Re:SpaceX FCC Application for over 4000 Internet Satellites
by walrus01 on Thursday November 17, 2016 @05:03PM
(#12982148)
> The Ka/Ku links are only for the initial uplink and downlink.
Then there's a huge bottleneck, if the links from the satellite constellation as a whole to the trunk earth stations (not the CPEs) are high capacity Ka-band, there's RF issues with capacity...
It's like if you have a network that's composed of a whole lot of 10GbE backbone links from router to router and your IP transit connection to upstream ISPs/the global v4/v6 routing table goes through one 1000BaseLX link.
Re:SpaceX FCC Application for over 4000 Internet Satellites
by jasonwatkinspdx on Wednesday November 23, 2016 @04:34PM
(#13025975)
No, it's nothing like that. They're talking about highly localized signals via phased arrays on both sides. Additionally you underestimate the capacity of wireless: LTE has no problem doing 30 bits per 1 hz of spectrum. These will run at a lot more than a 1 gbit globally shared last mile.
The filing states they'll be using free space optics / lasers between satellites. The Ka/Ku links are only for the initial uplink and downlink.
> But it's a pipe dream to say that satellite backhaul will ever be preferable to fiber carrying N x 10GbE circuits or a 100GbE circuit...
It is not a pipe dream. Free space optics in... well space, have a 50% propagation latency advantage vs terrestrial fiber. This helps equalize things somewhat.