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Cognitive Radios Could Increase Wireless Spectrum
schliz writes to tell us that a new intelligent radio technology, dubbed "cognitive radio," is being developed that adjusts operation based on input from its surroundings. Consumers wont likely see practical implementations of this tech for another five years, but it could have wide reaching applications from wireless networking to public safety devices. "Adaptive, cognitive radios could enable techniques such as dynamic frequency sharing, in which radios automatically locate unused frequencies, or share channels based on a priority system. In public safety, cognitive radios also could be used to provide interoperability between various signals and automatically adjust radio performance."
Share a scarce resource? Commie!
But as with any system of resource sharing (especially bandwidth), some devices/users will simply ignore the rules to improve their own performance: flag every transmission as ultra-high-priority and so forth. You can't expect users, or even manufacturers, to "play fair." And I'm not convinced that regulation can force people to play fair. Unlike objective measures like antenna transmission power, things like "priority" are more open to interpretation (or misinterpretation, if you prefer). I suppose the same solution as for cell-phones could be applied: if you charge someone for every transmission, they are forced to conserve bandwidth.
I love technology... but when it comes to safety and emergency systems, it's usually best to use the lowest-tech solution possible: cheaper, easier to repair/maintain, more robust, more reliable, and better understood. I don't know if I want my emergency call negotiating interoperability with other devices to reach someone (since any such operation is error-prone). The simplest solution (e.g. full-power transmission on a reserved channel) is probably better in such a case.
Will there be problems when there are many "Cognitive Radios" nearby at once?
My friend (who is in a position to know) says the problem with public safety communications is Motorola. They control the field (being the largest provider of equipment) and intentionally do not work well with others, Technology isn't going to be the solution to this problem.
Motorola have been working on this for years and I suspect so have all the other mobile handset makers. Frequency agile, power agile systems are used in all cell phones, base stations can direct and use a focused beam to reach a faint handset - this is in service stuff. Walk through hand off from a handset that uses DECT, then dials out and goes cellular seamlessley has been demonstrated, as have handsets that can ask others to dial power down etc. The only thing holding this back has been market forces - customers just haven't wanted it. Yet.
At least this one didn't make any "The FCC will be obsolete!" claims.
As someone else said, there's not much to prevent rogue radios from abusing the system. Also, wideband receivers are extremely difficult to design. If you design an extremely wideband receiver, you give up one of the following:
Low power
Good interference rejection
Low cost
All the DSP in the world isn't going to help you if your receiver frontend is overloaded.
retrorocket.o not found, launch anyway?
...just get wireless routers to be 'channel agile' properly. This only seems likely to work at the carrier level of the infrastructure.
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Although it seems like a neat idea, in general, the article seems to have the stink of "buzz" around it.
It's cognitive radio! It adapts, intelligently! If you go somewhere with a weak signal, your radio would get that signal some other way, intelligently! Wait, we mean broadcast towers would change their output and frequency whenever it gets crowded, and this allows things to be more crowded, but not in a bad way! The whole thing adapts, intelligently!
I would love to see details, instead of vague descriptions about how things might work. Also, who profits, and how?
Fnord.
Doesn't Bluetooth already do this?
It's called a trunking system.
What? This is almost mandatory when commenting on some new smart technology. So, I'll use the extended version. A-hem...
One thing is for certain: there is no stopping them; the radios will soon be here. And I for one welcome our new cognitive overlords!
Dynamic allocation of frequencies has been around for quite some time, it's called a trunked system.
I guess the hype here is that they're using SDR technology to do it and a few neat tricks with wifi as well. Must be about time to sell the next generation of new radios to the gov/corp worlds.
I tend to agree with the earlier poster who said simpler is better. At least having a simpler backup system seems reasonable here for the early adopters anyway.
My poetry site welcomes the unusual.
Uber high-end (such as Xirrus) Wifi-A/P's already turn their power down when needed. What is needed is a standardized and ieee ratified protocol so that an A/P can order its connected clients to lower their power as well. This allows for packing in more and more "cells" in a given area, thereby increasing the overall throughput. It also has a nice side effect of much extended battery life. (at least in cell phones/pda's...might not be significant with a laptop.) This is nothing new, and the cell-phone industry figured it out a long time ago.
I've seen these work in a test and development environment, although it was only slated to work in the typical 300MHz-3GHz environment. It's all fine and good when it is isolated from the communications systems of commercial services, it's when you start talking about roaming on other services that it really gets impractical considering the coordination of all the carriers that would be required.
