Spectro-Loki: The trickster in radio spectrum

In Techno-Loki, I argued that the Norse trickster god is a good metaphor for technology. I described how tech, like Loki and his exploits, has to be coerced into doing the right thing; follows impulse, skipping from one thing to the next; produces effects both good and bad, which are sometimes hard to distinguish; and is a shapeshifter. The examples in the previous post were a grab-bag of technologies; here are some from my current specialization, radio and spectrum.

Ofcom's DECT guard band award as a club good auction

Toby Youell (@tobyyouell, linkedin) pointed out to me that Ofcom’s 2006 sale of DECT guard band licenses was an auction of spectrum club goods (cf. my blog post). It’s a great insight, and a helpful comparison.

Evolving sharing

Now that it’s clear the Trump administration supports spectrum sharing (FierceWireless), this option will become even more salient in policy debates. I think the hardest question is how to allow a legacy incumbent to adjust their operation over time, potentially encroaching on the rights of new entrants.

Bringing a gun to a knife fight (spectrum edition)

As I pointed out in “Satellite spectrum efficiency” the satellite industry can’t win a spectrum auction fight with cellular since the cellular industry generates more $/Hz. This obviously generalizes to any number of industries competing in a license auction; the industry that generates the most $/Hz will always win. (The question of how overwhelming the win is, as a function of differences between industry $/Hz distributions, is left as an exercise.) So what?

Satellite spectrum efficiency

I’m no fan of the concept of spectrum efficiency, but it’s helping me understand the gulf between the cellular and satellite businesses.

Economic rivalry, interference and spectrum allocation

I’m intrigued by the questions:

• What is the relationship (if any) between rivalry and licensing regime in spectrum regulations to date? 
• And what should it be in the future? 

 I think such work could shed light on efforts to allocate and assign millimeter-wave spectrum (roughly, above 30 GHz).

Scale change and regulatory change

The current and forecast growth in the number of satellite systems is putting strain on how the FCC and other agencies regulate satellites. There’s a lot of talk of regulatory reform, and calls for comprehensive rather than incremental change.

That leads me to wonder: are there instructive precedents where a step change in the scale of an industry or activity forced a complete restructuring of regulation; or conversely, where change in regulation let to a change of scale?  Perhaps there are examples where one might take lessons for the reform of space governance.

Is harmful radio interference decreasing?

Spectrum analysts (including me) often proclaim that harmful interference is a growing problem, or at the very least a growing risk. That sounds plausible, given the growing profusion of radios, packed more and more densely together. But what if the opposite is true?

Spectrum is not a scarce natural resource

Almost every policy or technology story about radios starts with the litany that Spectrum is a Scarce Natural Resource. I will argue that this claim is false, and that it matters.

In short:

• Spectrum is no more a scarce natural resource than sound.
• It is more accurate and productive to talk about radio operation.
• Rather than saying “spectrum is scarce”, it’s better to say “radio coexistence is hard.”

The pay-off is that this alternative language makes us focus on what matters – the best way to arrange the operation of radios – rather than on ways to manage a resource (spectrum) that may or may exist.

You say you want a spectrum revolution

I’ll be attending the PTC’17 conference in a couple of weeks. Our panel is tackling the question The Spectrum Revolution: Where, What, Why, How?, which got me thinking…

3D Wireless: Managing spectrum in three dimensions

It is time to manage spectrum in three dimensions, rather than on a slightly wrinkled 2D sheet.

Q&A: Risk-assessment, harm claim thresholds and adjudication

In my testimony before the Senate Commerce Committee on Wednesday July 29, 2015 I recommended three spectrum management reforms. A summary and links to the written testimony and video are in an earlier blog post. This post offers some Q&A.

The three reforms were: (1) moving away from worst case interference analysis and using risk-informed methods that consider not only the consequences but also the likelihood of harmful interference; (2) providing more clarity about operators’ interference rights and obligations by specifying harm claim thresholds; and (3) giving any spectrum user the option of taking action directly against any other, either in front of an FCC judge or in a federal Court of Spectrum Claims.

Senate Testimony: Risk-assessment, harm claim thresholds and adjudication

I testified today before the Senate Commerce Committee hearing on “Wireless Broadband and the Future of Spectrum Policy.” My written testimony is here; this is the summary I presented during the hearing. I’ve posted some Q&A in a subsequent post. My remarks are recorded in the archived webcast, starting at 58:02; see also a question from Chairman Thune and my reply starting at 2:05:43.

Risk-informed interference assessment

I've spent the last year or so thinking about ways to complement worst-case interference assessment with a more comprehensive approach that considers many potential interference hazards, not just a possibly implausible nightmare scenario. I have concluded that quantitative risk analysis, used in many regulated industries, is a suitable tool.

Six weeks of spectrum auction tweets

I created an animated GIF to show how twitter traffic about spectrum auctions changed over the first six weeks of the AWS-3 auction, i.e. November 15 to December 27.

5G on Twitter: NodeXL social network analysis

A NodeXL SNApshot is a great way to catch up with who's saying what about a topic on Twitter. This post discusses the SNApshot http://bit.ly/snapshot-26748 that graphs the 1,963 tweets containing the hashtag #5G posted over the period 17 Jul - 29 Aug 2014.

