Long-range communication with devices that consume almost no power(washington.edu)
washington.edu
Long-range communication with devices that consume almost no power
http://www.washington.edu/news/2017/09/13/uw-team-shatters-long-range-communication-barrier-for-devices-that-consume-almost-no-power/
63 comments
Encryption is a easy. I doubt this will be a problem.
Encryption is easy on platforms with plenty of power and transistors and well-established libraries, which are the exact opposite of what we're talking about here. Encryption on very low-powered systems is a well-known problem.
Encryption for low data rate systems is actually a very easy problem. I have sensors in the field which transmit a 64 byte package once a day only 18 bytes of which is data and is encrypted. the encryption an one time pad in ROM which lasts the life of the device (8 years) the device does not receive.
I agree encryption is totally necessary for medical/sensitive data or two way devices but for other cases (such as irrigation data) no encryption or an encrypted ID is just fine and a problem that does not need to be solved.
I agree encryption is totally necessary for medical/sensitive data or two way devices but for other cases (such as irrigation data) no encryption or an encrypted ID is just fine and a problem that does not need to be solved.
Seemingly trivial data can be combined to form a detailed picture of someone. Regarding irrigation: How is the farmer's business doing? What kind of seed are they using and what is their schedule? Is the homeowner home? Are they following local water use laws or guidelines?
Doing reasonable encryption and authentication on interfaces with MTUs on the order of tens of bytes (which is common for various low-power IoT radio interfaces) is actually pretty complex problem.
Essentially all widely used and safe cryptographic constructions have overhead (IV and MAC tag for example) that would consume significant portion of your packet (or in some cases is actually larger that the packet).
Essentially all widely used and safe cryptographic constructions have overhead (IV and MAC tag for example) that would consume significant portion of your packet (or in some cases is actually larger that the packet).
The Internet of Shitty Things is always a problem, and you know people will be disabling encryption to save 10% energy.
Or two days' of developer time. Or a nickel on the manufacturing costs.
Oh the stories I've seen/been involved in over half a cent on a BoM.
If you have low power devices with basically no external input but a build in clock and a network interface that receives one packet every few minutes (often it even only sends data!), how do you create cryptographically secure random numbers for your encryption?
Noise.
Most - if not all - of these chips have analog to digital convertors because most of the applications involve monitoring some sort of signal. There's going to at least a bit or two of noise in the signal (or if not otherwise used, a floating input.) That's where I'd start if I was looking for entropy.
Same "noise" has to be at receiving crypto otherwise no key to decode it.
That's... not how modern crypto works.
For the sake of argument, I'll grant that encryption is easy.
Key management is not easy. Most people don't even understand, let alone appreciate, the problems, which is why there's substantially less bike-shedding in this domain. In the context of sell-and-forget (intentionally or unintentionally) IoT devices, there often may be more real security in simply giving up, to mitigate a false sense of security.
Key management is not easy. Most people don't even understand, let alone appreciate, the problems, which is why there's substantially less bike-shedding in this domain. In the context of sell-and-forget (intentionally or unintentionally) IoT devices, there often may be more real security in simply giving up, to mitigate a false sense of security.
No wonder the internet of shit exists when people have this attitude.
It's one thing to have a problem that can be solved mathematically.
It's a much more difficult thing to implement the solution correctly and uniformly.
It's a much more difficult thing to implement the solution correctly and uniformly.
I'm concerned with the environmental impact of:
"...farmers looking to measure soil temperature or moisture could affordably blanket an entire field to determine how to efficiently plant seeds or water. "
Littering chips all over the place?
"...farmers looking to measure soil temperature or moisture could affordably blanket an entire field to determine how to efficiently plant seeds or water. "
Littering chips all over the place?
Combine it with compostable plastics and organic circuits though and you might be able to build a low power sensor that biodegrades in a dozen years or so.
And largely these sensors are unnecessary. Such "precision agriculture" efforts are just doubling down on a broken agricultural paradigm.
Farmers might be interested in reclaiming the data for themselves, though. Right now, they're in a situation where John Deere uses sensors in the tires of the tractors the farmers license (they can't buy them) to get soil density and similar data as the farmers use them... then they sell that data to Monsanto and other seed companies. The farmers are completely cut out of it and can not benefit from the data. In fact, it would be against the law for them to try to intercept or peek at the data themselves.
What does that even mean? Plant seeds, water, temperature is just how nature works. What other "paradigm" of agriculture is there?
Maybe you mean everyone growing their own food? That's not sustainable.
Maybe you mean everyone growing their own food? That's not sustainable.
Two things:
* Sure, seeds germinate with water and warmth. But that's true today. In the words of an Australian farmer quoted in a research paper a few years ago: "Mate, we don't need a chip to tell us the soil's dry."
