From Static to Dynamic

The switch from static to dynamic wireless communication has huge consequences.
Technical approaches created to solve technical problems turn out to have major policy, business, and even social consequences.
These consequences, such as the possibility of replacing spectrum licensing with “commons,” have generated a great deal of attention.
They would not be possible without the technical advances we have described so far.

The first and biggest consequence of the radio revolution is that licensing of spectrum frequencies is no longer required.
Recall that the original basis for spectrum licensing by the government was the fear of ruinous and pervasive interference.
If devices can operate with sufficiently low power and high intelligence to avoid one another, exclusive rights are no longer necessary to prevent interference.
With a properly defined environment, users effectively can’t prevent each other from communicating.
That opens the door for a new regime that allows anyone to transmit within general technical guidelines.

If there is enough capacity to support a commons,exclusive rights are unnecessary. By analogy, the ocean is not infinite in size, but it is large enough that ships can be trusted to navigate around one another.
The ships, like dynamic wireless devices, can intelligently alter their routes to avoid collisions. There is no need to give companies exclusive shipping lanes, and prohibit other ships from using those routes unless they pay a toll.

Technology is making the wireless world look more and more like the ocean.

The second implication of dynamic wireless systems is that the business structure of markets changes. Static systems necessitate exclusivity.
The downside of exclusivity is that no one else can contribute to a network. The licensee must bear the total cost of building network infrastructure.
The licensee typically recovers that cost by charging.

There are, however, serious downsides. Deployment is slow because it is costly and requires proven models for recouping that cost. Innovation is constrained because only a few licensees control access to the market.
Uniformity and interoperability are enforced by the licensee, but services and equipment are costly because they are provided in limited volumes and based on proprietary standards.

As wireless devices become more intelligent and commons arrangements become viable, new market structures become possible.

Because those devices run on standards defined by industry bodies rather than mandated by spectrum licensees, there can be open, competitive markets to build better and more cost-effective equipment.
We move, therefore, from a market for centralized infrastructure and proprietary services, to a market for consumer devices, software, and ancillary services.

Users pay a significant fraction of the total network build-out costs directly, by purchasing hardware, greatly reducing the expenses service providers must undertake.
For many services, there are still core network costs—for access points, backhaul to wired Internet backbones, authentication, roaming, and security—but these are limited compared to the allencompassing network build-out that licensed operators must undertake.
“Change the technology,and the economics the law of spectrum must change, too.”

Furthermore, dynamic wireless devices allow for markets with greater diversity at several points. Many equipment vendors, several providers, and application or content providers can compete, because there is no mandatory control point and each provider can leverage the infrastructure built by others.

Intelligent or dynamic spectrum management techniques may be used in any regulatory environment. However, the nature of spectrum regulation heavily influences incentives for deployment of intelligent devices.
The traditional, and still dominant, environment is exclusive licenses for frequency bands.
Spectrum licensees have incentives to squeeze as much capacity as possible out of their spectrum.
On the other hand, they have incentives to make the devices users must purchase as inexpensive as possible.
In a static system, the money is all in the service; the devices are dumb. There is no need to make them robust against interference, because interference from other systems is prohibited and policed by the FCC.

Similarly, there is no great incentive to make the devices flexible, because the service provider is focused only on supporting its own service.
Indeed, to keep the cost of switching to another service provider high, licensed providers have an incentive to discourage software-defined radios, which could switch frequencies (and hence service providers) at the click of a mouse.

All that changes in a commons environment.
Because wireless devices in a commons have no legally guaranteed protection against interference, they must guard against it using technical means.

Fortunately, that is what dynamic wireless devices are good at.
Static systems create incentives to make the receivers as dumb as possible.

Dumber means cheaper, after all.
Because the central transmitter does the heavy lifting, there are no significant benefits from intelligence at the edge devices.
When end-user devices become dynamic, however, they contribute to the integrity and performance of the overall system.

Making them smarter and more robust improves performance.
And without license restrictions keeping other devices from transmitting on the same frequencies, robustness based on intelligence is the only path open.

“We need to think of ways to bring [WiFi]
applications to the developing world so as to
make use of unlicensed radio spectrum to
deliver cheap and fast Internet access.”

— UN SECRETARY GENERAL KOFI ANNAN

WiFi is the most prominent unlicensed wireless technology available today.
It is a family of spread spectrum wireless local area networking standards designed to allow users to send and receive data at 11-to-54 Mbps within a few hundred feet of another WiFi device or access point.
WiFi is a great case study for the impact of dynamic wireless technologies.

