3 ms·

Any idea on up/down bandwidth?

kashkhan 12y ago
at any time 200 of the 700 will be above land and half of those over desert/tundra. so basically 100 sats will serve 1 Billion people. Assuming each can do 10Gbps that's 1Tbps divided by 1B. so average of 10kbps per terminal. which is enough for basic web, texting, twitter and voice. Won't be enough for netflix or torrenting.
- benjamincburns 12y ago
  I think that's a good lower bound, as it assumes no packet scheduling, and that everyone on Earth will be attempting to consume all the bandwidth available to them all of the time. It also assumes that the "backhaul" between satellites wouldn't saturate under such a load. I'd wager that under those assumed numbers you'd more realistically be able to expect somewhere between 100Kbps and 1Mbps.
  - kashkhan 12y ago
    the first problem is the evening peak when everyone tries to get on at the same time and watch netflix/youtube. The second problem is the link equation from your hemi antenna handset to the satellite 1000km away that passes by in 100s. Yes with packet scheduling you can get higher peak bandwidth, but 1Mbps sustained over the course of a 5 minute youtube video is going to be hard. It's much better to target the whatsapp crowd. That facebook will pay for.
    - mrfusion 12y ago
      Would some kind of caching help with this? I guess it doesn't do much good to cache data on a satellite? It still has to send it to each user?
callesgg 12y ago
Based on current technologys and their numbers 5 kb/s to 5mb/s based on usage. Current consumer technology gives 300b/s to too 500 kb/s Depending on how much you want to pay. *speeds in bytes not bits
- psykovsky 12y ago
  > *speeds in bytes not bits Then you should use the correct metric prefix, kBps, not kbps. It would save you from having to give unnecessary explanations.
  - 4ad 12y ago
    Surely you mean kB/s, not kBps. Nobody uses kBps because it's misleading. The question always boils down to kB/s vs. kbps. In this respect, your parent also unfortunately used kb/s, which is also a misleading and confusing unit. People really should be using only kB/s and baud.
    - psykovsky 12y ago
      Nobody and everybody are always exagerations when you talk about what people "use". The / means per, so it means exactly the same as the p. What's misleading about it as long as you capitalize the units correctly?
      - 4ad 12y ago
        The standard units, as in units defined by various international standards like ISQ are B/s and b/s. bps is defined to mean b/s. Note that there is no Bps in any ISQ standard. The only reason b/s has an bps alias is to reduce confusion. Greater hamming distance means less potential for confusion. Now you want to add the confusion back. Luckily, units are standardised by international bodies, not individuals, and the industry seems to be happy with the standards and uses them. Very seldom I have seen kBps (and in the few cases where I have seen it, it was wrong anyway). kb/s, while correct, I have only seen used by mistake, or by malice (e.g. ISPs intentionally misleading customers). Luckily, most professionals agree on only using B/s and bps, and no other combination, correct or not.

at any time 200 of the 700 will be above land and half of those over desert/tundra. so basically 100 sats will serve 1 Billion people. Assuming each can do 10Gbps that's 1Tbps divided by 1B. so average of 10kbps per terminal. which is enough for basic web, texting, twitter and voice. Won't be enough for netflix or torrenting.

benjamincburns 12y ago
I think that's a good lower bound, as it assumes no packet scheduling, and that everyone on Earth will be attempting to consume all the bandwidth available to them all of the time. It also assumes that the "backhaul" between satellites wouldn't saturate under such a load. I'd wager that under those assumed numbers you'd more realistically be able to expect somewhere between 100Kbps and 1Mbps.
- kashkhan 12y ago
  the first problem is the evening peak when everyone tries to get on at the same time and watch netflix/youtube. The second problem is the link equation from your hemi antenna handset to the satellite 1000km away that passes by in 100s. Yes with packet scheduling you can get higher peak bandwidth, but 1Mbps sustained over the course of a 5 minute youtube video is going to be hard. It's much better to target the whatsapp crowd. That facebook will pay for.
  - mrfusion 12y ago
    Would some kind of caching help with this? I guess it doesn't do much good to cache data on a satellite? It still has to send it to each user?

callesgg 12y ago

Based on current technologys and their numbers 5 kb/s to 5mb/s based on usage. Current consumer technology gives 300b/s to too 500 kb/s Depending on how much you want to pay. *speeds in bytes not bits

psykovsky 12y ago
> *speeds in bytes not bits Then you should use the correct metric prefix, kBps, not kbps. It would save you from having to give unnecessary explanations.
- 4ad 12y ago
  Surely you mean kB/s, not kBps. Nobody uses kBps because it's misleading. The question always boils down to kB/s vs. kbps. In this respect, your parent also unfortunately used kb/s, which is also a misleading and confusing unit. People really should be using only kB/s and baud.
  - psykovsky 12y ago
    Nobody and everybody are always exagerations when you talk about what people "use". The / means per, so it means exactly the same as the p. What's misleading about it as long as you capitalize the units correctly?
    - 4ad 12y ago
      The standard units, as in units defined by various international standards like ISQ are B/s and b/s. bps is defined to mean b/s. Note that there is no Bps in any ISQ standard. The only reason b/s has an bps alias is to reduce confusion. Greater hamming distance means less potential for confusion. Now you want to add the confusion back. Luckily, units are standardised by international bodies, not individuals, and the industry seems to be happy with the standards and uses them. Very seldom I have seen kBps (and in the few cases where I have seen it, it was wrong anyway). kb/s, while correct, I have only seen used by mistake, or by malice (e.g. ISPs intentionally misleading customers). Luckily, most professionals agree on only using B/s and bps, and no other combination, correct or not.