[HN Gopher] ADSL works over wet string (2017)
___________________________________________________________________
ADSL works over wet string (2017)
Author : mgliwka
Score : 331 points
Date : 2021-12-04 13:25 UTC (9 hours ago)
(HTM) web link (www.revk.uk)
(TXT) w3m dump (www.revk.uk)
| rob_c wrote:
| Have seen this one a few times, still impressive
| WaitWaitWha wrote:
| I remember in the 90s when we were deploying a business campus,
| we first used ADSL services from the local carrier, but not for
| long.
|
| We discovered we can get "dry lines", basically just rent copper
| run from site-to-site, nothing on it from local carrier. Slap
| ADSL modems on each and we got max throughout, at a fraction of
| the cost. Then we upgraded to SDSL, and that was like hitting the
| jackpot.
| qeternity wrote:
| This thread is a good reminder to be very thankful for my
| PS20/month unmetered 1gbit central London FTTH.
| ksec wrote:
| There used to be a debate about going All-in on GPON or doing
| FTTX with G.Fast. Now G.Fast is pretty much dead or niche at this
| point. The end of DSL era. While DOCSIS is still doing well in
| many places.
|
| The next step would be to mandate fibre cables in all new
| housing. Along with ONT and Router in one solution.
| Nextgrid wrote:
| Better regulation around marketing would go a long ways to
| begin with. In the UK "fiber" is used as a catch-all term for
| any kind of internet connection even though in the majority of
| cases it's just fiber up to a certain point and then either DSL
| or coax, making it hard for consumers to tell exactly what
| they're signing up for. Same for bullshit terms such a
| "superfast" or "ultrafast" instead of actual up/down/latency
| numbers.
| derefr wrote:
| Can ADSL survive an acoustic coupler?
|
| To give it a fair shot, assume the driver and microphone are
| studio quality rather than the kind you'd find on a 1970s
| telephone handset. I bet it'd work pretty well.
|
| But the real question would then be: how much of an air gap could
| you create and still get a connection?
|
| Could you post to HN on an ADSL signal that's being screamed
| across the length of the room you're sitting in?
| detaro wrote:
| ADSL upstream _starts_ at 25kHz, downstream at >120kHz. So
| probably not. Purpose-designed ultrasonic hardware might be
| able to.
| londons_explore wrote:
| Or an acoustic coupler which also acts a little like an
| electrical coupler at higher frequencies because it has no
| electrical shielding...
| codeflo wrote:
| Not sure if this is within the spirit of the question, but:
| The individual ADSL bands are only 4 kHz wide, so you could
| modulate 4 or 5 of them down into the audible range (20Hz -
| 20kHz) and back up again after the transmission through the
| acoustic coupler. In theory, ADSL should then pick those
| bands to transmit the data.
| Faaak wrote:
| Related: ethernet over barbed wire:
| http://www.sigcon.com/Pubs/edn/SoGoodBarbedWire.htm
| throw0101a wrote:
| There are IEEE standards for single-pair Ethernet:
|
| > _In addition to the more computer-oriented two and four-pair
| variants, the 10BASE-T1,[17] 100BASE-T1[18] and 1000BASE-T1[19]
| single-pair Ethernet physical layers are intended for
| industrial and automotive applications[20] or as optional data
| channels in other interconnect applications.[21] The single
| pair operates at full duplex and has a maximum reach of 15 m or
| 49 ft (100BASE-T1, 1000BASE-T1 link segment type A) or up to 40
| m or 130 ft (1000BASE-T1 link segment type B) with up to four
| in-line connectors. Both physical layers require a balanced
| twisted pair with an impedance of 100 O. The cable must be
| capable of transmitting 600 MHz for 1000BASE-T1 and 66 MHz for
| 100BASE-T1. 2.5 Gb /s, 5 Gb/s, and 10 Gb/s over a 15 m single
| pair is standardized in 802.3ch-2020.[22] As of 2021, the
| P802.3cy Task Force is examining having 25, 50, 100 Gb/s speeds
| at lengths up to 11 m.[23]_
|
| *
| https://en.wikipedia.org/wiki/Ethernet_over_twisted_pair#Sin...
