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Aussie Claims Copper Broadband now 200x Faster

CmdrTaco posted more than 6 years ago | from the alarms-going-off-in-brain dept.

Networking 208

SkiifGeek writes "Winner of Melbourne University's Chancellor's Prize for Excellence, Dr John Papandriopoulos could soon find himself the focus of a number of networking companies and government agencies interested in wringing more performance from existing network infrastructure. Dr John developed a set of algorithms (US and Aussie patents pending) that reduce the impact of cross talk on data streams sharing the same physical copper line, taking less than a year to achieve the breakthrough. It is claimed that the algorithms can produce up to 200x improvement over existing copper broadband performance (quoted as being between one and 25 mbit/sec), with up to 200 mbit/sec apparently being deliverable. If the mathematical theories are within even an order of magnitude of the actual gains achieved, Dr John's work is likely to have widespread implications for future bandwidth availability across the globe."

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Finally! (4, Funny)

Rob T Firefly (844560) | more than 6 years ago | (#21098325)

My dreams of building a top-notch deathmatch LAN using old rolls of 1970s speaker wire from my basement could finally come true.

Metaphor please (5, Funny)

CRCulver (715279) | more than 6 years ago | (#21098337)

So is this like coating the series of tubes with an improved surface so that the trucks get better traction?

Re:Metaphor please (2, Informative)

arivanov (12034) | more than 6 years ago | (#21098605)


I can bet that it is a reuse of the 3G MAC ideas. 3G uses multipath to improve the signal to noise ratio by filtering the signal versus delayed samples.

Similar thing is possible with crosstalk as long as you handle all wires from the same duct in the same ASIC this usually is not the case. It will simply not work in countries where access to the copper is unbundled. In other places it will require major rewiring in the exchange.

I would hate to extinguish the hopes of all hopefuls which think that the holy grail has arrived. This type of algorithms provide O(LOG N) improvement and there is major improvement only for the first couple of filter buckets. Once you are past that each bucket adds less and less.

Re:Metaphor please (4, Interesting)

Omnifarious (11933) | more than 6 years ago | (#21098783)

Your post is labeled informative, but it is so filled with jargon that is missing any nice links to references that explain it that I find it quite unhelpful.

Re:Metaphor please (1, Insightful)

Anonymous Coward | more than 6 years ago | (#21099349)

At first I thought he was pulling everyone's leg, but then I realized what he was getting at. Basically, he believes that this new invention uses signal noise as error correction. i.e. If one wire is wirelessly pushing its signal on to another wire (a phenomenon known as crosstalk [wikipedia.org]), a microprocessor could use the noise from the crosstalk to do error correction on original signal. In that way you end up with a matrix of signals that are interrelated across a bundle of wires as opposed to each wire carrying a distinct signal. This allows faster communications since you can accept a higher error rate due to the ability of the microprocessor to infer the correct value of the transmitted bit.

The only catch is that crosstalk is considered bad. Wires are often isolated in attempts to reduce or eliminate the problem. Furthermore, the signals are rarely processed by the same microprocessor, but are instead handled in parallel. Which means that we need a new infrastructure in order to support this new idea. (Assuming, of course, that the original poster is correct in his "guess" as to how this works. TFA is pretty light on details.)

That's the way I understood him, anyway.

(Awesome captcha: Speakers!)

Re:Metaphor please (1)

Jay L (74152) | more than 6 years ago | (#21099675)

Disclaimer: I am not a hardware guy. I wanted to be, when I was little, but I finally realized around age 16 that I was never, ever going to understand how the little minuses got over to the big plus terminal, and that that was the easy part of electronics.

If one wire is wirelessly pushing its signal on to another wire (a phenomenon known as crosstalk), a microprocessor could use the noise from the crosstalk to do error correction on original signal...

The only catch is that crosstalk is considered bad. Wires are often isolated in attempts to reduce or eliminate the problem.

Given my disclaimer: I remember the days of telephone crosstalk, but I never got the impression that it was RF-related; I always assumed it had something to do with ground loops (are there ground loops in balanced telco?) or improper balancing or things like that.

