If this hasn't been tried already, you might have a WIFI survey app built into your router that can tell the strength and channel number of your neighbors' sign

If this hasn't been tried already, you might have a WIFI survey app built into your router that can tell the strength and channel number of your neighbors' signals. Or use an app on a WIFI device. You would have to log directly on to your router anyway if you decide to change its settings, you could carefully select a single (less crowded) channel for it to operate on rather than the automatic searching that normally is done. This alone might make it easier for your portable devices to stay connected, but the next step might be to set them each for the same fixed channel as your router. Remember you might need to set them back to auto when you leave the home.