eRAN
eRAN17.1
eRAN FDD Feature Documentation
Issue Date
2023-05-12
Copyright © Huawei Technologies Co., Ltd. 2024. All rights reserved.
No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei
Technologies Co., Ltd.
Trademarks and Permissions
and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.
All other trademarks and trade names mentioned in this document are the property of their respective holders.
Notice
The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the
products, services and features described in this document may not be within the purchase scope or the usage scope. Unless otherwise
specified in the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties,
guarantees or representations of any kind, either express or implied.
The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to
ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute a warranty of
any kind, express or implied.
Huawei Technologies Co., Ltd.
Address:
Huawei Industrial Base
Bantian, Longgang
Shenzhen 518129
People's Republic of China
Website:
https://www.huawei.com
Email:
support@huawei.com
Contents
Contents
1.1.1.1 PCI Conflict Detection and Self-Optimization
Contents
1 Change History
1.1 eRAN17.1 06 (2023-05-12)
1.2 eRAN17.1 05 (2023-03-25)
1.3 eRAN17.1 04 (2022-05-07)
1.4 eRAN17.1 03 (2021-06-26)
1.5 eRAN17.1 02 (2021-04-30)
1.6 eRAN17.1 01 (2021-03-05)
1.7 eRAN17.1 Draft A (2020-12-29)
2 About This Document
2.1 General Statements
2.2 Applicable RAT
2.3 Features in This Document
3 Overview
Intra-RAT PCI Conflict Detection and Self-Optimization
NG-RAN PCI Conflict Detection
4 Intra-RAT PCI Conflict Detection and Self-Optimization
4.1 Principles
4.2 Network Analysis
4.3 Requirements
4.4 Operation and Maintenance
5 NG-RAN PCI Conflict Detection
5.1 Principles
5.2 Network Analysis
5.3 Requirements
5.4 Operation and Maintenance
6 Parameters
7 Counters
8 Glossary
9 Reference Documents
1.1.1.1 PCI Conflict Detection and Self-Optimization
eRAN
PCI Conflict Detection and Self-Optimization
Feature Parameter Description
Issue
06
Date
2023-05-12
HUAWEI TECHNOLOGIES CO., LTD.
Copyright © Huawei Technologies Co., Ltd. 2023. All rights reserved.
No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei
Technologies Co., Ltd.
Trademarks and Permissions
and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.
All other trademarks and trade names mentioned in this document are the property of their respective holders.
Notice
The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the
products, services and features described in this document may not be within the purchase scope or the usage scope. Unless otherwise
specified in the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties,
guarantees or representations of any kind, either express or implied.
The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to
ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute a warranty of
any kind, express or implied.
Huawei Technologies Co., Ltd.
Address:
Huawei Industrial Base Bantian, Longgang Shenzhen 518129 People's Republic of China
Website:
https://www.huawei.com
Email:
support@huawei.com
Contents
1 Change History
1.1 eRAN17.1 06 (2023-05-12)
1.2 eRAN17.1 05 (2023-03-25)
1.3 eRAN17.1 04 (2022-05-07)
1.4 eRAN17.1 03 (2021-06-26)
1.5 eRAN17.1 02 (2021-04-30)
1.6 eRAN17.1 01 (2021-03-05)
1.7 eRAN17.1 Draft A (2020-12-29)
2 About This Document
2.1 General Statements
2.2 Applicable RAT
2.3 Features in This Document
3 Overview
4 Intra-RAT PCI Conflict Detection and Self-Optimization
4.1 Principles
4.1.1 PCI Conflict Types and Detection Methods
4.1.1.1 PCI Collision
4.1.1.1.1 Introduction
4.1.1.1.2 Detection Method
4.1.1.2 PCI Confusion
4.1.1.2.1 Introduction
4.1.1.2.2 Detection Method
4.1.2 Trigger Methods
4.1.2.1 Manual Parameter Modification Induced PCI Conflict Detection
4.1.2.2 ANR-based PCI Conflict Detection
4.1.2.3 X2 Message based PCI Conflict Detection
4.1.3 Reporting PCI Conflict Information
4.1.4 PCI Self-Optimization
4.1.4.1 Overview
4.1.4.2 PCI Reallocation Priority
4.1.4.3 PCI Reallocation Principle
4.2 Network Analysis
4.2.1 Benefits
4.2.2 Impacts
4.3 Requirements
4.3.1 Licenses
4.3.2 Software
4.3.3 Hardware
4.3.4 Others
4.4 Operation and Maintenance
4.4.1 Data Configuration
4.4.1.1 Data Preparation
4.4.1.2 Using MML Commands
4.4.1.3 Using the MAE-Deployment
4.4.2 Activation Verification
4.4.3 Network Monitoring
5 NG-RAN PCI Conflict Detection
5.1 Principles
5.1.1 PCI Conflict Types and Detection Methods
5.1.1.1 Introduction
5.1.1.2 Detection Method
5.1.2 PCI Conflict Detection Modes
5.1.2.1 Manual Parameter Modification Induced PCI Conflict Detection
5.1.2.2 ANR with NG-RAN-based PCI Conflict Detection
5.1.2.3 EN-DC X2 Message-based PCI Conflict Detection
5.1.3 Reporting PCI Conflict Information
5.2 Network Analysis
5.2.1 Benefits
5.2.2 Impacts
5.3 Requirements
5.3.1 Licenses
5.3.2 Software
5.3.3 Hardware
5.3.4 Others
5.4 Operation and Maintenance
5.4.1 Data Configuration
5.4.1.1 Data Preparation
5.4.1.2 Using MML Commands
5.4.1.3 Using the MAE-Deployment
5.4.2 Activation Verification
5.4.3 Network Monitoring
6 Parameters
7 Counters
8 Glossary
9 Reference Documents
1 Change History
This chapter describes changes not included in the "Parameters", "Counters", "Glossary", and "Reference Documents" chapters.
These changes include:
Technical changes
Changes in functions and their corresponding parameters
Editorial changes
Improvements or revisions to the documentation
1.1 eRAN17.1 06 (2023-05-12)
1.2 eRAN17.1 05 (2023-03-25)
1.3 eRAN17.1 04 (2022-05-07)
1.4 eRAN17.1 03 (2021-06-26)
1.5 eRAN17.1 02 (2021-04-30)
1.6 eRAN17.1 01 (2021-03-05)
1.7 eRAN17.1 Draft A (2020-12-29)
1.1 eRAN17.1 06 (2023-05-12)
This issue includes the following changes.
Technical Changes
None
Editorial Changes
Revised the description of new PCI delivery. For details, see 4.1.4.3 PCI Reallocation Principle.
Revised descriptions in this document.
1.2 eRAN17.1 05 (2023-03-25)
This issue includes the following changes.
Technical Changes
None
Editorial Changes
Revised the description of the procedure for proactive PCI conflict detection based on intra-RAT ANR. For details, see 4.1.2.2
ANR-based PCI Conflict Detection.
Revised descriptions in this document.
1.3 eRAN17.1 04 (2022-05-07)
This issue includes the following changes.
Technical Changes
None
Editorial Changes
Revised the definition of PCI confusion. For details, see 4.1.1.2.1 Introduction and 5.1.1.1 Introduction.
1.4 eRAN17.1 03 (2021-06-26)
This issue includes the following changes.
Technical Changes
None
Editorial Changes
Modified the description of operations on the MAE-Access. For details, see 4.4.1.2 Using MML Commands and 4.4.2
Activation Verification.
Revised descriptions in this document.
1.5 eRAN17.1 02 (2021-04-30)
This issue includes the following changes.
Technical Changes
None
Editorial Changes
Revised descriptions in this document.
1.6 eRAN17.1 01 (2021-03-05)
This issue does not include any changes.
1.7 eRAN17.1 Draft A (2020-12-29)
This issue introduces the following changes to eRAN16.1 03 (2020-05-21).
Technical Changes
Change Description
Parameter Change
RAT
Base Station Model
Canceled the compatibility with the BTS3911E as of this version.
None
FDD
BTS3911E
Editorial Changes
Revised descriptions in the document.
2 About This Document
2.1 General Statements
2.2 Applicable RAT
2.3 Features in This Document
2.1 General Statements
Purpose
This document is intended to acquaint readers with:
The technical principles of features and their related parameters
The scenarios where these features are used, the benefits they provide, and the impact they have on networks and functions
Requirements of the operating environment that must be met before feature activation
Parameter configuration required for feature activation, verification of feature activation, and monitoring of feature
performance
This document only provides guidance for feature activation. Feature deployment and feature gains depend on the specifics of the network
scenario where the feature is deployed. To achieve optimal gains, contact Huawei professional service engineers.
