Open Spectrum: The New Wireless Paradigm 99
prostoalex writes ""Almost everything you think you know about spectrum is wrong." - starts Kevin Werbach in his working paper Open Spectrum: The New Wireless Paradigm. He touches the possibilities of using open spectrum, and then dwells on such innovative products like software-defined radios, spread spectrum or cooperative wireless networking. Truly informative insight into where the U.S. government stands on the issues of wireless spectrum, where it should be, and how it will benefit society and individuals."
is it just me (Score:2, Flamebait)
Maybe it's just me.
Re:is it just me (Score:1)
Re:is it just me (Score:5, Funny)
So, if I understand you correctly, you're saying that paradigm is ok under the old paradigm for paradigm, but the new paradigm paradigm is unacceptable.
Re:is it just me (Score:4, Insightful)
Hm. I'll have to disagree with you there. Webster's defines "paradigm" as "An example; a model; a pattern." When you think about it, a lot of both business and technology follows patterns. The giving-out-handles-selling-blades method that worked so well for Gilette, frankly, is a "business paradigm." That business model's been tried again and again since then (Compare to today's
And in computer science, there's many different ways of writing programs. For instance, take "object oriented programming." If you use OO principles when engineering your software, you're using an "object oriented paradigm." I see no harm in a scholarly discussion of computer science using the term in this manner.
Yeah, sometimes people throw it around as a buzzword. But don't dismiss a term's applicability to two entire fields just because a few people try to sound impressive by repeating it.
Re:is it just me (Score:1)
I got this candy bar for a paradigms! (Score:1)
not everything (Score:3, Informative)
Re:not everything (Score:1)
Re:not everything (Score:2)
Re:not everything (Score:2)
You know what I meant.
Not really. Presumably you are under the impression that there's some isolated entity called "the government" that imposes laws upon society at will. The truth is much more complicated than that.
Not profits, but they will get their cut.
Please, define "they".
They auction off spectrum now and they will do it if the "paradigm" shifts.
Only parts of the spectrum are auctioned off. Others are regulated, others are completely unregulated, and others are given away for free.
Auctioning is certainly not the only solution. It's probably the best one, though, for this particular problem.
Re:not everything (Score:1)
Re:not everything (Score:1)
Too Little, Too Late (Score:4, Insightful)
They are heavily burdened by debt from Cell and cable modems.
Re:Keep dreaming (Score:1)
NewGenWireless.net
http://www.part-15.org/
Unlicensed, but not unregulated.
It's the perfect time (Score:2)
As we emerge from recession, the smart money will be trying to get ahead of the curve so they can be ready with product when people are ready to buy. The entrenched monopoly players can try to stop this with legislated and regulated restrictions, but there is always a way around if you are creative enough. Any given interest has a proprietary stake in only a very small part of the overall spectrum, and the process is by law required to accomidate the needs and desires of the public at large. What industry strategy could keep all of the spectrum locked up?
Some of the owners of existing licenses are on pretty shaky financial footing anyway, and opening their spectrum for more flexible sharing policies could be a way out. Buy them out and/or compensate them for the money they already sank into licenses and you might be able to create a new commons spectrum for flexible sharing and experimentation. There is so much potential for growth of services that it could easily be way more profitable than any existing plans. Yes, it would hurt some of the entrenched players, but none of them can lock up enough resources to keep enforcing monopoly conditions. This only works if there is a shortage, and it is pretty clear from the paper that the shortage has been only in our ability to be creative about sharing the space. The only monopolies are in narrow bands of allocated spectrum, the rest is pretty wide open if appropriate sharing rules are put in place.
No more! (Score:5, Funny)
Re:No more! (Score:1)
No it is true! (Score:2, Insightful)
Re:No it is true! (Score:5, Informative)
Welcome to the Slashkids Fun-Filled Fallacy Post!
Slashkids:Yay!
Today we're going to learn about The Post Hoc (Ergo Propter Hoc) Fallacy!
Slashkids:What's that?
Well kids, that's Latin for "after this therefore because of this."
For example, you could easily say that eating breakfast causes car accidents, because most people that have had a car accident had breakfast that day.
Slashkids:Ha ha ha!
Or that you started a new job, and then your hair fell out.
Slashkids:Then what caused the hair loss?
