How RSSI, SNR, Bit Errors, and Packet Loss Relate to Each Other
A common field-debugging sentence is: “The signal is good, so why does it still drop?” In many cases, “good signal” only means RSSI (Received Signal Strength Indicator) is not low. Wireless link quality is not determined by receive power alone.
A better model is:
receive signal strength + noise and interference -> SNR / SINR -> demodulation success -> frame errors -> retries / packet loss -> application experience
RSSI only says how much energy the receiver sees. It does not say how much of that energy is useful signal.