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It’s amazing to me that a satellite can pick up a signal from a normal-sized cell phone. What kind of advances have we had in the past few years that have made

It’s amazing to me that a satellite can pick up a signal from a normal-sized cell phone. What kind of advances have we had in the past few years that have made this possible without needing a bulky Iridium-style device? Have the satellites gotten much more sensitive, or are we somehow cramming more TX power into regular phones?

wyldfire 4y ago
And those bulky devices didn't work well without LOS to the sky.
- breckenedge 4y ago
  I’m fairly certain they will all require LOS or an external antenna.
  - lxgr 4y ago
    Iridium pagers supposedly worked indoors (close to a window), due to the very low modulation rate used. They were only one-way, though.
    - wyldfire 4y ago
      They did indeed.
    - Scoundreller 4y ago
      And same modulation used for ringing a device, so you could at least be prompted to run into LOS for incoming calls.
breckenedge 4y ago
Globalstar devices were already pretty small even 10 years ago. I think they only require a 2W transmitter, whereas Iridium requires 10W. And their satellites are in more normal orbits rather than Iridium’s polar orbits, so coverage isn’t truly global. The satellite has to see you and a base station at the same time. Edit: Globalstar modem data sheet: https://www.globalstar.com/Globalstar/media/Globalstar/Downloads/Products/STX3/STX3-Sell-Sheet.pdf https://www.globalstar.com/Globalstar/media/Globalstar/Downl...
- kotaKat 4y ago
  And Globalstar's network has been in a variety of decays ever since. There were periods of time that the Globalstar network was literally requiring you to use a "call times tool" to determine the paltry 10 to 20 minute windows at a time every hour you could even get a call out on the system. They were so desperate to keep customers that you could get a satphone for a whole $40 a month - with unlimited! calling. They then, finally, a few years back, launched their Sat-Fi2 service. Instead of using bent-pipe CDMA, they decided to use bent-pipe UMTS. As a Sat-Fi2 customer I can assure you I never got a working voice call, and barely working data. Globalstar was so impressed with their own technology they killed off this "next generation" service. Now to this day, they stopped selling satellite phones (while still allowing activation), dropped every single reference to the Sat-Fi and Sat-Fi2, and are pushing hard on their simplex burst data services.
  - GeekyBear 4y ago
    > Globalstar's network has been in a variety of decays >TAMPA, Fla. — Globalstar has signed a term sheet with a “large, global customer” to start deploying some of its spectrum for terrestrial use “in the U.S. and beyond,” the satellite operator said May 5. The operator said Feb. 24 it picked MDA and Rocket Lab to supply a set of 17 satellites to replenish its constellation after a “potential customer” agreed to fund most of the $327 million project. The agreement includes an option for up to nine additional satellites at $11.4 million each. https://spacenews.com/globalstar-agrees-terms-with-global-customer-for-terrestrial-connectivity/ https://spacenews.com/globalstar-agrees-terms-with-global-cu... A secret customer fronting large amounts of money to enable goods or services they want to offer is certainly in keeping with how Apple operates.
    - kylehotchkiss 4y ago
      $300mil is the cost of a widebody jet or two, that’s pretty reasonable for almost a constellation of satellites
- tedivm 4y ago
  > The satellite has to see you and a base station at the same time. The satellites aren't capable of a small amount of buffering? For text messages it shouldn't take up much space, and a lag on the delivery is better than no delivery at all.
matrix_overload 4y ago
Cheaper launches -> More satellites viable -> Lower orbit (shorter distance to the terminal at a cost of much smaller area covered by each satellite).
lxgr 4y ago
Iridium devices aren‘t bulky anymore. Look at a Garmin InReach: It‘s smaller than most smartphones. If you think about it, these satellites are only 1-2 orders of magnitude farther away than a typical cell base station. By scaling the data rate down by the same proportion, you can span that distance using roughly the same transmission power and antenna technology.

wyldfire 4y ago

And those bulky devices didn't work well without LOS to the sky.

breckenedge 4y ago
I’m fairly certain they will all require LOS or an external antenna.
- lxgr 4y ago
  Iridium pagers supposedly worked indoors (close to a window), due to the very low modulation rate used. They were only one-way, though.
  - wyldfire 4y ago
    They did indeed.
  - Scoundreller 4y ago
    And same modulation used for ringing a device, so you could at least be prompted to run into LOS for incoming calls.

breckenedge 4y ago

Globalstar devices were already pretty small even 10 years ago. I think they only require a 2W transmitter, whereas Iridium requires 10W. And their satellites are in more normal orbits rather than Iridium’s polar orbits, so coverage isn’t truly global. The satellite has to see you and a base station at the same time. Edit: Globalstar modem data sheet: https://www.globalstar.com/Globalstar/media/Globalstar/Downloads/Products/STX3/STX3-Sell-Sheet.pdf https://www.globalstar.com/Globalstar/media/Globalstar/Downl...

kotaKat 4y ago
And Globalstar's network has been in a variety of decays ever since. There were periods of time that the Globalstar network was literally requiring you to use a "call times tool" to determine the paltry 10 to 20 minute windows at a time every hour you could even get a call out on the system. They were so desperate to keep customers that you could get a satphone for a whole $40 a month - with unlimited! calling. They then, finally, a few years back, launched their Sat-Fi2 service. Instead of using bent-pipe CDMA, they decided to use bent-pipe UMTS. As a Sat-Fi2 customer I can assure you I never got a working voice call, and barely working data. Globalstar was so impressed with their own technology they killed off this "next generation" service. Now to this day, they stopped selling satellite phones (while still allowing activation), dropped every single reference to the Sat-Fi and Sat-Fi2, and are pushing hard on their simplex burst data services.
- GeekyBear 4y ago
  > Globalstar's network has been in a variety of decays >TAMPA, Fla. — Globalstar has signed a term sheet with a “large, global customer” to start deploying some of its spectrum for terrestrial use “in the U.S. and beyond,” the satellite operator said May 5. The operator said Feb. 24 it picked MDA and Rocket Lab to supply a set of 17 satellites to replenish its constellation after a “potential customer” agreed to fund most of the $327 million project. The agreement includes an option for up to nine additional satellites at $11.4 million each. https://spacenews.com/globalstar-agrees-terms-with-global-customer-for-terrestrial-connectivity/ https://spacenews.com/globalstar-agrees-terms-with-global-cu... A secret customer fronting large amounts of money to enable goods or services they want to offer is certainly in keeping with how Apple operates.
  - kylehotchkiss 4y ago
    $300mil is the cost of a widebody jet or two, that’s pretty reasonable for almost a constellation of satellites
tedivm 4y ago
> The satellite has to see you and a base station at the same time. The satellites aren't capable of a small amount of buffering? For text messages it shouldn't take up much space, and a lag on the delivery is better than no delivery at all.

matrix_overload 4y ago

Cheaper launches -> More satellites viable -> Lower orbit (shorter distance to the terminal at a cost of much smaller area covered by each satellite).

lxgr 4y ago

Iridium devices aren‘t bulky anymore. Look at a Garmin InReach: It‘s smaller than most smartphones. If you think about it, these satellites are only 1-2 orders of magnitude farther away than a typical cell base station. By scaling the data rate down by the same proportion, you can span that distance using roughly the same transmission power and antenna technology.