Cooperative Wireless Networking: Research challenges (in Kooperation mit der Lakeside Labs GmbH)

Dr. Paulo Mendes | October 17, 2018 | 10:00 | L4.1.114 – Lakeside Labs GmbH im B04.b.1


„Today’s internet is being populated, in its fringes, by large number of devices that are wireless and/or cellular enabled. Despite the fact that such devices are often in the vicinity of each other, communication among them follows the end-to-end principle and as such, traditional data transmission approaches do not take advantage of the physical proximity of devices.

In the area of computer networks, the concept of cooperation has been applied to mitigate such effects, in different layers of the OSI stack. For instance, in wireless networks, cooperative networking techniques are being applied in OSI Layer 1 (based on diversity); in OSI Layer 2 (based on overhearing); in OSI Layer 3 (based on estimation); and in the above layers, for instance, as occurred with overlaying (e.g., P2P).

This talk is based on the research findings and contributions that the speaker has been doing to the field of cooperative networking. The talk will go over the sustainability of cooperative networking, by studying the inclusion of derived models, such as user-centric networking, in the Internet wholesale model, and by investigating the basic requirements for the success deployment of cooperative networking mechanisms, in terms of the incentives that devices need to have to participate in cooperative activities. From a pure networking perspective the talk will focus on cooperative networking mechanisms related to few-hop relaying and cooperative routing aiming to take advantage of any opportunity to communicate in intermittently connected wireless networks.

The talk will end with an overview of the research challenges to apply cooperative networking principles to the development of an Internet encompassing a huge number of embedded devices able to produce a large amount of data, where there are potential advantages in combining communication and computation in what is called in this talk “cooperative computing”. As example, the talk will focus on autonomic vehicle technology, which is being driven by advances in sensing, computing and networking technologies. On the one hand, autonomous driving on urban roads has seen significant progress in recent years. On the other hand, autonomous Unmanned Aerial Vehicles (UAVs) have received increasing interest to tackle several use-cases from environment monitoring and emergency situations, to relaying communications to isolated areas.“

Paulo Jorge Milheiro Mendes

Paulo has 20 years of experience as computer engineer and 7 years as coordinator of research teams. Paulo has an entrepreneurial spirit, with the ability to take an idea from beginning to end, while dealing with fast-moving deadlines. He has a team leadership profile with capability to gather innovation funding. In 2004 he got his Ph.D. (summa cum laude) degree in Informatics Engineering from the University of Coimbra, having performed his thesis as a visiting scholar at Columbia University, New York (2000 – 2003).  He started building his research carrier at NTT Docomo research Labs in Munich, Germany. After that we co-founded the Internet Architecture and Networking research group at INESCTEC in Oporto, Portugal (2007-2010), and the Cognitive and People Centric Computing Lab (2010 – ) in Lisbon, Portugal. His research interests are in the field of self-organised systems (e.g. swarm intelligence), cognitive networks (e.g. orchestration of distributed edge systems) and cooperative wireless networks (e.g. relaying, opportunistic networking, named-data networking). His skills include Internet protocols, wireless networks, software engineering, sensing systems, as well as programming (C, C++, Java) for Linux and Android systems. Paulo Mendes has more than 80 articles in journals, magazines, books and conference proceedings and his inventions have been protected by 14 international patents.

Posted in TEWI-Kolloquium | Leave a comment

MIMO and Massive MIMO schemes: application to time reversal and spatial modulations

Prof. Maryline Hélard | September 5, 2018 | 15:00 | L4.1.01


To meet growing demand for higher throughputs, advanced digital communication techniques based on multicarrier modulations, multiple antenna systems (MIMO) and their extension to massive MIMO (M-MIMO), powerful coding schemes or interference coordination are always under study and could be combined with solutions based on network densification and deployment of heterogeneous infrastructures.

For a number of years now,  IETR (Institut of Electronics and Telecommunications of Rennes) Labs has being developed strong expertise in communications systems with several experiments associating OFDM and MIMO in some proofs of concept.

In the first part of this talk, one of the classical precoding technique, known as Time Reversal applied to digital communications will be presented as well as its easy combination with OFDM. A second part will be dedicated to spatial modulation applied either at transmit or receive side and its possible application to IoT. For both systems, the benefit of using a high number of transmit antenna will be highlighted and a description of the proofs of concept implementation carried out in our labs provided.

The talk will then concentrate on the researches carried out with some of our PhD students on hybrid beamforming techniques, mmWave communications and VLC communications.


