The networking industry began to grow in the 1980s and exploded in the 1990s with the culmination of affordable personal computers and growing popularity of the Internet and the World Wide Web. Already on an incredible trajectory in the late 1990s, the industry benefited from another incredible boost in the form of wireless networking—and there was another even bigger boost to come.
This "second wave" of networking was initially made possible as a result of a groundbreaking decision by the U.S. regulatory body in charge of telecommunication rules, the Federal Communications Commission (FCC)—the opening of several bands (contiguous ranges of radio frequencies) of the radio spectrum for unlicensed use in 1985. This was a big change, given that apart from ham radio, which was valued as a nationwide emergency communication system, the radio spectrum was a tightly controlled government asset that required licensed approval for use. This visionary decision (not a phrase often associated with a government regulatory body) had a profound effect on networking as well as on several other industries.
The frequency bands in question—900 MHz, 2.4 GHz, and 5.8GHz—had previously been reserved for things such as microwave ovens, among others. The FCC's decision allowed anyone to use these bands (or any company to build a product that used these bands) as long as they managed interference with other devices. This made products such as cordless phones and remote-controlled ceiling fans—and, soon, wireless networks—possible.
At first glance, it's hard to see exactly why wireless had such a huge impact. At the time, wireless performance was not that great. In fact, compared to a hard-wired Ethernet connection, it was pretty lousy. As it turned out, though, users were far more interested in convenience than performance—at least initially. Before the advent of WLAN, if you wanted to connect to a network, you had to go to where the computer was tethered to an Ethernet port. Or, if you had a laptop (these were also becoming cheaper), you had to go where the connection port was. This may not seem like a big deal, but "going to the computer" meant leaving where you were and dropping what you were doing.
Wireless networking changed all that. With WLAN, you brought your computer to where you wanted to be and connected to the network from there. The ability to connect in a meeting room or on your couch in front the TV far outweighed the slower connection speed, especially since there were very few high-speed network applications at the time. (Streaming media meant waiting 5 or 10 minutes to download one song, for example.) This convenience factor created a massive surge in WLAN usage. In response, manufacturers poured millions into research and development (R&D), which improved performance, which in turn attracted more users.
The first generation of WLAN operated at about 500 kilobits per second (Kbps) on an unlicensed frequency band. In this case, "unlicensed" meant that anyone could use it. It was not restricted or reserved for commercial or government use as long as the transmission power was kept low. The second generation boosted performance to 2 megabits per second (Mbps), a 400-percent improvement. (Note that the term "generation" is used here in the generic sense rather than as a name, as it is when describing mobile network technology.)
In 1990, the IEEE established a working group to create a standard for WLANs. In 1997, the IEEE 802.11 standard was ratified, specifying the use of the 2.4 GHz band with data rates of up to 2 Gbps. Different versions of the 802.11 standard were developed in subsequent years and were noted via extensions such as a, b, g, and n. Notationally, this would appear as "802.11b," for example.
Taken from : Wireless and Mobile Device Security
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