"cognitive radio"

DARPA's Spectrum Collaboration Challenge: finally some progress towards a "Cognitive Radio" future

For 17 years, I've been writing about the possibilities of "cognitive radio", in which radios sense which spectrum is available from moment to moment and collaborate to frequency-hop (and perform other tricks) to maximize the efficiency of wireless communications. Read the rest

WiFi firmware that can detect and route around interference from non-WiFi devices

In Airshark: Detecting Non-WiFi RF Devices using Commodity WiFi Hardware (PDF), researchers from U Wisconsin (Madison) document a firmware for WiFi access points that can detect and dynamically adjust to interference from vacuum cleaners, baby monitors, and other non-WiFi devices that operate in WiFi's radio spectrum. This kind of thing is the backbone of the theory of cognitive radio: devices that can use software defined radio, phased-array antennas, and cleverness to route around other devices in the band, which may, eventually, enable the a lot more data to occupy the radio spectrum. In Airshark's case, the cleverness is in using the wireless cards on the computers and other devices as a sensing array to triangulate on interference.

Airshark taps into the application programming interface of wireless cards used on access points to gather data about radio frequencies in the surrounding environment. The software has been trained to recognize signatures of various devices, and can pick them out from the ambient radio noise with more than 90% accuracy even if signals from multiple such devices are present.

False positives were .39% for environments with four or more interfering devices and using various signal strengths. The researchers found the rate was .068% for signals stronger than -80dBm. "We also found its performance to be comparable to a commercial signal analyzer," according to their research paper "Airshark: Detecting Non-WiFi RF Devices using Commodity WiFi Hardware."

Read the rest

Special Experimentation Zones to solve big problems?

Alex Steffen from WorldChanging sez, "We need lots of innovation, quickly, to solve the big problems we face. Right now, regulation, liability and social norms make certain kinds of innovation (in architecture, urban design, energy and water systems, gardening, product design and so on) extremely difficult. But what if we could set up experimentation areas to experiment with new solutions, the same way the Chinese set up special economic zones to try capitalism?"

Existence is the ultimate proof of the possible. Every time a bold new project is tried, and works, we advance our sense of the achievable. Given how much transformation we need in order to meet the challenges we face, we need many more attempts at innovation, and we're not getting them. The achievable is not advancing quickly enough. ...

In many ways, the Global North is as hamstrung in the face of bright green challenges as China was in the face of capitalism. What if the answer is a sustainability and social innovation equivalent of China's answers: a sort of "Special Innovation Zone"?

Imagine a place -- perhaps a shrinking city, or a badly savaged brownfield neighborhood -- where laws were set up to strip rules and regulations down to a do-no-harm minimum (maintaining criminal laws and protecting health, safety, workers' rights and civil liberties, but perhaps limiting liability and certainly slashing red tape and delays) allowing for wild deviations from existing patterns for buildings, systems and operations. Imagine a free-fire zone for sustainable innovations, where new approaches could be iterated and tested rapidly, and, when they work, sent to proliferate outside the Zone.

Read the rest

Radio chip inspired by human ear

MIT researchers built a radio chip inspired by the inner ear. The "RF cochlea chip" could be a key component in a "cognitive radio," a device that can determine the appropriate frequency and power consumption required and adjust itself accordingly. Such a universal radio architecture could efficiently handle a wide range of signals, from cellular to WiFi to television. From MIT News:

The RF cochlea mimics the structure and function of the biological cochlea, which uses fluid mechanics, piezoelectrics and neural signal processing to convert sound waves into electrical signals that are sent to the brain.

As sound waves enter the cochlea, they create mechanical waves in the cochlear membrane and the fluid of the inner ear, activating hair cells (cells that cause electrical signals to be sent to the brain). The cochlea can perceive a 100-fold range of frequencies -- in humans, from 100 to 10,000 Hz. Sarpeshkar used the same design principles in the RF cochlea to create a device that can perceive signals at million-fold higher frequencies, which includes radio signals for most commercial wireless applications...

The RF cochlea, embedded on a silicon chip measuring 1.5 mm by 3 mm, works as an analog spectrum analyzer, detecting the composition of any electromagnetic waves within its perception range. Electromagnetic waves travel through electronic inductors and capacitors (analogous to the biological cochlea's fluid and membrane). Electronic transistors play the role of the cochlea's hair cells.

