eRAN

Access Class Control Feature

Parameter Description

Issue Draft A
Date 2020-12-29

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2021. 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.

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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
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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
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Website: https://www.huawei.com
Email: support@huawei.com

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Access Class Control Feature Parameter Description Contents

Contents

1 Change History.........................................................................................................................1
1.1 eRAN17.1 Draft A (2020-12-29)........................................................................................................................................ 1

2 About This Document.............................................................................................................2

2.1 General Statements................................................................................................................................................................ 2
2.2 Applicable RAT......................................................................................................................................................................... 2
2.3 Features in This Document.................................................................................................................................................. 2

3 Overview....................................................................................................................................4
4 eNodeB AC Control..................................................................................................................5
4.1 General Principles.................................................................................................................................................................... 5
4.2 Static AC Control................................................................................................................................................................... 10
4.2.1 Principles.............................................................................................................................................................................. 10
4.2.2 Network Analysis............................................................................................................................................................... 11
4.2.2.1 Benefits.............................................................................................................................................................................. 11
4.2.2.2 Impacts.............................................................................................................................................................................. 11
4.2.3 Requirements...................................................................................................................................................................... 12
4.2.3.1 Licenses.............................................................................................................................................................................. 12
4.2.3.2 Software............................................................................................................................................................................ 12
4.2.3.3 Hardware.......................................................................................................................................................................... 12
4.2.3.4 Others................................................................................................................................................................................ 13
4.2.4 Operation and Maintenance......................................................................................................................................... 13
4.2.4.1 Data Preparation............................................................................................................................................................ 13
4.2.4.2 Using MML Commands............................................................................................................................................... 17
4.2.4.3 Using the MAE-Deployment...................................................................................................................................... 17
4.2.4.4 Activation Verification.................................................................................................................................................. 17
4.2.4.5 Network Monitoring..................................................................................................................................................... 17
4.3 Dynamic AC Control............................................................................................................................................................ 18
4.3.1 Intelligent Access Class Control.................................................................................................................................... 18
4.3.1.1 Principles........................................................................................................................................................................... 18
4.3.1.1.1 Overall Process............................................................................................................................................................ 18
4.3.1.1.2 Triggering of Intelligent Access Class Control.................................................................................................. 19
4.3.1.1.3 Entry to Intelligent Access Class Control............................................................................................................ 23
4.3.1.1.4 Exit from Intelligent Access Class Control..........................................................................................................24

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Access Class Control Feature Parameter Description Contents

4.3.1.2 Network Analysis........................................................................................................................................................... 24

4.3.1.2.1 Benefits...........................................................................................................................................................................24
4.3.1.2.2 Impacts........................................................................................................................................................................... 25
4.3.1.3 Requirements................................................................................................................................................................... 25
4.3.1.3.1 Licenses.......................................................................................................................................................................... 25
4.3.1.3.2 Software......................................................................................................................................................................... 25
4.3.1.3.3 Hardware....................................................................................................................................................................... 26
4.3.1.3.4 Others............................................................................................................................................................................. 26
4.3.1.4 Operation and Maintenance...................................................................................................................................... 26
4.3.1.4.1 Data Preparation.........................................................................................................................................................26
4.3.1.4.2 Using MML Commands............................................................................................................................................ 28
4.3.1.4.3 Using the MAE-Deployment................................................................................................................................... 29
4.3.1.4.4 Activation Verification...............................................................................................................................................29
4.3.1.4.5 Network Monitoring.................................................................................................................................................. 29
4.3.2 Dynamic SSAC.................................................................................................................................................................... 31
4.3.2.1 Principles........................................................................................................................................................................... 31
4.3.2.1.1 Overall Procedure....................................................................................................................................................... 31
4.3.2.1.2 Triggering of Dynamic SSAC................................................................................................................................... 33
4.3.2.1.3 Entry to Dynamic SSAC............................................................................................................................................ 33
4.3.2.1.4 Exit from Dynamic SSAC.......................................................................................................................................... 34
4.3.2.2 Network Analysis........................................................................................................................................................... 34
4.3.2.2.1 Benefits...........................................................................................................................................................................34
4.3.2.2.2 Impacts........................................................................................................................................................................... 34
4.3.2.3 Requirements................................................................................................................................................................... 35
4.3.2.3.1 Licenses.......................................................................................................................................................................... 35
4.3.2.3.2 Software......................................................................................................................................................................... 35
4.3.2.3.3 Hardware....................................................................................................................................................................... 35
4.3.2.3.4 Others............................................................................................................................................................................. 36
4.3.2.4 Operation and Maintenance...................................................................................................................................... 36
4.3.2.4.1 Data Preparation.........................................................................................................................................................36
4.3.2.4.2 Using MML Commands............................................................................................................................................ 38
4.3.2.4.3 Using the MAE-Deployment................................................................................................................................... 38
4.3.2.4.4 Activation Verification...............................................................................................................................................38
4.3.2.4.5 Network Monitoring.................................................................................................................................................. 39
4.4 Operator-specific AC Control............................................................................................................................................ 40
4.4.1 Principles.............................................................................................................................................................................. 40
4.4.2 Network Analysis............................................................................................................................................................... 40
4.4.2.1 Benefits.............................................................................................................................................................................. 41
4.4.2.2 Impacts.............................................................................................................................................................................. 41
4.4.3 Requirements...................................................................................................................................................................... 41
4.4.3.1 Licenses.............................................................................................................................................................................. 41
4.4.3.2 Software............................................................................................................................................................................ 42

