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Thursday, Jul 9, 2009
Call them hackers of the last computing frontier: The GNU Radio coders believe that any device with a chip should be able to do, well, anything.
Dec 18, 2002 | It's the vision that elicited a beatific smile from Alan Turing, a Bela Lugosi-like cackle from John von Neumann, and a cannabis-tinged giggle from 1970s-era PC creators: Imagine a universal machine, a computation device capable of mimicking the functionality of any other machine.
OK, now imagine the looks of terror on the faces of existing machine makers. Imagine if the only thing stopping your handheld PDA from simultaneously being a GPS receiver, phone, radio or miniature TV was your willingness to download and install some free software program.
For Eric Blossom, founder of the GNU Radio project, the vision plays itself over and over again, like a Möbius film strip. An electrical engineer by trade, Blossom knows better than most the thin barriers that separate one person's garage-door opener from another person's global positioning satellite receiver. He also knows the proprietary barriers that hinder technological innovation. Rather than curse those walls, Blossom has decided to gut the floor plan entirely with the help of free software. Sony, Philips and Nokia be damned.
"We're pretty much turning all hardware problems into software problems," Blossom says. "We want to facilitate evolution in the radio arena."
Turning hardware problems into software problems is, of course, an old trick. Since the days of Univac, computer programmers have written software to mimic the functionality of everything from mechanical calculators to videocassette recorders. Wireless communication devices -- radios, cellphones, televisions, etc. -- are merely the latest target, especially now that most carry sophisticated microprocessors. With device manufacturers jealously guarding hardware specs, however, the challenge to an independent programmer is stiff. To get the GNU Radio project started, Blossom has set his sights on a simple target: PC-based AM/FM radio.
"Radio has always been this dedicated hardware universe, a closed system really," says Blossom. In other words, it was just the kind of private party that free software was meant to crash. "Besides, we had to prove we could deliver on the basic idea," Blossom says.
So far, the GNU Radio project has made good on its promise. Blossom and development partner Matt Ettus have developed a software program that can make a PC receive two radio stations simultaneously. The only additional hardware components needed are a low-cost R.F. tuner, to pull the radio waves out of the air, and an analog-to-digital converter to convert each signal into digital samples.
Playing two stations at once may seem like a geeky pastime, but GNU Radio's goals get more ambitious over the long term. At its most basic level, GNU Radio is an attempt to do for radio-software developers what the original GNU Project did for Unix developers -- that is, provide a common set of nonproprietary tools that can be ported from one device to the next.
Step back a little, however, and GNU Radio changes shape. Viewed against the backdrop of digital "convergence," the marketing term for pouring data and communications functionality into a single device, GNU Radio becomes a steppingstone to the ultimate hybrid device: a handheld PC that can be converted into a walkie-talkie one minute and an HDTV the next.
"We're bringing the free-software ethic to radio," Blossom says. "Who knows what's going to come out of it?"
But that's not all: Even more intriguing is GNU Radio's political component. A look at recent Hollywood-backed legislation reveals a growing antipathy on the part of content providers toward modifiable consumer technology. Such laws, if passed, would limit the ability of hardware manufacturers to consort with software programs that let a user turn his or her home PC into a digital television or TiVo-style recorder.
Viewed against this backdrop, GNU Radio is a hacker's version of the preemptive strike. Rather than wait for Washington to set limits, the project is working to undermine existing device barriers.
"It shows pretty starkly what's at stake: that computer technology can empower people to do new and interesting things," says Edward Felten, a Princeton computer science professor whose Web site, Freedom To Tinker, has been offering periodic updates on the project. "And yet it is the very power and adaptability of that technology that people are most afraid of."