I also have developed the impression that the biggest speed barrier in copper is reflections, not crosstalk, although I suppose that's more true of CAT-5/6 than of untwisted telco wiring, which is what this invention is supposed to work with. Even more confusing is TFA's use of "the same physical copper line"; if they really mean that (a continuous strand of copper), then they can't be talking about crosstalk. But maybe they mean "the same cable (set of wires), and cables are made of copper". It really is vague.

Can any EEs shed some light on this? I imagine the same sort of noise-cancelling, echo-processing DSP that ameliorates crosstalk could also ameliorate reflections; that's why, now that I finally don't need a TDR anymore, the prices have dropped tenfold.


Re:Metaphor please (4, Informative)

ozmanjusri (601766) | more than 6 years ago | (#21099807)

Your post is labeled informative, but it is so filled with jargon

I think the premise that this tech is based on 3G multicast is wrong too.

Dr Papandriopoulos paper [ulos.org] suggests the algorithm works by iteratively lowering power, and therefore reducing crosstalk. The reduced crosstalk allows faster protocols like VDSL to be used on the copper that was previously only capable of ADSL2.

Re:Metaphor please (1)

morgan_greywolf (835522) | more than 6 years ago | (#21098611)

So is this like coating the series of tubes with an improved surface so that the trucks get better traction?
No, this is like cranking up the pressure on the liquid data running through the tubes. The liquid data looks kinda like the T2000, only it doesn't form into anything. I saw it on a Comcast 'Craptastic' commercial! The guy pulled some 'high speed' out of his Internet tube and rubbed it all over his hands [youtube.com] and a whole sinkful of dishes stacked to the gills done in like 5 seconds!

Re:Metaphor please (4, Funny)

Von Helmet (727753) | more than 6 years ago | (#21098991)

Well, if you're using like, then it's actually a simile.

That being said, I think the appropriate metaphor for your post would be "flogging a dead horse".

Re:Metaphor please (3, Funny)

Belacgod (1103921) | more than 6 years ago | (#21099687)

So the technology in TFA will allow us to flog dead horses 200 times as fast? Won't our arms get tired?

Sounds good.. (0)

LingNoi (1066278) | more than 6 years ago | (#21098341)

.. but I think I'll wait for the consumer verdict to come in as to if this actually works. Theory and practice never tend to be the same, with theoretical bandwidth limits never reaching their peak.

Hope for the best but expect nothing. :)

Static vs. Dynamic correction (1, Interesting)

G4from128k (686170) | more than 6 years ago | (#21098657)

I suspect that his algorithms require very very careful analysis of the cross-talk environment to remove its effects. The result is a very high-gain function on the high-frequencies to correct for crosstalk and modulation effects at high bandwidths. That's fine in a controlled environment, but won't work if the amount of crosstalk varies dynamically. Temperature, wind, rain, ice, humidity, and squirrels all change the crosstalk characteristics.

200 mbit/sec (1, Insightful)

FatAlb3rt (533682) | more than 6 years ago | (#21098349)

m != M ...or is it just me? MB and Mb...let's use them correctly. [/rant]

Re:200 mbit/sec (1, Funny)

Anonymous Coward | more than 6 years ago | (#21098437)

It may be just you. I can't recall the last time I read someone referring to fractions of a data bit.

Obligatory ... (1)

MacTO (1161105) | more than 6 years ago | (#21098441)

200 millibits per second. Wow, that's slower than the 300 bits per second modem that I had on my Apple II!

Re:Obligatory ... (1)

CastrTroy (595695) | more than 6 years ago | (#21098515)

How exactly would you measure fractions of a bit? A bit is the smallest unit you can measure. Either you have the bit, or you don't. You can't have half a bit. It would be like saying you have half an atom of hydrogren.

Re:Obligatory ... (3, Insightful)

smilindog2000 (907665) | more than 6 years ago | (#21098589)

Not true... information theory shows that a fractional bit is a probability of transmitting the desired bit correctly. A true source of random noise generates no bits, but a highly noisy channel transmits fractional bits per noisy bit sent. Fractional bits are well-founded mathematically.

Re:Obligatory ... (1)

dintech (998802) | more than 6 years ago | (#21098729)

Agreed. For example, most people don't take the idea of on average '2.4 children in family' as a literal quantity. Any value measured in 'per second' is probably going to be some kind of average anyway.