Functions mentioned in this document work properly only when enabled in the specified applicable scenarios (such as RAT and
networking). If a function not mentioned in this document is enabled or a function is enabled in a scenario not specified as applicable,
exceptions or other impacts may occur.
Software Interfaces
Any parameters, alarms, counters, or managed objects (MOs) described in this document apply only to the corresponding software
release. For future software releases, refer to the corresponding updated product documentation.
2.2 Applicable RAT
This document applies to FDD.
2.3 Features in This Document
This document describes the following FDD feature.
Feature ID
Feature Name
Chapter/Section
LOFD-002007
PCI Collision Detection and Self-Optimization
4 Intra-RAT PCI Conflict Detection and Self-Optimization
5 NG-RAN PCI Conflict Detection
3 Overview
Physical cell identifier (PCI) identifies a physical cell. Each evolved universal terrestrial radio access network (E-UTRAN) cell or
each NG Radio Access Network (NG-RAN) cell is assigned one PCI.
There are 504 PCIs in the LTE system and 1,008 PCIs in the NR system. PCI reuse is inevitable when there are a large number of
E-UTRAN cells on the LTE network or NR-RAN cells on the NR network. If two intra-frequency E-UTRAN cells or two intrafrequency neighboring NG-RAN cells using the same PCI are too close to each other physically, a PCI conflict will occur between
the two cells. As a result, the service drop rate increases and the handover success rate decreases. To eliminate or at least reduce
PCI conflicts on the network, Huawei has introduced the PCI conflict detection and self-optimization function.
This function includes the following subfunctions:
Intra-RAT/NG-RAN PCI conflict detection
Detects PCI conflicts between E-UTRAN cells or neighboring NG-RAN cells.
Intra-RAT PCI self-optimization
Based on the detected PCI conflicts between E-UTRAN cells, the eNodeB reallocates appropriate PCIs to the conflicting
cells, as shown in Figure 3-1.
Figure 3-1 PCI conflict detection and self-optimization
Intra-RAT PCI Conflict Detection and Self-Optimization
Figure 3-2 shows the network architecture for intra-RAT PCI conflict detection and self-optimization, and Table 3-1 describes the
functions of network elements (NEs) involved.
Figure 3-2 Network architecture for intra-RAT PCI conflict detection and self-optimization
Table 3-1 NE functions (intra-RAT)
NE
Function
UE
Sends measurement reports to the eNodeB during PCI conflict detection described in 4.1.2.2 ANR-based PCI Conflict
Detection. UEs are not involved in other detection modes.
eNodeB
Performs distributed PCI conflict detection and reports PCI conflict and conflict resolution data to the MAE-Access.
MAEAccess
Receives PCI conflict data reported by eNodeBs and implements PCI self-optimization for all eNodeBs by reallocating
PCIs to conflicting cells and sending the reallocated PCIs to eNodeBs.
NG-RAN PCI Conflict Detection
Figure 3-3 shows the network architecture for NG-RAN PCI conflict detection, and Table 3-2 describes the functions of NEs
involved.
Figure 3-3 Network architecture for NG-RAN PCI conflict detection and self-optimization
Table 3-2 NE functions (NG-RAN)
NE
Function
UE
Sends measurement reports to the eNodeB during PCI conflict detection described in 5.1.2.2 ANR with NG-RAN-based
PCI Conflict Detection. UEs are not involved in other detection modes.
eNodeB
Performs distributed PCI conflict detection and reports PCI conflict data to the MAE-Access.
gNodeB
Sends the configuration change information to the eNodeB during PCI conflict detection described in 5.1.2.3 EN-DC X2
Message-based PCI Conflict Detection. The gNodeB is not involved in other detection modes.
MAEAccess
Receives PCI conflict data reported by eNodeBs.
4 Intra-RAT PCI Conflict Detection and Self-Optimization
4.1 Principles
4.2 Network Analysis
4.3 Requirements
4.4 Operation and Maintenance
4.1 Principles
4.1.1 PCI Conflict Types and Detection Methods
Intra-RAT PCI conflicts are classified into PCI collision and PCI confusion.
4.1.1.1 PCI Collision
4.1.1.1.1 Introduction
A PCI collision occurs when the signal overlapped area between two or more cells using the same frequency and PCI cannot
implement signal synchronization and demodulation because of insufficient physical location spacing between these cells. As
illustrated in Figure 4-1, PCI collision occurs between cells A and B.
Figure 4-1 PCI collision
4.1.1.1.2 Detection Method
The eNodeB checks whether some local cells use the same frequency and PCI and whether a local cell and an external cell in the
neighboring cell list (NCL) use the same frequency and PCI. If they do, the eNodeB detects PCI collision. PCI collision detection
is controlled by the COLLISION_DETECT_SWITCH option of the ENodeBAlgoSwitch. PciConflictDetectSwitch parameter.
The NCL is an external cell list of an eNodeB. For details about the NCL, see ANR Management .
According to the LTE configuration rules, the same PCI cannot be configured for a local cell and its intra-frequency neighboring cell. Therefore,
an LTE cell and its neighboring cells will not have the same frequency and PCI. However, an LTE cell may have the same frequency and PCI as
its external cells or multiple local cells under an eNodeB may have the same frequency and PCI.
As illustrated in Figure 4-2, cells A and B use the same frequency and PCI. In the two scenarios, PCI collision can be detected
using this feature.
Figure 4-2 PCI collision detection
4.1.1.2 PCI Confusion
4.1.1.2.1 Introduction
A PCI confusion occurs when two or more neighboring cells of the serving cell have the same frequency and PCI, and the UE
reports any of such cells as the target cell meeting the handover conditions. In this case, the UE may fail to initiate a handover,
resulting in a service drop.
As shown in Figure 4-3, cells B and C are neighboring cells of serving cell A and use the same frequency and PCI, while cell B is
the target cell meeting the handover conditions.
If the UE does not support automatic neighbor relation (ANR) or the eNodeB is not enabled with ANR, the eNodeB cannot
determine whether the neighboring cell indicated in the received UE measurement report is cell B or C. Consequently, the UE
cannot initiate a handover, which may cause a service drop.
If intra-RAT event-triggered ANR is enabled and the UE supports ANR, the eNodeB can identify cell B based on the E-UTRAN cell global
identifier (ECGI) reported by the UE and initiate a handover to cell B if required.
Figure 4-3 PCI confusion
4.1.1.2.2 Detection Method
The eNodeB checks whether the neighboring relation table (NRT) of the serving cell contains two or more intra-frequency
neighboring cells with the same PCI. If it does, the eNodeB detects PCI confusion. PCI confusion detection is controlled by the
CONFUSION_DETECT_SWITCH option of the ENodeBAlgoSwitch. PciConflictDetectSwitch parameter.
An NRT contains information about the neighbor relationships of a local cell and other cells. For details, see ANR Management .
As illustrated in Figure 4-4, cells B and C use the same frequency and PCI. The eNodeB detects PCI confusion between cells B
and C.
Figure 4-4 PCI confusion detection
4.1.2 Trigger Methods
PCI conflict detection is triggered on the eNodeB when any of the following PCI-related changes occur:
Local cells are added to or deleted from the eNodeB, or the PCI/frequency of a local cell changes.
External E-UTRAN cells are added to or deleted from the NCL, or the PCI/frequency of an external E-UTRAN cell changes.
Neighboring cells are added to or deleted from the NRT, or the PCI/frequency of a neighboring cell changes.
For details about NCL and NRT, see ANR Management .
As shown in Figure 4-5, PCI conflict detection can be triggered by:
Manual parameter modification
The eNodeB triggers PCI conflict detection when eNodeB parameters are manually modified.
ANR-based modification
The eNodeB triggers PCI conflict detection when eNodeB parameters are changed based on ANR.
Information in X2 messages
The eNodeB triggers PCI conflict detection when it exchanges X2 messages with another eNodeB and these eNodeBs update
their respective neighboring cell parameters.
Figure 4-5 Trigger methods
4.1.2.1 Manual Parameter Modification Induced PCI Conflict Detection
The eNodeB triggers PCI conflict detection when eNodeB parameters listed in 4.1.2 Trigger Methods are manually modified.
4.1.2.2 ANR-based PCI Conflict Detection
Intra-RAT ANR based PCI Conflict Detection
The eNodeB uses the intra-RAT automatic neighbor relation (ANR) function to automatically identify missing neighboring cell
configurations, and to maintain the intra-RAT neighboring cell list (NCL) and neighboring relation table (NRT). If intra-RAT ANR
changes neighboring cell parameter settings, the eNodeB will trigger PCI conflict detection. For details about automatic detection
of missing neighboring cells and maintenance of intra-RAT NCL/NRT included in intra-RAT ANR, see ANR Management .
