Implementing Wi-Fi

To install and configure a Wi-Fi network requires a number of discrete steps. You should start with a site survey to determine any obstacles you need to overcome. All wireless networks require clients, so that's your next step. That's all the hardware you'll need for an ad-hoc network, but an infrastructure network takes a few more pieces, such as installing an access point and configuring both the access point and clients. Unless you have a small, personal network, you need to look at ways to extend the network so you have the coverage you want. Finally, you should put your network to the test, verifying that it works as you intended.

Site Survey

A site survey enables you to determine any obstacles to creating the wireless network you want. You should discover any other wireless networks in the area and create a drawing with interference sources clearly marked. This enables you to get the right kind of hardware you need to employ and makes it possible to get the proper network coverage.

What Wireless Is Already There?

Discovering any wireless network signals other than your own in your space enables you to set both the SSID and channel to avoid networks that overlap. Wireless networks send out radio signals along the 2.4- or 5-GHz band and use channels 1-11. If you have an 802.11g WAP and clients, for example, those devices would use the 2.4-GHz band and could be set to channel 1. A quick scan of the Wi-Fi networks in my neighborhood, for instance, shows five Wi-Fi networks, two with the SSID of Linksys, three using Channel 6, and two with both distinctive nondefault names and channels. If my network SSID were set to Linksys, which WAP have I used when I log onto the Linksys network?

Even if you change the SSID, why run on the same channel as other Wi-Fi networks? You'll see better performance if you're on a unique channel.

Interference Sources

It might seem like overkill in a small network, but any network beyond a simple ad-hoc one should have a sketched-out site survey with any potential interference sources clearly marked. Refrigerators, reinforced walls, metal plumbing, microwave ovens; all of these can create horrible dead spots where your network radio wave can't easily penetrate. With a difficult or high-interference area, you might need to move up to 802.11n equipment with three or four antennae just to get the kind of coverage you want. Or you might need to plan a multiple WAP network to wipe out the dead zones. A proper site survey gives you the first tool for implementing a network that works.