Best dBm Values for Wifi
URL:
https://support.randomsolutions.nl/827069-Best-dBm-Values-for-Wifi
And what about SNR (Signal to Noise Ratio)
SNR is not actually a ratio but the difference in decibels between the received signal and the background noise level (noise floor). For example, if a radio (client device) receives a signal of -75 dBm and the noise floor is measured at -90 dBm, the SNR is 15 dB. Data corruption and therefore re-transmissions will occur if the received signal is too close to the noise floor. In 802.11 networks, re-transmissions adversely affect throughput and latency.
How does RSSI (dBm) relate to signal quality (percent)?
Depending on your OS and application, WiFi signal strength is represented either as quality in percentage, or an RSSI value in dBm, i.e. -70db. RSSI is usually expressed in decibels from 0 (zero) to -120db and the closer it is to zero, the stronger the signal is. RSSI level less than -80db may not be usable, depending on noise.
While there is no simple precise solution that is used universally, we will try to explain the approximate correlation between signal (RSSI) and quality (percentage).
Generally,
db >= -50 db = 100% quality
db <= -100 db = 0% quality
For RSSI signal between -50db and -100db,
quality ~= 2* (db + 100) RSSI ~= (percentage / 2) - 100
For example:
High quality: 90% ~= -55db
Medium quality: 50% ~= -75db
Low quality: 30% ~= -85db
Unusable quality: 8% ~= -96dbDepending on your OS and application, WiFi signal strength is represented either as quality in percentage, or an RSSI value in dBm, i.e. -70db. RSSI is usually expressed in decibels from 0 (zero) to -120db and the closer it is to zero, the stronger the signal is. RSSI level less than -80db may not be usable, depending on noise.
While there is no simple precise solution that is used universally, we will try to explain the approximate correlation between signal (RSSI) and quality (percentage).
Generally,
db >= -50 db = 100% quality
db <= -100 db = 0% quality
For RSSI signal between -50db and -100db,
quality ~= 2* (db + 100) RSSI ~= (percentage / 2) - 100
For example:
High quality: 90% ~= -55db
Medium quality: 50% ~= -75db
Low quality: 30% ~= -85db
Unusable quality: 8% ~= -96db
https://support.randomsolutions.nl/827069-Best-dBm-Values-for-Wifi
Best dBm Values for Wifi
| Signal Strength | Required for | |
| -30 dBm | Max achievable signal strength. The client can only be a few feet from the AP to achieve this. Not typical or desirable in the real world. | N/A |
| -67 dBm | Minimum signal strength for applications that require very reliable, timely packet delivery. | VoIP/VoWiFi, streaming video |
| -70 dBm | Minimum signal strength for reliable packet delivery. | Email, web |
| -80 dBm | Minimum signal strength for basic connectivity. Packet delivery may be unreliable. | N/A |
| -90 dBm | Approaching or drowning in the noise floor. Any functionality is highly unlikely. | N/A |
And what about SNR (Signal to Noise Ratio)
SNR is not actually a ratio but the difference in decibels between the received signal and the background noise level (noise floor). For example, if a radio (client device) receives a signal of -75 dBm and the noise floor is measured at -90 dBm, the SNR is 15 dB. Data corruption and therefore re-transmissions will occur if the received signal is too close to the noise floor. In 802.11 networks, re-transmissions adversely affect throughput and latency.
How does RSSI (dBm) relate to signal quality (percent)?
Depending on your OS and application, WiFi signal strength is represented either as quality in percentage, or an RSSI value in dBm, i.e. -70db. RSSI is usually expressed in decibels from 0 (zero) to -120db and the closer it is to zero, the stronger the signal is. RSSI level less than -80db may not be usable, depending on noise.
While there is no simple precise solution that is used universally, we will try to explain the approximate correlation between signal (RSSI) and quality (percentage).
Generally,
db >= -50 db = 100% quality
db <= -100 db = 0% quality
For RSSI signal between -50db and -100db,
quality ~= 2* (db + 100) RSSI ~= (percentage / 2) - 100
For example:
High quality: 90% ~= -55db
Medium quality: 50% ~= -75db
Low quality: 30% ~= -85db
Unusable quality: 8% ~= -96dbDepending on your OS and application, WiFi signal strength is represented either as quality in percentage, or an RSSI value in dBm, i.e. -70db. RSSI is usually expressed in decibels from 0 (zero) to -120db and the closer it is to zero, the stronger the signal is. RSSI level less than -80db may not be usable, depending on noise.
While there is no simple precise solution that is used universally, we will try to explain the approximate correlation between signal (RSSI) and quality (percentage).
Generally,
db >= -50 db = 100% quality
db <= -100 db = 0% quality
For RSSI signal between -50db and -100db,
quality ~= 2* (db + 100) RSSI ~= (percentage / 2) - 100
For example:
High quality: 90% ~= -55db
Medium quality: 50% ~= -75db
Low quality: 30% ~= -85db
Unusable quality: 8% ~= -96db
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