B. Real-world Layer
The real-world layer corresponds to the physical world and
has the components such as humans, buildings, roads,
streets, etc. In this layer, the user’s position and direction
change constantly as the user moves along the street. The
user encounters forks during walks and wants to learn
regional data such as what building, service, or activities are
available on each of the accessible paths. The user views a
path with the mobile camera and queries are generated for
the street being captured in camera.
User behavior can be detected with the GPS and azimuth
sensor. The system then can decide which street is being
captured with the camera with the real-time data from the
sensors and street data. This is illustrated in Fig. 9.