Effect of Transmission Impairments in CO-OFDM Based Elastic Optical Network Design

TL;DR

This paper investigates how transmission impairments affect the design of CO-OFDM based Elastic Optical Networks, proposing an ILP model and heuristic algorithm for optimized routing and spectrum allocation considering physical layer limitations.

Contribution

It introduces a joint optimization framework for RSA in CO-OFDM EON that accounts for physical impairments, enhancing network performance and reliability.

Findings

The ILP model effectively balances load while minimizing delay and fragmentation.

The heuristic algorithm outperforms existing load balancing methods.

Considering physical impairments improves transmission reach and network efficiency.

Abstract

Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) based Elastic Optical Network (EON) is one of the emerging technologies being considered for next generation high data rate optical network systems. Routing and Spectrum Allocation (RSA) is an important aspect of EON. Apart from spectral fragmentation created due to spectrum continuity and contiguity constraints of RSA, transmission impairments such as shot noise, amplified spontaneous emission (ASE) beat noise due to coherent detection, crosstalk in cross-connect (XC), nonlinear interference, and filter narrowing, limit the transmission reach of optical signals in EON. This paper focuses on the cross-layer joint optimization of delay-bandwidth product, fragmentation and link congestion for RSA in CO-OFDM EON while considering the effect of physical layer impairments. First, we formulate an optimal Integer Linear Programming (ILP) that achieves load-balancing in presence of transmission impairments and minimizes delay-bandwidth product along with fragmentation. We next propose a heuristic algorithm for large networks with two different demand ordering techniques. We show the benefits of our algorithm compared to the existing load balancing algorithm.