I thought existing Starlink needed a phased array antenna to get decent signal strength. How the hell is a cell phone radio going to reach a satellite?
This is definitely what I am interested in-- how existing cell HW can be picked up by their satellites. Even at low data rates for emergency SMS, etc. (caveat, I'm not a HW or radio engineer), this seems like an incredible feat if they can get it to work.
GPS is an 'incredible feat', that's advanced magic. This is many orders of magnitude more signal strength, even without beam steering. That said, it will still require a pretty sensitive receiver, but nothing on the order of what your cell phone already contains for GPS.
It's straight up, line of sight. The biggest issue will be water in the atmosphere. Compared to your average urban canyon it probably isn't all that bad.
Consider that HAMs routinely work insane distances with extremely little power LOS is relatively easy, especially if one side is a satellite with a beefy antenna for both transmission and reception. I'm more interested in the power budget than whether or not they can close the distance and what the effect is on the cell phone's battery life.
GPS receivers in a cell phone work at or under the noise floor, which to me is advanced magic. This will be way above that.
Line of sight will be needed for upload transmit, definitely. However, with sufficient power on the satelites it should be able to transmit loud enough at lower frequencies (better penetration) so it should be receivable inside of a phone pocket or underneath something shallow.
It will be interesting to see how well it performs inside structures. Is there any info on what kind of power those satellites can output or is that classified?
If they're just going to be using this for sending texts for now, the signal to noise ratio can be really bad and still work. I suppose they could also fall back on buffering until a satellite is in an optimal position if it can't send immediately -- texts should arrive quickly, but they don't have to be quite real-time.
That's my guess anyways, there might be some other tricks involved and it's an impressive thing to do at any rate.
If you're really out in a super remote location you might be the only person in your zone, but if you're camping with a dozen friends you'll all be splitting that 2-4 megabits.
Still tremendously impressive though, if they're able to pull it off.
