Beta

Slashdot: News for Nerds

×

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!

Universal Radio Grabber: the USRP

timothy posted more than 8 years ago | from the more-than-you-can-eat dept.

189

Nethemas the Great writes "The Universal Software Radio Peripheral or USRP created by Matt Ettus and Eric Blossom gives a new perspective on the radio spectrum, as in just about all of it from DC to 2.9Ghz. With the right software and daughterboards, their USRPs can capture FM, read GPS, decode HDTV, transmit over emergency bands, track peoples movement via their mobile phones, and much, much more. With prices starting at just $550 this new toy is accessible by most anyone."

cancel ×

189 comments

The real question (5, Insightful)

Umbral Blot (737704) | more than 8 years ago | (#15475484)

The real question: how long before it becomes illegal to own or use one?

Re:The real question (1)

japhering (564929) | more than 8 years ago | (#15475511)

The real question: how long before it becomes illegal to own or use one?


If it touches the Cell phone frequencies .. it already is ...

Re:The real question (0, Flamebait)

Tweekster (949766) | more than 8 years ago | (#15475566)

so all transmitters are illegal?

hmm I did not know that. (Most transmitters can interfere with those frequencies already.)

Re:The real question (5, Informative)

zippthorne (748122) | more than 8 years ago | (#15475728)

Transmitters must be licensed. Even your 49 mhz walkie-talkie is licensed. It's not licensed to you specifically, it's type accepted, so the manufacturer can sell lots of them. If you were to modify it to transmit on another frequency, you would have an unlicensed transmitter and therefore subject to prosecution if you actually used it.

It makes sense to license transmitters. The EM spectrum of useful radio frequencies has finite bandwidth, and we must have some plan for use so that the most people can get the most benefit out of it. This includes astronomers, hobbyiests, emergency services, cell-phone users, television studios, and many more. Licensing solves the traffic jam problem.

It makes much less sense to license receivers. The radiation is there, passing through people, even. Frankly, I don't understand why anyone would think that I don't have the right to intercept any signal which passes through my personal space and process it however i please.

But that seems to be the case. Recievers capable of recieving cell-phone frequencies may not be sold. I am unsure of the legality of modifying or building your own equipment for that purpose, but I am sure the cell-phone companies have lobbied hard to make that illegal as well. As a longtime desirerer of encrypted cell-phones, it has frustrated me that they want to transmit "in the clear" and just make it a crime to recieve, especially as equipment from before there were cellphones exists that has no hardware blocks on those frequencies whatsoever. Fortunately, CDMA forces at least a rudimentary level of quasi-encryption.

Re:The real question (2, Insightful)

Intron (870560) | more than 8 years ago | (#15475805)

it has frustrated me that they want to transmit "in the clear"

Where "they" means the NSA, in this case.

Re:The real question (1)

esper (11644) | more than 8 years ago | (#15475904)

No, I rather doubt that it does. I remember hearing complaints about the decision to simply make it illegal for scanners to listen to cellphone frequencies instead of properly encrypting cell traffic going all the way back to the dawn of cellphones, well before we had a War on Terror or large-scale domestic snooping. I expect that this is the work of cheap cell providers and phone manufacturers, not nosy spies.

Re:The real question (1)

ps_inkling (525251) | more than 8 years ago | (#15476085)

The illegal to listen to cellphone frequencies comes from the Newt Gingrich and Clinton [google.com] era. Bah, even before then. Some [interesting-people.org] other [64.233.179.104] bills [cdt.org] . Your congresscritter Billy Tauzin [64.233.179.104] was the original sponsor of the Electronic Communications Privacy Act [wikipedia.org] .

Your searches may vary -- this is enough to get the ball rolling.

Re:The real question (5, Insightful)

egomaniac (105476) | more than 8 years ago | (#15475836)

It makes much less sense to license receivers. The radiation is there, passing through people, even. Frankly, I don't understand why anyone would think that I don't have the right to intercept any signal which passes through my personal space and process it however i please.

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night? After all, her naked body is reflecting electromagnetic radiation into my personal space. Amplifying it into a visible image, digitizing it, and making it available on the Internet seems like a perfectly logical step, doesn't it?

People have an expectation of privacy. They expect you won't be sneaking around peering into their windows at night, and they expect you won't be intercepting and decoding their personal telephone calls. Yes, you have the right to decode electromagnetic radiation. And yes, the callers have a right to privacy. Any time two different rights conflict, one or the other has to take precedence. Privacy is a much more desirable-to-society right than is the ability to spy on our neighbors, and so privacy wins.

Re:The real question (2, Insightful)

makomk (752139) | more than 8 years ago | (#15475952)

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night? After all, her naked body is reflecting electromagnetic radiation into my personal space. Amplifying it into a visible image, digitizing it, and making it available on the Internet seems like a perfectly logical step, doesn't it?

So I take it you think that we should ban all night vision scopes, then? Because that's effectively what's been done...

Re:The real question (1)

esper (11644) | more than 8 years ago | (#15475954)

Yes, but it's quite simple to cater to both the right to listen to the EM spectrum and the right to private phone calls: Stop making/using cellphones that transmit in the clear.

As for the neighbor analogy, you could just say "close your curtains", but that doesn't really hold up because it's something that the neighbor has to actively do to avoid having her privacy compromised. Encrypting cell transmissions can (and should) be automatic and transparent to the user, so the analogy breaks on that point.

The real question-PirateTV. (0)

Anonymous Coward | more than 8 years ago | (#15476026)

So does DirectTV have a right to privacy then?

Re:The real question (4, Insightful)

TheGratefulNet (143330) | more than 8 years ago | (#15476036)

People have an expectation of privacy

in the US?

in the MODERN US?

(have you not been reading the news at all, over the last say, year or two?)

Re:The real question (1)

jrockway (229604) | more than 8 years ago | (#15476046)

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night? After all, her naked body is reflecting electromagnetic radiation into my personal space. Amplifying it into a visible image, digitizing it, and making it available on the Internet seems like a perfectly logical step, doesn't it?


Actually, sounds pretty logical to me. If your neighbor is concerned, she should get some high-tech radio jamming technology called "insulation". Saves on heating, too.

Re:The real question (1)

ultramk (470198) | more than 8 years ago | (#15476057)

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night? After all, her naked body is reflecting electromagnetic radiation into my personal space. Amplifying it into a visible image, digitizing it, and making it available on the Internet seems like a perfectly logical step, doesn't it?

Ok, I'm with you so far.

