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Optical Cellphones
foondog writes "Here is a story over at News.com about optical cellphones. It seems that the Department of Defense has given a grant to the University of California to develop optical cellphones that are faster and more secure. This sounds a little strange to me since you would need a line of site with no obstacles in the way to use this. The article doesn't explain how this might work."
When was last time the DoD ever do anything that made sense ?
TM
Support TBI Research: http://www.raisinhope.org
"It seams that the Department of Defense has given a grant to the University of California to develop optical cellphones that are faster and more secure. This sounds a little strange to me since you would need a line of site with no obsticals in the way to use this. The article doesn't explain how this might work."
What about from a soldier/spy/diplomat straight to a comm sat?
It's easier to get line of sight to orbit.
That's because it won't.
It doesn't really say anything about how the optical cell phones would work inside a building. I'd be very curious to know how they plan on overcoming this obstacle. Of course, this is just a grant to study it. It may never come to *see the light of day*
(sorry... had to be said)
This sounds a little strange to me since you would need a line of site with no obsticals in the way to use this.
X-rays are light energy, and they don't seem to have a problem passing through.. well.. you, among other things.
The theory of relativity doesn't work right in Arkansas.
Intersting idea, but is it really possible to have a laser based cell phone? I guess a laser would have to be used.
:)
Besides the technical problems, I really don't see much use for it. I'm happy as long as I can talk on my cell phone and I don't need: games, internet, messaging, carwash, deodorant, floss, toothpicks, swiss army knife, lunch, soft drink incorporated into my cell-phone.
I'm not that important, neither is the rest of the Slashdot crowd
If you mod me down, I *will* introduce you to my sister!
Well, see, when your eye starts ringing...
;)
*i know, i'm just asking for it*
Desert. You can only use them in a desert.
Need line of sight. DoD likes lasers. Big lasers, with lots of power. Could be dangerous.
I wouldn't want to hold one of these up to the side of my head and start talking, it might make it's own line of sight to the nearest tower.
Ouch!
seems like handheld devices like this might be tricky, but mobile versions mounted in vehicles with the tranciever mounted on the roof might work quite well...
Current cellphones are already operating in bands where line of sight is quite critical to half-decent reception. What makes this feasible is that many surfaces are reflective of a lot of bands of EM radiation. This is why we can see things - they reflect light. This is why you can use your TV remote by pointing it away from the set - it bounces off the wall.
I agree that attenuation will be a big problem, but it's already getting almost that bad as we get higher and higher in the spectru.
Now, if they could only modulate the sun's rays...
"This sounds a little strange to me since you would need a line of site with no obsticals in the way to use this. The article doesn't explain how this might work."
Four words: Really Really Tall Towers
"Not knowing when the dawn will come, I open every door." - Emily Dickinson
A different technology in widespread use employs a method called wavelength division multiplexing, in which each cell phone uses a different wavelength of light, according to the researchers. In contrast, optical CDMA would encode each pulse, or bit of information, across a segment of wavelengths. The receiver uses a key to decode the signal and re-create the original pulse.
This sounds a lot like Ultra Wideband to me. Also, I'm guessing from reading the article that the author is confusing visible light with radio EMR.
Holy line of sight, Batman!
This is just a high-bandwidth version of the bat signal. This technology has been around since the sixties. Hopefully they can make it more portable.
- DoD's new "light emitting cell phones" cause massive outbreak of seizures. Spokesman says: "We're really shaken up about this."
- DoD investigating new "tin can and string" technology for secure landline communications.
It probably has something to do with the "seams" mentioned in the second sentence, or with the "obsticals" mentioned at the end.
We're always learning new things. For example, I always thought that an editor's job was to check for errors (spelling, grammar, factual, etc.) in articles before publishing them...
RMN
~~~
Maybe they found a way to modulate the output from the sun? Will probably make those night-time minutes REALLY expensive though!
My phone right now is fast enough and secure enough for me. If anyone's listening in, yes I'm going to be home at 5:30 for dinner and I'll pick up the dry cleaning on the way home.
Commence massive spelling correction project in
5...4...3...
Recursive: Adj. See Recursive.
