Wireless Hacks

802.11b: The De Facto Standard

Many people continue to use 802.11b, the protocol of the Wi-Fi revolution.

Throughout this book, I mainly discuss 802.11b (also known as Wi-Fi, but then, so is 802.11a). It is the de facto wireless networking standard of the last few years, and for good reason. It offers excellent range and respectable throughput. (While the radio can send frames at up to 11 Mbps, protocol overhead puts the data rate at 5 to 6 Mbps, which is about on par with 10baseT-wired Ethernet.) It operates using DSSS at 2.4 GHz, and automatically selects the best data rate (either 1, 2, 5.5 or 11 Mbps), depending on available signal strength. Its greatest advantage at this point is its ubiquity: millions of 802.11b devices have shipped, and the cost of client and access point gear is not only phenomenally low, but also ships embedded in many laptop and handheld devices. Since it can move data at rates much faster than the average Internet connection, it is widely regarded as “good enough” for general use.

Pros

• Near universal ubiquity in standard consumer devices, add-on cards, and APs.

• Extreme popularity and pressure from 802.11a/g has led to massively discounted hardware. Cards less than $40 and APs less than $100 are common as of this writing.

• 802.11b “hot spots” are available at many coffee shops, restaurants, public parks, libraries, and airports, further increasing its popularity.

• With many people using and experimenting with it, 802.11b is arguably the most hackable (and customizable) ...