Every question of this course

Q1.1 How many working groups does TSG RAN have, and how many of them still meet?

• Six groups, five still meeting
• Five groups, all still meeting
• Six groups, all still meeting

RAN1 to RAN6 are six. The group catalogue marks RAN6 as closed and the other five as still meeting. RAN6

Q1.2 How many of the 3599 active 3GPP documents does RAN own?

• 1059
• 3230
• 198

1059 active RAN documents against 3599 active 3GPP documents in the same catalogue, both counted on the same day. 198 of the 1059 are the plenary's own; 3230 is the count of pieces of work RAN has opened. 1059 active RAN specifications

Q1.3 What is an NG-RAN node, according to TS 38.300?

• Only a gNB
• Any base station connected to any core network
• Either a gNB or an ng-eNB

The first line of the architecture clause gives exactly two kinds — a gNB, which terminates NR towards the device, and an ng-eNB, which terminates E-UTRA towards it. §4.1

Q1.4 Does the RAN plenary own documents itself, or only chair the working groups?

• It owns documents but only study reports
• Only chair, the documents all sit in working groups
• It owns documents itself — 198 active ones

The catalogue records 198 active documents whose owning group is the plenary, including the old GSM numbers and the forward-looking studies. 198 active RAN plenary specifications

Q1.5 Where does TS 38.300 say the detail of the radio interface protocols lives?

• In companion specifications of the 38 series
• In TS 23.501
• In the same document, further down

The scope says the document is an overview and that the details are specified in companion specifications of the 38 series. §1

Q2.1 Which group owns TS 38.331, the document that defines every message of the radio connection?

• RAN2
• RAN3
• RAN1

38.331 is RAN2's, along with the three layer-2 protocols 38.321, 38.322 and 38.323 and the overall description 38.300. TS 38.331

Q2.2 Which of these documents does RAN3 own?

• 38.101-1, the phone's radio requirements
• 38.211, channels and modulation
• 38.413, the protocol to the core network

RAN3 owns the interfaces — 38.401 the architecture description, 38.413 to the core, 38.423 between base stations and 38.473 inside a split base station. TS 38.413

Q2.3 What does RAN4 write?

• The messages a phone sends
• Transmit power, receiver sensitivity and radio resource management requirements
• The test cases a phone has to pass

RAN4 is radio performance — the measurable side. Its three best known documents are 38.101-1 for the phone, 38.104 for the base station and 38.133 for radio resource management. 427 active RAN4 specifications

Q2.4 What happened to RAN6?

• It merged into RAN2
• It is closed, and has not met since 2020
• It never existed as a separate group

The group catalogue marks it closed, and the last RAN6 meeting on record was a one-day teleconference on 26 October 2020. 3GPPRAN6#18-Decision Teleconference

Q2.5 Who holds the renumbered GSM documents such as 44.018 and 45.005 now?

• RAN4
• RAN6, which still owns them although it is closed
• The RAN plenary

179 active documents from the 3G and GSM series sit with the plenary, not with the closed working group. 179 active documents the RAN plenary holds from the 3G and GSM series

Q2.6 In TS 38.300's layer-2 picture, what does the MAC sublayer offer upwards?

• Logical channels
• Radio bearers
• Transport channels

The physical layer offers transport channels to MAC; MAC offers logical channels to RLC; RLC offers RLC channels to PDCP; PDCP offers radio bearers to SDAP. §6.1

Q3.1 Which RAN group owns the most active documents?

• RAN3, with 168
• RAN1
• RAN4, with 427

RAN4 has 427 active documents. RAN3, the next largest working group, has 168. 427 active RAN4 specifications

Q3.2 Most of RAN4's active documents are of which kind?

• Test cases
• Specifications
• Study reports

352 of RAN4's 427 are study reports. Only 75 are specifications. 352 active RAN4 study reports (TR)

Q3.3 Which group is the exception to that pattern?

• RAN5, where 72 of 84 documents are specifications
• RAN1, where 51 of 66 are study reports
• RAN2, which is evenly split

RAN5 is the one group whose paper is mostly rules rather than homework — 72 specifications against 12 study reports. 72 active RAN5 specifications (TS)

Q3.4 Which group had the most people in the room at the meeting week of 18 May 2026?

