802.11 channel 14

This article in Daily Dot’s Kernel magazine, “The mystery of WiFi channel 14”, was recently posted in /r/TIL. This led me to discover that there apparently exists a conspiracy theory as to why WiFi channel 14 is not permitted in the United States.

This made me irrationally angry.

I have hence dug up the relevant FCC and even ITU regulations to explain why it’s not mysterious at all that channel 14 is not permitted.

Let us begin. What is channel 14? The 802.11 channels go like this:

(source: Wikimedia Commons. CC-BY-SA 3.0)

Channel 14 is all the way on the right there, spaced 7 MHz farther apart than usual.

It’s not just channel 14, for the record. As Wikipedia points out, channels 12 and 13 are generally not used either, because anything operating more than very low power will almost certainly cross into the restricted zone.

Wait. The restricted zone? Yes, there’s a restricted zone starting at 2483.5 MHz extending to 2500 MHz, per 47 CFR §15.205. No Part 15 device can transmit in this zone. The question becomes why. Part 15 doesn’t say.

So we look in the FCC allocation table (PDF warning). There’s conveniently an entry for 2483.5–2500 MHz:

Screen Shot 2016-05-29 at 12.43.46 AM

Let’s break it down. First, notice that this frequency band is allocated to a bunch of radio services mentioning satellites, in particular space-to-Earth communications. We then get a shitload of references to various notes. Let’s go through each of them. (Some of these notes do not appear in the FCC document and need to be searched for in the full ITU Radio Regulations. As of writing, it’s available here.)

5.150 defines the ISM bands. In particular, one of them is 2400–2500 MHz.

5.398 “In respect of the radiodetermination-satellite service in the band 2483.5-2500 MHz, the provisions of No. 4.10 do not apply.”

4.10 “Member States recognize that the safety aspects of radionavigation and other safety services require special measures to ensure their freedom from harmful interference; it is necessary therefore to take this factor into account in the assignment and use of frequencies.”

5.402 “The use of the band 2483.5-2500 MHz by the mobile-satellite and the radiodetermination-satellite services is subject to the coordination under No. 9.11A. Administrations are urged to take all practicable steps to prevent harmful interference to the radio astronomy service from emissions in the 2483.5-2500 MHz band, especially those caused by second-harmonic radiation that would fall into the 4990-5000 MHz band allocated to the radio astronomy service worldwide.”

US41 “In the band 2450-2500 MHz, the Federal radiolocation service is permitted on condition that harmful interference is not caused to non-Federal services.”

US319 “In the bands 137-138 MHz, 148-149.9 MHz, 149.9-150.05 MHz, 399.9-400.05 MHz, 400.15-401 MHz, 1610-1626.5 MHz, and 2483.5-2500 MHz, Federal stations in the mobile-satellite service shall be limited to earth stations operating with non-Federal space stations.”

US380 “In the bands 1525-1544 MHz, 1545-1559 MHz, 1610-1645.5 MHz, 1646.5-1660.5 MHz, and 2483.5-2500 MHz, a non-Federal licensee in the mobile-satellite service (MSS) may also operate an ancillary terrestrial component in conjunction with its MSS network, subject to the Commission’s rules for ancillary terrestrial components and subject to all applicable conditions and provisions of its MSS authorization.”

US391 “In the band 2495-2500 MHz, the mobile-satellite service (space-to-Earth) shall not receive protection from non-Federal stations in the fixed and mobile except aeronautical mobile services operating in that band.”

NG147 “In the band 2483.5-2500 MHz, non-Federal stations in the fixed and mobile services that are licensed under 47 CFR parts 74, 90, or 101, which were licensed as of July 25, 1985, and those whose initial applications were filed on or before July 25, 1985, may continue to operate on a primary basis with the mobile-satellite and radiodetermination-satellite services, and in the sub-band 2495-2500 MHz, these grandfathered stations may also continue to operate on a primary basis with stations in the fixed and mobile except aeronautical mobile services that are licensed under 47 CFR part 27.”


So. The reason channel 14 is restricted is because it conflicts with the allocation of 2483.5–2500 MHz to the mobile-satellite and radiodetermination-satellite services. In particular, that band is used for space-to-Earth communications, meaning any WiFi operation in that band would almost certainly overpower any satellite signals.

mystery solved…


Edit: One last note. On top of clearly doing absolutely no research whatsoever, the Daily Dot leaves us with this: “Though the channel is banned the consequences of using the restricted channel are not specified. It is considered a felony due to its illegality though it seems unlikely that the FCC will come knocking on your door.” The FCC takes its regulations extremely seriously: even in the Amateur Radio service, repeated willful interference can often lead to a forfeiture order well into the five figures. Should you ever cause interference to one of the satellite services mentioned above by operating a WiFi access point on channel 14–enough to be noticed, anyway–you most certainly can expect a knock on your door.

