OPS/OBS scheduling algorithms: Incorporating a wavelength conversion cost in the performance analysis

2015 27th International Teletraffic Congress

2015

Self Cite

Abstract-With ever-increasing demand for bandwidth, optical packet/burst switching is proposed to utilize more of the available capacity of optical networks in the future. In these packet-based switching techniques, packet contention on a single wavelength is resolved effectively by means of Fiber Delay Lines. The involved scheduling algorithms are typically designed to minimize packet loss and/or packet delay. By filling so-called voids, void-filling algorithms are known to outperform their non-void-filling counterparts. This however comes at a large computational cost as the void-filling algorithms have to keep track of beginnings and endings of all voids. This is opposed to the non-void-filling algorithms which only have to keep track of a single system state variable. We therefore propose a new type of algorithm that selectively creates voids that are larger than strictly needed, only when these will likely be filled. Results obtained by Monte Carlo simulation show that selective void creation can jointly reduce packet loss by 50% and packet delay by 18%, without imposing a high computational cost.

Section: Simulation: Iterative Approachmentioning

confidence: 99%

“…In [5], [6] we proposed new cost-based scheduling algorithms, both in a related setting with wavelength converters present. There, we were able to validate the usefulness of a cost-based approach and achieved an increased performance (decreased LP).…”

Section: Introductionmentioning

confidence: 99%

Fill the Void: Improved Scheduling for Optical Switching

Hautegem

Rogiest

2015 27th International Teletraffic Congress

2015

Self Cite

“…In [2] and [3] we proposed new cost-based scheduling algorithms, both in a related setting with wavelength converters present. In both, we were able to validate the usefulness of a cost-based approach and achieved an increased performance (decreased loss probability (LP)).…”

Section: Introductionmentioning

confidence: 99%

Void-creating algorithm in OPS/OBS: Mind the gap

Hautegem¹,

Rogiest²,

AIP Conference Proceedings

2015

Self Cite

Abstract. In optical packet/burst switching, packet contention on a single wavelength is resolved effectively by means of Fiber Delay Lines. The involved scheduling algorithm is typically designed to minimize packet loss, by filling so-called voids, and trying to keep the so-called gaps small. We propose a new type of algorithm that selectively creates voids that are larger than strictly needed, only when these will likely be filled. Results obtained by Monte Carlo simulation show that selective void creation can significantly reduce packet loss.

“…To reduce packet loss we propose a new cost-based scheduling algorithm in [2], improving performance (in terms of packet loss probability) by up to 22 % in comparison with current algorithms for a void filling setting and 7 % without void-filling for the considered assumptions. Because WCs are known to contribute significantly to the energy consumption of the switching element, the trade-off between performance (packet loss) and energy consumption was also explicitly examined, resulting in an algorithm with which energy consumption can be traded off for performance.…”

Section: Introductionmentioning

confidence: 99%

“…In [2], the main aim was to validate the usefulness of a cost-based approach, with results obtained under the assumption of unlimited wavelength conversion capability. Here, we here consider the case of a limited number of shared WCs, as it occurs in practical implementations.…”

Section: Introductionmentioning

confidence: 99%

Scheduling in optical switching: Deploying shared wavelength converters more effectively

Hautegem

Rogiest

2014 IEEE International Conference on Communications (ICC)

2014

Self Cite

As internet traffic will further increase in coming years, the current network infrastructure will have to grow along in terms of capacity. To this end, optical packet/burst switching have been proposed, allowing more efficient use of the available fiber capacity. To resolve packet contention in the involved optical switches, Fiber Delay Lines (for delay assignment) and wavelength converters (for wavelength conversion) are used to reschedule the contending packets, by means of a scheduling algorithm. Existing algorithms are effective when employed with an infinite number of converters, but generally perform poorly when the number of wavelength converters is small, as is the case in most switch prototype architectures. In this paper, several parametric cost-based scheduling algorithms are proposed that take scarcity of both FDLs and converters into account. Results obtained by Monte Carlo simulation show that these algorithms not only enable improved performance (in terms of packet loss probability), but also reduce the usage of the wavelength converters, and thus, the switch's overall energy consumption.