www.ietdl.org Published in IET Networks Received on 19th February 2014 Accepted on 20th February 2014 doi: 10.1049/iet-net.2014.0019
Special Issue on Teletraffic Engineering in Communication Systems ISSN 2047-4954
Editorial Special issue on ‘teletraffic engineering in communication systems’ This Special Issue on Teletraffic Engineering in Communications Systems brings together six of the best research papers from academia, and reflects some of the latest and original achievements, with three very different papers concentrating on the resource allocation for quality of service (QoS) guarantee, traffic modelling, Internet traffic anomalies modelling and traffic-aware routing in cognitive radio (CR) network. Although the substantial changes in teletraffic problems in recent years readily justify this special issue, our real motivation was the eighth event of the International Symposium of Communications Systems, Networks and Digital Signal Processing (CSNDSP), hosted by the Poznan University of Technology Poznan, Poland (18–20 of July 2012), and the fact that good papers were presented in related sessions. In addition to conference papers, we had also released an open call for papers in order to attract submissions from the wider scientific community. The paper by Shioda, ‘Fundamental Trade-offs between Resource Separation and Resource Share for QoS Guarantees’, sheds new light on the resource assignment strategy for QoS guarantee in the Internet. Based on network calculus, two resource allocations strategies are examined and compared, in terms of the provided QoS level. The first is the resource separation strategy, which corresponds to the IntServ model used in the Internet, and the second is the resource sharing strategy, which corresponds to the DiffServ model, also used in the Internet. It is shown that, although the resource separation (IntServ) strategy seems to be better than the resource sharing (DiffServ) strategy in general, the resource sharing strategy results in a much lower x-percentile end-to-end queuing delay, thanks to the statistical multiplexing effect. Therefore the preferable strategy depends on various conditions, like the specific QoS target. In the second paper by Brewka et al., ‘Integrated service resource reservation using Queueing Networks theory’, also the resource allocation for QoS guarantee in the Internet is examined. The authors concentrate on the IntServ model and consider a partial resource reservation mechanism, whereby a part of a traffic-flow has guaranteed access to a dedicated fraction of the link bandwidth, whereas the surplus traffic-flow shares the available resources in common with other traffic flows. The formulated model IET Netw., 2014, Vol. 3, Iss. 1, pp. 1–3 doi: 10.1049/iet-net.2014.0019
(a Markovian chain of the system) has a product-form solution, and therefore the provided analytical performance evaluation is accurate. What is actually innovative is the fact that the analysis is performed from the viewpoint of queuing theory. Resource allocation for QoS guarantee, when traffic is distinguished in a high-priority real time (RT) traffic, and a low-priority non-RT (NRT) traffic, is the subject of the third paper entitled, ‘Performance Approximations and Bounds for NRT Traffic in an Integrated Service System’ by Huang et al. The performance evaluation of communication links accommodating both NRT traffic (elastic traffic) together with RT traffic (stream traffic) is a challenging teletraffic issue. The authors consider an integrated service system that serves multi-rate RT traffic of non-Poisson arriving calls, together with Poisson NRT traffic, and evaluate it in a computationally efficient way. To this end, the non-Poisson RT traffic is substituted with an equivalent single-class of Poisson RT traffic, which preserves mean and peakedness of the number of calls in the system. The whole approach is based on the famous Equivalent Random Theory and the Hayward approximation. In the next paper by Arfeen et al., ‘Internet Traffic Modeling: From Superposition to Scaling’, the stochastic behaviour of traffic superposition (because of resource sharing, while traffic passes end-to-end) is modelled, to benefit the design and provisioning of resources in both access and core parts of Internet. As it has been observed, Internet traffic includes both heavy and non-heavy tailed distributions. The behaviour of non-heavy tailed traffic superposition has been well studied, but this paper belongs to the few studies of superposition of heavy tailed arrival patterns. Moreover, the authors study the process of traffic superposition and scaling, jointly in a non-asymptotic framework, so as to better understand the nature and dynamics of the cumulative arrival processes of Internet traffic. The state of the art of multiplexing, both heavy and non-heavy tailed traffic, and the resulting scaling phenomenon (burstiness at various time scales) is reviewed, whereas new results and their applicability in access and core networks are presented and discussed. Regarding Internet traffic anomalies, most of the published works concentrate on detection rather than modelling, 1
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www.ietdl.org although the latter is a prerequisite. Bandara et al. analyse and model Internet traffic anomalies through a novel approach composed of two main phases in their paper entitled, ‘A Spatiotemporal Model for Internet Traffic Anomalies’. In the first phase, a multi-scale analysis is performed, based on a spatiotemporal filter which extracts the duration and volume information of anomalies. In a second phase, the individual properties of the anomalies are characterised and integrated into a comprehensive model, which captures the input–output anomaly relationships at a node. Subsequently, the model is extended to describe the behaviour of anomalies at subnet levels; enabling, thus, hierarchical analysis of large and sophisticated networks. The authors concentrate on traffic intensity and volume anomalies, that is, unusual deviations in throughputs. However, the proposed modelling approach is applicable to other types of measurements, as long as they can be represented in a form of arrays of time-series. In the last paper by Mavromoustakis et al., ‘Energy Efficient Resource Sharing using a Traffic-oriented Routing Scheme for Cognitive Radio Networks’, a new routing protocol is proposed for an ad hoc CR network. The protocol is energy efficient and incorporates an intensive traffic-aware scheme, so that energy conservation is achieved, whereas efficient data flow coordination is enabled among