Slashdot Mirror
The Illusion of Spectrum Scarcity
Codeine writes "Presentations
to the Technical Advisory Council (TAC) of the FCC by Vanu Bose "Software
Radio: Enabling Dynamic Spectrum Management" and by David
Reed "How
wireless networks scale: the illusion of spectrum
scarcity." Counterintuitive results from multiuser information theory,
network architectures, and physics: Multipath increases capacity, Repeating increases capacity, Motion increases capacity, Repeating reduces energy (safety), Distributed computation increases battery life, Channel sharing decreases latency and jitter. Highly recommended presentation suggesting that the cost of spectrum management by "exclusive property rights" mandated by the State outweighs the advantages we could obtain
from a new model that acknowledges physics and the 70 years of receiver development since the regulatory model was adopted at the time of the sinking of the Titanic."
Like we need to encourage people to use more capacity! I have more waves buzzing around me already than I know what to do with! I can feel my nuts being sterilized as we speak...err, maybe I should take my Dell lAttitude with 802.11b off my lap.
Yeah, that's better.
On a serious note we really need this, I want technologies that can let my 802.11b network at home work without interfearing with my cordless phone and 2.4gig audio/video transitter and reciever. Right now they all fight for the same spectrum and all lose in someway or another.
-Pete
Soccer Goal Plans
it was better the first time.
underestimating the seriousnes of the article...
I think.
"The majority is always sane, Louis." -- Nessus
http://slashdot.jp
"It is a greater offense to steal men's labor, than their clothes"
I want technologies that can let my 802.11b network at home work without interfearing with my cordless phone and 2.4gig audio/video transitter and reciever.
Strangely enough, these are all on unlicenced bands. Sounds like we still need the regulatory bodies to keep the spectrum in some semblance of order.
This is not to say that we shouldn't look into the technologies (quite the opposite). We're just simply not there yet. It would be good to set aside some spectrum for this, though, as a playground for developing new transmission techniques and receiver designs.
"I have opinions of my own, strong opinions, but I don't always agree with them." -- George H. W. Bush
There will always be centralized overall spectral management. Communications may be able to be given blocks which are decentrallized but they are not the only users of the spectrum. For example radio astronomers are currently allocated particular bands for operation. Their observations won't be possible if J random cellphone is pouring energy into their band. Also radar systems of various types don't benefit from having increased nosie floors in their operating bands. GPS signals also don't benefit from increased noise floors, you would loose lock on the satellites more frequently.
Great idea. Let all frequencies be free for anyone that wants to transmit. I bet everyone would cooperate and noone would ever dream up something like "Hey, why dont we get ourself a really really strong TV tranmsitter and start tranmsitting 15 second blurbs on the same frequency that popular channel XYZ is using?"
So I guess you didn't bother reading the article then?
a new model that acknowledges physics and the 70
years of receiver development since the regulatory
model was adopted at the time of the sinking of
the Titanic.
The Titanic sunk in 1912, that's 90 years.
....Captain Scarlet would never abandon us to the Mysterons!
Games Workshop Petition
Slightly off-topic, perhaps, but the current limits of the radio spectrum are transient and purely technical. By definition, so is the need for government regulation.
I am no specialist in the area, but for all practical purposes signal-transmission "on the air" are limited only by the technology we use for transmission and reception. The need for regulation is strictly derived from the practically available technology at any given time.
Currently, transception(?) capacity at any given frequency range is dictated by the frequency bell-curve nature of any radiosignal (i.e. "channels" per range), and data density over time (i.e. bits per second per channel).
In theory we could cram an almost infinite number of bits into an almost infinitely small timeframe into an almost infinitely small frequency-range.
But not today... hence all this clueless babble.
The limits has changed in the past, and they will change again in the future. A lot! Take heed of this, Powers That Be.
For the sufficiently clueless, even trivial applications of common sense are indistinguishable from wisdom
This is a philosophical discussion, but let's also look at the technology.
There are reasons to control. As a licensed radio ham (VA3MVW) I can assure you that if everyone were allowed to broadcast on shortwave ( 30 MHz) we'd have chaos. A kid in Brazil who uses $15 in parts to create a 10W shortwave transmitter can make an entire band unusable in all of Europe. Shortwave covers the world and there is very little bandwith - all of shortwave is only 30 MHz.