The same concept has been in play for entire existence of Ethernet, which has proven very reliable. The only significant difference here is that instead of time based - single channel- collisions where you back off for a random amount of time, you back off and frequency hop.
-- The morphemes of your disquisition are ascertainable, but they have eschewed an ambit of transpicuous exposition.
Thanks but my Mom figured this one out in the early 90's when she asked me why he wireless phone couldn't become a cell phone when she left the house. I already have a cognative radio, its called a Nokia e71 and OMG it has Wifi and it is not asscrippled by Apple so it can have Skype, Google Chat, and putty all running at the same time.
Lets ask the second why. OK not only do we not have to have single channel devices we now have fractal antennas and multi band chip sets and even peer to peer mobile devices that can daisy chain. Put all these together and we could have no more channels. Imagine one cloud of spectrum where you could negotiate with any peer or base or tower around you to find the right mix of bandwidth and price back to the fiber of your choice. Sure we leave a slice or the FAA and the military (or just give them a competitive bidding rate) and make the whole thing one free market.
Oh wait, I forgot America is based on having senators bough and sold by oligopolies while people hammer on the table and talk about free markets. Wake up and smell the fact that it costs more to text message with ATT then to send data to the Hubble telescope. Free market my shit covered ass.
By the way don't bother looking for my phone at the local cell phone store because you can't buy something in the US that doesn't suck.
I've seen a demo of this from http://www.adapt4.com/ . This is something they and others have been working on for quite a while. In their demo, their box can see and avoid other services with or without cooperation from them. IMHO, there is a lot of hype, but there is lots of potential -- much of the spectrum is vastly underutilized. It is reserved for users who use it only occasionally.
Computers obey me.
In todays world most of the time in most places in most frequency bands there is no energy in the air, but it is still reserved for somebody. Even busy spots in city centers have a lot of radio energy only on limited bands in any given moment in time. There exists easily usable spectrum from 100 MHz to 5 Ghz. And it is trivial to pack more than one bit per Herz. The reason that we don't have gigabit radio communications is that a device certified to standard X can not use more than a tiny fraction of that sepctrum, even if the hundred bands reserved for other standards are idle at that spot in space and time.
Anssi Porttikivi / app@iki.fi
Interoperability of existing trunked systems for area-wide communications will make this work. We're doing it in Illinois with STARCOM-21. Price is an issue, but inter-departmental state-wide communications is now possible.
For tactical operations, like at the scene of a fire or police action, good ole two-way peer to peer radio works great. Low tech, grab a radio and go, put it on the right channel and you're there.
Bottom line, cool technology, might have some uses in some industries, but really nothing to see here. Keep moving people.
I didn't RTFA. I am thinking if we could revive the CDMA idea?
Where every handset must adjust their own output, if they don't play nice, the base tower couldn't decode their signal and hence is no good to themselves either.
Implies far more intelligence than is actually going. Perhaps marketing hype.
Cognitive radios!?? Oh no you don't! (Starts adding layers to tin foil hat.)
I for one welcome our new cognative, frequency sharing radio overlords
"In public safety, cognitive radios also could be used to provide interoperability between various signals and automatically adjust radio performance."
Interoperability is available today. Just choose compatible systems. Oh wait, will 'cognitive radio' solve the compatibility problem? Sure, if they cognite in compatible ways...
Automatically adjusting radio performance sounds great. Let's see, AGC, AFC, spread-spectrum, oh, we already do a lot of that. I wonder what will be new or better...
Sorry, call me cynical, but this sounds like software-defined radio. We need a enw name for this? It's not even well-adopted yet, and it already needs to be redefined. This sort of thing usually indicates market failure.
Kinda too bad. It was a good idea. Still is. Someone will do it right.
deleting the extra space after periods so i can stay relevant, yeah.
Ya see, there's this one group - called the 'FCC'....
Those bumbling buncha back slapping, hand shaking smilers can't even effectively legislate a bass-ackwards technology like BPL with out getting their dicks slapped to the dirt by a bunch of amateurs.
How the hell could they ever re-write a hundred years of bandwidth/licensing regulations to allow for something effective??
Death to tech by bureaucracy!!
Senior NCO in the fight against entropy. I've seen things, man. Things no one should have to see.....
Now if we can only get cognitive radio hosts and it will be worth something.
