RSSI (Received Signal Strength Indicator) is a measure of the power level that a receiving device (such as a phone, Wi-Fi router, or DAS/BDA system) detects from a transmitted signal. It provides an indication of the signal strength at the receiver’s end, typically represented in dBm (decibel-milliwatts), where lower numbers indicate weaker signals.

Key Points About RSSI:

  1. Measurement Scale:
    • RSSI values are typically negative; closer to 0 is stronger.
    • For example:
      • -30 dBm: Excellent signal strength (close to the transmitter).
      • -50 to -70 dBm: Good signal strength.
      • -90 dBm or below: Poor signal strength and likely to cause issues with connectivity.
  2. Applications:
    • Wi-Fi and Cellular Networks: Used to determine signal quality for devices like phones or laptops.
    • DAS (Distributed Antenna Systems): Helps monitor and optimize signal distribution in large buildings or areas.
    • BDA (Bi-Directional Amplifiers): Ensures signal strength is sufficient for both uplink (device to tower) and downlink (tower to device).
  3. Limitations:
    • RSSI only measures signal strength, not quality.
    • Factors like interference, noise, and multipath propagation can affect the actual usability of a connection even if RSSI indicates a strong signal.
  4. Usage in Troubleshooting:
    • Low RSSI can indicate the need for signal boosting or relocating antennas.
    • A high RSSI with poor connection may point to interference or congestion rather than weak signals.