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Open Spectrum: Free the Airwaves 148
akb writes: "Most of the RF spectrum in use is licensed for exclusive use. What do we get? Inefficient use through spectrum hoarding, political finagling to abuse the regulatory system to gain competitive advantage and access to the airwaves for only a few players. A good article over at CNET picks up on the example of 802.11b in using spread spectrum technology and unlicensed bands and proposes that model be applied to the rest of the spectrum. For the hardcore check out NYU law professor Yochai Benkler's writings, particularly this article (pdf) and Durga Satapathy's papers for the tech end of things."
I hate to be a stick in the mud but, (Score:4, Insightful)
Maybe more work needs to go into reforming the regulation policies instead of developing free-for-alls.
tcd004
Fear the box office [lostbrain.com] of Harry Potter!
Re:I hate to be a stick in the mud but, (Score:2, Insightful)
The flip side of this benefit of which you speak is the neccessity of smart, technologically adept professors being forced to endure hours of testimony to idiot balding white men in an attempt to free up frequencies for unlicensed public use, while these same idiot balding white men are being given gobs of cash from the licensees of the airwaves to encourage them to ignore those smart, technologically adept professors.
That other edge of the sword is pretty darn sharp, too!
Re:I hate to be a stick in the mud but, (Score:5, Insightful)
Re:I hate to be a stick in the mud but, (Score:2)
We aren't talking about you and your neghbor using cordless phones on the same frequencies anymore. We've gone Waaaay beyond that.
Re:I hate to be a stick in the mud but, (Score:2)
Actually, I have
We aren't talking about you and your neghbor using cordless phones on the same frequencies anymore. We've gone Waaaay beyond that.
Yes, I wasn't suggesting that either the technology or the regulatory regime that 802.11b exists in is up to the task of replacing say the cell phone network. Neither was the author of the article on CNET. 802.11b does establish a model for what is possible if you have an open standard and a regulatory environment that supports its.
Are you familiar w/ the work of the 802.16 [wirelessman.org] working group? They are seeking to implement technology and standards in cooperation w/ government to make ad hoc wireless metro area networks more feasible. 802.11b was not designed for that task and ultimately will not be able to scale for it, but the model is what's important.
Re:I hate to be a stick in the mud but, (Score:2)
The wireless MAN stuff is great, so is 802.11. It's all useless though if you signal can't get through. If you are trying to do something outside in a metro area then your pretty much screwed as far as getting a clean signal. Inside is quite a but easier since 802.11 doesn't penetrate very far and you aren't likely to be sharing that space with anyone.
Re:I hate to be a stick in the mud but, (Score:2)
Spoken like someone who has never tried to set up 802.11b in a populated area.
The band 802.11b operates in is not an ideally regulated band. Under ideal conditions, that band would be wider and restricted to unlicensed use of cooperative devices (whose design and behaviour would be regulated).
Currently, only signal strength is regulated. Thus, 802.11b devices try to cooperate and cordless phones, baby monitors, and such simply spew forth.
The article advocates a similar system except that ALL devices in the allocation would be required to cooperate.
Re:I hate to be a stick in the mud but, (Score:1)
Re:I hate to be a stick in the mud but, (Score:1)
I go into much more detail in the issue of Release 1.0 [release1-0.com] the column was based on.
-k-
Kevin Werbach
Editor, Release 1.0
http://www.edventure.com
Re:Didn't you read the article? (Score:3, Insightful)
Re:Didn't you read the article? (Score:2, Informative)
Not quite. Spread Spectrum is like pseudo-random radio "noise", constrained within a defined spectrum. Such transmitters have the effect of raising the "noise floor" in the spectrum they're using (and thus the error rate of the channel). This places an upper limit on the number of spread spectrum users a given channel can support. It's also a problem in spectrum (i.e. Amateur Radio and Astronomy) where weak signals are important.
One regulatory change that can be made is to allow use of spread spectrum on airwaves currently allocated for narrowband use where the narrowband noise margins are typically fairly good. In theory at least the two types of transmissions would not interfere with each other.
Re:Didn't you read the article? (Score:5, Insightful)
Bingo!
It's been a number of years since I was involved in this sort of work (so my memory may be a bit fuzzy) but this is an old problem. I was part of a group of engineers that were developing software to predict the problems that proposed FM transmitters might have on instrument landing system receivers. If you look at the frequency spectrum allocations you'd say that there shouldn't be any problem. Different frequency ranges so no problem. Right? Wrong. The landing system receiver receives all the freuqncies that the antenna picks up. Some of those FM transmission frequencies combine in the receiver's front end to generate harmonics that are in the landing system frequency band. Some ILS receivers are better than others at rejecting these but the point is that they're there and they affect the S/N (adversely) and degrade the landing system's performance. Not something you want happening. I recall some of the flight tests where other people were collecting real data to confirm out models. In one case, where the technicians had tapped into the guts of the ILS receiver, they could actually hear the audio from a nearby radio station. Similar concerns about interference of the ILS signals had to do with cable systems. You think your local cable TV provider is ensuring that all the connections on the poles aren't leaking RF energy?
And, if memory serves, lowering the S/N in a spread spectrum has an adverse effect on signal acquisition and tracking. Won't it be fun when everyone in the neighborhood has a spread-spectrum connection to the internet and you find that it performs like a dialup connection.
And I just love law professors who spout views on technology policies without having the necessary technical background. Just about as much as I enjoy professional politicians doing the same thing. There are technical reasons why the spectrum is/was carved up into protected bands. The trouble with politicians (and law professors who probably want to be politicians) is that they're mainly concerned with the economic aspects of spectrum allocation. And, IMHO, that's dangerous.
The G3 fiasco (Score:1)
This is big bucks in the Euro govt. coffers, which is more than what US gets for it's bandwidth, but it is a good example of an overvalued asset, imho.
Now I dont really know where I was going with all this.
spread spectrum technology and aliens (Score:1, Interesting)
Re:spread spectrum technology and aliens (Score:2)
Re:spread spectrum technology and aliens (Score:2)
While you can at least hear SS signals on a conventional receiver (they sound like more- or less-random noise), there are technologies coming down the pike that are completely undetectable without a time-correlated receiver.