• The plenary, with 396
• RAN1, with 710
• RAN4, with 344

RAN1 had 710 people at RAN1#125. RAN2 had 426, the plenary 396 at its own meeting, RAN4 344, RAN5 274 and RAN3 202. 710 people sat in the room at 3GPPRAN1#125

Q3.5 What is the heaviest single meeting week in this record?

• RAN4#118, with 3141 documents
• RAN#112, with 743 documents
• RAN1#125, with 1688 documents

RAN4#118 in February 2026 carried 3141 documents across five days. 3GPPRAN4#118

Q4.1 Which two interfaces join an NG-RAN node to the rest of the world?

• Uu to other base stations, NG to the core
• Xn to other NG-RAN nodes, NG to the 5G core
• F1 to other base stations, S1 to the core

The architecture clause says gNBs and ng-eNBs are interconnected by Xn and connected to the 5GC by NG — NG-C to the AMF and NG-U to the UPF. §4.1

Q4.2 What selects the AMF when a device attaches and nothing in what it sent points at one?

• The UPF
• The device
• The gNB or ng-eNB

Selecting an AMF at attachment, when no routing to one can be worked out from what the device provided, is on the list of functions the base station hosts. §4.2

Q4.3 How does the sub-carrier spacing of NR scale?

• It is chosen freely by the operator
• It is fixed at 15 kHz
• As 2 to the power µ times 15 kHz

The numerology clause gives the spacing as 2^µ × 15 kHz, with the allowed values of µ listed separately for synchronisation and for everything else. §5.1

Q4.4 How many physical resource blocks fit on one carrier at most?

• 1024
• 100
• 275

Twelve consecutive sub-carriers make one physical resource block, and the clause says up to 275 of them are supported on a carrier. §5.1

Q4.5 What is the difference between a transport channel and a logical channel?

• A transport channel says how data is carried, a logical channel says what is carried
• A transport channel is for the uplink, a logical channel for the downlink
• There is none; the two words are used interchangeably

The clause on transport channels says so directly, and warns that the two must be kept apart. §5.5

Q5.1 Which sublayer does the ciphering of user data?

• PDCP
• SDAP
• MAC

Ciphering and deciphering, integrity protection and verification, and header compression are all in the PDCP service list. §6.4.1

Q5.2 Which RLC transmission mode is used for signalling radio bearer 0, paging and broadcast system information?

• Acknowledged mode
• Transparent mode
• Unacknowledged mode

The clause says transparent mode for SRB0, paging and broadcast system information; acknowledged mode for other signalling bearers; and either unacknowledged or acknowledged for data bearers. §6.3.1

Q5.3 How many SDAP entities does a device have?

• One per device
• One per PDU session
• One per data radio bearer

The clause says a single protocol entity of SDAP is configured for each individual PDU session. §6.5

Q5.4 What is a bandwidth part?

• The bandwidth reserved for control signalling
• The whole bandwidth of the cell
• A subset of the cell's bandwidth, of which one is active at a time

Bandwidth adaptation configures the device with bandwidth parts and tells it which one is active; the width, the position in frequency and the sub-carrier spacing can all be changed. §6.10

Q5.5 Where do the schedulers live?

• In RRC in the gNB
• In the UPF
• In MAC in the gNB

The scheduling clause says MAC in the gNB includes dynamic resource schedulers that allocate physical layer resources for downlink and uplink. §10.1

Q5.6 In carrier aggregation, what does the multi-carrier nature of the physical layer get exposed to?

• Only MAC, which needs one HARQ entity per serving cell
• Every sublayer equally
• Only RRC

The clause says the multi-carrier nature is only exposed to MAC, which is why there is one independent hybrid-ARQ entity per serving cell. §6.7

Q6.1 In RRC_INACTIVE, who initiates paging?

• Nobody; a device in this state cannot be paged
• The 5G core
• The radio network

The state list says paging is initiated by NG-RAN in RRC_INACTIVE, and by the 5GC in RRC_IDLE. A device in RRC_INACTIVE also monitors for core-initiated paging. §7.2

Q6.2 What does the network keep while a device is in RRC_INACTIVE?

