New paper accepted in IEEE Transactions on Signal Processing

Congratulations to Leila Ben Saad, Baltasar Beferull-Lozano and Elvin Isufi for the journal paper "Quantization Analysis and Robust Design for Distributed Graph Filters" accepted for publication in IEEE Transactions on Signal Processing.

Figure: Squared norm of unquantized and quantized filtered streaming graph signals for the change point detection problem.

Title: Quantization Analysis and Robust Design for Distributed Graph Filters, Journal: IEEE Transactions on Signal Processing, Vol. 70, pp. 643 - 658, Dec. 2021.

Distributed graph filters have recently found applications in wireless sensor networks (WSNs) to solve distributed tasks such as reaching consensus, signal denoising, and reconstruction. However, when implemented over WSNs, the graph filters should deal with network limited energy constraints as well as processing and communication capabilities. Quantization plays a fundamental role to improve the latter but its effects on distributed graph filtering are little understood. WSNs are also prone to random link losses due to noise and interference. In this instance, the filter output is affected by both the quantization error and the topological randomness error, which, if it is not properly accounted in the filter design phase, may lead to an accumulated error through the filtering iterations and significantly degrade the performance. In this paper, we analyze how quantization affects distributed graph filtering over both time-invariant and time-varying graphs. We bring insights on the quantization effects for the two most common graph filters: the finite impulse response (FIR) and auto-regressive moving average (ARMA) graph filter. Besides providing a comprehensive analysis, we devise theoretical performance guarantees on the filter performance when the quantization stepsize is fixed or changes dynamically over the filtering iterations. For FIR filters, we show that a dynamic quantization stepsize leads to more control on the quantization noise than the fixed-stepsize quantization. For ARMA graph filters, we show that decreasing the quantization stepsize over the iterations reduces the quantization noise to zero at the steady-state. In addition, we propose robust filter design strategies that minimize the quantization noise for both time-invariant and time-varying networks. Numerical experiments on synthetic and two real data sets corroborate our findings and show the different trade-offs between quantization bits, filter order, and robustness to topological randomness.

New paper accepted in IEEE Transactions on Green Communications and Networking

Congratulations to Ravi SharanSiddharth DeshmukhSibi Raj B. PillaiBaltasar Beferull-Lozano for the journal paper publication in IEEE Transactions on Green Communications and Networking.

Title: Energy Efficient AoI Minimization in Opportunistic NOMA/OMA Broadcast Wireless Networks, Journal: IEEE Transactions on Green Communications and Networking.

Short description of the paper: Energy efficiency (EE) at the Access Point (AP) and timely update of information at the user equipment (UE)s form an important aspect in scheduling in the downlink. Age of Information (AoI) is a new paradigm which captures the freshness of information at the UEs. A Lyapunov based heuristic algorithm is proposed to analyze the trade-off between EE-AoI where the AP schedules the UEs in an opportunistic fashion following NOMA/OMA transmission schemes.

Award-winning research from WISENET at the prestigious IEEE Data Science and Learning Workshop 2021

Publication at UiA web site

The WISENET Centre at University of Agder (UiA) was recently awarded a prize for a paper during the prestigious IEEE Data Science and Learning Workshop 2021. Congratulations to the PhD. student Rohan Money , Postdoctoral Research Fellow Dr. Joshin Krishnan and Prof. Baltasar Beferull-Lozano.

The WISENET Centre seeks top quality research.

- What does it mean for WISENET centre and UiA to receive this award?
"It is really a proud moment for us to receive an award like this at such a competitive international conference, where the best researchers in the world in these areas publish their research results. This means that we have done something good.", as the PhD. student Rohan Money says.

WISENET - Part of National DIGIPRO Center

WISENET is participating in the National DIGIPRO Center initiative:

Centre web site:

The DigiPro Centre initiative focuses on the digitalization of the process industry, which involves a variety of areas, such as smart sensing, data science, machine learning, and communication network intelligence in harsh environments of the process industry. All the major companies of the process industry in Norway are involved.

Seven WISENET papers published! - Spring 2021

The WISENET Center has been very productive scientifically during the Spring Semester 2021, generating seven international high quality scientific publications, including also a Best Paper Award!:

These are the publications that have been generated:

Best paper Award - IEEE Data Science & Learning Conference

Congratulations !!!!

It is our pleasure to announce that Rohan Thekkemarickal Money's conference paper, co-authored with Dr. Joshin Parakkulangarayil Krishnan and Prof. Baltasar Beferull-Lozano, has received one of the Best paper Awards in the IEEE Data Science & Learning Conference:

Rohan Thekkemarickal Money, Joshin Parakkulangarayil Krishnan, Baltasar Beferull Lozano «Online non-linear Topology Identification from Graph-connected time-series», IEEE DSLW 2021.

See UiA news about this Award.