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Access Class Control Feature Parameter Description Contents

4.4.3.3 Hardware.......................................................................................................................................................................... 42
4.4.3.4 Others................................................................................................................................................................................ 42
4.4.4 Operation and Maintenance......................................................................................................................................... 42
4.4.4.1 Data Preparation............................................................................................................................................................ 42
4.4.4.2 Using MML Commands............................................................................................................................................... 44
4.4.4.3 Using the MAE-Deployment...................................................................................................................................... 44
4.4.4.4 Activation Verification.................................................................................................................................................. 44
4.4.4.5 Network Monitoring..................................................................................................................................................... 45
4.5 AC Bar Skipping..................................................................................................................................................................... 45
4.5.1 Principles.............................................................................................................................................................................. 45
4.5.2 Network Analysis............................................................................................................................................................... 46
4.5.2.1 Benefits.............................................................................................................................................................................. 46
4.5.2.2 Impacts.............................................................................................................................................................................. 47
4.5.3 Requirements...................................................................................................................................................................... 47
4.5.3.1 Licenses.............................................................................................................................................................................. 47
4.5.3.2 Software............................................................................................................................................................................ 47
4.5.3.3 Hardware.......................................................................................................................................................................... 47
4.5.3.4 Others................................................................................................................................................................................ 48
4.5.4 Operation and Maintenance......................................................................................................................................... 48
4.5.4.1 Data Preparation............................................................................................................................................................ 48
4.5.4.2 Using MML Commands............................................................................................................................................... 48
4.5.4.3 Using the MAE-Deployment...................................................................................................................................... 48
4.5.4.4 Activation Verification.................................................................................................................................................. 48
4.5.4.5 Network Monitoring..................................................................................................................................................... 49

5 UE AC Control.........................................................................................................................50
5.1 Emergency Call Access Decision Procedure................................................................................................................. 51
5.2 MO Data Access Decision Procedure............................................................................................................................. 51
5.3 MO Signaling Access Decision Procedure.....................................................................................................................52
5.4 AC Bar Skipping Decision Procedure.............................................................................................................................. 53
5.5 MMTel Voice Access Decision Procedure...................................................................................................................... 54
5.6 MMTel Video Access Decision Procedure..................................................................................................................... 55
5.7 CSFB Access Decision Procedure...................................................................................................................................... 56

6 Parameters.............................................................................................................................. 58
7 Counters.................................................................................................................................. 59
8 Glossary................................................................................................................................... 60
9 Reference Documents...........................................................................................................61

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Access Class Control Feature Parameter Description 1 Change History

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 Draft A (2020-12-29)

This issue introduces the following changes to eRAN16.1 01 (2020-03-30).

Technical Changes
Change Description Parameter RAT Base Station
Change Model

Canceled the compatibility None FDD BTS3911E

with the BTS3911E as of this
version.

Editorial Changes
None

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Access Class Control Feature Parameter Description 2 About This Document

2 About 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
NOTE

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 the desired gains, contact Huawei professional service engineers.

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 features.

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Access Class Control Feature Parameter Description 2 About This Document

Feature ID Feature Name Chapter/Section

LOFD-070207 Intelligent Access Class 4.3.1 Intelligent Access Class

Control Control

4.5 AC Bar Skipping

LOFD-008002 Dynamic Service-specific 4.3.2 Dynamic SSAC

Access Control

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Access Class Control Feature Parameter Description 3 Overview

3 Overview

Access class (AC) control is used to manage UE access to a network, as defined by

3GPP specifications.
1. With AC control, the eNodeB broadcasts AC control parameters using system
information block type 2 (SIB2) to all UEs in a cell.
For details, see 4 eNodeB AC Control.
2. UEs check whether access to the cell is allowed based on the AC information
on the SIM card, the RRC connection setup type, or the service type when
initiating an RRC connection setup.
For details, see 5 UE AC Control.
In accordance with section 5.3.3 "RRC connection establishment" in 3GPP TS
36.331 V11.2.0, barring evaluation and barring control are performed by UEs
originating services, rather than UEs handed over from other cells or UEs
terminating services, after the UEs receive AC control parameters from the
eNodeB.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4 eNodeB AC Control

4.1 General Principles

ACs
3GPP TS 36.331 defines 16 ACs (AC 0 to AC 15). As defined in the specifications,
each UE is allocated one of ACs 0 to 9, and may also be allocated one or more
special ACs (AC 11 to AC 15) as a high-priority UE. Table 4-1 lists the application
scope of ACs.