The reason things are getting easier now is twofild: technology and physics. Technology, because we can now transmit on GHz frequencies - unheard of just a few years ago. And physics: if you go up in frequency, bandwidth becomes almost infinitely available, antennas become shorter, and range becomes shorter (so less interference).
In other words, good reasons to control low frequencies and good reasons to allow much on wide bands of high frequencies. Which it seems to me is exactly the way it is happening.
Michael
---
BDOS ERR ON A:>
I would be willing to bet that you can.
Never trust an atom. They make up everything.
then it relays signals a short range to its neighbors...and doesn't broadcast all over the world. Spectrum at HF _is_ a scare resource because it bounces all over. But at line of sight frequencies, if radios have relaying and forwarding capability, then the total capacity grows with the density of radios.
Imagine every cellphone as repeater and network router able to forward several connections and software able to manage such a dynamic network. Then each connection only has RF signals that spread out around the path between all the routers. This means less radio signals falling on places that don't want to receive the signal.
He's just someone that understands physics and radio, unlike all these "armchair broadcasters" on Slashdot.
As ham radio operators, we know what it is really like out there, we know what an uncontrolled band is like.
Microwave is different, and more freedom there is justified, but when someone spouts bullshit like the original parent post, we have to call them on it.
I've had enough abrasive sigs. Kittens are cute and fuzzy.
Well, first of all, the market would definitely help out in this fashion -- if someone is hijacking your TV show that you're watching, notably, an advertiser, would you go out and purchase that Whopper or that Nissan or those Nikes, knowing full well they are paying for some spammer to overrun the show you're watching? I think not.
Without SOMEONE paying for the transmission costs, the blurbs won't last. And whoever pays for them will definitely see a huge backlash, even if just a few percentage of the viewers object to the frequent interruptions.
As a libertarian, I have fought for many years to try to convince people that if the airwaves are indeed public, and I believe all communications is speech (including computer code), Congress shall pass no law infringing on my right to speak.
If I am in a room with 10 morons spewing corporate advertisements out of their boomboxes, and I want to blast my boombox 3 times louder, none of us will get anything accomplished -- the same is true of the airwaves. Why doesn't the FCC control the vocal frequency band of transmission, it is no different than someone broadcasting a low-powered radio transmission, and it is done over airwaves.
Finally, after years of screaming that we have too much bandwidth, and people telling me I'm nuts, scientists who aren't bribed by the broadcast industry are coming out and showing that I've been right all along.
Now if only real scientists would start coming out and blasting the socialist fraud we call the "decaying environment." Oh, they already have. They're called the founders of Greenpeace, and they know the truth about the current socialists running that organization.
Freedom = Responsibility.
Government = Corporate Abuse
There was a similar article posted on Slashdot a week or so ago.
Yes, advances in technology have greatly increased spectrum efficiency, to the point where we are nearly at Shannon's theoretical limit. But so far, there is nothing at all that indicates we have any way whatsoever of passing those theoretical limits.
Yes, cellular techniques can greatly increase capacity. But the question is - Is the complexity worth the added cost? For some systems, such as the cellular telephone system, the answer is yes. But for others (such as broadcasting), the answer is most definately no. (This may change soon - If we ever get flatrate 3G services, there's a good chance that could replace broadcasting. But that is a LONG way away.)
And let's not forget the huge installed base invested in the old technology. Throwing that all into the junkyard is not worth using newer and more efficient (but much more expensive) technologies.
One of the earlier posters (a ham, like myself) made a number of very good points too. Even with "infinite" spectrum, the FCC has to exist to regulate the airwaves somewhat to prevent interference between stations, especially malicious interference. Someone said it would be nice if their cordless phone didn't kill their WLAN equipment - How would you like it if your neighbor's WLAN equipment was wiping out your cellular calls, and you had no legal recourse whatsoever against him? That's what the FCC is here for.
Anyone who argues that the spectrum is infinite is talking BS. The spectrum itself is infinite, but the USABLE part is not. There are physical limits to which frequencies we can and cannot use. Those limits are expanding rapidly, but resources are still finite.