• Only the device's identity
• Nothing; the context is deleted as in RRC_IDLE
• The device context and the core-network connection, at the last serving base station

In RRC_INACTIVE the last serving gNB keeps the context and the device-associated NG connection with the serving AMF and UPF, so the connection is suspended rather than torn down. §9.2.2.1

Q6.3 What happens to the radio keys when a device goes from connected to idle?

• The base station and the device delete them; the AMF keeps the core keys
• They are handed to the AMF for storage
• The base station keeps them in case the device comes back

On connected-to-idle transitions the gNB and the device delete NH, KgNB and the four derived keys and the related counter, while AMF and device keep the core keys. §13.3

Q6.4 What is an acceptable cell, as opposed to a suitable one?

• One in a forbidden tracking area
• One whose measurements pass and which is not barred, but which need not match the selected network
• One that is barred but reachable

A suitable cell also has to belong to the selected, registered or an equivalent network and not be in a forbidden tracking area. An acceptable cell only has to pass the measurement criteria and not be barred. §9.2.1.1

Q6.5 How does a device in RRC_INACTIVE know when to tell the network it has moved?

• It reports when it reselects a cell outside its RAN-based notification area, and periodically
• It never reports; the network tracks it
• It reports every cell change

A notification area update is sent periodically and whenever cell reselection picks a cell that is not in the configured area. §9.2.2.3

Q6.6 Which state is small data transmission designed for?

• RRC_IDLE
• RRC_INACTIVE
• RRC_CONNECTED

SDT allows data or signalling to be sent while remaining in RRC_INACTIVE, without transitioning to RRC_CONNECTED. §18.0

Q7.1 In the four-step random access procedure, what is in MSG1?

• A preamble on PRACH
• A preamble and a payload
• The device's identity and its first message to the core

MSG1 of the four-step type is a preamble on PRACH. The two-step type sends a preamble and a payload together, as MSGA. §9.2.6

Q7.2 Which node decides that a handover should happen?

• The device, from its own measurements
• The source base station, from the measurement report and its own radio information
• The AMF

Step 2 of the handover procedure is the source gNB deciding, based on the MeasurementReport and RRM information. The device measures and reports; it does not decide. §9.2.3.2.1

Q7.3 What is a conditional handover?

• A handover the core network may veto
• A handover the device executes itself once a configured condition is met
• A handover to a cell of a different radio technology

The device starts evaluating the execution conditions when it receives the configuration and executes the handover when one is met. The candidate configurations come from the candidate base stations, the conditions from the source. §9.2.3.4.1

Q7.4 Where does the device get the information it needs to access the target cell during a handover?

• The AMF sends it over NG
• It reads the target cell's system information after arriving
• It is in the reconfiguration message the source forwards

The message includes at least the cell identity and everything needed to access the target cell, so the device can get in without reading system information. §9.2.3.1

Q7.5 What does the device do first after declaring radio link failure in the ordinary case?

• Goes straight to RRC_IDLE
• Stays in RRC_CONNECTED, selects a suitable cell and starts re-establishment
• Waits for the network to page it

The device stays in RRC_CONNECTED, selects a suitable cell and starts re-establishment, and only enters RRC_IDLE if no suitable cell is found within a certain time. §9.2.7

Q7.6 At which two levels is a measurement filtered before it can trigger a report?

• At MAC and at PDCP
• At the device and at the base station
• At the physical layer and at RRC

Filtering happens at the physical layer to derive beam quality and then at RRC level to derive cell quality from multiple beams. §9.2.4

Q8.1 What is the finest granularity of quality-of-service differentiation in a PDU session?

• The data radio bearer
• The PDU session
• The QoS flow

The QoS clause says the QoS flow is the finest granularity at NAS level, identified inside a session by a QoS flow identifier carried in an encapsulation header over NG-U. §12.1

Q8.2 Where is user plane data ciphered?

• In the AMF
• In the gNB
• In the UPF

The security termination table gives the AMF for core-network signalling and the gNB for both RRC signalling and user plane data, ciphering and integrity alike. §13.2

Q8.3 What is reflective mapping?

• Two base stations mirror each other's bearer configuration
• The device copies the downlink flow-to-bearer mapping into the uplink
• The base station mirrors the core network's mapping rules

For each bearer the device watches the flow identifiers of downlink packets and applies the same mapping upwards. The other way is explicit configuration by RRC. §12.1

Q8.4 What does the radio network do with a core-network message it carries?

