Wireless Hacks

Hack 3 802.11b: 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) wireless protocol on the planet.

Cons

• The 11 Mbps data rate of 802.11b will never get any faster, and is already surpassed by 802.11a and 802.11g.

• 802.11b's channel scheme allows only for three nonoverlapping channels, making for considerable contention in the 2.4 GHz ISM band.

• Standard 802.11b security features have been revealed to be less than effective. See [Hack #87] and all of Chapter 7 for details.

Recommendation

While it is impossible to forecast the fickle weather patterns of the consumer marketplace, it is very likely that 802.11b has at least a few years left in it. Millions of devices have shipped, making it the most popular wireless networking protocol on the planet. Ironically, it will probably get a life extension from its competitor 802.11g, as the newer 802.11g equipment will work with existing 802.11b access points. This makes upgrades less of an immediate issue, and if there's anything that network administrators hate, it's upgrading the critical network devices.

Considering that average Internet speeds are still much slower than 802.11b, it is likely that 802.11b will be used as a mechanism for providing Internet access for some time yet. Backbone links and corporate networks may have an immediate need for the increased bandwidth of 802.11a and 802.11g, but for the average Internet user, 802.11b provides sufficient speed and a very simple mechanism for accessing networks. Even after three years of explosive growth, 802.11b continues to enjoy a lively general acceptance.