A final point - The increased complexity of cellular systems means reduced reliability. Their reliability is extremely high, but still, it is more likely to fail than other technologies, such as point-to-point radio, which will always have its place even though cellular phones are beginning to replace two-ways in many areas. 9/11 is an example - Despite being a theoretically higher-capacity system than "low-tech" NBFM two-way radio, the cellular system in NYC was quickly rendered useless by a combination of infrastructure damage and overloading. For at least a month and a half (I don't remember the exact time period), amateur radio (ham) operators provided a significant portion of the emergency communications capacity near the former Twin Towers.
retrorocket.o not found, launch anyway?
OK, so you've got an argument against that point. So, how about this?
I don't know if you are married. Let's suppose you are. Your wife is having a heart attack. You call 911.
Now, how would you feel if some kid with a 35W VHF transmitter goofing around on the police and ambulance dispatch frequencies prevents any help from reaching your house (or even knowing that they're needed), and your wife dies due to lack of proper medical attention?
Or your house burns down because someone's screwing around on the fire dispatch frequencies?
Thanks to the FCC, there is recourse against such people (HEAVY fines and serious jailtime - People don't take kindly to those who mess with emergency frequencies. Penalties are usually far less for someone broadcasting pirate radio (who the FCC may even overlook because they have better things to do) or someone intentionally screwing with a broadcast station.
Without the FCC, it's chaos, and our emergency services are in the Stone Age.
retrorocket.o not found, launch anyway?
The kid in Brazil is allowed to access the shortwave band as long as he uses the right equipment. He gets his license and he follows the rules established by everyone.
I think that bandwidth could be used a lot more efficently. Right now we are treating the spectrum like the analog medium it is. But a digital treatment is more justified. If we were to break everything up into packets, use reapeaters what not, we could achieve a far more efficent utilization of the airwaves. Nearly all bandwidth is allocated to something. But at the same time, most of it is unused at one instant. Using packets like the internet does could do a far better better job of utilization.
HOWEVER, it would require more control, not less. The government would need to mandate all radio equipment manufactors meet new standards (much more rigorous than they do now). All legacy equipment would need to be replaced. New laws would need to be drafted to regulate the medium better.
But so much more is possible. We're using an abundant natural resource like cavemen, and we could do better.
A good libertarian would tell you that getting his wife to the hospital is his responsibility, not the governments.
Likewise for the fire arguement.
-asparagus
Everyone uses the new technology model to handle radio waves.
If one person follows the old pattern, he can seriously degrade if not destroy an entire band capacity by throwing what the new model considers garbage into the stream.
Error-correction works only so far.
~ kjrose
I make this point to some degree in another post, but I'd like to make it clearer here.
The "pirate radio" phenomenon is the exception, not the rule. They are the example of a small few people who are responsible enough not to interfere with other users of the spectrum. Yes, they might be unlicensed, but they (in most cases) aren't trying to interfere, which is why the FCC puts little effort into shutting them down, and the FCC might not even know about many of them. (The FCC doesn't take place too much in active monitoring - They are more like an FBI of the airwaves, investigating complaints of users of the spectrum.)
The moment one of these "pirates" interferes with a major broadcast station, the FCC will come down heavy on them.
Screw with an emergency communications frequency (Police, fire, ambulance), and welcome to a whole new ballgame... One or two complaints is all that is needed for a few FCC vans full of DF equipment and probably a few conscientious hams (who may be likely also legit users of the frequencies you interfered with - many volunteer firemen, cops, and EMTs have ham licenses) hunting you down.
retrorocket.o not found, launch anyway?
Good luck with that puny little fire extinguisher against even a medium-sized fire.
The fire department and the ambulance crews are in possession of firefighting and life support equipment that you likely cannot afford. They are also likely to be far more highly trained than you are.
Knowing your limits and when it's better to hand things off to someone who knows what they're doing when you don't is as much a part of intelligence as your own skills.
retrorocket.o not found, launch anyway?
Politinian? bling bling!
-- OMFG = Oh My Floatse Goatse
... because they couldn't pass the 5 WPM! ^_^
(He-he-he! ^_^) 73!
Sounds like you could have the ultimate finger-pointing nobody-is-responsible multivendor nightmare. Everything works fine for the first couple of years when there isn't much of the stuff around... and then a few more years down the road nothing quite works because the spectrum has been polluted...
and the "cause" is twenty thousand different devices in your vicinity, two thousand of which aren't quite up to standard?
"How to Do Nothing," kids activities, back in print!
