[HN Gopher] Infrared may no longer be a punchline, as IEEE appro...
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Infrared may no longer be a punchline, as IEEE approves 9.6Gbps
wireless light
Author : el_hacker
Score : 77 points
Date : 2023-07-16 15:59 UTC (7 hours ago)
(HTM) web link (www.theverge.com)
(TXT) w3m dump (www.theverge.com)
| gnicholas wrote:
| Would this be easier to intercept from a distance?
| letitbeirie wrote:
| Probably harder in a practical sense - its signal doesn't
| travel through walls or most commercial windows so the
| intercepting sensor would have to be located in the same room
| (if indoors) or have a heroic signal/noise ratio to avoid
| getting washed out by sunlight (if not).
| gweinberg wrote:
| Strange title. If infrared is the punchline, what's the joke?
| antonvs wrote:
| I imagine the idea is that infrared communication itself is a
| joke, if you need higher speeds or have any objects in the path
| of the beam.
| ksec wrote:
| Oh FFS. So they approve 9.6Gbps Li-Fi aka IEEE 802.11bb, and the
| devices shown in the photo used inside a prototype is only
| capable of 1Gbps, but every article including one submitted last
| week said " _100x Faster_ " [1] than WiFi at 224 _GB_ /s or 1792
| _Gbps_.
|
| And just like 802.11be and 802.11ax, I had to read up on the
| actual Spec again to understand WTF is going on instead of
| relying tech reporting. And this isn't just a problem with
| reporting, the actual PR of Li-Fi cant even do half its job.
|
| [1] https://news.ycombinator.com/item?id=36707789
| coltonweaver wrote:
| Am I correct that this would require direct line-of-sight for any
| device using an antenna[0] enabling this? It seems a bit
| impractical for your typical consumer use-cases if so, but maybe
| beneficial for some more commercial scenarios.
|
| Would love to know if I am wrong here though! It seems very
| interesting.
|
| 0: https://www.purelifi.com/products/light-antenna-one/
| dist-epoch wrote:
| The idea is to put it in the ceiling (lightbulbs).
|
| Light bounce also works, so if you are in a typical room the
| walls also become antennas.
| hfkwer wrote:
| So if you turn your back on the ceiling light you lose your
| connection?
| assimpleaspossi wrote:
| Light reflects off most surfaces so not necessarily.
| PartiallyTyped wrote:
| Does anyone even need 9.6Gbps wireless?
| dvngnt_ wrote:
| wirelessly streaming vr
| supertrope wrote:
| Wireless laptop dock is one application. A 1080p monitor signal
| is 3.2 Gbps. Dual monitors is 6.4 Gbps. One "4K" display is
| 12.5 Gbps.
|
| Wireless is notorious for quoting numbers that include protocol
| overhead and assume a near zero noise and congestion
| environment. The typical layer 7 throughput of 802.11 is about
| half of the link rate. Of course it goes down from there
| without line of sight in the same room.
| sedatk wrote:
| 640Mbps ought to be enough for everyone.
| spdustin wrote:
| I'd be curious to know how it impacts things like FaceID. Or if
| bathing a room with rapidly modulated IR would affect
| thermography (as used in, say, energy efficiency audits).
| sp1rit wrote:
| I remember my old Nokia brick having the ability to send files
| and apps through an infrared thingy on its side. You could simply
| hold two phones side by side from each other and transfer data,
| but I remember handly anyone using it (I guess it was kind of
| akwad to use - but probably still simpler than getting the
| devices paird with bluethooth).
|
| It wasn't nearly as fast the advertised speeds mentioned in the
| article.
| readams wrote:
| I'm curious who has a problem that this solves. You need to have
| line of sight to something very nearby. So you'd need to wire
| 10Gb Ethernet to the LiFi points.
|
| But then why not just use wired Ethernet?
| haswell wrote:
| This would be fantastic in my current apartment. My immediate
| surroundings are completely saturated by WiFi access points
| across both 2.4 and 5.x GHz making all wireless connections
| unreliable at best, and the layout of my apartment is such that
| the only way to have a wired connection in the living room
| where my desktop sits is to run an ethernet cable across the
| floor.
