Practical scalability of wavelength routing switches

M. Rodelgo-Lacruz, C. López-Bravo, F. J. González-Castaño, H. Jonathan Chao

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Packet switches with optical fabrics can potentially scale to higher capacities. It is also potentially possible to improve their reliability, and reduce both their footprint and power consumption. A well-known alternative for implementing hardwired switches is Arrayed Waveguide Grating (AWG). Ideally, AWG insertion losses do not depend on the number of input-output ports, meaning that scalability is theoretically infinite. However, accurate second-order assessment has demonstrated that in-band crosstalk exponentially increases the power penalty, limiting the realistic useful size of AWG commercial devices to about 10-15 ports (13-18 dB) [1]. On the other hand, the in-band crosstalk at AWG outputs depends on the connection pattern set by the scheduling algorithm and this port count limitation is calculated for worst-case scenarios. In this paper, we show that distributed schedulers with predetermined connection patterns can be used to avoid these harmful arrangements. We also show that the probability of worst-case patterns is very low, allowing us to set a more realistic port limit for general centralized schedulers and very small losses. With these results, we calculate more realistic port count limits for both scheduler types.

Original languageEnglish (US)
Title of host publicationProceedings - 2009 IEEE International Conference on Communications, ICC 2009
StatePublished - 2009
Event2009 IEEE International Conference on Communications, ICC 2009 - Dresden, Germany
Duration: Jun 14 2009Jun 18 2009

Publication series

NameIEEE International Conference on Communications
ISSN (Print)0536-1486


Other2009 IEEE International Conference on Communications, ICC 2009


  • AWG
  • Crosstalk
  • Optical packet switching
  • Scalability

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Electrical and Electronic Engineering


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