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10mbps over 1km on a single pair of wires

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Re: 10mbps over 1km on a single pair of wires

#171

Post by hinkley »

jagger27 wrote: post #134
sethhochberg wrote: post #132

Earlier quoted context omitted.

These solutions for things like IP-over-copper-pair are typically designed for situations where you already have the cable buried or strung on poles or whatever - so the choice isn't whether to lay new copper or lay new fiber at roughly equal expense, its really whether to use the existing copper or lay the new fiber at much greater expense

Thank you, this wasn’t clicking for me until I read this. Of course there are countless places with a dead phone line hanging between them.

Or a fat old conduit that you can run a new wire through...

Re: 10mbps over 1km on a single pair of wires

#172

Post by Aloha »

rodgerd wrote: post #169
Aloha wrote: post #138

Earlier quoted context omitted.

Cost and Fragility. You can push around 1GHz of bandwidth on the normal hardline-feed line with taps system cable uses, each node is designed to pass by a certain number of households. Coax is.. cheap, forgiving, easy to terminate, and inexpensive to replace - Fiber is more expensive, unforgiving, and much harder to terminate.

https://www.chorus.co.nz/tools-support/broadband-tools/broad... New Zealand has fibre to the home for the majority of a country the side of the eastern seaboard of the US, with only 5 million people, and a lower per-capita GDP. It's doable. It's just a question of wanting to.

Its just not as efficient, you can deliver similar classes of service by HFC networks.

Re: 10mbps over 1km on a single pair of wires

#173

Post by bufferoverflow »

DannyBee wrote: post #48
silviot wrote: post #21

Earlier quoted context omitted.

What's the difference in price between 1km of fiber vs 1km or single pair wire? It might play a role in this solution being cheaper than immediately apparent.

The fiber is much cheaper because it's so much more common. For example: I/O fiber is about 0.10 cents a foot or less for 2 fiber cable. (12 fiber is only 20 cents a foot). OSP gel-filled direct burial is 0.55 cents a foot or less for 2 fiber cable. (12 fiber is only 65 cents). This is micro-armored OSP cable, resistant to chewing/damage as well. Basic 18 awg single pair shielded direct burial wire is about 0.80 cent…

Aren't you off by a factor of 100? Maybe dollars per foot, not cents per foot?

Re: 10mbps over 1km on a single pair of wires

#174

Post by tumetab1 »

icedchai wrote: post #152
tiffanyh wrote: post #125

Most don't realize, you can run 400mbps of data over your old in-home electrical wiring. https://www.digitaltrends.com/computing/everything-you-need-...

I experimented with powerline network adapters for a while. You might see 400 megabits on the same circuit. Between floors in your house on different circuits? Very unlikely. The latency was also pretty bad compared to wifi.

My experience is also that between floors (circuits) you loose bandwidth. With latency I see no issue and I find that weird.

Latency, with Wi-Fi or not, it’s probably correlated with transmission failures so there probably some bad circuitry or devices than create noise (like electrical motors).

Re: 10mbps over 1km on a single pair of wires

#175

Post by jagger27 »

hinkley wrote: post #171
jagger27 wrote: post #134

Earlier quoted context omitted.

Thank you, this wasn’t clicking for me until I read this. Of course there are countless places with a dead phone line hanging between them.

Or a fat old conduit that you can run a new wire through...

I can't imagine a scenario where you already have a 1km long conduit that doesn't already have copper or fibre in it. Why would you choose to push a kilometre of brand new copper twisted pair line down an existing conduit just to squeeze 10 Mbps out of it? The hard part is already done and fibre equipment is pretty cheap.

If the conduit already has a phone line in it that isn't being used, sure.

Re: 10mbps over 1km on a single pair of wires

#176

Post by DannyBee »

icedchai wrote: post #151
DannyBee wrote: post #48

Earlier quoted context omitted.

The fiber is much cheaper because it's so much more common. For example: I/O fiber is about 0.10 cents a foot or less for 2 fiber cable. (12 fiber is only 20 cents a foot). OSP gel-filled direct burial is 0.55 cents a foot or less for 2 fiber cable. (12 fiber is only 65 cents). This is micro-armored OSP cable, resistant to chewing/damage as well. Basic 18 awg single pair shielded direct burial wire is about 0.80 cent…

If you're in the position to bury new fiber cable, why would you use this product?