Drawing inspiration from nature to build a better radio Read the rest

Technology Review's 10 Emerging Technologies list

Technology Review magazine has posted a special report on ten emerging technologies they think are poised to have a big impact. The technologies they cover include:

Epigentics: Alexander Olek has developed tests to detect cancer early by measuring its subtle DNA changes.

Nuclear Reprogramming: Hoping to resolve the embryonic-stem-cell debate, Markus Grompe envisions a more ethical way to derive the cells.

Universal Authentication: Leading the development of a privacy-protecting online ID system, Scott Cantor is hoping for a safer Internet.

Cognitive Radio: To avoid future wireless traffic jams, Heather “Haitao” Zheng is finding ways to exploit unused radio spectrum.

Diffusion Tensor Imaging: Kelvin Lim is using a new brain-imaging method to understand schizophrenia.

Comparative Interactomics: By creating maps of the body’s complex molecular interactions, Trey Ideker is providing new ways to find drugs.

Nanomedicine: Kames Baker designs nanoparticles to guide drugs directly into cancer cells, which could lead to far safer treatments.

Link Read the rest

Lab Notes from UC Berkeley

In the March issue of Lab Notes, my research digest from UC Berkeley's College of Engineering:

* Pinhead petri dishes on chips

* Ethanol stirs eco-debate

* Cognitive radios

Link Read the rest

Mesh wireless conference call for papers

There's an upcoming mesh wireless conference in Boulder that's looking for papers on subject like Software Defined/Cognitive Radios, GPS, Galileo, Glonass Interoperability and standards, Effective Spectrum Management and Propagation Modeling in Urban Environment.

The ISART technical program committee is soliciting papers for the 7th annual International Symposium on Advanced Radio Technologies (ISART) to be held in Boulder, Colorado March 1-3, 2005. These papers will discuss new technologies, research and development, innovative ideas, enabling technologies, standards, protocols, business practices and policies, and government regulation for the purpose of forecasting the future development and application of radio frequency technologies into the next decade.


(Thanks, Sam!) Read the rest

Kerry's science and technology plan

Boing Boing pal Tom Kalil, former President Clinton's "point person" on science and technology, suggests we take a close look at John Kerry's just-announced sci/tech plan to accelerate innovation. Worth noting in the plan, Kalil says, are promises of "increased funding for research in bio, info and nanotechnology, and more spectrum for unlicensed uses and 'cognitive' radio."

From the document:

"George Bush has failed to lead on science, technology, and innovation. He has politicized or ignored scientific and technical advice. His budget plan cuts almost every area of research that is critical to our future economic growth. And during his tenure, America’s position as a leader in broadband Internet technology has eroded from 4th in the world to 10th in the world.

John Kerry’s plan will be paid for by accelerating the transition to digital television while ensuring that Americans continue to enjoy free, over-the-air television. This will provide wireless broadband for first responders, expand the spectrum that is available for unlicensed wireless broadband and also free up $30 billion of spectrum for public auction – paying for his investments in innovation."

Link to press release. Link to PDF of the plan. Read the rest

EFF's cognitive radio comments to the FCC

I've just turned in EFF's comments to the FCC's "Cognitive Radio" docket, which asked (among other things) whether the Commission should regulate Americans' access to digital-to-analog converters and whether Trusted Computing should be mandated for software defined radios (we didn't much like these ideas).

EFF asks the Commission to consider the question of enforcement separately from the question of functionality. The Commission should allow this proceeding, and others like it, to consider the question of the characteristics of the best possible design and operation of flexible radios without regard to enforcement questions. It should allow American technologists to build the devices that make most efficient use of spectrum and allow the greatest amount of speech over the public's airwaves.

As each new type of device and operational norm is approved, the Commission shoul dask, separately, how best to police the airwaves in light of the fact that the newly approved devices will soon proliferate. It must assume that Americans should and will acquire the best and most-capable radios possible and determine how to address the problems that may arise from this reality.

