Explain live signal-strength readings in RF docs

docs/carrier_wave.md

@@ -42,13 +42,19 @@ Use the local USB or BLE console for immediate replies and manual stopping.
 An on-air CLI reply must wait until the carrier ends because LoRa packets
 cannot transmit during the test.
 
-A second radio on the same frequency can detect the carrier using
-instantaneous RSSI. Compare readings before, during, and after transmission;
-CAD and packet counters are not carrier detectors. This confirms RF activity,
-not calibrated output power, frequency accuracy, antenna match, or SWR.
-Afterward, exchange ordinary LoRa packets to verify both RX and TX recovery.
+A second radio on the same frequency can detect the carrier by measuring
+**live signal strength** (RSSI, short for received signal strength indicator):
+how much radio energy the receiver sees right now, even when it cannot decode
+a packet. A less-negative reading in dBm means a stronger signal. Compare it
+before, during, and after transmission. The normal `stats-radio` command shows
+the **last received packet's** RSSI, not this live reading, so it cannot by
+itself confirm a continuous carrier. CAD and packet counters are not carrier
+detectors either. A rising live reading confirms RF activity, not calibrated
+output power, frequency accuracy, antenna match, or SWR. Afterward, exchange
+ordinary LoRa packets to verify both RX and TX recovery.
 
-The reproducible bench witness is `tools/hil/cw_observer.cpp`, built with
-`tools/hil/cw_observer.ini` on a separate RAK4631. It never transmits on its own.
+The reproducible bench receiver that provides this live reading is
+`tools/hil/cw_observer.cpp`, built with `tools/hil/cw_observer.ini` on a
+separate RAK4631. It never transmits on its own.
 See the [hardware validation](carrier_wave_validation.md) for measured results,
 reproduction steps, and the tested preamble settings.

docs/carrier_wave_validation.md

@@ -4,7 +4,8 @@ Tested on the MercerWoodMesh lab Pi on September 14, 2026 (Pacific), using
 base commit `9241ccc253ad2f8ac2c9a2fe756f59ba2f52505d` plus the CW changes.
 Test images are marked `v1.17.1.6-cw-test-9241ccc2`; they are development images.
 
-A separate RAK4631 sampled instantaneous RSSI every approximately 10 ms.
+A separate RAK4631 sampled live received signal strength (RSSI) about every
+10 ms, without needing to decode a packet.
 The transmitting boards ran the Full V4 repeater and Full T1000-E Companion
 builds. Both were configured for −9 dBm chip TX power, with profiles at
 909.5 and 919.5 MHz, BW125, SF7, CR5, and 32-symbol preambles.

docs/cli_commands.md

@@ -561,6 +561,10 @@ command `0x42` where the role supports the command; unavailable over LoRa.
 
 **Usage:** `stats-radio`
 
+`last_rssi` is the strength of the last received packet. It is not a live
+signal-strength meter and will not show an unmodulated carrier; see the
+[carrier-wave guide](carrier_wave.md) for a separate receiver that can measure one.
+
 **Local connection only:** USB, direct network CLI, or Companion binary
 command `0x42` where the role supports the command; unavailable over LoRa.
 

docs/preamble_detection_investigation.md

@@ -71,12 +71,12 @@ CRC error): two at +250 kHz with XIAO RX, and one each at +250 and +1,000 kHz
 with Indicator RX. Therefore **HeaderValid alone would not prove that these
 off-frequency indications are legitimate traffic**.
 
-In forward SF8 on-frequency controls, instantaneous RSSI at the first preamble
-was -42 to -41 dBm; at +/-250 kHz it was -91 to -88 dBm. These are instantaneous
-receiver readings, not calibrated measurements of transmitted leakage or a
-sensitivity test. Board positions and attenuation were not systematically
-varied. Reversing roles reproduces the behavior but does not isolate its
-physical path.
+In forward SF8 on-frequency controls, receiver signal strength (RSSI) sampled
+at the first preamble was -42 to -41 dBm; at +/-250 kHz it was -91 to -88 dBm.
+These are single-point receiver readings, not calibrated measurements of
+transmitted leakage or a sensitivity test. Board positions and attenuation
+were not systematically varied. Reversing roles reproduces the behavior but
+does not isolate its physical path.
 
 ## What this explains
 

docs/separated_radio_modulation_cache_validation.md

@@ -69,10 +69,10 @@ All 12 on-frequency probes delivered valid payloads. No off-frequency header
 or valid payload, silent preamble, device/read error, foreign valid payload,
 or trace overflow occurred. SF6 off-channel detections changed from 1/24 to
 0/24; SF8 from 32/48 to 4/48. These are small bounded samples, not sensitivity
-or packet-error-rate estimates. On-frequency instantaneous RSSI was -41 to
--40 dBm at SF6 and -42 dBm at SF8: the signal remains strong and readings are
-not calibrated attenuation measurements. Improvement cannot be attributed
-solely to separation or solely to normal gain.
+or packet-error-rate estimates. Signal strength (RSSI) sampled on-frequency
+was -41 to -40 dBm at SF6 and -42 dBm at SF8: the signal remains strong, but
+these are not calibrated attenuation measurements. Improvement cannot be
+attributed solely to separation or solely to normal gain.
 
 ## Four-channel SF6/125, 5.1-symbol visits