This paper is concerned with the stability of a preemptive repeat priority queueing system with multiple types of customers and customer transfers between queues. Using the mean-drift method and matrix-analytic methods, simple conditions for the queueing system to be stable or instable are found. The conditions indicate that system stability depends only on the service rate of customers of the ...

In many service systems, customers are not served in the order they arrive, but according to a priority scheme that ranks them with respect to their relative “importance.” However, it may not be an easy task to determine the importance level of customers, especially when decisions need to be made under limited information. A typical example is from health care: When triage nurses classify patie...

We examine an M/G/1 queue with several queueing disciplines. After reviewing some background material in probability theory, we consider a first-come first-served queue. Next, we examine an absolute priority queue, where high priority customers are always selected for service over lower priority customers, regardless of how long the latter have been waiting. We also review a method for calculat...

Consider a single server retrial queueing system with pre-emptive priority service and single working vacation in which two types of customers arrive in a Poisson process with arrival rates ?1 for low and ?2 for high priority customers. We assume that regular service times follow an exponential distribution with parameters μ1 and μ2 correspondingly. The retrial is introduced for low priority cu...

In 5], we introduced the notion of (m; k)-rm deadlines to better express the timing requirements of real-time streams. For a stream with (m; k)-rm deadlines, the quality of service is acceptable as long as at least m customers meet their deadlines in any window of k consecutive customers. If fewer than m customers meet their deadlines in a window of k consecutive customers, the stream is said t...

Consider a single server retrial queueing system with preemptive priority service and single working vacation in which two types of customers arrive in a Poisson process with arrival rates λ1 for low and λ2 for high priority customers. We assume that regular service times follow an exponential distribution with parameters μ1 and μ2 correspondingly. The retrial is introduced for low priority cus...

ABSTRACf. This investigation deals with a multi server queueing model in which customers leave the system in the same chronological order in which they arrive. The customers are assumed to arrive in Poisson fashion from two infinite priority and ordinary sources and their service times are identical and exponentially distributed. The priority customers may wait but the ordinary customers are lo...

The main aim of the present paper is to draw the attention of the readers of this special issue to the modeling issues of sensor networks. The novelty of this investigation is the introduction of servers vacation combined with priority customers for finite-source retrial queues and its application to wireless sensor networks. In this paper we analyze a priority finite-source retrial queue with ...

We consider a multi-server non-preemptive queue with high and low priority customers, and a decision maker who decides when waiting customers may enter service. The goal is to minimize the mean waiting time for high-priority customers while keeping the queue stable. We use a linear programming approach to find and evaluate the performance of an asymptotically optimal policy in the setting of ex...

We consider a 2-class, single-server, preemptive priority queueing model in which the high-priority customers form a classical M/M/1 queue, while the low-priority customers form the so-called Israeli Queue with at most N different groups and unlimited-size batch service. We provide an extensive probabilistic analysis and calculate key performance measures. Special cases are analyzed and numeric...