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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

#151

Post by icedchai »

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…

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

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

#152

Post by icedchai »

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.

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

#153

Post by Animats »

Aloha wrote: post #139
madaxe_again wrote: post #111

Earlier quoted context omitted.

Then you just install a lightning arrestor on your comms circuit - I have a mast way up the hill to provide our connectivity here, and use one on the Ethernet line down to prevent issues (like a house fire) from a strike.

You have to assume a direct hit by lightening will fry your hardware, period, full stop - proper grounding and lightning protection however will mean that the hardware does not catch fire.

There are lightning protectors that will absorb a direct lightning strike. Most antennas on hilltops and tall buildings have them. They take lightning strikes routinely. Here's some ARRL material on lightning protection.[1]

It's not difficult, but it's not miniature. A classic design was a soup-can sized device with a coax connector on each end and a hulking big ground connection on the can. Inside was a spark gap with dime-sized silver contacts, and a few turns of copper busbar as an inductor to smooth out the spike that got past the spark gap. That goes where the cable enters the building. Similar units today tend to be smaller. There will still be serious metal boxes.[1]

You need a serious ground. As in hulking big copper cable to a long ground rod. Grounding to a pipe is no longer allowed; there might be plastic pipe somewhere in the system, either now or in the future.

The next stage is a "central office protector". This is a gas tube with three terminals - both sides of the line, and ground. So it's an enclosed spark gap in an inert gas. An overvoltage will ionize the gas and short it to ground. Telco central offices have one of those on each line. They're plug-in devices that sometimes have to be replaced.

There's a lot of obviously fake stuff on eBay and Amazon in this area. 2D logos superimposed on curved surfaces, even. There's a standard, UL 497B. If it doesn't have that certification, don't buy.

[1] https://www.polyphaser.com/search?Category=Data+Surge+Protec...

[1] http://www.arrl.org/lightning-protection

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

#154

Post by oasisbob »

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…

> 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.

Mmm. This brings back memories of running private DSLAMs in a campus environment as a transitional pre-Ethernet stopgap in the early 2000s. 95% of the DSL lines worked great. The remaining 5% were a never-ending nightmare of troubleshooting and sudden breakage.

We didn't want to be DSL experts, we just wanted the hardware to work well-enough for long enough to make it all go away.

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

#156

Post by Aloha »

Animats wrote: post #153
Aloha wrote: post #139

Earlier quoted context omitted.

You have to assume a direct hit by lightening will fry your hardware, period, full stop - proper grounding and lightning protection however will mean that the hardware does not catch fire.

There are lightning protectors that will absorb a direct lightning strike. Most antennas on hilltops and tall buildings have them. They take lightning strikes routinely. Here's some ARRL material on lightning protection.[1] It's not difficult, but it's not miniature. A classic design was a soup-can sized device with a coax connector on each end and a hulking big ground connection on the can. Inside was a spark gap wi…

Well, Howdy!

I'm a licensed radio amateur since 1996, I've spent about 20 years working in the cellular/telecom/two way radio industry, and I've done Motorola R56 inspections (as well as other proprietary grounding standards).

I respectfully disagree, a direct lightning strike almost certainly will take out gear at a cell site, even when properly grounded. Similarly a direct strike to telco cable will certainly fuse the 16-20ga wire in the cable itself at the first point its near a ground. Carbons, Glass Tubes, and other similar hardware will protect you in the event of a nearby strike (like to a lightning rod on a tower, or building) - but wont save you if the infrastructure is struck itself.

Generally the point of lightning protection systems is to well ground the tower, to draw the lightening away - so the tower and grounding system can protect the equipment - that isn't a direct strike by what I'm saying here - a direct strike would be if it struck the antenna itself.

Thats the perspective I have from cleaning up from strikes at well grounded and protected tower sites.

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

#157

Post by jleahy »

oasisbob wrote: post #154
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…

> 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. Mmm. This brings back memories of running private DSLAMs in a campus environment as a transitional pre-Ethernet stopgap in the early 2000s. 95% of the DSL lines worked great. The remaining 5% were a never-end…

I actually ran a private DSLAM to get internet between upstairs and downstairs in my house only a few years ago (not a joke, G.fast).

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

#158

Post by bayindirh »

Aloha wrote: post #150
GreyStache wrote: post #147

Earlier quoted context omitted.

Regarding the termination: our local fiber provider handles the termination with some optical precision connector (forgot the name). Both to the sunken-in-sidewalk multiplexer and in the home to the optical termination point (both gpon). So for mass deployments fiber connections do not require fibre welds are not required. I have to see it play out in practice and I'm not a fan of the idea that one telco controls con…

I'm still a fan for cost reasons of FTTN, because I think with Coax in the last mile, you can deliver fantastic performance, so long as you're not also trying to delivery video too. Furthermore if you actually run Coax in duct for buried circuits, its easy to replace with fiber later.

Our telco converted all its infra to FTTN via fiber. So, I've actually have fiber connection up to the front of my building, then it's terminated and distributed via VDSL to the street.

I have a 50/8 mbps connection at home and, it gives all the performance it can give. The telco keeps the speeds a bit higher to handle VDSL overhead, so we have a real 50/8 mbps IP connection at premises.

I'd rather not rewire my home and use existing equipment (which can handle 350mpbs), rather than bringing in fragile fiber into the home.

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

#160

Post by madengr »

superkuh wrote: post #100

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.

Yeah, I did some EM simulations of that years ago when I read about it. Shame it never took off. The balloon tether is really cool.

http://www.corridor.biz/

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