Professor Maryline Hélard received the M.Sc and PhD degrees from INSA Rennes and the Habilitation degree from Rennes 1 University in 1981, 1884 and 2004 respectively. In 1985, she joined France Telecom as a research engineer and since 1991 she has been studying physical layer in the field of digital television and wireless communications. In 2007, she joined the National Institute of Applied Science (INSA) as a professor and she is now the co-director of the Signal and 2018 Communications department of IETR (Electronics and Telecommunications Institute of Rennes). She is co-author of more than 140 technical papers including 37 journal papers and of 30 patents. Her current research interests are in the areas of digital communications such as MIMO techniques, large MIMO, OFDM, MC-CDMA, channel estimation, equalization, spatial modulations and iterative processing applied to wireless communications and more recently to wire communications (ADSL, optical). She was involved in several collaborative research projects including digital television, MC-CDMA techniques, time reversal and spatial modulation.

Posted in TEWI-Kolloquium | Leave a comment

Towards power efficient transmitters with multicarrier waveforms: novel PAPR reduction techniques and optimisation of in-band and out-of-band distortions

Prof. Jean-François Hélard | September 5, 2018 | 14:00 | L4.1.01


OFDM multicarrier techniques are widely deployed in most wireless communication systems, in particular in cellular networks (LTE, LTE Advanced, 5G…), broadcast networks (DVB-T, DVB-T2, ATSC3.0…) and WiFi networks. However, multi-carrier modulations are characterized by a very large dynamic amplitude measured by the Peak to Average Power Ratio (PAPR). This large amplitude prevents radio frequency designers to feed the signal at the optimal point of the non linear High Power Amplifier (HPA) which reduces their energy efficiency and then increases dramatically the overall base station consumption. In literature, the PAPR reduction and the  linearization techniques are the main approaches to solve this HPA efficiency problem in cellular and broadcast networks

In recent years, tone reservation (TR) PAPR reduction techniques have been deeply studied and included for example in the DVB-T2 and the new American digital video broadcasting (ATSC 3.0) standards. It is based on a gradient iterative approach where, at each iteration, a predefined kernel is used to reduce one peak in the time domain. During this talk, we will present novel TR PAPR reduction techniques, namely grouped individual carrier allocation for multiple peaks (GICMP) based on a new kernel signal and fully compatible with the new broadcasting DVB-T2 and ATSC3.0 standards. An in-depth performance analysis based on simulation and experimental results demonstrated that the novel proposed PAPR reduction algorithm offers very good performance/complexity/latency trade-off.

In the second part of this talk, we will present intelligent solution for future implementations to control the reduction of PAPR and the linearization steps in a flexible way according to some predefined parameters so that they become adaptive and self-configurable. More specifically, our work focused on the analytical analysis of in-band measured by the Error Vector Magnitude (EVM) and out-of-band distortions measured by the Adjacent Chanel Power Ratio (ACPR) for multicarrier signals taking into account the PAPR reduction, the impact of non-linear amplification, the memory effects and the predistortion. Combining those complementary approaches, the power efficiency of the transmitters with OFDM multicarrier waveforms can be highly upgraded and/or the energy consumption reduced by 10 to 15 %


Professor Hélard received his Dipl.-Ing. and his Ph.D in electronics and signal processing from the National Institute of Applied Sciences (INSA) in Rennes in 1981 and 1992 respectively. From 1982 to 1997, he was research engineer and then head of channel coding for the digital broadcasting research group at France Telecom Research Center (Orange Labs) in Rennes. In 1997, he joined INSA Rennes, which is one of the « Grandes Ecoles » in France, where he is today Full Professor, Classe Exceptionelle, which is the highest rank. He was Director of Research of INSA Rennes during 3 years  from december 2010 to december 2013. He was also during 8 years Deputy Director of the Rennes Institute for Electronics and Telecommunications (IETR, UMR CNRS 6164), which is an academic research laboratory of 400 people, created in 2002 in association with the CNRS. His research interests lie in signal processing techniques for digital communications, such as space-time and channel coding, multi-carrier modulation, as well as multi-user communications and cross-layer techniques, power efficient and PAPR reduction techniques.  He is involved in several European and national research projects in the fields of digital video terrestrial broadcasting, mobile radio communications and cellular networks, power-line and ultra-wide-band communications, cooperative communications and relaying techniques. Prof. J-F. Hélard is a senior member of IEEE, author and co-author of more than 270 technical papers in international scientific journals and conferences, and holds 15 European patents.