|
| Including power delivery:
|
| > _The IEEE 802.3bu-2016[12] amendment introduced single-pair
| Power over Data Lines (PoDL) for the single-pair Ethernet
| standards 100BASE-T1 and 1000BASE-T1 intended for automotive
| and industrial applications.[13] On the two-pair or four-pair
| standards, power is transmitted only between pairs, so that
| within each pair there is no voltage present other than that
| representing the transmitted data. With single-pair Ethernet,
| power is transmitted in parallel to the data. PoDL initially
| defined ten power classes, ranging from 0.5 to 50 W (at PD)._
|
| > _Subsequently, PoDL was added to the single-pair variants
| 10BASE-T1,[14] 2.5GBASE-T1, 5GBASE-T1, and 10GBASE-T1[15] and
| as of 2021 includes a total of 15 power classes with additional
| intermediate voltage and power levels.[14]_
|
| * https://en.wikipedia.org/wiki/Power_over_Ethernet#PoDL
| toast0 wrote:
| Sadly, there's not much in the way of equipment for this. I
| could really use two small 10BaseT-1 to 10BaseT converters,
| preferably both powered from one end.
| throw0101a wrote:
| Seems to be mostly in the automative and industrial space,
| with some embedded stuff.
|
| I could also see it being useful for door security (badge
| readers, latch control).
| toast0 wrote:
| For me, I've got a gate with a keypad. It's got an
| ethernet port, but they only ran 3 pair to it, and it
| works best with 2 pair for voice communications, so I've
| only got one pair for data, not enough to use.
| giardini wrote:
| ADSL, being essentially a form of alternating current, will pass
| through an air gap. I was enlightened on this by an AT&T tech who
| pointed out that one of my ADSL lines had several breaks and
| could not carry DC but the ADSL signal still came through. The
| other line was dead so I was running essentially on one wire with
| an earth ground. Here is an interesting discussion:
|
| "Phone line with 1 broken wire still gets ADSL2"
|
| https://forums.whirlpool.net.au/archive/9yzp5wr3
|
| Anyway, my hat is off to the people who designed and implemented
| ADSL.
| geofft wrote:
| In some sense, that's "just" radio. An antenna is a wire...
| it's sending a signal and picking it up from a very nearby
| antenna. Radio transmissions are all AC.
|
| (Arguably, the real insight here is that the very existence of
| radio is impressive / unintuitive.)
| y04nn wrote:
| The gap on the line acts more as a capacitor than an antenna,
| AC pass through capacitors, but DC does not.
| tiernano wrote:
| this explains a problem i had in Ireland... ADSL worked, but
| phone line had to dial tone... engineer had no idea how it was
| working... mind you, ISP had sent him out to get better
| internet... i was on 8mb and was promised closer to 24... after
| he "fixed" it, it went to 6... so they were really not happy
| with the "engineer" when i canceled 2 days later...
| [deleted]
| DaiPlusPlus wrote:
| > Anyway, my hat is off to the people who designed and
| implemented ADSL.
|
| It's a blessing-and-a-curse: too many incumbent ISPs in highly-
| developed nations used ADSL's ability to run on anything as an
| excuse to put-off FTTH deployments (looking at you, BT).
| unixhero wrote:
| Telenor
|
| They also did the same, stalling and delaying, insisting on
| introducing ISDN 64/128kbit instead of going straight to DSL
| like Holland did.
| hungryforcodes wrote:
| Meh
| samwillis wrote:
| I think we (in Stamford Lincolnshire, UK) must be pretty
| unique right now with TWO competing FTTP startups both
| rolling out on the same streets. One day you will see
| Lightspeed Broadband pulling their fibre through the BT ducts
| and putting boxes on the top of telegraph polls. The next day
| Upp Brordband will be on the same street. So bizarre they
| they are doing the same town!
