Obstacles
As you are probably aware, RF is susceptible to signal loss resulting from the materials it has to pass through. This is known as attenuation. Typical office obstacles such as doors, windows, walls, and furniture result in attenuation.
For example, if a large bookshelf filled with books sits between two offices, you should expect some RF loss. This attenuation is in addition to the path loss resulting from simple range traveled between endpoints.
Again, use your building diagram to make appropriate annotations concerning the types of obstacles you expect to encounter. Start thinking about the minor changes required of your wireless access point placement to accommodate the anticipated attenuation caused by certain obstacles.
Interference
RF interference involves the presence of unwanted, interfering RF signals that disrupt normal system operations. Because of the 802.11 medium access protocol, an interfering RF signal of sufficient amplitude and frequency can appear as a bogus 802.11 station transmitting a packet. This causes legitimate 802.11 stations to wait for indefinite periods of time until the interfering signal goes away.
Depending on your environment, this may or may not be a problem during the planning stage. For example, healthcare environments are more susceptible to RF interference due to the numerous electronic medical devices in use. For 802.11a and 802.11g wireless LANs, microwave ovens, wireless phones, Bluetooth-enabled devices, and other wireless LANs can cause problems. The use of a spectrum analyzer (discussed in my next article) will provide a detailed report of possible interference.
However, initially, a simple walk-through in which you look around and note possible devices that may cause interference is sufficient. Also, talk to people within the facility and learn about other RF devices that might be in use. Either make plans to move these devices away from desired converge areas or plan on changes to your access point placement and/or configuration to counteract their interference. Don't forget to make a note of these on your diagram.
Mounting considerations
Now that you have a general idea of where you may place your access points, you should start analysing the various mounting considerations you may face. Will you be mounting the access point in the ceiling or attached to a column or maybe over a door? Consider your power and cabling needs when choosing a mounting location.
If you are fortunate enough to have inline power coming from your CAT5 cable, you will simply require an Ethernet connection to your access point. If this is not the case, however, you may have to look at placing the unit close to a power outlet. Of course, this can limit your choice for optimal RF coverage. You may need to have an electrician wire some additional outlets in places where you need access points.
Environmental operability should be considered as well. These factors include temperature, moisture, and plenum requirements. For instance, your building may allow only plenum-rated equipment to be mounted in the ceiling, forcing you to either purchase plenum-rated access points or mount the access points somewhere below the ceiling.
Finally, consider the aesthetic aspect. If you can't hide your access points, at least ensure that they complement or blend into their surroundings and do not look unprofessional--especially in an office setting where customers frequently come calling.
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dude, where is the network diagram.