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DARPA Wants Extreme Wireless Interference Buster

samzenpus posted about 4 years ago | from the no-down-time dept.

The Military 105

coondoggie writes "This month the Defense Advanced Research Projects Agency will begin looking for technology that will let wireless communications work through the most extreme interference. From the article: 'The CommEx program will assess next generation and beyond jamming threats and then develop advanced interference suppression and avoidance technologies to successfully communicate in the presence of severe, traditional, and novel types of interference that are orders-of-magnitude more severe than what are currently addressed by the most advanced systems, DARPA stated.'"

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distinct lack of content (3, Interesting)

advocate_one (662832) | about 4 years ago | (#33517786)

in the article... anyone got a better link?

Re:distinct lack of content (-1, Troll)

w00tsauce (1482311) | about 4 years ago | (#33517802)

http://meatspin.com/ [meatspin.com]

Re:distinct lack of content (-1, Offtopic)

Profane MuthaFucka (574406) | about 4 years ago | (#33517870)

It never stops. Why doesn't it stop?

Do NOT open this link! (2, Informative)

majorme (515104) | about 4 years ago | (#33518182)

Guys, do NOT open this link, under no circumstances. Fucking gay pr0n :(

Re:Do NOT open this link! (0, Offtopic)

kj_kabaje (1241696) | about 4 years ago | (#33519406)

Well at least it's Fucking gay pr0n. That shit is hot. I mean, the cuddling-and-smoking-after-the-act pr0n is soooo l@m3.

Seriously, potential homophobia aside, thanks for the tip.

Re:Do NOT open this link! (0, Funny)

Anonymous Coward | about 4 years ago | (#33519458)

Seriously, potential homophobia aside, thanks for the tip.

And the shaft!

Re:Do NOT open this link! (1)

TheNinjaroach (878876) | about 4 years ago | (#33519552)

What else do you think meatspin.com would refer to?

Re:Do NOT open this link! (2, Funny)

FatdogHaiku (978357) | about 4 years ago | (#33521292)

Gyro cooking? [tqn.com]

Re:distinct lack of content (1)

noidentity (188756) | about 4 years ago | (#33519446)

distinct lack of content in the article... anyone got a better link?

You just have to employ some counter-measures for the signal jamming advertising technology. There's a little bit of content that makes it through.

Re:distinct lack of content (0)

Anonymous Coward | about 4 years ago | (#33522514)

distinct lack of content in the article... anyone got a better link?

You just have to employ some counter-measures for the signal jamming advertising technology. There's a little bit of content that makes it through.

I'm having trouble locking anti-jamming missiles on the advertisers.

What can they hope for (4, Informative)

bugs2squash (1132591) | about 4 years ago | (#33517810)

LDPC, spread spectrum and more EIRP. Or are they hoping to overturn Shannon ?
Really, the state of the art is fractions of a dB away from theory. There are no further breakthroughs to be found. Unless you count social engineering the bad guys to block the wrong signals.

Re:What can they hope for (2, Informative)

russ1337 (938915) | about 4 years ago | (#33517888)

exactly. I'd speculate that these techniques have been combined and in use for some time.

Just look at how long GPS has been around. For those not aware, it uses spread spectrum CDMA, with a signal is well below the noise level. I've speculated (in my mind) that you could easily combine the techniques to transmit and receive reasonable data at a level 'below the noise threshold' for some time. Just like GPS, you just need some reasonable clocks (hand held GPS quality), some decent processing (like an FPGA), and the rest is how far you can push the bandwidth in the real world. You can include other comms techniques, phase, multi-band, etc. it just comes down to processing power and a heap of math that is way above my head.

the basics of GPS spread spectrum is here: http://alumni.cs.ucr.edu/~saha/stuff/cdma_gps.htm [ucr.edu]

Re:What can they hope for (2, Insightful)

digitalchinky (650880) | about 4 years ago | (#33518716)

As a former ELINT / EW drone, I'd like to make a correction good sir. I can tell you that the GPS spread spectrum transmissions (actually, all spread spectrum transmissions) are not below the 'noise level' - or noise floor. They are quite distinctive on a spectrum analyzer and the link you posted does show this. I say this sitting at the back end of several 20+ meter satellite dishes and do acknowledge that for some receive systems, the transmissions may indeed be below their noise floor - but, to qualify this, if something is below the noise floor, by extension this means it simply cannot be received. Including spread spectrum.

You are right about the technology having been around for a long time though - decades : )

Re:What can they hope for (3, Informative)

rcw-home (122017) | about 4 years ago | (#33519184)

if something is below the noise floor, by extension this means it simply cannot be received. Including spread spectrum.

