In this case and the fact we only have 11 WiFi channels it may be time to consider moving to a router with 5GHz channel support.

I'll keep it short since it's like shouting in a crowded room. It's going to be slow and painful.

http://en.wikipedia.org/wiki/List_of_WLAN_channels shows that in NA we have all of 3 non-overlapping channels. And with 11 WiFi networks, it's going to be a mess. I do not expect this to work well.

So this leads me to think it's time to consider the 5GHz WiFi solutions.
Bob