5G Idle Mode Mobility and 5G Dedicated Mode

5G Idle Mode Mobility and 5G Dedicated Mode

1. IDLEMODE MOBILITY

2. CELL SELECTION AND RESELECTION

3. CELL SELECTION PROCESS
Description:
Cell selection is performed by one of the following two procedures:
•Initial cell selection (no prior knowledge of which RF channels are NR carriers):
1.The UE shall scan all RF channels in the NR bands according to its capabilities to find a
suitable cell.
2.On each carrier frequency, the UE need only search for the strongest cell.
3.Once a suitable cell is found, this cell shall be selected.
•Cell selection by leveraging stored information:
1.This procedure requires stored information of carrier frequencies and optionally also
information on cell parameters from previously received measurement control
information elements or from previously detected cells.
2.Once the UE has found a suitable cell, the UE shall select it.
3.If no suitable cell is found, the initial cell selection procedure in a) shall be started.

4. INTRODUCTION
SIB types in 5G SA mode
Master Information
Block (MIB)
System Information
Block type 1 (SIB1)
Minimum SI
Information needed to access the cell and scheduling information for other SIBs
Common cell re-selection information
Neighboring cell information for intra-frequency cell re-selection
Information relevant for inter-frequency cell re-selection
System Information
Block type 2 (SIB2)
System Information
Block type 3 (SIB3)
System Information
Block type 4 (SIB4)
MIB includes parameters needed to define the initial Bandwidth Part (BWP) and Physical
Downlink Control Channel (PDCCH) resources in frequency and time domain
Information relevant for inter-RAT cell re-selection towards LTE
System Information
Block type 5 (SIB5)
Other SI

5. SYSTEM INFORMATION
•-SIB2 contains cell re-selection information, mainly related to the serving cell;
•-SIB3 contains information about the serving frequency and intra-frequency neighbouring
cells relevant for cell re-selection (including cell re-selection parameters common for a
frequency as well as cell specific reselection parameters);
•-SIB4 contains information about other NR frequencies and inter-frequency neighbouring
cells relevant for cell re-selection (including cell re-selection parameters common for a
frequency as well as cell specific reselection
•parameters);
•-SIB5 contains information about E-UTRA frequencies and E-UTRA neighbouringcells
relevant for cell reselection (including cell re-selection parameters common for a
frequency as well as cell specific re-selection parameters);
•-SIB6 contains an ETWS primary notification;
•-SIB7 contains an ETWS secondary notification;
•-SIB8 contains a CMAS warning notification;
•-SIB9 contains information related to GPS time and Coordinated Universal Time (UTC).

6. DEPLOYMENT ASPECTS
Cell selection/reselection in 5G SA multi-beam operations
UE
gNBSA Cell Reselection
Cell Selection
Measurement quantity of a cell is up to
UE implementation
Multi-beam operations
Then:
Derive a cell measurement quantity as the highest beam
measurement quantity (SS-RSRP/SS-RSRQ) value
For cell reselection, the measurement quantity of this cell is derived amongst the
beams corresponding to the same cell based on SS/PBCH block as follows:
If:
•nrofSS-BlocksToAverageis not configured in SIB2/SIB4;
Or
•absThreshSS-BlocksConsolidationis not configured in
SIB2/SIB4;
Or
•the highest beam measurement quantity value is below or
equal to absThreshSS-BlocksConsolidation:
Derive a cell measurement quantity as the linear
average of the power values of up to nrofSS-
BlocksToAverageof highest beam measurement
quantity (SS-RSRP/SS-RSRQ) values above
absThreshSS-BlocksConsolidation.
Else:
Parameters mapping for SIB2 (intra freqNR SA):
•nrofSS-BlocksToAverageNRCELL.nroSsbToAverage
•absThreshSS-BlocksConsolidation:
thresholdRSRPNRCELL.absThreshSsbRsrpConsolidation
thresholdRSRQNRCELL.absThreshSsbRsrqConsolidation
Parameters mapping for SIB4 (inter freqNR SA);
•nrofSS-BlocksToAverageNRIRFIM.numOfSsBlocksToAverage
•absThreshSS-BlocksConsolidation:
thresholdRSRPNRIRFIM.thresholdRsrp
thresholdRSRQNRIRFIM.thresholdRsrq

