Mobile computers often benefit from software which adapts to their location. For example, a computer might be backed up when at the office, or the default printer might always be a nearby one. In many existing systems, location-triggered actions are only possible for specific applications or with special infrastructure. This paper describes lcron, a system which supports user-configurable actions triggered on change in location or other events common to mobile computers. Key features of lcron are its use of existing clues for location information and mapping low-level location information into user-sensible terms. Lcron uses a number of existing sources of location such as network connection and base station ID, allowing it to work without special hardware or GPS receivers. We map sources of low-level information such as IP address and latitude/longitude into user-meaningful logical locations. We describe the design, implementation and our experiences with this system.
John S. Heidemann, Dhaval Shah