Intelligent Wi-fi Channel Selection

I wrote this with after a brief conversation with BT's @btcare twitter account during which I didn't get very far...

My home router is a BT Homehub 3, which is promoted using inaccurate language to describe the "BT internet signal" provided by it, allegedly more reliable than other ISP's "internet signals". Leaving aside the modicum of bullshit generated by the marketing department, The feature whereby the router intelligently chooses a wi-fi channel and monitors for changes in interference levels is a good idea, however I would like to see more user interaction with this feature.

Before I got this router, I used the excellent Wifi Analyzer app on my Android smartphone to choose a channel without excessive competing signals. Note at this point that a single channel is wider than the distance between the centres of two channels, with the signal strength dropping away further from the nominal frequency. The problem with this approach is that the graph produced by the App is calculated from information provided by the network stack, so interference from non-WiFi signals cannot be shown.

I theorise that as the BT advert describes "competing signals", it uses raw frequency analysis to calculate where the least interference would be experienced. There is no feedback on the data used to make the decision or information on what the interference is on the automatically chosen channel. As the channel chosen by my router didn't seem to correspond with the emptiest frequency range I could see, there must be non-wifi interference somewhere in the gap.

What I would appreciate is if the Homehub 3 admin screen showed a graph to help identify the sources of interference. I would then be able to relocate the router or the offending source to reduce or eliminate the impact.

There have been reports recently of high-speed Powerline Ethernet adaptors causing interference which conflicts with DAB signals. As a general rule, we should seek to eliminate these rogue signals rather than resorting to workarounds at the first opportunity.