Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

DARPA Funds a $300 Software-Defined Radio For Hackers

timothy posted about a year ago | from the turn-on-tune-in dept.

Security 94

Sparrowvsrevolution writes with this story from Forbes: "Over the weekend at the ToorCon hacker conference in San Diego, Michael Ossmann of Great Scott Gadgets revealed a beta version of the HackRF Jawbreaker, the latest model of the wireless Swiss-army knife tools known as 'software-defined radios.' Like any software-defined radio, the HackRF can shift between different frequencies as easily as a computer switches between applications–It can both read and transmit signals from 100 megahertz to 6 gigahertz, intercepting or reproducing frequencies used by everything from FM radios to police communications to garage door openers to WiFi and GSM to next-generation air traffic control system messages. At Ossmann's target price of $300, the versatile, open-source devices would cost less than half as much as currently existing software-defined radios with the same capabilities. And to fund the beta testing phase of HackRF, the Department of Defense research arm known as the Defense Advanced Research Projects Agency (DARPA) pitched in $200,000 last February as part of its Cyber Fast Track program."

cancel ×

94 comments

Sorry! There are no comments related to the filter you selected.

tune in to (-1)

Anonymous Coward | about a year ago | (#41727063)

First post

100 mhz to 6 ghz (1)

fyngyrz (762201) | about a year ago | (#41731237)

That's an interesting range... but there isn't a huge amount of stuff up top, and you can buy an SDR for $100 or less that'll give you coverage from 50 mhz to about 2 GHz, if 2 GHz-plus hasn't got something of particular interest to you. The funcube dongle [funcubedongle.com] is one; there are others.

And if you're into ham radio, particularly the HF bands, and willing to build, take a look into the softrock [wb5rvz.com] .

Me, I use a Funcube for 50 mhz to 2 GHz, and an RFSPACE SDR-IQ, which is a high performance (almost)DC-to-30 MHz SDR that is a great deal of fun for me, as I'm both a ham radio op and a shortwave listener.

I use this [flickr.com] as my operating software.

Antennas (5, Interesting)

burning-toast (925667) | about a year ago | (#41727069)

Antenna design for this must be miserable...

Anyone know if there is a good way to have relatively optimized reception over that whole spectrum without having to swap your antennas when changing frequencies?

- Toast

First post?

Re:Antennas (5, Informative)

Muad'Dave (255648) | about a year ago | (#41727089)

Log periodic [wikipedia.org] or discone [wikipedia.org] .

Re:Antennas (5, Informative)

burning-toast (925667) | about a year ago | (#41727145)

I appreciate that. I might be heavily vested into computers, but radio isn't something I have had the pleasure to tinker with too much.

Also, found the repo / blog for that board (article was lacking in details):

http://www.greatscottgadgets.com/hackrf/ [greatscottgadgets.com]

https://github.com/mossmann/hackrf [github.com]

- Toast

Re:Antennas (2)

burning-toast (925667) | about a year ago | (#41727151)

The picture in the article thankfully had the URL on the PCB, so it's not like I had to play super sleuth to find it...

Re:Antennas (4, Informative)

Muad'Dave (255648) | about a year ago | (#41727271)

You're welcome. Amateur radio folk have been on the forefront of DSP and SDR development for many years now. If you want to fool around with digital signal processing but don't want to invest in hardware, you can use the GNURadio [gnuradio.org] package, along with the GNU Radio Companion to create DSP chains using an IDE and signals to/from your soundcard or arbitrary sound files.

For very little cash you can get a USB TV dongle that can be used as a signal source for GNU Radio. Search around a bit and you'll find sources - some are mentioned on the GNU Radio site.

If you're interested in doing DSP/SDR 'for real' over the air, consider getting a Technician-class Amateur radio license. You have all privileges above 30 MHz, and can do really nifty stuff. No Morse code required anymore - all theory and regs.

Amateur Radio (1)

Anonymous Coward | about a year ago | (#41727763)

No morse code required for ANY license, including HF privileges.

I don't know that i would say that amateur radio is at the forefront of SDR and DSP, or has ever been. Yes, people holding licenses are doing forefront work, but they're getting paid for it, not doing it as a hobby. Amateur radio triggered some of the very inexpensive SDR approaches out there (SoftRock), but that's nowhere near state of the art in SDR.

And, in terms of software engineering for SDR, I would say that amateur radio, in general, is well behind the rest of the industry. The software for the amateur market leader FlexRadio, is ostensibly open source, but is a huge, undocumented, mass of stuff sort of glued together. GNU radio does only stuff that a PC can handle, and doesn't have very good support for the use of FPGAs, which are almost a necessity for wideband, high performance communications.

But, certainly, hams have a place in the SDR tinkering world.

Re:Antennas (1)

Anonymous Coward | about a year ago | (#41727857)

I have one of the super cheap rtlsdr dongles, and I'm in the process of making a discone antenna. Thus far I've been swapping dipole designs I threw together in the living room.

It's good fun. I'm not a radio guy, but it's a great way to start with something you know very little about on virtually no budget.

Highly recommend it for anyone that wants to tinker, but doesn't want to spend a lot of cash.

http://hackaday.com/2012/05/14/improving-a-software-defined-radio-with-a-few-bits-of-wire/ [hackaday.com]

Re:Antennas (0)

Anonymous Coward | about a year ago | (#41732959)

Amateurs are at the forefront? Then why are military radios costing $100,000 and up? I'd like to see an amateur radio do anything close to what non-free radios can do now with frequency hopping, etc.

Re:Antennas (1)

rubycodez (864176) | about a year ago | (#41728203)

yes, that is the reply my University education in the early 80s taught. But something exciting happened in the late 1988, Nathan Cohen of Boston University made elements of a category of antenna called "fractal antennas". Certain fractal antenna radiate equally well over all frequences, at least theoretically. It was then realized that log periodic was a fractal antenna design.

http://en.wikipedia.org/wiki/Fractal_antenna [wikipedia.org]

Re:Antennas (1)

Muad'Dave (255648) | about a year ago | (#41730181)

I'd heard of fractal antennas, of course, but I don't think they're widely available (other than LP's, as you mentioned). Here are some pics of the largest LP I've ever seen [hal-pc.org] . I'll be seeing it again next week. :-)

Re:Antennas (1)

rubycodez (864176) | about 2 years ago | (#41737021)

actually, they're in most cell phones now, that's where the antenna went! all manner of interesting patterns are employed, some look like snowflakes, some triangles within triangles, some like insects.

