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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"
It should never have happened. As pointed out above, government usurption of radio transmission is just another 20th Century fraud. There isn't anything *about* airwaves that means they could become the property of some official - after all, they have never actually stamped out "pirate" radio (note how they use the same terminolgy today for software). Left to free agents frequancy wavebands settle into agreed usage and custom leading to tradeable ownership, like everything else in the world that the government doesn't grab for itself. It just goes to show how outdated mandated systems of control are.
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.
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
I mean come on if the government isn't giving monopolies to business then what will all those contributions be for?
For the people by the people my ass. I just cant wait till I get rich enough to buy my own politicians.
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:>
...backwards compatibility.
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.
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?
The Titanic sunk more than 90 years ago, not 70.
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.
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?
gay prodidy reference.. you are a loser
... 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!
>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.
fag fucker
you're a fucking fuck shit cock fucker fag dork ass queer loser
without interfearing with
Come on, you really didn't think that it was spelled that way, did you? Let this be a lesson to all new parents: Hooked on Phonics doesn't work for ANYBODY!!
I can't figure out why Reed's talk states that capacity increases when repeaters are used, and cites Gupta and Kumar as support. Gupta and Kumar have shown the opposite, regardless of whether there are repeaters or not-- as the number of nodes grows, the capacity available to each "conversation" shrinks to zero. Now, admittedly, this holds when every node in the network has something to communicate, and the "conversations" are random, and thus possibly distant, pairs of nodes; but this is enough to show the infeasibility of a large scale flat wireless network.
Anyone familiar with G&K care to comment?
k
i am 39.. male.. single.. and naked.. i want your ass to eat
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
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.
An excellent example of the difficulty of starting a new format is L-band digital radio, the format chosen to replace AM and FM in Canada and Europe. The papers referenced are suprisingly short on technical details, but they apparently refer to an L-band type system. Five stations share a single (large) section of spectrum each transmitting an interleaved 256 kb data stream which they are free to partition into data and audio as they see fit. One paper seems to suggest little more then extending the data section to open garage doors, etc.
The companies I've worked for have been broadcasting in this format for about five years. We still quip that the only callers when there's a problem are chief engineers of other radio stations. Why? The radios, though essentially equivalent to a cell phone front end tied to a codec, are so damn expensive. The cheapest of them, a car radio, is still well over $500 in Canada. Alarm clocks or walkmans don't exist. This after a decades worth of intense lobbying, hard work and buy-in from all the major broadcast chains. L-band is a niche market with no incentive for manufacturers to fill.
Ironically, the system the referenced authours recommend was denied in the US for L-band use because the military has reserved that spectrum.
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.
Name Frequency Max distance Method
VLF 3KHz-30KHz world coverage lossy spherical wave guide
LF 30KHz-300KHz 1000 to 5000Km "ground wave"
MF 300KHz-3MHz 100 to 1000Km "ground wave"
MF "" "" 0 to 2000KM/hop ionospheric refraction
HF 3MHz-30MHz below 100Km "ground wave"
HF "" "" 50 to 4000Km/hop ionospheric refraction
Frequencies above 30MHz go through the ionosphere.
Communications via ionospheric wave (using refraction) can work with a limited number of "reflections" (say, one or two). You can hardly expect more than 6000Km if using HF.
"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
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.
As of a few years ago, taxicabs in Guatemala are using spectrum set aside internationally for amateur (ham) radio satellite uplinks. Thus, the taxicabs in Guatemala are interfering with other more legitimately established communications over the entire Americas, and occasionally even over Northern Europe.
If you are a amateur radio operator who cares, I invite you to join my boycott of all products made in Guatemala. (This isn't a big sacrifice; the only products I can find made in Guatemala are shirts sold by Sears. I just won't buy them.)
If you are a Guatemalan public official, how about encouraging your country to follow international laws?
N8KH
The idea that "gee we have a better idea but I want more government control" to me is a child's argument.
It encompasses two childlike views:
1) New, better, shiny, must have
2) Daddy will take care of me better.
Having worked for a Wireless Carrier for over 6 years, I can say that yes, wireless spectrum management can get better. And it will. 3G wireless communications not only gives us more features, it uses technologies easier to manage and more resilient to noise. While it's debatable which technology is better, i.e. Qualcomm vs WCDMA for example, the improvement of the competing technologies is certainly better than the existing systems.
Where carriers are running into problems is maintaining the older technologies aside the newer ones. WCDMA takes 5MHZ up and 5MHZ down per channel. Add GSM (200kHz) and TDMA (30kHz), Analog, CDMA, etc and you have a spectrum management nightmare. It's not just a matter of adding spectrum, there are problems with what we call guard band. If channels are too close to each other, the energy just outside the channel can interfere with the adjacent ones. Additionally, low signals can be 'blinded' by more powerful ones, even if the signal is spectrally further away. (Think that you can's see into a car/house window when it's brighter outside.)
Also, it is better for wireless technologies to use higher frequencies. This reduces the size of your devices, and reduces interference when frequencies are reused but reduces the distance you can go. Likewise, shortwave is ideal for distance yet requires larger antennas.
The spectrum is not split up ideally for use. Wireless carriers must use the chunk given to them regardless of its properties. For example, 1900MHz barely gets into buildings, which is why you have trouble in cities. 800MHz gets in there better, but reuse will cause interference. Some bands bounce all over the place, others are absorbed by trees and terrain.
ANYWAY, to make a long story short, spectrum management is more than modulation technologies and gov't management. There's a balance of interference, distances between towers, terrain, budget, device size, etc. To say we have plenty of spectrum and 3G will solve our problems, is simply... short sighted. We would have plenty of spectrum IF the FCC reallocated everything based on the properties of that band ideally suited for the use. This is why we see the wireless companies wanting the military chunk of spectrum...
What scares me is with all these 802.11 systems going up, you'll see your noise floors rise, which will greatly reduce the distance you can move in. The average person doesn't know how to frequency plan. If unregulated, bigger budgets mean bigger broadcasting power, meaning the little guy gets fried. OTOH, people would choose the freqs best for the job to get done and leave the other bands alone.
Just my 2C.
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.
Excellent point, market pressure is ideal at taking down unscrupulous advertisers. I've got a hypothetical example even... Say someone was to send EMail that was unrequested to many people simultaneously, for the sake of this argument I will call it 'spam' after my favourite lunchmeat, it would annoy people, and no one would buy the product it advertised. Since people need money to send out this 'spam' they would soon go out of business.
It must also be the reason why we don't see my hypothesised 'pop up advertising' (named after my love of children books) or other deliberately irritating advertising tactics.
...but seriously if 'band insertion' advertising proved unpopular for big name bands, that just means your favourite TV channel would be under attack from porn ads and diet pills. Even if it's unprofitable, you know there's going to be someone willing to try.
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.
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