Spectral analysis tools

Dear friends,

I know that ou probably discussed this before.
On a device with two radios, I would like to be able to use the second radio to make spectral analysis.

Dedicated or professional hardware is quite expensive, like Wi-Spy.
Horst seems very nice : http://br1.einfach.org/tech/horst.
Horst is supported by OpenWRT, but could not find it in LEDE.

Dp you plan to add Horst?
What other tools do you recommend for spectral analysis?

Kind regards,

Not quite the answer you were looking for, but I'm very fond of two programs:

  • Wi-Fi Analyzer by farproc - Free Android app that shows Wi-Fi activity in the neighborhood
  • WiFi Explorer for OSX (macOS) A small number of bucks on the Apple store

I don't have a good recommendation for Windows - do others have suggestions?

inSSIDer. It was free at version 3, but is now $29 for v4 with a 30 day trial. If you dig around you can still find links to download v3. I love it and paid for v4.


Some devices support spectral analysis, others don't.
Presently, (some or all) Atheros 802.11n chipsets supported by ath9 driver support spectral analysis.

I would prefer a traditional spectral analysis, like this one:

Here is a sample spectrum analysis done in Gqrx.
Not the correct band, but it shows how spectrum is displayed.

Ubiquity sells a USB key for spectral analysis, but it only supports 2.4Ghz networks:
Ubiquiti-Airview9 is available for 40 USD, more than 100 EUR in France.

I connected to my WDR3600 and CP210. Both are based on the ath9 chipset. So they should support spectral analysis. Using a CP510 could be very interesting as it could allow to carry the antenna and use it as a portable spectral analyser.

ath9 configuration is explained on this page:

And running
ls /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan_ctl
shows that both WDE3600 and CPE210 support spectral analysis.

Let's focus on what can be done.
I will try to install Horst.

DD-WRT has included some kind of basic spectral analysis for ath9k units. For sure wdr4900 & Archer C5v1 / C7v2

Though only one GUI option for configuration.

Reading TP-Link documentation:
CPE 510 and CPE210 have a built-in Spectrum Analyzer.
TP-Link other outdoor devices don't have a built-in analyser.
A sample spectrum is displayed (in kind of a "commercial" presentation).

So spectrum analysis can be done using an AP and requires no additional hardware.

Ubiquity Devices (Nanostation M2, M5m M5loco) also have spectral analysis tool inside stock firmware. you can use it to find video transmissions, the directional antenna is very important for these purposes..

for wifi-problems, f.i. with your own clients i also recommend HORST