EN-DC-Triggered Handover during
Connected Mode Mobility
Feature Description
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Copyright
© Ericsson AB 2020-2022. All rights reserved. No part of this document may be
reproduced in any form without the written permission of the copyright owner.
Disclaimer
The contents of this document are subject to revision without notice due to
continued progress in methodology, design and manufacturing. Ericsson shall
have no liability for any error or damage of any kind resulting from the use of this
document.
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Contents
Contents
1
Overview
1
2
Dependencies
3
3
Feature Operation
6
3.1
NR Frequency Selection
9
3.2
LTE Frequency Selection
10
3.3
Measurement Report Evaluation
11
3.4
Handover Evaluation
12
3.5
NR Frequency Selection for EN-DC Setup with Forwarded NR
B1 Measurement Result
B1 and A5 Measurement Configuration with Buffer-Based ENDC Setup
3.6
12
13
4
Network Impact
17
5
Parameters
18
6
Performance
21
7
Activate the Feature
23
8
Deactivate the Feature
24
9
Engineering Guidelines
25
9.1
25
9.2
Optimize the A5 Measurement Threshold Considering Poor
Coverage in Target Cell
Configure PLMN IDs for EN-DC on a Neighboring LTE Cell
9.3
Configure Buffer-Based EN-DC Setup
26
25
Appendix A: Feature Change History
28
Appendix A.a: 20.Q4: EN-DC-Triggered Handover during RRC
Reestablishment
28
Appendix A.b: 20.Q4: Setting up EN-DC Using Forwarded NR B1
Measurement Report
29
Appendix A.c: 21.Q4: Buffer-Based EN-DC Setup
30
Appendix A.d: 22.Q1: Subscriber Profile-Based B1 Measurement
Configuration for EN-DC
34
Appendix A.e: 22.Q2: MFBI Support for EN-DC-Triggered Handover
during Connected Mode Mobility
37
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EN-DC-Triggered Handover during Connected Mode Mobility
Appendix A.f: 22.Q4: Frequency-Differentiated B1 Measurement Trigger
Time and Quantity Configuration for EN-DC
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1
EN-DC-Triggered Handover during
Connected Mode Mobility Overview
The feature supports the handover of an EN-DC-capable UE in connected
mode from an LTE cell where setting up SCG radio resources is not possible
or from an LTE that supports EN-DC, triggered at an incoming handover.
Access Type
LTE
Feature Identity:
FAJ 121 5243
Value Package Name:
Intelligent Connectivity
Value Package Identity:
FAJ 801 1013
Node Type:
Baseband Radio Node
Licensing:
Licensed feature. One license is required for each
node.
Summary
The feature is used to move an EN-DC-capable UE in connected mode, triggered
at an incoming handover, to a neighboring LTE cell that supports EN-DC, in the
following cases:
— Handover is triggered from an LTE cell where setting up SCG radio resources
is not possible. The purpose of the handover is to move the UE that is unable
to set up SCG resources in a cell, to a neighboring LTE cell where setting up
SCG radio resources is possible.
— Handover is triggered from an LTE cell where setting up SCG radio resources
is possible. The purpose of the handover is to move the UE to a neighboring
LTE cell where it can set up a better EN-DC connection than the EN-DC
connection the UE uses originally.
The feature supports inter-frequency handover at the completion of incoming
IRAT and incoming intra-LTE handovers.
After the completion of an incoming handover, the eNodeB instructs the UE
to perform NR B1 measurement to select the target NR frequency and A5
measurement to select the target LTE frequency. The UE sends the measurement
reports to the eNodeB. These reports can trigger an outgoing handover. If
the UE is EN-DC-capable and has no NR restriction, the eNodeB attempts to
move it to an LTE cell where setting up SCG radio resources for the UE is
possible. The eNodeB considers NR coverage, prioritized NR frequencies, and
band combinations supported by the UE to select the target LTE cell.
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EN-DC-Triggered Handover during Connected Mode Mobility
With the feature activated, the UE has a better chance to be connected through
EN-DC with better throughput.
NR Cell with Higher
Prioritized Frequency
NR Cell with Lower
Prioritized Frequency
LTE Cell C - EN-DC-capable
Handover during RRC Connected Mode
LTE Cell B - Not capable of EN-DC
or EN-DC-capable
LTE Cell A - Not capabale of EN-DC
L0002739B
Figure 1 EN-DC-Triggered Handover during Connected Mode Mobility
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2
Dependencies of EN-DC-Triggered Handover
during Connected Mode Mobility
The feature has dependencies to features related EN-DC triggered handover
procedures.
Table 1
Feature Dependencies
Feature
Relationship
Description
Automated Neighbor Relation (FAJ 121 0497)
Related
If the UE reports an EN-DC capable cell in the
A5 measurement report, the CGI measurement by
the Automated Neighbor Relations feature is not
triggered even if an unknown PCI cell is included in
the report.
If the CGI measurement report contains an
unknown cell, a cell relation to the unknown cell
is needed to determine the EN-DC capability of the
unknown cell.
Basic Intelligent Connectivity (FAJ 121 4843)
Related
If the Basic Intelligent Connectivity feature is
activated in the target node, Basic Intelligent
Connectivity supports the EN-DC capable UE in
setting up EN-DC after the handover of the UE,
initiated by the EN-DC-Triggered Handover during
Connected Mode Mobility feature. EN-DC setup in
the target node is only allowed if preconditions are
fulfilled.
The followings can be controlled on a subscriber
profile basis for the Basic Intelligent Connectivity
feature with the ASGH Framework feature:
—
EN-DC restriction
—
B1 measurement timers
—
B1 measurement thresholds
These configurations are also applicable during the
feature operation of the EN-DC-Triggered Handover
during Connected Mode Mobility.
When the EN-DC configured UE performs LTE loadtriggered inter-frequency handover to the target
LTE cell, the LTE frequency from which the UE is
moved is excluded form LTE anchor cell selection for
the given UE.
With the
GUtranFreqRelation.timeToTriggerB1Override
and the
GUtranFreqRelation.triggerQuantityB1Overrid
e attributes, different trigger time and trigger
quantity can be configured for the B1 measurement
for each of the LTE-to-NR frequency relations.
The NR Restriction function of Basic Intelligent
Connectivity can be disabled by setting
ENodeBFunction.zzzTemporary67 to 1. In this
case, EN-DC-triggered handover is allowed for NRrestricted UEs to access Low-Band, Mid-Band, and
High-Band NR frequencies.
Device-Based Frequency Filtering (FAJ 121 5154)
Related
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The Device-Based Frequency Filtering feature is
used to configure and filter out unsupported
frequencies for specific UEs. The frequencies of
EN-DC-capable cells, which UEs cannot support,
are excluded from A5 measurement configuration
3
EN-DC-Triggered Handover during Connected Mode Mobility
Feature
Relationship
Description
messages for EN-DC-Triggered Handover during
Connected Mode Mobility.
Differentiated UE Handling (FAJ 121 4386)
Related
The Differentiated UE Handling feature can disable
the EN-DC-Triggered Handover during Connected
Mode Mobility feature for UEs with specified
IMEISV, if Basic Intelligent Connectivity is turned
off by Differentiated UE Handling.
Enhanced NR Restriction (FAJ 121 5212)
Related
If the Enhanced NR Restriction feature is activated
on the eNodeBs in the network, EN-DC-triggered
handover is allowed for the UEs with NR Restriction
to a Master Node that is connected to a Secondary
Node with Low-Band and Mid-Band frequencies.
LTE Extended N77 Band Support (FAJ 121 5482)
Related
If the LTE Extended N77 Band Support is activated,
the eNodeB includes 3,450-3,550MHz range of n77
band in B1 measurement configuration only if the
UE capability message indicates IRAT parameter
extendedBand-n77-r16.
