables.