TY - JOUR
T1 - Overcoming the Switching Bottlenecks in Wavelength-Routing, Multicast-Enabled Architectures
AU - Keykhosravi, Kamran
AU - Rastegarfar, Houman
AU - Peyghambarian, Nasser
AU - Agrell, Erik
N1 - Funding Information:
Manuscript received December 13, 2018; revised May 12, 2019; accepted June 5, 2019. Date of publication June 7, 2019; date of current version July 31, 2019. This work was supported in part by the Swedish Research Council under Grant 2014-6230, in part by the NSF Center for Integrated Access Networks under Grant EEC-0812072, and in part by the Natural Sciences and Engineering Research Council of Canada. (Corresponding author: Kamran Keykhosravi.) K. Keykhosravi and E. Agrell are with the Department of Electrical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden (e-mail: [email protected]; [email protected]).
Publisher Copyright:
© 1983-2012 IEEE.
PY - 2019/8/15
Y1 - 2019/8/15
N2 - Modular optical switch architectures combining wavelength routing based on arrayed waveguide grating (AWG) devices and multicasting based on star couplers hold promise for flexibly addressing the exponentially growing traffic demands in a cost-and power-efficient fashion. In a default switching scenario, an input port of the AWG is connected to an output port via a single wavelength. This can severely limit the capacity between broadcast domains, resulting in interdomain traffic switching bottlenecks. An unexplored solution to this issue is to exploit multiple AWG free spectral ranges (FSRs), i.e., to set up multiple parallel connections between each pair of broadcast domains. In this paper, we study, for the first time, the influence of the FSR count on the throughput of a multistage switching architecture and propose a generic and novel analytical framework to estimate the blocking probability. We assess the accuracy of our analytical results via Monte Carlo simulations. Our study points to significant improvements with a moderate increase in the number of FSRs. We show that an FSR count beyond four results in diminishing returns. Furthermore, to investigate the tradeoffs between the network-and physical-layer effects, we conduct a cross-layer analysis, taking into account pulse amplitude modulation and rate-Adaptive forward error correction. We illustrate how the effective bit rate per port increases with an increase in the number of FSRs.
AB - Modular optical switch architectures combining wavelength routing based on arrayed waveguide grating (AWG) devices and multicasting based on star couplers hold promise for flexibly addressing the exponentially growing traffic demands in a cost-and power-efficient fashion. In a default switching scenario, an input port of the AWG is connected to an output port via a single wavelength. This can severely limit the capacity between broadcast domains, resulting in interdomain traffic switching bottlenecks. An unexplored solution to this issue is to exploit multiple AWG free spectral ranges (FSRs), i.e., to set up multiple parallel connections between each pair of broadcast domains. In this paper, we study, for the first time, the influence of the FSR count on the throughput of a multistage switching architecture and propose a generic and novel analytical framework to estimate the blocking probability. We assess the accuracy of our analytical results via Monte Carlo simulations. Our study points to significant improvements with a moderate increase in the number of FSRs. We show that an FSR count beyond four results in diminishing returns. Furthermore, to investigate the tradeoffs between the network-and physical-layer effects, we conduct a cross-layer analysis, taking into account pulse amplitude modulation and rate-Adaptive forward error correction. We illustrate how the effective bit rate per port increases with an increase in the number of FSRs.
KW - Arrayed waveguide grating (AWG)
KW - blocking probability
KW - coupler
KW - free spectral range (FSR)
KW - multicast
KW - physical layer
KW - scheduling
KW - switch architecture
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U2 - 10.1109/JLT.2019.2921679
DO - 10.1109/JLT.2019.2921679
M3 - Article
AN - SCOPUS:85070442411
SN - 0733-8724
VL - 37
SP - 4052
EP - 4061
JO - Journal of Lightwave Technology
JF - Journal of Lightwave Technology
IS - 16
M1 - 8733093
ER -