School of Specs IMS — the call as an internet sessionOverview

Where it stands, and how to follow it · chapter 7 of 7 · 7 minutes

7 Following it yourself, and what the record cannot tell you

Search by the work item acronym and never by the title, and know the eleven things this record is silent about before you lean on it.

7.1 Search by the acronym, never by the title

3GPP's document store is organised around work item acronyms — the short name a piece of work is filed under, such as IMSProtoc20-CT or FS_IMSResil. Type the acronym and you get the whole conversation. Type a subject and you get a scatter.

For IMS that is not a preference but the only method that works. This register was built by matching the acronym, and the rule is one line: the three letters IMS with no capital letter in front of them. It takes in 345 work plan rows [1] under 177 different acronyms [2].

The lower-case letter is deliberate. 3GPP writes "enhanced" as a small letter in front of a name, so eIMS5G_SBA, eIMS_RP, enIMS and FS_enIMS_ARC are IMS work. A boundary that forbade a lower-case letter as well would leave 163 acronyms and throw those four out [3].

7.2 Four titles that prove the point

Nothing in this register was chosen by reading a name. These four rows are why.

Acronym Its title in the work plan Release
IMS IMS Provisioning of IP-based multimedia services Rel-5
IMS-CODEC IMS-CODEC Multimedia codecs and protocols for conversational PS services Rel-5
IMS_SSFDD IMS_SSFDD IM-SSF Application Server Service Data Descriptions (Stage 2/3) Rel-12
IMS_Corp2 IMS_Corp2 Transfer of ETSI business trunking specifications Rel-12

The first of them is the one that opened the whole subject, and its title does not contain the word IMS. A reader searching for the founding work item by name would conclude it does not exist.

7.3 What a count in this course is a count of

Every number in this course was produced by that same acronym rule, and knowing its shape tells you what each number can and cannot answer.

Documents are counted by matching the acronym in one column of the meeting document store: 4939 rows [4], out of 1629723 meeting documents the store holds altogether [5]. A document filed with no acronym at all is in neither figure.

Work items are counted from the work plan, which is a different file with different bookkeeping. 157 of the 177 acronyms have a work item description on this machine [6], and 36 work items are quoted in this register in their proposers' own words [7].

So a document count and a work plan count are never two views of one thing. They come from two stores that were never reconciled, and putting them in one sentence without saying so is the commonest way to mislead a reader here.

7.4 What this record does not hold

This is the part that keeps everything else honest. Eleven things are simply not in the data, and each one is a sentence somebody could otherwise write and be wrong.

  • No date for any release. The register holds release names, version numbers and meeting days, and nowhere the day a release froze. Never write that a release completed in a particular year.

  • No publication day for any version. What is stored beside a version is the day its file went up on the 3GPP server, which is a different day from the day it was published or approved TS 23.228.

  • No vote, ballot or objection count of any kind. 3GPP works by consensus and no column of any store here records a tally, so nothing in this subject was ever carried by a majority or voted through.

  • No reason for any decision. The stores record the outcome word a document was given — approved, agreed, revised, postponed, withdrawn — and never why the room settled on it SP-260686.

  • No status field for a work item. Nothing says whether work is running, stopped or finished. The only mark of that kind is a word typed into a row's own name: 22 acronyms begin "Deleted" [8] and 1 begins "STOPPED" [9].

  • No completion figure worth trusting as a status. 339 of the 345 rows stand at 100 per cent [10], and that field is a percentage the work plan keeps by hand.

  • No document before 2015-01-23 carries a work item acronym in this store [11], although the subject starts at Rel-5. Every document count in this course is a floor and never a total.

  • No upload time at all for 237 documents [12], which is why a count over one year and a count over the whole record answer different questions and may never be subtracted from each other.

  • No expansion of any abbreviation. The work plan carries an acronym and a title and nothing that says what either stands for. Anything this course says a name means was taken from a specification's own definitions clause.

  • No quotable work item description for 20 of the 177 acronyms. Either no description survives, or several do and none proves it belongs to that row. Nothing may be written about what those work items set out to do.

  • No comparison with any other area of 3GPP work. Nothing here counts positioning, ambient IoT or sensing as subjects of their own, so IMS may never be called the largest, oldest or most argued-over subject in 3GPP.

7.5 The one place the data contradicts itself

The Rel-20 architecture study has two document numbers, and they disagree.

The work item's own table names TR 23.801-03 as the report it will write FS_enIMS_ARC. The catalogue calls TR 23.801-03 a study on MC — mission critical — architecture evolution and 6G capabilities, owned by SA6, with no IMS documents against it at all TR 23.801-03.

Meanwhile 47 IMS documents name TR 23.801-04 in the column that says which document a change targets. Its catalogue title is "Study on IMS Architecture Enhancement", SA2 owns it, and it stands at version 0.1.0 — a number below 1.0.0 is a draft and not a published report TR 23.801-04.

Both numbers are in the register and neither may be quietly picked. If you are following this study, carry both and say which one your source used.

