Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
Communications The Internet Science

Ordinary Copper Telephone Wire Could Carry Gigabit Broadband Speeds (newscientist.com) 129

Fibre-optic cable is being laid across the globe at great expense to speed up people's internet connections, but researchers claim that the copper telephone wire already in use across the country can achieve data rates three times higher than currently seen at a fraction of the price, at least over short distances. New Scientist: Their technique to boost speeds may help to ease the transition to nationwide fibre optic, and may also be of use in countries that use similar twisted-pair copper wire. Ergin Dinc at the University of Cambridge and his colleagues say that twisted pairs of copper wire, of the type used for decades as telephone lines and now repurposed for broadband internet, can support a frequency fives times higher than is currently used, which would dramatically improve data transmission rates. Above that limit, the researchers found that the wire essentially acts as an aerial and transforms any signal sent along it into radio waves that dissipate before reaching their destination. "These cables are actually very old, invented by Alexander Graham Bell, and since then no one has looked into the theoretical limits," says Dinc. He and his colleagues say that their findings may allow houses near fibre-optic cables to achieve higher speeds than they currently enjoy without the expense of running fibre all the way to their home. Fibre-optic cables carry groups of photons to represent data, and huge numbers of these groups can be sent along the line one after another without waiting for the first to arrive. Fibre connections in use today typically operate at 1 gigabit per second, but theoretical speeds could be many thousands of times higher.
This discussion has been archived. No new comments can be posted.

Ordinary Copper Telephone Wire Could Carry Gigabit Broadband Speeds

Comments Filter:
  • One small problem (Score:5, Interesting)

    by omnichad ( 1198475 ) on Wednesday April 27, 2022 @03:18PM (#62484940) Homepage

    A large percentage of these copper wires are already in a sorry state and need replaced anyway. I don't think the marginal cost difference of replacing last-mile copper with copper vs replacing copper with fiber amounts to much compared to the labor cost.

    • Yeah, how "ordinary" are copper pairs any more?
      • Yeah, how "ordinary" are copper pairs any more?

        AFAIK most new homes still install phone connections to a house, even though few use them anymore... even if that is dying off, there are a LOT of pre-existing houses and apartments that all have old twisted pair wiring going to them.

        Last mile has always been the hardest hurdle so it would be great if you could use older wiring and get reasonable speeds.

        • by AntronArgaiv ( 4043705 ) on Wednesday April 27, 2022 @04:06PM (#62485114)

          When are we just going to bite the bullet and wire all homes for fiber?

          Twisted pair is dead, dead, dead, and no variant of DSL is going to make it different.
          Coax is damn near dead, what with its requirement for amplifiers, splitters, crimps, etc. It's a stunningly poor choice for data.
          Just put in fiber.

          • by Rhipf ( 525263 )

            You do realize that fiber also needs "amplifiers, splitters, crimps, etc". They just may be further apart on a fiber system compared to a coax system.

          • by kriston ( 7886 )

            Coax is damn near dead

            Not really. The "last mile" with coax was replaced a couple decades ago with fiber-to-the-neighborhood and much shorter coax loops. The bonus is that most of that coax is already installed and can carry 1 gigabit of data.

            Fiber-to-the-neighborhood is also used in many modern DSL plants.

            Have you noticed those big metal boxes mounted on utility poles? They are where the fiber terminates and the coax or telephone lines make their way to the home.

          • Coax is damn near dead, what with its requirement for amplifiers, splitters, crimps, etc. It's a stunningly poor choice for data.

            Interesting comment given how coax is used for the overwhelming majority of broadband and cable systems at speeds well and truly exceeding what any family currently needs.

            Please don't use the word dead to describe the living.

            Also amplifiers, splitters and crimps? I see you've never actually had anything to do with fibre before, not only do all the above exist for fibre they are significantly more difficult to work with.

        • For what it's worth, I just bought a home that was built in 2016. There is no RJ-11 wiring at all in this house. There is, however, some ethernet drops in various rooms as well as a data panel in the wall where those runs terminate, with electrical in it so you can power up a small gigabit ethernet switch in there. No, you aren't going to get a 48-port rackmount in there, but the vast majority of people don't need that, and those that do can figure out how to patch one in via an existing cable from anoth

        • by AmiMoJo ( 196126 )

          Even if they can get gigabit out of it, it's just going to keep falling behind.

          In major cities in Japan the standard is now 10Gb fibre, with 20Gb being available in some areas. It carries 8k TV as well as internet data.