See, for example, Time Domain [timedomain.com]'s technology. Ultra-wideband radio is fundamentally different from both DSSS/FHSS and conventional modulation technologies, and it may very well prove to be the Right Way to send and receive wireless signals in the long run.
If time-domain radio turns out to be the natural direction of evolution for wireless systems, we don't have a chance in hell of listening in on ET's phone conversations.
This is my biggest problem with SETI -- the assumptions they are making about the nature of an advanced civilization's communications traffic are almost all entirely unwarranted. I don't think we're going to find anything interesting by staring at frequency-domain FFT displays all day.
But people don't want to cooperate (Score:1, Troll)
One thing I learned at Worldcom is that the dirty little secret of CDMA, TDMA, and any other spectrum-sharing technology is that a small percentage of "rogue" devices that are designed to hog bandwidth or disrupt service will be able to do so, at the expense of everybody elses service.
Currently, if a terrorist wanted to block a wireless service (say, television or 802.11b), he would use a transmitter that is easy to locate through triangulation, and only focuses on one particular service. If, however, spectrum is shared amongst many services, that terrorist could take out all of those services and it would be almost impossible to tell which transmitter was his, and which belonged to legitimate users.
Although the idea sounds utopian and attractive, one must keep security in mind. And with security in mind, I pronounce the idea DOA.
~wally
Re:But people don't want to cooperate (Score:1)
No, this is what happens when a provider sells a level of service they can't sustain on the (unstated) assumption that the user will not take full advantage of it.
Re:But people don't want to cooperate (Score:2)
My point is that high use customers are using what they paid for. If they are slowing you down, your beef is with the provider.
Re:But people don't want to cooperate (Score:2)
RF bandwidth is finite.
No, RF bandwidth is not finite. This is what the 'cell' in cellular is all about. Different cell tower re-use the same frequency and bandwidth. You can increase the total bandwidth available by increasing the number of cells and decreasing the power of each cell tower.
Surely there are practical limits (only so many tower you can pack in an area), but we are far from optimal utilization of the resource. That's the point of the article.
Re:But people don't want to cooperate (Score:1)
a distributed network like this would easily route around network outtages, and single points of failure.
This is kind of the way the ricochet network worked. they add pole antennas all around the neighborhood that run at 19.2bps. depending on where you are, and how many antennas are around you, you can use multiples of antennas which give you a good overall bandwidth. (i think that's right, don't hold me to it).
How do you figure? (Score:2, Insightful)
How do they "take it out". While certainly they could render services useless in a certain specific geographic area by turning up the power, to do so on a wider basis would require more power which would make them real obvious. I don't really see how a change to more spread spectrum would make a terrorists job easier.
Re:But people don't want to cooperate (Score:3, Insightful)
Sorry, but doesn't spread spectrum modulation get rid of jamming?
Isn't that the reason why the military uses it?
AFAIK, jamming, sufficiently broad spectrum provided, requires a several magnitude more powerful signal than the signal to be jammed.
( Well, if a terrorist wanted to block a wireless service like 802.11b or Bluetooth, he just switches on his microwave.
Re:But people don't want to cooperate (Score:2)
And I believe that the military uses it more so because of the security features of spread sprectum tech then the anti-jamming. If you don't know where the signal is going to be next, then you can't decode a spread spectrum transmission. If there are multiple senders/recievers, then this will make it next to impossiable to decode.
Re:But people don't want to cooperate (Score:2)
In contrast to the sender, the jammer has to send on the whole spectrum A. The sender only sends on a small, but changing part of the spectrum B.
The energy required is proportional to the product of signal strength and spectrum width.
So, the jammer has to send a signal, which is roughly B/A times stronger than the data signal.
Re:But people don't want to cooperate (Score:1)
Re:But people don't want to cooperate (Score:2, Interesting)
There are several important things to consider when dealing with spread spectrum transmitters and their jamming. First, with regular spread spectrum devices, you don't have to jam all the frequencies involved. If you succeed in jamming, say, half of them, a lot of air time will be wasted for resend requests only, which will soon choke the link.
A way to deal with this is to equip the devices with some kind of link level diagnostics, which continously evaluates which frequencies are jammed, and avoid them. With a hop rate faster than the jammer, this would significantly reduce jamming influence. It does, however, add to complexity and cost of a system, which might be hard to justify in a commercial civilian system.
Second, if you want to use a very wide frequency band, there will be a problem with designing the antenna. Normally, an antenna is designed for a very specific frequency, but it can be made a bit "more" wide band with some circuitry. A very wide band antenna usually tends to get quite bulky because it physically has to respond to all the frequencies it is going to be used for.
Re:But people don't want to cooperate (Score:2)
Clearly, your posting holds to this statement. I mean, did you even read it? Should everything now be disallowed for the sake of the potential threat? What about elections, for example? There's always the threat of disruption there.
Anyways, from what I understand of CDMA, the transmission devices are traceable and identifiable, and will be throttled automatically via lost channel(s) when the board goes full.
I only hope one of our distinguished RF's comes along to debunk this in a cleaner and more learned manner than my own.
Again, methinks you doth protest too much, Mr. Bell.
Re:But people don't want to cooperate (Score:1)
You can build a device to monopolize any RF network type you choose. Now if it's an FCC regulated frequency block then the FCC or some company hired by the users of that block of frequencies can monitor for it. Just because the users are unlicensed doesn't mean the equipment doesn't have to be type-accepted. Part of the type acceptance process can be certain caps on bandwidth usage.
If you look at the FCC's SDR (software defined radio) initiatives you can see where this is going eventually. It's not going to work everywhere (ie - we still need a government only band for safety of life comms), but in the majority of cases FHSS systems degrade relatively gracefully in the face of interference from either fixed channel or other FHSS users.
Now is the time to discuss it and have a reasoned plan out so that as the HDTV conversion occurs over the next 5-6 years we can have a reasoned approach to refarming all the vacated spectrum. The current "land grab" approach just isn't going to cut it.
