A position aware information appliance

The information related to the user actual and previous position is a very important issue for research activities on new interaction paradigms navigating physical spaces. This information is obtained from a coherent use of infrared TXs and a developed software which computes the probability that the user is located and oriented in a specific way. A number of IR TXs are fixed to walls around the rooms, and an IR receiver is attached to the user handing a PDA. The received signals are then processed, on the PDA, to derive the user's location and orientation. Combinations of IR TXs can be used to discover location, distance and orientation. A standalone C++ application on the PDA, called Barriera, reads IR codes and processes the stream of codes to remove spurious readings. Hence Barriera does a probabilistic calculation on the readings to infer the orientation and location of the user.