          By the time these guys figure out how to get 1Gb out of copper that speed won't be particularly impressive. It probably won't be universally 1Gb either, it will be like all the other DSL standards where the exact speed depends on the condition and length of the wiring.

          It probably won't be sym

        • by jbengt ( 874751 )
          It's not even the last mile. In my case, it's the last 500 feet, and no phone company wants to replace individual buried lines to each house.
    • Here in the UK, most of the "copper twisted pair" phone lines are actually aluminium. The incumbent telco, British Telecom, switched away from using copper as a cost-saving/profit boosting exercise after it was split out from the GPO and privatised.

      So, while this research is interesting in the abstract, it has little to no practical use in the country where the research is taking place.

      As an aside, I'd also say that "These cables are actually very old, invented by Alexander Graham Bell, and since then no

      • In (the old) theory, the limit was based on frequencies under 1 GHz. This experiment deals with higher frequencies past a dead island of frequencies that won't work around 1GHz. The signal travels over the wire differently. Not likely to work very well with aluminum, though.

    • This. Australia's NBN tried that and it was a disaster. They had an anti-fibre policy, because politics, so they "upgraded" the network, found that it didn't work, and wound up replacing thousands of kms of copper.

  • by MikeDataLink ( 536925 ) on Wednesday April 27, 2022 @03:22PM (#62484948) Homepage Journal

    Right. ATT, Verizon, Bell Labs, Cisco, Ubiquiti, on and on. None of these companies have looked into the theoretical limits of CAT3.

    Oh wait. That's right. They did. That's how we got all the variants of DSL. And that's why we moved on to better tech, because CAT3 performance doesn't cut the mustard. They even admit the in TFA that these speeds could only be achieved over distances so short that they'd need to backhaul data closer to the customer.

    This whole article is D-U-M-B.

    • by omnichad ( 1198475 ) on Wednesday April 27, 2022 @03:31PM (#62484986) Homepage

      Everything the article says makes me think...hmm...useless for DSL but if you had 4 of these pairs it might be a good future Ethernet standard.

      • Everything the article says makes me think...hmm...useless for DSL but if you had 4 of these pairs it might be a good future Ethernet standard.

        If you're only interested in going 100m, sure.

        • That's not much different than the limits they were getting in their tests anyway.

        • I have a cable modem sitting on my desk next to a router. The router plugs into my wall. It then travels to different rooms in the house, where I have televisions hooked up to the wall, because 4K over wifi is daft. Downstairs, next to the TV, I have a NAS containing digital movies.

          All of that is easily within 100m and would benefit from that technology.

          • I have a cable modem sitting on my desk next to a router. The router plugs into my wall. It then travels to different rooms in the house, where I have televisions hooked up to the wall, because 4K over wifi is daft. Downstairs, next to the TV, I have a NAS containing digital movies.

            All of that is easily within 100m and would benefit from that technology.

            Why? Existing Ethernet and even Powerline ethernet would be far better alternatives. This is a solution looking for a problem.

            • Because maybe someone doesn't want to spend a lot of time / effort / money to run ethernet everywhere in a home they may or may not actually own? And powerline networking has great numbers, but never actually measures up, and sometimes doesn't work at all if there's surge suppression or noise filters between the endpoints.

              I don't know why everyone is being so curmudgeony towards another solution to higher bandwidth connections which happens to reuse wire in millions of structures that is not being used for

              • by Junta ( 36770 )

                Note that when my house was built, they just used cat5e for everything, including the RJ11 phone jacks. The subcontractor said it wasn't worth the effort to ever run less than cat5e, even for boring old telephony. This was nearly 20 years ago.

                So it's quite possible construction in the recent past already has cat5e, and just have to change out the jacks.

                Conversely, I don't know if this research shows anything practical to do for older construction that wouldn't be met by, say, MoCA, which uses commonly ran

                • That's in the house, dumbass. They're talking about the other side of the demarc and the telco sure as fuck didn't run a million cat5e cables four lines at a time from the CO...
                  • by Junta ( 36770 )

                    This thread was spawned by someone saying essentially 'ok, so maybe it wouldn't work for long haul, but I could use my phone wire as home networking even though my house isn't wired, so maybe this research could be released as a home networking solution if not a long-haul technology. To quote:
                    "Downstairs, next to the TV, I have a NAS containing digital movies.

                    All of that is easily within 100m and would benefit from that technology."

                    So before accusing someone of being a dumbass, try verifying the context of

                  • That's in the house, dumbass. They're talking about the other side of the demarc and the telco sure as fuck didn't run a million cat5e cables four lines at a time from the CO...