No, it doesn't mean that at all. It does mean that your error-free bitrate will be limited to less than the bandwidth (how much less depends on how much more noise than signal you have). GPS uses 1.023MHz of bandwidth (for the civilian signal - 10.23MHz for the military one) and has a bitrate of 50 bits/sec. Typical noise levels are -110dBm and typical signal levels are -130dBm.

Re:What can they hope for (0)

Anonymous Coward | about 4 years ago | (#33519734)

I don't agree. Spread spectrum buys you nothing against random noise, only correlated noise. GPS still has about 50 Hz BW after de-spreading. It's processing gain is 70 dB which works great against interference. The only "noise floor" that is relevant is in your base-band detection.

Re:What can they hope for (0)

Anonymous Coward | about 4 years ago | (#33519926)

Oops 43 dB. Need coffee.

jamming != white noise (4, Interesting)

tempmpi (233132) | about 4 years ago | (#33518036)

They are looking at intentional jamming, not at white noise. Your solution would be almost perfect for white noise channels but not for channels with jamming.
E.g.: No jammer will be able to distribute its noise evenly in both time and space. You should be able add a nice bit of performance if you are able to predict the behaviour of the jammer to some extend. So spread spectrum with non-uniform frequency distribution of the signal energy could be a topic. Some jammers might not even send real noise but pseudo random noise. Then you could try to subtract the jammer from your received signal.

Re:jamming != white noise (0)

Anonymous Coward | about 4 years ago | (#33518670)

I would expect this to become an arms-race between the range of frequencies covered by the spread spectrum and the range jammed by the jammers. Once you utilize the full radio spectrum (probably with multiple antennae) as a spread spectrum it becomes very impractical to jam this entire range of frequencies. The spread spectrum would of course interfere with a lot of other radio traffic, but when done in really short bursts and spread out enough the effects of this will be limited and surely not something the military would care about in a scenario when it's needed. The jamming signal however (if even possible with enough power) would kill all radio services...

Re:jamming != white noise (3, Interesting)

Aceticon (140883) | about 4 years ago | (#33518944)

And then let's not forget the spatial dimensions in addition to the frequency dimension - jamming signals originate from one or more sources at specific locations so this could also be used in eliminating interference from jammers.

I remebers from reading a bit of the GSM spec that mobile phones includes adaptative antenna and algorithms that allow retrieving a usefull signal not just from the direct line of sight transmission (from the mobile tower) but also from multiple reflections with different path lengths. Could not the same techniques be used to, instead of boosting a signal, offset that signal?

Re:jamming != white noise (1)

TheLink (130905) | about 4 years ago | (#33522210)

What you could do is have the sender have two or more antennas and the receiver too. Then put the antennas in different physical locations.

If you know where exactly they are, it'll be much harder to jam, you can use all sorts of tricks to deal with the jamming.

It's just like someone trying to jam your eyes by shining a randomly flickering bright light in your general direction. Assuming what they are sending is not bright enough to destroy your receivers (in which case why bother jamming), you could just have two or more people standing in different places and trying not to "look" in the wrong directions (or shield their "eyes"), and try to just look at the sending antennas and then recording down what they see, then combining the results to figure out what the actual message was.

Additional Nodes = Increased Adaptive Cognition (1)

bagoas (849560) | about 4 years ago | (#33523422)

Situations where a single transmitter and single receiver are the norm are almost never the case anymore (at least in the wireless domain). A favorite paper on the subject is: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1624625 [ieee.org] Cooperative MIMO, Spread Spectrum, and Cognitive networks potentially allow EM jamming to be avoided and more easily predicted. Perhaps DARPA suspects that the channel is, in reality, a non-zero-sum game. That would overturn Shannon alright!

Re:jamming != white noise (1)

Skapare (16644) | about 4 years ago | (#33518966)

Even a single carrier looks like white noise to a true spread spectrum receiver. Of course, a strong enough single carrier can look like strong enough white noise to obscure the information. Spreading wider reduces that effect. Smarter would be to have a system that detects such signals and applies active filtering, including modifying the transmission to not use frequencies around the interference (but maybe keep noise in there, anyway, to not let the interference operator know he was evaded). I'm sure a whole lot more can be done with really smart multi-frequency transmission systems.

Re:jamming != white noise (1)

Idbar (1034346) | about 4 years ago | (#33520306)

If your signal is bandlimited, you could assume the noise is white in your band of interest.But I get your point if you put for example high powered tones

I would be also interested on the distribution of the noise, more than its spectral characteristics. Many times it's easier to remove frequency shaped noise than distribution shaped noise.