|
| Apparently we are due to have BT put in their own fibre in
| the next few months too. Really don't understand why they are
| doubling up the infrastructure.
|
| Hoping for a local price war!
| rconti wrote:
| Very strange! Mine was not quite as happy a story, but here
| in Silicon Valley (1mi from Facebook) I got a local ISP
| announcing fiber, and the very next week AT&T was running
| their own lines. This was back in 2019, and it felt like
| "everyone" had fiber before we did. 2 years later I guess
| it feels like old hat. And the local ISP has not yet run
| the fiber they promised. But one fast ISP is better than
| zero!
|
| Good luck with your deployment. I'm still so happy about
| it.
| aphrax wrote:
| How strange to see my hometown mentioned! Still not too far
| away and yes hoping for some local competition
| mattlondon wrote:
| Here in high-density London, we're stuck with ~70mbps ADSL
| and not even cable.
|
| Not representative of all of London, but at least around my
| parts it is slow ADSL or nothing :(
| charcircuit wrote:
| Are you suggesting 70Mbps is slow ADSL? There are many
| places where not even a tenth of that speed is possible.
| 867-5309 wrote:
| it's the UK average for urban ADSL. and those many places
| are where the FTTH startups are springing up
| martinald wrote:
| Basically there is an enormous amount of capital (at least
| PS10bn from startup providers) out there going into UK FTTH
| builds. BT focussed too much of content (BT Sport) instead
| of FTTH and private equity now thinks there is an opp to
| steal marketshare from BT/VM.
|
| However BT have now now committed PS10-20bn, VM probably a
| few billion.
|
| It will quickly consolidate like it always does.
| samwillis wrote:
| Thanks, I figured it was something like that. One of the
| startups here is a bunch of former BT execs so I was
| assuming they were hoping to exit by selling either to BT
| or VM.
| samstave wrote:
| >>...*my hat is off to the people who designed and
| implemented ADSL.*
|
| Maybe a few will recall: San Jose California, in the
| epicenter of Silicon Valley -- but for some reason Comcast
| (was previously called * _COVID*_ ) -- and you couldnt get
| DSL in San Jose at the time .... literally down the street
| from Netflix, and freaking home DSL took YEARS for it to
| reach our houses...
|
| (My point is that it was ironic that in the heart of silicon
| valley we couldnt even get DSL due to COVID/Comcast
| toast0 wrote:
| Are you thinking of COVAD? IIRC, they were a competitive
| local exchange carrier, unrelated to Comcast.
|
| As a CLEC, they could place DSL equipment in the incumbent
| carriers (mostly Pacific Bell/ATT, but Los Gatos Telephone
| company was absorbed by GTE/Verizon and I think sold to
| Frontier) and use the existing wiring to run DSL. In
| silicon valley, this doesn't offer great coverage; to get
| reasonable line lengths, you need to be in the telephone
| company's remote terminals and that's not available to
| CLECs.
| ohyeshedid wrote:
| From previous personal experience in building new plants, and
| expanding existing plants: Cost of deployment and slow roi
| are the primary drivers of stagnating local networks.
|
| Complicated corporate accounting, carrier incumbency, and
| weak governments are the core causes. Carriers being publicly
| traded companies really screws up incentives to fix these
| problems. It seems to be mostly a binary decision at the top;
| more profit or better service?
| kazen44 wrote:
| also, the infra (which ADSL runs on) was build in a time
| when telephone companies used to be either state-owned or a
| single monopoly with heavy goverment involvement.
|
| Doing the same thing with fiber is necessary, but will not
| happen without strong govermental involvement.
| verve_rat wrote:
| Indeed. New Zealand has had a pretty successful fiber
| roll out over the last several years because the
| government awarded exclusive contracts to fiber providers
| that then have to provide access to their network to all
| ISPs.
|
| Works great. Even my village of several hundred people
| has fiber now.
