Definition
RSSI, the Received Signal Strength Indicator, is the absolute power a radio receiver measures at its antenna input, expressed in dBm. Because received power is a tiny fraction of a milliwatt, RSSI is almost always a negative number, and the closer it sits to zero the stronger the link. A reading of -30 dBm is an exceptionally strong signal sitting right next to the transmitter, while -120 dBm is at the edge of what a sensitive receiver can detect at all.
Why it matters for off-grid mesh
For sovereign Bitcoiners running LoRa mesh radios to relay messages or block data without infrastructure, RSSI is the first number to check when planning node placement. Most practical Meshtastic links in suburban terrain land between roughly -80 dBm and -115 dBm. RSSI tells you how loud the incoming signal is, but on its own it does not tell you whether a packet will actually decode, because a strong signal can still be drowned by local noise.
RSSI versus link quality
This is why RSSI is read alongside the signal-to-noise ratio. LoRa modulation can recover packets buried below the noise floor, so a marginal RSSI with a workable SNR may still carry traffic, while a healthy RSSI in an electrically noisy location may not. Treat RSSI as a coarse loudness gauge and confirm reliability with the noise figure before trusting a long-haul hop.
RSSI is a foundational metric for building resilient off-grid communications. See the related SNR (Radio) entry for noise-relative quality, and Link Budget for predicting received power before you climb the tower.
In Simple Terms
RSSI, the Received Signal Strength Indicator, is the absolute power a radio receiver measures at its antenna input, expressed in dBm. Because received power is…