The Open Spectrum Revolution

Kevin Werbach is an independent technology analyst that advises companies and writes about emerging technologies in communications, media, and software. The former editor of Release 1.0, he also previously serves as Counsel for New Technology Policy at the FCC.

Kevin Werbach is an independent technology analyst that advises companies and writes about emerging technologies in communications, media, and software. The former editor of Release 1.0, he also previously serves as Counsel for New Technology Policy at the FCC.


In his talk at South by Southwest Interactive, Werbach addressed the potential offered by open spectrum wireless communication, indicating its promise to foster innovation, revitalize the technology industry, and lower barriers to connectivity and collaboration. What follows is a partial transcript of his presentation.

I’m going to talk about the next communications revolution, which I’m fully convinced is as important and as significant as the last communications revolution, the Internet. And that’s open spectrum. I call my talk “Die Kitty Die!!!”

Right now, our thinking about spectrum is based on the idea that spectrum is scarce, that wireless capability is limited. What if spectrum wasn’t scarce? What if there were an ocean of wireless communication capacity? Spectrum is not scarce in the way we always thought it was. Spectrum is not scarce. We’re talking about radio waves. Radio waves run through one another. In free space, they propagate indefinitely.

Why do we think that a set of rules and expectations based on the technology of the 1920s will work with today’s technology? The reality is that we make spectrum scarce. We make spectrum scarce through regulation and technological architecture.

The idea we have is that when two people want to communicate, they send a message across a medium we call the spectrum. That thing has definite properties, and we can draw a chart of it. We have this idea that spectrum is a thing you can put in a box, chop up into different frequencies, and allocate to various users. The idea is that the spectrum is all used up. It’s all full.

The other metaphor is that of land. We think of spectrum like we think of a physical piece of property. We can’t build two houses on the same lot. If someone builds a noisy factory, I can’t build a house next door.

That’s not the way it works. Ultimately, radio waves are energy, and we understand them in the very deep and mysterious physics of quantum mechanics. Einstein was once asked to explain how radio works. He said, first let me explain how the telegraph works. The telegraph is a cat. Its tail is in one city, and its head is in another. You pull its tail, and it meows and screams in the other city. Radio is the same thing; only there’s no cat.

We need to stop thinking about the cat. The real world is different than that diagram I showed you where the spectrum was all full. Look at this chart created by Darpa. Most of it is empty. At least 90%, probably much more, is empty at any particular place, time, and frequency, That capacity could be used for more communication.

So what is the spectrum? It’s no one thing. It’s the collection of devices that we use. They create the network. The device that was developed 40 years ago, say, the telephone, will probably not be as good at picking up reception as something made today. Devices create more capacity. They allow more services to exist that happened before. It’s creating more spectrum.

Technology now allows us to exploit that potential. The idea behind open spectrum is that a set of technologies, user scenarios, and customer demand can create new potential for communication. Radio has remained a black art, but more and more of the functionality of radio devices is software. And it’s software that runs on common platforms. The other thing thats happening is that we’re beginning to understand a new set of techniques to use wireless communication.

What we’re trying to optimize is not one device or two devices, but a system of devices. It’s not just a network, it’s a network of networks. If we start to utilize the technology, then we open up a whole new set of techniques in which systems cooperate. I call it the Radio Revolution.

WiFi is something that we’re all very excited about, but it’s just the tip of the iceberg. WiFi is a proof of concept. The basic properties aren’t that new. Spread spectrum was first described in the 1940s. What hasn’t happened is taking those techniques and taking them to their logical potential. WiFi shows that this stuff works. Before WiFi, people could talk until they were blue in the face about a system in which people could share spectrum. The spectrum was out there. It was called the junk band. And that’s what WiFi jumped on.

This is happening despite the fact that WiFi is far from the cutting edge. What is the cutting edge? Take spread spectrum to its logical conclusion, and you get wideband underlay. Reduce the power enough, and it becomes invisible to the rest of the system. It falls below the noise floor of other existing services. Then there’s agile, cognitive radio. That would jump around taking advantage of temporary holes. Antennas are also improving. Using directionality, adaptiveness, and diversity, antennas become intelligent devices and do more communication. Finally, mesh networking, or using devices to relay the communication. This is being done for last-mile work right now, where houses would relay signal to their neighbors.

What does all this mean? There will be a vast increase in capacity. It also means that we don’t necessarily need traditional licenses. Dating back to the 1920s, people needed to get licenses from the government. Now we can have an ecosystem emerge. That will lead to rapid innovation, and we’ll be able to kill that cat.

What do we need to do? The first thing is make available the capacity for unlicensed use. That’s where there’s a playing field for innovation. You want to have a platform on which you can deploy a great new technology that works. That’s what happened on the Internet with Amazon, Ebay, and Yahoo. We also need to continue looking at ultra-wideband and broadcast band. The bands for broadcast television are the best spectrum, and most of it is dark. Maybe we should let that be used for something? We could also have “anything goes” bands at ultra-high frequencies.

But we can go beyond where government is looking today and think about the real potential of wireless communication. The supercommons is all of the capacity that’s around. Here’s the idea: There is no thing out there called spectrum. What government regulates is not that thing, but devices. They tell companies what they can build, and they tell people what they can do. The problem is that any set of regulation that determines how devices can act is inefficient. You can always come up with a new technology to allow for more capacity. If there’s no way to come up with a set of rules that’s efficient, let’s have no rules.

Let’s have a universal transmission privilege. Anyone can transmit anything, anytime, in any way. This is not anarchy. This is the supercommons. It can exist alongside the existing regime. Let’s allow communication to exist that uses free, unexploited capacity. We can also come up with a set of rules to resolve disputes. We’re only using a tiny sliver of what’s out there. We could use tort law, which considers the duty of care, which could be applied to wireless communication. There are also other safe harbors and back stops, but an important element most people don’t think about is the companies that make the devices.

Manufacturers want to sell as many boxes as they can. That means it’s in their interest to sell a box that plays well with other boxes. That set of incentives pushes toward cooperation. What I’m saying is not that radical. The acoustic spectrum, which we’re using for you to hear me talk right now, is not that different. Imagine 50,000 people in a football stadium. People are screaming at the top of their lungs, but you can still carry on a conversation. We don’t have governmental regulations determining who can talk at a football game.

What’s happening now is extremely powerful. What if there were 500 million broadcast channels? What if every person could carry a device that was a broadcast channel? We’re just starting to scratch the surface with WiFi, but we’re nowhere near the full potential. This is part of a broader trend toward decentralization. Centralized power is very precarious because there’s one single point of failure.

There’s an ocean of wireless capacity out there. But here’s the question: Can we handle the truth?

Update: The PowerPoing presentation for Werbach’s presentation is also available.