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Archive for the ‘Spectrum’ Category

FCC Approves White Spaces!

Wednesday, November 5th, 2008

This is incredible news. The FCC has done a wonderful thing, standing up to the broadcast TV lobby to benefit the people of America. What’s even better, four of the five commissioners are enthusiastically behind the decision:

It has the potential to improve wireless broadband connectivity and inspire an ever-widening array of new Internet based products and services for consumers. Consumers across the country will have access to devices and services that they may have only dreamed about before.

Some have called this new technology “Wi-Fi on steroids” and I hope they are right. Certainly, this new technology, taking advantage of the enhanced propagation characteristics of TV spectrum, should be of enormous benefit in solving the broadband deficit in many rural areas.

Today the Commission takes a critically important step towards managing the public’s spectrum to promote efficiency, and to encourage the development and availability of innovative devices and services.

While new broadband technologies are the most likely uses of these channels, the most exciting part about our action today is that we are creating the opportunity for an explosion of entrepreneurial brilliance. Our de-regulatory order will allow the market place to produce new devices and new applications that we can’t even imagine today.

The fifth commissioner, Deborah Taylor Tate, is only partly on board – she thinks some of this spectrum should be licensed, and she is concerned that not enough provision has been made for remediation in the event that interfering radios are deployed.

The FCC decision is a bold one – a more conservative positive decision would have been to approve a rural broadband access-only (802.22-style) use for now, but the commissioners went ahead and approved personal/portable use as well, which is what Google, Microsoft and numerous other computer and Internet industry companies have advocated.

The ruling imposed a geolocation requirement which will vastly increase the market for GPS silicon, though the trend in embedded GPS is to include GPS on the same die as other radios (like Bluetooth or cellular baseband) so whoever makes the White Spaces radio chips will probably be putting GPS on the same die by the second product generation.

The digital TV transition will open up the White Spaces spectrum in February 2009, but I will be very surprised if any white spaces consumer products appear in the market before 2010.

Green light for White Spaces

Wednesday, October 15th, 2008

The eagerly awaited White Spaces test report of the Office of Engineering and Technology of the FCC came out on Wednesday. The operational paragraph in the Executive Summary reads:

We are satisfied that spectrum sensing in combination with geo-location and database access techniques can be used to authorize equipment today under appropriate technical standards and that issues regarding future development and approval of any additional devices, including devices relying on sensing alone, can be addressed.

It is huge that the FCC leaves the door open to devices relying on sensing alone, because even Google had begun to back off from this idea.

As expected, the report is a little more enthusiastic about fixed wireless Internet access, the kind of use advocated by the IEEE 802.22 working group, than it is about the personal and portable use advocated by Microsoft and Google, among others:

It will… allow the development of new and innovative types of unlicensed devices that provide broadband data and other services for businesses and consumers without disrupting the incumbent television and other authorized services that operate in the TV bands. The Commission is considering whether to also allow “personal/portable” WSDs to operate in the TV spectrum.

I have been following the White Spaces saga for some time (click on the “White Spaces” tag below, and the links to the right of this column); it is a great idea in theory, and if it turns out to work as hoped, the concept could eventually be extended across much more spectrum, leading to a nirvana of effectively unlimited cheap wireless bandwidth.

The commissioners plan to discuss White Spaces at their November 4th meeting.

White Space update

Thursday, March 27th, 2008

The forthcoming transition to digital TV transmissions will free up about half the spectrum currently allocated to TV broadcasters. This freed-up spectrum was the subject of the FCC’s just-concluded 700MHz Auction, which yielded about $20 billion in license fees to the government. The fate of the other half of the TV spectrum, the part that will remain assigned to TV broadcasts after the digital transition, remains in contention.

This spectrum will be shared by licensed TV broadcast channels and wireless microphones, but even so much of it will remain mostly unused. These chunks of spectrum left idle by their licensees are called “White Spaces.” The advent of “spectrum sensing” radio technology means that it is now theoretically possible for transmitters to identify and use White Spaces without interfering with the licensed use of the spectrum.

The FCC has issued a Notice of Proposed Rulemaking and a First Report and Order to explore whether this is a good idea, and if so, how to handle it.

The potential users of the White Spaces have formed roughly two camps, those who see it best suited for fixed broadband access (similar to the first version of WiMAX), and those who see it as also suited for “personal/portable” applications (similar to Wi-Fi).

