When you were planning your WLAN, you took the time to survey your home or office and choose the most effective location for your access point (AP). Because speed and efficiency of the connection drop off with distance and construction materials in your home reduce this even further, you need to make sure that your access point is located where you will get the most efficient coverage.
Mount your access point as high up on a wall as possible or on top of a high cabinet or shelf. This increases the distance that the radio signal from the access point can travel and improves reception for clients. However, if you are mounting your AP upon a wall, make sure that you can swivel the antenna to a vertical position. This is important because the antenna is the part of the AP that broadcasts the radio signal. Its position affects signal strength, range, and quality.
The signal from an omni directional antenna that comes with an AP, or one than is added afterward, tends to spread horizontally, and the signal geometry reduces on the vertical axis. This means you will reduce the signal strength if you mount your AP on a wall and leave the antenna in its original position. If your AP has internal or fixed position antennas, mount it so that it remains in a level horizontal position, as if it were sitting on a shelf.
Of course, if you replace the antenna on your access point with a new antenna you can mount the antenna on a wall or ceiling instead of mounting the entire access point. However, this depends on the type of antenna that you selected and the maximum cable length between the access point and the antenna allowed by your equipment's manufacturer. Antennas are connected to an AP with a coaxial antenna cable, and the longer the cable, the less power will reach the antenna. This can reduce radio signal strength, preventing you from getting the best performance from the antenna.
Avoid mounting an AP flush against a wall or any other solid object. The wall or object will reflect the signal back onto the AP's antenna and create interference. Most Wi-Fi device manufacturers recommend that you leave at least 6 to 8 inches clear around an AP or antenna to avoid this problem.
If you are using multiple access points to cover a large house or office space, position the access points so that their signal propagation overlaps at the edges. This ensures that clients receive a good strong signal throughout the WLAN. This is especially important if you will be roaming, or moving through the WLAN space, such as with a Wi-Fi enabled PDA or a laptop.
You don't need to worry about choosing a location close to an electrical outlet for your access point. Many newer access points support Power over Ethernet (PoE). Using a PoE adapter, you can rim current to your AP over an Ethernet "cable. This is especially useful if you are connecting the AP to a broadband router to share an Internet connection.
In this case, you will only have to connect the router to the PoE adapter with an Ethernet cable and then run an Ethernet cable from the adapter to the access point.. The access point will receive power as well as data over the Ethernet cable. This is possible because Ethernet cable has pairs of wires (4/5 and 7/8) that aren't used in data transmission. PoE equipment takes advantage of this to power Ethernet equipment. PoE adapters range in price from $30 to $60 and are available from most manufacturers of wireless gear.
Avoid mounting an access point or any antenna adjacent to an electrical outlet, conduit, or concentration of electrical lines. This includes your house's circuit breaker box or outlets in a utility room (often 220 V). While these sources of electrical radiation are normally very low frequency, around 50 HZ, I have seen them interfere with the operation of an access point (not with the signal, but with the operation of the device itself).
For best performance, keep the line-of-sight path between the AP and WLAN clients free of obstructions that might affect signal strength. Avoid placing the AP inside a cabinet or similar enclosed space.
Also, ensure that there is adequate space all around the access point to allow proper airflow to cool the unit. Make sure that the location you choose remains within the temperature and humidity ranges specified by the manufacturer. Don't place an AP where it will be in direct sunlight or adjacent to a heat source such as a furnace or heating vent.