Folks, this has been going on since the invention of spread spectrum in the 1940's. Although there have been some significant advances, this is not a way to get new free radio spectrum for long-distance communications, only for short-distance ones. The main issue there is that two radios that are communicating with each other over long distance can't necessarily hear the other channel users as anything but noise, but still increase the noise level to those other channel users with their own transmissions. And as many other commenters have mentioned, the system depends on everyone following the rules. If you think that happens, take a look at the quality-of-service flags on net packets coming from a Microsoft system.
And for about 15 years I've heard people say this would make the FCC (and spectrum allocation in general) obsolete. Of course it won't, because the main purpose of spectrum allocation is to coordinate incompatible users, not compatible ones.
Someone's just trolling for investment with a good sounding but really old idea. Move along.
This has already been done.
You can't "increase the amount of wireless space". Spectrum is a finite substance, the only thing we can do is figure out a way to share it more efficiently.
The technology being talked about here is nothing more than a trunking system.
Reference Motorola and Erricson's trunk system as well as others.
--Toll_Free
Makes me poonwee.
Any one of us can experiment with this technology. It is not expensive and you can do it with home built equipment. What's happened here is that much of the functionality has moved from radio hardware into a computer. And a typical PC has enough power for this job. Google project names like "gnuradio" and "hpsdr" for leads on amateur projects. There are large on-line communities around several projects. If you want to transmit on higher power in is not easy to get a HAM license. You just pass an easy 35 question multiple choice test.
Obviously I didn't RTFA, but I fear for the future of the human race. I mean, just by looking at the name, you can tell that it is obviously on-par with Intelligent Design and Intelligent Falling, right?
(CAPTCHA: educator)
As a telecommunications engineer, I do not understand what is new with this.
If you want to check out something that will have a real impact on such video/radio applications, have a look at SVC.
I have some printet material here from this year's IBC where it seems NTT actually already have a software implementation of it.
The NTIA. http://www.ntia.doc.gov/osmhome/osmhome.html They are the ultimate arbitrators of frequency spectrum management in the USA. That is because they work for the military and government agencies, who will never give up a single hertz of an incredibly valuable military and law enforcement resource on a PRIMARY basis.
The FCC is second fiddle to them in practice, but the government does give lip service to the idea that the FCC works hand in hand with the NTIA. In reality its not true.
For example, many amateur radio bands and other public services use radio frequency spectrum allocated on a SECONDARY basis, with the military and federal agencies coming first. The best example of this recently, was when suddenly garage door remotes stopped working withing a wide distance of a military base. The military was simply exercising their right to primary usage of that spectrum..
Even more recently a large number of ham radio VHF and/or UHF repeaters had to be moved in frequency to satisfy the military that they would not cause any interference to whatever government system was involved- and those repeaters were licensed by the FCC. So you can see that the FCC has little power in these disputes.
Manufacturers of gadgets can be incredibly ignorant, especially when they originate out of China, and the FCC just rubber stamps Part 15 approval on them, not really giving a damn what might happen in the future.
Maybe adaptive, but cognitive is horribly inaccurate.
Well, there is a bit more to it than that. If you look at today's highly regulated frequency spectrum, it's really not very efficient. A lot of space for transmission ends up unused. Not only with respect to certain frequency bands, but also geographically. For instance, if you know that in your area the frequencies from 2.4 GHz up to 3.4 GHz are currently, right at this moment, unused, then why should your data transmission limit itself to the WLAN channel bandwidth? Or, if you know you will not need much transmission power because you're trying to reach another closely nearby station (think BlueTooth), why not go Ultra Wide Band and use what's available? As a result, you will get a much higher spectral efficiency -- the available spectrum can be used to transmit more information in total by being "reused" where it's available.
Of course anyone can abuse this, but face it, anyone can abuse the current system as well in much the same manner. What's more interesting, if someone jams your WLAN right now you're screwed. With a cognitive system, your local network can just find a free frequency band somewhere and keep working. One major obstacle here is, how do you find a needle in a haystack, i.e., a low-bandwidth signal in a huge frequency space -- say, a 50 MHz mobile phone signal somewhere between 500 MHz and 2 GHz? Nyqvist would tell you that you need to sample at 3 GHz in order to do that, which is not feasible (or at least, energy-intensive and expensive). Considering that you only need a 100 MHz sampling rate for the target signal it's definitely a waste. This is where a fairly new technique called Compressed Sensing or Compressed Sampling comes in useful: In fact, if you sample *randomly* in the right way, you will get away with somewhere around 200 MHz and be able to find your signal with a very high probability. This is a new, exciting field of research with applications not only to cognitive radios, but also a lot of other areas such as medical imaging.