The sell phoane comes with a set of special specticals that you put on and look at you're conversashion partner, who has an identicle set up. The phoanes then comunnicate via lazers in the specticals, thats why you have to look at each other.
(creative spelling purely intentional in homage to the original article)
What I really want is a phone with a freaking laser on it!
If you're going to get right down to it, any sort of EM radiation down to and including the microwaves currently used for wireless communications could be called "light." They just happen not to be different wavelengths and not visible.
I don't see what's so special about this system, unless you're going to make a comm system so secure that only people that the transmitter (which might be a laser) is pointed at would be able to receive the transmission. Kind of like "laser pulse" communications you sometimes see in sci-fi.
*Faster* than light.
Got it at Roswell. Can't comment further or *ack*
DT
Someone, either the author, or a source, is totally confused about what light is.
When I read the topic, it occured to me that they might have been talking about using quantum encryption (photon spin direction? what?) with cell phones. Then I realized it wasn't the year 2025.
Anyway. This will be interesting when someone who graduated high school writes an article about it.
There are no trails. There are no trees out here.
Uh... signal strength requirements?
come on fhqwhgads
shhhhhhhhhhhhhutup, who cares how it works? They're already hiking our fees up another 10%, we need the money.
It's not necessarily true that you need a line of sight with no obstacles in the way for an optical communications device to work. There are parts of the EM (optical) spectrum which pass through ordinary objects. Infrared, for example, can "bleed through" most walls, allowing infrared photography of the sort sometimes used by law enforcement to see behind closed doors. On the other hand, gamma rays and x-rays, which are very high frequency, are stopped by few things besides lead.
Actually, current cellphones are, in a way, optical, since they use RF. Radio waves are a kind of light of much lower frequency than the visible spectrum, and they easily leak through all kinds of solid objects. I would assume that this new research project aims at using *higher frequency* optical communications, possibly using a laser for focused rather than diffused (RF-style) transmission. Only transmitting on a direct line of sight has obvious utility for security, and that line of sight doesn't necessarily have to be onobstructed.
Anonymous Luddite: "What do you think of the dehumanizing effects of the Internet?"
Andy Grove: "Not Much."
You had to get close to an access point (Bar, railway station,...) and then you could phone. It just used TV-remote control kind of light. The system got wiped out with the arrival of GSM. The only reason to get it back would probably be ultra-high bandwith, and then combined with GSM/UMTS for use on the road I guess...
Correcting myself: grammar
Finally, math books without any of that base 6 crap in them.
Visible light is a small subset of the electromagnetic spectrum, the same spectrum phones already use, but at a non-visible wavelength. It sounds more like optical is being used as a buzzword in the article.
I'm not familiar with "wavelength division multiplexing," but it sounds like they're trying to apply the technique (which is traditionally optical) to the cell phone bands.
Some cell phone systems, such as those from Sprint PCS and Verizon Communications, already use a type of CDMA for radio waves, according to the researchers
:)
We need researchers to tell us that our phones use CDMA? So what ab out all those can you hear me now Sprint CDMA commercials?...must've been an optical illusion
Live for the present, learn from the past, and dream of the future!
Not an actual cell phone, but a point-to-point intercom involving binoculars and infrared transmissions. The voice was converted to (analog) IR light and transmitted through optics that created a very narrow beam. At the other end, the IR receiver was mounted in the eye piece of the binoculars and converted the light back to sound. The two devices had to be aimed very accurately at each other. That way a spy in the west could communicate with his pimp in the east across the border with very low probability of interception. They actually had this on the History Channel a few years back.
The DoD could care less about pratical consumer application, but it'd be real useful to them It it's line of site, the communication'll be a hella lot harder to intercept. The grant is for makeing the devivces more secuere also.
I'm sorry for the rant, but for the last couple of years Slashdot has become a swamp. Half the articles are from someone pushing their personal agenda ("Microsoft sucks", "Apple rules", "Person X is a bastard", etc.), and the other half are simply wrong. The readers then comment on the Slashdot "news items" without even bothering to read the original articles (thus propagating the ignorance) and finally the moderators mod things as "interesting" or "insightful" without bothering to see if they're even remotely true.
