
Stanford engineer aims to connect the world with ant-sized radios - sterlingwes
http://news.stanford.edu/news/2014/september/ant-radio-arbabian-090914.html?utm_content=bufferaae5e&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer
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bravo22
It is a very cool development but I see couple of issues with it:

1 - It works at about 60GHz. You are not getting a lot of distance or even
going through a wall at that frequency and (likely) very low power levels

2 - The devices still need a central "base station". Presumably they
rebroadcast to neighbouring nodes; but at lower power levels since they reuse
some of the received power for themselves. I doubt you'd get more than 2 - 3
hops out before you don't have much power to begin with.

3 - He cites including these in fridges, coffee makers, light bulbs, etc. None
of these are power constrained applications. You can put in $0.45 802.15.4
chip in them TODAY and it comes with a whole microcontroller inside to do what
you want to do.

The tech here is no doubt "cool" but I don't see any applicability for IoT. If
anything I think it would have some medical uses in pills you can swallow etc.
But IoT use is kind of a dud.

Most IoTs have pretty good power source and you can run the w/ existing
chipsets.

~~~
ars
> Presumably they rebroadcast to neighbouring nodes;

Unless you have a directional antenna, which these don't, you can not possibly
scavenge power and simultaneously hope to increase the range by
rebroadcasting.

So rebroadcasting is pointless, these simply communicate with the base
station.

But what do they do? I mean it's nice to communicate, but you have to have
something to say.

~~~
bradfa
The power scavenging circuit looks to not be the same frequency as the
communications radio circuit due to antenna size differences. Likely it's
harvesting power from 2.4 GHz or similar frequency and then using the higher
(24 GHz-ish) band for comms. With a decent meshing protocol this would be
quite interesting, although latency with many many short hops will be horrid.

~~~
bravo22
The antenna is way too small for 2.4GHz. It makes sense for higher frequency
(60GHz or whatever he said in the video). You can power harvest RF waves
straight up but what you absorb gives you very little to rebroadcast again.

There are others doing work on this for sensors you could embed into say a
wall to give you the pressure reading of the concrete (a simple piezo say) but
those usually modulate an RF wave (similar to NFC) instead of rebroadcasting.

------
ridgeguy
These seem like the beginnings of the localizers in Vinge's A Deepness in the
Sky, or maybe his earlier Fast Times at Fairmont High.

~~~
TheMagicHorsey
The Larson Localizers?

In the story those nodes were compute, storage, and transport. As well as
interface.

Amazing tech.

I would be interested in trading for a sample, or better yet, the specs of the
industrial base necessary to manufacture them.

------
userbinator
_Now Arbabian envisions networks of these radio chips deployed every meter or
so throughout a house (they would have to be set close to one another because
high-frequency signals don 't travel far)._

The whole concept is a bit creepy, but that particular sentence stood out.
It's not hard to envision these tiny devices all having microphones and
cameras... the Internet of Things That Watch You seems not far off.

~~~
jacquesm
Microphony in radio circuits is pretty much a given so even if there is no
overt microphone every one of these will exhibit a frequency shift when hit by
sound waves and that shift is detectable.

Hm. This makes me wonder if you could recover audio from wifi signals.

~~~
Stwerp
Maybe you can describe this a bit more. The Great Seal Bug was used for
wireless audio recording in the 40's, but this operated by using a
microphone/cavity to modulate the load of an antenna; thereby embedding audio
in the reflected fields.

Bell did a similar demonstration in the 1890s using a mirror to embed
reflections in ambient light and demonstrated wireless audio transmission over
200 meters.