To get to 1km, the spec requires 18awg cable, which nobody has around either ;)

Re: 10mbps over 1km on a single pair of wires

#177

Post by jaredhallen »

NegativeLatency wrote: post #115
hervature wrote: post #104

Earlier quoted context omitted.

Fiber optics cables are made of glass whose primary constituent is silicon dioxide and/or quartz which are the primary constituents of sand.

And therefore should be cheap in a naive estimate

To be fair, fiber cable itself is actually pretty cheap in the scheme of things. It's the installation and termination that account for the bulk of the cost

Re: 10mbps over 1km on a single pair of wires

#178

Post by DannyBee »

Aloha wrote: post #142
DannyBee wrote: post #48

Earlier quoted context omitted.

The fiber is much cheaper because it's so much more common. For example: I/O fiber is about 0.10 cents a foot or less for 2 fiber cable. (12 fiber is only 20 cents a foot). OSP gel-filled direct burial is 0.55 cents a foot or less for 2 fiber cable. (12 fiber is only 65 cents). This is micro-armored OSP cable, resistant to chewing/damage as well. Basic 18 awg single pair shielded direct burial wire is about 0.80 cent…

When everyone prices fiber, they fail to include the termination costs. How much are the termination costs on that fiber, per run? Also, you'd never install single pair direct burial, and almost never shielded (unless its audio and not phone type) - it'd be 4/6/12 pair direct bury gel-filled cable.

Termination is basically a non-cost anymore. The price a pack of 10 sc/apc field terminations (IE that a random DIY'ers could do) is The loss and ease of mechanical connectors has gotten good enough (0.15 db or better) that most of the folks i know will only fusion splice when they really have to.

I agree it wouldn't make sense to do single pair or single fiber, but that's the actually the comparison at which 10baset-1l is at all competitive.

I have buried a lot of fiber, and a lot of network cable over the years :)

I was just trying to be fair and present the best case for 10baseT1L

In practice you can do 12/24 strand fiber (or 6 strand fiber + power + whatever) for less than the price of whatever particular set of 18 awg twisted pair (which is what the spec requires at 1km) + other things you wanted. The cable would be smaller, and if you use A3 or B3 fiber, it would be more flexible/support a lower bend radius than the 18 awg twisted pair. By far. IT's not even close.

Re: 10mbps over 1km on a single pair of wires

#179

Post by DannyBee »

jandrese wrote: post #97
DannyBee wrote: post #48

Earlier quoted context omitted.

The fiber is much cheaper because it's so much more common. For example: I/O fiber is about 0.10 cents a foot or less for 2 fiber cable. (12 fiber is only 20 cents a foot). OSP gel-filled direct burial is 0.55 cents a foot or less for 2 fiber cable. (12 fiber is only 65 cents). This is micro-armored OSP cable, resistant to chewing/damage as well. Basic 18 awg single pair shielded direct burial wire is about 0.80 cent…

This product makes sense if you are reusing existing copper lines.

in which case unless you have 18awg copper lines around, you can't do 1km :)

I would be shocked if anyone has those. Maybe alarm wire I guess?

Re: 10mbps over 1km on a single pair of wires

#180

Post by watersb »

EvanAnderson wrote: post #121
tomhoward wrote: post #110

Earlier quoted context omitted.

Cool to see you here on HN. I hadn't heard the name PairGain since I worked for a small corporate ISP in the early 2000s. We'd recommend PairGain modems for clients who needed seriously high-speed links of 2Mbps! This was just before ADSL and SHDSL were rolled out en masse, or at least well before they were reliable enough for corporate use. We had to organise a special installation of a direct copper line from their…

The tariff in my locality allowed for dry copper pairs to be installed ("burglar alarm circuits") and some of my Customers took advantage of that along w/ PairGain devices to get high speed links between sites serviced out of the same central office. Relevant article: http://helices.org/commentary/dry_copper_pair.html

I can't tell exactly from a quick scan of Cringeley's commentary... but I get the impression that a "dry copper pair" the single-pair POTS equivalent of "dark fiber"... with the critical caveat that a dry copper pair can link two points only if they are serviced by the same central telephone company switch.
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