This article discusses positioning antennas, and avoiding obstacles.  

Consider the following:

• Placing antennas in a good location, at a good angle.
• Avoiding objects that block signals.
• Reducing the interference from other devices that transmit radio waves.

Before starting adjustment, make sure that antennas and cables are securely fastened!

If your network has several wireless devices, before you move things, decide which wireless devices are transmitting the heaviest load. NETGEAR products have automatic data rate fallback, which allows increased distances without losing connectivity. It also means that devices that are further away are inherently slower. Therefore, identify the more important links in your network are those where the traffic is high, and the distances are great. Optimize these first. The ones that are least important are links that have little, occasional traffic, and which have a strong signal strength.

Picking Good Locations for Antennas

• Antennas should be in line-of-sight of one another, where possible. Put your face next to one antenna, to find whether the other is visible.
• Place high, and clear of obstructions as practical.
• Keep antennas 2 feet from metal fixtures such as sprinklers, pipes, metal ceiling, reinforced concrete, metal partitions. (However, antennas on roofs do not necessarily give the best results. )
• Keep away from large amounts of water such as fish tanks and water coolers.
• Antennas transmit weakly at the base, where they connect. So don't expect good reception from the bottom of a router or access point.
• For multi-story buildings, placing antennas at 45 degrees (diagonally) or 0 degrees (straight out parallel to the floor) may be most effective.

Reducing Interference

Avoid windows unless communicating between buildings. Windows let in interference from outside.

Place antennas away from various electromagnetic noise sources, especially those in the 2400 – 2500 MHz frequency band.

Common noise-creating sources are:

• Computers and fax machines-- Place wireless equipment no closer than 1 foot.
• Copying machines, elevators and cell phones --No closer than 6 feet.
• Microwave ovens --No closer than 10 feet.