Starlink Successfully Tests Space Direct to Cell Mobile Service • Hacker News Board

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#111

Post by [deleted] » Sat, Jan 13, 2024, 10:13 PM UTC

drak0n1c wrote: post #59

alterego2 wrote: post #41

Earlier quoted context omitted.

It will not. Don't know about China, but Russian citizens already have almost unfiltered access to information. The only major western media outlet currently blocked in Russia is BBC. Anyone can read pretty much anything else - Reuters, Newsweek, CNN, whatever - right from their phones. Access to information is not the problem (at least for now). It is trivial to get access to uncensored news for anyone with a modicu…

Linguistic and cultural barriers are far stronger than informational barriers. Which may be an upside considering how other potentially self-destructive fads and attitudes spread so rapidly with the internet. We've seen the beginnings of that with the Arab Spring, and various culture wars across English-speaking western countries. If the world were even more homogenous the whiplash from such polarizing movements woul…

[deleted]

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#112

Post by lxgr » Sat, Jan 13, 2024, 10:16 PM UTC

tuatoru wrote: post #102

lxgr wrote: post #98

Earlier quoted context omitted.

These are more expensive than many current satellite messengers (including subscription fees for a few years!) and importantly don’t give you any feedback on whether your call has gone through (except for the newest ones using Galileo’s return channel) or way to communicate with the SAR team and specify the nature of your emergency.

Where I live PLBs have a lower sticker price than the InReach, only require a one-time payment for life, and they have a ten-year battery life. I don't know about EPIRBs or ELTs. You don't need feedback: Search and Rescue WILL send out a team that makes physical contact with you, even if you only turn the thing on for a couple of minutes. Seen this in action here in NZ. They are trained in tracking, too, so you can't…

Feedback has been shown to be both very important psychologically in a survival situation.

Practically it can also be crucial to know whether your signal went through or whether you should trade shelter for altitude (e.g. when hiking in a narrow ravine with limited sky visibility).

Two-way communication and being able to specify the nature of your emergency are invaluable as well.

PLBs/EPIRBs definitely have their uses, but I think they shine more in traditional aviation or marine SAR situations where longevity is paramount and it's pretty clear from context what type of help is needed.

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#113

Post by samstave » Sat, Jan 13, 2024, 10:17 PM UTC

toomuchtodo wrote: post #27

tra3 wrote: post #25

Earlier quoted context omitted.

You already have that with inreach or Zoleo devices. Of course once it’s integrated into phones it’ll be much more convenient.

With the rabbit it would be like talking to the starship enterprise as well.

"Beam Me Up Scotty" Should automatically get you home - either by directions or ordering you a cab or calling your emergency setting...

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#114

Post by lxgr » Sat, Jan 13, 2024, 10:19 PM UTC

paxys wrote: post #105

modeless wrote: post #5

I don't know if this has been announced before: "Operators in our network have access to reciprocal global access that allows their users to access the service when they travel to one of our partner countries." [1] It sounds like once SpaceX has partnered with at least one carrier in most countries then you'll be able to travel to almost any point on the surface of the Earth and still have baseline emergency cell tex…

They have partnered with T-Mobile, and T-Mobile already has these deals in place. This is how TMo subscribers get global data coverage as part of their plan.

Basically every mobile network in the world has roaming deals in place.

I don't think every roaming partner of T-Mobile will gain access this the Starlink-based service, though. It's probably going to be another tier of "Starlink roaming", only accessible to the subscribers of Starlink's respective local partner operators that are also lending their spectrum.

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#115

Post by lxgr » Sat, Jan 13, 2024, 10:20 PM UTC

dzhiurgis wrote: post #71

notatoad wrote: post #60

Earlier quoted context omitted.

>If you have an iPhone 14 or above, Apple offers similar capabilities to all iPhone users in about a dozen countries (so far) regardless of which mobile network you subscribe to at home. Apple only lets you communicate with an emergency dispatch service. the T-Mobile/starlink service appears to allow sending and receiving texts to any number.

Slight downside, but in many places you can’t text 911 or local equivalent

With Apple's service, you're not actually communicating with a regular 911 service, but rather a specialized service provider that relays your emergency call to local authorities (and more recently car roadside assistance services).

Relaying texts to a phone call is very likely part of what they do.

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#116

Post by lxgr » Sat, Jan 13, 2024, 10:22 PM UTC

modeless wrote: post #7

extheat wrote: post #6

Earlier quoted context omitted.

I assume this works like traditional cellular roaming, no? So this would mean you have to be a customer of one of the service providers to get reciprocated roaming capabilities abroad.

Yes, you would need service with one of the partners to get roaming on all of them. Although on terrestrial networks in the US at least 911 service is supposed to work even on phones without any carrier plan. Maybe they can eventually work it out so that texting emergency services works on any phone anywhere globally even without service. That would be a great achievement for humanity.

I think that's only technically possible for voice 911 calls.

Texting 911 requires you to be attached to a network, which in turn requires a phone plan and potentially a roaming agreement. Changing this would require some deep architectural changes to the 3GPP specs, or just allowing anyone on but filtering out all non-911 texts.

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#117

Post by modeless » Sat, Jan 13, 2024, 10:34 PM UTC

lxgr wrote: post #83

modeless wrote: post #61

Earlier quoted context omitted.

