Abstract:
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A new Passive Optical Network (PON)
for access, making use of Ultra Dense Wavelength
Division Multiplexing (UDWDM) by densely spacing
channels at few GHz, and introducing the
“wavelength-to-the-user” concept, is proposed. The
key challenge will be developing low-cost coherent
transceivers, providing an excellent selectivity while
avoiding filters, and furnishing high sensitivity,
which will allow high splitting ratios, large number
of users and long distance reach. The Optical
Distribution Network (ODN) at the outside plant is
based on splitters and kept compatible with legacy
systems. Optical Network Unit (ONU) designs
realized with coherent transceivers using one or two
lasers are presented and the corresponding Optical
Line Terminal (OLT) architectures are introduced.
The ONUs at customer premises own lasers with
limited thermal tunability and their wavelengths are
randomly distributed in a band. By using heuristic
Dynamic Wavelength Assignment (DWA) schemes and
extending the original working band, the required
optical band is obtained and optimized. In activation
processes, ONU acceptances up to 99.9% are achieved.
Furthermore, in operation scenario under indoors
and also under outdoors environmental conditions,
ONU blocking probabilities below 0.1% and ONU
availability ratios (OARs) up to 99.9% are
demonstrated. The PON is dimensioned according to
the number of deployed users and system reach;
moreover, power safety and also fiber nonlinearities
constraints are evaluated, illustrating the
characteristics of the projected network. Finally, the
coexistence with legacy networks is discussed. |