ANR Mobility

Contents
1 Introduction
1.1 Basic Characteristics
1.2 Benefits
1.3 Additional Information

2 Feature Operational Description

2.1 Network Requirements
2.2 Feature Operation Sequence Diagram
2.3 Process Steps

3 Parameters
3.1 Introduced Parameters
3.2 Affected Parameters

4 Network Impact
4.1 Subscriber Capacity
4.2 Network Performance
4.3 Hardware
4.4 Inter-Node Interface
4.5 Other Network Elements

5 Associated Features and Affected Functions

5.1 Prerequisite Features
5.2 Affected Features
5.3 Related Features
5.4 Affected System Functions

6 Performance
6.1 KPIs
6.2 Counters
6.3 Events

7 Operation and Maintenance

7.1 Activate the Feature
7.2 Deactivate the Feature
7.3 Engineering Guidelines

1 Introduction

This document describes the optional feature Automatic Neighbor Relations (ANR)
Mobility and its main benefits and impacts in the WCDMA RAN.

1.1 Basic Characteristics

This section describes the basic characteristics of the feature.

Feature FAJ 121 2551: ANR Mobility

identity:

Release: Introduced in W14.1, enhanced in W15.1

Dependencies

 This feature has no prerequisite features.

 This feature affects no other features.

1.2 Benefits
This section describes the benefits of this feature.

ANR Mobility is a Self Organizing Network (SON) feature implemented in the SRNC. The
feature off-loads the network by automatically detecting, identifying, and configuring
intra-frequency neighbor relations in the Neighbor Cell Lists (NCLs). The feature
improves the Active Set (AS), which contributes to improved retainability visible as lower
dropped calls ratio and improved mobility visible as increased number of IAF handovers
and reduced number of IRAT handovers.

The ANR Mobility feature is license controlled and activated on the RNC and cell level.
The operator can initially activate ANR Mobility in some cells and then gradually activate
ANR in additional cells. The feature is based on Detected Set (DS) measurement reports
sent by UEs in the real handover environment. It is not based on the 3GPP Rel-10 ANR
version.

The feature can perform handover to Undefined neighbor cells even when no neighbor
relation is configured from any of the AS cells to that cell (ANR-initiated handover). That
behavior increases the probability of maintaining the UE connection when a critical
neighbor relation is missing.

The main output from the feature is ANR-created intra-frequency neighbor relations in
NCLs, see Figure 1.

Figure 1 ANR Mobility Creating the Intra-Frequency Relations

A General Performance Event Handling (GPEH) event is sent, which lists the relation the
ANR Mobility feature fails to create.

The GPEH event is sent if any of the following conditions are fulfilled:

 The NCL is full.

  There is no space for another neighbor relation in SIB11 of source cell.
 Writing to database is deactivated.

ANR Mobility is based on populating and evaluating target cell candidates in statistics.
When a proper candidate is found, ANR Mobility creates a neighbor relation,
UtranRelation. The operator can prevent ANR Mobility from creating relations, and
therefore test the ANR Mobility without affecting the existing configuration.

1.3 Additional Information

More information about this feature and related topics can be found in the following
documentation:

 System Description
 Handover
 General Performance Event Handling

2 Feature Operational Description

This section describes the ANR Mobility feature in more detail, including network
configuration requirements and operation flows.

2.1 Network Requirements

The following must be fulfilled at feature activation:

 The license for ANR Mobility feature, CXC 403 0136 is enabled.
 RNC 3820 or Evo Controller 8200/RNC is used.

2.2 Feature Operation Sequence Diagram

Figure 2 gives a high-level overview of signaling in which ANR Mobility is involved.
Figure 2 ANR Mobility Diagram

The ANR Mobility feature is related to source cells in the SRNC which is the best AS cell
according to the measurement report. The feature creates intra-frequency neighbor
relations in the configuration database from a source cell in the SRNC (UtranCell):

 to another cell in the SRNC, represented by UtranCell.

 to the DRNC cell, represented by ExternalUtranCell in the SRNC.
 to a different cluster member cell in the RNC in Pool configuration,
represented by RemoteUtranCell in the SRNC.

In an RNC in Pool configuration, if Iub Redundancy is configured between two cluster

member RNCs, the ANR Mobility feature can create UtranCell relations to cells with the
Iub Redundancy configuration. For more information on Iub Redundancy refer to RNC in
Pool.

