On the Stability of Announced Retransmission Random Access Systems

A finite user model for stability analysis of announced retransmission random access (ARRA) systems is presented. It is shown that as in other ALOHA-type random access protocols, bistable behavior and saturation can occur unless a suitably long retransmission delay is used. The higher expected delay associated with an unconditionally stable nonadaptive system can be avoided by adaptively varying retransmission parameters with system backlog. Optimal retransmission control (ORC) policies of this type are derived and evaluated.