URL?

m-

Re:The real question (1)

david.given (6740) | more than 8 years ago | (#15476083)

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night?

I'm not sure that's a valid analogy --- there is, after all, a big difference between passive scattered photons that have occurred simply because an object is in a particular space, and explicitly generating EM waves with the intent to communicate information.

Yes, you have the right to decode electromagnetic radiation. And yes, the callers have a right to privacy.

Why? And that's a serious question. Why do you consider there to be such rights?

Talking about 'rights' is dangerous, because using that word leads you to believe that they're automatic. They're not. They are granted to you by the social contract in return for certain services (the major one being that you, in turn, adhere to the social contract). The key issue is that you must pay for them, in one way or another --- these privileges are expensive.

In this situation: can the social contract really afford to decree that people may not listen in to other people's EM-broadcast conversations? I'd suggest not. After all, it's practically unenforcable; there's no way of catching such eavesdroppers, and the only alternative is to go after the equipment manufacturers. Not only is this incredibly hard these days --- as this device is showing --- but doing this is going to have a major chilling effect on all kinds of fields of endeavour, from electronics manufacture to hobbiest radio hams. I simply don't think it's worth it any more. I'd rephrase as follows: you believe that the social contract grants you an expectation of privacy.

Re:The real question (1)

david.given (6740) | more than 8 years ago | (#15476103)

Just to point out that that last sentence shouldn't be there.

(mutters) friggin' textarea boxes...

Re:The real question (3, Insightful)

tacarat (696339) | more than 8 years ago | (#15476140)

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night? After all, her naked body is reflecting electromagnetic radiation into my personal space. Amplifying it into a visible image, digitizing it, and making it available on the Internet seems like a perfectly logical step, doesn't it?

Ummm. Radio transmitters are much more along the lines of your neighbor changing or whatever in the middle of a crowded public area with people that could turn around and watch at any point. Your example, peeking into her window, is more deliberate. For one thing, it's targeted. You knew specifically who you wanted to observe. Another is that she made an attempt to protect her privacy by going inside. In this example, you've taken steps to circumvent this by searching for and exploiting an opening (earn your white hat and let her know her curtains are open).

Personally, I'm waiting for the day when SETI gets sued (or disintegrated) for intercepting alien phone calls. I'm betting the first decoded message is for 1-900-UFO-HOTY

Re:The real question (4, Informative)

drinkypoo (153816) | more than 8 years ago | (#15476228)

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night?

But it is legal. Anything you can see from your property is fair game to look at, at least in the USA. Probably not legal to record it; almost certainly not legal to distribute if you do.

It's totally legal to look at naked people in their own house if you can see them without trespassing. If you choose not to cover your windows you give up your reasonable expectation of privacy.

Amusingly you're not legally trespassing until you have been told to leave, at least in California. Those "no trespassing" signs don't mean shit either, unless your property is completely encircled with fence and you have a gate which is locked.

Re:The real question (1)

DragonWriter (970822) | more than 8 years ago | (#15476245)

So it should be legal for me to use a night-vision scope to look into my neighbor's bedroom window at night?
It should be legal for you to build or own a night-vision scope. (Parallel to owning a receiver that can receive, among other things, the bands that cellular phones transmit in.) It might be that it should be illegal for you to use it for certain purposes.
After all, her naked body is reflecting electromagnetic radiation into my personal space. Amplifying it into a visible image, digitizing it, and making it available on the Internet seems like a perfectly logical step, doesn't it?
Well, no, it doesn't.

Thank You (1)

Tsen Wrath (953066) | more than 8 years ago | (#15475797)

Thank you Matt Ettus and Eric Blossom.. you have taken stalking to all new levels. I am eternally grateful.

Probably already is. (0)

Anonymous Coward | more than 8 years ago | (#15475562)

Probably already is.

If it's just receiving radio, that's probably ok. The hard part would be the transmitting. End users would have to have a license.

I don't give a shit though. I want one.

It seriously pisses me off that the U.S.A. is now almost entirely anti-innovation.

Combination of things like DMCA, software patents, and fascist-like coordination between big business and government has hurt. In a few years I expect all major technological development will be done outside the country.

Fucking bunch of morons in government. It's suppose to be 'In God We Trust', not 'We Trust Money, our God'.

Re:Probably already is. (1)

Beryllium Sphere(tm) (193358) | more than 8 years ago | (#15475629)

It's illegal to sell something that can receive in the bands for cellular voice. Haven't check whether this one's at risk.

Re:The real question (0)

Anonymous Coward | more than 8 years ago | (#15475634)

"The real question: how long before it becomes illegal to own or use one?"

For some radio services, it may already be. One of the tasks the goverment communications regulators must do is to insure that radion devices do not interfere. In the US, the FCC has certain technical requirements and standards that are based on the sophistication of the end user and the intended use. For instance, the "type acceptance" requirements for a 2 way mobile radio for the land mobile service is much tighter than for the Family Radio Service. This is because almost no one but Tommy and his mother care if Tommy's mom is interfered with. On the other hand, a paramedic trying to save a heart attack victim must be protected from adjacent frequency interferande to insure his communications are reliable.

It doesn't matter how sophisticated software is, if unwanted signals cause interferance the basic RF circuits then the signal is permanently damager and possibly unrecoverable. For some applications, a very wide receiver is needed (TV, HDTV, high speed data). Because of that that receiver will allow in strong unwanted signals that will either overload the receiver or reduce the receivers sensitivity to weak signals. These signals will result in signal corruption.

Wether we like it or not, there will be technical requirements that will apply to this radio and those requirements will be the legacy requirements until the regulators figure out how to make a one size fits all regulation.

Depends on the country (2, Informative)

Sycraft-fu (314770) | more than 8 years ago | (#15475646)

In the US it's not legal to have a device that listens in on certian bands, such as cell bands and military frequencies, and other than a few speicifc bands, you need a license for any transmitter. So the transmission components are almost certianly illegal in the US, at least to use. The reciever components, it depends on the range, and if the have holes where they should for given disallowed frequencies.

Now this applies to the US one, other countries do not necessairly have an FCC equivilant that regulates such things.

Re:Depends on the country (1, Interesting)

Anonymous Coward | more than 8 years ago | (#15475736)

The reciever components, it depends on the range, and if the have holes where they should for given disallowed frequencies.

From http://www.privacyrights.org/fs/fs2-wire.htm [privacyrights.org] :

LAWS REGARDING WIRELESS EAVESDROPPING

Is it legal to intercept other people's cordless or cellular phone calls?

