Small update.

Starlink beam diameter of 50 km. (Blue)

Advertised AST midband beam diameter is 24 km for comparison.(Red)

What it means practically is that spectum deployed with Starlink d2c will be used by 3.3 x more users per MHz.

Cutting area SE to 1/3 by this metric alone.
-It’s called SpectRum with an R, cat.

-Right. My mistake. I like all sorts of Rum

🍹 🌈🛜 no offense intended.

-What is ”area spectral efficiency, cat?

-It is the key performance metric of an 3GPP NTN system.

-What is it made of and why is it important?

-I’m glad you asked

The case for Low Earth orbit radar.

And sharing spectrum between DoD and Telecom.

This image shows the Chinese bomber fleet range. Previous and that of H-20 bomber project a bomber similar to the US flying wing stealth bombers.

As can be seen Hawaii is now within range.

1/n
A bit smaller regional nuclear capable strike aircraft like this one shown yesterday (JH-XX ?) are likely capable of reaching places like Guam and Japan.

The two types of aircraft are built for stealth, low observability. And likely capable of electronic warfare.

2/n

Let us look at the SDA opportunity.

What does $ASTS have that SDA might seek?

How does that fit with PWSA architecture and timelines.

Any hints there is a fit or work in progress between the two space architectures?

1/n
AST was selected to be part of HALO pool. From this pool they can be awarded contract for 2 space vehicles.

This is when AST themselves became a prime DoD partner.

In parallell we know that another AST partner which also has a prime contract staus with the DoD are testing OISL

There are many people speculating in revenue from AST satellites.

A year ago @thekookreport and I did some math.

It’s in his report.

1/n One simple key to understanding data transmission capacity in networks is the difference between bits and bytes.

A byte contains 8 bits.

2/n

Starlink withdraws a letter and gets an commercial license for direct to cell 4G text messaging.

A thread. 🧶🐈‍⬛

1/n Here is the filing Space-X withdrew.

Space-X no longer procent objects to FCC measures protecting NASA S-band installations from Starlink emissions abroad.

2/n

$ASTS Requests Testing Authority with Vodafone Spectrum.

Asks to start tests on december 10th 2024 using the five Block 1 BlueBirds.

1/n
Filed yesterday this requests testing in a band operated by Vodafone Turkey.

2/n

A guy in Switzerland listening in on S-band is picking up Bluebirds.

1/n


I belive that 400 MHz TT&C channel is registered much more frequently is due to more radio astronomers listening in that band which also is hobby radio astronomy babd. Not that the S-band isn’t as active. Just fewer listening in.

Still good to see activity.

2/n

And now for the cats take on how a Trump win affects $ASTS.

We will talk about geopolitics, satcom architecture choices and natural selection.

1/n Let me start by saying that I am a rural conservative politician with guns and military grade sensors as my hobbies.

I have no doubt I’d vote republican in a US context. And what I am about to say on Trump winning is not an endorsment of Harris.

I am not part of that division.

Starlink d2c is ising earth moving cells.

Scott (see attached tweet) noticed how this affects network IDs.
Let’s ask ChatGPT if this feature helps Starlink?

🧶🐈‍⬛

Note: AST has purpose built their technology to replicate terrestrial cell sites and AST is using earth fixed cells

https://twitter.com/scott23192/status/1839503316222353633

Oh no, not good.

2/3

Let’s talk about 600 MHz.

That FCC authorized for SCS use.

- who owns it?
- who can provide SCS from it?

1/n T-Mobile owns it.

And a few local/ minor other carriers.

2/n

BlueBirds have all flipped to radar cross section large.

They also exhibit this type of increase
in drag.

I conclude that detumbling was succesful and that the payload now consistently displays a large radar reflecting cross section towards earth.

Likely still inside the LVAs.

BlueWalker 3 exhibited the same signature change of increased drag coefficient and a RCS flip 2022-10-06

~ Launch + 26 days.

The 5 BB1s are all there Launch +10 days.

Practice makes perfect.

2/n

Applications in all four phases.

Observe - sensor input
Orient - coms
Decide - more coms
Act - electronic warfare

Communications use cases but also non communications use cases.

The specs of a set of formation flying BB1 FPGAs makes them FF-SAR FoPen AKA FOLPEN capable.

1/n

https://twitter.com/catse___apex___/status/1799490956737003584

Things has molecules in them. They react to electromahnetic fields differently.

And you can add resolution/ signature by formation flying, by dual polarization and by large bandwidth.