• Carries it as a sealed container over the signalling bearers
• Rewrites it for the radio interface
• Reads it and acts on it

NAS messages are sent in transparent containers in RRC, with reliable in-sequence delivery over signalling radio bearers. §7.6

Q8.5 What is an NCGI built from?

• The gNB identity alone
• The network identity plus the NR cell identity
• The tracking area code plus the cell identity

The NR Cell Global Identifier is constructed from the network identity the cell belongs to and the NR Cell Identity of the cell, and the gNB identity is contained within that cell identity. §8.2

Q8.6 What happens if a base station has no roaming and access restriction information for a device?

• It refuses all mobility
• It treats the device as unrestricted, except for the non-public-network case
• It asks the AMF every time

The clause says the gNB shall consider there is no restriction for subsequent mobility actions, with the PNI-NPN case called out as the exception. §9.4

Q9.1 How many active documents does the 38 series hold?

• 264
• 1059
• 3599

264 active documents whose number starts "38.". 1059 is every active RAN document across all series; 3599 is every active 3GPP document. 264 active documents in the 38 series

Q9.2 Which group owns the most of the 38 series?

• RAN2, with 22
• RAN4, with 138
• RAN1, with 34

RAN4's 138 is more than RAN1's 34, RAN2's 22 and RAN3's 35 put together. 138 active 38-series documents owned by RAN4

Q9.3 TS 38.307 sits in the block otherwise owned by RAN2. Who owns it?

• RAN4
• The plenary
• RAN2, like the rest of the block

The register records its owner as RAN4. It is a requirements document about release-independent frequency bands, which is RAN4 work whatever number it happens to carry. TS 38.307

Q9.4 Where do the renumbered GSM and 3G documents that RAN still maintains sit?

• They were all withdrawn
• With RAN6, which owned them
• With the plenary — 179 of them

179 active documents from the 25, 43, 44, 45, 48, 49, 50 and 52 series are the plenary's. 179 active documents the RAN plenary holds from the 3G and GSM series

Q9.5 How is a specification's information page addressed?

• By the owning group's code
• By its number with the dots removed
• By its title

The pattern is www.3gpp.org/DynaReport/ followed by the number without its dots, then .htm — so 38.331 becomes 38331.htm. address of one specification's information page

Q10.1 Which RAN document has the most documents changing it?

• 38.331, the radio connection protocol
• 38.133, the radio resource management requirements
• 38.300, the overall description

18987 documents change 38.133. 38.331 is second with 11787. 18987 RAN documents change 38.133

Q10.2 What is the commonest kind of document at a RAN meeting?

• Discussion papers
• Liaison statements
• Change requests

257341 RAN documents are marked "discussion" — more than the 190421 change requests. 257341 RAN meeting documents of type 'discussion'

Q10.3 How does the plenary approve change requests?

• One at a time, each with its own vote
• In bundles — 7012 change request packs are on record
• It does not; the working groups approve them

7012 documents of type "CR pack" exist. A pack collects the change requests a working group agreed and puts them to the plenary together. 7012 RAN meeting documents of type 'CR pack'

Q10.4 Which is changed more often, the 5G radio connection protocol or its 4G equivalent?

• They are within a hundred of each other
• 38.331, with 11787 against 6988
• 36.331, with 11787 against 6988

38.331 has 11787 documents changing it and 36.331 has 6988. Both are RAN2's and both are still being changed. 6988 RAN documents change 36.331

Q10.5 What does R4-2605235 do?

• Adds radio band n115 to the base station test document 38.141-1
• Reports RAN4's status to the plenary
• Opens a new study on satellite regulation

It is a change request from Nokia, agreed at RAN4#119, whose title is "CR to 38.141-1 on introduction of Band n115". R4-2605235

Q11.1 What opens a study?

• A liaison statement
• A change request
• A study item description put to the plenary

737 documents of type "SID new" exist. The description is put to the plenary, which may or may not accept it. 737 RAN meeting documents of type 'SID new'

Q11.2 What happened to RP-261197, a proposal to survey satellite regulations?