-- Rui del-Negro
If you celebrate Xmas, befriend me (538
Karma whores take note -- Slashdot would probably run stories on anything listed on that page. (You still get points for an accepted submission, right?) Some of them, like the nanotech stress sensor paint and the flying robots sound familiar, but just because they've been linked once doesn't mean they can't be linked twice!
What I'm listening to now on Pandora...
The article doesn't explain how this might work.
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Of course it doesn't
"This isn't a study in computer science, its a study in human behavior"
Consider that for one thing, this will almost definitely be a dual mode cell phone, capable of switching quickly between Cellular Mode and Optical Mode.
Additionally, the DoD has more experience then just about anyone in the world with getting long range optical systems to work correctly, can you say, Laser Guided Bomb? I knew you could.
For a group dedicated to the chronicalling the advancement of technology, there are sure a lot of disbelievers gathered here.
And you thought Tetris was impressive. These new cellphones have built-in Laser Tag!
The grant is not to make optical cell phones. The grant is to develop CDMA (a technology used in cell phones) to be used in fiberoptic communications. The title is a bit misleading.
So, why so much money to port a technology. CDMA allows more effective use of the bandwidth and as the article points out more security than frequency division multiple access. For radio frequency stuff, CDMA is what nearly everyone uses. For radios it requires a wide bandwidth output stage. That is the kicker. The optics guys use fairly narrow band laser output stages. Then the hook them together on the same cable. They don't interfere because they are at different frequencies. To do CDMA with your whole bandwidth requires a wide bandwidth output solution (either a single broadband output or some way to put multiple lowbandwidth stages together in a better way.)
The article doesn't explain how this might work.
I think that is the main reason they issued a grant for studying this?
In the perfect world someone in the government would search Google first and when nothing useful returns they figure they better outsource it!
This is pretty old news.
Username taken, please choose another one.
http://www.surveyhistory.org/the_heliotrope.htm
At long last, sir, have you no Morse?
"Your suns and worlds are not within my ken, I merely watch the plaguey state of men."
Thus the Army must have some kind of non-broadcast communications system. I have no direct knowledge of how they would do it, but it isn't hard to imagine. For example, suppose low-flying satelites broadcast a signal. Handsets on the ground listen for that signal, and then point a highly directional antenna (LASER, focussed RF or microwave, whatever) at the satelite, and then starts transmitting a narrow beam.
There is not enough economic motive to develop this for purely commercial purposes. But once it is developed for the military, the commercial benefits are there to deploy it. Directional signalling means much less interference, and therefore much less consumption of precious spectrum, and less need for those pesky and expensive cell towers.
Crispin
----
Crispin Cowan, Ph.D.
Chief Scientist, WireX Communications, Inc.
Immunix: Security Hardened Linux Distribution
Available for purchase
Also, some animals can detect light pulses going through shielded optical cables (sharks, for example, just love chewing on underwater fiber-optical cables).
Because of quantum effects, strange action at a distance, etc., there is no such thing as an event that is not detectable.
If all this should have a reason, we would be the last to know.
The phone is for use OUTSIDE buildings and directly connects to Satelites. The only real problem is cloud coverage.
excitingthingstodo.blogspot.com
From what I hear, every soldier has a mirror. On a sunny day, you can use the mirror to signal aircraft for miles.
The mirror has the advantage of not needing batteries, being resistant to shock, etc.
Of course it doesn't work in clouds or dark, and bandwidth, well... leaves something to be desired.
So if they can do this with infrared and talk through it, that seems perfectly reasonable to me. One advantage of LOS is that you have to get in the way of the thing to jam it. Of course the receiver has to be intelligent enough to ignore signals from the wrong part of town, or signals that don't carry the right code, but it's a solveable problem.
Of course, any signal, especially an IR laser, gives away your position if the enemy can see it.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
How to keep your cell phone from being jammed? Bathe it in grape jelly, instead...
What's this Submit thingy do?
Can you see me? ... Can you see me now? ...
"This sounds a little strange to me since you would need a line of site with no obstacles in the way to use this."