ANR Mobility activated in the SRNC does not create neighbor relations from a DRNC cell
to any other cells.

2.3 Process Steps

This section describes the process steps initiated by the main trigger for ANR Mobility,
that is, a reception of an Undefined cell DS measurement report. See Table 1 for the
different types of measurement reports that the UE sends in this context.

Table 1 UE Measurement Report Types

UE Measurement Report Types Report Receiver in SRNC
Monitored Set measurement report, which Handover Evaluation (legacy functionality)
contains one or more RNC defined Primary
Scrambling Codes, representing neighbor
cell relations.
Unmonitored Set DS report where at least Handover Evaluation (legacy functionality)
one cell is Defined. Issued if a DS report
contains one or more target cells Primary
Scrambling Codes where at least one
matches the Primary Scrambling Code of
minimum one of the neighbors of the AS
cells.
Unmonitored Set DS report where all cells ANR Mobility (when activated, otherwise the
are Undefined. Issued when a DS report DS report is discarded)
contains one or more target cells Primary
Scrambling Codes which does not match
the Primary Scrambling Code of any of the
neighbors to the AS cells.

Figure 3 gives an overview of the process steps and involved operator parameters in the
SRNC.
Figure 3 ANR Mobility Handling of Undefined Cell DS Report

2.3.1 Reception of Undefined Cell DS Report

The reception of an Undefined cell DS measurement report is the real-time trigger for
ANR Mobility. The trigger activates ANR Mobility if the license is enabled and the feature
is activated in the RNC and in the best AS cell. Otherwise, the DS report is discarded in
the same way as when ANR Mobility is deactivated or not supported.

2.3.2 ANR CPICH Filter

The CPICH filter can be used by the operator to control ANR Mobility sensitivity to CPICH
measured values that are reported in Undefined cell DS reports. The filter is enabled with
the anrDsReportFilterEnabled parameter and uses two parameters:

 Ec/No threshold (anrDsReportFilterEcNo)

 Received Signal Code Power (RSCP) threshold (anrDsReportFilterRscp)
When the filter is enabled, Undefined cell DS reports are compared with the thresholds. If
the corresponding thresholds are fulfilled, or if the filter is disabled, the DS report is used
by ANR Mobility. Otherwise, it is discarded.

2.3.3 ANR Black List

When an Undefined cell DS report is received, the reported Primary Scrambling Code is
checked against the ANR Black List. Some of the intra-frequency cells listed in ANR Black
List for the best AS cell (source cell) can have the same Primary Scrambling Code as the
reported Primary Scrambling Code. In such cases, the DS report is discarded. The ANR
Black List is defined by the anrBlackTargetCells parameter.

2.3.4 Cell Selection and ANR Handover Proposal

A received Undefined cell DS report triggers cell selection among the candidates in the
ANR Mobility internal statistics having the same Primary Scrambling Code and frequency.
An ANR-initiated handover is proposed to the selected cell.

2.3.5 New ANR Handover Attempt

If the selected cell passes admission check, an ANR handover is attempted and the
internal statistics is updated.

2.3.6 ANR Handover Success Result

In case of soft handover, a successful ANR-initiated handover is based on detecting

Uplink Synchronization in the candidate target cell. That is, the NBAP message "RADIO
LINK RESTORE INDICATION" is received. This information is used in ANR Mobility internal
statistics in the source cell. If Uplink Synchronization is achieved within 2 seconds, the
handover attempt is judged successful (correct candidate selected) and ANR Mobility
updates the internal statistics accordingly. If Uplink Synchronization is not achieved
within 2 seconds, the cell is removed from the active set again.

In case of softer handover, all ANR handover attempts are assumed to be successful, as
the UE is already synchronized with the RBS of a cell from the AS.

3 Parameters

This section describes parameters introduced by the ANR Mobility feature and parameters
affected by activating the feature.

3.1 Introduced Parameters

Table 2 describes the parameters introduced by the ANR Mobility feature.

