Matthias an der Heiden Michel Sortais Michael Scheutzow Martin Reisslein Martin Maier Multicast Capacity of Optical WDM Packet Ring for Hotspot Traffic http://arxiv.org/abs/0804.3215 2008 CoRR abs/0804.3215 db/journals/corr/corr0804.html#abs-0804-3215 informal publication