Shared LTE RAN (FAJ 121 0860)
Related
The Shared LTE RAN feature can restrict mobility to
a target LTE cell based on the HRL.
TCP Optimization (FAJ 121 1713)
Related
If the values of the age threshold for the BufferBased EN-DC Setup function is set higher than
the AQM minimum and maximum age thresholds
of the TCP Optimization feature, the user plane
packets might be discarded before configuring
measurement events, and delay or even prevent
meeting the monitoring criteria.
Uplink-Traffic-Triggered Mobility (FAJ 121 5044)
Related
The EN-DC-Triggered Handover during Connected
Mode Mobility feature and the EN-DC-Triggered
Handover during Setup feature direct EN-DCcapable UEs towards EN-DC-capable cells, if such
UEs are not allowed to enter the EN-DC setup in
the serving cell. If EN-DC-capable UEs are allowed
to enter the EN-DC-triggered handover process, the
Uplink-Traffic-Triggered Mobility feature is disabled
for these UEs.
Multiple Frequency Band Indicators (FAJ 121 3054)
Related
EN-DC triggered handover is enabled for
all LTE bands of neighbor cells that
are capable of EN-DC-triggered handover if
the ENodeBFunction.endcAwareMfbiIntraCellHo
attribute is set to true. Multiple Frequency Band
Indicators must be activated for all LTE bands of
neighboring cells for EN-DC-triggered handover.
MBMS Multi-Carrier Support (FAJ 121 3062)
Related
LTE Broadcast (FAJ 121 3021)
Related
A UE sending the MBMS Interest Indication
message is not considered for handover.
Hardware
No specific hardware requirements.
Limitations
— The feature is only applicable during incoming handover.
— The NR neighbor information is not transferred over X2 between eNodeBs.
— Load information is not considered for triggering handover.
— Inter-vendor handover is not supported because EN-DC cell resources are
transferred through X2 messages containing private IEs.
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— It is possible that there is no EN-DC band combination that the UE supports
between the following frequencies:
— NR frequencies with frequency relation from the current LTE cell
— LTE frequencies of the neighboring LTE cells
In this case, the feature does not trigger handover.
— When the Buffer-Based EN-DC Setup function is enabled, the B1 and
associated A5 measurement is configured once when the downlink user
plane data exceeds the configured thresholds. Otherwise, it is configured
during incoming handover or RRC Re-establishment.
Network Requirements
The feature requires an X2 connection between the eNodeBs.
The following attributes must be configured:
— EUtranFreqRelation.endcHoFreqPriority
— GUtranFreqRelation.endcB1MeasPriority
Additional frequency bands of LTE cells that have the Multiple Frequency Band
Indicators feature enabled are only considered for inter-frequency handover
if the ENodeBFunction.endcAwareMfbiIntraCellHO attribute is set to true
throughout the network.
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EN-DC-Triggered Handover during Connected Mode Mobility
3
Feature Operation of EN-DC-Triggered
Handover during Connected Mode Mobility
The feature enables the handover of an EN-DC-capable UE in RRC
connected mode to a neighboring LTE anchor cell where setting up SCG
radio resources for the UE is possible.
The UE can benefit from this feature on the following conditions:
— The UE is in RRC connected mode.
— The UE is EN-DC capable.
— One of the following cases:
— The UE has no NR restriction in HRL.
— The Enhanced NR Restriction feature is activated.
— The NR Restriction function is disabled by setting the
ENodeBFunction.zzzTemporary67 attribute to 1.
— The ENodeBFunction.endcAllowed attribute is set to true for the eNodeB
to allow EN-DC.
Allowing or restricting access to NR on the eNodeB can be
configured with the ENodeBFunction.endcAllowed attribute. This
setting can be overridden for specific subscriber groups with the
EndcUserProfile.endcAllowedOverride attribute.
If the EndcUserProfile.endcAllowedOverride attribute is set to false,
the UEs with matching EndcUserProfile MOs are restricted to use EN-DC.
Note:
It is recommended to set the endcAllowed and the
endcAllowedOverride MOs identically network-wide.
The NR Restriction function of Basic Intelligent Connectivity, and
the Enhanced NR Restriction feature can be disabled by setting
ENodeBFunction.zzzTemporary67 to 1. In this case, EN-DC-triggered
handover is allowed for NR-restricted UEs to access Low-Band, Mid-Band,
and High-Band NR frequencies.
Traffic steering is required to ensure that an EN-DC-capable UE can use ENDC. Traffic steering moves the UE to an EN-DC-capable LTE cell with priority
considered EN-DC band combination, if the UE camps on an LTE cell that does
not support EN-DC setup. The LTE cell, in which EN-DC is possible, has prioritized
EN-DC band combination configuration.
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The handover can be initiated from an LTE cell where setting up SCG radio
resources is not possible or from an LTE cell already in EN-DC.
Operational Process
Incoming handover
(IRAT or intra-LTE)
No
Is the UE EN-DC-capable
with no NR restriction?
No further action required.
Yes
NR B1 and A5 measurement report configuration.
Yes
Has the timer expired without
NR B1 and A5?
No
NR B1 and A5 measurements report reception.
Is the reported cell
in A5 EN-DC-capable?
No
Yes
Handover to EN-DC-capable target cell,
including NR B1 measurement results.
EN-DC setup with received
NR B1 measurement results.
L0002742C
Figure 2 EN-DC-Triggered Handover during Connected Mode Mobility
Operation
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EN-DC-Triggered Handover during Connected Mode Mobility
1. The feature initiates EN-DC-triggered handover procedure after the
completion of an incoming IRAT or incoming intra-LTE handover.
The handover is triggered even if the UE initiates an RRC Re-establishment
procedure.
2. The UE performs NR B1 measurement to search for a target NR frequency
and A5 measurement to select the target LTE frequency.
Note:
The NR B1 and associated A5 measurements are configured for this
feature in the same RRCConnectionReconfiguration message.
3. When the eNodeB receives the NR B1 measurement report, the NR B1
result is evaluated. If the measurement proves to be valid, the measurement
report is stored. Then the node waits for the A5 measurement report. If the
time for reporting NR B1 measurement interval elapses, the measurement
is considered to be invalid. If the A5 measurement is received within the
configured time for reporting NR B1 measurement, the handover evaluation
procedure begins.
The valid NR B1 and A5 measurement results are stored in the LTE
HANDOVER REQUEST message.
4. At reception of the measurement reports, the source and target eNodeBs
exchange information if it is possible to set up SCG radio resources for the UE
in the target LTE cell.
At least one of the Serving or Equivalent PLMN identities listed in the HRL
matches one of the identities configured in the following attributes for the
neighbor LTE cell:
— EUtranCellFDD.endcAllowedPlmnList
— EUtranCellTDD.endcAllowedPlmnList
If there is no HRL configuration, the primary PLMN identity matches the
EN-DC allowed PLMN list.
When these attributes are configured and the Basic Intelligent Connectivity
feature is operable, the information about the possibility of setting up SCG
radio resources in the target LTE cell is exchanged between the nodes
through the following X2 messages with private IE:
— X2 SETUP REQUEST
— X2 SETUP RESPONSE
— X2 ENB CONFIGURATION UPDATE
5. If it is possible for the UE to set up SCG radio resources in the reported
LTE cell, and the handover evaluation process is successful, a handover is
triggered to the reported target LTE cell.
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6. The valid NR B1 measurement results are forwarded in the LTE HANDOVER
REQUEST message to the target LTE cell. The information allows the target
cell to perform EN-DC setup without any further NR B1 measurements
executed in the target cell by the UE.