| zaphirplane wrote:
| In hind sight wouldn't 5g have been a better investment than
| fiber to home, I mean companies will have to have 5g to stay
| competitive in mobile anyway
| andoma wrote:
| Same thing happened once at my parents house. Quite confusing
| for some :)
| Terry_Roll wrote:
| Its DC. If you had to imagine it, think of it as a range of
| radio stations being broadcast down a wire instead of over the
| air and your router can tune in to all the radio stations at
| the same time and then piece together the different bits of
| data being broadcast. Long Wave would be ADSL, ADSL2, Medium
| Wave ADSL2+, and FM would be higher forms of ADSL to give you
| your 40Mb, 80Mb, 100Mb download speeds.
|
| With this broadcasting of signals down a wire now known, it
| becomes somewhat unsurprising anything capable of transmitting
| an electrical voltage & current would be capable of
| transmitting ADSL. Not knocking their effort though, Arnold and
| Arnold have always like to demonstrate their knowledge. One of
| them has a personal blog which can be quite interesting.
|
| I wonder if they have considered trying to adapt an SDR dongle
| to become an ADSL transmitter?
| hereforphone wrote:
| What's DC? "Radio stations" communicate via alternating
| quantities (EM waves)
| Terry_Roll wrote:
| The telephone cable coming into the house is 50volts DC is
| not AC like a powerline. I know radio waves are just that,
| waves, its how things like noise cancelling headphones
| work. Different frequency's give you different ranges or
| distances for 1 watt, which is why you can bounce Long wave
| around the planet.
| Terry_Roll wrote:
| I wasnt taught that radio waves were to be considered
| identical to AC power down a cable but when thinking
| about it, they probably are identical with waveform
| properties and the difference being the medium they are
| travelling through.
| leoedin wrote:
| Radio waves down a wire are by definition AC. Otherwise
| they don't work. The voltage must change, thus the
| current must change, thus it is AC. Just because it's not
| 50/60Hz AC like a powerline doesn't change that.
|
| There might be a DC component, but ultimately all the
| ADSL modem cares about is the AC part.
| hereforphone wrote:
| 48VDC but yes. Sounds like we're agreed that the
| information is being transmitted via AC or another
| alternating signal.
| traceroute66 wrote:
| Why is this 2017 blog suddenly appearing here in 2021 ? Not
| surprisingly, it has already been covered many times:
| - https://news.ycombinator.com/item?id=15908107 -
| https://news.ycombinator.com/item?id=15922239 -
| https://news.ycombinator.com/item?id=26868780
|
| The world has also moved on since 2017. Most people's question
| now is "how soon can I get fibre" not "how can I tweak my ADSL
| line to scrape some extra performance".
| agumonkey wrote:
| Since seeing this article I've been curious about organic
| conductors .. apparently most carbohydrates / celluloses are
| really not good basis for conduction but maybe there are tricks
| to change that.
|
| - https://www.quora.com/Is-cellulose-fibre-conductive?share=1
|
| - https://duckduckgo.com/?t=ffab&q=conducting+polymers+example...
| hashimotonomora wrote:
| Essentially you need loose electrons to conduct.
| VHRanger wrote:
| That's not exactly correct. Electrons don't flow through
| wires - there's a one-way flow of the ambient electrons
| around the wire from the field created.
|
| See here: https://www.youtube.com/watch?v=bHIhgxav9LY
| hashimotonomora wrote:
| That video is misleading. Electrons must be relatively
| loose in their orbitals in order for the electromagnetic
| field to be established with reasonable strength. This does
| not mean that electricity is the literal flow of electrons.
| However, electrons actually do flow at a speed of about 1
| mm/min due to the electrostatic field in DC circuits. This
| is not what's called electricity but they do flow.
| pjc50 wrote:
| Well .. they do flow _in_ the conductor, and in particular
| they flow through silicon junctions or none of the
| semiconductor physics would make sense, but the energy is
| carried in the field which is indeed outside the conductor.
