If your WLAN performance is suffering from interference, you may get better results by selecting another channel. If your WAP has two antennas, you may be able to select one antenna or let the WAP use diversity to automatically select the antenna with the best signal. On some APs, you can adjust transmission rate, transmit power, or "distance" between WAPs. These tuning "knobs" differ by product, so take a good look at your WAP's config interface and admin guide. Don't forget to consider tuning options on WLAN client(s) as well.
I assume that you have already tried to place your WAP in the best possible location in your house. Try to avoid barriers like metal doors, I-beams, and reinforced concrete walls. Mounting a WAP with integrated antennas on the ceiling or higher up on a wall, above furniture and other obstructions, can also help. Try moving client desktops or laptops with integrated antennas away from adjacent walls, air vents, and pieces of heavy furniture.
If your WAP accepts an external antenna, you may find that a different kind of antenna or more central placement of an external antenna will boost your signal. Trevor Marshal wrote a nice article that describes different types of antennas for BYTE.com. RF amplifiers can be placed between your WAP and external antenna to compensate for signal loss over very long cable runs.
This was first published in October 2002