Two (or more) radio transmitters on the same frequency within range of the same receiver will interfere with each other to the extent that usually one of them will not be heard well (or at all). The idea of "software radio" changes nothing unless every transmitter conforms to the same sets of rules and knows exactly where all the other transmitters are and what they are doing.
Even at microwave frequencies someone with a baby monitor on all the time at 2.4gHz will likely cause you problems with your WiFi network if it's close enough; or between you and the main antenna. One unmanaged device would be enough to create problems for everyone in its vicinity even using the software radio methods.
Government regulation of radio frequency spectrum was designed to minimize interference and create "bands" where users could reasonably expect the service they want to be located. Otherwise you would have to search through 10gHz of spectrum to find NBC news. Their concept of "software radio" only works if these radios know every source of possible interference in a geographical area and moves in the right way to avoid it. Who determines which way is the right way seems to me to be important and I'd much rather have a government entity do it.
In addition, the implementation of this system would pretty much require that all the other transmitters be confiscated and destroyed to keep them from mucking up the works.
No one ever had to evacuate a city because the solar panels broke!
Or did you mean S/S Titanic perhaps? ;-)
--
If you moderate this, then your children will be next.
>70 years
The Titanic sunk in 1912, that's 90 years.
After Sonny Bono's heirs get done with it, it'll be 110 years.
Will I retire or break 10K?
The kid in Brazil is allowed to access the shortwave band as long as he uses the right equipment. He gets his license and he follows the rules established by everyone.
s/everyone/entertainment industry lobbyists/
Will I retire or break 10K?
Government regulation of radio frequency spectrum was designed to minimize interference and create "bands" where users could reasonably expect the service they want to be located. Otherwise you would have to search through 10gHz of spectrum to find NBC news.
Likewise, government regulation of Internet addresses was designed to minimize interference and create "bands" where users could reasonably expect the service they want to be located. Otherwise you would have to search through 4 billion IP addresses to find MSNBC.
Their concept of "software radio" only works if these radios know every source of possible interference in a geographical area and moves in the right way to avoid it. Who determines which way is the right way seems to me to be important and I'd much rather have a government entity do it.
Sounds logical. After further research into packet radio protocols is completed, I propose government-regulated location service on a dedicated location band and then a band for simply broadcasting packets.
Will I retire or break 10K?
5 WPM???
:)
Bah, not even that hard. I have a Tech-class license due to laziness.
Right now, that's what - a 55 question multiple choice exam that normal 7 year olds can pass (and have done so numerous times?)
I'll get my Extra one of these days. (General? Bah, why settle for that when the diff. is one more multiple-guess exam these days?)
retrorocket.o not found, launch anyway?
If I set up a 138db WW II vintage air raid siren in my back yard for fun and start testing it out -- in all likelihood I'll be dealt with by the local authorities who will be called in by just about everyone in a 1km radius.
On the other hand, if I'm talking to my neighbor over the back fence and some Feds showed up to stop our "noise" the local authorities (presuming this is a jurisdiction that doesn't receive a lot of Federal subsidies) would likely arrest them.
Seastead this.
Even without increased capacity, there are ways to share the airwaves without having anyone own them.
Sorry, but the idea of the government -- or a company -- controlling or having the rights to a certain frequency is about as obnoxious as the government saying they own all the air in the US.
The very same technology that regulates printing in LAN's at universities can regulate the airwaves. Two people send a request to a printer to print a document at the same time; the printer doesn't know which to process first, so it waits a random number of milliseconds (different # for each terminal) and then sends a repeat request; whichever one gets back first is printed first. Another way to do it would be to have the printer just randomly pick one. An alternate, and superior way, would be for the printer to print the shorter document first.
Similar algorithms could govern who is using any particular frequency at any particular time.
Furthermore, let us not forget that we don't have to deregulate the entire spectrum in one swoop. We could deregulate half of it first and let the technologies for controlling access to that half perfect.
The point is, everyone should have access to the airwaves. It should not be based on how much money you have. No one has any right to claim they own the air or the airwaves, just as no one has the right to claim they own their air: that's bullshit.
social sciences can never use experience to verify their statemen
Similarly you talk about fighting a fire with nothing more than a fire extinguisher - why the hell wouldn't a commercial service exist like with everything else you need? Fire protection would become a branch of the insurance industry like it was in the past.
Your argument is inconsistant.
