Understand Noise with Wi-Fi SNR
SNR, or Signal to Noise Ratio, also dBm, or decibel margins, is a measurement of how strong a signal is through the noise of the medium it is traveling through. It is the ratio of Signal to Noise. For example, a Signal of -24dBm with a noise of -90dBm would yield a SNR of 66dB.
| SNR | Connection Quality |
|---|---|
| 10dB – 15dB | Unreliable Connection |
| 16dB – 24dB | Poor |
| 25dB – 40dB | Good |
| 41dB or Greater | Excellent |
Noise can be any of the following:
• Microwave Ovens
• Cordless Phones
• Bluetooth Devices
• Game Controllers
• Wireless Surveillance Systems
• Wireless Game Controllers
• Wireless Keyboards and Mice
• Fluorescent Lights
• etc.
SNR with higher values equates to faster data rates, fewer retransmissions and overall better throughput.
The SNR can be improvement by mitigating sources of noise, increasing the number of Access Points (better signal strength). Antenna orientation and placement can also influence SNR.
Most modern Wi-Fi network analyzers can help measure SNR and or troubleshoot low SNR related issues.