Asymptotic analysis of retrial queue with constant retrial rate and priority customers

In the paper, a single-server retrial queueing system with constant retrial policy and priority customers is considered. The priority customers interrupt a service of non priority customers, which go to an orbit. There are two orbits for each class. The constant retrial policy means that only the first customer from an orbit has access to a server. Service, inter-arrival and inter-retrial times have exponential distributions. The method of partial asymptotic analysis under a condition of a heavy load of one class of customers is proposed. During the research, the asymptotic characteristic function of the number of customers of the priority class under a heavy load by other class customers is derived.