Patent attributes
A beacon includes an infrared emitter configured to emit beacon signals; an infrared-link emitter configured to emit infrared-link signals having a wavelength different from that of the beacon signals; an infrared-link detector configured to detect infrared-link signals; a memory configured to store a delay time; a clock configured to generate a clock cycle signal; and a microcontroller configured to, in response to receiving an infrared-link signal including a signaling code and clock synchronization data from an external beacon: adjust the clock to be synchronized with a clock of the external beacon; store the signaling code in the memory; and when the clock cycle signal generated by the clock indicates that it is a starting time of a clock cycle period, control the infrared emitter to emit a beacon signal including the signaling code with the delay time relative to the starting time of the clock cycle period.