Starlink direct to cell (was SpaceX & T-mobile event 25 Aug 2022)

[Robotbeat]

You have the relationship mixed around. SpaceX is helping T-Mobile fill in their coverage maps using Starlink.

[oldAtlas_Eguy]

You have the relationship mixed around. SpaceX is helping T-Mobile fill in their coverage maps using Starlink.

Probably such that they would not need 12,000 sats. Yes.

How many? Is a question and answer that T-Mobile may not know for sure other than a model which may be correct or even way off.

Basically a system design from the standpoint of Starlink sats the transmit signal levels received by the cell phones would be generally always less than in most cases where there is a signal from a terrestrial tower. This would cause where there is overlaps between sat signal cells and terrestrial signal cells, the terrestrial cell tower is selected because it has the stronger signal. Also it is possible for SpaceX to turn on and off the transmitter depending on terrestrial coverage in an area. Although natural disasters have a tendency to damage and take out cell towers or after a short time 24-48hrs battery/generator backups which would need to then add larger areas in those locations for sat support.

[gongora]

The first gen constellation is ~4k sats, not ~12k.

[Danderman]

"in addition we would uh fold out the um the sort of cell spectrum antenna that would be also quite large so on the order of uh five or six meters uh on on a side so roughly 25 square meters and then can you get those in the falcon 9 payload fairing "

Should be interesting to see how that fits inside a Falcon 9 fairing on a mini.

A more interesting question I wish someone had asked is which shell will v2 be targeting first. I don't think you can do 70 degrees from Texas (phase 1  shell 2). I wonder if the first cape Starship launches will thread a needle to 70 degrees... I could see a really large benefit for coverage in Alaska and Northern Canada.   

Handhelds are going to require the shell at 52 degrees, so I suspect the plan is to launch that shell first.

[Danderman]

I am hearing that Starlink handheld service is only available at 1.9 - 2.0 MHz, which is  T-Mobile spectrum in the US. I am not sure why Starlink chose this frequency (apart from the T-Mobile partnership), since AFAIK, they aren’t licensed for this frequency elsewhere.

It would be an odd design choice if that was a hardware limitation.  Are you sure that's not just the frequencies they're choosing to use in the US?

First item: isn't the frequencies 1.9 - 2.0 GHz? Which gives T-Mobile 100Mz of bandwidth. Else Mhz would give T-Mobile 100KHz of bandwidth.

In the initial 12,400 sat constellation to be fully operational on or before Nov 2027 (the FCC licensing date). Would give T-Mobile excellent coverage. For the more advanced constellation of 30,000 sats which would be fully operational on or before 2030. Could have total of 3 cell phone providers each have 10,000 dedicated sats each. which would result in at least 3 cell phone providers from sat just by Starlink plus the other sat constellations that also implement cell services. Such that by 2030 you could have more than a dozen cell phone providers operating from orbit.

Additionally what SpaceX and Starlink design may be going for is to be like a cell phone tower operator that receives a fixed fee for each operational tower. As more "towers" (sats) are added the more revenue that SpaceX would get and the more advantage that T-Mobile would have in capabilities to have a solid connection space that covers all of US and territories. Which should bring in to T-Mobile more subscribers since they can cover areas and customers that no one else can.

I highly doubt T-Mobile would let SpaceX use 100Mhz of specturm... probably 5Mhz, and maybe they can use 2-3x 1.4Mhz LTE channels -- 1.4Mhz gets you 3Mbps.

AFAIK, the plan is to use the old Sprint spectrum at 1.9MHz.

There would be problems using other frequencies.

[Danderman]

I am hearing that Starlink handheld service is only available at 1.9 - 2.0 MHz, which is  T-Mobile spectrum in the US. I am not sure why Starlink chose this frequency (apart from the T-Mobile partnership), since AFAIK, they aren’t licensed for this frequency elsewhere.

It would be an odd design choice if that was a hardware limitation.  Are you sure that's not just the frequencies they're choosing to use in the US?

First item: isn't the frequencies 1.9 - 2.0 GHz? Which gives T-Mobile 100Mz of bandwidth. Else Mhz would give T-Mobile 100KHz of bandwidth.

In the initial 12,400 sat constellation to be fully operational on or before Nov 2027 (the FCC licensing date). Would give T-Mobile excellent coverage. For the more advanced constellation of 30,000 sats which would be fully operational on or before 2030. Could have total of 3 cell phone providers each have 10,000 dedicated sats each. which would result in at least 3 cell phone providers from sat just by Starlink plus the other sat constellations that also implement cell services. Such that by 2030 you could have more than a dozen cell phone providers operating from orbit.

Additionally what SpaceX and Starlink design may be going for is to be like a cell phone tower operator that receives a fixed fee for each operational tower. As more "towers" (sats) are added the more revenue that SpaceX would get and the more advantage that T-Mobile would have in capabilities to have a solid connection space that covers all of US and territories. Which should bring in to T-Mobile more subscribers since they can cover areas and customers that no one else can.

