zlacker

>>alden5+(OP)
So that is "432 Mbit/s per laser, and 9000 lasers total". I don't know you guys but I find that statement much more relatable than "42 PB/day". Interestingly, they also say each laser "can sustain a 100Gbps connection per link" (although another part of the article even claims 200 Gbit/s). That means each laser is grossly underused on average, at 0.432% of its maximum capacity. Which makes sense since 100 Gbit/s is probably achievable in ideal situations (eg. 2 satellites very close to each other), so these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away and no longer are within line of sight of each other.

And with 2.3M customers, that's an average 1.7 Mbit/s per customer, or 550 GB per customer per month, which is kinda high. The average American internet user probably consumes less than 100 GB/month. (HN readers are probably outliers; I consume about 1 TB/month).

>>mrb+b46
>these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away

The way Starlink satellites are in orbit, the same satellites will remain "ahead" and "behind" you in the orbital plane. Those laser links (specifically!) will remain relatively persistent. This arrangement is similar to Iridium FYI.

FTA: "in some cases, the links can also be maintained for weeks at a time"

>>schiff+096
FTA: "in some cases, the links can also be maintained for weeks at a time"

I think there is a lot of variance. The article also states about 266,141 “laser acquisitions” per day, which, if every laser link stayed up for the exact same amount of time, with 9000 lasers, means the average link remains established for a little less than an hour: 9000 (lasers) / 266141 (daily acquisitions) * 24 * 60 = 49 minutes

So some links may stay established for weeks, but some only for a few minutes?

>>mrb+pa6
I would guess that the links between satellites on the same orbit stay for weeks, but the ones that cross between orbits have to constantly re-established.

>>jandre+Tf6
Correct.

I believe Starlink (like Iridium) doesn't even try to establish connections "across the seam," ie the one place the satellites in the adjacent plane are coming head on at orbital speed.

This make side-linking easier because the relative velocity is comparatively low, but in general you unavoidably still need to switch side-link satellites (on one side) twice per orbit. Hence 49 minutes: this average must be calculated per connection not per second, so the front/back links (plus random noise) count less, so it only drags the average from 45 minutes up to 49 minutes.

>>schiff+Oh6
I believe Starlink (like Iridium) doesn't even try to establish connections "across the seam," ie the one place the satellites in the adjacent plane are coming head on at orbital speed.

The slide showing the multiple possible paths traffic can take seems to disagree with this statement?

>>try_th+4Y7
Impossible to tell from the slide, because such a seam only occurs at one longitude, and moves over the day.

However looking at other sources, it seems Starlink (having more satellites) actually wraps the orbital planes 360° around the Earth (vs Iridium's minimalist 180° configuration), overlapping both North-moving and South-moving satellites in the same sky simultaneously. This means the Iridium seam disappears entirely. Neat! TIL.

Another problem that vanishes simply by being "hardware rich."