The Federal Communications Commission (www.fcc.gov) ruled that as of April 1994 no radio scanners may be manufactured or imported into the U.S. that can pick up frequencies used by cellular telephones, or that can be readily altered to receive such frequencies. (47 CFR Part 15.37(f)) The law rarely deters the determined eavesdropper, however.


The important part is the "readily altered to receive such frequencies." This product seems to receive the entire spectrum by default. I guess you could apply bandpass filters to limit the user, but it would be trivial to bypass those filters.

Re:Depends on the country (5, Informative)

mindriot (96208) | more than 8 years ago | (#15476240)

This product seems to receive the entire spectrum by default.

No. The USRP motherboard is capable of handling anything from DC to 2.9 GHz, but you need the matching daughterboards for specific ranges. Daughterboards [ettus.com] include:

  • BasicRX, 0.1-300 MHz receive
  • BasicTX, 0.1-200 MHz transmit
  • LFRX, DC-30 MHz receive
  • LFTX, DC-30 MHz transmit
  • TVRX, 50-860 MHz receive
  • DBSRX, 800-2400 MHz receive
  • RFX400, 400-500 MHz Transceiver
  • RFX900, 800-1000 MHz Transceiver
  • RFX1200, 1150-1400 MHz Transceiver
  • RFX1800, 1500-2100 MHz Transceiver
  • RFX2400, 2250-2900 MHz Transceiver

Also, you obviously need to have the matching antenna to actually receive something useful in a given frequency range.

Now, whether or not receiving particular frequencies is allowed or not will obviously depend on the FCC and similar regulatory organizations (in most, if not all countries, for instance, receiving police radio frquencies is illegal). Maybe the FCC regulation you mentioned is taking things a bit too far... cell phone standards like GSM are encrypted anyway (unless, of course, you go for a man in the middle attack [wikipedia.org] ).

As to your FCC quote, I suppose the question is whether being able to buy another daughterboard/antenna means it can be "readily altered to receive such frequencies." With respect to transmitting, the FAQ [ettus.com] states that since it's sold as test equipment, you don't need a license. I wonder if the "test equipment" status supersedes that FCC statement as well?

Nifty. (-1, Troll)

r3zurector (964298) | more than 8 years ago | (#15475490)

Ooooo First Reply.

You fail it. (-1)

Anonymous Coward | more than 8 years ago | (#15475519)

You fail it.

Ouch $550 (4, Insightful)

9mm Censor (705379) | more than 8 years ago | (#15475498)

I would hardly call _starting at_ $550 accessable to almost anyone.

Re:Ouch $550 (1)

sk8dork (842313) | more than 8 years ago | (#15475523)

accessible to anyone that would find use of it, or more importantly, mis-use of it.

Re:Ouch $550 (4, Informative)

davidbro (13842) | more than 8 years ago | (#15475559)

Especially since it appears that the $550 gets you the motherboard, without any radio modules. The $550 will get you something that you need to spend more money on until it is functional. I think this is just a case of the journalist not really digging into it more than superficially, but the guy the reporter was talking to should have also pointed out how much a minimally configured system would cost.

At a minimum you will need the motherboard, a radio module, some cable (which isn't cheap, especially for doing higher frequency work), and a useful antenna (those tiny ones they advertise on the website will be fine for higher frequencies, but if you want to do anything else, you are looking at an external antenna and more cable).

However, this is a very cool project. A lot of good will come from this work. But $550 is not the starting price. The starting price is higher.

Re:Ouch $550 (1)

morgan_greywolf (835522) | more than 8 years ago | (#15475847)

Note also that if you intend to do any FPGA programming with the USRP, according to this faq [ettus.com] you will need to spend and additional $300 to get 2 of each of the BasicRX and BasicTX boards for debugging purposes.

With my $550 (1)

slashnik (181800) | more than 8 years ago | (#15475894)

I'd by a Garmin GPS, a Yupiteru scanner and a decent FM/LW/SW radio (not Sony: DRM)

Re:Ouch $550 (1)

RedMagus77 (743500) | more than 8 years ago | (#15476029)

It makes you wonder what basic "accessable price to everyone" is considered. $550 is not in that range though, in my opinion. Also, why would most people want to own one of these kits? Does the average person really want to know or care about what's floating over their airwaves? It seems like another niche item to waste money on.

Re:Ouch $550 (1)

222 (551054) | more than 8 years ago | (#15476096)

SCE head Ken Kutaragi was quoting as saying "It's probably too cheap."

Re:Ouch $550 (0)

Anonymous Coward | more than 8 years ago | (#15475615)

Almost anyone can get a job at second (or third) job McDonald's working minimum wage. Even at part time it should only take a month or two to pay for it. Sounds accessible to me. Perhaps not practical or easy, but definitely accessible.

Sure it is... (0, Troll)

Hamster Lover (558288) | more than 8 years ago | (#15475637)

Hell, it's actually $50 less than a PS3! Buy two at that price, one for each hand so you don't feel compelled to shoot Jack Thompson in the face.

Au contraire (0)

Anonymous Coward | more than 8 years ago | (#15475674)

Compared with trying to produce this functionality any other way, this is very very cheap. It will get cheaper if there is enough demand.

Software defined radio is really where it's at if you're interested in radio at all. It provides a chance to implement anything in the communications text on real equipment. A lab set of these wouldn't even break the bank. Mere begging, wheedling and pleading should do the trick. I'm very excited.

Re:Ouch $550 (1)

Lithgon (896737) | more than 8 years ago | (#15475701)

That's why they said: almost anyone.

Re:Ouch $550 (1)

wild_berry (448019) | more than 8 years ago | (#15475831)

Well, you've got that kind of money to thow on a Playstation 3 don't y... ...oh.

P2P Telephone? (3, Interesting)

Mantrid42 (972953) | more than 8 years ago | (#15475501)

My first thought on seeing this is, if it can simultaneously recieve and transmit, couldn't you create a truely decentralized telephone system? With the NSA wiretapping everything, isn't a simple solution to just take away the wires?

Re:P2P Telephone? (2, Insightful)

CRCulver (715279) | more than 8 years ago | (#15475552)

Amateur ("ham") radio operators have had a decentralized telephone network for almost a century. However, the FCC regulations governing transmission on bands accessible to the public require that no encryption be used so that the FCC and volunteer ham regulators can monitor activity.

Re:P2P Telephone? (1, Insightful)

Anonymous Coward | more than 8 years ago | (#15475594)

Because broadcasting your conversation is much more secure?

