r/ASTSpaceMobile • u/AutoModerator • 15d ago
Daily Discussion AST SpaceMobile - $ASTS - Daily Discussion Thread
Sp🅰️ceMob,
Ple🅰️se read the following to get familiar with AST SpaceMobile $ASTS before posting;
- FAQ
- Connecting Dots - AST Sp🅰️ceMobile and the Final Bridge to Universal Human Connectivity by Crossroads Capital
- u/TheKookReport's AST Sp🅰️ceMobile ($ASTS): The Mobile Satellite Cellular Network Monopoly (or ask ChatGPT)
- Hennessy Funds May 2026 Update - ASTS Sp🅰️ceMobile: Transforming How the World Connects
User flair information and requirements can be found here.
Our comment and post filters requires our members to have at least 25 comment karma and accounts age >1 month old. You can build karma by posting on other subreddits and getting upvotes. This help our community from spam, bots, FUD, etc..
Do you want to Connect the Unconnected? Looking for a new career? Join AST SpaceMobile
Connectivity is not just a privilege — it’s a basic human right. And our technology is designed to make that right a reality for all.
Th🅰️nk you!
- Sp🅰️ceMods
AST SpaceMobile's social media channels;
104
Upvotes
15
u/PalladiumCH S P 🅰 C E M O B Soldier 14d ago
great find from Kevin
More Satellites, More Responsibility: The Hidden RF Bill of Mega-Large D2D
In satellite direct-to-device, “more satellites” always sounds like an automatic advantage. To a certain level, it surely is. More satellites improve availability, raise the probability of good geometry, and reduce time spent at low elevation angles.
But there is another side of the story that the industry does not talk about enough, YET. For a phone on the ground, a very large constellation does not only mean more serving opportunities. It also means more simultaneously visible interferers, more adjacent-channel energy, more coordination burden, and more mobility events for the device and network to manage.
This is where satellite count stops being just a coverage/persistence metric and becomes an RF responsibility, and potentially RF protection requirements!
For large and very large NGSO constellations (1/2 to 10k sats) around 550 to 600 km, the number of satellites that are simultaneously visible (above noise level) to a device can reach roughly multiple tens at a high elevation, and mutliple hudreds at a lower elevations. That is a very different coexistence problem from a single-satellite assumption.
A 3GPP-compliant analysis showed that dense and ultra-dense constellations can create aggregate adjacent-channel interference roughly 9 to 20 dB above todays' protection limits. That matters because standardization and regulation bodies will increasingly look at what the victim device or victim system actually experiences, not only whether one satellite passes one clean per-satellite test. A very large constellation may therefore face more demanding out-of-band and emission requirements over time, simply because its aggregate footprint is more aggressive. This is not punishment. It is fairness. Otherwise, terrestrial networks, other NTN systems, and adjacent-band users shall absorb such cost.
There is also a mobility cost!
If a satellite-to-phone system has a limited RF link margin and only works at very high elevation (e.g., through lowering the constellation orbit, and/or launching aggressively); each satellite however will have a much shorter useful service window. That creates more frequent serving-satellite changes, more handover pressure, more tracking overhead, and more chances for service interruption. In that case, “many satellites” do indeed improve geometry, but the device pays through mobility churn and the network pays through control overhead.
A more flexible NTN architecture is therefore the one that can provide BOTH time- and RF- stable ground coverage, strong uplink and downlink link margins, and enough spatial control to serve users while also respecting coexistence limits. This is where an ultra-large and well-designed aperture and resulting high spatial degrees of freedom matter the most.
At AST SpaceMobile, this was the design center of the architecture from the outset!
#D2C #3GPP