RSSI (Received Signal Strength Indicator)
RSSI is the indication of the signal level measured at the receiver's input stage and is usually reported as a negative number in dBm. Its absolute accuracy can vary by manufacturer, but it is reliable for relative comparison. It is the most practical tool for choosing antenna position and seeing the range limit during installation.
The value of RSSI lies not in its absolute calibration but in its comparative use. Placing the antenna at two different points and comparing the readings shows beyond argument which position is better.
- Typical levels: -40 to -60 dBm at close range, -90 dBm and below as the range limit is approached.
- Rule of interpretation: RSSI alone is not enough; it must be assessed together with the noise floor. -80 dBm is comfortable on a quiet site and marginal on a noisy one.
- An improvement of 6 dB theoretically means double the range; that is the threshold sought in antenna position trials.
On bidirectional systems the RSSI can also be reported back to the remote control, and the operator sees in advance that the range limit is being approached. AXI's XRF protocol is built on bidirectional communication and status feedback; on systems transmitting one way you can only measure link quality on the receiver side.
Context in which this term is used: Wireless remote control installation: pairing, relay, safety