Abstract: Estimating the unknown causal dependencies among graph-connected time series plays an important role in many applications, such as sensor network analysis, signal processing over cyber-physical systems, and finance engineering. Inference of such causal dependencies, often know as topology identification, is not well studied for non-linear non-stationary systems, and most of the existing methods are batch-based which are not capable of handling streaming sensor signals. In this paper, we propose an online kernel-based algorithm for topology estimation of nonlinear vector auto-regressive time series by solving a sparse online optimization framework using the composite objective mirror descent method. Experiments conducted on real and synthetic data sets show that the proposed algorithm outperforms the state-of-the-art methods for topology estimation.

New paper accepted in IEEE Transactions on Signal Processing

Congratulations to Siavash Mollaebrahim for his second journal paper accepted in IEEE Transactions on Signal Processing! :

S. Mollaebrahim, B. Beferull-Lozano, "Design of Asymmetric Shift Operators for Efficient Decentralized Subspace Projection" (Accepted), To appear in IEEE Transactions on Signal Processing, 2021.

Successful defense of PhD thesis by Yves Teganya

Dr. Yves Teganya a PhD Research fellow at WISENET Center, Department of ICT, University of Agder defended his thesis entitled Machine Learning Tools for Radio Map Estimation in Fading-Impaired Channels“ on Friday 13 November 2020.

Congratulations to Yves!!!

The thesis is available here: PHD_Thesis_Yves Teganya

He also presented a trial lecture entitled “mmWave communications for immersive media delivery”



First opponent: Associate Professor Olav Tirkkonen, Aalto University, Finland.

Second opponent: Associate Professor Suzan Bayhan, University of Twente, Zilverling, NL.

Associate Professor Lei Jiao, Department of Information and Communication Technolog, University of Agder, is appointed as the administrator for the assessment commitee.

Supervisors were Associate Professor Daniel Romero (main superviosor) and Professor Baltasar Beferull-Lozano (co-supervisor).

Successful defense of PhD thesis by Bakht Zaman

Bakht Zaman a PhD Research fellow at WISENET Center, Department of ICT, University of Agder defended his thesis entitled “Online Machine Learning for Graph Topology Identification from Multiple Time Series“ on Thursday 29 October 2020.

Congratulations to Bakht!!!

The thesis is available here: PhD_Thesis_Bakht Zaman-Print

He also presented a trial lecture entitled "Covariance Estimation: Theory and Applications"

His PhD project is funded by the PETROMAKS (Norwegian only) Smart-Rig grant 244205, see also Petromaks 2 - Large-scale Programme for Petroleum Research.


Bakht Zaman: (1990, Mardan, Pakistan) B.S degree in Electronics Engineering from COMSATS Institute of Information and Technology, Abbottabad, Pakistan (2012) and M.S degree from Faculty of Electrical Engineering, Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Pakistan (2015). In January 2016, he started his studies towards the PhD degree at WISENET Center, Department of ICT, University of Agder, Norway.


First opponent: Professor Antonio Garcia Marques, University King Juan Carlos, Spain

Second opponent: Professor Antonio Ortega, University of Southern California, USA

Professor Christian Walter Peter Omlin, Department of ICT, University of Agder, is appointed as the administrator for the assessment commitee.

Supervisors were Professor Baltasar Beferull-Lozano, UiA (main supervisor), Associate Professor Daniel Romero, UiA and Postdoctoral Research Fellow Luis Miguel Lopez Ramos, UiA (co-supervisors)


Successful defense of PhD thesis by Mohamed Elnourani

Dr. Mohamed Gafar Ahmed Elnourani a PhD Research fellow at WISENET Center, Department of ICT, University of Agder defended his thesis entitled Non-convex Optimization for Resource Allocation in Wireless Device-to-Device Communicationson Friday 9 October 2020.

Congratulations to Mohamed!!!

The thesis is available here: PhD_Thesis_Mohamed Elnourani-Print

He also presented a trial lecture entitled “Machine Learning for Resource Allocation in Wireless Networks”



First opponent: Professor Carlo Fischione, KTH Royal Institute of Technology, Sweden

Second opponent: Professor Kimmo Kansanen, NTNU - Norwegian University of Science and Technology

Associate Professor Lei Jiao, Department of Information and Communication Technology, University of Agder, is appointed as the administrator for the assessment commitee.

Supervisors were Professor Baltasar Beferull-Lozano, Department of Information and Communication Technology, UiA (main supervisor) and Associate Professor Daniel Romero, Department of Information and Communication Technology, UiA  (co-supervisor)




New paper accepted in IEEE Internet of Things journal


Congratulations to our colleague Leila Ben Saad for another successful acceptance of her latest paper in IEEE Internet of Things journal.

L. Ben Saad, B. Beferull-Lozano, “Accurate Graph Filtering in Random Wireless Networks”, IEEE Internet of Things Journal, Vol. 7, pp.11431 – 11445, 2020.

Exchange students WISENET - Top Indian Institutions, NFR INTPART INCAPS Project

The INTPART Project Indo-Norwegian collaboration in Autonomous Cyber-Physical Systems (INCAPS) is led by the WISENET Centre and involves several exchange students between Norway and India. The first exchange Master student has been Prabhat Rai from IIT Hyderabad. Associate Prof. Linga Reddy Cenkeramaddi is coordinating this Indo-Norwegian collaboration network with the support of several other researchers from the Center.

