The Wireless manufactures are relatively careful. They usually claim a solid distance when they put the equipment on two towers with no Visual and electrical interference.
Indoors it is any body guess, in part, because our environment includes a lot of transmission obstructions. (Electrical Screening).
Most of Houses has Insulation with Aluminum Foil cover, metal screens, cordless telephones, microwave etc. Out door trees, buildings, electrical lines etc.
As a result, Indoor residing entry level Wireless Instruments end up with a typical range of 30? ?70?. Out door with an unobstructed view, you can get a little more.
You have a chance if you use the two-second level Wireless Instruments. One at the source, and one in your house.
Combine it with two Hi Gain Antennae, and install them high on walls that face the direction of each house.
Example for the hardware:
EZ Connect Wireless Access Point/Bridge.
Buy.com price: : $435.95
And equip it with Hi gain Antenna.
EZ Connect Wireless High Gain Antenna Kit.
Buy.com price: $213.95