Who knows? It could be something in the water, it could be any number of other factors. How do we avoid this type of thinking?
Slashkids:With control group studies, double-blind and random tests!
That's right!
Remember Slashkids, sequential patterns != causation AND correlation != causation!
Next lesson: The ad hoc hypothesis
Slashkids:Yay!
*insipid childrens show music, credits, cut to commercial*
(Sorry, I'm a prick and I couldn't resist
Re:No it is true! (Score:1)
True, it could be any number of factors. The constant, freezing, horid weather. The volcano gasses in the air from the local geothermal plant. The EM Radiation. Or the fact that I hate my job.
But I gotta keep a positive outlook. So the joke here is that were all going bald and sterile from the evil radiation.
Wow, not so funny when I try and explain it.
Re:No more! (Score:1)
Re:No more! (Score:1)
Sure (Score:4, Funny)
Ironically, the FCC has been metric for YEARS! (Score:2)
Obligatory Simpsons Quote (was Re:Sure) (Score:2)
Re:Sure (Score:2, Insightful)
<G> It has about as much chance of taking over all parts of the broadcast spectrum; the most massive/extreme implementation ain't happening any time soon.
But, as the author points out, "Open Spectrum" is already the status quo in the band occupied by 802.11*. More to the point, reserving large chunks of the broadcast/communication spectrum for the exclusive use of single radio or television stations is wasteful.
It reminds me of what Deutsche Telekom was doing in Germany in the early 1990s -- they allowed only 1200 kBD analog modems with acoustic couplers, and required that customers buy or lease them from Deutsche Telekom. Most of the Germans I knew who were online back then ignored DT and bought and installed (then) state-of-the-art 9600 kBD modems.
I know it's ethnic stereotyping to say this, but most Germans I know are a LOT less prone to ignore stupid and pointless rules than Americans are, especially American geeks. ;>
My guess is that, if the technology is developed to allow users to share a spectrum without stepping on the exclusive/analog signal, people will start using it, with or without official approval.
If the U.S. government recognizes that the rules need to change to keep up with the state of technology, all will be fine and good. If, as I expect, the government refuses to change the rules in a timely fashion, I doubt that will change what people do. Washington has bigger concerns than arresting geeks who aren't interfering with anyone, and will catch up with the rest of us eventually. :>
Re:Sure (Score:1)
Being that the TV stations which use those channels for live shots are licensed, they can, and have, taken action against some ISPs whose 802.11 equipment has caused interference to their systems. The SBE (Society of Broadcast Engineers) has lots of information on this.
The biggest obstacle to the "open spectrum" is incumbent users and their investment in current technology... just to displace the lower end of 2 GHz point-to-point users to clear it out for PCS is costing many millions of dollars... according to the PCIA, an average path relocation costs $220,000, and over $250,000,000 has been spent to date to clear that chunk of spectrum for the PCS folks.
So, open spectrum still has a long way to go...
--mws
http://www.scanchattanooga.com/
With public domain frequencies... (Score:5, Interesting)
I would personally love to see open hardware designed to utilize wireless technology available similar to the projects at OpenCores [opencores.org].
Re:With public domain frequencies... (Score:4, Insightful)
I have a question: If you have two different sources broadcasting digitally on the same frequence, then you can seperate the two based on encryption standards or protocols, right? However, wouldn't having both transmitters sending data jam each other's signals? Seems to me like they'd have to hear each other and cooperate in order to work efficiently.
In other words, I don't think you can set up two 802.11 nodes with different SSID's and have them work at full capacity.
I'm really naieve here, so if anybody can explain to me if I'm wrong (or even right) I'd really appreciate it. My education on this topic is very basic.
Re:With public domain frequencies... (Score:4, Insightful)
As for spectrum coexisting, DSSS (discrete sequence spread spectrum) was originally developed for military usage. DSSS provides several advantages - extremely hard to detect or jam, and works very well even when other DSSS transmissions are occuring in the same region.
DSSS used to be extremely difficult to implement, but now is commonplace and cheap.
The whole reason that the radio spectrum is used is because it is an effective way to send information. Technology has provided a way to transmit significantly more information in less bandwidth, except that it is against the law...
