Building Wireless Community Networks, Second Edition

Chapter 3. Network Layout

A common mistake that peoplemake when trying to design somethingcompletely foolproof is to underestimatethe ingenuity of complete fools.

—Douglas Adams

As we saw in Chapter 2, there is an astounding variety of wireless networking equipment available on the consumer market today. While the champion technology of wireless community networks is still 802.11b, simply choosing equipment that is “Wi-Fi” compliant won’t necessarily guarantee a successful network project.

While equipment features, capabilities, and prices tend to change drastically in a short time, the essential network functions that they perform are still very straightforward. Let’s look at what your devices need to provide in order to fulfill your wireless networking dreams.

Layer 1 (Physical) Connectivity

Before any two components of your network can talk to each other, they must share a common physical medium through which they communicate. In the wired world, this is obvious; you would never try to connect a copper CAT5 cable to a piece of fiber and expect it all to “just work.”

In the wireless world, every device from your network to your cordless phone to your garage door opener must share the same physical medium: electromagnetic waves radiating through the air. It is possible for all of these devices to communicate without interfering with each other because they can be made sensitive to a particular portion of the vast electromagnetic spectrum. This is analogous to tuning channels on a radio ...