Long-range communication with devices that consume almost no power
washington.edu
washington.edu
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?
It's a much more difficult thing to implement the solution correctly and uniformly.
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.
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).
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.
"...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?
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.
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.
Maybe you mean everyone growing their own food? That's not sustainable.
* 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.
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.
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.
Traditional agriculture is about the least productive way to interact with Nature.
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.
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.)
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.
But I would argue that all these practices are part of the aforementioned "traditional agriculture".
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.
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 ...
2.8km... is that line of sight?
This article is beneath HN.
Link to the paper: http://longrange.cs.washington.edu/files/loRaBackscatter.pdf
Obviously it's ISM band, and these researchers are in the United States.
Does it really need to tell you that it's ~900MHz?
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.
> 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.
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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.
Thanks for double-checking. Serves me right for trying to be helpful on my phone!
> 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?
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.