Patent ID: 8218971

Claim:
A method for determining a position of a mobile device in a room comprising: determining via a processor a position within a room of a mobile device based upon sensed optical signals detected by optical sensors connected to the mobile device, where each of the sensed optical signals is geographically focused within a spatially constrained zone, each of the sensed optical signals comprising digitally encoded data indicating an optical source that emitted a corresponding one of the sensed optical signals and a spatially constrained zone of the corresponding one of the sensed optical signals, wherein said determining of the position is based on determining a grid within the room within which the mobile device is located, said grid being defined by overlapping ones of spatially constrained zones that the sensed optical signals are focused within; and determining a facing direction within the room of a person wearing said mobile device based upon the sensed optical signals received by the optical sensors and based upon which of the sensors detected the sensed optical signals, wherein the optical sensors move when a head of the person moves.