Wireless Signal Strength and Noise Levels

To make sure that all users in your environment receive a strong wireless signal, consider these guidelines when you install your WatchGuard APs.

Signal Strength

The signal strength is the wireless signal power level received by the wireless client.

  • Strong signal strength results in more reliable connections and higher speeds.
  • Signal strength is represented in -dBm format (0 to -100). This is the power ratio in decibels (dB) of the measured power referenced to one milliwatt.
  • The closer the value is to 0, the stronger the signal. For example, -41dBm is better signal strength than -61dBm.

Noise Level

The noise level indicates the amount of background noise in your environment.

  • If the noise level is too high, it can result in degraded strength and performance for your wireless signal strength.
  • Noise level is measured in -dBm format (0 to -100). This is the power ratio in decibels (dB) of the measured power referenced to one milliwatt.
  • The closer the value to 0, the greater the noise level.
  • Negative values indicate less background noise. For example, -96dBm is a lower noise level than
    -20dBm.

Signal to Noise Ratio

The signal-to-noise ratio (SNR) is the power ratio between the signal strength and the noise level.

  • This value is represented in decibels (dB).
  • In general, you should have a minimum of +25dB signal-to-noise ratio. Lower values than +25dB result in poor performance and speeds.

For example:

  • If you have a -41dBm signal strength, and a -50dBm noise level, this results in a poor signal-to-noise ratio of +9dB.
  • If you have a -41dBm signal strength, and a -96dBm noise level, this results in an excellent signal-to-noise ratio of +55dB.

See Also

Wireless Environmental Factors

Wireless Modes and Channels

Wireless Placement