7. CELL SELECTION CRITERION
ThecellselectioncriterionSinnormalcoverageisfulfilledwhen:
Srxlev>0ANDSqual>0
Where:
Srxlev=Q
rxlevmeas
–(Q
rxlevmin
+Q
rxlevminoffset
)–P
compensation
–Qoffset
temp
Squal=Q
qualmeas
–(Q
qualmin
+Q
qualminoffset
)–Qoffset
temp
•ThesignalledvaluesQ
rxlevminoffset
andQ
qualminoffset
areonlyappliedwhenacellisevaluatedforcell
selectionasaresultofaperiodicsearchforahigherpriorityPLMNwhilecampednormallyina
VPLMN.
•DuringthisperiodicsearchforhigherpriorityPLMN,theUEmaychecktheScriteriaofacellusing
parametervaluesstoredfromadifferentcellofthishigherpriorityPLMN.

8. CELL SELECTION CRITERION
Srxlev Cell selection RX level value (dB)
Squal Cell selection quality value (dB)
Qoffset
temp
This specifies the additional offset to be used for cell selection and re-selection. It is temporarily used in case the RRC Connection Establishment fails on the cell as specified in
TS 38.331 [3] (dB).
i.e.Oncethe timer used to supervise the RRC connection establishment procedure “T300” has expired a consecutive connEstFailCounttimes on the same cell, Then for a period
as indicated by connEstFailOffsetValidity:
Qoffset
temp
= connEstFailOffsetfor the concerned cell when performing cell selection and reselection according to TS 38.304 [20] and TS 36.304 [27]
Q
rxlevmeas
Measured cell RX level value (RSRP)
Q
qualmeas
Measured cell quality value (RSRQ)
Q
rxlevmin
Minimum required RX level in the cell (dBm). If the UE supports SUL frequency for this cell, Qrxlevmin is
obtained from q-RxLevMin-sul, if present,in SIB1, else Qrxlevmin is obtained from q-RxLevMin in SIB1.
Q
qualmin
Minimum required quality level in the cell (dB)
Q
rxlevminoffset
Offset to the signalled Q
rxlevmin
taken into account in the Srxlev evaluation as a result of a periodic search
for a higher priority PLMN while camped normally in a VPLMN [9]
Q
qualminoffset
Offset to the signalled Q
qualmin
taken into account in the Squal evaluation as a result of a periodic search
for a higher priority PLMN while camped normally in a VPLMN [9]
P
compensation
If the UE supports the additionalPmaxin the NS-PmaxList, if present, in SIB1:
max(P
EMAX1
–P
PowerClass
, 0) –(min(P
EMAX2
, P
PowerClass
) –min(P
EMAX1
, P
PowerClass
)) (dB);
else:
max(P
EMAX1
–P
PowerClass
, 0) (dB)

9. CELL RESELECTION EVALUATION PROCESS
Reselection Priorities Handling
•Absolute priorities of different NR frequencies or inter-RAT frequencies may be provided to
the UE in the system information, in the RRCReleasemessage, or by inheriting from another
RAT at inter-RAT cell (re)selection.
•In the case of system information, a NR frequency or inter-RAT frequency may be listed
without providing a priority (i.e. the field cellReselectionPriorityis absent for that frequency).
•If priorities are provided in dedicated signalling, the UE shall ignore all the priorities
provided in system information.
•The UE shall only perform cell reselection evaluation for NR frequencies and inter-RAT
frequencies that are given in system information and for which the UE has a priority
provided.

10. CELL RESELECTION EVALUATION PROCESS
Reselection Priorities Handling
•The UE shall delete priorities provided by dedicated signaling when:
•the UE enters a different RRC state; or
•The optional validity time of dedicated priorities (T320) expires; or
•a PLMN selection is performed on request by NAS
•The UE shall only perform cell reselection evaluation for NR frequencies and inter-RAT
frequencies that are given in system information and for which the UE has a priority
provided.
•The UE shall not consider any black listed cells as candidate for cell reselection.
•The UE shall inherit the priorities provided by dedicated signallingand the remaining validity
time (i.e. T320 in NR and E-UTRA), if configured, at inter-RAT cell (re)selection.