Proactive Intra-RAT ANR-based PCI Conflict Detection
Proactive intra-RAT ANR-based PCI conflict detection is used to detect PCI confusion between configured and unconfigured
neighboring cells, or PCI confusion among unconfigured neighboring cells. This detection requires the intra-RAT ANR function.
When ANR is enabled, the ANR. ActivePciConflictSwitch parameter determines whether to enable proactive intra-RAT ANRbased PCI conflict detection. If this parameter is set to ON, a time range specified by ANR. StartTime and ANR. StopTime will
be configured for the eNodeB to read neighboring cell's ECGI and add unknown neighboring cells, and then to trigger PCI
conflict detection, following the procedure shown in Figure 4-6.
Figure 4-6 Proactive ANR-based PCI conflict detection
1. The eNodeB selects UEs for proactive PCI conflict detection, and sends them the measurement configurations related to
event A3 or A4, requesting the UEs to measure frequencies of the serving cell and inter-frequency neighboring cells. The
UEs that are selected for proactive PCI conflict detection meet all of the following requirements:
UEs that newly access a local cell (excluding cell access by incoming handovers)
UEs that support intra-RAT ANR
Non-VoLTE UEs
Non-CSFB UEs
UEs that are selected depending on the value of the ANR. CaUeChoseMode parameter
If the ANR. CaUeChoseMode parameter is set to CA_UE_CAP, the UEs for which CA cannot take
effect in the serving cell are selected.
If the ANR. CaUeChoseMode parameter is set to CA_UE_CARRIER_NUM, the UEs having only
one serving carrier are selected.
If the ANR. CaUeChoseMode parameter is set to ANR_UE_CAP, the ANR-capable UEs are selected.
Events A3 and A4, used in proactive PCI conflict detection, are triggered more easily than those used in handover. When a
UE has been selected for measurement involved in proactive PCI conflict detection:
If a bearer with QCI 1 has been set up for the UE, the eNodeB decides whether to delete ECGI measurement results
related to proactive PCI conflict detection, depending on the value of the GlobalProcSwitch. VoipWithGapMode
parameter.
If this parameter is set to ENABLE, the eNodeB does not delete such ECGI measurement results.
If this parameter is set to DISABLE, the eNodeB delivers an RRC Connection Reconfiguration message
to delete such ECGI measurement results.
If the eNodeB receives a CSFB indication from the UE again, the eNodeB decides whether to delete ECGI
measurement results related to proactive PCI conflict detection, depending on the setting of the
CSFB_MEAS_DEL_ACT_PCI_MEAS_SW option of the CellAlgoSwitch. MeasOptAlgoSwitch parameter.
If this option is deselected, the eNodeB does not delete such ECGI measurement results.
If this option is selected, the eNodeB delivers an RRC Connection Reconfiguration message to delete such
ECGI measurement results.
2. The UE sends a measurement report to the eNodeB of the serving cell. Only the neighboring cell with the best signal
quality is included in the measurement report.
3. The eNodeB obtains the neighboring cell information based on the received measurement report and requests the UE to
report the parameters of this neighboring cell. These parameters include the ECGI, tracking area code (TAC), and public
land mobile network (PLMN) ID list.
4. The UE reports these parameters to the eNodeB of the serving cell.
5. The eNodeB performs either of the following operations based on the ECGI and PCI of the neighboring cell.
ECGI not included in the NCL
The eNodeB adds this neighboring cell to the NCL and to the serving cell's NRT, and starts PCI conflict detection.
ECGI included but PCI not included in the NCL
The eNodeB uses the PCI corresponding to the ECGI in the NCL as the PCI of the neighboring cell, adds the
neighbor relationship involving the ECGI to the NRT, and starts PCI conflict detection.
If the serving cell has two or more neighboring cells with the same frequency and PCI, the eNodeB detects PCI conflicts.
4.1.2.3 X2 Message based PCI Conflict Detection
When an X2 interface is set up or eNodeB configurations on both ends over the X2 interface change, the local and peer eNodeBs
exchange information over the X2 interface to add cells to the NCL or update NCLs/NRTs and trigger PCI conflict detection.
Figure 4-7 illustrates the procedure for adding an NCL based on X2 messages.
Figure 4-7 X2 setup signaling procedure
Upon receiving an X2 message from the peer eNodeB, the local eNodeB adds all cells under the peer eNodeB to its NCL and
triggers PCI conflict detection.
Figure 4-8 illustrates the procedure for updating the NCL or NRT based on the ENB CONFIGURATION UPDATE message.
Figure 4-8 Signaling procedure of NCL or NRT update
If cells are added to or deleted from the local eNodeB or if the PCI/frequency of a configured cell changes, an X2 message is
sent to notify the peer eNodeB of the change. The peer eNodeB will accordingly add or delete the external cells or
neighboring cells in the NCL or NRT, or update the parameters of neighboring cells in the NCL/NRT to trigger PCI conflict
detection.
X2 message-based PCI conflict detection requires NCL/NRT update based on X2 messages. For details about NCL/NRT update
based on X2 messages, see ANR Management .
4.1.3 Reporting PCI Conflict Information
When the eNodeB detects an intra-RAT PCI conflict, if CellAlgoSwitch. PciConflictReportSwitch is set to ON, it reports the PCI
conflict information to the MAE-Access. The up-to-date PCI conflict information is displayed in the PCI Optimization Task
window on the MAE-Access. COLLISION_REPORT_SWITCH determines whether to report the PCI collision result to the
MAE-Access. CONFUSION_REPORT_SWITCH determines whether to report the PCI confusion result to the MAE-Access.
In addition, the eNodeB can report ALM-29247 Cell PCI Conflict to the MAE-Access and LMT. This is enabled by setting the
ENodeBAlgoSwitch. PciConflictAlmSwitch parameter to ON. The eNodeB reports the alarm with the Conflict Type parameter
set to Collision or Confusion.
For details about ALM-29247 Cell PCI Conflict, see 3900 & 5900 Series Base Station Alarm Reference in 3900 & 5900 Series Base Station
Product Documentation.
4.1.4 PCI Self-Optimization
4.1.4.1 Overview
Intra-RAT PCI self-optimization is implemented on the MAE-Access. Once a user has created and started a PCI self-optimization
task on the MAE-Access, the MAE-Access performs PCI self-optimization analysis for eNodeBs based on the reported PCI
conflict information. Within a PCI self-optimization period:
If the MAE-Access reallocates a new PCI to the conflicting cell, PCI self-optimization suggestions are displayed on the
MAE-Access.
If the MAE-Access does not reallocate a new PCI to the conflicting cell, this cell continues using the old PCI, and PCI selfoptimization suggestions are not displayed on the MAE-Access.
The reallocated PCI takes effect to resolve the PCI conflict only after it is delivered to the eNodeB. After the MAE-Access
delivers the reallocated PCI, the cell will automatically reset to allow the PCI to take effect. Before the PCI change, the eNodeB
reduces the reference signal power of the cell to proactively hand over online UEs to other cells to reduce the number of possible
service drops.
PCI self-optimization can be used even if some eNodeB engineering parameters are not configured.
These eNodeB engineering parameters include longitude, latitude, azimuth, and beamwidth.
4.1.4.2 PCI Reallocation Priority
If multiple cells experience PCI conflicts, the MAE-Access reallocates PCIs to conflicting cells.
The following is the PCI reallocation priority in descending order:
1. Cells with higher user-specified priorities
The PCI optimization priority of an LTE cell can be specified on the MAE-Access as high, low, or locked.
During PCI self-optimization, a conflicting cell with a high priority is preferentially reallocated a new PCI. A conflicting
cell with a locked priority will not be assigned a new PCI.
2. Cells experiencing serious PCI conflicts with other cells
If the PCI of a cell conflicts with those of a large number of cells, changing the PCI of this cell significantly reduces PCI
conflicts on the network.
3. Newly deployed cells or cells with recently changed PCIs
There are two reasons for this:
The probability of data configuration faults for these cells is high.
Changing the PCIs of the cells involved in network reconfiguration has only a minor impact on the live network.
Cells with recently changed PCIs can be identified based on the OldCellThreshold Value and SameBatchInterval Value
parameters.
If the number of days elapsed from a PCI change to the current time for a cell is less than the value of the
OldCellThreshold Value parameter, the cell is considered as a new cell. Otherwise, the cell is an old cell and not
prioritized by PCI change time.
New cells are prioritized according to the value of the SameBatchInterval Value parameter. If the interval between
the PCI changes for two cells is less than the value of the SameBatchInterval Value parameter, the two cells are
considered to have been changed in the same batch and will be equally prioritized for a PCI change.
4. Cells with few neighboring cells
Blocking a cell with few neighboring cells has only a minor impact on the live network. If multiple conflicting cells are
equally prioritized for a PCI change according to the preceding rules (rules 1 to 3), cells with few neighboring cells will be
preferentially reallocated PCIs.
