6 ms·

For land based: 1. First thing to understand - bandwidth is cheap. 1MBps continuous is well under 25 cents for an ISP at this point. They do have to have the n

For land based: 1. First thing to understand - bandwidth is cheap. 1MBps continuous is well under 25 cents for an ISP at this point. They do have to have the network to get it to your home however. 2. Over-subscription of the link is not only usual, it is standard practice. A passive splitter setup might have 32 or 64 or more customers on it - all of whom share 1, 1Gbps link on what is basically a fancy Ethernet switch. As this equipment gets upgraded, they will be able to share 10Gbps amongst 64 or 128 customers. If there are data caps, they are there either to sell you something higher-priced later or else to cover up for their over-subscription. For StarLink, it of course depends on their setup - is there enough public information to determine what their bandwidth really is between all the different parts of their network?

pencilguin 4y ago
https://xkcd.com/1656/ https://xkcd.com/1656/ Seriously, though, they are probably compensating for failure to get the "can" launching system (aka "starship") online that would enable lofting new higher bandwidth satellites. The cans would have more and, more importantly, bigger payload. If it takes too long to get the can going, they could probably shift to Falcon Heavy and a bigger shroud. But without the can, it costs too much to operate, steady-state. Starlink is pretty severely limited on aggregate bandwidth. They could do a lot to mitigate this by coming up with ways to deliver the hottest realtime streams (e.g. World Cup) via a broadcast protocol, and to partner with Akamai etc. to cache a few hundred TB of other content aloft, to save on uplink bandwidth. Capping is easier.
- ftth_finland 4y ago
  It’s really hard to cache content pre-emptively. Netflix uses multiple Gbps per cache node during off hours to refresh content in order to get decent hit rates. And Netflix is just one service with a limited content library.
  - pencilguin 4y ago
    The laser links between satellites may be much less burdened than the uplink from the ground hub station nearest to the subscriber. SpaceX can upload content to the constellation via more-lightly loaded ground hubs, and propagate to the rest. They have the advantage that they can know what was being streamed in an area a satellite is about to enter, and can preload the parts it will need to downlink while there. Of course all this requires intimate cooperation with the streaming service, because it is at a much higher level than packets.
ftth_finland 4y ago
Minor nitpick: GPON is 2.5G/1G, not 1G/1G, and use 10G uplinks, but the basic point stands. Also, when upgrading to 10G PON, split ratios aren’t usually increased, but kept at the same 1:32. Wholesale bandwidth is less than 5 cents per Mbps, and that’s for bandwidth you have to pay for. Settlement free peering and content caches (like Netflix uses) are free of usage fees. This can account for up to 80% of traffic.

pencilguin 4y ago

https://xkcd.com/1656/ https://xkcd.com/1656/ Seriously, though, they are probably compensating for failure to get the "can" launching system (aka "starship") online that would enable lofting new higher bandwidth satellites. The cans would have more and, more importantly, bigger payload. If it takes too long to get the can going, they could probably shift to Falcon Heavy and a bigger shroud. But without the can, it costs too much to operate, steady-state. Starlink is pretty severely limited on aggregate bandwidth. They could do a lot to mitigate this by coming up with ways to deliver the hottest realtime streams (e.g. World Cup) via a broadcast protocol, and to partner with Akamai etc. to cache a few hundred TB of other content aloft, to save on uplink bandwidth. Capping is easier.

ftth_finland 4y ago
It’s really hard to cache content pre-emptively. Netflix uses multiple Gbps per cache node during off hours to refresh content in order to get decent hit rates. And Netflix is just one service with a limited content library.
- pencilguin 4y ago
  The laser links between satellites may be much less burdened than the uplink from the ground hub station nearest to the subscriber. SpaceX can upload content to the constellation via more-lightly loaded ground hubs, and propagate to the rest. They have the advantage that they can know what was being streamed in an area a satellite is about to enter, and can preload the parts it will need to downlink while there. Of course all this requires intimate cooperation with the streaming service, because it is at a much higher level than packets.

ftth_finland 4y ago

Minor nitpick: GPON is 2.5G/1G, not 1G/1G, and use 10G uplinks, but the basic point stands. Also, when upgrading to 10G PON, split ratios aren’t usually increased, but kept at the same 1:32. Wholesale bandwidth is less than 5 cents per Mbps, and that’s for bandwidth you have to pay for. Settlement free peering and content caches (like Netflix uses) are free of usage fees. This can account for up to 80% of traffic.