I highly doubt T-Mobile would let SpaceX use 100Mhz of specturm... probably 5Mhz, and maybe they can use 2-3x 1.4Mhz LTE channels -- 1.4Mhz gets you 3Mbps.

SpaceX would only use the T-Mobile spectrum where there are no cell towers. Otherwise T-Mobile can use its spectrum to serve terrestrial customers.

[Danderman]

Why is the SpaceX announcement good for Lynk?

Now, some analysts are claiming that satellite cellphone may be the biggest space market ever. It’s always good to be the industry leader in a large market.

Starlink can only serve one cell phone company per market. So, where do the other cell phone companies to service this market?

[Robotbeat]

Don’t companies share towers all the time?

[M.E.T.]

Why is the SpaceX announcement good for Lynk?

Now, some analysts are claiming that satellite cellphone may be the biggest space market ever. It’s always good to be the industry leader in a large market.

Starlink can only serve one cell phone company per market. So, where do the other cell phone companies to service this market?

The T-Mobile CEO was right next to Elon on stage when Elon said that they welcome partnerships from other cell providers too. Now I can’t quite recall whether he meant outside of the US only, but it would seem that, in principal, exclusivity is not part of the proposed collaboration.

[Asteroza]

Don’t companies share towers all the time?

Assuming frequency overlaps, RF/baseband capability, roaming agreements between MNO's and the MVNO's riding on top of them. 5G really cranks up the network slicing. If you can't physically deal with a frequency, it's not going to happen, but after that...

Old 2G GSM had huge macrocells (think single tower for a large metro area), in premium low band frequencies for long range/building penetration (900MHz stuff was prime for that), at the cost of reduced bandwidth. All the high speed stuff now is higher frequencies (2.x GHz and the 5.x GHz stuff)  at reduced ranges. The 5G mm wave stuff, you probably can see the antenna with the naked eye, it's that short ranged.

The real limiter is what hardware is attached to that deployable antenna on Starlink for transmit/receive frequencies. After that it's all SDR work in this day and age. Power consumption (on top of regular Starlink duties) ain't nothing to laugh at though.

This might be an interesting opportunity for novel antennas, but if SpaceX had access to that, they would probably already be using it. The fact that they want to sideline the secondary payload with a deployable antenna that carries deployment risks makes it somewhat sacrificial. Plus increased visual spectrum reflectivity might be a problem unless it's a mesh reflector.


Brain fart:

I wonder if they are cheating and putting the transmitter/receiver on the dorsal side of Starlink, and laying another phased array flat panel or two there hiding under the solar array during deployment? Do we have any dorsal Gen2 pics? The edge surfaces are already pretty busy with the 3 lasercomm terminals, reaction wheels, and the main thruster.

[MP99]

…
Since the V2 mini sats don’t support handhelds,

Where does this claim come from??

Quit repeating it or provide a solid source. It has not been well-established yet. It seems pretty unlikely given this is such a big part of the whole rationale for V2, and it’s awfully convenient come from someone who is literally invested in a competitor.

Direct comment from Elon at the event.

Mini because no mobile antenna.

Could someone please point me to where Elon supposedly said this?  I don't remember it and he didn't say it when replying to Eric Berger.

But before looking at the transcript in detail, I could've sworn I heard it too.
It's kind of implied.
He says "5x5m cell antena big, meant for Starship. If Starship late, Starlink V2-mini will go on F9".
But it's true at the start he says "primarily for v2 sat" which does not imply "exclusively".

um yeah so we we think like the the service will be primarily a starlink uh v2 uh satellite the starlink v2 is uh the main body of the satellite is about seven meters long uh so call it maybe 40 in longer than an suv and then the uh the antennas that we're talking about here would be supplemental to the ku and ka antennas that we're currently using on sonic 1 and uh to the the laser links so the sonic 2 will satellites uh we tend to have uh k a k u improve ku and um obviously all the laser links and then in addition we would uh fold out the um the sort of cell spectrum antenna that would be also quite large so on the order of uh five or six meters uh on on a side so roughly 25 square meters and then can you get those in the falcon 9 payload fairing uh the starlink v2 is meant for starship um we we might yeah there's another starship like those things um so the the starlink v2 satellites are are very large and uh and too big to fit in a falcon 9. uh but the uh we are we are actually looking at an interim uh solution which is like a sort of starlink v2 mini that would um maybe launch uh if if starlink if the starship is program is delayed uh longer than expected would launch a sort of a small a smaller uh starlink v2 kind of mini that would fit on a falcon 9

Okay, so he DIDN’T say it.

His tone was pretty clear that he didn’t really acknowledge the “mini” as a real V2. In fact, he seemed slightly put out by Eric even referring to the mini version, which to Elon seems to be an irrelevant distraction from the real V2.