|
| So I run an ethernet cable across the floor, and it's not
| great.
|
| I also think VR/AR use cases may benefit from this eventually.
| wyldfire wrote:
| I wonder, does this pollute the IR on your apartment so that
| your TV remote would no longer work? Although with streaming
| set-top boxes, those are using RF most of the time these
| days.
| robinduckett wrote:
| Two university buildings separated by a privately owned house
| or two springs immediately to mind. Not sure if they still do
| but my local university used to have IR links between
| buildings.
| readams wrote:
| They're not talking about point to point links here, but end-
| user devices.
| blincoln wrote:
| Once it's widespread in consumer gear, I'm sure it's only a
| matter of time before people start hacking it to operate
| over longer distances, similar to what's been done with
| custom WiFi antennas, parabolic dishes, etc.
| ugjka wrote:
| airports would be one case
| antonvs wrote:
| Just a vaguely related anecdote, I consulted for a company that
| had two offices on a river, in old converted houses, separated
| by a marina. Running a cable proved problematic for various
| reasons, both bureaucratic and relating to the nature of the
| site.
|
| To connect the networks between the two buildings, they had a
| laser connection set up in the widow's walk on the buildings.
| It worked great except when it was foggy or raining very
| heavily, or when the marina moved a sailboat so that its mast
| blocked the beam.
| NortySpock wrote:
| Conference halls, open plan offices, LAN parties, maybe data
| scientist teams sharing large datasets around a room...
| lxgr wrote:
| Signals not propagating through doors or walls can be an
| advantage for many applications, both for capacity and privacy
| reasons.
| flashback2199 wrote:
| I'm imagining offices that put Li-Fi devices on the ceiling and
| laptops made with Li-Fi in the edge of the screen lid so that
| you can just open your laptop and it will start using the Li-Fi
| for faster speeds.
| afavour wrote:
| > But then why not just use wired Ethernet?
|
| This is a recurring question and one often answered by "people
| rent houses/apartments and can't just run cables through the
| walls".
|
| I'm not all that sure what I'd use this specific technology for
| over Wifi but I can understand why people don't use wired
| Ethernet.
| mabbo wrote:
| I own my condo but have this exact issue. There are 1Gb Cat5
| cables inside the cement walls and I cannot replace them if
| they ever break, nor upgrade them.
|
| Already this is a problem as I have 1.Gbit internet.
|
| Edit: I am silly and wrote Mbit instead of Gbit.
| ericbarrett wrote:
| > There are 1Gb Cat5 cables inside the cement walls
|
| I believe you when you say you can't replace them, but I'm
| curious why? Every wire I've ever seen run through concrete
| was in a conduit that could have replacements pulled
| through it. Did they just run the wires and pour over them?
| nullc wrote:
| There is no such beast as 1Mb cat5. Do you mean 1gb?
| Assuming the cables are in conduit you may be able to use
| the existing cables to pull new cables. This usually works.
| mabbo wrote:
| Thank you, I had a brain fart and meant Gbit.
| rayiner wrote:
| What is one meg cat5? Isn't cat5 rated to one gig?
| ElectricalUnion wrote:
| CAT5 is in theory only rated for Fast Ethernet (100M)
| while CAT5e is rated for Gigabit Ethernet. In practice is
| very hard to actually find a cable that meets only CAT5
| and not CAT5e.
| sthuck wrote:
| if you have coax cables in the walls then MoCA is a pretty
| good solution. (Powerline is not)
|
| also dear god I hope it's a typo and you meant 1Gb
| debaserab2 wrote:
| Is MoCA reliable? Just bought a new house and wiring
| Ethernet into some of the rooms will be tricky, but a
| previous owner already did coaxial in the whole house.
| Klathmon wrote:
| Extremely reliable, but it can get expensive to have to
| buy a moca to Ethernet adapter at each point.
|
| You want to stick with moca 2, and there might be some
| gotchas with older coax wiring, but I previously ran it
| for years without issue.
