Unlimited Airwaves

Dan Gillmor has an article concerning the notion of scarcity of the airwaves, which has long been a testament of faith at the FCC. Recent advances in technology may render that testament false.

Comments

Finger waggling...

[KFury]

Let's watch our semantics here: Breakthroughs in technology would render the testament obsolete. Rendering the testament false implies an admission that the testament was made while ignoring the technological realities. That isn't the case here.

Re:Finger waggling...

[nanojath]

Unfortunately this is an issue where the people who are exercising any real authority are unlikely to be parsing the finer shades of semantics or logic. The radio cabal has a significant investment in the notion of "interference..." after all, its how they gutted the low-power FM movement with its troubling potential to make radio something communities could do for themselves rather than solely something Clearchannel manufactures on a computerized assembly line sometimes in a completely different state. I doubt anyone will be debating the notion of obselesence versus falsity, but I wouldn't be surprised to see our old friend "junk science" (defined as any scientific assertion that does not support the proponents political platform) show up as we try to bust up anopther (maybe) artificial scarcity. Next week lets take on the diamond cartels. Well, I'm sure the FCC will help out 'cause federal beaurocracies are always eager to make themselves "obsolete." Good point though.

Re:Finger waggling...

[KFury]

The story post says "Recent advances in technology may render that testament false. "

Given the context of that statement, we're talking about recent advances. If we're talking about RF-hopping that has been around since the 50s, then that's a different sentence, and not the one I'm talking about, thanks.

Re:Finger waggling...

[thogard]

If you don't like clearchannel, get a few thousand of your friends to all complain to the FCC that they aren't providing enough comunity service and ask that their license not be renewed. If the FCC gets a thousand complaints from anyone they have to act on it and even more so if the the letters are all CC:ed to the local Hose of Rep memeber.

Re:Finger waggling...

[unitron]

Whether scarcity of the airwaves is an obsolete notion or a false notion is irrelevant. The FCC exists because the airwaves are the property of the people as a whole and the government, which is charged with the protection of the rights and property of the people, established the FCC to exercise stewardship over the airwaves on behalf of the people.

I have a feeling that spectrum and bandwidth will only be nearly unlimited for those with nearly unlimited amounts of money to spend on electronic equipment or politicians or both.

Re:Finger waggling...

[nanojath]

Wow! I did not know that... Thanks for a great corporate-hassling strategy. A useful reply on slashdot... hoo, I'm feeling a little dizzy, better sit down...

-'jath

Implications for Radio Astronomy. . .

[PhxBlue]

While radio waves may not interfere with one-another directly the way sound waves do, what would happen to radio astronomy if we opened up every possible frequency to exploitation? Is it even remotely possible that's what the FCC bureaucrats are considering, and not simply their own necks?

As an aside: the Internet should have made the TelCos obsolete years ago; but it hasn't happened yet. I wouldn't hold my breath on newer radio technology making old radio obsolete anytime in the next ten years, at least.

Re:Implications for Radio Astronomy. . .

[Bonker]

As an aside: the Internet should have made the TelCos obsolete years ago; but it hasn't happened yet. I wouldn't hold my breath on newer radio technology making old radio obsolete anytime in the next ten years, at least.

Ah, but it has. Something you don't see in the U.S., but something you do see going on in the rest of the world is internet telephony and VoIP services springing up left and right. The Telcos have been and are currently fighting tooth and nail to keep internet telephony and similar services out of reach in the U.S. just so they don't come unglued.

You think the current hype about the record industry fighting MP3's is big? Wait until it's the baby Bells fighting against the first 'big' internet telephony service available in the U.S.. The amount of legislation bought and sold in that time will make laws like the DMCA look reasonable.

Re:Implications for Radio Astronomy. . .

[donnacha]

As an aside: the Internet should have made the TelCos obsolete years ago;

PC telephony has always been too messy to make much of a dent. The way things are gearing up, it now looks as if it will be Microsoft that finally puts a final bullet in the telcos' heads.

Re:Implications for Radio Astronomy. . .

[KjetilK]

I agree.

As much as I'd like to do away with scarcity, and as much as this argument:

I'm talking about free speech. Regulation of the airwaves has specifically included curbs on speech, such as the FCC's commands to the nation's TV and radio broadcasters about what may or may not be said on the air.

...appeals to me, being an astronomer, I fear that we here on earth will drown out the tiny signal that some day may put us on the track of something far greater than nice bandwidth.

Re:Implications for Radio Astronomy. . .

[smallduck]

While radio waves may not interfere with one-another directly the way sound waves do, what would happen to radio astronomy if we opened up every possible frequency to exploitation?

Radio astronomers will have to put their gear on the far side of the moon, where all telescopes belong.

Re:Implications for Radio Astronomy. . .

[3waygeek]

The way things are gearing up, it now looks as if it will be Microsoft that finally puts a final bullet in the telcos' heads.

Gee, first this, now the above! Where's the anti-MS ranting we've come to expect from Slashdotters?

Re:Implications for Radio Astronomy. . .

[HeyBob!]

We'll just have to build our dishes on the far side of the moon - zero interference.

Re:Implications for Radio Astronomy. . .

[Starcub]

I don't think anyone is seriously advocating that the entire spectrum be opened. I think the idea is to initially open a very small portion of the spectrum for use as a test bed for packet radio network experiments.

In any case, if I'm not mistaken, RF Astronomy is mostly confined to a relatively small band of low frequency radiation.

Re:Implications for Radio Astronomy. . .

[Skjellifetti]

So we put our radio observatories out in space just like we did with the Hubble telescope.

Heh

[GigsVT]

The second way that reality defies the old logic is what happens when you add wireless devices to networks. I won't go into the details of Reed's argument, which you can find on his site, but he contends that you end up with more capacity -- the ability to move bits of data around -- than when you started.

This guy never owned a CB radio apparently.

(Yes I know AM is terrible compared to SSB or Spreadspectrum, but those just mitigate the limitations, not eliminate them.)

Re:Heh

[Eil]

He's talking about the digital capcity of the network the wireless devices form, not the signals themselves. CB radio is to networks as public bulletin boards are to Time Magazine.

It's a matter of finding things again...

[Quixadhal]

So, like so many other computer/data related things, it will amount to how well new equipment would be able to sort through the overlapping radio transmissions to find the one you actually want to capture and decode.

Essentially, current radio tuners are serial, in that they lock onto a single frequency and attenuate all others down. Reed's suggestion is basically to receive many frequencies in parallel and toss them out as you decode them and they prove to not be the one you want?

Sounds good. It would make security through adaptive modulation interesting.

Re:It's a matter of finding things again...

[Anonymous Coward]

Sure. Looks like he's talking about spread
spectrum. There are 2 kinds in wide use, FH
and DS (frequency hopping and direct sequence).
Common 802.11 uses spread spectrum with wide
bandwidth front ends (well, wider then narrow
band single carrier modulation schemes).

But he's wrong over all. Spread spectrum
techniques only achieve a limited (practical)
increase in signal to noise ratio. You can't
infinitely increase the S/N. In general, one
uses a spreading code to, well, spread the
spectrum of the signal. In the reciever,
the despreading (corrilation) also spreads
any other (interference) signls.

However gain is doubled by a doubling of length
of the spreading code, so this is no silver
bullet for bandwidth. In actual fact, this is
old technology. It was patented in the second
World War (by the very talented Heady Lamar :-)

http://users.breathemail.net/country.talking/act re sses/HedyLamar

Re:It's a matter of finding things again...

[Coz]

Good synopsis.

One of the problems with his proposal is that there's so much old equipment out there that doesn't tolerate interference - so you have to retire a "use" for a band before you can free it up for spread-spectrum, or the SS signals generate noise for the existing users, who're using 20 year old technology. That's been done successfully once, to my knowledge - when the FCC made the wireless carriers pay to relocate and reequip point-to-point microwave relays in the A band. $Billions spent.

Of course, if you want to go spread spectrum, you have to have codes - and the more users you have, the more complex the codes need to be - there is a limit to the number of users you can have, based on the uniqueness of any given code set.

Gawd, I'm having a grad school flashback!

Re:It's a matter of finding things again...

[HiThere]

Of course, if you want to go spread spectrum, you have to have codes - and the more users you have, the more complex the codes need to be - there is a limit to the number of users you can have, based on the uniqueness of any given code set.

Would IPv6 suffice? If not, then add a couple of more hex digits. Codes aren't really the problem. Keeping the packets straight, etc. and routing are the real problems. Esp. routing.

A hybrid system based on local stations feeding into fiber-optic based base stations of a relatively standard design would be a system that could handle more throughput. OTOH, a pure wireless system with no central node ... if you could solve the routing problem with that one, then you would have a truly decentralized network. (YEAH!) But that's a pretty big problem.

Still, as to unlimited bandwidth...
Light is pretty fast, so if one had a purely wireless network, one could build a Beowulf cluster with wireless interconnects. Would the transmission rate be fast enough to make that reasonable? How close would the computers need to be in order for this to be a reasonable solution? Wouldn't it be easier to connect them with fiber optic cables?

I really don't think that you can call the bandwidth unlimited, not even in terms of today's technological needs. (OTOH, I guessed at the answers to the above questions, instead of working them out. So if I'm wrong...)

Re:It's a matter of finding things again...

[Coz]

It's not a routing question - these aren't necessarily point-to-point links - if you want to implement those, you'll have to look higher in the protocol stack :). The technology here is down in the physical layer. IPv6 is WAY above this.

Spread-spectrum is based on codes and pseudo-random numbers and fast clocks. The codes determine the uniqueness of the chip sequence for each user; the clocks determine when the chips occur; the pseudo-random numbers determine the chip sequence based on the code and the clock tick. At least, in some versions ;) It's not simple, and not very cheap - it's taken years for the cellular industry to get CDMA to affordable levels, and that's one of the fundamental technologies needed for spread-spectrum applications.

You can do optical networking without fiber - and in about 6 more weeks of grad school, I'll be able to tell you all about it (ugh).

Re:It's a matter of finding things again...

[HiThere]

Yeah, but with fiber you don't need to align your lasers and mirrors so carefully. And you suffer less from dust or fog in the air.

As for the routing problem... if you want "unlimited bandwidth" what I hear you asking for is the ability to transfer a signal from arbitrary here to arbitrary there without worrying about frequency, speed, time delays, etc. A dream system! In a local block, the hardware sync issues will dominate, but in a local block there isn't a real bandwidth problems anyway. PCM with a bank of tuned infrared lasers would probably get you more throughput than even today's chips could handle. And since lasers are directional, you don't need to worry about interferrence. So that's not the problem being addressed.

You are right, I don't know the details about how spread spectrum is done. But it can't possibly handle more than some number (which is determined by power level, interferrence, etc. -- Claude Shannon wrote the equation, but I forget what it's called). This can be handled, however, by DECREASING signal strength, and using blocks of transmitters and repeaters (preferably with directional antennas). In a sufficiently local area it just isn't a problem. The fancy stuff is so that you can manage the connections that go or come from outside the local block. And that brings us to higher level protocols. This is what you use to target the transmissions so that messages only need to go through appropriate blocks on their way to their intended destination. Which decreases the throughput requirements in each particular block. So the repeaters need to decide whether or not they should forward the signal. Or, if they have directional antennas, they need to decide in which direction to forward the signal.

OTOH, you might mean that the current local coding schemes (hardware level) are insufficient. With shorter numbers exponential increase doesn't give you the same benefit from adding a bit or two to a code string. The way you solve this is by making each block smaller, and lowering your transmission power. That does, however, increase the number of hops needed to reach the destination.