Here's the Gallery Glimpse video:

Adjudication versus Enforcement

Mike Marcus (web site) has suggested that enforcement problems can be divided into two categories:

#1. Cases where behavior explicitly violates existing rules, e.g. use of the wrong frequency, or equipment that doesn't comply with rules.

#2. Unanticipated interactions between systems that either lead to service degradation but do not self-evidently violate any rules, or raise complex legal issues of whether there is a violation.

Mike suggests that the second category includes "cellular booster" interference to cellular systems, police radar detector "fuzzbuster" interference to VSATs, the Nextel/public safety intermod problem in 800 MHz, and impairment of 700 MHz cellular due to FM transmitter harmonics (discussed on Mike’s blog).

The fact that the spectrum community informally refers to both categories as enforcement problems while the second is actually a question of adjudication highlights a problem caused by the FCC’s rudimentary judicial function: while it has more than 250 people in the Enforcement Bureau (2014 Budget), it only has one (!) administrative law judge.

It seems to me that (1) being clear about the enforcement/adjudication distinction and (2) actually having an adjudication function separate from both rule making (the legislative function) and enforcement (the executive function) would not only help us think more clearly about spectrum problems but would also lead to quicker resolution, to everyone's benefit.

Discussion

As an administrative agency (caveat: IANAL) the FCC combines the three branches of government under one roof: legislative, judicial and executive. It makes rules (legislative), decides whether they have been broken (judicial), and takes action to detect alleged violations, and punish them if violations are found (executive).

Mike’s Category #1 (explicit violations of existing rules) is enforcement, defined by the OED as “the act of compelling observance of or compliance with a law, rule, or obligation”: it presupposes that adjudication has already taken place. The examples in Category #2 (unanticipated interactions) are actually questions of adjudication, i.e. “A formal judgment on a disputed matter” per the OED: they're difficult precisely because it's not clear whether there's been a violation, or by whom.

The FCC is very loosey-goosey on this distinction, as has been pointed out over the years; see e.g. Ellen Goodman’s 2004 Telecosm paper, Phil Weiser’s 2009 FCC Reform paper and our recent Hamilton Project paper.

Distinguishing clearly between these two categories could also address a blind spot about the need for enforcement in the Dynamic Spectrum Access (DSA) community. If enforcement is addressed at all by advocates of Spectrum Access Systems (SAS), it’s usually waved away with assurances that the rules in the database will solve all problems. (Jerry Park’s presentation at the January 2014 FCC 3.5 GHz SAS workshop is an exception, but even he focuses on attacks on the database, rather on how to decide disputes.)

Mike's distinction made me realize that the DSA/SAS community probably equates enforcement with Category #1. It's then plausible to believe that a system that prevents explicit rules violations solves, or more accurately obviates, "enforcement problems." However, the arcane interactions between radio systems in the wild and the difficulty in assigning responsibility for them make it important to highlight the Category #2 problems: these unintended issues are not only more likely to cause problems – and cause them unexpectedly – that failures in rule sets, but by their nature they will require judgment (in both a legal sense, and in the sense of requiring assessment of hard-to-compute complexities) to resolve.

RF Mirror Worlds: Supercomputing meets propagation models, 3D terrain data and ubiquitous sensors

Petri Mähönen has observed that wireless researchers haven’t exploited supercomputing as much as one might expect, especially in comparison with other scientific disciplines such as aerospace, meteorology, oceanography, biology, sociology... If they had, we could be exploring thousands or millions of “Test Cities” rather than just the one contemplated in the PCAST Report (pdf, Chapter 6 and Appendix G). The PCAST budget for the first three years of a Test City (Table G.1) runs to $21 million in operating expenses and $15 million in capital expenses – that would buy a lot of computation!

I suspect (hope!) we’re on the verge of a step change in using software simulation, aka “mirror worlds”, to understand and manage radio systems. The underlying technology has been on the exponential growth curve we’ve all heard about, but hasn’t broken through to high profile visibility. It may soon.

DoD treats Spectrum as Territory

The U.S. Department of Defense released a spectrum strategy document on Thursday (press release, pdf). I’ll leave discerning what (if anything) is actually new in it to the Pentagon watchers.

I was struck by the implications of the language used: the DoD conceives of spectrum as a place. Given that military success often seems to be framed as controlling or denying territory, this is not an auspicious starting point for spectrum sharing – which is about wireless system coexistence in many intangible dimensions, rather than all-or-nothing control of territory.

Unlicensed’s success: physics, not regulation?

Unlicensed allocations have generated a massive, and to many surprising, amount of innovation and value (see the References below). The question is: Why?

Almost all of the value so far has come in the 2.4 GHz ISM band, mostly due to Wi-Fi but also to a lesser extent Bluetooth applications. There is never a single, simple answer to a Why question about a complicated nexus of technology, politics and user behavior, but my impression is that unlicensed partisans believe that it's due pretty much exclusively to the techno-economic characteristics enabled by the rights assignment regime: “openness” (Benkler), “managed commons” (Milgrom, Levin & Eilat), or “rule-based access” (Thanki).

I think it's at least plausible that Wi-Fi's undoubted success has been due to a fortuitous coincidence of band choice, physics and timing as much as to regulation: It turned out that the interference range was small enough that users didn’t really degrade each other’s performance; and the networking needs of their applications could be met by the bandwidth available around them. In other words: the capacity of the channel was larger than the number of people who interfered with each other, multiplied by the data they wanted to move.