RELATED INFORMATION
Handover Evaluation
NR Frequency Selection
LTE Frequency Selection
3.1
NR Frequency Selection
The NR frequency selection happens before the LTE frequency selection. The
purpose of the NR frequency selection is to find the NR frequencies that have a
target NR cell for SCG radio resources from neighboring LTE cell.
For detailed information on NR frequency selection in a priority-based order and
priority group policy, see NR Frequency Selection for B1 Measurement-Based
EN-DC Setup in the Basic Intelligent Connectivity.
NR frequencies once selected to be configured by the Basic Intelligent
Connectivity feature are excluded from being candidates for EN-DC-triggered
handover.
Note:
The time window for the selection of the B1 measurement report that
contains the frequency batch with the highest priority NR frequency,
that is the configuration of the UeMeasControl.endcB1MeasWindow
attribute, is not applicable.
The NR Restriction function can be disabled by setting the
ENodeBFunction.zzzTemporary67 attribute to 1. In this case, EN-DC-triggered
handover is allowed for NR-restricted UEs to access Low-Band, Mid-Band, and
High-Band NR frequencies.
Another possibility is to have the Enhanced NR Restriction feature activated, and
set the ENodeBFunction.zzzTemporary67 attribute to a value other than 1. In
this case, EN-DC-triggered handover is allowed for the UEs with NR restriction to
Low-Band and Mid-Band NR frequencies, but not to High-Band NR frequencies.
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EN-DC-Triggered Handover during Connected Mode Mobility
RELATED INFORMATION
Feature Operation of EN-DC-Triggered Handover during Connected Mode
Mobility
3.1.1
Targeting Highest Prioritized NR Frequency
The eNodeB is able to direct the UE to the highest prioritized NR frequency
visible to the UE by configuring the parameters of the ReportConfigA5EndcHo
MO under the UeMeasControl MO class. As a result, the eNodeB targets the
highest prioritized NR frequency for the UE to set up SCG radio resources, in
addition to considering the lower priority NR frequencies. The eNodeB directs the
UE to the target LTE cell with the highest prioritized NR frequency visible to the
UE for better connection even if the EN-DC connectivity is possible on the LTE
serving cell.
3.2
LTE Frequency Selection
Inter-LTE frequency selection is configured to find an LTE cell where setting up
SCG radio resources for the UE is possible.
Note:
Selecting intra-LTE frequency for the same purpose is not supported.
LTE frequency selection operates through the following process:
1. The list of LTE frequencies is sorted as configured in the
EUtranFreqRelation.endcHoFreqPriority attribute.
The LTE frequencies are excluded from the list by setting
EUtranFreqRelation.endcHoFreqPriority to -1.
Frequencies that are not supported by the UE are excluded based on the UE
capability. E-UTRA - NR capability is only considered to filter out the LTE
frequency.
Frequencies with no EN-DC-capable cells are excluded.
The Device-Based Frequency Filtering feature is used to configure and filter
out unsupported frequencies for specific UEs. For more information, see
Device-Based Frequency Filtering.
If the UE is moved to the target cell after LTE load balancing-triggered
handover, the LTE frequency of the source cell is excluded from the list for the
UE.
2. The maximum number of LTE frequencies is selected from the remaining
LTE frequencies in the list. The frequency of a handover target LTE cell must
be on the list in a priority order of inter-frequency measurement objects.
Selection is started from the highest priority.
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RELATED INFORMATION
Feature Operation of EN-DC-Triggered Handover during Connected Mode
Mobility
3.3
Measurement Report Evaluation
The NR B1 measurement results are stored and wait for the associated A5
measurement report. If the time allocated to the report interval for the NR B1
measurement report elapses, the stored NR B1 measurement becomes invalid
and gets discarded.
When the A5 measurement report for the EN-DC-triggered handover is received,
it must be valid within the report interval for the associated NR B1 measurement
report received beforehand. The A5 measurement result is invalid without the
associated NR B1 measurement result.
First batch of
Measurement
B1/A5 measurement
report
configuration
is ignored
eNodeB
A5
measurement
report
UE
Valid measurement
report
Second batch of
B1/A5 measurement
configuration
Time
B1
measurement
report
A5
measurement
report
Time
reportInterval for B1
L0003072A
Figure 3 Measurement Report Handling
After the UE sent the report, the triggering condition that is based on either
RSRP or RSRQ, as set by the ReportConfigA5EndcHo.triggerQuantityA5
attribute, is considered to be already satisfied. However, if the
ReportConfigA5EndcHo.reportQuantityA5 attribute is set to BOTH, then the
eNodeB also checks for the non-triggering quantity that is not set by the
ReportConfigA5EndcHo.triggerQuantityA5 attribute.
Table 2 ReportConfigA5EndcHo.reportQuantityA5 and
ReportConfigA5EndcHo.triggerQuantityA5 for EN-DC-Triggered Handover
reportQuantityA5
sameAsTriggerQua
BOTH
ntity
RSRP
Select highest
RSRP
triggerQuantityA
5
1. RSRQ threshold
check
2. Select highest
RSRP
RSRQ
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Select highest
RSRQ
1. RSRP threshold
check
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EN-DC-Triggered Handover during Connected Mode Mobility
2. Select highest
RSRQ
At least one EN-DC-capable LTE cell must be in the A5 measurement report
as a handover candidate. Then, with valid NR B1 and A5 measurement report,
handover evaluation is performed.
3.4
Handover Evaluation
If the associated A5 measurement report is received in time, a handover is
initiated if the following conditions are fulfilled:
— Setting up SCG radio resources for the UE is possible on the reported target
cell.
— The EUtranCellRelation.isHoAllowed attribute is set to true.
— The EUtranCellRelation.mobilityStatus attribute is set to available.
— The ExternalENodeBFunction.mfbiSupport attribute is set to true.
— In case of inter-gNodeB handover, the overlapping LTE band
appears in the ExternalEUtranCellTDD.additionalFreqBandList or
ExternalEUtranCellFDD.additionalFreqBandList of the target cell.
— In case of intra-eNodeB handover, the overlapping LTE
band appears in the EUtranCellTDD.additionalFreqBandList or
EUtranCellFDD.additionalFreqBandList of the target cell.
— The HRL of the UE allows a handover to the target cell. For more information,
see Shared LTE RAN.
— MBMS interest indication is not set to the source frequency.
— The reported target cell is not blocked because of high load or cell status.
RELATED INFORMATION
Feature Operation of EN-DC-Triggered Handover during Connected Mode
Mobility
3.5
NR Frequency Selection for EN-DC Setup with
Forwarded NR B1 Measurement Result
If there are multiple B1 measurement results for applicable EN-DC band
combinations, the target frequency with the highest priority set by the
GUtranFreqRelation.endcB1MeasPriority attribute is selected. If multiple NR
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frequencies share the highest priority, the NR frequency that can support EN-DC
on the serving band is selected.
Note:
3.6
If there is no NR frequency that can support EN-DC on the
serving band, the first frequency supporting EN-DC according
to the EUtranCellFDD.additionalFreqBandList attribute or the
EUtranCellTDD.additionalFreqBandList attribute is selected.
B1 and A5 Measurement Configuration with BufferBased EN-DC Setup
EN-DC-triggered handover can be configured based on the user plane
conditions of the UE.
The Buffer-Based EN-DC Setup function allows EN-DC-triggered handover by
configuring B1 and associated A5 measurement only when the downlink user
plane buffer exceeds the thresholds. The operator can configure thresholds
for user plane measurement that triggers the EN-DC-triggered handover.
Configuring the Buffer-Based EN-DC Setup function avoids unnecessary
SCG configuration and unnecessary B1 and associated A5 measurement
configuration with measurement gap for EN-DC-triggered handover when the
UE has short data session. It also eliminates user plane interruption by EN-DCtriggered handover procedure when the UE has short data session.
