This paper examines the Bernoulli admission control policy for the two phase bulk arrival retrial queueing system wherein the customers has the option either to take second phase of service or to leave the system after completing first essential phase of service. In addition, the arrival rate of the customers depends upon the server status. After the service completion of each individual custom...

We represent the classical Engset-loss model by the stochastic process counting the number of customers in the system. A fluid limit for this process is established for all the possible values of the various parameters of the system, as the number of servers tends to infinity along with the number of sources. Our results are derived through a semi-martingale decomposition method. A numerical ap...

A retrial queueing system with two types of batch arrivals, called type I and type II customers, is considered. Type I customers and type II customers arrive in batches of variable sizes according to two different Poisson processes. Service time distributions are identical and independent and are different for both types of customers. If the arriving customers are blocked due to the server bein...

Five different classical bulk queueing models with variations are considered from chapter II to chapter VI. This chapter and chapter VIII are devoted for the analysis of two different retrial queueing models. Retrial queueing system is characterized by the feature that the arriving customers, who encounter the server busy, join a virtual pool called orbit. An arbitrary customer in the orbit gen...

The approximate solution technique for the main M/M/c retrial queue based on the homogenization of the model employs a quasi-birth-death (QBD) process in which the maximum retrial rate is restricted above a certain level. This approximated continuous-time Markov chain (CTMC) can be solved by the matrixgeometric method, which involves the computation of the rate matrix R. This paper is motivated...

The M/M/1 retrial queue with working vacations and negative customers is introduced. The arrival processes of positive customers and negative customers are Poisson. Upon the arrival of a positive customer, if the server is busy the customer would enter an orbit of infinite size and the orbital customers send their requests for service with a constant retrial rate. The single server takes an exp...

We examine an M/M/1 retrial queue with an unreliable server whose arrival, service, failure, repair, and retrial rates are all modulated by an exogenous random environment. Provided are conditions for stability, the (approximate) orbit size distribution, and mean queueing performance measures which are obtained via matrix-analytic methods. Additionally, we consider the problem of choosing arriv...

An M/G/1 retrial queue subject to disasters and N-policy vacation is investigated in this paper. Both positive and negative customers arrival in Poisson processes independently, and positive customers receive service immediately if the server is idle upon their arrivals. Otherwise, they enter a retrial orbit and repeat their attempt again after a random time period. Once negative customers arri...

This paper analyses a discrete-time Geo/G/1 retrial queue with batch arrivals in which individual arriving customers have a control of admission. We study the underlying Markov chain at the epochs immediately after the slot boundaries making emphasis on the computation of its steady-state distribution. To this end we employ numerical inversion and maximum entropy techniques. We also establish a...

Abstract: This paper examines the steady state behavior of an M/G/1 queue with repeated attempts in which the server may provide an additional second phase of service. This model generalizes both the classical M/G/1 retrial queue and the M/G/1 queue with classical waiting line and second optional service. We carry out an extensive stationary analysis of the system, including existence of statio...