Anyway you go as you try to pack more signals though the same airspace the approaches either get more complex, start interferring with each other, or stop working. There really are limits. (Of course, if you're clever enough they can be pushed way out there.)

If, on the other hand, you are considering broadcast, then there isn't any decent way out that I can see. Spread spectrum doesn't buy you anything in this case (except a bit of noise immunity, and that only at the cost of increased power). It's true that better coding practices could allow you to pack more signal into a particular bandwidth. I believe that the HDTV people are planning to do this. But that's the limit. And each frequency has a fastest intelligible switching rate. You might even do better to stop thinking about frequencies, and start concentrating on switching rates. When you go digital the sine waves don't really exist, anyway. What you are doing is PCM with some particular switch speed (possibly encoded). And in that case, does it even make any sense to talk about spread spectrum?

Possibly I totally misunderstand the options here. I'm certainly well out of my field. But that's the way that I understand it.

Re:It's a matter of finding things again...

[thogard]

Has this guy seen how modern radios work? You start out with a binary signal. Then you find out where you modify your carrier on of say 64 different ways based on the next 4 bit patterns. (some of them aren't used as type of sanity check)
Modern radios will do sevral bits per Hz while his charts are showing about 1 bit per 10Hz. Now back to thouse 64 different patterns when you only need 16. What happens when another radio steps on your signal? You get one of thouse other bits and your reciever decides not to accept that bit and hope your forward error correction copes with it. Some radios work by taking the signals and spliting them into 8 groups, inverting some of them ina pseudo random way and transmitting them either serialy or on silghtly different frequencies. The reciever at the other end can take all them at once do a bit of voting and then check aginst the ECC code to help get rid of th noise.

This all works well until you have too many transmitters in one are all talking at once. Think about hearing converstations in a loud bar. Its the smae problem but you tend to only hear the people near you or the very loud ones. You can't hold a conversioation at a moderate volume with someone far away. Human speech has much better noise imunity than most radio signals.

Re:It's a matter of finding things again...

[thogard]

The optical transmitters are teh easy part. That
bit has been solved to the rate of about 3.6petabites/second. The problem is the recivers can't do that (not to mention that 10baseT device you want to plug in).

Now that people are looking at optical as RF and not as visable light, some of the sensors technology that is in R&D labs right now is good for 25km in rain and fog in the gigabit range. Its still point to point but the research is going places and I expect the line of site radio links are going to be gone in 15 to 20 years.

We need to do

[line-bundle]

"We need to do for spectrum," he said, "what the Internet did for the network."

Screw it up??

Re:We need to do

[chuckcolby]

Expose it to millions of malicious users?

Re:We need to do

[SomeoneGotMyNick]

Bombard you with ads....

(wait, already done..)

Transmit Pr0n!!!!!!

Re:We need to do

[Daniel Dvorkin]

[sigh]

http://www.snopes2.com/quotes/internet.htm

http://www.mids.org/mn/904/vcerf.html

Will you please shut up now?

Re:We need to do

[jxs2151]

...that even if his phrasing was 'ackward'...

Or perhaps even awkward.....

Re:We need to do

[karmawarrior]

Except that it was at least accurate. Vint Cerf, who, with Jon Postel really can claim to have "invented the Internet", backs up Gore and believes he made a significant difference. Read the Cerf article.

Re:We need to do

[jxs2151]

Cerf's support is strained at best. At the level these guys play, anything less than a ringing endorsement is the same thing as no support at all. I would hardly call Mr. Cerf's statement fully supportive.

Re:We need to do

[bafu]

When I saw those links I thought... "Oh man, people have been wrong about Gore saying he invented the Internet." I followed the links thinking I should learn the info there in case I needed to pass it on when someone brings it up in the future. I just want to thank you for wasting my time.

Let's see. According to the first link, Al Gore said:

During my service in the United States Congress, I took the initiative in creating the Internet. I took the initiative in moving forward a whole range of initiatives that have proven to be important to our country's economic growth and environmental protection, improvements in our educational system.

So... Al Gore never said he invented the Internet... he really said that he took the initiative to create the Internet. In fact, those are the exact words that appeared in the Wired story that was apparently among the first to start making fun of the claim. I see. Perhaps that interviewee BS phraseology was hard for people to remember. Maybe that's why they don't quote Gore saying, "I took the initiative in creating the Internet," they just say, accurately enough, that "Gore said he invented the Internet", without quoting his exact words. That's actually unfortunate for people who aren't big fans of Al Gore since the original manages to be more embarrassing in its awkwardness. Oh well, too bad for them.

According to the second link, Vint Cerf (who is presumed to know who invented the Internet) said:

VP Gore was the first or surely among the first of the members of Congress to become a strong supporter of advanced networking while he served as Senator. As far back as 1986, he was holding hearings on this subject (supercomputing, fiber networks...) and asking about their promise and what could be done to realize them. Bob Kahn, with whom I worked to develop the Internet design in 1973, participated in several hearings held by then-Senator Gore and I recall that Bob introduced the term ``information infrastructure'' in one hearing in 1986. It was clear that as a Senator and now as Vice President, Gore has made it a point to be as well-informed as possible on technology and issues that surround it.

So... he goes out of his way to point out that he and Bob Kahn developed the Internet design in 1973. He says they also were at hearings that Al Gore's committee held when he started showing interest in the Internet some 13 years later. It also seems that the term "information superhighway" may have been based on a term Bob Kahn brought to Gore's attention in 1986.

Well, gee, you really debunked that one and earned the right to tell someone else to shut up. Tool.

To be honest, I'm mainly just pissed off at myself that I wasted this time following and reading your links since I thought you actually had something there. Grrrr

Re:We need to do

[Saib0t]

[sigh] [snip] Will you please shut up now?

Come on man, can't you see it was a joke?

From your past comments, I'd recommend you and your oversized ego to simply move on and shut up...

Free Air Waves

[WellHungYungWun]

I don't know, I would kind of like to see some test results first. Everyone in the neighborhood gets a Wireless router and what happens, something...nothing. I know that when 2 radio stations are competing for a similiar frequency you get crosstalk. Kind of like when you get on a cb radio and someone is using more wattage they talk across more than one channel. I don't want to be trading my packets with anyone, I don't know about you.

Re:Free Air Waves

[jxs2151]

you get crosstalk

The whole point is that with new technologies you don't get crosstalk.

This is not CB radio where everyone competes for the same frequency. Technologies like Spread Spectrum, UWB and CDMA ensure that this doesn't occur. A side benefit would be that we could lower transmission power.

Anyone care to guess whether the noise floor would rise or fall?

They should be regulated

[Anonymous Coward]

Ok, there may be lots of bandwidth and frequencies, but to unregulate all of it is to say the same as "The USA has a lot a land that people could drive on, so why have traffic laws?". Not quite on point, but food for thought....

Re:They should be regulated

[MonsterChicharo]

Ok, there may be lots of bandwidth and frequencies, but to unregulate all of it is to say the same as "The USA has a lot a land that people could drive on, so why have traffic laws?". Not quite on point, but food for thought....

'unregulate' is one thing. Stop selling exclusive rights on certain frecuencies is another. The point here is that when a resource is no longer scarce, it no longer can be sold (for there would be no buyers). Governments around the world would have to stop selling frecuencies. They would regulate them alright, but not sell them.

Re:They should be regulated

[bafu]

Do they really sell the frequencies (in certain areas) or do they just sell the permission to use them? If they actually sold them, the buyer would presumably be free to sell it to another later under whatever terms they liked. That might actually make it worth it to explore tech that would make more use of the freq. If you could buy the freq once and then later sell it multiple times (and have each "piece" work, of course ;-) ), then that's a huge incentive to have the tech in place that would make that possible.

Described before?

[dknj]

I believe a work around was described before, by each radio device using a certain time slot. It was described like several people in a room speaking a different language, and you could easily pick out your native language. It was posted on slashdot awhile back, does anyone remember the article?

-dk

Re:Described before?

[dknj]

I seemed to have answered my own question, the article i was refering to was the Ultra Wide Band. Additionally, this article seemed interesting.

-dk

Re:Described before?

[Falcula]

I, Cringely had this to say about UWB.

I think this is one of those things that is kind of sneaking up on a lot of people and is going to hit all at once, providing we can keep it from getting squished before it gets a chance.

Wishful thinking?

[axlrosen]

So, he doesn't like government regulation of the airwaves, but can't find a way around it if the radio spectrum is scarce. And, he says he's found that there's a way to actually add bandwidth by adding more receivers, so maybe radio spectrum isn't scarce after all, although, "to be sure, there are experts who disagree with him." Maybe it's true, but it sounds like wishful thinking to me. Plus, how expensive would these new systems be, and would we have to scrap all our old systems?

Re:Wishful thinking?

[WolfWithoutAClause]

Ok, here's an example of what he's saying. If we have 3 transmitters/receivers, and A and C are a way apart with B inbetween, but B doesn't let you route through him, then the radio spectrum is scarce, in fact everyone gets just 1/3 of the spectrum each, because A has to shout so C can hear him and vice versa, and so B would have to shout too to be heard.

On the other hand if B lets A route through him, then A can whisper to B and B can whisper to C. Then the radio bandwidth doesn't degrade so quickly; and in fact the more people you have the more total bandwidth there is, but ultimately it gets noisy.

Not only that, but if everyone uses highly directional antennas for both transmission and reception, then pretty much the amount of bandwidth scales linearly with the number of users- the radio gets absorbed and there's less noise around because you can talk more quietly.

Maybe it's true, but it sounds like wishful thinking to me.

I don't consider this to be wishful thinking, it's a very good point.

Re:Wishful thinking?

[GigsVT]

Not only that, but if everyone uses highly directional antennas for both transmission and reception, then pretty much the amount of bandwidth scales linearly with the number of users

Why not take it a step futher, and enclose the signal in a sort of waveguide, with a central wire and a copper braid to protect from the signal leaking out? You could just run these "simul-axial waveguides" from transceiver to transceiver.

Just think, in the future, we may be able to modulate light and send it down a similar enclosed waveguide, for miles at a time!

Re:Wishful thinking?

[esonik]

You're intentionally trying to not understand. Just remember how the network for cellular phones works..and image how it would be if everyone would try to get a end-to-end connection in the old amateur radio or CB fashion: you'd need high power senders and a lot of bandwidth. The cellular networks work fine for a very high number of users, they only break down if you have too many users in one cell. Btw. their hubs do use directional antenna.

Re:Wishful thinking?

[WolfWithoutAClause]

Yeah. And based on your 'new' idea, I'm gonna invent a concept called 'fiber splicing' which I'll need to do everytime I move by more than a few hundred feet.

Seriously though, you missed something- the antennas can be electronically steered; they're actually phased arrays. This isn't some dish aerial that has to be carefully set up by hand, you can move about plenty.

Short term, the radio waves will be *more crowded*

[CathedralRulz]

As many radio commercial radio stations within the year are changing to digital audio (along with their analog signal), the signal will be bifurcated.

As it stands, radio stations only occupy a narrow band of their assigned frequency, so you can stack many stations close together, especially at the bottom of the band where a lot of non-commercial and religios type stations are (like wfmu.org).

When the commercial stations go to digital audio, along with better reception and CD quality sound, the signal will take up more of the band that they are assigned and cause them to 'bleed' a little bit.

The unfortunate result is that a lot of the smaller, non-commercial and religious stations who can't afford the $100k-200k upgrade to digital audio will have thier signal squelched.

FCC is killing me.

[BrookHarty]

Watching TechTV and they had a story about Northpoint Wireless.