In the past, a community of people dontated their time and effort to put out fires. If the fire department were commercialized, the cost to put out fires would skyrocket and be less effective. Eventually, there would be firemen's union demanding more benefits, more money and less work.
(Right now I think there are FM unions, but since they are gov't employees they aren't allowed to strike.)
Government control of important services is a requirement because greed and power are too important in a capitalist nation.
"The area of penetration will no doubt be sensitive." ~ Spock
I don't understand how the use of repeaters can increase capacity. Since a repeater uses twice the bandwidth (instead of a single channel now you have an input channel and an output channel) you are using twice the spectrum as direct communications.
Repeaters increase range. That is all they do.
. Quit playing Monopoly with Bill. Switch to one of many non-Microsoft products today.
There are plenty of ways free agents can control unlimited broadcasting - just look at the Usenet Death Penalty. In the most recent case, the UK cable company Blueyonder was allowing unlimited news relays off its cable-modem customers. With the threat of the U.D.P. from other ISPs worldwide they voluntarily isolated their network from Usenet and started to clean up their act.
There is every reason to think that broadcasting would be the same. Merely broadcasting on someone elses band in a given area (with areas getting smaller with the wavelength) is merely inviting a blocking transmission from everyone else - so it would achive nothing and the rights of existing broadcasters would be upheld. Very soon people would respect wavebands as much as they do now.
I don't buy the big winge about cops and ambulances. Why can't they use a modern technology like voice over 802.11b or at least make some attempt to drag themselves out of the 1930s? Both the police and healthcare providers should have the same rights as other citizens, no more.
Criticisms of maxi-min arguments coming from a Libertarian... how ironic... You might want to ask yourself why local governments took over the role of firefighting from the insurance companies in the first place. Clue: It wasn't so that they could raise taxes and thus oppress the freedom loving taxpayers with a second rate fire department. And few fire departments are second rate...
You are not alone. This is not normal. None of this is normal.
When radio first started being used, it was not regulated. Anyone could use any frequency they wanted at any time. The end result was that the radio spectrum became virtually unusable due to massive interference. This was why the ITU was founded, and why the FCC was created. Left to free agents, frequency wavebands have been proven to settle into utter chaos. Read up on a little RF history, before you decide to repeat failed experiments.
I don't know that this is true. in that the 300 mhz of bandwidth is still 300 mhz of bandwidth.
That said, the original article I cited has this info:
Please note that channels are not defined as a percentage of the total frequency, but are defined as the bandwidth needed for a specific application. A TV Video channel is much wider than an Audio channel because of the off the much wider bandwidth needed to handle video data. It is so much range of data signal communicated on or at a specific frequency.
You could very easily have AM radio in the gighertz band. 44khz band width (CD audio. etc) on a frequency of 4 giga hetrz. But it would be rather line of site, among other technical issues.
take a look at FM Radio. Frequency modulation only varies enough frequency enough to carrier the Audio as well as specialty signals like stereo information, etc. This makes an FM channel wider than AM (56khtz wide) but very small compared to a gigahertz range.
so there are a lot of channels there. This is why you see FM radio stationsd at 100.1, 100.3, 100.5, 100.7, 100.9, etc - Each of these are a single FM channel.
"It is a greater offense to steal men's labor, than their clothes"
It seems clear many posts are off the mark.
There were two main subjects. Software radio and how networking affects spectrum capacity. Note that this has little or nothing to do with UWB (ultrawideband).
(1) Software radio: This technology is still expensive, but costs are dropping rapidly. Normal radios are hardware designed for specific tasks, work at a specific frequency band, use fixed modulation schemes, and fixed energy levels. A software radio does all the work with a CPU. Just load up a new program and all aspects of the device are upgradeable. One device can work as a digital or analog cellphone using US or european protocall, or any future protocall. It can be reprogramed as a CB, TV, Walkie-talkie, HAM radio, beeper, intercom, 802.11, or bluetooth device. Heck, you could leave it on your dashboard as a police-radar detector. New protocalls can be downloaded on-the-fly. You can then upgrade the system without replacing $billions of obsolete hardware. Bandwidth can also be dynamically allocated were it is needed. Much radio capacity currently goes to waste - it's like reserving 15% of your bandwith for browsing, 10% for streaming audio, 20% for video, 20% for games, 5% for email, 15% for FTP, etc. Current regulations are an obstacle to software radio.
