Reed prefers to talk about "RF [radio frequency] color," because the usual alternative is to think of spectrum as some large swatch of property. If it's property, it is easily imagined as finite and something that can be owned. If spectrum is color, it's a lot harder to think of in that way. Reed would recast the statement "WABC-AM has an exclusive license to broadcast at 770 kHz in NYC" to "The government has granted WABC-AM an exclusive license to the color Forest Green in NYC." Only then, according to Reed, does the current licensing policy sound as absurd as it is.

But if photons don't interfere, why do our radios and cellphones go all crackly? Why do we sometimes pick up two stations at once and not hear either well enough?

The problem isn't with the radio waves. It's with the receivers: "Interference cannot be defined as a meaningful concept until a receiver tries to separate the signal. It's the processing that gets confused, and the confusion is highly specific to the particular detector," Reed says. Interference isn't a fact of nature. It's an artifact of particular technologies. This should be obvious to anyone who has upgraded a radio receiver and discovered that the interference has gone away: The signal hasn't changed, so it has to be the processing of the signal that's improved. The interference was in the eye of the beholder all along. Or, as Reed says, "Interference is what we call the information that a particular receiver is unable to separate."

But, Reed says, "I can't sign on to 'It's the receiver, stupid.'" We have stupid radios not because we haven't figured out how to make them smart but because there's been little reason to make them smart. They're designed to expect signal to be whatever comes in on a particular frequency, and noise to be everything on other frequencies. "The problem is more complex than just making smart radios, because some of the techniques for un-confusing the receiver are best implemented at the transmitter, or in a network of cooperating transmitters and receivers. It's not simply the radios. It's the systems architecture, stupid!"

One of the simplest examples of an architecture that works was invented during World War II. We were worried that the Germans might jam the signals our submarines used to control their radio-controlled torpedoes. This inspired the first "frequency-hopping" technology: The transmitter and receiver were made to switch, in sync, very rapidly among a scheduled, random set of frequencies. Even if some of those frequencies were in use by other radios or jammers, error detection and retransmission would ensure a complete, correct message. The U.S. Navy has used a version of frequency-hopping as the basis of its communications since 1958. So we know that systems that enable transmitters and receivers to negotiate do work -- and work very well.

So what architecture would Reed implement if he were king of the world or, even less likely, chairman of the FCC?

Here Reed is dogmatically undogmatic: "Attempting to decide what is the best architecture before using it always fails. Always." This is in fact a one-line recapitulation of the end-to-end argument he and his coauthors put forward in 1981. If you want to maximize the utility of a network, their paper maintained, you should move as many services as feasible out of the network itself. While that may not be as counterintuitive as the notion of photons not occupying space, it is at least non-obvious, for our usual temptation is to improve a network by adding services to it.

That's what the telephone companies do: They add Caller I.D., and now their network is more valuable. We know it's more valuable because they charge us more for it. But the end-to-end argument says that adding services decreases the value of a communications network, for it makes decisions ahead of time about what people might want to do with the network. Instead, Reed and his colleagues argued, keep the network unoptimized for specific services so that it's optimized for enabling innovation by the network's users (the "ends").

That deep architectural principle is at the core of the Internet's value: Anyone with a good idea can implement a service and offer it over the network instead of having to propose it to the "owners" of the network and waiting for them to implement it. If the phone network were like the Internet, we wouldn't have had to wait 10 years to get caller I.D.; it would have been put together in one morning, implemented in the afternoon, and braced for competitive offerings by dinnertime.

For Reed the question is, What is the minimum agreement required to enable wireless communications to be sorted out? The less the system builds into itself, the more innovation -- in ideas, services and business models -- will arise on the edges.

Recent Stories