Wireless Speed in the Real World
As we discuss various wireless networking technologies, we
invariably discuss speed. All the technologies have a maximum speed in which
they can transfer data. The data transfer rate is often referred to as
bandwidth, or throughput. For instance, Fast Ethernet, a wired technology, can
transfer data over cables at up to 100 megabits per second. 802.11a and 802.11g,
the fastest current wireless standards, top out at 54 megabits per second. And
802.11b, the most popular standard, transfers data at 11 megabits per second.
These speeds are the maximum rate at which data can travel. In the real world,
however, wireless networking equipment is likely to offer something on the order
of half these speeds.
Compatibility among Manufacturers
As we mentioned earlier, this book concentrates on Wi-Fi (also
known as 802.11b) wireless networking equipment. You can purchase 802.11b
wireless networking equipment from different manufacturers, and it should work
together. I say should because a few 802.11b
devices are not compatible with the majority of 802.11b equipment. To ensure
compatibility among manufacturers look for the Wi-Fi logo, which is displayed on
equipment that has met the requirement set up by the Wireless Ethernet
Compatibility Alliance (Figure 1.5). You
can find out more information about the wireless standard at www.wi-fi.com.
Importantly, 802.11b does not work with a newer, faster, and
more expensive networking standard called Wi-Fi5 (or 802.11a).
Wi-Fi5 is, as you might have guessed, about five times as fast as Wi-Fi
equipment. Wi-Fi5 can carry data at a maximum of 54 megabits per second, where
Wi-Fi equipment has a maximum speed of 11 megabits per second. Figure 1.6 shows a Wi-Fi5 access point from Proxim. Even
newer is 802.11g, which offers the same speeds as 802.11a and is thankfully,
compatible with the older and more widely used 802.11b.
As seen in Figure 1.6,
Wi-Fi5 (802.11a) equipment, such as this access point from Proxim, works at up
to five times the speed of Wi-Fi (802.11b) wireless networking equipment.
All of the 802.11 standards offer plenty of speed for surfing
the Web, printing documents, and listening to MP3 files. The bottom line is that
you should make sure that your products are compatible (by asking the seller or
vendor or by looking for the Wi-Fi logo). You'll then be able to purchase
equipment from any vendor you choose.
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