There are a number of factors that can impact the range of wireless devices.

1. Keep the number of obstructions to a minimum. Each obstruction can reduce the range of a wireless device. Position the wireless devices in a manner that will minimize the amount of obstructions between them.
2. Building materials can have a large impact on your wireless signal. In an indoor environment try to position the wireless devices so that the signal passes through drywall or open doorways or space.
3. Antenna position can also have a large impact on your wireless signal. Use the adapter's site survey tool to determine the best antenna position for your wireless devices.
4. Interference from devices that produce RF noise can also impact your signal. Position your wireless devices away from Microwaves, UPS's, monitors, HAM radios, etc. Also, anything operating on the 2.4ghz frequency will cause interference. Such as 2.4ghz cordless phones or other wireless remotes operating on the 2.4ghz frequency.

If you are experiencing low, or no, signal strength consider repositioning the wireless devices, repeating the signal or using stronger antenna's to boost the signal strength.