IEEE 802.11b has another name that you’ll likely see on product advertisements, literature, or boxes in stores: Wi-Fi, which stands for Wireless Fidelity. (Kinda like that cutting-edge Hi-Fi stereo from the ’60s and ’70s, where Hi-Fi stands for High Fidelity.) Most folks proclaim Wi-Fi as only 802.11b, but Apple has adopted the term to describe all flavors of wireless Ethernet.
Don’t be confused when you see “Wi-Fi” within Lion’s Network pane in System Preferences. To Apple, any wireless Ethernet — including the much faster 802.11n that’s standard equipment on MacBooks today — is Wi-Fi hardware.
802.11b was the first version of wireless Ethernet. This version of wireless runs at speeds up to 11 million bits per second, or 11 Mbps, which is roughly the equivalent of 10 Mbps wired Ethernet. The actual speed at which the data is transferred depends on things like signal strength and quality.
When the conditions are such that your signal strength or quality is decreased — such as an inconvenient concrete wall or a circuit breaker box between you and your AirPort Base Station — you might find that your wireless connection changes down to 5.5 Mbps, 2 Mbps, or even as slow as 1 Mbps.
802.11b has been largely supplanted in current wireless networking, and almost all the equipment you can buy today is either 802.11g or 802.11n. However, if you’re working with older computers and existing 802.11b hardware, any new networking equipment you buy today should be backward compatible with 802.11b.
Apple’s AirPort network cards and standard-issue AirPort Base Station used 802.11b. In fact, it’s time for Mac owners to swell with pride yet again: Apple was the first computer company to ship 802.11b hardware. (Back then, in 1999, it was the original AirPort Base Station.) Now, of course, Apple has raised the bar with AirPort Extreme and the AirPort Express mobile Base Station.
In theory, 802.11b network cards have the ability to communicate with other wireless Ethernet devices and WAPs that are up to 1,000 feet away. Having said that, realize that 1,000 feet is a generous estimate when outdoors on a clear day with no wind blowing. (You’re more likely to see a wildebeest wearing a hula skirt in your living room than see that kind of distance indoors.)
In reality, when you set up your wireless network, things such as walls — especially concrete walls, as in basements — and areas with lots of electrical wiring decrease the distance that you can cover. If you use a WAP, plan on no more than 150 feet between wireless computers and the WAP. However, your mileage might vary.
That 11 Mbps bandwidth is shared between all computers using it. Collisions can also occur if more than one computer tries to communicate at the same time. If you have a lot of people on your wireless network, the network will get noticeably slower because of increased collisions.
Remember that the total bandwidth is shared among the computers on the wireless network. This applies not only to 802.11b but also to the 802.11a and the 802.11g standards.
One last thing about 802.11b networking: It uses the 2.4 GHz frequency range. (It actually uses 11 different channels, but they’re all around the 2.4 GHz range.) If you’re using a 2.4 GHz cordless phone or even a microwave, using either device can definitely interfere with or even shut down your wireless network.
Keep this in mind when you buy your next phone or wonder why your file transfers stop when you’re communing with Orville Redenbacher in the microwave.
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Source:http://www.dummies.com/how-to/content/basic-wifi-80211b-on-your-macbook.html
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