Monitoring systems and protocols are disclosed that are flexible in mode
operation and format depending on the environment in which they are used. Such
monitoring systems and protocols are able to change their utilization automatically,
or by received instruction to do so. A location detection system includes one or
more low frequency transmitters, one or more radio frequency monitoring tags and
one or more receiving devices. The low frequency transmitter transmits location
identification information, such as the transmitter ID, to a tag in the vicinity
of the transmission. The tag relays the transmitter ID using a higher frequency
transmission sent from the tag to the receiver. Communication protocols are disclosed
that enable deciphering of multiple tag transmissions starting simultaneously.