RFID device for object monitoring, locating, and tracking

摘要

An RFID monitoring arrangement comprises a first RFID device and a second RFID device for monitoring the first RFID device. The first RFID device transmits at least two messages each including unique identifying information and a power level code, wherein the transmitter power level corresponds to the power level represented by the power level code in each transmitted message. The second RFID device receives messages transmitted by the first RFID device and processes the identifying information and the power level code to provide an indication of a condition. Messages received from said first RFID device, the indication of a condition, or both the messages received from said first RFID device and the indication of a condition, may be relayed to a remote location.