| ryukafalz wrote:
| I think I'm running into some of those gotchas with older
| wiring. I've got moca adapters set up between a few rooms
| and have periodic dropouts on one of them, which
| unfortunately is the room with my wifi AP.
|
| Traced the cables and the only splitter I can find is a
| moca 2 aware one, and the coax cable that would have been
| used for cable internet is unplugged so that's not
| interfering.
|
| Nice when it works, real pain to troubleshoot when it
| doesn't.
| supertrope wrote:
| The same reason people use Bluetooth audio. It's more
| convenient because there's no cord. (But there's a battery to
| manage, interference, pairing, and inferior audio quality).
| jimmytidey wrote:
| I remember reading that Royal Navy engineers maintaining nuclear
| submarines use Li-Fi to connect their workstations to the
| network.
|
| They said it was a security requirement - does seem
| extraordinarily elaborate. It feels like using wires could have
| been a simpler answer...
| jchanimal wrote:
| Wires likely permit too much side-channel to be safe.
| throitallaway wrote:
| Interesting and agreed. Is it more secure (or less detectable)
| than Ethernet? I suppose Ethernet has some form of magnetic
| radiation. I wonder what all this infrared light bouncing
| around will do to us monkeys.
| woah wrote:
| Make us infinitesimally warmer?
| njanirudh wrote:
| Is https://youtu.be/Rw-QZuGVP3o somehow related to the technology
| in the article.
| hparadiz wrote:
| If I have a room full of these can they communicate with each
| other to provide a connection? This reminds me of base stations
| for my VR setup where my feet trackers will sometimes lose
| connection due to a physical obstacle like a desk. The solution
| is to add more base stations typically or make your space more
| sparse.
| gochi wrote:
| They ran a case study at a school, you can scroll down and see
| their overview setup which did what you're talking about, a
| room full of them providing a connection:
| https://www.purelifi.com/case-studies/lifi-in-the-classroom/
| deepnotderp wrote:
| One day the use of self-accelerating beams (which can bend/turn
| by themselves) may remove the line of sight limitation.
|
| https://www.mdpi.com/2076-3417/7/4/341
| blincoln wrote:
| Seems like the fact that it's a "tightbeam" vs. WiFi's broad
| coverage could result in some fun niche hacks like tiny
| autotracking IR transceiver turrets that follow devices around a
| room or (working together to hand off the connection) a building,
| or larger versions that keep two transceivers pointing at each
| other over a longer point-to-point link. Who will be the first
| hobbyists to establish a LiFi link bounced off of one of the old
| retroflectors on the moon?
|
| If the IR is bright enough, it might even make sense to put a NIR
| camera in every access point so it can double as an unobtrusive
| security camera, and/or track devices (for beam-forming, forensic
| information for physical security staff, etc.).
| jdblair wrote:
| No mechanical turrets needed! Just use a flat, stationary,
| phased array infrared emitter.
| nuccy wrote:
| Do you have a reference on any of those? I can only find
| papers about lab setups. Since wavelength of IR is much
| shorter phase control of different emitter is much harder to
| accomplish than in the radio. Moreover thermal deformation of
| the device would affect the phases much more significantly.
| hilbert42 wrote:
| Why such a puny speed?
| fulafel wrote:
| People seem to be conditioned to the choppy and slow wifi
| speeds, so slower-than-Ethernet speeds can still sound
| appealing in comparison.
| hilbert42 wrote:
| Right, I think conditioning is definitely part of it, but my
| point was (as I hinted elsewwhere) the move to optical would
| have allowed for a vastly better performance with little
| additional overhead.
| coltonweaver wrote:
| The theoretical limit of WiFi 6E is 2,500Mbps:
| https://www.highspeedinternet.com/resources/wi-fi-6-vs-wifi-...
|
| This would be nearly 4X that.
| hilbert42 wrote:
| Perhaps so, but this new standard reminds me of the born-dead
| USB1 standard, which at the time of its launch was so slow as
| to be almost useless.
