Karyn Benson Benjamin E. Birnbaum Esteban Molina-Estolano Ran Libeskind-Hadas Competitive analysis of online traffic grooming in WDM rings. 984-997 2008 16 IEEE/ACM Trans. Netw. 4 http://doi.acm.org/10.1145/1453698.1453717 db/journals/ton/ton16.html#BensonBML08