Performance of fiber delay‐line buffers in asynchronous packet‐based optical switching networks with wavelength conversion

Abstract

SUMMARYA major challenge in asynchronous packet-based optical networks is packet contention, which occurs when two or more packets head to the same output at the same time. To resolve contention in the optical domain, two primary approaches are wavelength conversion and fiber delay line (FDL) buffering. In wavelength conversion, a contending packet can be converted from one wavelength to another in order to avoid conflict. In FDL buffering, contending packets can be delayed for a fixed amount of time. While the performance of wavelength conversion and FDL buffering has been evaluated extensively in synchronous networks with fixed-sized packets, in this paper, we study the performance of FDL buffers in asynchronous packet-based optical networks with wavelength conversion. An analytical model is proposed to evaluate the performance in terms of packet loss probability and average delay. Extensive simulation and analytical results show that, with appropriate settings, FDL buffers can perform much better in switches with wavelength conversion than in switches with no conversion.

On blocking time in multi‐class optical burst switching nodes

“…Resolving contention is an important issue in OBS networks [11]. One of the possible remedies for resolving contention is buffering [12]. The contending bursts are delayed by means of fiber delay lines.…”

“…By the calculating procedure of Steps 1 through 5 in Algorithm 1, one obtains the probability density of the blocking time for burst-1 and burst-2, respectively. One also obtains the average blocking time by (12). For the purpose of numerical illustration, we implement the performance measures in MATLAB (MathWorks, Natick, MA, USA).…”