Or maybe because warrants aren't required to listen in on wireless conversations so there's no controversy?

Re:P2P Telephone? (2, Interesting)

Wesley Felter (138342) | more than 8 years ago | (#15475630)

If you want some sort of wireless P2P phone system, you'd probably be better off starting with a PDA with a high-power 802.11 card in it. SDR sounds like overkill.

Re:P2P Telephone? (2, Insightful)

misleb (129952) | more than 8 years ago | (#15475677)

Each device would need a unique channel and each device would need to be able to transmit the total distance bbetween any two phones. And that just makes wiretapping easier. For everyone, not just the NSA. Really, the simple answer to wiretapping is just encrypted VoIP. And if you want wireless, use a WiFi phone.

-matthew

Re:P2P Telephone? (2, Interesting)

Eravnrekaree (467752) | more than 8 years ago | (#15475730)

I dont think using radio signals, instead of wires is really going to help your privacy much. How is transmitting something over the air where anyone can recieve it better than sending it over wires, which someone has to tap into physically?

If you really want privacy, what you want is some really strong, good encryption. I would, if you are paranoid, encrypt your messages many times each time with a different key.

People often claim wireless is the solution to everything. It definitely is not. RF spectrum is very dear and limited, and there are often quite a few fights over who will get to use which bands. Its not an unlimited resource. Fiber optics can deliver far greater data capacity than wireless ever will.

Re:P2P Telephone? (1)

Intron (870560) | more than 8 years ago | (#15475849)

How is transmitting something over the air where anyone can recieve it better than sending it over wires, which someone has to tap into physically?

Radios don't have an IP address.

So what? (2, Informative)

Slithe (894946) | more than 8 years ago | (#15475937)

IP Adresses can be changed, and MAC addresses can be spoofed. If you are TRULY paranoid, connect to a random Access Point with a spoofed MAC address and talk using an encrypted VOIP connection. Simple, easy, and cheap (you can buy a laptop, microphone, and wifi card for less than the cost of the USRP motherboard.

Re:P2P Telephone? (1)

billcopc (196330) | more than 8 years ago | (#15475998)

Thing is, the NSA doesn't physically "tap" into anything anymore, they just get the telco to send them a copy of the audio stream. This way they can monitor as many people as they like, simultaneously. Heck, they could keep archives of every single call you make, automatically. Sure it requires massive storage, but what's money when you're the government ? :P

How is this legal? (4, Interesting)

Valdrax (32670) | more than 8 years ago | (#15475504)

Aren't radio transmitters/receivers legally required to not be able to access certain bands without proper licenses?

Re:How is this legal? (1, Redundant)

vinn01 (178295) | more than 8 years ago | (#15475569)

I know that certain frequencies must be blocked by any radio receiver sold in the US.

A friend of mine bought WinRadio from Austrailia in order to get the full spectrum version.

Re:How is this legal? (4, Informative)

prichardson (603676) | more than 8 years ago | (#15475591)

From their FAQ... http://www.ettus.com/faq.html [ettus.com]

Are there any license requirement for the transmit or transecive daughterboards?

The USRP is sold as test equipment, which has no licensing requirements. If you choose to use your USRP and daughterboards to transmit using an antenna, it is your responsibility to make sure that you are in compliance with all laws for the country, frequency, and power levels in which the device is used.

Re:How is this legal? (3, Informative)

Bloke down the pub (861787) | more than 8 years ago | (#15475992)

The USRP is sold as test equipment [...] If you choose to use your USRP and daughterboards to transmit using an antenna, it is your responsibility to make sure that you are in compliance with all laws
Reminds me of a story I heard: during prohibition, you could buy a health drink that was basically grape juice concentrate. The instructions said something like "Do *not* dilute and certainly don't add yeast. If accidental yeast contamination occurs, don't even think about leaving it in a warmish place for roughly two weeks".

best thing since sliced bread (1)

itak.karstaag (913380) | more than 8 years ago | (#15475518)

Now we can stalk the girlfriends we don't have and spam emergency bands with crap!

In all seriousness, though, this sounds like a lot of fun. The legal uses, I mean.

Uh, prices don't begin at $550 (4, Informative)

drinkypoo (153816) | more than 8 years ago | (#15475536)

Just the motherboard is $550. You will need at least one daughterboard to actually do anything. The cheapest ones (2-200MHz transmitter, 2-300MHz receiver, 30MHz transmitter, 30MHZ receiver) are $75 each. In order to just transmit, you will need to spend at least $625, unless you are a member of "TAPR, AMSAT, SARA, or SETI League" in which case you get $25 off the motherboard.

Interestingly, though the sales page lists "extra" power supply, usb cable, and standoff sets, nowhere on the sales page does it actually say that the unit comes with any of these things. If you're going to run a business, run it right.

Re:Uh, prices don't begin at $550 (1)

slashhax0r (579213) | more than 8 years ago | (#15475750)

Everyone needs to quit bitching. This thing is great. Look at what a "DC to daylight" ham rig costs you.. and you have no where near the control.

Re:Uh, prices don't begin at $550 (1)

drinkypoo (153816) | more than 8 years ago | (#15476207)

I'm bitching more about the story submission than anything else, although I do think the website is incredibly unprofessional. If they like fielding annoying questions in email, like does it come with the basic stuff you need to use it, then that's OK with me, I just think it's stupid. The price is great, but the story submission is dumb.

Homebrew SETI? (5, Interesting)

superdan2k (135614) | more than 8 years ago | (#15475541)

Imagine a not-quite-Beowulf cluster of these -- your own homebrewed VLA. It'll receive in the "waterhole band" [daviddarling.info] , and VLBI [wikipedia.org] ain't too hard to figure out. Set up enough ground stations and switch between them as-needed to compensate for what you're viewing and the rotation of the Earth, and you've got a fulltime radio telescope with a dish effectively as large as the earth, whenever you want it...

Open source radio astronomy anyone?

Re:Homebrew SETI? (1)

MrShaggy (683273) | more than 8 years ago | (#15475766)

Upon opening the box, you can exclaim, 'Oh my GOD! Its full of STARS!'

Re:Homebrew SETI? (1)

sik0fewl (561285) | more than 8 years ago | (#15476210)

We could call it... SETI@home!

Whee! (1)

houdini_cs (876959) | more than 8 years ago | (#15475551)

Looks like a fantastic project piece, but the price tag means I won't have one any time soon. $550 is steep for a toy.

Re:Whee! (1)

Ryz0r (849412) | more than 8 years ago | (#15475784)

>>$550 is steep for a toy.