The INTPART Programme promotes International Partnerships for Excellence Education, Research and Innovation, developing long-term relations between Norwegian higher education and research institutions and strong internationally recognized research groups and institutions from other countries.

The project INCAPS involves a wide variety of research topics, such as smart sensing for autonomous systems, mmWave sensors, prototypes of wireless communication systems, low-altitude UAV tracking and communication, machine learning and artificial intelligence.

BS. Agam Bhatia BML, BS. Aarav Pandya BML, MS. Prabhat Kumar Rai IITH, BS. Aveen Dayal BML, BS. Mehak Jindal BML, MS. Jyoti Bhatia IITI

The Consortium of INCAPS includes the following world-class research and education Institutions: University of Agder (Coordinator), Indian Institute of Science (IISc), Bangalore, Indian Institute of Technology, Hyderabad (IITH), International Institute of Information Technology, Hyderabad (IIITH) and Birla Institute of Technology and Science (BITS), Hyderabad and Norwegian Universities and research Institutes, Norwegian University of Science and Technology (NTNU) and Norwegian Institute for Water Research (NIVA).


WISENET Centre & Mechatronics Centres lead NFR INTPART Project INMOST

The Mechatronics and WISENET Centre at University of Agder will lead the new INTPART Project INMOST which will allow to build a strong collaboration in several research areas with various highly reputed and top Indian Universities.

This project will establish a multi-international network for interdisciplinary research in Intelligence for offshore Mechatronics systems, including Artificial Intelligence, Machine Learning, Data Science, Deep learning, cognitive process control, Autonomous sensor systems, Wireless sensors networks,  Cyber-Physical Systems and Condition-based monitoring for cranes, vessels, drilling and O&G production systems, wind turbines and other offshore Mechatronics systems.

The project will build an international network to enable PhDs, researchers and students acquiring this interdisciplinary background. It will also obtain complementary transferable skills for careers in academia and industry. Participation in different scenarios with the use of multiple platforms from the consortium, and the supervision from leading research partners will allow to acquire critical knowledge with a holistic approach. This will enhance the R&D competitiveness in offshore industry both in Norway and India.

The main objectives are:

  • Strengthen collaborative network between industry (both public and private enterprises) and academia and develop models for technology transfer, innovation and entrepreneurship.
  • Increased value creation by using smart sensing, machine and deep learning techniques, robotics and advanced control in offshore mechatronics systems.
  • Facilitate education and knowledge sharing through better mobility for students and researchers.
  • Create an arena for generation of research and innovation projects.
  • Increased utilization of research infrastructure in Norway and India.

Full project name: INTPART Project Indo-Norwegian collaboration in Intelligent Offshore Mechatronics Systems (INMOST)

Funding: INTPART Programme, Research Council of Norway

Principal Investigators: Prof. Jing Zhou, Prof. Linga Reddy Cenkeramaddi, Prof. Baltasar Beferull-Lozano, Prof. Ajit Jha

Participant Institutions: University of Agder (Coordinator), NTNU, NORCE, IIT Indore, NIT Goa, IIT Tirupati, IIT Palakkad.

Period: 2020 – 2023

WISENET Centre & Mechatronics Centres lead NFR Frontier Project DEEPCOBOT

The WISENET Centre and Mechatronics Centre at UiA have joined forces in a new multidisciplinary frontier research project that combines Artificial Intelligence and Robotics. They have received NOK 16 million (total budget 20 NOK million) from the Research Council of Norway to develop the next-generation artificial intelligence for industrial collaborative robots. The project is called Collective Efficient Deep Learning and Networked Control for Multiple Collaborative Robot Systems (DEEPCOBOT). The project period for DEEPCOBOT is from 2020 to 2025. The plan is for the project to have three PhD candidates and one postdoctoral fellow.

News published at UiA web site here



Two papers accepted at IEEE ANTS 2019

- Henning Idsøe, Linga Reddy Cenkeramaddi, Soumya J and Baltasar Beferull Lozano, "Phase-noise Impact on the Performance of mmWave-RADARs", IEEE International Conference on Advanced Networks and Telecommunication Systems, 2019.

- Anders Frøytlog, Magne Haglund, Linga Reddy Cenkeramaddi and Baltasar Beferull Lozano, "Design and implementation of a long-range low-power wake-up radio and customized DC-MAC protocol for LoRaWAN", IEEE International Conference on Advanced Networks and Telecommunication Systems, 2019

Prof. Phaneendra Yalavarthy, IISc Bangalore, visits the WISENET Center

Phaneendra Yalavarthy is visiting WISENET center as visiting associate professor from June 14, 2019 to July 15, 2019 and main cooperating partner of International Indo-Norwegian partnership funded by Research Council of Norway through NFR projects INCAPS and LUCAT, between WISENET and IISc, Bangalore. His research interests including computational methods in medical imaging and inverse problems. His visit during this period will include the kick-off of NFR projects INCAPS and LUCAT and will be also delivering a Guest Lecture on June 26, 2019.

