On the stability of a partially accessible multi-station queue with state dependent routing

We consider a multi-station queue with a multi-class input process when any station is available for the service of only some (not all) customer classes. Upon arrival, any customer may choose one of its accessible stations according to some state-dependent policy. We obtain simple stability criteria for this model in two particular cases when service rates are either station- or class-independent. Then, we study a two-station queue under general assumptions on service rates. Our proofs are based on the fluid approximation approach.