@article{discovery1431930, volume = {26}, month = {May}, pages = {1057 -- 1060}, note = {{\copyright} 2014 IEEE. This work is licensed under a Creative Commons Attribution 3.0 License. For more information, see http://creativecommons.org/licenses/by/3.0/}, year = {2014}, title = {Congestion Aware Routing in Nonlinear Elastic Optical Networks}, number = {10}, journal = {IEEE PHOTONICS TECHNOLOGY LETTERS}, author = {Savory, SJ}, url = {http://dx.doi.org/10.1109/LPT.2014.2314438}, abstract = {In elastic optical networks, digital coherent transceivers modify their symbol rate, modulation format, and forward error correction to best serve the network demands. In a nonlinear elastic optical network, these parameters are inherently coupled with the routing algorithm. We propose to use congestion aware routing in a nonlinear elastic optical network and demonstrate its efficacy for the NSFNET reference network (14 nodes, 22 links). The network is sequentially loaded with 100 GbE demands until a demand becomes blocked, this procedure being repeated 10000 times to estimate the network blocking probability (NBP). Three routing algorithms are considered: 1) shortest path routing; 2) simple congestion aware algorithm; and 3) weighted congestion aware routing algorithm with 50, 25, 12.5, and 6.25 GHz resolution flexgrids. For NBP = 1\% using a 50 GHz grid, congestion aware routing doubles the network capacity compared with the shortest path routing. When congestion aware routing is combined with a 6.25 GHz resolution flexgrid, a fivefold increase in network capacity is afforded.}, keywords = {Optical fiber communication, networks, routing, adaptive modulation, extreme value distributions}, issn = {1041-1135} }