| NovemberWhiskey wrote:
| You're confusing the electrons and the electromagnetic
| fields. The electrons absolutely do migrate through the
| wires; the electric field does not. P.S. that video appears
| to have been written to confuse/generate controversy and
| does a terrible job of actually explaining.
| SV_BubbleTime wrote:
| > The electrons absolutely do migrate through the wires;
|
| That's true. But very slowly in electrical terms. If I
| remember right the actual electronics in a reasonable
| circuit I read about was something like 1" per second.
| The vast majority of work done is an electron shuffle of
| bouncing into the next one in space.
| NovemberWhiskey wrote:
| When you say "work", what do you mean? I get the
| impression you're talking about a model like there's a
| long tube full of ball-bearings and when you push one in,
| one drops out the other end?
|
| That model isn't right; think about a transformer -
| energy is transferred between conductors that are not
| physically connected at all.
| agumonkey wrote:
| But maybe you could have different organic crystalline
| structures allowing AC currents to flow. Wildly speculating
| of course.. I was just hoping to tape in forest materials to
| manufacture low power electric devices :)
| pjc50 wrote:
| Graphite counts; if you want to manufacture it from forest
| materials, compressed bonded charcoal might work. https://w
| ww.sciencedirect.com/science/article/abs/pii/S01675...
| agumonkey wrote:
| True but its resistance might be too high maybe ? also
| it's not easy to make graphite.
|
| Thanks a lot for the link though. Are you into green
| electronics by any means ?
| rahimiali wrote:
| Conductive polymers are commonly used these days. Pedot:pss can
| be engineered expressly this way, but less exotic ones like
| polyamides can do this too.
| sdflhasjd wrote:
| Paper and cotton were both used in cable insulation in ye olden
| days, impregnated with oils and tars
| hammock wrote:
| What do they use now?
| sdflhasjd wrote:
| 3.5Mbit!? Says a lot about my parents paltry 1Mbit. Perhaps their
| line was low on sodium.
| iso1631 wrote:
| 3.5mbit over 2 metres
| cunthorpe wrote:
| Your parents' ADSL noodle soup is a little bland.
| tyingq wrote:
| The cable analyzer is showing about 55db of loss across 2
| meters. That's about equivalent to the loss across 4km of
| "good" copper.
| sdflhasjd wrote:
| I kid, the issue was solved some time ago - a telecom
| engineer pinned it down to a soggy junction box.
| SV_BubbleTime wrote:
| That's funny because my SO's parents have 1.5Mbps DSL by
| contract. For only $100/mo they can jump up to 12Mbps. USA
| and 1 hour from me where I have gigabit docsis 3.1.
|
| If they had 1Mbps because of a fault that would be more
| unfortunate than unfair.
| techdragon wrote:
| I'll go one better, ADSL doesn't even need two continuous wires
| to work, one is good enough as long as the other is just barely
| electrically coupled. I had a 12 month epic journey to get a
| performance fault fixed on my line. In the end it took 6
| technician visits, three senior technicians and finally one smart
| experienced technician to check the "not in the textbook" faults
| for a performance degradation and he discovered that my line had
| was actually mis-wired! I had one wire connected to the exchange
| and another was a barely connected lose joint (actually
| disconnected but still technically in the plastic joint housing)
| about half way to the exchange. I was still getting a few
| megabits with intermittent drop outs for months on what amounted
| to a single wire!
| Shikadi wrote:
| That's impressive af!
| codeflo wrote:
| That fact that this delivers 3.5 MBit/s really makes you wonder
| how many low speed connections out in the wild are literally
| broken cables that still have some amount of coupling somewhere.
| ajsnigrutin wrote:
| A lot of the problem lies with distance.
|
| 10km of fiber (with transcievers made for that kind of fiber
| and distance)... gigabits without any issues.
|
| 10km of copper pairs for *dsl? Good luck.
| mbreese wrote:
| I had a bonded DSL line for a while when I lived in the Bay
| Area with service coming from two different twisted pair lines.