Phaneendra Yalavarthy received B.Sc. and M.Sc. degrees in physics from Sri Sathya Sai University, Puttaparthy, India in 1999 and 2001 respectively. He also obtained a M.Sc. degree in Engineering from Indian Institute of Science, Bangalore, India in 2004. He received a Ph.D., working as a U.S. Department of Defense Breast Cancer Pre-doctoral Fellow, in biomedical computation from Dartmouth College, Hanover, USA in 2007. He worked as a post-doctoral research associate in the Department of Radiation Oncology, School of Medicine, Washington University in St. Louis, USA from 2007-2008. Currently he is working as an associate professor in the Department of Computational and Data Sciences, Indian Institute of Science, Bangalore, India. He served as the chair of the department for the period 2016-2018. He is currently serving as the chair of Office of International Relations (OIR) and Institute coordinator of Prime Minister’s Research Fellowship (PMRF) scheme at IISc, Bangalore. He is a recipient of the Apple Laureate award in the year 2009. He also received Department of Atomic Energy young scientist research award in 2010 and a coauthor of the work chosen for the International Society for Magnetic Resonance in Medicine (ISMRM) Merit Award (Summa Cum Laude) in 2012. He is a recipient of Indian National Academy of Engineering (INAE) young engineer award and Innovative Young Biotechnologist Award (Government of India) for the year 2013. He also received the National Academy of Sciences, India (NASI)-Young Scientist Platinum Jubilee Award in the year 2014. He spent one year (2015) of sabbatical at Health and Medical Equipment (HME) Division of Samsung R&D Institute, Bangalore, working on post-processing algorithms for clinical applications of MR Imaging. His research interests include Computational methods in medical imaging, medical image processing (reconstruction/analysis), physiological signal processing, diffuse optical imaging, and photoacoustic imaging. He is a senior member of IEEE & SPIE and serves as an associate editor of IEEE Transactions on Medical Imaging. For more details:

Best Master Thesis Award in Information and Communication Technologies (ICT) - UiA, 2019

Master Thesis: "Design and implementation of wake-up radios for long-range wireless IoT devices"

Master Student Anders Frøytlog, did his Master Thesis under the main supervision of Associate professor Linga Reddy Cenkeramaddi and co-supervision of Assistant Professor Magne Arild Hauglund. Project task is defined by Assoc. Prof. Linga Reddy Cenkeramaddi. The solutions (especially DC-MAC protocol along with wakeup radio) proposed in the thesis greatly reduce the power consumption in the long-range wireless IoT devices. Summary of the thesis can be found below.

Summary of the thesis: As the development within Internet of things (IoT) increases rapidly and the market starts to utilize its potential, an enormous effort is being made in both academia and industry to optimize solutions according to the market demands. The demands vary from case to case and some of them include high data rate, long battery lifetime, low latency and long range/area coverage depending on application scenarios. The numerous use cases and demands for IoT resulted in various IoT technologies.

In many IoT applications, especially Wireless IoT applications, energy-efficiency and battery lifetime are the most important performance metrics. The wireless access mechanisms used in current technologies utilize Duty-cycling (DC) to reduce power consumption. DC allows a node to turn the radio on and off in specific intervals in order to reduce power consumption. These DC-MAC protocols suffer from overhearing, idle listening or unnecessary transmission of advertisement packets. The different protocols may also include long delay time caused by the inactive period in the MAC protocol. The recent research and development of Wake-up Radios (WuRs) address some of these problems. A WuR is a simple low power radio receiver which always listens to the channel to detect a Wake-up Call (WuC). A wake-up radio receiver (WuRx) is attached to the main radio which is always OFF, except when it is supposed to send data. The WuRx and the main radio (MR) are two parts of an IoT node. The use of WuRx eliminates the unnecessary power consumption caused by idle listening and reduce the overhearing consumption as well as the latency. Many articles have been published about WuRs. However, most of the current WuR solutions focus on short range applications. The objective of this thesis is to design a WuRx for long-range applications (10km to 15km range), implement a WuRx and evaluate the results and compare to existing solutions.

System Overview

To reduce the power consumption in long-range IoT applications, a WuRx has been proposed, tested and evaluated. Performance of the proposed WuRx integrated with LoRaWAN node is compared to a LoRaWAN node without a WuRx. A DC-MAC protocol which is combined with a WuRx to reduce the power consumption is also investigated. The result of this thesis is a Long-Range IoT node with an average power consumption of only 0.032mA.

Two papers accepted at IEEE SPAWC 2019

These are the papers accepted at IEEE SPAWC 2019:

Mohamed Elnourani, Baltasar Beferull-Lozano, Daniel Romero, Siddharth Deshmukh,  "Reliable Underlay Device-to-Device Communications on Multiple Channels", IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2019.

