What means RSSI in wireless transmission?

RSSI stands for Received Signal Strength Indicator.

In wireless transmission, RSSI is a measurement of the power level (signal strength) that a receiving device (like a phone, router, or IoT sensor) detects from a transmitting device (like a Wi-Fi access point or Bluetooth beacon).

Key points about RSSI:

It does not have a fixed standard unit, but it’s often represented in dBm (decibels relative to one milliwatt), where 0 dBm is strong, and negative numbers (like -30 dBm) are weaker but still very good.
Higher (closer to 0) values indicate stronger signals.
A lower (more negative) RSSI means a weaker signal, potentially leading to slower data rates or disconnections.
RSSI is commonly used in Wi-Fi, Bluetooth, ZigBee, and other wireless protocols for signal quality assessment.

Typical RSSI ranges in Wi-Fi:

RSSI Value	Signal Strength	Quality
-30 dBm	Excellent	Max performance
-50 dBm	Very Good	Reliable
-60 dBm	Good	Still OK
-70 dBm	Fair	Some degradation
-80 dBm	Poor	Might disconnect
-90 dBm	Very poor	Likely unusable