Northpoint wireless wants to offer wireless broadband (tv/music/inet) but the FCC wants to charge for the spectrum, which northpoint owns the copyright for. They believe they should have it for free, its their technology that makes it work. And they cant afford the outrageous prices the FCC wants for the spectrum. They say they can deploy to 90% of the USA.

Who knows, sounds interesting. Maybe someone on slashdot is testing it?

Re:FCC is killing me.

[PhxBlue]

Northpoint wireless wants to offer wireless broadband (tv/music/inet) but the FCC wants to charge for the spectrum, which northpoint owns the copyright for.

This is silly. You can't own a copyright for a radio frequency.

Re:FCC is killing me.

[MonsterChicharo]

This is silly. You can't own a copyright for a radio frequency.

No, they don't have a copyright over the frecuency. Instead, they "invented the technology that made the spectrum capacity possible." That is why they find the FCC decision to auction off the spectrum a wrong move.

Re:FCC is killing me.

[Overzeetop]

90% of the USA, or 90% of the population? I suspect the latter, meaning only about 10% of the USA. They're willing to put wireless broadband where wired broadband already exists, but not to offer it to those who have no broadband at all.

I suspect if they called their congressman and offered to make wireless broadband available, starting with the sparsest populated areas and moving up (2000 census data), they'd get the spectrum gratis. In fact, there's probably money the in the current Farm Bill to help them out in those rural areas they seem so desparate to serve. There's really no sense in giving them free spectrum so they can cherry pick the population centers.

The proof's in the pudding, though. They are offering Austin, TX and Washington D.C. as test areas? Why not choose anywhere in Alaska, the Dakotas, Utah, or Maine - all states they admit are without DBS service. It's clear they want the spectrum for free so they can deploy in urban areas without licensed competition - they have no desire to service the whole country.

Re:FCC is killing me.

[Big Boss]

huh.. Don't tell my DirecTivo Utah isn't served by DBS!! I'll be pissed if it suddenly figgures it out!

DTV and DishNet are CONUS (Contenental US). That means what it says, the lower 48 have DBS. Even Canada and Mexico can receive our DBS signals much of the time. That's why all the DBS hacking goes on in Canada, liberal laws and they can pick up the signal. Hawaii and Alaska have some coverage, but the LOS to the satelites gets hard if you have anything in the way. It's more "flat" where our dishes tend to point more "up".

Test areas for a new service are eaiser to get going in populated areas at first. More potential testers, law of averages and all that. Not that I like Northpoint. It might interfere with my DBS that I don't have. ;)

IMO, if it's going to be a pay-to-transmit game and everyone else has to pay, NorthPoint should too. If we're going to change the rules, they need to be the same for everyone.

Flag Day for consumers

[srmalloy]

While it is true that the signal-processing capability has expanded to the point where it is technically feasible to pack the spectrum more tightly, the premise fails to address either the economic or political feasibility. How many people would be interested in having two hundred more stations in the FM band if it meant that they had to rip out their existing car stereo and replace it with a $500 (low end) software-controlled radio to listen to them, and if they didn't, all they'd get on their stereo was a random hash of noise because their old radio can't separate the stations?

Look at how effectively HDTV has replaced the existing television broadcasts, for example. Unless you can replace all the hardware in use on a spectrum band at the same time, you're faced with the choice of retaining backward compatibility -- which defeats the purpose of the upgrade -- or cutting off the people who don't want or can't upgrade.

For specific and short-range purposes, such as wireless LANs, it may be practical to require a complete end-to-end replacement, but there are large parts of the EM spectrum that are currently in use for which the entrenched interests will lobby strongly against any disruption

Re:Flag Day for consumers

[Ooblek]

I can listen to the radio in my car? Wow, I thought my unit only played CDs and MP3s! Someone told me that they don't play anything but commercials on the radio anymore, so I guess I just never bothered to look and see if it had a tuner.

Re:Flag Day for consumers

[WolfWithoutAClause]

How many people would be interested in having two hundred more stations in the FM band if it meant that they had to rip out their existing car stereo and replace it with a $500 (low end) software-controlled radio to listen to them, and if they didn't, all they'd get on their stereo was a random hash of noise because their old radio can't separate the stations?

Nobody obviously. But that isn't the question. The real question is 'Who would be willing to install a new radio in their car if it meant they could get two hundred more stations on a newly allocated frequency and/or download web pages and/or make VOIP calls?'

Re:Flag Day for consumers

[cdrudge]

It's bad enough that people are talking on their cell phones while reading the newspaper while driving...I really don't think they need to surf the web while they are at it.

Re:Flag Day for consumers

[TheSync]

While it is true that the signal-processing capability has expanded to the point where it is technically feasible to pack the spectrum more tightly, the premise fails to address either the economic or political feasibility

Two words: software radios.

For instance, at NAB, KLAS-DTV was sending out a 1 Mbps Windows Media Stream multiplexed & encapsulated in their ATSC MPEG-2 stream. Think about that...while we're pretty set on MPEG-2 video codecs for digital television, the truth is that once you go digital and have a programmable receiver, you can send anything.

Corallary: expect DTV stations to look for a wide range of interesting datacasting revenue alternatives to mux in with advertising supported unecnrypted MPEG-2 video.

Re:Flag Day for consumers

[gila_monster]

Unless you can replace all the hardware in use on a spectrum band at the same time, you're faced with the choice of retaining backward compatibility -- which defeats the purpose of the upgrade -- or cutting off the people who don't want or can't upgrade.

And there are sometimes reasons to retain backward compatibility. During disasters (tornadoes, WTC, etc), the phone systems (both cell and traditions) go down almost immediately -- they get overloaded. This requires alternate, reliable means of communication. The lower the tech, the more likely it is to handle some of the conditions found during disasters. If it can't run on a 12-volt gel cell, it's probably not going to last long in the field.

The FCC may also need to retain spectrum to accomodate the older technologies. If, for example, amateur radio operators have a coordination net set up on the 2m band, they need to have the band clear. 500+ signals packed into the spectrum would prevent emergency traffic from being passed. Thus, the FCC is often reluctant to reallocate spectrum to newer services or technologies.

gm

Re:Flag Day for consumers

[uberdave]

It would be fairly easy to reserve a bunch of emergency bands, just as is done now. Besides, one reason that cell nets and phones go down is that they both rely on physical wires. Once a wire breaks, it cannot carry a signal. Also, telcos tend to base equipment deployment based on probable usage models, not on "everyone at once" models. When everyone starts calling on a system that is designed for 40-60% peak usage, it is bound to fall over.

Software radios on the other hand would just seek out a clear frequency, squirt out a few bytes, and look for the next clear frequency. I would think that that would be more robust than everyone jumping onto channel 9 (or whatever) and getting into all sorts of crosstalk problems.

As far as power goes, why would you think that these things couldn't be powered by 12-volt gel cells?

Scarcity?

[SkewlD00d]

Consider that people in a crowded restaurant are all talking on basically the same frequencies... the reason you can "listen" to someone is that the brain can do time-delay comparison to lock onto the sender... so, why not have two antennas on devices to enable them to pick signals out of the soup of signals in the air? The military has used this technique to make jamming GPS less practical (requiring more power from the jammer). Note, that a signal or conversation can still be jammed by a high-power source or a loud patron, respectively.

The EM spectrum has alot of bandwidth; i think it could allocated more efficiently and fairly, while still maintaining channel integrity.

Re:Scarcity?

[srmalloy]

Consider that people in a crowded restaurant are all talking on basically the same frequencies... the reason you can "listen" to someone is that the brain can do time-delay comparison to lock onto the sender... so, why not have two antennas on devices to enable them to pick signals out of the soup of signals in the air?

To make this work, you have to know where the transmitter is and where you are, so you can calculate what the proper delay between the two antennae should be. This requires even more hardware when you're dealing with something like a car stereo, where the position of the receiver changes. This is one of the things that the military uses GPS for; is GPS going to be a mandatory add-on to cars just to have a functioning car stereo?

Re:Scarcity?

[Dimensio]

I'm sure that the US government would love to mandate GPS tracking devices in all automobiles for "national security" issues -- why not one put it to good use?

Re:Scarcity?

[thogard]

Thats wat a GPS reciever does until it knows where it is and what sats it can find. It searches all the posabilities until it locks on to one sats signal and then starts downloading a list of what stats are up and where they are. Once it has that, it uses its last known position and tries to lock onto other stats. If that position is good, it can do it quickly otherwise it could take a good reciver nearly 15 minutes. The data messages from GPS sats are at something like 50 baud in the 1.2Ghz range but the signals are below the noise floor by the time they get to the front end of the reciver.

Re:Scarcity?

[SkewlD00d]

No shit sherlock. Jammers are usually on the ground, i.e. below you if you are a missle or a plane and the GPS constellation is above you. Hell, use GPS and a laser-ring INS to get your position and you can easily do phase comparison for a phased array receiver.

Btw, high-end GPS products are able to "count" the number of wavelengths to a satellite to determine position w/ 95% confidence interval within Differential GPS or kinematic (position is accurate while moving) differential GPS can get down to the SUB-centimeter range !!! This requires an accurately measured fixed based station and a broadcast channel for updates; mostly for farms, mines (the mineral kind), power plants, construction, etc. On the conus (the us mainland), the coast guard and others broadcast DGPS corrects that are publically available.

Differential GPS also defeats the old inserted error for non-military keyed receivers, it's a mute point because there is no error.

wait one second.

[the_2nd_coming]

I thought that radiowaves can interfear by weakening the signal of each other if the colide based on the reletive vector to ach other and their Amplitude.

Specious nonsense.

[blair1q]

There are not an unlimited number of channels, though there are more now than when the FCC was created.

Modern signalling often reuses bandwith by dividing a channel into accesses* on some other dimension (code-division, time-division, etc, spatial-division, etc). But those divisions are limited within their own scope in ways similar to the bandwidth limits of radio-frequency division, and should be regulated in exactly the same way to prevent overlap and interference.

--Blair

* - A channel is a communications connection medium. An access is an individual division of a parameter differentiating channels. E.g., channel 538 could use frequency access 7, time access 4, code accesses 3-9, and so on.

Re:Specious nonsense.

[the_2nd_coming]

all new technology is doing is making the channel differensiation more fine grained. if you can take 1 MHz and divide it up 1000 times into smaller equal Frequencies then develop a chip that will be able to read the each Frequency with out any trouble, that is effectivly creating more bandwidth out of the same amount of frequency.

if you take this out infinatly, you have unlimited frequencies, though the tech will get more and more difficult to develope.

Re:Specious nonsense.

[TheSync]

bandwith by dividing a channel into accesses* on some other dimension (code-division, time-division, etc, spatial-division, etc). But those divisions are limited within their own scope in ways similar to the bandwidth limits of radio-frequency division, and should be regulated in exactly the same way to prevent overlap and interference.

Interference is not noise (it is another signal). That is one of the keys to understanding that the transport capacity of wireless networks increases with the number of nodes, and can get very close to O(nodes). Check out this paper.

Mind you, we're not talking about the old school single-transmitter multiple receiver model, but a wireless network of transmitting/receiving nodes.

Saying that wireless bandwidth is limited is like saying that the total bandwidth of the Internet was 1.544 Mbps when no one used links faster than T-1's. But is is actually more than that when you realize that interference is not noise.

Re:Specious nonsense.

[blair1q]

Interference is not noise if you simultaneously decode all signals and delete the ones you don't want (e.g. superheterodyning to elide all but the bandpass from the wideband antenna input).

But that does not change the fact that you need some means of differentiating one signal from the others. That means creates accesses. In any given system there is a finite density of accesses. The system may change (due to newer equipment creating the ability to make finer-grained accesses) and Reed implied (unclearly) that the crux of his argument is that the system always changes, but that just means that the FCC needs to regulate the accesses differntly within each iteration of the system.

