Archive for May, 2010

Twenty-Five Years of Unlicensed Spread Spectrum

Monday, May 10th, 2010
Telesystems' ARLAN

The first commercial spread spectrum product, Telesystems' ARLAN, a radio LAN introduced in 1988. Source: FCC.

Today, the Wi-Fi Alliance and the Wireless Gigabit Alliance announced an enhancement to the current suite of 802.11 standards (Wi-Fi) which promises multi-gigabit wireless networking, in the 60 GHz frequency band.  The two associations expect that devices which have the new enhancement will be tri-band, also able to operate in the 2.4 and 5.8 GHz bands where Wi-Fi currently operates.

However, I am not sure if the Wi-Fi Alliance or the Wireless Gigabit Alliance realize the auspiciousness of the occasion of their announcement.  The announcement comes twenty-five years and one day after a much ignored FCC decision.  On May 9, 1985, FCC adopted rules which permitted the operation of spread spectrum systems in the ISM bands (902-928 MHz, 2.4-2.48 GHz and 5.725-5.85 GHz).  This rule change enabled the commercial rise of Wi-Fi, as well as so many other products and technologies take for granted today, such as Bluetooth, cordless phones, and baby monitors.

The FCC took this decision on its own initiative, rather than relying on requests for rule changes from the industries it regulates.  (In fact, many of the companies which initially opposed the rule change now earn millions of dollars of revenue from selling products that operate in these bands.)  One important person diving the FCC proceeding was national treasure Mike Marcus.  Marcus published a terrific account of the FCC proceeding in the journal info last year.  (I published in the same issue, and beat him out for best paper).  For his vision and insight in pushing the rule change through, Marcus was rewarded with nine years of exile to the outer Bureaus of the FCC.

Insight:  It never ceases to amaze me that a well-made decision can have exponential implications down the line.  Relying on the industry to tell the regulator can be helpful; however, this approach does not always serve the public interest.  In all instances, the regulator should exercise independent judgment.

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The New Dutch Auction

Friday, May 7th, 2010

A Dutch auction is typically one where prices go down.  The auctioneer starts with a high price and then asks for lower prices.  The first person to call out gets the item at that price.  However, this is not how it worked in Holland last week.

A week ago, the Dutch telecommunications regulator Agentschap Telecom completed a spectrum auction for licenses in the 2.6 GHz band.  Five bidders spent just over €2.6 million to acquire 130 MHz of the 190 MHz in the band, but they did so in an unusual way.  Agentschap’s auction had two parts.  In the first part, bidders vied for a certain amount of spectrum.  In the second round, the bidders competed for specific 5 MHz blocks, with the option of single 5 MHz blocks of unpaired (TDD) spectrum or 2 x 5 MHz blocks of paired (FDD) spectrum.  This determined the pairing the band.  No FDD spectrum was acquired.

In this way, the auction determined whether the spectrum would be used for cellular type uses (FDD) or for WiMax-type uses (TDD).  To my knowledge, Agentschap’s auction was only the second time an auction was used to determine not just assignment but allocation as well.  In 2008, ComReg in Ireland used a very similar auction in the 26 GHz band.

Insight:  In a previous Cool Stuff, I wrote about my work to design an auction which could not determine not only who gets the spectrum rights, but what the contours of those rights are.  I called this approach: Price-Guided Radio Policy.  Now, we have two data points to suggest that this approach can work and can efficiently determine not only spectrum assignments but allocations as well.

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The Spoon

Wednesday, May 5th, 2010
Don't try to bend the spoon.

Don't try to bend the spoon.

In the classic 1999 film The Matrix, the protagonist, Neo, played Keanu Reeves, goes to see an oracle.  In the waiting room, he happens upon one of the oracle’s child disciples who is sitting zazen and melting a metal spoon with mind.

Spoon boy: Do not try and bend the spoon. That’s impossible. Instead… only try to realize the truth.

Neo: What truth?

Spoon boy: There is no spoon.

Neo: There is no spoon?

Spoon boy: Then you’ll see, that it is not the spoon that bends, it is only yourself.  (Source IMDB)

By the same token, I have long wondered if there is no radio spectrum.  This fact is among the reasons that the unlicensed regime works so well.  It is spectrum policy, just without the spectrum

The jurisprudence underlying the Part 15 rules is that unlicensed spectrum is not spectrum at all…. It is merely an idea – a concept – a way of describing and organizing the physical world in our minds and in our actions. Spectrum is a legal and engineering construct to control for an immutable fundamental physical property… (Source: Unlicensed to Kill)

The Part 15 rules simply consider what is the maximum amount of irradiated power which can be emitted by a device without an unacceptable probability of causing harmful interference.

However, most of spectrum policy other than the Part 15 rules deals with regulating the “airwaves”.  Yet treating radio operations as spectrum or airwaves or property is a false paradigm.  This point was driven home to me a few years ago when I was an FCC staffer.  I was once filling out my timesheet at the FCC.  One of the lines on the sheet was “spectrum” and it dawned on me that I was spending more than 66.7% of my time dealing with something which had momentum, but no mass.  Somewhat paradoxically, electromagnetic energy behaves simultaneously like a wave and like a particle, carried by photons.  This is an important and powerful observation.  In fact, it was for this observation (the so-called photo-electric effect), and not General or Special Relativity, that Albert Einstein was awarded the Nobel Prize.

So, while we are regulating the airwaves, who is regulating the photons?!

Insight:  I raise this issue now because just last week the FCC announced the (re)establishment of its Spectrum Task Force.  Honestly, I am not exactly sure what implications for radio policy of considering the dually of electromagnetic radiation as both a wave and a particle might be; however, going forward perhaps the STF should undertake critical rethinking of this crucial policy area from the basics up.

Since we cannot bend the spoon, perhaps it is time we bend ourselves.

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