Table 2 Introduced Parameters

Parameter Description
Anr::anrCellAddRelationMax Defines the maximum number of relations per
source cell that can be added by ANR Mobility
during each evaluation period. This limit on the
rate of instance creation can be used to limit the
amount of O&M load caused by the feature.
AnrIafUtran::anrAddRelationEnabled Enables or disables the ANR UTRAN intra-
frequency feature ability to create intra-
frequency neighbor relations in the RNC
configuration database.
AnrIafUtran::anrCandidateAbsPropThresh Defines the threshold for the absolute number of
ANR-initiated handover proposals needed for a
target cell candidate to reach reliable statistics.
Reliable statistics is required for determining a
good intra-frequency neighbor relation.
AnrIafUtran::anrCandidateExpirePeriod Defines the expiry period for candidate cells in
ANR internal statistics. After this time, if a good
neighbor relation has not been found before, the
ANR statistics is removed.
AnrIafUtran::anrCandidateLowerThresh Defines the threshold to determine if the degree
of successful ANR handovers is too low. When
the degree is too low, ANR Mobility is prevented
from performing handover to such candidates.
AnrIafUtran::anrCandidateUpperThresh Defines the threshold to determine if the degree
of successful ANR handovers is high enough.
When equal or higher than the threshold, the
ANR candidate is used for evaluation of a new
intra-frequency neighbor relation.
AnrIafUtran::anrDsReportFilterEcno Defines the Ec/No threshold used by the ANR
CPICH filter. DS reports having a CPICH Ec/No
value lower than the threshold are not
considered by the ANR UTRAN intra-frequency
feature.
AnrIafUtran::anrDsReportFilterEnabled Enables or disables the ANR CPICH filter, which
is used only when ANR Mobility is activated, to
filter the required certain levels of Ec/No and
RSCP in Detected Set measurement reports.
AnrIafUtran::anrDsReportFilterRscp Defines the RSCP threshold used by the ANR
CPICH filter. DS reports having a CPICH RSCP
value lower than the threshold are not
considered by the ANR UTRAN intra-frequency
feature.
AnrIafUtran::anrEnabled Enables or disables the ANR UTRAN intra-
frequency feature on the RNC level.
UtranCell::anrIafUtranCellConfig Enables or disables the ANR Mobility function in
this cell for intra-frequency relations.
UtranCell::anrIafUtranCellConfig::anrEnabled Enables or disables the ANR Mobility function in
a cell.
UtranCell::anrIafUtranCellConfig::relationAddEnabled Enables or disables creation of relations by the
ANR Mobility in a cell.
UtranCell::AnrBlackList::anrBlackTargetCells Lists the references to target cells which ANR
Mobility is not allowed to use when performing
handovers or creating relations.
UtranRelation::createdBy Indicates if the instance of UtranRelation is
created by the operator or ANR Mobility. Read-
only attribute.
UtranRelation::creationTime Indicates the date and time when the neighbor
relation is created. Read-only attribute.

3.2 Affected Parameters

The implementation of this feature affects no parameters.

4 Network Impact

This section describes how the ANR Mobility feature impacts the network functions and
capabilities.
4.1 Subscriber Capacity
No feature-specific information is identified.

4.2 Network Performance

This section provides information on the impact of the feature on network performance.

ANR Mobility is based on ANR internal statistics where target cell candidates are
populated and evaluated with handover attempts to the candidates. To evaluate neighbor
relation, a number of handover attempts is required.

The time needed to detect a neighbor cell relation depends on:

 The network configuration.

 The degree of scrambling code reuse on a frequency.
 ANR configuration (see Section 7.3.2).
 Intensity of the UE mobility in the cell area.

After evaluation period, ANR Mobility improves retainability shown in lower dropped calls
ratio.

4.3 Hardware
This section provides information on the impact of the feature on hardware.

This feature is supported for the following node types:

 RNC 3820
 Evo Controller 8200/RNC

4.4 Inter-Node Interface

This section provides information on the impact on inter-node interfaces.

The following interfaces are affected when the ANR Mobility feature is activated:

 NBAP: signaling intensity can increase with ANR-initiated handovers and UL

Synchronization results (with the following messages: "RADIO LINK SETUP",
"RADIO LINK ADDITION" and "RL RESTORE INDICATION"). Signalling
intensity can increase when ANR performs handover evaluation to candidate
cells.
 RRC: signaling intensity increases with ANR-initiated handover (with the "AS
UPDATE" message).

4.5 Other Network Elements

No feature-specific information is identified.

5 Associated Features and Affected Functions

This section describes how the ANR Mobility feature affects other features and functions.

5.1 Prerequisite Features

This feature has no prerequisite features.

5.2 Affected Features

This feature affects no other feature.