Try telling that to Sony..

Re:Whee! (1)

houdini_cs (876959) | more than 8 years ago | (#15475867)

I don't own an XBox 360, and I probably won't buy a PS 3. You could say I've already told them :)

Open Spectrum (1)

Doc Ruby (173196) | more than 8 years ago | (#15475565)

Who's got the rest of the software that combines multiple SW radios with phased arrays of smart antennas [wikipedia.org] ? A mobile "phone" that can transceive in any band without any required registration (of frequency, time or code) because its signal is unique due to its unique spatial position. Bandwidth would be limited only by the power efficiency of the electronics.

Nothing new here... (4, Informative)

Jizzbug (101250) | more than 8 years ago | (#15475579)

It has been on the market since Nov. 2004.

http://www.comsec.com/wiki?UsrpProgress [comsec.com]

Re:Nothing new here... (0)

Anonymous Coward | more than 8 years ago | (#15475712)

I'm glad some other people feel the same way, this has been covered on Engadget, Boing Boing, Digg, and now Slashdot because some 'intrepid' Wired reporter found it finally after nearly two years. I've had my USRP ever since it was mentioned on the Open EEG newsgroup, some other electronic hacker forum, or just typed 'open' in front of radio in Google. Figured by now this was common knowledge since Matt Ettus was even at the last Make conference. Omg btw have you heard of the Open EEG project too? I should be a Wired reporter.

NOW I can finally (3, Funny)

EW87 (951411) | more than 8 years ago | (#15475584)

Stalk Vida Guerra via cell phone...

Cracking satelite using regular TV card (1)

yoriz (979805) | more than 8 years ago | (#15475642)

There already exists some software that decodes some protected satelite channels using a regular Hauptpage TV card. Does that work by (ab)using the Hauptpage to only pick up the signal and then do all the processing *in software* (similar to the USRP in the article) rather than using the Hauptpage hardware?

If so, that would mean were already able to do TV decoding in software for years!

Re:Cracking satelite using regular TV card (1)

elleomea (749084) | more than 8 years ago | (#15475704)

There are many TV/DVB cards that do their processing in software, it's probably one of these cards that you're refering to rather than somehow forcing a hardware decoding card to output the unprocessed data. I can easily receive the encrypted DVB-T channels with my Hauppauge Nova-T USB device (though I've made no effort to try and decrypt them).

Re:Cracking satelite using regular TV card (1)

Xciton (84642) | more than 8 years ago | (#15475959)

No no no. The two projects are COMPLETELY different. Please don't compare the two together. The real magick is USRP. Satellite receiving and decoding the digital into MPEG while descrambling is nothing new.

USRP (soft radio) is a totally different concept in tuning and demodulation.

People vs. FCC (1)

novus ordo (843883) | more than 8 years ago | (#15475661)

"It enables everybody to be a broadcaster," he says.
Not quite [freeradio.org] .

some misconceptions in the posts (0)

mdmarkus (522132) | more than 8 years ago | (#15475675)

Some people both here and in Wired's comments are concerned with this being used to transmit. Nothing in the article talked ab't transmitting; this is a receive only technology. When they're talking ab't using this for radar, they're doing it passively; using the existing commercial FM transmitters as the basis signal being reflected (for this, i think multiple antennas will be necessary).

Also, so far as i know, in the US, there's no restriction on what frequencies can be listened to. In the UK, i think there's licensing issues, but nothing should restrict this in the US.

Re:some misconceptions in the posts (1)

mdmarkus (522132) | more than 8 years ago | (#15475719)

Ok, reading further (on the USRP FAQ page [ettus.com] ), i see that they are selling transmitters (and transceivers). They push the legal compliance to the user which might not hold up, but let's see...

Re:some misconceptions in the posts (1)

elleomea (749084) | more than 8 years ago | (#15475725)

Transmission modules are available, the motherboard doesn't have transmission capabilities but many of the daughterboards available for it do.

Re:some misconceptions in the posts (1)

jrockway (229604) | more than 8 years ago | (#15475739)

This is wrong, the GNU Radio software has no trouble transmitting. I believe that an 802.11b card is being worked on, for example.

No restrictions in the US? (1, Interesting)

Anonymous Coward | more than 8 years ago | (#15475774)

Think again...
http://www.afn.org/~afn09444/scanlaws/ [afn.org]
Let freedom ring...

Sorry... not universal (3, Funny)

modmans2ndcoming (929661) | more than 8 years ago | (#15475679)

It can not capture Zero-Point Energy, so it is NOT universal.

decoding HDTV? (3, Interesting)

mackermacker (250587) | more than 8 years ago | (#15475708)

Ok, I must be missing here (the details of HDTV were not very specific). Do other people NOT decode HDTV, and is that milestone? Any product by DVICO will also decode HDTV. My Dvico USB unit decodes it. All you need is an antenna. Granted, only local stations are picked up. But it doesnt matter, you can copy everything else too using other methods. Is he referring to cracking the RCE broadcast flag that certain HDTV channels have (INHD/INHD2 in certain areas?). Does my comcast box not already decode HDTV? I guess I don't fully understand the issue. Even if the RCE broadcast flag is set in the HDTV content, you can still plug in a firewire cable (at least in the Motorola/comcast boxes), and output to your workstation, capturing the raw .ts HDTV streams. All the ports are already open (as required by law), just no firmware for the boxes. YOu can even verify the active firewire using the command power-select-select, then going to section 11 and verifying the active ports changed from 0 to 1. Once you have these .ts streams saved, you can output back to your HDTV using DVI if you have it. And doesnt the RCE flag (again, required by law) require you be able to save it at least ONCE (common for pay-per-view on demand). In that case you capture it while it is playing, and you still get it. You don't have to respect the flag, it's up to the client (comcast). If they didn't though, they would loose all their advertising money. However, I don't know why a client on a workstation would need to repsect the broadcast flag. And if you are that interested in saving your HDTV content: http://www.avsforum.com/avs-vb/showthread.php?s=&t hreadid=353608&highlight=windows+xp+firewire [avsforum.com]

Re:decoding HDTV? (5, Informative)

TheRaven64 (641858) | more than 8 years ago | (#15476127)

The Slashdot summary was monumentally bad. My first thought on reading it was 'this sounds like the kind of thing you could use with GNU Radio." Clicking on TFA, I discovered GNU Radio was in the article title. Strange how Slashdot, usually GNU-obsessed, would miss that out.

