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Software-Defined Radio Could Unify Wireless World
mjdroner writes "Technicians in Ireland are testing a device capable of skipping between incompatible wireless standards by tweaking its underlying code. The article states: 'The device can impersonate a multitude of different wireless devices since it uses reconfigurable software to carry out the tasks normally performed by static hardware. The technology promises to let future gadgets jump between frequencies and standards that currently conflict. A cellphone could, for example, automatically detect and jump to a much faster Wi-Fi network when in a local hotspot.'"
I've been researching similar technologies over the past few years because I believe we can see an amazing communications "utopia" by deregulating (or at least minimizing regulations) all the frequencies we're blocking for specific uses.
Software radios are not new technology, but the implementation has been fairly worthless as frequencies are set up for specific purposes. At any given moment in any given area, there is a ton of bandwidth going unused. Frequency hopping is already pretty well documented in how to maximize its use, and power allocation specifications have been out since pre-cell phone days. Combine that with a much wider bandwidth and we can see higher data rates, lower battery usage and maximum bandwidth allocation everywhere you go.
I know the FCC will never give up the bandwidth to the open market -- it is too lucrative for the few who are in cahoots with the licensing body. But I see so much happening just in the WiFi "unreglated" spectrum that I would really love to live in a world where all that analog TV, digital TV, analog radio, digital radio, CB, HAM and every other heavily regulated piece of spectrum could be allocated to being used for just information transmission. Software radios would set themselves to the best frequency possible to maximize transmission distance (as needed) and minimize power consumption (as needed).
What we have now is more kludge than efficiency. Can you imagine how incredible the Internet would be if we had nearly infinite spectrum to use (compared to the limited spectrum we have now)?
Sure, some people will say "What prevents Megacorp YYY from blasting 100,000 watts over every frequency?" That's pretty simple -- energy costs make it prohibitive to transmit anything but profitable data. The FCC has existed long past its useful life, maybe it is time to open up little bits of unregulated spectrum piece-by-piece and let's see what happens. These software radios are a huge step in the right direction.
What's the big deal here? The US military and public safety sectors have been using radios with software defined waveform capability for over a decade. Expensive, but Moore's Law will drive the cost down to make devices using this technology commerically viable.
Before the FCC auctions off the analog TV spectrum for new proprietary, old technological uses (and filling the U.S. government's coffers), the technological community should educate the masses on why doing that could be a bad thing for new radio transimission/reception technologies.
At least the FCC is recognizing some of the newer radio technologies, like Ultra Wideband, and conditionally approving their use (within specified spectral ranges).
Can you imagine what will happen when people find the free hotspots they're providing are constantly saturated by cell phone connections? At least until they firewall whatever protocol a phone would be using to wrap the equivalent of VoIP.
It is because it is basically a software defined radio. You have a DPS and a set of AD/DA converters and a baseband (low freqency) to RF (high freqency) converter.
Only difference here is that they are hacking the firmware for their Atheros wifi cards a bit more than the rest of us.
I think you need to remember that the RF spectrum is a finite resource and as such needs to be managed to prevent noise. Deregulate and you would have people lusing HF to go across town and I didn't pass the ham exams to have some bitch in kentucky's email to her boyfriend blocking DX when he lives down the street.
First, how are you going to get the dynamic range you need for RF intense areas if the radio front end has to remain wide open for octaves?
Second, energy costs for radiating Kilowatts are relatively cheap.
Third, what about the near-far problems with spread spectrum?
Fourth, how do you regulate narrowband emergency frequencies in a spread spectrum world?
Fifth, if you're going to push everyone to unlicensed spread spectrum, how do we resolve interference disputes?
I could go on, but I think you can figure out where I'm coming from. The problem is that if we didn't have radio and we were starting from scratch, you might be able to make a case for this technology. But since you clearly don't know how the standards got to where they are today you have no technical basis for trashing them.
Keep dreaming until you get a clue...
Nearly fifty percent of all graduates come from the bottom half of the class!
Sure, some people will say "What prevents Megacorp YYY from blasting 100,000 watts over every frequency?" That's pretty simple -- energy costs make it prohibitive to transmit anything but profitable data. The FCC has existed long past its useful life, maybe it is time to open up little bits of unregulated spectrum piece-by-piece and let's see what happens. These software radios are a huge step in the right direction.
That's just nonsense. With no regulation at all, no frequency would be safe from a fly-by-night operation disrupting service. TiVos would fly right out of the window because they're all dependant on a show being broadcast on a designated channel at a designated time. If TV channels could be jammed by absolutely anybody, TV as we know it would cease to exist. Radio as we know it would cease to exist. DirecTV, Dish Network, Sirius, and XM would all have their investments in satellites wasted. (Only cable would be safe, because cable network signals spend most of their distance traveled on fiber anyway, and they can sheild the "last mile" of coax against anything given a thick enough wire.)
Of course, your answer to that would be that's the whole point, you want the existing license-holders evicted to free up everything for one big utopian mesh network. That's great on the chalkboard, but fails to stand up to real-world attacks. Just how are you going to avoid man-in-the-middle attacks and eavesdropping? "Encryption!" you say? That's nice, but you can't encrypt routing data. You have to put the address you're headed to outside of the enveleope, otherwise it's not going to get there. Basically, every partisipating router is a chance to be logging, and worse yet tampering with every packet. Meshes don't work as soon as somebody intent on not playing fair joins.
You basically want to obsolite nearly every RF telecom device in existance, and in that system's place subsitute chaos. It's just not gonna fly. Don't bother.
It's easy to see where this will go.
1. They'll be successful, and the world will benefit from their tool.
2. Some two-bit company from Podunk, Indiana, will claim that they have a patent on the technology. A lawsuit causes the court to issue an injunction against using software radio.