Re:Antennas (4, Informative)

Chrisq (894406) | about a year ago | (#41727121)

Antenna design for this must be miserable...

Anyone know if there is a good way to have relatively optimized reception over that whole spectrum without having to swap your antennas when changing frequencies?

- Toast

First post?

This appears to be an area of hot research. Ideas include switch band antennas [ittelkom.ac.id] and Software defined antennas [wikipedia.org] .

Re:Antennas (1)

rrohbeck (944847) | about a year ago | (#41731409)

The wiki article on SDA is a bit slim - this is basically a phased array with many small elements, right?

Hmm... how about using TFT manufacturing to create a huge array of elements, each with a transistor and a varactor? Dunno if you can make decent varactors with standard TFT tech.

Re:Antennas (1)

Big_Gay_Mike (2758415) | about 2 years ago | (#41736143)

Some plasma antennas feature low insertion loss (http://en.wikipedia.org/wiki/Insertion_loss) and capable of replacing conventional switching technologies RF MEMS or RF switches (PIN Diodes or FETs). The technology gets cheaper with increased frequency, which is a big plus. There are stealth and wide-band surveillance applications. Would love to play with one.

Re:Antennas (1)

Big_Gay_Mike (2758415) | about 2 years ago | (#41735889)

We're abstracting everything these days as soft-objects. Soon it will be Software defined Consciousness. The Singularity approaches! :)

Re:Antennas (4, Informative)

vlm (69642) | about a year ago | (#41727153)

You need an app that requires coverage from 100 MHz (why not down to 75 MHz for international FM broadcast band RX? Only need down to 87 or so in the USA..)

Usually wide band antenna design is not much of an issue in RF projects at the higher frequencies. Its pretty hard to make a dipole that covers the entire ham radio 3.5 to 4 mhz band than to cover a much smaller octave range at microwave bands.

Also "relatively optimized" is kinda non-specific. My antenna for 2M is optimized for clean pattern first and gain second and bandwidth a distant 3rd... I don't believe it can be used above 145 MHz or so. Which for my use is perfectly OK.

A "good" example of an antenna optimized for wide bandwidth would be an old fashioned VHF-lo thru UHF rooftop TV antenna. Miserable gain but crazy almost 10:1 frequency range.

Re:Antennas (1)

fyngyrz (762201) | about a year ago | (#41731329)

(why not down to 75 MHz for international FM broadcast band RX? Only need down to 87 or so in the USA..)

One thing about FM broadcast is that it's unusually wide-band compared to most signals, television excepted; many of the inexpensive SDR's can't provide that wide-band a signal. The FunCube, for instance, is good to 96 khz, which doesn't cut it. SDRs that are designed for SW or ham radio often provide even less bandwidth, as they're designed with 10 khz AM SW channels and 3 kHz sideband in mind. Or CW, which is just hundreds of hz in typical use.

So, again using the Funcube as an example, there's not a great deal of point in extending down to 75 MHz, as that stuff isn't really receivable.

Re:Antennas (0)

Anonymous Coward | about a year ago | (#41727225)

Regardless of the tuner, software or whatever.... antennas have to follow laws of physics. For reception, generally larger is better.... but antennas must be tuned for transmission. Even if the finals could take nonharmonic transmission (read: lossy) for a period of time, transmitting from an untuned antenna would be inefficient at best. You would probably cause all sorts of sideband issues, too.
Now, I HAVE heard of people who have had some success with antennas that can be tuned on-the-fly... and certainly switching between multiple antennas is an option. One is the headache you've described. The other is like sandblasting a soda cracker.

Re:Antennas (1)

vlm (69642) | about a year ago | (#41727439)

Regardless of the tuner, software or whatever.... antennas have to follow laws of physics.

The A/D sampler on the board only runs at 20 MSPS with a lower cutoff around 100 MHz so worst case antenna work is at the lower end 100 MHZ +/- 20 MHZ or so which is not terribly heroic we figured out "FM radio" and "TV antennas" a long time ago. At the high end as a percentage, the rather optimistic 6 GHZ +/- 20 MHZ is so narrow I cannot build a filter that narrow much less an antenna narrower than that.

I don't know the settling rate/speed of the synths so freq hopping may be (or may not be) out of the question so you're pretty much stuck with narrow-ish band operation.

Re:Antennas (0)

Anonymous Coward | about a year ago | (#41727493)

Wasn't there a story here recently about an antenna that basically worked like an FPGA, able to shorten or lengthen itself on the fly? Probably limited to quarter waves that would reasonably fit on a PCB, but that's still a chunk of the interesting spectrum.

Re:Antennas (1)

confused one (671304) | about a year ago | (#41728287)

For receiving only, a long-wire antenna should work fine.

Re:Antennas (1)

Mashdar (876825) | about a year ago | (#41729099)

Anyone know if there is a good way to have relatively optimized reception over that whole spectrum without having to swap your antennas when changing frequencies?

A general answer would be fractal antennas:
http://en.wikipedia.org/wiki/Fractal_antenna [wikipedia.org]

Log Periodic antennas are a subset of fractal antennas.

Since they are fractal (ie scaleless), you can expand them to pretty much any wavelength range you need.

Re:Antennas (0)

Anonymous Coward | about a year ago | (#41731311)

Logarithmic Spirals have always been good for this application, having relatively stable +3dBi across the VHF/UHF band, circularly polarized, with 'relatively consistent' lobes and rough omnidirectionality. cf: www.ctsystemes.com/zeland/publi/pg32.pdf

Re:Antennas (1)

bobzzwhite (2758473) | about 2 years ago | (#41736763)

Actually you cover the whole band with two off the shelf double ridge horn antennas, one covers 100 MHz to 1 GHz and the second covers 400 MHz to 6 GHz. The 400 MHz to 6 GHz antenna is fairly portable, less than 20 inches (50 cm) in any dimension. I strongly prefer horn antennas for experimental work for safety as they have a strong and obvious directionality. Discone and related designs such as Bicones have a doughnut mode (no directionality in one plane) and log periodic antennas can have unexpected spikes in their response and they get pretty big below 1 GHz. Unless you are trying for communications out of slot canyon, bouncing for distance or legacy analog why would I care about anything below 1 GHz.

Why? (0)

Anonymous Coward | about a year ago | (#41727073)

So, part of me wondered, "Why would they do this when A) there's a growing cheap-SDR market out there and B) it's potentially contrary to US defense interests?"

