1 What TSG RAN is, and why the radio gets a group of its own

1.1 The problem that makes a committee necessary

A phone bought in one country has to work on a mast in another, built by a different company, running software from a third.

Nothing in the phone and nothing in the mast can fix that on its own. The only thing that makes it work is a written agreement, settled before either was built, about what is sent over the air and what it means.

The radio is where the agreement bites hardest. Two boxes that disagree about a message on a wire can be patched; two boxes that disagree about the shape of a signal in the air simply do not hear each other.

It is also the part with the most kinds of question in it at once. The signal, the conversation over that signal, the links between masts, the transmitter limits and the proof that a given phone obeys all of them are five different skills, and no single room does them all well.

1.2 Three words that keep coming back

Before the group makes sense, three of its words have to.

A specification — a TS — is a rule other people have to follow. A study report — a TR — is a piece of homework a group did before deciding anything. A change request is the only way a published specification is ever altered.

Almost everything counted in this course is one of those three, or a paper arguing about one of them.

1.3 What the group is made of

TSG RAN — the technical specification group that standardises the radio side of a mobile network — is a plenary plus six working groups RAN.

The six are RAN1, RAN2, RAN3, RAN4, RAN5 and RAN6. Five of them still meet; RAN6 is the only one the group catalogue marks as closed RAN6.

Each has one job. RAN1 takes the signal itself, RAN2 the protocols spoken over that signal, RAN3 the connections between the boxes, RAN4 the measurable radio performance, RAN5 the tests a phone has to pass, and RAN6 the old GSM radio RAN1 RAN2 RAN3 RAN4 RAN5.

The next chapter, The six working groups and the line between them, takes each of them in turn.

1.4 The plenary decides, and it also writes

It is easy to read "plenary" as a rubber stamp, and here it is not one.

Two kinds of paper sit there. One is the old work: the renumbered GSM documents such as 44.018 and 45.005, 179 active documents from the 3G and GSM series in all TS 44.018 TS 45.005 ^[3].

The other kind is the forward-looking homework — a study report is a piece of work a group does before deciding anything. The plenary holds 38.913 on the requirements that became 5G, and 38.914 on 6G TR 38.913 TR 38.914.

1.5 How much of 3GPP this is

RAN owns 1059 active documents ^[2].

All of 3GPP together owns 3599 ^[4], and 1059 of those are RAN's.

Paper from meetings tells the same story more loudly. The local database holds 811563 RAN meeting documents ^[5] out of 1629581 for all of 3GPP ^[6].

And 3230 separate pieces of work were opened by a RAN plenary document ^[7].

1.6 The document this course reads

Every claim in this course about the radio itself comes from one specification: TS 38.300, the overall description of NR and the NG-RAN. NR is the 5G radio, and NG-RAN is the network of base stations that speaks it.

It belongs to RAN2, not to the plenary TS 38.300.

It says plainly what it is and what it is not:

So it is a map, not a manual. It names the boxes, the interfaces and the layers, and points at the document that carries each one in full.

The same sentence draws a second line, this one between radio technologies: the 4G radio hanging off a 5G core is covered in the 36 series, not here §1. Which document series a thing lives in is how 3GPP keeps two radios apart inside one network.

That shape shows immediately. A base station in this network is one of two things — a gNB, which speaks NR, or an ng-eNB, which speaks the 4G radio into a 5G core — and both are joined to each other and to the core the same way §4.1.

1.7 The beat the group runs on

The work is not continuous. It arrives in weeks.

The plenary meets four times a year, usually for four days, and the five open working groups meet together in their own week — same week, same place, five days 3GPPRAN#112 3GPPRAN1#125.

The plenary then sits a few weeks after that week, deciding on work the groups have just finished: the groups met on 2026-05-18, the plenary on 2026-06-08 3GPPRAN1#125 3GPPRAN#112.

That is the shape to hold on to. Groups draft, the plenary decides, and the calendar in How to follow TSG RAN yourself, and what the record will not tell you fills in the rest.

1.8 Where the numbers on this page come from

Every count on this page was read out of a database or a folder on one machine, and the register behind the course records the exact question that produced it.

That is worth saying out loud, because it also fixes the limits of the course. The counts describe what this machine holds, not what 3GPP holds. Where the difference could matter, the text says "the local record".

The last chapter, How to follow TSG RAN yourself, and what the record will not tell you, sets out what else the record cannot tell you — and there is a good deal of it.