B. Krishna Kumar

An M/G/1 Retrial Queueing System with Two-Phase Service and Preemptive Resume

An M/G/1 retrial queueing system with additional phase of service and possible preemptive resume service discipline is considered. For an arbitrarily distributed retrial time distribution, the necessary and sufficient condition for the system stability is obtained, assuming that only the customer at the head of the orbit has priority access to the server. The steady-state distributions of the server state and the number of customers in the orbit are obtained along with other performance measures. The effects of various parameters on the system performance are analysed numerically. A general decomposition law for this retrial queueing system is established.

The M/G/1 retrial queue with Bernoulli schedules and general retrial times☆

Abstract This paper is concerned with the analysis of a single-server queue with Bernoulli vacation schedules and general retrial times. We assume that the customers who find the server busy are queued in the orbit in accordance with an FCFS (first-come-first-served) discipline and only the customer at the head of the queue is allowed access to the server. We first present the necessary and sufficient condition for the system to be stable and derive analytical results for the queue length distribution, as well as some performance measures of the system under steady-state condition. We show that the general stochastic decomposition law for M/G/1 vacation models holds for the present system also. Some special cases are also studied.

Transient solution of an M/M/1 queue with catastrophes

Abstract A transient solution for the system size in the M/M/1 queueing model with the possibility of catastrophes at the service station is derived in the direct way. Asymptotic behavior of the probability of the server being idle and mean queue size are discussed. Steady-state probabilities are also obtained.

The M/G/1 retrial queue with feedback and starting failures

This paper discusses a retrial queue with Bernoulli feedback, where the server is subjected to starting failure. The retrial time is assumed to follow an arbitrary distribution and the customers in the orbit access the server under FCFS discipline. The necessary and sufficient condition for the stability of the system is derived. Various performance measures are obtained. Some numerical results are illustrated. The general decomposition law is shown to hold good for this model also. Some of the existing results are deduced as special cases.

Transient analysis of a single server queue with catastrophes, failures and repairs

Abstract A transient solution is obtained analytically using continued fractions for the system size in an M/M/1 queueing system with catastrophes, server failures and non-zero repair time. The steady state probability of the system size is present. Some key performance measures, namely, throughput, loss probability and response time for the system under consideration are investigated. Further, reliability and availability of the system are analysed. Finally, numerical illustrations are used to discuss the system performance measures.

An M/M/2 queueing system with heterogeneous servers and multiple vacations

In this paper, a Markovian queue with two heterogeneous servers and multiple vacations has been studied. For this system, the stationary queue length distribution and mean system size have been obtained by using matrix geometric method. The busy period analysis of the system and mean waiting time distribution are discussed. Extensive numerical illustrations are provided.

A single server feedback retrial queue with collisions

A Markovian single server feedback retrial queue with linear retrial rate and collisions of customers is studied. Using generating function technique, the joint distribution of the server state and the orbit length under steady-state is investigated. Some interesting and important performance measures of the system are obtained. Finally, numerical illustrations are provided.

Performance analysis of an M/G/1 queueing system under Bernoulli vacation schedules with server setup and close down periods

This paper is concerned with the analysis of a single server queueing system subject to Bernoulli vacation schedules with server setup and close down periods. An explicit expression for the probability generating function of the number of customers present in the system is obtained by using imbedded Markov chain technique. The steady state probabilities of no customer in the system at the end of vacation termination epoch and a service completion epoch are derived. The mean number of customers served during a service period and the mean number of customers in the system at an arbitrary epoch are investigated under steady state. Further, the Laplace-Stieltjes transform of the waiting time distribution and its corresponding mean are studied. Numerical results are provided to illustrate the effect of system parameters on the performance measures.

Transient Analysis of an M/M/1 Queue Subject to Catastrophes and Server Failures

ABSTRACT A transient solution for the system size in the M/M/1 queueing system with the possibility of catastrophes and server failures is analyzed. The steady state probabilities of the system size are also derived. Some important performance measures are discussed. Finally, the reliability and availability of the system are obtained.

Mx/G/1 Retrial Queue with Multiple Vacations and Starting Failures

This paper is concerned with the analysis of a single-server batch arrival retrial queue with Bernoulli service schedule and multiple vacation with general retrial times and the server being subjected to starting failures. We assume that the customers who find the server busy are queued in the orbit in accordance with an FCFS (first-come-first-served) discipline and only the customer at the head of the queue is allowed for access to the server. We first present the necessary and sufficient condition for the system to be stable and derive analytical results for the queue length distribution as well as some performance measures of the system under steady-state condition. We show that the general stochastic decomposition law for Mx/G/1 queue with multiple vacation models holds for the present system too. Some special cases are also studied.