Re:What can they hope for (2, Interesting)

Trepidity (597) | about 4 years ago | (#33518044)

I think that's probably true for algorithms, but it might not be for deployed systems. Current communications devices can't use all the available theoretical techniques over all possible frequencies in all possible configurations, so there might be some significant gains on that front with new transmitters/receivers/etc. For example, most spread-spectrum systems operate over relatively narrow portions of the spectrum, at least compared to the whole electromagnetic spectrum--- nobody is spreading over everything from radio waves to x-rays, or anything close to that. Using larger parts of it has both some technical and operational challenges, since if your spread is over very large parts of the spectrum, parts of your signal are being transmitted on frequencies with extremely different properties.

Re:What can they hope for (2, Informative)

mattj452 (838570) | about 4 years ago | (#33518326)

I'd imagine that not only will they look at those techniques (FEC, spread spectrum etc), but also techniques related to intelligent channel switching when a channel is jammed. Also, there are other methods than noise to interfere with the reception. For example, sending out false signals, repeated signals etc which also needs to be considered.

Re:What can they hope for (2, Interesting)

AK Marc (707885) | about 4 years ago | (#33518474)

You need signal/noise of some level. Jamming acts like noise. You can't add power past some point, so that means you must subtract noise. How? Well, you can try MIMO techniques that try to essentially lock on to the jamming signal and subtract it out. Or lock on to the generated signal with rejection of the jamming signal. Right there are two possibilities that don't violate the theory and should be able to get real gains. Maybe not the best possible, as moving jammers or moving desired signals would be an issue. But that's just a napkin thought. There are more out there. Jamming may affect the signal like noise, but it isn't.

Re:What can they hope for (2, Insightful)

HungryHobo (1314109) | about 4 years ago | (#33518498)

they could come up with some kind of missile designed to go after transmitters broadcasting interference, they'd be pretty loud and easy to spot.

of course this is probably for drone tech so if you armed a drones as such and programmed them to attack the transmitters if their command channel was blocked the first thing any amoral adversary would do would be to stick an interference transmitter in a preschool with a camera crew nearby.

Re:What can they hope for (1)

OeLeWaPpErKe (412765) | about 4 years ago | (#33518996)

And then the taliban uses their favorite tactic : place the jammers in a kindergarten with journalists in the next building, camera's ready. Obviously the cameras won't flash when the journalists help the muslims kick a few more children directly into the weaponized zone, but they will flash after a rocket strikes.

So avoiding the issue altogether, if you can, is probably a better idea.

Re:What can they hope for (1)

iammani (1392285) | about 4 years ago | (#33519616)

Not if they EMP it!

Re:What can they hope for (1)

mcgrew (92797) | about 4 years ago | (#33520930)

of course this is probably for drone tech so if you armed a drones as such and programmed them to attack the transmitters if their command channel was blocked the first thing any amoral adversary would do would be to stick an interference transmitter in a preschool with a camera crew nearby.

Not all bombs are munitions. You could kill the transmitter with an EMP burst. Nobody gets hurt except the electronics.

I think I need to start buying old vaccuum tubes -- EMP is ineffective against non-solid state gear.

Re:What can they hope for (1)

icegreentea (974342) | about 4 years ago | (#33522074)

They already have a weapon similar to this. It's called a HARM (High Speed Anti Radiation Missile). They were developed/used to take out radar sites. Similarly, they can be used to take out radar jammers (at least theoretically, I don't know if they ever have) since they operate on the same frequencies. So if you could tune the antenna/software to the right frequencies, then you can now go after communications jammers (and assuming some sort of IFF).

Re:What can they hope for (0)

Anonymous Coward | about 4 years ago | (#33519524)

A lot of work to be done still on multichannel receivers/transmitters (since a jammer is localized in space and can be nulled with spatial (multichannel) diversity).

But... (1, Funny)

Anonymous Coward | about 4 years ago | (#33517828)

How long after they develop the extreme wireless interference buster that someone develops the supreme wireless interference generator?

Re:But... (0)

Anonymous Coward | about 4 years ago | (#33518766)

Thats why I gots this intereference buster Buster!

Re:But... (1)

zarthrag (650912) | about 4 years ago | (#33519590)

Oh yeah? "That's why we got the interference buster buster BUSTER 'fo dat as$!"

Re:But... (1)

GameboyRMH (1153867) | about 4 years ago | (#33525830)

Sort of like VG-2 and Spectre speed radar. There's a huge list of technologies in a cat-and-mouse game between these radar guns and the detectors. Here's an idea of how it goes:

1. Police invent new speed radar
2. New detector comes out that can detect it
3. Police update technology to evade detection and detect detector (they detect some radiation the detector emits in operation from what I understand)
4. New detector comes out that can detect the updated radar gun and avoid detection
5. Steps 3-4 may repeat a few times
6. Cops say "fuck it" and switch to laser
7. Speeders keep a sharp lookout and stomp on the brakes when the laser warning goes off. Maybe they stop speeding.
8. Speeders go un-caught and/or revenue from tickets drops. Cops want a better speed radar. GOTO 1

Ok, an interesting challenge. (4, Interesting)

jd (1658) | about 4 years ago | (#33517830)

The conventional approach by NASA is to use Turbo Codes to handle burst errors and Reed-Solomon to handle randomly-distributed errors. You'd need to increase the error correction bits to handle really significant errors, but that seems like a good starting point. If you were to imagine the data as a cube, then produce the error-correction codes for each and every line you could draw through that cube, then each unit within that cube is represented by three sets of error-correction codes.

