Welcome
This is the first English language issue that was put together by the new Editorial Board appointed in July this year. We thought that this issue would be a good opportunity to introduce our colleagues to the international readers. We hope that most names sound familiar to those working in the respective fields, not only in Hungary but at international level, as well.
• István Bartolits (National Communications Authority) – telecommunication management and regulation
• István Bársony (Research Institute for Technical Physics and Material Science of the Hungarian Academy of Sciences) – new communication devices and technologies
• Levente Buttyán (Budapest Institute of Technology and Economics – BUTE, Dept. of Telecommunications) – information security
• Erzsébet Gyôri (BUTE, Dept. of Telecommunications and Media Informatics) – telecommunication software
• Sándor Imre (BUTE, Dept. of Telecommunications) – mobile comunications and computing
• Csaba Kántor (Hungarian Telecom) – satellite and space communications
• László Lois (BUTE, Dept. of Telecommunications) – multimedia communications
• Géza Németh (BUTE, Dept. of Telecom. and Media Inform.) – speech processing, service automation
• Géza Paksy (BUTE, Dept. of Telecom. and Media Inform.) – optical telecommunications
• Gergô Prazsák (National Council for Communications and Information Technology) – society-related issues
• István Tétényi (Computer and Automation Institute of the Hungarian Academy of Sciences) – research networks and testbeds
• Gyula Veszely (BUTE, Dept. of Broadband Com.) – propagation, antennas, electromagnetic compatibility
• Lajos Vonderviszt (National Communications Authority) – the Internet and WWW
The new Editorial Board would like to pay tribute to György Lajtha who was editing our journal during the last 5 years. Professor Lajtha, the always youthful “great senior” of telecommunications, has played a critical role in renewing our journal and maintaining its quality over these years. His unprecedented professional experience and never ceasing interest in all areas of the wide scope of our journal made it possible to develop its technical level and bring its content to a wide comunity of readers. We can only hope that Prof. Lajtha will stay with us by giving valuable advice, and – needless to say – we’ll gladly publish his papers!
The present issue contains English versions of reviewed research papers, selected from the preceeding five Hungarian issues. We intend to continue with this practice, but we also welcome submissions intended directly for the English issues. We also hope we will be able to gradually increase their number from two per year to maybe four per year, yielding to shorter waiting times for those wishing to submit their results for these issues. Now let us briefly introduce the papers selected for this English issue. Horváth and Telek investigate the class based weighted fair queueing (WFQ) used to model a number of computer and communication systems and present a very simple approach that provides a fast approximation for the queue length and waiting time measures.
Data mining is an area of increasing importance, with it’s goal to extract implicit, unknown and useful information from large data sets. Neural networks can be effectively used for nonlinear function approximation (regression) problems. The paper of Valyon and Horváth deals with some special types of networks, namely Support Vector Machines.
QoS requirements toward VoIP services necessitate adequate Operations and Maintenance (OAM) support, as well as a specialized fault management system. The study of Varga et al describes a complex fault management system customized for VoIP service providers.
In the paper by Buchholcz et al, we propose a new TCP variant (called TCP-ELN) which is capable to considerably improve the transfer rate over radio channels. The paper of Hottmar deals with modelling of doubleprocessor system by closed service network, presents a queueing system as a method of modelling and analyses the performance and quantifies the time characteristics of the processor systems.
Rónai et al propose a middleware called MAIPAN that provides a uniform computing environment for creating dynamically changing personal area networks (PANs). In this solution session transfers and dynamic session management are tightly integrated with strong and intuitive access control security.
The paper by Lois et al deals with multi-view video encoding and presentation. Based on the OpenGL system, the authors present a Depth Image-base Representation (DIBR) method to render an image from several existing reference pictures in a multi-view environment.
The provision of the sophisticated mobile services over IPv6 requires efficient transport protocols. The paper by Gál et al investigates the effect of mobility on the TCPv6 and UDPv6 protocols using comparative measurements. Lastly, we would like to use this opportunity to wish a Happy and Prosperous New Year to our authors, reviewers and readers!
László Zombory Csaba A. Szabó
President of the Editorial Board Editor-in-Chief