Wednesday, December 26, 2007

The Dark Side of Spectrum Renewal

Fifty years ago, the federal government was avidly supporting a process called urban renewal. The idea was that some areas in major cities were just too far gone to be refurbished. Instead, whole city blocks were demolished and rebuilt as housing projects or re-purposed to support new highways out to the suburbs.

Today, we're seeing a parallel approach to radio frequency spectrum allocation. In this case, portions of the RF spectrum are considered too valuable to be used for what are considered to be out-of-date technologies. Most notable are the upcoming shutdowns of over the air analog television broadcasting and analog cell phone service.

What's driving this "spectrum renewal"? It's not lack of use or demand by the public. Just the opposite is true. Hundreds of millions of analog TV sets built over the last 60 years are running just fine, to the delight of their owners. Sure, everybody wants a shiny new HDTV set so they can see the grain of the football or the individual hairs in the lion's mane on their own big-screen. But how many of us can afford to instantly replace a collection of a half-dozen sets acquired over the years and deployed throughout the house?

The AMPS mobile phone system is in a similar pickle. Sure, all the cool new cell phones and Blackberries are 100% digital. But there may be as many as a million mobiles still using the original analog cells on the AT&T, Verizon Wireless, and Alltel networks. AMPS is at the heart of about 500,000 OnStar equipped cars sold since 2003. It's also used by as many as 400,000 home security alarm systems. When the service is shut down on February 18, 2008 many of these users will be left in the lurch as their systems are too "old" to be upgraded.

So if the public isn't clamoring to get rid of these technologies, then why is it happening? The answer is fierce competition for a scarce resource.

It wasn't always this way. When FM radio was developed it was in addition to the already popular AM service. Radios were mandated to receive both bands. Over the years, FM listenership has grown and AM's has declined. But both are still in service. When UHF television channels were opened, nobody demanded that the VHF channels be turned off. New sets had UHF tuners in addition to the familiar VHF tuners. Even color television was mandated to be backward compatible with the millions of black and white sets already in use, so that no TVs would become virtual snow globes.

They will after February 17, 2009. Hundreds of millions of analog TVs that work just fine today will receive no over the air signals after that date. Some will live on, with signals provided for awhile by Cable TV systems, Satellite receivers or ATSC converter boxes. Many more will take their toxic chemicals with them to an early grave in the city landfills.

The problem with enabling new technology is oddly similar to dealing with decaying factories, now moved to China, or run down residential areas long abandoned to the poorest of the poor. Will Rogers once quipped: "Invest in land. They ain't making any more of the stuff." Today he might say the same thing about spectrum.

The radio frequency spectrum encompasses everything from power line radiation to radio, TV and cell phone channels, satellite transmissions, heat, light and out to Gamma rays. Back when our technology could only use small parts of this spectrum, you could locate new services on undeveloped frequencies. But unused frequencies are hard to find now. Worse, everybody wants the prime real estate areas of the spectrum. Those are the frequencies that offer large amounts of bandwidth to accommodate voice, data and video services, and also have good propagation characteristics. That means covering large areas and easily penetrating buildings. Generally, the higher you go in frequency, especially in the coveted microwave bands, the easier it is for buildings, tree leaves, and rain storms to block the signal.

There's a sweet spot in the spectrum covering the UHF TV and cellular bands around 700 to 900 MHz that offers an especially good combination of high bandwidth and excellent propagation. Squatter's rights would say that AMPS mobile should stay right where it is and digital TV signals should be an addition to the analog broadcasts already established. But demand for more cell phones, more public service radio channels and wide area wireless broadband services that have no place to locate in the spectrum creates a competitive pressure to tear down the old technologies and replace them with new ones.

Urban renewal programs got a black eye for destroying established neighborhood cultures, tossing people out into the streets and favoring those with wealth and connections. Spectrum renewal has an equally dark side to it. The billions of dollars that the FCC is collecting from spectrum auctions has certainly hastened the demise of analog television. BPL or Broadband Over Power Line radiation threatens to poison the short wave bands for ham radio operators and short wave listeners. All analog radio services seem likely to get the ax at some future date. In fact, if the Internet Protocol networking becomes ubiquitous, any non-IP services could meet their demise.

Is this a good thing or a bad thing? In the long run it's a necessary thing, as long as we want more and better mobile services. The real and perhaps unmet challenge is to minimize the pain and disruption as new technologies displace and replace the ones we've become accustomed to.

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