4.1.4.3 PCI Reallocation Principle
By default, all PCIs (0 to 503) can be reallocated. Users can set Available PCI range for the cell to specify a PCI reallocation
range.
PCI reallocation adheres to the following principles:
A new PCI must be different from the PCI of any first-order or second-order intra-frequency neighboring cell of the
conflicting cell.
First-order intra-frequency neighboring cells consist of the cells in the intra-frequency NRT (neighboring cells set using the
EutranIntraFreqNCell MO) and cells in the intra-frequency neighboring cell blacklist (intra-frequency neighboring cells set using the
EutranBlkNCell MO).
A first-order intra-frequency neighboring cell of another first-order intra-frequency neighboring cell has a second-order intra-frequency
neighboring relationship to the serving cell. For example, if cell B is a first-order neighboring cell of cell A and cell C is a first-order
neighboring cell of cell B, cell C is a second-order neighboring cell of cell A.
A new PCI must be different from the PCI of any first-order intra-frequency extended neighboring cell of the conflicting cell.
The DSP EUTRANEXTENDEDNCELL command output provides first-order intra-frequency extended neighboring cells.
The blacklist must be considered.
A new PCI must be different from the PCI of any blacklisted intra-frequency cell of the conflicting cell.
If the conflicting cell is not a blacklisted intra-frequency E-UTRAN cell of its first-order neighboring cells, the new
PCI cannot be within the range specified by IntraFreqBlkCell. PhyCellId and IntraFreqBlkCell. PhyCellIdRange
. Figure 4-9 illustrates an example.
If a conflicting cell is not a blacklisted inter-frequency E-UTRAN cell of its first-order neighboring cells but there is
a blacklisted inter-frequency E-UTRAN cell that uses the same frequency as the conflicting cell, the new PCI cannot
be within the range specified by InterFreqBlkCell. PhyCellId and InterFreqBlkCell. PhyCellIdRange . Figure 4-9
illustrates an example.
The UE does not perform measurements on blacklisted cells or send measurement reports of blacklisted cells to the eNodeB. This way, the
previously measured conflicting cells are still measurable after PCI self-optimization.
Figure 4-9 Example of blacklisted cells
The following factors must be considered for PCI reallocation:
If all of the PCI-related eNodeB engineering parameters listed in Table 4-1 have been configured:
Three cells with adjacent azimuths under an eNodeB, or a virtual eNodeB, are expected to have different
primary synchronization codes. That is, the PCI mod 3 values of these cells are different.
In FDD mode, a virtual eNodeB is formed by clustering geographically adjacent cells served by a distributed eNodeB, among
all cells near and far away from each other.
Downlink reference signals are expected to transmit on different frequency-domain positions in adjacent cells.
If they are transmitted on the same frequency-domain position in adjacent cells, the quality of these signals will be
poor even when the network load is light. Frequency-domain positions of downlink reference signals are related to
the value of PCI mod 3.
Uplink reference signal sequence group numbers are different for adjacent cells.
If they are the same for adjacent cells, uplink capacity is adversely affected. The uplink reference signal sequence
group number is related to the value of PCI mod 30. For details, see section 5.5 "Reference signals" in 3GPP TS
36.211 V9.1.0.
If the new PCI is the same as the PCI of another cell, the two cells must be as far as possible, with as many
eNodeBs as possible between the two cells.
Table 4-1 NE engineering parameters
Location Parameter
Antenna Parameter
LOCATION. LONGITUDEDEGFORMAT /LOCATION. LONGITUDESECFORMAT
RETDEVICEDATA. BEARING
Location Parameter
Antenna Parameter
LOCATION. LATITUDEDEGFORMAT /LOCATION. LATITUDESECFORMAT
RETDEVICEDATA. BEAMWIDTH1
RETDEVICEDATA. BEAMWIDTH2
RETDEVICEDATA. BEAMWIDTH3
RETDEVICEDATA. BEAMWIDTH4
If not all PCI-related eNodeB engineering parameters are configured, or if some are incorrectly configured, a new PCI
assigned by PCI self-optimization to a conflicting cell may not be the optimal though it can still resolve the PCI
conflict.
You are advised to set the PCI reallocation optimization parameter on the MAE-Access based on the PCI conflict detection
policy of the eNodeB. If the COLLISION_REPORT_SWITCH option of the CellAlgoSwitch. PciConflictReportSwitch
parameter is selected on the eNodeB, you are advised to set the PCI reallocation optimization parameter to OFF. In this
scenario, the following additional principles must be considered for PCI reallocation:
A new PCI must be different from the PCI of any intra-frequency external cell in the NCL of the conflicting cell.
A new PCI must be different from the PCI of any intra-frequency cells under the same eNodeB as the conflicting cell.
If Keep PCI Mod3 value to be the same as the current value is selected on the MAE-Access, ensure that the mod 3 value of the
reallocated PCI is the same as the current PCI mod 3 value.
In FDD, if a cell with PCI conflicts or its neighboring cell has a Double Deck cell, the PCI constraints for Double Deck cells will
be considered for PCI reallocation. For details about the PCI constraints, see Flexible Bandwidth based on Overlap Carriers
(FDD) .
After the MAE-Access delivers a new PCI to a cell, the procedure for the new PCI to take effect is as follows:
1. The eNodeB sets the cell to the unavailable state.
2. The eNodeB reduces the pilot power of the cell so that online UEs in the cell are proactively handed over to other cells
where possible.
3. The eNodeB sets the cell to the available state.
4. After the PCI of the cell is changed to the new PCI, the cell automatically resets to make the new PCI take effect.
If possible, ensure that a new PCI is delivered during off-peak hours to prevent service drops during the procedure for the new PCI to take
effect.
The cell where a new PCI is delivered may be unavailable for a long period of time during the procedure for the new PCI to take effect. If
the cell unavailability lasts for more than 10 minutes, contact Huawei technical support.
4.2 Network Analysis
4.2.1 Benefits
The PCI conflict detection and self-optimization function reduces or eliminates PCI conflicts on the network, decreasing the
Service Drop Rate and Call Drop Rate (VoIP) ; and increasing the Intra-Frequency Handover Out Success Rate and InterFrequency Handover Out Success Rate .
It is recommended that this function always be enabled on commercial networks. It helps detect PCI conflicts in a timely manner
and performs optimization if required. When RRUs are installed remotely, only PCI confusion detection is recommended to
prevent incorrect PCI collision detections.
PCI self-optimization requires engineering parameters of neighboring cells. However, engineering parameters of neighboring cells managed by
different MAE-Access systems cannot be obtained, and PCI self-optimization is impossible for cells managed by different MAE-Access systems.
In this situation, PCI self-optimization is not recommended. If PCIs of such cells conflict, manually set the PCIs.
To provide maximum gains, enable intra-RAT PCI conflict detection for the following scenarios:
ANR-based PCI conflict detection
Intra-RAT ANR based PCI conflict detection
This function requires intra-RAT ANR. The policy for enabling this function is the same as that for enabling intra-RAT
ANR. For details about the policy for enabling intra-RAT ANR, see ANR Management .
Proactive intra-RAT ANR-based PCI conflict detection
In multi-vendor scenarios involving different MAE-Access systems, you are advised to enable this function
for cells that suffer from high service drop rates or low outgoing handover success rates when serving a large
number of UEs.
If the configuration parameters (such as PCI-related parameters) change frequently and there are no X2
interfaces configured on the network, you are advised to enable proactive ANR-based PCI conflict detection
to update network-level parameters.
In other scenarios, do not enable this function. For example, do not enable this function if all eNodeBs on the
network are managed by the same MAE-Access. An eNodeB can add conflicting cells to its NRT by using
intra-RAT event-triggered ANR based on UE historical information, triggering PCI conflict detection.
X2 message based PCI conflict detection
This function requires NCL/NRT update based on X2 messages. The policy for enabling this function is the same as that for
enabling NCL/NRT update based on X2 messages. For details about how to enable NCL/NRT update based on X2 messages,
see ANR Management .
4.2.2 Impacts
Network Impacts
PCI conflict detection based on ANR jeopardizes system capacity. To obtain ECGIs, a UE in connected mode needs to work in
discontinuous reception (DRX) mode. When the UE works in DRX mode, services cannot be performed and uplink and downlink
throughputs decrease.
After PCI self-optimization is complete, delivering PCI optimization suggestions will result in an automatic cell reset to make the
new PCI take effect. The cell becomes unavailable during the reset, and therefore the number of online subscribers decreases in
this period of time.
During PCI conflict detection, eNodeB operations, such as the processing and delivery of measurement information, consume
excessive CPU and memory resources.
