What is RSSI and why is it relevant in wireless networking?

• A. Radio Signal Strength Index; it estimates interference levels
• B. Relative Signal Strength Indicator; it measures distance to access point
• C. Router Signal Strength Indicator; it indicates router uptime
• D. Received Signal Strength Indicator; it reflects signal strength and helps gauge connection quality

Answer: (D)

RSSI stands for Received Signal Strength Indicator, and it measures how strong the wireless signal is when it reaches the receiver. It’s usually shown as a value in dBm or a device-specific unit—the closer to zero (less negative) the stronger the signal. A strong RSSI means the link can support higher data rates with fewer errors, while a weak RSSI suggests potential slowdowns, retransmissions, or disconnects. This measurement helps determine overall link quality, guide decisions about which access point to connect to, and inform when a device should roam to a better signal. Remember that RSSI reflects signal power, not noise, so it doesn’t alone predict throughput or reliability; factors like interference and environment also matter, and different devices report RSSI differently, so thresholds aren’t universal. For a fuller picture, look at RSSI alongside SNR and observed performance.