Ø Infrared
q uses IR diodes, diffuse light, multiple reflections (walls, furniture etc.)
Ø Advantages
q simple, cheap, available in many mobile devices
q no licenses needed
q simple shielding possible
Ø Disadvantages
q interference by sunlight, heat sources etc.
q many things shield or absorb IR light
q low bandwidth
Ø Example
q IrDA (Infrared Data Association) interface available everywhere