Now what does irk me is Nextel. In several markets I've been in they bought up all the private trunked systems and shut them down to drive sales of their own networks. All that 800/900Mhz spectrum is currently sitting idle in those markets. Take a look at a wideband RF survey of almost any metropolitan area. You'll find vast gulfs of spectrum that are almost totally empty. Then go do a search on licensees in that frequency range. Part of this stems from the way the FCC auctions are run (BTAs usually).
I'd like to see more use-it-or-lose-it requirements from the FCC on licensees. If they can't measure significant use within the intended service class within 24 months then the licensee can kiss the frequencies good-bye.
Perhaps we need to catagorize bands? (Score:1)
Re:Perhaps we need to catagorize bands? (Score:1)
Not the same as bandwidth... (Score:5, Insightful)
Re:Not the same as bandwidth... (Score:2)
sounds familiar... (Score:1)
do companies have to use wavelengths that are gov't regulated? would the gov't really track down people who use these frequencies?
aren't there any old frequencies that aren't in use anymore that we can free up?
Don't forget Amateur Radio. (Score:2, Interesting)
Re:Don't forget Amateur Radio. (Score:1)
Re:Don't forget Amateur Radio. (Score:5, Insightful)
Re:Don't forget Amateur Radio. (Score:1)
Fortunately however, the ham bands are internationally regulated. The USA (or any individual nation) could not reallocate these frequencies to other services without securing those frequencies through ITU [itu.int] proceedings, which would be far more difficult than simply giving the FCC "heavy pressure".
It is important to remember that radio, particularly HF radio, knows no borders, and the FCC is not an international authority.
Re:Don't forget Amateur Radio. (Score:3, Insightful)
And the sad thing is that the amateur radio community itself is largely to blame for this. All of these years continuing to drag their feet on licensing simplification, removal of extraneous licensing requirements like morse code knowledge, and continuing to protect bandwidth for ancient modes while limiting bandwidth for newer modes, has allowed the community to turn into a small group of old farts, waiting to die. It's a shame you guys couldn't see the value of growing your ranks vs. keeping your sacred Advanced licenses and your private frequency reserves. But elitism always tries to preserve its advantage. Adapt or die, baby. Auction 'em off, I say - and good riddance...
P.S. The anti-government wackos who seemed to be the more vocal inhabitants of the ham bands didn't help endear you to the powers-that-be, either. This is something that the tech community should probably keep in mind when using that new shared communication medium called the Internet.
Re:Don't forget Amateur Radio. (Score:2)
As far as ancient modes, is digital network packets not new enough for you? HAM is the place for tinkerers to try out new techniques. I bet quite a few of the pioneers of electronics devices started out as kids using ham as a hobby.
And let the greedy megacorporations make hand-over-fist in money by monopolizing the radio frequencies? Then we'll let their corrupt execs run our economy into the ground countless times, causing layoffs to a lot of us, while they have total control over the airwaves that flow around and above our homes.And in the event of emergencies, we'll just let the corporations to convey our essential emergency communications for us... I'm sure they'll be very reliable in this respect. I'm sure a big earthquake or hurricane won't knock out everything they have and that there will be plenty of electricity around to run their transmitters and repeaters.
There's nothing anti-governmental about it. Ham operators for the most part help preserve a very vital medium for keeping our citizens safe and preserving our liberties. The First Amendment does apply here, since the government would be involved in taking away the frequencies.Re:Don't forget Amateur Radio. (Score:1)
I've been getting more interested in Ham and Shortwave radio. My question is this (for you more knowledgable types) - Can you suggest any receivers or transceivers for the PC? I'd like to have one on a PCI card or maybe even a USB connectable box.
Where can I find such a beast? TIA
Her banner yet waves
Radio for your PC (Score:1)
Re:Don't forget Amateur Radio. (Score:1)
bogusflow
Re:Don't forget Amateur Radio. (Score:1)
BTW, it's called a HARM missile or a cluster bomb. It's known to be *VERY* effective in shutting down a problem transmitter.
Re:Don't forget Amateur Radio. (Score:2)
Hams have a lot of spectrum that is very under-utilized. 420-440 is vacant in most places. If it wasn't a secondary allocation (shared with the government), it would have been gone a long time ago. 6 meters (except the SSB/CW stuff) is virtually nonexistant in most places. 220, 900, 1200 and everything above that are dead almost everywhere but New York and California.
Why? Because nobody has equipment for them. The Japanese companies don't build it, so we don't have it. There's no easily modified commercial gear (though 900 has some) like there was to get 2 meters and 440 jumpstarted. If a company built a 2.4GHz wireless lan that could operate in the ham band, the ARRL would freak and get the FCC to block it. Why? We need that gear. We, as hams, should be happy to trade some of our bands to commercial interests if they agree to build their gear so that we can modify it for ham bands. (Just don't make it too easy.)
802.11b as an example? (Score:3, Insightful)
Specifically, I recall a post here on slashdot about someone's 2.4ghz phone interfered [slashdot.org] with their pr0n surfing.
The death of LPFM is a perfect example (Score:5, Insightful)
There was broad political and popular support for it--but (you know what's coming) the major radio broadcasters lobbied like sons of bitches to have it turned down, using a lame excuse of interference and degradation of signal. Eventually, if I remember correct, LPFM was killed as a last-minute amendment to a bill, an amendment bought by lobbyists no doubt representing Clear Channel Communications and the other bigwigs that bring us the same pap we hear on every FM station in this country.
Don't let big corporations continue to buy up all the bandwidth and hold us hostage with it. We need to get LPFM back on track. Hell, support your local pirate radio station by just listening. You'll be seeing the effect that LPFM should be bringing us and you'll actually hear differing viewpoints, and--dare I say it?--interesting programming.
Re:The death of LPFM is a perfect example (Score:1)
Or, in the case of LPFM, those hypocrits [current.org] at NPR [npr.org].
Re:The death of LPFM is a perfect example (Score:2)
The real problem isn't the stalling (testing), but the licensing. Current pirate operators were given amnesty a few years ago if they ceased operations. Since legal LPFM isn't up and running yet (and probably won't be for a while), this amnesty period was a waste. Now, any currently functioning pirate station is ineligible for a legal license - they have no choice but to continue operating illegally or shut down completely. Groups eligible for LPFM licenses only include non-profit groups without current media ties (no small newspapers, etc.). Additional restrictions and licensing selectivity resulted in the majority of the 250 or so LPFM licenses approved so far going to religious groups. So much for general interest local programming.
