Presented at: 5th International Workshop on Reliable Networks Design and Modeling(RNDM), Almaty, Kazakhstan, September 10-12, 2013.
Researchers: Cicek Cavdar and Aras Tarhan.
Abstract: Recently, the Internet traffic demand has been rising up by approximately 40% every year, corresponding to the doubling of the demand every two years. Furthermore, it is very likely that this trend will continue due to the massively increasing use of Internet services such as Video on Demand (VoD), high definition Internet Protocol (IP) TV, cloud computing and grid applications requiring high amount of data rate.
To meet these high data rate demands, Wavelength Division Multiplexing (WDM) technique has mainly been used as a backbone carrier in telecom networks. However, it is not possible to fit data rates over 100 Gb/s such as 400 Gb/s and 1 Tb/s into the fixed grid space in WDM networks. Another problem is wavelength-routed networks require full allocation of a wavelength to a connection even if the whole grid is not necessary. This leads to waste of spectrum in the fixed grids as depicted in the Figure. Elastic optical networks (EONs) evolved as a response to these drawbacks enabling scalability and flexibility for bandwidth allocation.
Survivability plays an important role in EONs. A link failure may lead to a huge data loss for data rates between 1 Gb/s and 1 Tb/s, therefore resource efficient protection techniques need to be developed to guarantee the recovery of such failures. A link disjoint backup path is assigned for each primary path to guarantee protection against a link failure in the network.
In this work, we developed a novel Routing and Spectrum Allocation (RSA) algorithm applying different strategies for primary and backup resource allocation called Primary First-Fit Modified Backup Last-Fit (PF-MBL) aiming to reduce the fragmentation and to increase the sharability of spare capacity. As a result overall bandwidth blocking probability is significantly reduced in the network. Results show that PF-MBL can improve the performance in terms of bandwidth blocking probability by 24% up to 59% compared to the current outperforming algorithm.
Figure: Spectrum allocation in conventional WDM network and Elastic Optical Network (OFDM network) along the frequency domain
Aras Tarhan and Cicek Cavdar, “Shared Path Protection for Distance Adaptive Elastic Optical Networks under Dynamic Traffic” in Proceedings of 5th International Workshop on Reliable Networks Design and Modeling(RNDM), Almaty, Kazakhstan, September 10-12, 2013.