GNU Radio is a pretty amazing piece of software. I attended a talk about it at Linux '05, and was amazed by the capabilities. When they say they are decoding HDTV, they mean that they are doing it in software. All of it. Not just decoding the MPEG-2 streams, but everything this side of the analogue to digital convertor. They are not running it through a decoder box and grabbing it from a FireWire connection, they are capturing the radio signals, converting them into digital signals in hardware and then doing everything else in software.

The basic architecture of GNU Radio is a filter API. Individual filters are written in C++ for performance and then they can be joined together and controlled with Python, making the barrier to entry very low for anyone who wants to tinker with it. Don't be fooled into thinking you need an expensive receiver like the one in TFA to play with it either, it will accept input from a large number of ADCs, including sound cards. You can use it to apply transformations to any digital waveforms.

You can use it to implement something like 802.11 entirely in software, generate telephone dialling tones on your sound card, modulate your voice to sound like a Dalek, decode HDTV signals, or a huge range of other things. It turns your PC into a hugely powerful programmable DSP.

The hardware in TFA is just icing on the cake. As I recall, the specs for a slightly simpler model are available from the GNU Radio site, so you can build one yourself if you have (a lot) more time than money.

Re:decoding HDTV? (1)

gfilion (80497) | more than 8 years ago | (#15476175)

Ok, I must be missing here (the details of HDTV were not very specific). Do other people NOT decode HDTV, and is that milestone? Any product by DVICO will also decode HDTV. My Dvico USB unit decodes it.

The milestone is that it's done entirely with open-source software, instead of a proprietary chip.

I hear hype... (2, Informative)

SuperBanana (662181) | more than 8 years ago | (#15475747)

"Here," he explains, "I'm grabbing FM." "All of it?" I ask. "All of it," he says. I'm suddenly glad the soundcard isn't working.

Not quite- in order to fit the swath of FM radio into that USB2 pipe, it isn't sampling it in any great detail. If you tried to decode one station, it'd most likely sound like a tin can, unless you sampled a narrower slice of the FM band. So don't get too excited. Claiming the motherboard or these devices are "universal" is extremely misleading. You buy modules that transmit or receive on different bands. They're usually pretty wide in frequency spectrum, but they also generally aren't anywhere near as good as dedicated receivers for those bands, and they're not "universal."

Claims of being able to receive GPS are also misleading- you'd be able to decode individual satellites and perhaps obtain a fix within a mile or so, but getting accuracy anywhere near what a $100 handheld GPS unit can do, would require incredible timing accuracy that board just doesn't have. Remember...GPS works by timing how far radio waves w/time signals take to travel...down to about 10 feet in some cases. Think hard about what kind of timing accuracy and precision that requires.

Re:I hear hype... (4, Interesting)

David Bengtson (87963) | more than 8 years ago | (#15475808)

Sorry, GPS location requirements don't rely on the timing on the board, all of the timing and position is derived from the received signal. You need to be able to receive 3 or more satellites for a fix. There are several folks working on GPS receive applications for the USRP right now.

Dave

timing BETWEEN SIGNALS, nanosecond range (2, Informative)

SuperBanana (662181) | more than 8 years ago | (#15476226)

Sorry, GPS location requirements don't rely on the timing on the board, all of the timing and position is derived from the received signal. You need to be able to receive 3 or more satellites for a fix

I don't think you understand how GPS works. Simplifying- a GPS receiver looks at when signals with the same timestamp arrive, and deduces how far it is from each satellite from that. If a signal from Satellite A saying "hey, it's 12:01:05 right NOW arrives a second after a similar signal from Satellite B, then the receiever knows that it is 1 light-second further away from Satellite A than B (this is a gross exaggeration of the scale of time involved.) With 3-4 satellites, you get a position fix.

Modern receivers can track 12-20 satellites at once and get accuracy down to 10 feet or so. There are two things the receiver must do which are timing-related:

1)Figure out what time it -really- is, so it can set an internal chronometer, so it can know the exact distance it is from satellites, versus relative distances

2)Record as exactly as possible when each satellite's particular timestamp came in

Both require -staggering- accuracy that a PC, or your USRP board, are incapable of providing. Clock skew considered perfectly acceptable in a PC is considered monumentally inaccurate in a GPS receiver...and the timing resolution isn't anywhere near good enough either. You're talking about comparing timing in LIGHT FEET, and light takes 1/299,792,458th of a second to travel a meter. It's about one NANOSECOND a foot, so you need resolution exceeding 10nS.

You've got to do a lot of signal processing to ignore spurious signals, as GPS signals love to bounce off some things, and get absorbed readily by others. You've got to have an incredibly low noise, highly sensitive receiver, as GPS is readily absorbed by just about anything, and that includes trees.

The current state of the art is SiRF's SiRF-3 chipset; I've got a Garmin handheld with one, and I can get a 30 foot position lock inside my house, under treecover. I can get a 10 foot lock if I'm outside with enough satellites in view and a WAAS differential signal. I'd -really- like to see you try to beat that.

Re:I hear hype... (5, Informative)

lowen (10529) | more than 8 years ago | (#15476099)

I have two of these personally. At PARI we have four of them. They work. And work well, for radio astronomy.

As to capturing the entire FM band at one fell swoop, I know for a fact that the USRP and a good USB 2.0 High-Speed host can sustain 32MB/s transfers. This becomes an actual sampling rate of 8MS/s in quadrature, which means a full 8MHz band can be sampled at 12 bit precision. The FM band is 107.9-87.9=10MHz wide. At 12 bits, no, you can't get the whole band in. However, the USRP can go 16MS/s at 8 bits (again, in quadrature, which effectively doubles the sample rate), and consume 32MB/s across the USB. Since FM (frequency modulation) doesn't require large dynamic range in terms of bit depth, it is possible that you could get nearly full fidelity audio out of all FM channels simultaneously: but you would need one big honking PC to demodulate in real-time.

As I am a licensed Amateur, I can use this as a transmitter, in the bands and with the modulations to which my license class is allowed. I have the 400-500MHz transciever board; I am of course limited to the 70cm Ham band for transmission, and I of course honor that. It works quite well.

For radio astronomy, I have the DBS_RX board, and it directly tunes several radio astronomy bands, including the Hydrogen line at 1.42GHz. It works quite well for both continuum and spectrum studies, although I still have some bugs (with considerable help for the GNUradio project and other programmers) to work out.