| One line was consistently ~18Mbps, the other barely 3-5. It was
| pretty clear that one of the pairs was good and the other was
| broken somewhere alone the way. The lines were all in a bundle,
| with no way to discern what was what any individual strand was
| in the bundle (or which was broken or shorted). No one had any
| motivation to find the break and repair it. And because the
| line was technically "working", ATT wouldn't move it to a
| different pair. Sonic was the ISP with ATT handling the
| physical lines.
|
| Still amazing that it worked at all.
| londons_explore wrote:
| You can do time domain reflectometry to find out where the
| breaks, sharp corners and reflections are in the cable.
|
| Some modems have special debug modes in that can do this too
| - then you get to know exactly how many meters along the wire
| the break is. When you get close, you can hook a resistor to
| the line and rerun the test and it'll tell you how many
| meters forward or back you need to go to find the issue.
|
| Pretty easy to track issues down that way.
| mbreese wrote:
| Yeah, this was in a neighborhood bundle with many... many
| lines together. No one was going to dig into that to find
| which line a mouse or squirrel had chewed the insulation
| off of. I remember running a few diagnostics, but as it was
| "working", no one was going to try to fix it. The ISP
| couldn't even convince ATT to move the bad line to a
| different pair. Which was sad. I was supposed to be in the
| 40Mbps range, but could only get ~18-20. Also -- this was
| enough bandwidth for us at the time, so I just ran off of
| the single line and was good. Given some of the dsl horror
| stories, we weren't too and off.
| pteraspidomorph wrote:
| I lived in a forested area as a kid and the copper wire was
| always breaking for various reasons (falling branches, old
| deployment, temperature and humidity, etc). The ISP would
| always attempt to reduce the speed and leave it at that. It
| took a lot of effort as well as personally locating the
| breakage to get them to come and repair it properly (and it
| still took forever).
| whalesalad wrote:
| Sums up my youth on ADSL in the hills of LA. Couldn't get a
| static IP address on coax/cable so I convinced my family to pay
| out the ears for speakeasy.net DSL w/ a static IP. Performance
| was terrible!
| someperson wrote:
| Potentially apocryphal, but Telstra's copper cable network
| supposedly had its insulation made of paper, not rubber. I
| remember when it rained the curbside pits fill with water,
| causing slowdowns and frequent ADSL dropouts (until things
| dried out).
| xattt wrote:
| Many parts of rural Prince Edward Island (PEI) has DSL
| running on a phone system that's probably original from
| modernization initiatives in the 1960s - 1980s. Party lines
| were the norm in some areas up west until late-1980s.
| spookthesunset wrote:
| Back when a whole family had the same number and you had to
| ask whoever answered that you want to talk to so and so.
| Now days everybody has their own number and with caller id
| you (sometimes) know who is calling.
|
| My daughter is gonna grow up not knowing any of the "shared
| phone line" etiquette because it is largely obsolete.
| kube-system wrote:
| A party line is not when "a" whole family shares a line,
| it's when several separate houses share a line.
| xattt wrote:
| The party lines I'm talking about are shared loops
| between a group of residents in a rural area.
|
| Some of the first-hand accounts I've read talked about
| neighbours listening in on conversations. People could
| tell a snooper was on the line because the volume of the
| other caller would drop. There was a social aspect to the
| whole enterprise because you could tell the one nosy
| neighbour to get off the line and the volume would
| magically raise.
|
| (1) http://www.islandregister.com/phones/partyline.html
| Finkregh wrote:
| You spelled Germany wrong... X_x
| tenebrisalietum wrote:
| I think this is common in places where they don't expect
| moisture to reach, but then things change and it gets there
| anyway.
|
| If your POTS lines are down and the telecom company is
| telling you a "wet pulp repair" is underway, your phones are
| going to be down for a while because a bunch of paper-
| insulated cables need to be manually rewired because they got
| wet and corroded.
|
| I found this interesting: http://etler.com/docs/bsp-
| archive/629/629-295-300_I3.pdf - guess it's standard practice
| to dry out the lines, wrap in cloth, put dessicant and then
| seal it.