Table 4-1 ACs

AC Application Scope

AC 0 to AC 9 Services of common UEs

AC 10 Emergency calls initiated by UEs of

ACs 0 to 9 or UEs without an
international mobile subscriber
identity (IMSI)

AC 11 PLMN management services

AC 12 Security services

AC 13 Services of public utilities, such as

water and gas suppliers

AC 14 Emergency services

AC 15 Services of PLMN staff

Access Barring Information Types

Based on the UE access cause and service type, the types of access barring
information broadcast in SIB2 include:

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

● Emergency call
● MO data
● MO signaling
● Multimedia telephony (MMTel) voice
● MMTel video
● CS fallback (CSFB)
● AC bar skipping for MMTel voice
● AC bar skipping for MMTel video
● AC bar skipping for short message services (SMSs)

The CellAcBar.AcBarringInfoCfgInd parameter specifies whether access barring

information is broadcast.

NOTE

When selecting a cell to camp on, a UE does not consider access barring information, which
means that a UE of a specific AC can camp on a cell even if this AC is barred. In addition,
the UE does not perform cell reselection when the access barring information changes.

AC Control Methods
AC control is classified into the following types:

● Static AC control: The eNodeB does not consider network loads during the
settings of AC control parameters. For details, see 4.2 Static AC Control.
● Dynamic AC control
– Intelligent access class control: The eNodeB intelligently determines
whether to adjust and deliver settings of AC control parameters in a cell
based on the cell congestion status. For details, see 4.3.1 Intelligent
Access Class Control.
– Dynamic service-specific access control (SSAC): The eNodeB dynamically
determines whether to adjust and deliver settings of AC control
parameters in a cell based on the cell disaster and congestion states. For
details, see 4.3.2 Dynamic SSAC.

Table 4-2 describes applicable types of access barring information for the
preceding AC control methods.

Table 4-2 Applicable types of access barring information for AC control methods

AC Control Method Applicable Type of Access Barring

Information

Static AC control ● Emergency call

● MO data
● MO signaling
● MMTel voice
● MMTel video
● CSFB

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

AC Control Method Applicable Type of Access Barring

Information

Dynamic AC control Intelligent access class control

● MO data
● MO signaling
Dynamic SSAC
● MMTel voice
● MMTel video

If a cell needs to be reserved as a candidate cell for a specified operator's UEs of

certain ACs or AC control needs to be specific to access barring information types
for specific operators, operator-specific AC control can be used. For details, see 4.4
Operator-specific AC Control.
AC bar skipping can be used for the following three types of access barring
information. For details, see 4.5 AC Bar Skipping.
● AC bar skipping for MMTel voice
● AC bar skipping for MMTel video
● AC bar skipping for SMS

AC Control Parameters
Table 4-3 lists AC control parameters defined in 3GPP specifications.

Table 4-3 AC control parameters

3GPP-defined AC Huawei AC Control Parameter Description
Control Parameter Parameter

ac- CellAcBar.AcBarringFor This parameter specifies

BarringForEmergency Emergency whether to prohibit
emergency calls from
accessing a cell. If this
parameter is set to True,
access barring is started for
emergency calls.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

3GPP-defined AC Huawei AC Control Parameter Description

Control Parameter Parameter

ac-BarringFactor ● CellAcBar.AcBarringF A random number (rand) is

actorForCall generated by a UE after it
● CellAcBar.AcBarringF initiates an access request.
actorForSig If the value of rand is less
than the value of ac-
● CellAcBar.AcBarFact BarringFactor, the UE
orForMVoice proceeds with the access
● CellAcBar.AcBarFact procedure. If the value of
orForMVideo rand is greater than or
● CellAcBar.AcBarFact equal to the value of ac-
orForCsfb BarringFactor, the UE is
prohibited from the access
procedure.

ac-BarringTime ● CellAcBar.AcBarTime Based on the access

ForCall probability factor, these
● CellAcBar.AcBarTime parameters specify the
ForSig duration for barring an
access request as follows:
● CellAcBar.AcBarTime
ForMVoice Access barring duration =
(0.7 + 0.6 x rand) x ac-
● CellAcBar.AcBarTime BarringTime
ForMVideo
When this duration elapses,
● CellAcBar.AcBarTime the eNodeB determines
ForCsfb whether the UE is allowed
to access the network
again.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

