Cheat sheet

Satellites — a base station in orbit

3GPP's satellite work in one morning

Depth: Overview
Chapters: 7
Reading: 50 min
Questions: 35
Sources cited: 226

Back to the course

The shape of it

1 What it is and why it was wanted

2 The two halves, and who runs them

3 What exists, and where it stands

Keep these in your head

1.3 What a non-terrestrial network is
Transparent payload: the satellite shifts the frequency, filters and amplifies, and the thinking happens on the ground. Regenerative payload: the satellite demodulates and decodes, so part of the base station is in orbit. Release 17's radio rules assumed the transparent one ^[1].
2.2 Why anyone wanted it
The stated reason for the internet-of-things satellite work is coverage where there is none, with transport and logistics named first. Everything else in that line of work — the phases, the bands, the power saving — is refinement on top of that one sentence.
3.3 How the work is cut up, and who carries it
The line of work this course is about begins in Release 15. Everything older in the work plan under this subject — a positioning row, two North American band items and a television return channel — carries no meeting document at all.
4.2 The radio half, release by release
Release 17 is where the satellite subject stops being homework. Before it there are two study reports; after it there is TS 38.108 TS 38.108, what a satellite base station must transmit and receive, and TS 38.181 TS 38.181, its tests. That work item's core part carries 4346 documents ^[2].
5.3 The system half: 5GSAT, phase by phase
Phase 2 of 3GPP's satellite system work has one subject, and its work item names it — satellite discontinuous coverage. Everything in that phase is about a link that is there, then gone, then back ^[3].
6.6 What is on the shelf, and why the bands weigh so much
A large share of 3GPP's 155 satellite short names are one radio band each, split into a core part, a performance part and often a conformance part, and every one of them changes the same handful of documents again ^[4]. That repetition is where the biggest counts in the subject come from.
7.1 Where it stands, how to follow it, and what the record cannot say
The 3GPP work plan holds no status word. A row gives a planned day and a number between 0 and 1, so "this work is finished" is a sentence the record cannot support — only "the plan for this row is complete".

Easy to get wrong

1.2 What a non-terrestrial network is
A satellite access node is not "the satellite". TS 38.108 defines it as covering the payload on the platform and the satellite-gateway and base-station functions together. Somebody who hears SAN and pictures only the thing in orbit will misread every requirement written about it.
2.1 Why anyone wanted it
"Why 3GPP did satellites" has no answer in this data. What exists is why each piece of work was proposed, written by whoever proposed it. A reason quoted here is a proposer's argument, never a group's decision: no store on this machine records why a room settled on anything.
3.2 How the work is cut up, and who carries it
"155 work items" and "183 work items" are both wrong on their own. There are 155 short names and 183 work plan rows, and the two answer different questions. Anybody quoting a size for this subject has to say which of the two they counted.
4.1 The radio half, release by release
TR 38.811 and TR 38.821 are study reports, not rules. Nobody builds equipment from them; they are the homework the Release 17 rule-writing rested on. This school holds no parsed text of either, so both can be named and counted here and never quoted.
5.7 The system half: 5GSAT, phase by phase
TS 22.261 is not a satellite specification. It is the 5G system's service requirements for everything, and satellite work arrives in it as added paragraphs — five of these work items name it in their own table of what they change TS 22.261.
6.5 What is on the shelf, and why the bands weigh so much
TS 38.133 being the heaviest document in 3GPP's satellite register does not make it a satellite document. It is the general radio resource management specification for NR, and satellite work reaches it as change requests — 1306 of them TS 38.133.
7.5 Where it stands, how to follow it, and what the record cannot say
A completion value of 1 does not mean a piece of work is finished, and a value below 1 does not mean it is late. The value is what the plan says about the plan. The plan holds no field for running, stopped or finished, so neither does anything read out of it.

The numbers, and where each came from

Every one was counted out of a file on this machine. Hover a row to read the question that produced it.

Where to look it up

The 197 named sources it cites, by what they are.

Work item 65

ANSS IoT_SAT_ARCH_EPS L_Band_LTE_ATC_MSS S_Band_LTE_ATC_MSS IMSSat IMSSat-SA1 FS_NR_nonterr_nw FS_NR_NTN_solutions NR_NTN_solutions NR_NTN_enh NR_NTN_Ph3 NR_NTN_GNSS_resilient NR_NTN_IoT_NTN_ext_guard NTN_bands_Features_R20 NR_IoT_NTN_req_Ph2 LTE_TN_NR_NTN_HO LTE_TN_NR_NTN_mob FS_LTE_NBIOT_eMTC_NTN LTE_NBIOT_eMTC_NTN IoT_NTN_enh IoT_NTN_Ph3 IoT_NTN_Ph4 IoT_NTN_TDD FS_5GSAT 5GSAT FS_5GSAT_ARCH 5GSAT_ARCH 5GSAT_ARCH-CT FS_5GSAT_Ph2 5GSAT_Ph2 FS_5GSAT_Ph3 5GSAT_Ph3 FS_5GSAT_Ph3_ARCH 5GSAT_Ph3_ARCH FS_5GSAT_Ph4 FS_5GSAT_Ph4_ARC 5GSAT_Ph4-ARC 5GSAT_Ph4-CT 5GSAT_Ph4-SEC 5GSAT_Ph4-APP FS_5GSAT_Ph4_CH FS_5GSATB 5GSATB 5GSATB_CH 5GSATB_OAM TEI20_QoS_MWAB_SAT TEI20_QoS_MWAB_SAT-CT FS_ULBC NR_NTN_LSband NR_NTN_Sband NR_NTN_Ku_bands NR_NTN_combinedLband NR_NTN_CBW_30MHz IoT_NTN_extLband IoT_NTN_FDD_LS_band IoT_NTN_FDD_S_band LTE_band_5G_bcast_GSO LTE_band_246_5G_bcast_GSO_BWs NR_NTN_solutions-Core NR_NTN_solutions-Perf NR_NTN_solutions_plus_CT-UEConTest NR_NTN_Ph3-Core NR_NTN_Ph3-Perf NR_NTN_Ph3-UEConTest NR_NTN_combinedLband-Perf