* There are other paradigms of agriculture that are actually sustainable. Agroecology is a good example of an alternative scientific paradigm for agriculture, one that thinks of agriculture in ecological terms.
* Sure, seeds germinate with water and warmth. But that's true today. In the words of an Australian farmer quoted in a research paper a few years ago: "Mate, we don't need a chip to tell us the soil's dry."
* There are other paradigms of agriculture that are actually sustainable. Agroecology is a good example of an alternative scientific paradigm for agriculture, one that thinks of agriculture in ecological terms.
Not all things are farmed like you seem to think. I own a commercial wild blueberry operation. Knowing this information, with less effort and cost, can improve harvesting methods and may do things like reduce the reliance on chemical weed mitigation strategies.
I'm not convinced by the Australian farmer.
Microclimates are a thing. Water is not evenly distributed across any sizable plot of land. Being able to tell where the water is (or more importantly isn't) can surely help deploy resources more efficiently.
But, I'm a desk jockey, and hope to never, ever be a farmer.
Microclimates are a thing. Water is not evenly distributed across any sizable plot of land. Being able to tell where the water is (or more importantly isn't) can surely help deploy resources more efficiently.
But, I'm a desk jockey, and hope to never, ever be a farmer.
You are right. I've been working a bit with the software for water management (although related to measurements of humidity over the day). Local management of resources does increase yields and sometimes just saves the crop.
The Australian farmer might not, but the machine that replaces him will.
Only if the same machine has to run on every farm in the world, without the option of learning what local conditions are or having them configured.
Machines operating farms in Australia can easily just assume the soil is dry, like the farmers do, as long as they don't also have to operate farms in Louisiana.
Machines operating farms in Australia can easily just assume the soil is dry, like the farmers do, as long as they don't also have to operate farms in Louisiana.
Applied ecology (Permaculture).
Traditional agriculture is about the least productive way to interact with Nature.
Traditional agriculture is about the least productive way to interact with Nature.
As demonstrated by the modest results (population growth from a few hundred thousands to 7.5 billion). /s
That's actually the conversion of oil into biomass.
https://en.wikipedia.org/wiki/History_of_fertilizer
Details and other topical information can be had here:
"Toby Hemenway - How Permaculture Can Save Humanity and the Earth, but Not Civilization" https://www.youtube.com/watch?v=8nLKHYHmPbo
Long story short: even a grossly inefficient process can produce massive growth if you have a torrent of free energy.
https://en.wikipedia.org/wiki/History_of_fertilizer
Details and other topical information can be had here:
"Toby Hemenway - How Permaculture Can Save Humanity and the Earth, but Not Civilization" https://www.youtube.com/watch?v=8nLKHYHmPbo
Long story short: even a grossly inefficient process can produce massive growth if you have a torrent of free energy.
That's at least partially true. World population in 1850 (before the use of modern fertilizers) was about 1.6 billion. Then you have to take in account mechanization of agriculture and genetic selection of varieties, which also probably multiplied the yields several times.
But I would argue that all these practices are part of the aforementioned "traditional agriculture".
But I would argue that all these practices are part of the aforementioned "traditional agriculture".
Well, mechanization is powered by oil, yes? And genetic engineering could be applied in any case.
In any event, you haven't made an argument that "traditional agriculture" is more efficient than applied ecology (Permaculture is an (the?) exemplar.)
Yield per acre is greater in a Permaculture farm than in a traditional farm, often by as much as an order of magnitude or more. Inputs are fewer too.
More importantly, under Permaculture the soil improves over time, while in traditional agriculture it is degraded and eventually becomes desert or wasteland.
In any event, you haven't made an argument that "traditional agriculture" is more efficient than applied ecology (Permaculture is an (the?) exemplar.)
Yield per acre is greater in a Permaculture farm than in a traditional farm, often by as much as an order of magnitude or more. Inputs are fewer too.
More importantly, under Permaculture the soil improves over time, while in traditional agriculture it is degraded and eventually becomes desert or wasteland.
A well-designed permaculture system should exceed industrial farming if you are talking about productivity per square meter. The problem is that the amount of labor required is totally unsustainable to feed billions of people.
That's where I see smart technology playing a role. Industrial agriculture involved building farming techniques around the machinery we have available. We "just" need to invert that approach and build smart machinery that enables us to glean food from highly-productive ecosystems.
That's where I see smart technology playing a role. Industrial agriculture involved building farming techniques around the machinery we have available. We "just" need to invert that approach and build smart machinery that enables us to glean food from highly-productive ecosystems.
> the amount of labor required is totally unsustainable to feed billions of people.
I disagree: in a well-designed system there may be a lot of labor in the beginning, but it should fall off within a year or two to a very low level, much lower than conventional farming.
(I admit a lot of "Permies" don't seem to set it up this way.)
