Some protocols and applications in mobile computing require that a device knows as to how many other devices exhibiting a certain attribute are in its radio coverage. Obtaining this cardinality information by message exchange between devices is reliable but inefficient in dense networks in terms of overhead and delay. Performing an estimation of the cardinality using probabilistic trials is an alternative.

Adam, Yanmaz, and Bettstetter pursue such a probabilistic approach by proposing cardinality estimator protocols that require no coordination among polled devices but are based on a simple random access scheme with busy tones exploiting the number of empty slots to infer about cardinality. Their forthcoming article in IEEE Transactions on Mobile Computing compares three estimators with different levels of adaptability and feedback from the query device and discusses suitability for IEEE 802.11 and low power sensors.

Helmut Adam will receive the dissertation award of the Austrian Society for Information and Communication Technologies (GIT-OVE) for his dissertation on cooperative diversity protocols in wireless networks. The award ceremony will take place in Vienna in May 2012. Adam was research and teaching staff member in Klagenfurt's mobile systems group from mid 2006 until mid 2011 and is now a senior engineer at easyplex software.

Interference has significant impact on the performance of wireless communication systems. A comprehensive understanding of its dynamic behavior over time is important for the design of diversity schemes and protocols, whose performance can severely degrade in case of highly-correlated interference.

Schilcher, Bettstetter, and Brandner aim at advancing this emerging field from a theoretical perspective. Their forthcoming article to be published in the IEEE Transactions on Mobile Computing derives closed-form expressions and calculation rules for the correlation coefficient of the overall interference power received at a certain point in space. "We take into account three sources of correlation: node locations, channel, and traffic," Schilcher says. It took the team more than one year to find solutions for 27 scenarios presented in the article. The hard work payed off.

Schilcher recently also defended his doctoral thesis with distinction. "This is an important research direction," the external PhD examiner, Martin Haenggi from the University of Notre Dame (USA), says. "The spatial and temporal structure of interference has been largely ignored, although it is critical to the performance of wireless networks. The Klagenfurt group made an original contribution that greatly enhances our understanding of interference."

Computers processors have been leaving offices and become more and more embedded into everyday objects. Enhanced with sensors and networked via wireless connections, these computerized objects allow new fields of application, such as smart homes and remote health monitoring.

The IEEE/ICE Summer School on Networked Embedded Systems features research-oriented lectures on selected topics in this emerging area. Being part of the Erasmus Mundus PhD program Interactive and Cognitive Environments (ICE), it takes place in Klagenfurt from September 3-7 and is open to the public upon registration.

Speakers include, among others, Ian F. Akyildiz (Georgia Tech) on nano networks, Andrea Cavallaro (QMUL) on camera networks, Carlo Regazzoni (Genova) on data fusion, and Kay Römer (Lübeck) on sensor networks. A dinner talk is given by Infineon Austria CTO Reinhard Petschacher. The event is technically co-sponsored by the IEEE. The social event includes a hiking tour.

(Photos by W. Schriebl, University of Klagenfurt)

Crisostomo, Schilcher, Bettstetter and Barros investigate probabilistic information dissemination in stochastic networks. The following problem is studied: A source node intends to deliver a message to all other network nodes using probabilistic flooding, i.e., each node forwards a received message to all its neighbors with a forwarding probability ϖ. Question is: which minimum ϖ-value needs to be met by each node to ensure receipt of the flooded message by all nodes with high probability?

Their forthcoming article in the journal Computer Networks presents a generic approach to this problem in arbitrary networks and then focuses on Erdős Rényi graphs (ERGs) and random geometric graphs (RGGs). An exact solution is given for ERGs. An asymptotic expression is given for RGGs, which is shown to be an approximation for networks with high node density. In both cases, unreliable links are taken into account.

The synchronous flashing of fireflies is a spectacular example for self-organization in nature. Thousands of fireflies gather in trees and flash in unison using a distributed mechanism that can be understood using the theory of coupled oscillators. This theory has successfully been used for modeling many other synchronization and coordination phenomena, such as sleep cycles, firing of neurons, and vibration of bridges.

Researchers at Lakeside Labs aim at advancing this field of science and transferring it to technological applications, in particular to wireless communication networks. “Synchronization is an important building block in large networks of embedded systems,” project leader Christian Bettstetter argues. Synchrony should emerge in a distributed manner without having to rely on central entities.

Indeed the team has developed a solution that seems to work well in wireless systems. It is now being implemented in a programmable hardware platform for field tests. Johannes Klinglmayr is already very excited about the results. “Let's see whether measurements in a real-world environment will confirm our promising simulation results” the researcher and PhD candidate at the University of Klagenfurt says.

