V. Anantharam, THE INPUT-OUTPUT MAP OF A MONOTONE DISCRETE-TIME QUASI-REVERSIBLE NODE, IEEE transactions on information theory, 39(2), 1993, pp. 543-552
A class of discrete-time quasireversible nodes called monotone, which
includes discrete-time analogs of the ./M/infinity and ./M/1 nodes is
considered. For stationary ergodic nonnegative integer valued arrival
processes, the existence and uniqueness of stationary regimes are prov
en when a natural rate condition is met. Coupling is used to prove the
contractiveness of the input-output map relative to a natural distanc
e on the space of stationary arrival processes that is analogous to Or
nstein's dBAR distance. A consequence is that the only stationary ergo
dic fixed points of the input-output map are the processes of independ
ent and identically distributed Poisson random variables meeting the r
ate condition.