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Spark Gaps and Ultra Wide Band Data Transmission
Embedded Geek writes: "It sounds like the revenge of Marconi, but Scientific American has a story about the use of spark gap technology for Ultra Wide Band (UWB) data transmission to send data at 100 to 500 Mbps across short distances (five to ten meters). As with every new technology, 'engineers expect these UWB units to be cheaper, smaller and less power-hungry than today's narrowband radio devices,' but there might be some truth to the hype. The secret appears to be the lack of a carrier wave, allowing use of wide swaths of the spectrum for transmission (the few comments I read at the FCC site referenced in the article addressed spectrum allocation)." Read below for a few more links, too.
"The article pitches the technology as a challenger or succesor to Bluetooth and 802.11a. There are several commercial companies investigating the technology (Aetherwire, Multispectral, and others are cited in the article) and Intel has a paper cited in the article. Spin off applications from the components needed to make this technology work might include a GPS style system accurate to one meter and a radar technology that would allow seeing through walls for construction, rescue, and (ahem) law enforcement."
These are supposed to look like noise to anything else transmitting. Since they spread the signal around a LOT of specturm, they are generally just raising the level of background noise.... What happens when enough of these devices get out there, and the noise floor rises to equal Everest?
What, me worry?
What is the benefit when the applicable distance is so short?
Skiers and Riders -- http://www.snowjournal.com
Think about it: Short-wave radios fabricated on a chip that are capable of 100-500 Mbits/sec.
t ml
1. Your PDA would be your CPU + Memory
2. You could put your harddrive in your coat pocket.
3. When you walk towards a monitor, you could wirelessly dock to it or the neighboring keyboards/mice.
This is actually an old article, but I honestly believe if Intel gets this right, UWB is going to be HUGE.
Here's another article:
http://zdnet.com.com/2100-1105-840393.h
"Communism is like having one [local] phone company " - Lenny Bruce
I wonder who said that. Bill Gates was dead wrong when he tried to cap things at 640k - but 56k? Old Billy-Boy may be vindicated! :)
We who were living are now dying
With a little patience
Avoiding Interference
"Communism is like having one [local] phone company " - Lenny Bruce
"...For example, rather than picking up recorded movies at the video store, we may end up downloading films using a portable mass-storage unit and UWB wireless transmission while filling the car up at the fuel pump..." The whole spark gap transmiter + gasoline fumes seems bad for some reason.
This is not a panacea. While using a wider bandwidth does allow for the use of less power, Shannon's theorem still holds so there is a limit to how much the power can be reduced. And yes, with UWB, just like with spread spectrum, other signals contribute to the "noise" so as more people use it the overall performance will degrade. The proponents of this technology often "overlook" these facts when pushing it.
100-500 Mbits/sec can pretty much serve as a wireless bus for most of your components. With that kind of speed, you could physically seperate your (CPU+Memory) (Harddrive) (Monitor)
Not to mention all of the wireless possibilities linking to Home Entertainment system, Car, Access Control Devices, Etc.
Given Intel's goals to make UWB cheap as they're trying to fabricate it on CMOS it would be everywhere where wires used to be.
"Communism is like having one [local] phone company " - Lenny Bruce
Don't spark gap transmitters cause a great deal of interference across all radio bands? I thought they were outlawed or something for that very reason. Unless they've come up with a way to prevent that, isn't that going to be an issue?
1/3000 of a cell phone.
Ultrawideband communications systems would share the same problem except that they deliberately operate at power levels so low that they emit less average radio energy than hair dryers, electric drills, laptop computers and other common appliances that radiate electromagnetic energy as a by-product. This low-power output means that UWB's range is sharply restricted--to distances of 100 meters or less and usually as little as 10 meters. For well-chosen modulation schemes, interference from UWB transmitters is generally benign because the energy levels of the pulses are simply too low to cause problems.
A typical 200-microwatt UWB transmitter, for example, radiates only one three-thousandth of the average energy emitted by a conventional 600-milliwatt cell phone.
"Communism is like having one [local] phone company " - Lenny Bruce
But isn't this the same thing as this?
It's hard to believe that's how Micronians are made. Why don't we see it right now by having you both kiss one another?
