Abstract: The disclosure describes a real-time location system for tracking assets at a site. The system includes one or more tracking tags for carrying by or on the assets, one or more locating device nodes and a processing application. Each tracking tag includes a short-range radio frequency signal transmitter configured to transmit a beacon signal with unique identification information of the tracking tag. Each locating device node includes a signal receiver configured to receive the beacon signals at a received signal strength and a long-range radio frequency transmitter configured to transmit, using a spread spectrum, long-range modulation over a wide area network, locating signals including the unique identification information of the tracking tag and a received signal strength indicator representing the received signal strength. The processing application is configured to associate tracking tags and locating device nodes based upon the received signal strength indicator.

Abstract: A tracking tag system includes a tag case, a first tag case back plate and a second tag case back plate. The tag case has a mating surface and is configured to house a PCB having a transmitter and circuitry for controlling the transmitter. The first tag case back plate is configured to mate with the tag case to enclose and totally protect the PCB, the transmitter, the circuitry and a battery of a first type against ingress of water during immersion and against dust ingress. The second tag case back plate configured to enclose and totally protect the PCB, the transmitter, the circuitry and a battery of a second type against ingress of water during immersion and against dust ingress.

Abstract: A security system including tracking units or readers carried or mounted on mobile units to operatively communicate status signals indicating identity, location, direction of travel, and a number of alarm conditions to a local monitoring station. The tracking units or readers are equipped with an infrared receiver to receive infrared location signals transmitted by fixed infrared transmitters located throughout the area to be monitored. Each infrared transmitter transmits a unique location signal. The tracking unit is operative to transmit a radio frequency watchdog signal that includes the last two location signals received, indicating the time lapsed since receipt of those location signals, a unique identification signal indicative of the and any applicable alarm signals triggered by predetermined conditions to which the tracking unit is also operative to detect.