RSSI

In telecommunications, Received Signal Strength Indication (RSSI) is a measurement of the power present in a received radio signal.RSSI is generic radio receiver technology metric, which usually is invisible to the user of device containing the receiver, but is directly known to users of wireless networking of IEEE 802.11 protocol family.RSSI is often done in the intermediate frequency (IF) stage before the IF amplifier. In zero-IF systems, it is done in the baseband signal chain, before the baseband amplifier. RSSI output is often a DC analog level. It can also be sampled by an internal ADC and the resulting codes available directly or via peripheral or internal processor bus.
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