Thread

1. yanis_t · 1790247676 · focus · HN ↗

   For anyone interested, there’s another part of the Starlink besides the satellites and your dish - ground stations (gateways) [].

   These are the large clusters of antennas that communicate with the satellites and connect the Starlink network to the Internet on Earth. Looks like one of these was set on fire.

   <a href="https:&#x2F;&#x2F;starlink.com&#x2F;support&#x2F;article&#x2F;45d1d256-171e-0f67-4895-5d248fa63b66" rel="nofollow">https:&#x2F;&#x2F;starlink.com&#x2F;support&#x2F;article&#x2F;45d1d256-171e-0f67-4895...

   1. kamranjon · 1790248317 · focus · HN ↗

      Huh… I always thought direct satellite connection was one of the things that distinguished starlink from cellular tech like 4g or 5g, and that low earth orbit was what made it possible… what actually makes starlink different?

      Edit: oh I think? I understand now, these basically relay the internet itself up to the satellites - so your individual starlink dish is still talking directly to a satellite but the satellite resolves your request for a website through these ground stations. I think?

      1. mbreese · 1790251140 · focus · HN ↗

         All satellite based internet access works the same way… (mostly)

         1) you send a signal to the satellite

         2) the satellite relays the signal down to a ground station

         3) from here your packets go out on the Internet like any other ISP

         The answer then goes in reverse: back to the ground station, up to the satellite and down to your dish.

         Starlink’s special sauce is the low earth orbit. Older satellite internet companies operated in geosynchronous orbit. This meant they only needed one or two satellites to cover a large area. You also only needed a small number of ground stations. The satellite needs to be able to see your dish and the ground station at the same time. But this is very high up, so latency was horrible (the distance up and down before the packet even hits the internet). Bandwidth was also limited, but much less of an issue.

         With low earth orbits, you have great latency. But, because you still need to be able to see the ground station and the customer’s dish, this means that you need more ground stations. This is just geometry.

         Starlink adds one more feature that is relevant here - direct satellite to satellite communication. Instead of the signal going from:

         Customer - satellite - ground station - internet

         The signal can go from:

         customer - satellite A - satellite B - ground station - internet.

         This later setup might be what you were thinking about. You still want to limit the number of hops from satellite to satellite you have (latency again), but this should make the service more resilient to the loss of a single ground station.

         1. lxgr · 1790256537 · focus · HN ↗

            &gt; Starlink’s special sauce is the low earth orbit.

            Arguably Starlink&#x27;s special sauce is quantity of satellites and massively higher bandwidths combined with high-gain, electronically steered beams on both sides (i.e. terminal and satellite).

            None of these are net-new as technologies: We&#x27;ve had LEO based telecommunications satellites for over two decades now (Iridium and Globalstar, the former of which even has in-space forwarding as well), as well as directional beams on both sides, but rarely all in one system and never at this scale.

            1. mbreese · 1790266345 · focus · HN ↗

               In my opinion, the quantity of satellites needed is a function of the height of the satellites. You only need a large constellation because they are moving so fast relative to the earth. This means that each satellite can only see a limited arc at a time. So, in order to cover a large enough area, you have to have multiple satellites following after each other.

               The phased array antenna is also a function of this. Each satellite is moving so much that you need to have an antenna following the satellite across the sky.

               So, once Starlink decided to have a low earth orbiting constellation (for better latency and bandwidth), the other features (quantity and a steerable antenna) became requirements to have a functional system.

               1. lxgr · 1790270542 · focus · HN ↗

                  Altitude does impose a lower bound for the number required for global coverage but they have much, much more than geometrically needed. Iridium gets by with about 70 and is only marginally higher.

                  As for steered terminals, you actually only really need these once you have more than one satellite visible in the sky at the same time. Without that, they’re purely a power efficiency feature.

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