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EN-DC-Triggered Handover during Connected Mode Mobility
Operational Flow
Master
Node
UE
Secondary
Node
Incoming handover / RRC Re-establishment completed
User plane buffer monitoring initiated by the Master Node
RRC
RRCConnectionReconfiguration (without B1/A5 measurement request)
RRC
RRCConnectionReconfigurationComplete
User plane buffer monitoring is stopped if the user plane buffer exceeds the configured thresholds
RRC
RRCConnectionReconfiguration (with B1/A5 measurement request)
RRC
RRCConnectionReconfigurationComplete
RRC
MeasurementReport (B1/A5)
Handover is triggered if the preconditions are fulfilled
Secondary Node Addition without additional B1 measurement configuration initiated by the Master Node
EN-DC is set up based on the UE buffer status
L0003161A
Figure 4 Operational Flow for NR B1 and A5 Configuration with Buffer-Based
EN-DC Setup
1. An incoming handover or RRC Re-establishment procedure is completed.
Note:
The RRC connection reconfiguration for the B1 and associated A5
measurement configuration is triggered once if the downlink user
plane buffer exceeds the thresholds.
2. The Master Node initiates user plane buffer monitoring. The following
procedures trigger the buffer monitoring if split bearers are allowed to the
UE:
— Incoming S1 Handover
— Incoming X2 Handover
— LTE RRC Re-establishment
— E-RAB Setup
— E-RAB Release
— E-RAB Modify
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— Intra-Cell Handover by TTI Bundling Deactivation
— Intra-Cell Handover to Additional Band
Note:
In case of incoming S1 or X2 Handover, or LTE RRC Reestablishment, the UE is in high buffer status in the following
scenarios:
— The SCG is configured by the UE and the UE must transmit or
receive data in the source cell.
— An incoming S1 or X2 Handover is initiated with forwarded B1
measurement and the UE must transmit or receive data in the
source cell.
In such cases, the following apply:
— B1 and associated A5 measurement is configured without
buffer monitoring.
— The LTE mobility without PSCell change and the EN-DC setup
with forwarded NR B1 measurement functionalities have no
impact in the target cell. Therefore, EN-DC is set up without
buffer monitoring and B1 and associated A5 measurement
configuration.
3. The Master Node sends the RRCConnectionReconfiguration message
without B1 and associated A5 measurement request to the UE.
4. The UE sends the RRCConnectionReconfigurationComplete message to
the Master Node.
5. If the user plane buffer exceeds the configured packet age and packet
volume thresholds, the Master Node stops user plane buffer monitoring.
6. The Master Node sends the message with B1 and associated A5
measurement request to the UE.
7. The UE sends the RRCConnectionReconfigurationComplete message to
the Master Node.
8. The UE sends the B1 and associated A5 measurement report to the Master
Node.
9. If the preconditions for handover are fulfilled, the handover procedure is
triggered.
10. The Master Node triggers the Secondary Node Addition procedure with
forwarded B1 measurement report from the source node without additional
B1 measurement configuration.
11. EN-DC is set up based on the UE buffer status.
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EN-DC-Triggered Handover during Connected Mode Mobility
RELATED INFORMATION
Configure Buffer-Based EN-DC Setup
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4
Network Impact of EN-DC-Triggered
Handover during Connected Mode Mobility
The feature increases the inter-frequency measurements and the number of
inter-frequency handovers.
Capacity and Performance
The subscriber capacity is slightly lowered because of increased CPU load. The
feature relies on UE inter-frequency measurements to identify the UE that is
suitable for EN-DC-triggered handover.
An increase in the RRC signaling associated with inter-frequency measurements
and the handover-related signaling can be expected. When using this feature, the
number of inter-frequency handovers increases even in good radio conditions.
Interfaces
No impact.
Other Network Elements
No impact.
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EN-DC-Triggered Handover during Connected Mode Mobility
5
Parameters for EN-DC-Triggered Handover
during Connected Mode Mobility
This feature introduces and uses existing parameters to perform EN-DC
triggered handover.
Table 3
18
Parameters
Parameter
Type
Description
EndcUserProfile.endc
SetupDlPktAgeThrOver
ride
Introduced
See MOM description.
EndcUserProfile.endc
SetupDlPktVolThrOver
ride
Introduced
See MOM description.
EUtranCellFDD.endcSe
tupDlPktAgeThr
Introduced
See MOM description.
EUtranCellFDD.endcSe
tupDlPktVolThr
Introduced
See MOM description.
EUtranCellTDD.endcSe
tupDlPktAgeThr
Introduced
See MOM description.
EUtranCellTDD.endcSe
tupDlPktVolThr
Introduced
See MOM description.
ReportConfigA5EndcHo
.reportConfigA5EndcH
oId
Affecting
ReportConfigA5EndcHo
.a5Threshold1Rsrp
Affecting
The eNodeB is able
to direct the UE to
the highest prioritized
NR frequency visible to
the UE by configuring
the parameters of the
ReportConfigA5EndcHo
.a5Threshold2Rsrp
Affecting
ReportConfigA5EndcHo
.a5Threshold1Rsrq
Affecting
ReportConfigA5EndcHo
.a5Threshold2Rsrq
Affecting
ReportConfigA5EndcHo
.reportAmountA5
Affecting
ReportConfigA5EndcHo
.reportIntervalA5
Affecting
ReportConfigA5EndcHo
MO under the
UeMeasControl MO
class.
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Parameter
Type
Description
ReportConfigA5EndcHo
.triggerQuantityA5
Affecting
ReportConfigA5EndcHo
.timeToTriggerA5
Affecting
ReportConfigA5EndcHo
.hysteresisA5
Affecting
ReportConfigA5EndcHo
.reportQuantityA5
Affecting
ReportConfigA5EndcHo
.maxReportCellsA5
Affecting
UeMeasControl.endcMe
asTime
Affecting
The time interval
in which the UE
applies the different
B1 configurations
requested in each RRC
reconfiguration message
for EN-DC.
GUtranFreqRelation.e
ndcB1MeasPriority
Affecting
The priority for GUTRAN
frequencies is set by
this parameter. The
prioritized GUTRAN
frequencies are selected
from all the frequencies
related to cells the
UE can use at featuretriggered handover.
The lowest priority is
represented by a value of
0.
A value of -1 means
that the frequency is
excluded from the B1
measurement.
EUtranFreqRelation.e
ndcHoFreqPriority
Affecting
This parameter is used
to set the priority
for EUTRAN frequencies
among all frequencies
related to cells for ENDC-capable UEs that
support EN-DC-triggered
handover.
Value 0 represents the
lowest priority.
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EN-DC-Triggered Handover during Connected Mode Mobility
Parameter
Type
Description
Value -1 means that
the frequency is
excluded from event A5
measurement selection.
EndcUserProfile.b1Th
resholdRsrpOverride
Affecting
EndcUserProfile.b1Th
resholdRsrqOverride
Affecting
These parameters
configure the B1
measurement threshold
on a subscriber profile
basis.
EndcUserProfile.hyst
eresisB1Override
Affecting
EndcUserProfile.time
ToTriggerB1Override
Affecting
GUtranFreqRelation.t
imeToTriggerB1Overri
de
Affecting
Allows the configuration
of different trigger times
for B1 measurement on
each of the different
LTE-to-NR frequency
relations. Overrides
ReportConfigB1GUtra.
timeToTriggerB1 when
configured and when the
UE is not defined in a
subscriber group.
GUtranFreqRelation.t
riggerQuantityB1Over
ride
Affecting
Allows the configuration
of different trigger
quantities for B1
measurement on each of
the different LTE-to-NR
frequency relations.
Overrides
ReportConfigB1GUtra.
triggerQuantityB1
when configured.