11. MEASUREMENT RULES FOR CELL RESELECTION
Following rules are used by the UE to limit needed measurements:
•If the serving cell fulfils Srxlev> SIntraSearchPand Squal> SIntraSearchQ, the UE may
choose not to perform intra-frequency measurements.
•Otherwise, the UE shall perform intra-frequency measurements.
•The UE shall apply the following rules for NR inter-frequencies and inter-RAT frequencies
which are indicated in system information and for which the UE has priority provided as
defined
•For a NR inter-frequency or inter-RAT frequency with a reselection priority higher than
the reselection priority of the current NR frequency, the UE shall perform measurements
of higher priority NR inter-frequency or inter-RAT frequencies.
•For a NR inter-frequency with an equal or lower reselection priority than the reselection
priority of the current NR frequency and for inter-RAT frequency with lower reselection
priority than the reselection priority of the current NR frequency:
•If the serving cell fulfils Srxlev> SnonIntraSearchPand Squal> SnonIntraSearchQ, the
UE may choose not to perform measurements of NR inter-frequencies or inter-RAT
frequency cells of equal or lower priority;
•Otherwise, the UE shall perform measurements of NR inter-frequencies or inter-RAT
frequency cells of equal or lower priority

12. MOBILITY STATES OF A UE
The UE mobility state is determined if the parameters (TCRmax, NCR_H, NCR_M and
TCRmaxHyst) are broadcasted in system information for the serving cell.
State detection criteria:
Normal-mobility state criteria:
•If number of cell reselections during time period TCRmaxis less than NCR_M.
Medium-mobility state criteria:
•If number of cell reselections during time period TCRmaxis greater than or equal to NCR_M
but less than NCR_H.
High-mobility state criteria:
•If number of cell reselections during time period TCRmaxis greater than NCR_H.
The UE shall not consider consecutive reselections where a cell is reselected again right after
one reselection for mobility state detection criteria

13. MOBILITY STATES OF A UE
State transitions:
The UE shall:
•If the criteria for High-mobility state is detected:
•Enter High-mobility state.
•Else if the criteria for Medium-mobility state is detected:
•Enter Medium-mobility state.
•Else if criteria for either Medium-or High-mobility state is not detected during time period
T
CRmaxHyst
:
•Enter Normal-mobility state.
•If the UE is in High-or Medium-mobility state, the UE shall apply the speed dependent
scaling rules

14. MOBILITY STATES OF A UE
Scaling Rules:
UE shall apply the following scaling rules:
•If neither Medium-nor High-mobility state is detected:
•No scaling is applied.
•If High-mobility state is detected:
•Add the sf-Highof "Speed dependent ScalingFactorfor Q
hyst
" to Q
hyst
if broadcasted in
system information;
•For NR cells, multiply Treselection
NR
by the sf-Highof "Speed dependent ScalingFactor
for Treselection
NR
" if broadcasted in system information.
•If Medium-mobility state is detected:
•Add the sf-Mediumof "Speed dependent ScalingFactorfor Q
hyst
for medium mobility
state" to Q
hyst
if broadcasted in system information;
•For NR cells, multiply Treselection
NR
by the sf-Mediumof "Speed dependent
ScalingFactorfor Treselection
NR
" if broadcasted in system information.
•In case scaling is applied to any Treselection
RAT
parameter, the UE shall round up the result
after all scalingsto the nearest second

15. CELL RESERVATIONS AND ACCESS RESTRICTIONS

16. CELL RESERVATIONS AND ACCESS RESTRICTIONS
•There are two mechanisms which allow an operator to impose cell reservations or access
restrictions.
•The first mechanism uses indication of cell status and special reservations for control of
cell selection and reselection procedures.
•The second mechanism, referred to as Unified Access Control, shall allow preventing
selected access categories or access identities from sending initial access messages for
load control reasons.

