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The Journey of Radios From Hardware to Software
An anonymous reader writes "The New York Times is carrying a story all about the process of replacing radios with software. The article tells the tale of Vanu Bose, son of the man who started the Bose company, and his quest to bring software to what was previously a hardware-only enterprise. He met a lot of resistance in the 90s to his ideas, because processor technology was not up to the task. Now that technology has caught up with Vanu, his software (and other products like it) are increasingly replacing now-outdated hardware components. 'Well-established companies like Motorola and Ericsson now use elements of software-defined radio for their base stations. But Mr. Bose was the first to come to market with software that could handle multiple networks with the same equipment. Software radio appears to offer an elegant solution to what has been a vexing problem: how to have a single handset, like a cellphone, communicate across multiple networks. For instance, the G.S.M. standard, for global system for mobile communications, is used broadly in Europe, and most notably in the United States by AT&T.'"
It's amazing what can sometimes be done in software. You can make a simple AM-band transmitter using a microcontroller and two resistors -- with everything done in software. MCUs are fun!
Paleotechnologist and connoisseur of pretty shiny things.
This seems like a "duh" improvement. If you can hard-wire some logic then clearly you can implement the same logic in software, gaining the ability to update the logic, or make it more flexible in other ways, at the cost of speed and, possibly, power. Haven't there been a number of other devices that have evolved in this way?
Philosophy.
As long as they're not restricted to Windows (see: Winmodems) :D
US businesses that currently accept chip and PIN/signature
It's not that a single software-defined radio is all that important. It's that you can do the transforms on the incoming waveform and then extract N different channels with one signal processing system. That's what's been making cellular base stations go for almost two decades. (All the hard work is on the receive side; transmission is easy.)
First generation cellular base stations (i.e. AMPS) had one big analog card per channel, each heavily shielded from its neighbors. The amount of hardware required was huge, and cell sites tended not to be fully populated with channel cards, so they were easy to overload.
Then things started to go digital, with combinations of analog and DSP components processing the signal. Both GSM and CDMA inherently assume digital processing, and in early systems, hard-wired special purpose components were used. As CPUs get faster, there's a steady trend toward using general purpose CPUs.
It's still rare to actually process RF directly in software. Usually, there's a local oscillator and mixer to down-convert the desired band to a working IF frequency, which is then digitized and processed. So it's only necessary to digitize at maybe 10-100MHz, not up in the gigahertz range.
For lower bands, though, a true software RF receivers are available. These just suck up everything from 0 to 30MHz and digitize it. An attached PC does all the hard work.
GNU Radio.
Companies seem to forget that there is still a market for the simple. It took me two weeks of looking to find a piece of stand alone desktop equipment that satisfactorily met the following requirements:
1) AM/FM radio
2) AC plug
3) Headphone jack
4) Let's try keeping it under $30
5) Doesn't look like crap.
Sometimes, all you want is to listen to the baseball game on the radio. I didn't want to stream online (especially paying the usurious fees charged by MLB). I didn't want to change batteries. I didn't want to bother the folks in the rest of the office. Is that too much to ask, or is it simply not sexy enough for the modern consumer electronics market?
The 'true software receivers' are interesting, but ultimately I think they're overkill once you get out of the HF bands. Maybe this will be one of those 'who needs more than 128k?' comments, but I really don't see any reason why you need to sample the RF directly when you're dealing with VHF or UHF, it just seems excessive. If you want to digitize a 1GHz input, you're going to need to sample it at least 2GHz, and probably significantly higher if you want to do any cool DSP-type stuff. That's gotta start doing nasty things to the system's power consumption.
The satellite communications people have been using block downconverters for decades; every pizza-box satellite dish has one, to take the incoming signal from the feedhorn and drop it down to a level that can be sent down the coax to the set-top box without huge line losses. Some of them can work on fairly broad frequency ranges (like several GHz at once, for some of the Ku-band ones), and are real engineering marvels.
That seems like a much more practical approach for cellphones than a direct-digitization one. I don't know if you'd be able to make one block downconverter/upconverter that would cover all the bands currently used by GSM phones (800-1200 MHz, I think?), but if not, it would be the only part you'd need to change when designing for one region vs another. As long as it used the same IF output, the SDR would only have to be designed around one frequency range, and could be heavily optimized in order to improve battery life.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
I read this and end up believing that my next radio will be delivered to me as a software printout on a sheet of paper.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
I hope it's better than his fathers hardware. Overpriced crap that only clueless people who like to pay too much for popular brand name products buy. And unavoidably bought by millions of car buyers that don't have a choice.