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6
Performance of EN-DC-Triggered Handover
during Connected Mode Mobility
The feature has handover-related impact on performance.
KPIs
Table 4
Key Performance Indicators
KPI
Description
Handover Success Rate
The Handover Success Rate KPI
includes both mobility-triggered
handovers and handovers that are
not triggered with mobility. The KPI
covers both the preparation of target
cell resources and the move from the
source cell to the target cell.
Table 5
Performance Indicators
PI
Description
Buffer-Based EN-DC Setup Avoidance
Rate
This PI indicates the rate of the ENDC setups that are prevented by the
configuration of Buffer-Based EN-DC
Setup.
Counters
— EUtranCellFDD.pmEndcHoA5MeasRepUe
— EUtranCellTDD.pmEndcHoA5MeasRepUe
— EUtranCellFDD.pmEndcHoB1MeasRepUe
— EUtranCellTDD.pmEndcHoB1MeasRepUe
— EUtranCellFDD.pmEndcHoQualifiedUe
— EUtranCellTDD.pmEndcHoQualifiedUe
— EUtranCellFDD.pmEndcSetupBufMonConfig
— EUtranCellFDD.pmEndcSetupBufMonReport
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EN-DC-Triggered Handover during Connected Mode Mobility
— EUtranCellTDD.pmEndcSetupBufMonConfig
— EUtranCellTDD.pmEndcSetupBufMonReport
— EUtranCellRelation.pmHoExeAttLteInterFEndcHo
— EUtranCellRelation.pmHoExeSuccLteInterFEndcHo
— EUtranCellRelation.pmHoPrepAttLteInterFEndcHo
— EUtranCellRelation.pmHoPrepSuccLeInterFEndcHo
The following counters are introduced to distinguish the impact on performance
of the inter-frequency handover performed by this feature from other types of
inter-frequency handover:
— EUtranCellFDD.pmCellHoPrepAttLteInterFEndcHo
— EUtranCellTDD.pmCellHoPrepAttLteInterFEndcHo
— EUtranCellFDD.pmCellHoPrepSuccLteInterFEndcHo
— EUtranCellTDD.pmCellHoPrepSuccLteInterFEndcHo
— EUtranCellFDD.pmCellHoExeAttLteInterFEndcHo
— EUtranCellTDD.pmCellHoExeAttLteInterFEndcHo
— EUtranCellFDD.pmCellHoExeSuccLteInterFEndcHo
— EUtranCellTDD.pmCellHoExeSuccLteInterFEndcHo
Events
— INTERNAL_EVENT_UE_ENDC_HO_MEAS
— INTERNAL_EVENT_UE_ENDC_HO_QUAL
— INTERNAL_EVENT_ENDC_SETUP_BUF_MON_REPORT
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7
Activate EN-DC-Triggered Handover during
Connected Mode Mobility
To use the feature, it must be activated following the usual feature
activation procedure.
Prerequisites
— The license key is installed in the node.
— CCTR is active for at least one week before this procedure to collect enough
troubleshooting data.
Steps
1. Set the attribute featureState to ACTIVATED in the
FeatureState=CXC4012504 MO instance.
After This Task
Keep CCTR active for at least one week after this procedure for continued
collection of troubleshooting data.
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EN-DC-Triggered Handover during Connected Mode Mobility
8
Deactivate EN-DC-Triggered Handover
during Connected Mode Mobility
If the feature is no longer needed, it can be deactivated following the
usual feature deactivation procedure. It must also be deactivated before the
activation of any conflicting feature.
Prerequisites
— CCTR is active for at least one week before this procedure to collect enough
troubleshooting data.
Steps
1. Set the attribute featureState to DEACTIVATED in the
FeatureState=CXC4012504 MO instance.
After This Task
Keep CCTR active for at least one week after this procedure for continued
collection of troubleshooting data.
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9
Engineering Guidelines for EN-DC-Triggered
Handover during Connected Mode Mobility
9.1
Optimize the A5 Measurement Threshold Considering
Poor Coverage in Target Cell
1. Configure the following attributes to ensure that the UE stays in the target
cell:
— ReportConfigA5EndcHo.a5Threshold2Rsrp
— ReportConfigA5EndcHo.a5Threshold2Rsrq
Configure the A5 threshold attributes with a value higher than the threshold
of the A2 measurement event of poor coverage in the target cell.
For more information on the configuration of thresholds for measurement
events of poor coverage, see Coverage-Triggered Inter-Frequency Session
Continuity.
9.2
Configure PLMN IDs for EN-DC on a Neighboring LTE
Cell
1. Configure the following attributes on each node by adding PLMN IDs for
which EN-DC must be supported in the neighboring LTE cell:
— EUtranCellFDD.endcAllowedPlmnList
— EUtranCellTDD.endcAllowedPlmnList
Results
At UE setup, PLMNs sent in the HRL to the Master Node from the MME are
compared with PLMNs configured for the neighboring LTE cells. If a match for at
least one PLMN ID is found, EN-DC-triggered handover during setup is allowed
for the UE in the neighboring LTE cell.
If the Master Node does not receive an HLR from the MME, EN-DC-triggered
handover during setup is allowed for the UE only if the primary PLMN ID of the
neighboring LTE cell is added to either of the following attributes:
— EUtranCellFDD.endcAllowedPlmnList
— EUtranCellTDD.endcAllowedPlmnList
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EN-DC-Triggered Handover during Connected Mode Mobility
9.3
Configure Buffer-Based EN-DC Setup
The volume of EN-DC setups can be configured by adjusting the criteria for
the age and volume threshold of the RLC SDUs of the DRB.
The percentage of the EN-DC setups that are blocked if the configured criteria is
not met varies depending on the MO attribute configuration. The Buffer-based
EN-DC Setup Avoidance Rate PI shows the rate of the EN-DC setups that the
configuration prevents.
The INTERNAL_EVENT_ENDC_SETUP_BUF_MON_REPORT PM event contains
information about the configured thresholds and the values of age and volume
metrics that cause the thresholds to be crossed. If there is a significant
discrepancy between the threshold value and the reported value for any metric, it
might mean that the other metric prevents the EN-DC setups in a high rate.
The monitoring criteria must be lowered to allow the thresholds to be met sooner
if the following conditions apply:
— The value of the Buffer-based EN-DC Setup Avoidance Rate PI is not
satisfactory.
— The delay reported by the INTERNAL_EVENT_ENDC_SETUP_BUF_MON_REPORT
PM event is high.
Table 6
Configuration Value Examples for Buffer-Based EN-DC Setup
Number of
PM Event
Sequences
Age
Threshold
Actual Age
Volume
Threshold
Actual
Volume
1
50 ms
100 ms
100 kB
102 kB
2
50 ms
125 ms
100 kB
108 kB
In these examples, the volume criteria are stricter than the age criteria: the actual
age value at the time of crossing both thresholds is higher than the age threshold.
To allow for more EN-DC setups in such cases, the volume threshold must be
adjusted.
If the values of the age threshold for the Buffer-Based EN-DC Setup function
is set higher than the AQM minimum and maximum age thresholds of the
TCP Optimization feature, the user plane packets might be discarded before
configuring measurement events, and delay or even prevent meeting the
monitoring criteria.
Steps
1. Set any of the following attributes to a value other than 0:
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— EUtranCellFDD.endcSetupDlPktAgeThr
— EUtranCellFDD.endcSetupDlPktVolThr
— EUtranCellTDD.endcSetupDlPktAgeThr
— EUtranCellTDD.endcSetupDlPktVolThr
To configure the subscriber group-specific threshold values of the UEs, do the
following:
2. Set the value of the SubscriberGroupProfile.endcUserProfileRef
attribute to the same value as the EndcUserProfile MO instance.