17. CELL STATUS AND CELL RESERVATIONS
•Cell status and cell reservations are indicated in the MasterInformationBlockor
SystemInformationBlockType1 (SIB1) message [3] by means of three fields:
•cellBarred(IE type: "barred" or "not barred")
Indicated in MasterInformationBlockmessage. In case of multiple PLMNs indicated in SIB1,
this field is common for all PLMNs
•cellReservedForOperatorUse(IE type: "reserved" or "not reserved")
Indicated in SystemInformationBlockType1message.In case of multiple PLMNs indicated in
SIB1, this field is specified per PLMN.
•cellReservedForOtherUse(IE type: "reserved" or "not reserved")
Indicated in SystemInformationBlockType1message. In case of multiple PLMNs indicated in
SIB1, this field is common for all PLMNs.
•When cell status is indicated as "not barred" and "not reserved" for operator use and "not
reserved" for other use,
•All UEs shall treat this cell as candidate during the cell selection and cell reselection
procedures.
•When cell status is indicated as "reserved" for other use,
•The UE shall treat this cell as if cell status is "barred".

18. CELL STATUS AND CELL RESERVATIONS
•When cell status is indicated as "not barred" and "reserved" for operator use for any
PLMN and "not reserved" for other use,
•UEs assigned to Access Identity 11 or 15 operating in their HPLMN/EHPLMN shall treat
this cell as candidate during the cell selection and reselection procedures if the field
cellReservedForOperatorUsefor that PLMN set to "reserved".
•UEs assigned to an Access Identity in the range of 0 to 10 and 12 to 14 shall behave as
if the cell status is "barred" in case the cell is "reserved for operator use" for the
registered PLMN or the selected PLMN
Note: Access Identities 11, 15 are only valid for use in the HPLMN/ EHPLMN; Access Identities
12, 13, 14 are only valid for use in the home country

19. CELL STATUS AND CELL RESERVATIONS
•When cell status "barred" is indicated or to be treated as if the cell status is "barred",
•The UE is not permitted to select/reselect this cell, not even for emergency calls.
•The UE shall select another cell according to the following rule:
•If the cell is to be treated as if the cell status is "barred" due to being unable to acquire
the MasterInformationBlockor the SystemInformationBlockType1:
•The UE may exclude the barred cell as a candidate for cell selection/reselection for up
to 300 seconds.
•The UE may select another cell on the same frequency if the selection criteria are
fulfilled.

20. CELL STATUS AND CELL RESERVATIONS
•Else
•If the field intraFreqReselectionin MasterInformationBlockmessage is set to "allowed",
the UE may select another cell on the same frequency if re-selection criteria are
fulfilled;
•The UE shall exclude the barred cell as a candidate for cell selection/reselection for 300
seconds.
•If the field intraFreqReselectionin MasterInformationBlockmessage is set to "not
allowed" the UE shall not re-select a cell on the same frequency as the barred cell;
•The UE shall exclude the barred cell and the cells on the same frequency as a
candidate for cell selection/reselection for 300 seconds.
•The cell selection of another cell may also include a change of RAT

21. 5G RRC SUB LAYER

22. FUNCTIONS OF RRC LAYER
The RRC protocol includes the following main functions:
•Broadcast of system information:
•Including NAS common information;
•Information applicable for UEs in RRC_IDLE and RRC_INACTIVE, e.g. cell (re-)selection
parameters, neighboring cell information and information (also) applicable for UEs in
RRC_CONNECTED, e.g. common channel configuration information.
•Including ETWS notification, CMAS notification
•Inter-RAT mobility including e.g. security activation, transfer of RRC context information;
•Measurement configuration and reporting:
•Establishment/ modification/ release of measurements (e.g. intra-frequency, inter-
frequency and inter-RAT measurements);
•Setup and release of measurement gaps;
•Measurement reporting;

23. FUNCTIONS OF RRC LAYER
•RRC connection control:
•Paging
•Establishment/ modification/ suspension / resumption / release of RRC connection,
including e.g. assignment/ modification of UE identity (C-RNTI), establishment/
modification/ release of SRBs, access class barring
•Initial security activation, i.e. initial configuration of AS integrity protection (SRBs) and AS
ciphering (SRBs, DRBs)
•RRC connection mobility including e.g. intra-frequency and inter-frequency handover,
associated security handling, i.e. key/ algorithm change, specification of RRC context
information transferred between network nodes
•Establishment/ modification/ release of RBs carrying user data (DRBs)
•Radio configuration control including e.g. assignment/ modification of ARQ configuration,
HARQ configuration, DRX configuration
•In case of DC, cell management including e.g. change of PSCell, addition/ modification/
release of SCG cell(s)[FFS, and addition/modification/release of SCG TAG(s)].
•Recovery from radio link failure