Delivering a new PCI to a cell causes the cell to automatically reset. As a result, the cell becomes temporarily unavailable. This
process affects UE access, normal services, and handovers, decreasing access and handover success rates. When the new PCI
takes effect on the eNodeB, PCI conflicts between adjacent E-UTRAN cells will be reduced or even eliminated, decreasing
Service Drop Rate and Call Drop Rate (VoIP) , and increasing Intra-Frequency Handover Out Success Rate and InterFrequency Handover Out Success Rate .
Function Impacts
RAT Function
Name
Function
Switch
Reference
Description
FDD Intra-RAT
ANR
None
ANR
Management
PCI conflict detection is triggered when intra-RAT ANR changes neighboring cell
information.
FDD Super
combined
cell
None
Super
Combined Cell
(FDD)
After the super combined cell function is activated, cells with the same operating
frequency and PCI can be configured in the same neighboring cell list or external
cell list. If the eNodeB detects that the PCIs of SFN cells in a super combined cell
are the same during PCI conflict detection, the eNodeB does not report a PCI
conflict alarm.
4.3 Requirements
4.3.1 Licenses
RAT
Feature ID
Feature Name
Model
Sales Unit
FDD
LOFD-002007
PCI Collision Detection and Self-Optimization
LT1S0PCICD00
per Cell
If this license has not been activated, the eNodeB will not report PCI conflicts to the MAE-Access PCI self-optimization module, and therefore
PCI conflict information will not be displayed in the PCI Conflict Optimization window or in the SON logs.
4.3.2 Software
Before activating this function, ensure that its prerequisite functions have been activated and mutually exclusive functions have
been deactivated. For detailed operations, see the relevant feature documents.
Prerequisite Functions
RAT Function
Name
Function Switch
Reference
Description
FDD PCI selfoptimization
None
OSS Feature
Description
The PCI conflict detection and selfoptimization function requires the OSS
feature WOFD-170200 Automatic PCI
Optimization.
FDD Intra-RAT
ANR
Event-triggered ANR:
ANR
IntraRatEventAnrSwitch option of the
Management
ENodeBAlgoSwitch. AnrSwitch parameter
Fast ANR: IntraRatFastAnrSwitch option of
the ENodeBAlgoSwitch. AnrSwitch parameter
Mutually Exclusive Functions
None
ANR-based PCI conflict detection requires
ANR.
4.3.3 Hardware
Base Station Models
No requirements
Boards
No requirements
RF Modules
No requirements
4.3.4 Others
Ensure that the MAE-Access delivers a new PCI to a cell during off-peak hours, because the cell will automatically reset for
the new PCI to take effect. For details about other requirements for the time to deliver a new PCI, see 4.1.4 PCI SelfOptimization.
Requirements specific to proactive intra-RAT ANR-based PCI conflict detection
UEs on the network are DRX-capable and support ANR-related measurements on intra-frequency or inter-frequency
neighboring cells.
Intra-RAT event-triggered ANR or intra-RAT fast ANR must be activated on the eNodeB.
4.4 Operation and Maintenance
4.4.1 Data Configuration
4.4.1.1 Data Preparation
Table 4-2 describes the parameters for activating the intra-RAT PCI conflict detection function, and Table 4-3 describes the
parameters for activating the intra-RAT PCI self-optimization function.
Table 4-2 Parameters used for activating intra-RAT PCI conflict detection
Parameter
Name
Parameter ID
Setting Notes
PCI Conflict
Detect Switch
ENodeBAlgoSwitch.
PciConflictDetectSwitch
Set the CONFUSION_DETECT_SWITCH option based on the network plan.
PCI conflict
alarm switch
ENodeBAlgoSwitch.
PciConflictAlmSwitch
Set this parameter based on the network plan.
PCI Conflict
Report Switch
CellAlgoSwitch.
PciConflictReportSwitch
Set the CONFUSION_REPORT_SWITCH option based on the network plan.
ANR Active
PCI Conflict
Detection
Switch
ANR.
ActivePciConflictSwitch
If this parameter is set to ON within the period specified for proactive PCI conflict
detection, proactive PCI conflict detection is enabled. If this parameter is set to OFF,
proactive PCI conflict detection is disabled or stopped.
If PCI conflict information reporting to the MAE-Access is enabled, you can view PCI
conflict information in the PCI self-optimization window on the MAE-Access. In this
situation, you are advised to set this parameter to OFF. If PCI conflict information
reporting to the MAE-Access is not enabled, you are advised to set this parameter to
ON so that you can view PCI conflict information on the alarm console.
You are advised to set this parameter to ON for cells that experience high service drop
rates or low outgoing handover success rates.
Parameter
Name
Parameter ID
Setting Notes
Start time
ANR. StartTime
If the ANR. ActivePciConflictSwitch parameter is set to ON, proactive PCI conflict
detection is started at the time specified by this parameter.
It is recommended that this parameter be set to a time when a large number of UEs
camp on the network. PCI conflicts are more likely to be detected at that time.
Stop time
ANR. StopTime
If the ANR. ActivePciConflictSwitch parameter is set to ON, proactive PCI conflict
detection is stopped at the time specified by this parameter.
This parameter is used with the ANR. StartTime parameter. It is recommended that
proactive PCI conflict detection be performed when a large number of UEs camp on
the network.
No Handover
Set Mode
ANR. NoHoSetMode
If this parameter is set to PCI_CHECK, the automatic optimization of neighbor
relationships against an abnormal intra-RAT ANR-based handover success rate will
trigger the eNodeB to perform PCI conflict detection.
Intra-RAT ANR must be enabled before PCI conflict detection based on intra-RAT ANR. For details about how to enable intra-RAT ANR,
see ANR Management .
PCI conflict detection based on X2 messages requires NCL/NRT update based on X2 messages. For details about how to enable NCL/NRT
update based on X2 messages, see ANR Management .
Table 4-3 Parameters used for activating intra-RAT PCI self-optimization
Parameter Name
Parameter ID
Setting Notes
OldCellThreshold
Value
None. This parameter is set on the
MAE-Access.
The default value of this parameter is 0, indicating that all cells are old
cells. This means that all cells are not prioritized by cell deployment time
or PCI change time by default. You are advised to set this parameter to
30 (unit: day) if you need to prioritize conflicting cells based on the cell
deployment time or PCI change time. In this case, a cell that was
deployed more than 30 days ago or a cell whose PCI was changed more
than 30 days ago is considered an old cell.
SameBatchInterval
Value
None. This parameter is set on the
MAE-Access.
The default value of this parameter is 0. You are advised to set this
parameter to 7 (unit: day) if you need to prioritize conflicting cells based
on the cell deployment time or PCI change time. In this situation, two
cells with a deployment time or PCI change time interval of less than 7
days are considered as being changed in the same batch.
The parameter value must be less than or equal to the value of
OldCellThreshold Value.
Available PCI
range for the cell
None. This parameter can be set on
This parameter can be set to a consecutive or discrete PCI range. The
the MAE-Access or by importing the default PCI range is 0 to 503. The PCI range of a border cell must be
parameter template into the MAEnegotiated with the peer end.
Access.
Optimization
Priority
None. This parameter can be set on
the MAE-Access or by importing the
parameter template into the MAEAccess.
The default value of this parameter is Low. If an eNodeB provides
coverage for a VIP area, set the Optimization Priority parameter to
Locked so that the PCIs of the cells under this eNodeB cannot be
changed.
Parameter Name
Parameter ID
Setting Notes
PCI Reallocation
Optimization
None. This parameter can be set on
the MAE-Access or by importing the
parameter template into the MAEAccess.
You are advised to set this parameter based on the PCI conflict detection
policy on the eNodeB. If the COLLISION_REPORT_SWITCH option
of the CellAlgoSwitch. PciConflictReportSwitch parameter is selected
on the eNodeB, you are advised to set this parameter to OFF. If the
COLLISION_REPORT_SWITCH option of the CellAlgoSwitch.
PciConflictReportSwitch parameter is deselected on the eNodeB, you
are advised to set this parameter to ON.
Longitude With
Degree Format
LOCATION.
LONGITUDEDEGFORMAT
Set these parameters by using MML commands or importing an
engineering parameter template into the MAE-Access.
Longitude With
Second Format
LOCATION.
LONGITUDESECFORMAT
In PCI self-optimization scenarios, set the longitude and latitude based
on actual conditions.
Latitude With
Degree Format
LOCATION.
LATITUDEDEGFORMAT
Latitude With
Second Format
LOCATION.
LATITUDESECFORMAT
Antenna Bearing
RETDEVICEDATA. BEARING
Beamwidth1
RETDEVICEDATA.
BEAMWIDTH1
Beamwidth2
RETDEVICEDATA.