LPFM was a nice idea, but it just isn't going to happen in a band populated by extremely large broadcasting conglomerates (thank you deregulation...). The spectrum belongs to the public just like the government works for the public - not much.
Re:The death of LPFM is a perfect example (Score:2)
Re:The death of LPFM is a perfect example (Score:2)
Re:The death of LPFM is a perfect example (Score:2)
Money owns the FCC (Score:2)
Good luck changing things. IMHO, its not possible. There is too much money backing a closed network.
What about the small guys... (Score:1)
Naturally, when the whole thing came tumbling down, the big telcom guys came in and picked up the pieces for pennies on the dollar. Oh, and did I forget to mention, all this was to line the pockets of a few big players, and the US Govt. (of course)
Newt-dog
Just a thought (Score:3, Insightful)
Just another thought (Score:2)
What if there were no control over the HTTP protocol? Then every browser manufacturer would implement the protocol however they wanted...
As this is basically the case now, what can we observe? Well, there are incompatable HTML tags and such between browsers, but by and large, things work--because it is in the interest of the protocol implementors to follow the protocol (generally, if not exactly).
Like I said elsewhere, a central authority controlling the airwaves has positives, but has negatives as well. Which is worse?
Re:Just another thought (Score:2, Informative)
This is really comparing apples to oranges. As well. You can't mess up someone who isn't viewing your webpage with a messed up http implementation. While you can really mess up the radio spectrum if you send out bad signals.
Re:Just another thought (Score:2)
What if someone decided to make a device that used the same frequencies as directTV? It might tick off a few users. So think about the real world next time you decide everything should be free and no one should control anything.
Re:Just a thought (Score:1)
> frequency to market their latest wireless service
> in the same location? And what if that same
> frequency was in use by someone else's device? Who
> would be the final arbiter in these situations?
Simple: Verizon and MCI. There need not be a third party involved. If their tech doesn't work together in the same location, either one leaves, or they find a way to make the tech work together.
In a very short time, you'll have protocols like 802.11 and BlueTooth which can work together in the same frequency band(s), robustly. Problem solved.
Doug
Re:Just a thought (Score:2)
Remember in the DOS days when developers could write apps that took resources and never gave them back? Remember 100 years ago before the FDA people would sell colored water and pass it off as medicine? Or no regulation in food quality?
Re:Just a thought (Score:1)
> on the same frequency? And I decide I don't care
> about working with Verizon, MCI or anyone else if
> my device interferes with their service? I guess
> you won't be talking on your cell phone very
> much.
> Remember in the DOS days when developers could
> write apps that took resources and never gave
> them back?
Yup. Which regulatory body stepped in and fixed that, again? You might say MS, but that's not true; UNIX stopped that from happening long before DOS ran into it. All the OSes nowadays use a better system, not because they were forced to, but because they realized the issue and fixed it.
> Remember 100 years ago before the FDA people
> would sell colored water and pass it off as
> medicine? Or no regulation in food quality?
Regulating life's necessities and regulating frequency bands are two separate topics entirely.
Doug
Re:Just a thought (Score:1)
Cryptographic spread spectrum (Score:2, Interesting)
It's just too bad for those pathetic suits that authorised $Billions to be spent on tiny slices of the microwave spectrum for the 'next generation' wireless phones. So it goes for those that invest unknowingly!
Today we can transmit huge amounts of data and NOT cause any noticable interferrence. In time the world will catch on. There will allways be winners and losers.
Re:Cryptographic spread spectrum (Score:1)
"My heart goes out to all those poor corperations that litteraly 'bought air' for Billions of dollars" Hehe
Not all that it's cracked up to be? (Score:2, Interesting)
I have a phone and an 802.11 network card which constantly conflict with one another. And yet both claim to be 2.4 GHz spread spectrum... I had also tried (and returned) one of those remote TV boxes and that also interfered with the phone.
What's up with that?
-Kekoa
Re:Not all that it's cracked up to be? (Score:2)
Radio Spectrum is like the Internet (Score:3, Insightful)
Just as each computer needs a unique address (let's leave NAT out of this) to successfully transmit and receive their data; radio transmitters must use specific frequencies, power levels and operating times to avoid interferience (the operating times make the spectrum allocations work like dymanic IP).
So someone has to retain control of the spectrum "for the public interest". That's why we human beings create organizations.
Chris
About regulation of RF spectrum (Score:5, Insightful)
But now regulation clearly could serve the opposite purpose. After all, if all regulations were eliminated, and everybody were allowed to transmit wherever they like, the big corporate interests (cellphone companies, broadcasters, etc.) would probably be able to effectively claim everything, since they could run higher-power transmitters and more of them than any individual could hope to. If there is to be any kind of non-commercial use of RF, it clearly needs exclusive bandwidth protected by the FCC (as hams, CB users, GPRS/PRS, wireless networks, etc. already have).
Of course regulation as it stands serves the opposite purpose...making as much money as possible auctioning off public spectrum to cellphone companies, etc. But that does not mean that its elimination would solve the problem of the commercialization of public spectrum.
Time for a change? (Score:4, Interesting)
The main problem with the radio spectrum today is that is has been portioned out over many decades. Over that time both needs and technology have changed. I don't think the entire spectrum should be opened up, but it would be smart to reevaluate and reorganize it, leaving more spectrum open for personal use, consolidating the entertainment bands to more efficiently use space with digital technologies like this [slashdot.org], and leaving clear bands for scientific and emergency use. And of course, desiging devices so they don't transmit louder than they absolutely have to.
The only real problem with this are legacy devices, namely TV, mobile phones, and especially radio, and their transmission towers. If the transition can be eased for those devices (with adapters or cheap replacements and some gov't subsidy to upgrade transmitters) then I think things would go fine.
It will never happen (Score:3, Interesting)
Control- absolute control for the governmrnt over communication.
