QTNA

In this paper we consider a time slotted cognitive radio (CR) network with N wireless channels and M secondary users (SUs). We focus on a random access policy where each SU stochastically decides whether to access idle channels or not based on the given ...

We consider the M/M/m preemptive last-come, first-served queue without customer's priority classes. We focus on the analysis of the time interval from the arrival to either service completion or to abandonment of an arbitrary customer. We formulate the ...

In this paper, we study the delay characteristics of a discrete-time queue with a reservation-based scheduling mechanism. The objective is to provide a better quality of service to delay-sensitive packets at the cost of allowing higher delays for the ...

With ever-increasing demand for bandwidth, both optical packet switching and optical burst switching are proposed as alternatives to increase the capacity of optical networks in the future. In these packet-based switching techniques, Fiber Delay Lines ...

This paper considers a BMAP/M/∞ queue with a batch Markovian arrival process (BMAP) and an exponential service time distribution. We first prove that the BMAP/M/∞ queue is stable if and only if the expectation of the logarithm of the batch-size ...

In this paper, we present a fluid-flow model to characterize the behavior of the overloaded Session Initiation Protocol (SIP) server with a finite buffer. Our model includes a priority-based request scheduling mechanism (PRSM) which diminishes redundant ...

In this paper, we consider a multi-server queueing-inventory system with non-homogeneous Poisson arrivals, where the service times and lead times are exponentially distributed. The arrival process of the customers depends on the inventory level. When ...

Advanced Metering Infrastructure (AMI) has been attracting considerable attention for effective use of energy. In the system, smart meters installed in houses, factories, and other buildings automatically and periodically measure power consumption data ...

In this paper, we examine the key issue of how to conserve the energy of base stations (BSs) in "green" Cognitive Radio Networks (CRNs). In order to meet the demand for more sustainable green communication, we introduce a multiple sleep mode for ...

In this paper, we consider a cognitive radio network with multiple secondary users (SUs). The SU packets in the system can be divided into two categories: SU1 packets and SU2 packets, where SU1 packets have transmission priority over SU2 packets. ...

This paper considers an M/M/1 retrial queue where the server not only receives incoming calls but in idle time makes outgoing calls of two types whose durations follow the same exponential distribution. The outgoing calls of type 1 are directed to the ...

This paper considers the problem of system-level fault diagnosis in highly dynamic networks. The existing fault diagnostic models deal mainly with static faults and have limited capabilities to handle dynamic networks. These fault diagnostic models are ...

The energy harvesting wireless sensor networks are explored in order to enable environmental monitoring without maintenance for a long term. In this paper, we propose a task scheduling algorithm which performs fair and periodic data collection from all ...

The role of optical fibres as a medium for information transfer has found many applications. One of these is in environmental sensing, where slight perturbations in the surrounding environment can be remotely detected through modulation of light at ...

Different wireless Peer-to-Peer (P2P) routing protocols rely on cooperative protocols of interaction among peers, yet, most of the surveyed provide little detail on how the peers can take into consideration the peers' reliability for improving routing ...

The rapid ageing population is posing challenges to many countries all over the world, particularly in the provision of care to the growing number of elderly who are living alone. Allowing the elderly to age-in-place, i.e., live safely and independently ...

We consider an M/G/1 Markovian feedback queue with multiclass customers. We derive functional equations for the stationary distribution of the queue size and the total response time. A system of linear equations is also derived for the moments of the ...

In server-hosting service with cloud computing, servers are hired and released depending on the number of jobs in the system. Considering setup cost which is incurred each time new servers are hired, it may save the total cost if one keeps idle servers ...

We consider a Markovian single-server retrial queueing system. Customers in orbit retry after an exponentially distributed amount of time, the retrial rate depending on the number of times the customer has retried before. Moreover, the number of ...

We address the problem of stabilizing control for complex queueing systems with known parameters but unobservable Markovian random environment. In such systems, the controller needs to assign servers to queues without having full information about the ...

Phase-type distributions constitute a very versatile class of distributions. They have been used in a wide range of stochastic modeling applications in areas as diverse as telecommunications, finance, queueing theory, survival analysis, inventory ...

This paper considers a multiserver retrial queue with setup time which is motivated from application in data centers with the ON-OFF policy, where an idle server is immediately turned off. The ON-OFF policy is designed to save energy consumption of idle ...

This paper considers the QBD approximation of a special class of two-dimensional reflecting random walks (2D-RRWs). A typical example of the 2D-RRWs is a two-node Jackson network with cooperative servers. The main contribution of this paper is to ...

The second order measures such as the variance and covariance of the output process in a production system are very useful to design and control the systems in a more effective way. This paper concerns to the two-station system with a buffer of finite ...

RFID systems are getting popular for management of things. In this paper, we consider BFSA (Basic Framed Slotted ALOHA) and DFSA (Dynamic Framed Slotted ALOHA) protocols for identification of passive RFID tags, and focus on the tag identification time ...

The purpose of this paper is to obtain product form solution for retrial - queueing - inventory system. We study an M/M/1 retrial queue with a storage system driven by an (s, S) policy. When server is idle, external arrivals enter directly to an orbit. ...