Then the paranoid responded, "A) If they own it, they can stop it and B) Who says they're not transmitting a serial number with each unit."

Re:Why? (0)

Anonymous Coward | about a year ago | (#41727101)

A) government back doors
B) government back doors

Re:Why? (2)

Muad'Dave (255648) | about a year ago | (#41727113)

Who says they're not transmitting a serial number with each unit.

That would be very hard to hide from anyone with a even just a little test equipment. SDRs typically operate by taking user-generated in-phase and quadrature (I/Q) signals from the data source. These have the desired data waveform already encoded in them. Additional modulation (to sneak in a serial number) would appear as undesired spurs or noise.

Re:Why? (1)

eyegor (148503) | about a year ago | (#41727143)

most people who are likely to use this will be transmitting their call sign every time they broadcast. Letting Joe or Jane Average play with one of these will be like putting a green laser in the hands of every 6th graders hands.

Re:Why? (1)

Muad'Dave (255648) | about a year ago | (#41727223)

I wasn't commenting on the chaos that would ensue if these were widely available to every wannabe pirate radio hax0r or anarchist. I agree that would be a CB-esque mess. I was commenting on how hard it would be for 'Big Brother' to embed a hidden serial number in the transmitted waveform to track users for their own governmental nefarious purposes. Anyone with a pair of these could easily see the secret modulation.

most people who are likely to use this will be transmitting their call sign every time they broadcast.
If by 'most people' you mean amateur radio operators, then I heartily agree (although we are not allowed to 'broadcast' [thefreedictionary.com] in the common definition of the word).

Re:Why? (1)

TheLink (130905) | about a year ago | (#41727711)

Anyone with a pair of these could easily see the secret modulation.

If you're paranoid you'd say anyone with a suitable trusted 3rd party receiver would see the modulation. Because if they do it right the receiver won't show you the secret modulation. ;)

Seriously though I'm sure the much sneakier bunch can figure out ways to fingerprint stuff that are hard to detect. You don't need to send out the identifier at a high rate. If it's a bit a minute who will notice?

Re:Why? (0)

Anonymous Coward | about a year ago | (#41727129)

They obviously want to turn it into a weapon. If Starfleet had this technology adapted to use with their phasers, then fighting the Borg would be a cinch.

Re:Why? (3, Insightful)

fuzzyfuzzyfungus (1223518) | about a year ago | (#41727131)

I don't know why DARPA would necessarily feel the need to contribute to work in an area that is already receiving attention(The guys at Ettus will sell you a competent little package for under $2k, sometimes rather far under, depending on the frequency ranges you want, which is hardly free; but isn't exactly "If you have to ask, you may be in the wrong store." money); but I'd imagine that whatever sub-unit of DARPA made the decision is the sub-unit where people who realize that 'obscurity' ain't gonna cut it as a security strategy in the future hang out.

While, yes, the US Intelligence Community certainly wet-dreams about a world of full spectrum dominance and Total Information Awareness, anyone who hasn't fully removed themselves from empiricism has to admit that that isn't really on the table. Especially for assorted hacker shenanigans, there are just too many parties who can drum up enough nerds to at least go after soft targets.

In such an environment, the US(as a country deeply dependent on complex electronic infrastructure) is probably better off if friendly security researchers have cheap toys to work with, at the risk that enemy ones will as well, rather than a situation where friendly security researchers find that the tools they need are expensive or illicit; but anybody doing work for even fairly cruddy little nation-states has what they need to pump out the zero-days.

Re:Why? (2)

vlm (69642) | about a year ago | (#41727509)

where people who realize that 'obscurity' ain't gonna cut it as a security strategy

They made certain RF / DSP / digital design decisions that provide a rather hard constraint. If they can flood the market using govt money, no one out there will have gear with IMD performance better than 8 bit, sample rates higher than 20 Msps, the RF chain probably means miserable performance both at very weak signals and very strong, and board PCB routing probably means some interesting (intentional?) RF birdies both in RX and more importantly in TX.

So... once you've put non .mil research into a carefully specified box, you can quite easily do your real .mil work outside the carefully specified box. Use a modulation that has to sample 100 MHz of spectrum to demodulate. Who knows.

Its an effort to stop market convergence, to drive them apart / separate more so than to open up an already thriving open environment.

Re:if ..."security researchers" have cheap toys (1)

TaoPhoenix (980487) | about a year ago | (#41727681)

One problem as I see it, is that the government is playing Left Hand - Right Hand games. The left hand likes to make these cool cheap toys and give/sell them to get innovation for half the security boys. The right hand is busy saying that anyone who shows learning of any kind not authorized in the manual is a terrorist. "Just think of all the danger of these radios falling into the wrong hands!" They want the end results of cleaned up innovation without the mess of the pioneer-process that produces it.

Re:Why? (1)

confused one (671304) | about a year ago | (#41728363)

Well, in a simple minded way I can see an obvious answer. If, by pushing a little innovation, they can reduce the cost from $2k to $300, that's a 6x reduction in cost. When multiplied by, oh, the entire U.S. military population, that becomes a substantial dollar amount.

Re:Why? (0)

Anonymous Coward | about a year ago | (#41728947)

Fuck you. Not everyone has $2000 to drop on a hobby. Some of us are unemployed, desperately empoverished and very close to being homeless. We are smart, and we have free time, but we have no money BECAUSE we don't have a job to occupy our time.

I'd love to play with an software defined radio. Hell, I'd love to play with a radio, period! Unfortunately, even though I am licensed, I can afford neither.

Why don't you say "let them eat cake," while you're at it? That would complete the image of upperclass snobbery, which you are projecting here.

Re:Why? (0)

Anonymous Coward | about a year ago | (#41728801)

A) I agree with this one. This point does make it seem a little odd.
B) The SDR is only a platform. Sure you can look at everything on the 100MHz - 6GHz band, but you could do that with other radio equipment anyways already. There may be a lower barrier to entry, but you still wouldn't be able to get any meaningful data from scanning for transmissions coming from a soldier on the battlefield. You would actually need to know all the inner workings of the communication protocol and have the right cryptographic key to be able to get anything meaningful.

Different HW Needed? (1)

Doc Ruby (173196) | about a year ago | (#41727083)

Is this really "software-only defined radio"? Doesn't the radio need different hardware for different types of radios? Different antennas for different frequencies (and signal amplitude ranges in those frequencies)? Different analog for RF conditioning and glue from (different) antenna to logic?

