Transformations on channel graphs
M. Kraetzl, Charles J. Colbourn · IEEE Transactions on Communications · 1993
A channel graph is a directed acyclic graph with a unique source vertex and a unique sink vertex, in which all edges are partitioned into stages according to their distance from the source. The blocking probability of a channel graph is the probability that every source to sink path is blocked. A general transformation that never decreases the blocking probability is developed. This transformation leads to a short proof of a generalization of a theorem of K. Takagi (1971) and a theorem of F. R. K. Chung and F. K. Hwang (1978) in the case of the binomial model.>