24. FUNCTIONS OF RRC LAYER
•RRC connection control:
•Paging
•Establishment/ modification/ suspension / resumption / release of RRC connection,
including e.g. assignment/ modification of UE identity (C-RNTI), establishment/
modification/ release of SRBs, access class barring
•Initial security activation, i.e. initial configuration of AS integrity protection (SRBs) and AS
ciphering (SRBs, DRBs)
•RRC connection mobility including e.g. intra-frequency and inter-frequency handover,
associated security handling, i.e. key/ algorithm change, specification of RRC context
information transferred between network nodes
•Establishment/ modification/ release of RBs carrying user data (DRBs)
•Radio configuration control including e.g. assignment/ modification of ARQ configuration,
HARQ configuration, DRX configuration
•In case of DC, cell management including e.g. change of PSCell, addition/ modification/
release of SCG cell(s)[FFS, and addition/modification/release of SCG TAG(s)].
•Recovery from radio link failure

25. UE STATES AND STATES TRANSITIONS
INCLUDING INTER RAT
•There are three RRC States are available in 5G as follows:
•Connected State -Data Transmission/Reception
(Same as LTE)
•IDLE State -Power Saving (Same as LTE)
•Inactive State-(Not in LTE)
•Transition to RRC Connected state upon Paging
•Downlink Data Notification , instead of Idle to
Connected Transition Lesser Call Setup Time?)
•A UE is either in RRC_CONNECTED state or in
RRC_INACTIVE state when an RRC connection has been
established.
•The UE will be in RRC_IDLE state if no RRC connection is
established.

26. UE STATES AND STATES TRANSITIONS
INCLUDING INTER RAT
RRC_IDLE:
•A UE specific DRX may be configured by upper layers;
•UE controlled mobility based on network configuration;
•The UE:
•Monitors a Paging channel;
•Performs neighbouringcell measurements and cell (re-
)selection;
•Acquires system information.

27. UE STATES AND STATES TRANSITIONS
INCLUDING INTER RAT
RRC_INACTIVE:
•A UE specific DRX may be configured by upper layers or
by RRC layer
•UE controlled mobility based on network configuration
•The UE stores the AS context
•Monitors a Paging channel
•Performs neighboring cell measurements and cell (re-
)selection
•Performs RAN-based notification area updates when
moving outside the RAN-based notification area
•Acquires system information.

28. UE STATES & STATES TRANSITIONS INCLUDING INTER
RAT
RRC_CONNECTED:
•The UE stores the AS context.
•Transfer of unicast data to/from UE.
•At lower layers, the UE may be configured with a UE
specific DRX.
•For UEs supporting CA, use of one or more SCells,
aggregated with the SpCell, for increased bandwidth;
•For UEs supporting DC, use of one SCG, aggregated with
the MCG, for increased bandwidth;
•Network controlled mobility, i.e. handover within NR and
to/from E-UTRAN.
•Monitors a Paging channel;
•Monitors control channels associated with the shared
data channel to determine if data is scheduled for it;
•Provides channel quality and feedback information;
•Performsneighbouringcell
measurementsandmeasurement
reporting;
•Acquiressysteminformation

29. UE STATE MACHINE AND STATE TRANSITIONS IN
NR
•Following figure illustrates an overview of UE RRC state machine and state transitions in NR.
•A UE has only one RRC state in NR at one time.

30. UE STATE MACHINE AND STATE TRANSITIONS
BETWEEN NR/NGC AND E-UTRAN/EPC
•Following figure illustrates an
overview of UE state machine and
state transitions in NR as well as the
mobility procedures supported
between NR/NGC and E-UTRAN/EPC.
•The UE state machine, state transition
and mobility procedures between
NR/NGC and E-UTRA/NGC is FFS

31. SYSTEM INFORMATION BROADCAST
•TheNASisinformedifthecellselectionandreselectionresultsinchangesinthereceivedNAS
systeminformation.
•TheUEshallmonitorthePagingOccasions(POs)toreceiveSystemInformationchange
notificationsinRRC_IDLEandRRC_INACTIVE.
•Thechangesinthesysteminformationarenotifiedbythenetworkusinga Pagingmessageor
viapagingindication.
•WhenthePagingmessageorpagingindicationnotifiessysteminformationchanges,thenthe
UEshallre-acquiretheconcernedsysteminformation.

