Understanding How a Wireless LAN Works

Before you can protect against a security breach of any kind, consider how a wireless network operates.

In short, a wireless local area network (WLAN) provides access to the Internet without the need for cables or other wires hooking directly into your computer. Instead, an access point (AP) connects other wireless devices to your local area network (LAN). Then high-frequency radio waves transmit the signal from the LAN to your mobile computer. Figure 5-1 shows you an overview of this process.


Figure 5-1: Overview of a wireless network.

images Wireless connections are classified by IEEE 802.11 standards, commonly known as Wi-Fi. The original IEEE 802.11 now has lots of other versions, all bearing the number 802.11 followed by a lowercase letter. Each letter represents different features or speeds of the wireless network. For example, 802.11b is a wireless capability that operates at 2.4 GHz. You find this capability built in to most laptops, which makes it possible for you to connect with public WLANs. When buying wireless equipment, be sure to match versions. Although you may still see 802.11a and 802.11b, 802.11g is now considered the most common version. In fact, most public wireless LANs (such as in coffee shops) now use 802.11g, and are continually ...

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