3GPP-defined AC Huawei AC Control Parameter Description

Control Parameter Parameter

ac-BarringForSpecia- ● CellAcBar.AC11Barfo These parameters specify

lAC rCall whether UEs of AC 11 to
● CellAcBar.AC12Barfo AC 15 are allowed to
rCall initiate access requests.
● CellAcBar.AC13Barfo According to 3GPP
rCall specifications, ac-
BarringFactor can only be
● CellAcBar.AC14Barfo set to P00 (that is, 0%)
rCall when any of the bits of ac-
● CellAcBar.AC15Barfo BarringForSpecialAC are set
rCall to 1. In this case, UEs of AC
● CellAcBar.AC11BarFo 0 to AC 9 cannot access the
rSig network. For details, see
section 6.3.1 "System
● CellAcBar.AC12BarFo information blocks" in
rSig 3GPP TS 36.331 V11.2.0.
● CellAcBar.AC13BarFo
rSig
● CellAcBar.AC14BarFo
rSig
● CellAcBar.AC15BarFo
rSig
● CellAcBar.SpecialAC
BarForCsfb
● CellAcBar.SpecialAC
BarForMVideo
● CellAcBar.SpecialAC
BarForMVoice
ac-BarringSkipForMM- MMTELVoicePreferCf- When this parameter is set
TELVoice gInd option of the to True, a UE originating
CellAcBar.VoLTEPreferC MMTel voice services
fgInd parameter ignores the received AC
control parameters in the
access stratum.

ac-BarringSkipForMM- MMTELVideoPreferCf- When this parameter is set

TELVideo gInd option of the to True, a UE originating
CellAcBar.VoLTEPreferC MMTel video services
fgInd parameter ignores the received AC
control parameters in the
access stratum.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

3GPP-defined AC Huawei AC Control Parameter Description

Control Parameter Parameter

ac-BarringSkipForSMS SMSPreferCfgInd option When this parameter is set

of the to True, a UE originating
CellAcBar.VoLTEPreferC SMS over IP or common
fgInd parameter SMS services ignores the
received AC control
parameters in the access
stratum.

4.2 Static AC Control

4.2.1 Principles
The eNodeB does not consider network loads during the settings of AC control
parameters. This function takes effect only when the
CellAlgoSwitch.AcBarAlgoSwitch parameter is set to ACBAR_SWITCH_STATIC.

Figure 4-1 shows how this function works.

Figure 4-1 Static AC control

The configuration indicators for access barring information types in the preceding
figure are configured using the parameters listed in Table 4-4.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Table 4-4 Configuration indicators for the corresponding access barring

information types

Applicable Type of Access Barring Parameter

Information

Emergency call CellAcBar.AcBarringForEmergency

MO data CellAcBar.AcBarringForMoDataCf-
gInd
MO signaling CellAcBar.AcBarringForMoSigCfgInd

MMTel voice CellAcBar.AcBarForMVoiceCfgInd

MMTel video CellAcBar.AcBarForMVideoCfgInd

CSFB CellAcBar.AcBarForCsfbCfgInd

When the eNodeB delivers control parameters for specific ACs, information such
as the access probability factors and average access barring duration needs to be
specified. For example, the access probability factor and average access barring
duration for mobile originated (MO) data are controlled by the
CellAcBar.AcBarringFactorForCall and CellAcBar.AcBarTimeForCall parameters,
respectively. The access probability factor and average access barring duration for
MO signaling are controlled by the CellAcBar.AcBarringFactorForSig and
CellAcBar.AcBarTimeForSig parameters, respectively. For more parameters, see
AC Control Parameters.

For details about the list of barred ACs and how a UE determines its AC, see
chapter 4 "Access control" in 3GPP TS 22.011 V10.0.0 and section 3.4 "Access
control" in 3GPP TS 23.122 V10.0.0.

4.2.2 Network Analysis

4.2.2.1 Benefits
This function can be used only when a large number of UEs simultaneously access
the network.

This function ensures smooth UE access and relieves cell congestion.

4.2.2.2 Impacts

Network Impacts
Enabling this function imposes the following network impacts:

● If this function is enabled when the CPU resource is sufficient (for example,
when the eNodeBFlowCtrlPara.DynAcBarPolicyMode parameter is set to
CPULOAD and the eNodeBFlowCtrlPara.CpuLoadThd parameter is set to a
value less than 80), a certain proportion of UEs is barred from accessing the

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

network, affecting access experience. In addition, the busy hour call attempts
(BHCA) specifications of the eNodeB may fail to be reached.
● If the RRC connection setup success rate decreases because of flow control on
the main control board or baseband processing units (BBPs), or resource
allocation failure due to the number of UEs exceeding the specifications,
enabling static AC control prevents some UEs from accessing the cell. This
helps relieve cell congestion, increasing the RRC connection setup success
rate. The increase in the RRC connection setup success rate depends on the
cell congestion level, AC control parameter settings, and proportion of UEs
that support AC control on the network. If UE access is barred, the access
experience will be affected.

Function Impacts
None

4.2.3 Requirements

4.2.3.1 Licenses
There are no license requirements.

4.2.3.2 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 Function Reference Description
Name Switch

FDD System None Idle Mode AC control parameters

information Managem are broadcast in SIB2.
broadcast ent

Mutually Exclusive Functions

None

4.2.3.3 Hardware

Base Station Models

No requirements

Boards
No requirements

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

RF Modules
No requirements

4.2.3.4 Others
Table 4-5 lists the requirements for UEs.

Table 4-5 Requirements for UEs

Access Type Requirement

Emergency call/MO UEs must support the AC control mechanism

signaling/MO data defined in 3GPP Release 8 or later.