Re:Obligatory ... (4, Funny)

WombatDeath (681651) | more than 6 years ago | (#21098745)


0 = one bit
( = half a bit

1 = one bit
' = half a bit

You need to use an appropriate font, obviously.

I don't know what you people would do without me to solve these little problems for you.

Re:Obligatory ... (1)

MacTO (1161105) | more than 6 years ago | (#21099231)

[quote]How exactly would you measure fractions of a bit? A bit is the smallest unit you can measure. Either you have the bit, or you don't. You can't have half a bit. It would be like saying you have half an atom of hydrogren.[/quote] 200 millibits per second * 5 seconds = 1000 millibits = 1 bit.

Re:Obligatory ... (1)

somersault (912633) | more than 6 years ago | (#21099273)

It would be like saying you have half an atom of hydrogren.
You mean like saying you have a proton or an electron?

Re:200 mbit/sec (1)

Mr. Underbridge (666784) | more than 6 years ago | (#21098449)

m != M ...or is it just me? MB and Mb...let's use them correctly. [/rant]

No, this guy's just finally managed to get 200 millibits per second. Get yer bits, once every 5 seconds...

Re:200 mbit/sec (2, Funny)

alexhs (877055) | more than 6 years ago | (#21098601)

Actually, Aussies just discovered ADSL networking, now 200x as fast as their current POTS [wikipedia.org] network :)

I kid, please don't bite ;)

Re:200 mbit/sec (1)

Tony Hoyle (11698) | more than 6 years ago | (#21099719)

Australia is one of the first to roll out ADSL2, and my australian boss just got 2MB SDSL for less than I pay for my ADSL link over on the other side of the planet (SDSL here costs about 20x as much)... so don't be so quick with the jokes :p

more like b != B (0)

Anonymous Coward | more than 6 years ago | (#21098721)

I think there are more people who confuse bits with bytes than people who confuse thousandths and millions. Unless, of course, on the Verizon staff.

Re:200 mbit/sec (0)

Anonymous Coward | more than 6 years ago | (#21099747)

"m != M ...or is it just me? MB and Mb...let's use them correctly. [/rant]"

This is 200 millibit, not megabit.

200x??? Hardly... (2, Informative)

funfail (970288) | more than 6 years ago | (#21098351)

(Up to 200 mbit/sec) / (Up to 25 mbit/sec) = 8x improvement...

Re:200x??? Hardly... (1, Funny)

Andy_R (114137) | more than 6 years ago | (#21098391)

On the upside, this does mean that getting 'within an order of magnitude' of the claims shouldn't be too hard!

Re:200x??? Hardly... (1)

funfail (970288) | more than 6 years ago | (#21098431)

Another upside is that it is now possible to say that "current technology (up to 25 mbit/sec) is an improvement of 25x over the current technology (as low as 1 mbit/sec))"

Re:200x??? Hardly... (1)

ThinkingInBinary (899485) | more than 6 years ago | (#21098507)

Hey, I hear Comcast is looking for writers to create the ads that say their 8 Mb cable is "10x faster" than the "768kb" DSL we're all apparently using.

Re:200x??? Hardly... (0)

Anonymous Coward | more than 6 years ago | (#21098751)

There's a difference between maximum theoretically possible and what's likely to be achievable in the real world. The 200x is the absolute maximum of this new technology, the existing 25mb/s is the maximum currently possible, and the 200mb/s is the realistic estimate. You are comparing the wrong numbers.

Re:200x??? Hardly... (0)

Anonymous Coward | more than 6 years ago | (#21099059)

I dont see the problem. They seem to be claiming the same sort of fantasy figures as the current ADSL2 service providers do.

Sounds good, but... (1)

mastershake_phd (1050150) | more than 6 years ago | (#21098355)

can it compete with fiber?

Re:Sounds good, but... (2, Informative)

bflynn (992777) | more than 6 years ago | (#21098461)

Exactly. Without intending offense to Dr. Papandriopoulos, this is really not news, nor does it have widespread implications for future bandwidth availability across the globe. Global bandwidth is more about high speed backbones, which this technology does not even begin to approach. It is only useful in solving the last mile problem of getting things off the backbone to a terminal. And by the time this gets commercialized, I think we can count on at least three other technologies being faster still, with cellular style broadband probably at the top of the list.