Right now, the FCC only has power over radio-frequency division, and we leave it to corporate interests to apportion other types of accesses created by their proprietary technology. (In the case of the Internet, we let the IANA do the numbers and the domain registrar do the text, and have somehow been conned into letting the feckless ICANN have the numbers and the malicious Verisign have the text).

The FCC should have it all under its wing. They've been organizing channel regulation nationally and internationally for nearly a century.

What they shouldn't be doing is censoring the speech that transits those channels. The language access is still the province of the speaker.

--Blair

New?

[Strange Ranger]

My radio knowledge is severely lacking so flame away if necessary.

Hasn't this always been the case? E.g. - I can add digits to infinity to any radio station so that instead of tuning into 95.3 I could tune into 95.3000 - 95.3999. If the hardware/software can differentiate between such small differences in frequency then in the example above we just turned one setting on the radio dial into 1000. Why stop there? Am I missing something?

Re:New?

[Gordonjcp]

Bandwidth. Right, consider a *very* precise signal, at exactly 100MHz. Look at it with a spectrum analyser - you'll see a very very thin spike. Once you modulate it, it will spread out on either side. So, for example, a conventional voice radio channel, with a bandwidth of 300-3400Hz roughly (the same as an ordinary phone) will spread to 100MHz +/- 3.5kHz. To leave room for different channels you need a "guard band", so the channels are usually 10kHz apart.

This is one of the reasons Morse code is still so popular with amateur radio enthusiasts - you can send extremely narrow band signals that allow you to communicate fairly quickly. If someone is really good at it, they can communicate almost as fast as speech, over a channel a few *tens of Hertz* wide.

Re:New?

[TheDick]

Because you need bandwidth to transmit, the width of the band.....

So if you want 2 mhz of room, your channels need to be at least 2 mhz apart... goober.

Re:New?

[SomeoneGotMyNick]

That's an understandable perception and theoretically will work. Consider this enlightenment and not a flame.

Current FM radio modulates the signal above and below the designated carrier frequency. Therefore a 20Khz signal (peak of human hearing) will modulate a 95.3MHz carrier between 95.28 and 95.32MHz. IIRC the full 40Khz deviation accounts for both channels of a stereo broadcast.

There's additional use for Broadcast radio. I forget where I saw it, but I believe there is an offset from the designated frequency to place a mono only 20Khz band away from the stereo part of the transmission for mono FM radios to pick up properly. This may however be an outdated use of the extra bandwidth.

Additional bandwidth can be used for other data/audio signals to be carried independent of the main broadcast for Broadcast FM plus 'padding' between stations.

Re:New?

[mprinkey]

You have hit upon the crux of the argument. Old analog tech transmitters and receivers did not possess sufficiently narrow frequency response, so the whole system is a little "sloppy." Off-frequency rejection can now be quite high and so much tighter channels are possible. Although, in principle channels could be separated by less than 1 kHz as far as the transmitter and receiver are concerned, there is potential atmospheric effects and other interference which would probably dictate larger channel width. Nevertheless, the channels should be much smaller than current allocations.

An additional factor in the "scarcity" of spectrum use is the encoding technology. With high-quality encoding schemes (think *DSL), the potential throughput of the FM band is enormous. Note the fast ethernet runs at one frequency, 100 MHz, with a trivial encoding scheme and moves 100 Mbps. 100 MHz is right in the middle of the FM band.

Re:New?

[Gordonjcp]

The stereo system used on FM radio works like this. Your normal FM carrier has a mono signal (L+R), and modulated on a 38kHz subcarrier is the difference signal (L-R). The mono radio can hear only the L+R signal, the higher band L-R being filtered out. In a stereo decoder, the L-R signal is demodulated, and mixed with the L+R to give L only, which is then subtracted from L+R to give R only.

It's sometimes called M/S (mid/side), so we can express it like this:

M=L+R, S=L-R when transmitting.

L=M+S, R=M-L

Clear as mud, right?

Re:New?

[TheDick]

Damn I wish I hadn't posted earilier so I could mod this. good post.

Re:New?

[TheSync]

BTW, Digital AM and FM are coming very soon, using Ibiquity's IBOC system:

IBOC technology makes use of the existing AM and FM band (In-Band) by adding digital carriers to a radio station's analog signal, allowing broadcasters to transmit digitally on their existing channel assignments (On-Channel). A station will convert to iBiquity Digital's IBOC technology and begin transmitting a simultaneous analog and digital signal, known as the "Hybrid Mode".

AM will soon sound like FM.

Re:New?

[GigsVT]

Cat5 has a nominal bandwidth of 100Mhz, you are confusing bandwidth and frequency.

Try this URL if you want the details.

http://216.239.51.100/search?q=cache:vRq6AoANKp0 C: www.molexpn.com.au/solution/files/ufab.pdf+etherne t+frequency+and+bandwidth&hl=en&ie=utf-8

Re:New?

[GigsVT]

AM will soon sound like FM.

I very seriously doubt that. That low you don't have enough cycles to work with to encode more than 300-600bps or so.

Re:New?

[TheSync]

That low you don't have enough cycles to work with to encode more than 300-600bps or so

In the AM band, the total allowable channel is about 30 khz wide. The total area outside typical analog broadcasts is 20 khz, but IBOC also adds digital signals in the analog area as well. Using QAM, that gives you 120 kbps. In this day and age, a static-less pop-less 30-40 kbps audio sounds pretty sweet.

Re:New?

[God! Awful]

Hasn't this always been the case? E.g. - I can add digits to infinity to any radio station so that instead of tuning into 95.3 I could tune into 95.3000 - 95.3999. If the hardware/software can differentiate between such small differences in frequency then in the example above we just turned one setting on the radio dial into 1000. Why stop there? Am I missing something?

I still remember this stuff from my undergrad EE days. It's basic communications theory. For any radio broadcast (let's take FM as an example, but this also applies to AM), your signal to noise ratio is determined by the amount of power you put into the signal. FM stands for Frequency Modulation, so you are not actually using a fixed frequency; you are actually modulating the frequency within a small range.

If someone else sends a signal in a neighbouring band, their signal will appear as noise to you (in AM, you would hear a faint version of their broadcast; in FM it's just static). Therefore, you need a guard band to separate the signals. Fortunately, the amount of interference falls off pretty quickly (exponentially, I believe) with the size of the guard band, so the guard band doesn't have to be very big.

It is completely possible to reduce the bandwidth you require without losing signal quality, simply by increasing your signal to noise ratio. It is infeasible to reduce the noise, so you really need to increase the power of the signal (I seem to remember that S/N is directly proportional to power, but it might be a square law). But if you increase the power of your signal (and also reduce the size of the guard band), then you create more noise on each of the neighbour bands, so they have to increase their power output as well. The result is that we can have as many radio stations as we want, as long as each one comes complete with its own power plant.

As for the suggestion in the referrant article, I wish they had provided some facts about the science behind this guy's claims. Digital audio can certainly reduce bandwidth consumption, but it's not a panacea. Broadcasting on multiple bandwidths sounds like it will just increase ambient noise. Sure, bandwidth will go up, but so will power consumption. And that, as I've just illustrated, is nothing new.

-a

Re:New?

[unitron]

Actually you wind up with (L + R) + (L - R) which gives you 2L and (L + R) + (-L + R) which gives you 2R. The sum (L + R) and the difference (L - R) are added together in one channel and the sum and the inverse of the difference (-L + R) are added together in the other channel.

Re:New?

[unitron]

Although bandwidth and frequency are not the same thing, I suspect that Cat5's 100MHz bandwidth starts somewhere around 0MHz and goes up, topping out somewhere around 100MHz. Just because it has a bandwidth of 100MHz doesn't mean that you could use it for 6789MHz to 7789MHz.

Re:New?

[GigsVT]

But it also doesn't mean you can transmit ethernet on the FM radio band, just because the FM radio band includes 100Mhz, that was the point I was responding to. I think FM radio has a bandwidth of something around 300khz per channel.

Re:New?

[unitron]

The FM broadcast band runs from (approximately) 88 MHz to 108 MHz, which is only 20 MHz for the whole thing, so yes, it would be mighty tricky to shoehorn 100MHz worth of signal into it (although if you figure out a practical way to do it, how 'bout letting me in on the ground floor, pre-IPO?).

Re:New?

[Gordonjcp]

Correct. I was talking in qualitative terms, rather than quantitative, though. But you're quite right. Of course, in a "practical" decoder, rather than the "ideal" decoder described here, you'd have various losses and gains in the circuitry, so it wouldn't work out exactly like that.

isn't he actually suggesting...

[simpl3x]

that the notion of having to occupy a specified portion of the spectrum is no longer a necessity? and, that multiplexing over channels does no harm to the signal? the summary would then be that as opposed to x slots in the spectrum, there are now infinite slots. having read similar arguments to the spectrum issue, there is not discussion of moving up or down the spectrum. but, certain companies have been pushing for just that.

Re:isn't he actually suggesting...

[Coz]

You still have to "bound" the area of the overall spectrum that you look for signal in. The size of the slots is a function of the speed of your clocks, size of your code, and a lot of other technology-specific issues.

Multiplexing over channels doesn't harm the signal provided the code/time space is large enough for all the users - it is still possible to get interference, but it should look like white noise to the receiver, which is why the "noise floor" keeps getting referenced. The more users, and the more power each emits, the higher the noise floor - and beyond a certain level, you can't find the signal in all the noise.

Isn't he talking about Ultra Wide Band?

[greensquare]

Seems like he is talking about Ultra Wide Band to me. That has been covered on Slashdot a couple of times all ready.

Check this:
http://slashdot.org/article.pl?sid=02/04/18 /215525 4&mode=thread&tid=126

Sure...if you forget about all the legacy equip.

[ALecs]

Sure, he's got a point: better ways (that we have now) of using radio spectrum may eliminate the "bandwidth limits" that we have now. But that's just not the case with many modes.

Consider your typical FM transmitter. FM broadcast radio worked so well because of a lot of factors, including the "capture effect". In FM, when you have two transmitters nearby your reciever, one of them (unless they are extreamly close) will "capture" your reciever, preventing the other from being heard. This greatly reduces the appearence of interference from distant-but-still-within-reception-range transmitters.

AM and SSB transmissions don't have/suffer from this. That's why SSB ham nets work so well - SOMEBODY is bound to be able to hear you even if your signal overlaps with others.

Now, I don't know as much about spreadsprectrum as I do other radio modes but I assume the idea is "listen to a lot of spectrum and pick out what you're interested in". Now, if my signal completely captures your reciever, just exactly what are you planning on picking up from other stations?

I'm not sure exactly what makes Gillmor believe that more devices using a given portion of spectrum increases the bandwidth. Perhaps he means that more information is being transmitted between more devices -- more bps, more "bandwidth". This assumes, however, that all these devices are compatible in spectrum, mode, capablility, etc. The minute I key up my 2.4GHz FM transciever for sattelite work things may change.

Spread Spectrum combined with TDMA?

[jxs2151]

There is so much more available now than we once thought. Technologies like Spread Spectrum and TDMA and CDMA have the potential to unlock vast amounts of underutilized spectrum.

Think about it:
Vinnie's Cab Company in Newark, NJ is allocated the frequency of 152.125 Mhz and makes use of it maybe 15 total minutes a day. We can improve on that and also allocate 152.125 Mhz to Joyce's Cab Company in Denver, CO so you get more use out of the available spectrum by dividing it geographically.
Now how about if we could take every cab company in the US, regardless of location, and not assign them any frequency at all but provide them with technology such as CDMA or Spread Spectrum that assures no interference. In essence you have freed huge amounts of the 'limited' spectrum for other uses. Once spectrum is freed there is no longer the psychological or bureaucratic limitation on new ways to use spectrum.

