100 times faster than WiFi
- Thread starter techElder
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grim_reaper
Senior Member
That article is a bit scarce on detail! I had to read it twice before I understood what they were going on about!
I guess since Wi-Fi started out as 10-BaseT that got faster then transmittable through radio, this is the equivalent evolution of fibre optics!
I guess since Wi-Fi started out as 10-BaseT that got faster then transmittable through radio, this is the equivalent evolution of fibre optics!
binary1248
Senior Member
Careful Hippy, remember when Microsoft founder Bill Gates said "Nobody would ever need more than 512 Kb memory in their home computer"
Bill G has it that it was more that he said most people would not need more than whatever amount it was, being many times greater than had been available, for the technology of the time. With Bill G being an engineer it seems a more sound comment to have made than how it is normally presented.
It is, as you say, entirely impossible to predict where we will end up and what will become standard or necessary. I am sure sure Bill G knew that just as well as anyone.
It is, as you say, entirely impossible to predict where we will end up and what will become standard or necessary. I am sure sure Bill G knew that just as well as anyone.
4K is "only" 40 Mbits/sIt would be kinda distracting trying to stream a movie with the lights going on and off
8K even more...
grim_reaper
Senior Member
That opens up a whole new host of sci-fi movies (I'm thinking along the lines of Minority Report) where hackers can steal corporate information by just looking into the office windows.
I'd love 80Gbit/s at home! Even with a 1Gbit/s wired LAN at home, I find myself being impatient when the 8.4GB .iso takes "too long" to move!!
I'd love 80Gbit/s at home! Even with a 1Gbit/s wired LAN at home, I find myself being impatient when the 8.4GB .iso takes "too long" to move!!
Hi,
The principle is easy enough, I believe it's already been used (with fluorescent lights at low frequency) for supermarket "intelligent" (LCD) shelf-edge price displays. It's even easier to modulate the light output from LEDs, but the "dimmable" LED "bulbs" still seem to sell at a considerably higher price than the non-dimmable type. The brightness might be modulated by only a few percent and/or at very high frequency, so the eye will never see it. The average brightness can be constant because the data probably will be ac-coupled anyway.
However, even at 1 Gigabit/second (and most reports seem to be claiming 1 GByte/sec), light travels only around 30 cms (1 foot) so the "data" reflected off a wall will be out of phase with the "direct" path. Thus the modulation may need to be a scheme similar to that used for digital TV or DAB radio (COFDM). Certainly not PICAXEable; even dedicated DSPs seem to need lots of mA and crash on a fairly regular basis.
But IMHO there are much more fundamental issues, what about the data "return path" (aka interactivity) ?. Also, an advantage of light is that it DOESN'T pass through walls and ceilings, so your TV Remote Control doesn't switch off your neighbours' TV, or the one in your bedroom. But that's not too good if you want to use your iPad there, probably with little or no main lighting switched on. And how does the "data" get to the room-lighting LEDs? Mains cables weren't designed for 1 Gb/B per second; "Powerline" comms. don't work well in my house AND they interfere with the Hi-Fi.
Cheers, Alan.
The principle is easy enough, I believe it's already been used (with fluorescent lights at low frequency) for supermarket "intelligent" (LCD) shelf-edge price displays. It's even easier to modulate the light output from LEDs, but the "dimmable" LED "bulbs" still seem to sell at a considerably higher price than the non-dimmable type. The brightness might be modulated by only a few percent and/or at very high frequency, so the eye will never see it. The average brightness can be constant because the data probably will be ac-coupled anyway.
However, even at 1 Gigabit/second (and most reports seem to be claiming 1 GByte/sec), light travels only around 30 cms (1 foot) so the "data" reflected off a wall will be out of phase with the "direct" path. Thus the modulation may need to be a scheme similar to that used for digital TV or DAB radio (COFDM). Certainly not PICAXEable; even dedicated DSPs seem to need lots of mA and crash on a fairly regular basis.
But IMHO there are much more fundamental issues, what about the data "return path" (aka interactivity) ?. Also, an advantage of light is that it DOESN'T pass through walls and ceilings, so your TV Remote Control doesn't switch off your neighbours' TV, or the one in your bedroom. But that's not too good if you want to use your iPad there, probably with little or no main lighting switched on. And how does the "data" get to the room-lighting LEDs? Mains cables weren't designed for 1 Gb/B per second; "Powerline" comms. don't work well in my house AND they interfere with the Hi-Fi.
Cheers, Alan.
At slow speeds it's probably fairly east. A project with an LDR and read morse code sent with a torch would be a fun project and IRIN with a suitable remote does it a somewhat faster and invisibly.
At higher speed it gets more complicated, and for moving huge amounts around harder still. Not only does all the infrastructure in the house have to be able to handle it, but the equipment receiving and using it, and of course the infrastructure in the street has to handle it for all houses.
Maybe we need one big light bulb for everyone; modulate the sun perhaps ?
At higher speed it gets more complicated, and for moving huge amounts around harder still. Not only does all the infrastructure in the house have to be able to handle it, but the equipment receiving and using it, and of course the infrastructure in the street has to handle it for all houses.
Maybe we need one big light bulb for everyone; modulate the sun perhaps ?
BeanieBots
Moderator
Even the more 'traditional' method of sending data with monochromatic LEDs has problems.
An LED takes time to turn OFF as well as on.
There is no such thing as a white LED (in the true sense of a junction emitting light). Semiconductor devices which emit what appears to be white are either multiple dies of different wavelength or UV leds and a phosphor.
Using multi-junction devices has potential with the possibility of using each colour for a different data stream.
Unless there is a new type of phosphor that can respond quicker than the ones I'm familiar with, I do not see that type of LED being anywhere near fast enough to be of any use for high speed data.
Maybe somebody here has equipment that could test this. I would be very curious as I no longer have access to such equipment to try myself.
Last time I tried this myself it was difficult to get sub 1uS pulses from a high power LED but that was when a blue LED cost more than an hour's wages, needed several amps of drive current and the lights dimmed down to see if it was on. Maybe things have moved on since then!
An LED takes time to turn OFF as well as on.
There is no such thing as a white LED (in the true sense of a junction emitting light). Semiconductor devices which emit what appears to be white are either multiple dies of different wavelength or UV leds and a phosphor.
Using multi-junction devices has potential with the possibility of using each colour for a different data stream.
Unless there is a new type of phosphor that can respond quicker than the ones I'm familiar with, I do not see that type of LED being anywhere near fast enough to be of any use for high speed data.
Maybe somebody here has equipment that could test this. I would be very curious as I no longer have access to such equipment to try myself.
Last time I tried this myself it was difficult to get sub 1uS pulses from a high power LED but that was when a blue LED cost more than an hour's wages, needed several amps of drive current and the lights dimmed down to see if it was on. Maybe things have moved on since then!
Hi,
I wonder if the author even appreciates the difference between Gb and GB ? And IMHO the original quotee (?) was probably talking through his @ss. Apart from the notorious Bill G quote, I remember another prediction that "Electricity will be so cheap that it won't need to be metered". Hmm, maybe one day.
Cheers, Alan.
But at what data rate? I'm with BB.
I wonder if the author even appreciates the difference between Gb and GB ? And IMHO the original quotee (?) was probably talking through his @ss. Apart from the notorious Bill G quote, I remember another prediction that "Electricity will be so cheap that it won't need to be metered". Hmm, maybe one day.
Cheers, Alan.