Archive for July, 2008

The Bandwidth Dipstick

Thursday, July 31st, 2008

Yesterday, Prof. Tim Wu of Columbia Law School published an Op-Ed in the New York Times on the subject of bandwidth.  In the article, he compares bandwidth to oil in terms of its percentage of the average household’s expenditures and in terms of the cartels which produce it.  He says:

Like energy, bandwidth is an essential economic input. You can’t run an engine without gas, or a cellphone without bandwidth. Both are also resources controlled by a tight group of producers, whether oil companies and Middle Eastern nations or communications companies like AT&T, Comcast and Vodafone. That’s why, as with energy, we need to develop alternative sources of bandwidth.

While Prof. Wu’s might be right in his conclusions, I have to take exception to some of the points he makes along the way, particularly regarding cost of bandwidth.

To begin with, the price of oil is based, to some large measure, on the cost of its production and not necessarily the cost of its consumption.  The cost of production includes the cost to pump the oil out of the ground, refine it, and distribute it.  The cost of consumption would include the societal cost of pollution such as global warming caused by greenhouse gasses.  Here in Europe where a gallon of gasoline exceeds $9, most of which is tax, the retail price may better reflect the cost to society not only production but consumption as well.  The cost of the production of bandwidth includes both network CapEx and OpEx.  The cost of its consumption includes the negative effects of congestion felt by competing would-be users at times of peak use.  It is effectively zero, when use is non-rivalrous.  The price of bandwidth, as well as other resources subject to high negative externalities, should reflect the cost its production and consumption.  This maximizes the benefits which society obtains from the resource.

This is precisely why, contrary to Prof. Wu’s assertions, the FCC is working on such ideas.  FCC: OSP Working Papers #41, #42, and #43, on which I am a proud coauthor/collaborator, look at precisely these issues.  We designed and tested a system which instead of assigning spectrum in static blocks, would co-ordinate use of the spectrum to an efficient optimum.  Beyond the overly simplistic bandwidth dipstick, the FCC work also modeled other dimensions of performance, such as latency, and could be extended to include jitter, reliability, robustness, etc.  Nonetheless, the economic congestion protocols we developed would allocate bandwidth in real-time based on willingness to pay when there is congestion and it would be free otherwise.

To be fair, a business model which relies solely on congestion-based prices for its economic logic would not be sustainable.  Imagine an airline which would allow its passengers to fly for free, unless more passengers show up than there are seats, in which case it will charge all the passengers based on their willingness to pay.  One would expect such an airline to have very small planes, or, more likely, very large seats in its planes.  Without a way to ensure rivalry among its passengers for its capacity (i.e., seats), such an airline would surely go out of business.  Thus, a sustainable price for bandwidth must reflect the cost of both production and consumption of the resource.

Insight: I continue to tout these papers in my blog because they are important, cutting-edge work.  We sought to lay the groundwork for a better system which incorporates the best of the licensed and unlicensed approaches to spectrum access.  This system would be, to use Eli Noam’s words, would be “open, but not necessarily free.” As such, it would maintain sufficiently low barriers to entry, which would make it sufficiently difficult to obtain monopoly rents.  It would be nice if Prof. Wu would put forward some of the available solutions to “alternative supplies of bandwidth” in addition to pointing out the problems.

TV White Spaces and the Tragedy of the Commons

Tuesday, July 29th, 2008

For more than nine decades, lawyers, engineers, and economists have argued that radio spectrum regulation is needed due to the fact that without some form of intervention, it is impossible to exclude or limit the use of a common resource such as spectrum.  Without exclusion, users consume the spectrum without regard to their usage’s impact on the benefits obtained by other would-be users.  They, therefore, tend to overuse the spectrum, causing interference to other users.  This reduction in social welfare due to overuse is referred to as the Tragedy of the Commons.However, we can now observe from the debate surrounding the TV White Spaces that the ability to exclude certain users is not sufficient to remedy the Tragedy of the Commons. A relatively small number of over-the-air TV households are able to use these spectrum bands without regard to the costs their use imposes on the rest of Americans.  Indeed, according to the most recent FCC statistics, in 2005 only about 14% (See Appendix B, Table B-1) of US TV households receive their TV over-the-air. The remaining 86% get no direct benefit from this spectrum.

The National Association of Broadcasters is now opposing tests the FCC is currently conducting which will measure the impact of unlicensed use of the White Spaces on digital TV reception. In order to protect digital TV receivers, potential White Space users must be excluded, and the NAB is throwing its weight around to ensure that outcome.  According to a quote from NAB spokesman Dennis Wharton, “We’re not going to be engaging in threats or anything, but about 70 members of Congress have already sent letters in expressing concern.” Well, as I wrote in a previous entry on Cool Stuff, at least one of those 70 letters is total bunk. Nonetheless, the cost to all of society of affording interference protection to this minority must also be considered.

Insight: If the NAB’s argument is accepted without scrutiny, the 14% of TV households will prevent the other 86% of US TV households (plus the TV-less households) from using those radio frequencies for broadband Internet, baby monitors, new forms of low-power broadcast, and other RCS (really cool stuff).  This lost benefit will not be compensated.  The exclusion of certain competing uses is necessary but not sufficient to ensure that society reaps the maximum benefit from the radio spectrum.  A means through which spectrum users can bear the costs they impose on others by excluding them is also necessary.

Unlicensed and Unleashed

Monday, July 28th, 2008

My article Unlicensed to Kill: a Brief History of the FCC Part 15 Rules has just gone to press and will be published in the journal Info.  I originally gave the paper at The Genesis of Unlicensed Wireless Policy conference organized by Tom Hazlett at George Mason University Law School.  (Yes, dear reader, Tom Hazlett hosted a conference on unlicensed.  The Seventh Seal is broken and the End of Days is truly upon us.)

The conference looked at the origin and evolution of the FCC’s Part 15 rules.  There were several interesting takeaways.  Most of these are lessons which we already know, but all too often take for granted.  Keynote speaker Michael Marcus reminded the audience that people frequently act in their short term interest, in a way in which they foreclose long-term opportunities for themselves.  Dr. Marcus described the regulatory battles of the 1980s during the FCC’s rulemakings where cordless manufacturers fought fiercely, opposing certain rule changes.  These rules now enable most of the cordless phones these manufacturers now sell.  The closing keynote, Dewayne Hendrix pointed out how spectrum policy the cognitive dissidence spectrum policy faces in affording interference rights.  We allow licensees to “whine” about interference when they use decades old technologies which do not have the ability to reject unwanted signals which more modern gear does.

Insight: In the US, there is no such thing as unlicensed spectrum.  Rather, and this is an important distinction, the FCC allows low power operation on a sufferance basis, proved the devices cause no harmful interference and accept all received by them.  Operators have a right, but not a vested right to continued operation.  The FCC has historically viewed the radio energy emission from these devices as not rising to a level sufficient to call “spectrum”.  This has left me wondering if there is no such thing as spectrum at all.  Spectrum is a legal and engineering construct to control for an immutable fundamental physical property.  When multiple electromagnetic waves, used as carrier waves to transmit information are incident in time, harmonic in frequency, and alight on the same reception antenna, they degrade one another’s ability to transmit information.  Next generation radio policy will focus more on solving the coordination/congestion problem, and not on “spectrum” per se.  (I also gave a really cool PowerPoint.  (Click to start, click to advance each slide after the animation stops).