Or maybe a single "multi-antenna" with generic RF analog circuits can serve any radio. Isn't that a lot more expensive?

If I want my receiver to do say WiFi right now, but switch to Zigbee later, and to Enocean after, and to Z-Wave later than that, and to 6Lowpan after that, can I start with just HW that does WiFi, and upgrade only SW over the next several years as the protocols are finalized? How about if later I want to switch among those radio types on demand, every few minutes (or milliseconds)?

Re:Different HW Needed? (5, Informative)

Muad'Dave (255648) | about a year ago | (#41727191)

If you have SDR equipment that can operate on 2.4GHz and has enough bandwidth, you could operate WiFi, ZigBee, and other protocols at the same time. You could have WiFi on channel 1, ZigBee on 11, etc. As long as the chipping codes don't collide, you can go nuts. As an example of relatively simple SDRs, check out these Web SDRs [websdr.org] . These are single radios that digitize large swaths of spectrum. Each web user gets their own software virtual receiver that is tunable across the sampled spectrum. These radios can support hundreds of users at the same time, each listening to different freqs in different modes.

The radio hardware remains the same. The parts that can change are external to the actual 'radio' part - preselector filters, preamps, antennas, etc. Once you get the signal of interest to the radio, the processing is identical. Look around for descriptions of I/Q modulation - by supplying in-phase and quadrature signals, you can generate any modulation you want.

Re:Different HW Needed? (1)

codemaster2b (901536) | about a year ago | (#41728401)

I worked for a company that produced a software-controlled radio base-station. You have to know the secret to these devices: they can't actually cover more than 10 MHz at a time. There is a 10 MHz (or maybe a little better) band-width Yig that can be set in software to any given frequency between say 100 MHz and 6 GHz. This Yig limits sending and receiving channels to within 10 MHz of each other. Since Wifi channels are about 20 MHz each, your use case is not feasible. You could only use one channel at a time.

Now with more Yigs, you can use multiple channels at a time, but you are limited by the hardware. Yigs are very much not cheap, last I knew. A $300 software radio that can compete reasonable well with a Motorolla $5000 radio.... probably isn't running more than 1 Yig.

Re:Different HW Needed? (0)

Anonymous Coward | about a year ago | (#41728999)

Or you could use an FPGA. Those of us over in oscilloscope design land have no problem capturing the multiple gigasamples/second necessary to get wider than 100 MHz.

Re:Different HW Needed? (2)

Muad'Dave (255648) | about a year ago | (#41730135)

That was your use case - for many other uses, YIGs are unneeded - a simple NCO/PLL will work just fine. There are plenty of A/D's that can sample more than 10 MHz at 16+ bits. For the 2.4 GHz use case you would not have to sample the RF signal directly - that would be silly. You would first downconvert the desired signal to a more reasonable IF (intermediate frequency) and then sample that. If you don't have image rejection requirements you could shift it to DC and sample that. Read up on superheterodyne receivers to start with, then digital up- and down-converters.

This company [flex-radio.com] makes the Flex-6000 series Amateur transceivers - they are all digital and directly sample the HF and VHF bands from 30 kHz to 77 MHz continuously. This radio has every bell and whistle, and has incredible performance stats. It's expensive, but it is indicative of the amount of spectrum you can simultaneously sample.

Re:Different HW Needed? (0)

Anonymous Coward | about a year ago | (#41731431)

It's also a problem with GNU Radio to run certain protocols. For example, GSM they can do, but UMTS they cannot. The reason is that the spec requires you to receive something, make a simple decision, and transmit a reply, with very low latency. GNU Radio makes the FPGA very dumb and feeds all the data over a long-delay pipe---ethernet/usb, host operating system, userland process---so it can't make swift decisions.

The physical radio might be able to do it, but then you're not in magical software-defined radio land any more. You're almost designing real radios, if you're implementing on FPGA. GNU Radio cannot do it.

Another thing that would be fantastic to do would be zig-zag decoding of 802.11. The zig-zag paper used software-defined radios, but instead of implementing their protocol, they stored minutes or hours of data, then ran their software-defined radio algorithm on it hypothetically, and wrote a paper about "this is how good the radio would perform, if we could build it." The problem here is also the deep pipelines. There are a couple places in the zig-zag design where you must make a decision in ~thousands of bit-times.

Re:Different HW Needed? (1)

Muad'Dave (255648) | about 2 years ago | (#41739605)

GNU Radio makes the FPGA very dumb and feeds all the data over a long-delay pipe---ethernet/usb, host operating system, userland process---so it can't make swift decisions.

IIRC, the default firmware for the FPGA does a simple transform and pipes the I/Q samples over USB or ethernet. That is not to say that you couldn't put more of the functionality on the FPGA. I disagree that fiddling with FPGAs is "almost designing real radios, if you're implementing on FPGA". If you're processing the signal in the digital domain, it's still SDR, even though the 'S' is burned into an FPGA. 'Real Radios (tm)' require arcane analog/RF knowledge - things like filter design, mixer design, VCO design, etc - all the stuff that is frequency-dependent. SDR requires Hilbert transforms, Hamming windows, that sort of thing.

If I were trying to implement a specific protocol, I might test the algorithm out in GNU Radio, but I'd use a module like the Ettus SBX [ettus.com] and put the radio logic in an FPGA or (very) fast CPU.

Re:Different HW Needed? (1)

ledow (319597) | about a year ago | (#41727219)

This is, I think, the last barrier to myself literally just buying an SDR to tinker with. I know nothing of radio beyond simple physics and all SDR's that I see have various antenna/tuner/amplifier/whatever-they-are stages that cater for different frequencies. I keep going back to things like GNU Radio to see if they've got something for me, but it's all prototypes and "just add your own antenna worth more than my car".

As such, it's out of my tinker-budget because I can't justify spending that money on something that will need extras that might not do what I want, especially if I spend hours listening to static because I don't *know* that it can't pick up the signal I want to tinker with. I just want to see Wifi pop up on my screen as a waveform that I can dig into, play with the neighbour's doorbell, see the protocol of my external weather station on 433MHz so I can extend it myself, listen out for the MSF atomic clock signal (though that's at 60KHz which is a LONG way down the scale this device can manage), pick up FM and DVB-T and capture a screenshot, etc.

