Abstract
Orthogonal frequency-division multiplexing (OFDM) has been proposed as an enabling technique for elastic optical networks to support heterogeneous traffic demands by enabling rate and modulation adaptive bandwidth allocation. The authors investigate the energy efficiency of optical OFDM-based networks. A mixed integer linear programming model is developed to minimise the total power consumption of rate and modulation adaptive optical OFDM networks. Considering a symmetric traffic, the results show that optical OFDM-based networks can save up to 31% of the total network power consumption compared to conventional Internet protocol over wavelength division multiplexing (WDM) networks. Considering the power consumption of the optical layer, the optical OFDM-based network saves up to 55% of the optical layer power consumption. The results also show that under an asymmetric traffic scenario, where more traffic is destined to or originates from popular nodes, for example data centres, the power savings achieved by the optical OFDM-based networks are limited as the higher traffic demands to and from data centres reduce the bandwidth wastage associated with conventional WDM networks. Furthermore, the achievable power savings through data compression have been investigated, considering an optical OFDM-based network.
Highlights
Following the increase in the networks size, the power consumption of network equipment, such as servers, amplifiers, routers, storage devices and communication links, has rapidly increased [1]
Considering a linear profile to estimate the Orthogonal frequency-division multiplexing (OFDM) transponder power consumption, the results show that optical OFDM-based networks under a symmetric traffic demand with linear power profile save 10, 14 and 31% of the network power consumption compared to conventional Internet protocol (IP) over wavelength division multiplexing (WDM) networks with 10, 40 and 100 Gb/s wavelength rates, respectively
Under an asymmetric traffic demand, the advantage of OFDM is limited as the higher traffic demands to and from data centres reduce the bandwidth wastage associated with conventional WDM networks
Summary
Following the increase in the networks size, the power consumption of network equipment, such as servers, amplifiers, routers, storage devices and communication links, has rapidly increased [1]. Recent technological advances in optical networks have enabled data rates per wavelength of 40 and 100 Gb/s with extended transmission distance. The rigid nature and coarse granularity of WDM networks result in inefficient capacity utilisation because of the bandwidth mismatch between the application layer with bandwidth requirements varying from several to hundreds of Gb/s, and the wavelength channels with data rates of 10 Gb/s and beyond. Current WDM networks address this mismatch by allowing sub-wavelength granularity connections to be groomed onto a single lightpath which results in extra cost and power consumption [6], or by allocating multiple wavelengths to a connection if the requested bandwidth is higher than that of a single wavelength, such an approach suffers from low spectral efficiency as adjacent wavelengths must be separated by guard bands
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
