Recent comments in /f/gadgets

GodsendNYC t1_j3978x8 wrote

I've read about it and it's pretty interesting. I'd like to know more about the technical details of how that could work. You can pick up a satellite signal on a phone without much of a problem because it's a powerful transmitter but how does the return signal get to the satellite since it's a small device with a low-power transmitter designed for local communications? SAT phones usually are larger and have a much bigger external antenna so how can they do it on a normal smartphone is very interesting.

6

doxx_in_the_box t1_j392fr9 wrote

> if ground stations are the bottleneck

You’re half way right and I think this is why Iridium is claiming speed - they’re reusing marketing material without specifying which conditions hold true.

Ground stations are the bottleneck in two situations:

  • example: customer is in Australia tracking a product on other side of planet. It needs to somehow get the data back to Australia.
  • example: a user wants to send an emergency message to another user, like using Garmin SOS device.

But with emergency SOS the ground station nearest you will be the one handling your request, so beaming across multiple satellites is pointless.

Also iridium has less total number of ground stations, so less coverage on earth, they just make up for it with better satellite-to-satellite coverage

1

dnick t1_j38z7hm wrote

Hmm, maybe Iridium can only transmit straight back down, and it has to go through terrestrial switching stations to get to a central processing location, that then goes back out and activates EMS, rather than one or two steps through line-of-site satellites and directly to a central location?

Not sure, but if their claim is that ground stations are a bottleneck, getting more information on that seems like the question rather than just saying 'hmm, I don't know about that...'.

1