However, I'm not sure why audio would cause a frequency shift in a radio
circuit. Perhaps you are meaning the antenna will be perturbed and that could
possibly be recovered? I'd be interested to know.

~~~
jacquesm
In the times that I was still building radio transmitters (for a very illicit
living, selling them to pirate radio stations in Amsterdam) I had to hot-melt
each and every long wire and coil in place so that it wouldn't vibrate.

The oscillator circuitry of a transmitter is (even when crystal controlled)
sensitive to mechanical perturbation, which typically leads to spurious AM and
FM modulation of the outgoing signal. To demonstrate the effect I once held a
half our session on air with a guy on the other side of the city by just
talking to the circuit board.

In a PLL or crystal controlled transmitter modulating the carrier in such a
coarse way is much harder. Typically the modulation is done using a capacitive
diode (a varicap) which is a diode whose capacitance changes with the reverse
voltage. Because this voltage has to be applied to the diode somehow (in the
days before SMD) this meant that that wire was again susceptible to microphony
because air pressure on the wire changed it's location relative to the ground
plane and that caused a measurable frequency shift. Not nearly as big a shift
as in the older stuff but it was definitely a factor.

Wifi radios as _much_ more robust than the stuff that I built. But I suspect
that given a sensitive enough detector a residual audio component might be
extracted from an otherwise non-audio signal by direct interaction between the
sound waves and the transmitter hardware.

In a nutshell, it is very much harder to make something that does not exhibit
microphony than to make something that does. You'd have to take that into
account from the beginning of the design.

------
otakucode
This sounds almost exactly like amorphous computing... but not. Was that bit
just left out of the article? Is the intention that these chips will be used
one-at-a-time and perform significant computation onboard rather than (as with
amorphous computing) having computation be an emergent property of the
internetworking of many such chips?

~~~
jfoutz
This is going to sound a little harsh, but that's not the intention. I am
genuinely curious about emergent phenomenon of computation.

I spent a lot of time messing around with toy evolutionary algorithms. I never
really got any satisfaction out of those experiments. eventually I found this
[1], and felt sort of foolish.

Has anything really happened with emergent properties in the last 10 years or
so?

[1]
[http://lesswrong.com/lw/iv/the_futility_of_emergence/](http://lesswrong.com/lw/iv/the_futility_of_emergence/)

~~~
farmerjack
I've never seen emergence "used as an explanation in its own right." I also
don't understand why you would feel foolish after reading this.

~~~
TeMPOraL
Actually, most of the uses of the word "emergent" I encounter are exactly as
the LW article describes. If you'd replace the word "emergent" with "magic",
you'd learn nothing more and nothing less from a sentence. [0]

As for feeling foolish after playing with evolutionary algorithms - I'm not
the OP but I can relate somewhat given how I saw people learning evolutionary
algorithms and neural networks at my university (and I'm pretty sure it's not
a local phenomenon). Evolutionary algorithms are usually explained as inspired
by biological evolution, with implicit (and sometimes explicit) note that
"evolution made us, therefore evolution is superpowerful, therefore
evolutionary algorithms - which are just evolution in code - will be
superpowerful too!". Except they're not, and the whole concept is bullshit.
It's a belief in Random Number God. Throw enough shit at the wall and
something will stick. Evolution is terribly, terribly inefficient, and so are
the evolutionary algorithms.

Sure, this inefficiency gives them some interesting properties that may help
them avoid particular types of local optimas, etc. But those are mathematical
features of an algorithm type, and have nothing to do and share no power with
evolution, or magic.

The whole problem stems from people trying to transfer virtues of biology to
computing by using a surface metaphor. There's a post on LW that covers it
nicely:

[http://lesswrong.com/lw/vx/failure_by_analogy/](http://lesswrong.com/lw/vx/failure_by_analogy/)

" _So... why didn 't the flapping-wing designs work? Birds flap wings and they
fly. The flying machine flaps its wings. Why, oh why, doesn't it fly?_"

Or about neural networks,

" _A backprop network with sigmoid units... actually doesn 't much resemble
biology at all. Around as much as a voodoo doll resembles its victim. The
surface shape may look vaguely similar in extremely superficial aspects at a
first glance. But the interiors and behaviors, and basically the whole thing
apart from the surface, are nothing at all alike. All that biological neurons
have in common with gradient-optimization ANNs is... the spiderwebby look._"

I encounter a lot of similar "medieval thinking" in CS departments. I don't
know why. It probably goes in common with the concept of not caring about how
the world works.

Oh, this one is also good:
[http://lesswrong.com/lw/rj/surface_analogies_and_deep_causes...](http://lesswrong.com/lw/rj/surface_analogies_and_deep_causes/).