Re:Ok, an interesting challenge. (0)

Anonymous Coward | about 4 years ago | (#33518690)

If you were to imagine the data as a cube, then produce the error-correction codes for each and every line you could draw through that cube, then each unit within that cube is represented by three sets of error-correction codes.

Wrong, you are educated evil. In the cube there would be four sets of codes.

Re:Ok, an interesting challenge. (2, Interesting)

jd (1658) | about 4 years ago | (#33525252)

Any given point in a cube exists along three lines - one parallel to X, one parallel to Y and one parallel to Z. If you wish to find a fourth orthogonal axis, please do so. Your TARDIS awaits.

Regardless, three is plenty. If you want to improve reliability still further, then if turbo codes are mapped onto X, use LDPC (low-density parity-check code) alone -X.

Since Reed-Solomon is for random errors, you'd probably want to use a conventional ten-bit system - 8 bits of data, 2 bits of ECC. A layout used by a lot of modern electronics. Since turbo codes and LDPC are intended to fix bursty errors, they're useless if the block size used is smaller than the size of burst that you can expect. In the scenario the DoD is interested in, it's extremely hard to say what to do here. If the block size is too big, then the error correction codes have an increased probability of being damaged by such a burst. Thus, not only is there a lower limit but there is also an upper limit.

NB: If you not only want to ECC each line but also each plane using turbo codes, then you have a further constraint. The line cannot exceed the minimum size but the plane cannot exceed the maximum size.

My thinking is that each line's turbo codes would also cover the Reed-Solomon codes, and each planar turbo code would also cover all of the turbo codes for each line within that plane.

Since the same object is mapped from three (or six, using LDPC) different perspectives and the probability of the noise being such that all three/six perspectives are damaged in mathematically identical ways is extremely low, you can generate a set of the most probable original messages at that level. This could be done by combining the probabilities generated from each of the algorithms, a voting system, or some sort of statistical analysis. How doesn't matter that much, so long as you can produce a bounded set of messages that could be described by the codes.

Here, you can use Reed-Solomon not as an error-correction code but as an error-detection code. You know for a fact that the original pattern will satisfy each and every one of the Reed-Solomon ECCs. Any one of the candidate original messages that does not meet this constraint is incorrect. It has to be.*

If the slices used are one bit thick and each line drawn has a diameter of one bit, then I see no possible way for any aliasing effect to occur, which means you'll end up with exactly one reconstituted message even if fairly extensively damaged in transit. That's probably still true even if working using byte-sized atoms, but bit-planes have some definite advantages for this kind of work.

*Ok, it may be possible to inject deliberate corruption such that the resultant turbo codes would produce a candidate solution which aliased onto the Reed-Solomon codes. It'd be better if you could use cryptographic hashes, but those tend to be big and therefore more subject to being corrupted via a wireless connection. You could break the data into fixed-sized chunks, cryptographically hash each chunk, append the hash to that chunk, then do the whole process as outlined for the composite message. If you did this, then you would test the turbo code candidates against the hashes and if they all failed then you'd use the Reed-Solomon to re-fix the messages before testing against the hashes again.

This method is by no means foolproof, it is not intended to be optimal, it has not been evaluated for every possible scenario to see if it's watertight, it is not FDA-approved and it's likely signals analysts and crypto experts would regard it skeptically. It is not intended as an actual submission to the DoD. What it is intended to do is show that the problem does not require any tools that do not already exist. Indeed, it does not require any tools that aren't already being used by industry to tackle some subset of the problem. There is no novelty in this problem, beyond what combination of tools it will take to defeat deliberate interference of arbitrary nature.

Re:Ok, an interesting challenge. (2, Funny)

digitalchinky (650880) | about 4 years ago | (#33518782)

I remember way back being taught about trellis code modulation - 8am - squeaky white board marker - "Right, today we'll cover a very simple 2 bit trellis code modulation scheme' - I thought I was a frigging rocket scientist back then, 2 bits, heh, some kind of noob joke?! I have to say after 2 minutes I'd actually glazed over, just like everybody else... : )

Who dreams this stuff up! Seriously! These guys and girls don't actually think like the rest of us.