Uh, no...all you'd need is a huge network of mirrors or a lot of little collection points. Use VoIP technology to manage packets of data. Blinks of light work as well as packets of radio and because of their higher frequency they provide more bandwidth.
blog |
The technique is called "spread spectrum" and helps enormously in reducing noise (and intentional jamming). Also, I don't think the author is confusing anything: I think the researchers are trying to adapt the techniques used in RF CDMA to optical wavelenghts (400nm-700nm). Hence the reference the author makes to "optical CDMA"
I think this is an ideal technology, that doesn't take up valuable bandwidth in the frequency range we use for radio transmissions.
;-)~
'Course, there are drawbacks... You have to stand REALLY still, in just the right spot...
oops.
If it proves to be a gov't-use-only technology, why worry about it?
Instead of looking for specific levels of brightness, look for the delta of those levels. Or even delta^2.
Given that current satellites are able to read print the size of license plates, and we have a lot of computing power available these days, I would imagine that software could track a single point signal source and ignore others.
This is a supreme advantage of optical over other methods. We have CCDs that can see visible light and infrared, but no hi-rez CCD that can "picture" radio sources.
Jamming is only useful if all your signals come in over the same antenna. It's much, much less effective if you can easily distinguish the locations of multiple sources, then authenticate against the source you want to communicate with.
Granted, this means cell-to-satellite is easy. Not satellite-to-cell.
What's this Submit thingy do?
is wading through 'it ain't the same ol' Slashdot anymore' rants
People are posting about "why?"
Consider the havoc that nuclear explosions play with radio frequencies.
Consider having a method of secure remote communications which does not rely on radio frequencies of any type in such a situation.
Kinda makes you stop and think about things.
"You worthless post!"
-Shakespeare, 2 Gentlemen of Verona, 1. 1. 147
I'm going to dub this the 'Laser Phone'. The Laser Phone will not be made for general public use. Laser Phones will be made for military and corporate entities that require ultra secure communications.
You maybe asking: âoeWhy would you need such a clunky method of communication? Line of site is not practical.â
The answer is very simple: Supercomputers and triangulation.
You see any voice communication has certain pitch and volume amplitude modulations. Pitch and volume amplitude modulations are part language and part human physiology. No matter how you scramble and encode the communication the human voice will always have certain keys that can be easily discerned in a conversation.
An enemy can easily grab and record a radio signal. Then the digitally recorded file can be feed in a Beowulf cluster of cheap computers. That data can within a few minutes can decode your voice and thus get your tactical information.
Another advantage of optical communication is that it is almost untraceable. Anytime you use a radio you sending out a beacon saying, "I'm right here; bomb the snot out of me!" An enemy can use simple triangulation to locate you.
A Laser Phone will be virtually impossible to intercept, track, and decode.
BTW: Anyone remembers those World War I movies where the soldiers would use mirrors to send Morse code message?
You say things that offend me and I can deal with it. Can you?
That's what I call making good use of your mod points. Don't bother modding down trolls or modding up good posts. No, waste your time modding down any post that points out the errors of Slashdot editors. Maybe if no-one sees those posts, the errors will go away. Or maybe they'll change the English language to match Editorspeeck...
Though it sounds like you know this, maybe it should be clarified for other people...
the optical spactrum is a (small) part of a much larger range of frequencies, making up the electro-magnetic spectrum
Having said this, there is no reason that something that you can do in the radio frequencies can't be done in the optical spectrum. Materials (buildings, glass, etc) will react differently to the different frequencies but if this is not a limitation, there really is no reason not to move to shorter wavelengths (higher frequencies) as the band-width is somehow controled by the frequency (beyond the scope of this post)
Additionally, it should be noted the article makes no reference to lasers (or "lazers" to some of you). Hence, flashing a light on and off would almost satisfy this criteria. How about your TV remote? How does this talk with your TV? If you answered "Infra-red radiation", you get a happy-face sticker. In most peoples books, the IR spectrum is still included in the "optical spectrum" even though you can't see it (1.5um wavelength lasers are used almost exclusively in optical fiber communication, which is roughly double the wavelength we can see with our eye).
Sorry, straying off topic - I love your tag line! Speaking of recursive, what do you think of NT Technology? or PHP Hypertext Preprocessor?
"The large print giveth, and the small print taketh away" -- "Step Right Up", Tom Waits
If you've got line of sight, just SHOUT.
