scispace - formally typeset
Journal ArticleDOI

Elastic Bandwidth Allocation in Flexible OFDM-Based Optical Networks

TLDR
This work introduces the Routing, Modulation Level and Spectrum Allocation (RMLSA) problem, as opposed to the typical Routing and Wavelength Assignment (RWA) problem of traditional WDM networks, proves that it is also NP-complete and presents various algorithms to solve it.
Abstract
Orthogonal Frequency Division Multiplexing (OFDM) has recently been proposed as a modulation technique for optical networks, because of its good spectral efficiency, flexibility, and tolerance to impairments. We consider the planning problem of an OFDM optical network, where we are given a traffic matrix that includes the requested transmission rates of the connections to be served. Connections are provisioned for their requested rate by elastically allocating spectrum using a variable number of OFDM subcarriers and choosing an appropriate modulation level, taking into account the transmission distance. We introduce the Routing, Modulation Level and Spectrum Allocation (RMLSA) problem, as opposed to the typical Routing and Wavelength Assignment (RWA) problem of traditional WDM networks, prove that is also NP-complete and present various algorithms to solve it. We start by presenting an optimal ILP RMLSA algorithm that minimizes the spectrum used to serve the traffic matrix, and also present a decomposition method that breaks RMLSA into its two substituent subproblems, namely 1) routing and modulation level and 2) spectrum allocation (RML+SA), and solves them sequentially. We also propose a heuristic algorithm that serves connections one-by-one and use it to solve the planning problem by sequentially serving all the connections in the traffic matrix. In the sequential algorithm, we investigate two policies for defining the order in which connections are considered. We also use a simulated annealing meta-heuristic to obtain even better orderings. We examine the performance of the proposed algorithms through simulation experiments and evaluate the spectrum utilization benefits that can be obtained by utilizing OFDM elastic bandwidth allocation, when compared to a traditional WDM network.

read more

Citations
More filters
Proceedings ArticleDOI

A practical layered model for flexible-grid optical networks to reduce the routing complexity

TL;DR: In this paper, the authors propose a new model that can represent the slot usage and the status of each possible slot groups in a flexible-grid optical network, which facilitates visualizing the current network state in a graphical form as well as a proper data structure in the memory.

in Mesh Elastic Optical Networks

TL;DR: It is shown that spectrum assignment in networks of general topology is a special case of scheduling multiprocessor tasks on dedicated processors, and efficient and effective algorithms for mesh and chain networks that build upon list scheduling concepts are developed.
Proceedings ArticleDOI

Optical Path Design Method for Reducing Maximum Spectrum Slot Number by Selecting Alternative Routes and Using GNPy

TL;DR: In this paper , a routing, modulation, and spectrum allocation (RMSA) method in optical networks is proposed in consideration of transmission quality and transmission parameters by GNPy, which improves the spectrum utilization of the optical network by selecting the route with the smaller spectrum slot number.
Proceedings ArticleDOI

The Constrained-Routing and Spectrum Assignment Problem: Extended Formulation and Branch-and-Cut-and-Price Algorithm

TL;DR: In this paper , an extended integer linear programming formulation for the constrained-routing and spectrum assignment (C-RSA) problem is proposed, and a column generation algorithm is developed to solve its linear relaxation.
Journal ArticleDOI

A novel strategy to enhance the quality of service (QoS) for data center traffic in elastic optical networks

TL;DR: The concept of connectivity degree and Kuhn-Munkres multi-objective optimization for spectrum allocation is introduced and the obtained results show that the proposed algorithm is highly effective in reducing the traffic failure and blocking probability for EODCNs.
References
More filters
Journal ArticleDOI

Combinatorial optimization: algorithms and complexity

TL;DR: This clearly written, mathematically rigorous text includes a novel algorithmic exposition of the simplex method and also discusses the Soviet ellipsoid algorithm for linear programming; efficient algorithms for network flow, matching, spanning trees, and matroids; the theory of NP-complete problems; approximation algorithms, local search heuristics for NPcomplete problems, more.
Journal ArticleDOI

OFDM for Optical Communications

TL;DR: In this paper, the authors give a tutorial overview of OFDM and highlight the aspects that are likely to be important in optical applications, and discuss the constraints imposed by single mode optical fiber, multimode optical fiber and optical wireless.
Journal ArticleDOI

Spectrum-efficient and scalable elastic optical path network: architecture, benefits, and enabling technologies

TL;DR: This article proposes a novel, spectrum- efficient, and scalable optical transport network architecture called SLICE, which enables sub-wavelength, superwa wavelength, and multiple-rate data traffic accommodation in a highly spectrum-efficient manner, thereby providing a fractional bandwidth service.
Journal ArticleDOI

Distance-adaptive spectrum resource allocation in spectrum-sliced elastic optical path network [Topics in Optical Communications]

TL;DR: A concept of a novel adaptation scheme in SLICE called distance-adaptive spectrum resource allocation, which can save more than 45 percent of required spectrum resources for a 12-node ring network, is presented.
Journal ArticleDOI

Optical burst switching: a new area in optical networking research

TL;DR: This tutorial gives an introduction to optical burst switching and compare it with other existing optical switching paradigms, and describes a prevailing protocol for OBS networks called just-enough-time (JET).
Related Papers (5)