Wireless data networking services have been What made WiFi such a success, especially compared to previous wireless data systems.
After all, WiFi provides only short-range connections; on its own, one access point can’t provide ubiquitous coverage in a neighborhood or city.
WiFi has thrived because it has benefited from an ecosystem that could only exist with the type of technology it uses.
Because WiFi is a low-power, spread-spectrum technology, WiFi devices can coexist without the requirement of spectrum licensing to prevent interference.
That means there is no need for service providers, cell towers, controlled hardware markets, or expensive spectrum licenses.
Anyone can buy a WiFi device and establish a network.

Because WiFi is an open standard and an equipment-centered rather than service-centered market (again, both of which flow from the nature of the technology), costs are subject to computer industry downward pressure.

Broadband connectivity to homes is a topic of great consternation in the communications industry today.
Telephone companies are deploying DSL and cable TV operators are deploying cable modem systems.
However, many millions still have neither available to them, and a greater number have only one option.
Prices of these broadband services, approximately $50/month, are high compared to the rest of the world.

These services are generally asymmetric,providing far more bandwidth down to the user than up from the user to the Internet. Combined with terms of service restrictions, this architecture limits users from running home servers and other actions. For business users, who typically need higher bandwidth than homes, the only viable option is often a traditional T-1 line at $1,000 per month or more.
There is thus great interest in alternatives.

Basic WiFi or its variants, 802.11a and 802.11g,cannot simply be put into service for last-mile deployments.
WiFi is a short-range technology designed primarily for connections to a nearby hotspot.
Even if every home in a neighborhood had a WiFi access point, few of those nodes would see one another.

We can, however, envision scenarios for unlicensed wireless last-mile connectivity based on technology that is in the market or likely to be soon.

For businesses or residences wanting more bandwidth, an 802.16 wireless MAN technology could be used to deliver tens of megabits per second over many miles.
This same technology, or a variant, could be used to reduce the costs of backhaul, replacing costly wired connections.

An end-user would buy a device, whether a dedicated piece of wireless hardware, a broadband “residential gateway,” or a piece of general-purpose hardware such as a laptop. The device could be designed to operate with a particular unlicensed wireless network, it might be deployed by a service provider, or it might have “discovery” capability to automatically locate and connect with nearby access points or wireless end-users.

It is typically assumed today that last-mile broadband networks are designed to provide access to the Internet .
Certainly, any broadband customer will want to access Internet-based services available through the World Wide Web.

Mobile phone networks today are self-contained entities.
In the U.S., for example, there are six competing national networks.
Each has its own network of transmission towers.
If you are within range of five of those towers, but not the one for your service provider, you won’t get service.
Things are a little better in Europe, where universal adoption of the GSM standard allows for more roaming agreements between carriers, but each carrier still must maintain its own complete network.

As mobile phones evolve into SDR devices, the structure of the business may change. Carriers will be able to share infrastructure much more widely, because their subscribers will be able to transparently access transmissions from whatever.

Think Globally, Act Locally:

Governments should recognize and embrace the tremendous potential of the radio revolution.

Because radio signals do not respect political boundaries, spectrum policy is inherently international.
Equipment vendors can better justify the investment needed to develop new products when they can foresee a global market.

As a general matter, the federal government should recognize that the objective of spectrum policy is not to minimize interference, but to maximize usable capacity.
It should move away from command-and-control toward more flexible approaches, recognizing that there is value in a diversity of legal regimes.
In experimenting with exclusive property rights and secondary markets, it should balance the potential gains against the opportunity cost.

Because spectrum has long been highly regulated and controlled by a small group of licensees, opportunities for experimentation have been limited.
WiFi happened almost by accident, because the 2.4 GHz “junk band” spectrum was so congested with devices such as microwave ovens that it was considered unusable for licensed systems.

Because the band was unlicensed and open to public access, engineers and companies interested in wireless local area networking could use it for their commercially and technically unproven technologies.
The government should ensure that its rules for unlicensed bands allow for the broadest possible experimentation.
It should also ensure that it provides ample opportunities for experimental authorizations that go beyond the existing rules, so that innovators can develop novel techniques.

A large block of high frequency spectrum (above 50 GHz) that is currently unassigned could be designated as an open space for completely unregulated unlicensed activity.

I add my own vision of Wireless quality:

A good VoIP transmission makes your voice so sharp that you can say " Dog" in Europe and it "bytes" somebody in China.