Statistical analysis of blocking probability and fragmentation based on Markov modeling of elastic spectrum allocation on fiber link
2015 (English)In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 354, 362-373 p.Article in journal (Refereed) Published
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 cart 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.
Place, publisher, year, edition, pages
[Rosa, A. N. F.; Costa, J. C. W. A.] Fed Univ Para, Dept Elect & Comp Engn, Appl Electromagnetism Lab LEA, BRA-6607511 Belem, PA, Brazil. [Rosa, A. N. F.; Wiatr, P.; Wosinska, L.] KTH Royal Inst Technol, Sch Informat & Commun Technol, Opt Networks Lab ONLab, SE-16440 Kista, Sweden. [Cavdar, C.] KTH Royal Inst Technol, Sch Informat & Commun Technol, COS RADIOSYST LAB RS LAB, SE-16440 Kista, Sweden. [Carvalho, S. V.] Natl Inst Space Res, Comp & Appl Math Lab LAC, BRA-1224597 Sao Jose Dos Campos, SP, Brazil., 2015. Vol. 354, 362-373 p.
Elastic optical networks, Spectrum allocation, Spectrum fragmentation, Blocking probability, Markov modeling
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:kth:diva-174204DOI: 10.1016/j.optcom.2015.03.039ISI: 000360904800056ScopusID: 2-s2.0-84934920029OAI: oai:DiVA.org:kth-174204DiVA: diva2:861404
QC 201510162015-10-162015-10-022015-11-25Bibliographically approved