We consider an IvI Ilv!1 c queue with two classes of customers. We examine the effect of different priority policies on the optimal number of servers to minimize the long-run expected average server and holding costs of the system. Three different policies are considered; the non-idling non-preemptive and preemptive policies as well as the idling policy which minimizes the long-run expected ave...

This paper addresses the problem of scheduling periodic messages in demand priority network standardized by IEEE 802.12 Committee. As regards the real-time property of the demand priority network, unnecessary blocking time due to its round-robin-based MAC protocol may cause periodic messages to miss their hard deadlines and result in low schedulability of periodic messages. We propose a new mes...

An analysis of single server preemptive priority retrial queue with at most J vacations where two types of customers called (priority customers and ordinary customers) are considered in this paper. The priority customers do not have queue and they have higher priority to receive their services over ordinary customers. If negative customer is arriving during the service time of any positive cust...

Priority scheduling for packets is becoming a hot topic, as attemps are being made to integrate voice services in existing data networks. In this paper, we consider a discrete-time queueing system with head-of-line (HOL) non-preemptive priority scheduling. Two classes of traffic will be considered, i.e., high-priority and lowpriority traffic, which both generate variable-length packets. We will...

Work-stealing schedulers focus on minimizing overhead in task scheduling. Consequently, they avoid features, such as task priorities, which can add overhead to the implementation. Thus in such schedulers, low priority tasks may be scheduled earlier, delaying the execution of higher priority tasks and possibly increasing overall execution time. In this paper, we develop a decentralized work-stea...

In many cognitive radio applications, there are multiple types of message queues. Existing queueing analysis works in underlay CR networks failed to discuss packets heterogeneity. Therefore high priority packets with impatient waiting time that have preemptive transmission opportunities over low class are investigated. We model the system behavior as a M/M/1+GI queue which is represented by a t...

We study a vacation queueing system with a single server simultaneously dealing with an M/G/1 and an M/D/1 queue. Two classes of units, priority and non-priority, arrive at the system in two independent Poisson streams. Under a non-preemptive priority rule, the server provides a general service to the priority units and a deterministic service to the non-priority units. We further assume that t...

Real time and non-real-time data packets are the two types of scheduling packets which is used at sensor nodes with resource constraints in WSN of importance to reduce sensors energy and end-to-end delays. Existing First Come First Served, starvation of high priority real-time data packets due to the transmission of a large data packet in nonpreemptive priority scheduling, starvation of nonreal...

A number of authors have recently suggested solving quasi birth-and-death (QBD) processes through the use of eigenvalue-based methods. These methods take on a special form when there are multiple eigenvalues present. We investigate this problem in a general setting as well as in the context of a specific preemptive priority queueing model.