                    Did you actually follow this thread or just start commenting? You're completely out of context here.

    • by iikkakeranen ( 6279982 ) on Wednesday April 27, 2022 @04:13PM (#62485142)

      DSL is a tradeoff between distance and speed. This is a slightly different tradeoff with more speed at a shorter distance, that was not of interest to the telcos when DSL was developed. However, this could well be of great interest to condo buildings, apartment complexes and the like. If you only need to pull fiber to one spot in a development that already has mostly-unused copper going from that spot to each individual apartment, it's a lot faster and cheaper than pulling new fiber to every unit.

      • DSL is a tradeoff between distance and speed. This is a slightly different tradeoff with more speed at a shorter distance, that was not of interest to the telcos when DSL was developed. However, this could well be of great interest to condo buildings, apartment complexes and the like. If you only need to pull fiber to one spot in a development that already has mostly-unused copper going from that spot to each individual apartment, it's a lot faster and cheaper than pulling new fiber to every unit.

        Even then, it's just a stop gap for 5 or less years.

      • by kriston ( 7886 )

        That's already being done in many, if not most, places. In the US, cable companies started doing fiber-to-the-neighborhood over two decades ago and DSL started a few years after that.

        Some phone companies, like Verizon, opted to go for broke on fiber-to-the-premises, but they're not doing that anymore and sold off a few of their FiOS plants to Frontier many years ago. The only places where FiOS is still being expanded are DC and NYC because they sued Verizon to keep building FiOS.

    • They even admit the in TFA that these speeds could only be achieved over distances so short that they'd need to backhaul data closer to the customer.

      Just what do you think FTTC and FTTN are? The whole point of this is to extend the last very short distance from fibre to the end user. Nothing dumb about it, a technical solution to a fucked up fibre rollout that never bothered to do that last little step needed in the name of saving costs which unfortunately is very relevant in a few countries.

    • Fiber to the curb allows different techniques than fiber to the node.

      The DSL techniques have been invented for fiber to the node.

      • Which isn't to say I see much advantage of trying to dig up phone cable at the curb. They can already tunnel fiber horizontally to homes underneath yards quite efficiently, so there's little point.

    • There's a market you're not thinking of though - this could be used to great effect by running fiber into older multi-tenant building that has pre-existing telephone wiring, and using this to give everyone in that building a somewhat decent connection without having to run drops into each and every unit. Put in a single fiber drop in a utility closet, bridge it to the building telephone wiring, and light it up.

      Apartment and small office building owners might love something like this where they aren't going

    • by kriston ( 7886 )

      distances so short that they'd need to backhaul data closer to the customer

      ...which is what modern coax cable internet already started doing with "fiber-to-the-neighborhood" decades ago.

  • by Junta ( 36770 ) on Wednesday April 27, 2022 @03:25PM (#62484960)

    We can push a lot more over UTP than we do today. However, it's not easy to do over significant distance (which would be needed) and even at short distance, it's a power hog to try to push it that hard. To try to use copper, it would require digging up a bunch of it anyway, get power to more places along the line to actively repeat, and then probably fail due to the general decrepit state of the wiring.

    • significant distance (which would be needed)

      Why? The point of this is not to run internet over your phone line back to your phone exchange ala DSL. The point of this is to do the last hop from FTTC or FTTN. The distances are not significant. In some cases we're talking about 10m.

  • PopSci explanations (Score:5, Informative)

    by Netdoctor ( 95217 ) on Wednesday April 27, 2022 @03:31PM (#62484982)

    It's gotten to be an art trying to understand technically what these popsci articles are describing in layspeak.

    Anyways, here's a direct link to the paper: https://www.nature.com/article... [nature.com]

    Basically, they're talking about matching a standard telco twisted pair with a balun, and find they can keep it behaving as a transmission line until 5GHz, and higher frequencies by increasing the twists.

    • Basically, they're talking about matching a standard telco twisted pair with a balun, and find they can keep it behaving as a transmission line until 5GHz, and higher frequencies by increasing the twists.

      None of what the authors conclude is particularly surprising. Twisted pair is basically a variant on the standard two wire transmission line and they demonstrate that if you can make a decent broadband balun then you can get energy in and out of it.

      However, it seems to me that the paper has demonstrated a theoretical possibility whilst overlooking a range of practical problems.

