Lunch Talk: Wavelength Defragmentation Problem in Optical Networks

The University of Toronto Operations Research Group (UTORG) is hosting a lunch talk by Hamed Pouya. The talk is entitled “Wavelength Defragmentation Problem in Optical Networks”. Lunch and coffee will be provided. Hope to see you there!

Who: Hamed Pouya, Postdoc, University of Toronto


When: Thursday, January 24th @ 12:00pm – 1:00pm

Where: BA8256


Bio-sketch:  I am a Ph.D. student at Concordia University, Montreal. I will start my postdoc from March in U of T with Dr. Merve Bodur. I have been collaborating with Ciena Co. (a world leading company in telecommunications) since 2015. My focus in Ph.D. is on using decomposition methods to tackle large scale problems in the telecommunication industry.

Abstract:  Future optical networks, in particular, Software Defined Optical Networks (SDONs), are expected to provide reconfigurable services while maintaining an efficient usage of wavelength resources. I’ll present a make before break wavelength defragmentation process, which provides the best possible lightpath network provisioning, i.e., with minimum bandwidth requirement. We propose an original solution scheme which, at defragmentation times, (i) computes an optimal lightpath provisioning, (ii) check if it is made before break reachable from the fragmented current one, (iii) if not, go on with an iterative process which recomputes a lightpath provisioning using a Nested Column Generation scheme subject to additional constraints for eliminating the rerouting deadlocks.