The day someone makes a USB-encapsulated, single-antenna design that's "good enough" over a huge range of frequencies and comes with enough software to actually see, analyse (I'm thinking specifically of a Wireshark-like capture where you can specify what protocol it *should* be hearing and it can work out what's being said in a nice format), record and playback the signal, I will have one. Until then, it seems they are still firmly in the realm of the radio ham.

Incidentally, it'll also put Wireshark's nose out of joint because their main sponsor is the manufacture of the AirPCap which does what this does but only for Wifi.

Re:Different HW Needed? (1)

Malvineous (1459757) | about a year ago | (#41727351)

You do realise that the $11 USB DVB-T dongles do about 75% of what you want? Sure the software still needs a bit of work, but the hardware is already able to receive many of these signals, and if you're willing to use a different program for each signal type, many of them can already be decoded. Sure you can't transmit anything yet in this price range, but there's a lot of stuff to listen to.

Funnily enough right now I'm half way through planning a Wireshark style program very similar to what you describe... I'm hoping to leverage the GPU to perform as much of the signal processing as possible, since this is typically the bottleneck with SDR. (Many people are surprised to find it takes a significant chunk of CPU power just to listen to one FM radio station.)

Re:Different HW Needed? (1)

fuzzyfuzzyfungus (1223518) | about a year ago | (#41727239)

My (layman's) understanding is that that varies: Given that all real components have various limitations and finite performance, nobody sells a 'DC-to-daylight' frequency range in a single package, just not in the cards. Some SDR products are explicitly modular [ettus.com] (see 'Daughterboards Table' tab), some, generally in exchange for lower cost, support a single slice of spectrum and hope that your area of interest falls inside it.

This is a lot more expensive. This is why $300 is cheap for an SDR; but $30 is expensive for a wifi dongle.

As for protocol switching, that may actually be easier than the relatively broad spectrum support side of things, given how many distinct protocols boil down to various uses and misuses of frequencies right around 2.4GHz. The hard part, for general-purpose interaction with wireless data standards(as opposed to prodding them with specially formed inputs) is that you might find yourself needing some serious punch to do all the crunching in pure software fast enough that the device you are talking to doesn't give up on you and time out. Of course, you may end up with a $300 BT dongle that consumes a core or two of a modern CPU running at full tilt; but it should work(just remember to whistle innocently about any patents that you definitely aren't violating by implementing the standard...) This is why full SDR designs have largely lost out in consumer products. It sure would be elegant if my cellphone had a universal RF communications module that adapted to my requirements at any given moment; but shoving in Wifi and Bluetooth courtesy of broadcom and cellular courtesy of Qualcomm costs two factors of ten less, so which one am I going to pick?

Re:Different HW Needed? (1)

vlm (69642) | about a year ago | (#41727573)

This is why $300 is cheap for an SDR; but $30 is expensive for a wifi dongle.

$21 is cheap for a SDR... kit. I built this one for 30M band back when it was about $12. If you are lucky you can get the correct assembled TV dongle off ebay for $10 or so.

http://fivedash.com/ [fivedash.com]

At the other end, if you'd like to spend four figures for cutting edge performance, there's always

http://www.flex-radio.com/ [flex-radio.com]

Re:Different HW Needed? (1)

fuzzyfuzzyfungus (1223518) | about a year ago | (#41727751)

Interesting. I have one of the little RTL2832/E4000 dongles plugged in right now, and I'm familiar by reputation with the USRP stuff; but my knowledge of the midrange, and any of the gear that has evolved from the hobbyist radio side, or that is designed for crunching RF down to something that a soundcard works with, is pretty much zero.

Re:Different HW Needed? (1)

Shavano (2541114) | about a year ago | (#41727659)

With just an ADC you can produce any kind of modulation. You're limited in bandwidth by the sample rate, which I assume is adjustable. You're limited in out of band emissions by the precision and the converter design.

combine that with computing power.... (2)

Razgorov Prikazka (1699498) | about a year ago | (#41727087)

I don't have a lot of knowledge in this, but it seems to me that one should be able to crack scrambled comm's much more easy right?
Eavesdrop on GSM's, listen out on dect-telephones for example? Or 'tinker' with that new 'smart-meter' the neighbours had installed.
Just some suggestions... not saying you should, but you could ;-)
Sounds absolutely interesting!

Re:combine that with computing power.... (4, Interesting)

ledow (319597) | about a year ago | (#41727179)

The point is that you've always been able to do that. Radio hams have been building radios and you've been able to buy scanners that will let you listen and transmit on any frequency you like for decades.

That's part of the article summary - people STILL using "security by obscurity" because they don't expect people to bother to record, modify and playback openly-available data is LUDICROUS. See the article just now about being able to scam public transport because of homebrew-encryption used over the airwaves.

The problem is not the airwaves, or the devices available to read them. They've existed since Marconi, if you had the brains. It's that people still deploy systems where the wireless part is treated like some mystical, magical medium that stops people doing things to it.

You can already listen to GSM. Radio hams found and cracked the encryption on it before it was even standardised. 3G technologies have similar problems. DECT, also. Smart-meters, some of them too. The problem is relying on untested encryption or no encryption/authentication at all in order to make things work and then being shocked when someone clones your phone.

This is nothing new. It just makes it slightly cheaper and more convenient.

Re:combine that with computing power.... (1)

Razgorov Prikazka (1699498) | about a year ago | (#41727967)

I know that this was possible already, but my suggestion is that it is more easy now than it was before. Just as you answered: yes it is.
There must be millions of interesting things to receive, things that one would (normally) never even think of.
For example these RFID locks on the company's door here. It must be quite interesting to check that out, see if there is a difference in 'fingerprint' between the several different doors that keep people out of areas where they dont need to be.
And no, I dont (necessarily) need to know the answers from people here, I just want to check it out myself. You know, like when you're a kid and do little experiments to see if there really IS hydrogen coming of that electrode ;-)
This must be the RF equivalent of "x-ray-glasses" :-D

Re:combine that with computing power.... (2)

b5bartender (2175066) | about a year ago | (#41728367)

We've already seen at least one successful brute force method to retrieve P25 encryption keys [slashdot.org] via GNU Radio..

"Dark" mesh networks FTW (1)

Anonymous Coward | about a year ago | (#41727093)

Good. Now we have a backup plan just in case government or industry tries to shut down free communications through the net.

SDR in Linux/FPGA? (1)

Doc Ruby (173196) | about a year ago | (#41727095)

Is there a SDR project for Linux that implements some of the circuits in FPGA?

