@Article{RosaWiCaCaCoWo:2015:StAnBl,
author = "Rosa, A. N. F. and Wiatr, P. and Cavdar, C. and Carvalho, Solon
Ven{\^a}ncio de and Costa, J. C. W. A. and Wosinska, L.",
affiliation = "{Universidade Federal do Par{\'a} (UFPA)} and {KTH Royal of
Technology} and {KTH Royal of Technology} and {Instituto Nacional
de Pesquisas Espaciais (INPE)} and {Universidade Federal do
Par{\'a} (UFPA)} and {KTH Royal of Technology}",
title = "Statistical analysis of blocking probability and fragmentation
based on Markov modeling of elastic spectrum allocation on fiber
link",
journal = "Opitcs Communications",
year = "2015",
volume = "354",
pages = "362--373",
month = "Nov.",
keywords = "Blocking probability, Elastic optical networks, Markov modeling,
Spectrum allocation, Spectrum fragmentation.",
abstract = "In Elastic Optical Network (EON), spectrum fragmentation refers to
the existence of non-aligned, small-sized blocks of free
subcarrier slots in the optical spectrum. Several metrics have
been proposed in order to quantify a level of spectrum
fragmentation. Approximation methods might be used for estimating
average blocking probability and some fragmentation measures, but
are so far unable to accurately evaluate the influence of
different sizes of connection requests and do not allow in-depth
investigation of blocking events and their relation to
fragmentation. The analytical study of the effect of fragmentation
on requests' blocking probability is still under-explored. In this
work, we introduce new definitions for blocking that differentiate
between the reasons for the blocking events. We developed a
framework based on Markov modeling to calculate steady-state
probabilities for the different blocking events and to analyze
fragmentation related problems in elastic optical links under
dynamic traffic conditions. This framework can also be used for
evaluation of different definitions of fragmentation in terms of
their relation to the blocking probability. We investigate how
different allocation request sizes contribute to fragmentation and
blocking probability. Moreover, we show to which extend blocking
events, due to insufficient amount of available resources, become
inevitable and, compared to the amount of blocking events due to
fragmented spectrum, we draw conclusions on the possible gains one
can achieve by system defragmentation. We also show how efficient
spectrum allocation policies really are in reducing the part of
fragmentation that in particular leads to actual blocking events.
Simulation experiments are carried out showing good match with our
analytical results for blocking probability in a small scale
scenario. Simulated blocking probabilities for the different
blocking events are provided for a larger scale elastic optical
link.",
doi = "10.1016/j.optcom.2015.03.039",
url = "http://dx.doi.org/10.1016/j.optcom.2015.03.039",
issn = "0030-4018",
language = "en",
urlaccessdate = "27 abr. 2024"
}