7.6 Where the reading goes next

Start with TS 23.228, the stage 2 description: everything else refers to it TS 23.228. Then TS 24.229 for what is actually on the wire TS 24.229. Those two are the spine, and what sits around them is What they write: the IMS family of specifications.

For what IMS is supposed to do rather than how it is built, TS 22.228 is the requirements document TS 22.228. For what is being decided this year, the papers named in Maintenance, and what is running now are each a work item description, and section 4 of one of those is the objective in the proposers' own words.

The same subject is written twice more in this school. The quick-start course is an hour and leaves you able to say what IMS is and who writes it. The in-depth course is the working reference, for somebody who has to open the documents rather than follow a conversation about them.

This school carries the text of none of the 241 specifications this work touches [13]. It tells you which number answers which question, and hands you a link; the reading happens on 3gpp.org.

Where the numbers in this chapter come from

  1. 345 rows of the 3GPP work plan are IMS work rows of table `item` in /var/www/whatthespec.net/data/database/api/wp.sqlite whose acronym matches the regular expression (?:^|[^A-Z])IMS — the three letters IMS with no capital letter in front of them — out of 9495 rows altogether, read 2026-08-05
  2. 177 different work item acronyms carry IMS distinct values of the acronym field over those 345 rows, read 2026-08-05
  3. 163 of those acronyms survive a boundary that also forbids a lower-case letter the same rows counted with (?:^|[^A-Za-z])IMS instead, which throws out the lower-case 'enhanced' prefix 3GPP writes on eIMS5G_SBA, eIMS_RP, enIMS and FS_enIMS_ARC. Recorded so the rule this register uses can be checked, read 2026-08-05
  4. 4939 IMS meeting documents rows of table `tdoc` whose work item column holds, as a whole word, one of the 177 IMS acronyms — 159 different spellings of that column match, because it sometimes carries two work item names at once, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05
  5. the document store holds 1629723 meeting documents altogether rows of table `tdoc`, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05; 852617 of them carry any work item acronym at all
  6. 157 of the 177 IMS acronyms have a work item description on this machine folders under /var/www/whatthespec.net/data/data/wis holding a converted description that proves it belongs to that work item, read 2026-08-05
  7. 36 work items are quoted here in their proposers' own words work items chosen by name for what they did, plus the 12 with the most documents behind them; each is quoted only where a description in its own folder proves it belongs to it, read 2026-08-05
  8. 22 IMS work item acronyms carry the word Deleted at the front of their own name rows taken in by the acronym rule whose name field begins 'Deleted', read 2026-08-05. The prefix is written by hand into the title and is the only mark of the kind the work plan carries; it is not a status field (FS_IMSRE_SEC, FS_eIMS_IBCF, IMS-EMER, IMS-RT, IMS-SE, IMS8, IMSLocal, IMSProtoc5, IMSProtoc6, IMS_Comm_GqRx_Harm, IMS_RegCon, IMS_RegCon-CT, IMS_RegCon-CT1, IMS_RegCon-CT4, IMS_RegCon-del1, IMS_RegCon-del2, IMS_TELEP_S4, IMS_WebRTC-holmb, IMS_WebRTC-yusef, IRTSD-IMSCS, RANimp-RABSE-IuEnhIMS, VoIMS)
  9. 1 IMS work item acronyms carry the word STOPPED at the front of their own name rows taken in by the acronym rule whose name field begins 'STOPPED', read 2026-08-05. The prefix is written by hand into the title and is the only mark of the kind the work plan carries; it is not a status field (IMSProtoc17_dataCH-UEContest)
  10. 339 of the 345 IMS work plan rows stand at 100% rows taken in by the acronym rule whose completion field reads 1, read 2026-08-05. The field is a percentage the work plan keeps by hand and it is not a status word
  11. the earliest IMS document on record went up on 2015-01-23 the smallest upload stamp over the IMS documents that is 1999-01-01 or later. This is where the store's work item labelling begins and not where IMS work began: the work plan's own Rel-5 rows carry planned days from 2000-01-03, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05
  12. 237 IMS documents carry no upload time IMS documents whose upload column is empty, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05, which is why the per-year counts do not add up to the total and why a count over a year and a count over the whole record answer different questions
  13. 241 specifications this work touches catalogue rows for every document a work item names as one it changes, plus every one named in the change-request column of at least 3 IMS documents, asked of /var/www/whatthespec.net/data/database/api/spec_catalog.sqlite on 2026-08-05

Every source this course is built on

Check yourself

Answers appear when you pick one, with where they come from.

Q7.1 What is the right thing to type into a 3GPP document search to follow this work?

Q7.2 IMS_Corp2 is IMS work. What is it called in the work plan?

Q7.3 339 of the 345 work plan rows stand at 100 per cent complete. What does that tell you?

Q7.4 The earliest IMS document on record went up on 2015-01-23. What does that date mark?

Q7.5 The Rel-20 architecture study sits under two document numbers. What should a reader do with that?

This chapter was built from a source register generated 2026-08-05. A fresher build of the register may hold different numbers.