The only way to get "freedom" in the airwaves is the same way we gained "freedom" in 1776
It's called a public uprising that torches the government buildings, locks the public officials in stockades and publically humilates them and thne throws them in a boat and told to never come back.
The best you can hope for is that the damage done to the public sections is very limited from year to year.
They sell off ham frequency sections on a regular basis, to UPS, to whoever wants them. The ham frequencies are the property of the US citizens or citizen of that country that resides below that section of Z axis.
you cant stop it, and they will ignore any cries to stop it.
Factually incorrect. (Score:1, Interesting)
ONCE in the last 50 years, hams have lost a (small) portion of their allocation.
Hams, in fact, are likely to gain MORE spectrum before they lose any. The ARRL has petitioned the FCC for a new HF allocation around 5 MHz. It's likely to be approved in the next year and be available to hams by 2004 or 2005.
Why is the FCC giving hams more space? Simple. Hams are a cadre of men, women and kids who can, in a time of national emergency, provide critical communications and support to the government. Nobody else can do this.
Picture this. It's 3 AM. You're up late playing the latest mind-fuck console game from Sony. A massive-ass tornado hits your neighborhood. At the same time, a giant fucking hurricane slams into the coast. Your entire state is ruined, you're now living in a tent where your pool used to be. Roads are impassible. No cell phones, no internet access, no power. Nothing. Yet, a competent ham radio operator in the neighborhood has an antenna strung up in the last remaining tree, and he has his Kenwood TS-850 hooked up to a couple of deep cycle gel-cell batteries. Your neighbors are lining up to make phone-patches through another ham two states away, so they can call their relatives and let them know they are alright.
Hams can provide this service that nobody else can. When the lights go out, and I mean *REALLY* go out, hams will get the message through. Bluetooth will not save you.
Re:Factually incorrect. (Score:2)
B.S. I'm a ham and have been heavily involved in disaster work. Government agencies, at least where I live, have figured it out. Yeah, they have their fancy 800MHz trunking systems that are so fragile. But they also have portable repeaters, antenna trailers, go packs of radios, etc. One agency I've dealt with even made sure to purchase AA-cell packs for their portables.
In the last 3 storms, we've never had enough hams on hand to cover communication needs. But everywhere we needed to talk to had a deputy with a radio. We didn't have to worry about the deputy showing up drunk, smelly, acting crazy, hitting on women, having a heart attack, walking off the job, fighting with others over the air, or just rag-chewing on the air. You may think I'm bullshitting you, but I've had every one of those happen. And I've had dozens of cases where hams showed up at critical positions with equipment that was either broken or insufficient, with no backup gear available.
Hams will still have their place, but they are no longer a critical part of the disaster response equation. The ARRL will tell you (and FCC/congress) that they are, but they're wrong.
Oversimplistic (Score:5, Informative)
While bandwidth is an oversimplistic way of either looking at things, or regulating them, it is a fact that any communications system can be analyzed (roughly) in terms of bandwidth. And this means that any communications system can interfere with any other communications system if they share frequencies in any sense.
For a real world example of why you can't ignore bandwidth, try running WiFi in a house where you have some 2.4GHz phones. It may work. But sometimes it doesn't - the reason - radio frequency interference. They share the same bandwidth.
Ah, you say... so they don't use good enough systems... or aren't broad-band enough... or something! Not true... there are hard physical limits that no amount of scheming will get around. The rest of this post discusses that in more technical detail.
All signaling systems (INCLUDING Time-Modulated Ultra-Wide-Band)require a separation of signal from noise. Noise is either natural (thermal, atmospheric, solar, etc), incidental (power line leakage, etc) or other radio systems. Regardless of what kind of signaling system is used, it has a limit as to the amount and kind of noise that can be tolerated in any given situation. The other limits described below affect the amount of noise reduction/signal enhancement that is possible.
Limits to processing gain. WiFi and other modern technologies (CDMA cell phones) use spread spectrum to reduce the effects of interference. Unfortunately, this does not eliminate interference. In engineering terms, it is the equivalent of adding gain to the desired signal. The gain is roughly the bandwidth occupied by the transmitted signal divided by the bandwidth required to send the signal without modulation (the baseband bandwidth). This value is measured in decibels, and is typically 20-30 dB, although it can increase. But the higherhe data rate, the lower the processing gain!
The effect of distance - radio signal energy decreases by an inverse square law. This means that a nearby interference source can have a much stronger signal, proportionally, than the desired signal from a farther source. Some numerical examples:
This illustrates that a signalling system, by itself, will not prevent interference - defeating the main argument. Specific factors are:
Imperfections in equipment. Real equipment will not reach theoretical levels of performace.
Limited dynamic range. If you have a 100,000 watt transmitter 3 feet from your receiver, there is a good chance that no matter what its technology, it will not be able to pull out the desired signal. In digital terms, this is the equivalent of running out of bits in your integer! If a number is too big, you either overflow your math, or you scale it down, losing the little bitty number you wanted.
Limited bandwidth - there is a limited amount of bandwidth, useful for a given purpose, at any place and time. This bandwidth, for many purposes, is between 1GHz and 25GHz (although for ionospheric radio, it is only 30 MHz). This means that if someone is generating a strong signal in the bandwidth you are using, there may be no other bandwidth you can jump to.
Intermodulation. Any nonlinearity in the system, including incidental nonlinearities such as a nearby rusty pipe, will cause all the RF signals impinging on them to be mixed, and the mixing products re-radiated. Receivers have inherent nonlinearity, which unfortunately gets worse as the power used by the receiver is reduced.
Leakage. You may have a great receiver, but an interfering transmitter that is close enough may leak through its plastic case and get into an intermediate stage of your receiver.
etc.
Without regulation, some other system must arise to arbitrate needs for radio spectrum, or chaos will result
Re:Oversimplistic (Score:2)
License free (open, if you will) 900mhz and 2.4ghz are a different model of spectrum regulation resulting from equipment manufacturers (particularly apple in the 802.11b case), rather than content providers, taking the lead in working with government to work out the regs and in the standards bodies. The new NII band in 5ghz is a refinement of this process, a new partnership of government and industry centered around open standards. Heck a member of NIST's NWEST [nist.gov] group is the chair of the 802.16 [wirelessman.org] working group. The kinds of partnerships that are taking place are very much like those that the open source community are looking for in advancing its movement, as Benkler's writings will bear out.