| [deleted]
| jcims wrote:
| I know there are some telecom folks on here that may be
| provoked to correct me but pulp was standard before the
| advent of cheap plastic insulation in the 1950s on up. I
| live in the midwest and my brother is a lineman for AT&T.
| There is an astonishing amount of pulp-insulated phone line
| still in service today.
|
| In order to keep it dry, the conduit that the pulp lines
| are run through is pressurized to 5-10psi. Anyone that has
| worked with air compressors knows that pumping ambient
| pressurized air down into underground pipes is a recipe for
| condensation, so high capacity air driers are required to
| remove the water before it goes underground.
|
| Any kind of outage on the compressor or dryer is
| effectively an emergency because water infiltration can
| happen almost immediately, creating an outage and extremely
| expensive repair.
| ComputerGuru wrote:
| > I know there are some telecom folks on here that may be
| provoked to correct me
|
| Aka Cunningham's law
|
| > Any kind of outage on the compressor or dryer
|
| I'm confused: isn't a bigger concern any physical damage
| to the conduit anywhere in the run that is too large for
| the compressor to overcome? Or are we talking football-
| field-sized compressors here?
| BoorishBears wrote:
| http://www.airtalk.com/z_ref-4_1.html
| stefan_ wrote:
| The more you learn about this ancient cable technology
| the more absurd it becomes. We shower these fuckers with
| money but they would rather keep their _paper insulated
| phone lines with permanent compressors and dryer running_
| than braindead simple fiber. No wonder it is permanently
| broken and they can 't keep a single 9 of reliability.
| oasisbob wrote:
| Fiber may be simple, but the way we use it is not. Unlike
| copper, a GPON fiber install is going to have active
| electronics and splice trays for every several dozen
| subscribers.
|
| Plenty of opportunities for water ingress to still cause
| problems.
| kazen44 wrote:
| Also, sending a singal across fiber is definitely not
| easy.
|
| ADSL is basically modulating a radio wave over a cable
| directly to another device. Fiber requires high quality
| optics, high quality lasers, tons of active hardware if
| you want to do it at scale. (not to mention the mind
| boggling physics and manufacturing required for things
| like DWDM, optical path switching etc).
|
| Fiber optics have existed since the 80's yes, but prices
| of high quality fiber solutions have only dropped
| massively in the last decade or so.
| stefan_ wrote:
| Exactly. That all sounds infinitely easier than buried
| air pipes. Mind boggling physics are what gives us CPUs,
| but the final product is reliable bar none.
| NavinF wrote:
| Meh. Fiber has been cheaper than copper per mile for a
| long time and 10km optics are like $20.
| jcims wrote:
| I would bet this is a capex/opex thing.
| kabdib wrote:
| It took over a year for Ziply to repair the land line of my
| 90-year-old parents. 30+ hours on the phone with support,
| multiple visits by techs who were simply not interested in
| doing any work. I had a tech tell me, literally to my face,
| "this line is working fine" when the line was stone dead.
| Another told me that I had to buy all new phones because the
| ones my parents had were "out of date". (To humor him, I
| bought a $15 phone from a local electronics store, plugged it
| in and showed the tech that it wasn't working. He did
| nothing).
|
| I have now learned that the WA state utilities commission is
| pretty interested when providers try to pull stunts like
| this. You can also dig out useful company contact information
| from the commission's website.
| rootusrootus wrote:
| > I have now learned that the WA state utilities commission
| is pretty interested when providers try to pull stunts like
| this.
|
| A number of years ago I worked at a CLEC, during that short
| window of time when they could exist. One of the more
| useful things I learned is how much power the PUC has.
| Every phone company has a team that deals with complaints
| coming in via the PUC and they are eager to resolve them.
| Not something I'd necessarily use in lieu of regular old
| customer service for most issues, but when the first and
| second attempts fail, calling the PUC will work 100% of the
| time.
| Eduard wrote:
| Our homes' water supplies are untapped options for data
| connectivity.