The FCC is regulating based on the limited resource model and it is now outdated. Time for a change. With the way that new technologies conserve spectrum we are using a fraction of what is theoretically available.

Re:Spread Spectrum combined with TDMA?

[Whispers_in_the_dark]

And how about this on top: no more voice where it isn't needed. You can save a lot of spectrum by sending TEXT messages instead of voice calls. In the event voice communication is needed, standard cellular would do the trick I would think. Additionally confusion from static would be minimized and actual communication would improve, reducing the need for retransmission (say again?). Toss in the ability to encrypt the data and it sure seems like one way to optimize the spectrum.

Re:Spread Spectrum combined with TDMA?

[unitron]

Vinnie's probably uses 152.125 MHz a lot more than 15 minutes per day and there's probably another cab company using that same frequency that's located a lot closer to Newark than is Denver.

Unless Vinnie and Joyce are both using transmitters that are powerful enough to reach almost half of the way to each other there's no reason that a lot of other cab companies in cities in between Newark and Denver can't use that same frequency also.

If Vinnie and Joyce were both in Newark they could still both use the same frequency if there were a way to insure that they didn't try to use it at the same time. But then if ABC, FOX, CBS, and NBC would agree to only broadcast for an hour once every 4 hours, they could all use channel 2 or 11 or 37 or whatever.

Now if Joyce and Vinnie were both in Newark and you could connect both of their transmitters to the same timebase and they could alternate using that frequency every one-one millionth of a second and the radios in the cabs gated the tuners at 1,000,000Hz then theoretically Vinnie's messages could get through to Vinnie's drivers and Joyce's messages could get through to Joyce's drivers. But the transmitters and receivers would cost a lot more than they do now. Do you want to be the one to tell Vinnie that he needs to spend thousands and thousands of dollars on a new transmitter and recievers 'cause you need more bandwidth so that you can download porn faster?

Re:Spread Spectrum combined with TDMA?

[jxs2151]

You missed the point badly.

Re:Spread Spectrum combined with TDMA?

[unitron]

Perhaps I was confused by your extreme understatement of the amount of time per day a cab company dispatcher is on the air and your extreme overstatement of the usual or necessary amount of geographical separation between transmitters. If you were exaggerating for the purposes of illustration, perhaps you should have said so.

Re:Spread Spectrum combined with TDMA?

[jxs2151]

If you were exaggerating for the purposes of illustration, perhaps you should have said so.

I would venture that by the fact that you are mentioning it, you realized that I was posting examples that were not intended to be taken literally.

The point of exaggeration is that intelligent people don't need to be told that the examples are overstatements, they can tell by the context and the content of the posting.

Re:Spread Spectrum combined with TDMA?

[unitron]

My original impression wasn't that you were exaggerating but that you didn't know as much about radio as you thought that you did. Perhaps I was mistaken.

Re:Amateur radio

[TooTallFourThinking]

Woulnd't that be nice. More frequencies would be great. Honestly, I just wanted to post my call sign. ;) I'm egotistical that way!

KC2JPU.

He isn't talking about Ultra Wide Band?

[JohnDenver]

UWB is a technology that uses the entire spectrum. He's talking about using traditional radio technology more effiently.

Re:He isn't talking about Ultra Wide Band?

[WolfWithoutAClause]

More accurately, he's talking about optimal use of bandwidth period. This can include UWB, narrow band, anything pretty much. The claim the guy makes (if you pull out the pdf file) is that the bandwidth is linear per user- i.e. everyone gets exactly equal bandwidth if you do it just right.

It sounds bizarre, but in the case of people actually sitting on the earth surrounded by reflective/absorbant stuff, it probably makes a great deal of sense. If you are in free space, where there's less things to absorb/reflect radio, then lasers are probably the way to go though.

Re:How do you copyright a spectrum? (FCC killing m

[greensquare]

How do you patent a DNA sequence?

Several problems with this.

[Mr Krinkle]

One if you have no regulations on the spectrum what is to say I am not going to manufacture a 100 kw router to go in everyone's home? The theory being well as long as my device is the most powerful on the block I will be fine. If someone else has a receiver nearby it would be very likely I could cook their receiver. Also this is rf. The more you fill it the more likely we are going to have collisions etc. If you assume a set wave length will have perfectly coded packets with unique IDs so that only the desired machines will decode and understand the signal you will eventually hit a point where you are receiving so many packets that your machine has collisions decoding them (similar to running your standard network at 95% capacity it does weird things) For these reasons I see there having to be regulations for a long time to come.

Re:Several problems with this.

[CyberGarp]

Absolutely. I worked on fixing a system that sent controls to five dams to set their spill gates. These dams were far out in the woods. It sent the commands over an "unused" radio band assigned by the FCC. Besides the obvious fact that the moron who put it together didn't even bother to use CRC to check the packets for correctness, there was a bible thumping preacher broadcasting rants and raves out of his house on a regular basis. The upshot of the preacher's preaching all over a radio band he didn't own (and it wasn't on your radio dial so one wonders who was listening), was that the gates on the dams would go up and down for no apparent reason.

After the FCC shut the preacher's broadcasting done, I recommended CRC validation of the packets and an ACK/NAK two-phase commit to the movement of the spill gates.

Warren's Wisdom

[donnacha]

There's a great scene in the Warren Beatty film "Bulworth" in which his character, Senator Jay Billington Bulworth, explains how the current distribution of the airwaves works. I can't remember the exact lines but the general jist was as follows:

The government takes a resource that's everyone's, that's just there, freely accessible to everyone, and calls it property.

It then auctions that property off to the networks for an absolute pittance because they depend on the donations of the networks' corporate owners (GE, Disney etc).

The politicians desperately need this money because, in order to get re-elected they must be able to buy TV commercials, tiny minute-long slices of the broadcast spectrum, back from the networks.

No politician can afford to confront this system or even acknowledge the massive warping effect it has upon democracy because, if they do, none of what they say will be reported by the mainstream press and they certainly won't be able to afford to get re-elected.

Maybe this unlimited bandwidth idea will solve that rotten cycle but I've got a bad, baaaad feeling that too many powerful people would have too much to lose.

Just what is he saying ?

[sane?]

Having trawled through the presentation on his site, it appears it boils down to:

• If you use better technology (low power, repeaters, signal extraction) then you can fit more information into the same bandwidth.
• You could always use more bandwidth.
• Private industry is better at cooperating than the government is a regulation.

At no point does he really try and dispute Shannon, there is a finite limit to the information that can be transmitted, he just thinks we should be smarter at approaching that theoretical limit. He does the usual job of trying to confuse the issue and make it more complicated than it actually is, but when you get down to it, its fairly obvious.

Now I'd tend to agree that we could do with being smarter. But to say that the commercial world is going to make systems that all work nicely together is just plain ignoring realities. Look at the 802.11 / Bluetooth cockup - in reality the aim will be the fast buck and market share. If you can do that by riding roughshod over the competition, so much the better.

In the end you need to engineer a balance between the short term and long term perspectives. I'd agree that its wrong at the moment, but that is a call to shake up the regulations and those that create them, not to throw out all long term thought in an orgy of competing, incompatible systems.

Maybe we could start by allocating bandwidth to particular purposes on a lease term basis. Once you reach the end of your term, you have to show that continuing to allow you that bandwidth is the optimum use for the next lease period, if not, then no bandwidth.

Maybe then we would have faster evolution, and even revolution, in the use of the EM spectrum.

Re:Just what is he saying ?

[WolfWithoutAClause]

Now I'd tend to agree that we could do with being smarter. But to say that the commercial world is going to make systems that all work nicely together is just plain ignoring realities.

The internet is a counterexample. There are plenty of ways to deliberately mess up the IP protocol- some of which may sometimes give you more bandwidth. However, in most cases people/companies don't do this.

Also, it's quite possible for the FCC to put conditions on licensing particular parts of the spectrum- 'we only allow hardware that follows standard XXX' or some such ruling. Manufacturers would then have to produce hardware that followed the relevant standard, or they'd be sued by their consumers.

Look at the 802.11 / Bluetooth cockup - in reality the aim will be the fast buck and market share. If you can do that by riding roughshod over the competition, so much the better.

If you can... don't forget that some of the equipment around may decide not to talk to you if you break the rules. That may even be part of the standard.

Re:Just what is he saying ?

[sane?]

Two counterpoints

1. IPv6 takeup
2. He's postulating no FCC, no ITC, so no regulations. Now I tend to agree that not limiting 'who' can use bandwidth, but saying 'how' is workable, but his argument is competition red in tooth and claw.

Imagine a scenario where someone sells a "802.11 killer". Set it up and it kills off bandwidth for any such devices, but still allows Bluetooth to function. Call it a 'router enhancer'.

Sure people will complain, but it isn't likely to do them any good in this low regulation environment. Don't forget, they already sell jammers for mobile phones !

What occured to me after posting the last message is that this is very similar to Dubya's solution to global warming - minimise the regulation and the money will push technology to solve all your problems. It seems to be a pecularly US viewpoint - most everyone else recognises the limitations of the market in rational decision making.

There is a whole other question of where the optimum regulation vs market balance is - maybe that's what this guy should be researching instead?

Where will we get the "flying attack porcupines"?

[Christopher Thomas]

After looking over the lecture slides a few links in, the authour seems to just be saying that congestion (and hence spectrum scarcity) will be a non-issue if we just switch to point-to-point transciever schemes instead of broadcast schemes (either by using cells and a backbone or by clever coding).

This is great, and would indeed increase bandwidth to silly levels... except for the fact that implementing a pervasive point-to-point network with high local bandwidth and low leakage is a PITA of vast proportions.

Summary: Good idea, and it'll certainly see greater use in the future, but it's not "unlimited airwaves" by a long shot.

Re:Specious nonsense.(Shannon's Law)

[Beryllium Sphere(tm)]

Yes.

There is an absolute upper limit on the number of bits per second you can get through a given frequency range.

Like most abolute upper limits, you can play with it by tinkering with the assumptions, for example by doing geographic reuse.

But the new technology is providing smarter and more efficient sharing, not changing the laws of information theory. We can do more bits per second per Hertz than we used to, but not an infinite number.

We may still want to change the regulatory regime away from "ownership" of frequencies and something more like rental, or good behavior requirements. Which isn't a revolution -- cellular phones lease a frequency or a time slot or a code for the duration of a call, and their maximum power and antenna gain are limited.

Technology should regulate traffic not Beauracracy

[JohnDenver]

Nobody's suggesting we just unregulate everything. If you read the article, you would have noticed the following:

Reed wants the FCC to open up some spectrum for these more open wireless networks, giving entrepreneurs a new public space in which to innovate and create value for the rest of us.

It sounds like this guy wants to open up a spectrum that would use a very smart/adaptive protocol for open data/voice communications.

What's so crazy about that?

Bandwidth!

[phliar]

I can add digits to infinity to any radio station so that instead of tuning into 95.3 I could tune into 95.3000 - 95.3999. If the hardware/software can differentiate between such small differences in frequency then in the example above we just turned one setting on the radio dial into 1000. Why stop there? Am I missing something?

Yes -- it's called bandwidth. If you have an AM station broadcasting at 1550 kHz, and the audio signal is band-limited to 10 kHz, then the signal uses frequencies from 1540 kHz to 1560 kHz. This means other stations can be no closer than 1530 kHz or 1570 kHz.

