His main research interests lie in the area of communication networks, with emphasis on the analysis, optimization and performance evaluation of mobile and distributed systems, wireless networks and complex systems, Internet of Things.

His research has been recognized and funded by many industry and government international organizations including, European Commission under several Framework Programs and H2020, European Space Agency (ESA), General Secretariat for Research and Technology (GSRT) in Greece, National Science Foundation (NSF), US Army, MITRE Corp., Panasonic, Nortrhrop-Grumman, New Jersey Commission on Science and Technology etc. He has an established record of publications in his field of expertise, with more than 250 technical journal and conference published papers. He received the Best Paper Award in IEEE INFOCOM’94, the AT&T Division Recognition and Achievement Award in 1997, the US National Science Foundation Career Award in 2003, the Best Paper Award in IEEE WCNC 2012, the Excellence in Research Grant in Greece in 2012, the Best Paper Award in the 7th International Conference on Ad Hoc Networks (ADHOCNETS 2015) in 2015 and the Best Paper Award in the 23rd International Conference in Telecommunications (ICT) in 2016. Dr. Papavassiliou also served on the board of the Greek National Regulatory Authority on Telecommunications and Posts (2006– 2009). He has been Associate Editor for IEEE Transactions on Parallel and Distributed Systems (2010-2014), Technical Editor for IEEE Wireless Communications Magazine (2011-2015), Editor of IEEE Communications Letters (2016-now), Member of the Editorial Board of the International Journal "Sensors" MDPI (2016-now), Member of the Advisor Board of the International Journal “Ad Hoc & Sensor Wireless Networks” (2009-now), etc.. He has also serves a guest editor for several special issues of international journals while he has held several positions in the organizing committees of international conferences (including General Chair, Technical Committee Program Chair, etc.).