In Punjabi if you need it to be secure. None of the goras (whites) will know what you're saying.
Tee hee hee.
How is this redundant? Had anyone asked the same question before? You do know what 'redundant' means, don't you? Maybe Slashdot's editors should just add a new moderation "-5, I don't like what he said", and then use that one over and over gain.
RMN
~~~
The longer the effective distance the light spends in the cavity, the narrower your beam will be.
You can increase your effective distance by lengthening your mirrored cavity, and by increasing the silvered amount of your semisilvered mirror at the front.
What's this Submit thingy do?
"Back in the 60's, I developed a weather changing machine which was in essence a sophisticated heat beam which we called a 'laser.'"
"You know, I have one simple request...and that is to have sharks with frickin' laser beams attached to their heads. Now evidently, my cycloptic colleague informs me that that can't be done. Ah, can you please remind me what I pay you people for? Honestly, throw me a bone here...what do we have?"
Sorry, with all the laser talk I couldn't resist.
"An unarmed man can only flee from evil, and evil is not overcome by fleeing from it." Col. Jeff Cooper
lame first post, dude.
The only problem with this idea is that it stops making sence once you run out of marijuana.
Cheers,
Bowie J. Poag
No matter how you scramble and encode the communication the human voice will always have certain keys that can be easily discerned in a conversation.
gzipped and rijndaeled voice is not voice anymore.
Triangulation, OTOH, is a meaningful worry.
I'm busting out Beejee's when I get home for ThanksGiving. I can't wait for this!!
If you read my 'rolling data center' comment earlier you know I was talking about walking around festooned with digital stuff.
Optical MIGHT be the way for all these to communicate IF bluetooth crashes and burns AND people get nervous about all that radio radiation around them, and only one good cancer report might do it, AND it's only used on items that have a line of sight with each other AND they can make it secure (easy but will it be done?)
This might be an answer looking for a problem it will never find...
It's Christmas everyday with BitTorrent.
Just what I need. Not only are these jerks interupting my theater experience when their cell phones go off, but now they have the added bonus anoyance of laser beams shooting all over the screen. All the more reason to boycott the RIAA and avoid the theaters I suppose...
"To lead the people, you must walk behind them"
we had the same problem already: the bad guys (hard to tell now who was who) would try and triangulate on our signals. so we just set up remotes and decoys. took a little more time but i am here to tell you about, so i guess the missions were successful.
can you see me now? good.
can you see me now?
all you need is mirrors...mirrors will be everywhere...and behind those mirrors will be clones of tom ridge on john ashcroft. oh the end is near.
My cell phone never works inside an elevator. With this new technology we...errr wait
Cell phones, radios, 802.11 - they are all optical since theysend photons of light, they just don't use the visible spectrum. I know what they mean, but the term "optical" doesn't really make sense here.
This is also my read on the grant.
CDMA (a technology first widely used in cell phones) for fiber-optics, not optic(al) cell phones!
BThis is exactly the same as semaphore, a well-established (if 18th-century) military communication technology. A satellite serves as a very tall relay tower :-)
the line of cocaine the admins of this web site do before posting articles (and modding, let me add).
sulli
RTFJ.
It's called a heliograph and a CD would make a very good substitute. ;)
Take a CD and an ice lolly stick. Make a hole in one end of the stick and hold the CD up in front of your face, shiny side facing out. Be facing the sun, more or less.
Hold the lolly stick up in front of that (about 12 inches away) and sight through the hole in the CD and the hole in the lolly stick at the aeroplane, boat, visitor craft or whatever you are trying to signal to. Now wiggle the CD until the shadow of the hole in the middle of the CD falls over the hole in the lolly stick. Now you are shining your light right at your target. By flicking your hand, you can turn the light on and off and so make morse. Or binary. Whatever.
If you do do this to a visitor, they will probably just decode the information on the CD and try to work out the meaning. Do not expect to be rescued. Expect instead to get Barry Manilow's greatest hits beamed back to you some days later.
If this saves your life, paypal me!
All things in moderation; including moderation
A low tech, old age solution to a high tech, new age problem.
smoke signals!
Non impediti ratione cogitationus.
Dude, that's redundant, not recursive.
