It may be useful to try one of the more powerful WiFi routers. I had good results in a long 2500 square foot house using the E4200.
Today I would try an EA4500
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homestore.cisco.com/en-us/Router···od.htmor an E4200 if you can find them.
The other good choices I have read about are the ASUS routers »
www.asus.com/Networks/Wireless_R···/RTN66U/»
www.asus.com/Networks/Wireless_R···RTAC66U/One off the wall solution might be Open Mesh »
www.open-mesh.com/Using a OM2P
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www.open-mesh.com/index.php/prof···-us.html, you could add additional devices by plug in to electrical power outlets to get to your destination. It is strongly recommended that each device be protected by a small UPS if your electrical supply is subject to surges or sags. The network can stay up long enough for orderly shut downs if you have a power failure. I have been told that the absolute maximum is to use 3 OM2Ps, 2 hops, in any direction. You can go in multiple directions, say North, East, South, and West, but use no more than 2 additional OM2Ps to mesh with the main OM2P connected to the modem in any direction. So you could have a 9 device system. I have used other mesh technology and that advice is good from my experience.