5.3 Related Features

It is recommended, but not required, to activate the OSS-RC feature Automatic Neighbor
Relation Management, FAJ 121 3261, which facilitates controlling ANR Mobility
parameters.

It is also recommended, but not required, to activate the OSS-RC feature, FAJ 121 3701:
Automatic Scrambling Code Selection. The feature limits the risk of scrambling code
collisions in the network which can have an adverse effect on the ANR relation detection
accuracy.

5.4 Affected System Functions

Table 3 lists functions affected by the ANR Mobility feature.

Table 3 Affected System Functions

Function Description
Handover ANR-triggered handover is performed on many of the received Undefined cell DS
reports. When the ANR Mobility feature is deactivated or not installed, the reports
are discarded.

6 Performance

This section describes performance indicators, counters, and events associated with the
ANR Mobility feature.

6.1 KPIs
Table 4 lists the main Key Performance Indicators (KPIs) associated with the ANR
Mobility feature.

Table 4 KPIs
KPI Description
Retainability (or drop rate) It is expected to improve in the long term (AS becomes better), after the ANR
Mobility evaluation period.
Mobility It is expected to improve in the long term (AS becomes better), after the ANR
Mobility evaluation period. IRAT HO (to GSM) is expected to reduce, IAF HO is
expected to increase.
Soft/Softer handover It can change over time. For example, it can be increased initially when ANR
Mobility is activated and decreased in the long term when ANR mobility
contributes to better ASs.
ANR-Initiated handover The handover counter on UtranCell level can be compared with the sum of all
handover counters on UtranRelation (IAF) level. The difference corresponds to
ANR-initiated handovers.

6.2 Counters
More information about counters can be found in Managed Object Model RNC and
Managed Object Model RBS.

6.2.1 Introduced Counters

Table 5 lists the counters introduced by the ANR Mobility feature.

Table 5 Counters Introduced by ANR Mobility Feature

Counter Description
UtranCell::pmAnrRelationAdd Incremented by one when ANR Mobility adds a neighbor relation in
the configuration database, regardless of the neighbor frequency or
IRAT relation type.

6.2.2 Affected Counters

When the ANR Mobility feature is activated, Undefined cell DS reports received by the
SRNC are handled by ANR Mobility instead of being discarded. The feature uses ANR
internal statistics where target cell candidates are evaluated by handover attempts. As a
result, some PM counters listed in Table 6 can be affected, especially during the ANR
Mobility candidates evaluation period.

Table 6 lists a number of existing counters that the ANR Mobility feature can affect.
Definitions of counters do not change. However, the counter valuse can change since
ANR Mobility performs handover to Undefined cells during its evaluation of target cell
candidates.

Table 6 Counters Affected by ANR Mobility Feature

Counter Description
IurLink::pmNoOfRlForDriftingUesPerDrnc
UtranCell::pmNoOfRlForDriftingUes
UtranCell::pmNoOfRlForNonDriftingUes
UtranCell::pmNoSysRelSpeechNeighbr
UtranCell::pmNoTimesRlAddToActSet
UtranCell::pmNoTimesRlDelFrActSet
UtranCell::pmNoTimesRlRepInActSet
UtranCell::pmRlAddAttemptsBestCellCsConvers
UtranCell::pmRlAddAttemptsBestCellPacketHigh
UtranCell::pmRlAddAttemptsBestCellPacketLow The PM counters are affected by ANR Mobility as
handover is done to Undefined cells.
UtranCell::pmRlAddAttemptsBestCellSpeech
UtranCell::pmRlAddAttemptsBestCellStandAlone
UtranCell::pmRlAddAttemptsBestCellStream
UtranCell::pmRlAddSuccessBestCellCsConvers
UtranCell::pmRlAddSuccessBestCellPacketHigh
UtranCell::pmRlAddSuccessBestCellPacketLow
UtranCell::pmRlAddSuccessBestCellSpeech
UtranCell::pmRlAddSuccessBestCellStandAlone
UtranCell::pmRlAddSuccessBestCellStream
Handover::pmSofterHoAttemptNonIur
Handover::pmSofterHoSuccessNonIur
Handover::pmSoftHoAttemptNonIur
Handover::pmSoftHoSuccessNonIur
Handover::pmSoftSofterHoAttemptIur
Handover::pmSoftSofterHoSuccessIur

6.3 Events
Table 7 provides the events introduced by the ANR Mobility feature, Table 8 lists the
events that are modified, and Table 9 lists events that are affected.

