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AnchorDesk

David Coursey
How the wireless boom could soon hit the wall

David Coursey
Executive Editor, AnchorDesk
Wednesday, Mar. 3, 2004
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There was a time when salt was amongst the world's most valuable substances. Now you can buy it for only pennies a pound. Diamonds retain their value, but only because a cartel makes them artificially scarce.

Top wireless products
Get 'em while you can: As long as there's enough spectrum to carry data signals, these adapters are your best bets for connecting to wireless networks.
I'M THINKING about this today because of an excellent article I read in the online edition of IEEE Spectrum  magazine, written by Gregory Staple and my friend Kevin Werbach. Entitled "The End of Spectrum Scarcity," it convincingly presents a view that I'm still not sure I can accept, to wit: Soon, we will have all the radio frequencies we need for all the technology we want to implement.

My immediate reaction to that is, "Keep dreaming." While technology is both increasing spectrum efficiency and raising the upper limits of the frequencies we can use, not all frequencies are created equal, and spectrum efficiency often comes at a price measured in both dollars and performance.

All these new technologies must be carefully designed to coexist with existing uses and users of radio frequencies. For example, I've been writing lately about the ongoing fight over broadband over power line (BPL), which could possibly cause worldwide radio interference.

Likewise, when people talk about ultrawideband, which uses a huge swath of radio spectrum but no single frequency for long enough to be noticed, I wonder how many of these systems can coexist without interfering with whatever is already using those frequencies. Maybe ultrawideband really is magic, but I'm reminded that rarely is the lunch free.

THEN THERE ARE the terrestrial relays used by the satellite radio companies, Sirius and XM. Those relays have been accused of raising the noise floor on neighboring frequencies used by Wi-Fi systems. I'm not sure how well-founded those allegations are, but they're worrisome.

At the same time, it's possible to fit a lot of information into a little swath of spectrum. Those satellite radio systems, for example, are cramming all that programming into a little bit of space--just 25MHz of bandwidth. The low end of the spectrum from 0 to 25MHz manages to contain the AM broadcast band, some radio navigation, all the ham and shortwave broadcast bands, and almost all the frequencies capable of global reach. Wi-Fi started out using only 84MHz of spectrum.

Technologies like mesh networks (which use a zillion transceivers to create ad hoc data networks) exploit frequencies beyond 1GHz. But there are limitations up there. At those high frequencies, antennas generally have to be pointed right at one another for communications to take place. And many of these high frequencies really don't like to travel very far; windows, the leaves on trees, and passing thunderstorms can physically block them.

And you can't ignore the question of power. People often talk about how little power mesh networking products use. Of course, if you add all the devices together, the total power output is substantial. Remember that at high power levels, these frequencies cook things. There have been suggestions that even at low power (like what your cell phone uses), such products are capable of causing cancer.

Now I'm not saying radio frequencies (RF) cause cancer. But I'm very concerned about living in a world with an unlimited amount of microwave signals passing through my body. My prediction is that, if we look closely at this, we'll end up with some fairly strict and perhaps low limits to RF exposure. That or we need a better cancer cure.

I'M ALSO concerned about how the radio spectrum is being monetized. Some genius decided that that best way to assign new frequencies was to auction them off. (The proceeds from which were supposed to help pay off the national debt.)

That didn't work out quite as planned. If we're moving from scarce radio spectrum to abundance, as the Spectrum  article promises, these frequencies won't be worth auctioning off. Which means that, instead of a "marketplace solution," the FCC may actually have to set a regulatory policy. That scares me, because the FCC is (as I have said before) a lapdog to monied interests, which it somehow equates to public interest.

Finally, let me mention the marketplace and public interest, though in a different context. People seem to think there is a bottomless pot of money to pay for all this new technology. And there seems to be an assumption that the public--the marketplace--has the interest and the ability to pay. I'm not certain that's the case.

So while we may indeed be moving from scarce spectrum to abundance, it will take a while (think about the glacial conversion to digital television). And the benefits of that shift are still, to me, uncertain.

What do you think? Is the end of spectrum scarcity here? Is that a good thing? TalkBack to me below! 

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