I had a wireless connection to my observatory for a couple of months after moving to this new property, but I had the inconvenient problem that if I closed the door of the observatory (roof open or not) the wireless connection would drop out - I think it was close to dropping out anyway, and the observatory is colourbond metal.
So I've reverted to a 20m CAT5 cable.
Sure is handy having internet available at your observing site - google for NGC images, use sites like heavens-above, keep in touch on the forums, etc.
Roger.