Prof. Costas D. Sarris, Dept. Electrical and Computer Engineering, University of Toronto, to speak at ECE-NTUA on February 19, 2020, at 15:30 (Multimedia amphitheater, Central Library of NTUA)

Lecture Title: Electromagnetic Field Based Wireless Channel Propagation Models: Fundamental Advances, Integration with Network Protocol Design and Applications to 5G

Abstract: Transforming metropolitan areas into "smart" cities requires the large-scale deployment of enabling information and communication technologies. From smart-grid monitoring to wireless control of mass transit systems, point of care and public safety applications, these technologies are based on geographically distributed wireless access points. The financial feasibility of installing and maintaining such networks of access points, meeting standards for "green" (energy efficient) and safe (in terms of radiation exposure of the population and compatibility with other systems) operation, depends on the availability of accurate computational planning tools. The importance of such computational tools increases as a plethora of new wireless services is being deployed, notably in the IoT and 5G areas, alongside legacy systems. A prominent example of interest is Communication Based Train Control (CBTC), which is aimed at providing control and signaling for rail transportation systems. These operate in environments that combine tunnel and open air sections, as well as busy stations, coexisting with Wi-Fi and cellular communication networks. Characterizing electromagnetic wave propagation and interference in such diverse environments is most efficiently achieved by hybridizing several computational electromagnetic techniques rather than relying on a single one.
This talk will present our research on hybrid techniques, combining the vector parabolic equation (VPE) method, ray-tracing and FDTD, to model wireless propagation across entire railway networks, reserving the ray-tracer for complex station geometries, while applying the VPE method to long tunnel sections and FDTD to interference problems including models of the train and its interior. We discuss practical aspects such as modeling arbitrary antenna patterns, accounting for surface roughness and evaluating geometric and material uncertainties. Validation data have been provided by a 2.4 GHz measurement campaign in the complex environment of the London (UK) underground -one of the largest and most successful validation studies ever reported in the relevant literature. Beyond a conventional accuracy analysis of our propagation models, we ask the question: what if we entirely relied on those models, instead of measured data, to choose the position of access points and even configure network-level protocols for CBTC? How good are electromagnetic field based propagation models as decision making tools all the way to the network level? We show that our accuracy is sufficient to drive such decisions, paving the way for integrating field solvers with network planning tools. Finally, we discuss the development of field-based propagation models for 5G systems and a hybrid technique to model diffuse scattering from rough surfaces in indoor propagation studies, as well as the role of machine intelligence in transforming such computationally intensive models into real-time tools.

Short Bio: Costas Sarris received a Ph.D. in Electrical Engineering and a M.Sc. in Applied Mathematics from the University of Michigan, Ann Arbor, in 2002. He also received a Diploma in Electrical and Computer Engineering (with distinction) from the National Technical University of Athens (NTUA), Greece, in 1997. He joined the University of Toronto in 2002, where he is now a Full Professor at the Department of Electrical and Computer Engineering. In 2009-2010, he was a Visiting Associate Professor at the Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign.

His research interests are in the area of numerical electromagnetics, with emphasis in high-order, multiscale/multi-physics computational methods. He is involved with basic research in novel numerical techniques, as well as applications of time-domain analysis to wireless channel modeling, wave-propagation in complex media and meta-materials, electromagnetic compatibility/interference (EMI/EMC) problems and modeling under uncertainty. He also teaches undergraduate courses in electromagnetics and wireless systems, and graduate courses in numerical electromagnetics and antenna theory.

Prof. Sarris was a recipient of the 2013 IEEE MTT-S Outstanding Young Engineer Award. He also received the Early Researcher Award from the Ontario Government in 2007, the Canada Foundation for Innovation New Opportunities Fund Award in 2004, and a Student Paper Award at the 2001 International Microwave Symposium. His students have received student paper awards at the 2015 IEEE Wireless Power Transfer Conference, the 2009 IEEE MTT-S International Microwave Symposium, the 2008 Applied Computational Electromagnetics Society conference and the 2008, 2009, 2018 IEEE International Symposia on Antennas and Propagation.

On the teaching side, Prof. Sarris received the Gordon R. Slemon (teaching of design) award in 2007 and a Departmental Teaching Award (by confidential vote of ECE students, for excellence in undergraduate teaching) in Fall 2018, 2016 (3rd year Fields and Waves) and Spring 2005 (4th year Radio and Microwave Wireless Systems).

Prof. Sarris is the Editor-in-Chief of the IEEE Journal of Multiphysics/Multiscale Computational Techniques (JMMCT) and the Chair of the IEEE MTT-S Technical Committee on Microwave Field Theory (MTT-15). He was an Associate Editor for the IEEE Transactions on Microwave Theory and Techniques (2009-2012) and the IEEE Microwave and Wireless Components Letters (2007-2009), as well as Guest Editor of the IEEE Microwave Magazine Special Issue on Time-Domain Methods for Microwave CAD (April 2010). He was the Technical Program Committee Chair for the 2015 IEEE Int. Symposium on Antennas and Propagation and URSI North America Meeting in Vancouver, BC; Vice Chair of the Technical Program Committee of the 2012 IEEE MTT-S International Microwave Symposium in Montreal, QC; Technical Program Committee co-Chair for the 2010 IEEE Int. Symposium on Antennas and Propagation and URSI North America Meeting in Toronto, ON. He has served as Chair of the Sub-Committee on Time and Frequency Domain Methods of the Technical Program Committee of the IEEE MTT-S International Microwave Symposium. Professor Sarris was an Associate Chair of the Division of Engineering Science, University of Toronto, between September 2011 and July 2014.

*This lecture is co-organized by the DIVISION OF INFORMATION TRANSMISSION SYSTEMS AND MATERIAL TECHNOLOGY of ECE-NTUA and the Greek Section of IEEE Communications Society.