|
| This new _optical_ standard is only about 50% faster than the
| now-ancient _copper_ SATA standard of 6Gbps. It has stuff-all
| reserve for future development!
|
| Every time we have one of these new standards, Wi-Fi
| whatever, they are just a bit above the previous standard and
| never at the limits of the tech. There is never enough
| reserve to give them decent longevity. It's as if those
| manufacturers involved in setting standards were making a
| standard that would be quickly obsolescent--that is, they'd
| guarantee ongoing production/sales without much effort.
|
| It's been such a consistent problem for so long that it has
| shades of the Phoebus cartel about it. As always, the user
| ends up paying more because of premature (planned)
| obsolescence.
| yjftsjthsd-h wrote:
| It's not competing with SATA, it's competing with WiFi.
| supertrope wrote:
| Electronics is an extremely cost conscious industry.
| There's not a viable market for massive jumps forward if
| the laptop would cost 10x. Approaching the Shannon Limit
| also is at odds with maximizing battery life. Recent
| Macbooks only have 2x2 MIMO. Presumably 3x3 MIMO used
| relatively too much power, space, or BOM.
| fulafel wrote:
| IR is 0.3-100 THz, so the bands can be very wide and
| don't need to approach theoretical bandwidth efficiency
| limits to get lots of bits over, no?
| hilbert42 wrote:
| Fine but this is an optical standard, and if worried
| about power then automatic and or fixed limit throttling
| could remedy the problem.
|
| The link _sp332_ has provided says it all, reckon it
| supports my case.
| zokier wrote:
| > This new optical standard is only about 50% faster than
| the now-ancient copper SATA standard of 6Gbps
|
| you are surprised that free-space optical transfer over
| many(?) meters is "only" 50% faster than data transfer over
| <1m carefully constructed differential coax-pairs?
| eropple wrote:
| _> It 's been such a consistent problem for so long that it
| has shades of the Phoebus cartel about it._
|
| Which wasn't what the general public thinks it is and, much
| like equating short-run in-device transports with lossy,
| room-distance ones, is a good signal that one is comparing
| apples and trailer trucks.
|
| https://www.youtube.com/watch?v=zb7Bs98KmnY
| Pet_Ant wrote:
| Well the speed is the speed of light, ideally this should have
| low latency. The datarate will be effected by how quickly you
| can turn on and off the light and that will have some limits.
| manmal wrote:
| Latency in WiFi comes from interference and contention (wait
| until other devices have finished sending; this has improved
| with Wifi6 AFAIK), and some other, probably less significant
| factors. Travel time of the signal through air should be the
| same.
| bragr wrote:
| As apposed to radio waves which also travel at the speed of
| light?
| bombela wrote:
| Light and radio waves are the same physical phenomenon. The
| difference is the frequency. Light is much much higher
| frequency than radio. Nuclear radiation are even higher
| frequency. Maximum throughput with maximum damage!
| sp332 wrote:
| The LiFi page claims much higher speeds. https://lifi.co/lifi-
| speed/
| zokier wrote:
| That 224GB/s figure is some serious bullshitting. For
| comparison, the fastest optical ethernet transfer over fiber
| is 800Gbps or 100GB/s, and even that is over 8 fiber pairs
| and still in-development tech. Claiming to do over twice of
| that in free-space with "common household LED light bulbs" is
| pretty ridiculous.
| hilbert42 wrote:
| Right, now look at this standard by comparison.
| dist-epoch wrote:
| It's faster than most computers wired Ethernet.
| letitbeirie wrote:
| This is pretty cool - being able to identify/segregate traffic by
| its _physical room_ seems like it would be a useful tool for
| anyone in security, university professors giving exams, etc.
|
| I can't really see it totally replacing WiFi though. It's hard
| enough to get a TV remote to work outside in the shade - getting
| higher-bandwidth IR-based WiFi to work outside in the sun
| seems... ambitious?
| dragontamer wrote:
| IrDA above 115kbps is basically dead, and I don't think anything
| beyond 4MBps is feasible (ie: months spent on an FPGA to handle
| all the issues)
|
| I'm a big fan of using simplified IrDA in 2023 in hobby
| electronics. But I don't see a smooth path to 9.6Gbps.
