2005

In recent years, wireless Internet service providers (WISPs) have established Wi-Fi hotspots in increasing numbers at public venues, providing local coverage to traveling users and empowering them with the ability to access email, Web, and other Internet applications on the move. In this paper, we observe that while the mobile computing landscape has changed both in terms of number and type of hotspot venues, there are several technological and deployment challenges remaining before hotspots can become an ubiquitous infrastructure. These challenges include authentication, security, coverage, management, location services, billing, and interoperability. We discuss existing research, the work of standards bodies, and the experience of commercial hotspot providers in these areas, and then describe compelling open research questions that remain.Anand Balachandran has been a member of the research staff at Intel Research, Seattle since October 2003. His research interests include wireless networking systems, wireless Internet, infrastructure and ad-hoc networks, and mobile and ubiquitous computing. He received his Bachelor of Technology degree from the Indian Institute of Technology, Madras in 1995, his Master’s degree from Columbia University, in 1997, and his Ph.D. degree in Computer Science and Engineering from the University of California at San Diego in 2003.Geoffrey M. Voelker is an assistant professor at the University of California at San Diego. His research interests include operating systems, distributed systems, networking, and mobile computing. He received a BS degree in Electrical Engineering and Computer Science from the University of California at Berkeley in 1992, and the M.S. and Ph.D. degrees in Computer Science and Engineering from the University of Washington in 1995 and 2000, respectively. In 2000, he received the first Computing Research Association (CRA) Digital Government Fellowship, and in 2002 he received the Hellman Young Faculty Fellowship at UCSD.Victor Bahl is a Senior Researcher and the Manager of the Networking Group in Microsoft Research. His research interests span a variety of problems in wireless networking. In addition to making many product contributions, he has authored over 65 scientific papers, 44 issued and pending patent applications and several book chapters. He is the co-founder and Chairman of the ACM Special Interest Group in Mobility (SIGMOBILE); the founder and past Editor-in-Chief of ACM Mobile Computing and Communications Review, and the founder and Steering Committee Chair of ACM/USENIX Mobile Systems Conference (MobiSys); He has served on the editorial board of IEEE Journal on Selected Areas in Communications, and is currently serving on the editorial boards of Elsevier’s Adhoc Networking Journal, Kulwer’s Telecommunications Systems Journal, and ACM’s Wireless Networking Journal. He has served as a guest editor for several IEEE and ACM journals and on networking review panels organized by the National Science Foundation (NSF), the National Research Council (NRC) and European Union’s COST. He has served as the General Chairman, Program Chair and Steering Committee member of several IEEE and ACM conferences and on the Technical Program Committee of over 45 international conferences and workshops. He is the recipient of Digital’s Doctoral Engineering Award (1994) and ACM SIGMOBILE’s Distinguished Service Award (2001). He is a Fellow of the ACM, a Senior Member of the IEEE and a past president of the electrical engineering honor society Eta kappa Nu-Zeta Pi. Dr. Bahl received his Ph. D in Computer Systems Engineering from the University of Massachusetts Amherst.This revised version was published online in August 2005 with a corrected cover date.