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This paper aims to introduce the relationships between some Voice over IP Key Performance Indicators (KPIs) and to address them through the background of possible network or platform problems, resulting in KPIs degradation. We present extensions of a generic Quality of Service (QoS) monitoring strategy by describing a variety of correlations between the QoS metrics. For echo correlation for instance,...
This paper discusses the condition under which the jitter buffer at the receiver is to be operated for minimum output variance in a TDMoIP framework. The above study would be useful in the design of synchronization algorithms at the receiver of a TDMoIP network. This work uses the results derived in [1] to the above problem. We model the receiver jitter buffer as a M/G/1 queueing system with EARMA...
The performance of cognitive radio is determined by the spectrum occupancy, which is correlated in space, time and frequency. In this paper, the theory of random fields is applied to model the spatially correlated spectrum occupancy. The entire cognitive radio networks are modeled as a plenary grid or a straight line. Two dimensional and one dimensional Ising models are applied to model the joint...
In this paper we have evaluated the main functionalities of NetEm, a popular Linux based network emulator, which we have used to stress test the performance of the Games@Large distributed gaming system. We have performed a number of tests on different NetEm functionalities in order to evaluate their practical performance conformity and validity versus the NetEm description and theoretical expectations...
The swift acceptance and the widespread use of virtual environments has substantially increased the stress on networks as each of the operating systems running in parallel sends out packets over the same network. As an increased number of packets traverse a network, the importance to continuously monitor whether the network is providing satisfactory service has increased. The metrics for such analyses...
Distributed Interactive Multimedia Environments (DIMEs) enable geographically distributed people to interact with each other in a joint media-rich virtual environment for a wide range of activities, such as art performance, medical consultation, sport training, etc. The real-time collaboration is made possible by exchanging a set of multi-modal sensory streams over the network in real time. The characterization...
Wireless Area Networks are commonly used for a great variety of applications. Actually, more and more people are using them as the access network technology for their home network or to access to Internet through a wireless router. In many cases, the access is performed in outdoors, not only in indoors. On the other hand, networks are experiencing a huge demand of services such as VoIP and IPTV that...
We develop a QoS/QoE correlation model for IPTV QoE evaluation. With the growth of QoE interest, IPTV providers need a method to control QoE when QoE is not satisfied by subscribers. Network providers can evaluate subscriber's QoE using QoS parameters weight and some analyzed values which is from the proposed model, and control QoE as deduce QoS parameters(delay, loss, jitter etc) associated with...
Traditionally, IP Network planning and design is mostly based on average delay or loss constraints which can often be easily calculated. Jitter, on the other hand, is much more difficult to evaluate but this is particularly important to manage the QoS of real-time and interactive services such as VoIP and streaming video. In this paper, we propose a simple model for the delay jitter that is fast enough...
This paper explores the perceptual effect of network delay jitters on consumers' quality of experience during packet-based VoIP conversations. Novel parametric speech quality models are proposed to faithfully capture speech quality impairment caused by network delay jitter and de-jittering buffer settings. The proposed models have been rigorously conceived following a regression analysis approach...
This paper is described the properties of the pseudo-ternary M-sequence such as the periodic autocorrelation function, the balance properties, the preferred pairs and so on. This paper is also discussed the tracking performances of the spread spectrum (SS) systems with the delay locked loop (DLL) using the pseudo-ternary M-sequence. As a result, the tracking error performance can be improved by the...
The goal of this paper is to present a new objective method for evaluating the quality of streaming audio - PESAQ (perceptual evaluation of streaming audio quality). According to our experiments, we found that the ITU recommended objective evaluation method - PEAQ(perceptual evaluation of audio quality) can not fit the subjective quality of streaming audio accurately. To develop the new method PESAQ,...
Delay jitter is a critical factor that must be considered in networked real-time applications that require accurate prediction of packet delivery times. Delay jitter can be smoothed by holding packets in a play-back buffer for a certain time called a play-back delay. In this paper, we propose a scheme to enhance the prediction of the play-back delay in Networked Control Systems (NCSs) with no need...
Delay jitter adversely affects the performance of networked real-time applications that require accurate prediction of packet delivery times. Delay jitter can be smoothed by holding packets in a play-back buffer for a certain time called a playback delay. In this paper, we propose a scheme to enhance the prediction of the play-back delay in networked control systems (NCSs) with no need for clock synchronization...
This paper presents a time-interleaved sampling delay circuit to be used in an autocorrelation receiver for impulse-radio UWB. It applies a 10 GHz time-interleaved sampling and readout operation for analog signal storage and reconstruction. The delay function is achieved by shifting the sampling and reading clock sequence by a particular time interval. System analysis shows the feasibility of using...
In this paper, we described the correlations between uplink TCP packet latency, behavior of TCP and behavior of application. Pearson product moment correlation analysis and partial correlation analysis are worked out to characterize correlations between five user perceived parameters. Our study demonstrated that the packet latency in uplink direction mainly caused by TCP setup time instead of the...
In this paper, we described the correlations between user perceived Web response time and the asymmetrical link characteristics. Our study demonstrated that the HTTP compression strongly affects the Web response time when uplink resources are limited. The constraints on uplink degrade Web performance seriously. In addition, we also found that it is possible to reduce Web response time through cross...
Due to the increased random variations in nanometer silicon process technology as well as voltage and temperature variations, it is very hard to guarantee performance characteristics with traditional corner-based timing analysis method. The variations, together with the issues like crosstalk and jitter, make it difficult to get a good silicon correlation with simulation and to meet target performance...
Nowadays, it is very important to study the behavior of the wireless networks due to the variety of applications that make use of this technology. These applications frequently require a minimum QoS in order to work properly and guarantee a good service to the user. This paper aims to find a relationship between signal to noise ratio (SNR) and a 802.11g networkpsilas QoS in terms of latency, packet...
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