Every question of this course

Q1.1 In their own definitions clause, what do the documents call IMS?

• The IM CN subsystem
• The IP core
• The multimedia gateway

TS 22.228 defines "IM CN subsystem" as all the core-network elements that provide IP multimedia applications over IP multimedia sessions. IMS is the short name everybody uses for it. "IM CN subsystem" as 22.228 defines it

Q1.2 Which document says it defines the stage-2 service description?

• TS 24.229
• TS 23.228
• TS 22.228

TS 23.228 opens by saying it defines the stage-2 service description for the IP Multimedia Core Network Subsystem. the scope of 23.228

Q1.3 What does TS 24.229 say it defines?

• The service requirements of users and operators
• How the elements of the subsystem fit together
• A call control protocol based on SIP and the associated SDP

Its scope names the Session Initiation Protocol and the associated Session Description Protocol, and calls what it writes a call control protocol. the scope of 24.229

Q1.4 What does access independence mean in TS 22.228?

• Subscribers can reach their IP Multimedia services over any access network capable of providing IP-connectivity
• Every access network has to offer the same speed
• The subsystem works with no access network at all

The definition is about reach and nothing else, and any access network that can provide IP connectivity will do. "Access independence" as 22.228 defines it

Q2.1 What did the first IMS work item set out to define?

• A security assurance specification for IMS network products
• The bytes a phone sends to set up a call
• Concepts regarding general service requirements and service features for Release 2000

Its objective names Release 2000 — an evolved Release 99 plus IM services — and says those services shall support multiple media components per call. what IMS set out to do

Q2.2 Why was interworking with circuit switched networks opened in Release 6?

• So IP-based multimedia services could support basic voice calls to and from PSTN, ISDN and GSM/UMTS circuit switched networks
• Because the radio was too slow for voice
• Because the IETF asked for it

The justification of IMS-CCR-IWCS names those four kinds of network by name, and the objective says the point is basic voice calls. why IMS-CCR-IWCS was proposed

Q2.3 What made 3GPP open WebRTC access to IMS in Release 12?

• The old codecs had run out
• The IETF RTCWEB group and the W3C WEBRTC group were specifying a browser based client for communication services
• Operators had asked for video conferencing

The work item's justification starts outside 3GPP, with two other standards bodies already writing a browser client. why IMS_WebRTC was proposed

Q2.4 How many 3GPP releases does IMS work spread over?

• 345, one per work plan row
• 5, Rel-15 to Rel-20
• 16, Rel-5 to Rel-20

The release field over the 345 IMS work plan rows holds 16 different values, Rel-5 to Rel-20. 345 is the number of rows, not of releases. IMS work items are spread over 16 releases, Rel-5 to Rel-20

Q3.1 Which group has the most IMS documents in this register?

• SA1, the requirements group, with 88
• CT1, with 2169
• SA2, the architecture group, with 429

CT1 has 2169 IMS documents over 66 meetings, the largest count in this register, and it owns TS 24.229. CT1

Q3.2 What kind of document is most of the IMS pile?

• Study reports
• Liaison letters between groups
• Change requests — 3509 of the 4939 documents

A change request is the only way a published specification is ever altered, and it is the largest kind here by a wide margin. 3509 IMS documents are of type CR

Q3.3 How many different names appear as the writer of an IMS document?

• 374, with Ericsson ahead at 602 documents
• 4939, one per document
• 14, one per group

374 distinct names in the writer column. 4939 is the document count and 14 is the number of groups. 374 different names appear as the writer of an IMS document

Q3.4 The earliest IMS document on record went up on 2015-01-23. What does that mean?

• Everything before 2015 was withdrawn
• The store's work item labelling starts there, so every count here is a floor
• IMS work started in 2015

IMS work starts at Release 5, long before this store labels anything. No count in this chapter says a word about the years before 2015-01-23. the earliest IMS document on record went up on 2015-01-23

Q4.1 Which document should somebody open first to see how IMS is put together?

• TS 29.163, interworking with circuit switched networks
• TR 23.801-04, the Release 20 architecture study
• TS 23.228, the stage 2

TS 23.228 is the stage-2 service description and everything else refers back to it. TS 24.229 is the one to read next. TS 23.228

Q4.2 What does this record hold about why a group decided something?

• Nothing beyond the outcome word beside a document number
• The vote counts
• A summary of the discussion

A paper carries a word such as approved, and that word is about the paper. No store here records a reason or a tally. CP-260044

Q4.3 What can this record say about the day Release 16 was frozen?

• It gives the month
• Nothing — no date for any release is stored anywhere in it
• It gives the exact day

Release names, version numbers and meeting days are held; the day a release froze is not. IMS work items are spread over 16 releases, Rel-5 to Rel-20

Q4.4 How many specifications does IMS work touch?

• 345
• 177
• 241

241 specifications. 345 is the number of work plan rows and 177 the number of work item short names. 241 specifications this work touches