BEAMWIDTH2
Beamwidth3
RETDEVICEDATA.
BEAMWIDTH3
Beamwidth4
RETDEVICEDATA.
BEAMWIDTH4
Use either the longitude with degree format or the longitude with second
format.
Use either the latitude with degree format or the latitude with second
format.
When RET antennas are configured, set parameters using MML
commands. When RET antennas are not configured, set parameters by
importing an engineering parameter template into the MAE-Access.
If an omnidirectional antenna is used, set the Antenna Bearing
parameter to 0, and set the Beamwidth1, Beamwidth2, Beamwidth3,
and Beamwidth4 parameters to 359 in the engineering parameter
template.
4.4.1.2 Using MML Commands
PCI Conflict Detection
Activation command examples
Before using MML commands, refer to 4.2.2 Impacts and 4.3.2 Software and complete the parameter configurations for related
functions based on the impact and dependency relationships between the functions, as well as the actual network scenario.
//Enabling PCI collision detection
MOD ENODEBALGOSWITCH: PciConflictDetectSwitch=COLLISION_DETECT_SWITCH-1;
//Enabling PCI confusion detection
MOD ENODEBALGOSWITCH: PciConflictDetectSwitch=CONFUSION_DETECT_SWITCH-1;
//Enabling proactive PCI conflict detection based on intra-RAT ANR
MOD ANR: ActivePciConflictSwitch=ON, StartTime=11&50&12, StopTime=11&50&15;
//Enabling PCI collision information reporting to the MAE-Access
MOD CELLALGOSWITCH: LocalCellId=0, PciConflictReportSwitch=COLLISION_REPORT_SWITCH-1;
//Enabling PCI confusion information reporting to the MAE-Access
MOD CELLALGOSWITCH: LocalCellId=0, PciConflictReportSwitch=CONFUSION_REPORT_SWITCH-1;
//Enabling PCI conflict alarm reporting to the MAE-Access and LMT
MOD ENODEBALGOSWITCH: PciConflictAlmSwitch=ON;
//(FDD) Setting the handover prohibition mode
MOD ANR: NoHoSetMode=PCI_CHECK;
Deactivation command examples
The following provides only deactivation command examples. You can determine whether to restore the settings of other
parameters based on actual network conditions.
//Disabling PCI collision detection
MOD ENODEBALGOSWITCH: PciConflictDetectSwitch=COLLISION_DETECT_SWITCH-0;
//Disabling PCI confusion detection
MOD ENODEBALGOSWITCH: PciConflictDetectSwitch=CONFUSION_DETECT_SWITCH-0;
//Disabling PCI collision information reporting to the MAE-Access
MOD CELLALGOSWITCH: LocalCellId=0, PciConflictReportSwitch=COLLISION_REPORT_SWITCH-0;
//Disabling PCI confusion information reporting to the MAE-Access
MOD CELLALGOSWITCH: LocalCellId=0, PciConflictReportSwitch=CONFUSION_REPORT_SWITCH-0;
//Disabling PCI collision alarm reporting to the MAE-Access and LMT
MOD ENODEBALGOSWITCH: PciConflictAlmSwitch=OFF, PciConflictDetectSwitch=COLLISION_DETECT_SWITCH-0;
//Disabling PCI confusion alarm reporting to the MAE-Access and LMT
MOD ENODEBALGOSWITCH: PciConflictAlmSwitch=OFF, PciConflictDetectSwitch=CONFUSION_DETECT_SWITCH-0;
PCI Self-Optimization
Prerequisites
Configurations of available PCI ranges, PCI optimization priorities, and PCI reallocation optimization
Configure them on the MAE-Access or by importing an engineering parameter template into the MAE-Access. To
import an engineering parameter template into the MAE-Access, the template to be imported has to follow the format
of the following table.
Figure 4-10 Parameter template example
Up to 100,000 parameters can be imported into the MAE-Access using this parameter template. You can choose to import all
parameter values or only parameter values that need to be added to an existing configuration.
A single PCI range for LTE cells is shown as [StartPCI-EndPCI]. If there is only one PCI in the PCI range, it is shown as [PCI].
Discontinuous PCI ranges are separated by commas, for example, [0-100],[500].
Available PCI ranges, PCI optimization priorities, and PCI reallocation optimization switches for all cells under the eNodeB can be
viewed by exporting the template.
To view or set the available PCI range, PCI optimization priority, and PCI reallocation optimization switch for LTE cells on the
MAE-Access, first select LTE cells on the MAE-Access. Cells of up to 1000 eNodeBs can be selected and viewed on the MAEAccess.
Engineering parameter configurations related to PCI self-optimization
Configure engineering parameters using MML commands or by importing an engineering parameter template into the
MAE-Access. To import an engineering parameter template into the MAE-Access, prepare the template to be imported
according to the following table.
If PCI self-optimization parameters for a sector have been configured both by running MML commands and by
importing an engineering parameter template, Longitude, Latitude, and Azimuth from the parameter template take
effect; Beamwidth configured by running an MML command takes effect.
Figure 4-11 Example of the engineering parameter template related to PCI self-optimization
If the eNodeB is configured with the RET antenna and the corresponding antenna parameters are configured in the engineering
parameter template, DeviceNO and SubunitNO in the engineering parameter template must be set to the same values as RET.
DEVICENO and RETSUBUNIT. SUBUNITNO configured in the eNodeB, respectively. In other scenarios, ensure that the values
of DeviceNO and SubunitNO are unique for each sector in the engineering parameter template.
Activation procedure
Create and start a PCI self-optimization task as follows:
1. On the MAE-Access, choose SON > LTE PCI Conflict Optimization. The LTE PCI Conflict Optimization window is
displayed.
To view the latest PCI conflict information reported by all eNodeBs managed by the MAE-Access, click the refresh button in the PCI
Conflict Info area.
2. (Optional) Configure self-optimization parameters.
a. Import an engineering parameter template.
On the LTE-LTE PCI Conflict tab page, click
in the PCI Conflict Info area to import an engineering
parameter template. If the engineering parameter template is not updated, use the engineering parameter template
that has been saved on the MAE-Access. In this situation, template import is not required.
If the engineering parameters are not configured, PCI mod 3 and PCI mod 30 will not be considered between adjacent cells
when PCIs are allocated, which negatively affects PCI optimization.
b. Configure available PCI ranges, PCI optimization priorities, and the PCI reallocation optimization switch.
On the LTE-LTE PCI Range tab page, click
to import the parameter template or click
to set the available
PCI range, PCI optimization priority, and PCI reallocation optimization switch for the cell.
If this step is skipped, the default values are used.
3. Start an optimization task.
In the Optimization Task area of the LTE-LTE PCI Conflict tab page, perform the following operations:
a. Click
to configure the Start optimization task and Apply optimization parameters.
b. Click
to configure the OldCellThreshold Value and SameBatchInterval Value parameters. You can select
Migrate users before adjusting PCI values and Keep PCI Mod3 value to be the same as the current value as
required.
Migrate users before adjusting PCI values: The eNodeB transfers UEs from this cell to other cells before PCI values are
adjusted.
Keep PCI Mod3 value to be the same as the current value: The eNodeB reallocates a PCI meeting the following requirement:
The result of this PCI mod 3 is the same as the current PCI mod 3 value.
The following table describes the Start optimization task and Apply optimization advice parameters.
Parameter
Name
Setting Notes
Start optimization Mode for starting a PCI self-optimization task.
task
If this parameter is set to Immediate, the MAE-Access immediately starts a PCI self-optimization task. To
manually start a PCI self-optimization task, view the PCI conflict information on the MAE-Access and then start
the task if PCI conflicts are not frequently changed.
If this parameter is set to Periodic, the MAE-Access starts a PCI self-optimization task at fixed time points each
day. Set the parameter to this value if you want to enable periodic execution of a PCI self-optimization task.
Apply
optimization
advice
Mode for delivering PCI optimization suggestions.
If this parameter is set to Manual, you can manually deliver a new PCI after the PCI self-optimization process is
complete. Set the parameter to this value if you want to confirm PCI self-optimization results.
If this parameter is set to Immediate, the MAE-Access automatically delivers a new PCI immediately after the
PCI self-optimization process is complete.
If this parameter is set to Scheduled, the MAE-Access delivers the latest appropriate PCI at fixed time points each
day.
The precautions for delivering PCI optimization suggestions are as follows:
The time for delivering PCI optimization suggestions must be different from the time for executing a PCI selfoptimization task. This ensures that PCIs are not delivered during PCI self-optimization task.
The interval between the time that a PCI self-optimization task is started and the time that a new PCI is delivered
should not be too long. This ensures that the new PCI is calculated based on the latest PCI conflict information. The
network parameter settings may be changed frequently during the initial phase of network deployment. Therefore, it is
recommended that PCI optimization suggestions be delivered immediately after the PCI self-optimization task is
complete.
