School of Specs Satellites — a base station in orbitIn depth

680 checked sources · In depth · 185 minutes

Satellites — a base station in orbit

The line of work this course follows opens with one Release 15 radio study, and the local record now holds 183 rows of the work plan under 155 short names, 35306 meeting documents over 550 meetings, 2664 different names as the writers of those documents, and 102 specifications the work created or changed. There is no single document behind it, so this course is a map rather than a guided read: what the words mean in 3GPP's own definitions, why each piece of work said it was needed, how the radio half and the system half were run phase by phase, why RAN4 carries 7490 of these documents and no other group comes near, what the shelf of specifications now holds, and how far each piece has got. Every statement hangs on an entry in a register built from files and databases on this machine, and the course stops where they stop — the last chapter is a full account of what the record cannot say, which for a subject counted only by its work item short names is a long list.

Start at chapter 1 The whole thing on one page Sit the final test

This course was built from a source register generated 2026-08-05.

Same subject, different depth: quick start · overview ·

The chapters

Part 1 What it is and why it was wanted

  1. 1 What a non-terrestrial network is, in 3GPP's own words Every word this subject rests on, quoted from the document that defines it, and the picture those words draw from a phone to a core network. 12 min
  2. 2 Why anyone wanted it, and who said so The reasons groups wrote down for themselves when they asked to open this work, quoted where the register holds them, and an honest count of how often it does not. 11 min
  3. 3 How the work is cut up, and who carries it What counts as satellite work and what was deliberately left out, why 155 short names sit on 183 work plan rows, and which groups carry the weight of the 35306 documents. 14 min

Part 2 The radio

  1. 4 NR over satellite, release by release The main radio line from the Release 15 study to the Release 20 split, with the objectives quoted, the leading group read off each work item's own line, and the document counts that show where the effort went. 15 min
  2. 5 The same idea on the older radio, for things that are not phones The internet-of-things satellite line from the Release 17 study to Release 20, including the time-division mode, store-and-forward operation, and the one work item that had to fix the older core network first. 13 min
  3. 6 Bands, and why RAN4 carries more of this than anybody A large share of the short names in this subject are one radio band each, every one led by RAN WG4, and together they are where the biggest document counts come from. 14 min
  4. 7 Proving it works — the conformance shelf RAN5, the third row of every radio work item, the shelf of test documents behind it, and why a rule can stand at a completion value of 1 while its tests stand at 0.14. 11 min

Part 3 The system

  1. 8 What the system was asked to do SA1's phases, the three study reports they produced, the one specification they all write into, and the four small items that each ask for one thing. 12 min
  2. 9 The architecture, phase by phase — and backhaul, which runs the other way SA2's line from the first architecture study to phase 4, the four study reports behind it, and satellite backhaul, which points the same technology in the opposite direction. 14 min
  3. 10 What the phone says to the network The CT groups turn every architecture decision into messages a device actually sends — CT1 leading three phases of it, with CT3, CT4, CT6 and the CT plenary around them. 11 min
  4. 11 Security, the bills, the management, the layer above and the voice The four groups a reader meets last — SA3, SA5, SA6 and SA4 — each running a study per phase and then a work item that edits somebody else's documents. 14 min

Part 4 What exists, and reading the record yourself

  1. 12 The specifications this work created, and the ones it changes The shelf in two halves — the documents that did not exist before satellites, and the ones that already existed and took the hardest editing. 16 min
  2. 13 What the shape of the paperwork says, and where the work stands Reading the pile itself — what kind of paper it is, what the outcome words mean, why the yearly counts are a floor, and the only measure of progress the work plan actually carries. 15 min
  3. 14 Reading the record yourself, and what it cannot tell you How to search the record with the short names that actually work, which four documents to read to follow what happens next, and the full honest list of every question this data cannot answer. 12 min

Testing yourself

Every question at once

66 questions, chapter by chapter, on one page — for revision after you have read the course.

Open all the questions

The final test

15 questions drawn across the whole course, marked at the end. 70 per cent to pass, and every miss says which chapter to go back to.

Sit the final test

What this course is built on

Chapters
14
Words written for you
34,922
Checked sources
680
Sources this course cites
433

Every source