Received signal strength indication link like other metrics such as travel time measurement (time of arrival). Received signal strength indication In telecommunications, received signal strength indicator (RSSI) is a measurement of the power present in a received radio signal. RSSI is usually invisible to a user of a receiving device. However, because signal strength can vary greatly and affect functionality in wireless networking, IEEE 802.11 devices often make the measurement available to users. RSSI is often derived in the intermediate frequency (IF) stage before the IF amplifier. In zero-IF systems, it is derived in the baseband signal chain, before the baseband amplifier. RSSI output
The Thing (listening device) with a simple diode detector/demodulator, similar to some field strength meters. Two additional State Department employees, John W. Ford and Joseph Bezjian, were sent to Moscow in March 1951 to investigate this and other suspected bugs in the British and Canadian embassy buildings. They conducted a technical surveillance counter-measures "sweep" of the Ambassador's office, using a signal generator and a receiver in a setup that generates audio feedback ("howl") if the sound from the room is transmitted on a given frequency. During this sweep, Bezjian found the device in the Great Seal carving. The Federal Bureau of Investigation set about