It is recommended that PCIs be delivered in off-peak hours. This is because the cell will be automatically reset when
the MAE-Access delivers PCI optimization suggestions.
4.4.1.3 Using the MAE-Deployment
For detailed operations, see Feature Configuration Using the MAE-Deployment .
4.4.2 Activation Verification
PCI Conflict Detection
If no PCI conflict exists on the network, simulate a PCI conflict scenario before performing activation observation.
To verify the activation of PCI conflict detection, use any of the following methods:
Querying the PCI conflict alarm: Check whether ALM-29247 Cell PCI Conflict is reported to the MAE-Access alarm
console. If the alarm is reported, PCI conflict detection has been successfully activated.
Checking for PCI conflicts: On the MAE-Access, choose SON > LTE PCI Conflict Optimization. In the LTE PCI
Conflict Optimization window, click the refresh button in the PCI Conflict Info area of the LTE-LTE PCI Conflict tab
page and check for any PCI conflicts. If any PCI conflict information is displayed, PCI conflict detection has been
successfully activated, as shown in Figure 4-12.
Figure 4-12 PCI conflict information
Querying SON logs: On the MAE-Access, choose SON > SON Log > Query SON Log. In the Query SON Log window,
select LTE PCI Conflict Optimization Log for Log Category and All for the other parameters. Click Query, as shown in
Figure 4-13. If any PCI conflict information is displayed in SON logs, PCI conflict detection has been successfully activated.
The SON log information on the MAE-Access is automatically synchronized once a day. You can also click Synchronize at the lower right
corner of the Query SON Log window to manually synchronize SON logs.
Figure 4-13 PCI conflict optimization log
Querying PCI conflict records: Run the DSP CELLPCICONFLICT command on the LMT. If there are PCI conflict
records, PCI conflict detection has been successfully activated.
PCI Self-Optimization
To verify the activation of PCI self-optimization, use either of the following methods:
The MAE-Access generates optimization suggestions after the PCI self-optimization process is complete. If these
optimization suggestions can be queried, PCI self-optimization has been successfully activated. The optimization suggestions
are described as follows:
If the MAE-Access provides new PCIs for the conflicting cells, the cells that need to be allocated new PCIs, their
current PCIs, and the recommended PCIs are displayed under Optimization Advice of the LTE-LTE PCI Conflict
tab page.
If PCI self-optimization cannot provide new PCIs for the conflicting cells, the value of Recommended PCI is Not
set in the PCI Conflict Neighboring Cell area of the LTE-LTE PCI Conflict tab page, and no such cells are
displayed under Optimization Advice of the tab page.
Querying SON logs
On the MAE-Access, choose SON > SON Log > Query SON Log. In the Query SON Log window, select LTE PCI
Conflict Optimization Log for Log Category and All for the other parameters. Click Query. If any PCI self-optimization
information is displayed in SON logs, PCI self-optimization has been successfully activated.
4.4.3 Network Monitoring
When the eNodeB detects a PCI conflict and reallocates a new PCI, service drops and handover failures caused by the PCI
conflict are resolved. The decrement in the service drop rate and the increment in the outgoing handover success rate are affected
by the cell PCI, neighboring cell configuration, and coverage, and therefore cannot be quantified. The specific gains depend on the
live network environment.
Service drop rates are as follows:
Service Drop Rate (All)
Service Drop Rate (All) = L.E-RAB.AbnormRel/(L.E-RAB.AbnormRel + L.E-RAB.NormRel)
Call Drop Rate (VoIP)
Call Drop Rate (VoIP) = L.E-RAB.AbnormRel.QCI.1/(L.E-RAB.AbnormRel.QCI.1 + L.E-RAB.NormRel.QCI.1)
Outgoing handover success rates are as follows:
Intra-Frequency Handover Out Success Rate
Intra-Frequency Handover Out Success Rate = (L.HHO.IntraeNB.IntraFreq.ExecSuccOut +
L.HHO.IntereNB.IntraFreq.ExecSuccOut)/(L.HHO.IntraeNB.IntraFreq.ExecAttOut +
L.HHO.IntereNB.IntraFreq.ExecAttOut)
Inter-Frequency Handover Out Success Rate
Inter-Frequency Handover Out Success Rate = (L.HHO.IntraeNB.InterFreq.ExecSuccOut +
L.HHO.IntereNB.InterFreq.ExecSuccOut)/(L.HHO.IntraeNB.InterFreq.ExecAttOut +
L.HHO.IntereNB.InterFreq.ExecAttOut)
Table 4-4 Counters related to the service drops and handovers
Counter ID
Counter Name
1526726686
L.E-RAB.AbnormRel.QCI.1
1526726687
L.E-RAB.NormRel.QCI.1
1526727546
L.E-RAB.AbnormRel
1526727547
L.E-RAB.NormRel
1526726996
L.HHO.IntraeNB.IntraFreq.ExecAttOut
1526726997
L.HHO.IntraeNB.IntraFreq.ExecSuccOut
1526726999
L.HHO.IntraeNB.InterFreq.ExecAttOut
1526727000
L.HHO.IntraeNB.InterFreq.ExecSuccOut
1526727002
L.HHO.IntereNB.IntraFreq.ExecAttOut
1526727003
L.HHO.IntereNB.IntraFreq.ExecSuccOut
1526727005
L.HHO.IntereNB.InterFreq.ExecAttOut
1526727006
L.HHO.IntereNB.InterFreq.ExecSuccOut
5 NG-RAN PCI Conflict Detection
5.1 Principles
5.2 Network Analysis
5.3 Requirements
5.4 Operation and Maintenance
5.1 Principles
An NG-RAN PCI conflict refers to a PCI conflict between two NG-RAN cells neighboring to an E-UTRAN serving cell.
5.1.1 PCI Conflict Types and Detection Methods
NG-RAN PCI conflicts include only PCI confusion.
5.1.1.1 Introduction
A PCI confusion occurs when two or more neighboring cells of the serving cell have the same frequency and PCI, and the UE
reports any of such cells as the target cell meeting the handover conditions. In this case, the UE may fail to initiate a handover,
resulting in a service drop.
As illustrated in Figure 5-1, cell B is the detected cell meeting the handover conditions and is a configured neighboring cell of the
serving cell.
When the UE does not support ANR or the eNodeB is not enabled with ANR with NG-RAN, if the UE reports information about
the detected cell B to the eNodeB, the eNodeB cannot determine whether the neighboring cell detected by the UE is cell B or C.
As a result, the handover from cell A cannot be initiated and service drop occurs.
If NG-RAN inter-RAT event-triggered ANR is enabled and the UE supports ANR, the eNodeB can identify cell B based on the NR cell global
identifier (NCGI) reported by the UE and initiate a handover to cell B if required.
Figure 5-1 PCI confusion
5.1.1.2 Detection Method
The method of NG-RAN PCI conflict detection is the same as that of intra-RAT PCI conflict detection. For details, see 4.1.1.2.2
Detection Method.
This is controlled by the NR_CONFUSION_DETECT_SWITCH option of the ENodeBAlgoSwitch. PciConflictDetectSwitch
parameter.
5.1.2 PCI Conflict Detection Modes
When a neighboring NG-RAN cell is added to or deleted from the NRT or the PCI or frequency of a neighboring NG-RAN cell
changes, the eNodeB performs NG-RAN PCI conflict detection.
For details about the NRT, see ANR Management .
As shown in Figure 5-2, PCI conflict detection can be triggered by:
Manual parameter modification
The eNodeB triggers PCI conflict detection when eNodeB parameters are manually modified.
ANR with NG-RAN-based PCI conflict detection
The eNodeB triggers PCI conflict detection when eNodeB parameters are changed based on ANR.
EN-DC X2 message-based PCI conflict detection
The eNodeB performs PCI conflict detection when it exchanges EN-DC X2 messages with the gNodeB and updates the
neighboring NG-RAN cell parameters.
Figure 5-2 PCI conflict detection modes
5.1.2.1 Manual Parameter Modification Induced PCI Conflict Detection
The eNodeB performs PCI conflict detection when eNodeB parameters listed in 5.1.2 PCI Conflict Detection Modes are manually
modified.
5.1.2.2 ANR with NG-RAN-based PCI Conflict Detection
The eNodeB uses the ANR with NG-RAN function to automatically identify missing neighboring cells, and to maintain the NGRAN NCL/NRT. If ANR with NG-RAN changes neighboring cell parameter settings, the eNodeB will perform PCI conflict
detection. For details about the ANR with NG-RAN and NG-RAN NCL/NRT functions, see ANR Management .