• It is recorded as "not pursued"
• It was withdrawn before the meeting
• It was approved

Its status in the database is "not pursued". Not every study item description is accepted, and the record says so without saying why. RP-261197

Q11.3 How many of the 3230 pieces of work opened by a RAN plenary document are studies?

• 3627
• 217
• 737

217 of the 3230 work items are studies. 737 is the number of study item descriptions ever filed, and 3627 the number of work item descriptions. 217 of the RAN work items are studies

Q11.4 What turns a finished study into real drafting work?

• A liaison statement
• A work item description
• A change request pack

3627 documents of type "WID new" exist. RP-260923 is one of them, opening conformance work on gateway devices for mission critical communication. 3627 RAN meeting documents of type 'WID new'

Q11.5 How does a working group report progress to the plenary?

• Only through change request packs
• It does not; the plenary reads the minutes
• Each group's chair files a status report, and there are also work item status reports

RP-260832 is RAN1's status report at RAN#112 and RP-260834 is RAN2's. Separately, 7249 work item status reports are on record. RP-260832

Q12.1 How often does the RAN plenary meet?

• Twice a year
• Every month
• Four times a year

The five meetings on record run June 2025, September 2025, December 2025, March 2026 and June 2026 — a quarterly cycle. 3GPPRAN#112

Q12.2 When the five open working groups meet, how are they arranged?

• One group per week, five weeks running
• All in the same week, in the same place
• Each group picks its own dates

RAN1#125, RAN2#134, RAN3#132, RAN4#119 and RAN5#111 all ran from 18 to 22 May 2026 in China. 3GPPRAN1#125

Q12.3 What is a "bis" week?

• An extra working-group week between two ordinary ones
• A repeat of a meeting that failed
• A plenary held online

RAN1, RAN2, RAN3 and RAN4 all met again from 13 April 2026 in Saint Julian's, between the February and May weeks. 3GPPRAN1#124-bis

Q12.4 Which working group does not take the extra week?

• RAN5
• RAN1
• RAN3

RAN5's meetings run 9 February 2026 and then 18 May 2026, with nothing in April, while the other four met in Saint Julian's in between. 3GPPRAN5#110

Q12.5 How is the plenary sequenced against the working-group week?

• A few weeks after it, so it decides on work just finished
• In the same week, in the same place
• Before it, to set the agenda

The groups met on 18 May 2026 and the plenary on 8 June 2026, three weeks later. 3GPPRAN#112

Q12.6 When did RAN6 last meet?

• It still meets quarterly
• 26 October 2020, for one day, by telephone
• It has never met

The last RAN6 meeting on record is a one-day decision teleconference on 26 October 2020. 3GPPRAN6#18-Decision Teleconference

Q13.1 What is the mechanism for one 3GPP group to ask another a question?

• A change request against the other group's document
• A liaison statement
• A joint meeting

20742 outgoing liaison statements carry a RAN document number. It is a letter from one group to another, tabled as a numbered document. 20742 RAN meeting documents of type 'LS out'

Q13.2 R2-2602996 is a draft reply. Who was it replying to?

• SA5
• The plenary
• RAN1

Its title is "Reply LS on SA5 LS with questions on pairing ID handling for two-sided models" — a question that arrived from outside RAN entirely. R2-2602996

Q13.3 Who decides which QoS treatment a traffic stream gets?

• The radio network, from its own measurements
• The core network, which sends a QoS profile the radio network applies
• Both, by negotiation on every packet

The profile — the identifier, the priority, and the bit rates for a guaranteed flow — is provided by the 5GC to the NG-RAN, which uses it to decide the treatment on the radio interface. §12.1

Q13.4 What does the NG Setup procedure exchange?

• The radio node's supported tracking areas and the AMF's network identity, among other things
• The keys for every device
• Nothing; the interface is statically configured

Once the transport is up, the two nodes exchange application-level configuration over NGAP — supported tracking areas from the radio side, network identity from the AMF side — and only then is the interface operational. §15.3.1.3

Q13.5 What does this course's register hold about the other 3GPP groups?

• The same data, for every group
• Nothing — it covers RAN only
• Only their meeting dates

The register was built from RAN's rows alone. Nothing in this course measures another group, so no comparison with them can be made here. 1059 active RAN specifications

Q14.1 Which group writes the test cases a phone has to pass?

