Consolidated optical flow switching in cloud data centers

Houman Rastegarfar, Alberto Leon-Garcia, Madeleine Glick, Nasser N Peyghambarian

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


We propose a flexible, software-defined optical switching fabric for cloud data centers, enabling multi-petabit per second network capacities. Our design is based on the cyclic interconnection pattern of arrayed waveguide grating (AWG) devices, whose routing functionality is complemented with recirculation fibers. Unlike traditional optical data center network proposals that rely on two independent fabrics for supporting mice and elephants, our design enables the support of flows of various sizes and requirements using a single AWG-based fabric and yields bandwidth flexibility by integrating wavelength and subwavelength switching granularities. There are two sets of connections paths in our design: dedicated paths between each pair of AWG input and output ports, and shared paths that are set up by multiple recirculation fibers. The recirculation fibers enable the statistical multiplexing of mice. As well, they provide for flexible, on-demand circuit provisioning between input and output ports. Applying Birkhoff-von Neumann matrix decomposition on a residual traffic matrix comprising the demands that cannot be supported through the dedicated paths, we come up with a weighted sum of permutation matrices that get mapped onto the set of available recirculation fibers. The calculated coefficients determine the proportion of a timeframe that the permutation matrices are serviced by distinct fibers. The matrix decomposition requires the combined scheduling of wavelength and time domains so that the AWG can operate as an adaptive flow switching device. Enhancing the functions of our wavelength-routing design with space switching using an optical MEMS switch results in extreme network scales, spanning millions of processing cores.

Original languageEnglish (US)
Title of host publicationMetro and Data Center Optical Networks and Short-Reach Links
EditorsYouichi Akasaka, Atul K. Srivastava, Madeleine Glick
ISBN (Electronic)9781510616059
StatePublished - 2018
EventMetro and Data Center Optical Networks and Short-Reach Links 2018 - San Francisco, United States
Duration: Jan 30 2018Jan 31 2018

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherMetro and Data Center Optical Networks and Short-Reach Links 2018
Country/TerritoryUnited States
CitySan Francisco


  • Arrayed waveguide grating
  • data center
  • elephant flow
  • mouse flow
  • permutation matrix
  • recirculation fiber
  • space switching
  • wavelength routing

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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