Setting Up a Wireless Network
Currently, most wireless networks are based on the 802.11b standard. Although 802.11a is faster than 802.11b, it is considerably more expensive and has less
range. In addition, 802.11a and 802.11b aren’t compatible with each other because 802.11a transmits at 5 GHz and 802.11b transmits at 2.4 GHz. As a
result, 802.11a and 802.11b devices can’t receive each other’s signals.
The new standard, 802.11g, solves this problem by enabling high-speed con- nections at 2.4 GHz. As a result, 802.11g devices are compatible with existing
802.11b networks.
802.11b networks operate on the same radio frequency as many cordless phones: 2.4 GMHz. If you set up an 802.11b network in your home and you
also have a 2.4GHz cordless phone, you may find that the network and phone occasionally interfere with each other. The only way to completely avoid the
interference is to switch to a 900MHz phone or use more expensive 802.11a network components, which transmit at 5 GHz rather than 2.4 GHz.
Home on the Range
The maximum range of an 802.11b wireless device indoors is about 300 feet. This can have an interesting effect when you get a bunch of wireless comput-
ers together — such that some of them are in range of each other, but others are not. For example, suppose that Wally, Ward, and the Beaver all have wire-
less notebooks. Wally’s computer is 200 feet away from Ward’s computer, and Ward’s computer is 200 feet away from Beaver’s in the opposite direction
see Figure 10-2. In this case, Ward can access both Wally’s computer and Beaver’s computer, but Wally can access only Ward’s computer, and Beaver
can access only Ward’s computer. In other words, Wally and Beaver won’t be able to access each other’s computers, because they’re not within range of
each other. This is starting to sound suspiciously like an algebra problem. Now suppose that Wally starts walking towards Ward at 2 miles per hour,
and Beaver starts running towards Ward at 4 miles per hour . . .
Although the normal range for 802.11b is 300 feet, the range may be less in actual practice. Obstacles such as solid walls, bad weather, cordless
phones, microwave ovens, backyard nuclear reactors, and so on can all conspire together to reduce the effective range of a wireless adapter. If
you’re having trouble connecting to the network, sometimes just adjusting the antenna helps.
Also, wireless networks tend to slow down when the distance increases. 802.11b network devices claim to operate at 11Mbps, but they usually achieve
that speed only at ranges of 100 feet or less. At 300 feet, they often slow down to 1Mbps. You should also realize that when you’re at the edge of the wireless
device’s range, you’re more likely to suddenly lose your connection due to bad weather.
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