An example would be: Suppose that the transportation industry was regulated in the same manner. In the old days, the only delivery option was horse-drawn cart. Now technology has developed trains, planes, and trucks. However, only a few routes are legally available for the trains/trucks/planes to go on - everything else is still regulated to use horse-drawn carts. Obviously, there would be significantly less deliveries across the country.
Re:With public domain frequencies... (Score:2)
Re:With public domain frequencies... (Score:2)
But first - why would you put them next to each other? If you need a wireless network, why have several, when one would do?
There are two answers - first, if you needed to have more connections. The 5.7GHz band for 802.11a has more channels, and hence can support more users simultaneously, at a higher data rate. It has more channels because more spectrum allocated to ISM (industrial, scientfic, medical) use.
Second, if you had two different networks (e.g. you and a neighbor's). And the answer is yes, they would work. However, you might see a drop in the data rate.
Re:With public domain frequencies... (Score:2)
What actually got me thinking down that line was that story a few weeks about about Starbuck's offering wireless service in Portland and it interferred with somebody providing free WS service in the same location. In essence, one was jamming the other.
I think that's why Nanogater brought it up.
I was a Ham Radio back in my youth (10 years old) and the FCC made a HUGE deal about jamming other people. One reason that the FCC tests devices so heavily (like your GameCube or your laptop) is to make sure they don't cause interference with things like TV's.
Now I'm not claiming to know anything about how the FCC works. It is my understanding (polite corrections invited) that a good chunk of what the FCC does is license frequences so that there isn't interference. If you get a Ham Radio license, that's not an instant "you can transmit anywhere!" license. It's a license to use a specific band. When you promote your license, you get access to more frequencies. You also have rules like "You must identify yourself with your call-sign every 5 minutes during a convo." My guess about the reasoning for that provision is to prove you're licensed. (again, polite corrections invited.)
Unfortunately, I wasn't able to read the article (no PDF viewer installed right now. Thus I look even less informed heh.) but I'm working under the assumption that free use of the air waves (at least in a particular band) is being advocated here. Assuming I'm understanding this guy (again, polite corrections or clarifcations invited, sorry I don't have Adobe installed) digital doesn't change the playing field that much.
It does allow one to make their broadcasts public or private. It does make it easier for devices to share a similar spectrum. But, there is still the jamming problem. To be honest, I'm surprised that the Starbuck's case hasn't caused an overblown case for regulation of the 2.4ghz band. The problem is that more and more devices are going to use this band, and people are actively seeking to boost the range of these devices.
If taken to an extreme, a city might Portland could end up with so much noise from that band that nobody'll get a clear signal. Is that likely to happen? I don't know... but it did happen with Starbuck's and
Anyway, that's my concern. I again point out my naievity. If there's a hole in my reasoning I'd really like to know what that is.
That misses the point of the paper (Score:5, Informative)
The rules of and assumptions underlying the way the FCC is carving up spectrum are based on 1930's technology. It assumes transmitters and receivers have poor filters, and cannot tolerate adjacent or overlapping signals. It assumes no spread spectrum or channel agility / frequency hopping technology. Fast forward 70 years. Technology has marched on. Spread spectrum and channel agility are cheap and commonplace. Transmitters meet much stricter tolerances for sideband and out-of-band emissions. Receivers can pick up weaker signals, and much more successfully distinguish their signal from other overlapping or closely adjacent signals. Thus we can now pack several times the data per unit of spectrum than the current rules assume we can. Yet the rules prevent us from doing this on a large scale because the unlicensed bands in which we can operate are so few and small. Users of the licensed bands (most of them anyway, cell phones being the one big exception) have little incentive to deploy these technologies and make maximum use of their spectrum because the rules guarantee them enough free spectrum that they can use older, less efficient technology with abandon, and still get done everything they want to.
THAT is the point of this paper. We shouldn't be asking what if both nodes are at 2.4GHz. We should be asking why does the guy at 2.3GHz get to be so wasteful with his bandwidth when technology now makes it cheap and easy for him to get more done with less, and we're all crammed in here together at 2.4GHz?
Re:That misses the point of the paper (Score:1)
Re:With public domain frequencies... (Score:2, Informative)
If I understand correctly (Score:4, Interesting)
Re:If I understand correctly (Score:4, Interesting)
The idea that spectrum is a limitless resource is a myth, however. The author does say as much somewhere, but mostly he talks as if the spectrum will bear an unlimited number of users, which is bollocks. Having lots of spread-spectrum devices in the same area and frequency band will affect the performance of these devices. If that was not the case, why the hell would we even need to follow the author's suggestion to open up more spectrum for such use beyod the current 2,4 GHz band?
With that said, current analog transmission technology does not make a good use of the spectrum, and assigning a whole band over a large area to one transmitter is terribly wasteful. While I disagree with the picture the author paints in his article, I endorse his plea to make more use of spread spectrum and to assign more bands to unlicenced use.
Re:If I understand correctly (Score:4, Insightful)
No. I think he's right. Certainly, if you reduce the power you transmit to the absolute minimum to reach just the nearest nodes then the bandwidth goes up. Then if you route through the other nodes, the bandwidth goes up. Direction aerials, bandwidth goes up. Optimal filtering to make good effect of the reflections in the room, bandwidth goes up. I truly think that the available bandwidth is very, very, very large. Sure it's lots of extra hardware, and there's lots of processing, but they're getting cheaper and cheaper. Also, as the users, and if properly designed, the room, tends to absorb microwaves, then the amount of bandwidth scales with the number of users- the noise floor just simply doesn't keep going up, since the users get in the way.
Re:If I understand correctly (Score:1)
no, it is not. you just have to make smaller cells. there is no limit (in theory) how small a "cell" can be.
where with normal bands you can't have the same frequency in neighbouring cells, with spread spectrum you can. this gives the spread spectrum a 7 times more data boost from the start. (actually more like 3-4)
Having lots of spread-spectrum devices in the same area and frequency band will affect the performance of these devices.
sure, but, oh, how much better spread spectrum devices are in this regard compared to "narrow band". you can actually tune to multiple transmiters on the same frequency. also, multiple path signal (off the buildings, etc) is actually boosting the signal, and does not interfere with it as with old tech, so you can transmit with less power.
The author does say as much somewhere, but mostly he talks as if the spectrum will bear an unlimited number of users, which is bollocks.
you can easily have 50 times more data transmited compared to old methods. with meshes you can probably do 100 to 1000 times more.
let's say that you put a transmiter and receiver in each house. then you can transmit with low power, and with routing and a new economy model that would support it, everybody can, in fact, have the complete spectrum for himself. think about it, each house a cell.
Re:If I understand correctly (Score:5, Informative)
However, the ideas of Open Spectrum, applied carefully and with good engineering understanding, can indeed significantly increase the usage of spectrum. However, unlike many of the subsequent posters on this thread will assume, it will *not* work without appropriate regulation (as the author recognizes). It is a different and superior method of spectrum management, not spectrum anarchy.
The idea of setting aside spectrum "parks" for the unlicensed services, and then applying strict technical regulations to those systems is the most promising. Setting aside channels 60-69 would free up 60 MHz of very useful bandwidth for mobile and portable applications. The appropriate standards would allow proper sharing of the underlying spectrum without licensing individual users or sites.
However, some of the techniques that allow this sort of operation may not be that inexpensive to create. They will require substantial processor power and probably power consumption. This will limit their use in extremely inexpensive uses (such as keychain transmitters for auto alarms). For these kinds of uses, different spectral parks may be required.
In other words, one may need some spectrum for dirt cheap devices (where an additional $.01 is a significant cost increase), and other spectrum for sophisticated devices where the value allows greater costs. Likewise one may want different spectrum and rules for wide area systems than local ones. Furthermore some systems can tolerate significant random interruption (remote meter reading, for example) while others must work well all of the time in real time (police communications, air traffic control, etc). These may again require different parts of the spectrum in order to be protected from inadvertent interference from nearby non-cooperating unlicensed systems.
Furthermore, one needs to make sure that failure modes of these devices don't screw up a whole area!
Hmmm... this starts to sound a lot different from just turning folks loose on unlicensed bands! It illustrates the complexity and the need for sophisticated standards and associated regulation.
Underlay is IMHO much more dubious than the author lets on.
In practice it can be very hard to do well. Existing narrow-band systems use techniques that *cannot be used* in wideband receivers. The techniques (such as very high Q low loss RF filters) allow the narrow band receiver to operate with very weak signals, signals which could not be adequately detected by a wideband underlay system, and which would then be interfered with by that system. These existing systems are engineered, and regulated, to use the minimum power needed - and thus are inherently susceptible to this new interference.
There are a number of physical factors that limit receiver sensitivity. They range from thermal noise in the receiver to exotic topics such as intermodulation, desensitization, and quantization noise. It is not possible to optimize for all of these in a frequency agile receiver to nearly the degree one can in a narrow band receiver.
In addition, some of the techniques are inherently expensive. Moore's law doesn't apply to the fabrication of precision metal resonators, for example.
What this means is that for an underlay service to be truly non-interfering, it requires either a very expensive, big and power consuming receiver, or it needs to be on a portion of the spectrum where these techniques are not applied by existing users of that spectrum.
Other approaches, such as using spread spectrum - or wideband as the autho prefers -(so you don't have to detect systems you are interfering with) have different problems. A wideband system distributes its power across a wide spectrum, but that power is still not zero. This means that if it is too close to a traditional narrow band receiver, or another wideband receiver it will cause damaging interference.
Overall, however, the Open Spectrum initiative is a good thing and can have enormous economic value. But it should not be viewed as a magic solution or one that can rely strictly on anarchy or unregulated cooperative development.
Re:If I understand correctly (Score:4, Informative)
Re:If I understand correctly (Score:3, Insightful)
The FCC's attempt to regulate this is awfull. It is like no one is alowed to make a peep - accept the people with the FCC megaphones. If people did that with speech, we would see it like one of those pro fidel castro rallies, but when we do it with spectrum (which physics wise is the same) people just take it on faith that without the FCC - we would all be ruined. It is very disheartening.
Re:If I understand correctly (Score:2)
I am reasoning based on an understanding of radio technology and signal processing, including spread spectrum (call it wideband if you wish). The 50,000 people talking in a stadium can be quite enough to keep you from hearing a cricket chirping nearby, but if your particular need is to hear that cricket, you are screwed. And they have no incentive to stop talking so you can hear the cricket.
There are always limits in communications. Furthermore, without rules, there are often incentives to keep yelling louder and louder. This is what caused the FCC to be created in the first place. It is also what happened to the Citizen Band frequencies when the FCC decided not to waste resources enforcing the rules.
Re:If I understand correctly (Score:2)
No, you are reasoning by analogy.
In this analogy, the physics is the exact same for EMF and sound, it uses the exact same mathematical equasions, and has the exact same kind of interference.
I am reasoning based on an understanding of radio technology and signal processing, including spread spectrum (call it wideband if you wish). The 50,000 people talking in a stadium can be quite enough to keep you from hearing a cricket chirping nearby, but if your particular need is to hear that cricket, you are screwed. And they have no incentive to stop talking so you can hear the cricket.
If the cricket is chirping at a different frequecny than everyone else, then you are saved. They can scream all they want, but it would be a cakewalk to hear the cricket.
There are always limits in communications. Furthermore, without rules, there are often incentives to keep yelling louder and louder. This is what caused the FCC to be created in the first place. It is also what happened to the Citizen Band frequencies when the FCC decided not to waste resources enforcing the rules.
The cicizen band problem is analgous to eveyone trying to yell to everyone at the same time. But that's just the real world, just because someone wants to broadcast to everyone with one voice doen't entitle them to do so by shutting everyone else up. That's their problem, not mine or societies. I'm sure we'd survive by finding more polite ways to communicate without locking everyone else out.
Re:If I understand correctly (Score:2)
As for you last paragraph leaving the citizen band problem to the real world, and declaring it isn't your problem. I think that adequately describes your approach to analyzing this problem.
Everything I know... (Score:1)
Everything I know about spectrum is right, because I know nothing about spectrum.
Not unless they refactor the laws for tort ... (Score:5, Interesting)
Courts (in torts against trespass to chattels w.r.t. deciding spam cases) have rules that having an electronic signal impacting on the computer system is sufficient to be "in contact". Now extend this to a generic wireless world and you can see the potential combinations of potential problems. If my wireless car activates someone elses' garage leading to a theft then are you liable? Medical instrumentation are a major concern, as are anything which records ownership (cf person entering building with wireless and downloading trade secrets).
Wireless will change how we interact provided we can sort out how social responsibilities and obligations are partitioned.
LL
Re:Not unless they refactor the laws for tort ... (Score:3, Insightful)
What is your point on the wireless wheelchair? I think that interference concerns are overblown. Circuits need to be designed with care to insure that they aren't susceptible to interference, but they need to be designed that way now. You have to deal with cell-phone towers, microwave ovens, and even fluorescent lights.
Contradictory (Score:5, Interesting)
Improving existing unlicensed bands isn't enough. Most are so narrow and congested that their utility for open spectrum is limited.
So here he's saying exactly the opposite, that congestion is a serious problem for open spectrum! Which is it?
It's also bogus to claim that WiFi proves that open spectrum works. The truth is that WiFi is so sparsely implemented that congestion hasn't yet been an issue. For all the hype, my town of 175,000 people has no wireless public access points. Even in the big cities they're not so close that congestion is a problem.
The article could just as well have used cordless phones and baby monitors (which use the same frequencies) as evidence that open spectrum works. The only difference is that they don't score as high on the hype meter. All these examples prove is that the technology works when the range and distribution of the transmitters is sufficiently limited, which everyone knew already.
Re:Contradictory (Score:3, Informative)
It's a bit of both. The existing protocols lack some features you really need to make best use of the bandwidth, for example, node routing and power control are both absolutely critical, and WiFi does neither out of the box.
Human Nature and The Status Quo (Score:4, Interesting)
He had me until this sentence. Getting the government to act in the best interests of the American people is not on the agenda. The current licensing scheme guarantees profit for the few. The few, in turn, guarantee $$$ to the government. Anything that threatens this simply will never happen.
Re:Human Nature and The Status Quo (Score:2)
Yes, this is the primary danger that might keep anything like this from being implemented anytime soon. OTOH, just like the DRM debates, there are powerful forces on both sides. WiFi exploded onto the scene in the last few years, and a lot of people are making money selling the equipment. They have $$$ to spend on politics too.
The basic competition is between existing network providers who own licenses to pieces of the spectrum and equipment manufacturers who stand to make billions selling hardware. I don't have the numbers in front of me, but I think there is a lot more potential money to be made in harwdare than existing and near term network services.
At some level, I think this is an opportunity for the US to jump ahead of Europe in terms of wireless technology. The 3G stuff is coming on more slowly than expected both because the networks are trying to get as much as they can from their existing equipment, and the fact that the 3G apps are not that compelling. WiFi is also cutting into the potential market for 3G.
You also have to look at how this relates to telcos and ISPs. They want to maximize what they can make from their sunk infrastructure investments, and the telcos have even been pretty successful in squeezing new players off the playing field. I don't really see how that can continue for long. The bottom line is that if established interests succeed in keeping the status quo for a while, they will become completely uncompetetive and disappear when the dam finally breaks.
One of the dynamics is that the US is behind in the deployment of both high speed internet (DSL and cable modem) and advanced celular systems. When growth and investment start to return, the smart money is going to be looking to leapfrog the competition, and the installed base they have to compete with is mostly a generation behind. Some interesting things were already happening before the bubble burst and swept a lot of it away. People are aware of all of this, and could be ready to move quickly when the economy really starts to turn up again.
Cruel and Unusaul Punishment (Score:2, Funny)
Software Defined Radio (Score:5, Insightful)
Um, like uh ok.
Are you likening a radio with a wide receive and transmit to a um Win Modem?
I understand what you mean but I really hate your terminology. Software defined agile radio, OMG lets just make all this kewl stuff sound like a pansy made it.
This really isn't anything new the idea in some forms exists now and has for some time and has been implemented. The only new thing is trying to convince the FCC to allow you to work in unused TV channels and other under-utilized bandwidth because your equipment is smart enough to know there isn't anything in there... ...kewl
Coulda said that in one line rather than such a verbose article.
Re:Software Defined Radio (Score:2)
Re:Software Defined Radio (Score:1)
I've been looking for something that can read RFID tags that uses modern radio design (like using a DSP) but so far I've found nothing.
Re:Software Defined Radio (Score:2)
The point has been made that the specific purpose equivalents will be simpler, cheaper and use much less power than the same thing done with SDR, so you are going to need other compelling reasons to want SDR. The other point is that with time, Moore's law makes the SDR shrink in cost and power to the point that it is practical in a lot of situations. If instead of a car radio, you have a car computer with an SDR, it would be able to do AM, FM, TV, GPS, Digital Radio, ... as well as managing data for the car, and downloading music from your collection at home.
