A portable GPS device is linked to a cellular telephone containing a modem. Carrying this device, a person (e.g. a mailman) runs through the city.
The data are transmitted to another location (e.g. a museum) via the telephone line. These data are then processed in a PC in which a digital city map is stored. Lastly, a video beam makes the situation visible on a projection screen.
(M. Bielicky)