CONNECTIONS_53-e

Trends
The Future
after 10 Gigabits
Fiber optic networks still have a lot more potential. 10 Gbit/s downstream is not
the end of the performance road for FTTH customers. ITU and IEEE workgroups have
now raised the bar. What can we expect of EPON and NG PON2?
Growing user demands are increasing the
pressure on Passive Optical Networks (PONs),
which have to deliver the pictures and videos
of our latest family event on time. The industry
is also reacting on time by creating new
standards that will help implement modern
networks in an efficient and backward-compatible
way. It is mainly the ITU and the IEEE
who are pushing their respective standards
to reach higher bandwidths.
After the GEPON and 10GEPON standard
(which allowed transmission at 10Gbit/s in
both directions), the IEEE is now working on
a 100 Gbit/s solution.
In the meantime, the ITU has evolved the
GPON standard to XG-PON and now XGS-
PON, which allows symmetric transmission at
10 Gbit/s over a 20 km range. The XGS-PON
can indeed be seen as a part of a bigger network
architecture, the Next generation PON
or NG-PON2. In this new scheme, up to 4-8
channel pairs can be used in such a way that
multiplexing is not only happening in time,
but also in wavelength.
The implementation of such a network
may require the use of tunable lasers which
are currently still expensive. However, this
network architecture can be organized on a
«pay as you grow» basis, meaning that not
all the wavelengths or channels need to be
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