I'd be interested to hear what you thought of the technical papers that I reference, or the work of the 802.16 working group to hear if they address any of your concerns.
Re:Oversimplistic (Score:2)
John
Re:Oversimplistic (Score:1)
I understood the article to be suggesting more unlicensed spectrum, based on the fact that there are some quite successful technologies already operating in unlicensed bands, such as 802.11*.
The circumstances at the time the current spectrum regulation was created were different majorly in that there wasn't any technology to allow efficient medium sharing. Thus, I can see that it was logical to restrict any single spectrum band to single players.
The situation today is different in that there exists technology which can allow multiple cooperating parties to efficiently share a piece of spectrum. For example, multiple 802.11 devices can divvy up the 11 mbps or so of total bandwidth without much loss due to collisions. Note that the multiple devices do not talk simultaneously; they use a medium access protocol to take turns using the entire channel bandwidth. Also note that the use of spread spectrum is irrelevant for this purpose.
This naturally begs the argument that not all devices in an unlicensed band can be expected to cooperate (i.e. run the same MAC protocol); there are examples of say, Bluetooth, or various cordless phones like you mention above, which can seriously degrade 802.11 performance. I believe that this is not a serious problem if the unlicensed bands are regulated properly-- and in particular, if the transmitting power is limited like in the ISM band. The result is that any uncooperating devices potentially only disturb users within a very small area. The situation gets even less problematic with directional antennas.
You have got to admit it would be nice to have a 1GHz wide chunk of spectrum for unlicensed, power-limited use. Think 802.11h at 1Gbps.
~
Re:Oversimplistic (Score:1)
My main argument is not that we can "prevent interference." It's the following, quoting from the piece:
In practice, there are still limits on how many users can communicate effectively, depending on available frequencies, power, competing uses and the design of transmitters and receivers. The benefit of open spectrum is that it's more efficient than the traditional licensing model, and that gap will widen over time.
There's much more detail in the issue of Release 1.0 [release1-0.com] that the column was based on (though unfortunately it's not available for free).
And no, I don't claim to be an engineer... which is why I rely on engineers like David Reed, Tim Shepard and Dewayne Hendricks who've done work in this area (both theory and practice).
-k-
Kevin Werbach
Editor, Release 1.0
http://www.edventure.com
Two minor observations: (Score:1)
the FCC decries "interference" from LPFM sources, when FM now a days is so over taxed a radio station, local, highpower, less than 5 mile away gets blotted out by NO LESS than 3 other stations.
It is quite disconcerting to be rocking out to a good rock/metal song and have a country tune of "my dog left me, took my truck and ran over my girl on the way out"... sheesh. And on a daily basis no less.
Changing channels does not matter, same sh*t, different station.
Oh, and wouldn't it be funny if this were on *Wired's* website first?
(heh, electronics tech before I was a 'puter tech...some habits never leave)
Free Airwaves (Score:1)
Who will pay for it ? (Score:1)
The government also creates markets and wealth - Yes, cell companies have spent 17 billion on a slice of spectrum (look for the NextWave fiasco) and will be spending countless billions building up the networks. This provides over 500,000 jobs in the US alone !!! Plus, with the communications infrastructure developed - it helps create efficiency and wealth in other domains. With a cell phone, you now have more time and control over your communications (business and pleasure).
If you remove the exclusivity - who would have put cash on the table to build these networks ? The internet is kick ass because I can spread the cost of infrastructure accross a greater population - who remembers how much a leased line cost 10 years ago
Thats my take.
Re:Who will pay for it ? (Score:2)
Open spectrum is part of the FCC mandate... (Score:3, Informative)
The real problem is dynamic range (Score:2, Insightful)
The separation of channels by frequency has two special properties that help with this problem:
1. There are no common physical processes that change frequency much between the transmitter and receiver (Doppler and changing refraction effects are generally small).
2. It is possible to get very large channel separation with frequency-selective filters.
You give up these special properties with broadband schemes. Time-division and code-division separation of channels are particularly sensitive to multipath propagation, a ubiquitous property of radio. While multipath can produce fading and distortion in narrowband transmission, it cannot cause one channel to spill into others.
*sigh* not this idiotic idea again (Score:1)
1. TV fringe reception goes from usable to unusable, so fewer pops, so fewer advertising dollars, so less profit for TV stations (who are already hurting by the way). Thats a direct to the bottom of the GDP spreadsheet example of why UWB is bad.
2. How about instrument landing systems. Gee.... when do they have the least noise margin: in bad weather, close to the ground. Gee... what would UWB wipe out? How many planes do you want UWB to crash?
These are only two examples. Advocates for UWB need to go through the math service by services (and there are 100's) and show that they don't kill people or rob people. They ain't done that yet.
This will all be moot before it ever happens. (Score:1)
Quantum entanglement transcievers.
Never heard of it? That's not suprising. It's a really weird physics phenomena (OK, so maybe you have heard of it.) where 2 particles start acting as if they're a single particle. Even after they are seperated by a distance. You can push particle A and particle B moves... things like that. Now, imagine that you can "entangle" these particles for an indefinite period of time... well, at this point, you merely have to put them each into seperate hardware devices. I propose gigabit ethernet as the tech of choice for this.
*grin*
(Note: Actually, each transciever would have 2 particles, a Rx and a Tx, while the mated transciever would have 2 particles paired to each them.)
So you take yours home to your switch, and plug it into an uplink port, or straight into the nic in the back of your linux box. You mail the mated transciever to a friend, or any geek that has plenty of ethernet ports free (like me). When I plug it into my switch, boom! Wireless long distance gigabit. You could be buried in a lead vault, and it wouldn't matter. A few moutain ranges in between? No biggy. Aliens have abducted you, and they didn't think to confiscate the laptop? Big deal... even if you're already on the other side of the universe.