Faraday FTW! (3, Funny)

nacturation (646836) | about 4 years ago | (#33517836)

This is so easy. All you need to do is roll out a point to point Faraday cage between the two parties that wish to communicate. To build the Faraday cage, go to your local hardware store and purchase all the rolls of chicken wire they have in stock. Now take the chicken wire and form a loop about 5 meters in diameter. Keep on doing this and stitch the loops together until you have a big enough tunnel to reach from your source to the destination. Remember! There must be line of sight for your wireless to properly function. I recommend getting wooden pallets to smooth out any hills and valleys so that you can see clear through.

Now the fun part. To make a proper Faraday cage you need to run current through the chicken wire. Experiment with the right voltage, but I find that running a chainsaw through a local wooden power pole will score you a big fat power cable capable of delivering the right amount of juice. Strip the power cable and attach the positive and negative wires to the chicken wire. CAREFUL!!! Make sure you're wearing latex gloves to protect your hands against the current. If you don't have latex gloves, fashion your own gloves out of banana peels.

Once the power is hooked up, you have now created an impenetrable electromagnetically shielded tunnel through which your wireless transmissions can propagate. Place the transmitter at one end and the receiver at the other and enjoy your interruption free communications!

Re:Faraday FTW! (4, Funny)

angiasaa (758006) | about 4 years ago | (#33517894)

I think they could use sandpaper instead of wooden pallets to smoothen out the hills.

You give a very good textbook solution to the problem.

Personally, I'd just switch to shielded cables though. :P

Re:Faraday FTW! (3, Funny)

foobsr (693224) | about 4 years ago | (#33517914)

Indeed, and this is to be called ALAS (Advanced Layer Augmented Shielding).

BTW, IMHO, the outlined approach is a paradigm regards advanced technological solutions: if a given system does not work as demanded, create another layer and hope that the increase in complexity will automagically solve the problems.

CC.

Re:Faraday FTW! (2, Funny)

L4t3r4lu5 (1216702) | about 4 years ago | (#33518412)

Is there some way we can get both XML and violence into this situation? They somehow seem appropriate...

Re:Faraday FTW! (2, Funny)

mcgrew (92797) | about 4 years ago | (#33521474)

Is there some way we can get both XML and violence into this situation? They somehow seem appropriate...

Ok, here you go... "XML is the last refuge of the incompetent" -- Salvor Hardin [wikipedia.org]

Re:Faraday FTW! (1)

MonoSynth (323007) | about 4 years ago | (#33518062)

Let's call it 'Coaxial WiFi' :)

Re:Plasma tunnel? (0)

Anonymous Coward | about 4 years ago | (#33518080)

What about a plasma tunnel shield? It's basically what you are suggesting, but it is orders of magnitude more practical.

Re:Faraday FTW! (0)

Anonymous Coward | about 4 years ago | (#33519152)

Mod up.
And you can put pigeons or chickens in the cage to pass messages - and feed others at the other end.
Of course optic fiber is the miniature version of the chicken wire solution.

Darwin Alert! (1)

Hasai (131313) | about 4 years ago | (#33520168)

Anyone want to bet that someone in this lunatic bin won't try this?
];)

Wireless Engineering (2, Funny)

HRbnjR (12398) | about 4 years ago | (#33517926)

Just make sure the CommEx program doesn't contract the electrical engineers behind the iPhone 4 antenna - I hear they are looking for work :P

Suppression? (1)

TubeSteak (669689) | about 4 years ago | (#33518000)

'The CommEx program will assess next generation and beyond jamming threats and then develop advanced interference suppression...

This is the only suppression I'm familiar with:
  http://en.wikipedia.org/wiki/Wild_Weasel [wikipedia.org]

Busta busta (1)

emeade (123253) | about 4 years ago | (#33518008)

Sounds more like when you're trying to bust someone busting you.

Drones are the future. (3, Insightful)

Dutchmaan (442553) | about 4 years ago | (#33518018)

This has drone research written all over it! Take out a signal to a drone and it's as good as shooting it down. It's probably easier to mess with a drone signal than shooting it down as well, but that's just pure speculation on my part.

Re:Drones are the future. (1)

Jahava (946858) | about 4 years ago | (#33518806)

This has drone research written all over it! Take out a signal to a drone and it's as good as shooting it down. It's probably easier to mess with a drone signal than shooting it down as well, but that's just pure speculation on my part.

I wouldn't be surprised if the drone has enough wherewithal to at least attempt to make it home when command-and-control and/or GPS signals fail. Even assuming whatever radio channels it uses are jammed, it still shouldn't have too much trouble using magnetic / visual orientation to return to base. Seems unlikely that there aren't quite a few layers of redundancy in there.