Posted in TEWI-Kolloquium | Leave a comment

How software systems of the future will manage themselves

Alois Reitbauer |  August 23, 2018 | 15:00 | E.2.42


You may have heard of autonomous self-driving cars, but what is autonomous self-driving software. Dynatrace has been running their software systems following a NoOps approach for several years now. Based on their experience they have developed a new approach to manage software applications using concepts like unbreakable delivery pipelines and self-healing deployments. Learn what is behind the idea of NoOps and how to build applications that run and manage themselves, what can be built today and what the future will bring.


Alois Reitbauer is the Chief Technology Strategist of Dynatrace and leads the Dynatrace innovation lab. Alois has successfully developed several solutions in the application performance management space and brought them to market. Currently he is working with his team on building autonomous software systems that manage themselves. Alois is further interested in the impact of new collaboration technologies like voice or Augmented Reality. In both areas he currently works with customers to develop market-ready products. Alois is also a frequent speaker at technology conferences and the chair of the W3C Distributed Tracing working group.

Posted in TEWI-Kolloquium | Leave a comment

Machine Learning Applications to Internet of Things

Dr. Hari Prabhat Gupta |  June 22, 2018 | 11:00 | Lakeside L4.1.04


Internet of Things (IoT) is growing rapidly in decades, various applications came out from academia and industry. IoT is an amazing future to the Internet, but there remain some challenges to IoT for human have never dealt with so many devices and so much amount of data. Machine Learning (ML) is the technique that allows computers to learn from data without being explicitly programmed. Generally, the aim is to make predictions after learning and the process operates by building a model from the given (training) data and then makes predictions based on that model. Machine learning is closely related to artificial intelligence, pattern recognition and computational statistics and has strong relationship with mathematical optimization. In this talk, we focus on ML applications to IoT. Specially, we focus on the existing ML techniques that are suitable for IoT. We also consider the issues and challenges for solving the IoT problems using ML techniques.


Dr. Hari Prabhat Gupta received the B.E. degree in Computer Engineering from Government Engineering College Ajmer, Ajmer, India, the M.Tech. and Ph.D degrees in Computer Science and Engineering from the Indian Institute of Technology Guwahati (IITG), Guwahati, India. He worked with Samsung R&D Bangalore, India. He has received a research fellowship from TATA Consultancy Services, India. He is currently working as Assistant Professor in Department of Computer Science and Engineering, Indian Institute of Technology (BHU), Varanasi, India. His research interests include wireless sensor networks, wireless ad hoc networks, and distributed algorithms. He has published various IEEE and ACM conference papers and Journals in the field of wireless sensor networks.


Posted in TEWI-Kolloquium | Leave a comment

Autonomous Flying access Networks

Omid Esrafilian, MSc |  June 25, 2018 | 3 pm | Lakeside B04, B4.1.114


The use of drones, a.k.a. unmanned aerial vehicles (UAVs) as a flying radio access network (RAN) is currently gaining significant attention. It holds promises as a complement to classical fixed infrastructure by allowing ultra flexible deployments, with use cases ranging from disaster recovery scenarios to improving the performance and coverage of the network. Beyond obvious challenges within regulatory, control, navigation, and operational domains, the deployment of autonomous flying-RANs also come with a number of exciting new research problems such as the issue of autonomous real-time placement of the drones in non-trivial propagation scenarios (i.e. scenarios where the optimal placement is not just dictated by a trivial geometry or statistical argument due to shadowing effects, e.g. in cities). We present several different approaches, lying at the cross-roads between machine learning, signal processing, and optimization. Some approaches involve the reconstruction of a city map from sampled radio measurements which can have application beyond the realm of communications.


Omid Esrafilian has started his Ph.D. since 2016 in the Communication System department of EURECOM under the supervision of Professor David Gesbert.

He received both his Master’s and Bachelor’s degree in Control-Electrical Engineering from K.N.Toosi University of Technology in 2016 and 2014, respectively. He graduated as first ranked among M.Sc. students of control major in his university. The subject of His Master’s Thesis was „Simultaneous localization and mapping and autonomous flight of a Quad-Rotor robot using a monocular camera“.

From 2012 to 2016, he worked as a research assistant and head of Quad-Rotor robotic team at the Advanced Robotics and Automated Systems lab (ARAS), K.N.Toosi University of Technology in Iran. During this period, he participated in some robotic competitions and won some prizes.

From 2014 to 2015, he was an assistant professor at Instrumentation Laboratory, K.N.Toosi University of Technology in Iran.

His research interest is robotic (UAVs) and communication and since the beginning of his PhD he published some publications on the topic of UAV-aided Radio Access Networks. Moreover, he was involved in the PERFUM’s first demo of the autonomous cellular flying relays.

