Cache management in a mobile device

摘要

A method and apparatus are disclosed for providing information about a real-world space such as an exhibition space. In a preferred embodiment, a user (30) visiting a hall (10) is equipped with a mobile device (31) in communication with a service system (35). The mobile device (31) is arranged to deposit virtual markers with the service system (35) as the user progresses around the hall (10). These markers are aggregated with markers deposited in respect of other users thereby enabling information such as trail information to be built up for subsequent use.