Lakeside Labs also investigates robustness aspects of self-organizing synchronization against faulty devices. What happens if one or more devices misbehave in some manner? The idea is to use an approach from neuroscience and combine it with own results. “We have mathematically proven that the resulting algorithm converges,” Klinglmayr proudly concludes. “Our latest results will appear in the ACM Transactions on Autonomous and Adaptive Systems.”

The Federation of Carinthian Industry recently awarded the young scientist with a 10.000 Euro scholarship to promote his work and spend a sabbatical at the Max Planck Institute for Dynamics and Self-Organization in Germany.

How to improve the robustness of WLAN communications? Researchers at Klagenfurt's mobile systems group lead by Christian Bettstetter aim at answering this question. “I expect performance gains using the concept of cooperation between devices,” the 38-year old professor says. If data transmission between a notebook and a WLAN station fails, another notebook or any mobile device will be of assistance.

“Sounds simple but in fact is quite an engineering challenge,” senior researcher Wilfried Elmenreich points out. It took the project team several months to develop a communication protocol that realizes the concept of cooperation. “The backwards compatibility to existing IEEE 802.11 WLAN systems is an important feature,” PhD candidate Helmut Adam adds.

The ideas of the three scientists were filed as patent applications at the European and US patent offices. The manuscripts have recently been published and are available for download using identifiers EP 2326029 and EP 232630.

The research team is now busy implementing the communication protocol on a programmable hardware platform to field-test and evaluate the inventions. Students who would like to join the research project are very welcome.

Lakeside Labs is now offering content on Apple iTunes U, the leading platform for educational videos. Categories include lectures from scientists, courses on academic careers, interviews with researchers, and research highlights.

Launch it now on your computer, iPad, or iPhone. Users of other tablets or smart phones are invited to check the Lakeside Labs channel on YouTube. Videos are available in both standard and high definition.

About 50 participants from 16 countries attended the Fifth International Workshop on Self-Organizing Systems hosted by Martina Zitterbart and her team in Karlsruhe (Germany).

The two-day event started with an exciting keynote address of Hermann Haken, a pioneer in the field of self-organizing systems. He outlined his work ranging from laser theory to information theory and pattern recognition to nano robots.

The workshop featured ten paper presentations in four sessions on the design and analysis of self-organizing systems, wireless networks, and peer-to-peer networks. Topics included evolutionary design, distributed clustering, self-localization, self-repair, and routing. All papers have been published in the book „Self-Organizing Systems” edited by the program chairs Christian Bettstetter and Carlos Gershenson. The best paper award was conferred on François Cantin and Guy Leduc from the University of Liège (Belgium).

In two poster sessions, 17 PhD students and PostDocs presented their work and discussed their ideas with fellow researchers. The award for the best poster was given to Helmut Lindner, who is a PhD student at Klagenfurt's NES institute.

Cornell professor Hod Lipson concluded the workshop with an inspiring keynote talk on „self-reflective machines.” He demonstrated several experiments with self-aware mobile robots that evolve ways to walk. According to Lipson, such reflective processes are essential for achieving meta-cognitive capacities.

The ZKM, a center for art and media technology, provided a fancy setting for the social event.

(Photos by D. Martin and C. Bettstetter)

Information and communication systems become increasingly complex. Sascha Aumüller from the daily newspaper Der Standard talked with Christian Bettstetter about this problem.

The interview „Nobody wants to call the sysadmin” is about self-organization that can help to overcome the limitations of today's technological possibilities. Lakeside Labs founder Bettstetter also talks about his current projects and Klagenfurt as a science location.

Lakeside Labs is a science and innovation cluster focusing on self-organizing networked systems. The bull's-eye shown on the right hand side (click to zoom) illustrates the research areas: The core constitutes theoretical and methodological aspects of self-organization and networks in general. It is surrounded by the technology topics wireless communications, multimedia and sensor systems, and autonomous robots. The outer ring states the main application areas: disaster management, environmental monitoring, traffic management, and energy management.

The specific research topics currently investigated are as follows:

• Engineering self-organizing systems (projects DEMESOS, MESON)
• Engineering proprioception (EPiCS)
• Synchronization & coordination (Triple-S, ROSSY)

• Collaborative microdrones (cDrones)
• Cooperative relaying in wireless networks (RELAY)
• Energy management for mobile devices (PowerDCDC, PowerMODE)
• Large scale emergency management (BRIDGE)
• Robust sensors in traffic (ROSIT)
• Self-organizing multimedia architecture (SOMA)
• Smart resource-aware multi-sensor network (SRSnet)

Lakeside Labs is mainly driven by the University of Klagenfurt and Lakeside Labs GmbH. Most projects are managed by Lakeside Labs GmbH; others are directly managed at the University of Klagenfurt. Current industrial and non-academic partners include ASFINAG, EADS, EyeTech, Infineon Technologies, infoFACTORY, and SWARCO. A use case partner is the national park Hohe Tauern.

