Ideally, you should construct your WLAN to please all your users. However, as time passes, it is likely that the network will start to slow down. This section examines some common sources of throughput deterioration in WLANs.
Cisco APs are robust, little machines. Each one can handle dozens of wireless clients. Unfortunately, it's easy to take for granted how many clients each one can handle. Each time another client associates to an AP, performance drops a little. If clients transfer large amounts of data, performance takes another hit.
How do you know if you have too many devices on your WLAN? The first step is through some preventive efforts. A solid site survey can help you understand how many APs you need to handle the load.
Another issue comes from the understanding of the radio channels available. For example, in 802.11b and 802.11g networks, there are 11 channels available in the U.S. Therefore, you might think that you can have a total of 11 networks that run in a given area. In theory, that is correct. In practice, however, it is a different story. Although there are 11 channels, you can use only three of them (channels 1, 6, and 11). This is because neighboring frequencies overlap and interfere with one another.
Of course, capacity is somewhat of a moving target. It is likely that when more clients are added to your environment, they will use more bandwidth. Therefore, it is important to watch your WLAN and know the demands placed upon it.