      • Whilst they discuss the losses in the FR4 dielectric used to make their balun, they are rather quiet on the dielectric losses o
  • The second link is pretty comprehensive and not paywalled. It mentions Tbit/s DSL. Now we're talking...
    • Tbps on a 10 meter span (30 feet in the USA), if you read the article...And 100Mbps limit of about 300 meter (1000 feet in the USA)...hardly any useful for neighborhood to CO connectivity.
  • Dedicated data use (Score:5, Interesting)

    by Dan East ( 318230 ) on Wednesday April 27, 2022 @03:32PM (#62484992) Journal

    Unless I'm mistaken, one of the main technical limitations capping data rates over twisted pair telephone lines is to preserve the quality of legacy analog voice communication (IE what the lines were originally meant for 140 years ago). That is preserving analog phone on the pair the data is on, as well as preventing it from bleeding over to the adjoining pairs of copper that are bundled together.

    It seems to me if that was not a concern then data rates could use that bandwidth as well, thus increasing data bandwidth.

    • Maybe it's time in some regions to do what they did for TV, switch to digital.

      Give people a few years to buy a converter box or replace their POTs equipment and then re-cast the infrastructure as digital only

      • While we're putting digital transceivers in the field for anyone looking for PSTN service, let's just convert the whole thing lock-stock-and-barrel into IP connectivity and give them a VoIP transceiver instead. I mean, that's only been around for like 20 years now, and packets are packets.

        Let's stop pretending that analog voice that has had the upper and lower frequencies hacked off is anything more than it is, and start treating it as real-time streamed data like any other real-time streamed data.

    • by subreality ( 157447 ) on Wednesday April 27, 2022 @05:06PM (#62485288)

      I don't think that's actually a problem. Here's how the spectrum is allocated:

      https://en.wikipedia.org/wiki/... [wikipedia.org]

      Annex A and M are the ones you'll usually see when it's combined with POTS. Annex B allows it to coexist with ISDN.

      Even with the generous guard band up to 25kHz - high enough to prevent crosstalk from being a problem - analog voice is less than 2% of the available spectrum.

      The only time it would matter is if you're on a very long line (living in the sticks with traditional DSL to the CO, instead of neighborhood DSLAMs that most areas have). In that case the upper spectrum is progressively lost, and at some point you might want to reclaim the bottom end (I or J), or boost the power of lower frequencies while cutting high frequencies to stay in the required power envelope (L). Very few places deploy these though because it increases crosstalk and it only helps if you're way out in the country - the bottom end is a rounding error unless your line is already terribly attenuated.

  • by Comboman ( 895500 ) on Wednesday April 27, 2022 @03:33PM (#62485002)

    Above that limit, the researchers found that the wire essentially acts as an aerial and transforms any signal sent along it into radio waves that dissipate before reaching their destination.

    Not to mention pissing off a lot of ham radio operators.

  • by bn-7bc ( 909819 )
    Yes by all neans leets keep floghing the old distance lmited ( the higher spoed the shorter the sustance get ) pots copper lines, instead if rolling our something yhat us mideratly future oroof and is far kess limited when jt comes to distance ( ie fiber ). Yea i know roll out costs, but once the fiberbis in you have at least 10KM reach with no active components (thus no need for heating/cooling) between the node and the costumer those okd copper lines are iften in poor condition, mightpr be multiplexed, of
    • 10KM reach with no active components

      also reduces the impact of power outages..If you and the CO have power, you have connectivity...If they have copper that needs repeaters every 500 feet, that's a lot of active failure points and power outages along the way (we KNOW how battery maintenance goes) can kill everything.

      Also much of the existing copper plant (at least in the USA) is 50-70 years old, well beyond its lifespan, between weather, rodents, electrolysis, and other stresses, many areas have very fe

  • by chipperdog ( 169552 ) on Wednesday April 27, 2022 @03:45PM (#62485034) Homepage

    Most of the copper pair infrastructure is well past its lifetime, at least in the USA, technicians keep running out of good pairs in some segments...weather, rodents, etc. have done their damage over the last 70 years.... replacing it with fiber is cheaper than replacing the copper

    Also, reading through the article, the longest distance I see mentioned is 300m (about 1000 ft in the USA), the need isn't in the 1000 foot drop to the premise (heck, if nothing else, one could AirFiber that), but rather the 1-10 miles to the CO where the real bottle neck is. /P

    • There was Huawei funding in the research. Consider distribution within newer high rise apartment blocks, 30 year old cable, no weather exposure or rodents: modern urban Asia. We'll leave the random festooned masses of wire cascading from pole to sidewalk in Saigon (2007 observation) as a separate topic. The building probably is already served by fiber. Your description of US outside plant matches my local situation: I have had 3 extended POTS outages from wire that was too wet to draw dial tone. Amusi
  • https://www.blog.adva.com/en/t... [adva.com]

    I have tried many of the point-to-point magic black boxes that hook to the end of copper pairs and guess what?

