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How much telecom traffic goes via satellite vs. ground towers and fiberoptic cable? What percentage of capex cost for a telecom is rocket launches? I have abso

by dmoy 9y ago

How much telecom traffic goes via satellite vs. ground towers and fiberoptic cable? What percentage of capex cost for a telecom is rocket launches? I have absolutely no clue, but I feel it would affect this analysis greatly.

gfodor 9y ago
I don't know either, but considering the complete lack of existence of the kind of network SpaceX is proposing, or anything close to it, if it's not deployment costs it would have to be some other factor coupled with operating a ~1000 sat network.
- pjc50 9y ago
  It's similar to, although much larger than, Iridium. Building it is one thing but making it profitable is another, as it making people accept the latency tradeoffs of satellite.
  - Game_Ender 9y ago
    There network will have minimal (30-40ms) latency hit vs ground based systems because there satellites are 300-1000 miles up vs the 20k miles that the current geostationary ones are at.
  - randall 9y ago
    Ars says the latency is 25ms. https://arstechnica.com/information-technology/2018/02/spacexs-satellite-broadband-nears-fcc-approval-and-first-test-launch/ https://arstechnica.com/information-technology/2018/02/space... They say it's due to lower orbits. Iridium is fewer satellites so they have to be higher. More w/ lower orbits means lower latency. Do you know if this is too good to be true?
  - smoyer 9y ago
    Most terrestrial systems are now using fiber optics ... the speed of photons in a fiber is about 2/3rds the speed of light. The transmission of radio signals in the vacuum of space is theoretically at the speed of light so: 40000 / pi / 2 = 6366 40000 / 2 * 3 = 60000 60000 / pi / 2 = 9550 9550 - 6366 = 3184 Per the above, any satellite Internet system below about 3000 km above the earth will have latency that's competitive with fiber optics on earth (note that I haven't done the simultaneous solution to account for the uplink/downlink distance so it's actually a bit less). For the SpaceX system, there should be better latency than the terrestrial Internet. Please ignore the rounding ... this is a back-of-the-envelope exercise. Fiber optics are great and far less susceptible to interference than radio - but if you Google articles on how high-frequency trading companies are installing line-of-sight microwave for their networks you'll see that fiber isn't our fastest technology.

by dmoy 9y ago

gfodor 9y ago

I don't know either, but considering the complete lack of existence of the kind of network SpaceX is proposing, or anything close to it, if it's not deployment costs it would have to be some other factor coupled with operating a ~1000 sat network.

pjc50 9y ago
It's similar to, although much larger than, Iridium. Building it is one thing but making it profitable is another, as it making people accept the latency tradeoffs of satellite.
- Game_Ender 9y ago
  There network will have minimal (30-40ms) latency hit vs ground based systems because there satellites are 300-1000 miles up vs the 20k miles that the current geostationary ones are at.
- randall 9y ago
  Ars says the latency is 25ms. https://arstechnica.com/information-technology/2018/02/spacexs-satellite-broadband-nears-fcc-approval-and-first-test-launch/ https://arstechnica.com/information-technology/2018/02/space... They say it's due to lower orbits. Iridium is fewer satellites so they have to be higher. More w/ lower orbits means lower latency. Do you know if this is too good to be true?
- smoyer 9y ago
  Most terrestrial systems are now using fiber optics ... the speed of photons in a fiber is about 2/3rds the speed of light. The transmission of radio signals in the vacuum of space is theoretically at the speed of light so: 40000 / pi / 2 = 6366 40000 / 2 * 3 = 60000 60000 / pi / 2 = 9550 9550 - 6366 = 3184 Per the above, any satellite Internet system below about 3000 km above the earth will have latency that's competitive with fiber optics on earth (note that I haven't done the simultaneous solution to account for the uplink/downlink distance so it's actually a bit less). For the SpaceX system, there should be better latency than the terrestrial Internet. Please ignore the rounding ... this is a back-of-the-envelope exercise. Fiber optics are great and far less susceptible to interference than radio - but if you Google articles on how high-frequency trading companies are installing line-of-sight microwave for their networks you'll see that fiber isn't our fastest technology.