8 The post — who wrote to 3GPP, and who 3GPP wrote back to

8.1 A plenary as a post office

3GPP does not work alone. Other standards bodies, industry groups and public authorities have views on what a mobile network should do, and 3GPP's own groups have to tell each other things too.

All of that arrives as a liaison statement — a letter with a document number, handled at a meeting like any other paper. The plenary is where the letters addressed to TSG SA land, and where the letters TSG SA sends are approved.

The agenda gives it a place of its own near the front: item 2, which took twenty-two documents ^[1].

8.2 The traffic

• 18 incoming liaison statements ^[2]

• 2 outgoing ones ^[3]

• 18 documents typed "LS in" ^[4] — the same eighteen, counted from the document database rather than from the report's annex, which is the best kind of agreement between two sources.

Eighteen in and two out is the ratio to remember. A plenary reads far more than it writes.

8.3 Three kinds of correspondent

The eighteen letters do not all come from the same kind of place, and the difference changes what the plenary can do about them.

• Another 3GPP group. SP-260372 is SA WG2 telling the plenary where the 6G architecture study has got to. This is internal traffic: the plenary can act on it directly, because the group that wrote it reports into the room.

• An industry body. SP-260385 is the NGMN Alliance on 6G deployment timeframes. 3GPP has no authority over the sender and the sender has none over 3GPP, so the exchange is information, not instruction.

• A sector that is worried about being left out. SP-260382 is the Utility Technology Council asking that gas and water metering and long-life low-power devices keep a path into 6G.

The third kind is the one worth watching. A letter like that is a group with no seat at the drafting table using the only channel it has, and the plenary's answer — noting it — is neither a promise nor a refusal.

8.4 What usually happens to an incoming letter

It is read and filed. Sixty-eight documents ended the meeting noted ^[5], and almost every incoming letter is among them.

Three of this meeting's letters, all noted:

• SP-260372 — SA WG2 reporting where the 6G architecture study stands. One 3GPP group writing to another.

• SP-260385 — the NGMN Alliance on when 6G can realistically be deployed.

• SP-260382 — the Utility Technology Council, asking that gas and water meters and long-life low-power devices not be forgotten in 6G.

8.5 The one that got an answer

Exactly one document of the meeting carries the status "replied to" ^[6] — SP-260363, from ETSI TC EMTEL, about accessibility parameters in emergency communications.

The answer is SP-260655, approved and sent.

A second draft of the same reply was written by a different company and did not survive: SP-260613, from Nokia, ended merged — folded into the document that went out. Two documents of the meeting ended merged ^[7].

That is worth pausing on, because it is the whole of 3GPP's method in one exchange. Two companies wrote competing answers to the same letter. Neither was voted down. One was folded into the other and one document left the room.

The meeting also approved a study item on additional capabilities for emergency communications SP-260654. It is the same subject, decided at the same meeting. The record does not state that one caused the other, and neither does this course.

8.6 How an answer gets written

That one exchange contains the whole mechanism, and it is worth setting out as steps because the next plenary will do the same thing.

• L1. The letter arrives and gets a number and an agenda item like any other document SP-260363.

• L2. Somebody drafts a reply. More than one somebody, in this case. A draft reply is a document of the meeting in its own right, with its own number and its own status.

• L3. The drafts converge. Nokia's ended merged SP-260613. Nothing was voted down; one text absorbed the other.

• L4. The surviving draft is approved and becomes an outgoing letter SP-260655 — one of only two at this meeting ^[3].

• L5. The incoming letter's status changes to "replied to", which is why exactly one document of the meeting carries that word ^[6].

Five steps, four documents, one answer. Every other incoming letter stopped at step one.

8.7 The other outgoing letter

SP-260697, on 6G terminology, went out to the working groups of the other two TSGs.

It is the tail of the naming decisions chapter Release planning — the timeline, the checkpoint and the names covers: "It was decided to use '6GC' or '6G CN'." ^[8] for the core network's name, and a request that SA WG2 develop the 6G interface names and report to the TSGs in September 2026 ^[9].

An outgoing liaison statement is how a plenary makes a decision stick outside its own room. Deciding to call it "6GC" is worth little if the radio side keeps calling it something else, so the decision travels as a letter.

8.8 The arithmetic of the liaison item

The liaison item carried twenty-two documents ^[1]. The meeting took 18 letters in ^[2] and sent 2 out ^[3], and one of the two outgoing ones was handled under early treatment rather than here SP-260697.

The difference is the paper an exchange generates about itself: draft replies like SP-260613, which are documents of the meeting even though they never leave the building.

It is a small sum and it makes a general point. An agenda item's document count is not a count of the subject it is named after. Chapter How to read a plenary agenda makes the same point about the change-request bins.

8.9 What the postbag says, and what it does not

Every letter named above is about 6G in some form: the architecture study's progress, the deployment timeframe, the device classes that must not be stranded, and the vocabulary.

That is a fair reading of this meeting's postbag, and it is as far as the reading goes. The record does not say who agreed with any of the letters, how many companies shared a view, or what 3GPP will do next about any of them.

There is one more thing the postbag is good for, and it costs nothing to check. Compare the incoming letters of two consecutive plenaries and you can see what the outside world has started worrying about, months before it shows up as a work item. At SA#112 the answer is 6G: its architecture, its timing, its vocabulary and the devices it might strand.

One more paper belongs in this chapter even though it is not a liaison statement. Ten public bodies wrote asking for 6G to be designed to be secure from the start SP-260584. It was noted, and its revision was withdrawn during the meeting SP-260643. Outside voices reach a plenary in more than one shape.

8.10 Where this leads

That completes the substance of the meeting. Part 3 weighs it: first what the release numbers say about where the work is going, in Release 20 at this meeting, and what the numbers will not say, and then what the record it is all written in is actually worth, in The report is a draft, and it shows.