چکیده (انگلیسی):

In addition to the ever-increasing demand for broader bandwidth
per user, which results from the continuous development of new bandwidthhungry
services and applications, the consequent upgrade from the currently
deployed Time-Division Multiplexing Passive Optical Networks (TDMPONs)
to Next-Generation Optical Access Networks (NG-OANs) has
become inevitable. Different architectures for creating a NG-OAN have been
proposed in the literature. Among those architectures, the DWDM and
TDM/DWDM-Based OANs are very promising candidates. They were
mainly proposed to exploit the large wavelength counts available in the fibre
(its virtual unlimited bandwidth) to achieve a significant increase in the
system capacity. Moreover, they allow coexistence in an open access
environment among different network operators. In this study, we first
analyze the impact of in-band crosstalk, out-of-band crosstalk to evaluate the
performance of the Arrayed Waveguide Grating (AWG). The reason to focus
on the AWG is due to this optical device is used almost in all DWDM and
TDM/WDM-PONs. We then turn our attention to analyze the impact of
group velocity dispersion GVD to estimate the maximum allowable bit rate
for optical transmission without the need for using a Dispersion Management
Technique (DMT) and/or a Forward Error Correction Technique (FECT).
The analysis was performed using Matlab software (The Math works, Inc.,
Natick, MA, USA) and confirms that the in-band crosstalk has a stronger
effect than the out-of-band crosstalk because its noise floor is reached at a
lower crosstalk noise and with fewer crosstalk components. The in-band
crosstalk noise should be kept below -37 dB and -34 dB to maintain a power
penalty of less than 1 dB if 15 and 7 in-band crosstalk components are
considered, respectively. The out-of-band crosstalk noise should be kept
below -20.3 dB and -17.18 dB to maintain a power penalty of less than 1 dB
if 240 and 56 out-of-band crosstalk components are considered, respectively.
It was observed that the GVD noise floor is reached at a shorter fiber length
as the bit rate increases and it was confirmed that a significant improvement
in which the GVD noise floor is reached at longer fiber can be achieved if an
externally modulated, small spectral-width source is used when a bit rate of
622 Mbps, 1 Gps, or 2.5 Gbps is used. However, a dispersion management
technique becomes necessary if the bit rate increases to 10 Gbps or more.