Table 7 Events Introduced by ANR Mobility

Event Event Parameter Description
INTERNAL_ANR_ADD_RELATION_PREVENTED EVENT_PARAM_PREVENTED_RELATION_TYPE, When ANR Mobility is
EVENT_PARAM_PREVENTED_RELATION_REASON prevented from creating
an intra-frequency
neighbor relation, the
GPEH event indicates
the relation and reason.

This event is reported

when:

 Neighbor Cell
List (NCL) is
full in a source
cell.
 Writing of
detected
relations is
deactivated
either on RNC
or source cell
level.
 There is no
space for
another intra-
frequency
neighbor
relation in
SIB11 of a
source cell.
Table 8 Events Modified by ANR Mobility
Event Event Parameter Description
INTERNAL_SOFT_HANDOVER_EXECUTION EVENT_PARAM_ANR_INITIATED, The GPEH event
EVENT_VALUE_ANR_ADD_CELL_ATTEMPT with the
indicated
parameter is
generated when
ANR Mobility
triggers an ANR
handover
attempt.

This event value

indicates that
the handover
execution is
caused by an
Undefined cell
DS report, which
triggers the
 addition of ANR-
initiated Radio
Link (RL).

The GPEH event,

triggered by
Defined cell DS
reports is not
affected.
EVENT_PARAM_ANR_INITIATED, The GPEH event
EVENT_VALUE_ANR_REPLACE_CELL_ATTEMPT with the
indicated
parameter is
generated when
ANR Mobility
triggers an ANR
handover
attempt.

This event value

indicates that
the handover
execution is
caused by an
Undefined cell
DS report, which
triggers the
addition of ANR-
initiated RL and
the removal of
an existing RL
from the AS.

The GPEH event,

triggered by
Defined cell DS
reports is not
affected.
EVENT_PARAM_ANR_INITIATED, The GPEH event
EVENT_VALUE_ANR_ADDED_CELL_REMOVED_NO_UL_SYNCH with the
indicated
parameter is
generated when
ANR Mobility
triggers an ANR
handover
attempt.

This event value

indicates that
the handover
execution is
caused by an
Undefined cell
DS report, which
triggers the
removal of ANR-
initiated RL,
when no Uplink
Synchronization
is achieved
before timer
expiry.

The GPEH event,

triggered by
Defined cell DS
reports is not
affected.
Table 9 Events Affected by ANR Mobility
Event Event Parameter Description
INTERNAL_SOHO_DS_MISSING_NEIGHBOUR No specific event parameter. Captured at the reception of a
measurement report for event
1a, event 1c, or event 1d where
the triggering cell is not
included in Neighbor Set.

When ANR Mobility is activated,

the event can be less frequently
reported.
INTERNAL_SOHO_DS_UNMONITORED_NEIGHBOUR No specific event parameter. Captured when handover
proposal is received, where the
proposed cell is included in the
neighbor set, but not included
in the monitored set.

When ANR Mobility is activated,

non-full neighbor cell lists can
increase in size, which can
increase the frequency of this
event.
Note:
More GPEH events applicable during Soft Handover procedures can be
generated. The GPEH data can be mitigated by not activating the events that
are frequently generated.

The INTERNAL_SOFT_HANDOVER_EXECUTION event is recommended to be

activated to verify the behavior of the ANR Mobility feature, which can reflect
if a Soft Handover is executed because of the ANR Mobility.

Another way to mitigate high GPEH data volumes is to activate the ANR
Mobility in clusters rather than in a whole RNC directly.

More information about events can be found in General Performance Event

Handling RBS and General Performance Event Handling RNC.

7 Operation and Maintenance

This section provides Operation and Maintenance (O&M) information for the
ANR Mobility feature.

7.1 Activate the Feature

7.1.1 Preconditions

This feature has no preconditions for activating.

7.1.2 Activate the Feature

The feature is license-controlled for each RNC (CXC 403 0136). The
operator can activate ANR in the chosen cells and then gradually increase
the number of ANR-activated cells.
 To activate the feature, do the following:

1. Set the featureState attribute to ACTIVATED for RncFeature

instance MO AnrMobility.
2. Activate the feature on node level by setting the anrEnabled
attribute in the AnrIafUtran MO to TRUE.
3. Activate the feature on cell level by setting the
anrIafUtranCellConfig.anrEnabled attribute in a specific
UtranCell MO instance to TRUE.

