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WHITE SPACE - Not everyone appreciates free air

Sun, 05/31/2009 - 8:40pm
Jim Barthold, Contributing Editor

White space broadcasting could be a broadband boon or a catastrophe for cable.

Even gas stations don’t give out free air anymore, so it’s little wonder that the federal government’s offer of free air – unpaid access to the wireless radio spectrum known as white space – is meeting a mixture of skepticism, confusion, and even some resistance throughout the telecom space.

After raffling off a great percentage of the 700 MHz spectrum used for analog TV broadcasts that is in the process of being vacated, the FCC in November designated anything left over, including the buffer zone between channels (the white spaces), as restrictively free for use by wireless players.

The government’s position was that the valuable spectrum would be useful for innovative broadband connectivity schemes, and all the better if used in rural areas. That spectrum has potential for becoming a more potent Wi-Fi in-home networking play.

Transmit power (dBW EIRP toward receiver) vs. distance to receiver for maximum tolerable
Figure 1: Transmit power (dBW EIRP toward receiver)
vs. distance to receiver for maximum tolerable. DPU
reception interference with one intervening wall.

Of course, the feds attached more strings than the violin section of The Philadelphia Orchestra to the deal. The tightest of them is a requirement that a working white space database be set up and deployed for consumer devices to access in order to determine available channels in the vicinity before sending or receiving signals – an additional precaution against interference.

While major wireless vendors such as Motorola believe this is not only a reasonable request, but also one that can easily be achieved, others, like the cable industry, don’t think it goes far enough. The NCTA made that clear by filing a Petition for Reconsideration with the FCC, claiming the Commission had not done enough to protect cable subscribers from interference and asking that the power levels for portable devices be lowered, while seeking greater separations between fixed devices and cable households. On a second point, the NCTA also asked the FCC to provide more protection from interference for cable headends.

The NCTA commissioned Carl T. Jones Corp. (CTJ) to look at spectrum interference issues and, based on CTJ’s report, concluded that “the 100 mW power output level adopted for personal/portable devices will interfere with cable television viewing … and could adversely impact cable modem Internet access and other cable services in the home.” The filing added that the FCC’s “cable headend protections are inadequate, and some provisions need further clarification.”

Cable’s quick-draw attack on white space might be a little shortsighted, argued Miguel Myhrer, senior executive and lead of the North America Wireless Network practice at Accenture, because the spectrum might actually prove useful to cable operators.

“The first significant jumpstart will be the security applications, which will have more money behind them and have solutions that the cable guys are already providing for commercial customers,” Myhrer said. “I think this will be a natural fit for them to look at white space in that context.”

In the long term, cable’s opposition is probably just a speed bump compared with all of the other issues surrounding the path to making white space a broadband reality.

Those issues should all eventually be smoothed – either through revisions within the FCC or by compromise with opposing parties – because the spectrum is too valuable to be ignored, said Steve Sharkey, senior director of regulatory and spectrum policy for Motorola.

“The basic approach is still sound,” Sharkey said. “NCTA has raised concerns about some of the specific implementation.”

Cable isn’t the only one questioning how the FCC has gone about this thing, but none of the bellyaching is in the realm of an outright uprising.

“Opposition may be a bit strong of a word,” said Jake Ward, a spokesman for the Wireless Innovation Alliance, a coalition of companies like Microsoft, Google and others.

“There are industry-wide policies by the wireless carriers of not taking a position, [and] cable has said various things, mostly focusing on the idea of interference rather than having an issue of who’s going to deliver what.”

White space, added Sharkey, was, from the start, a “very complicated proceeding with a lot of different interests involved, a lot of different aspects, a lot of things that you needed to protect and work around. As the FCC did its analysis and put all of that together, it’s not surprising that you ended up with something that is not perfect for everyone, and we need to make some adjustments.”

Filtered down to its essence, white space appears to have two very real deployment possibilities. First, broadband solutions making use of white space spectrum could be especially practical in rural spaces where there’s no broadband of any kind now, and where in many cases there were no television stations to begin with.

“If you envision the blue and red part of the U.S. political map, the red tends to be the rural states and the heartland states [where] there are substantially fewer existing television stations,” said Marc Berejka, senior director of technology policy and strategy for Microsoft. “The amount of spectrum available in rural America would be phenomenal.”

