– This paper compares VoATM and VoIP in terms of their suitability for carrying voice traffic over DSL. ATM is currently the preferred protocol due to its built-in QoS mechanisms. Through simulations we show that IP QoS mechanisms can also be used to achieve comparable performance for voice traffic over DSL. Our performance metrics are the ETE delay of voice packets across the DSL access networ...

QoS Provisioning for 3P over xDSL remains a challenging task due to the effects of line impairments on such services. Differently from simple data, video and voice services have strict requirements for loss and delay tolerance. The accurate assessment of final service quality is part of this provisioning process, but its direct measurement is yet not practical. In this paper we explore the poss...

The very rapid adoption of new applications by some segments of the ADSL customers may have a strong impact on the quality of service delivered to all customers. This makes the segmentation of ADSL customers according to their network usage a critical step both for a better understanding of the market and for the prediction and dimensioning of the network. Relying on a “bandwidth only” perspect...

When videophone images are compressed to low bit rates (< 64 kbits/s) for transmission over telephone lines, the image quality deteriorates when there is a great deal of movement in the frame. If the coder has knowledge of the videophone user's location, this information can be used to enhance the area of interest (the user) at the expense of the unchanging and/or uninteresting background. It h...

Research on Component-Oriented Business Applications has focussed on Specifications of Components and Component Markets. Another approach based on Mass Customization and Software Product Lines is presented here. Mass Customization is a strategic concept used in many industries to offer products that are customer-individual, but based on a limited number of building blocks. Thus, customer value ...

The dynamic voltage restorer (DVR) is used to regulate the voltage at the load terminals from various power quality problems like sag, swell, harmonics, unbalance etc., in supply voltage. This paper presents modelling aspects of several types of Dynamic Voltage Restorer (DVR) working against various voltage sags by simulation in PSCAD/EMTDC. The reference signal for the series connected DVR is ...

The paper deals with a harmonic detection algorithm for hybrid power filters called DQ axis with Fourier (DQF) algorithm. This algorithm is a combination of the advantages of DQ axis method and sliding window Fourier analysis (SWFA). It is flexible and suitable in terms of design for hybrid power filters. This paper also presents the harmonic elimination by using the DQF algorithm for both thre...