Re:Sounds good, but... (1)

Kyojin (672334) | more than 6 years ago | (#21099635)

If Telstra can extract another 10 years out of the existing copper before paying for fibre, they will.

Re:Sounds good, but... (2, Insightful)

CastrTroy (595695) | more than 6 years ago | (#21098563)

It could on cost. Using fiber in many areas requires that you lay new lines. Even if it's not quite as fast as copper, or has a little more latency (light is faster than electrical signals), you could probably make quite a bit of money since there's a much smaller investment.

Re:Sounds good, but... (0)

Anonymous Coward | more than 6 years ago | (#21098693)

I think you will find that Electrons actually travel faster down copper than light does through fiber, part of this is due to the photons continuously bouncing off the walls of the fiber !

Not for distance (2, Interesting)

Russ Nelson (33911) | more than 6 years ago | (#21099133)

Not for distance. You're still subject to the 18Kfeet (max) limitation imposed by the resistance (gauge) of the wire.

Little scarce (1)

ilovegeorgebush (923173) | more than 6 years ago | (#21098365)

Both linked articles are a little scarce of details, but it's an interesting concept.

One thing though, is this the point at which companies should either get rid of the existing technologies and invest in newer, more stable, scalable and flexible telecommunications hardware & wiring? To me it is very much like the software-development stage where it's best to rewrite everything from scratch, than to patch the existing codebase (sorry, code-head, no better analogy available; sue me). Is there a risk of over-using what we have instead of just biting the bullet and (the telcos) investing in newer gear?

Re:Little scarce (1)

jimboindeutchland (1125659) | more than 6 years ago | (#21098681)

This is actually a pretty big deal for Australia. Most Australians are aware of the problems the country has with even providing phone lines to some areas. Basically it's because there's a lot of space but not enough population to make wiring everywhere profitable.

The same goes with broadband.

If you want to install new infrastructure (even in cities), you've got to roll out a lot of new cable. Perth, my old home town is roughly 100km (yeah, metric you imperial pussies) from north to south. It has roughly the same population as Munich (where I now live), which is about a tenth of the size. Not surprisingly, my 3M connection here kicks my old (back home) 512k connection's arse.

Something like this technology would enable Telstra to provide higher speed broadband while it invests in new technology. In light of this, it's not too surprising that this sort of technology is being researched in Australia.

Re:Little scarce (0)

Anonymous Coward | more than 6 years ago | (#21099411)

Then what Australia does should serve as a guide for what we in the U.S. should do. Despite our country being mostly industrialized, we still have a great deal of suburban and rural areas without high speed access.

Re:Little scarce.. what about his home page (1)

N Monkey (313423) | more than 6 years ago | (#21099723)

Both linked articles are a little scarce of details, but it's an interesting concept.

Well, I would hazard a guess that this is his home page [ulos.org] and that links to a far more informative paper.

Across the globe == developed nations (1, Insightful)

BadAnalogyGuy (945258) | more than 6 years ago | (#21098373)

The growing availability of wireless technology makes the wired world an interesting evolutionary dead end. The speeds that are described are impressive (if you consider only 4x the speed of 802.11g impressive), but the future is not in copper wires. The only technology that has any future these days is wireless.

So thanks, Mr. Aussie guy. You've breathed some life into the geriatric hobbling of copper. I hope you get a big payout, because you've basically done the equivalent of developing the world's fastest webserver running on Windows 95.

Re:Across the globe == developed nations (1)

Alioth (221270) | more than 6 years ago | (#21098529)

802.11g isn't the last mile, though - is it? It's the last 25 metres if you're lucky (with packet loss), or less if you have walls with aluminium coated insulation.

Comparable wireless (from the phone exchange to the subscriber's home) that's widely avaialable at the moment is GPRS (slightly faster than a modem that's 15 years old, with latency 10 times worse), 3G (about the speed of broadband 5 years ago, with latency ten times worse), or WiMAX (very good quality, and low latency - but only available in very few places, and only up to about 4Mbit/s).

