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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

#91

Post by aidenn0 »

cm2187 wrote: post #87
geozimm wrote: 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.

Magnetic coupling removes any issues with potentials, and if it's not AC at the same frequency as what's in the wall, the phase is irrelevant.

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

#92

Post by midasuni »

unwind wrote: post #74
gandalfian wrote: post #70

I'm 1km of copper to green box, then fibre rest of way to telephone exchange. VDSL 40mb down and 6mbs up. That's on a 1980's buried copper cable.

Neat, but is that copper a single pair?

Yes that’s how the traditional phone system works, single pair from your house back to the exchange (via a jumper block in a cabinet nearby). Modern DSL equipment can get upto 50mbit aggregate speed over 1km of traditional phone wire (so 40/10, or 30/20 or however you would want to set it up)

Condition of the wire will effect it of course, aluminium wire, ground conditions, cross talk etc could lower your speed.

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

#93

Post by baldfat »

netsharc wrote: post #88
geozimm wrote: 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/

Why ruin a good meme with FACTS! People

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

#94

Post by geozimm »

baldfat wrote: post #93
netsharc wrote: post #88

Earlier quoted context omitted.

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/

Why ruin a good meme with FACTS! People

absolutely - a good meme takes on a life of its own...

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

#95

Post by jandrese »

midasuni wrote: post #92
unwind wrote: post #74

Earlier quoted context omitted.

Neat, but is that copper a single pair?

Yes that’s how the traditional phone system works, single pair from your house back to the exchange (via a jumper block in a cabinet nearby). Modern DSL equipment can get upto 50mbit aggregate speed over 1km of traditional phone wire (so 40/10, or 30/20 or however you would want to set it up) Condition of the wire will effect it of course, aluminium wire, ground conditions, cross talk etc could lower your speed.

I think the difference with this product is the transceivers are $150 each and you don't need anything else to use them except for a couple of power supplies.

I do find it interesting that their box diagram claims a 2km range.

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

#97

Post by jandrese »

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…

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

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

#98

Post by upofadown »

midasuni wrote: post #89
cm2187 wrote: post #87

Earlier quoted context omitted.

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)

... also lightning strikes hitting the ground somewhere in the area. That can induce large voltage differences between the power grounds on the buildings. The voltage difference might be large enough to arc across any isolation provided by the physical network implementation.

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

#100

Post by superkuh »

If you use a surface wave transmission line with RF launcher cones on the ends you can send gigabits over a single 28 awg copper wire at very low loss from 100 MHz to ~10 GHz. The only problem is that the line has to be suspended and away from conductors.
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