The fact that the spectrum is in the potent 700 MHz range is another boost, because that means it can go long distances, leap tall buildings and penetrate short ones. Developing this spectrum is “about lowering the collective cost of extending the network out to people who currently are not on the network. White space offers the opportunity to extend coverage into areas where there is none – at a low cost – and the opportunity to make a low-cost offer available to people who might not be able to afford 50 bucks a month,” Berejka continued.

Maybe. Then again, maybe that’s not going to happen, either – at least as Microsoft envisions it.

“Spectrum licenses cost a lot of money, so when unlicensed spectrum hits the market, it does leave some opportunities that don’t cost quite as much; but still, to do a quality build-out, you have to have a fair number of capital funds, and the markets have not been too good lately for new companies to access capital,” said Chris Pearson, president of 3G Americas, a mobile advocacy group whose members may or may not be interested in taking advantage of white space and, conversely, may or may not see those bidding to use the space as competitors. “It’s a difficult scenario to say how white space or unlicensed spectrum might go into the rural areas. It’s just a little bit too early until we understand exactly everything.”

Barry West, president and chief architect of WiMAX provider Clearwire, understands two sides of the equation: financing and spectrum. Clearwire is building its business in a tough economy with funding it’s getting from partners like Comcast, Time Warner Cable, Bright House Networks, Google and Intel, so he knows how much it costs to build a new wireless network. He also knows what the market thinks about this kind of thing since all of his partners are taking varying degrees of financial hits from the financial markets for their participation.

Figure 2: Maximum tolerable undesired field strengths
at headend-receiving location.

West, who has experience in the mobile wireless space, also knows the competitive advantage of owning the spectrum when going into a new market. Besides eliminating interference possibilities, it also eliminates competitive possibilities in many instances.

“I’m not a big advocate of the whole unlicensed part in terms of driving a mass market. You have to have a spectrum policeman, which is usually an operator that’s looking at the quality of service and tuning it,” West said.

Because the 700 MHz band “goes a long way,” white space technology becomes attractive as a means for providing fixed wireless broadband, West said. The caveat about establishing a commercial service using unlicensed white space spectrum, West added, is that “it’s not regulated, so you’re into the world of Wi-Fi.”

That world is the second, albeit potentially first-to-market, opportunity for white space spectrum.

“To the extent that Wi-Fi is an 802.11 family of standards, you could certainly implement the technology in this spectrum,” Motorola’s Sharkey said.

And existing Wi-Fi devices could coexist with white space-based devices, added Ward, who believes “there’s a business plan there that says the further your range, the better, and that’s how you convince somebody to carry a higher volume center – by making it desirable to have better range and higher fidelity.”

Things aren’t quite that easy or compatible, argued Edgar Figueroa, executive director of the Wi-Fi Alliance.

“At a high level, maybe some of the operating modes could be very similar to the way that Wi-Fi works now; but under the hood, we could be doing some very different things that would be needed to operate in this mode: the power, the frequency, the transmission,” he said.

Wi-Fi is a developed space that’s moving along quite nicely without any intrusions.

“In terms of the synergies that exist with what’s been defined, the requirements are for some adaptive radio and dual-location types of mechanisms. You can do that with Wi-Fi now; in fact, a lot of solutions do those kinds of things,” Figueroa said. “There are a lot of things that are not yet defined, and that’s why, from the members of the Wi-Fi Alliance, we’re just monitoring at this time.”

Perhaps, then, Wi-Fi is too restricted a space for white space spectrum that might be better suited for something like WiMAX, which, coincidentally, has been working to set interoperability standards for 700 MHz equipment.

“It’s an excellent band because it has a long reach,” said Mohammad Shakouri, vice president of the WiMAX Forum. “We believe 700 MHz would be a band that we eventually can build WiMAX technology. The question has to do with regulation – how much power you can have. The biggest question on the white space is more regulation and policy to be defined so that a different ecosystem as an industry could leverage it.”

While everyone sees different potential for the spectrum, there is one area of across-the-board agreement: White space use and deployment isn’t going to happen overnight.

“Ultimately, down the line, five or 10 years out, it provides a great spectrum, but it still needs development and an ecosystem behind it,” said Accenture’s Myhrer.

“I don’t think there will be a business model day one, or even a couple years out. It will be a couple years. It provides an interesting area of opportunity, especially for cable clients looking to provide security solutions, [and] provides a very strong spectrum to take advantage of for certain applications.”

Those applications might be for cable; they might be an adjunct to wireless plays like 3G and evolving 4G already in the market, such as the Clearwire WiMAX deployment; or they might be new plays altogether.

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