802.11g with a home made cantenna doesn't count. Wireless doesn't come anywhere near close 250Mbit/sec between the subscriber and the phone exchange. Copper wires already in the ground and already paid for have a good few years, possibly decades, before they are obsolete if this technology meets the hype. (And that's a big 'if'. The details don't even say what kind of distance is possible).

Re:Across the globe == developed nations (1)

bibi-pov (819943) | more than 6 years ago | (#21098537)

That'd be true if you compared wireless to a wired network where everybody shares the same link (think hub or old coax wiring). But unlike current (and probably future) wireless network where that bandwidth has to be shared among all the users, this can be the bandwidth of a single household. Much more interesting in my opinion. So, as nice and easy as it seems, I don't see wireless ever replacing wired networks in every setup, maybe it's the solution of choice for scarcely populated areas, but in the cities wired is the way to go IMHO, especially since wires are already there for most people.

Re:Across the globe == developed nations (1)

CastrTroy (595695) | more than 6 years ago | (#21098641)

I still find that wires (or optical cables for that matter) offer many advantages to wireless. For one, they are much less susceptible to interference. They are much faster. I'm not sure where they get their numbers from, but I have gigabit Ethernet at my house, and that's 1000 Mbits/s. That's 18 times faster than 802.11g. Now, if you have a good switch, you can get that same speed to the any number of computers on the same network. With wireless, all the computers on the same network are sharing whatever bandwidth is available. So if you have 10 computers on your wireless network, your effective bandwidth is 5.4 Mbits/s per computer.

Re:Across the globe == developed nations (1)

BadAnalogyGuy (945258) | more than 6 years ago | (#21098701)

However, it doesn't require any physical infrastructure investment aside from the nodes to set up a wireless network. So for countries which do not yet have existing infrastructure, setting up wireless networks is cheaper and easier than laying wire to each and every house.

Perhaps the title of my original post was not clear enough.

Regardless of whatever advantages wires have over wireless, in the long run it is going to be supplanted by wireless technologies. It will probably take a lot longer in developed countries which have already paid significant costs to get wires to each home, but at some point (probably starting with home networks) wires are going to go the way of the dodo.

Re:Across the globe == developed nations (2, Interesting)

CastrTroy (595695) | more than 6 years ago | (#21099143)

But the wireless spectrum is very limited. For the first 100,000 people or so on the wireless network, it could probably remain pretty fast. But try running all the computers in New York City on a wireless network, and see what kind of speed you can achieve at each node. So as a starter point, to get the first few people in the country on a network, or to connect a small village, wireless networks could prove extremely useful. However, if you want to take all the network communication in a large city and try to accomplish that without wires, you'd probably fail very quickly. Don't even start to mention current cellular networks, because there's still a lot of wires involved.

Re:Across the globe == developed nations (1)

BadAnalogyGuy (945258) | more than 6 years ago | (#21099239)

However, as technology progresses, these roadblocks will be overcome and efficiency and scability should rise. Of course what we have now is wholly insufficicent for usage levels, however this is by no means always going to be the case (though you could make the argument that usage levels will outpace technology growth rates).

There's still a ways to go before wireless can meet wired capacities, but there will be a point where investment in new wires will be cut off and the only real new investment will come either, as this article describes, from research into making existing technology last longer and more flexible or from research into making wireless technologies work better and faster and cheaper. The sunk costs of copper and fiber are huge and there's no doubt that companies will be trying to make their money back, but for a large chunk of the world there is very little sunk cost in wires, so those will be prime areas of early uptake of wireless technolgies. For a while the two will be symbiotic, but the fact is that one is a declining technology and one is a growing technology. The declining technology is vastly larger and more entrenched than the growing technology, but an immovable object will always fall to the irresistable force.

Re:Across the globe == developed nations (1)

deniable (76198) | more than 6 years ago | (#21098875)

You should go back a few decades and look at how people thought satellites would replace undersea cables. It hasn't happened yet.

color me skeptical (-1, Offtopic)

jollyreaper (513215) | more than 6 years ago | (#21098389)

Aussies also claim that sheep are warm and gentle lovers. I'll believe it when they show the proof. (the broadband part, nothing will convince me about the sheep)

i'm offended (0)

Anonymous Coward | more than 6 years ago | (#21098401)

how dare slashdot use a hunter s thompson quote at the page footer? maybe taco likes to think that he's hip but the truth is that hunter thompson stood firmly against the weak good for nothing liberal mindset that is pushed on slashdot as the only way to do things.

