Google's Wi-Fi Dreams

Tech giants and broadcasters tussle over vacant TV channels.

The new Wi-Fi:

Next year's digital-TV transition will free up empty TV channels for use by broadband companies.

Google wants to use them to create what it calls Wi-Fi 2.0 services.

With next year's transition to digital television sparking fierce debate over how to use the newly vacant TV channels, Google has offered a plan that it says could vastly improve U.S. broadband service.
For several years, policy makers, technology companies, and broadcasters have been debating the best use for this newly available wireless real estate. This "white space" between operating TV channels is of particular interest to broadband companies, because wireless signals sent at these frequencies will have the ability to penetrate walls and other obstructions more easily than do cell-phone or Wi-Fi signals.
Google submitted its new proposal to federal regulators late last week, outlining a plan to utilize the unused channels for what the company calls Wi-Fi 2.0: a loosely regulated set of broadband services with the potential for gigabit data speeds. The company stopped short of saying that it would seek to operate a broadband network itself, but it clearly sees business potential, telling federal regulators that it would provide other companies with "the technical support necessary" to turn the TV frequencies into broadband data conduits, free of charge.
"The unique qualities of the TV white space--unused spectrum, large amounts of bandwidth, and excellent propagation characteristics--offer a once-in-a-lifetime opportunity to provide ubiquitous wireless broadband access," wrote Google attorney Richard Whitt in the company's proposal to the Federal Communications Commission (FCC).
Indeed, the soon-to-be-freed TV airwaves represent some of the last, and potentially most valuable, swathes of U.S. wireless spectrum still suitable for providing broadband services. Naturally, the debate over how they will be used--and who should use them--has been fierce.
Technology companies such as Google, Microsoft, and Motorola say that these frequencies are particularly well suited for providing rural areas with high-speed Internet service, as well as for short- or medium-range networking applications that might provide data transfer rates of gigabits per second, as opposed to the roughly 54 megabits per second of today's 802.11g-based Wi-Fi networks.
Regulators have already approved the use of some fixed devices, but the tech companies want approval for mobile devices such as handhelds and laptops as well, and they're seeking rules that would let companies offer services using the spectrum without having to get new licenses. Google has said that the TV white space would be ideal for mobile data devices using its open-source Android platform, for example.
However, TV broadcasters are worried that unlicensed devices sending data on unused TV channels--say, a vacant channel 29--might interfere with the program signals being broadcast on channel 28 or 30. Similarly, they're concerned that mobile devices able to operate across a range of frequencies might accidently choose a channel being used locally for TV service and scramble nearby TV viewers' signals.
Technology companies say that they can control for this problem. They've advocated a technique called spectrum sensing, in which the portable devices, transmitters, and receivers alike would scan channels before using them to make sure that they are indeed vacant. Detecting the presence of TV signals or other authorized users would keep a "white-space device" from using that channel.
However, FCC tests of spectrum-sensing prototype devices have been spotty at best. A first round of testing last year had disappointing results. Another round of FCC testing, with a new batch of prototype devices from four different companies, is now under way.
Google's new proposal aims to deflect concerns about those tests. To this end, the company has adopted three alternative ideas that were previously advocated by Motorola and others for protecting against interference.
The first aspect of this protection would create a publicly accessible database listing all licensed TV stations and their geographic location. Any device attempting to use the TV spectrum would first have to establish its own geographic location, by using GPS readings or another means, and then check this database to avoid conflict with a licensed TV station in that area.