Your statement about Tesla sir is verry ignorant, and perhaps should you have paid more attention to his work/patents you would have noticed that even the most modern PC's have his inventions in them (IE electromotor, ALTERNATING CURRENT (AC) Transformers in your power supply....). And yes he made many bad mistakes in his life...while in germany working for edisons german subsidiary Eddison promised him 20 000$ (at that time!)to move to US and finish some work on his patents, upon completition Edison said: " We had no legal contract, welcome to America..and live with it". So his only problem was that he never acually worked on his image nor did he have thirst for money to charge thousans for kis inventions. Please make more informed judgement next time.
Live for the present, learn from the past, and dream of the future!
Why should it be a problem? Driving a car doesn't pose a health risk, and those sparks go off 3000RPM*V6=18000 times a second. /do/ pose health risks - 30kHz to 300kHz (correct me if I'm wrong) is extremely dangerous to human organs, but is widely used for shortwave radio. Cell phones operate on microwave frequencies, and both of the above transmit 100s of watts and go 100s-1000s of miles; this spark gap goes all of ten feet; I see no health risk unless you touch it...
And our narrowband transmissions
No, I don't think the problem is a health one, but as has been pointed out, I think it will up the background noise level, meaning that other users of the rf spectrum will have less chance of using weak signals as they will be lost amid the higher noise levels. Ask any amateur radio enthusiast about computer/cordless phone noise etc, and other man made interference.
Radio HAMS are to radio like we are to computers, they see the problems before most people have heard of the cause. Marconi spark transmitters can have a vast range, due to HF emmisions ( a Marconi spark transmitter made the first America-England transmission), OK these things are going to have a bandwidth limitation, but people use 3ghz ++ too, If these devices become common, then services on these microwave bands will suffer to some extent.
Best mitigating circumstance is that amateur/professional microwave stuff is going to be using highly directional antennas, which will help keep signal/noise ratio high. There will I think be a detrimental effect though overall.
Merlin --- We're an autonomous collective... Help, Help, I'm being oppressed!!
Yes, and about 5 thousand watts were being broadcasted in almost every direction just to do 3 watts of lighting. It's emmensely inefficient. Fun, and interesting. But impractical beyond belief.
Contrary to popular belief, coding is not all free blow-jobs and beer. Those things cost MONEY!
S/N is the signal-to-noise ratio, W is the bandwidth, C is the (theoretical maximum) data capacity.
It's easier to get capacity by raising the bandwidth consumption than by raising the power level, since the S/N is inside the logarithm. Then a virtuous circle gets started, because you can drop power level, which means someone nearby can operate without having you interfere with them, which means more people can each have whatever data rate C turns out to be.
This is really just a radical extension of spread spectrum radio.
Is anyone else worried about the fact that this increases background noise radiation across the entire spectrum?
no.
Won't this cause a massive health risk?
no.
UWB gives us a dose of everything
no.
just a friendly reminder.
The Science Museum in London has the only Spark Gap Transmitter licence in the UK. You can press a button to transmit a message using the spark, to a receiver across the corridor.
Kevin
"It's not the cough that carries you off, it's the coffin they carry you off in" O. Nash
Two companies that have been pioneers in UWB are Pulson and Aetherwire.
Pulson (and its predecessor company, Time Domain) has been desparately trying to commercialize this technology for radio communication for years. More than five years ago they demonstrated a few-milliwatt UWB radio with 100-mile range. They have mostly been held back by patents taken out by Lawrence Livermore. Livermore claims to have invented all of this stuff, and has been rediculously rough on licensing. Also, the FCC has been unclear until very recently on how it would license UWB.
Aetherwire has attempting to use UWB technology to build localizers, basically extremely short range, extremely low-power peer-to-peer short-range version of GPS. The localizers would all cooperate at keeping track of where the other ones were within a few hundred meter radius. If you've read A Deepness in the Sky by Vernor Vinge, it's all about localizers.
Now that the FCC has cleared the way, I expect to see tremendous progress in UWB. It's going to revolutionize many fields, from radio to positioning to radar.
thad
I love Mondays. On a Monday, anything is possible.
Seriously, UWB emits less radiation than a hair dryer and 1/3000 of a cell phone.