Dominik Egarter, being a student staff member in the mobile systems group since 2007, and his colleague Christoph Unterrieder finished second in this year's European Analog Design Contest initiated by Texas Instruments. They were awarded 4.000 Euro for their experiment Playing Music over Tesla, which exploits electromagnetic induction to generate sparks that play a piece of music. A total of 45 teams from 17 universities participated in the contest.

The University of Klagenfurt and the Lakeside Park will host the 2010 Science Night (Lange Nacht der Forschung) on November 5. At over 100 stations, scientists and engineers will introduce and demonstrate their research topics to the public.

Bettstetter's team will participate with the following stations:

• How do microdrones explore a disaster area?
• Fireflies playing in an orchestra
• Mozart meets Darwin: Can evolution create art?

The annual ITG symposium on future perspectives of communication networks will this year focus on Self-Organization: Opportunities and Challenges. To be held in Stuttgart on October 7, it will cover a broad variety of topics and a well-balanced set of speakers, not only from academia but also from industry. The keynote speech will be given by the perspective of Deutsche Telekom. The strong industry participation highlights the timeliness and importance of the topic self-organization in industry. Bettstetter will give a talk Self-Organizing Synchronization: From Fireflies to Wireless Systems, which will include a live synchronization experiment.

The mobile systems group at the University of Klagenfurt released a new flyer. It gives a quick overview of research and teaching activities, infrastructure, collaborations, awards, Lakeside Labs, and the European doctoral school ICE.

Download a high-res electronic version or order a free paper copy.

The International Workshop on Self-Organizing Systems (IWSOS) serves as an annual multidisciplinary event dedicated to self-organization in networked systems. The fifth workshop of this series, to be held in Karlsruhe in February 2011, will feature research, challenge, and keynote talks on various aspects of self-organization in technological networks, including communication and computer networks, transportation networks, energy networks, and robot networks.

Full papers and challenge papers need to be submitted by September 26, 2010. The call for papers and further information about the event can be found at the Website iwsos2011.tm.kit.edu.

Together with Carlos Gershenson, Christian Bettstetter serves as technical program chair. Keynotes will be given by Hermann Haken and Hod Lipson. The workshop will be hosted by Martina Zitterbart and her team.

The Lakeside Labs project Collaborative Microdrones performs research on networked unmanned aerial vehicles (UAVs) and their application to emergency and disaster response. Current work focuses on UAV routing, image stitching, and system integration.

The video on the right hand side (click to get a large view) demonstrates the following use case: An emergency response person specifies an area of interest in a map, and the system software computes appropriate waypoints and routes. Using GPS navigation, the UAVs autonomously overfly the specified area and deliver pictures to the ground station. The ground station runs an online image stitching algorithm creating a real-time update of the area map. In this way, the emergency assistants obtain an up-to-date overview image of the area. The service platform enables coordinated flights of multiple UAVs and is independent of the used UAV technology; it can also provide input to UAV simulations.

The newspaper Der Standard reports in its weekly science and technology section about cooperative relay communications in wireless systems. Based on an interview with Christian Bettstetter, the article "Gemeinsam gegen die Funkstille" explains that mobile devices could help each other to achieve higher energy efficiency and better radio coverage.

Since its foundation in the year 2007, the Institute of Networked and Embedded Systems (NES) has acquired 6.4 million Euro of third-party research funding, corresponding to a monthly rate of 50.000 EUR per professor. The grants and contracts include about 1.5 million from the EU, 1 million from national funds, 1 million from industry, and 2.5 million via the Lakeside Labs research cluster. By the end of this year, NES is expected to provide 40 full-time jobs, where 3/4 of the researchers are funded externally.

The research proposal "Robust Self-Organizing Slot Synchronization in Networked Embedded Systems" (for short: ROSSY) received a three-year full funding from the Austrian research funding agency FFG.

Our goal is to design and assess a robust self-organizing synchronization algorithm suited for wireless networked embedded systems. The algorithm operates in a completely distributed manner and is adaptive to changes in the network topology. Based on Bettstetter’s and his group's preliminary results in this area, the project deals with two issues: (a) The robustness of self-organized slot synchronization against faulty and malicious nodes. (b) The implementation and test of an improved algorithm in a programmable hardware platform. This work will be complemented with technical contributions to the modeling and performance assessment of self-organizing synchronization.

