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.

Figure 1.5. The Wireless Ethernet Compatibility Alliance is a trade group that promotes 802.11b compatibility.

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.

Figure 1.6. Wi-Fi5 (802.11a) wireless network equipment.

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.