"Communism is like having one [local] phone company " - Lenny Bruce
This is just a different method of sharing spectrum among different users. The currently used methods are pretty good. They have been under development for about 100 years. The Rf spectrum is a limited resource. The amount of information that can be transmitted over the spectrum is limited by Shannon's theorem (read his 1949 paper). This limit can't be increased. What UWB does is spreading its information over really wide bandwidth, raising the noise floor for everybody else. If there are enough UWB transmitters around, they will interfere with each other to the point of uselessness. Also, this will f**k up every other user of the Rf spectrum. In addition, with UWB, the spectrum can't be managed by assigning different frequency bands to different entities. Everyone jsut uses all of the spectrum all the time. The strongest transmitter wins. Sounds like this technology has a good chance of being approved in the US...
"Argue with idiots, and you become an idiot." -- Paul Graham
I think you're refering to this quote:
These pulses give UWB wireless the ability to discern buried objects or movement behind walls, capabilities that could be important for rescue and law-enforcement missions
So in essence you might be able to see that your neighbors are moving, but it would not be like completely removing the wall.
Things you think are in the Constitution, but are not.
Is anyone else worried about the fact that this increases background noise radiation across the entire spectrum? Won't this cause a massive health risk?
No.
Dahlmann tightly grips the knife, which he may have no idea how to use, and steps out into the plain.
As I understood it from when i last read up on this it was to do with having monocylcic pulses spread across the entire frequency range, and the analogy to a spark gap is a pretty poor one.
A spark gap interferes with the entire radio spectrum - using it to send only one bit of data.
UWB sends very brief signals over the entire radio specturm but jamming no part of it for any more than a tiny fraction of a second. Even then power output can be so low that to conventional radio a UWB transmission will fade into background noise.
Well obviously it's in the developer section. It's a clever /. ploy to make you look around sections other than the main page so that you are exposed to more advertising.
How much bandwidth could they get out of the spark plugs in an average V-8 engine? Enquiring minds want to know...
In Soviet Russia, Jesus asks: "What Would You Do?"
Jesus fscking Christ, some people just need to be shot in the head. Tesla WAS a genius, the fact was that he got screwed over too many times. If he had more business sense, his accumulated wealth would make Gates look poor. Westinghouse had a deal going with him for $1 per hp generated by his electric motors, westinghouse started to go poor so Tesla ripped up the contract.
Tesla wanted to transmit power and allow people free use of it but his financer (J.P.Morgan) realised that he wouldn't be able to make a profit off of it so he canned the funding (part of the reason was that Tesla had previously told him that he wanted the money to build a global communications network but was building a facility to transmit power instead).
Every day your life is affected in some way by Tesla-tech. AC in all its forms for starters and then even the ignition coil in your car is Tesla-tech, as is the flyback transformer in your TV/CRT.
Then there was his research on 'scalar' waves, these were standing EM waves. I thought this was fantasy, but I did some calculations the other night and they work:
Start with four sine waves of different frequency, a,b,c and d
Multiply a and b and c and d
Then add the two resultant waves:
(a * b) + (c * d)
Now plot them, but have the four waves changeing as if you are watching a window of the transmission, have a few cycle of each on screen and change phi so they move.
The moving vector waves, when computed together to form the scalar wave will have an interesting effect. A scalar wave will be created that has nodal points in free space and have a varying amplitude. It is a bit ricky to explain without images but you have enough info to do that yourself.
Some of the claims regarding scalar waves have yet to be proven to me, I still have some experimentation to do (I do B of C, no CS at this uni. campus so all in free time) to justify these facts to myself, but it is claimed that scalar waves can propagate FTL and it is possible to modulate the speed. Also when two scalar waves are combined, they recreate a vector wave, I proved this to myself last night. The theory goes that if you can send out two scalar wave at different speeds and with a suitable time separation, you can cause them to re-create a vector wave at a certain point and somehow be able to receive that vector wave at full power (fan-fscking-tastic for wireless networking). This can also be used to generate EMPs at a distance, create force-fields (Tesla shield) or create fantastic explosions (Tesla's death ray). Tesla claimed to have caused the Tunguska explosion with early experimentation on this.
For more info on scalars do a Google on Tom Bearden.
Just my $0.0106 (Aussie dollar picking up!)
Even more efficient modulation techniques can be found at this PSK31 site.