3. Set any of the following attributes to a value other than 0:
— EndcUserProfile.endcSetupDlPktAgeThrOverride
— EndcUserProfile.endcSetupDlPktVolThrOverride
RELATED INFORMATION
B1 and A5 Measurement Configuration with Buffer-Based EN-DC Setup
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EN-DC-Triggered Handover during Connected Mode Mobility
Appendix A: Feature Change History
This section lists changes that affected this feature and the impact it had on
the network.
Appendix A.a: 20.Q4: EN-DC-Triggered Handover during RRC Reestablishment
The enhancement allows the EN-DC-triggered handover of the UE during
RRC reestablishment procedure.
Feature Name:
EN-DC-Triggered Handover during Connected Mode Mobility
Feature Identity:
FAJ 121 5243
Value Package Name:
Intelligent Connectivity
Value Package Identity:
FAJ 801 1013
Node Type:
Baseband Radio Node
Access Type:
LTE
Benefits
The enhancement increases the chances of the UE to be connected by
supporting the EN-DC-triggered handover of the EN-DC-capable UE during RRC
reestablishment in the following cases:
— The UE is on an LTE cell where the UE cannot set up SCG radio resources.
The enhancement allows the handover to a cell where the UE can set up SCG
resources.
— The UE is on an LTE cell connected to a low-priority NR cell in EN-DC.
The enhancement allows the handover to an LTE cell connected to a higher
priority NR cell.
Improved EN-DC connectivity is achieved by considering the followings to select
the target anchor LTE cell:
— NR coverage
— Prioritized NR frequencies
— Band combinations supported by the UE
Capacity and Performance
No impact.
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Feature Change History
Operation
No impact.
Interfaces
No impact.
Hardware
No impact.
Other Network Elements
No impact.
Appendix A.b: 20.Q4: Setting up EN-DC Using Forwarded NR B1 Measurement Report
The enhancement supports the EN-DC-capable UE in setting up EN-DC on
the target LTE cell without performing the NR B1 measurement event.
Feature Name:
EN-DC-Triggered Handover
during Connected Mode
Mobility
EN-DC-Triggered Handover
during Setup
Feature Identity:
FAJ 121 5243
FAJ 121 5097
Value Package
Name:
Intelligent Connectivity
Intelligent Connectivity
Value Package
Identity:
FAJ 801 1013
FAJ 801 1013
Node Type:
Baseband Radio Node
Baseband Radio Node
Access Type:
LTE
LTE
Benefits
During an EN-DC-Triggered Handover procedure, the source node stores the
NR B1 measurement results that the UE uses to search for NR frequencies.
The enhancement allows forwarding the stored NR B1 measurement report in
the handover request to the target node. As a result, after a successful EN-DCTriggered Handover procedure, the UE can set up EN-DC in the target node
without remeasuring the NR frequencies.
The enhancement has the following benefits:
— Less measurement configuration is needed for the UE.
— Reduces the time of EN-DC setup in the target node.
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EN-DC-Triggered Handover during Connected Mode Mobility
Capacity and Performance
The enhancement improves traffic control based on the NR frequency priority for
the EN-DC-capable UE.
As fewer measurement configurations are needed for the UE, the battery life of
the UE improves.
The enhancement improves throughput as fewer measurement gaps occur.
Operation
The NR B1 measurement results are stored and forwarded in the LTE HANDOVER
REQUEST message.
Interfaces
No impact.
Hardware
No impact.
Other Network Elements
No impact.
Appendix A.c: 21.Q4: Buffer-Based EN-DC Setup
This feature enhancement allows for the configuration of the eNodeB
behavior to set up EN-DC based on the user plane conditions of the UE.
30
Feature Name:
Basic Intelligent
Connectivity
EN-DC-Triggered
Handover during
Connected Mode
Mobility
EN-DC-Triggered
Handover during
Setup
Feature Identity:
FAJ 121 4843
FAJ 121 5243
FAJ 121 5097
Value Package
Name:
Intelligent
Connectivity
Intelligent
Connectivity
Intelligent
Connectivity
Value Package
Identity:
FAJ 801 1013
FAJ 801 1013
FAJ 801 1013
Node Type:
Baseband Radio
Node
Baseband Radio
Node
Baseband Radio
Node
Access Type:
LTE
LTE
LTE
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Feature Change History
Summary and Benefits
This enhancement provides the following benefits for UEs with short data
sessions:
— Eliminates user plane interruption that is caused by unnecessary EN-DC
setup, based on the UE buffer status.
— Improves the UE battery consumption by avoiding unnecessary SCG
configuration.
— Reduces the traffic and signaling load on the Secondary Node.
— Reduces RRC signaling by avoiding unnecessary B1 measurement
configuration with measurement gap for EN-DC setup.
Note:
Uplink throughput gain is expected when the B1 measurement
configuration is not triggered.
Capacity and Performance
User plane interruption might happen because of intra-cell handover as EN-DC
setup can be triggered during downlink data transfer.
The UE battery consumption can be improved and the traffic and signaling load
on the Secondary Node can be reduced.
The EN-DC setup and the SCG addition can be delayed or not be triggered.
EN-DC setup and SCG addition are triggered when the downlink user plane
traffic exceeds the threshold.
Uplink heavy traffic might not trigger B1 measurement configuration for the
EN-DC setup if the generated downlink data is not enough. As a result, uplink
peak throughput might not be reachable.
The time to reach stable downlink peak throughput might be delayed because
the EN-DC setup is delayed as much as downlink buffer monitoring time.
Operation
This enhancement can be activated by setting any of the following attributes to a
value other than 0:
— EUtranCellFDD.endcSetupDlPktAgeThr
— EUtranCellFDD.endcSetupDlPktVolThr
— EUtranCellTDD.endcSetupDlPktAgeThr
— EUtranCellTDD.endcSetupDlPktVolThr
This enhancement introduces the following attributes:
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EN-DC-Triggered Handover during Connected Mode Mobility
— EndcUserProfile.endcSetupDlPktAgeThrOverride
— EndcUserProfile.endcSetupDlPktVolThrOverride
— EUtranCellFDD.endcSetupDlPktAgeThr
— EUtranCellFDD.endcSetupDlPktVolThr
— EUtranCellTDD.endcSetupDlPktAgeThr
— EUtranCellTDD.endcSetupDlPktVolThr
This enhancement introduces the following PM counters:
— EUtranCellFDD.pmEndcSetupBufMonConfig
— EUtranCellFDD.pmEndcSetupBufMonReport
— EUtranCellTDD.pmEndcSetupBufMonConfig
— EUtranCellTDD.pmEndcSetupBufMonReport
This enhancement might decrease the following PM counters depending on the
configured thresholds and the UE behavior:
— EUtranCellFDD.pmEndcSetupUeAtt
— EUtranCellFDD.pmEndcSetupUeSucc
— EUtranCellFDD.pmEndcSetupScgUeAtt
— EUtranCellFDD.pmEndcSetupScgUeSucc
— EUtranCellFDD.pmMeasConfigB1Endc
— EUtranCellFDD.pmB1MeasRepEndcConfig
— EUtranCellFDD.pmB1MeasRepEndcConfigRestart
— EUtranCellFDD.pmEndcHoA5MeasRepUe
— EUtranCellFDD.pmEndcHoB1MeasRepUe
— EUtranCellFDD.pmEndcHoQualifiedUe
— EUtranCellTDD.pmEndcSetupUeAtt
— EUtranCellTDD.pmEndcSetupUeSucc
— EUtranCellTDD.pmEndcSetupScgUeAtt
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Feature Change History
— EUtranCellTDD.pmEndcSetupScgUeSucc
— EUtranCellTDD.pmMeasConfigB1Endc
— EUtranCellTDD.pmB1MeasRepEndcConfig
— EUtranCellTDD.pmB1MeasRepEndcConfigRestart
— EUtranCellTDD.pmEndcHoA5MeasRepUe
— EUtranCellTDD.pmEndcHoB1MeasRepUe
— NRCellCU.pmEndcSetupScgUeAtt
— NRCellCU.pmEndcSetupScgUeSucc
— NRCellCU.pmEndcSetupUeAtt
— NRCellCU.pmEndcSetupUeSucc
This enhancement introduces the
INTERNAL_EVENT_ENDC_SETUP_BUF_MON_REPORT PM event.