Leila Ben Saad, Baltasar Beferull-Lozano, "Graph Filtering of Time-Varying Signals over Asymmetric Wireless Sensor Networks", IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2019.

WISENET leads the INTPART project Indo-Norwegian collaboration in Autonomous Cyber-Physical Systems (INCAPS)

WISENET at University of Agder will lead the new INTPART project INCAPS, where our Center will collaborate with several highly reputed and top Indian Universities. This project establishes a long-term collaboration between top ranked Indian Universities, including Indian Institute of Science (IISc), Bangalore, Indian Institute of Technology, Hyderabad (IITH), International Institute of Information Technology, Hyderabad (IIITH) and Birla Institute of Technology and Science (BITS), Hyderabad and Norwegian Universities and research Institutes, University of Agder (UiA), Norwegian University of Science and Technology (NTNU) and Norwegian Institute for Water Research (NIVA) in world-class research and education says project manager, Prof. Linga Reddy Cenkeramaddi.

Key participants from University of Agder are researchers from WISENET Lab, including Prof. Linga Reddy Cenkeramaddi, Prof. Baltasar Beferull Lozano and Prof. Daniel Romero. Other key researchers involved in the project are, Prof. Kimmo Kansanen from NTNU, Dr. Christopher Harman from NIVA, Prof. Phaneendra K. Yalavarthy from IISc Bangalore, Prof. Abhinav Kumar from IIT Hyderabad, and Prof. Soumya J from BITS Hyderabad.

Only the foremost established and excellent research communities can apply for this INTPART grant and this is highly competitive as the competition is among the world renowned research centers. Major goals are to strengthen the competitiveness and innovation capacity, solving major societal challenges and developing high-quality academic environments. WISENET Lab obtains this grant by competing with the best research centers across the nation. Main objective is to create sustainable partnerships with the best international institutions and research communities across the globe.

This project considers broad areas of research which include smart sensing for autonomous systems, mmWave sensors based system design, analog, digital and mixed signal circuit design, prototyping of wireless communication systems, low-altitude UAVs tracking and communications, de-centralized wireless communications, in-network processing and intelligence for heterogeneous wireless sensor and communication networks, machine learning and deep learning for autonomous systems, data analytics, energy harvesting based smart electronic systems, smart water networks and inference methods for timely detection and prediction, cognitive control and adaptive learning in autonomous cyber-physical systems.


WP6 Workshop on Graph Signal Processing

On October 25 the WP6 Leader prof. Baltasar Beferull Lozano organized a workshop on the fundamentals of Graph Signal Processing, together with his colleagues Dr. Daniel Romero and Dr. Luis Miguel Lopez Ramos. Several participants from industry attended, in addition to researchers from UiA. The agenda for the workshop was as follows:

10-12: Basics of Graph Signal Processing, possible applications in different domains (within the SFI OM project) and Feedback from industrial partners.

13-14: Brief review of already well-functioning cooperation cases with industrial partners in WP6.

14-15: Exploration of new cooperation opportunities with industrial partners, associated use cases and strategies.

Awarded Best Master’s Thesis in ICT 2018

Development, Deployment & Evaluation of Wireless IoT Devices with Energy Harvesting


Students Rolf Arne KjellbySvein Erik Løtveit & Thor Eirik Johnsrud, did their Master Thesis under main supervision of Associate professor Linga Reddy Cenkeramaddi and co-supervision of Assistant Professor Geir Jevne. Project task is defined by Assoc. Prof. Linga Reddy Cenkeramaddi. Students designed and developed self-powered and ultra-low powered wireless IoT devices for indoor and outdoor applications. These nodes are tested and work up to 1.8 km and can be deployed in remote places where the accessibility is limited. The nodes can also be deployed in harsh-weather conditions without requiring any maintenance. Designed nodes are of professional market-quality, market-ready, efficient, self-powered and maintenance free. Many possibilities for further research based on these nodes including a start-up company.

Automation of indoor climate is becoming increasingly popular for both household and industrial use. Through automation, comfort increases and power consumption decreases. In order to deploy an automation system, sensors are required.

This master thesis proposes two wireless sensor nodes based on ATmega328p along with the nRF24l01+ transceiver and nRF52840 with various capabilities in both star and multi-hop network configurations. The designed nodes are fully self-powered through energy harvesting, and the nodes are completely self sustainable with no wires, and no user intervention is required during the lifetime of the components. In addition, these nodes do not require any maintenance and can be deployed in remote places. The wireless sensor nodes can be deployed anywhere as long as they are in range of a gateway or nodes that can forward towards a gateway, and as long as there is sufficient light level for the solar panel, such as indoor lights. Fully functional wireless sensor nodes are designed and tested, and compared the performance of both star and multi-hop topologies. The developed nodes consume less power than what is harvested in both indoor and outdoor environments.

UAV project LUCAT granted (INDNOR)

Wisenet Lab has been granted a UAV project called “Low-altitude UAV Communication and Tracking (LUCAT)", under Indo-Norwegian researcher projects within ICT call (INDNOR), in collaboration with IISc Bangalore, India.

