US Patent 9064225 Method and apparatus for asset tracking in constrained environments

Wireless tracking systems and devices to detect the status of cargo containers, such as aircraft cargo. The system has a transmitter device, a router, and intelligent software. The transmitter device has automatic on-off capability during use, without the need for human intervention. The transmitter device has a basic “listening state” and the router has a basic “beacon broadcast state.” Only when the transmitter device is within range of the router's beacon does the device transmit data via RF signal to the router.