Spectrum: What it is, and why it matters
A common thread in a few communications policy debates today is the scarcity of spectrum in America. Whether discussing the possible merger of AT&T and T-Mobile USA, or the issues surrounding LightSquared and GPS systems, spectrum is a term that pops up repeatedly.
Electromagnetic spectrum at a physical level is a scientific and mathematical concept, something scientists and engineers chart and study, but it also has an impact on our daily lives. We must therefore have a basic understanding of the subject. Otherwise, how can we make intelligent policy decisions?
So, what is spectrum? Spectrum is a way of categorizing light waves by their frequency. It’s frequencies of light that distinguish the colors we see, such as red and blue. We can also think of radio waves, X-rays and every other range of spectrum as some color of light that only our gadgets can see. Different users of spectrum must use different “colors” or else they will interfere with each other, in the same way that two red spotlights will merge into a blur if they are shined on the same spot.
For the purposes of telecommunications, arguably the most important difference between one frequency and another is the size of the light waves themselves. The higher the frequency, the shorter the wave length. Long-range communications — such as television, radio and mobile phones — require waves so large, they are able to pass through objects and travel far. What good is a phone you can only use outdoors? It’s these far infrared parts of the spectrum that are useful for broadcasts and long-distance communications. Like beachfront property, the natural world only gives us so much prime broadcast spectrum.
Our uses for that prime broadcast spectrum are unlimited. Consider radio, television, GPS, cellular phones, wireless Internet, air traffic control and first responder communications. All of these compete for access to that finite range of spectrum.
It’s up to the FCC and ultimately the Congress to balance these competing interests and ensure all needs are met. Remember the legally mandated transition to digital television? We made old televisions obsolete, but by switching to new technology we greatly reduced the spectrum used by broadcast stations. What was left was free for use by first responder and civil defense communications, and of course wireless phone and Internet services.
However the more wireless services we use (consider 2G voice and text, 3G data and the new 4G technology coming out), the more competing companies offer wireless services, and the more of us that use wireless, the more spectrum we need to devote to wireless phone and Internet services. Some say we’re addicted to oil, but we’re just as addicted to wireless spectrum.
That’s why LightSquared and the GPS manufacturers are fighting: each claims the other is intruding on its precious spectrum. That’s why AT&T is fighting so hard for T-Mobile USA: AT&T wants to augment its spectrum from T-Mobile’s holdings. That’s why the late “super committee” was lobbied about both incentive auctions and white spaces: spectrum policy is vital to public and private interests in this country. Until we make it a national priority to reassign enough spectrum to keep up with our national wireless Internet use, we will continue to see more spectrum flare-ups in the policy arena.
AT&T and LightSquared are the symptoms. Spectrum scarcity is the problem.
Neil Stevens is a freelance software and web developer in Southern California. He contributes in his spare time to RedState.com and UnlikelyVoter.com.