5.1.2.3 EN-DC X2 Message-based PCI Conflict Detection
When an EN-DC X2 interface is set up or the gNodeB configuration is updated, the eNodeB updates the NG-RAN NCL/NRT
through an EN-DC X2 message to trigger PCI conflict detection.
Figure 5-3 illustrates the procedure for updating the NCL/NRT based on EN-DC X2 messages.
Figure 5-3 EN-DC X2 setup signaling procedure
Upon receiving an EN-DC X2 message from the gNodeB, the eNodeB updates the configured neighboring cell parameters in
the NCL/NRT and triggers PCI conflict detection.
Figure 5-4 illustrates the procedure for updating the NCL/NRT based on the gNodeB configuration update message.
Figure 5-4 Signaling procedure of gNodeB configuration update
If cells are added to or deleted from the gNodeB or if the PCI or frequency of a configured cell changes, the gNodeB sends
an EN-DC X2 message to notify the eNodeB of the change. The eNodeB will accordingly add external cells or neighboring
cells into or delete them from the NCL/NRT, or update the parameters of neighboring cells in the NCL/NRT to trigger PCI
conflict detection.
EN-DC X2 message-based PCI conflict detection requires NCL/NRT update based on EN-DC X2 messages. For details about
NCL/NRT update based on EN-DC X2 messages, see ANR Management .
5.1.3 Reporting PCI Conflict Information
When the eNodeB detects an NG-RAN PCI conflict, if the NR_PCI_CONFUSION_RPT_SW option of CellAlgoExtSwitch.
NCellAlgoSwitch is selected, the eNodeB reports the NG-RAN PCI confusion information to the MAE-Access.
In addition, the eNodeB can report ALM-29247 Cell PCI Conflict to the MAE-Access and LMT. This is enabled by setting the
ENodeBAlgoSwitch. PciConflictAlmSwitch parameter.
For details about ALM-29247 Cell PCI Conflict, see 3900 & 5900 Series Base Station Alarm Reference in 3900 & 5900 Series Base Station
Product Documentation.
5.2 Network Analysis
5.2.1 Benefits
This function automatically detects PCI confusions between neighboring NG-RAN cells and helps properly plan neighboring NGRAN cells.
5.2.2 Impacts
Network Impacts
This function does not entail any action after detecting PCI confusions between neighboring NG-RAN cells. Therefore, this
function has no impact on the network.
Function Impacts
RAT Function Name
Function
Switch
Reference
Description
FDD ANR with NGRAN
None
ANR
Management
PCI conflict detection is triggered when ANR with NG-RAN changes
neighboring cell information.
5.3 Requirements
5.3.1 Licenses
RAT
Feature ID
Feature Name
Model
Sales Unit
FDD
LOFD-002007
PCI Collision Detection and Self-Optimization
LT1S0PCICD00
per Cell
5.3.2 Software
Prerequisite Functions
None
Mutually Exclusive Functions
None
5.3.3 Hardware
Base Station Models
No requirements
Boards
No requirements
RF Modules
No requirements
5.3.4 Others
None
5.4 Operation and Maintenance
5.4.1 Data Configuration
5.4.1.1 Data Preparation
Table 5-1 describes the parameters for activating NG-RAN PCI conflict detection.
Table 5-1 Parameters used for activating NG-RAN PCI conflict detection
Parameter Name
Parameter ID
Setting Notes
PCI Conflict Detect
Switch
ENodeBAlgoSwitch.
PciConflictDetectSwitch
Set the NR_CONFUSION_DETECT_SWITCH option based on
the network plan.
PCI conflict alarm switch ENodeBAlgoSwitch.
PciConflictAlmSwitch
Set this parameter based on the network plan.
Neighboring Cell
Algorithm Switch
Set the NR_PCI_CONFUSION_RPT_SW option based on the
network plan.
CellAlgoExtSwitch.
NCellAlgoSwitch
ANR with NG-RAN must be enabled before you enable ANR with NG-RAN-based PCI conflict detection. For details about how to enable
ANR with NG-RAN, see ANR Management .
EN-DC X2 message-based PCI conflict detection requires the NCL/NRT update based on EN-DC X2 messages. For details about how to
enable NCL/NRT update based on EN-DC X2 messages, see ANR Management .
5.4.1.2 Using MML Commands
Activation Command Examples
Before using MML commands, refer to 5.2.2 Impacts and complete the parameter configurations for related functions based on
the impact relationships between the functions, as well as the actual network scenario.
//Enabling PCI conflict detection
MOD ENODEBALGOSWITCH: PciConflictDetectSwitch=NR_CONFUSION_DETECT_SWITCH-1;
//Enabling PCI conflict detection information reporting to the MAE-Access
MOD CELLALGOEXTSWITCH: LocalCellId=0, NCellAlgoSwitch=NR_PCI_CONFUSION_RPT_SW-1;
//Enabling PCI conflict alarm reporting to the MAE-Access and LMT
MOD ENODEBALGOSWITCH: PciConflictAlmSwitch=ON;
Deactivation Command Examples
//Disabling PCI conflict detection
MOD ENODEBALGOSWITCH: PciConflictDetectSwitch=NR_CONFUSION_DETECT_SWITCH-0;
//Disabling PCI conflict detection information reporting to the MAE-Access
MOD CELLALGOEXTSWITCH: LocalCellId=0, NCellAlgoSwitch=NR_PCI_CONFUSION_RPT_SW-0;
//Disabling PCI conflict alarm reporting to the MAE-Access or LMT
MOD ENODEBALGOSWITCH: PciConflictAlmSwitch=OFF;
5.4.1.3 Using the MAE-Deployment
For detailed operations, see Feature Configuration Using the MAE-Deployment .
5.4.2 Activation Verification
If no PCI conflict exists on the network, simulate a PCI conflict scenario before performing activation observation.
To verify the activation of PCI conflict detection, use either of the following methods:
Querying the PCI conflict alarm: Check whether ALM-29247 Cell PCI Conflict is reported to the MAE-Access alarm
console. If the alarm is reported, PCI conflict detection has been successfully activated.
Querying PCI conflict records: Run the DSP CELLPCICONFLICT command on the LMT. If there are PCI conflict
records, PCI conflict detection has been successfully activated.
5.4.3 Network Monitoring
This function does not entail any action after detecting PCI confusions between neighboring NG-RAN cells. Therefore, this
function has no impact on the network and does not involve network monitoring.
6 Parameters
The following hyperlinked EXCEL files of parameter documents match the software version with which this document is
released.
Node Parameter Reference : contains device and transport parameters.
eNodeBFunction Parameter Reference : contains all parameters related to radio access functions, including air interface
management, access control, mobility control, and radio resource management.
eNodeBFunction Used Reserved Parameter List : contains the reserved parameters that are in use and those that have been
disused.
You can find the EXCEL files of parameter reference and used reserved parameter list for the software version used on the live network from the
product documentation delivered with that version.
FAQ 1: How do I find the parameters related to a certain feature from parameter reference?
1. Open the EXCEL file of parameter reference.
2. On the Parameter List sheet, filter the Feature ID column. Click Text Filters and choose Contains. Enter the feature ID,
for example, LOFD-001016 or TDLOFD-001016.
3. Click OK. All parameters related to the feature are displayed.
FAQ 2: How do I find the information about a certain reserved parameter from the used reserved parameter list?
1. Open the EXCEL file of the used reserved parameter list.
2. On the Used Reserved Parameter List sheet, use the MO, Parameter ID, and BIT columns to locate the reserved
parameter, which may be only a bit of a parameter. View its information, including the meaning, values, impacts, and
product version in which it is activated for use.
7 Counters
The following hyperlinked EXCEL files of performance counter reference match the software version with which this document is
released.
Node Performance Counter Summary : contains device and transport counters.
eNodeBFunction Performance Counter Summary : contains all counters related to radio access functions, including air
interface management, access control, mobility control, and radio resource management.
You can find the EXCEL files of performance counter reference for the software version used on the live network from the product
documentation delivered with that version.
FAQ: How do I find the counters related to a certain feature from performance counter reference?
1. Open the EXCEL file of performance counter reference.
2. On the Counter Summary(En) sheet, filter the Feature ID column. Click Text Filters and choose Contains. Enter the
feature ID, for example, LOFD-001016 or TDLOFD-001016.
3. Click OK. All counters related to the feature are displayed.
8 Glossary
For the acronyms, abbreviations, terms, and definitions, see Glossary .
9 Reference Documents
1. 3GPP TS 36.211, "Physical channels and modulation"
2. Flexible Bandwidth based on Overlap Carriers (FDD)
3. ANR Management
4. Multi-Band Compatibility Enhancement
5. Super Combined Cell (FDD)
6. 3900 & 5900 Series Base Station Alarm Reference in 3900 & 5900 Series Base Station Product Documentation