Abstract An unprecedented and precise time-scheduled rollout for the vaccine is needed an effective vaccination process. This study based on development of a novel mathematical model considering delay in due to inability book slot one go system. Two models are proposed which involve differential equation whose dynamical analysis done show how can destabilize Further, this led formulation queuin...

Purpose: We consider a discrete-time retrial queue where the retrial time follows a general distribution, the server subject to Bernoulli vacation policy and the customer has preemptive resume priority, Bernoulli feedback strategy. The main purpose of this paper is to derive the generating functions of the stationary distribution of the system state, the orbit size and some important performanc...

This note develops two-moment approximations for blocking probabilities in overflow systems with repacking. The approximations are based on fixed point schemes, iteratively relating the arrival rate at the primary channels to the mean number of calls at the overflow channels. The analysis focuses on layered cellular mobile communications networks, but can also be applied to multiple retrial que...

In this paper, we discuss the maximum of the mean response time that appears in finite-source retrial queues with orbital search when the arrival rate is varied. We show that explicit closed-form equations of the mean response time can be derived by exploiting the block-structure of the finite Markov chain underlying the model and using an efficient computational algorithm proposed by Gaver, Ja...

This paper is concerned with the performance analysis of finite-source retrial queues with heterogeneous sources operating in random environments. All random variables involved in the model construction are assumed to be exponentially distributed with a parameter depending on the source index and on the state of the corresponding random environment. The novelty of the investigation is the invol...

This paper studies a single-server retrial queue with two types of calls (incoming and outgoing calls). Incoming arrive at the server according to renewal process, N?1 (N?2) categories occur independent Poisson processes. Upon arrival, if is occupied, an incoming call joins virtual infinite called orbit, after exponentially distributed time in orbit enters again, while are lost busy their arriv...