This is absolutely true. Bose products are junk, but years of marketing have convinced the public that they sell "premium" sound equipment.
Buy an alarm clock from a drug store. They often have AM/FM radios thrown in there.
Why does it have to "not look like crap?" Why can't it look like you didn't overspend on sony quality?
Now.. whatever happened to mass-produced small crystal radios? Those'd be interesting for hurricane kits, especially if they could tune the broadcast FM band (but obviously not as an FM receiver. You can still hear FM with an AM reciever, it just doesn't sound all that great. Voice is fine, though.)
Can you be Even More Awesome?!
I'd really like to see this sort of thing being implemented in cell phones. Unfortunately, where I live, the provier with the best rate plans uses CDMA for their network. All the cool phones I'd like to have use GSM. Having a phone that could switch between the two would be freaking awesome.
God is dead -- Nietzsche
Nietzsche is dead -- God
Zombie Nietzsche lives! -- Zombie Nietzsche
Come up with a new division algorithm for sampling RF? Like, divide 3 instead of 2? I am not an EE but I remember reading it
What I don't understand is the reason for switching from DSP's to general purpose CPU's. DSP's usually use much less power and can do work faster if the job fits their design. Is it simply for the conveniences that off the shelf CPU's offer such as easier development because of their ubiquity?
actually, there is gnuradio, which is a project (including available hardware) that lets people experiment with software radio. there are quite a few interesting things the folks from the project have done.
if anyone's interested, more here:
http://www.gnu.org/software/gnuradio/doc/exploring-gnuradio.html
and a bunch of links on wikipedia:
http://en.wikipedia.org/wiki/Gnuradio
Sure, Bose speakers are WAY over-rated, but they do a good job producing adequate* sound from very small boxes by using some dirty electronic tricks. For people with "tin ears" who put a premium on space, it is a winning combo.
As for true high-fidelity "audiophile" sound, they are a joke. There is simply no way to get truly good sound out of a single cone in a box that small. The physics just don't work out.
But if some of the math Bose came up with to make bad speakers is actually useful in a software radio, then hey, give the man his props.
*for most people who are not critical listeners. Remember, tons of people go around listening to 128k or less mp3s on the crappy iPod headphones and think it sounds awesome.
I think the title of this posting could be construed as a bit misleading, in that it says 'radio' but when you read the attributed article, they're talking about cellphones, not things like broadcast radio or other areas where RF transmission and reception are necessary. It may or may not be obvious to anyone, but there's no way that tuned RF circuits can be completely eliminated, at least if you're talking about over-the-air transmissions; you still need to at least provide amplification (which must be a tuned circuit) and impedance-match to your antenna (which again must be a tuned circuit).
In older days, his father Amar Bose's company was made possible because MIT let him have the patent for nothing. Now that Amar is (presumably) a billionaire from his high profit-margin products that gross $600 million a year, he has donated $6 million back to MIT. Whether or not that is generous, given that MIT made it all possible, is a matter of opinion I suppose.
For those who think the Boses should have owned the patents on their technologies outright, and not MIT, it is a complicated issue. I don't know about the Bose's particular cases, but keep in mind that usually PhD theses are not developed in a vacuum: ideas are discussed, topics are suggested, usually the thesis advisor is interested in the topic if not actively working on it already, there is a support staff to help develop it, etc.
I'd like to see the technology used to solve some of the inter-agency communications roadblocks that afflict the USA. Every agency has their own frequencies, protocols and hardware. In an emergency, they often find that they can't talk to any of the other responders. In addition, it would be great if the radios could work with the current cellular networks. This is one of the reasons that the military is investing money in SDR. Many people still remember the soldiers in Grenada who had to request close air support by using a phone card and making a call on a local wireline phone to Fort Bragg.
Mea navis aericumbens anguillis abundat
The Joint Tactical Radio System (JTRS or 'jitters') is currently being tested by the US Army... it aims to be "everything in one box," and it was "originally planned to span a frequency range of 2 megahertz to 2 gigahertz. JTRS has been expanded to frequencies above 2 GHz to satisfy space communications requirements"
:)
That's a direct quote from the Wikipedia article (which looks like it's pretty accurate), located here: http://en.wikipedia.org/wiki/JTRS
I'm in the Army, and buddies of mine have played with it and can attest that "it's pretty cool"
Here's to the crazy ones
If you think that's impressive, think about what has to happen to an aerial to support all those different frequencies.
The aerials for these things are mostly ignored but are nothing short of impressive.