How about SDR where some of the RF analog is implemented in FPAA (analog array)?

Re:SDR in Linux/FPGA? (1)

fuzzyfuzzyfungus (1223518) | about a year ago | (#41727265)

The Ettus Research USRPs all appear to include FPGAs onboard, as does the Per Vices Phi device. I'm less familiar with the rather higher priced Serious Commercial Offerings; but it seems to be a pretty standard feature for allowing the user to do some amount of the heavy crunching before handing off to the CPU.

This should be popular in the ham radio community (4, Informative)

eyegor (148503) | about a year ago | (#41727125)

Software radios are becoming more popular in the amateur radio community. There are several manufacturers of very fine radios and quite a few build-it-yourself radios available too. I'll be watching this with great interest since one of the biggest problems with the lower-cost software radios is band coverage.

As Toast said a moment ago, antenna selection would be hard. Most radio amateurs would use an antenna tuner and/or a multiband antenna for the HF frequencies and an antenna switch for other bands of interest. I do just that. I have a 40 meter full wave horizontal loop antenna and use an antenna tuner and a 4:1 balun and can transmit on all bands from 40m through 10m and have very good results. It's also usable on 6m, but have never had a lot of luck with any kind of distant contacts.

Re:This should be popular in the ham radio communi (2)

vlm (69642) | about a year ago | (#41727359)

quite a few build-it-yourself radios available too

The device announced is basically equivalent in specs to the couple years old UHFSDR (not a terribly creative name) as seen at

http://wb6dhw.com/For_Sale.html#UHFSDR [wb6dhw.com]

Main difference is this board has a 8-bit 20 Msps A/D onboard and the UHFSDR has it offboard (assuming you'll use a "16" bit 44+ Ksps soundcard)

You can see quite a difference in implied project design here.... Is it even possible to pass FCC regs for IMD trying to transmit a 8-bit SSB signal, and obviously a audio soundcard doesn't sample wide enough to do wifi or whatever fast digital stuff you'd like. So its broadband digital strong signal type of toy as opposed to something like a UHFSDR which is the opposite.

Can you really shove 20 Msps thru a USB reliably? I used to think no, but...

I'll be watching this with great interest since one of the biggest problems with the lower-cost software radios is band coverage.

I didn't see any switchable bandpass filters, or anything like that. I haven't found a schematic but you can just look at the board and figure out whats going on. It looks like its buildable for on board PCB antenna or external, like solder in the SMA jack OR the 0-ohm jumper at the arrow to connect the pcb antenna. Looks like 2 stages of RF amp MMICs before it hits a mixer. You can see the "I" and "Q" PCB traces in the upper left for both the TX and RX mixer. Apparently the design goals are all half duplex but the actual board design appears to use separate TX and RX stages at the hard/expensive end. Where's the VCOs or more likely DDS synths? I'm guessing on the other side of the board? I bet if I spent more than 5 minutes looking at it, perhaps with the wiki page open and looking at some of the device data sheets while looking at the PCB, I could tell you a lot more about the design.

From looking at the board layout I don't think it's going to work at 6 GHz or at least not work to maximum specs. You can tell the designer came from the "digital camp" into SDR work rather than up from the "analog camp" into SDR work. Little things like how signals are run, some layout choices, some design choices.

For a good time, look at the board picture, which has a URL silkscreened on it, click thru to

https://github.com/mossmann/hackrf/wiki [github.com]

The "design goals" "hardware components" and "clocking", combined with the PCB, could tell you pretty much everything you need to know about this design.

Re:This should be popular in the ham radio communi (1)

tlhIngan (30335) | about a year ago | (#41729749)

Main difference is this board has a 8-bit 20 Msps A/D onboard and the UHFSDR has it offboard (assuming you'll use a "16" bit 44+ Ksps soundcard)

You can see quite a difference in implied project design here.... Is it even possible to pass FCC regs for IMD trying to transmit a 8-bit SSB signal, and obviously a audio soundcard doesn't sample wide enough to do wifi or whatever fast digital stuff you'd like. So its broadband digital strong signal type of toy as opposed to something like a UHFSDR which is the opposite.

Most SDRs use commonly available 192KHz/24bit ADCs and DACs these days which work fairly well (thanks to heavy commercialization of home theatre gear, these parts are cheap, common and work REALLY well).

I didn't see any switchable bandpass filters, or anything like that. I haven't found a schematic but you can just look at the board and figure out whats going on. It looks like its buildable for on board PCB antenna or external, like solder in the SMA jack OR the 0-ohm jumper at the arrow to connect the pcb antenna. Looks like 2 stages of RF amp MMICs before it hits a mixer. You can see the "I" and "Q" PCB traces in the upper left for both the TX and RX mixer. Apparently the design goals are all half duplex but the actual board design appears to use separate TX and RX stages at the hard/expensive end. Where's the VCOs or more likely DDS synths? I'm guessing on the other side of the board? I bet if I spent more than 5 minutes looking at it, perhaps with the wiki page open and looking at some of the device data sheets while looking at the PCB, I could tell you a lot more about the design.

Most SDRs are using I/Q encoding and decoding and then mxiing to bring the signal up to the desired frequency band. I say most because there are a few "direct conversion" SDRs that take an antenna input, broadband amplify it, and stick it into a ADC - you can get 250Msps 8/10/12/14/16 bit ADCs these days (thanks to Nyquist, that's DC to 125MHz or so). A bit pricey (you're looking at a couple hundred dollars per chip, in 1000 quantities), but doable. Of course, you'll need to find a way to offload that data or reduce it.

Can you really shove 20 Msps thru a USB reliably? I used to think no, but...

Depends on the bit-depth, but for USB 20-40MB/sec (160-320Mbps or 8/16 bit) is acheivable on most PCs. Though the problem is less USB bandwdith and more the lack of isochronous bandwidth. If you want to do this reliably, you need FireWire at a minimum (which even though is only 400Mbps, it can achieve those rates quite readily) or faster interface.

Nice try DARPA (0)

Anonymous Coward | about a year ago | (#41727133)

Just above the frequencies used by neural interfaces. Keep trying to flood the market with your crap, but we'll stick to the likes of the Phi and see what you fuckers are really doing with those sats.

But it's only $300! (0)

Anonymous Coward | about a year ago | (#41727137)

Here, let me demonstrate the problem with this technology.