Heavy Vaporware Feeling (1)

damaki (997243) | more than 6 years ago | (#21098419)

Am I the only one who feels a vaporware smell? Tiny details, huge promises.

Re:Heavy Vaporware Feeling (0)

Anonymous Coward | more than 6 years ago | (#21098805)

Vaporware companies/individuals don't file patents.

Re:Heavy Vaporware Feeling (1)

alienw (585907) | more than 6 years ago | (#21098957)

Yeah, like it's difficult to file a patent on a vaporware technology. Hell, there are hundreds of patents for perpetual motion machines.

Realism... (2, Insightful)

Danathar (267989) | more than 6 years ago | (#21098423)

"Dr John's work is likely to have widespread implications for future bandwidth availability across the globe."

Given what I've seen in the past and knowing how greedy telecommunications companies are, I doubt the above statement.

Famous scam? (1)

sam_handelman (519767) | more than 6 years ago | (#21098509)

Even if this is true - and I'll allow those with a better background in this field to explain why it probably isn't - isn't this suspiciously similar to a scam from a few years back where this guy was peddling a supposedly similar gain in transmission speed over telephone lines? He had this elaborate setup to supposedly demonstrate it that he wouldn't let anyone examine closely?

  I must be remembering some of the details wrong because I can't find the article - I remember that it was on slashdot as well as elsewhere, maybe 3 or 4 yrs ago? The guy attracted all kinds of venture capital and then was convicted of fraud, IIRC.

  Anyway, even if this is true, I think he'll have trouble getting support for this reason.

Re:Famous scam? (5, Informative)

femto (459605) | more than 6 years ago | (#21098625)

I know this guy though having attended conferences with him. I know he is not a scam artist. I also think he is brainy enough to do this. He is not a fly by nighter but a serious communications theory researcher with a track record. As I've just emailed to my supervisor, "It's not every day a communications theorist makes the mainstream media". John Papandriopoulos is easy to find on google.

Hope not (0)

Anonymous Coward | more than 6 years ago | (#21098511)

"Dr John developed a set of algorithms..."

Hope the calculation wasn't on Excel 2007

Yes!Networking article with anti-Microsoft... only on Slashdot.

and here comes the off-topic mod.

lies, damn lies and statistics (1)

buddyglass (925859) | more than 6 years ago | (#21098527)

The 200x speedup is only if you consider 1Mbit broad band. My DSL provider's top plan is 6Mbit. So 200Mbit would be a 33x speedup. Modify that by an order of magnitude as the submitter states, and we're looking at a 3.3x speedup or 20Mbit. That's still a nice gain, especially considering it comes with little additional infrastructure, but it's not as wildly fantastic as the article might lead you to believe.

Re:lies, damn lies and statistics (1)

fatphil (181876) | more than 6 years ago | (#21098687)

I saw a demonstration of 55Mb/s HDSL over a kilometre of class 5 bell wire back in 1998.
For 9 years, this is not an enormous leap at all.

The limit has been exceeded.... (2, Interesting)

mks113 (208282) | more than 6 years ago | (#21098577)

And we learned, in Electrical Engineering, that the theoretical maximum bandwidth for a phone line was 2400 bps.

Using basic bandwidth calcs for voice (500 to 4000hz?) and imposing a modulated signal inside that, the distortion created by the physical arrangement of the wires would cause the limit.

I'm glad that some people aren't scared off by theoretical physical limits.

(That was in about 1986, A Hayes 1200 baud modem was an amazing piece of equipment and cost about $700)

Re:The limit has been exceeded.... (1)

east coast (590680) | more than 6 years ago | (#21098665)

A Hayes 1200 baud modem was an amazing piece of equipment and cost about $700

I was a Boca Research man myself. I use to get screaming transfer rates on the local BBSs. I held the 1200 baud record for a long time on one of the more prominent systems.

