a real - time method and system for locating a mobile object or person in a tracking environment in which a plurality of sensors are located are provided . the method includes providing a tracking tag wearable by the person or attachable to the object . the method further includes modulating a first carrier signal with a first packet including a first set of data to obtain a modulated first signal . the method still further includes transmitting from the tag to a sensor nearest the tag the first signal , the first signal containing the first packet and having a first precision and a first range within the environment . the method further includes repeating the steps of modulating and transmitting until a modulated second signal is received at the tag from the nearest sensor within a time period after the step of transmitting . the second signal contains a second packet including a second set of data and has a second precision and a second range within the environment . the method still further includes receiving the second signal at the tag within the time period . the method further includes demodulating the second signal to obtain the second packet . the method still further includes determining location of the tag within the environment based on the second packet of the received demodulated second signal .