Further, the Commission should seek to backstop enforcement by hardening existing radio applications against harmful interference, spoofing and other attacks: for example,if air-traffic control signals carried cryptographically secured signatures, the risk of spoofed signals would be greatly reduced. Our government has already required that airlines install reinforced cockpit doors: reinforcing the cockpit radios is a logical next step.

104K PDF Link Read the rest

FCC Cognitive Radio workshop tomorrow

The FCC is hosting a workshop on Cognitive Radio -- frequency-agile radio systems that cooperate to reduce interference and allow more communication in the same band -- tomorrow from 9AM to 5PM, EDT. There's a webcast of the event (see link below) and a 112K PDF release announcing the details.



(Thanks, Lisa!) Read the rest

Eric Blossom and Matt Ettus's talk on GNU Radio at ETCON

Here are my running notes from Eric Blossom and Matt Ettus's talk on GNU Radio at ETCON.

GNU Radio is a free software toolkit for realtime signal processing things -- radio included. Works for sonar, medical imaging, etc.

Get as much stuff as we can into software, out of hardware.

Turn all the hardware problems into software problems -- all wave forms are encoded, decoded, modulated and demodded in software.

What can you do with it?

* Conventional radio

* Spectrum monitoring

* Multichannel

* Morph mode

* Morph on the fly

* Better spectrum utilization

* Cognitive radio


Discuss Read the rest

"Easement commons" isn't enough

Michael "Director of the New America Foundation Spectrum Policy Program" Calabrese. Although easements offer some compromise, this converts common ownership of the airwaves by the American public to one where the spectrum is owned by a few. If there is any property interest in spectrum, it's the right to freely use the airwaves in your home, business and community. Preventing interference justified regulation, but increased propertization could turn sharing into trespassing.

Licenses themselves are easements against the public's ownership of the airwaves and speech rights. Flexibility can be accomplished through licenses from limited, short periods. Spectrum scarcity isn't inevitable -- exclusive licenses are scarce, not spectrum. Cognitive radio can ease scarcity, property rights foreclose their possibility.

Regarding the Big Bang -- auctioning as much spectrum as possible -- a better Big Bang could be achieved now by moving to spectrum leasing with limited terms. Rather than giving away the public's property, the FCC could offer incumbents flexible, property-like rights in exchange for modest lease payments.

Discuss Read the rest

Farber and Faulhaber's argument for commons spectrum allocation

Gerry "Former Chief Economist of the FCC" Faulhaber is presenting a paper he and Dave "Former CTO of the FCC" Farber wrote. Starting with Coase's problem: FCC allocated Spectrum by administrative fiat, in exclusive use blocks. This created massive inefficiencies. Coase proposed moving to a market allocation, with exclusive use. Given the technology of the day, it was all that was workable.

We've given away all the spectrum, granting licenses that we can't take back. We've auctioned off a little cellular spectrum, but not really, since license-holders can't flexibly use their spectrum.

Most spectrum is now not in use (except for the WiFi band).

New tech promises more efficient use of the spectrum, by breaking with exclusivity -- mesh/UWB and cognitive radio don't interfere with each other, but require the end of exclusivity.

This is enabled best by spectrum commons, but how will it be managed and who will manage it?

Fact is, it need not be either/or. You could market property rights in spectrum that were subject to a "noninterfering easement" -- anyone can use my spectrum as long as they do not interfere with my use of it. Cognitive radios can opportunisitically use the parts of my spectrum that I'm not using, providing you vacate within 2ms of my attempt to use the signal.

This creates a commons across the entire spectrum to accommodate the new tech, as well as protecting incumbents, like FM radio and airport radar.

Ownership is subject only to technical limitations, and this encourages "private commons." Read the rest

Reed's keynote: when propagation gets worse, capacity can go up!

Reed's Talk. Reed is the radical mad scientist of open spectrum, who maintains that spectrum is not scarce, except due to a policy framework that is obsolete in the current technological reality. He's the appropriate opening keynoter for this conference.

Does spectrum have a "capacity?" This is the key question. If spectrum is limited, then there's a reason for apportioning it carefully. If it doesn't, then making spectrum scarce is scary First Amendment country.

The radio tradition developed from 1900-1950. In the beginning, all radios received all frequencies. Resonant systems allowed users to divide spectrum for different apps. Different frequencies had different properties -- low-frequency would go around the world, high frequency would bounce off the ionosphere. Increasing power lets you go farther.

