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.

We have built a network, called the CHOICE network, which globally authenticates users and then securely connects them to the Internet via a high-speed local area wireless network. Our network provides easy-to-use, individualcentric, service-oriented wireless Internet access in places other than the traditional corporate offices and homes. Our architecture is hardware and protocol agnostic and is built on an easily deployable software module called the Protocol for Authorization and Negotiation of Services or PANS. PANS provides authorization, access, privacy, security, policy enforcement, quality of service (QoS) and accounting. In this paper, we describe PANS in detail. We discuss our system design and operation, implementation, and performance. We evaluate PANS and show that it is scalable and secure. Our network has been deployed and is operational at a local mall in Bellevue, Washington.

We would like to acknowledge and thank several individuals who have helped develop the CHOICE network. In particular, Anand Balachandran, and Srinivasan Venkatachary are two of the original designers and implementers of PANS. Stephen Dahl helped us deploy the network at the Crossroads Mall; Pierre De Vries handled the legal formalities and helped us with usability issues while being our liaison with the product groups Paul Hoeffer designed our web interaction. We also thank Prof. Dave Johnson of Rice University, and Prof. Mary Baker of Stanford University for the well appreciated constructive discussions.

Abstract. 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.