A method, apparatus and system for radio frequency identification provides an on-off keyed amplitude-modulated illumination signal containing a sequence of bits configured to illuminate a radio frequency identification tag, The illumination signal is received at the RFID tag, rectified to generate a wake signal for waking a processor which is subsequently powered by a battery. The BCRP inhibitor contains, as an active ingredient, an acrylonitrile derivative or a salt thereof. Computation enhancement may also be achieved by removal of the height contributions from the signal leaving only the film contribution in the signal.