Re:Drones are the future. (0)

Anonymous Coward | about 4 years ago | (#33519142)

Even cheesy R/C craft fly in big circles in place of crashing, maintaining a signal for the hours it would take to crash a drone would make you a target as well

Re:Drones are the future. (1)

Ksevio (865461) | about 4 years ago | (#33523704)

Actually, being a drone it'll just fly around in circles or to somewhere that it can get signal. Shooting it down would be better for an adversary as there wouldn't a drone anymore.

Re:Drones are the future. (0)

Anonymous Coward | about 4 years ago | (#33524044)

Interesting idea. If people are shooting your drones though, you can shoot the interference. Some Taliban in the desert can't be throwing out that much power. If they are, it's a beacon for some B-52 overhead. If the interference is directional towards the drone, fly it in a pre-programmed recon path and then use the information to track the attackers. The info will be a bit stale, but if the transmitter is that powerful the enemy might have a hard time moving the power source and/or the transmitter.

Of course you can use some kind of LOS laser or microwave transmitter back to a mother ship too. I'd like to see them interfere with that.

I'm more inclined to think they're concerned about GPS jammers, or transmissions of codes accross nations with which we're hostile yet not at war.

Neutrinos (1)

davaguco (771514) | about 4 years ago | (#33518040)

Use neutrinos.

Re:Neutrinos (1)

davaguco (771514) | about 4 years ago | (#33518252)

Re:Neutrinos (1)

MichaelSmith (789609) | about 4 years ago | (#33519204)

The author obviously wants a chunk of the military research budget. Are they going to make the output of their accelerator steerable? Or position one in space at the Lagrange 2 position so it can spray the whole Earth with muons. Sounds like a nice try.

I've got one for them!!! (2, Interesting)

syousef (465911) | about 4 years ago | (#33518108)

It's called cat5e.

Re:I've got one for them!!! (0)

Anonymous Coward | about 4 years ago | (#33518394)

A strong EMP will distrupt CAT5. Unless you use it to pull the other man's finger in morse code! Disrupt that!!

Re:I've got one for them!!! (2, Interesting)

L4t3r4lu5 (1216702) | about 4 years ago | (#33518402)

Wrap your Cat5 in a coil made of the power lead to your PC, then turn your PC on. Tell me it's immune to EM interference using that computer.

If it catches fire, that counts as "successfully blocked signal".

Re:I've got one for them!!! (2, Informative)

Anonymous Coward | about 4 years ago | (#33518560)

its immune to EM interference using that computer

Re:I've got one for them!!! (1)

Idbar (1034346) | about 4 years ago | (#33520386)

Actually, I thought of X.25.

hey (-1, Offtopic)

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The technology exists.... (3, Funny)

Kaptain Kruton (854928) | about 4 years ago | (#33518196)

IP over Avian Carriers. (IPoAC). With the pigeons, you don't have to worry about EM radiation interrupting the signal. http://en.wikipedia.org/wiki/IP_over_Avian_Carriers [wikipedia.org]

Re:The technology exists.... (2, Funny)

L4t3r4lu5 (1216702) | about 4 years ago | (#33518382)

They would indeed be impervious to the jamming effects of EM interference.

However, unlike EM waves, they are totally at the mercy of buckshot.

Re:The technology exists.... (1)

John Hasler (414242) | about 4 years ago | (#33519340)

> They would indeed be impervious to the jamming effects of EM interference.

Not if there is enough of it.

> However, unlike EM waves, they are totally at the mercy of buckshot.

I think you mean birdshot.

Re:The technology exists.... (1)

kevinNCSU (1531307) | about 4 years ago | (#33520144)

I think you mean birdshot.

This is DARPA we're talking about, we need to spend millions on improving the state of the art pigeons until they're bandwidth is greatly increased and you'll need buckshot to down them.

Re:The technology exists.... (0)

Anonymous Coward | about 4 years ago | (#33518520)

i think you could use em to mess with pigeon navigation and reroute packets or perhaps do a mitm
or you could deploy falcons or other pigeon eating birds to create a "loss of signal"
and of course sending thousands of you own pigeons carrying random data to "jam" the signal might also work

then to get around false pigeon jamming other birds could be used to carry data that way an opponent would have to send false birds of all the types you are using to completely jam the signal
and some sort of algorithm for finding the correct birds and throw away the false ones will also help if jamming attempts arent powerful enough to jam the whole message retrieval process for that type of bird

Re:The technology exists.... (0)

Anonymous Coward | about 4 years ago | (#33518764)

IP over Avian Carriers. (IPoAC). With the pigeons, you don't have to worry about EM radiation interrupting the signal.

Sir, you are mistaken. However, microwave-cooked pigeon is succulent and tasty.