[0] - it's also a good trick I picked up while hanging on LW; if you don't
know why something happens, label it as unknown explicitly. Say "this process
is driven by magic", or "caused by Divine Intervention" instead of trying to
invent equivalently-informative but sciency-sounding labels like "emergent
behaviour" or "spontanous self-organization". This way you'll never forget
that your theory still has holes that need to be filled in, and you won't
accidentally confuse yourself (or others).

~~~
farmerjack
Who is saying that the analogously named models are equivalent the analogs
themselves? Analogous terminology and metaphors exist so that people can ease
themselves into a deeper understanding of a subject. I agree that some people
can incorrectly draw grand conclusions from a simple name, but that doesn't
mean the people who use these "things" with these "names" only understand
their mechanisms on a superficial level. Seriously, good luck explaining _any_
model without introducing an analog that we, as humans, can relate with.

~~~
TeMPOraL
Sure, I'm not saying analogies are the problem. They're not, we need them,
they're important parts of our cognition.

My point was twofold: a/ beware inference from surface analogies, always
strive to understand where the border between similar and different properties
lie, and b/ it does happen. People do draw conclusions and build their
understanding on superficial analogies _in a systematic way_. That's why I
mentioned the anecdote of CS students I know. I've seen it in real life. Also
known as cargo-culting, it's unfortunately not a rare phenomenon.

Also, I'm not the CDDDDARP ((cddddar this-comment)-poster), but I hazard a
guess that he "felt sort of foolish" because he discovered he accidentally did
some inferring from surface analogies and ended up disappointed.

~~~
jfoutz
Exactly that. I inferred from surface analogies and was disappointed.

------
janekm
I've just read the paper; it's academically very cool yet practically useless
(at least for now). It uses 24GHz for RX, 60GHz for TX so retransmission is
just a fantasy of the "journalist". It requires +45dBm output power (32watts!)
at the Basestation to power it at 50cm range, so less practical than regular
RFID for now really (and absolutely no chance of ever working as a mesh).

~~~
Stwerp
45 dBm is crazy! Do you know the FCC limitations for that frequency? For the
ISM bands its +36 dBm EIRP maximum. I'm not familiar with the rules for the
higher GHz frequencies.

------
tim333
You'd think it might work better if they had a bit of wire attached as an
arial. Then they could use lower frequencies, get more range and so on,
perhaps? Having mucked about connecting bits of wire to oscilloscopes it seems
most of the signal that you could use to power something is 50/60Hz picked up
from the mains. It would still cost cents given a bit of wire is not terribly
expensive.

------
hcarvalhoalves
A light bulb _I_ can control is nice, but one that _anyone_ can control
doesn't seem very useful. How does one implement security on top, since this
is passive?

~~~
icebraining
The article says it has a CPU, therefore in theory it can check digital
signatures.

That said, I don't see why would it need to be passive if it's in a light
bulb, or any other device that can be actuated. It'll need more energy to do
whatever you tell it to, so it can also use that energy to actively power the
CPU.

------
induscreep
Comparing with existing wireless sensor network "motes", this is much much
smaller - but do it's processing/networking capabilities match those of motes?

------
morenoh149
I'd like to know more about how it's powered. Didn't see anything on that.
Seems like it's powered by proximity to that purple square.

~~~
XorNot
They say it's energy scavenging - like passive NFC tags essentially.

~~~
tkinom
Agree, the whole demo looks like an passive NFC tag.

What's new here?

~~~
Stwerp
Its far-field, so it couples completely differently than NFC tags. Also, NFC
communicates by reflecting signals, this device communications by active
transmission (according to the article, I haven't read their paper yet).

What's new? Its tiny, and I'm very curious how they got that an oscillator to
work at extremely low powers. But, it is really just an extension of
RFID/NFC/IoT miniaturization work. But then again, just about everything
starts out that way.

------
pkaye
What is this... a radio for ants? But seriously speaking, at the frequencies
used, I'm guessing it is meant for some bluetooth application?

------
chubot
Is it programmable? That is, does it have CPU/memory? The article wasn't clear
on this.

------
JoeAltmaier
Isn't this an RFID tag? What makes it different?

------
grendelt
"What is this? A radio for ants?" "I don't wanna hear your excuses! The radio
has to be at least... three times bigger than this!"