3. Some other two-bit company from South Podunk, Iowa, files a suit claiming that software radio diminishes trade opportunities. The US government agrees and bans the technology. They try to get the EU to ban it as well, and a tussle ensues.
4. Large corporations take over the technology and introduce a tiered system of access.
5. Microsoft says they were planning it all along.
In the end, no one benefits from the groundbreaking technology.
Or, at least, that's how these things seem to be going these days.
Did I mention the patent infringement lawsuit?
-- The reason it's called the right wing? Irony.
Same old anarchic anti-government trolls, huh dada21?
Yes, because of all the legacy equipment still in-use. You can't phase it out overnight can you? Everyone is bitching that the FCC is forcing broadcasters to shut-off their TV signal, all the while saying the FCC should be much quicker in forcing OTHER PEOPLE to replace all their radio equipment... no, that's not hypocritical at all.
Actually, it's quite ironic that the organization you want to do-away with has, in-fact, been the force gradually making companies reduce their spectrum use through newer technologies.
Sure, if you take the bandwidth away from somebody else, and use it for your own purposes, you'll get better data rates...
And "maximum bandwidth allocation is just a euphamism for noise all across the spectrum...
No, I can't imagine it being all that wonderful really. How does that solve any of the problems of the internet? Bandwidth would be somewhat cheaper, and you wouldn't be tied-down to a landline, but that wouldn't stop spam, trolls like yourself, DDoS attacks, worms, etc. It wouldn't really increase the content on the web, make it more useful, or make it more accessible to people in poor nations.
While not completely unregulated, the CB band is wide-open, and getting practically no use. Before you start complaining that you don't have enough spectrum for public use, why not try utilizing what is available first?
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
I find it sad that the first post rated "Informative" is almost all political.
Can't we look at this technology without the technology government bashing and utopian (and ignorant) libertarian rants?
SDR is not a new technology, but it is rapidly becoming a good way to do things, as the hardware (digital and analog) to enable it is being designed and built.
Cell phone companies are (or will soon be) using SDR to much more efficiently handle their multichannel cell sites. Instead of having a radio per conversation, or a radio per channel, they can have one or a few radios containing very high speed DSP SDR code. This saves cost and has the obvious flexibility of field upgradeability.
GNU ( http://www.gnu.org/software/gnuradio/doc/exploring -gnuradio.html#software ) has had an SDR project going for quite a while (I do wish they would do APCO P-25 reception, since I don't have the time). Hams have been doing various forms of SDR also - for example, the very narrowband systems that use a PC to do the DSP for HF data communications.
Contrary to what some might think, SDR doesn't give magical powers to radios - the ability to operate on all frequencies at once. Radios have hardware filters in them for reasons that cannot be solved in software: to compensate for the non-linearities in the analog (or digital) software - which especially causes problems in high dynamic range situations. Radios may have to separate signals that differ in power by factors of 10^12 or more, which are relatively close in frequencies. Transmitters have to avoid emitting spurious signals at similar ratios to their output power.
More specifically, if you put two signals (assume sine waves for now) into a non-linear device, it is the equivalent of putting those time-domain functions into a polynomial of degree 2 or more. This means that those sine waves will be multiplied by each other and themselves (and a coefficient which you try to make as small as possible). The result is output at the sum and difference frequencies and the harmonics of the original signals. Non-linearity can crop up in surprising ways. The most common one seen in radio is receive and transmit amplifiers, which are *always* non-linear. In addition, parasitic devices (such as two wires touching each other somewhere nearby) can act as non-linear mixers, generating spurious signals. Anyone who has worked on systems at crowded radio sites knows the fun of tracking down "intermod" signals (which are the result of this process). SDR's do nothing to improve this situation. On the contrary, they may require wider bandwidth amplifiers, which increases the odds of spurious signals. Furthermore, the very process of sampling with non-infinite bit-width A/D's and D/A's is itself a non-linear process that generates mixing.
So SDR still has to deal with the issues at the antenna that analog radios deal with.
Where it gets cool is at the baseband - in other words, at the modulation=baseband level (or in the case of multi-channel receivers/transmitters, at an intermediate level). This is where you take the information you want to send/receive, and convert it into/from the RF representation of that information. A simple example is FM modulation (used in most older land mobile radios - police, fire, cell phones, ham repeaters, etc, and in TV and FM radio broadcast). Here the SDR will take the modulation (voice or music or whatever), and use it to generate the signal equivalent to having it quickly alter the frequency of a carrier wave. Depending on the system, it may literally output a sine wave modulated this way. In other systems, it may generate some intermediate representation that then goes to the radio.
But a far more interesting system might be a trunked narrow-band digital public service radio system (which US public safety organizations are converting to at FCC insistence). These systems are designed for improved flexibility (
The only good weather is bad weather.
We could create an army with self-routing radio communications. But it'd be expensive as all hell.
It would only be expensive to develop. That requires a bunch of smart programmers who are willing to go against the commercial grain. But it's really just a SMoP (Small Matter of Programming. Once implemented, the hardware wouldn't be materially more expensive than the ad-hoc mess that is currently in use.
The real barrier has been the same all along: Commercial suppliers have a strong incentive to try to block communication with the competitor's equipment. This was a large part of why ARPAnet was funded in the first place. And commercial obstructionism still has the upper hand.
To get a truly capable comm system that works with all vendors' equipment and is resiliant to equipment failures (e.g., from a missile strike, an ISP's QoS tactics or a government's censorship) requires some smart programmers who aren't in the pay of any of the vendors.
But once implemented, software can be replicated almost for free.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.