(2) Second was an analysis of the obsolete paradigm of treating radio spectrum as "property". This was based on a fundamental result that data capacity is equal to bandwidth, and that bandwidth is limited. The more devices in the system, the less data capacity each device can get. Try to use 1000 cellphones (or wireless laptops) in one place and the system dies. This is a result of analyzing a simple point-to-point or broadcast system. New systems working as a network throw the old rules out the window. With the proper protocalls each device added to the system can increase total capacity enough so that with more devices in the system, each device still gets the same data capacity. Data capacity per device is no longer a limited resource. It is also based on an obsolete interpertation of interference. In current radios, when two signals at the same frequency arrive at the same place there is interference and the information is lost. This is merely a flaw of current designs. Using "smart" antennas multiple signals at the same frequence can be received without interference. It turns out that multi-path "interference" can actually increases capacity, as does motion. It also allows lower power levels to be used. These results fly in the face of traditional electrical engineering, but they are solid physics/mathematical results. (Watch the presentaion before you argue that I'm wrong.)
In the next serveral years we may be in for a radical change in the way radio is used and regulated. These changes will enable "always-on" wearable networked computing.
-
- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
"Multipath increases capacity, Repeating increases capacity, Motion increases capacity, Repeating reduces energy (safety), Distributed computation increases battery life, Channel sharing decreases latency and jitter."
People seem to forget technology is the great equalizer when it comes to limited resources. It's why we won't run out of oil in 2010 and why crowding won't remain a problem. It's using what you have more effciently, not basing your results on a static idiology when the world you live is in a dynamic progression.
You need a FREE iPod Nano
Now, how does this compare to, say, dealing with an abusive transmitter? If Fred Smith wants to insert his own commercials over the frequency of the local rock station, what exactly prevents him from doing so in the unregulated libertarian paradise you apparently believe is possible?
Can the rock station deal with it? If so, how? Can Fred Smith's customers boycott him? Would it not depend on what he's selling? Would it not depend in part on whether enough listeners ignore any boycott over something that he wouldn't have advertised a normal way anyway - look at spammers for an example of this business model. What if he seriously doesn't care - what if what he's saying isn't an advert, but, say, an attempt to get a message out about something (maybe he's a crackpot libertarian... ;-), or a musician trying to get airtime, or a politician knowing that the news is going to be unflattering so putting out garbage to block it? What if he just hates rock music, being some John Ashcroft type who believes it's the devil's work?
Arguably, there should be less regulation of the airwaves, and there should have been less even in 1911. But it's a long step from that to "should (never) have been controlled by the government". Very all or nothing. The, er, "maxi-min" argument, as someone was complaining about earlier. Oh wait, that was you...
Basically it goes like this: Cops and ambulances are there to protect us. If their job is as unhampered as possible, they are likely to find it easier to deal with and prevent life threatening situations.Now, if you want to tell me that cops shouldn't be given carte-blanch rights to imprison anyone they feel like, invade private homes without warrant, etc, then I'd agree with you. I'm a big supporter of the Miranda ruling, the fourth ammendment, etc. But giving them some frequencies to work on so they can communicate without, say, someone on a cordless phone in the local vincinity cutting them off, seems a damned good idea to me. It doesn't exactly cause undue hardship to everyone else.
Kind of like I think it's a good idea we pay them wages. It's a small slice of my wage packet to do so, but I'm figuring they'll do a hell of a lot better job protecting my life and property if they don't starve to death.
You are not alone. This is not normal. None of this is normal.
just look at the Usenet Death Penalty.
It's just a little bit harder to build a huge faraday cage around a rouge transmitter, than it is to null route someone. Your posts show a lack of basic understanding of radio.
is merely inviting a blocking transmission from everyone else - so it would achive nothing and the rights of existing broadcasters would be upheld.
These "blocking transmissions" would prevent the legitimate owner from using the band as well. Do you know anything at all about radio?
I've had enough abrasive sigs. Kittens are cute and fuzzy.
Repeating is a method to relay a signal where a direct path does not exist. The idea of inserting repeaters into a path simply to reduce emission levels where a direct path does exist is not going to reduce the energy required to establish communication.