Someone else mentioned the hidden node problem. Indeed this is a problem as you can't always be sure that just because you don't hear someone else he isn't disturbed by you speaking. And how exactly you negotiate which frequencies to use is up to debate (and much further research) as well.
Someone also said that "this is not new", citing a 9-year-old IEEE publication. Well, of course the scientific community has been working on this for quite some time. But it's still "new" in the sense that there still isn't anything out there, market-ready, that is anything near cognitive. Don't hold your breath, it's gonna be a while. But it's definitely something worth following.
Elements of cognitive radio are already in use, many of them for quite some time. A good example is adaptive power control: it's fundamental to the operaton of CDMA cellular telephony. As far as dynamic frequency selection, that's almost required if you're doing any sort of guaranteed-QOS work in the U.S. ISM bands (900 MHz, 2.4 GHz, 5 GHz). Examples here include Avnera's wireless audio solutions (disclaimer, former employer) and Bluetooth's Adaptive Frequency Hopping (AFH). Avnera's system continually scans the 2.4 GHz band to determine the most- and least-used channels, then chooses the one with the least occupancy. If the system encounters interference, it dynamically selects another channel. I suppose antenna diversity, widespread in many different technologies including WLAN, could be considered cognitive as well, given that it requires real-time information on the quality of each transmission path. Bottom line: there's interesting stuff to come, but it'll be evolutionary, not revolutionary.
I worked on a dispatching style radio for a customer that had several such products. One of those was New York taxicab drivers.
He told me the way a cab is dispatched is by the blat-blat system. Basically the dispatcher calls out the location of a pickup, then all the taxicab drivers key down on their radios, which sends their identifier back to the dispatcher. The first guy in is notified that he is to pick up the customer.
They ARE out to get you simply because They are in it for themselves and they don't care about you.
Cognitive radios?
Uh oh...
Que Terminators, stage right.
Disclaimer: The opinions and actions of the US Gov't are in no way representative of those held by this author or its ci
Cognitive Radio (also known as "Opportunistic Spectrum Access") was first coined in an IEEE journal and is now considered the holy grail of communications research by many electrical/communications engineers.
To understand cognitive radio one must first be familiar with software radio. The operating parameters of a traditional radio (center frequency, modulation type, bandwidth, etc.) are defined in hardware and static in type. A software radio is a device which, in affect, brings the "software to the antenna" i.e. replaces the encoder/modulator/awgn/slicer with software. This allows much more flexible radio devices as they can use any frequency, with any modulation type, etc.
The next thing we must understand is that spectrum is scarce and increasingly expensive. The FCC's old spectrum licensing paradigm of fixed frequency assignment is outdated and can easily be improved. Here's an example: Verizon Wireless ownes (say) 1800 MHz nationwide and at all times but, if I could ensure little to no interference with Verizon's operations in the middle of the desert or at 4AM, shouldn't I be able to sub-license (or sub-lease) the spectrum?
This is where cognitive radio comes in: they scan the spectrum looking for "holes" (barely used frequencies), adjust their center frequency accordingly, find the best modulation type, etc. and transmit/receive at these frequencies. This will open up a lot of spectrum (the FCC noted spectrum utilization typically varies between 15% and 85%) and decrease the cost of spectrum access (or make the FCC a ton of money either way). The problem is that the engineering challenges are formidable (hidden terminal problem, collaborative sensing, etc.) and expensive (if we make a mistake, me might knock Verizon off the air) but eventually fixed licensing will be a thing of the past and we'll have devices that will operate at whatever frequency/modulation type/etc. they determine best and pay per usage (or some similar model).
For more info:
http://www.eecs.ucf.edu/tccn/(The Technical Committee on Cognitive Networks (TCCN) of the IEEE Communications Society)
http://www.ieeep1900.org/ (IEEE Cognitive Radio Information Center)
http://www.sdrforum.org/pages/aboutSdrTech/relatedTechnologies.asp (SDR Forum)
Basically it sounds like radio that has frequency hopping.
Big deal. This is in development now for desktop PC's (software defined radio) for a while now.
So this is just a handheld version of that idea.
March 2003
June 2002
sic