For other modulation techniques, similar things apply; FM bandwidth usage is not a simple relation as in AM but similar. The "richer" your signal is, the more bandwidth you need. CD quality audio will need more bandwidth than what we get with commercial AM stations. TV signals require more bandwidth still.

Spread-spectrum techniques etc. work in a different way but the concepts are similar. The theoretical limit is that the information carrying ability depends on the signal-to-noise ration and the bandwidth. Add to this the fact that electronics, antennae, wires, propagation through the atmosphere etc. all behave very differently in different parts of the EM spectrum -- as a practical matter, the information carrying ability of the airwaves is very much a limited resource.

Re:Yeah right

[Subcarrier]

Imagine if we had cars that could pass through each other and through people without any resistance. I would be the end of traffic jams!

It's not off-topic you moron, it's an analogy.

Spread spectrum modulation technologies are interference limited. The more power is pumped into the spectrum, the harder it is for a receiver to pick a signal out of the noise. If the signal is too weak compared to the noise, you're out of luck.

So, while radio waves pass through each other without doing any harm, it's no good to anyone if you can't pick up a signal. Granted, anyone can transmit as much as they like.

Why don't we just go to Subspace?

[teamhasnoi]

Subspace transmissions don't have any of the limitations of RF band. Infinite bandwidth, FTL transmission, and superior SN ratio. They are subject to antilepton interference, but that is rare at best.

Hello? FCC...this really is a no-brainer.

Not like HTDV!

[aaarrrgggh]

The idea of software controlled transcievers fails if you look at it as a "new radio." It's not like HTDV, though; the purpose of putting one of these fancy things into your car wouldn't just be "FM", (or, for that matter anti-theft devices, GPS/directions systems which are also prevalant today), but maybe also movies for the kids, internet access... whatever.

Sure, you have to create a need for it, but... with the rate that people want to be unteathered, you have to make better use of the spectrum.

credibility?

[hackman]

This article comes across like a sci-fi movie, very aloof. The writer paraphrases and quotes from what another guy supposedly said, with no indication of technical facts or other groups or individuals that agree. I have no reason to believe the author and subject are credible, making it hard to trust the article. I'm not the most knowledgable on the FCC's policies, but I don't tend to believe this "evangalist" in general.

However technically speaking, there are some points that sound feasible and are likely true. I would expect that the FCC does inhibit inventors and small companies that have good ideas. Their licensing fees and other policies do make startup "disruptive technologies" difficult, which is exactly what the established companies that already have spectrum want. However some areas of the spectrum (i.e. 2.4GHz, etc) are open, and he fails to address the collision problems that exist in those areas. I think we are now beginning to see hardware in the free spectrums that is capable of dealing with very noisy environments, but in my eyes that equipment is still in it's infancy. (If someone knows more on that please reply to this post on this subject..)
I would say once these technologies are proven, the FCC should listen, but in the meantime there is a LOT of equipment that isn't capable of dealing with this and could become rather useless if the spectrum is opened up. Seems like a logical approach, before changing the regulation system. Prove your point, man! Gimme some examples.

Re:credibility?

[decefett]

As soon as I read that he is a CS guy not an RF guy I had my doubts.

Re:credibility?

[scubaed]

What this guy is saying is not really new, cell phones technology is an advance in that direction, and can anyone say Bluetooth?. However, as has been pointed out elsewhere, he is not a radio expert by any means. So let me put this forward:

Scenario 1: We trash all the existing technology in favor of this new and improved one. Everyone owns a jog/car/home radio that can act as a repeater, low power transmission at the source is all that is needed. This would work great in cities, as long as, everyone keeps their radio powered-up, nobody minds the (large) losses in battery life due to the necessary transmission power (and more than inneficient transmission antennas and paths). if you decide to go driving out of town, well, you better turn on your CD player anyway, or, wait a minute, the FCC allocated some spectrum to satelite radio, right?, but that's clearly a no-no.

Scenario 2: We admit that there are applications that would benefit from this kind of thinking. Hey, guess what, we are doing that already, packet radio, 802.11 (not really there, but most of the radio technology, if not the protocol itself, is already there), Bluetooth (exactly the scheme this guy proposes), ultra-wide-band radio, and we keep going...

Spread spectrum is not the solution, it is a more efficient technology, true, but its capacity is also limited, in all of the writer's slides he does not account for the "noise" that is introduced to the channel by the presence of other transmitters (for your neighbours cell phone, yours is just noise). In the case of "older" technologies, this is even worse, other transmitters generate noise that is strongly correlated with your signal, so there is no way to separate them (and no signal processing magic can do that, no matter what software guys say).

Antennas is another issue completely ignored by the writer, while we can have very efficient, small, directional antennas at high frequencies (GHz ranges), at low frequencies (i.e. AM band) we need 150 square meter antennas to get any hope of directionality, and a reasonable fraction of that to get any hope of transmitter efficiency. So, sorry, physics are not in this proposal favor (stick with the software please).

I agree that there are some valid points to be made, and that more (high) bandwith should be allocated for these kind of applications, but I percieve that the FCC is moving in that direction already.

Re:How do you copyright a spectrum? (FCC killing m

[Ooblek]

Plop down $5k or so (with maybe a little extra for the filing clerk) and j00 R 0wn3d! My house needs cleaning, so get over here. You have to work for the right to procreate since you need to buy a license from me.

So, you see, the patent process is just that easy.

(Yes, this is a lame attempt at humor, so don't mod me as flamebait if you don't get it.)

Paradox of the Best Network

[cpeterso]

This is an example of the Paradox of the Best Network:

• The best network has the fewest added features and functions
  
• The best network just moves bits
  
• But a stupid bit-moving network is a commodity
  
• The telcos like smart networks
  
• The Internet succeeds because it's stupid
  
• The Internet's success threatens the telcos
  
• This is about politics, not just business

Radio kindergarten Part II

[Strange Ranger]

Thanks for the explanation.

Being a radio "goober", I am still inclined to wonder why it can't be 'split' much more. Given a 10kHz spread for modulation.. why not modulate much more minutely... lots of quick itty bitty (getting technical here I know) modulations that don't spread out so far? In effect hitting the zoom button on the analyzer so the very thin spike looks huge. Bandwidth of 3000-34000 1/10th Hz? Guess I should RTFM.

Admitting ingorance on /. is like going out naked with only a mask on.

Re:Radio kindergarten Part II

[TheDick]

Because those smaller pulses are harder to pick out on the other end :) and Would be affected much more by noise

Re:Radio kindergarten Part II

[Gordonjcp]

Because the higher the frequency of the modulation, the further from the centre frequency you go. For example, given the precise 100.000MHz signal above, if you modulated it with a 1kHz signal, you'd get a spike at 99.999MHz and a spike at 100.001MHz, as well as the original 100.000MHz one, right? If you then increased it from 1kHz to 10kHz, the spikes would be at 99.99MHz and 100.01MHz. If you increased the signal to 1MHz you'd have spikes at 99MHz and 101MHZ.

I recommend that you get hold of the ARRL handbook from your local library, or indeed the RSGB book if you're in the UK. These are the standard works on amateur radio, and explain all these things far better than I can....

Re:Radio kindergarten Part II

[Newander]

Because the higher the frequency of the modulation, the further from the centre frequency you go.

With FM yeah, but with AM you should be able to make the band as narrow as you can build a bandpass filter.

Re:Radio kindergarten Part II

[Aceticon]

sin(x)*sin(y) = cos(x+y)/2 + cos(x-y)/2
(or something like that, i sorta forgot the precise formula)

Anyways
- Assume x is the frequency of the carrier wave
- Assume y is the frequency of the modulating wave
- sin(x)*sin(y) is the carrier wave modulated by the modulating wave

Draw your own conclusions...

Re:Radio kindergarten Part II

[Gordonjcp]

Still doesn't work like that. When you amplitude modulate the signal, you still spread the spectrum of the carrier. I'm not sure why, but you do. I think it's to do with the modulated carrier no longer being a sine wave.

I'll go and dig out the RSGB Handbook and look it up.

Re:actually

[GigsVT]

The radio waves don't care about the packet headers in the data they are carrying.

We are talking about fundamental things here, like noise floor, and front end overload.

Offbase.

[mindstrm]

Yes, we can make more efficient use of spectrum now, and the fcc should change it's rules to reflect this. This would enable a whole new world of wireless communications.

However, it's not a bottomless glass. Spectrum is still quite limited.
The much-hyped ultra-wide-band is not a final solution, though it may be more efficient.

This will probably come out "ignorant"...

[cr0sh]

Ok, my knowledge of radio is very low, but I have often wondered why the following couldn't be implemented, at least for "one-way" broadcasts (ie, similar to what FM is now):

1. Allocate a section of frequency bandwidth, enough for a 32-56Kbps transmission system.

2. Each "radio" is "tuned" to this "station".

3. All broadcasts have "addresses", and are packetised (ie, digitized, then the packet of digital signal has a header attached with this "address").

4. The user "tunes" to an "address", and starts receiving packets from that address, which are buffered, then reprocessed (D2A) into sound.

Ok, maybe the "bandwidth" would have to be bigger than what I proposed above to get enough "stations" into play, and the packets would have to be either ordered in some manner or randomised to ensure that the radio's buffer never underruns or whatnot - and maybe this is why this whole scheme has not been tried (can't transmit the packets fast enough because of bandwidth limits, etc).

I am just curious if this would work, or if it would be a failure (I tend to think the latter, otherwise it would have been done by now, if it hasn't already)...

Re:This will probably come out "ignorant"...

[Permission Denied]

To implement what you're talking about, you need some sort of time sync. Basically, what you're talking about is very similar to how ethernet works, but there are two fundamental differences between ethernet and radio at one specific frequency: with ethernet, you can both listen and broadcast at the same time (which means you can detect when you have a collision, thus CSMA/CD); with radio, you cannot listen while you're transmitting because your signal will drown out any incoming signal. This means you need some way of saying "OK, you can broadcast now." You could do this either on a time-slice basis (like 802.11) or with a token-passing scheme (and there are some wireless protocols that do token-passing). Another problem is that you might have three radios, like this:

A ---- B ---- C

where A is four dashes away from B and B is four dashes away from C. Suppose that a signal "lasts" for five dashes. That means A and C can't see each other, but B can see both. This brings up other nasty problems with simple protocols (and wireless protocols like 802.11 deal with this).

So, the simple packet-addressing scheme won't work for two-way communication. As for one-way communication, there's no need to "label" the recipient of a broadcast; radio is inherently broadcast, so everyone can hear everything anyway.

Re:This will probably come out "ignorant"...

[cr0sh]

So, the simple packet-addressing scheme won't work for two-way communication.

I know that - I was speaking of it's use for only a "one-way" scheme.

As for one-way communication, there's no need to "label" the recipient of a broadcast; radio is inherently broadcast, so everyone can hear everything anyway.

I wasn't labling the recipient, I was labling the "station" or "sender" - ie, the address of the "station" would be in the packet. There would be a main broadcasting system for all "stations", which would spew packets for all of them out over radio to the user's receivers. In other words, there would be one transmitter ONLY, for the area being broadcasted to. Radio "stations" would send packets (with the address of the station) to this main transmitter, where they would be sent out, to be recieved by the user's radio, who would select a station's address, and the radio would start buffering the data, then begin "playback" of the stream.

Think of a single radio transmitter sending out a packet stream like so:

ABCBCACABCABACABACBCABCBABABAC...etc

If the user's radio is "tuned" to recieve packets marked "A" only, then those would be buffered and played back. Switch to address "B", and those would be buffered and played back.