(Note: To create something much more cool, you and 20 friends chip in for a 24port gigabit switch, and decide who gets the burden of maintaining it. You each plug one of your transciever pairmates into his switch, and take the other home with you. As more people do this, you interconnect the switches. Since distance doesn't matter, no telling where they might be. You might even set up scenarios where you interconnect anonymously. Totally cool possibilities, if you ask me.)
Oh, and if they catch me using this to pirate MP3's? They STILL can't use my transciever to trace it back to you. No such thing as triangulation.
Now, why, you ask, if I'm such a depressed pessimistic asshole, do I think this will happen, and realtively soon at that??? Because, you see, people like you and I will NEVER... I repeat NEVER EVER get to use this. Military, official goverment use. Built-in GPS that sends location info via another split muon, included for just that purpose, and a tamper proof mechanism that ruins the transciever, if you try to remove it. (Doubtless transmitting the location to some fucking scary NSA place, where all this is monitored) It will be outlawed for the average citizen, and it's incredibly doubtful that it will be homebrewable.
The universe sucks, doesn't it?
Re:This will all be moot before it ever happens. (Score:1)
Butm I was just thinking - another little quirk of this technology is that it would basically allot nformaion t travel in time. These partiles are intertwined, right? Well, send one through a wormhole or put it in a spaseship that goes at some large fraction of the speed of light. Now, time goes much faster for one side than the other, but messages will be sent at the same relative time. That means, the time would be the same from the moment of creation. So, the message sent from the comp. on the ship would arrive on the home computer before it is sent.
This would probably be a disadvantage, as really big companies/rich people/the government would be the only ones who could use this
Re:This will all be moot before it ever happens. (Score:1)
I just wish this was something a guy like me could play with. Not without a million dollar lab though, it would seem.
Re:This will all be moot before it ever happens. (Score:1)
The particles have to have the same spin. you slightly change the spin of the particle, the other reflects that. you could rig up some sort of binary method, where, if the particle snaps 90 degrees left, it's a 1, and otherwise, it's a zero... Imagine parallel particle transmission (PPTx), 1 Gbit each particle, 8 particles...
the particle has to be kept in a magnetic field, for control and containment. meaning batteries, and sealing the particle chamber. but, if the container is opened, the particle gets freed, and you need to match particle pairs again.
NASA should be jumping on this for comms to mars/ Alpha Centauri/wherever. imagine realtime video of your loved ones, or, playing CS with 10 ping from the JPL OC-* for fun during the ~6 months transit time... trolling
Re:This will all be moot before it ever happens. (Score:1)
I, of course, think gigabit, or whatever the next incarnation of ethernet is, is the ideal networking medium... but there's more to it than just that. For instance, I can see them using this on a microscopic level on cpu's... those things keep shrinking the dies, and yet the buses still aren't as fast as they'd like. Or how bout the PCI bus? You could have little QE busses and links all over your motherboard, as soon as they perfect it, if they were to let this tech go public.
NASA probes with this would be cool, but I have an even better application for it... and this is good. Imagine that the entangled particles are electrons, and the spin isn't the state that is entangled. You might be able to have something the size of a AA battery, to plug into your gameboy, but its mated device plugs into the wall back home. It would beam power instantly across the distance, and your "battery" would never go dead. Good for just gameboys? Hardly. High power versions could supply electricity to remote regions of third world countries... we could kill the internal conbustion engine for good, and, even more exciting, the possibility of cheap and easy space travel.
See, when a rocket launches, 95% or more of the weight is fuel. Fuel is good for 2 things, one of which is power. If the rocket doesn't have to bring its "power" with it (and presumably the high power QE battery would weigh much less), then you only need fuel for the other part, the reaction mass. And heck, maybe there are ways to even get around that. I'm thinking some sort of space plane that uses props to get it above 40k ft, where it boosts to orbit from there. Or maybe it can scoop up air on the way up, and ionize it for reaction mass.
And we might even be able to plant some solar power plants REALLY close to the sun (as close as we can get without melting them), and beam the power straight to earth. Nearly endless energy. As long as a space vessel had adequate reaction mass (or could find it along the way), it could continue to accelerate indefinitely. Within a solar system, maybe you could even use the magnetics/plasma fields as a solar sail (previous slashdot articles) ditching the need entirely.
This technology could finally give us the universe. And it will probably be strictly controlled, not for public consumption, so that the powers that be can protect their privileges. Just imagine the communications aspect alone. Cell phones would be pointless (you'd simply use a transciever plugged into your home phone). Long distance would be even more worthless than the internet made it (call grandma for free? Just ship her one half of a transciever pair). Warez dudes would use this to setup super-highspeed ftp sites, and busting them would be next to impossible, since you can't use one to track down another. They wouldn't be able to tap our phones, if we didn't want them to. The FM radio industry would die. Why listen to the 3 cruddy FM stations that you can recieve in your car, when there is a guy halfway around the world, that plays the music you want, for a $5 subscription per month (and he doesn't necessarily license the music from whoever you legally have to). I'm sure secure communications have some tax evasion aspect too...
And this is just the communications application of QE. They simply won't let us have this (unless it was doable by a Joe Sixpack like me, and I published plans on how to make your own on the 'net, try to put that genie back in the bottle). State sanctioned devices will certainly include 2 links, one to whereever you are using it, and the other to the monitoring agency, complete with GPS coordinates so they can make sure you aren't "misusing" it. I hate humanity, don't you?
There's abuse of the system? (Score:2)
The cellular frequency lotterys where also a joke. For example the one that Ms Clinton bought for $1000 because she won the lottery. She had about a 1/10 chance of winning because the rules were stacked aginst most people but it was common at the time to sell out to a major carrier at 100x or more than the license cost.
Its not just the US that has stupid rules about spectrum use. In Melbourne Australia, there is a big hill that has line of sight coverage to about 2 million people. None of the compaines that bought the 2.4ghz licenses intend to offer real internet service and most of the licnese are still not in use and I don't think most of them will ever be paid for considering the finicial state of most of the winners.