Hamlet (2015)

This is possibly the least-timely blog post I’ve written (and I wrote it mostly at 3am), but late is better than never. Also, it’s a nice conduit for me to write about some aspects of Hamlet that I’ve been meaning to write about for over five years.

My thoughts on the Benedict Cumberbatch Hamlet (National Theatre , October 15).

Disclaimer: the only other version of Hamlet I’ve actually seen is the BBC/RSC David Tennant one (which I loved), and some of the Kenneth Branagh movie (which I thought was comically overdone). Otherwise my only experience with the play is having studied it in quite some depth in high school.

Ophelia: How Ophelia is portrayed seems to get a lot of critical attention, possibly because she tends to get less attention from producers than she perhaps deserves. The first and obvious glaring question: why is she always carrying a small camera. It’s never really explained and yet all the recent productions I know of do it. This production has telegraph keys going off in the background, so it’s also almost certainly anachronistic to boot. Basically it seems to happen just to 1) give Ophelia something to do so she isn’t just randomly hanging around (which is a really bad and lazy reason) and 2) to explain the “remembrances” that she returns to Hamlet in the nunnery scene (which are of course letters, not photos, but we’ve already established that none of this makes any sense anyway).

The flowers scene was confusing and muddled, which I hope isn’t reflecting a lack of research on the producers’ part. She really does not have very good singing, to the point where it seems possible that it was intentionally bad (it’s apparently in vogue to have Ophelia do this scene in a deranged crying fit, which isn’t exactly conducive to melodious singing. Personally I’d rather have the singing than the bawling). Overall, her character seems to suffer from a problem several critics have identified recently, which is that she isn’t exactly a strong female character—she’s Hamlet’s apparently-emotionally-unstable love interest with an overbearing (and frankly quite sexist) father, who ends up committing suicide under very obscure circumstances. That’s pretty much it. There’s not much to work with here.

But there are certain aspects that could be expanded on to at least make Ophelia an interesting character, if not a feminist one. My favorite theory regarding the flowers is from a relatively unknown paper that holds Ophelia is covertly signaling to Gertrude (via the specific types of flowers she presents in that scene) that she is pregnant (i.e., with Hamlet’s child) and in particular, has taken or intends to take crude abortifacients, and crucially, that Gertrude understands this signal, making this whole bizarre flower scene intended as a sort of female bonding backchannel/empathetic moment between the young Ophelia and the older Gertrude (the unwanted pregnancy of course, also neatly explaining why Ophelia has suddenly fallen into such extreme emotional distress).  This theme was entirely absent from the play (and absent from most productions, I gather), which instead turns Ophelia into a dumb chick who goes suicidally insane for no reason and Gertrude a befuddled, powerless woman at a total loss for what to do.

On top of that, the process of Ophelia turning insane then suicidal really isn’t shown very well. She goes from seemingly okay, perhaps even playful (in conversation with Laertes as he leaves—for which, as a sidenote, the RSC version has a hilarious, much better interpretation, involving Ophelia finding condoms in Laertes’s luggage) straight to deranged and from then directly to suicidal, with no reasons given for any of this. Basically it’s not bothering to repudiate Polonius’s twisted and troubling conception of womanhood at all. Even the “fishmonger” scene, which is Hamlet’s opportunity to point out Polonius’s creepy obsession with his daughter, seemed played down, almost discarded. (This isn’t disappointing from just a storytelling perspective either; that scene has some of the best wordplay in the entire work.)

If you read this far down expecting my comments on other characters to also be this in-depth, I am afraid you will be disappointed. The above is most of what I have to say about Hamlet.

Ciaran Hinds as Claudius is excellent. I (and I suspect many others) recognized him only from his Game of Thrones role as wildling chief Mance Rayder. He has that same vaguely sinister look that he has on GoT, and it is very fitting to the role of Claudius. It sets up an immediate tension at the first dinner scene, making it crystal clear that Claudius and Hamlet have a mutually adversarial relationship from the very beginning (i.e., even before Hamlet meets the Ghost). The prayer scene was well acted, with the repudiation of the prayer at the end again, fittingly sinister. And when he banishes Hamlet to England, there is a convincing anger present. The only disappointing part was in The Murder of Gonzago, where I didn’t feel the sudden guilty indignity that the scene calls for. (I’m also bitter that they cut the call for “lights!” that ends the scene. In fact, they also cut the dumbshow entirely, and had Hamlet act out the second part of the play from the audience. I don’t understand this at all. Also, the Fall of Troy speech from the First Player was merely okay. It’s supposed to be moving-people-to-tears-level emotional and eloquent, dammit.)

