The aim of this paper is to provide a more realistic description of priority-discipline queueing models by using Fuzzy Set Theory. It develops and optimizes two fuzzy queueing models with priority-discipline, a model with nonpreemptive priorities system and a model with preemptive priorities system, denoted by M̃i /M̃i /1 and M̃i /Fi /1. The first symbol is for a queueing system where arrivals and...

In the today’s Internet and TCP/IPnetworks, the queueing of packets is commonly implemented using the protocol FIFO (First In First Out). Unfortunately, FIFO performs poorly in the Adversarial Queueing Theory. Other queueing strategies are researched in this model and better results are performed by alternative queueing strategies, e.g. LIS (Longest In System). This article introduces a new que...

Fair queueing is a well-studied problem in modern computer networks. There are two classes of queueing algorithms. One focuses on bounded delay and good fairness properties. The other focuses on the performance of the scheduling algorithm itself. However in embedded networks working under real time constraints, equally important is the deadline imposed by the application. Modern queueing algori...

We study queueing strategies in the adversarial queueing model. Rather than discussing individual prominent queueing strategies we tackle the issue on a general level and analyze classes of queueing strategies. We introduce the class of queueing strategies that base their preferences on knowledge of the entire graph, the path of the packet and its progress. This restriction only rules out time ...

Java Modelling Tools (JMT) is a suite of open source applications for performance evaluation and workload characterization of computer and communication systems based on queueing networks. JMT includes tools for workload characterization (JWAT), solution of queueing networks with analytical algorithms (JMVA), simulation of general-purpose queueing models (JSIM), bottleneck identification (JABA)...

In this paper we present a study of queueing delays experienced in Delay Tolerant Networks with topology based on deterministic contact plan schedules. We examine a generic scenario and propose a sampling procedure that extracts measurements of queueing rates and queue lengths. Sampling queueing information is transmitted to network nodes, which then form time series and can be used to forecast...

Queueing network models have been extensively applied to represent and analyze resource sharing systems such as communication and computer systems and they have proved to be a powerful and versatile tool for system performance evaluation and prediction. Product form queueing networks have a simple closed form expression of the stationary state distribution that allow to define efficient algorit...

We use a mathematical model of an open queueing network in heavy traffic. The law of the iterated logarithm for the extreme virtual waiting time of a customer in heavy traffic in open queueing networks has been presented. Finally, we present an application of the theorem a reliability model from computer network practice. Key–Words: mathematical models of technical systems, performance evaluati...

Many authors have analyzed queueing systems with server breakdowns. Kendall (1953) studied stochastic processes occurring in the theory of queues and their analysis by the method of imbedded Markov chains. Buzacott and Hanifin (1978) classified the machine failures as operation dependent failures and time dependent failures. Shanthikumar (1982) analyzed a M/G/1 queueing system with time and ope...

In this paper, we propose the use of a control theoretical approach in the design of fair queueing algorithms based on the Scalable Core (SCORE) / Dynamic Packet State (DPS) architecture. In particular, we make use of the Linear Quadratic control method from optimal control theory to design stable and robust systems that are simple to implement. Simulation results show that this approach gives ...