I disagree: in a well-designed system there may be a lot of labor in the beginning, but it should fall off within a year or two to a very low level, much lower than conventional farming.
(I admit a lot of "Permies" don't seem to set it up this way.)
They're unnecessary, but mainly because tractors have equipment that do this anyway. So unless it's needed more frequently than when the tractor's driving around, it's probably not worth the extra cost.
I've seen a drone scanning over a large corn field, dropping sensors seems silly when you can outfit infrared tempature sensors/humidity sensors/etc on a drone.
I thought it was till, plant, harvest, and in between you just wait for nature to take its course. Do they have occasion to patrol a field with tractors more often than that?
On some crops yes, you spray all kinds of things after plating. On other crops you don't dare passing a tractor around them, else they would be ruined.
I'm sad to see eutropia's comment downvoted - it's a valid point that needs consideration. We only get one earth.
I didn't downvote him/her, but speaking from a general perspective as a longtime HN reader, this site seems to be intended to appeal to people interested in new technologies and interesting applications. It's just not a good home for knee-jerk naysaying and virtue signalling.
Those kinds of posts -- while sometimes relevant and valuable when they have actual numbers behind them -- should be held to a more critical standard on HN than they often are, IMO.
Those kinds of posts -- while sometimes relevant and valuable when they have actual numbers behind them -- should be held to a more critical standard on HN than they often are, IMO.
Why are you throwing "knee-jerk naysaying" and having a conscience and an awareness of the recklessness and greed of some, and of the lack of spine of others in one bucket?
What about the knee-jerk cheerleading? How does that express more and deeper interest than discussing potential pitfalls? I don't know about anyone else, but when I code I spend more time thinking about what could go wrong and how to address that, than admiring the parts that work perfectly.
When someone gushes at the mouth about how "awesome" it is that it took many very talented people a lot of time to make a toaster play music, the heretics are quiet already. What more do you want?
There seems to be a trade-off of chilling effects here, on the one hand, nobody would show off things they made to a community that just bashes it, on the other hand, nobody would show off their serious thoughts to a community that just wants fluff.
> sometimes relevant and valuable when they have actual numbers behind them
Oh, "actual numbers". Do you have any actual numbers proving they aren't held to the standard they should be held to? If you do, I changed my mind, I now want actual Egyptian hieroglyphs of a seer announcing you making that claim; I can make up arbitrary, oddly convenient demands too.
What about the knee-jerk cheerleading? How does that express more and deeper interest than discussing potential pitfalls? I don't know about anyone else, but when I code I spend more time thinking about what could go wrong and how to address that, than admiring the parts that work perfectly.
When someone gushes at the mouth about how "awesome" it is that it took many very talented people a lot of time to make a toaster play music, the heretics are quiet already. What more do you want?
There seems to be a trade-off of chilling effects here, on the one hand, nobody would show off things they made to a community that just bashes it, on the other hand, nobody would show off their serious thoughts to a community that just wants fluff.
> sometimes relevant and valuable when they have actual numbers behind them
Oh, "actual numbers". Do you have any actual numbers proving they aren't held to the standard they should be held to? If you do, I changed my mind, I now want actual Egyptian hieroglyphs of a seer announcing you making that claim; I can make up arbitrary, oddly convenient demands too.
I think its a valid point, but perhaps throwing these things into a crop was just "an example" illustrating how inexpensive these things are? The researchers aren't necessarily interested strictly in agricultural applications.
Researchers at my alma mater created paper transistors, maybe they could be biodegradable after EOL?
Wow, the old-time KGB would have loved this:
https://en.wikipedia.org/wiki/The_Thing_(listening_device)
(A passive resonant bug presented in a gift to the US Embassy in Moscow in 1945, designed by Léon Theremin, ancestor of today's RFID devices.)
The modern bugging applications don't even bear thinking about ...
https://en.wikipedia.org/wiki/The_Thing_(listening_device)
(A passive resonant bug presented in a gift to the US Embassy in Moscow in 1945, designed by Léon Theremin, ancestor of today's RFID devices.)
The modern bugging applications don't even bear thinking about ...
I didn't see Mhz one time in the article and frequency only once with no numbers.
2.8km... is that line of sight?
This article is beneath HN.
Link to the paper: http://longrange.cs.washington.edu/files/loRaBackscatter.pdf
2.8km... is that line of sight?
This article is beneath HN.
Link to the paper: http://longrange.cs.washington.edu/files/loRaBackscatter.pdf
You can't look at that trace antenna and guess the frequency?
Obviously it's ISM band, and these researchers are in the United States.
Does it really need to tell you that it's ~900MHz?
Obviously it's ISM band, and these researchers are in the United States.
Does it really need to tell you that it's ~900MHz?
Yes, actually, it does.
