I was reading the white papers of this technology but I did not underestand if it is only available or one can take advantage of the technology only in conjunction with WCS?
If it is available as stand alone as well, is there an interoperability with Cisco Spectrum Expert tool?
WCS is not required. the WLC displays indicators of the air quality on its own.
However the key point with cleanair is to display the interference location on a map I think, hence WCS is shown as a key component.
The WLC cannot interoperate with Spectrum Expert.
Actually the question was if the APs have interoperability with Cisco Spectrum Expert according to the white paper "Any CleanAir access point can be configured as a network-connected sensor to see the spectrum plots directly as received by the radios on the access point."
Also, which WLC models are capable to use this feature and again does it work as stand alone Access Point?
WLC software 7.0 supports the cleanair APs. So all current WLC models support it.
The cleanair APs are not available as standalone (IOS).
Yes you can integrate a cleanair AP to Spectrum Expert software to view the spectrum that the AP sees :
You need to change the AP to SOMM mode, it will reboot and rejoin WLC and is then a dedicated Spectrum Expert sensor.
The WLC will show an NSI key for that AP, you can put the ip of the AP along with NSI key to attach the AP to Spectrum Expert 4.0 or higher.