Yes, you MUST forget those PAST technologies for the sake of consumerism, or call it progress. Analog shortwave must be sacrificed for a variety of economics reasons; the Media giants no longer want analog transmission. Never mind it's inherent simplicity and beauty, it is destined to be all DIGITAL; on a chip and mostly undecipherable except by the handful of chip engineers who make it happen. Capacitors and Inductors, Transistors and Valves, given over to algorithms.
how sad a time to be involved in (Electronics) technology, and I am not normally a Luddite.
Send me back to the 40's.
First off, how much use is there for high-speed radio links that span 5 to 10 meters? It's not enough for an office network. It's not even enough to get a TV signal to the back bedroom.
Most of the claimed applications sound very similar to those claimed for Bluetooth. Remember Bluetooth? Besides, do we really need half a gigabit for PDA synchronization?
What this is really about is a spectrum grab. The RF spectrum is full of underutilized channels which use obsolete technology, like AM television. You could probably put a spread-spectrum cell phone system right on top of a TV band and all TV viewers would see is a little more snow, if anything. But the TV industry would howl.
All the hype about "ultrawideband" is to allow putting spread-spectrum signals (which is what ultrawideband signals are) on top of other channels. Initially, the proposals are for very low power levels, but once the technology is deployed, there will be pressure to allow higher power levels, even if it degrades the old-technology channels a bit. The ultrawideband stuff will have lousy range until the power levels increase.
Think of this as a political migration path to an all-spread-spectrum world. Judge it in those terms.
-- ;-)
Kuro5hin.org: where the good times never end.
-- ;-)
Kuro5hin.org: where the good times never end.
We all use the same band to talk to and hear each other.
But we only receive those who are sending from locations near to us.
--Blair
If you want people to listen to you, then you should give them enough credit to provide them with the information and rationale that you used to come to your conclusions rather than just telling us parrots what to repeat.
.2 mW, (Range) 10m, (Spacial Capacity) 1000kbs/m^2
Aside from your first two points (which I more than happy to agree with)
1. UWB does use the spectrum
2. UWB does have a carrier
Can you back up your last couple of assertions?
You go on to tell us that we should be using COFDM or 802.11 instead of UWB. I'm nothing close to an expert, but even I can see that 802.11 and UWB are for different type of applications.
UWB - Very Short Range, Very High Bandwidth (100-500 Mbit/sec up to 30ft)
802.11 - Wireless LAN (10 Mbits/sec up to 300 ft)
Why should I replace UWB with 802.11 when I can use both?
1. What is COFDM?
2. What kind of bandwidth, range can I get out of it?
3. Why isn't the industry pushing COFDM?
4. How expensive is it to integrate COFDM onto a small device, such as a PDA?
5. What's the spacial capacity?
6. How much power does it use?
SPATIAL CAPACITY, a gauge of operational efficiency important when comparing short-range wireless systems, favors UWB technology. Measured in kilobits per second per square meter (kbps/m2), spatial capacity focuses not only on bit rates for data transfer but on bit rates available in the confined spaces defined by short transmission ranges.
SPACIAL CAPICITY SPECS
IEEE 802.11b - (Power) 50 mW, (Range) 100m, (Spacial Capacity) 1kbs/m^2
BLUETOOTH - (Power) 1 mW, (Range) 10m, (Spacial Capacity) 30kbs/m^2
IEEE 802.11a - (Power) 200 mW, (Range) 50m, (Spacial Capacity) 55kbs/m^2
UWB - (Power)
"Communism is like having one [local] phone company " - Lenny Bruce
Some time ago /. mentioned this story about inventor Larry Fullerton, who spent 25 years developing radio burst technology in his backyard lab. His company, Time Domain, is listed in the Entrepreneurs box of the SciAm article. It's nice to see 2 things happening: 1) the technology has not disappeared, and 2) one of the original pioneers is actually getting a piece of it.
/.
I'm afraid you recall incorrectly; both Marconi and Tesla used spark gaps as well as coil antennas for various purposes.
Marconi's title of "Inventor of Radio" was given in error, as evidenced by the supreme court decision awarding the discovery to Tesla; however, it's pretty likely that both men "invented" radio independently and are equally deserving of credit.
I'm not aware of Tesla using any "50ft tall tower" - are you referring to the Wardenclyffe installation or the Colorado Springs coil? The Wardenclyffe tower was well over 100ft, and projected more than 100ft below the ground as well.
--Charlie