Hey! Can anyone here loan me $300? I promise I'll pay you back.

Most hackers use $30 TV tuners (2)

petes_PoV (912422) | about a year ago | (#41727157)

Rather than spend $300 I think most people use RTL2832U/E4000 based TV tuners. Typically these have a tuning range from 60-ish MHz up to 1 - 2 GHz depending on the specifics of the design.

Sadly, the chips used are getting scarce these days so the price of the products (available from your favourite chinese website) is going up. But it still beats $300 by a long, long way.

Re:Most hackers use $30 TV tuners (2, Informative)

Anonymous Coward | about a year ago | (#41727185)

They can't transmit though.

Re:Most hackers use $30 TV tuners (0)

Anonymous Coward | about a year ago | (#41727293)

and only 8bit

I cant seem to find specs on this new one, whats the max sample bandwidth ? and 8bit, 12bit, 16bit or higher ! highly doubt higher.

Re:Most hackers use $30 TV tuners (0)

Anonymous Coward | about 2 years ago | (#41735521)

20 Msps and 8 bit

Re:Most hackers use $30 TV tuners (2)

petes_PoV (912422) | about a year ago | (#41727445)

They can't transmit though.

That's correct. Although since it's illegal to own a transmitter for frequencies you don't hold a licence to transmit on (and nobody holds a licence to transmit on "from 100 megaherz [sic] to 6 gigaherz") these proposed SDRs would have a big problem getting any sort of electrical conformance/approval certificate for sale in most countries.

Re:Most hackers use $30 TV tuners (0)

Anonymous Coward | about a year ago | (#41728051)

Not totally correct (at least in Canada and I suspect other parts of the world). It's illegal to TRANSMIT on frequencies that you are not licensed on.

Owning a transmitter that could transmit on frequencies that you are not license on is complete legal.

Re:Most hackers use $30 TV tuners (0)

Anonymous Coward | about a year ago | (#41727413)

Although the RTL stuff is fun and cheep is only has a 8 bit a/d capability with limited bandwidth. This looks like it will fix both of these issued without the 2k price tag.

Mixing (0)

Anonymous Coward | about a year ago | (#41727161)

It can both read and transmit signals from 100 megahertz to 6 gigahertz

But I guess it will use a hardware mixer to bring these frequencies down to something manageable.

it hertz it hertz (0)

Anonymous Coward | about a year ago | (#41727235)

"... 100 megaherz to 6 gigaherz ..." sheesh

Another TOY SDR (2, Informative)

Anonymous Coward | about a year ago | (#41727515)

Uses only 8 bit sampling which will severely limit the dynamic range. You might as well use one of the $30 RTL2832U/E4000 based TV tuners. DARPA throwing them $200,000 for the effort is a WASTE of taxpayer's money for these guys to build a 'TOY' SDR!

Re:Another TOY SDR (1)

mc6809e (214243) | about a year ago | (#41730643)

Uses only 8 bit sampling which will severely limit the dynamic range.

In my experience, anything more than 8 bits per sample is a waste. It takes a very quiet em environment and input amp to reliably resolve more than 8 bits. Besides, most of the dynamic range is already handled by an amplifier with programmable gain.

MUCH more important, IMO, is input bandwidth, especially in an environment where a signal can suffer from a lot of reflections. Your 16 or 24 bits per sample is useless if the narrow band you're focusing on just happens to be at a frequency where reflections are completely destroying the signal through destructive interference.

A great way to avoid these dead ranges without constantly varying a carrier is to simply provide a very wide bandwidth signal. And to some extent, a greater number of samples can make up for a lack bits per sample.

If the choice is between 8 bits per sample at 20 Msps, and say 16 bits per sample at some lower rate, I'm taking 8 @ 20M.

Re:Another TOY SDR (1)

Mr2cents (323101) | about a year ago | (#41733885)

I guess that having a high dynamic range can be useful if you are sampling at a large bandwidth: in such a case you will probably be receiving multiple transmissions, if you get a very strong signal and a very weak one, how are you correctly going to sample them simultaneously? Compare it with HDR photography: normally you'd say it's overkill, but it does allow you to see detail in darker regions in an otherwise bright photo.

However, you are correct in that you can increase the resolution by downsampling (delta-sigma modulation if I'm correct)..

Feel free to correct me if I'm talking nonsense.

not for hackers (0)

Anonymous Coward | about a year ago | (#41727687)

for govt spies . quit the bs lies in titles

What? no HF/Shortwave (2)

FudRucker (866063) | about a year ago | (#41727699)

I would not want it if they were giving it away free, it is junk without HF/Shortwave & SSB

Re:What? no HF/Shortwave (1)

Anonymous Coward | about a year ago | (#41727829)

Check out AFREDRI SDR. Well under $300 shipped and features 0-30Mhz, 1300 Khz bandwidth, and both usb and ethernet.

Re:What? no HF/Shortwave (0)

Anonymous Coward | about a year ago | (#41732925)

Ummm...I think the parent is referring to Single Sideband (SSB), not USB. I'm assuming your USB doesn't refer to Upper Sideband.

Re:What? no HF/Shortwave (1)

Malvineous (1459757) | about a year ago | (#41734927)

Why is it junk without HF? I thought the primary purpose of SDR was to deal with wide(er) band digital signals, and most of them are well above HF. If you really need HF, there are plenty of upconverters that bring HF up to 100MHz+ so most SDR devices can receive the signals. (I don't think any of the current crop let you transmit though, since none of the current cheap SDR devices can transmit.)

Also SSB is done in software, so any SDR can do SSB on any frequency.

I want one (0)

Anonymous Coward | about a year ago | (#41727723)

Ohhh, I want one, where do I buy?

What a reception (0)

Anonymous Coward | about a year ago | (#41728481)

I wonder if all the wet blankets criticizing this project are going to fess up to being wrong headed in the future when people are doing incredible shit with these radios?

Ettus Research hasn't been doing shit to make the USRP accessible to the rest of us. Personally, I think the majority of the negative reactions are just sour grapes and jealousy because they didn't get a free radio.

DARPA continues to kick ass and lead innovation. Cudos to Mike Ossman!

Realtime spectrum analyzer (1)

Spectrumanalyzer (2733849) | about a year ago | (#41728575)

Now....if we could use that thing as a real time spectrum analyzer, wed be in business.

Until then, SDRs arent that impressive. Ill take my AOR 8200 MK-III and NRD 535D over SDR any day.

