In other words, the UK is now gearing up for a proper rollout next year (if everything goes well in the trial), with potential uses including rural broadband and the internet of things. Here’s what Ofcom chief executive Ed Richards said in a statement on Friday:

“Ofcom is preparing for a future where consumers’ demand for data services will experience huge growth. This will be fuelled by smartphones, tablets and other new wireless applications.

“White space technology is one creative way that this demand can be met. We are aiming to facilitate this important innovation by working closely with industry.”

The term “white spaces” refers to the gaps between heavily-used radio frequency bands. These are buffer zones that were deliberately left empty in order to stop the services using these various bands – generally TV broadcast services — from interfering with one another.

However, a few years ago people started playing around with the idea of using white spaces for digital communications. They tend to be low-frequency, which makes them ideal for sending data over long distances, and their exploitation now seems quite viable, depending on which bands are already in use in a particular geographical area.

This is why databases of frequencies and coverage are absolutely crucial to white space usage – unlike with Wi-Fi, which can be used anywhere without a license, Ofcom wants to make sure that devices using white space frequencies only do so when they can avoid interfering with surrounding bands. The devices, which will generally use cognitive radio technology in order to hop between frequencies as needed, will therefore need to get clearance from an Ofcom-approved database before they can start transmitting.

Those of you who have been following white space technology will know that Google is compiling its own database of frequency usage, and this is the sort of database that Ofcom might theoretically approve for official use in the UK.

Google’s database is currently being tested in the U.S. by the FCC, the American counterpart to Ofcom, and is also being deployed in a white space trial in Cape Town, South Africa. Meanwhile, Microsoft has already conducted tests in the UK (the Cambridge pilot) and Singapore, and is now active in Kenya. Other, similar initiatives are underway in Finland, Ireland and France.

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White spaces are the gaps in between broadcast TV channels in the radio spectrum. These gaps are left empty as buffers, in order to avoid the TV channels bleeding into each other, but they also have the capacity to carry wireless broadband. And, because the spectrum we’re talking about is quite low-frequency, it is very good at carrying that wireless broadband over great distances – hence the technology’s promise for mostly rural areas that lack good fixed-line broadband (Google has been trialling white space broadband in the rural U.S. since 2010).

The Cape Town trial, launched on Monday, is experimenting with white spaces as a way of bringing connectivity to schools. The base stations are being sited on the Tygerberg hill, which is next to several heavily-populated areas (I’m from Cape Town, as it happens), so the trial should provide a good idea of how white space broadband interferes – or hopefully doesn’t – with licensed spectrum holders in the vicinity.

Google’s involvement extends to sponsorship and the use of its newly-launched spectrum database, while others taking part include the Council for Scientific and Industrial Research (CSIR), the Tertiary Education and Research Network of South Africa (TENET) and of course the local telecoms regulator, ICASA. The equipment comes from Neul and Carlson Wireless.

The trial will last six months. According to TENET’s explanation, each of the 10 schools involved will get a “dedicated 2.5Mbps service with failover to ADSL” – hardly impressive speeds, but this is still an experiment after all.

According to Fortune Mgwili-Sibanda, Google’s public policy manager in South Africa, Google’s intention here is partly to drive regulatory change there. Like Wi-Fi spectrum, white space spectrum can be used license-free in the U.S. This may also happen in the UK, depending on what the regulator Ofcom decides. “We hope the results of the trial will drive similar regulatory developments in South Africa and other African countries,” Mgwili-Sibanda wrote in a blog post.

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Part of the FCC’s agreement to allow for white spaces initially included the formation of a central geo-location database of licensed spectrum use by broadcasters around the country. Such a database would help mitigate potential interference between unlicensed spectrum use and licensed broadcasts. Essentially, it would ensure that white space network access on a smartphone, for example, would have zero impact on any digital television broadcasts nearby. Although far more television content is provided by wired methods — think cable and fiber — over-the-air digital television is still watched by many, so the FCC can’t allow for potential interference issues. Other details have to be addressed as well: The level of transmission power, for example, may require FCC guidelines, else devices become confused by a wireless shouting match.

The white space situation arose a few years ago as part of the transition to digital television in the U.S.; certain frequencies were freed up for non-television use. Indeed, the 700 MHz spectrum auction netted nearly $20 billion as Verizon, AT&T and others took advantage of the freed-up wireless resource. However, not all the spectrum is in use, which means there’s opportunity. Spectrum Bridge (see disclosure below) is one of those seeking to offer unlicensed wireless access with the unused channels and has successfully trialed the use of a white space network in a rural area of Virginia: a typical place where a cellular 3G signal may not be available. The white space spectrum in this case covers the final few miles from wired backhaul, enabling residents to wirelessly connect to the web over a range wider than that of Wi-Fi. The unlicensed nature means consumers have the freedom to set up their own networks, just as they do today with Wi-Fi.