This enhancement introduces the Buffer-Based EN-DC Setup Avoidance Rate PI.
Interfaces
No impact.
Hardware
No special hardware requirements.
Other Network Elements
It is recommended to use ENM version 21.3 or later to support the MOM changes
introduced by this feature enhancement. If the Release Independence Manager
application is used, the MOM changes are supported on earlier ENM versions
also.
RELATED INFORMATION
Basic Intelligent Connectivity
EN-DC-Triggered Handover during Connected Mode Mobility
EN-DC-Triggered Handover during Setup
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EN-DC-Triggered Handover during Connected Mode Mobility
Appendix A.d: 22.Q1: Subscriber Profile-Based B1 Measurement Configuration for EN-DC
This feature enhancement enables the configuration of subscriber profilebased B1 measurement threshold for UEs using the ASGH framework.
Feature
Name:
Basic Intelligent
Connectivity
EN-DC-Triggered
Handover during
Connected Mode
Mobility
EN-DC-Triggered
Handover during
Setup
Feature
Identity:
FAJ 121 4843
FAJ 121 5243
FAJ 121 5097
Value
Package
Name:
Intelligent
Connectivity
Intelligent
Connectivity
Intelligent
Connectivity
Value
Package
Identity:
FAJ 801 1013
FAJ 801 1013
FAJ 801 1013
Node
Type:
Baseband Radio
Node
Baseband Radio
Node
Baseband Radio
Node
Access
Type:
LTE
LTE
LTE
Summary and Benefits
The feature enhancement enables a group of UEs defined in the ASGH
framework to be configured with custom B1 measurement thresholds. This
allows for differentiated B1 measurement configuration for these designated
UEs.
Capacity and Performance
Throughput-related integrity KPIs can improve.
Operation
The enhancement introduces the following attributes:
— EndcUserProfile.b1ThresholdRsrpOverride
— EndcUserProfile.b1ThresholdRsrqOverride
— EndcUserProfile.hysteresisB1Override
— EndcUserProfile.timeToTriggerB1Override
The PM counters decrease when a higher B1 threshold is set and increase when a
lower B1 threshold is set.
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Feature Change History
The following PM counters associated with Basic Intelligent Connectivity are
affected:
— EUtranCellFDD.pmEndcSetupUeAtt
— EUtranCellTDD.pmEndcSetupUeAtt
— EUtranCellFDD.pmEndcSetupUeSucc
— EUtranCellTDD.pmEndcSetupUeSucc
— EUtranCellFDD.pmEndcSetupScgUeAtt
— EUtranCellTDD.pmEndcSetupScgUeAtt
— EUtranCellFDD.pmEndcSetupScgUeSucc
— EUtranCellTDD.pmEndcSetupScgUeSucc
— EUtranCellFDD.pmMeasConfigB1Endc
— EUtranCellTDD.pmMeasConfigB1Endc
— EUtranCellFDD.pmB1MeasRepEndcConfig
— EUtranCellTDD.pmB1MeasRepEndcConfig
— EUtranCellFDD.pmB1MeasRepEndcConfigRestart
— EUtranCellTDD.pmB1MeasRepEndcConfigRestart
The following PM counters associated with EN-DC-triggered handover are
affected:
— EUtranCellFDD.pmCellHoPrepAttLteInterFEndcHo
— EUtranCellTDD.pmCellHoPrepAttLteInterFEndcHo
— EUtranCellFDD.pmCellHoPrepSuccLteInterFEndcHo
— EUtranCellTDD.pmCellHoPrepSuccLteInterFEndcHo
— EUtranCellFDD.pmCellHoExeAttLteInterFEndcHo
— EUtranCellTDD.pmCellHoExeAttLteInterFEndcHo
— EUtranCellFDD.pmCellHoExeSuccLteInterFEndcHo
— EUtranCellTDD.pmCellHoExeSuccLteInterFEndcHo
— EUtranCellFDD.pmEndcHoA5MeasRepUe
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EN-DC-Triggered Handover during Connected Mode Mobility
— EUtranCellTDD.pmEndcHoA5MeasRepUe
— EUtranCellFDD.pmEndcHoB1MeasRepUe
— EUtranCellTDD.pmEndcHoB1MeasRepUe
— EUtranCellFDD.pmEndcHoQualifiedUe
— EUtranCellTDD.pmEndcHoQualifiedUe
If EndcUserProfile.b1ThresholdRsrpOverride or
EndcUserProfile.b1ThresholdRsrqOverrideis used together
with GUtranFreqRelation.b1ThrRsrpFreqOffset or
GUtranFreqRelation.b1ThrRsrqFreqOffset respectively, differentiated B1
threshold offset per frequency level must be provided.
Note:
The ReortConfigB1GUtra.b1ThresholdRsrq and
GUtranFreqReleation.b1ThrRsrqFreqOffset attributes are described
to take effect as New connection but actual behavior is Next usage.
Taking effect of EndcUserProfile.b1ThresholdRsrqOverride is
New connection. Therefore, if ASGH is used, the taking
effect between EndcUserProfile.b1ThresholdRsrqOverride and
GUtranFreqReleation.b1ThrRsrpFreqOffset can be different. These
the new attributes are applied across all of the cells.
Interfaces
No impact.
Hardware
No special hardware requirements.
Other Network Elements
It is recommended to use ENM version 22.1 or later to support the MOM changes
introduced by this feature enhancement. If the Release Independence Manager
application is used, the MOM changes are supported on earlier ENM versions
also.
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Feature Change History
Appendix A.e: 22.Q2: MFBI Support for EN-DC-Triggered Handover during Connected
Mode Mobility
The feature enhancement enables all configured LTE bands in neighbor
cells for EN-DC triggered handover.
Feature Name
EN-DC-Triggered Handover during Connected Mode
Mobility
Feature Identity
FAJ 121 5243
Value Package Name
Intelligent Connectivity
Value Package Identity
FAJ 801 1013
Node Type
Baseband Radio Node
Access Type
LTE
Summary and Benefits
The feature enhancement enables EN-DC triggered handover for all LTE bands of
neighbor cells for that are capable of EN-DC triggered handover. With additional
bands available, EN-DC connectivity is improved.
Capacity and Performance
The feature enhancement improves EN-DC connectivity by enabling additional
LTE bands for EN-DC triggered handover.
Operation
The feature enhancement requires that the
ENodeBFunction.endcAwareMfbiIntraCellHo attribute is set to true
The following PM counters are introduced:
— EUtranCellRelation.pmHoExeAttLteInterFEndcHo
— EUtranCellRelation.pmHoExeSuccLteInterFEndcHo
— EUtranCellRelation.pmHoPrepAttLteInterFEndcHo
— EUtranCellRelation.pmHoPrepSuccLteInterFEndcHo
— GUtranCellRelation.pmEndcSetupUeAtt
— GUtranCellRelation.pmEndcSetupUeSucc
— GUtranCellRelation.pmEndcSetupScgUeAtt
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— GUtranCellRelation.pmEndcSetupScgUeSucc
The feature enhancement increases the following PM counters:
— EUtranCellTDD.pmEndcSetupUeAtt
— EUtranCellFDD.pmEndcSetupUeAtt
— EUtranCellTDD.pmEndcSetupUeSucc
— EUtranCellFDD.pmEndcSetupUeSucc
— EUtranCellTDD.pmEndcSetupScgUeAtt
— EUtranCellFDD.pmEndcSetupScgUeAtt
— EUtranCellTDD.pmEndcSetupScgUeSucc
— EUtranCellFDD.pmEndcSetupScgUeSucc
— EUtranCellTDD.pmRrcConnReconfAttNoMobEarfcnEndc
— EUtranCellFDD.pmRrcConnReconfAttNoMobEarfcnEndc
— EUtranCellTDD.pmRrcConnReconfSuccNoMobEarfcnEndc
— EUtranCellFDD.pmRrcConnReconfSuccNoMobEarfcnEndc
Interfaces
No impact.