I guess if you wanted to look hard for a benefit you could say that the field strength will be less at each transmit location. Maybe that's a good thing. Certainly the transmit power and antenna system requirements will be less at each location which would make the equipment last longer and make it much smaller.
But actually reduce the energy? Come on!
. Quit playing Monopoly with Bill. Switch to one of many non-Microsoft products today.
Am I missing something here? Or are these guys just loopy?
This article and the one from last week seem to be saying the same thing: that since it's politically inconvenient for spectrum to be limited, the authors will just declare physics to be null and void and there will no longer be such a thing as wave interference.
Sure, if you can convince everybody to destroy all their old equipment and replace it with new equipment that uses software scanning you can get more virtual bandwidth out of the same spectrum. But it's not going to be infinite and a few jerks with a few kilowatts of transmit power are going to be able to cause a bunch of problems with this scheme. And considering how much luck there was getting much consensus among shortwave users about trivia such as dropping morse code requirements for licensing, how much cooperation does anyone anticipate on something as blue-sky as this mess?
That way, they get more $$ for it when they auction it off.
The 'steward' of the public's airwaves has become nothing more then a money grubbing whore, whose main existance is to fill the treasury's coffers.
Yes, the Squadron of Orange Geese, oops... The fleet of roaming digipeaters is more efficient than the point-to-point connections requiring a lot of power or the cellular network requiring the ground-based backbone. But:
The roaming digipeaters use the power which is much more expensive than the cellular base power: the battery power of tiny pocket devices. It means that my cellphone will, say, work during 1 hour instead of 8 but the collaborating cellphones will provide the absolute coverage without gaps. I am not sure it's worthy the battery.
And the second. The business model of the cellular as well as wireless Internet providers is to spend their money for the equipment and to collect fees. So they can invest to the cellular networks. The fleet of roaming repeaters may be technologically efficient but IMO there is no incentive for services provided with such devices, which means that the self-supported community without the big business support will never buy enough devices to drive prices low. Moreover, the self-supported community is the competitor for the traditional cellular systems and as such will be suppressed.
As an illustration: There is a voice-over-IP technology. There is 802.11 technology. Show me the 802.11 voice-over-IP pocket phone with builtin repeater. I fear such a device will never be able to compete.
Hopefully I can help clear up some of the extreme misunderstanding of this topic. I am not an expert but I think I understand what is going on better than average.
1) Data capacity is being measured in bit-meters/second because the important question is how quickly can I transfer data between point a and point b. His claim is that technology exists that can make this total capacity grow linearly with the number of participants (and hence essentially no interference occurs between unrelated connections).
The traditional technique to move data from point a to point b is to broadcast at point a with power enough to reach point b on a single fixed frequency slice. imagine point a and b on a map, draw a circle around point a with point b on the circumference. All of the area of the circle has been polluted with the signal. Instead we can use low powered repeaters and have a chain of small circles. Most of the area is unpolluted. Together with spread spectrum, and clever processing with multiple antennas we can pack a lot of information into the available physical and bandwidth space.
The claim is not that our current stupid allocation of radio broadcast stations can be used by everyone at the same time, but that there does exist a technology that will work.
The technology he is talking about is to use low powered high frequency software controlled radios. Each station would be a receiver and relaying transmitter.
Using some system like ipv6 or something cleverer, data is routed through a tight path from radio to radio until it reaches its destination. Because of the nature of radio (and the inverse square law) transmitting this way uses far less total power, and interferes with far less of the world (because the path is a series of tight little circles instead of one enormous circle of radius = distance between endpoints).
The addition of land based cable or optical routing repeaters could scale this even further.
By using radios that can be controlled by software we can continuously improve the bandwidth allocation and routing technology and better sharing of the overall spectrum without the problem of legacy hardware.
Together with intelligent processing of interference with multiple antennas and signal processing techniques, we can scale our wireless data carrying capacity (bit-meters/sec) several orders of magnitude over what we are currently able to use.
If we build the system in layers, we can add application layer protocols like voice over inter-radio, and video over inter-radio, and soforth. If the protocol is smart it can also be linked to land based fiber networks and improved further.
As it is with only a few people controlling fixed slices of bandwidth, I would guess that we might scale total wireless information capacity usable by individuals by 6 to 9 orders of magnitude using these techniques.
((lambda (x) (x x)) (lambda (x) (x x))) http://www.endpointcomputing.com a scientific approach to custom computing.