Re:The limit has been exceeded.... (1)

NormalVisual (565491) | more than 6 years ago | (#21099613)

VenTel here. My 1200 baud modem worked great until a friend of mine plugged it into his Amiga, which provides power on a couple of pins. All the magic smoke got out shortly thereafter. I remember a few years later thinking that the new 14.4K modems were PFM, and it was nice having high speeds without giving up the real estate for a Courier HST - you could just about put legs on a Courier and use it as a coffee table.

Re:The limit has been exceeded.... (2, Insightful)

Anonymous Coward | more than 6 years ago | (#21098765)

That's only true if the bandwidth is limited to 3 kHz, as it is in voice circuits.

Plug a 3 kHz bandwidth and about 35 dB signal-to-noise ratio into the formula for channel capacity and you get about 35,000 bits per second. This is consistent with the last generation of analog modems (33.6 kb/s).

Now if the bandwidth is not artificially limited (remove transformers, filters, bridged taps, etc.) the theoretical capacity will increase by a large amount.

Re:The limit has been exceeded.... (1)

T00lman (1020903) | more than 6 years ago | (#21099445)

Ok, IANAEE but I started doing this, 75 Baud was breakneck speed. first - the bandwidth limit is not measured in bps it was measured in Baud, (then the term Symbol Rate which never caught on). Baud is the number of times an analog signal can change state per second. People have been exchanging bps and baud since the beginning when the bps rate was equal to the baud rate. ie 300 (digital) bits per second sent on an (analog) line using 300 Baud, the digital throughput was the same as the analog speed. This was only true when 300 bps was "breakneck speed". In contemporary standards there are upwards of 8 bps encoded into every Baud, so higher throughputs are squeezed through the line. Second - the "limit" is based on three things, signal/noise ratio, available B/W on the line, and quantization noise. The available B/W was set by Shannons law (1937) at 2400 Baud (on an analog line). Things have changed... Like digital infrastructure. When using *DSL, rates in the MBaud range are routine. Sorry I've got a thing about bps and Baud, I couldn't stop myself.

Re:The limit has been exceeded.... (0)

Anonymous Coward | more than 6 years ago | (#21099469)

2400bps wasn't any limit.

The real limit is Shannon law which is far older than Hayes modems.

For 3400Hz bandwidth the theoretical limit (and SNR=1500) is 33600bps. For higher SNRs it's obviously higher.

Re:The limit has been exceeded.... (1)

Detritus (11846) | more than 6 years ago | (#21099771)

Your professor was incompetent, or you have left out some facts.

There's a big difference between the theoretical limits on information transmission and the practical limits imposed by economics and the current state of technology. I saw 9.6k full-duplex modems in widespread use in the 1970s. They were available to anyone who could afford their steep price ($20K each).

Shannon-Hartley theorem [wikipedia.org]

C. E. Shannon (Jan. 1949). "Communication in the presence of noise". Proc. Institute of Radio Engineers vol. 37 (1): pp. 10-21.

Slashdot readers (1)

CalicoDreams (1159251) | more than 6 years ago | (#21098579)

So pessimistic, has everyone who reads Slashdot become so downtrodden that they can no longer appreciate the work of another person (regardless of their status as a student).

Fast Forward to Slashdot 2009 (2, Funny)

dada21 (163177) | more than 6 years ago | (#21098585)

Geek Post Subject: Comcast Throttles Bandwidth, Breaks Contract

Geek Post Comments: I can't believe Comcast! They promised me an unlimited 200mbit connection and all I am getting is 60mbit! I want what I paid for, who cares how fast my connection was 3 years ago! I demand my 200mbit connection, and at $50 per month!11!

Geek Post Moderation: +5, Insightful

Re:Fast Forward to Slashdot 2009 (1)

Opportunist (166417) | more than 6 years ago | (#21098689)

And rightfully so. If you can't handle 200mbit, don't sell 200mbit.

When I sell something I don't have, I go to jail for fraud. Why should it be different for ISPs?

good grief. (1)

apodyopsis (1048476) | more than 6 years ago | (#21098613)

200x faster net access, that's remarkable if its true.

On a related note, I note that hospitals are quietly getting ready to increase their budgets for coping with an influx of wrist related repetitive strain injuries and severe myopia. Not to mention a lack of sleep.

