The final test

E1 Which protocol document does CT1 change most often over the whole record?

• TS 24.301, with 5422 change documents
• TS 24.229, with 3413 change documents
• TS 24.501, with 15623 change documents

E2 What does the scope of TS 24.501 say the document applies to?

• Every function of the 5G core network
• The UE, the AMF, the SMF and the PCF
• The UE and the base station

E3 When may a device start a 5GS session management procedure?

• As soon as the radio connection is established
• Only once a 5GMM context exists and the AMF has started secure exchange of NAS messages
• Only while a registration procedure is running

E4 A registration is accepted and the session request piggybacked inside it is rejected. Is that possible?

• No, the two always succeed or fail together
• Only when the device is roaming
• Yes — the success of the mobility procedure does not depend on the piggybacked session procedure

E5 What is in the first octet of every 5GS NAS message?

• The message authentication code
• The message type
• The extended protocol discriminator

E6 What does a receiver send back on getting a message type it does not recognise?

• A status message with cause #97, message type non-existent or not implemented
• A security mode reject
• Nothing; the message is silently discarded

E7 In a 3GPP version number x.y.z, what does a first digit of 3 or greater mean?

• The document belongs to Release 3 or later
• The document is approved and under change control
• The document has been presented for approval

E8 At meeting C1-161, which outcome word was recorded on the most documents?

• noted, with 53
• agreed, with 174
• revised, with 259

E9 CT5 does not appear in either liaison statement table. What follows?

• CT5 is not a CT working group
• CT5 exchanged no letters with CT1 in the year
• Only that CT5 is not among the four busiest partners in that direction

E10 Why can a twelve-month CT1 document count not be compared with an all-time one?

• 7181 documents carry no upload date, so they are in the all-time counts and cannot be in the yearly ones
• The yearly counts are estimates
• The all-time counts stop in 2015

E11 Which spelling of the group's name appears in front of every one of its document numbers?

• C1
• CN1
• CT1

E12 What does the reference list of TS 24.501 call TS 23.501?

• Service requirements for the 5G system; Stage 1
• System Architecture for the 5G System; Stage 2
• Procedures for the 5G System; Stage 3

E13 How many CT1 specifications are active?

• 199
• 237
• 229

E14 What are the two protocols defined inside TS 24.501?

• EPS and 5GS
• 5GMM and 5GSM
• NAS and RRC

E15 How many types of 5GMM procedure does the document distinguish?

• Three — common, specific, and connection management
• Five, one per message pair
• Two — network-initiated and UE-initiated

E16 Who can start a registration procedure?

• Only the device
• Only the AMF
• Either side

E17 What is in the first octet of every 5GS NAS message?

• The sequence number
• The message type
• The extended protocol discriminator

E18 What does the second digit of a 3GPP version number mean?

• The number of change requests in that version
• The Release the document belongs to
• It is incremented for all changes of substance

E19 How many documents were put to meeting C1-161?

• 174
• 617
• 4235

E20 Which group received the most outgoing liaison statements from CT1 in the last twelve months?

• RAN2, with 44
• CT4, with 8
• SA2, with 19