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Comment by greatjack613 | Hacker News Reader

While the bandwidth numbers seem terrible given this is from an entire beam at it's peak and beams are wide, this is super useful for things like sms where bandwidth is not a concern. At 17 Mb/s you can have thousands of simultaneous sms sends without issue

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Yeah, it could be god sent for natural disasters and truly remote locations. But it is not replacement for regular mobile service.

For emergencies in truly remote locations. In a natural disaster, you have everybody at once refreshing news and checking in on friends and family that even undamaged networks could struggle.

When the network has broken down you'd better be prepared to have teams fixing what is fixable, and the ability to deploy pop-up cells on the ground. If you have skimped on that preparation betting on satellite cells to save the day the contribution of Starlink to disaster preparedness might end up being a net negative.

That being said, pop-up cells on a startlink as their backhaul could become huge in disaster preparedness. Some contract scheme for standby basestations might actually become a big component of the Starlink business model. The good news is that all talk to regular phones can't overlap with regular starlink frequencies, so unless it blocks some other bottlenecks like SDR DSP capacity it won't compete with regular connections (certainly won't have a meaningful impact on orbital backbone load)

I am thinking true disasters, where a simple message with your location can save lives.

I believe it should be possible to disable all communication except basic sms and emergency communication like 911 or similar can be accessed without SIM.

Surely this is an ideal usecase for IP multicast? Given that SpaceX controls effectively the entire LEO retail internet at the moment they’re in an ideal position to push a standard for multicasting emergency or regional updates.

You are talking about layer 3 while people are talking about layer 2.

I hope there's some broadcast stuff planned (does cellular support multicast like that?). So I can just point my phone at the sky and get some news/weather/traffic updates "off-line". Maybe a radio station or two? It's pretty impressive what can fit into 32kbps (or less!) these days.

Yes, that's how SMS emergency alerts work

https://en.wikipedia.org/wiki/Cell_Broadcast

> is part of the 2G, 3G, 4G LTE (telecommunication) and 5G standards

Interesting as Canada's system only works on LTE or higher (we still have 3G here).

I camped on 3G for a while because they kept sending out Amber Alerts at the "Presidential" level for custody disputes. Gov repeatedly denied any issue but haven't sent any for a while. Either people stopped "abducting" their own kids or they changed their threshold-to-blast.

Was your 3G on CDMA2000 rather than the 3GPP UMTS/WCDMA/HSDPA standards? That could account for the difference

One of our two big networks was, the other was not.

Viasats service supported this via USB plug in drive on the modem to load some content. Don't think it was released out of beta.

Hmm, but SMS rely on the cellular tower protocol, basically being carried on the status messages that cellphones already constantly send/receive anyway - they don't use the IP (at least until the tower).

So I'm not even sure they can be sent/received by satellite ??

Starlink is using 5G, a cellular tower protocol. The only other option would be WiFi which can not do long distance, at least without both ends being designed for it (which a cellphone is not).

Iridium should be worried.

There is a 3GPP standard for satellite to phone connectivity which Iridium is adopting:

https://www.iridium.com/project-stardust/

Their 66 satellites are going to support a much lower aggregate constellation throughput and spot beam count vs StarLink. They’re fundamentally constrained by lift costs and low constellation satellite count.

Iridium has 48 spot beams per satellite each covering 250 miles. Each StarLink cell covers ~15 miles with a similar spot beam count, with 5,442 satellites currently operational (as of this comment).

https://planet4589.org/space/con/star/stats.html

(Disclosure: StarLink customer, no other affiliation)

Most of those sats don't support direct to cell though. But more will come of course.

And are the spot beams for direct to cell the same in size and quantity?

Good question. I could not find the cell size specifically for the LTE coverage, and agree it will take time for the constellation to turn over to maximize the direct to phone capability. Regardless, SpaceX launches more StarLink satellites in three flights (~69) than Iridium has in its entire constellation.

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