The problem is that with more "stations" (addresses), the more packets that have to be sent out, and the faster the packets need to be sent to prevent buffer underruns at the user's radio. Thus, this would require more bandwidth. It sounds like a simple method, but as I noted before, if it were, it would be being done already.

Re:This will probably come out "ignorant"...

[J'raxis]

What youre describing sounds like streaming media over multicast. I believe (Im no expert on this) that everyone transmits to the same IP address, something like 224.0.0.0, and clients pick out what packets they want based on the sender address. The buffer overrun problem certainly hasnt been solved, but current streaming media protocols already deal with these problems (somewhat) effectively.

Selling frequencies?

[ApharmdB]

Correct me if I'm wrong, but weren't the HDTV frequencies' exclusive rights just given to broadcaster's for free?

The End of the Anonymous Listener?

[Dan Crash]

Reed's quote about "network operation increasing capacity" obscures an important loss -- the loss of the anonymous listener. It seems that for this technology to work, receivers are going to have to be independently addressable, broadcasting your listening or viewing choices to the public. How's that grab you?

The anonymous listener is fundamental to democracy. Imagine a world where you fear to stay on a given channel too long, for fear that someone is going to associate you with the views being expressed. This is the kind of thing that we should be steering away from with new technologies, not toward.

Couple this with the fact that there's not exactly a lack of spectrum in the first place: 90% of the channels on your UHF dial are sitting there doing nothing right now because the FCC and Congress prefer THAT to leasing them to nonprofit organizations at a reduced rate.

Like most of our current "technological" problems, what's broken isn't electronic but human.

Re:The End of the Anonymous Listener?

[unitron]

"90% of the channels on your UHF dial are sitting there doing nothing right now because the FCC and Congress prefer THAT to leasing them to nonprofit organizations at a reduced rate."

Those channels aren't leased, they are licensed, just as are the VHF channels. The main thing that keeps those non-profits from applying for a license to use one of those UHF channels in any particular geographic area is most likely that providing a transmitter, tower, and antenna and paying for the operation thereof ain't cheap, and that's before you spend anything on content and studio equipment to get that content to the transmitter as a video and audio signal. And you have to convince the FCC that the broadcasting of that content is sufficiently "in the public interest" (those airwaves belong to us, remember?) to deserve the use of that UHF channel allocation.

Re:The End of the Anonymous Listener?

[Dan Crash]

Thanks for the correction.

I don't think broadcasting a UHF or VHF station needs to be as expensive as all that, though. With a modern transmitter, a tall building, and a volunteer staff, you could run a small station for virtually the cost of electricity. (Okay, slight hyperbole there, but cheap.)

Content doesn't have to be a problem, either. Desktop editing and current high-level consumer cameras are more than acceptable, and there are hundreds of frustrated indie filmmakers who would love a bigger venue for their work (think GNN). This sort of thing is definitely in the public interest.

If nothing else, it would be an interesting experiment. Licenses for noncommercial, nonprofit stations like this should be $100, and distributed in a lottery to applicants every 3 years. Now that would kick cable's ass.

Ten percent of the spectrum needs to be open

[gone.fishing]

Ten percent of the spectrum needs to be "open" for exparamentation, testing, and demonstration of new methods and technologies. This space needs to be broadly applied so that different technologies can be tried across a wide variety of bands.

This way when something better comes along, it can be proven and space made available for it where it best belongs.

I like the concept of spread-spectrum communications where enough redundancy is built in so that thousands of signals can share the same space without interference. From what I understand, the space of a single TV channel could handle an entire city's "personal communications" (two way radio, cellular, paging, SMS and etc.) needs with lots of room left over.

When you think about the un-used potential in the airwaves, you just gotta drool.

Re:Ten percent of the spectrum needs to be open

[dwm]

Ten percent of the spectrum needs to be "open" for exparamentation, testing, and demonstration of new methods and technologies. This space needs to be broadly applied so that different technologies can be tried across a wide variety of bands.

It's called Amateur Radio.

Re:Ten percent of the spectrum needs to be open

[thogard]

It's called Amateur Radio.

Which is generally not open to experimentation, testing or demonstration of new methods and technologies.

Re:Ten percent of the spectrum needs to be open

[Kirkoff]

It's called Amateur Radio.

Which is generally not open to experimentation, testing or demonstration of new methods and technologies.

Umm, what Amateur Radio are you dealing with? The license I hold does allow me to experiment with new techniques. For example PSK-31 was invented in 199\8 or 1999 and is widespread. Yes, there are some limits, for example, you can't use more bandwidth then a voice channel on HF for new modes, but that's just common sense. Up above 3GHz, you're pretty much open to anything you want, including spread spectrum. You can do SS on everything above 70cm. If it's currently not allowed, the FCC does grant 6 month at a time experiment permits. If it works, the FCC will allow it. For example, see the ARRL's experiments in the 60m band.

--Josh

Telcos RIAA

[Andy Dodd]

Unlike the RIAA, the telcos accept that new technology is going to change the way they do business drastically, and trying to fight the oncoming tide of VoIP, etc. is suicide.

AT&T was the first to see the light - AT&T put quite a lot of research into VoIP techniques, believe it or not. MCI, another major telco, controls a LARGE portion of the US Internet backbone.

Why do you think all of the telcos have been branching into the ISP business? The telcos have a lot of the infrastructure needed for network backbones (Mainly dark fiber and rights to lay more cable where they already have cable/fiber), the Internet is not a threat to them, it is simply the direction their business is evolving. This is why you see telcos now becoming major large-scale ISPs - They know it is their only way to survive, and they also have the capital and infrastructure to succeed in the new market.

At one time, the telcos fought against the Internet and VoIP, but unlike the RIAA, the telcos have seen that fighting the new wave is futile.

The war you're anticipating has already happened and passed. It wasn't much of a war either, more like a small street gang firefight.

won't happen

[Cheeze]

nothing in that article will happen with the current "business-friendly" presidential administration.

Re:This makes no sense.

[soft_guy]

Right! There will always be mallicious people out there who would try to jam certain radio frequencies, such as the example you cited. Or people might jam stations that air views they disagree with. So, I agree you don't want to totally get rid of the FCC and have a free-for-all. I agree that maybe the FCC should be reformed.

Re:actually

[HiThere]

There will always be limits, but with low powered transmissions, packet switching retransmissions, etc. you can increase the level of em usage remarkably. I'm not sure of the details of what he's arguing (slashdot is largely down right now, so navigation is difficult), but spread-spectrum mainly buys you higher noise immunity at any given power level. It's the packet switching transmission and reduced power levels at each transmitting station that up the throughput.

OTOH, this might have its downside, too. It everything goes wireless then the amount of exposure to em radiation at numerous wavelengths will increase. This is bound to have effects, if nothing more than raising the temperature. It might, however, have substantially worse effects, even if those are hard to forsee. This kind of thing should be tested in small areas at first, and again for each increase in power concentration or spectrum coverage. I suspect that at least an entire town would need to be used as a guinea pig here, since we don't even know what effect we are looking for. Possibilities that occur to me are:
1) Increased level of cancer
2) Increased mould growth
3) Increased food spoilage
4) Increased glaucoma (i.e. opacity of the vitreous humor)
5) Faster proliferation of weeds
6) Increased pregnancy rate
7) Decreased pregnancy rate
8) ...
And I've though of reasonable mechanisms for all of the mentioned effects. (Of course, there's a big difference between a reasonable mechanism and a probably effect.)

FM band

[SlugLord]

Well everyone here seems to like talking about the limitations set by the FM band. It seems the measures suggested in the article would indeed eliminate the "anonymous listener" which is, indeed, important for the free dissemination of information, specifically to prevent fear of being tracked in listening to "subversive" speech. Bandwidth could easily be used more efficiently without eliminating that. Just go to a digital system, so stations could easily be placed much closer together. CDs give (for all practical intents and purposes) better quality than tapes. Just set up bits transmitting every 44kHz or however fast CDs sample.
I doubt there would be much trouble setting up such a system, with the only limitations being the willingness of consumers to buy the new technology. This could be easily remedied by giving a licence to every station that already exists in the old band a station in the new. Then say the old band will go away in X years. people will buy new cars with hybrid receivers until everything is transmitted on the new band. There goes all that bandwidth wasted by FM... and AM ... and TV, etc.

... oh yeah, and you can polarize the signals, too... that gives you at least double (maybe triple if they get longitudinal polarizaiton to work) the bandwidth.

Baby steps...

i dont get it

[isorox]

Why cant we just use higher and higer frequencies? 2GHz full? Use 20GHz? Or 50GHz? Or a googlehertz?

Re:i dont get it

[Indy1]

two words: quantum mechanics

As you go higher and higher in frequency, each photon generated takes more energy to generate. thus, for a given amount of energy, the higher the frequency you go, the less generated photons, and in general, the less range you have. Also higher energy photons can have nasty effects on biological material (aka humans). You know what your microwave does to that day old pizza right ? :)

Re:i dont get it

[isorox]

i usually eat the day old pizza before it gets to the microwave, but I digress.

Dont microwaves run on 2.4GHz? same as your wifi/bluetooth phone?

What about satelites that beam signals down to earth (long range, lots of people) at 10GHz+?

Re:i dont get it

[CarlDenny]

> Why cant we just use higher and higer frequencies? 2GHz full? Use 20GHz? Or 50GHz? Or a googlehertz?

Because, the higher the frequency, the shorter the wavelength.

And the shorter the wavelength, the less "penetrating power" the signal has, and the more the signal is absorbed by intervening walls/clouds/.../and eventually air.

In short, 100Ghz signals can't even make it across a room without getting in trouble.

Re:i dont get it

[isorox]

So why cant we use really low frequencys (1Hz, 0.5Hz) etc. Because they dont have neough bandwidth?

How about minor variations in frequency. Eg 100,000,000Hz, 100,000,000.5Hz etc. Or is that what the article is going on about (its late, I'm tired, and I hate RF)

Re:i dont get it

[bugg]

Your reasoning is slightly flawed. Visible light is 400nm-700nm which works out to be 7.5*10^14 Hz and 4.3*10^14 Hz- much larger than 100GHz. I have no trouble seeing the light from my lightbulb across the room.

Re:i dont get it

[Anonymous Coward]

Well, the problem with low frequencies such as 5000hz is noise. There are two main types of noise present in RF and electrical signals. White noise's strength is independent of frequency. And the killer of the low-frequency range, 1/f noise. 1/f noise increases as the frequency decreases-- basically the amplitude is proportional to the multiplicative inverse of the frequency. It kills the low frequency bands because the noise masks the signal. Increasing signal strength improves the signal/noise ratio but there are practical limits to the amount of power used, i.e. battery capacity, electricity cost, human safety, etc.

Re:i dont get it

[Sentry21]

The higher your frequency, the higher the bandwidth, and the less reliable the signal.

My (digital) cellular phone, which I got back in the days of mostly analog phones, had great quality compared to the analogs (it was digital, and on a much higher frequency), and held a signal great, but if it weren't for the fact that it was very new technology as well as the phone company having built a network solely for that phone, I wouldn't have been able to get a signal in as many places, because it's more line-of-sight. High wavelength signals suffer more corruption from reflecting off surfaces.

Aside from that, if we keep going up and up from what we're at now, we hit microwaves (which is great, download your pr0n and warm your cocoa at the same time), and then infrared. At this point, we're pretty much entirely line-of-sight unless you have a lot of fairly reflective surfaces. Then we get into visible light (lasers), ultraviolet, x, and gamma rays.

