Noise level in the radio

Technical Discussion
1

is it possible for RTL8720DN to measure the noise level in the radio?

not the signal strength of the packet!

thanks

2

@Aleksandr_Shilov

The function you are describing seems to be direct RF measurement. To my knowledge this function is not exposed, a software defined radio might be more suitable for your needs.

3

So sorry

Other transceivers are able to show the noise level, for example TKA52, sx1280

How can we choose the best channel if we can’t evaluate it in any way?

4

@Aleksandr_Shilov

I misunderstood you, I thought you were not interested in using WiFi at all.

It is possible to do a scan on a single WiFi channel, get the number of APs broadcasting, and use that as an estimate of channel congestion.

5

So we will see interference only from WiFi, and you need to see all the interference

Some APN WiFi (Qualcomm Atheros) are able to detect the noise level

6

can you provide some examples of these noise level outputs?

7

root@TP-Link ~ # iw dev wlan0 survey dump | egrep ‘(frequency|noise)’

frequency: 2412 MHz [in use]
noise: -92 dBm
frequency: 2417 MHz
noise: -93 dBm
frequency: 2422 MHz
noise: -94 dBm
frequency: 2427 MHz
noise: -93 dBm
frequency: 2432 MHz
noise: -93 dBm
frequency: 2437 MHz
noise: -93 dBm
frequency: 2442 MHz
noise: -62 dBm
frequency: 2447 MHz
noise: -68 dBm
frequency: 2452 MHz
noise: -91 dBm
frequency: 2457 MHz
noise: -92 dBm
frequency: 2462 MHz
noise: -95 dBm
frequency: 2467 MHz
noise: -95 dBm
frequency: 2472 MHz
noise: -94 dBm

8

@Aleksandr_Shilov

Unfortunately, this feature is not available, as least in the publicly available SDK.
A commercial customer or an NDA might be able to request for this feature.