Benedict Cumberbatch as Hamlet: very competent. It’s a high-pressure role, and he clearly feels that pressure keenly, but he pulls it off. He portrays a distinctly different kind of insanity than David Tennant’s: clearly and unambiguously faked, and not an angry, deranged sort of crazy, but more of a “how far can I troll Claudius and Polonius”, silly kind of messing-around. (Representative example: when Rosencrantz and Guildenstern enter, he’s screwing around with a toy rifle, wearing a red soldier’s costume, in a play fort he’s constructed in the middle of a hall.)  One of my favorite scenes in the RSC production is when Hamlet physically assaults Guildenstern in the “You would play upon me” scene (Act III, scene 2, after the play). I sort of prefer that interpretation, which leaves it up in the air as to whether Hamlet has actually gone insane or not (and somewhat more importantly, actually has Hamlet angry at people. I feel like this production missed the mark there).

Polonius: mediocre. Then again, much like his daughter that he can never shut up about, he’s another one-dimensional character without much flexibility. But as mentioned earlier, there are certain things that could have been done, which were not. The clouds scene could have been much better: it sounded cut short, almost as if either he or Cumberbatch had forgotten the lines (again, this is largely me being bitter about my favorite scenes being largely axed). Under the theory that Polonius exists largely as comedic relief, he could have been much funnier: a serious production and a funny Polonius should not be mutually exclusive. (The other comedic relief, the gravedigger, also fell flat for me, although I think all the jokes in the text did make it into the production.) If he is not taken to be comedic relief (which would just be silly), then he exists to be an anti-feminist, patriarchal prototype to be poked at, but this production doesn’t do anything interesting in that direction either. Again, a shallow character that could have been so much more interesting.

Gertrude: I don’t remember much (which means nothing particularly interesting). The bedroom scene was competently executed but had nothing particularly new. Gertrude is another incredibly passive female character, despite nominally being in a position of power. Possible places where her character could be extended: as before, in her relationship with Ophelia (at her burial: “Sweets to the sweet! Farewell. // I hoped thou shouldst have been my Hamlet’s wife”. This just comes out of nowhere!), and also, as sharply pointed out in the bedroom scene, in how she ended up married to her dead husband’s brother. Was it coerced, or was she involved? Did she, as one theory holds, marry Claudius with the aim of protecting the life of her (ungrateful and misunderstanding) son Hamlet? (As it follows he, as the son of the king, would necessarily have been Claudius’s next target otherwise, see: Macbeth.) This production just doesn’t seem to care.


I’ve spent a lot of time criticizing how they’ve portrayed all the characters. On a positive note, the special effects (and set design in general) were absolutely fantastic throughout the play, although especially in the closing of the first half and the beginning of the second. (Particularly as it’s all done live!) It was not just visually appealing and technically neat, but genuinely thought-provoking. (Perhaps I just need to see more plays.) Unfortunately this is one of those parts where I feel like I can’t talk too much about it without totally spoiling it.

The fencing scene was… okay. The ending was a bit rushed, although perhaps I confused that with chaos, which would have been appropriate. Laertes’s rage was unconvincing. If he’s not foaming-at-the-mouth mad at Hamlet, why is he trying to murder him with a poisoned sword? And why on earth is he so pathetically bad at it? Regarding deliveries of lines: in my imagined mental conception of the play, the line “Follow my mother” is shouted in rage (!!1!1!!), not quietly whispered (Cumberbatch seems to be incapable of real anger entirely). It all feels wrong. And Hamlet messing with Osric about the temperature got cut, which is absolutely unacceptable.

Finally, there is the issue of live broadcast (this was an NTLive broadcast). In order to have actually been live, it would have had to have played at the Barbican in London from 2am to 5am on Friday October 16. Clearly this was not actually the case, since it plays on Thursday evenings. Therefore it was not, as advertised, live. This gives even less of an excuse for the several very distracting mic issues.

