Prof. Nitin H. Vaidya
Department of Electrical and Computer Engineering, and Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, USA

Multi-Channel Wireless Networks: Theory to Practice


Wireless technologies, such as IEEE 802.11, provide for multiple non-overlapping channels. With the availability of multiple channels, network capacity may be increased by using all the available channels within a given network. However, the number of interfaces per node in a network is expected to be typically much smaller than the number of channels, and therefore a single node cannot simultaneously use all the channels.

In this talk, we present capacity results for multi-channel wireless networks, considering constrained as well as unconstrained channel assignments. In the constrained channel assignment scenario, we show that for a random network of n nodes using just one interface each, asymptotically, there is no capacity degradation so long as the number of channels is O(log n).

The capacity results indicate that, in theory, multiple channels can be used within a single network to improve network capacity significantly, even with a small number of interfaces per node. However, in practice, many challenges have to be addressed before the capacity improvement can be realized. This talk will present the insights obtained from the capacity analysis, which are useful in designing practical multi-channel protocols for wireless mesh and ad hoc networks, and also discuss some of the design decisions made while implementing the Net-X multi-channel multi-interface testbed at the University of Illinois.

This talk is based on joint research with graduate students Vartika Bhandari, Rishi Bhardwaj, Chandrakanth Chereddi, Pradeep Kyasanur and Nistha Tripathi.

Short biography

Nitin Vaidya received Ph.D. from the University of Massachusetts at Amherst. He is presently a Professor of Electrical and Computer Engineering at the University of Illinois at Urbana-Champaign. He has held visiting positions at Microsoft Research, Sun Microsystems and the Indian Institute of Technology-Bombay. His current research is in wireless networking and mobile computing. He co-authored papers that received awards at 1998 ACM MobiCom and 2003 Personal Wireless Communications (PWC) conferences. Nitin is a recipient of a CAREER award from the National Science Foundation. He served as program co-chair for 2003 ACM MobiCom and General Chair for 2001 ACM MobiHoc, and presently serves as the Editor-in-Chief for the IEEE Transactions on Mobile Computing. For more information, please visit