Patent ID: 7071825

Claim:
A system for determining presence of a device, comprising: a radio frequency identification (RFID) tag disposed on the device; and a rack in which the device is maintained, the rack comprising: an antenna adapted to transmit interrogation signals to the RFID tag, and receive presence signals from the RFID tag; and a presence and occupancy discovery (pod) unit comprising an RF interrogator and an RF controller, the pod unit adapted to receive and decode the presence signals from the antenna, and to determine the presence of the device in the rack based on the decoded presence signals, and to monitor the continued presence of the device in the rack by directing interrogation signals to be transmitted via the antenna at predetermined times and confirming detection of received presence signals from the device, wherein if a presence signal is not received from the device, the pod unit starts a timer, and if the timer elapses before another presence signal is received from the device, at least one of an indicator is activated, an absence entry is logged in storage, and a warning signal is provided to a central controller.