For more information about licenses, refer to Licenses and Hardware

Activation Codes.

7.2 Deactivate the Feature

7.2.1 Preconditions

This feature has no preconditions for deactivating.

7.2.2 Deactivate the Feature

The ANR feature can be deactivated in two ways:

 For an RNC (anrEnabled), regardless of cell activation/deactivation.

 For a cell (anrIafUtranCellConfig), assuming activation on RNC
level.

ANR Mobility-specific functions can also be deactivated partially, for

example:

 ANR Mobility can be prevented from creating neighbor relations in

the configuration database (anrAddRelationEnabled).
 ANR Mobility can be prevented from considering Undefined Cell DS
reports with poor received signal strength
(anrDsReportFilterEnabled).
 ANR Mobility can be prevented from performing a handover to cells
using a specific Primary Scrambling Code. ANR Mobility can be also
prevented from adding an intra-frequency neighbor relation to such
cells (AnrBlackList::anrBlackTargetCells).

For more information about licenses, refer to Licenses and Hardware

Activation Codes.

7.3 Engineering Guidelines

The purpose of this section is to provide additional information on practical
engineering aspects about how to use parameters to achieve certain
behaviors.

7.3.1 Setting the DS Report CPICH Filter

 The DS report CPICH filter is used to filter the Undefined Cell DS reports
regarding Ec/No or RSCP, or both. The operator can, for example, use this
filter to avoid triggering ANR Mobility by too weak DS reported cells.

Both thresholds are checked by ANR Mobility independently. If only one is

required to be checked by ANR Mobility, the other one must be set to the
lowest possible value: -24.0 dB (-240 * 0.1 dB) for Ec/No and -120 dBm for
RSCP.

7.3.2 Performing Candidate Cell Evaluation

As a detected cell Primary Scrambling Code can be used by many cells on

the same frequency, ANR Mobility handles a number of Detected Set
Reports to identify a correct target cell to create a UtranRelation in the
RNC. Because the DS report contains only a scrambling code of the
detected cell, ANR Mobility tries out all cells using the same scrambling code
and the same uarfcnDl and uarfcnUl.. These cells are used as candidates for
handover. At each DS report, ANR Mobility chooses the next candidate cell
and a handover to that cell is performed. If the correct cell was chosen
(assessed on the basis of detected Uplink Synchronization), ANR Mobility
updates the internal statistics.

Four parameters control detecting the good cell candidate:

anrCandidateAbsPropThresh, anrCandidateLowerThresh,
anrCandidateUpperThresh, and anrCandidateExpirePeriod, see Section
3.

The anrCandidateAbsPropThresh controls the number of handover

attempts per each candidate cell which are required by ANR Mobility to
perform evaluation of the statistics. Until that requirement is fulfilled, ANR
Mobility tries all candidate cells in a round-robin manner. Once all
candidates have been proposed required number of times, ANR Mobility
performs the initial evaluation of candidate cells statistics.

Candidate cells for which a successful handover ratio is lower than

anrCandidateLowerThresh are excluded from further evaluation (the
number of unnecessary handover attempts to the wrong candidate is
limited). If other candidate cells handover success ratio is above
anrCandidateLowerThresh but still below anrCandidateUpperThresh, the
selection of candidate cells for handover continues until there is a candidate
cell showing a handover success ratio above anrCandidateUpperThresh.
When such a cell is detected, the cell relation is ready to be written into the
RNC configuration database.

If a cell relation is not detected within anrCandidateExpirePeriod time,

the ANR statistics for this Primary Scrambling Code is removed from the
source cell.

7.3.3 Assessing Candidate Cells in Neighbor RNCs and Cluster Member

RNCs

A potential candidate target cell belonging to a neighbor RNC or cluster

member RNC is also populated in ANR Mobility internal statistics if the
reported cell is defined in the SRNC as ExternalUtranCell for neighbor
RNC cells or as RemoteUtranCell for cluster member RNC cells.

If the Undefined Cell which the UE reported belongs to a neighbor RNC but
is not configured as ExternalUtranCell or as RemoteUtranCell in the
SRNC, then ANR Mobility cannot perform handover attempts to that cell.