mrl515's recent activity
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Comment on The hidden world of undersea cables in ~tech
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Comment on The hidden world of undersea cables in ~tech
mrl515 LinkI work in the subsea optical transport space, and frustratingly the author falls victim to the same false notion that sharks have ever 'attacked' cables. Don't get me wrong, it's silly, but it...I work in the subsea optical transport space, and frustratingly the author falls victim to the same false notion that sharks have ever 'attacked' cables. Don't get me wrong, it's silly, but it shows a lack of attention to detail on the subject (one of the top comments on the embedded video debunks this immediately)--one which is genuinely fascinating given how little many people know about just how information is physically exchanged around the world. It's a dumb thing to get worked up over, I'll concede, but if the author is going to educate people on the matter they could at least fact check this bizarre claim. Cables are armored for a myriad of reasons outside of shark bites. The rest of the piece is interesting enough, and I highly recommend folks look into the coherent optical systems that transmit data over these cables (and all long haul terrestrial cables) if they're more curious about how the optical layer of the world's networks really function.
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Comment on Alabama's Nick Saban retiring after seven national titles, most in major college football history in ~sports.american_football
mrl515 (edited )Link ParentAs someone who attended the University of Alabama (from out of state, though not far off) during coach Saban's tenure, it's difficult to describe--even having witnessed it live--the impact he's...As someone who attended the University of Alabama (from out of state, though not far off) during coach Saban's tenure, it's difficult to describe--even having witnessed it live--the impact he's had not just on the sport, but the University itself, the city of Tuscaloosa, and the lives of countless people like me who would not have attended Alabama if not for the indirect effects he had on the school.
The amount of new construction that occurred before I got to campus, while I was there for my degrees, and after I left, cannot be overstated. Chancellor Whit, a former chancellor of the school and one of the folks in charge when Saban was brought in gave a talk to my graduate school cohort and estimated the financial impact of this one man's hiring to have had a billion+ dollar impact on the school and surrounding community.
It's hard to believe that a person I've never even met (though I did get to stand next to him by merit of being in the marching band, which was cool) has had such an outsized but traceable impact on my life and the lives of so many others.
I'll take a stab at it, sure! So the amplifiers used in subsea cables are called repeaters, which is a bit of a misnomer as they don't regenerate the signal, but what they do (besides power monitoring as these systems are far more sensitive than terrestrial) is match the total output power along the cable at regular intervals and along each individual fiber pair (as that can vary from pair to pair depending on potential use of different modulation schemes/transmission modes to support different client types), which allows for very minimal noise gain due to tighter component tolerance and better power monitoring than what is used in standard EDFAs terrestrially.
Additionally, relative to the signal to noise ratio, what is often done for subsea is that for a coherent transponder that might be capable of running at 1.6Tbps, it will be tuned down to maybe 1.4T or 1.3T to allow FEC to better overcome the total noise on the system. This is done in terrestrial applications too for long haul but is extremely prevalent for long subsea reaches.
Raman amplification is only typically used on short subsea links that are closer to terrestrial deployments than the subsea links I'm talking about.