Measurement and analysis of the spatial locality of wireless information and mobility patterns in a campus

An environment is characterized by spatial locality of queries and information when it is likely that users in close geographic proximity query for similar data. Information exhibits spatial locality when it is coupled to a real-world place. For example, play reviews are most relevant in a theater; and users in a Dental school may be particularly interested in web sites on related subjects. The prevalence of such spatial locality is related directly to the feasibility of deploying locationdependent services. Intuition suggests that a high degree of spatial locality of information exists because people often gather to exchange information. As such, we expect that appropriate location-dependent services may harness the spatial locality effectively. The web is not primarily a location-dependent service, but it provides a ready testbed to study the prevalence of spatial locality and mobile users. This paper results from a three-week study of spatial locality phenomena among mobile web users on a major university campus using the 802.11 [11] wireless infrastructure. We show that users are often near other users with similar interests. In addition, we categorize the urls and present a classification of the wireless information as a function of the location from which it was accessed. We also model the associations of wireless users to access points. Finally, we discuss the implications on the feasibility of location-dependent services and potential improvements of the wireless access using caching mechanisms.