AST does all of that. ✅✅✅👀

2/n

Constellation level aggregated out of band emmission interference is a showstopper for Starlink.

This is due to crazy big leakage in adjacent bands/channels.

So when constellation increase from 300 to 4500 (15x) they need to cut radiated power down to 15%
The system can’t scale There is a term for such a system:

Non-scalable architecture. In technical contexts, this is often referred to as negative scaling or diminishing returns.

2/n

Here are some Carrier to noise specifications of AST SpaceMobile.

In a filing today to the FCC Starlink reveals more of their d2c system.

Click link twice.

1/n licensing.fcc.gov/myibfs/downloa…

https://twitter.com/catse___apex___/status/1822296804903301543

Space-x Starlink d2c will drop from being able to do 5dB SINR (voice) to 0dB (texts)

If they were to comply with FCC rules.

We can now compare this to $ASTS.

2/n

Scotia analysts apparenly read some of the DD shared by the SpaceMob community.

If You want Alpha or ”edge” investing in the nascent SCS market, so should You.

Previously thought by many to be the more technically advanced satcom operator Starlink is not getting approval.

1/n

https://twitter.com/catse___apex___/status/1833538524571963589

🐾 ACLR. Adjacent Channel Leakage Ratio.

Recent requests by Starlink and some math (I was more kind to them than RKF engineering)

Is for Starlink ~-24.6 dBW/m2/MHz
And for AST ~-45 dBW/m2/MHz

This relates to quality of RF equipment.

A 20dB delta.

2/

https://twitter.com/catse___apex___/status/1832574789128454191

A few aspects of a NTN system design affects the area spectral efficiency of the system.

I have touched on them and how they relate to Shannons law.

High directivity that creates narrow beams and small cells is key.
See my pinned tweet.

Then there is also interference.🧶🐈‍⬛ We can think of this as the area spectral efficiency aSE as the main metric by which MNOs will choose which Satellite Network Operator Mobile to work with.

And interference is the metric by which regulators select which SNO-Ms are allowed to operate at all.

Gain affects both
/2

T-Mobile and a Freudian slip.

Decimation. What is that?

🧶🪓🐈‍⬛

Adhering to interference regulations of aggregate OOBE PFD limits would require a deficient system, such as Starlink d2c v2 mini, to use very wide guard bands and/or throttle (shrink) their power.

1/n

https://twitter.com/no_privacy/status/1827007734107025877

PCS spectrum block that Starlink and T-Mobile intends to use is very narrow to begin with this has a large impact.

They need to maximize its use in power and in bandwidth to make the system profitable.

If they do that with deficient / sub par technolgy it affects others.

2/n

Live view of @FCC regulatory staff watching recent Starlink and T-mobile filings asking to be exempt from new rules they helped greate and want to see imposed on others.

🧶🐈‍⬛

1/n

https://twitter.com/spacanpanman/status/1824790814272127409

In 2020 T-mobile asked FCC not to allow ASTs system w/o filings to show that they do not cause harmful interference to terrestrial networks.

$TMUS also requested new rules that FCC started.

AST showed their system doesn’t cause interference. ASTS design criteria since 2018.
2/n

Let’s unpack this $ASTS picture.

First and foremost 150+ heroes building revolutionary technology.

Many Thanks to the @AST_SpaceMobile staff.

🧶🐈‍⬛

1/n It is the same guys as in this picture from january.

But a few things have progressed.

Notice the evolved (as in much more simple & easy) contraption to furl an array on the left.

2/n

https://twitter.com/ast_spacemobile/status/1743421561422430357

There was a meeting between FCC and AST SpaceMobile representatives on July 8th 2024.

What can we learn from the Ex Parte filing?

1/n





”The parties reviewed the current status of AST SpaceMobile’s unopposed amendment, filed on March 11, 2024, converting its Petition for Declaratory Ruling seeking market access to an Application to Launch and Operate under the jurisdiction of the United States (“Amendment”)2”
2/n

CatSEs li’l thread on risks and chance.

Did you know an AST BB block 2 has three seperate redundant Telemetry control links. (S-band, UHF and embedded in the Q/V feeder link).

Why this extreme 3x redundancy?

🎲🐈‍⬛

1/n If you consider success and failure as mutually exclusive dichotomy type entities

All is well v/s total failure.

Then you get:

Probability of succes = 1 - probability of failure.

I can re-label that as:

Chance% = 100% - Risk%

2/n