Edward G. Coffman Jr. Nabil Kahale Frank Thomson Leighton Processor-Ring Communication: A Tight Asymptotic Bound on Packet Waiting Times. 1221-1236 1998 27 SIAM J. Comput. 5 http://epubs.siam.org/sam-bin/dbq/article/26863 db/journals/siamcomp/siamcomp27.html#CoffmanKL98