32. CELL CATEGORIES
Thecellsarecategorizedaccordingtofollowing4typesbasedontheservicestheyoffer:
Acceptablecell:
•ACellonwhichtheUEmaycamptoobtainlimitedservice(originateemergencycallsand
receiveETWSandCMASnotifications).
•Suchacellshallfulfilthefollowingrequirements,whichistheminimumsetofrequirementsto
initiateanemergencycallandtoreceiveETWSandCMASnotificationinaNRnetwork:
•Thecellisnotbarred
•Thecellselectioncriteriaarefulfilled
BarredCell:
•Acellisbarredifitissoindicatedinthesysteminformation[3].
Reserved cell:
•A cell is reserved if it is so indicated in system information [3].

33. CELL CATEGORIES
Acellisconsideredassuitableifthefollowingconditionsarefulfilled:
•Thecellispartofeither:
•TheselectedPLMN,or:
•APLMNoftheEquivalentPLMNlist.
•Thecellselectioncriteriaarefulfilled,seesubclause5.2.3.2;
•Acellisservedbytheselected/registeredPLMNandnotbarred.
AccordingtothelatestinformationprovidedbyNAS:
•Thecellisnotbarred,seesubclause5.3.1;
•ThecellispartofatleastoneTAthatisnotpartofthelistof"ForbiddenTrackingAreas"[12],
whichbelongstoaPLMNthatfulfilsthefirstbulletabove.

34. CONNECTED MODE MOBILITY

35. MOBILITY EVENTS
•Event A1 (Serving becomes better than threshold)
•Event A2 (Serving becomes worse than threshold)
•Event A3 (Neighbourbecomes offset better than SpCell)
•Event A4 (Neighbourbecomes better than threshold)
•Event A5 (SpCellbecomes worse than threshold1 and neighbourbecomes better
than threshold2)
•Event A6 (Neighbourbecomes offset better than SCell)
•Event B1 (Inter RAT neighbourbecomes better than threshold)
•Event B2 (PCellbecomes worse than threshold1 and inter RAT neighbour
becomes better than threshold2)

36. 12/22/2022 68
Handover Procedure
Intra-gNodeB-DU Handover

37. 12/22/2022 69
Inter-gNodeB-DU Handover

38. 12/22/2022 70
Xn-based Handover

39. 12/22/2022 71
NG-based Handover

40. 12/22/2022 72
LTE-NR Handover( Handover from NR to LTE)

41. 12/22/2022 73
Handover from LTE to NR

42. 12/22/2022 74
LTE-NR Redirection

43. NR EVENT TRIGGERS

44. MOBILITY
Counter name Measurement
The number of intra gNB intra frequency PSCell change attempts 55120: NR Intra Frequency PSCellChange
The number of intra gNB intra frequency PSCell change failures due to TDCoverall
timer expiry
55120: NR Intra Frequency PSCellChange
The number of intra gNB intra frequency PSCell change failures due to MeNB
refusal
55120: NR Intra Frequency PSCellChange
The number of intra gNB intra freq PSCell change failures due to target cell
resource alloc failure
55120: NR Intra Frequency PSCell Change
The minimum duration of executed intra gNB intra frequency PSCell changes55120: NR Intra Frequency PSCellChange
The maximum duration of executed intra gNB intra frequency PSCell changes55120: NR Intra Frequency PSCell Change
The total duration of executed intra gNBintra frequency PSCellchanges55120: NR Intra Frequency PSCellChange
RA setup attempts for dedicated preambles corresponding to SSB beam 00 –6355306: NR Rach Usage
RA setup completions for dedicated preambles 55306: NR Rach Usage
Dedicated Preamble Rx opportunities for SSB beam 00 –63 55306: NR Rach Usage
Number of PDCP PDU retransmitted -QoSGroup 1 –20 55312: NR PDCP Report
Volume of PDCP PDU retransmitted -QoSGroup 1 –20 55312: NR PDCP Report

45. THANK YOU