In its proposal, Google said that it would be willing to maintain "open geo-databases" to support this function, as well as provide intellectual property, reference designs, and technical support to other companies.
A second tool would be aimed at protecting the wireless microphones commonly used by news crews, conference speakers, and others, all of which today send signals over parts of the vacant TV spectrum.
Following earlier suggestions, Google is proposing the creation of an inexpensive "beacon" device, which would let microphone users broadcast the fact that a particular channel, in a particular area, is in use. White-space devices would be required to monitor and respect these active beacon signals, and to avoid broadcasting on the same channel.
Lastly, channels 36 through 38 would be set aside as a "safe harbor," to be used only by wireless microphones.
"We think Google did a good job of recognizing the high level of protection provided through this approach," says Steve Sharkey, senior director of regulatory and spectrum policy for Motorola, which submitted a proposal with similar features last year. "There is no question that this will be able to fully protect the [TV broadcast] incumbents and the devices that are supposed to be protected."
Others are less convinced.
"There is nothing in [Google's proposal] other than a laundry list of so-called protections that quite candidly have been debated for the last several years," says David Donovan, president of Maximum Service Television, a lobbying group that works closely with broadcasters. "There is no new technical information. There is no evidence put forth by Google, nor is there evidence in the record that any of this actually works."
At this date, with analysis of spectrum-sensing prototype devices still under way, and the alternative proposals still untested, there is no guarantee that the big technology companies, such as Google and Motorola, will have their way.
Indeed, this week the Cellular Telephone Industry Association (CTIA) offered an alternative proposal, under which the white-space channels would be used instead by licensed operators--much as cell-phone frequencies are used today--to offer broadband services. Broadcasters have said that they are more willing to accept this model, since any TV interference could be tracked immediately to a licensee, instead of to an unknown, unlicensed device.
However, the allure of spectrum-sensing devices hasn't diminished, despite testing hiccups and Google's new compromise proposal.
Google's proposal itself envisions a transition system, in which new devices' spectrum-sensing features could be continually checked against the information in the TV database, and any mismatches could be used to improve the technology.
Once spectrum sensing does mature, whole new generations of devices will be able to comb the airwaves looking for unused space, even beyond the TV channels now under discussion, the company says. Google has outlined a way of allocating this unused spectrum on the basis of "dynamic auctions," in which network service providers would bid for and gain access to the unused spectrum on a real-time basis, using an online auction tool.
Any such system would face considerable regulatory and technical hurdles, and it would almost certainly inspire political opposition from other, more traditional wireless users. But the idea of broadband devices that can find and utilize virtually any vacant spectrum has inspired technologists who see a more efficient use of the airwaves as a way to eliminate bandwidth constraints.
"We soon could see a low-cost and open infrastructure, supporting a near-unlimited bandwidth Internet service, improving every year as computer and radio technologies continue to evolve," wrote Google's Whitt. "This would be akin to a faster, longer range, higher data rate Wi-Fi service--'Wi-Fi 2.0' if you will."

Foldable, Stretchable Circuits

Researchers have made sheets of high-performance silicon circuits that can bend, fold, and even stretch around complex shapes
Stretching silicon: The top image is of a twisted silicon circuit on a flexible polymer. Below it are optical micrographs of inverters--circuit components--from the above circuit. The ripples in the circuit are due to the fact that it was affixed to the polymer when the polymer was stretched. Seen here, the polymer is in a relaxed state.
Credit: Science / AAAs


Researchers at the University of Illinois, Urbana Champaign, and Northwestern University, in Evanston, IL, have shown that electrical circuits can be made to fold and stretch and still match the performance of circuits built on rigid wafers. Made of thin sheets of silicon on plastic or rubber, these bendable circuits could pave the way for such applications as wearable computers and implantable health monitoring systems.
John Rogers, a professor of materials science at the University of Illinois, and his colleagues have demonstrated that it is possible to use ultrathin silicon to build entire sheets of foldable and stretchable circuits made of devices such as transistors, amplifiers, and logic gates. The results were published in this week's Science. Previously, Rogers made foldable and stretchable ribbons of silicon transistors, but the new work shows that it is possible to use the technique to put sheets of complex circuits on stretchable surfaces. "We expanded on the notion at the circuit level to make the entire circuit system as thin as possible," Rogers says. "The entire thickness is 1.5 microns, and that includes the plastic substrate, metallization, silicon, dielectrics--everything. A circuit with that thin a form factor is naturally bendable just by the mechanics."
Bendable electronics aren't new: researchers have previously stamped, printed, and sprayed circuitry on plastic sheets. However, these circuits are made of organic semiconductor materials--useful for applications such as transistors in roll-up displays, but simply too slow to be used for more-complex computing.
In 2005, Rogers found a way to make single-crystalline silicon--the kind used to make computer chips--fold and stretch by adhering ultrathin ribbons of it to strained rubberlike substrates, and then letting the rubber snap back into place. (See "Stretchable Silicon.") Because the silicon was so thin--only a few hundred nanometers thick--it buckled, without breaking, into waves on the rubber that could be restretched again and again.
The new work exploits that ultrathin geometry to make two types of circuits. One type is merely foldable: silicon-based circuits were placed on unstrained plastic sheets, resulting in circuitry that can fold up like a piece of paper. To ensure that the circuit would work well no matter what direction it is twisted or bent, the researchers place the silicon, or whatever part of the circuit is most fragile, at a distance between the top and bottom of the circuit sheet that experiences the least amount of strain. Placing the fragile components of the circuit in the appropriate place within the circuit sheet optimizes the electronics and allows them to work as well as those on a solid wafer, says Rogers.
The researchers made a second type of circuit by taking the optimized circuit sheets and bonding them to prestretched rubber that was extended in both directions. When the rubber is allowed to relax, the silicon layer buckles in a complex, wavy pattern, Rogers says. "We understand completely, through extensive analytical and computational modeling presented in the paper, how those wavy shapes form and how the layouts of the circuits...determine [the waves'] spatial geometries," he says. While the foldable circuits are fully optimized, he says that his team is still working to optimize the stretchable circuits. Since the researchers can locate positions across the circuit where the wavy structures will form when the rubber is released, Rogers says, they can choose these locations so that they do not overlap any fragile or strain-sensitive components of the circuit. This aspect is a refinement to the current work, he notes, and it will appear in a future paper.
The research offers "a completely new circuit concept," says Zhenqiang Ma, an electrical-engineering and computer-science professor at the University of Wisconsin-Madison. Ma has previously built ultrafast silicon transistors on bendable substrates, which operate at high frequencies, making them useful for antennas built onto the wings of airplanes, for instance. (See "Record-Breaking Speed for Flexible Silicon.") While Rogers's transistors are slower, his integrated circuits have the advantage of being designed with the wavy geometry of thin silicon in mind, so that they can be optimized on a stretchy substrate.
Rogers says that one field in which the foldable, stretchable circuits could be useful is neuroscience. (See "TR10: Personalized Medical Monitors.") He is working on a project that could enable a thin sheet of electronics to wrap around the brain, monitoring electrical activity for indicators of future seizures in people with epilepsy. In addition, Rogers and his colleagues are building latex surgical gloves with integrated electronics that could add sensing functionally or, in some cases, provide tactile feedback for training surgical students.
"There are many applications for these new types of circuits," says Ma. "In some of the applications ... stretchable and foldable integrated circuits may be the only choice." He adds that the new integrated-circuit concept "has filled an important application gap" that rigid, chip-based circuits can't fill.

