Abstract

In this paper, a large deviation probability in a single-server retrial system is considered. In this model, if server is busy, an arriving customer joins the so-called virtual orbit and then attempts to enter server again. We consider constant retrial rate discipline, in which case only the top (oldest) orbital customer makes the attempts. The input is assumed to be a general renewal process, service times are iid with a general distribution and the retrial attempts follow an exponential distribution. Such models are motivated by numerous applications in modelling modern communication systems. We focus on the decay rate of the probability that the orbit size reaches a high level N within busy period. We compare retrial system to equivalent classic system with service times of a special type. Simulation results show that original retrial system can be approximated with the classic buffered model.