Queues with nonstationary inputs

In this paper we study single server queues with independent and identically distributed service times and a general nonstationary input stream. We discuss several notions of being in equilibrium. For queues with a doubly stochastic Poisson input we survey continuity and bounds of moments of some performance characteristics. We also discuss conjectures posed by Ross 34] to the effect that for a more stationary input we have a better performance characteristics. Some results are reviewed to typify a problem and then it is followed by a discussion, questions and related bibliography.