Re:Realtime spectrum analyzer (1)

Gordonjcp (186804) | about a year ago | (#41729003)

The whole point of an SDR is that it is inherently a "real-time spectrum analyser". You snarf down a large chunk of band, do an FFT on it, and display the spectrum.

Take a look at this screenshot [gjcp.net] showing a 48kHz-wide chunk of the 40m amateur band. It's only limited to 48kHz because that's the rate I was sampling at. I could go wider by sampling at a higher rate, or I could "fake" it by using the same technique that "conventional" spectrum analysers do by tuning the centre spot up and down.

Re:Realtime spectrum analyzer (1)

MindPrison (864299) | about a year ago | (#41732645)

Uhm, I don't think that's what he means.

He probably refer to a real spectrum analyzer (these costs in the range of 10K towards 250K) which essentially can display a whole frequency spectrum in one go on the screen, represented as curves (not the garbled graphics dot hell your screen shot shows)

Here's a typical spectrum analyzer view: http://www.radaufunk.com/pictures/hp8569b/hp8569br.jpg [radaufunk.com]
The curve in the image COULD represent a signal found at ex 300 MHz, and the curves size could represent the bandwidth the signal is occupying (ex 6 MHz wide), and this signal is usually shown on the spectrum analyzer CRT as a real time signal, meaning it can show in a split second, if it vanishes, the curve is gone from the screen too.

Imagine you have a spectrum of 0.1 khz to 2 ghz, scanning at 20ms (the old HP 8590A does this), then you could effectively monitor any activity across the bands and immediately spot anyone transmitting in between the 0.1 kHz and 2 GHz and it will show up as a curve peaking in between start & stop of the scan (across the screen).

At least that's what I think he means. These instruments costs a fortune, but are quite useful. I have a HP 8590 myself.

Re:Realtime spectrum analyzer (1)

Gordonjcp (186804) | about a year ago | (#41732711)

I wrote an SDR display widget that shows the output as a spectrum analyser trace instead of a waterfall, but it wasn't as useful as a bandscope. It's a Small Matter Of Programming.

Re:Realtime spectrum analyzer (1)

Gordonjcp (186804) | about a year ago | (#41732765)

Oops, hit post instead of preview.

Anyway, scanning from 100Hz to 2GHz in 20ms really isn't going to happen, because there's just no way to generate a sensible sweep that quickly. You're either going to miss massive chunks, or scan slowly. There are a lot of tricks you can use (DDS, "magic number" synthesis) to speed up the lockup time but it's nontrivial to scan any wide bandwidth like that.

I'm not sure why seeing DC to light on one screen would be terribly useful, anyway. How wide would a single SSB or NBFM transmission be on that scale?

Understandable (0)

Anonymous Coward | about a year ago | (#41729363)

Well.. it's understandable that DARPA wants to funds like SDR. It would be good that soldier just carry 1 radio (instead of several like now) in order to connect with their peers/superiors. If you want to talk to terestrial secured phones you need one radio. To talk to HF you need another one. To talk to satellite civilian you need another. Another want if you want to talk to MILSTAR sats. Having 1 radio to do the communication in multi-freq, multi protocols, multi comm-mode (Burst, CW, SSB, FM, AM, ODFM, you name it) would be a welcome changes for the soldier in the fields. And it make a flexible comm system. Where you can change all the above by just downloading a new software for it (instead of changing to another radio). So, yes i understand why DARPA funds this project.

And actually the military circle know this as you can see on one of their offerings:
http://www.spectrumsignal.com/products-services/carriers-modules/fn-rf-boards/rf-4902/
(Yes, it can be used for communication, eavesdropping & jamming. depend on what you want it to do. It can even stored to hardisk the portion of received band of your choice for later "decryption" by your software)

SDR has been with us for sometimes. The phone that can change protocols from GSM to GPRS, EDGE, 3G, CDMA, EVDO, LTE are in fact processed in the same baseband processor. That's why you sometimes had update for your Radio firmware for your baseband-RF processor.
en.wikipedia.org/wiki/Altair_Semiconductor#Products
wwwen.zte.com.cn/en/solutions/wireless/gsm_umts/201103/t20110314_224013.html

Amateur Radio have for sometimes enjoyed this SDR radio:
www.flex-radio.com
microtelecom.it/perseus/

Even this "cheap" China-made CB-radio is already using SDR for its modulation generation.
cbradiomagazine.com/Radio%20Reviews/Alpha%20Max%2010%20AM-1000/Alpha%2010%20Max%20AM-1000%2010%20Meter%20CB%20Radio%20Review.htm

A good SDR radio can have a high dynamic-range and intercept-point that rival its normal (complicated, multi conversion radio).
www.sherweng.com/table.html

However as you can see also, the price is way above reach for most "down to earth" amateurs. So I would welcome this research that can make the price go down. A US$ 300,- for a complete Amateur Transceiver (be it UHF/VHF combo or even better to include the HF portion of the bands that would be very nice). I definitely would buy one.

Re:Understandable (1)

Mr2cents (323101) | about a year ago | (#41734113)

I recently heard that DARPA projects don't necessarily need to be military related, and that research in the US is traditionally heavily sponsored by the military. In this contract I suspect the goal is not to make some military application, but to get more people interested in SDR and DSP. There might be some shortage in knowledgeable people in this field.

All you need (0)

Anonymous Coward | about a year ago | (#41730659)

All you need is (besides one of these) is a 100MHz IF oscillator and a mixer and you can get HF too! Then you could go from DC to 6 GHz! A 100MHz IF oscillator is basically a 100MHz crystal (about $2.50-$5.99) and a 1 Hz - 200MHz transistor (the guts of the mixer) ranges from $0.010 - $0.10 in lots of 10. Of course there is more than just that, eg: varicap diodes that let you adjust for 1:1 SWR for the tank circuit. But they don't cost much either. Oh and a long wire antenna.

I just want to know (1)

stifler9999 (1184283) | about 2 years ago | (#41736927)

What was written under the blacked out mark?

Syncable? (1)

Casandro (751346) | about 2 years ago | (#41737723)

The next mayor improvement would be if that device was syncable . That way you could set up multiple devices and do MIMO. That's just a tiny thing, but could make a huge difference.
Also ditch that USB port. If you have ever used an USRP you can see that it's mayor flaw is the USB port which is just to slow and unreliable to do anything useful with it. Use Ethernet.

Check for New Comments
Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>