Received signal strength indication 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 is often a DC analog level. It can also be sampled by
Cathode-ray tube amusement device care". The cathode-ray tube amusement device was invented by physicists Thomas T. Goldsmith, Jr. and Estle Ray Mann. The pair worked at television designer DuMont Laboratories specializing in the development of cathode ray tubes that used electronic signal outputs to project a signal onto television screens. Goldsmith, who had received a Ph.D. in physics from Cornell University in 1936 with a focus on oscilloscope design, was at the time of the device's invention the director of research for DuMont Laboratories in New Jersey. The two inventors were inspired by the radar displays used in World War II, which Goldsmith had