The project will strengthen research collaboration between Norway and India within smart environments, communication technologies and address societal challenges by improving environmental monitoring and security and robustness in energy infrastructures.

Total number of applications processed for the call: 50
Number of projects awarded funding: 5
Total funding of LUCAT project: 10.3 MNOK (NFR funding: 10 MNOK)

Big data for norsk verdiskapning

Big Data meets Graph Signal Processing
Baltasar Beferull-Lozano, professor, Universitetet i Agder

Oslo: Møte 21. februar 2018 at Norske Videnskaps-Akademi

There has been significant recent progress in the development of signal processing tools that operate directly over graph-structured data. Many datasets in multiple real applications can be modeled flexibly in terms of the so-called graph signals, where each node of the graph represents essentially one or several data time-series and the links connecting the nodes represent some type of space-time dependencies among the various data time-series. The emergence of very diverse and ubiquitous computing, communicating and sensing devices has led to an era where huge amounts of data (big data) are generated constantly. Examples of applications include industrial plants, cyber-physical networked sensor systems, water distribution networks, connectivity brain networks, finance networked systems and social networks, among others. This talk will provide an overview about the recent area of Graph Signal Processing, exploring recent results, challenges and applications. We will illustrate the key concepts and cover different data processing methods for machine learning tasks over graph signals, their computational efficiency, and their impact in several important applications.

Møtet er åpent for alle interesserte

6 WISENET papers accepted at IEEE ICASSP 2018!

The WISENET Lab has managed to get 6 papers accepted at the IEEE ICASSP 2018 international conference. The IEEE ICASSP is the top international conference in the area of signal and data processing. These are the papers accepted:

  • Y. Teganya, L. M. Lopez-Ramos, D. Romero, B. Beferull-Lozano, "Localization-Free Power Cartography", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018.
  • M. Elnourani, M. Hamid, D. Romero, B. Beferull-Lozano, "Underlay Device-to-Device Communications on Multiple Channels", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018.
  • M. Hamid, B. Beferull-Lozano, "Joint Topology and Radio Resource Optimization for Device-to-Device Based Mobile Social Networks", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018.
  • T. Weerasinghe, D. Romero, C. Asensio-Marco, B. Beferull-Lozano, "Fast Distributed Subspace Projection via Graph Filters", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018.
  • C. Asensio-Marco, B. Beferull-Lozano, "Energy efficient consensus over directed graphs", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018.
  • D. Ramírez, D. Romero, J. Vía, R. López-Valcarce, I. Santamaría, "Locally optimal invariant detector for testing equality of two power spectral densities", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018.

IKTPLUSS project INDURB funded!

The WISENET Lab has obtained also funding for the project "Data-driven cyber-physical networked systems for autonomous cognitive control
and adaptive learning in industrial & urban water environments (INDURB)" project from the IKTPLUSS Program, Research Council of Norway. The project INDURB focuses on data-driven cyber-physical networked systems for autonomous cognitive control in water environments.

Only two long-term research projects (out of more than 100 project proposal applications) were selected in the whole IKTPLUSS Call, one of them INDURB, led by the WISENET Centre at UiA.

The INDURB project involves highly multidisciplinary research across different areas, and in addition to international cooperation, it will have a direct strong impact on both the Sørlandet region and national-wise through the various water-related circuits and problems.

News published about INDURB project at UiA web site can be found here

UIA Wisenet-project in IKT pluss

The skills generated by this projects will be a long-term resource for digitalization in business and public sector, 23 projects are on to the second round when the Research Council is to strengthen basic ICT research in Norway. UiA WISENET leads one of the projects that are in for the second round.

Two IEEE CAMSAP papers accepted

Two IEEE CAMSAP papers accepted:

The papers are:

  • B. Zaman, L.M. López-Ramos, D. Romero, B. Beferull-Lozano, “Online Topology Estimation for Vector Autoregressive Processes in Data Networks”, International Conference on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP), 2017.
  • M. Ramezani, B. Beferull-Lozano, “Graph Recursive Least Squares Filter for Topology Inference in Causal Data Processes”, International Conference on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP), 2017.

Prof. Antonio Ortega (USC) visits WISENET

Antonio Ortega, Professor, University of Southern California, visited the WISENET Lab from August 15th to August 18th. Prof. Ortega gave a very interesting Talk "Learning Graphs from Data" and attended several presentations given by PhD students in our Lab related to Graph Signal Processing, providing useful feedback.


