Monday, October 10, 2011

Partition, not sharing: An alternative approach to the Fed/non-Fed spectrum divide

South Sudan. Serbia/Kosovo. India/Pakistan. Britney Spears and Kevin Federline. Sometimes a clean break is best for everyone, particularly when there are fundamental differences in mindset. Enforced coexistence is not, for many couples, the best way to live.

Sharing between Federal and non-Federal wireless users (aka Fed and non-Fed) is a favored way to realize the FCC’s dream of finding 500 MHz for commercial mobile broadband services; as reported in, “It is unclear where the 500 megahertz of spectrum will come from, but a large portion will likely come from government agencies that do not use the frequencies efficiently.”

Fed/non-Fed sharing can be made to work, and worthy efforts are being made. However, I doubt it’s worth the effort, given the insane difficulty of negotiating band re-allocations, let alone sharing agreements; questions over whether 500 MHz is, in fact, either needed or would make a dent on cellular companies’ problems; and fundamental concerns about jurisdiction (see my August 2011 post No Common Authority: Why spectrum sharing across the Fed/non-Fed boundary is a bad idea).

It would be a better use of time and effort to go in the opposite direction: make the partition between Federal and non-Federal as clean as possible, and let each group of figure out sharing among its own constituents.

The difficulty of re-allocation and sharing is not only a matter of institutional recalcitrance or missing incentives; it’s that the same technologies and scenarios – and vendors! – that are driving the demand for commercial wireless broadband also apply to Federal uses. In addition, some applications of particular interest to government are very bandwidth-hungry. The US Army is buying 1,300 RQ-11B Raven aerial surveillance drones per year (The Economist). These back-packable snap-together drones weigh only two kilos and deliver real-time streaming video, which chews up bandwidth. If such devices were cleared for use in domestic airspace, Federal agencies would line up deploy them – as would state and local public safety departments.

And even if a few dimes-worth of “unused spectrum” were found between the Feds’ sofa cushions, swapping or sharing a tens or even hundreds of MHz between Federal and non-Federal jurisdictions is just not going to be worth the pain. Experience suggests that such re-allocation attempts are contentious, time-consuming, and often fruitless.

Hence, partition: make the Fed/non-Fed divide clearer, not murkier, and let each side get on with improving the value of radio operations in ways that make most sense in its particular institutional context. Three steps come to mind:

The first task is to minimize sharing between Federal and non-Federal services in the same band, since the lack of a common authority complicates dispute resolution as well as negotiation, particularly since the goals and rewards of Fed and non-Fed users are quite distinct (except for state and local public safety agencies which fall under the FCC's "non-Fed" jurisdiction, but are much more similar to Federal operations - more on this below). This means reducing the number of bands where jurisdiction is shared between the NTIA (nominally the manager of Federal radio operations) and FCC. Reducing, not eliminating; some services such as GPS will always be shared, since Fed and non-Fed users depend on the same infrastructure. And in some cases, sharing has been recently imposed and can’t be rolled back again, e.g. Wi-Fi systems coexisting with weather and military radars at 5GHz.

Second, minimizing sharing also requires reducing the number of Fed/non-Fed band boundaries. Radio systems in adjacent bands affect each other because real-world receivers cannot reject all the energy radiated outside their allocated frequencies. This amounts to defragging the US frequency allocation chart. The required band swaps won’t be easy, but should be easier than transferring a band from Federal to non-Federal use with nothing in return. Since the swaps would be local in frequency, the cost of hardware change should be manageable. Some swaps won’t be possible; just as some files on a hard disk can’t be moved, some allocations are fixed by physics (e.g. frequencies used for radio astronomy) or treaty (e.g. agreements reached at the World Radio Conference).

Third, and most aggressive, is the prospect of moving state and local government allocations out of the FCC’s jurisdiction and over to the NTIA. I expect this will require legislation (if it is even possible, constitutionally…) but the similarity of goals, incentives and culture among Federal and state & local users should make for much more harmonious (or at least less acrimonious…) coordination of interests. The failure to share the 700 MHz D (as in “Doomed”) Block between public safety and commercial users demonstrates the difficulties of cross-culture coordination even within the FCC's remit, and is just a taste of the deadlocks that will be the hallmark of attempts to foster extensive Fed/non-Fed sharing.

It’s an empirical question how much sharing occurs in the current band plan, and whether it’s increased or decreased. Appendix B in the September 2011 draft report on Spectrum Efficiency Metrics of the FCC Technological Advisory lists some examples of spectrum sharing, many but not all of them Fed/non-Fed; a more exhaustive inventory probably exists, but I haven’t found it yet. More to come...

This partition proposal does not preclude sharing; in fact, it gives it the best possible chance to succeed. Organizations that are all tasked to work for the greater public good are more likely to develop the trust required for effective wireless sharing among themselves, and likewise, organizations that are all measured by commercial metrics are more likely to find a mutually beneficial sharing solution. Federal and non-Federal users will continue to share some bands, and rub shoulders in others, but fewer fences will make for better neighbors.

No comments: