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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."
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Open Spectrum: The New Wireless Paradigm

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  • or are people who use the word "paradigm" almost always talking out their ass.

    Maybe it's just me.
    • No, only people who use "paradigm" in a business or technology-related manner. It's a perfectly valuable philosophical construct when used properly.
      • by Waffle Iron ( 339739 ) on Friday October 18, 2002 @06:28PM (#4482186)
        No, only people who use "paradigm" in a business or technology-related manner. It's a perfectly valuable philosophical construct when used properly.

        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)

        by Jester99 ( 23135 ) on Friday October 18, 2002 @09:24PM (#4482931) Homepage
        No, only people who use "paradigm" in a business or technology-related manner [talk out of their asses].

        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 /. article on selling XBoxen as loss leaders to gain $$$ on selling games).

        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.
    • almost always? I'd say ALL the time.
    • Well, now you know that it isn't just you who's talking out your tail... *I* am too...
  • not everything (Score:3, Informative)

    by dirvish ( 574948 ) <> on Friday October 18, 2002 @06:12PM (#4482104) Homepage Journal
    One thing I do know about it that I am fairly certain is not wrong: the government will attempt to regulate it. It doesn't matter what shape it takes the government will make sure it makes a profit from it.
    • Yeah, that government makes so much in profits.
      • You know what I meant. Not profits, but they will get their cut. They auction off spectrum now and they will do it if the "paradigm" shifts.
        • 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.

    • Profit? Nah, That would mean a budget surplus =)
    • Ummmmm. Did you read the article? It's all about putting spectrum into 'the commons'. It would be a bit hard to make something free and profit from it at the same time. And it's not like this guy invented something new.
  • by WittyName ( 615844 ) on Friday October 18, 2002 @06:13PM (#4482106)
    Even if the FCC goes along with this, the telecom industry can not afford to roll it out.

    They are heavily burdened by debt from Cell and cable modems.

    • Who says the telecom industry is needed to do this? Look at the spread of WiFi, it's driven by individuals and organizations putting in infrastructure for their own needs, and for the most part, the telcom industry is out of the loop. Home users that share DSL over WiFi could be targetted, but most ISPs have a pretty Laissez Faire attitude about this unless you really spike up your overall bandwidth. Some companies don't even like you sharing with a wired network in your house, but others do nothing to actively prevent it.

      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)

    by t0qer ( 230538 ) on Friday October 18, 2002 @06:14PM (#4482114) Homepage Journal
    I swear I think all this extra radiation is adversly affecting my health. (places tinfoil hat on head)
    • No kidding... hasn't anyone here seen Johny Mnemonic? I'm as geeky as the next, but I try to keep all of those wireless things as far away from me as I can (which is why my cell phone lives in my back pocket - I figure that if I get cancer, it'll be in a place I can spare to lose a few pounds when it's removed)
    • No it is true! (Score:2, Insightful)

      by qwijibrumm ( 559350 )
      Don't even kid about that, it's true! I work in a room with 30 10kw HF transmitters, two 40kw LF transmitters, and one 200kw VLF transmitter. The antennas for these are less than 500 meters away. My co-workers' and my own hair is already falling out and I'm 23 years old.
      • Re:No it is true! (Score:5, Informative)

        by IIRCAFAIKIANAL ( 572786 ) on Friday October 18, 2002 @08:27PM (#4482726) Journal
        *insipid childrens show music*

        Welcome to the Slashkids Fun-Filled Fallacy Post!


        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


        *insipid childrens show music, credits, cut to commercial*

        (Sorry, I'm a prick and I couldn't resist :)
        • It's okay, I can take a joke. The fact of the matter is, although there have been no studies here. It seems we are all starting to loose our hair at work. Some of us are just plain old. Others are as young as 19.

          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.
    • Be careful, what if that tinfoil just happens to act like an antenna and amplifies the signals. Then you can really claim to be hearing voices in your head.
    • I worry very much about radiation that is why i turn my computer on only once a month, and I turn my monitor backkwards towards the wall so the radiation-o-trons dont get me, as of right now i am connected through the internet on my ti83 because i used this month's computer use on downloading pornography
  • Sure (Score:4, Funny)

    by ArchieBunker ( 132337 ) on Friday October 18, 2002 @06:15PM (#4482123) Homepage
    This has about as much chance as the US switching over to the metric system tomorrow.

    • The FCC has been metric for years. Go figure
    • My car gets 40 rods to the hogshead, and that's the way I likes it!
    • Re:Sure (Score:2, Insightful)

      by sakeneko ( 447402 )
      This has about as much chance as the US switching over to the metric system tomorrow.

      <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. :>

      • "Open spectrum" being the status quo in the 2.4 GHz band is sorta true... 2.4 GHz spread-spectrum data applications are secondary in nature to operations by amateur radio operators, and more importantly, television remote pickup stations (i.e. live shots), which occupy that band as three ENG channels.

        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...

  • by kpansky ( 577361 ) on Friday October 18, 2002 @06:20PM (#4482145)
    there are some really interesting possibilities. Think of software-defined radio letting you join different wireless networks that are decentralized and encrypted using something ala freenet []. If you were to couple unfettered access to wireless frequencies where people's ingenuity sets the standard, and not self-interested corporations.

    I would personally love to see open hardware designed to utilize wireless technology available similar to the projects at OpenCores [].
    • by NanoGator ( 522640 ) on Friday October 18, 2002 @06:29PM (#4482190) Homepage Journal
      "Think of software-defined radio letting you join different wireless networks that are decentralized and encrypted using something ala freenet []. "

      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.
      • by chriso11 ( 254041 ) on Friday October 18, 2002 @07:05PM (#4482381) Journal
        Yes you could put two 802.11 nodes together - an 802.11a @ 5.7GHz and and 802.11b/g @ 2.4GHz.

        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.

        • What if both nodes are at 2.4 ghz?
          • Yeah, that answer was a cop-out.
            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.

            • "But first - why would you put them next to each other?"

              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 ... oh man I can't remember the name of the other place that was involved.

              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.

          • by Chazman ( 6089 ) on Friday October 18, 2002 @09:56PM (#4483034) Homepage
            Yes, if both transmitters are broadcasting at the exact same frequency with the same modulation scheme, they interfere with each other. The point of this paper is to ask why are we cramming ourselves into just a few tiny nooks of the spectrum, thus creating this interference problem, when the spectrum is so large and underutilized. The paper points at the various incarnations of 802.11 as efficient use of a small patch of spectrum. If we did that with a few more patches, we'd easily have enough space for colocated wireless networks to work around each other -- change their frequency utilization automatically based on what other networks are nearby to minimize interference. 802.11b has such an option already; it's called channel agility. Unfortunately, since there are only three truly non-overlapping channels (1, 6, 11) within the USA/FCC mandated spectrum for 802.11b, areas of heavy wireless activity can easily find themselves without a clear channel to switch to. However, with say, a few dozen nonoverlapping channels to choose from, channel agility becomes a powerful and effective tool in colocating many wireless networks with a minimum of interference and degradation.

            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?

        • DSSS (discrete sequence spread spectrum) was originally developed for military usage.
          DSSS [] stands for direct-sequence spread spectrum.
  • by drhairston ( 611491 ) on Friday October 18, 2002 @06:22PM (#4482158) Homepage
    While the author is correct in stating that modern advances in digital spread spectrum allow digital signal processors to place multiple signals in the same frequency, he ignores the impact this would have on existing analog technologies which are incapable of this feat. I personally do not wish to be walking down the street the day it starts raining model airplanes [].

    • by JaredOfEuropa ( 526365 ) on Friday October 18, 2002 @06:41PM (#4482258) Journal
      He does suggest to limit this to certain bands, such as the current 2,4GHz band, or to do this in existing bands using extremely low power. Neither should affect existing analog technology such as model airplane transmitters.

      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.
      • by WolfWithoutAClause ( 162946 ) on Friday October 18, 2002 @06:55PM (#4482327) Homepage
        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.

        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.

      • The idea that spectrum is a limitless resource is a myth, however.

        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.

    • by mesocyclone ( 80188 ) on Friday October 18, 2002 @06:48PM (#4482285) Homepage Journal
      I wouldn't say he ignores it, but there is one assumption about underlay that is incorrect. The proposed mechanism of underlay is for the the underlay system to detect that it is causing interference and cease to do so within a few milliseconds.

      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.
      • by chriso11 ( 254041 ) on Friday October 18, 2002 @07:10PM (#4482405) Journal
        Actually, you need to be aware that the unlicensed bands ARE regulated - for example, you can only use channels a certain width at max (say 1MHz), and need to use a spectrum conserving modulation, such as FHSS (frequency hopping spread spectrum). You also have maximium tranmission power requirements and so on.
      • I think you're thinking of it wrong. You need to think of it like 50,000 people talking in a stadium. Yes it will be more hard to talk to your neighbor, yes you may half to yell a little louder, or talk directly torard his ear, but you can still do it and exchange information without regulating everyone in the stadium. Also, when talking, you likely have plenty of incentive to yell and direct just loud enough to make sure your neighbor gets your message without alot of wasted effort.

        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.
        • No, you are reasoning by analogy.

          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.

          • 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.

            • The physics is NOT the same for radio and sound, although it is similar. But you are still reasoning by analogy.

              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.
  • "Almost everything you think you know about spectrum is wrong"

    Everything I know about spectrum is right, because I know nothing about spectrum.
  • by LL ( 20038 ) on Friday October 18, 2002 @06:26PM (#4482175)
    (tort is the legal action against harm within common law jurisdictions). Let's consider a future where individuals have wireless wheelchair, interacting with their environment (like doors/cars/etc). How do you prevent individuals being careless (cf case of leaving a concrete block on road for car to hit)?

    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.

    • If your wireless car opens someone else's garage and they get robbed, then yes, someone is liable - the manufacturer of the garage door opener. Unless you send the correct sequence, that garage door shouldn't open.

      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)

    by SiliconEntity ( 448450 ) on Friday October 18, 2002 @06:29PM (#4482192)
    The paper goes on and on about how WiFi shows that open spectrum works, there's no problem with congestion, no need for ownership or frequency allocation. Then in recommendation 2 we read this:

    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.
    • So here he's saying exactly the opposite, that congestion is a serious problem for open spectrum! Which is it?

      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.

  • by Iguanaphobic ( 31670 ) on Friday October 18, 2002 @06:30PM (#4482198)
    It is time to question our long-held assumptions, and explore new policy approaches that could generate tremendous benefits for the American people.

    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.

    • The few, in turn, guarantee $$$ to the government. Anything that threatens this simply will never happen.

      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.

  • How dare someone post such a LONG article that is interesting at the EOB on a Friday. Man, now I have to stay at work late.
  • by Anonym1ty ( 534715 ) on Friday October 18, 2002 @06:37PM (#4482246) Homepage Journal
    Software-Defined Radio Every radio can be tuned to pick up a certain range of frequencies and it takes some amount of time to change the tuning. Traditionally, these characteristics are fixed in the radio hardware. Thus, for example, the same radio can't pick up both FM radio and mobile phone transmissions, or both 2.4 GHz and 5 GHz wireless LAN signals. Software-defined radios, by contrast, can tune dynamically over a wider range of frequencies. A software-defined radio can receive or transmit different kinds of wireless transmissions automatically. If it is a so-called "agile radio," it could adapt to the local environment and seek out open frequencies to communicate. Even in licensed bands, most of the spectrum is empty most of the time. Agile radios could take advantage of that empty space, moving out of the way when another transmission appears.

    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.

    • No - he is going after something more than. A software radio is a tremendous enhancement. Right now, if you wanted to build the best possible decoder for AM, would you use A) the traditional frequency translation to a baseband signal, or B) directly digitize the captured signal with a DSL ADC and perform DSP to extract the captured signal?

      • One takes a $.20 chip and can run for a week on a 9v battery, the other a lots of power, complex software and it might just work better but I haven't seen an example.

        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.
    • Yes, the analogy to the WinModem is more or less accurate, except that the bandwidth is much more, so this is pretty high speed stuff. See the GNUradio stuff (on /. a week or two back, or just Google or try the logical domain names gnuradio.*). There were some links to this idea in the /. interview, but the open specrum stuff was pretty raw. This paper is very well written and a pretty complete description of the important issues.

      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.

  • by Newer Guy ( 520108 ) on Friday October 18, 2002 @06:42PM (#4482260)
    Why? Our whole enterprise system is based upon monopolies. Look at the FCC these days... they've been making the monopoly of the airwaves BIGGER! In most cities, instead of having 15 or 20 different radio owners, it's now down to three or four. The U.S. radio spectrum policy is based as much (if not more) on politics as on physics and technology. As long as it stays this way (and it will, trust me), the status quo will prevail. The unlicensed bands are few compared to the licensed (read: monopolized) ones...they are less then 1 % of the electromagnetic spectrum. This isn't likely to change, either.
    • Particularly with the 'underlay' concept, if you could quitely start using spectrum in ways that don't interfere with existing uses, who would know? In the regulatory space, spectrum license holders are always arguing against new uses because they *might* interfere with their bands even though there is precious little evidence that there would be problems.

      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.

      • The FCC gets involved with the manufacturing, importing and sale of items too. For example, a whole boatload of 2 Ghz cordless phones recently got impounded border because they transmitted too far (ie: did not meet Part 15 Specifications). Yes, you can probably build your own transmitter and if you don't cause (obvious) interference, run it without being hassled for years. BUT...if you try to manufacture and sell them on any large scale, it won't be long before the FCC shuts you down. Also, if you think that receiving signals isn't against the law, think again! Scanners have been cellular blocked for years in this country. It's illegal to intercept most Federal govt. radio transmissions. It's illegal to divulge police calls to a third party. It's against the law to listen to broadcast stations' auxilary frequencies. Should I go on?
        • Not to disagree with any of this, you seem to have gotten my point, but from a different angle.

          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.

  • by Ed Avis ( 5917 ) <> on Friday October 18, 2002 @06:53PM (#4482320) Homepage
    I'm afraid it's true. Open Spectrum beats current wireless networking technologies hands down.

    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.
  • by VistaBoy ( 570995 ) on Friday October 18, 2002 @07:08PM (#4482398)
    Writer: "'Paradigm' and 'Proactive'...aren't those just buzzwords that stupid people use to sound smart?"

    *Blank looks from the managers*

    Writer: "I'm fired, aren't I?"

    Manager: "Yes."
  • by Dolphinzilla ( 199489 ) on Friday October 18, 2002 @07:22PM (#4482454) Journal
    If you ever work with Satellite communications systems (spread spectrum included) you will quickly find that even with all the so called "Draconian rules" in place, there is a high probability of someone stepping on your signal and satellite channel - the same has been my experience with other more conventional line of site RF systems - The ONLY way that whis would ever be feasible is if we took all the existing systems and simultaneously destroyed them before wheeling out the "Open Spectrum" systems. I for one don't believe that "free for all" RF spectrum is ever going to be practical or desireable. Does anyone else remember the days of the CB radio arms race and home built 100 W linear amplifiers ? As hard as it is to accept government regulation this is one area we don't want to let go to anarchy - if we do all we'll hear on our fancy Spread Spectrum radios will be static.
  • Humm (Score:4, Insightful)

    by Wyatt Earp ( 1029 ) on Friday October 18, 2002 @07:37PM (#4482508)
    I read the .pdf and then I popped over to the New America Foundation and looked at the Senior Staff bios.

    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 - - 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?
  • by Tjp($)pjT ( 266360 ) on Friday October 18, 2002 @08:55PM (#4482843)
    There are a host of problems with ad-hoc networking schemes such as this. I have a few solutions to them, but mostly they would be overpriced in the consumer market. One such beast that will start to bite you on the * really hard is hidden transmitter syndrome . This is where your controlling nodes overlap, and say node A is visible to base B and base C but base B and Base C are out of each others range. If B and C don't "hear" each other they can't work in unison without a third party. So when Node A (mobile presumably) hunts for a connection, both B and C try to talk at the same time to A, thus hampering the usable bandwidth. Lots more lessons can be learned by just searcjing for the syndrome and reading the other problems mentioned around it.
    • ... say node A is visible to base B and base C but base B and ase C are out of each others range. If B and C don't "hear" each other they can't work in unison without a third party. So when Node A (mobile presumably) hunts for a connection, both B and C try to talk at the same time to A, thus hampering the usable bandwidth.

      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)

    by zentec ( 204030 ) < minus painter> on Friday October 18, 2002 @10:22PM (#4483149)

    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)

    by Usquebaugh ( 230216 )
    Clive GPL'd the roms?
  • by davecl ( 233127 ) on Saturday October 19, 2002 @05:17AM (#4484053)
    With greater use of the spectrum, and the potential for software defined radios to use any frequency they want to transmit on, we're going to close out the possibility of ground based radio astronomy. This is not a good thing!

    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 [].

    • If you read the document carefully, you'll see that he doesn't advocate complete deregulation, and that radio astronomy is explicitly mentioned as a service that needs protecting.

      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 []) 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...

  • What tends to be overlooked in the "open spectrum, new wireless paradigm" jargon is that persons always have had freedom to emit radio energy in certain ways. Like being alive (infrared body-heat radiation), putting on wool sweaters (ultra-wideband spark transmissions), and starting car engines (a very significant source of RF emissions). For details, see "Revolutinary Ideas for Radio Regulation," pp. 59-62, available at [] and on SSRN [].

    A key policy question is how to recognize natural rights and freedoms to use radio to communicate.
  • This is the first numerical problem I ever did. It demonstrates the
    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...

It is not for me to attempt to fathom the inscrutable workings of Providence. -- The Earl of Birkenhead