Hardware
No specific hardware requirements.
Other Network Elements
The UE must support Feature Group Indicator 31.
It is recommended to use ENM version 22.2 or later to support the MOM changes
introduced by this feature enhancement. If the Release Independence Manager
application is used, the MOM changes are supported on earlier ENM versions
also.
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Feature Change History
Appendix A.f: 22.Q4: Frequency-Differentiated B1 Measurement Trigger Time and Quantity
Configuration for EN-DC
This feature enhancement allows the configuration of a different trigger
time for EN-DC B1 measurements for each LTE-to-NR frequency relation.
An overriding parameter for trigger quantity is also introduced.
Feature Name
EN-DC-Triggered
Handover during
Connected Mode
Mobility
EN-DC-Triggered
Handover during Setup
Feature Identity
FAJ 121 5243
FAJ 121 5097
Value Package Name
Intelligent Connectivity
Intelligent Connectivity
Value Package Identity
FAJ 801 1013
FAJ 801 1013
Node Type
Baseband Radio Node
Baseband Radio Node
Access Type
LTE
LTE
Impact at Upgrade
Optional
Optional
Summary and Benefits
Multiple B1 measurements can be configured for the UE with different times to
trigger the B1 measurement for each NR frequency in an LTE-to-NR frequency
relation. The Master Node can apply a waiting time for the B1 measurement
report, which is calculated based on the following values:
— The configured time during which the UE can perform B1 measurements.
— The largest time to trigger value for a B1 measurement for a frequency
relation. If this is not configured, the cell-level trigger time configuration is
used.
The trigger quantity of the B1 measurements can also be configured for the
different frequency relations. This way, different NR frequencies can be assigned
different trigger quantities for triggering EN-DC-triggered handover.
The feature enhancement has the following benefits:
— Different NR frequencies can be treated according to operator requirements
to trigger EN-DC-triggered handover with the optimized trigger time and
trigger quantity.
— Different NR frequencies in the same priority group can be further prioritized
for EN-DC-triggered handover on the frequency range level. This is done
in a single RRC RRCConnectionReconfiguration message, reducing RRC
signaling load.
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EN-DC-Triggered Handover during Connected Mode Mobility
Capacity and Performance
The number of EN-DC-triggered handover preparations and executions can
increase or decrease depending on the trigger time and trigger quantity
configuration on the different LTE-to-NR frequency relations. The Handover
Success Rate KPI shows the change in the number of successful EN-DC-triggered
handovers.
When the trigger time overriding attribute value is lower than the cell-level
trigger time value, a higher number of EN-DC-triggered handovers is possible. As
a result, the number of EN-DC setup failures can also increase. However, if the
trigger time overriding attribute value is higher than the cell-level trigger time
value, the number of possible EN-DC-triggered handovers decreases. This might
result in a decrease in EN-DC setup failures. The behavior can be observed with
the following cell-level and cell relation-level PM counters:
— EUtranCellFDD.pmCellHoPrepAttLteInterFEndcHo
— EUtranCellTDD.pmCellHoPrepAttLteInterFEndcHo
— EUtranCellFDD.pmCellHoPrepSuccLteInterFEndcHo
— EUtranCellTDD.pmCellHoPrepSuccLteInterFEndcHo
— EUtranCellFDD.pmCellHoExeAttLteInterFEndcHo
— EUtranCellTDD.pmCellHoExeAttLteInterFEndcHo
— EUtranCellFDD.pmCellHoExeSuccLteInterFEndcHo
— EUtranCellTDD.pmCellHoExeSuccLteInterFEndcHo
— EUtranCellFDD.pmEndcHoB1MeasRepUe
— EUtranCellTDD.pmEndcHoB1MeasRepUe
— EutranCellRelation.pmHoExeAttLteInterFEndcHo
— EutranCellRelation.pmHoExeSuccLteInterFEndcHo
— EutranCellRelation.pmHoPrepAttLteInterFEndcHo
— EutranCellRelation.pmHoPrepSuccLteInterFEndcHo
— EUtranCellFDD.pmEndcSetupUeAtt
— EUtranCellTDD.pmEndcSetupUeAtt
— EUtranCellFDD.pmEndcSetupUeSucc
— EUtranCellTDD.pmEndcSetupUeSucc
— GUtranCellRelation.pmEndcSetupUeAtt
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Feature Change History
— GUtranCellRelation.pmEndcSetupUeSucc
— GUtranCellRelation.pmEndcSetupScgUeAtt
— GUtranCellRelation.pmEndcSetupScgUeSucc
Integrity-related uplink and downlink KPIs might be affected as EN-DC-triggered
handover is performed for some NR frequencies more than for others.
Operation
The feature enhancement introduces the following attributes:
— GUtranFreqRelation.timeToTriggerB1Override
— GUtranFreqRelation.triggerQuantityB1Override
The GUtranFreqRelation.timeToTriggerB1Override attribute overrides the
ReportConfigB1GUtra.timeToTriggerB1 attribute if the following conditions
apply:
— The UE does not belong to a subscriber group for
which the EndcUserProfile.timeToTriggerB1Override attribute is
configured. If the UE belongs to a subscriber group, the
EndcUserProfile.timeToTriggerB1Override attribute is used, if it is set
to a value other than default.
— The GUtranFreqRelation.timeToTriggerB1Override attribute is set to a
value other than default.
If the UE belongs to a subscriber group, the waiting time
for the B1 measurement report is calculated with the value
of the EndcUserProfile.timeToTriggerB1Override attribute, if it is
set to a value other than default, and the value of the
EndcUserProfile.endcMeasTimeOverride attribute.
If the UE belongs to a subscriber group, but the
EndcUserProfile.timeToTriggerB1Override attribute is set to the default
value, the waiting time for the B1 measurement report is calculated as the sum of
the following values:
— The largest value among the
GUtranFreqRelation.timeToTriggerB1Override attributes configured for
each LTE-to-NR frequency relation
— The value of the EndcUserProfile.endcMeasTimeOverride attribute
If the UE does not belong to a subscriber group, the waiting time for the B1
measurement report is calculated as the sum of the following values:
— The largest value among the
GUtranFreqRelation.timeToTriggerB1Override attributes configured for
each LTE-to-NR frequency relation
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EN-DC-Triggered Handover during Connected Mode Mobility
— The value of the UeMeasControl.endcMeasTime attribute
The GUtranFreqRelation.triggerQuantityB1Override attribute, if
set to a value other than default, overrides the
ReportConfigB1GUtra.triggerQuantityB1 attribute.
Interfaces
No impact.
Hardware
No specific hardware requirements.
Other Network Elements
It is recommended to use ENM version 22.4 or later to support the MOM changes
introduced by this feature enhancement. If the Release Independence Manager
application is used, the MOM changes are supported on earlier ENM versions
also.
RELATED INFORMATION
EN-DC-Triggered Handover during Connected Mode Mobility
EN-DC-Triggered Handover during Setup
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