MMTel voice/MMTel video UEs must support the AC control mechanism

defined in 3GPP Release 9 or later.

CSFB UEs must support the AC control mechanism

defined in 3GPP Release 10 or later.

4.2.4 Operation and Maintenance

4.2.4.1 Data Preparation

Table 4-6 describes the parameters used for function activation. Table 4-7, Table
4-8, Table 4-9, Table 4-10, Table 4-11, and Table 4-12 describe AC control
parameters of different ACs.

Table 4-6 Parameters used for activation

Parameter Name Parameter ID Setting Notes

AC barring information CellAcBar.AcBarringI Set this parameter to

configure indicator nfoCfgInd CFG.

AcBar algorithms switch CellAlgoSwitch.AcBar Set this parameter to

AlgoSwitch ACBAR_SWITCH_STA
TIC.

Table 4-7 AC control parameters related to emergency calls

Parameter Name Parameter ID Setting Notes

Emergency call barring state CellAcBar.AcBarringF Set this parameter to

orEmergency its recommended
value.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Setting Notes

AC11 barring state for CellAcBar.AC11Barfor Set this parameter to

originating call Call its recommended
value.

AC12 barring state for CellAcBar.AC12Barfor Set this parameter to

originating call Call its recommended
value.

AC13 barring state for CellAcBar.AC13Barfor Set this parameter to

originating call Call its recommended
value.

AC14 barring state for CellAcBar.AC14Barfor Set this parameter to

originating call Call its recommended
value.

AC15 barring state for CellAcBar.AC15Barfor Set this parameter to

originating call Call its recommended
value.

Table 4-8 AC control parameters related to MO data

Parameter Name Parameter ID Setting Notes

AC barring for mobile data CellAcBar.AcBarringF Set this parameter to

configure indicator orMoDataCfgInd its recommended
value.

Access probability factor for CellAcBar.AcBarringF Set this parameter to

originating call actorForCall its recommended
value.

Mean access barring time for CellAcBar.AcBarTime Set this parameter to

originating call ForCall its recommended
value.

AC11 barring state for CellAcBar.AC11Barfor Set this parameter to

originating call Call its recommended
value.

AC12 barring state for CellAcBar.AC12Barfor Set this parameter to

originating call Call its recommended
value.

AC13 barring state for CellAcBar.AC13Barfor Set this parameter to

originating call Call its recommended
value.

AC14 barring state for CellAcBar.AC14Barfor Set this parameter to

originating call Call its recommended
value.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Setting Notes

AC15 barring state for CellAcBar.AC15Barfor Set this parameter to

originating call Call its recommended
value.

Table 4-9 AC control parameters related to MO signaling

Parameter Name Parameter ID Setting Notes

AC barring for mobile signal CellAcBar.AcBarringF Set this parameter to

configure indicator orMoSigCfgInd its recommended
value.

Access probability factor for CellAcBar.AcBarringF Set this parameter to

signaling actorForSig its recommended
value.

Mean access barring time for CellAcBar.AcBarTime Set this parameter to

signaling ForSig its recommended
value.

AC11 barring state for CellAcBar.AC11BarFo Set this parameter to

signaling rSig its recommended
value.

AC12 barring state for CellAcBar.AC12BarFo Set this parameter to

signaling rSig its recommended
value.

AC13 barring state for CellAcBar.AC13BarFo Set this parameter to

signaling rSig its recommended
value.

AC14 barring state for CellAcBar.AC14BarFo Set this parameter to

signaling rSig its recommended
value.

AC15 barring state for CellAcBar.AC15BarFo Set this parameter to

signaling rSig its recommended
value.

Table 4-10 AC control parameters related to MMTel voice

Parameter Name Parameter ID Setting Notes

AC barring for MMTEL voice CellAcBar.AcBarForM Set this parameter to

configure indicator VoiceCfgInd its recommended
value.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Setting Notes

Access probability factor for CellAcBar.AcBarFacto Set this parameter to

MMTEL voice rForMVoice its recommended
value.

Mean access barring time for CellAcBar.AcBarTime Set this parameter to

MMTEL voice ForMVoice its recommended
value.

AC 11-15 barring state for CellAcBar.SpecialACB Set this parameter to

MMTEL voice arForMVoice its recommended
value.

Table 4-11 AC control parameters related to MMTel video

Parameter Name Parameter ID Setting Notes

AC barring for MMTEL video CellAcBar.AcBarForM Set this parameter to

configure indicator VideoCfgInd its recommended
value.

Access probability factor for CellAcBar.AcBarFacto Set this parameter to

MMTEL video rForMVideo its recommended
value.

Mean access barring time for CellAcBar.AcBarTime Set this parameter to

MMTEL video ForMVideo its recommended
value.

AC 11-15 barring state for CellAcBar.SpecialACB Set this parameter to

MMTEL video arForMVideo its recommended
value.