|
| 1Mbps to 10Mbps is already exhausting for me to think about.
|
| --------------
|
| Is there any industry chip with planned development to handle
| this standard? Finding a damn LED and Photodiode that is
| guaranteed faster than 20ns to feasibly handle 4Mbit is
| horrifying. Let alone the signal processing circuits (I think you
| need 20Mhz OpAmps which isn't a 6001 or lm358 if you know what I
| mean) or FPGAs needed to handle this relatively low speeds.
|
| Or are we doing some kind of multi-frequency multi LED thing? Are
| there any LEDs or Photodiode that can emit and detect such a
| narrow band? What are the sources of IR noise to mess with those
| frequencies?
|
| -------
|
| Oh, but 115kHz is plenty useful for a hobbyist and I highly
| recommend people playing with that.
| _trampeltier wrote:
| There are much faster IR Links for industrial application. They
| are for example used in automatic crane application. I don't
| know the data rate just now, but we have a crane with a such
| Profibus link since over 20 years in our factory.
|
| https://www.leuze.com/en-us/products/optical-data-transmissi...
| flashback2199 wrote:
| Edit: I re-read your comment and I think I see what you might
| have meant now. I think you were asking if there would be a
| solution for low speed devices to use this standard.
| dragontamer wrote:
| I'm asking if the LEDs that support 9.6Gbps (what is that? A
| 1ns or faster LED?) even exist in any substantial way.
|
| Isn't that like, laser speeds? Not overhead LED speeds. And
| over the air? Not inside a fiber line?
|
| This is basically a 10Gbps standard for fiber lines except
| over the air. All those issues need to be solved without the
| guarantees or isolation that fiber optic lines provide.
|
| That's just transmit. Receive has to deal with the same
| issues, amplifiers and other electronics that move at the
| requested speeds.
| Scene_Cast2 wrote:
| Could one PWM such a light to display high bit color
| content? By my estimates: to send 9.6Gbps, you need (at
| least) 9.6 GHz, and that's 160,000,000x faster than 60hz.
| log2(160 million) = 27.3 bits.
|
| I'm sure that this idea is more of a fun hackaday-style
| gimmick (i.e. not productionizable for various reasons),
| but would be fun to see.
| sudosysgen wrote:
| Couldn't you just use a laser and a lens?
| [deleted]
| [deleted]
| zokier wrote:
| I suspect that IEEE 802.15.7 might be more up your alley, maybe
| also .13 (esp the pm phy variant).
| wiradikusuma wrote:
| "..instead of having wifi that someone can tap into.." so, use
| Ethernet cable?
| throitallaway wrote:
| A lot of this does feel like reinventing the wheel. However,
| it's slightly more convenient than being tethered with a wire.
| gochi wrote:
| Sure let me attach an ethernet cable to my VR headset, and then
| magically pull another from the wall to attach to my laptop.
| Can't forget the mystical third wire which I need for my phone!
|
| Hopefully it doesn't take much to grasp the benefits of
| ethernet without a cable directly to your device at all times,
| right?
| DaSHacka wrote:
| But those devices, particularly the VR headset and mobile
| phone, are not good candidates for an IR-based networking
| solution as their use-case inherently has a lot of movement.
| What good is a VR headset that loses connection with the host
| computer when you accidentally block the receiver while
| moving around?
| RobotToaster wrote:
| As someone pretty sensitive to CFL/LED flicker, the idea of this
| being everywhere is worrying.
| newaccount74 wrote:
| LED flicker is 50 or 60 Hertz, this technology would be Giga-
| Hertz. And it's infrared. Your eyes won't see a thing.
| mrob wrote:
| 50 or 60Hz is low enough that even people who aren't
| sensitive can notice it. Cheap LED lighting more often
| flickers at 100 or 120Hz, using a bridge rectifier with a
| series capacitor to limit the current.
| fatfox wrote:
| it's invisible
| zadler wrote:
| Years later, we'll find out that it messes with people's sleep...
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