Virtual Smartone allows you to perform spectrum analysis of all APs (Troubleshooting menu), regardless of the location of the APs. In addition to spectrum analysis, the client's 802.11 protocol behavior can be diagnosed when it cannot access the network. In addition, WIRESHARK packet streams from both the AP and the tunnels can be stored.
But why is the airtime graph so much better than just looking at the signal levels? The problem is based on the CSMA / CA algorithm, namely that the Wi-Fi device always listens to the spectrum of the slot time period and when it hears a signal higher than -85dB, it has to wait, so the network capacity depends on it. Thus, this graph shows best the time slots when the network is actually unusable. And this algorithm doesn't differentiate on whether it's your networks or your neighbors'.