Posted in TEWI-Kolloquium | Leave a comment

Solving x’=?

Prof. Konstantin Mischaikow  | 6. Juni 2018 | 16:00 Uhr | Z.1.09


With the advent of every improving information technologies, science and engineering is being being evermore guided by data-driven models and large-scale computations.  In this setting, one often is forced to work with models for which the nonlinearities are not derived from first principles and quantitative values for parameters are not known.

With this in mind, I will describe an alternative approach formulated in the language of combinatorics and algebraic topology that is inherently multiscale, amenable to mathematically rigorous results based on discrete descriptions of dynamics, computable, and capable of recovering robust dynamic structures.

To keep the talk grounded, I will discuss the ideas in the context of modeling of gene regulatory networks.


Konstantin Mischaikow earned his Master and PhD degree at the University of Wisconsin–Madison in 1983 and 1985, respectively. Currently he is a Distinguished Professor at Rutgers University, New Jersey, USA. His main research interests are topological methods for the analysis of dynamical systems, computational topology and mathematical biology.  Professor Mischaikow has supervised 16 PhD theses and has been advisor of 21 postdocs. He has over 110 publications, including four books.

He is a leading expert of Conley theory, as well as of rigorous computer-assisted computations. One of his most celebrated results is the proof of chaos in the Lorenz attractor, which serves as a prominent example of the application of both techniques.  In 2014, in recognition of his contributions to dynamical systems as well as to applied and computational topology, Professor Mischaikow was elected to be a fellow of the American Mathematical Society.


Posted in TEWI-Kolloquium | Leave a comment

Teaching and practicing the students‘ knowledge using games

Dr. Karel Perutka | 13. Juni 2018 | 10:00 Uhr | Z.1.09


The main idea of this strategy is based on the essential textbook of pedagogy Orbis sensualium pictus which was written according to Komenský’s belief that the school should be a game. It was first published in Nürnberg in 1658. He believed, contrary to the teaching practices at the time, that the pupils should be able to teach learned matter not only to renounce mechanically but to understand what they were learning. He, therefore, provided a textbook with some illustrations so that it would be captivating for the children. It was about biology (living and inanimate nature), theology and man, something that can now be called the foundations of social sciences.

Modern times have brought new opportunities to implement this strategy.

For example, using simple computer games for practicing and verifying the student’s knowledge. During the lecture, several computer games created for this purpose will be presented. Games are primarily designed to teach automation and programming in MATLAB software at university.

They are created in the way that the data about the matter are read from an external file. This file is enough to be edited and used for any subject of the study program. In the lecture, there will also be introduced several electronic aids facilitating the teaching of work with graphics programs and programs in the office at secondary schools in the Czech Republic. All these games and utilities were rated by students using questionnaires after the completion of the courses, and these results will be presented, too.



Karel Perutka received his Ph.D. degree in 2007 at Tomas Bata University in Zlin, Faculty of Applied Informatics, Czech Republic, where he is the senior lecturer. Technical Cybernetics was the principal branch of his first research. Karel Perutka was the editor of the book about MATLAB (, the author of one monograph about MATLAB, several book chapters about MATLAB and control theory, and author or co-author of more than 80 papers in the conference proceedings. He is a member of the organizing and reviewing committees of several conferences. He lead more 100 Bachelor and Master Theses.

Karel Perutka is teaching MATLAB programming, electronics, microelectronics, diagnosis of digital systems and modulations and demodulations of signals. He is the most popular teacher of curriculum IT for administrative studies voted by students where he teaches the software used in the office.

His main research interests are adaptive control, real-time control, control of multivariable systems, application of MATLAB and new methods of teaching programming and creating didactic aids for secondary schools, programming in C++ and VBA in MS Excel.

He is working on the topic Teaching and practicing the students knowledge using games for last 6 years. He lead the students of Master degree Teachers of Informatics for 6 years, he published 15 papers about this topic, created several teaching games and multimedia tools with the focus in the control theory, the computer graphics, the software in office.

He gave lectures at universities in Europe, mostly in Portugal where he visited ISEP Porto, IST Lisboa, UTAD Vila Real, UA Faro.

He speaks 4 foreign languages. Austria is his favorite country. He goes in Austria also for vacation every year.