Re:The technology exists.... (0)

Trivial Solutions (1724416) | about 4 years ago | (#33518886)

ESP

a_screw_loose on_occassion naughty in_other_words industrious
wrath prosparity crazy small_talk envy awesome thats_right
little_fish Im_grieved silly_human the_enquirer blessing
whale hypocrite fer_sure hit insane I_made_it_that_way
crazy exorbitant far_out_man do_not_disturb I_hate_when_that_happens
you_talkin_to_me bizarre You_know Jesus I_see_you bug
once_upon_a_time CIA crazy Tomorrow rip_off lying you_commie
Give_me_praise I_made_it_that_way well_golly Give_me_praise
au_revoir You_owe_me wheres_the_love genius desert figuratively
au_revoir theft Varoom I_love_this soda relax epic_fail
are_you_feeling_lucky off_the_record hang_in_there atrocious
goods jealousy Im_not_sure fortitude off_the_record small_talk
If_had_my_druthers high_mucky_muck horrendous you_dont_say
break_some_woopass_on_you doh once_upon_a_time now_that_I_think_about_it

Re:The technology exists.... (0)

Anonymous Coward | about 4 years ago | (#33519356)

Disagree. With enough EM radiation, your signal will still drop. I suggest serving your dropped signal with chestnut puree and a red port sauce.

Use a wired connection? (1)

BigMeanBear (102490) | about 4 years ago | (#33518220)

Seems like the best way to me...

Re:Use a wired connection? (2, Informative)

f3rret (1776822) | about 4 years ago | (#33518802)

I think there's a practical problem with running wires to Predator or Global Hawk drones...

Re:Use a wired connection? (0)

Anonymous Coward | about 4 years ago | (#33519156)

How about a point-to-point link by laser, either to another drone or to the base?

Frequency Hopping.... more? (5, Interesting)

NouberNou (1105915) | about 4 years ago | (#33518314)

Not really sure what they can advance on besides frequency hopping routines that are quicker and cover a larger spectrum. SINCGARS, HAVE QUICK I/II and SATURN are pretty good at counter-jamming already, as long as the sequence can not be easily predicted and the fills are updated regularly (every 24 hours or so) then jammers will have to invest quite a bit into the infrastructure of their broadcasting equipment. It certainly wouldn't be portable, and it'd be loud and easy enough to find and take out by more traditional means.

The only thing, like I mentioned above, is moving to waveforms that are spread across larger frequency ranges (which can be problematic) and are faster so the jamming equipment can't keep up with the normal signal. Beyond that, digital data over RF can be reinforced by better packet correction and error handling.

Of course you could always just overpower every other signal on your band, but I do not think battery tech has reached that level yet for portable radios, and well... Most soldiers prefer not to be cooked alive if they have a choice.

Re:Frequency Hopping.... more? (1)

ColoradoAuthor (682295) | about 4 years ago | (#33521648)

They may be hoping to promote communication techniques based on "new" theories such as concurrent codes. Early demonstrations of the BBC algorithm [usafa.edu] , for example, are simply breathtaking. BBC allows jam-resistant spread spectrum without needing to coordinate a shared secret (such as a frequency hopping sequence) between the sender and receiver.

Don't we all (1)

jasper_amsterdam (788332) | about 4 years ago | (#33518514)

Seriously, doesn't everyone on slashdot want this as well? I'm surprised it doesn't have the 'want' tag yet. =)

Flag semaphore and interference cancellation (2, Informative)

Catbus (699258) | about 4 years ago | (#33518524)

Flag semaphore remains highly resistant to electromagnetic interference. http://en.wikipedia.org/wiki/Flag_semaphore [wikipedia.org] There is more to be done with interference cancellation techniques using active multiple-antenna systems, that can place a null toward the source of interference.

Re:Flag semaphore and interference cancellation (1)

Arimus (198136) | about 4 years ago | (#33519008)

Might be safe against EM interference but interference from a sniper...

Re:Flag semaphore and interference cancellation (1)

dargaud (518470) | about 4 years ago | (#33519276)

Flag semaphore remains highly resistant to electromagnetic interference. http://en.wikipedia.org/wiki/Flag_semaphore [wikipedia.org] .

You fail at both funny and informative: it's enough to block the electromagnetic spectrum from 390 to 750 nm to render those inoperative. It can happen with fog, or be done with smoke or any material placed in the line of sight. Guess why IR communications are hardly used for anything except TV remote controls even though they've been around for decades...

About as impossible as a secure connection. (0)

Psaakyrn (838406) | about 4 years ago | (#33518568)

Almost any sort of wireless interference can be used to break the security of connections. Almost any method of breaking a secure connection can be used as interference as well.