Materials (buildings, glass, etc) will react differently to the different frequencies but if this is not a limitation, there really is no reason not to move to shorter wavelengths (higher frequencies) as the band-width is somehow controled by the frequency (beyond the scope of this post)
But isn't the way materials react to light a limitation? Radio happens to be a great place in the electromagnetic spectrum to transmit and receive data because it can pass through some solid objects. Light bounces off of solid objects, which is how we are able to see them. It seems that these cell phones would need a direct line of sight (ugh...grammar check time, slashdot editors) to the cell towers to be able to work.
I've heard of "cloudbouncing", lighting up clouds with lasers to transmit data while another entity watches and receives, but you can't always count on there being a cloud around when you need one (that both you and the tower can see), and it seems like such a medium would be prone to congestion.
This is what puzzles me. It wasn't answered in the article, and I haven't read a post that explains what's going on.
leave it to slashdot to say how stupid something is without bothering to try and understand it.
to the end user, these phones are the same as any other. in this case, optical refers to where the multiplexing is happening: in the media instead of in dsp. it does not mean cell phones using lasers or visible spectrum to transmit data.
Not sure if anyone has heard of the SMURFO project, but the DoD commissioned it a few years ago, and it's been research by the cream of the University of Arkansas.
A picture from the project can be viewed here: http://www.ualr.edu/~isdept/snp/systems/images/tin can.jpg
--- Why are you wearing that stupid bunny suit? | Why are you wearing that stupid man suit?
In general, this is called FSO (Free Space Optical Communication).h tml
For electronic freaks out there:
http://www.imagineeringezine.com/air-bk2.
What some people already figured out: This principle may be very good for installation on top of the roofs... Some kind of "Light Houses" as Internet Access Points.
Actually, You've touched on why the navy still uses spotlights to communicate to this day. You know those movies where you have some seamen flipping the shades on a spotlight to send morse code to another ship? That's what I'm talking about. Unless you are along the line of sight which the light beam is travelling, it's virtually impossible to intercept the signal.
I thought we already had optical cell phones in California. All the teenagers seem to be carrying phones with lots of sparklies and blinking lights.
Look, the title of the news article is false.
There is absolutely no effort to create "optical cellphones".
Certain cellphone networks use CDMA technology (Code Devision Multiple Access), as opposed to earlier TDMA (Time DMA) or the GSM technologies.
Instead of using Frequency division for optical networking, as is currently the case, this new effort is developing CDMA technology for optical WIRED networking.
So the only connection between "optical" and "cellphone" is that the former may use CDMA which is currently used by the latter, in some cases.
Am I wrong?
If you really want to read about some cool optical stuff, look up Erbium Doped Optical Amplifiers!
Avoiding the "bomb down your shorts" is one of the reasons that the military has been developing and using spread spectrum communications for many years. With DSSS (direct sequence spread spectrum) and a high chip rate, the carrier is spread over a wide swath of spectrum. It can actually be below the noise floor. If you look for the signal with a spectrum analyzer, the most that you will see is a small elevation in the noise level. The tricky part of this is synchronizing the sequence generators in the transmitter and receiver.
Mea navis aericumbens anguillis abundat
- seams -> seems
- obsticals ->obstacles
- line of site -> line of sight
I was using a Unix system back in 1978, I seem to recall there was a spell checking utility. Maybe they could look around on Sourceforge and see if this is still maintained. Perhaps a venture capitalist might invest in this, there really seems to be a place in the market for such an innovation.but not
People are being PAID to be editors and they can't be fucked to check the three or four paragraphs of text they post a day.
It is too bad the moderators didn't realize your good sense of humor. To others who didn't realize it, the moderators changed several misspellings in the post, but not the glaring "line of site" error. I guess they have a spell checker, but no automatic tool for proper English usage.
My other first post is car post.
.... just aim the laser where you want to... if the target didn't start of within line-of-sight, it will soon end up that way :)
Hope I'm not going to mung this comment.
MUNG: first known recursive acronym: MUNG Until No Good.
According to convention there is a sweet and a bitter, a hot and a cold,
and according to convention, there is an order. In truth, there are atoms
and a void.
-- Democritus, 400 B.C.
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