TIME: 10:30 11:45,
ROOM C2 041

There has been significant recent progress in the development of tools
for graph signal processing, including methods for sampling and transforming
graph signals In many applications, a graph needs to be learned from data
before these graph signal processing methods can be applied A standard
approach for graph learning is to estimate the empirical covariance from the data
and then compute an inverse covariance ( matrix under desirable
structural constraints We present recent results that allow us to solve these
problems under constraints that encompass a broad class of generalized graph
Laplacians These methods are computationally efficient, can incorporate
sparsity constraints, and can also be used to optimize weights for a given known
topology We illustrate these ideas with examples in image processing and other
Antonio Ortega received the Telecommunications Engineering degree from
the Universidad Politecnica de Madrid, Madrid, Spain in 1989 and the Ph D in
Electrical Engineering from Columbia University, New York, NY in 1994 In 1994
he joined the Electrical Engineering department at the University of Southern
California ( where he is currently a Professor and has served as Associate
Chair He is a Fellow of the IEEE 2007 and a member of ACM and APSIPA He is
currently a member of the Board of Governors of the IEEE Signal Processing
Society and the inaugural Editor in Chief of the APSIPA Transactions on Signal
and Information Processing He has received several paper awards, including
most recently the 2016 Signal Processing Magazine award and was a plenary
speaker at ICIP 2013 His recent research work is focusing on graph signal
processing, machine learning, multimedia compression and wireless sensor
networks About 40 PhD students have completed their PhD thesis under his
supervision at USC and his work has led to over 300 publications in international
conferences and journals, as well as several patents.


The authors: Leila Ben Saad, Cesar Asensio-Marco and Baltasar Beferull-Lozano

The large number of nodes forming current sensor networks has made essential to introduce distributed mechanisms in many traditional applications. In the emerging field of graph signal processing, the distributed mechanism of information potentials constitutes a distributed graph filtering process that can be used to solve many different problems. An important limitation of this algorithm is that it is inherently iterative, which implies that the nodes incur in a repeated communication cost along the exchange periods of the filtering process. Since the sensor nodes are battery powered and radio communications are energy demanding operations, in this work, we propose to redesign the network topology in order to reduce the total energy consumption of the filtering process. An accurate energy model is proposed and extensive numerical results are presented to show the efficiency of our methodology according to this energy model.

Our paper "Topology Design to Increase Network Lifetime in WSN for Graph Filtering in Consensus Processes" has been accepted at EUSIPCO 2017

The authors: Leila Ben Saad, Thilina Weerasinghe and Baltasar Beferull-Lozano

Graph filters, which are considered as the workhorses of graph signal analysis in the emerging field of signal processing on graphs, are useful for many applications such as distributed estimation in wireless sensor networks. Many of these tasks are based on basic distributed operators such as consensus, which are carried out by sensor devices under limited energy supply. To cope with the energy constraints, this paper focuses on designing the network topology in order to maximize the network lifetime when applying graph filters. None of the existing works in the literature have studied such problem when graph filters are used. The problem is a complex combinatorial problem and in this work, we propose two efficient heuristic algorithms for solving it. We show by simulations that they provide good performance and increase significantly the network lifetime.

Our Paper “Adaptive consensus-based distributed Kalman filter for WSNs with random link failures” accepted at IEEE DCOSS 2016.

Wireless Sensor Networks have emerged as a very powerful tool for the monitoring and control, over large areas, of diverse phenomena. One of the most appealing properties of these networks is their potentiality to perform complex tasks in a total distributed fashion, without requiring a central entity. In this scenario, where nodes are constrained to use just local information and communicate only with one-hop neighbors, iterative consensus algorithms enjoy great popularity due to their simplicity. In this work, we propose a consensus-based distributed implementation of a Kalman filter for state estimation, in a sensor network whose connections are subject to random failures. As a result of this unreliability, the agreement value of the consensus process is a random variable. Under these conditions, we ensure that the estimator is unbiased, and adaptively compute the gain of the filter by considering the statistical properties of the consensus process. To the best of our knowledge, this is the first time that the distributed implementation of the Kalman filter is addressed by considering the random error introduced by the consensus. We present some numerical results that confirm the validity of our approach.

Prof. Baltasar Beferull-Lozano appointed as Senior Associate Editor for IEEE Trans. on Signal Processing

Prof. Baltasar Beferull-Lozano has been appointed as of March 15, 2016, Senior Associate Editor for IEEE Transactions on Signal Processing.

Our project WISECART has been selected to be funded within the FRIPRO TOPPFORSK Programme!!

The Research Council of Norway has published the evaluation results here. Our project WISECART is one of the only two research projects funded in Norway within the FRIPRO TOPPFORSK Programme, in the area of Information and Communication Technologies. These are excellent news for the WISENET Lab, as well as for the Department of Information and Communication Technologies and the Faculty of Engineering and Science at University of Agder.

Our Paper "Adaptive consensus-based distributed detection in WSN with unreliable links" accepted at IEEE ICASSP 2016

Event detection is a crucial tasks in wireless sensor networks. The importance of a fast response makes distributed strategies, where nodes exchange information just with their one hop neighbors to reach local decisions, more adequate than schemes where all nodes send observations to a central entity. Distributed detectors are usually based on average consensus, where all nodes iteratively communicate to asymptotically agree on a final result. In a realistic scenario, communications are subject to random failures, which impacts the performance of the consensus. We propose an alternative detector, which adapts to the statistical properties of the consensus and compensate deviations from the average. Simulation results show that this adaptive detector improves the performance and approximates to the one of the optimal detector.