Re:I hear hype... (4, Informative)

lenhap (717304) | more than 8 years ago | (#15476215)

You obviously read the article, but did you think to read any details on the actual device? The baseboard/motherboard has a ADC that can capture 10 million samples per second at 12 bits per sample. So doing simple math and ignoring protocol overhead to transmit all 10 million samples would require 12bits per smaple * 10 million samples per second = 120 million bits per second. USB2 has theoretical bandwidth of 480 million bits per second, so the rough back of the envelope calculations would suggest that the full 10 million samples the ADC can capture could be transmitted to the computer over USB2.

So if we assume that the all of the data can get to the computer, could the device grab all of the FM in such a format that it could be "decoded" into normal FM quality audio? Short answer, yes. The daughter cards for the baseboard/motherboard convert the signal down to an IF (intermediate frequency) within the range of the ADC. If you really want to know how IF and all that stuff works, look up FM radio on wikipedia.

What really annoys me is how you try (key word is "try") to explain that this device cannot do GPS. You do NOT need accurate timing to do GPS. Time is part of the GPS solution, so you only need a simple realitively accurate clock. The $100 handheld GPS units don't have anything more accurate than the clock in your pc, which this device would have access to (the clock in your pc, that is). In fact GPS is often used to provide timing for applications like NTP servers. Again you would need one of the daughter cards to convert the GPS signals down to an IF. The actual GPS signal (C/A-Code) is transmitted in the L1 band (1575.42 MHz) which when converted down to an IF could be handled by the ADC in the device. From there you would only need to aquire 4 satelites to get a simple PVT solution (position, velocity, and time). And, FYI, GPS in certain applications and situations can give accuracy to within cm range (mm range if using differential GPS and post processing which this device could do).

So before posting as if you are an expert, look up some stuff on what you are writing...or at least explain that you aren't positive on how everything works but you don't think it could do what it claims. And yes, I actually work doing military GPS for a company and have a BS in EE with a concentration in communications (so I should hopefully know what I am talking about).

Well (1, Interesting)

Anonymous Coward | more than 8 years ago | (#15475788)

People, keep in mind, this is a dangerous tool. A simple software patch could make this into a GPS jammer or satellite distress beacon spoofer. Or, it could jam cell phones, emergency frequencies, listen in on cell phone conversations (I read something about the encryption being cracked years ago?), ignore the HDTV broadcast flag, allow you to emulate someone else's cell phone, send the cops away on another call by jamming or overriding dispatch, jam 802.1 networks or allow you to wardrive from extreme distances (since the tranceiver is NOT subject to the power limitations of standard network cards, combined with the right antennae you could break into any network within line of sight). You could start a pirate HDTV station on an unused piece of spectrum that broadcasts 100% porn.

Phrasing it that way, this sounds kind of cool, but you bet your ass they will make these illegal

Miserable future... (1)

Ryz0r (849412) | more than 8 years ago | (#15475885)

From the Article:

"Ettus paints a picture of radio bringing about a many-to-many revolution, like blogging, but for a wider segment of the world. "It enables everybody to be a broadcaster," he says."

I think i prefer Orwell's future! Imagine turning your USRP enabled TV on and catching this:

"And Now, Coming To You Live From Sophie's Bedroom, Iiiiiiiiiiiiiiiiiiiit's: FEED THE CAT!!
Tomorrow, Tune In For EmoJake's Visual Guide: Getting the Most Attention from Cutting Yourself with the Least Amount of Pain!"

Similar package for less than $600 complete (2, Informative)

ps_inkling (525251) | more than 8 years ago | (#15475926)

The ICOM PCR1500 [universal-radio.com] (Japanese [icom.co.jp] ) already receives everything from DC to 1.3GHz (minus analog cell frequencies, unless you're a government user). No additional modules required, and uses USB and fairly open software controls.

Or, for even cheaper ($350), Ten-Tec's RX-320D [tentec.com] , with digital radio. Everything from DC to 30MHz (shortwave).

I've never used any of them, your milage may vary, etc.

Erm... not exactly everything. (1)

acid06 (917409) | more than 8 years ago | (#15476216)

From the same link you provided about the ICOM PCR1500: "Incredible coverage is yours with reception from 10 kHz to 3300 MHz (less cellular and minor gaps)."

Also, the real thing about USRP is that all its processing is done in software. This is important from a "freedom" point of view because hardware can be regulated extremely easily by governments. But this situation is not quite true for software (DeCSS anyone?).

In fact, I think they'd never be able to outlaw the USRP motherboard itself but some of the daughterboards could be. But that's the whole point of it: the daughterboards could be home-made if necessary - they're simple enough and just need to capture the radio signals (since the processing is done in software).

Good for DXing? (1)

elgee (308600) | more than 8 years ago | (#15475944)

I will have to look at this closely to see if it might be sensitive engough to qualify as a good shortwave receiver. It would be cool to control it from my computer. I know some top end receivers already offer that option, but this is affordable.

MythUSRP (1)

Flimzy (657419) | more than 8 years ago | (#15475996)

I'll buy one as soon as there's a MythTV plugin for it!

"the right daughterboards" (5, Informative)

Erandir (578490) | more than 8 years ago | (#15476049)

Be careful of that seemingly innocuous qualification: "with the right software and daughterboards"... both imply serious limitations to the technology.

Firstly, the "right" software: Even with a reasonably fast processor (say 3 GHz) today, you are typically only be able to process, at most, a few million samples per second -- especially if you are performing complicated modulation/demodulation, coding/decoding, filtering and protocol processing. Each sample may require substantial computation, and that limits the number of samples you can process per second. That, in its turn, affects the bandwidth that a processor can address (i.e. how wide a part of the radio spectrum you can "see" at any one time).

Secondly, the "right" daughterboards: To be able to address a wide bandwidth, we require digital-to-analog and analog-to-digital converters with high sampling rates. These are limited by the state of the art in signal conversion technology -- typically a couple of million samples per second if we want a reasonable number of bits per sample (at a reasonable price). Push it beyond that, and we have to be happy with fewer bits per sample (may 10 or 8 bits). This introduces noisiness to the signals being transmitted or received, degrading the fidelity of the software-defined radio.

Also, a daugterboard usually has some form of signal translation hardware ("mixers") to translate the low-frequency signals that computers can generate to and from the higher parts of the radio spectrum. Although broadband mixers are available, they need tunable oscillators (reference frequencies), and these tend to be limited to narrower parts of the spectrum. Also, analogue filters, amplifiers and antennas (which all form part of a typical software radio front-end), usually are limited to specific ranges of the radio spectrum.