    FIBER IS BETTER.

    Anything over a meter's length worth of cable and you are back to 100 mb/s.

    The copper is not twisted, suffers from crosstalk, and capacitance over long runs. Also, getting dry pairs in a city point-to-point is difficult.

    • The copper is not twisted, suffers from crosstalk, and capacitance over long runs.

      Telephone wires have been twisted since some times in the 19th century. It keeps out magnetic interference at audio frequencies, and minimises crosstalk. Capacitance over long runs is dealt with by appropriate impedance matching, which is around 110 ohms for twisted pair. In the old days of wired telephony, the nominal impedance was 600 ohms, so loading inductors were need to make the cable look like 600 ohms impedance over long distances, but only for audio frequencies.

      The trouble is, there is no way that

  • Have we forgotten? (Score:3, Interesting)

    by Quatermass ( 579087 ) on Wednesday April 27, 2022 @04:08PM (#62485116)

    In the local box outside the house we've got aluminium wires mixed with copper simply twisted together.
    These effectively act like terminators at high frequencies.

  • First dial up, ADSL, then DSL (I am surely missing a few in between) It is effectively at it's usable peak. The reason is all the interconnecting hardware that is simply not designed to carry anything more than a voice signal, plus the age of current installations. Also there is that pesky 'works for short distances' problem.

    No one disputes that wire on it's own can do great speed. The connection points and constant splices from repairs are the problem.
    • Also being waterlogged, rodent bites in the cable, etc...And a good portion of our copper infrastructure isn't even twisted. The twists and carefully controlled connections seem to be key when I skimmed through the article.
  • I am using that fiber to the node AT&T via Sonic, a local excellent provider. I did have them run a new line into the house so we can keep our current 2 landlines. My brother has the fast Comcast at his home and both times we compared, via DSL reports, I beat him every time, not by much, still ahead of his cable. Not bad for twisted pair. My other is using netflix and prime wireless a lot and my Imac Pro is Ethernet attached all running well. Only caviat is the internet phone is junk, keepin my wires, I
  • by Pollux ( 102520 ) <speter@[ ]ata.net.eg ['ted' in gap]> on Wednesday April 27, 2022 @04:33PM (#62485184) Journal

    You don't need to be a research scientist to figure out you can get some really fast speeds over unshielded-twisted pair using ridiculously high frequencies. But the higher the frequency, the shorter its propagation distance.

    DSL is already on borrowed time, and the last thing we need are absentee-landlord ISPs like CenturyLink to eek out a slightly higher performance for urban residents while rural residents suffer from a lack of sufficient broadband for another decade. Out here in rural Minnesota, there are many households that are still stuck on DSL on speeds of 1 Mbps or lower because they're too far away from the PBX. What we need is a full investment in fiber infrastructure nationwide.

  • In 2015 the FCC voted to accelerate the demise of copper and released carriers from needing to maintain existing copper and not require them to install copper in new builds. https://www.lermansenter.com/f... [lermansenter.com]
    Copper is to be completely sunset by August of 2022. Trying to use copper now is attempting to use garbage that has been ignored and not maintained for almost 7 years. This is too little, too late and really stupid.
  • One big problem is that telcos, trying to support voice, didn't use twisted pair. They used pairs that are unshielded and not usually twisted. The transition to the use of TP for the local loop didn't start until the late 1980s, so newer neighborhoods might have it, but older telco wiring was plain balanced pairs. Yes, a bit of cross-talk was common, but people were used to it.

    Getting DSL to move it's specified max of 24 Mb/s seemed pretty amazing, but was seldom (if ever) achieved and that came only in re

  • Who the fuck has twisted pair from the telco? It's parallel strand if it was put in "decades ago"
  • Sigh. I can't believe someone actually wrote that in a published _science_ article.
  • So we had to struggle with 56k (and worse!) analog modems for YEARS, and now they want to try improving the speeds over old-ass tech?

    Fuck right off. There's better technology out there and we've already moved on.

The 11 is for people with the pride of a 10 and the pocketbook of an 8. -- R.B. Greenberg [referring to PDPs?]

Working...