• RAN5
• RAN2
• RAN4, which wrote the requirements

RAN5 is mobile terminal conformance testing, with 84 active documents, of which 72 are specifications. RAN5

Q14.2 Which document tests what 38.133 requires?

• 38.508-1
• 38.523-1
• 38.533

38.533 is the radio resource management conformance specification and pairs with 38.133, the radio resource management requirements. 38.523-1 tests protocol, 38.508-1 holds the common settings. TS 38.533

Q14.3 Who owns base station conformance testing?

• RAN4
• RAN3
• RAN5, like device testing

38.141-1 and 38.141-2, the conducted and radiated base station conformance tests, are RAN4's. RAN5's name is mobile terminal conformance testing, and mobile terminal is meant literally. TS 38.141-1

Q14.4 How are a device's radio capabilities structured?

• By a category number that fixes the peak data rate
• One flag per feature, for the whole device
• Per device, per duplex mode, per frequency range, per band and per band combination

The capabilities clause gives exactly that hierarchy, and says explicitly that NR does not rely on categories. §14

Q14.5 Are NR device categories signalled to the network?

• Only for devices supporting carrier aggregation
• Yes, as in earlier generations
• No — they exist for marketing only and are not signalled

The clause says categories associated with fixed peak data rates are defined for marketing purposes and not signalled; the peak rate is computed from the capabilities of each carrier instead. §14

Q15.1 How do you find one meeting's document list?

• Only by asking a delegate
• By searching the file server by date
• By its meeting number on the 3GPP portal, which has an address of its own

The portal generates a document list from a meeting id, and the meeting's own portal page is addressed by the same id. address of one meeting's document list

Q15.2 Where does a single meeting document live?

• Only inside the meeting's minutes
• On the specification's information page
• As a zip file under its meeting's folder on the file server

The pattern is the group folder, then the meeting folder, then Docs, then the document number with .zip. address of one meeting document

Q15.3 Which document tells you what a plenary intended to do?

• The change request packs
• The status reports
• The agenda, written by the chair

RP-260830 is the agenda for RAN#112, written by the chair. The draft report of the previous meeting, RP-260831, tells you what had already been settled. RP-260830

Q15.4 When and where is the next RAN plenary after June 2026?

• Fukuoka, 9 March 2026
• Madrid, 14 September 2026
• Boston, 7 December 2026

RAN#113 is Madrid on 14 September 2026 and RAN#114 is Boston on 7 December 2026. Fukuoka was RAN#111, already held. 3GPPRAN#113

Q15.5 Where would you find who has chaired a RAN working group?

• In this course
• On the group's officials history page on 3gpp.org
• In the meeting minutes only

This course names no person at all. The chair history is a page of its own, addressed by the group's code. address of one group's chair history

Q16.1 Why does this course never name a chair or a rapporteur?

• Because the names change too often
• Because the register carries a company or a role and never a person
• Because the names are confidential

The register records "RAN Chair (Samsung)", "ETSI MCC", "Nokia" — the organisation or the role. No human being's name is in the data, so no chapter may write one. RP-260830

Q16.2 What does a document's status tell you about why it was decided that way?

• Nothing — the status is approved, revised, noted, withdrawn or not pursued, and stops there
• The reason is in the count entries
• The reason is recorded alongside the status

The database records the outcome and no argument. RP-261197 is "not pursued" with no reason attached, and this course does not invent one. RP-261197

Q16.3 How much of RAN's active documentation can this course quote from?

• Only TS 38.300
• All 1059 documents
• 470 are parsed into text here; the rest are known by number and title only

470 of the 1059 active RAN documents are parsed into readable text on this machine. The rest are not, and none of RAN6's are. 470 of the 1059 active RAN specifications are parsed into text on this machine

Q16.4 Can this course tell you whether RAN is busier than the other 3GPP groups?

• No — the register covers RAN only, so nothing here measures the others
• Only for the specification counts
• Yes, from the document counts

Every count was built from RAN's rows. A comparison drawn from a one-sided register would be worthless, so none is made. 1059 active RAN specifications

Q16.5 What does the register hold about 6G?

• Nothing at all
• The scope and timetable of the study
• That a study report numbered 38.914 exists and one draft was agreed at RAN#112

One document number and one agreed draft. No date, no scope, no content. RP-260870