Abstract: According to one embodiment, a safety system can comprise at least one receiver, each located in a restricted access area; a safe operation monitor coupled to the at least one receiver configured to detect signals from the at least one receiver; wherein: the at least one receiver is configured to receive signals from a transmitter, the transmitter being used by a worker within the restricted access area; the safe operation monitor is configured to protect the restricted access area, based on the receipt of a signal from the transmitter; and causing an alert on the transmitter.