If the FCC does remove the final roadblocks for white space network use as expected, an entirely new industry could rise, similar to that of the Wi-Fi market over the past dozen or so years. New and updated baseband chips to support such frequencies will be needed for smartphones and notebooks. Municipal wireless projects could see new life because the greater range of white space spectrum could reduce implementation costs of city-wide hotspots. Web-connected devices like e-book readers, media players, smart meters and even vehicles might rely less on 3G or 4G networks for connectivity due to free or lower-cost white space network access. The future isn’t written yet, but white spaces could reduce the hunting and seeking of that short-range hotspot.

(Disclosure: Spectrum Bridge is backed by True Ventures, a venture capital firm that is an investor in the parent company of this blog, Giga Omni Media. Om Malik, founder of Giga Omni Media, is also a venture partner at True.)

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Google’s Latest White Space Push: The Smart Grid

The big idea behind the untapped white space is that now that analog TV channel operators have moved to digital, very valuable, spectrum — nationwide and free to use because it is unlicensed (not owned by any company but guided by rules) — has been unleashed. Several years ago Google launched a campaign called Free The Airwaves in an effort to draw attention to the idea of using white space for wireless consumer broadband services.

But how to manage white space has been under debate at the Federal Communications Commission (FCC) for years, because there have been concerns that using white space for Internet services would interfere with other wireless devices like microphones in nearby frequencies. While a variety of companies like Spectrum Bridge (a True Venture portfolio company, see below), Microsoft and Motorola have managed to show that there is no problem with interference in white space, the FCC still has yet to give a final ruling on the subject.

The lack of an FCC ruling is why the world’s first-ever smart grid white space project is tiny and experimental. Spectrum Bridge, which has an experimental license with the FCC, first wired up the Plumas-Sierra utility with a white space network for its substations, enabling the utility to do substation automation. The network ended up working so well that Spectrum Bridge brought in Google to create a smart meter-style network using white space, where Google provided its in home energy management software PowerMeter and also brought in Energy Inc’s TED energy devices as the defacto smart meter.

Only a dozen TED devices were used, explained Spectrum Bridge’s VP of Business Development and Marketing, Neeraj Srivastava, to me, which shows just how small the network is. Spectrum Bridge can only create a commercial smart grid white spaces network when the FCC gives a final ruling (expected in Q3 of 2010, says Srivastava). Once that happens device and software makers can develop and sell white space-certified gear.

Why should you care about a smart grid via white space? It’s unlicensed spectrum (that’s free folks), is available in cities across the U.S., it’s completely untapped, and already has a lot of high profile backers like Google, Microsoft, Dell, and Motorola. For more of my thoughts on how the application of the smart grid can make white space a reality, check out GigaOM Pro (subscription required).

Spectrum Bridge is backed by True Ventures, a venture capital firm that is an investor in the parent company of this blog, Giga Omni Media. Om Malik, founder of Giga Omni Media, is also a venture partner at True.

Image courtesy of Spectrum Bridge.

Working with researchers at Harvard University, Microsoft developed a set of protocols for wireless Internet networks using “white space,” the unlicensed spectrum previously used for broadcast television signals, in a manner similar to today’s Wi-Fi systems. They call it “White-Fi.” Redmond has been working on such technology for more than two years and was one of several companies to get a license from the Federal Communications Commission to create prototype white-space devices. Google, Dell, HP, Philips and Intel have all voiced plans to develop white-space devices, with many seeing the former TV spectrum as a way to bypass the last-mile networks of incumbent broadband providers like AT&T and Qwest Communications. In addition, the white-space spectrum Microsoft is using (between 512 megahertz and 698 MHz) offers a longer range than today’s 2.4GHz Wi-Fi networks, promising greater reach in rural areas.

One of the key obstacles for Microsoft was creating a technological fix that would comply with the FCC’s strict white-space regulations that ban anyone using the spectrum from interfering with its primary existing user, usually a TV broadcaster. And it’s not easy to predict which part of the spectrum that incumbent is using at any given time. It’s also tricky because wireless microphones, which operate in the same spectrum, can suddenly become active without warning, and even a single-packet transmission can cause audible interference.

Microsoft dealt with this by creating an “adaptive spectrum assignment algorithm” with which devices measure the spectrum around them and work with other gadgets to find available frequencies, much like laptops search for and identify Wi-Fi networks. If interference occurs, the devices move to a backup channel in a different frequency range. In Microsoft’s experiment, its devices would switch to the backup channel within 3 seconds of a wireless microphone being turned on.

Other researchers have already focused on the first step: finding a way to establish a single link between an access point and user device without interference. Microsoft made the next move, designing an entire network with an access point and multiple clients (like Wi-Fi), leaving for another day the task of tackling multiple access points.

White-Fi won’t yield as much bandwidth as WiMAX or LTE networks, and its speed will depend on how much spectrum is available in each particular area. (It could be comparable to Wi-Fi but with a much longer range.) But unlike WiMAX or LTE, which will be deployed in urban areas, the spectrum isn’t owned by major carriers, so it lets new providers get in the game, and because no one has to buy the spectrum, the network’s cost would be lower as well. Of course, whoever is providing the service will still have to pay for the backhaul to connect the White-Fi network back to the Internet.

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