Patent ID: 7940675

Claim:
A method of operating a communication network including a full functional device (FFD) having a wireless transceiver and a plurality of reduced function devices (RFDs) each having a wireless transceiver and assigned to the FFD, the method comprising the steps of: positioning the RFDs such that each RFD is in communication range with the FFD and at least one other RFD, such that the RFDs can talk directly when connection is lost with the FFD; and activating the FFD to perform a test procedure during which: the FFD sends a test initiating signal to the RFDs indicating that the test procedure is being performed, each RFD which receives the test initiating signal stays online during the test procedure; the FFD sends a signal to one of the RFDs to transmit a test message; each other RFD which receives the test message directly from the one RFD sends a confirmation signal to the FFD; and activating an alarm when the test signal from the one RFD is not received directly by any of the other RFDs.