Combinatorial Properties and Defragmentation Algorithms in WSW1 Switching Fabrics


  • Wojciech Kabaciński Poznan University of Technology
  • Remigiusz Rajewski Poznan University of Technology
  • Atyaf Al-Tameemi Poznan University of Technology


A spectrum defragmentation problem in elastic optical networks was considered under the assumption that all connections can be realized in switching nodes. But this assumption is true only when the switching fabric has appropriate combinatorial properties. In this paper, we consider a defragmentation problem in one architecture of wavelength-space-wavelength switching fabrics. First, we discuss the requirements for this switching fabric, below which defragmentation does not always end with success. Then, we propose defragmentation
algorithms and evaluate them by simulation. The results show that proposed algorithms can increase the number of connections realized in the switching fabric and reduce the loss probability.


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