A series of radio frequency identification (RFID) systems are delineated.
One such RFID system comprises an RFID signpost, and a plurality of
infrared transmitters, wherein each infrared transmitter of the plurality
of infrared transmitters is arranged to cover, when transmitting, a
distinct sector relative to the RFID signpost. Another RFID system
comprises an RFID signpost having a transmitter for transmitting signals
of a predefined type, and a receiver for receiving signals of the
predefined type, wherein the transmitter for transmitting signals of the
predefined type cannot transmit until a determination is made that the
predefined type of signal is not present at the receiver. Still another
RFID system comprises an RFID signpost including a transmitter having a
continuous power dissipation rating, and a processor for controlling the
transmitter such that peak pulse power of a transmission from the
transmitter multiplied by its duty cycle does not exceed the continuous
power dissipation rating for the transmitter.