444 Int. J. Communication Networks and Distributed Systems, Vol. 5, No. 4, 2010 Copyright © 2010 Inderscience Enterprises Ltd. An overview of achieving energy efficiency in on-chip networks Masud Al Aziz and Samee Ullah Khan* NDSU-CIIT Green Computing and Communications Laboratory, Department of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58108-6050, USA E-mail: masud.aziz@ndsu.edu E-mail: samee.khan@ndsu.edu *Corresponding author Thanasis Loukopoulos Department of Informatics and Computer Technology, Technologicl Educational Institute (TEI) of Lamia, 35100 Lamia, Greece E-mail: luke@teilam.gr Pascal Bouvry Faculty of Science, Technology and Communication, University of Luxembourg, 6 rue Coudenhove Kalergi, L-1359 Luxembourg, Luxembourg E-mail: pascal.bouvry@uni.lu Hongxiang Li Department of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58108-6050, USA E-mail: hongxiang.li@ndsu.edu Juan Li NDSU-CIIT Green Computing and Communications Laboratory, Department of Computer Science, North Dakota State University, Fargo, ND 58108-6050, USA E-mail: j.li@ndsu.edu