What defines RSSI in radio signal measurements?

RSSI, or Received Signal Strength Indicator, is a measure of the detected power level of a radio signal at the receiver, expressed in dBm. It reflects the strength of the wireless signal received by the client or access point and is a critical metric for assessing coverage, link quality, and roaming decisions. Higher RSSI values (closer to 0 dBm) indicate stronger signals, while lower values (more negative) represent weaker signals. RSSI is used by Cisco wireless controllers and clients to make roaming decisions, select access points, and optimize transmit power levels. Option B, noise generated by interference, affects signal-to-noise ratio but does not define RSSI. Option C, QoS packet marking, pertains to network traffic prioritization, not RF measurements. Option D, wireless radio service ID, refers to identifying services on a network and is unrelated to signal strength measurement. Understanding RSSI is fundamental in RF planning, AP placement, and troubleshooting wireless coverage issues. Cisco Wireless Core Technologies emphasize monitoring RSSI to maintain adequate signal levels across the deployment, ensuring seamless connectivity and performance in high-density or challenging RF environments. Reference topics:RF Fundamentals — RSSI, signal strength, link quality, roaming, RF planning.