In short, software radio daughterboards tend to be fairly application-specific (or at least spectrum-specific). We can do a lot of things in software, but a "universal" software radio needs a lot of hardware swapping. I think that makes it a bit less "universal". It might also push the cost of a truly multi-purpose system quite a bit beyond $550.

But I'm glad to see this technology receiving such mainstream attention, and I applaud the efforts of the designers. I just think that TFA (and the post) could maybe be a bit less sensasionalist.

And yes, IAASDRE.

G-J

Re:"the right daughterboards" (2, Insightful)

lowen (10529) | more than 8 years ago | (#15476168)

The Right Software: The GNUradio stack.
The Right Duaghterboards: The USRP is outfitted with two Analog Devices AS9862 MxFE chips, each possessing two 64MS/s 12 bit ADC's, two 128MS/s 14 bit DAC's, and assorted auxiliary ADC's and DAC's for things like AGC.

The daughterboards themselves are just RF frontends. The DBS_RX, for instance, uses a Maxim satellite receiver chip that quadrature downconverts from the RF directly to plus and minus baseband. One MxFE can do quadrature, and is a good match to the single RF input I/Q output DBS_RX board to 900-2400MHz receive.

The USRP gets this 64MS/s bitstream munged down to a manageable size by use of an Altera Cyclone FPGA, which, using CIC and half-band filters implemented with CORDIC, bitmashes things down to a rate that will fit over the USB 2.0 High-speed interface.

Re:"the right daughterboards" (1)

Erandir (578490) | more than 8 years ago | (#15476321)

Sure -- don't get me wrong. I'm not arguing that good techniques exist for both software signal processing and for analog front-ends: I'm just emphasising the point that these techniques are limited by (a) the computational power of the CPU, and (b) the frequency limitations of the hardware. It sounds as if the daughterboards come with state-of-the-art converters -- this comes at a price. Also don't neglect the fact that, the broader the part of the spectrum you want to receive, the more dynamic loss you have. Roughly, each time you double the frequency of the band you want to address, you lose one bit of precision, because different frequencies "add together" to swallow up your available dynamic range. How far are you willing to push the bandwidth before this dynamic loss becomes unacceptable?

It's great to hear that the front-end uses quadrature conversion! (Well, not that I think this wide range of addressable frequencies would have been possible using any other technology :) But this also comes with a bit of a price -- quadrature converters have inaccuracies of their own, usually introducing spurious components in the transmitted/received signal. There are ways to address this, but, AFAIK the efficient techniques are not quite mainstream yet.

CIC is a great downsampling technique, and an FPGA implementation a very efficient way of getting things done in real time. Once again, kudos to the designers: This really sounds like an excellent SDR implementation. I'm just saying "remember, it still has some limitations".

Even if USB 2.0 can crunch 480 Mbps (let's say 48 MS/s), the "managable size" that fits over USB 2.0 may still be a far cry from the "managable rate" that the processor can handle doing, say OFDM demodulation. I stand by my point that the processor's capabilities represent the fundamental limitation to the bandwidth that such a device can handle. Fortunately, Moore's law plays in our favor here: If we develop the technology now, capable hardware will arrive -- eventually.

Things are a bit more difficult at the antenna side. Even the smartest of antennas cannot cover all the interesting bits of spectrum from LF to V-band. At this point in time, some hardware swapping to accomodate specific applications seems inevitable.

I want to emphasize again: I love what these guys are doing, and the way that they're doing it. I just want the bounds of our current art to be clearly demarcated.

G-J

WinRadio (2, Interesting)

femto (459605) | more than 8 years ago | (#15476094)

Surely these guys should give acknowledgement to WinRadio [winradio.com] ? I first played with one of these around 1995. That particular model was a PCI card able to receive from close to DC through to 3GHz.

Re:WinRadio (1)

suwain_2 (260792) | more than 8 years ago | (#15476351)

How well do these cards handle noise from the computer? For quite some time now, I've wanted to put a handful of cards into a machine and set up a 'scanner' that would log everything to MP3 files. My concern is that every computer I've ever owned has spewed noise over various portions of the spectrum; I can only imagine what would happen if I put it inside a computer. Or are the cards really well-shielded somehow? (And for that matter, are they worth the money? I seem to recall them being very expensive.)

What this is and what this isn't (4, Insightful)

AB3A (192265) | more than 8 years ago | (#15476137)

This is a huge step forward for computer assisted modulation techniques and wide band scanning. However, I should point out one very important limitation: Dynamic Range.

For those of you who are too lazy, read this [radio-electronics.com] .

Now let me point out that while the A/D converter is fast, it only has 12 bits. This will give you about 72 dB of dynamic range. Modern reciever design can yeild dynamic ranges of 100 dB or better (depending on how you measure it). Some day we'll get this performace from 16 bit A/D converters. When that happens, expect the designs of radio to change to software over hardware.

This is the trade off for building a reciever of this sort. There is no free lunch folks...

Re:What this is and what this isn't (1)

John Miles (108215) | more than 8 years ago | (#15476239)

16-bit, 100-megasample+ ADCs are already on the market, actually. The current USRP design is a couple of years old; I'd expect them to upgrade their ADCs pretty soon if they haven't already.

A lot of potential.... (2, Insightful)

DrBuzzo (913503) | more than 8 years ago | (#15476250)

This unit isn't actually that new. I've been looking into software defined radios for a while. They offer a real lot of flexability and power in areas where other hardware is lacking.

With the transition to digital communications, it's becoming harder for the scanner/receiver hobbiest to surf the airwaves. While low-speed signals can often be decoded through a sound card, more wideband communications need another solution. Generally, this means special hardware for each type of signal. Weather satellite data, DVB video, HD RADIO, ATSC Video all require different receivers. And if a format is being broadcast out of band, you could be out of luck.

Software defined radios offer a solution to this, but it comes at a price: because all the demodulating is done in software, it can take a huge amount of computing power to do some very simple receiving. Thus, things like HDTV cannot be decoded in real time.

Also, GNU Radio, while certainly an exciting project, is still in the early and experimental stages. It has not yet reached the point of "general purpose radio reciever/transmitter."

What I'd really like to see is some sort of hybrid hardware/software based recieved, in which general purpose hardware demodulators are able to do most of work, and for greater analysis, or in cases where the hardware is not capable of demodulating a given signal, then software is used instead. Perhaps something which could connect to the IF output of a wideband receiver would be a good first step.

Of course...just because something is a real strain on processing power now, doesn't mean it will be later on down the road...
Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

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>
Create a Slashdot Account

Loading...