My sense is that Elon is looking longer term (as always), past the short term challenges, and that the mini version won’t be around for long if he can help it.

So in other words... yes, he didn't say it.

Let's not claim it's a "direct comment" (as two separate posters did) if we're actually just reading between the lines. That's how persistent myths and misinformation get started.


Now surely Danderman wouldn't intentionally spread misinformation about a competitor. I'm 100% certain it was an honest mistake. Still, it's not a good look.

I personally believe that is what he was trying to say (and how I "heard" it listening live), but apologise for presenting it as "Elon confirmed it", because I agree that the comment is pretty muddled if that's what he meant.

Cheers, Martin

Sent from my Lenovo TB-X606X using Tapatalk

[waveney]

Old 2G GSM had huge macrocells (think single tower for a large metro area), in premium low band frequencies for long range/building penetration (900MHz stuff was prime for that), at the cost of reduced bandwidth. All the high speed stuff now is higher frequencies (2.x GHz and the 5.x GHz stuff)  at reduced ranges. The 5G mm wave stuff, you probably can see the antenna with the naked eye, it's that short ranged.

Early 2G was better than that.  It only needed 4 or 5 towers to give entire UK coverage - there were no dead zones.   It was a fabulous service when the user base was a few thousand.  (However, the phones looked like bricks and weighed a kilo).

(I was a senior technical consultant in telecoms and had a very early mobile, but not the brick).

[Danderman]

Don’t companies share towers all the time?

Yes.

Some cell towers indeed have multiple cell antennas.

What’s your point?

[Danderman]

…
Since the V2 mini sats don’t support handhelds,

Where does this claim come from??

Quit repeating it or provide a solid source. It has not been well-established yet. It seems pretty unlikely given this is such a big part of the whole rationale for V2, and it’s awfully convenient come from someone who is literally invested in a competitor.

“ um yeah so we we think like the the service will be primarily a starlink uh v2 uh satellite the starlink v2 is uh the main body of the satellite is about seven meters long uh so call it maybe 40 in longer than an suv and then the uh the antennas that we're talking about here would be supplemental to the ku and ka antennas that we're currently using on sonic 1 and uh to the the laser links so the sonic 2 will satellites uh we tend to have uh k a k u improve ku and um obviously all the laser links and then in addition we would uh fold out the um the sort of cell spectrum antenna that would be also quite large so on the order of uh five or six meters uh on on a side so roughly 25 square meters and then can you get those in the falcon 9 payload fairing uh the starlink v2 is meant for starship um we we might yeah there's another starship like those things um so the the starlink v2 satellites are are very large and uh and too big to fit in a falcon 9. uh but the uh we are we are actually looking at an interim uh solution which is like a sort of starlink v2 mini that would um maybe launch uh if if starlink if the starship is program is delayed uh longer than expected would launch a sort of a small a smaller uh starlink v2 kind of mini that would fit on a falcon 9”

Do you think that the mini V2 satellites will have a 25 sq meter antenna that supports handhelds?

[Robotbeat]

Sounds like the smaller satellites might have less performance, but nothing in there says they wont be capable of cell coverage /at all/.

[AC in NC]

Sounds like the smaller satellites might have less performance, but nothing in there says they wont be capable of cell coverage /at all/.

To my ear, I thought I heard that 25 m² was the necessary to support cell and so the question hinges on whether the mini form-factor can still support that size antenna.

[kevin-rf]

It comes down to the cellular coverage requires a secondary 5m antenna. Will mini v2 have that secondary antenna and can that secondary antenna fit inside a Falcon 9 fairing. How many fewer v2 will ride with that extra mass.  An extra 5m antenna would not be light.

if you stare at the words he said hard enough,  you can make it sound like they could.  Think most of us interpret what he said as a no.

[Asteroza]

Sounds like the smaller satellites might have less performance, but nothing in there says they wont be capable of cell coverage /at all/.

Of note, the previous tests by Lynk and SpaceMobile from orbit for their initial proof-of-concept and link testing used much smaller antennas.

Which would have been flooded by existing terrestrial user transmissions, which they have to filter. That only gets worse as the gain goes up with a bigger antenna.

[DanClemmensen]

Sounds like the smaller satellites might have less performance, but nothing in there says they wont be capable of cell coverage /at all/.

Of note, the previous tests by Lynk and SpaceMobile from orbit for their initial proof-of-concept and link testing used much smaller antennas.

Which would have been flooded by existing terrestrial user transmissions, which they have to filter. That only gets worse as the gain goes up with a bigger antenna.

A bigger antenna has higher gain because it has higher directivity: it is looking at a smaller spot. Therefore is sees fewer but stronger signals. Big antenna:small spot. Small antenna: big spot.

[su27k]

Elon seems to be rather dismissive of the v2 mini concept, not sure he would want to spend the resources to add cell tower antenna to mini. I mean if mini is just a temporary stopgap, any additional work on it would be wasted once it's phased out in a few (hopefully short) years.