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Magnets To Replace Bluetooth?
aceat64 writes "News.com is carrying a story that suggests magnets could eventually replace Bluetooth as a cheaper and more energy effiect wireless solution. The concept of magnetic induction isn't new, but Aura has managed to shrink the technology onto a single chip. The first device to be made using the technology is a wireless headset that will cost between $60 and $80."
I can just now see the new line of infomercials talking about combining the freedom of a wireless headset and the 'healing power' of magnets! Sweet Jesus...
Marketing bullshit
My bluetooth headseat lasts far more than 2 weeks on 2 AA batteries, and I use it for several hours every working day.
They obviously have a useful product if it can last three months on one battery, but saying "only a number of hours" for bluetooth equivalents would be like saying a DVD can store a whole movie but a CD can store "only a few seconds of video". Big marketing exaggeration, which makes me distrust them from the start.
Radio waves are referred to as "electro-magnetic radiation". There is no such thing as a magnetic component without an electrical component, or vice-versa. The two fields compliment eachother.
Another interesting thing mentioned in the article was that this magnetic field made a "bubble" that "stopped" at four feet. Magnetic field strength decays at the same rate as the electrical component. If you want a smaller "bubble" for wireless, just cut the power down. I don't see a difference here, unless they are just planning on running really low power as a general rule, and I suppose this would also explain the longer battery life they describe.
I'm really not seeing the difference here. The only thing the article mentions that really separates this from radio is the frequency, which they only vaguely described as "used by industrial and medical" applications. I'm going to guess this means either very high frequency or very low frequency. Very high frequency is far from efficient, and is already staked out well in the bandplan. If they're targetting very low frequency, (VLF) then there's no way they'll have the bandwidth necessary for video as the article suggests.
The article also said "interferance is not an issue". 640k of memory will be plenty, too. I normally don't slam on people, but this article just reeks of lack of forethought and research. It's only natural that any new technology niche has breathing room, until it becomes popular. I'm sure cell phone makers 10 yrs ago didn't expect to ever use even 30% of their allotted spectrum.
I work for the Department of Redundancy Department.
Assuming this isn't all complete bollocks, about which I'm going to hold an open mind, as I'm not entirely sure how this thing would work near computers or pylons, or electrified rail tracks, or power mains, unless it has some AMAZINGLY good filtering in it.
Anyway, assuming that, does that mean we get a chip on a usb stick (say), that would allow Van Eck Phreaking to be done at home? I mean, if you can send useful amounts of data through this technology, it must be good enough to pick up clock signals and keyboard presses?
I know this post is amazingly vague, but so is the technology.
I don't believe that the magnetic fields would need to be so strong that they would cause a problem for magnetic media, but there are probably too many variables to generalize. Think "speakers" here. These generally use magentic coupling too to send information wirelessly (albeit at acoustic frequencies).
Degaussing your monitor emits just a short pulse every 5 seconds or so. I don't think it's enough "magnetic noise" to saturate headset receiver, especially if the communication itself is digital over magnetic waves/fields with error correction and all.
When I first read the article I thought I smelled BS too. The number of "you can't have a varying magnetic field without a varying electric field!!" post's below also indicate a frustration with the marketroid speek that pervades the article and a general lack of scientific cluelessness of the writer.
.5 pi wavelengths away while the transition zone to the farfield is from .5 pi to 1 wavelength away. Since the magnetic field is decaying with the inverse CUBE of the distance away from the antenna (along its axis anyway) and the electromagnetic field is only decaying with the suare of the distance, eventually the EM field dominates at a certain distance from the emitter (the FARFIELD). These sites helped me understand this much better than I did a few minutes ago :-]. http://www.caves.org/section/commelect/mm/mm06.htm l and http://www-training.llnl.gov/wbt/hc/NonIonizing/Ne arFields.html. again nothing new here just a rehash of a discovery made by Faraday et. al.
The key to understanding how this thing works (and yes the technique is old) is getting to understand the difference between NEARFIELDS and FARFIELDS. The nearfield is the zone CLOSE to the antenna less than
- "Hear that?! The percolations are imminent! Cease your ingress!"
Even if the magnetic feild falls off like 1/r^6, that doesn't mean you can't "hear" what's going on inside the field from farther away.
As the field modulates it will, generate electromagnetic radiation. And while the Aura recievers won't pick up anything outside the feild. A good RF reciever operating at the same frequecies could easily pick up the signal from the "bubble".
Correct me if I'm wrong. I'm not quite sure what kind of amplitude the EM radiation would have. I think it would be pretty substantial, but I could be wrong.