A New Divide in Social Networks

MySpace and Yahoo support Google's OpenSocial standard; Facebook does not.






Not just Google’s anymore: The OpenSocial Foundation (logo shown above), founded by Yahoo, Google, and MySpace--but not joined by Facebook--aims to make it possible for developers to write an application for one social-network site, then easily adapt it for another. Although Google started OpenSocial, the company says that the foundation is meant to protect the standard from the control of any one organization.
Credit: OpenSocial Foundation

On the heels of social-networking sites such as Facebook and MySpace have come social applications, games, and services in the form of widgets that employ the data that users store and maintain on social networks. Since Facebook, the first company to open its doors to outside applications, launched its Platform last May, more than 20,000 applications have been built for the social network. Google, meanwhile, has been spearheading OpenSocial, a standard aimed at making it easier for applications to be used on multiple networks. Earlier this week, Yahoo announced its support of OpenSocial--which Facebook has not done--and joined Google and MySpace to form the OpenSocial Foundation, a nonprofit organization that the companies say would will be responsible for protecting the standard.
Joe Kraus, director of product management at Google, said in a press conference earlier this week that the foundation is meant to provide "safe harbor for intellectual property ... by making it clear that OpenSocial's use will be forever free and unencumbered, and to make sure that the OpenSocial Foundation stays community driven so that no one company ever has undue influence." Kraus said that the companies plan to have the OpenSocial Foundation up and running in about 90 days.
OpenSocial is intended to allow developers to write an application for one social network and easily adapt it for another. In contrast, Facebook's Platform requires the use of Facebook-specific programming techniques. Google announced OpenSocial last fall, and social networks including MySpace, hi5, and LinkedIn stepped forward during the following months to join in. So far, OpenSocial applications have only been launched on Google's Orkut and on MySpace; hi5 plans to launch them on Tuesday. Between these three networks, Kraus said at the press conference, developers will have access to about 200 million users with a single application.
A Facebook spokesperson responded to the announcement by saying, "Facebook is a supporter of open source and sees value in any contributions the foundation may make to the industry. Facebook is not joining this foundation, but the company remains focused on advancing Facebook Platform to benefit the developer community and help users communicate and share information more efficiently." Facebook has, however, begun working with Microsoft to allow people to use some of the data they've stored on Facebook in other contexts. Called Windows Live Contacts, the tool allows Facebook users to communicate with Facebook friends through services such as Windows Live Messenger, Microsoft's instant-messaging client. "Facebook will continue to work with other trusted partners to explore new initiatives around data portability," Facebook's spokesperson said.
So far, Yahoo has given few details on the exact nature of its involvement with OpenSocial. Wade Chambers, vice president of platforms at Yahoo, said at the press conference that Yahoo decided to support the standard because it complements some existing Yahoo tools, such as the photo-sharing site Flickr, and developer tools, such as the Yahoo User Interface library. Chambers also pointed to Yahoo's support of other standards, such as OpenID, which allows users to maintain log-in information that works on multiple sites.