Some administrators might have you believe that setting up wireless access points for optimal coverage is an exact science. Let me first dispel that notion. Selecting the best spot for your wireless access points can be a little like trying to use an old radio dial to tune in a distant station. At best, it's an art that you become better at with experience. For those who have not mastered this art, this first of a two-part series will guide you through the information necessary to plan your wireless access point placement.
Building diagram
If your coverage area is extremely large, possibly consisting of thousands of square feet, a scaled building diagram is extremely important in the initial planning process. Hopefully, you can acquire a copy of the diagram from the building contractor or architect. If not, you may need to create one yourself.
You can do this by simply using a pencil, paper, ruler, and measuring tape, but if I had my guess, I'd say you would rather use a program such as Visio. The drawing does not have to be in great detail. The key is to have an accurate scale and a view of square footage, complete with walls, windows, and doors. This diagram will essentially turn into the project plan for your wireless access point implementation. I have provided a sample Visio diagram you can download. (For those who don't have Visio, the download includes a snapshot of the drawing you can view.)
Coverage area
An access point's transmission radius is called a cell. Overlapping cells using multiple access points creates seamless access as you roam from one cell to another. In a setting with overlapping cells, mobile devices and access points frequently check the strength and quality of transmission, handing off users to the access point with the strongest and highest quality signal. For that reason, it is important to not have roaming areas that extend outside the coverage of any given cell.
The size of your cell will depend largely on two factors: the type of 802.11 used and possible obstacles and interference that the radio frequency (RF) signal may encounter. We'll discuss planning for obstacles and interference later in the article. You've probably read numerous articles detailing the difference between the A, B, and G variations of 802.11.
You have likely chosen a standard that you believe will work best for your budget and network requirements. If so, use your building diagram to show your anticipated cell coverage. When creating your cells, use a circumference slightly less than the maximum range for your standard, ignoring (for now) possible obstacles and interference. For example, if planning for an 802.11b implementation, I might use a range of 250 feet instead of the reported 300 feet.
Number and placement of clients
Theoretically, hundreds of clients can associate to a single wireless access point. This is typically not a good idea, since your access point will more than likely be connected to a 100-MB Ethernet cable. Depending on the network performance required by your end users, bringing the number of clients down to 15 or 20 will yield better network response (20 users for a 100-MB connection provides 5 MB each).
You can adjust this number up or down based on the equipment you select and on your configuration. Simply note on your building diagram the number of clients you expect to associate in a cell. At this point, you may need to adjust your diagram to the number of cells required to provide coverage for heavily occupied areas, such as cubicle clusters and conference rooms.
dude, where is the network diagram.