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LazMan
Premium
join:2003-03-26
canada

3 recommendations

Long-Haul Fibre Amp site

Was out in the field doing some work the other day, and took a few pictures...

This is an amplifier site for a long-haul (total distance for this system, terminal to terminal is about 1500 km). There's about 240 Gbps passing through; 16 x 10 gig on one system, 2 x 40 gig on the other... This system follows a rail-line across country; and the huts are in some pretty remote locations. This one isn't actually too bad to get to; but it is still about 300km north of Toronto.

Old system is limited to 10 gig channels, 'new' system is good for up to 100 gig per channel (although we're only running at 40 right now...)

Self contained, there's HVAC, fire control, a small DC plant with batteries, fibre splice panels, and the actual equipment, in a 10x15 room...

There's an amp site every 60-100km, every 5th amp site is a regenerator, where the wavelengths are dropped out, cleaned up, and re-mux'd, to keep the SnR within acceptable limits.


Remote huts

Door, looking in


Powerplant

Old transport system


Multi-wave amp

Dispersion Comp


New Transport system


GM85
Click, Click

join:2002-07-02
London, ON

Thanks a lot for posting this, it's really interesting so see some of the larger-end equipment that is in place.



TomS_
Git-r-done
Premium,MVM
join:2002-07-19
London, UK
kudos:5
reply to LazMan

Always amazing to see how much smaller new equipment is compared to older equipment.

Also is it just me, or does ~500km seems really short for needing to re-gen 10g waves?

Ive heard of 100g waves being able to go 1500km or so before needing re-gen.



LazMan
Premium
join:2003-03-26
canada
reply to LazMan

Tom - the old system is ~15 year old technology... Fibre quality was a LOT lower back then, hence the need for re-generators so often. We've stretched some spans to 7 amps between regen - but that's about as far as we can go, with the cable that's in the ground.



zed173

join:2010-07-17
Mississauga, ON

said by LazMan:

Fibre quality was a LOT lower back then, hence the need for re-generators so often. We've stretched some spans to 7 amps between regen - but that's about as far as we can go, with the cable that's in the ground.

Yup, I remember sitting on a conference call with the CN splicers overnight several years ago while they were cutting over the cables to the other side of the ROW through Burlington (making way for new track construction primarily for Go Trains). Took forever because the fibers in the FOSCs kept breaking due to the glass/splices were so brittle because they had been there for so long. Good times


TomS_
Git-r-done
Premium,MVM
join:2002-07-19
London, UK
kudos:5
reply to LazMan

So I guess that fibre was put in with a different technology era (like lower speed SDH/SONET), and running 10G over it is just pushing it as far as possible?

I guess that would make sense.



LazMan
Premium
join:2003-03-26
canada
reply to LazMan

When most of this route was built, 2.5 gig/oc-48 was the latest and greatest... That 40 and 100 gig wavelengths pass cleanly was a surprise to some of our engineers...



battleop

join:2005-09-28
00000

1 recommendation

reply to zed173

You must be mistaken. According to DSLR only copper can degrade and fiber has an indefinite lifespan. It's simply not possible for older fiber to be brittle because of age.

* For those who didn't get it that's a little sarcasm and not a post directed at anyone who has posted in this thread.
--
I do not, have not, and will not work for AT&T/Comcast/Verizon/Charter or similar sized company.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
reply to LazMan

said by LazMan:

When most of this route was built, 2.5 gig/oc-48 was the latest and greatest... That 40 and 100 gig wavelengths pass cleanly was a surprise to some of our engineers...

I think optical frequency stays same as 10G but the new gear transmits using QPSK modulation in both polarizations (DP-QPSK) to carry 4 bits instead of just 1 bit per period.

I get a bit sad seeing the Nortel logo. I worked there in the 1990s before the big bust.



LazMan
Premium
join:2003-03-26
canada

The spacing between wavelengths is tighter on the new gear; the reduced seperation means less tolerance to dispersion in the glass...

And fibre certainly does degrade over time; it becomes more brittle... The optical qualities don't change dramatically, but it does become less forgiving for splicing.



GM85
Click, Click

join:2002-07-02
London, ON

said by LazMan:

And fibre certainly does degrade over time; it becomes more brittle... The optical qualities don't change dramatically, but it does become less forgiving for splicing.

Never realized that (although it makes sense). Back in June we had fibre line installed to our office building and part of the process involved splicing into a 16 year-old fibre line that existed in our complex.

The fibre techs didn't have any issues with splicing the pairs together. However, a lack of documentation meant they had to be re-spliced in 2 locations since the pairs didn't match up (guess that's what happens when a line passes through 5 service provider acquisitions over the years).

Hahausuck
Premium
join:2003-12-14
kudos:2
reply to lutful

Then you'd probably cry if I posted some photos I've taken recently of some old Nortel BTSs. Big brown ones. They've obviously been turned down and abandoned in place for "newer" S8000's.

I have a feeling those will be turned down and removed in the near future as well, in favor of newer technology.
--
"Above all, I would teach him to tell the truth. Truth-telling, I have found, is the key to responsible citizenship. The thousands of criminals I have seen in 40 years of law enforcement have had one thing in common: Every single one was a liar."
J.E.H.



pstewart
Premium,VIP
join:2005-10-12
Peterborough, ON
kudos:1
reply to LazMan

Just curious that you use in these remote sites for fire suppression? Thanks



LazMan
Premium
join:2003-03-26
canada
reply to LazMan

"Clean" gas systems... Either InerGen or FM-200; typically.


cooldude9919

join:2000-05-29
kudos:5
reply to zed173

said by zed173:

said by LazMan:

Fibre quality was a LOT lower back then, hence the need for re-generators so often. We've stretched some spans to 7 amps between regen - but that's about as far as we can go, with the cable that's in the ground.

Yup, I remember sitting on a conference call with the CN splicers overnight several years ago while they were cutting over the cables to the other side of the ROW through Burlington (making way for new track construction primarily for Go Trains). Took forever because the fibers in the FOSCs kept breaking due to the glass/splices were so brittle because they had been there for so long. Good times

Ive seen this same thing first hand. We are on an older sonet ring with ATT at our office that was put back in the late 90's early 2000s. They where updating some fiber paths in the area and wanted to redo some things so they came in after hours one night to do so. We had an old mechincal splice that they re did with a fusion splice. I think it took them 4 times before it took without the fiber cracking/breaking. You could obviously see it in the fusion splice screen, plus it would fail the loss test.