The green PCB looks more like a 2.4GHz antenna to my eye. The epidermal patch is much longer so looks like 900MHz to me. And there is also 27MHz for ISM. The lower the frequency, the further it tends to go.
https://en.wikipedia.org/wiki/ISM_band
The green PCB looks more like a 2.4GHz antenna to my eye. The epidermal patch is much longer so looks like 900MHz to me. And there is also 27MHz for ISM. The lower the frequency, the further it tends to go.
https://en.wikipedia.org/wiki/ISM_band
dupe-ish: LoRa Backscatter [pdf] | https://news.ycombinator.com/item?id=15201692 (1 day ago)
> ac29: 900MHz is heavily used in the US and describing the noise as "background" or "random" is disingenuous at best.
> Nelkins: There has been some prior work on this:
> junkcollector: Active RFID. The same technology in any meaningful sense.
--
related: LoRaWAN packet received at record distance of 702 km | https://news.ycombinator.com/item?id=15201692 (7 days ago)
> aw3c2: From a balloon in almost 40km altitude.
> ac29: 900MHz is heavily used in the US and describing the noise as "background" or "random" is disingenuous at best.
> Nelkins: There has been some prior work on this:
> junkcollector: Active RFID. The same technology in any meaningful sense.
--
related: LoRaWAN packet received at record distance of 702 km | https://news.ycombinator.com/item?id=15201692 (7 days ago)
> aw3c2: From a balloon in almost 40km altitude.
That's the same link twice...did you mean to post two different HN links?
Oops, my bad -- the first link to the dupe should have been: https://news.ycombinator.com/item?id=15246659
Thanks for double-checking. Serves me right for trying to be helpful on my phone!
Thanks for double-checking. Serves me right for trying to be helpful on my phone!
This stuff has some really cool implications but...
> For example, flexible electronics — from knee patches that capture range of motion in arthritic patients to patches that use sweat to detect fatigue in athletes or soldiers — hold great promise for collecting medically relevant data.
Sorry this just sounds lame, whenever people try to suggest applications of new technology they almost always seem to be A) not particularly useful and B) unimaginative.
> sweat to detect fatigue in athletes.
Really? don't you think it might be simpler, faster, cheaper (better in every single way) to just ask them?
> For example, flexible electronics — from knee patches that capture range of motion in arthritic patients to patches that use sweat to detect fatigue in athletes or soldiers — hold great promise for collecting medically relevant data.
Sorry this just sounds lame, whenever people try to suggest applications of new technology they almost always seem to be A) not particularly useful and B) unimaginative.
> sweat to detect fatigue in athletes.
Really? don't you think it might be simpler, faster, cheaper (better in every single way) to just ask them?
To play devil's advocate, there definitely is a disconnect between when you think you're fine and when you're dehydrated
It took me some 15 years to realize I had been chronically lacking sodium.
Fixed that problem; running is better than ever.
Sometimes you know you're not fine, but the cause isn't obvious. An athlete who is dehydrated might feel something is off, but not pin it on dehydration. Maybe just a bad day, or not enough sleep, or recovery from some earlier workout or whatever. That's a problem: even if the body tells you something, the message isn't always interpreted right.
Fixed that problem; running is better than ever.
Sometimes you know you're not fine, but the cause isn't obvious. An athlete who is dehydrated might feel something is off, but not pin it on dehydration. Maybe just a bad day, or not enough sleep, or recovery from some earlier workout or whatever. That's a problem: even if the body tells you something, the message isn't always interpreted right.
Any endurance athlete can verify. You learn quickly to force liquids and energy because by the time you realize you're dehydrated or weak, the competition might not be finished but your race is.
It's unclear what your comment is meant to contribute. Criticizing ideas you don't find useful or imaginative is not especially useful or imaginative.
Really? care to explain, how exactly would anything progress without criticism. Lets all just pat each other on the back and not bother telling each other the flaws in what we produce or think, that will work out just fine.
Some Standford students seem to have done something quite similar already.
https://web.stanford.edu/~skatti/pubs/sigcomm15-backfi.pdf
That paper is referenced in the paper cited in this article. Number 52: http://longrange.cs.washington.edu/files/loRaBackscatter.pdf
The Washington guys are definitely the leaders when it comes to backscatter stuff.
I'm late to the party, I've been doing work instead of keeping up with HN, but this was discussed yesterday:
https://news.ycombinator.com/item?id=15246659
https://news.ycombinator.com/item?id=15246659
Oops, hadn't seen that! Didn't mean to double-post, and the original title was too long so I had to modify it.
Finally something that might create a commercial incentive for a lowered RF noise floor!
I'm ecstatic at the possibilities this has for reducing the power cost of communication[0]. Please use the savings on some (at least half-decent) crypto.
[0] Seriously, can this work for a consumer handset communication network?