3 ms·

That doesn't seem right. Napkin math: GEO Satellite is 22,236 miles above sea level[1]. Speed of light is 186,282 miles per second[2]. Therefore the absolute

by umvi 8y ago

That doesn't seem right. Napkin math: GEO Satellite is 22,236 miles above sea level[1]. Speed of light is 186,282 miles per second[2]. Therefore the absolute fastest information could travel on a GEO network is 22236/186282 = 119 milliseconds (one way at the speed of light), which is 238 ms round trip. In reality there are going to be internal and network latencies so I would expect something more like ~300-500ms RTT. [1] https://en.wikipedia.org/wiki/Geosynchronous_orbit https://en.wikipedia.org/wiki/Geosynchronous_orbit [2] https://en.wikipedia.org/wiki/Speed_of_light https://en.wikipedia.org/wiki/Speed_of_light

shaklee3 8y ago
That's right. Geo will typically be around 600ms. The speed metric is incorrect/misleading as well. Both Hughes and ViaSat offer multiple speed plans that are vastly different. You can't simply take an average, or your speed isn't representative of what the service could do. Of course, satellite internet will pack a lot of users in there to fill up the satellite. I don't be naive about that, SpaceX will do the exact same thing.
- studentrob 8y ago
  > You can't simply take an average, or your speed isn't representative of what the service could do. Why not? We're just comparing current satellite broadband offerings' known latency to what Starlink could potentially offer.
  - shaklee3 8y ago
    If your cable service offers 10, 25, 50, and 100Mbps plans, how is an average speed at all meaningful? It's just representative of how many people sign up per plan.
    - studentrob 8y ago
      An existing offering does 60ms average, meaning its best case is better. Starlink would offer 25ms best-case scenario.
      - shaklee3 8y ago
        My post is clearly about bandwidth, not latency. You don't choose your latency.
studentrob 8y ago
> That doesn't seem right. broadbandnow.com is a legit site that tracks internet providers and speeds by aggregating data.
- umvi 8y ago
  Yeah but... it's claiming information can travel faster than light... It must be averaging in terrestrial network latencies or something, because GEO satellites are literally hundreds of light-milliseconds away from earth

by umvi 8y ago

shaklee3 8y ago

That's right. Geo will typically be around 600ms. The speed metric is incorrect/misleading as well. Both Hughes and ViaSat offer multiple speed plans that are vastly different. You can't simply take an average, or your speed isn't representative of what the service could do. Of course, satellite internet will pack a lot of users in there to fill up the satellite. I don't be naive about that, SpaceX will do the exact same thing.

studentrob 8y ago
> You can't simply take an average, or your speed isn't representative of what the service could do. Why not? We're just comparing current satellite broadband offerings' known latency to what Starlink could potentially offer.
- shaklee3 8y ago
  If your cable service offers 10, 25, 50, and 100Mbps plans, how is an average speed at all meaningful? It's just representative of how many people sign up per plan.
  - studentrob 8y ago
    An existing offering does 60ms average, meaning its best case is better. Starlink would offer 25ms best-case scenario.
    - shaklee3 8y ago
      My post is clearly about bandwidth, not latency. You don't choose your latency.

studentrob 8y ago

> That doesn't seem right. broadbandnow.com is a legit site that tracks internet providers and speeds by aggregating data.

umvi 8y ago
Yeah but... it's claiming information can travel faster than light... It must be averaging in terrestrial network latencies or something, because GEO satellites are literally hundreds of light-milliseconds away from earth