This is a book about two revolutions: free software and free wireless networking.
The first revolution was born in 1991, when a lone Finnish hacker named Linus Torvalds used the GNU Project’s free C compiler to build Linux, a free Unix-like operating system kernel. One of the hallmarks of this kernel was its release under the GNU Public License, which guaranteed that anyone would be able to customize and improve the Linux kernel to suit their computing needs, and that those improvements would be shared with the other users of the Linux kernel.
Today, Linus Torvalds is virtually a household name, and his brainchild has gone on to star in millions of personal computers, web servers, supercomputing clusters, embedded devices, mainframes, and more. Bolstered by the success of Linux and its BSD-derived cousins, a globe-spanning Free Software movement has taken hold, spawning thousands of community-supported projects, and fundamentally altering how software is made and distributed in the 21st century.
Although the second revolution has been lurking in the background for years, it received a major boost in 1999 from the publication of the IEEE 802.11b standard, a specification for wireless data networking that made use of the 2.4 GHz microwave band, which had long been considered “junk” spectrum in the U.S. As consumer 802.11b devices hit the market, more and more people were able to use computers and access the network from an ever widening array of locales—living room couches, conference rooms, coffee shops, and even sunny park benches.
Meanwhile, ordinary individuals were discovering that, using nothing more than off-the-shelf radio hardware and the right antennas, they could build wide-area—and even metropolitan-area—IP network infrastructure for the first time ever, without the need for costly or restrictive government licenses. The result has been a quantum leap in ubiquitous computing, with millions of 802.11 devices in use across the world. The newer IEEE 802.11a and 802.11g standards are now implemented to offer even more possibilities for free data networking.
The operative word at the heart of both of these revolutions is the word “free,” but the concept it refers to is freedom. Trivially, they offer the opportunity to download an operating system free of charge or perhaps to escape the tyranny of Ethernet cables. But on a deeper level, these revolutions promise basic freedoms of action and of speech—the freedom to employ your computing hardware to communicate with others as you see fit, and not merely as commercial interests dictate. Unlike many of the technical choices available to you today, Linux and 802.11 serve to enhance your freedom and expand your options, rather than to constrain them.
As the title implies, Linux Unwired guides you through configuring and using Linux with the 802.11 protocols, as well as Bluetooth, IR, cellular data networking, and GPS. Ultimately, though, this is a book about freedom. This book shows you how to harness the combined power of these technologies to expand your options and your technical horizons.
Welcome to the revolution(s). May you do good work!
—Schuyler Erle February, 2004