Title:

White space & the FCC: a chance to do the right thing

By: Scott Bradner

One of the few unqualified success stores in recent US spectrum policy has been the unlicensed spectrum that is now used by devices ranging from car door openers to WiFi. If the current schedule holds the FCC may vote on November 4th (US election day) to expand this spectrum considerably. Such a vote might make some traditional broadcasters upset it would clearly be a big win for most of the population.

The spectrum in question is the currently unused "white space" between licensed broadcast channels and if the FCC enables its unlicensed use it will be with major restrictions. But, even with those restrictions, we could be on the brink of a major expansion of useful technology enabled by this expansion.

As is too often the case, the arguments against changes in spectrum licensing policy have been distorted by hyperbole. For example, David Donovan, head of the Association for Maximum Service Television (http://www.mstv.org/), which appears to be a TV industry lobbying group, was quoted by the Broadcast and Cable web site as saying that the FCC proposal will "decimate over-the-air TV." My dictionary defines decimate as " kill, destroy, or remove a large percentage of." I rather doubt that the FCC would permit anything like this to happen and the FCC's report on testing of sample devices do not show that the death of broadcast TV is in the offering. (Executive summary - http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-08-2243A2.pdf - report http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-08-2243A3.pdf ) David is not the first person to way overstate their case in spectrum policy discussions (See What are they so worried about? - http://www.sobco.com/nww/2002/bradner-2002-09-30.html) and he is not likely to be the last. But, the discussions would be a lot more productive if some modicum of reality were the norm rather than the exception.

The restrictions proposed by the FCC include restricting devices using this new spectrum to low transmitter power, requiring that they be able to figure out where they are and, based on that information, look up in a database what channels are unused in that area before deciding what frequency to use. While these restrictions are a reasonable stopgap approach, in the long run a far more flexible approach is that taken by cognitive radio and tested in the FCC tests. A cognitive radio (http://en.wikipedia.org/wiki/Cognitive_radio) listens to the world around it to determine what frequencies are unused and then communicates on those frequencies. The FCC tests indicated a lot of promise for such approaches but also showed that they are not yet ready for prime time.

The FCC proposal opens up some additional unlicensed spectrum but its benefits come nowhere near what a general cognitive radio approach would yield. Most of the currently allocated spectrum is unused most of the time. (See www7.nationalacademies.org/bpa/Spectrum_Study_June2007_Presentation_Roberson.pdf) An aggressive cognitive radio approach could open up all of this spectrum for alternative use.

If history is any guide, permitting the same type of essentially unlimited use by approved devices that has been the case with the current unlicensed spectrum would be a huge, but largely unpredictable, boon to technology development. The existing unlicensed spectrum supports a far wider range of devices that was ever guessed at back in 1985 when the experiment started.

(See: Unlicensed and Unshackled: A Joint OSP-OET White Paper on Unlicensed Devices and Their Regulatory Issues (2003) - http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-234741A1.pdf)

I've not been all that nice to the FCC in this column, with good reason, but this is a case where they just might make a next step along a path that could lead to a far better use of spectrum and, not incidentally, to a new explosion of technology development.

disclaimer: I know of no stated Harvard opinions on the FCC and its ability to not get things right so the above hope is mine alone.