Placement of your router.
No matter what type of WiFi or wireless router you have:
802.11a, 802.11b, or 802.llg, or a combination, the placement of
the device may have more impact on your signal than you know.
You want your router in a central location. If possible, place
it near the middle of the home, both on the floorplan and
vertical level. It's important to keep your router away from
walls, and especially metal objects. These things will
interefere with the signal, making it weaker. A weaker signal
may result in slow connections.