Table 4-12 AC control parameters related to CSFB

Parameter Name Parameter ID Setting Notes

AC barring for CSFB configure CellAcBar.AcBarForCs Set this parameter to

indicator fbCfgInd its recommended
value.

Access probability factor for CellAcBar.AcBarFacto Set this parameter to

CSFB rForCsfb its recommended
value.

Mean access barring time for CellAcBar.AcBarTime Set this parameter to

CSFB ForCsfb its recommended
value.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Setting Notes

AC 11-15 barring state for CellAcBar.SpecialACB Set this parameter to

CSFB arForCsfb its recommended
value.

4.2.4.2 Using MML Commands

Activation Command Examples

//Enabling the static AC control function
MOD CELLACBAR: LocalCellId=0, AcBarringInfoCfgInd=CFG;
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch=ACBAR_SWITCH_STATIC;

Optimization Command Examples

//Setting parameters related to static AC control for MO data with the access probability factor for MO
data set to 95% and the average access barring duration for MO data set to 4s
MOD CELLACBAR: LocalCellId=0, AcBarringForMoDataCfgInd=CFG, AcBarringFactorForCall=P95,
AcBarTimeForCall=ACCESS_BARRING_TIME_S4;

Deactivation Command Examples

//Disabling the access barring function
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch= ACBAR_SWITCH_DISABLE;

4.2.4.3 Using the MAE-Deployment

For detailed operations, see Feature Configuration Using the MAE-Deployment.

4.2.4.4 Activation Verification

On the MAE-Access, observe whether ac-BarringInfo is included in SIB2 traced over
the Uu interface.
If included, this function has taken effect.

4.2.4.5 Network Monitoring

If a cell is congested due to the access of a large number of UEs, monitor counters
listed in Table 4-13 to determine ACs for which static AC control is required.

Table 4-13 Counters related to static AC control

Counter ID Counter Name

1526728217 L.RRC.ConnReq.Att.Emc

1526728220 L.RRC.ConnReq.Att.MoSig

1526728221 L.RRC.ConnReq.Att.MoData

1526728321 L.CSFB.PrepAtt

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.3 Dynamic AC Control

When configuring AC control parameters for a cell, the eNodeB determines
whether to adjust and deliver AC control parameters in the cell, depending on
whether the cell is congested.
Dynamic AC control includes the following:
● 4.3.1 Intelligent Access Class Control
● 4.3.2 Dynamic SSAC

4.3.1 Intelligent Access Class Control

4.3.1.1 Principles
The eNodeB periodically and intelligently determines whether to adjust and
deliver AC control parameters in a cell based on the cell congestion status.
This function takes effect when both of the following conditions apply:
● The CellAlgoSwitch.AcBarAlgoSwitch parameter is set to
ACBAR_SWITCH_DYNAMIC.
● The DYNAMIC_FOR_MO option of the
CellAlgoSwitch.AcBarAlgoforDynSwitch parameter is selected.
If dynamic SSAC is not enabled, ensure that the DYNAMIC_FOR_SSAC option of
the CellAlgoSwitch.AcBarAlgoforDynSwitch parameter is deselected.

4.3.1.1.1 Overall Process

Figure 4-2 shows how intelligent access class control works.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Figure 4-2 Process of intelligent access class control

In the preceding figure, the CellAcBar.AcBarringForMoDataCfgInd and

CellAcBar.AcBarringForMoSigCfgInd parameters specify the access barring
configuration indicators for MO data and MO signaling, respectively.

4.3.1.1.2 Triggering of Intelligent Access Class Control

The eNodeB periodically checks whether a cell is congested. The period is specified
by the CellDynAcBarAlgoPara.DynAcBarStatPeriod parameter. If the number of

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

consecutive periods during which the cell is congested reaches the value of the
CellDynAcBarAlgoPara.MoTriggerCondSatiPeriods parameter, intelligent access
class control is triggered, and EVT-29252 Cell Intelligent Access Class Control Event
is reported.
Whether a cell is congested or recovers from congestion depends on the
eNodeBFlowCtrlPara.DynAcBarPolicyMode parameter setting. For details, see
Table 4-14.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Table 4-14 Conditions for determining whether a cell is congested or recovers

from congestion
Value of the Condition for Condition for
eNodeBFlowCtrlPar Determining Whether a Determining Whether a
a.DynAcBarPolicyM Cell Is Congested Cell Recovers from
ode Parameter Congestion

