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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

#161

Post by Animats »

Aloha wrote: post #156
Animats wrote: post #153

Earlier quoted context omitted.

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…

Yes, few antennas really need to remain operational against direct hits. Nor do they usually need to be the highest thing on the tower.

Data cables aren't usually up that high, fortunately. Power cables, though, are. In some areas high tension towers carry a ground wire between the peaks of the towers for lightning protection. It's impressive to see those systems take repeated direct hits without the lights even flickering. I've seen that in Florida.

Worst case is probably is an AM broadcast station where the tower is isolated from the ground at the base. WSM in Nashville TN is like that. They had a pipe ground vaporized and windows blown out in a lightning strike in December 2019. They lost the tower lighting and some transmission components were damaged, but they apparently stayed on the air.

The Empire State Building takes about 25 lightning hits a year. I wonder what their lightning protection looks like.

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

#162

Post by neilalexander »

Unless you absolutely need to go 1 kilometre specifically, what are the advantages to this over using G.hn? On shorter runs G.hn will go anything up to 1.8Gbps and will still manage well over 100Mbps on anything up to about 700-800 metres. Even better/further with coaxial instead of twisted pair.

I’ve been using a pair of GIGA Copper G4201TMs to take advantage of twisted pair wiring at home rather than having to rip it out and it also appears more cost-effective: https://www.gigacopper.net/web/en/ghn_faq_en.html

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

#163

Post by superkuh »

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.

madengr responded with a completely on topic link to a surface wave transmission line start-up. But it looks like that comment, and 2/3 of their other on-topic posts are getting grayed out [dead]. I don't think they know.

madngr: your account my be shadowbanned and only viewable by those like me that show dead posts.

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

#164

Post by gorkish »

xhrpost wrote: post #49
trollied wrote: post #40

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...

There's also Ethernet over barbed wire: http://www.sigcon.com/Pubs/edn/SoGoodBarbedWire.htm

Back in the day I ran X.25 over an actual barbed wire fence for a customer. It connected a serial terminal in a field house at a local feedyard back to their SCO box in the main office. Probably about 1500 feet. It was reliable!

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

#165

Post by serf »

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/

>Al Gore never claimed that, btw,

GORE: “During my service in the United States Congress, I took the initiative in creating the Internet. I took the initiative in moving forward a whole range of initiatives that have proven to be important to our country’s economic growth and environmental protection, improvements in our educational system.”

There are three ways to read the first sentence, two of which take the presumption that Al Gore invented the internet.

Snopes is so half-wrong that it's getting to be easy to ignore.

In other words , he did say that, he just didn't mean for people to interpret his ambiguous statement in that fashion.

aside : the word of the day is initiative.

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

#166

Post by zokier »

baybal2 wrote: post #37
hericium wrote: 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.

DSL and 10BASE-T1L are not quote the same. 10BASE-T1L PHY fits on a single chip, without much of analog trickery, and the whole line encoding, signal processing is much simpler. 10BASE-T1L is what will go into 1 dollar devices, not a $100 modem.

> 10BASE-T1L is what will go into 1 dollar devices, not a $100 modem.

Which is why this $150 media converter product feels bit baffling tbh.

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

#167

Post by mbarras_ing »

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…

Dr Z! I've recently started at Tunstall Healthcare and you are frequently referenced when refering to SPE. I'm the first person they've had working full time on SPE, so hoping to make some progress :)

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

#168

Post by zakki »

Youden wrote: post #55
vicek22 wrote: post #43

- 1km of fiber optic cable - https://www.amazon.com/Jeirdus-Launch-Singlemode-Measuring-O... - 1Gb modem - https://www.amazon.com/TP-Link-Ethernet-Converter-Multi-Mode... The price for two modems and the cable is just under $120

You linked unterminated single-mode fiber and a dual-fiber multi-mode media converter, you can't actually use these together. You need something more like this: - Terminated single-mode fiber: https://www.fs.com/products/74355.html?attribute=255&id=3029... - 2x SFP transceivers: https://www.fs.com/products/75335.html - 2x media converters (or NICs): https://www.fs.com/products/96396.html The price is over $200.

If you look closely in the parent’s fiber product photo (last picture), the seller providing the connector for free.

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

#169

Post by rodgerd »

Aloha wrote: post #138
repiret wrote: post #135

Earlier quoted context omitted.

Last summer the local cable company replaced all their cables in town in order to begin offering digital cable and internet service. I was flabbergasted that they they spent all that money on linemen but still ran coax rather than fiber. As far as I can tell talking to their linemen, its not even FTTN, just FTT-central-office. Assuming its not run by morons, which I'll accept is a bit of a stretch for a cable company…

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.

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

#170

Post by hinkley »

hericium wrote: 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.

As long as you weren't stringing those cables off of rooftops. I heard too many stories of lightning strikes burning out a lot of expensive equipment.
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