secondary communicating nodes with heterogeneous spectrum availability in CR networks. The authors exploit the pattern of incoming traffic into primary nodes in order to minimise the consumption of energy of secondary nodes. The routing algorithm is actually a multi-criteria routing algorithm, which uses Fibonacci backward difference traffic estimation for energy conservation. The proposed protocol is validated through extensive simulations. We would like to congratulate the authors on their valuable research results and the succeeding publication in the framework of this Special Issue on Teletraffic Engineering in Communications in IET Networks. Besides, we sincerely hope that the aforementioned selection of published papers satisfy the expectation of the readers. Finally, we would like to express our deepest thanks to the reviewers for their invaluable and timely remarks on the technical content of the papers, and, of course, the IET Networks editorial team for giving us the opportunity to put together this Special Issue, as well as for their advice and guidance. Prof. Mariusz Głąbowski received the M.Sc., Ph.D. and D.Sc. (Habilitation) degrees in telecommunication from the Poznan University of Technology, Poland, in 1997, 2001 and 2010, respectively. Since 1997, he has been working in the Department of Electronics and Telecommunications, Poznan University of Technology. He is engaged in research and teaching in the area of performance analysis and modelling of multiservice networks and switching systems. Prof. Mariusz Głąbowski is the author/co-author of four books, several book chapters and of over 140 papers which have been published in communication journals and presented at national and international conferences. He has refereed over 150 papers for many international conferences and magazines, including: IEEE Globecom, IEEE ICC, IEEE Transactions on Communications, IEEE 2
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Communications Magazine, IEEE Communications Letters, IET Networks, IET Circuit, Devices and System, Performance Evaluation, European Transactions on Telecommunications. Professor Glabowski is a vice-chair of the European Section of the Institute of Electronics, Information and Communication Engineers (IEICE). He is also a member of International Academy, Research and Industry Association (Fellow), Institute of Electrical and Electronics Engineers (Senior member), Federation of Telecommunications Engineers of the European Community and Polish Association of Telecommunication Engineers. He has organised four international conferences and workshops. Assistant Prof. Ioannis D. Moscholios received the Dipl.-Eng. degree in Electrical & Computer Engineering from the University of Patras, Patras, Greece, in 1999, the M.Sc. degree in Spacecraft Technology & Satellite Communications from the University College London (UCL), London, UK, in 2000 and the Ph. D. degree in Electrical & Computer Engineering from the University of Patras, Greece, in 2005. From 2005 to 2009, he was a Research Associate at the Wire Communications Laboratory, Department of Electrical & Computer Engineering, University of Patras, Greece. During the same period, he was in the Core Network Planning Group of Vodafone Greece. From 2009 to 2013, he was a Lecturer in the Department of Telecommunications Science and Technology, University of Peloponnese, Greece. Currently, he is an Assistant Professor in the Department of Informatics & Telecommunications, University of Peloponnese, Greece. His research interests include simulation and performance analysis of communication networks, queueing theory, whereas his main interest is on teletraffic engineering where he has published more than 85 papers in international journals and conferences. His work has received more than 190 (non-self) citations. He is a member of the Technical Chamber of Greece (TEE). Professor Michael D. Logothetis received his Dipl.-Eng. degree and Doctorate in Electrical Engineering, both from the University of Patras, Patras, Greece, in 1981 and 1990, respectively. From 1982 to 1990, he was a Teaching and Research Assistant at the Laboratory of Wire Communications, University of Patras, and participated in many national and EU research programmes, dealing with telecommunication networks, as well as with office automation (including natural language processing). From 1991 to 1992, he was Research Associate in NTT’s Telecommunication Networks Laboratories, Tokyo, Japan. Afterwards, he was a Lecturer in the Department of Electrical & Computer Engineering of the University of Patras, and since 2009 he has been elected (full) Professor in the same Department. He teaches the courses: Broadband Telecom Networks; Computer Networks, Teletraffic Theory and Communications Systems. His research interests include teletraffic theory and engineering, traffic/network control, simulation and performance optimisation of communications networks (Internet, wireless, optical, NGN). He has published over 170 conference/journal papers, books/proceedings, a teletraffic book in Greek IET Netw., 2014, Vol. 3, Iss. 1, pp. 1–3 doi: 10.1049/iet-net.2014.0019
www.ietdl.org (second issue in 2012), whereas he has over 550 third-party citations (h = 13). He has organised the Fifth IEEE International Conference on Communications Systems, Networks and Digital Signal Processing, CSNDSP 2006, and he is a member of the Steering Committee of the CSNDSP. He has reviewed many conference and journal papers. He served/is serving on the Technical Program Committee of several international conferences. In addition, he has organised and chaired several technical sessions and has offered tutorial lectures in conferences. He has become a Guest Editor in five journals: (a) Mediterranean Journal of Electronics and Communications, (b) Mediterranean Journal of Computers and Networks, (c) IET Circuits, Devices & Systems, (d) IET Networks and (e) Ubiquitous Computing and Communication Journal. He participates in the Editorial
IET Netw., 2014, Vol. 3, Iss. 1, pp. 1–3 doi: 10.1049/iet-net.2014.0019
Board of the following international journals: ‘IARIA International Journal on Advances in Telecommunications’, ‘Advances in Electronics and Telecommunications’ – ‘Poznan University of Technology’ and ‘Hindawi Communications and Networking’. He is a member of the IARIA (Fellow Member), IEEE (Senior Member), IEICE, FITCE and the TEE. MARIUSZ GLABOWSKI
[email protected] Faculty of Electronics and Telecommunications, Poznan University of Technology, Mariusz Glabowski, ul. Polanka 3, Poznan 60965, Poland
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