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[March 10, 2006]

Welcome to the open source cellphone

(New Scientist Via Thomson Dialog NewsEdge)Would you pay $400 for a handful of microchips and, armed with only a circuit diagram, build your own cellphone? With elegant, powerful phones already on sale for a fraction of the price it's not something that will appeal to many.

Yet despite the cost and inconvenience, a growing group of techies are attempting to build the first practical home-made cellphones. They hope to spark greater innovation in cellphone design and, more crucially, in the software that makes the phones work. Their aim is to develop a critical mass of free software that will lead to a flowering of new cellphone applications. Some foresee phones acting as affordable hand-held computers running novel applications tailored to the needs of the developing world.

The movement is riding on the back of a burgeoning market in wireless devices for machine-to-machine communication. These devices are, in effect, stripped-down cellphones, and a typical application combines them with position sensing systems in trucks, which can then be tracked while on the move (New Scientist
, 20 December 2003, p 30). To turn one of these basic cellphone modules into a fully functional phone suitable for chatting to friends, you add a microprocessor, typically running the open-source Linux operating system, along with a speaker and microphone, screen, battery and keypad.

"Five years ago, you wouldn't have been able to build a cellphone," says Surj Patel, a telecommunications engineer who now spends his spare time building cellphones. "You could have bought bits and pieces, but you would have needed a million-dollar lab to put everything together." Even now, it's not easy. Designing the circuits and writing the software is a slog. Moreover, home-brewed phones are clunky, oversized and burn through a battery in half an hour.

So what's the motive? For many, it is the urge to play around with devices that are an integral part of all our lives. They would like to add modules such as radio frequency identification (RFID) readers to scan the increasingly widespread wireless ID chips, or GPS units so that a phone knows exactly where it is. They can then program custom capabilities into the devices: to allow them to spot which of their friends are nearby, for example.

Such tasks are beyond the capability of most ready-built phones. RFID readers on phones are still rare, and though many existing phones have GPS units they can often only be used by paying a monthly fee to the network company. The cost of writing new applications is another factor favouring home-made phones. Since most cellphone makers keep the software that controls them a closely guarded secret, high licensing fees and royalties effectively bar everyone except large, well-funded companies from modifying the hardware or coding their own applications, Patel says.

Deva Seetharam, an engineer at sensor company TagSense in Cambridge, Massachusetts, ran into this problem while developing RFID readers for commercial cellphones. "There is no freedom for users, researchers and hackers to build anything," Seetharam says. "So I said, OK, I'll build something so people can customise the phones the way they want." Seetharam teamed up with Patel to build their own handset, which they named TuxPhone after Tux, Linux's penguin mascot.

Most of the enthusiasts working on their own phones are committed to the open source ethos that has driven the development of Linux and many of its applications. The principle behind open source software is that anyone is free to use or modify the software code, on condition that their modified code must in turn be freely available for others to modify if they wish. In this spirit, Patel intends to make public the schematics for his phone once he has the details ironed out.

Vibrant communitySimilarly, Cina Hazegh, a graduate student at the University of California, Irvine, and Nathan Seidel, who owns the electronics supply company Spark Fun Electronics in Boulder, Colorado, have teamed up to create a website called opencircuits.org for sharing wiring diagrams.

The pioneers are convinced that if cellphone software becomes more open, it will foster a community of programmers who will create new applications and software add-ons. An example of how powerful this approach can be is the open source web browser Firefox, which has long had a slew of add-ons available for free, most of them coded by individuals to add specific features not included in the base program. These include advert blockers or add-ons that meld hits from several search engines into a single page. In contrast, Microsoft's Internet Explorer and Apple's Safari have little tweakability and less vibrant communities of programmers working on extensions.

Patel has created a cellphone application called Ringfo that can be used to call a toll-free number and enter a book's ISBN or a CD's code (http://ringfo.com
). This calls up a computerised voice reading key snippets of information from online retailer Amazon's website, such as a book's average rating and prices for new and used copies. Because this voice call does not incur data download charges, Ringfo is cheaper and easier to use than a cellphone's web browser, Patel says.

Ringfo is just the start. With an open source phone, Patel says he could experiment with more efficient interfaces: for example, one that allows the user to issue a command by voice and receive a response on the screen. Or the phone could look for book reviews on a social networking system such as myspace.

Another possibility is to enhance cellphone address books so that they work in a similar way to instant messaging systems. The phone could then tell you, for example, when a friend's phone is switched off or busy. "These applications are not developed because there's no inexpensive open platform," Patel says.

Still another approach could be to exploit the powerful microprocessors inside even modest cellphones to run software tailored to the needs of people who can't afford an ordinary PC. "In the developing world, mobile phones are a really promising computing platform," says Tapan Parikh, a computer science student at the University of Washington in Seattle.

Phones have advantages over PCs, he says: "They are cheaper, they are smaller, they have a battery, people are used to using them, and they give this immediate connectivity and voice feature." Parikh is testing a system in rural India that uses camera phones to record bookkeeping details for the microfinance groups through which local people pool their money and distribute loans. His system uses Nokia phones that run the Symbian operating system, and though Symbian is fairly accessible to software developers it is not ideal. If cellphone software were more open, he says, there would be more potential to explore other computing applications.

"It's really important to get a developer community together and have some openness in experimentation," Parikh says. That way, local developers stand a better chance of meeting the needs of local people. "There's no way for a centralised application developer to have an idea of what applications would be useful in rural India."

Dump that operating systemMason Inman As an alternative to building their own handsets to experiment with new cellphone applications, engineers are attempting to bypass the existing operating system on phones and install a new one. It's not just independent-minded programmers who welcome this approach. The phone manufacturers would benefit too, as they would no longer have to pay operating systems licence fees.

Though a few engineers have already installed Linux on commercial PDAs and smartphones, it takes a great deal of effort to make the software work, and even then it cannot always control all the phone's functions. "It is really a stopgap until we can see a device like the TuxPhone make it big," says Matthew Mastracci, a software engineer who was the first to run Linux on a Treo 650 phone. He and others are working to install the software on as many phone models as possible, to prove it can work. He hopes it will demonstrate to manufacturers that Linux is a viable alternative.

A number of open source software groups are working with handset manufacturers, chip-makers and software developers to coordinate research into using Linux for mobile devices. They are also trying to tackle broader issues, says William Weinberg, of Open Source Development Labs, one of the groups involved. "The handset manufacturers want their devices to become platforms for innovation. To do that, they need to expand the number of people who can actually enhance the devices with software, and for that they need to increase openness."

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