Google, along with Microsoft and some other computer industry companies, advocates the personal/portable use. The FCC’s Office of Engineering and Technology (OET) is currently lab-testing some devices from Microsoft and others to see if their spectrum-sensing capabilities are adequate to address the concerns of the broadcast industry, which fears that personal/portable use will cause interference.

Google filed an ex-parte letter with the FCC on March 24th, weighing in on the White Spaces issue. The letter is well worth reading. It concedes that in the introductory phases it makes sense to supplement spectrum sensing with other technologies, like geo-location databases and beacons. The letter asserts that these additional measures render moot the current squabble over a malfunction in the devices in the first round of FCC testing, and that the real-world data gathered in this introductory phase would give the FCC confidence ultimately to repeal the supplemental measures, and perhaps to extend open spectrum-sensing uses to the entire radio spectrum, leading to a nirvana of effectively unlimited bandwidth for everybody.

The kicker is in the penultimate paragraph, where Google recycles an earlier proposal it made for the 700MHz spectrum auction, suggesting a real-time ongoing “dynamic auction” of bandwidth. Google now suggests applying this dynamic auction idea to the white spaces:

For each available spectrum band, the licensee could bestow the right to transmit an amount of power for a unit of time, with the total amount of power in any location being limited to a specified cap. This cap would be enforced by measurements made by the communications devices. For channel capacity efficiency reasons, bands should be allocated in as large chunks as possible. The airwaves auction would be managed via the Internet by a central clearinghouse.

Current expectations are for spectrum-sensing use of the whites spaces to be unlicensed (free, like Wi-Fi). Now Google appears to be proposing “sub-licensed” rather than unlicensed spectrum use. The word “auction” implies that this could be a revenue producer for TV broadcast licensees, who received their licenses free from the government. This is a very different situation than the original context of the dynamic auction proposal, which applied to spectrum for which licensees paid $20 billion. Depending how it is implemented, it could fulfill the telcos’ dream of directly charging content providers for bandwidth on a consumer’s Internet access link, a dream that Google has opposed in the network neutrality wars. Google may ultimately regret opening the door to this one, even though it presumably sees itself cashing in as the ideal candidate to operate the “central clearinghouse.”

Update April 10th: Interesting related posts from Michael Marcus and Sascha Meinrath.

FCC 700 MHz “Open Platform” Auction Completed

Thursday, March 20th, 2008

It took a while, and 261 rounds of bidding, but its over. Click here for the write-up from Wired.

The attractive thing about the 700 MHz spectrum that was freed up by the move to digital TV broadcasting is that transmissions at these frequencies pass through walls. The unusual thing about the “C Block” of this spectrum is that the FCC attached “open access” conditions to the license. This was at the behest of the computer industry, spearheaded by Google, who may even have made a bid on this block. But as the Wired story points out, Google had already won their victory with the imposition of the open access rules – winning the spectrum would have been more of a headache for them than losing it.

Don’t confuse the spectrum licensed in this auction with the White Spaces spectrum. The White Spaces spectrum is the spectrum that the TV broadcasters retained for their transition to digital transmissions in February 2009. The White Spaces issue is still unresolved by the FCC. The FCC is deliberating over whether to allow unlicensed use of the digital TV spectrum when it is not being used by a TV broadcast (hence “White Spaces.”) This use depends on effective functioning of “cognitive radio,” which lets transmitters sense by listening (and other means) when spectrum is available for use. If the FCC allows it, they still have to decide whether to allow only fixed broadband replacement like 802.22, or to allow “Personal and Portable” use as well.

700MHz Spectrum Auction Starts Tomorrow

Wednesday, January 23rd, 2008

700MHz is particularly valuable spectrum because it passes through solid barriers more easily than other frequencies. The New York Times has a good background article:

The radio spectrum licenses, which are to be returned from television broadcasters as they complete their conversion from analog to digital signals in February 2009, are as coveted as oil reserves are to energy companies. They will provide the winners with access to some of the best remaining spectrum — enabling them to send signals farther from a cell tower with far less power, through dense walls in cities, and over wider territories in rural areas that are now underserved.

The links to the right will take you to the FCC site for this auction, and to Wired Magazine’s FAQ.