Minimizing Blocking Probability in Elastic Optical Networks by Varying the Bandwidth Granularity Based on Optical Path Fragmentation

Al Tarawneh L,Taebi S

doi:10.4172/2469-410x.1000149

Abstract

Elastic optical networks (EONs) based on orthogonal frequency-division multiplexing (OFDM) are considered a promising solution for the next optical network’s generation. It basically makes it possible to choose an adequate portion of the available spectrum to satisfy the requested capacity. In this paper, we consider the impact of spectrum fragmentation along the optical single/multipath routing transmission on the efficiency of the EONs. This involves reducing the fragmentation effects by dynamically updating and controlling the minimum bandwidth allocation granularity (g).We adopt linear and nonlinear dynamic mechanisms, which are denoted as LDAEi and NLDAEi, respectively, to choose proper band width granularities that are proportional to the optical link/path bandwidth fragmentation status. In order to avoid neither splitting the capacity request over many routing paths, which would increase the management complexity, nor encouraging single path transmission, the proposed schemes aim to choose a proper bandwidth allocation granularity (g) of a predefined set of suggested values. Simulation results show that varying the bandwidth granularity based on the optical path fragmentation status can offer improved performance over fixed granularity with respect to the bandwidth blocking probability, the number of path splitting, the throughput, and differential delay constraint issue in terms of: the network bandwidth utilization and multipath distribution.

Highlights

The current optical transport network based on wavelength optical networks (OTN-WDM) suffers from serious limitations because of the expected capacity crunch in the physical capacity of the current optical fibers [1,2,3]
Using orthogonal frequency-division multiplexing (OFDM) for Elastic Optical Networks (EONs) offers a finer granularity mechanism, which makes it possible to slice off the right amount of available spectrum resources to save more resources in order to serve
We focus on the role of granularity (g) that can be considered, in general, as a control parameter for increasing the spectral efficiency, thereby reducing the blocking opportunity, the number of path splitting occurrences, and other networks’ parameters

Summary

Introduction

The current optical transport network based on wavelength optical networks (OTN-WDM) suffers from serious limitations because of the expected capacity crunch in the physical capacity of the current optical fibers [1,2,3]. In addition to the dramatic increase in the network services for new generations of bandwidth consuming applications (in the presence of fixed rate and the rigid frequency grid of the wavelength-routed optical networks 50 GHz), the mismatch of granularity between the cooperative layers (Client-layer & WDM-layer) results a degradation of the efficiency of the spectral utilization over the current OTN [4]. In order to tackle these limitations, a new generation of flexible or Elastic Optical Networks (EONs) need to be adopted [5]. In EONs, the principle of optical orthogonal frequency-division multiplexing (O-OFDM) has been considered a promising technique for the optical network future because of its helpful characteristics [7], and a possible implementation of elastic networking. Using OFDM for EON offers a finer granularity mechanism, which makes it possible to slice off the right amount of available spectrum resources to save more resources in order to serve

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Results

Conclusion