Oh yay! (1)

Helix666 (1148203) | more than 6 years ago | (#21098629)

So now the ISPs, etc. have another excuse for not upgrading the infrastructure.
yay for broadband across old copper(!)

I would much rather have them lay fiber, than try to squeeze more bits down the aging copper. But they won't. They'll just carry on trying to survive as long as possible without upgrading, which isn't good for the customer in the long run.

Re:Oh yay! (0)

Anonymous Coward | more than 6 years ago | (#21099003)

It's never about what's good for the customer. It's about what's profitable for the company.

As soon as more people will get that attitude through their heads, we'll take control of the market by voting smarter with our dollars. Yes, even in telecom we'll find a way.

Details? Here are some links. (4, Informative)

martyb (196687) | more than 6 years ago | (#21098695)

The slashdot summary and linked articles are rather short on details. A little googling located some details:

NOTE: I did a quick skim of it and had not seen any empirical evidence of the advance; seems to be entirely theoretical. I don't mean to lessen his accomplishments, but my experience is that reality usually has unforeseen factors. I certainly hope he IS on to something here!!

(*) I didn't know anyone used the &ltblink> tag any more. :/

Re:Details? Here are some links. (0)

Anonymous Coward | more than 6 years ago | (#21099249)

The Slashdot summery implied this was some serious work, then the linked article is a local newspaper bragging about some PhD student applying for a patent. Big deal.

Trans-Oceanic Latency (1)

mark99 (459508) | more than 6 years ago | (#21098739)

i don't want more bandwidth - I want less latency. I have enough bandwidt to do anything I want except maybe watch HDTV real-time, and I don't care about that.

But I hate waiting 5-10 secs for the server I cliked on to respond - partially due to all those redirects and things - but also the 120 ms across the Atlantic and 300 ms across the Pacific is a big contributor. That is like 6 times slower than the speed of light.

Where are all those optical routers :(

Re:Trans-Oceanic Latency (2, Funny)

WombatDeath (681651) | more than 6 years ago | (#21098799)

That sounds expensive. We should probably just increase the speed of light instead.

Re:Trans-Oceanic Latency (1)

StripedCow (776465) | more than 6 years ago | (#21099061)

or slow-down the speed of the user's brain ... hey, aren't there chemicals for that? hmm, this needs some experimentation ...

Re:Trans-Oceanic Latency (1)

Kjella (173770) | more than 6 years ago | (#21099295)

You shouldn't by any chance also go by the nick Q (no, not the James Bond character)?

Re:Trans-Oceanic Latency (1)

WombatDeath (681651) | more than 6 years ago | (#21099409)

If you think that changing the gravitational constant of the universe would help, I'm willing to give it a shot!

Biggest Research Scam in Slashdot History?! (1)

dslmodem (733085) | more than 6 years ago | (#21098915)

He is a postdoc or a research fellow now. If his contribution is so substantial, I would see him on the faculty list somewhere.

His work is in the field of channel capacity computation. The paper has very limit impact due to its model and its assumptions.

Sorry, there will be no 200x DSL. :-)

Mr Sheen (1)

stainlesssteelpat (905359) | more than 6 years ago | (#21098977)

Amusingly enough australia has piss poor adsl, baring in mind Mr sheen (AKA John Howard the PM down here) has just decided to spend billions making the problem worse with a useless wireless solution their is a distinct sense or irony implicit here. Maybe Dr John should suggest to Mr Sheen that he put his considerable cleaning prowess into practise.

Downloading ascii art maybe (0)

Anonymous Coward | more than 6 years ago | (#21099591)

When 56k modems were first being developed they quoted over a 100kbs due to compression. In reality if you downloaded ascii art with long strings of identical characters it would do well over a 100kbs by compressing them but on anything remotely normal you got the standard 44kbs ish. Whats the odds this will amount to similar?

Double standards (0, Offtopic)

DaveDerrick (1070132) | more than 6 years ago | (#21099763)

Can we try to keep the same level of respect when writing about other nations, as you do your own. For instance "(US and Aussie patents pending)". US is a formal designation, whereas Aussie is not. Please either write "(Yankee and Aussie patents pending)" or "(US and Australian patents pending)". Thank you.
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