Insert
Any one interested in creating a new breed of software based radio scanners (those radios used to monitor police, fire, ems, and other signals) for modes not supported on current scanners or to add features can bring their skills to:
http://groups.yahoo.com/group/gnu_radio_scanner/
This is a group looking to build on the GNU Radio blocks.
1311393600 - Back to Black
How come an article like this does not contain a link to GNU Radio?
FCC
/http://www.softwarefreedom.org/resources/2007/fcc-sdr-whitepaper.html/
http://www.dslreports.com/forum/r18623835-FCC-says-freeopen-source-software-radio-drivers-are-OK/
Are not particularly practical for FM. Yes, an AM radio can demodulate FM through a technique known as "slope detection". Crystal radios bandwidth slope is so spread out that, even if crystal radios worked well at 88 to 108 MHz frequencies, the recovered modulation would be so small as to not be usable, even though that's wide-band FM. Years ago I had some reasonable luck receiving FM broadcast signals with a home built super-regenerative receiver using a single tube, but that's far from being a crystal set.
I've got a fair amount of experience with crystal sets for the AM broadcast band and even short-wave to a lesser extent. I built the wonderful Heathkit CR-1 back when I was about 11 years old and was able to receive stations from all across the US and even Cuba in the Winter. I built a number of them from scratch, too. Lots of fun, even today, but you do have to have an outside antenna and a ground for them to work at all well.
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
In theory, software (solid-state digital circuits) has huge advantages over hardware. Software offers extreme flexibility, no wear-and-tear, etc. If it worked as well as it should, in theory, there wouldn't be mechanical linkages just about anywhere, anymore. All the controls in your car would be electric, and a significant portion of your car's engine would be gone (no more cam shaft). The same would be true of most everything... If not replacing significant numbers of mechanical components, at least using software to precisely control it, and getting much better efficiency as a result. Yes, your refrigerator, microwave, etc. could all greatly benefit from software control.
There are just two big problems that have made software control a non-starter.
First is customization. Put a spring in the mechanics of an engine, and I can replace it with a shorter/longer/stronger/weaker spring. I can heat it up to weaken it, grind it down, etc... With software, you are given a black box, binary-only, with no documentation on how it works, and definitely no common interface to access and modify it. So every time car companies add another function to their cars' onboard computers, and take away mechanical systems, there's extreme resistance, as buyers know they're out of the loop, and if they want to adjust anything, or if something should go wrong, they can only take it to the select few company-blessed shops, which have paid the necessary bribes to get enough info to do just a few basic things with the onboard computer. And you're entirely screwed if you want more changes than that, because the company doesn't WANT you to, and without man millions of dollars on the line, you're not even a blip on their radar.
Despite what many believe, cost is almost never a problem. For low cost products, low-end micro-controllers can be found for pennies, and even cheaper are the basic I/O elements like thermistors, power meters, transistors, relays, etc. Yet even the dirt cheap processors sold today can do many millions of calculations per second, far faster than could be needed for damn near any products.
Second, and perhaps more important, is reliability. Computer hardware is EXTREMELY reliable. You can go buy a dirt cheap commodity CPU, RAM and MOBO, and be pretty damn sure it will run for 20 years without a SINGLE error. The only big exception to this is power supplies... a marginal one, not supplying enough power will cause a crash, but that generallyonly happens in the case of the cheapest no-name junk. What's more, go up a small step to a high quality MOBO, ECC RAM, redundant PSUs, UPS, etc., and you'll never ever see a hardware-induced glitch.
The reliability problem comes ENTIRELY from poor software, and mostly commonly available kernels, at that. People don't want to believe that, but the facts are that computers are 100% pure math machines, and math is 100% accurate. A computer will do exactly what you tell it to do, but most people are trying to program their computer through several million lines of indirection... If you write, in hex, a simple loop with a bit of processing, a computer will run it error-free, from here until doomsday, but programing a complex system in hex is much too hard, and human programmers aren't perfect enough to do so.
The only real possibility to ensure reliability with reasonable development time is something very much like a micro-kernel. You need a tiny bit (a few hundred KBs) of EXTREMELY-thoroughly audited code, that can very strictly manage memory, do strict input and bounds checking, carefully manage communications between independent modules of code, instantly tear-down and restart any bit of code which shows the slightest signs of an error, and also strictly ensuring real-time operation.
I'm not endorsing any product here. The fact is nothing like this exists. That is why we aren't seeing mechanical systems having components being replaced by software as quickly as they can be redesigned. Open source operating systems
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
People keep on forgetting the KISS principle, "Keep it Simple Stup*d". I can design a simple AM crystal detected with maybe 3 components. No amplifiers, very few points of failure.