Re:About as impossible as a secure connection. (0)

Anonymous Coward | about 4 years ago | (#33519418)

But you can make it harder to interupt. Widen the spectrum. Include redundent methods, operating on different frequency bands entirely. Install better directional antennas to reject signals from the wrong direction, so the jammer would need more power. It's still possible to jam - but the harder it is, the more skill and expense your opponent will need.

So.... (1)

RichiH (749257) | about 4 years ago | (#33518674)

All I need to do to block those devices is to use a lot of those devices. The definition of "lot" depends on frequency spread, distance, power used, algorithmic magic etc, but...

It's easy (0)

Anonymous Coward | about 4 years ago | (#33518678)

You can communicate through almost any amount of noise/interference. Of course, your data bandwidth goes down to almost nothing.

I used to have my students detect a signal through noise whose amplitude (volts) was ten times that of the signal. All you can see on the oscilloscope is the noise.

If you're not worried about being detected, you can just push up the power. It's all about signal to noise ratio after all.

handbags wholesale (-1, Offtopic)

didtrade (1884658) | about 4 years ago | (#33518818)

dumping linuxville.com on ebay? (0)

Anonymous Coward | about 4 years ago | (#33518988)

.net, & .org included?. doesn't appear to represent much value? may go for what it's worth? what a goof? kind of like the 'community'?

I don't get this (0)

Anonymous Coward | about 4 years ago | (#33519092)

OK, is this really such a difficult problem?
Original Input IF from multiple out of phase antenna sources (Think of what a birthday cake would look like for a 100 year old, each candle is an antenna)
Identification of phase and amplitude of desired signal (no intelligible information needed for decode at this point)
Identification of alien RF desired to be removed in same step
Selection of desired signal by amplitude frequency and "phase"
All signal from desired multiple out of phase inputs is phase shifted and summed with all signal summed at 0 degree point
All signal from undesired signal is phase shifted 180 degrees and summed to eliminate
Phase and amplitude of source content is recovered and as phase and amplitude information is updated for desired and alien signals sent back to start
There's a ton of other stuff that can be done, and all of that stuff is well documented already

Use Neutrinos (1)

Decomas (1342753) | about 4 years ago | (#33521174)

If they really wanted to go scifi, they could develop neutrino communication. A beam of neutrinos can go through a light-year thick wall of lead with only a 50% loss!

Re:Use Neutrinos (1)

tarpitcod (822436) | about 4 years ago | (#33526402)

Good luck modulating it unless you have a very electrically charged big-bang tiny black hole that you convinced not to evaporate.

Tesla (0)

Anonymous Coward | about 4 years ago | (#33523720)

Maybe they shoulda asked Tesla, instead of working *against him at every flippin' turn...

A couple more options (1)

dslmodem (733085) | about 4 years ago | (#33524322)

1) spatial domain: beamforming: make sure that the receiver, the transmitter, and the interferer are not aligned in a line. 3D: assume the interferer is on the ground. as long as one of the transmitter or the receiver is in the air/space, there is a good chance to use beamforming to improve reception.

2) narrow band or long code: Effectively, this is slowing down the data rate. In this way, the SINR for a message can be good enough.

Ya Gunnybaggers now ya want an amp? (0)

Anonymous Coward | about 4 years ago | (#33524612)

hahaha

Active cancelation of interference with anti phase (2, Funny)

tarpitcod (822436) | about 4 years ago | (#33524650)

Antiphase? Have a receiver transmitter pair that receives the interference and then transmits the 180 degree out of phase equivalent - hopefully cancelling it out. For extra points deploy multiple stations, and for a bonus credit, don't evern transmit your signal, just modulate your antiphase to leave your signal as a remanant. Physics Problems: Can you near instaneously send the anti phase (those radio waves travel quite quickly)... What happens for moving receivers.....

Multiple antennas (1)

Yossarian45793 (617611) | about 4 years ago | (#33524692)

They can take advantage of multiple antennas, directional antenntas, or both to lock onto the interference sources as well as the intended signal and use DSP to subtract out the noise and recover the original signal. Others have posted about how cellphones can take advantage of multipath interference to actually improve the received signal rather than degrade it. As long as the enemy is using a small number of stationary or slow-moving transmitters for their interference, you can locate them all and use DSP to remove the noise, OR if you can arrange for your signal to arrive from a different direction than the enemy's jamming just use a directional antenna. It would get more difficult if the enemy had hundreds of jamming transmitters moving around and covering your receiver from all directions. In the case of jamming a drone, your enemy would need either space-based jammers or airborne jammers to cover you from above. Space based jammers are impractical though (because of the distance) and airborne jammers are laughably easy to shoot down. It seems to me that the simple solution is to deliver your signals from above (satellites), use a directional antenna to ignore noise coming up from the ground, and then shoot anything out of the sky that makes noise which interferes with your signal.
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