This makes sense..but probably won't happen.... (Score:5, Insightful)
With clever use of SDR, they might not notice (Score:3, Interesting)
Of course, this is the big conceptual problem with Open/Free Source SDR in general. Recieving is fine, but as soon as you want to transmit, the FCC wants to regulate the device. Now you are getting into the same problems you have with Open Source and DRM, if the end user has control, they can circumvent any controls by taking them out and recompliling. Buggy or malicious software could interfere in a big way, although the range of the interference would be limited by limiting the power of the transmitter which couldn't be easily overriden.
I like the paper's analogy to ships on the ocean, and I think it is very accurate for spectrum use. Most of the time you can put on the autopilot and sleep without much danger, but you'd better be on watch to adjust your course when you're near the shipping lanes. In any location, most of the spectrum will be silent most or even all of the time, and most modern recievers are pretty good at cancelling interference, so nobody will even notice if you use nearby frequencies.
The TV bands have all kinds of space in them, and there is all sorts of interference already unrelated to unlicensed transmitters. I'm still using my TV antenna in an urban area, and the big problem is multipath interference from all the large steel frame buildings. I wouldn't have any way to know that unused channels were being used for underlay digital comm., and I wouldn't care much either.
What you say is true....except that... (Score:1)
Re:What you say is true....except that... (Score:2)
BUT...if you try to manufacture and sell them on any large scale, it won't be long before the FCC shuts you down.
That's why it is necessary to get the general concept of SDR transmitters approved. The question is what rules support SDR in an Open Source context. The GNUradio people are experimenting with hardware now, not necessarily in the US, so FCC rules might not come into play. If I understand correctly, you have a wide-band digital front end driving a software controlled radio transceiver. The system software plus the tranceiver define how it can work. Once the radio part is programmed, there is full access to the a wide chunk of some part of an overall spectrum, so you can limit the transmit power, and generally what bands can be programmed in the transceiver, but any fine grained control would have to be in the software.
I'm not saying they can't regulate it, just that any regulation is difficult to justify except basic power level limits, and a requirement not to interfere with other uses. Again, we have a stark choice of either freedom with responsibility, or very intrusive regulation that would have to outlaw Open Source or be unenforceable. You'd have to make it illegal to re-flash your SDR unless you are a certified technition or something.
Also, if you think that receiving signals isn't against the law, think again! ...
Same thing on the receive side. SDR makes a joke of current regulations. If you want your transmissions private, you had better use sufficiently strong encryption. Once the hardware and the software exist, you can't assume it isn't available to an adversary, regulations or not. Again, the only way to maintain the current situation is with silly laws that do nothing to actually protect the communication. Simple prudent operational precautions would tell you not to rely on this kind of protection, and it is irresponsible to do so.
At some level, the right to transmit and receive radio signals are basic freedoms. As the paper points out the transmit side has a natural connection to free speech rights, and restrictions really have to be justified. Although this seems to have been understood when the FCC was first established, and they did it anyway because there was a technical need. If you can transmit without bothering other spectrum users, there should be a presumption that it is ok to do so. On the receive side, I seem to recall that there is legal precident for a basic right to receive signals. I don't recall how the restrictions you mention are handled. A good analogy might be with the windows of your home. Just because something is visible from the street doesn't make it perfectly legal to go out of your way to peek in. Prudence tells you to draw the shades as well if you really care about privacy.
Yes, the RF can be quite bad (Score:5, Funny)
The clock frequency of the Z80 processor is well-optimized for generating long- and short- range RF waves. With the Spectrum case Open, the highly advanced rubber keys act as efficient waveguides, particularly helped by the printed-on aerials (square shapes with one half or one quarter cut out, depending on the phase of the waveform).
The only snag is that due to an unfortunate typo, the Sinclair Microwave communication device ended up as the bizarre Sinclair Microdrive.
Obligatory Simpsons Quote! (Score:5, Funny)
*Blank looks from the managers*
Writer: "I'm fired, aren't I?"
Manager: "Yes."
Open Spectrum means chaos (Score:4, Insightful)
Humm (Score:4, Insightful)
Wow I am so stunned at why anyone gives a rip what these jokers put out.