Johannes Klinglmayr will be hired for the project. He graduated from the University of Michigan (2008) and TU Wien (2007) and was recipient of the 2006 Infineon scholarship. In September 2008, he joined NES and the Lakeside Labs cluster in Klagenfurt, working toward his doctorate degree in self-organizing synchronization. An interview with him can he found here (bottom of page).

As part of her student project in the mobile systems group, Cam Lai Ngo developed and programmed the iPhone application BUZZflies. With this fun application, you can easily synchronize a set of iPhone devices in time and then let them play a song together, either a song from your library or a built-in song. BUZZflies is thus simulating a distributed loudspeaker. The synchronization is achieved by exchanging sound signals between the devices and employing and demonstrating a synchronization algorithm inspired from nature. The application is available free of charge at Apple's "App Store".

Cam Lai Ngo is a master student in information technology at the University of Klagenfurt. An interview about her experience and life in Klagenfurt, her project, and her goals for the future can be watched here.

The two professors Mario Huemer and Christian Bettstetter and Infineon's CTO, Reinhard Petschacher, discussed about the topic of cooperation between industry and universities. How does cooperation start? How are win-win situations achieved? What are sensitive issues in such collaborations?

The dialog is part of the book Wissen schaffen, which illustrates the variety of research activities at the University of Klagenfurt. "Our goal was to create a book that people like to read", editor and vice president Menschik-Bendele explains, a book that is both illustrative and informative. On 168 pages, it covers projects, scientists, dialogs, and facts, accompanied by a large number of high-quality photos. (Photo: Johannes Puch).

Slot synchronization is an essential requirement in communication and control networks, used for medium access, scheduling of sleep phases, and collaborative sensing, to give some examples. Having been inspired by the biological phenomenon of synchronously flashing fireflies, a method for self-organizing slot synchronization suited for wireless systems has been developed. It is based on the theory of pulse-coupled oscillators, but goes beyond this theory by taking an engineering perspective and considering the inherent characteristics and capabilities of radio communications.

The basic idea is as follows: devices multiplex a synchronization word with each data packet; a receiving device that detects the known synchronization word adjusts its local clock according to some rule. A network-wide slot structure emerges seamlessly over time as devices exchange packets. In this way, a dedicated synchronization phase is avoided, making the method suited for dynamic meshed networks. These properties gave the method its name Meshed Emergent Firefly Synchronization (MEMFIS).

The MEMFIS concepts, architecture, and performance results will be published in a forthcoming article in the IEEE Transactions on Mobile Computing.

The proposal for the Erasmus Mundus Joint Doctorate school Interactive and Cognitive Environments has been accepted for funding. This new training and research program will be offered by the University of Klagenfurt in cooperation with the University of Genoa (coordinator), UPC Barcelona, TU Eindhoven, and Queen Mary (University of London). The doctoral school is expected to offer ~40 PhD scholarships in five classes from fall 2010 until 2017.

Erasmus Mundus promotes scientific excellence and mobility in higher education in Europe. The selection process of the doctoral schools was very competitive: Out of about 150 proposals, 13 proposals have been selected. Klagenfurt is the only Austrian university participating in an Erasmus Mundus doctorate program.

A full week of discussions, talks, and group work on self-organizing networked systems is the concept of Research Days, organized for the second year by Lakeside Labs. Speakers included the experts Alain Barrat, Francis Heylighen, Hermann de Meer, Raissa D'Souza, and Marc Timme, along with other guests, Lakeside Labs professors, and researchers. Major discussion topics included robustness in self-organizing systems, modeling of self-organizing systems, and courses for university education in the area of self-organizing networked systems.

Lakeside Labs hosted a one-day international workshop with presentations and discussions on cooperation and self-organization in communication networks (July 29). The program included keynote speeches, project overviews, research talks and demonstrations. The workshop was part of the 30th meeting of the VDE/ITG working group "IP and Mobility". Further information can be found here.

The content of this website has been visualized in terms of a word cloud. Simply click on the preview on the right hand side or here. The cloud nicely illustrates Bettstetter's research and teaching topics, collaborators, conferences, and working places. The more frequently a word appears on the website, the larger it appears in the cloud. The cloud was created using the Web application Wordle.

A further word cloud refers to the NES institute.

The publication "Multi-Hop-Aware Cooperative Relaying" by Helmut Adam, Christian Bettstetter, and Sidi Mohammed Senouci received the Best Student Paper Award at the 69th IEEE Vehicular Technology Conference (VTC).

