I have a couple of devices that appear unable to see my router's WiFi signal when its put up on channel 12, 13, or 14. Some newer devices work fine without any problems. Others cannot see the signal. I can confirm the non-working devices can't see my wireless signal at all — If I use inSSIDer and look at the "2.4 GHz channels" tab which shows the channel layout of my WiFi channel vs my neighbours', channels 12-14 will show nothing on the non-working devices while the working devices show my WiFi signal nice and strong.
When searching on Google "WiFi channels 12-14" I've also noticed several posts about channels 12-14 not working for certain people another post about 12-14 being added to newer versions of android.
My suspicion is that channels 12-14 were added in 802.11n but some of 802.11n draft devices don't support those channels. If that's the case, however, I'm surprised that my router would even choose these channels during auto selection since I set it to be compatible with 802.11b/g/n devices.
Best Answer
Channel 14 has been there since 802.11b, it is the least overhang of any wireless channel which means that by selecting it, there is a low chance of interference from other devices.
However, due to wireless licensing laws, only Japan allows channel 14, in addition, channels 12&13 are not allowed in the USA. Apart from this, most countries allow 1-13.
If your router allows you to select one of these upper channels, it is most likely due to either selecting the wrong region on your router or you simply have an unlocked one.
As for devices, I am not entirely sure what is going on here - I would assume that you typed in the region on some / they are location aware and block out channels they are not allowed to connect on, and the newer devices simply see the channel of the router and as someone must of set it, they think it is ok to connect!
Wikipedia has a good article here