The head guy, the dude the Washington Post profiled last year, Ted Halstead - President and CEO, he doesn't do research. I work with people that don't do reseach, I call them the Grounds Crew.
He went to Harvard woohoo, Presidents Bush and W Bush went to Yale, having exclusive school deploma doesn't mean one is a genius. Harvard Business School didn't consider anything Internet to be "business" until about 1998-99.
Ooh Hollywood types and CongressCritters like them. Another nail in the coffin of respectablity.
The head joker at NAF is the buttmunch that told Warren Beatty to run for President.
"Previously, Mr. Halstead was Executive Director of Redefining Progress, another public policy institute that he founded to promote new approaches to economic and environmental policy." - Thats alot of words to say "He sat around and talked about cloud-cookoo-land."
"Kevin Werbach" - the guy that wrote the paper linked here - "is a technology consultant, author, and founder of the Supernova Group." He also has some 'leet HTML skillz - http://werbach.com/home.html - He uses a Mac, a point in his favor.
They throw out buzz words and do 20 pages and we are suposed to care why?
Learn from amatuer packet radio ... (Score:5, Interesting)
Protocol smarts can solve this. (Score:3, Informative)
But mobile node A can BE the "third party". If base stations B and C have unique (or at least non-colliding) identifiers then mobile node A can say, as part of its transmission, "I'm talking to B." or "I'm talking to C."
There are variants that work even if mobile node A is saying "Who's out there for me to talk to?". Look at the IP address resolution protocols for working examples. For starters, the a similar case arises on an Ethernet when a machine that wants to be booted uses RARP, broadcasting its Ethernet address and asking potentially redundant servers for its IP address. (Granted the servers COULD hear each other. But the protocol works even if they can't.)
Won't Work (Score:3, Insightful)
A couple reasons come to mind as to why this Open Spectrum nonsense won't work and won't be applied.
First and most importantly, the federal government rakes in tons of money from spectrum auctions and licensing fees. However arcane, that simply won't be eliminated because something "better" has come along that's in the interest of the people. Reducing taxes are in the interest of the people, and we know how resistant the government is to that!
Despite what the author believes, spectrum allocations are a sane way to managing RF. Granted, spread spectrum doesn't interferre with other transmissions *when technically sound methods are used*. But when left to their general devices, the public sometimes eschews technically sound ideas and does stupid things. No matter how robust spread spectrum claims to be, when the front-end of the receiver is overloaded because of a dirty transmitter down the block, things quit working.
I've never had to DF (direction find) a spread spectrum transmitter, but I suspect that it's a far cry more difficult than finding a spur created from a faulty paging server.
48K or 128K ? (Score:1, Offtopic)
What about radio astronomy? (Score:4, Interesting)
Radio astronomy produced many of the basic technologies that todays wireless communications revolution depends on, but is seeing none of the (financial) benefits and is gradually getting squeezed out of its own very limited parts of reserved spectrum. Maybe there should be a 1% levy on all radio licenses dedicated to help astronomers get around this problem and properly police their parts of the spectrum. Or maybe all the money raised from spectrum auctions should be dedicated to establishing space-based astronomy in the radio - probably on the backside of the moon to get away from all the noise!
There are needs for regulation to protect the other users of spectrum that wireless networkers forget about. Total spectrum freedom is not possible or a reasonable goal.
For more information see:
AAS webpages [aas.org].
Re:What about radio astronomy? (Score:3, Interesting)
As extremely broad-band radio astronomy receivers (think GHz rather than tens of MHz) are on the way (e.g. the plans for the EVLA [nrao.edu]) radio astronomers are going to have to abandon the idea of completely RFI-free bands (already a myth at 1.4 GHz and below) and concentrate on ways of automatically detecting and removing it instead. Of course, large numbers of small, frequency-agile transmitters are pretty much the worst nightmare in this sort of scenario...
natural freedoms and radio rights (Score:1)
A key policy question is how to recognize natural rights and freedoms to use radio to communicate.
Last Post! (Score:1)
power of computers:
Enter lots of data on calorie & nutritive content of foods. Instruct
the thing to maximize a function describing nutritive content, with a
minimum level of each component, for fixed caloric content. The
results are that one should eat each day:
1/2 chicken
1 egg
1 glass of skim milk
27 heads of lettuce.
-- Rev. Adrian Melott
- this post brought to you by the Automated Last Post Generator...