Thus, we have to play around in the sub-microwave range, which is good anyway because it's the best suited for what we want. The requirement now is that perfect balance - high bandwidth, high resistance to signal degredation, high range. This is why AM radio is mono, and FM is stereo - more bandwidth. 802.11[a|b] is [|realdamn ]great for the bandwidth, but is more line-of-sight. 802.11a is worse for this than b, as it uses higher frequencies (correct me if I'm wrong on this, but I'm pretty sure).

Thus, to answer your question, there is a relatively small range of frequencies that work for what we as a society need (want), and they vary between bandwidth and reliability. It's all about choice.

--Dan

Re:i dont get it

[Sanga]

How sure are you that you are receiving all the information that the bulb is transmitting?

That is the key

Re:actually

[kableh]

You hit the nail on the head right there. Check out my employer's website, since that is the crux of what we are doing today. Actually, Fox News just did a story on us, which should go national soon. I'm the one running the computer in the video, and yes I'm busy surfing Slashdot ;)

Basically, instead of transmitting at high power to a base station, the transciever finds the path that takes the least amount of power. By transmitting at lower power, you get better spectrum reuse in a given area. One conventional cell becomes thousands of picocells. It really doesnt make sense to try to run a packet switched protocol like IP over circut switched networks like CDMA, et al.

This guy does have the right idea, but I think some people are reading the article the wrong way. He isn't calling for deregulation, just more bands for people to experiment in, like the ISM band.

What? Bill was right again!?

[Noel]

We'll have infinite bandwidth in a decade's time.
Bill Gates, PC Mag, 11 Oct 1994

Who would have guessed?

Mod this up!

[teamhasnoi]

90% of the channels on your UHF dial are sitting there doing nothing right now because the FCC and Congress prefer THAT to leasing them to nonprofit organizations at a reduced rate. Excellent! Excellent points.

Re:Amateur radio

[TooTallFourThinking]

True. And anyone listening to me on the airwaves can look me up and flame me as well. Oh well, they only have my name and address. (And from that my telephone number.) I am already suspicious of large boxes sent to me. ;)

The same argument can be used for my website or any other time I post my name on the net.

I don't normally flame people, but I will take your advise under consideration.

why not PM?

[PsiPsiStar]

If they can use aplitude modulation and frequency modulation to send signals, why don't they also use polarity modulation and get one more channel?
Since it's free, PM could be reserved for digital devices.

Re:why not PM?

[Kirkoff]

Actually there is a good reason:
Phase Modulated signals actually end up being the same as FM signals. They have to be "remixed*" because the frequency responce is a bit different, but otherwise they're the same. Also, the problem isn't with these modulation techniques.The problem is the amount of frequency space left in the RF specturm. In other words you could put an AM signal in the FM Broadcast frequency range, but it would be noise to your reciever.

As a side note AM can be done in stereo, the trick is to use Phase Modulation on the carrier. There is some information about that in part 73 of FCC code. (Yeah, I was bored the other night.

*The PM's audio sounds tinny because compared to FM it over emphasizes the higher frequencies.

Telcos & ISP

[MountainLogic]

For that matter who do you think the AOLs, MSN etc buy much of their dial up capacity from. Teleco!

Seti-At-Home

[DanThe1Man]

I guess if there is unlimited frequences, then it would be hard to scan for alien ones when they could be useing a way different scale.

Re:Seti-At-Home

[wbav]

Ah, there is a problem with your logic. The idea is that software can tell the diffrence between two diffrent carriers. With searching for any signal, you don't need the software. Thus the seti project is still valid.

Voice Dropouts

[uberdave]

You can actually drop quite a bit of packets before vocal communication becomes garbled. There was a demonstration at a local science centre about that. Vocal communication has a lot of built in error correction.

Re:Where will we get the "flying attack porcupines

[CaseyB]

Or the all caps may have been for emphasis, and he was talking about a thin flat bread pocket.

Bill, bandwidth, 1994?

[distributed.karma]

??? How could he talk about "bandwidth" in 1994? I thought Microsoft invented the Internet in 1995 when they integrated MSIE with Windows. ;-) And "bandwidth" is a purely Internet concept that has nothing to do with radio waves. ;-]

802.11 / Bluetooth work well together

[GPS Pilot]

My Mac communicates with AirPort networks and Bluetooth devices seamlessly, and simultaneously.

I'll take the FCC over corporations any day

[Ryan C.]

Watching the current battle for HDTV adoption makes me think that the FCC is really trying (somewhat ineptly) to work for the public good.

Media companies aren't interested in giving higher quality content to the public, but they need to deal with the FCC to get at the public's airwaves. Even then, they're fighting tooth and nail to only deliver the same old crud (480i) and pass it off as the HDTV they promised congress. Oh, and by the way, they want to encrypt the content and control all receivers to eliminate that pesky "time shifting" thing that seems to be all the rage.

Deregulating the airwaves, even though it might be a good idea technically in the long run, would remove the only stick the republic has to hit corporations with. IMHO, information flow is too important to risk for the sake of maximizing profits.

-Ryan C.

Reserved Bands & power

[gila_monster]

Concerning bands: those reservations last only as long as convenient. Many bands face regular challenges (the more recent being a spate of "little LEOs), and there is no guarantee they will remain as is. In fact, much of the pounding the FCC takes stems from their decisions on these spectrum challenges.

Concerning power: Point taken. I was not entirely clear. Sure, they can run on a 12-volt gel cell, but for how long? Many people thought that digital was a panacea for ermergency communications, but they forgot that you need a lot of batteries to keep a full packet rig running for two days.

There is also a question of the cost of the equipment to the emergency volunteer, who is often on a budget.

gm

Re:Reserved Bands & power

[uberdave]

...you need a lot of batteries to keep a full packet rig running for two days.

I'm sure it would, but is that because it is digital, or because the circuitry was not designed for power economy? The two are not mutually exclusive. I'm sure that there are many examples of "straight" rigs that would drain a gel cell if left on for two days. The software rigs are still in their infancy. When the demand for long life comes around, the crack design teams will whip up the necessary hardware.

But power isn't the point. The point is this: can you have more software radios operating in a frequency band in a particular area, or more "straight" ones? I think you could get more software ones.

Re:Reserved Bands & power

[gila_monster]

Yes, you could get more software ones. What are the power levels on the radios? If you have too many, you get what's called "desense," which means that the back end gets overwhelmed by the overall signals coming in, making it more difficult to pick the one you want.

There are arguments for and against, and I think we've established that. :)

Of course, the best way to improve a signal is to improve the antenna, regardless of the radio....

gm

Re:Reserved Bands & power

[uberdave]

Of course, the best way to improve a signal is to improve the antenna, regardless of the radio....

There are those who think that removing Country Music, Howard Stern, and Commercials, also improves the signal :-)

What he is saying is there is room for all.

[Erris]

Maybe we could start by allocating bandwidth to particular purposes on a lease term basis. Once you reach the end of your term, you have to show that continuing to allow you that bandwidth is the optimum use for the next lease period, if not, then no bandwidth.

Who would you appoint king to divide the oceans?

The whole point is that there is NO scarcity of bandwith. I'm not a PhD from MIT like Reed is so let's quote the article then the man:

David P. Reed gave a provocative talk to the Federal Communications Commission's Technological Advisory Council. He told the group of experts, in effect, that the FCC's fundamental mission is flawed, maybe obsolete.

Wow, heavy stuff. The FCC invited Reed to tell them they are impeeding the march of progress. That's impressive, perhapse they will listen, you too now:

``Radio waves pass through each other,'' Reed said. ``They do not damage each other.'' In the early days of radio, the gear could easily be confused by overlapping signals. But we can now make devices that can sort out the traffic.

Let's go to Reed's site to learn some more. Woops, freaking Real, encrypted pdfs requiring a non US plugin for ghost script. OK, enlightenment there will have to wait a little.

The basic concept is that there is more specturm than everyone needs, and therfore no need to regulate what was once considered scarce. Haven't you been convinced by the use of a single frequency to handle everyone's cell phones, bluetooth, 802.11 what not? Imagine if the entire specturm was allocated that way, free for everyone. Kinda like air. People like you would like to lease me the air I breath, wouldn't you? Hopefully, technical demonstrations will prove their worth before the FCC crushes everything by encouraging 2.4 GHz light bulbs. The revolution will come when people like you get out of the way and let the rest of the world do as it pleases with a virtually unlimited resource.

Re:What he is saying is there is room for all.

[sane?]

*sigh*

What he says is there is no scarcity of bandwidth, providing you totally change the way you use that spectrum.

The problem you seem to ignore is how you move from where you are now, to where you would like to be. You (and he) seem to say "scrap the regulations, let the market decide". Well, this is the market that fights in court over software patents. This is the market that makes other smaller companies "offers they cannot refuse". This is the market where betamax lost.

Now I'd agree that the government-bound, big business-bound, regulation authorities that you have at the moment are not ideal - BUT YOU NEED SOME REGULATION - some long term thought, some arbiter of fair play.

You seem to be taking a statement that "there is no scarcity of bandwidth" as an article of faith, a personal religion to add to your other god of the free market. You ignore that while technically it maybe possible to significantly increase total bandwidth (but it will never be unlimited) there are a whole host of problems that tend to prevent it happening. These are NOT majorly the problem of the evil FCC getting in the way of the good private enterprise, but problems to do with bandwidth already being used by systems that would need to be replaced in your future world. Who is going to pay for that? Do you have deep pockets?

Whether you like it or not, you need a workable process, and yes regulation, to effect change.

Wishful thinking and a loud voice don't cut it.

public air

[ironfroggy]

Personnally, I believe we need to work on these ideals and work towards the abolishing of owned spectrum space.

With a full, publically owned spectrum, freedom will be unbelievably enhanced. Internet could become faster, free, and available almost anywhere.

Corporations shouldn't be afraid of this. They have to pay for the space they use now. They wouldn't have to pay for this. And, no or less FCC could lead to at least some tax cuts, if they don't feed it into FBI Terrorism agecies.

Re:Short term, the radio waves will be *more crowd

[isdnip]

FM stations use most of their bandwidth already, not a "narrow band". Even if they don't run a subcarrier, they're still using most of the 200 kHz channel. Inband On Channel (IBOC) digital FM sticks on subchannels which essentially broaden the shoulders of the frequency pattern, but it doesn't significantly impact how tight the spectrum can be.

The FCC's original LPFM rules were realistic. Some IBOC advocates thought that 2-channel spacing *might* be a problem, but Congress really overturned the FCC on behalf of big broadcasters who didn't want the competition. That's the issue in broadcasting now, not technology.

Space-Time Coding

[femto]

There seems to be a lot of misinformation flying about on this topic. Reed really is talking about a break through, not just about squeezing in more channels by adding repeaters or optimizing the gaps between frequency multiplexed channels.

Shannon's Law says that for a given signal to noise ratio, there is a maximum error free bit rate which can be supported. Recent advances have shown that Shannon's law applies on a per antenna basis. If your transmitter and receiver each have 'n' antennas, it is possible to transmit 'n' times the information which one tx/rx antenna pair can transmit. To my knowledge, there is no limit on how large 'n' can be. Researchers are currently trying to figure out if there is a limit.

Repeating myself in different words. It not only matters at what frequency you radiate (frequency diversity) and when you radiate (time diversity), it also matters where you radiate from (spatial diversity). Since available time and frequencies are limited, it was thought that spectrum was limited. Add space (of which there is lots) to the equation, as recent advances did, and the available spectrum becomes unlimited (though new boundaries may show up with more research).

This is not pie in the sky stuff. Space-Time coding techniques allow such capacities to be realised. Bell labs have already demonstrated a working system in the lab.

John