An FM detector, a little more complex, but none too bad.
People think software is the cure to all ills. Software is simple the answer to the question nobody asked. Sure you can design a multi PROTOCOL system using Software (CDMA/TDMA, etc), but the underlying HARDWARE is where the real design complexity is.
It takes a skilled analog designer or electrical engineer to design the REAL decoding hardware. Any code monkey can eventually figure out the rest.
I'll stick to my trusty AM/FM/ShortWave radio, simple, elegant, and unlike most CodeMonkey ware (TM), it 'just works'.
Advanced Communications Technologies (ACT) in Australia was doing this with GSM back in 2000 (probably before). AFAICT they never did manage to make it work. Spent millions.
Anyone from ACT/SDR reading this could perhaps fill in more details.
I think the company is out of business now. Here's an early press release:
http://www.rmit.edu.au/browse/News%20and%20Events%2FFor%20Media%2FNews%2Fby%20date%2F2000%2F;ID=poid0yrprddq;STATUS=A
-- Rich
I suspect that the FCC and DHS will somehow control
software defined radio so as to quash most of the great
things that the open source world might come up with.
After all, SDR is really, really threatening to the
status quo in wireless communications.
Unfortunately, the potential revolution in wireless
may mirror the outcome in wired communications:
pretty much the powers that were remain the powers
that are.
If Bose products suck so bad someone should tell Michael Jackson... even during pre-insaity days he was using Bose 802s. If there's anything he ever had done right it was music production. If you look up all the people he's toured with he only picks the best. Along with his studio production people/equipment. I also am a bass player and I went to a show where a guy was setting up to play w/ a SWR "workingman" head through a Bose 802 and I thought it was silly. But then he started playing and it sounded amazing.
Oh, no-
You don't get away THAT easily.
Yes. I would like to see a picture.
Two resistors: A couple of zig-zigs with some 'Omega' symbols attached.
The ummm, third component: "And then a miracle happens"
Please elaborate with a simple schematic of the 3rd component.
Long ago I built a tube radio. The only part I could not have done easily myself was the glass, tungsten and vacuum crapola in the radio tubes. The rest was a snap.
Given a bit of time I could have built them too.
And this was long after the transistor made its appearance
Try and make an IC. You have two weeks.
.
- aqk
F U
I think you've neglected the hard part of producing a functional vacuum tube. I'll give you a hint, it's the first part of the phrase "vacuum tube." You've also failed to mention what you'd use for a getter, but I doubt you'd be able to achieve the high vacuum necessary in the first place, so maintaining it is somewhat less of an issue.
;)
The third component is a microprocessor. Those things have like..dozens of transistors.
I suppose you could say that the software is the magic, but you don't ask for a schematic of software. You ask for a listing.
Can you be Even More Awesome?!
As I said:
;-)
the only part I could not have done easily myself was the glass, tungsten and vacuum crapola in the radio tubes
I remember the Barium and other getters.. As a brief Chemistry student, always wanted to develop that stuff.
And most current microprocessors contain many manymore than like..dozens of transistors.
Like, like I said: Gimme the schematic. Of the hardware.
The software is easy. Or at least it used to be.
But then, when I think about it, could I have drawn a 100' copper wire from ore? Or the cat's whisker? The crystal in the crystal radio was the easiest part!
.
- aqk
F U
"No highs, no lows..."
Having actually swept set of Bose 901's with Audio Precision gear and a calibrated mic, I can tell you that they've got one of the flattest responses I've seen. (Assuming of course you use the big equalizer box that comes with it...)
Problem is people nowadays have become accustomed to "XLOUDPHATDXBASS". People listen to portable radios with the "loudness" switch set to the on position. They listen to radio stations which heavily process their audio with excessive bass and treble, with their stereos which have the bass and treble settings maxed out. They listen to their MP3 player with the "Rock" EQ preset. And they buy home theater speaker systems with 2" cube speakers that only produce 200+ Hz and combine them with a subwoofer that's EQ'ed +10dB with the low pass set at 75Hz.
So now when people listen to a set of decent speakers and hear that "midrange" stuff they haven't heard in years, they think "WTF? oh gnoes! they stoled mah hiez and lowez!" Listen to a good set of studio monitors and you're in for the same disappointment.
That being said, I'm not 100% defending Bose here. "No highs, no lows" is inaccurate. Charging entirely too much money for stuff that isn't *that* great, now that's factual.