Q: I want to set up two different wireless networks in the same room. Each one has a different Service Set Identifier (SSID). I am using two Symbol 4121 access points for one network, set to channels 1 and 11. Two Linksys access points for the second network are set at channels 4 and 8. Again, both networks use a different SSID but both use the same WEP key. Is this a workable situation? Is there a better way? - Gil B.

The wizards gaze into their crystal ball and respond:

Leonid Kalika, Strix Systems

This is definitely not the most effective way to set up different wireless networks in the same physical location. First, the fact that both sets of access points are using the same WEP key is somewhat irrelevant, aside from the fact that should someone get the key, they will have access into both networks. Secondly, WEP is not a particularly effective means of securing a network. Unless you are running voice clients and don’t have any option, the first thing I would suggest is you move to a more advanced security scheme.

You have made a good effort at keeping the access points from interfering with each other by selecting the channels you did. However, there is a better way for you to create multiple wireless networks in the same physical location. Many access points can create virtual wireless networks using the same equipment. For example, you can install only two access points, and configure them to broadcast multiple SSIDs, or even multiple Basic SSIDs (BSSID), so it will appear that there are multiple wireless networks installed, when in fact there is only one. Then the access points can do the work for you and auto-select channels to minimize interference.

Typically, vendors that offer these types of solutions will let you set up different security schemes by SSID and virtual network, so one virtual network might be using WEP for encryption, while the second virtual network might use WPA.

Finally, for vendors that offer the more advanced BSSID option, you can even create separate access control lists per BSSID since they will each appear to have their own MAC address.

Jason Luther, Airwave

This doesn't sound like an optimal solution. Within the unlicensed spectrum used by your Wi-Fi devices, there are only three channels that do not overlap with other channels:  1, 6, and 11.  In your example, your access points on channels 1, 4, 8, and 11 are going to interfere with one another and affect performance. You're better off using channels 1, 6, and 11.