FLOWCONTROL A cell is considered to be The cell recovers from

congested if any of the congestion if all of the
following conditions following conditions apply:
applies: ● The ratio of the flow
● The ratio of the flow control duration to the
control duration to the value of the
value of the CellDynAcBarAlgo-
CellDynAcBarAlgo- Para.DynAcBarStatPer-
Para.DynAcBarStatPer- iod parameter is less
iod parameter in the than or equal to the
cell is greater than or value of the
equal to the value of CellDynAcBarAlgo-
the CellDynAcBarAlgo- Para.DynAcBarCancelT
Para.DynAcBarTriggerT hd parameter.
hd parameter. ● The ratio of the
● The ratio of the duration duration within which
within which the RRC the RRC rejection ratio
rejection ratio exceeds exceeds the value of the
the value of the CellDynAcBarAlgo-
CellDynAcBarAlgo- Para.RrcRejectCongTrig
Para.RrcRejectCongTrig gerThld parameter (=
gerThld parameter (= Duration within which
Duration within which the RRC rejection ratio
the RRC rejection ratio exceeds the congestion
exceeds the congestion triggering threshold/
triggering threshold/ CellDynAcBarAlgo-
CellDynAcBarAlgo- Para.DynAcBarStatPer-
Para.DynAcBarStatPer- iod) is less than or
iod) is greater than or equal to the value of
equal to the value of the CellDynAcBarAlgo-
the CellDynAcBarAlgo- Para.DynAcBarCancelT
Para.DynAcBarTriggerT hd parameter.
hd parameter. ● The number of UEs that
● The number of UEs that have accessed the
have accessed the network is less than or
network is greater than equal to the value of
the value of the the CellDynAcBarAlgo-
CellDynAcBarAlgo- Para.UeNumCongClear
Para.UeNumCongThld Thld parameter.
parameter.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Value of the Condition for Condition for

eNodeBFlowCtrlPar Determining Whether a Determining Whether a
a.DynAcBarPolicyM Cell Is Congested Cell Recovers from
ode Parameter Congestion

CPULOAD A cell is considered to be The cell recovers from

congested if either of the congestion if both of the
following conditions following conditions apply:
applies: ● The ratio of the
● The ratio of the duration duration in which the
in which the CPU usage CPU usage of the main
of the main control control board or BBP for
board or BBP for a cell is a cell is greater than or
greater than or equal to equal to the value of
the value of the the
eNodeBFlowCtrlPara.C eNodeBFlowCtrlPara.C
puLoadThd parameter puLoadThd parameter
(= CPU overload (= CPU overload
duration/ duration/
CellDynAcBarAlgo- CellDynAcBarAlgo-
Para.DynAcBarStatPer- Para.DynAcBarStatPer-
iod) is greater than or iod) is less than or
equal to the value of equal to the value of
the CellDynAcBarAlgo- the CellDynAcBarAlgo-
Para.DynAcBarTriggerT Para.DynAcBarCancelT
hd parameter. hd parameter.
● The number of UEs that ● The number of UEs that
have accessed the have accessed the
network is greater than network is less than or
the value of the equal to the value of
CellDynAcBarAlgo- the CellDynAcBarAlgo-
Para.UeNumCongThld Para.UeNumCongClear
parameter. Thld parameter.

The value of the CellDynAcBarAlgoPara.DynAcBarCancelThd parameter must be

less than or equal to the value of the
CellDynAcBarAlgoPara.DynAcBarTriggerThd parameter.

To lower the threshold for determining the cell congestion status based on the
number of UEs (specified by the CellDynAcBarAlgoPara.UeNumCongThld
parameter), modify the parameter directly.

To raise the value of the CellDynAcBarAlgoPara.UeNumCongThld parameter:

● If the cell is congested, change the values of the

CellDynAcBarAlgoPara.UeNumCongClearThld and
CellDynAcBarAlgoPara.UeNumCongThld parameters in sequence. For
example, to raise the threshold from 150 to 200, set the
CellDynAcBarAlgoPara.UeNumCongClearThld parameter to 200 first, and
then change the value of the CellDynAcBarAlgoPara.UeNumCongThld
parameter from 150 to 200.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

● If the cell is not congested, change the value of the

CellDynAcBarAlgoPara.UeNumCongThld parameter directly.
For details about flow control, see Flow Control.
For macro eNodeBs, flow control is triggered by a large amount of RRC access
signaling or RACH signaling.
Flow control is performed at board level. If the number of access signaling (RRC
access signaling or RACH signaling) messages is imbalanced between cells served
by the same board, you are advised to set the
eNodeBFlowCtrlPara.DynAcBarringTrigAllCellSw parameter to OFF to avoid
impacts of flow control in heavy-load cells on UE access to light-load cells.
If the eNodeBFlowCtrlPara.DynAcBarPolicyMode parameter value is changed
within the measurement period specified by the
CellDynAcBarAlgoPara.DynAcBarStatPeriod parameter, the cell states obtained
using both policies within the period will be collected. The eNodeB determines
whether the cell is congested based on the obtained cell states.
For example, during a 20s measurement period, the flow control-based policy is
used in the first 10s, and the CPU usage-based policy is used in the next 10s. 20
cell states are obtained within the measurement period, with the first 10 states
obtained when the flow control policy is used and the second 10 states obtained
when the CPU usage policy is used. Based on these 20 cell states, the eNodeB
calculates the proportion of time during which the cell is congested to determine
whether the cell is congested within the measurement period.

