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ADSL works over wet string (2017)

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Re: ADSL works over wet string (2017)

#101

Post by stefan_ »

kazen44 wrote: post #99
oasisbob wrote: post #89

Earlier quoted context omitted.

Fiber may be simple, but the way we use it is not. Unlike copper, a GPON fiber install is going to have active electronics and splice trays for every several dozen subscribers. Plenty of opportunities for water ingress to still cause problems.

Also, sending a singal across fiber is definitely not easy. ADSL is basically modulating a radio wave over a cable directly to another device. Fiber requires high quality optics, high quality lasers, tons of active hardware if you want to do it at scale. (not to mention the mind boggling physics and manufacturing required for things like DWDM, optical path switching etc). Fiber optics have existed since the 80's yes,…

Exactly. That all sounds infinitely easier than buried air pipes. Mind boggling physics are what gives us CPUs, but the final product is reliable bar none.

Re: ADSL works over wet string (2017)

#102

Post by zaphirplane »

DaiPlusPlus wrote: post #45
giardini wrote: post #23

ADSL, being essentially a form of alternating current, will pass through an air gap. I was enlightened on this by an AT&T tech who pointed out that one of my ADSL lines had several breaks and could not carry DC but the ADSL signal still came through. The other line was dead so I was running essentially on one wire with an earth ground. Here is an interesting discussion: "Phone line with 1 broken wire still gets ADSL2…

> Anyway, my hat is off to the people who designed and implemented ADSL. It's a blessing-and-a-curse: too many incumbent ISPs in highly-developed nations used ADSL's ability to run on anything as an excuse to put-off FTTH deployments (looking at you, BT).

In hind sight wouldn’t 5g have been a better investment than fiber to home, I mean companies will have to have 5g to stay competitive in mobile anyway

Re: ADSL works over wet string (2017)

#103

Post by NavinF »

kazen44 wrote: post #99
oasisbob wrote: post #89

Earlier quoted context omitted.

Fiber may be simple, but the way we use it is not. Unlike copper, a GPON fiber install is going to have active electronics and splice trays for every several dozen subscribers. Plenty of opportunities for water ingress to still cause problems.

Also, sending a singal across fiber is definitely not easy. ADSL is basically modulating a radio wave over a cable directly to another device. Fiber requires high quality optics, high quality lasers, tons of active hardware if you want to do it at scale. (not to mention the mind boggling physics and manufacturing required for things like DWDM, optical path switching etc). Fiber optics have existed since the 80's yes,…

Meh. Fiber has been cheaper than copper per mile for a long time and 10km optics are like $20.

Re: ADSL works over wet string (2017)

#104

Post by kube-system »

spookthesunset wrote: post #92
xattt wrote: post #57

Earlier quoted context omitted.

Many parts of rural Prince Edward Island (PEI) has DSL running on a phone system that’s probably original from modernization initiatives in the 1960s - 1980s. Party lines were the norm in some areas up west until late-1980s.

Back when a whole family had the same number and you had to ask whoever answered that you want to talk to so and so. Now days everybody has their own number and with caller id you (sometimes) know who is calling. My daughter is gonna grow up not knowing any of the “shared phone line” etiquette because it is largely obsolete.

A party line is not when "a" whole family shares a line, it's when several separate houses share a line.

Re: ADSL works over wet string (2017)

#105

Post by leoedin »

Terry_Roll wrote: post #94
hereforphone wrote: post #86

Earlier quoted context omitted.

What's DC? "Radio stations" communicate via alternating quantities (EM waves)

The telephone cable coming into the house is 50volts DC is not AC like a powerline. I know radio waves are just that, waves, its how things like noise cancelling headphones work. Different frequency's give you different ranges or distances for 1 watt, which is why you can bounce Long wave around the planet.

Radio waves down a wire are by definition AC. Otherwise they don't work. The voltage must change, thus the current must change, thus it is AC. Just because it's not 50/60Hz AC like a powerline doesn't change that.

There might be a DC component, but ultimately all the ADSL modem cares about is the AC part.

Re: ADSL works over wet string (2017)

#106

Post by xattt »

spookthesunset wrote: post #92
xattt wrote: post #57

Earlier quoted context omitted.

Many parts of rural Prince Edward Island (PEI) has DSL running on a phone system that’s probably original from modernization initiatives in the 1960s - 1980s. Party lines were the norm in some areas up west until late-1980s.

Back when a whole family had the same number and you had to ask whoever answered that you want to talk to so and so. Now days everybody has their own number and with caller id you (sometimes) know who is calling. My daughter is gonna grow up not knowing any of the “shared phone line” etiquette because it is largely obsolete.

The party lines I’m talking about are shared loops between a group of residents in a rural area.

Some of the first-hand accounts I’ve read talked about neighbours listening in on conversations. People could tell a snooper was on the line because the volume of the other caller would drop. There was a social aspect to the whole enterprise because you could tell the one nosy neighbour to get off the line and the volume would magically raise.

(1) http://www.islandregister.com/phones/partyline.html

Re: ADSL works over wet string (2017)

#107

Post by martyvis »

Suchos wrote: post #42
joncrocks wrote: post #26

Earlier quoted context omitted.

joking aside, I remember a while back that there has at least been cursory investigation into running high-speed internet cables through water pipes. Presuming you have water pipes to your property, could be easier than digging up roads etc. Only issue might be if you have a leak and need to shut off your water!! https://www.theguardian.com/technology/2021/aug/09/uk-launch...

There is company in Czechia which provides optics via sewage. I guess it is cheaper to use existing infrastructure than to place new pipes under roads.

Sounds a bit like this "How TiSP Works" https://archive.google.com/tisp/install.html

Re: ADSL works over wet string (2017)

#108

Post by Terry_Roll »

Terry_Roll wrote: post #94
hereforphone wrote: post #86

Earlier quoted context omitted.

What's DC? "Radio stations" communicate via alternating quantities (EM waves)

The telephone cable coming into the house is 50volts DC is not AC like a powerline. I know radio waves are just that, waves, its how things like noise cancelling headphones work. Different frequency's give you different ranges or distances for 1 watt, which is why you can bounce Long wave around the planet.

I wasnt taught that radio waves were to be considered identical to AC power down a cable but when thinking about it, they probably are identical with waveform properties and the difference being the medium they are travelling through.

Re: ADSL works over wet string (2017)

#109

Post by charcircuit »

mattlondon wrote: post #93
samwillis wrote: post #61

Earlier quoted context omitted.

I think we (in Stamford Lincolnshire, UK) must be pretty unique right now with TWO competing FTTP startups both rolling out on the same streets. One day you will see Lightspeed Broadband pulling their fibre through the BT ducts and putting boxes on the top of telegraph polls. The next day Upp Brordband will be on the same street. So bizarre they they are doing the same town! Apparently we are due to have BT put in th…

Here in high-density London, we're stuck with ~70mbps ADSL and not even cable. Not representative of all of London, but at least around my parts it is slow ADSL or nothing :(

Are you suggesting 70Mbps is slow ADSL? There are many places where not even a tenth of that speed is possible.

Re: ADSL works over wet string (2017)

#110

Post by 867-5309 »

charcircuit wrote: post #109
mattlondon wrote: post #93

Earlier quoted context omitted.

Here in high-density London, we're stuck with ~70mbps ADSL and not even cable. Not representative of all of London, but at least around my parts it is slow ADSL or nothing :(

Are you suggesting 70Mbps is slow ADSL? There are many places where not even a tenth of that speed is possible.

it's the UK average for urban ADSL. and those many places are where the FTTH startups are springing up
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