PhD defense Hussein Chouman: Impairment-aware design and performance evaluation of all-optical wavelength convertible networks


  • M. Cédric WARE, Télécom ParisTech : Directeur de thèse
  • me. Mounia LOURDIANE, Télécom SudParis : Encadrant de thèse
  • M. Bernard COUSIN, Université de Rennes 1, IRISA : Rapporteur
  • M. Idelfonso TAFUR MONROY, Eindhoven University of Technology : Rapporteur
  • Mme. Christine TREMBLAY, École de technologie supérieure : Examinatrice
  • M. Philippe GRAVEY, IMT Atlantique : Examinateur
  • Mme. Hind CASTEL, Télécom SudParis : Examinatrice
  • Mme Catherine LEPERS, Télécom SudParis: Invité
    – M. Dominique CHIARONI, Nokia Bell Labs France: Invité


The continuous growth of Internet traffic implies an increased power consumption due to the many optical-to-electronic (OEO) conversions required by routers and switches. Transparent networks could curb this uncontrolled growth, but keeping the data in the optical domain has two adverse consequences: physical layer impairments accumulation which strongly degrades the performance due to amplification noise and non-linearities; and the wavelength continuity constraint (WCC) to keep the optical signal’s wavelength unchanged in wavelength-division-multiplexed (WDM) optical networks which degrades network blocking performance. Wavelength converters (WCs) can alleviate the WCC constraint, but the only commercially available devices are the OEO-based WCs (OEO-WCs), however, their cost increases with bit-rates. On the other hand, all-optical wavelength converters (AO-WCs) have been demonstrated in research laboratories albeit with a limited conversion range and a performance that degrades converted signal’s quality.

In this thesis, we design the transmission layer using two different modulation formats sets with different bit-rates ranges; and consequently different performance estimation models. At the network level, our analyses show that WCs’ contribution depends on traffic demands serving ordering in the planning phase of the network; that using fixed-alternate routing (FAR) or least-loaded routing (LLR) algorithms and first-fit (FF) wavelength assignment algorithm, AO-WCs give the same performance enhancement as OEO-WCs. Moreover, we identify an optimum AO-WC conversion range and cascadability which shows that LLR requires a lower number of conversions per channel compared to FAR.