20120262338 | PROXIMITY MONITORING - Presented is a proximity monitoring apparatus and method. The apparatus comprises: a transmitter adapted to transmit a electromagnetic signal in a periodic time slot defined with reference to a master clock signal; and a detector adapted to receive the electromagnetic signal transmitted by the transmitter, to determine the period of the received electromagnetic signal, and to determine that the received electromagnetic signal was transmitted by the transmitter of the proximity monitoring apparatus if the determined period is within a predetermined range of values | 10-18-2012 |