I disagree that Apple's capability is similar. The feature only allows texting emergency services, requires holding the phone in a specific orientation to send or receive, is separate from your carrier service (only two years are free with purchase), and is exceedingly slow. SpaceX's service will allow texting and receiving texts from anyone using your carrier number, plans to support third party messaging apps such…

Elon has mentioned a speed of about 7 Mbit/s for an entire cell (which in these systems usually means a circle with a radius of a few hundred kilometers). That's within an order of magnitude of current LEO systems. The innovation here is that it'll supposedly work with unmodified off-the-shelf phones. (Personally I'm assuming that at least messaging software will have to be modified in order to use the available band…

Apple hasn't disclosed the bitrate of their Emergency SOS feature but from FCC filings I believe it uses Globalstar's L-Band at 1610 Mhz for uplink, and I believe the bitrate Globalstar supports in that channel is 9.6 kbps. So almost three orders of magnitude less than the SpaceX system, not one. In addition I believe that the typical achieved bitrate is even less than that in Apple's case due to the lack of a large dedicated antenna. In demos it typically takes many seconds up to several minutes to send a single message, during which time you are directed to continuously point the phone at the satellite for best reception.

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#118

Post by [deleted] » Sat, Jan 13, 2024, 10:43 PM UTC

modeless wrote: post #117

lxgr wrote: post #83

Earlier quoted context omitted.

Elon has mentioned a speed of about 7 Mbit/s for an entire cell (which in these systems usually means a circle with a radius of a few hundred kilometers). That's within an order of magnitude of current LEO systems. The innovation here is that it'll supposedly work with unmodified off-the-shelf phones. (Personally I'm assuming that at least messaging software will have to be modified in order to use the available band…

Apple hasn't disclosed the bitrate of their Emergency SOS feature but from FCC filings I believe it uses Globalstar's L-Band at 1610 Mhz for uplink, and I believe the bitrate Globalstar supports in that channel is 9.6 kbps. So almost three orders of magnitude less than the SpaceX system, not one. In addition I believe that the typical achieved bitrate is even less than that in Apple's case due to the lack of a large…

[deleted]

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#119

Post by modeless » Sat, Jan 13, 2024, 10:44 PM UTC

lxgr wrote: post #116

modeless wrote: post #7

Earlier quoted context omitted.

Yes, you would need service with one of the partners to get roaming on all of them. Although on terrestrial networks in the US at least 911 service is supposed to work even on phones without any carrier plan. Maybe they can eventually work it out so that texting emergency services works on any phone anywhere globally even without service. That would be a great achievement for humanity.

I think that's only technically possible for voice 911 calls. Texting 911 requires you to be attached to a network, which in turn requires a phone plan and potentially a roaming agreement. Changing this would require some deep architectural changes to the 3GPP specs, or just allowing anyone on but filtering out all non-911 texts.

Interesting. I expect that SpaceX will start supporting voice calls with this system in the not too distant future, so maybe that will make it work automatically. Unless the telcos can get their act together before then and change their standards to support text-to-911 without a service agreement.

Re: Starlink Successfully Tests Space Direct to Cell Mobile Service

#120

Post by lxgr » Sat, Jan 13, 2024, 10:44 PM UTC

modeless wrote: post #117

lxgr wrote: post #83

Earlier quoted context omitted.

Elon has mentioned a speed of about 7 Mbit/s for an entire cell (which in these systems usually means a circle with a radius of a few hundred kilometers). That's within an order of magnitude of current LEO systems. The innovation here is that it'll supposedly work with unmodified off-the-shelf phones. (Personally I'm assuming that at least messaging software will have to be modified in order to use the available band…

Apple hasn't disclosed the bitrate of their Emergency SOS feature but from FCC filings I believe it uses Globalstar's L-Band at 1610 Mhz for uplink, and I believe the bitrate Globalstar supports in that channel is 9.6 kbps. So almost three orders of magnitude less than the SpaceX system, not one. In addition I believe that the typical achieved bitrate is even less than that in Apple's case due to the lack of a large…

The 7 Mbit/s are for an entire cell, i.e. all devices simultaneously transmitting in it, not per device.

Iridium (a comparable system) used to support about 10 Mbit/s per satellite in its first satellite generation, which had 48 spot beams each. The second generation supports about a megabit per modem, but these have larger antennas than a regular satphone.

> Apple doesn't disclose the bitrate of their Emergency SOS feature but it uses Globalstar's L-Band for uplink and I believe the bitrate of that channel is 9.6 kbps.

I'm almost certain Apple doesn't even use the full 9.6 kbit/s modulation scheme for their emergency SOS feature: As you mention, it's way too slow for that (having used it myself – even just transmitting my location takes a couple of seconds, and that's a message of only a few bytes).

Globalstar satellites are bent-pipe relays, so Apple could be using whatever custom modulation and coding scheme they need to stay within the constraints of their power and SNR envelope. With the iPhone's built-in antenna and transmit power (around 2 watts or so, if I remember correctly), I'd be surprised if it was more than a couple hundred bits per second.

Regular (i.e. non-smartphone) satellite messengers are much faster than that and only take a few seconds to transmit and receive messages of hundreds of bytes.