Public WLAN Hotspot Deployment and Interworking

Wireless data networking is becoming more and more popular, and network operators of various kinds (cellular providers, wireless Internet Service Providers, etc.) are beginning to deploy public Wireless Local Area Network (WLAN) hotspots around the world. However, broad adoption of these hotspots may be inhibited by technical obstacles such as ease of use, security, and the inability of users to roam across hotspots as they can with cell phones today. The latter problem in particular highlights the need for a common hotspot architecture that is based on open standards and is acceptable to different service provider communities. Such an architecture must also be flexible to accommodate users with a variety of mobile device form factors and login credential types, as well as different billing models. We begin with a brief survey of the state and deployment of hotspots today and go on to describe a unified public hotspot architecture that addresses the technical obstacles mentioned above. A major theme of the paper is the transition from the insecure Universal Access Method (UAM) to more robust authentication and link security based on Wi-Fi Protected Access (WPA*). While much of the discussion centers on authentication and authorization for internet access, we also touch upon issues that need to be addressed to enable more advanced services to be deployed and accessed from such hotspots in the future.