Quoted wording 47

"non-terrestrial networks" as 38.108 defines it "Satellite Access Node" as 38.108 defines it "Very Small Aperture Terminal (VSAT)" as 22.887 defines it "UE-Satellite-UE Communication" as 23.700-19 defines it "NTN" as 38.108 spells it out "satellite" as 38.108 defines it "SAN" as 38.108 spells it out "Transparent payload" as 38.863 defines it "Regenerative payload" as 38.742 defines it why NR_NTN_enh-Core was proposed "Service link" as 38.863 defines it "feeder link" as 38.108 defines it "satellite-gateway" as 38.108 defines it "NTN Gateway" as 23.700-19 defines it "GEO" as 38.108 spells it out "LEO" as 38.108 spells it out "Geostationary Earth Orbit" as 38.108 defines it "Serving satellite" as 23.700-19 defines it "Satellite beam" as 38.742 defines it "satellite access" as 22.887 defines it "Resilient Notification" as 22.887 defines it why LTE_NBIOT_eMTC_NTN was proposed why NR_NTN_Ku_bands-Core was proposed why FS_ULBC was proposed why IoT_NTN_Ph3-Core was proposed why IoT_NTN_TDD-Core was proposed the objective of FS_ULBC why FS_5GSAT_Ph4_ARC was proposed the objective of NR_NTN_solutions-Core the scope of 38.742 the objective of LTE_NBIOT_eMTC_NTN the objective of NR_NTN_Ph3-Core the objective of 5GSAT_ARCH-CT the objective of 5GSAT_Ph2 why 5GSAT_Ph3_ARCH was proposed the objective of FS_5GSAT_Ph4_ARC the objective of 5GSATB the scope of 22.865 the scope of 23.700-29 the scope of 38.108 the scope of 38.181 the scope of 38.101-5 the scope of 38.521-5 the scope of 36.108 the scope of 36.102 the scope of 38.863 the scope of 23.700-19

Specification 47

TS 38.108 TR 38.863 TR 38.742 TR 22.887 TR 23.700-19 TR 38.811 TR 38.821 TS 38.181 TR 36.763 TS 38.101-5 TS 36.108 TS 36.102 TR 22.822 TS 22.261 TR 23.737 TS 23.501 TS 23.502 TS 23.503 TR 24.821 TR 23.700-28 TR 22.865 TR 23.700-29 TS 24.301 TR 23.700-27 TR 33.700-28 TR 33.700-29 TR 33.700-30 TR 28.844 TR 28.846 TR 28.894 TR 28.808 TR 28.841 TR 28.874 TR 23.700-01 TR 23.700-02 TR 26.940 TS 38.521-5 TS 36.181 TS 36.521-4 TS 38.133 TS 36.133 TS 38.331 TS 23.401 TS 24.501 TS 38.300 TR 38.741 TR 36.764

Wg 18

RAN5 RAN4 RAN2 RAN1 SA2 CT1 RAN3 RAN SA5 SA1 SA3 SA6 SA4 CT3 CT4 CT SA CT6

Release 9

Rel-8 Rel-10 Rel-12 Rel-15 Rel-16 Rel-17 Rel-18 Rel-19 Rel-20

Meeting document 8

RP-101284 RP-110775 RP-171450 RP-190710 RP-261568 SP-260423 CP-261281 RP-253813

Meeting 3

RP-76 RP-83 RP-112

Where to go from here

The same subject, quick start — Under an hour, four chapters, the shape of the thing.
The same subject, in depth — The working reference: every mechanism, every parameter.
Every question of this course — 35 of them, on one page.
The final test — 12 questions, 70 per cent to pass.
Every source behind the course — 680 of them, each with its method.

The raised numbers on this page

why NR_NTN_enh-Core was proposed — section 3 of the work item description /var/www/whatthespec.net/data/data/wis/941106/RP-232669 R18 WID NR_NTN_enh_v19.md, read 2026-08-05
4346 documents carrying the work item NR_NTN_solutions-Core — rows of the tdoc table whose work item column names NR_NTN_solutions-Core as a whole word; the first and last meeting are those of its earliest and latest upload time, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05
the objective of 5GSAT_Ph2 — section 4 of the work item description /var/www/whatthespec.net/data/data/wis/989998/SP-230109_clean_S2-2303910_WID_5GSAT_Ph2.md, read 2026-08-05
155 Satellites work item acronyms — distinct acronyms over the 183 work plan rows this subject's rule selects, asked of /var/www/whatthespec.net/data/database/api/wp.sqlite on 2026-08-05