Global Trend

The Radio Frequency Spectrum Explosion

In the last few years, the electromagnetic spectrum has quietly become a critical part of contemporary life. It enables you to communicate with mobile phones, use remote controls, tune in TV stations, pop corn in the microwave, open your car door without a key, listen to radio stations, and surf the Internet when you’re sipping coffee at Starbucks.

How we cordon off some parts of this wide spectrum of frequencies is becoming so crucial that battle lines are forming that will have an impact on thousands of businesses and hundreds of millions of consumers.

But before we explore where this is all leading, let’s consider some background. Electromagnetic radiation has a wide range of frequencies, measured in wavelengths that are determined by how rapidly the electromagnetic waves vibrate. Along this spectrum are a series of frequency bands, some of which are regulated by the government, and some of which are paid for by businesses.

Television and radio stations, for example, have exclusive use of certain frequencies so that they may broadcast their content without interference ? that is, without competing companies sending out signals over the same frequency and hence muddying the clarity of the content. The government, specifically the FCC, regulates the telecom and media use of these frequencies as a way of policing what they consider a limited resource for the public good.

Last July, the FCC granted Nextel access to areas of the spectrum in exchange for avoiding frequencies that caused interference with police, fire, and hospital radio systems. If this arrangement is finalized, Nextel will pay the government $3.25 billion for the privilege of occupying the new spectrum. Nextel’s competitors are up in arms, claiming Nextel got a bargain at the expense of the public welfare. Whatever your point of view, the staggering prices for small amounts of spectrum real estate attest to the potential value that can be created by those who control it.

But there is another, starkly contrasting view of the airwaves. Consider the popularity of WiFi Internet connectivity. People whose laptops have wireless capability can enter a hot spot and dial up their Internet service to do whatever business they want. Some sections of cities are preparing to make WiFi available to everyone, and even entire regions are gearing up.

WiFi operates in the area of the spectrum that the government doesn’t regulate. It is among the bands that the FCC has purposely left unlicensed in order to foster technological experiments. If activity on those bands interferes with other users, the parties are left to sort it out among themselves.

This situation reflects two schools of thought about how the electromagnetic spectrum should be used. The traditional school of thought has a linear history. Because of the limitations of radios themselves, if two signals were received at the same time, the result would be noise. So the government passed legislation that divided the frequency spectrum and doled out rights in various ways to avoid noise.

When economists, notably Ronald Coase, determined that the government oversight of scarce spectrum resources was inefficient, governments began selling slices of the spectrum by auction. However, today’s auctions only account for roughly 2 percent of the radio frequency spectrum. The rest is either given to broadcasters with the understanding that part of their gift involves broadcasting content for the public good, or assigned to specific user segments such as the military, civil aviation and so forth.

However, under the current system, much of the spectrum is underutilized, if not outright wasted. The National Telecommunications and Information Administration, which oversees the federal government’s radio frequency use, estimates that 95 percent of its allotted spectrum is not being used at any one moment.

The other school of thought, the one gaining momentum today, is referred to as the “open spectrum” movement. It argues that there is an abundance of spectrum for anyone to use. Open spectrum proponents believe that the idea of spectrum scarcity is based on a misunderstanding of the underlying physics.

According to Kevin Werbach, an associate professor at the Wharton Business School, one myth about electromagnetic waves is that if they meet, they’ll bounce off each other. They don’t. They move right through each other.

What that means is that radio interference is not a physical problem; it’s a limitation of radios and other receivers being unable to distinguish between signals. “Radio interference really doesn’t exist,” explains David Reed, co-director of the viral communications lab at MIT Media Laboratory. “It is not a property of radio waves, but rather a byproduct of badly designed receivers.”

According to The Economist, there are several ways new technology could capitalize on this insight. One is “wideband” ? a method of spreading a signal across a wide range of frequencies at low power. This is the opposite notion to casting a high power signal over a narrow band of frequency. WiFi is an example of wideband.

But most backers of the “open spectrum” idea are less enthusiastic about wideband than they are about the prospect of a so-called, software-defined radio, or SDR. Such a device has been understood for some time, but it was impractical for most applications. As Reed explains, “Twenty years ago it was pointless to run SDR on anything but a supercomputer. Today we all carry around that much computing power in our pockets.” The implications for this change in technology and its applications are enormous. “Communication is no longer a matter of frequency, but of computation,” says Kevin Kahn, the head of communications research at Intel.

A normal radio responds to a particular frequency band. To change the kind of signal that radios can receive ? for example, FM rather than AM ? the radio needs to use a different circuit. SDRs are not so constrained. Its software searches for any signal to process. A recent issue of New Scientist describes a software-defined mobile phone that can shift from its regular cell phone frequency to a faster WiFi frequency whenever it is near a hot spot. Intel already has a prototype of this phone it calls the Universal Communicator. It uses four communication protocols: GMS, GPS, WiFi, and Bluetooth.