Posted in TEWI-Kolloquium | Leave a comment

Aktivierende Elemente in der Lehrer(innen)bildung

Dr. rer. nat. Markus Alexander Helmerich | 24. Mai 2018 | 18:15 Uhr | L.1.0.14


Die Leitidee der Siegener Lehrer(innen)bildung ist es, die angehenden Lehrerinnen und Lehrer zu einem reflektierten Handeln in Lehr-Lern-Situationen zu befähigen. Die Umsetzung dieser Leitidee erfordert eine starke Aktivierung der Lehramtsstudierenden in den Lehrveranstaltungen.
In unseren Vorlesungen, Übungen und Seminaren wurden verschiedene aktivierende Elemente und didaktische Prinzipien für eine aktivierende Lehre zur Förderung einer bewussten Haltung eingesetzt.
Beispielhaft für diesen Ansatz wird das Seminar „Schüler handeln, forschen und entdecken“ vorgestellt und diskutiert werden. Darin konzipieren Studierende Mathematik-Projekte, die mit Lerngruppen in der Siegener MatheWerkstatt durchgeführt werden, und analysieren anschließend  die Lehr-Lern-Prozesse. In dieser praxisorientierten Auseinandersetzung mit mathematischen Inhalten und der Gestaltung von Lernarrangements lernen die Studierenden, ihr Handeln und ihre Erfahrungen mathematikdidaktisch zu reflektieren.
Präsentiert werden das Siegener Leitbild für die Lehrer(innen)bildung sowie die unterschiedlichen Planungsdimensionen des Seminars anhand von Erlebnissen und Analysen der Studierenden.


HelmerichMarkus Alexander HELMERICH ist wissenschaftlicher Mitarbeiter in der Abteilung Didaktik der Mathematik des Departments für Mathematik an der Naturwissenschaftlich-Technischen Fakultät und im Sommer-semester 2018 Gastprofessor für Didaktik der Mathematik an der Alpen-Adria-Universität Klagenfurt. Nach dem Abschluss des Diplom-studiums in Mathematik an der Technischen Universität Darmstadt (2002) widmete er sich im Rahmen seiner Dissertation zu „Linien-diagrammen in der Wissenskommunikation“ (2008, ebenfalls TU Darmstadt) der Verbindung von Methoden der formalen Begriffs-analyse, der Semiotik und der Mathematikdidaktik. Von 2005-2009 war er Geschäftsführer des Ernst-Schröder-Zentrums für Begriffliche Wissensverarbeitung e.V. in Darmstadt. Der interdisziplinären Verbindung fachwissenschaftlicher, wissenschaftshistorischer und -philosophischer sowie fachdidaktischer Ansätze widmete er sich über seine Dissertation und die Tätigkeit am Ernst-Schröder-Zentrum hinaus als mehrfacher Mitveranstalter der Tagungsreihe zur „Allgemeinen Mathematik“ und als Mitherausgeber der entsprechenden Reihe von Sammelbänden im Springer-Verlag.  Von 2013-2015 war er Sprecher des Arbeitskreises „Mathematik und Bildung“ der Gesellschaft für Didaktik der Mathematik. Seit 2009 lehrt und forscht Markus Helmerich im Bereich Didaktik der Mathematik an der Universität Siegen. Einen Schwerpunkt seiner aktuellen mathematikdidaktischen Arbeit stellen Untersuchungen zur Rolle von Experimenten, Vorstellungen und Reflexionen für handlungsorientiertes Lehren und Lernen im Mathematikunterricht aller Schulstufen und in der Mathematiklehrer(innen)ausbildung dar.


Posted in TEWI-Kolloquium | Leave a comment

Virtual and Augmented Reality and its Applications

Rositsa Radoeva, PhD | May 22, 2018 | 10 am | L.1.0.14


The talk focuses on virtual and augmented reality technologies and examines various devices and technologies in the field of three-dimensional visualization and different applications of these technologies. The author presents a software for 3D interactive visualization, supporting disassembly and assembly processes of specialized equipment that have been developed by the VR-Team. Also, it will give a look at the development process of the presented software.


Rositsa Radoeva is Assistant Professor at the Dept. of Computer Systems and Technologies of the Faculty of Mathematics and Informatics (FMI) at University of Veliko Tarnovo “St. Cyril and St. Methodius”. She obtained her PhD in Informatics at the Dept. of Computer Systems and Technologies, FMI at University of Veliko Tarnovo “St. Cyril and St. Methodius” in 2016. Since 2013 she is affiliated with the Dept. of Computer systems and technologies, FMI at University of Veliko Tarnovo “St. Cyril and St. Methodius”. Currently she is involved in research in the field of three-dimensional visualization, virtual and augmented reality. Since 2017, she is a part of the “VR-Team” – a team for the development of virtual and mixed reality software solutions.

Posted in TEWI-Kolloquium | Leave a comment