Diversity in tech: a different view

“Innovation and disruption do not come from homogeneous groups of people.” —PepsiCo president Brad Jakeman

Credit for this post goes to Selena Larson, who wrote on the problems that some had with the 2015 Anita Borg Institute Grace Hopper Celebration of Women in Computing conference. In particular, she pointed out that diversity efforts in tech focus a lot on gender to the exclusion of race, and that gender diversity in tech is often code for “more white women in tech”. (At least, that’s what I read out of it.)

This all hit very close to home.

I was compelled to take a second look at the UC Berkeley demographics information available in Cal Answers, this time at degrees awarded (i.e., actual outcomes) rather than admissions and student body makeup (inputs). The following table is a full listing of degrees in EECS and CS awarded by UC Berkeley in this millennium, broken down by race and gender.


In the past 15 years, seven black women have graduated with a computer science degree from UC Berkeley—as the administration likes to tout, the predominant source of elite engineers in Silicon Valley. Seven. Out of a total of several thousand. In more than half of the years—and in one entire six year stretch—not a single black woman graduated out of either EECS or L&S CS. In no year were there more than two. Hispanic women make up not much more.

We are not making any progress.

Is there a pipeline problem?

…and what if there isn’t?

This is the admissions data for UC Berkeley EECS and L&S CS for 2015 vs. 2014, made available on August 3.

Compiled by the author. Source for data in italics: Cal Answers.

A few thoughts:

On the pipeline issue, which gets so much press these days. The gender ratio among applicants has improved. In fact, there is a 34% increase in female applicants to EECS and a mind-boggling 55% increase for L&S CS. It remains, however, quite high.

The main thing about this chart that makes me think there must be something other than pipeline issues at work here is the yield rate.

While the admissions process improves the gender ratio somewhat, the ratio among SIRed applicants remains abysmal for EECS. There is a stark contrast between EECS, which actually has a worse gender ratio among SIRs compared to last year, to L&S CS, which has a substantially better one (with an astounding 120% increase in female SIRs). L&S CS has a 8.4% point improvement in female yield ratio, but for EECS there is a year-on-year decline. Clearly something about L&S CS is making it more attractive, because its female yield rate is now almost double that of EECS. We have to ask ourselves: why? There are many possible explanations for this disparity, and none of them involve pipeline.

An explanation offered on a Facebook discussion thread for this chart was that female admits are rarer and stronger, and thus generally have a wider selection of schools to choose from, pushing down their yield rates. This is a convincing theory, but without interviewing all 86 women who declined the EECS department’s admissions offer, there can be no proof. But if this is indeed the explanation, it does not reflect well on the department.

A note on acceptance rates: female applicants are accepted at a higher rate than male ones. The first instinct is that perhaps this is to balance out the much lower yield rate for women, since admissions departments generally target a certain number of matriculants, not admissions. Yet this is clearly not the case: for EECS, in order to match the 5:3 ratio in yield rates, the gender ratio for acceptance rates would need to be 0.60, not the 0.78 that actually happened.

Further evidence: looking at L&S CS, the admit ratio is nearly identical, despite their yield rate ratio being much better. Thus for L&S CS the admissions department was a net positive for gender equality, but for EECS it was actually a net negative.

The headline statistic is basically this: the EECS department had 3x higher year-on-year growth in female admissions over male ones, but by the time in came to SIRs that increase completely disappeared.

From all of this, the one thing we can conclude is that gender disparity in the yield rate appears to be a major problem blocking progress. And that’s something that can’t be blamed on the pipeline.

“one step ahead of the Wangses”

Yes, another linguistics post.

Yesterday on The Economist’s Gulliver blog:

the status of being able to afford to go abroad, ensuring you keep one step ahead of the Wangses, may be a factor

This is almost certainly wrong ungrammatical. Our writer M.D. bases this turn of phrase on the idiom keep up with the Joneses. But in that usual one, we get an -ses because the surname is Jones. Since we can’t have Joness—because by English rules it would be pronounced /dʒoʊ’nɛs/, which really wouldn’t do—we change the -s prefix to -es, giving us the Joneses.

But the Chinese surname is Wang! There’s no word-final -s. The family with the last name Wang are the Wangs.

Lest I be accused of pedantry or prescriptivism here, allow me to note that “keep up with the Wangses” has merely 21 Google hits (although this number will probably rise when Googlebot sees this post), and that’s with “omitted results included”. “Keep up with the Wangs” on the other hand has 54,900 Google hits, and in the top few are a Wall Street Journal blog, an article in The Telegraph, a New York Times article (from 1993, no less), and a paper by a Princeton economics professor.