| joncrocks wrote:
| joking aside, I remember a while back that there has at least
| been cursory investigation into running high-speed internet
| cables through water pipes.
|
| Presuming you have water pipes to your property, could be
| easier than digging up roads etc.
|
| Only issue might be if you have a leak and need to shut off
| your water!!
|
| https://www.theguardian.com/technology/2021/aug/09/uk-launch...
| ixfo wrote:
| The linked article (and government push to do this)
| completely ignores the fact that this is done frequently now.
|
| It's used to get the last few metres into the home, e.g. from
| the boundary to the inside of the house. You put a swept tee
| in at each end, _after the stopcock_. Water off, dig down
| adjacent to stopcock, cut pipe, shove a drinking water rated
| duct down the pipe through the small port on a swept tee.
| Shove some chlorine tablets in the pipe and couple up to the
| new swept tee. Repeat interception at other end outside or
| indoors, and then use standard fibre cable blowing through
| the inner microduct, and away you go.
|
| There's a huge amount of disused water pipes in most
| developed nations which are frequently used, similarly using
| sub-ducting, and you can run cable through mains - but have
| to come out every time there's a valve, so practically it's
| usually cheaper to dig. Where it comes in handy is where
| there's areas you can't practically dig up, e.g. major roads
| with old pipes underneath.
|
| Source: Have done a bunch of this for a major UK telco.
|
| https://www.craley.com/craley-in-pipe-fibre
| Suchos wrote:
| There is company in Czechia which provides optics via sewage.
| I guess it is cheaper to use existing infrastructure than to
| place new pipes under roads.
| martyvis wrote:
| Sounds a bit like this "How TiSP Works"
| https://archive.google.com/tisp/install.html
| DaiPlusPlus wrote:
| > I remember a while back that there has at least been
| cursory investigation into running high-speed internet cables
| through water pipes.
|
| Oblig:
|
| https://archive.google.com/tisp/index.html
|
| https://archive.google.com/tisp/install.html
| hereforphone wrote:
| I think this relies on the particular string being a linear time-
| invariant channel. There is some limit where the string won't
| react accordingly (at a certain low or high frequency). What is
| that later phenomenon called, anyone know?
| NavinF wrote:
| Hmm the author had to use salt water to get it working. Maybe
| resistance is the limiting factor rather than dispersion. In
| which case a higher power modem or some sort of amplifier would
| get this working over >2m distances.
| stkdump wrote:
| I guess my home internet connection as a kid used wet string
| then.
| account-5 wrote:
| This is the article I'm sending to Sky next time my broadband
| goes down.
| Nextgrid wrote:
| Given the state of some telephone cabinets and junction boxes
| that I've seen, your broadband most likely already has some wet
| string in the path.
| fghorow wrote:
| Wet string? OK, fine.
|
| But I defy ADSL to work over something really challenging. Like
| Telstra copper in Australia.
| hedora wrote:
| You think the outback's bad? Try getting it to work over AT&T
| copper in heart of Silicon Valley!
| dang wrote:
| Discussed at the time:
|
| _ADSL over wet string_ -
| https://news.ycombinator.com/item?id=15908107 - Dec 2017 (88
| comments)
| nabla9 wrote:
| Most HDMI and Coaxial cables are little more than wet string
|
| https://ec.europa.eu/docsroom/documents/46433
|
| >only 10% of the HDMI RMCD met an acceptable EMC quality of at
| least 50 dB coupling attenuation
| mmastrac wrote:
| The miracle of modern signal processing!
| Dylan16807 wrote:
| RMCD sure is an awkward way of spelling "cable". Especially
| when nobody else seems to use this acronym?
| shireboy wrote:
| I'm pretty sure this is exactly how my ATT DSL comes in.
| stefan_ wrote:
| If you want to try this at home, keep in mind that powerline is
| essentially the same thing - you don't necessarily need some
| DSLAM. Also these things spew so much RF they can frequently pair
| through thin air, just from radiated emissions.
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