Shannon invented information theory in the 50s, and invented the bit -- a measurement of info regardless of the form it takes.

C = W log (1+(P/N0W)), where C = Capacity in bits/sec; W = bandwidth in Hz, P = power in Watts and N0 = Noise power in Watts/Hz.

Channel capacity is roughly porportional to bandwidth and log of power. Capacity is analogous to bandwidth, but bandwidth is not the same as capacity.

This is only part of the story, though. The original theorem is a simple model consisting of a sender, a receiver and noise, with no consideration of geography and other transmitters (we treat other transmitters as noise).

Interference: this is the other key question. If interference exists, we need strong regulation to limit it. Read the rest

WiFi amplifier coming from Linksys

Linksys has introduced a new WiFi amplifier -- of dubious legality, I fear -- that boosts the signal of your access point to get it through walls and over great distances. I am of mixed feelings on this. On the one hand, there are times when turning up the gain makes a lot of sense and does no harm (for example, if you live on a farm and want to get the signal in the main house to radiate through the barns and so on, and are confident that this won't interfere with anyone else's activity due to your remoteness). On the other hand, this sort of technology, if deployed in a dense area, would interfere with the signals generated by other APs that might be preferable for some users -- say, because your network is closed and others' are open.

Ideally, the gain (and channel selection) would be adaptive, shouting as loudly as it can without interfering with any other signal on the band. This is basically what Cognitive Radio is supposed to do. I wonder, though -- imagine that I am using channel foo and shouting at bar decibels. I feel secure in doing so because I cannot detect any signals in normal range of me on foo that are attempting to use the band. What if there is someone out there, in range of my emissions, that is communicating at very low power (sufficient to send positional and click signals from a mouse to a CPU a few inches away), on channel foo? Read the rest

Howard Rheingold on SmartMobs on the WELL

Howard Rheingold is being interviewed in the WELL's public conference about his book SmartMobs. Nice stuff.

The FCC was set up to regulate the spectrum on behalf of its owners -- the citizens. It happened in the wake of the Titanic disaster, where "interference" was an issue. Radio waves don't physically interfere with each other -- they pass through each other. But the radios of the 1920s were "dumb" insofar as they lacked the ability to discriminate between signals from nearby broadcasters on the same frequencies. So the regime we now know emerged -- broadcasters are licensed to broadcast in a particular geographic area in a particular frequency band. For the most part, licenses to chunks of spectrum are auctioned, and the winner of the auction "owns" that piece of spectrum. We have seen in recent years that the owners of broadcast licenses have amassed considerable wealth, and that those owners have consolidated ownership in a smaller and smaller number of more and more wealthy entities. And of course, political power goes along with that wealth. These aren't widget-manufacturing industries. These are enterprises that influence what people perceive and believe to be happening in the world.

Recently, different new radio technologies have emerged. Cognitive radios are "smarter" in that they have the capability to discriminate among competing broadcasters. Software-defined radio makes it possible for devices to choose the frequency and modulation scheme that is most efficient for the circumstances. Ultra-wideband radio doesn't use one slice of spectrum, but sends out ultra-short pulses over all frequencies.

Read the rest

Open spectrum explained for the laity

Seattle Times has run a great story on the group of "lawyers, engineers and telecommunications analysts" who are lobbying the FCC for cognitive radio and open spectrum.

In an ideal world, the FCC would treat the airwaves like a highway system nobody owns and enforce rules governing how people use its lanes without crashing into each other, the group says. And in cases where this isn't possible, the FCC would allow people to drive across other people's "property" as long as they keep a low profile and don't do any damage.

Given this freedom, inventors and entrepreneurs would invent new vehicles and new ways of using the highway, the thinking goes. Consumers would finance the development of the airwaves by buying the devices that suit them best and abiding by the rules of the road that prevent nasty accidents.

But to make this vision a reality, the devices need a slice of the spectrum that would form a virtual park or an airwaves commons where equipment makers and others could experiment. In addition, common protocols — industry standards that allow devices to understand each others' communications — and rules are needed to prevent accidents and to make sure everyone gets a fair shake.



(Thanks, Howard!) Read the rest

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