5 ms·
Long-range communication with devices that consume almost no power
- cstross 9y agoWow, the old-time KGB would have loved this: https://en.wikipedia.org/wiki/The_Thing_(listening_device) 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 ...
- ryanmarsh 9y agoI 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 http://longrange.cs.washington.edu/files/loRaBackscatter.pdf
- tinix 9y agoYou 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?
- bsder 9y agoYes, 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 https://en.wikipedia.org/wiki/ISM_band
- neoh 9y agoSome Standford students seem to have done something quite similar already. https://web.stanford.edu/~skatti/pubs/sigcomm15-backfi.pdf https://web.stanford.edu/~skatti/pubs/sigcomm15-backfi.pdf
- jotux 9y agoThat paper is referenced in the paper cited in this article. Number 52: http://longrange.cs.washington.edu/files/loRaBackscatter.pdf http://longrange.cs.washington.edu/files/loRaBackscatter.pdf
- anonymousDan 9y agoThe Washington guys are definitely the leaders when it comes to backscatter stuff.
- andrewflnr 9y agoWe need to talk about the security implications of low-power devices broadcasting data. I cringed when the article talked about broadcasting "medically relevant data" for kilometers, in the clear. That's not OK. Everyone needs to be clear on the fact that that's not OK. 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?
- andrepd 9y agoEncryption is a easy. I doubt this will be a problem.
- gwern 9y agoThe Internet of Shitty Things is always a problem, and you know people will be disabling encryption to save 10% energy.
- pavel_lishin 9y agoOr two days' of developer time. Or a nickel on the manufacturing costs.
- vvanders 9y agoOh the stories I've seen/been involved in over half a cent on a BoM.
- LeifCarrotson 9y agoIt'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.
- andrewflnr 9y agoEncryption 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.
- eutropia 9y agoI'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?
- jrowley 9y agoI'm sad to see eutropia's comment downvoted - it's a valid point that needs consideration. We only get one earth.
- crispyambulance 9y agoI 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.
- CamperBob2 9y agoI 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.
- musage 9y agoWhy 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.
- j_s 9y agodupe-ish: LoRa Backscatter [pdf] | https://news.ycombinator.com/item?id=15201692 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 https://news.ycombinator.com/item?id=15201692 (7 days ago) > aw3c2: From a balloon in almost 40km altitude.
- ColanR 9y agoThat's the same link twice...did you mean to post two different HN links?
- j_s 9y agoOops, my bad -- the first link to the dupe should have been: https://news.ycombinator.com/item?id=15246659 https://news.ycombinator.com/item?id=15246659 Thanks for double-checking. Serves me right for trying to be helpful on my phone!
- tomxor 9y agoThis 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?
- celim307 9y agoTo play devil's advocate, there definitely is a disconnect between when you think you're fine and when you're dehydrated
- DoubleCribble 9y agoAny 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.
- kazinator 9y agoIt 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.
- sowbug 9y agoIt's unclear what your comment is meant to contribute. Criticizing ideas you don't find useful or imaginative is not especially useful or imaginative.
- 9y ago
- grandalf 9y agoFinally something that might create a commercial incentive for a lowered RF noise floor!
- adam_seeliger 9y agoNot impressive at all. In a university lab back in 1999, we were doing this.
- ColinWright 9y agoI'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
- sverige 9y agoOops, hadn't seen that! Didn't mean to double-post, and the original title was too long so I had to modify it.