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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

#81
post #36
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.

I don't think the wire itself would be the expense, but the laying of it?

The cost of laying wire is virtually the same as laying fiber, so the difference really comes down to the material costs. The only good reason to use wire would be existing installations, as you sidestep that cost entirely.

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

#82
post #36

Earlier quoted context omitted.

I don't think the wire itself would be the expense, but the laying of it?

The cost of laying wire is virtually the same as laying fiber, so the difference really comes down to the material costs. The only good reason to use wire would be existing installations, as you sidestep that cost entirely.

But perhaps the wire is already there. I don't think anybody advocates for building entirely new datalinks using this. Laying another 1km of cable is much more expensive than 2x200 USD to reuse existing cable.

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

#83
post #21
post #7

Earlier quoted context omitted.

> Any application requiring a simple, low cost, robust connection between physically disparate devices At $195 it's definitely not low cost.

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.

A copper wire can be bent in just about every which way (such as tangled when being tethered to an underwater drone), while fiber cannot.

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

#84
All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium.

While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that most DSL involves a service provider managing the network - with specialized skills, practices and setup.

In the 2010's I was spending time with the Ethernet folks, and in particular industrial folks with large plants. I ended up chairing IEEE Std 802.3cg which developed the 10 Mb/s 1km technology. Not really a speed increase - more an application refocus. As the networking world developed, many realized that converging networks above the physical layer added network complexity and therefore setup and ongoing operating costs... So we now also have SPE - pure Ethernet at DSL-like distances...

Similar tech with different use models, enabling connectivity for whatever...

I'm not Al Gore - I won't claim to have invented the internet. I just an engineer who happened to have a hand in both of these technologies, and am still pleased to see that people use them.

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

#85

Why are you mostly ignoring fiber comments in this thread? It seems like a no-brainer.

There are lots of reasons to choose something other than fiber, this isn't/shouldn't be a discussion of why you, or anyone else, would choose fiber instead of this product. It's pretty obvious that there is fiber in the world and saying "but there's fiber!" isn't very constructive.

Some off the top of my head reasons why I wouldn't choose fiber:

- runs that require turning very sharply, beyond what fiber can handle.

- applications where the cable can undergo sheering forces causing sharp bends or damage.

- applications where the cabling already exists.

- in cases where the cabling is already owned thus this becomes quite cheap.

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

#86

A few years ago, revk (owner of an ISP in the UK) did ADSL over wet string: https://www.revk.uk/2017/12/its-official-adsl-works-over-wet...

The HN post at the time: https://news.ycombinator.com/item?id=29440681

RevK is the owner of AAISP (an xkcd/806 compliant organisation).

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

#87
post #84

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium. While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that m…

Fiber doesn’t conduct electricity, a wire does. I remember reading somewhere to be careful with running a wire over any long distance between two houses that are not connected to the grid with the same meter. Something to do with phase or different potential, can’t remember, but the point was it could fry your equipment. Fiber sounds a lot safer to me.

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

#88
post #84

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium. While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that m…

Al Gore never claimed that, btw, but he did recognize its importance and provided political support, even Vint Cerf said so: https://www.snopes.com/fact-check/internet-of-lies/

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

#89
post #87
post #84

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium. While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that m…

Fiber doesn’t conduct electricity, a wire does. I remember reading somewhere to be careful with running a wire over any long distance between two houses that are not connected to the grid with the same meter. Something to do with phase or different potential, can’t remember, but the point was it could fry your equipment. Fiber sounds a lot safer to me.

The biggest problem is lightning strikes hitting the cable. The phase wouldn’t matter - and even different earthing wouldn’t matter as long as you only connect any shield at one end.

But fibre is so much more versatile if you’re running new cables (unless you want to run power)

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

#90
post #5

DSLs were capable of at least 8Mbit/s speeds close to 20 years ago. I worked for a small ISP and where were more than 100 meters (theoretical limit for cat5) between residential buildings, we were setting up 8 modems on a single UTP cable. With home internet speeds back then it wasn't a bottleneck.

Wait, can DSL modems talk to each other instead of a DSLAM line card?

Its true that the specs are not symmetric in ADSL. The CO (Central Office) end is different from the CPE (Customer Premises Equipment) end, and two CPE devices cannot talk to each other. Among other things, the engineering work had to take into account that at the CO end a bunch of wires would come together and leak RF between each other.

G.SHDSL is more common in a 1:1 configuration (although I think the ends may still be not symmetric) because it was designed as a T1 replacement.

However some devices that could do a single line of CO were made, that can therefore talk to a CPE.

See also https://www.revk.uk/2017/12/its-official-adsl-works-over-wet...

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