But even the Universal Communicator doesn’t really do justice to SDR’s potential for changing the communication game. With software-defined radio, you can broadcast anywhere over the entire radio spectrum instantaneously and at no appreciable cost. It represents a potent challenge to how we regulate the airwaves.

A company called GnuRadio is already developing software-defined radios and plans to distribute them for free ? to make the point that software radio is beyond regulation.

Naysayers to open spectrum, which of course include the telecom companies that have already ponied up vast sums for their slice of the frequency pie, are skeptical about the idea. Brian Fontes, a Cingular lobbyist, warns, “Unlicensed spectrum is sounding like crack cocaine: the ultimate high that solves all your problems.”

Critics fear that it will create some new problems while solving others. Stagg Newman, a former chief technologist with the FCC, understands that creating a balance between license-holders and innovators will take time. Cell phone regulation started in the 1960s, and the work wasn’t finished for 20 years. SDR technology exists now. What happens when people simply start using it? Newman asks, “Suppose someone fiddles with the software and suddenly they’re operating on the air traffic control frequency?”

To prevent such a catastrophe, regulators are considering three approaches for controlling the technology:

First, make sure the hardware identifies the origin of the software.

Second, make the receiving device evaluate downloads to ensure they conform to certain standards.

Third, design the devices so that they are unable to use software that runs afoul of certain protocols.

And there might be other ways to address the concerns of licensees, while at the same time allowing for more spectrum accessibility. For example, regulators could permit transmitting signals in the unused portion of a licensed spectrum without interfering with the license holder’s transmissions. This “underlay” might diffuse the political disruption of asking established users to vacate their bands.

Whatever the accommodation, FCC chairman Michael Powell has made it clear that he favors unlicensed bands. But there are others who disagree. Among them is Dewayne Hendricks, head of the wireless Internet service provider the Dandin Group, who contends that “all the spectrum we need is already in play.”

Besides, with the proliferation of digital TV, broadcasters will not need as much bandwidth. This is especially promising because broadcasters occupy prime spectrum real estate ? those low frequencies that are better at navigating weather and walls. This is what allows people to receive an FM station in their cars even when driving through a tunnel.

And so even a very small amount of low-frequency unlicensed bandwidth would have a substantial impact. It could be the vehicle by which new cable and modem connections could be made, without the crippling expense of tearing up roads and laying physical cable. Ken Griffin, who runs Microsoft’s spectrum initiatives, points out, “Amazing things have been done with WiFi in garbage spectrum. The pregnant question is: What if we took a tiny amount of good spectrum and repurposed it?”

Looking ahead, here are five important events we see emerging from this phenomenon:

First, regulators will establish an open spectrum system whereby frequencies are shared. Michael Powell of the FCC isn’t alone in pushing for this change. The National Telecommunications and Information Administration, which regulates spectrum in the U.S., proposed in June 2004 that it select, along with the FCC, another 10MHz slice of spectrum that can be opened up for experimentation.

Second, SDR will threaten the profits of media and telecom companies by letting users pirate the airwaves. SDR enthusiasts ? who have already acquired software that decodes HDTV ? will soon target proprietary frequencies and tap into mobile phone protocols, such as GSM and UMTS, to use the service and bypass the provider.

Third, license holders can be expected to fight the opening of the airwaves. One argument they are likely to use is that SDRs can have mischievous ? even criminal or terrorist ? applications.

Fourth, software-defined radio in some forms will start to crop up in a variety of devices regardless of regulatory issues. Some of the earliest applications may be in computers and PDAs.

Fifth, a revolutionary new device called the “agile radio” will emerge sometime after 2014. This device, based on U.S. military research into SDR, will be able to switch instantly and automatically from cluttered airwaves to empty spaces in the spectrum. In a recent report, Business Week3 called the agile radio “the ultimate solution to the wireless future.” Funded by DARPA, this amazing device promises to expand our ability to use the airwaves by 1,000 percent.

References List :
1. The Economist, August 14, 2004, "On the Same Wavelength." ⓒ Copyright 2004 by Economist Newspaper N.A., Inc. All rights reserved.2. New Scientist, June 26, 2004, "WiFi: The Urban Positioning System," by Celeste Biever. ⓒ Copyright 2004 by Reed Business Information, Ltd. All rights reserved.3. Business Week, December 15, 2003, "Beyond Wi-Fi: A New Wireless Age," by Catherine Yang. ⓒ Copyright 2003 by The McGraw-Hill Companies, Inc. All rights reserved.