Helmut Adam is working towards his dissertation in the area of cooperative relaying, a new wireless communication technique promising significant gains in throughput and energy-efficiency. The awarded paper proposes a concept to exploit routing information in the relay selection protocol. The work is an outcome of a bilateral project between the University of Klagenfurt and France Telecom's Orange Labs.

VTC is the semiannual conference of the IEEE Vehicular Technology Society. VTC Spring 2009 took place in Barcelona from 26 to 29 April 2009, featuring 656 research papers, several panels and invited talks.

The Institute of Networked and Embedded Systems (NES) of the University of Klagenfurt released its annual report 2008. The 100-pages brochure summarizes the major activities of the NES institute in research and teaching. "The second year of existence [..] was a very important one for us," institute head Christian Bettstetter says. "We had to reflect on the starting phase and think about what went well and what needs to be improved." The number of scientific staff members rose from 14 to 25, and the team became truly international, with researchers coming from Austria, Belarus, France, Germany, Hungary, Italy, Macedonia, Portugal, and Turkey.

Crisostomo, Schilcher, Bettstetter and Barros recently studied a fundamental question related to probabilistic flooding in random networks. Modeling a network as a random graph with given link probability between nodes, they ask: What is the minimum message forwarding probability of the nodes such that a flooding message reaches each network node with high probability? The authors derive bounds for this probability and show by simulation that these bounds are tight. The results will be published and presented at the IEEE Intern. Conf. on Communications (ICC) taking place in Dresden in June 2009. A preprint of the paper, titled "Analysis of probabilistic flooding: How do we choose the right coin?" is available for download.

Christian Bettstetter has been elevated to the grade of Senior Member in the IEEE, one of the world's largest professional associations for the advancement of technology. About 12% of all 382,000 members hold this grade, which requires significant professional maturity and achievements. Christian joined the IEEE in 1998 and is currently serving as program committee member of several major IEEE conferences, such as IEEE ICC and IEEE GLOBECOM.

Based on a self-assessment report and a two-day visit of three external university professors, the Networked and Embedded Systems institute was evaluated. The peers are "positively surprised and impressed by the scientific productivity, the success in teaching and institute management achieved in short time".

The Lakeside Labs project cDrones aims at advancing the state-of-the-art in the domain of collaborative, networked microdrones. We develop algorithms, concepts, and methods for three key technological areas: flight formation, mission planning and control, and sensor data interpretation. Although the developed technology should be of general applicability, we focus on networked microdrones for fire rescue scenarios.

At Austria's long night of research on November 8, 2008, several night flights were presented to a large audience. The audience awarded our presentation with the second price out of 55 competitors in Klagenfurt.

A demonstration video is available. The funded project started officially on January 1, 2009.

A fully updated, third edition of GSM: Architecture, Protocols, and Services written by Eberspächer, Vögel, Bettstetter, and Hartmann is out now. The book is both an introductory textbook for graduate students and a reference resource for telecommunications engineers and researchers.

Special features include a detailed introduction to the General Packet Radio Service (GPRS) and EDGE for packet-switched services and a description of multimedia messaging (MMS). New content also includes capacity enhancement methods like sectorization, the application of adaptive antennas for Spatial Filtering for Interference Reduction (SFIR) and Space Division Multiple Access (SDMA)

Alexander Tyrrell, Gunther Auer, and Christian Bettstetter received an award for the best paper with a doctorate student as main author. The award was issued at the Intern. Symp. on Applied Sciences in Biomedical and Commun. Techn. in Denmark. The awarded paper "On the accuracy of firefly synchronization with delays" investigates distributed synchronization applied to a wireless mesh network.

Udo Schilcher, Michael Gyarmati, and Christian Bettstetter received the best paper award at the 67th IEEE Vehicular Technology Conference. The awarded publication "Measuring Inhomogeneity in Spatial Distributions" was written together with Yun W. Chung and Young H. Kim from Seoul, Korea, within a common project on modeling and simulation of wireless systems. The scientists address the question as to how inhomogeneity in spatial user distributions can be defined. The proposed mathematical model was also compared with human intuition of inhomogeneity, using a Web survey.

Out of 1.536 submissions, 379 papers were accepted to be presented in Singapore from May 11-14, 2008. Further 234 poster presentations took place. A second best paper award was given to researchers from MIT and Kyung Hee University.

It was the first conference presentation for Schilcher - a great start. "I didn't expect at all that we receive this award," project leader and advisor Bettstetter says. Gyarmati is already writing on a new paper that studies how inhomogeneity will change over time in case of random user mobility.