180 research outputs found
Modelling Self-similar Traffic Of Multiservice Networks
Simulation modelling is carried out, which allows adequate describing the traffic of multiservice networks with the commutation of packets with the characteristic of burstiness. One of the most effective methods for studying the traffic of telecommunications systems is computer simulation modelling. By using the theory of queuing systems (QS), computer simulation modelling of packet flows (traffic) in modern multi-service networks is performed as a random self-similar process. Distribution laws such as exponential, Poisson and normal-logarithmic distributions, Pareto and Weibull distributions have been considered.The distribution of time intervals between arrivals of packages and the service duration of service of packages at different system loads has been studied. The research results show that the distribution function of time intervals between packet arrivals and the service duration of packages is in good agreement with the Pareto and Weibull distributions, but in most cases the Pareto distribution prevails.The queuing systems with the queues M/Pa/1 and Pa/M/1 has been studied, and the fractality of the intervals of requests arriving have been compared by the properties of the estimates of the system load and the service duration. It has been found out that in the system Pa/M/1, with the parameter of the form a> 2, the fractality of the intervals of requests arriving does not affect the average waiting time and load factor. However, when ≤2, as in the M/Pa/1 system, both considered statistical estimates differ.The application of adequate mathematical models of traffic allows to correctly assess the characteristics of the quality of service (QoS) of the network
Dimensioning of Telecommunication Network Based on Quality of Services Demand and Detailed Behaviour of Users
The aim of this paper is to be determined the network capacity (number of necessary internal switching
lines) based on detailed users’ behaviour and demanded quality of service parameters in an overall
telecommunication system. We consider detailed conceptual and its corresponded analytical traffic model of
telecommunication system with (virtual) circuit switching, in stationary state with generalized input flow, repeated
calls, limited number of homogeneous terminals and losses due to abandoned and interrupted dialing, blocked
and interrupted switching, not available intent terminal, blocked and abandoned ringing (absent called user) and
abandoned conversation.
We propose an analytical - numerical solution for finding the number of internal switching lines and values of the
some basic traffic parameters as a function of telecommunication system state. These parameters are requisite
for maintenance demand level of network quality of service (QoS). Dependencies, based on the numericalanalytical
results are shown graphically.
For proposed conceptual and its corresponding analytical model a network dimensioning task (NDT) is
formulated, solvability of the NDT and the necessary conditions for analytical solution are researched as well. It is
proposed a rule (algorithm) and computer program for calculation of the corresponded number of the internal
switching lines, as well as corresponded values of traffic parameters, making the management of QoS easily
Evaluation of Pareto/D/1/k Queue by Simulation
The finding that Pareto distributions are adequate to model Internet packet interarrival times has
motivated the proposal of methods to evaluate steady-state performance measures of Pareto/D/1/k queues.
Some limited analytical derivation for queue models has been proposed in the literature, but their solutions are
often of a great mathematical challenge. To overcome such limitations, simulation tools that can deal with general
queueing system must be developed. Despite certain limitations, simulation algorithms provide a mechanism to
obtain insight and good numerical approximation to parameters of queues. In this work, we give an overview of
some of these methods and compare them with our simulation approach, which are suited to solve queues with
Generalized-Pareto interarrival time distributions. The paper discusses the properties and use of the Pareto
distribution. We propose a real time trace simulation model for estimating the steady-state probability showing the
tail-raising effect, loss probability, delay of the Pareto/D/1/k queue and make a comparison with M/D/1/k. The
background on Internet traffic will help to do the evaluation correctly. This model can be used to study the long-
tailed queueing systems. We close the paper with some general comments and offer thoughts about future work
The application of non-linear dynamics to teletraffic modelling.
PhDAbstract not availableEngineering and Physical Science Research Council (EPSRC) and NORTE
Delay Bound: Fractal Traffic Passes through Network Servers
Delay analysis plays a role in real-time systems in computer communication networks. This paper gives our results in the aspect of delay analysis of fractal traffic passing through servers. There are three contributions presented in this paper. First, we will explain the reasons why conventional theory of queuing systems ceases in the general sense when arrival traffic is fractal. Then, we will propose a concise method of delay computation for hard real-time systems as shown in this paper. Finally, the delay computation of fractal traffic passing through severs is presented
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