Have a look at what the Dandin Group is doing. (Score:1)
Dewayne found out that he could prove his concepts in "regulatory havens" like Tonga and tribal lands. This stuff is being done today! Eventually the FCC is going to have to wake up and realize that it actually makes sense, in spite of the lobbys.
It's not about congestion, but censorship (Score:2)
Most people don't understand that the broadcast media are not a true free press, but a limited free press. The content is very heavially regulated ... you half to play certain types of music, you half to have programs that show no more than such and such percent nudity, you half to show a certain amount of childrens programs, you half to give certain percentials of political coverage, and so on. This is all made possible by federal regulations and the FCC - that would be impossible without bandwidth regulations. And it does much to ensure that the powers that be are never exposed to ideas too far outside the "main-stream". You'd be a fool to believe that anybody involved in the process ever cared about a tragedy of the commons ever, that is simply bull - it is such a lie, it almost hurts.
In fact, the FCC regulations are some of the few laws in human history that protect against something that we have never even witnessed, ever. You would think that with all these regulations, they would at least have some example of why we need them. for all this regulation - there was never even a single exapmle of this happening
Why Digital Radio Is Bad (Score:1)
For starters, this would mean U.S. commercial radio stations would have to pay double royalties to broadcast the same music they do now. (Check out the Digital Performance Right in Sound Recordings Act of 1995 [loc.gov].)
Also, I think any switch that eliminates the current spectrum model would be disastrous for other reasons, too. (Fragmenting the current unified, ubiquitous radio audience into groups with and without digital receivers, for one thing.)
I'm not a lawyer or a (legal) broadcaster. Just so you know. But I think digital radio is a Bad Idea(tm).
Re: (Score:2)
Re:Sarnoff started the whole mess. (Score:2)
Right down the pooper (Score:2)
Present IEEE standards issues (Score:2, Informative)
The author is out of touch with the issues now facing those of us now working on IEEE 802.11 [ieee802.org], .15 [ieee802.org], and .16 [ieee802.org] standards. The primary problem 802 has at the moment is that almost all of its draft wireless standards (e.g., 802.11g, 15.1, 15.3, 15.4, etc.) are being planned for the 2.4 GHz ISM band, due to its combination of near-worldwide unlicensed availability, suitable (i.e., relatively wide) bandwidth, and technical practicality (small antennas, possibility of cheap CMOS RF implementation, etc.). The major exceptions are in 802.16, the WirelessMAN(tm) Metropolitan Area Network standards, which typically employ such a high data rate that even the 2.4 GHz band is too narrow; however, even there, the 802.16b task group is developing a standard for the unlicensed 5-6 GHz band.
The difficulty is coexistence, or how all these standards will affect each other when networks using them are placed into service. This concern started as a Working Group issue, and was addressed by coexistence task groups (e.g., 802.15.2 [ieee802.org], 802.16.2a [ieee802.org]), but has now bubbled up to the 802 LMSC itself, with the recent formation of the 802 COEX coexistence study group. 802.11 has become the 800-lb. gorilla in the 2.4 GHz band, microwave ovens included, and it is far, far from the truth to say that just because every system involved is spread spectrum the band may automatically be shared among many users.
Spread spectrum offers protection only to the extent of its processing gain which, for direct sequence systems, is defined as the ratio of chip rate to data rate. Present FCC regulations for the 2.4 GHz band specify a minimum of 10 dB processing gain; this requires a chip rate that is 10x the data rate. As one can see, to get significant processing gain one either (a) raises the chip rate, and the associated current drain of the product, to a high value, or (b) reduces the data rate to a low value. Neither of these is attractive when one considers that even a ratio of 40 dB (10,000x) is insufficient in many interference scenarios; worse, the FCC is proposing to eliminate the 10 dB requirement completely so that OFDM (Orthogonal Frequency Division Multiplex) signals, like those proposed for 802.11g, may be used.
CFR 47 15.247 devices, like 802.11 and .15 devices, are sold under the condition that they must accept interference to them caused by other devices. This was essentially a regulatory passing of the buck to the "free market," which has a spotty record in telecom (cf. U.S.' multiple cell phone standards vs. GSM). Since 802.11b has the largest installed base, any standard that follows that produces interference with 11b devices will have a hard time gaining marketplace acceptance; at the same time, brute force technologies to avoid interference, such as the use of processing gain, are insufficient. This leads standard and product designers to design ad hoc coexistence mechanisms to identify and avoid specific, predetermined interferers, an inefficient, piecemeal approach that places later, next-generation devices at a disadvantage over existing ones. The result is that 802.11 derivatives are going to defacto own the 2.4 GHz band in most corporate and (later) home environments; anything new in the band must carry the coexistence burden with it.
So, if 802.11b is the model for "Free airwaves," it's a poor model; it's more MS open spectrum than linux open spectrum.
Re:Present IEEE standards issues (Score:1)
802.11 isn't a model; it's an illustration. Despite all the problems you describe, *and* the fact the FCC had no intention to facilitate widespread short-range wireless data connectivity, that's what we got with WiFi.
What if the FCC started with the goal of facilitating effective spectrum sharing? What if engineers had more latitude in defining the rules? Sure, there would still be plenty of interference issues, but overall we'd have more efficient spectrum utilization and more innovation.
That's my point in the column and my open letter to the FCC, which is at http://www.edventure.com/conversation.
-k-
Kevin Werbach
Editor, Release 1.0
kevin@edventure.com
Re:Present IEEE standards issues (Score:1)
Kevin, my point is, Wi-Fi is *all* you're going to get in that band; its economic value to (mostly corporate) users will ensure that sources of potential interference will be carefully scrutinized. Other applications of 2.4 GHz will have a difficult time overcoming real or percieved interference issues (cf. Bluetooth's PR problems now). Significant (in the economic sense) future innovation is most certainly not going to occur at 2.4 GHz; users of Wi-Fi wouldn't allow it unless it could coexist and, as I've stated earlier, designing low cost, low power wireless devices to do so is a nontrivial task.
The FCC *did* start its regulation of the 2.4 GHz ISM band with the goal of spectrum sharing
(And Keven, you're right: Don't complain about being called "the author" -- many authors of
Re:I made a machine that used gamma waves (Score:2)
Bruce Banner