Summary: Shared­Per­Wavelength Asynchronous Optical Packet
Switching: A Comparative Analysis I
N.Akar a , C.Ra#aelli b , M.Savi b , E.Karasan #,a
a Electrical and Electronics Engineering Department
Bilkent University, Ankara 06800, Turkey
b DEIS ­ University of Bologna, Viale Risorgimento 2, I­40136 Bologna ITALY
Abstract
This paper compares four di#erent architectures for sharing wavelength
converters in asynchronous optical packet switches with variable­length pack­
ets. The first two architectures are the well­known Shared­Per­Node (SPN)
and Shared­Per­Link (SPL) architectures, while the other two are the Shared­
Per­Input­Wavelength (SPIW) architecture, recently proposed as an optical
switch architecture in synchronous context only, which is extended here to
the asynchronous scenario, and an original scheme called Shared­Per­Output­
Wavelength (SPOW) architecture that we propose in the current article. We
introduce novel analytical models to evaluate packet loss probabilities for
SPIW and SPOW architectures in asynchronous context based on Markov
chains and fixed­point iterations for the particular scenario of Poisson input
tra#c and exponentially distributed packet lengths. The models also account
for unbalanced tra#c whose impact is thoroughly studied. These models are

Source: Akar, Nail - Department of Electrical and Electronics Engineering, Bilkent University

Collections: Engineering