Retrial queues have been widely used to model many problems arising in telephone switching systems, telecommunication networks, computer networks and computer systems, etc. It is of basic importance to study reliability of retrial queues with server breakdowns and repairs because of limited ability of repairs and heavy influence of the breakdowns on the performance measure of the system. Howeve...

We describe main models and results of a new branch of the queueing theory, theory of retrial queues, which is characterized by the following basic assumption: a customer who cannot get service (due to finite capacity of the system, balking, impatience, etc.) leaves the service area, but after some random delay returns to the system again. Emphasis is done on comparison with standard queues wit...

The research in the area of retrial queues focused mainly on the fact that the retrials operate under classical retrial policy, which suppose that the intervals between successive repeated attempts are exponentially distributed with total rate jθ (j is the number of customers in the orbit). There is another discipline, called constant retrial policy, where the total retrial rate does not depend...

In this work, we review the stochastic decomposition for the number of customers in M/G/1 retrial queues with reliable server and server subjected to breakdowns which has been the subject of investigation in the literature. Using the decomposition property of M/G/1 retrial queues with breakdowns that holds under exponential assumption for retrial times as an approximation in the non-exponential...

We consider basic M/M/c/c (c ≥ 1) retrial queues where the number of busy servers and that of customers in the orbit form a level-dependent quasi-birth-and-death (QBD) process with a special structure. Based on this structure and a matrix continued fraction approach, we develop an efficient algorithm to compute the joint stationary distribution of the numbers of busy servers and retrial custome...

Mean value analysis is an elegant tool for determining mean performance measures in queueing models. We use the technique to analyze the M/G/1 retrial queue with exponential retrial times. We also show how the relations can be adapted to obtain mean performance measures in more advanced M/G/1-type retrial queues.

In this paper, we investigate the fuzzy logic based system characteristics of MX/G/1 retrial queuing system with Bernoulli vacation schedule. The service time and vacation time are assumed to be generally distributed. It is found in many practical situations that the queuing models with fuzzy parameters are much more realistic than the classical crisp parameters based queuing models. We have...

Retrial queueing systems are characterized by the fact that a primary request, finding all servers and waiting positions busy upon arrival, leaves the service area but after some random time, repeats its demand. Between retrials, the customer is said to be in “Orbit”. So the repeated attempts for service from the group of blocked customers are super imposed on the normal stream of arrivals of p...

This article describes the application of the theory of retrial queues in capturing certain aspects of self-organizing behavior that arises, for example, in Peer-to-Peer networks. It can be shown that retrials have a fair effect on the performance of such self-organizing systems, and thus, should be taken into account adequately during the design and evaluation of these systems. Moreover, it ca...