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FIBRE OPTIC CABLING
HD Fibre
By Richard Cann, Technical
Services Manager, Mayflex
www.mayflex.com
Working with high-density fibre
to keep up with growing data
both now and in the future
With the increasing demand for global data, as we all
depend on the Internet and cloud services for our daily
transactions, information, communication, music, video etc.
The importance of robust, flexible and future-proof optical
networks within data centres is continuing to grow. Data
centres are increasing in size and density.
The medium of choice for data transmission remains to
be fibre optics, as it offers significantly more data density
and consumes much lower energy than copper systems.
Technology in both the optical transceiver and fibre is
continuing to move on and provide the ability to transmit
more and more data along a single fibre, or parallel over a
number of fibres.
Single or multi-mode fibre?
OM3 multi-mode (MM) fibre and single VCSEL transmitters
have proved to be an ideal solution for data centres,
providing 10GBit/sec transmission over 300m max. OM4
offers increased bandwidth and/or extended distance over
OM3. Multi-fibre connectors such as the MTP/MPO with
OM3/OM4 fibre offer 40GBit/sec (and up to 100GBit/sec)
over four pairs using parallel optics.
Now we have emerging OM5 technology, which uses
wideband optical fibre – designed to efficiently transmit
wavelengths between 850nm and 950nm. This is intended
for use with Short Wavelength Division Multiplexing
transceivers (SWDM), allowing at least four different
wavelengths to be simultaneously transmitted and received
along a pair of fibres. This will provide 40GBit/sec (and up
to 100GBit/sec) transmission over a duplex pair.
Another option is to use single-mode (SM) fibre. With
new low cost/low power SM transceivers this is becoming
an increasingly viable option and will facilitate greater
bandwidths over longer distances. As data centres are
getting larger, will the 300m/550m range offered by OM3/
OM4/OM5 be sufficient? Will single-mode become the
necessity? As always, the correct choice of fibre to use will
depend on the bandwidth requirements, distance and cost.
Density requirements
Another important factor to consider is the density required
for presentation and connection of the fibres. Usually
facilitated with patch panels in cabinets/frames or optical
distribution frames (ODFs), this element is also becoming
ever more critical. As data rates increase, not only do we
need more bandwidth per fibre, we also need more fibres.
The more we can fit in the space we have, the better. This
has led to increasing the capacity within the patching
frame. A typical 1U patch panel, not so long ago, would
accommodate only 24 or 48 fibres, now 144 fibres are
commonplace (72 duplex pairs). Not only are 144 fibres
common in 1U, we also now have no need for additional
U-space being consumed by patchcord management bars,
as this is incorporated within the 1U panel design, either
with the use of integrated management or angled panels.
Modular or cassette-based patch panels offer the best
flexibility – often allowing for several interconnection
options all within the same panel. These panels allow for
splicing, pre-termination options and MTP-LC cassettes. The
panel can be installed initially with just one or two cassettes,
and the system can be expanded upon as required, allowing
for a relatively low initial cost.
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