Professor, University of Stavanger, 1998-current.
Visiting Chair Professor, Tsinghua University, 2011-2013.
Visiting Professor, Stanford University, 2009-2010.
Chair of the Steering Board, Cloud Computing Association (CloudCom), 2008-current.
Research Coordinator for China, POSC Caesar Association, 2008-current.
member of the board, Norwegian Information Security Network (NISNet), 2007-current.
Guest Professor, Sun-Yat Sen University, 2009-current.
Guest Professor, Beijing Jiaotong University, 2008-current.
Adjunct Professor, UniK/University of Oslo, 2005-2009.
Chairman of the Board, Assocaition of the Norwegian Informatics Conference (NIK), 2005-2007.
PostDoc, Simula Research Laboratory, 2001-2003.
Visiting Scholar, University of Southern California (USC), 1996-1997.
Research Fellow, University of Bergen, 1995-current.
Editor's Choice 1999 by the Discrete Mathematics (Elsevier).
Editorial Board member:
International Journal of Smart Home (IJSH), since 2007.
International Journal of Mobile Communications (IJMC), 2003 - 2006.
CloudCom 2009 - the 1st International Conference on Cloud Computing, Beijing, December 1-4, 2009.
CSA 2009 - the 2nd International Conference on Computer Science and its Applications, Jeju, South Korea, December 10-12, 2009.
IEEE International Symposium on Security in Networks and Distributed Systems (SSNDS):
* Program chair, Canada, 2007.
International Conference on Ubiquitous Intelligence and Computing (UIC):
* General chair, Norway, 2008.
Conference Steering Committees:
Founder & Steering chair: the Cloud Computing Association (CloudCom) and its associated conference and workshop series, since 2008.
International Conference on Communications and Electronics (ICCE), Vietnam, since 2010.
Teacher, Municipality of Bergen, 1989-1995.