Corporate controlled fire departments? You have to be joking. You think an occasional 30-minute response time is bad... I don't even want to think about what FDs would be like if they were commercial and privatized. 30 minutes would still be an exception - But exceptionally fast instead of exceptionally slow. Such things are the trend in corporate America. And would you take a care to guess one of the possible causes of slow response times? I suggest you take a look earlier in this thread and you'll see where I'm going.
I've never heard of a fire department "holding a city for ransom" - Hell, probably 50-75% of all firefighters are VOLUNTEERS. The government provides the equipment, not the salary.
retrorocket.o not found, launch anyway?
What Gupta and Kumar showed was that total capacity scales as sqrt(n) (repeating DOES increase TOTAL capacity! not just range). However per conversation capacity scales as n/sqrt(n) = 1/sqrt(n) -> 0 as n -> inf.
But Gupta and Kumar assume that when one station is transmitting, all others within its radius must be silent.
What Reed claims to be able to take advantage of is the technology of spatial and multi-path deconstruction using software radios that use multiple antennas to seperate multiple signals arriving at the same time on the same frequency. This technology is known as BLAST, and can be found at: ATT bell labs site
He seems to claim that the combination of multi-path software signal processing, cooperative repeaters, motion of many stations, and a cellular type access to wire or fiber backbones mean that for every new user the total capacity increases enough to support that user without degrading everyone else.
He doesn't seem to have a mathematical proof, but I am thoroughly convinced that we can at least massively scale individual's access to radio based data transmission with better technologies, and it is already the case that the regulations are terrible. So many of his points are right even if hhis theoretical result isn't perfect.
((lambda (x) (x x)) (lambda (x) (x x))) http://www.endpointcomputing.com a scientific approach to custom computing.
I agree the GOVT should not grab spectrum but I totally disagree with your thesis that spectrum should be private property.
When things are "privatized" they become subject to rent capture, you dummy! NY and DC just print as much money as necessary to capture anything in god's universe that can return RENTS. To NY and DC, the world is nothing but hydroelectric sites. Wherever there is a narrows or a chokepiont in ANY economic process, they capture rents. Isnt' that NICE? Grrrr.
Todd Boyle CPA Kirkland WA. Overthrow the Govm't!
You don't need smart antennas or anything expensive at all.
p df
There are already mesh routing products like Nokia Rooftop that
achieve the 'multiplying bandwidth' phenomenon.
The mathematics of mesh networks and swarmcast demonstrate an interesting phenomenon that the more nodes who stick their antenna into the cloud, the more routes appear and there is a virtuous circle of improving performance. This principle is supported by Nokia papers on the 802.16 workgroup's site. http://wirelessman.org/ "Mesh coverage & robustness improve exponentially as subscribers are added" http://wirelessman.org/tga/contrib/S80216a-02_30.
Instead of heat death, from packet congestion you get a virtuous cycle of greater capacity because more paths are available. Unregulated, and all but unregulatable. Just like oral speech and visual eyesight-- except having unlimited range.
There is a voracious, out-of-control design and chipmaking industry, realizing this vision which will happen with shocking suddenness, as hardware manufacturers create the transceivers and home-owners and apartment dwellers just stick them on the roofs. You will buy these at Walmart and in drug stores for $50 in about 12 months from now,
Todd Boyle www.gldialtone.com
You have a point. Having airwaves owned by governments is a Bad Thing. Having them regulated by government agencies is also a bad thing, as that is just like the ownership - if you can regualte something you by implication have ownership of it. How about letting nature take its course and waiting for a non-government ownership model to arise? Spontanious order and all that?
In nature there's really no such thing as anarchy. When you have anarchy the very next thing is one person or group of people form a dictatorship.
Good anarchy requires a minimum of rules, I think, and that would be the essence of democracy. What takes terrific amount of work is to dislodge the special interests who exploit the power.. etc. etc.
They should teach in elem. school, the problem of distributed costs and concentrated benefit (the special interst problem) instead of bullsh*t like the pledge of allegiance to Wash. DC
Sorry for the digression... my instinct just tells me, today, radio spectrum is ridiculously SCARCE and until technology makes it abundant, some mechanism is necessary for allocation of the scarce resource instead of allowing it to be wasted in arbitrary ways!
Thanks fr your patience
Todd
Todd