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Won't they be at low enough altitude that they'll need more hops than fiber to get around the globe, where each hop adds at least some delay?



Not sure what you mean by "hops" here? The current beta sats mostly act as "bent pipes", where they relay directly between user terminals and ground stations which then go to out to the regular net from there. But the final deployment sats are intended to have free space optical links between satellites (these are currently deployed and testing on the most recent polar orbit ones), so a connection can go entirely through the mesh in space until it reaches the nearest physical ground station (probably with some weighting for congestion and priority of course). The orbital RTT penalty will only be paid once, and with tens of thousands of sats the optical route will actually be much more direct for many people when crossing oceans than going through whatever undersea fiber links there are. Compared to regular fiber, final Starlink will definitely win on latency over sufficient distances.

But Starlink will never match the bandwidth and reliability that fiber can do, nor is it meant to. So it's not a replacement, just another awesome option.


Also just to run the math on an example for "actually be much more direct for many people when crossing oceans": say someone is somewhere on the southern coast of Alaska, be it more towards King's Cove or back towards Newhalen, and want to talk to someone in Sapporo Japan. As the bird flies that's something like a 2500-3000 mile distance. But in practice there is no undersea cable direct linking Alaska and Asia (unless that's changed in the last year or two). Instead a connection probably has to go to Anchorage, then to Seattle, then probably to Tokyo, and then out to the rest of Japan from there. This could easily turn a 2500 mile path into a 7300 mile path. Starlink satellites in the current plan AFAIK are going to heavily be in shells 214 to 350 miles high (including Ku/Ka band current ones and future V-band ones). At 350 mi orbit, so maybe a 700-1000 mile up/down penalty, total distance could still be half the cable distance in this example, even before latency advantages.


When you're traveling at the full speed of light in vacuum, compared to 2/3rds in fiber, even a few extra hops can leave you with significantly lower latency.


Right, if they are using standard OTN framing, the hop latency should be ~3 microsecond (which is <1km of light propogation)




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