Prof. Baltasar Beferull elected as Member of Agder Academy of Sciences and Letters, Norway

Prof. Baltasar Beferull was elected as new Member of the Agder Academy of Sciences and Letters, Norway. The ceremony will take place on October 30th, 2015, at Klubben, in Kristiansand.

The main mission of the Academy is to contribute to strengthening the scientific activity in Norway, and increasing the general understanding of the vital importance of science in society. This mission is accomplished in particular by organizing public meetings, conferences and seminars, and by focusing on outstanding academic achievements through the awarding of academic prizes.

Prof. Baltasar Beferull invited to the NI RF & Communications 5G Round Table 2015 in Vienna

Prof. Baltasar Beferull has been invited to attend the National Instruments RF & Communications 5G Round Table 2015 in Vienna. This invitation-only event aims at bringing together a network of leading European researchers and educators active in the area of new communication technologies. This year, the event will have a strong focus on technologies supporting vehicular connectivity, 5G research and development and for prototyping as well as test bed implementations.

Key topics covered this year:

  • Massive MIMO
  • Dense networks
  • PHY enhancements
  • mmWave
  • Vehicular connectivity
  • LabVIEW Communications System Design Suite

This two-day event is limited to a small number of preeminent group leaders and professors, to allow for effective networking and feedback with NI executives, R&D representatives and senior experts as well as experienced Communications platform users. The aim is to prioritize case studies that discuss the use of LabVIEW Communications to accelerate research by reducing the time needed to get from research concept to real-time test bed implementation.

WISENET is co-organizing CySWater 2016

WISENET is co-organizing together with ICS-FORTH (Signal Processing Lab) the 2nd International Workshop on Cyber-Physical Systems for Smart Water Networks (CySWater2016) during the CPS (Cyber-Physical Systems) Week in Viena.

The objective of the 2nd International Workshop on Cyber-physical Systems for Smart Water Networks (CySWater2016) is to bring together for the second time researchers and engineers from the fields of Communications/Networking, Learning/Processing, and Control and practitioners from the Water Industry to both share their experiences, as well as formulate novel CPS paradigms for fulfilling the vision of Smart Water Networks (SWN). Emphasis will be given to both theoretical modelling, as well as modern exemplars that respond to different aspects of the water life-cycle.

The proposed, multi-disciplinary agenda attempts both to stimulate the research and engineering questions, as well as to solicit CPS-based solutions, for addressing the problem of water crisis. As such CySWater aspires to serve as the application-driven forum, where CPS modelling, deployment, and evaluation are tailored to the specific needs of an emerging societal challenge. Therefore CySWater both fits perfectly the purposes of the CPS Week, and complements the agenda of the CPS Week conferences.

Topics of interest include, but are not limited to:

Data Acquisition, Processing & Learning: Infrastructure & smart sensor devices for SWN; Signal sampling, classification & anomaly detection for SWN; Decentralized multi-sensor fusion, learning & data analytics.

Communications, Networking & Control: Underground & underwater CPS; Mobile network agents for large-scale CPS; Networked Control Systems architecture, incl. cloud computing aspects; CPS and security for SWN.

Analysis, Performance, & Applications: Testbeds, field studies, & performance analysis; Novel CPS application paradigms for modern water applications, s.a. water treatment, water recycle and reuse, waste/sewage/storm water management; Standardization and policies for enabling SWN.

WISENET Lab staff growing

The WISENET Lab is currently growing in size with the hiring of three new PhD. and three new Postdoctoral researchers.

SMART-RIG Research Project begins

Off-shore – On-shore Collective Analytics & Intelligence based on Heterogeneous Wireless Networks

Full project name: Off-shore–On-shore Collective Analytics & Intelligence for condition-based monitoring in drilling & operations using heterogeneous networks (SMART-RIG)


Funding: Researcher Project, Research Council of Norway

Principal Investigator: Prof. Baltasar Beferull-Lozano

Topic: This project is motivated by the grand challenge of providing a new ICT solution for collective off-shore–on-shore intelligence for predictive CBM of drilling rigs, covering: a) the distributed acquisition of sensor signals, including data pre-processing,adaptive sampling rate optimization and collaborative calibration capabilities (Network Tier 1), b) in-network cooperative processing and distributed context-aware intelligence to perform essential data analytics tasks such as local event prediction and detection, low-level feature extraction, decision-making support and learning, c) design of semantic sensor management tools at micro-server nodes (Network Tier 2), with higher resources in terms of computation and communication capabilities, providing data aggregation across different inter-related subsystems and an intermediate medium-to-high level inference about the data collection, i.e., high-level diagnostics (fault detection, isolation and cause identification) and prognostics (fault & degradation prediction), tracking continuous consistency with the on-shore high-level analytics running at the servers (Network Tier 3) of Control Centers, providing recommendations or direct actions if necessary. The proof of concept will be demonstrated with the support from Lundin, Frigstad and MHWirth.

Role: Coordination and Leader of all technical WorkPackages.

Period: 2015 – 2019