rssi

RSSI stands for Received Signal Strength Indicator. It is a measurement used in wireless communications to indicate the power present in a received radio signal. It is intended as a relative indicator of link quality, rather than a precise measure of transmitted power, and its meaning varies by technology and hardware.

In many devices and standards, RSSI is reported as either a dBm value or as a scaled, device-specific unit. When expressed in dBm, stronger signals have less negative values (for example, around -30 dBm is strong, -90 dBm is weak). However, some chipsets report RSSI on a 0–255 scale or 0–100 scale, which is an arbitrary representation and not directly comparable across devices.

RSSI is used in network association and handover decisions, for adaptive data rate and power control, and in indoor localization by fingerprinting.

Limitations: RSSI is sensitive to interference, multipath, and antenna orientation; it does not directly measure SNR or achievable throughput; there is no universal standard, so values can vary widely between vendors.

In practice, RSSI is often used in conjunction with other metrics such as SNR, BER, and link quality indicators to assess performance. See also: signal strength, link quality, SNR.