4.3.1.1.3 Entry to Intelligent Access Class Control

If intelligent access class control is not triggered in the previous period, an initial
value of the access probability factor for MO signaling or MO data (specified by
the CellAcBar.AcBarringFactorForSig or CellAcBar.AcBarringFactorForCall
parameter) is configured by using the
CellDynAcBarAlgoPara.MoFactorInitialValue parameter.
After intelligent access class control is triggered, the eNodeB delivers settings of
AC control parameters in SIB2 to dynamically adjust the access probability factor
for the MO signaling or MO data (specified by the
CellAcBar.AcBarringFactorForSig or CellAcBar.AcBarringFactorForCall
parameter), as shown in Figure 4-3.

Figure 4-3 Adjusting the access probability factor

If a cell does not exit intelligent access control triggered in the previous period,
either of the following scenarios occurs:

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

● The cell is still congested and conditions for an exit from intelligent access
class control are not met.
The eNodeB adjusts the step based on the
CellDynAcBarAlgoPara.MoFactorAdjStep parameter to gradually reduce the
access probability factor of the cell and increase the proportion of barred UEs.
The minimum access probability factor is P05 (that is, 5%) to ensure that
some UEs can access the cell. If the cell does not recover from congestion
after the access probability factor is set to P05 (that is, 5%), then P05 (that is,
5%) is retained until the cell recovers from congestion.
● The cell recovers from congestion, but the number of consecutive periods
during which the cell recovers from congestion has not reached the value of
the CellDynAcBarAlgoPara.MoCancelCondSatiPeriods parameter.
The eNodeB adjusts the step based on the
CellDynAcBarAlgoPara.MoFactorRetreatStep parameter to gradually roll
back the access probability factor for MO signaling or MO data.
During adjustment, AC barring durations (specified by the
CellAcBar.AcBarTimeForCall and CellAcBar.AcBarTimeForSig parameters) are
the same as those configured for static AC control.

4.3.1.1.4 Exit from Intelligent Access Class Control

Intelligent access class control is canceled in either of the following scenarios:
● If both of the following conditions are met, the eNodeB sends SIB2 without
the settings of AC control parameters for MO signaling or MO data to cancel
AC control for MO signaling or MO data, and reports EVT-29252 Cell
Intelligent Access Class Control Event.
– The cell recovers from congestion.
– The number of consecutive periods in which the cell recovers from
congestion reaches the value of the
CellDynAcBarAlgoPara.MoCancelCondSatiPeriods parameter.
● ac-BarringFactor can only be set to P00 (that is, 0%) if any of the bits of ac-
BarringForSpecialAC for MO signaling and MO data are set to 1. In this case,
EVT-29252 Cell Intelligent Access Class Control Event is reported, and the
eNodeB exits from intelligent access class control. For details about the
parameters corresponding to ac-BarringForSpecialAC and ac-BarringFactor,
see Table 4-3.

4.3.1.2 Network Analysis

4.3.1.2.1 Benefits
This function is recommended only when a large number of UEs simultaneously
access the network, in the case of special events such as holidays, concerts, and
sporting events or in the case of disasters such as earthquakes and tsunamis. This
is because this function imposes impact on UE access experience. If UE access is
barred, the UE-perceived access delay increases.
If this function is enabled in a congested cell, new UEs may not be able to access
the network. However, if this impact is acceptable, this function can be enabled
permanently to relieve cell congestion, even unpredictable congestion.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

This function:

● Controls UE access for MO data or signaling to prevent a sharp increase in

signaling load.
● Performs dynamic AC control based on the cell congestion state without
manual intervention.

4.3.1.2.2 Impacts

Network Impacts
Enabling this function imposes the following network impacts:
● If this function is enabled when the CPU resource is sufficient (for example,
when the eNodeBFlowCtrlPara.DynAcBarPolicyMode parameter is set to
CPULOAD and the eNodeBFlowCtrlPara.CpuLoadThd parameter is set to a
value less than 80), a large number of UEs are barred from accessing the
network, affecting access experience. In addition, the BHCA specifications of
the base station may fail to be reached.
● If the RRC connection setup success rate decreases because of flow control on
the main control board or BBPs, or failures in resource allocation due to the
number of UEs exceeding the specifications, intelligent access class control
prevents some UEs from accessing the cell. This function relieves cell
congestion, increasing the RRC connection setup success rate. The increase in
the RRC connection setup success rate depends on the cell congestion level,
AC control parameter settings, and proportion of UEs that support AC control
on the network. If UE access is barred, the access experience will be affected.

Function Impacts
None

4.3.1.3 Requirements

4.3.1.3.1 Licenses

RAT Feature ID Feature Name Model Sales

Unit

FDD LOFD-070207 Intelligent Access LT1S00IACC00 per cell

Class Control

4.3.1.3.2 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.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Prerequisite Functions
RAT Function Function Reference Description
Name Switch

FDD System None Idle Mode AC control

information Manageme parameters are
broadcast nt broadcast in SIB2.

Mutually Exclusive Functions

None

4.3.1.3.3 Hardware

Base Station Models

No requirements

Boards
No requirements

RF Modules
No requirements

4.3.1.3.4 Others
UEs must support AC barring control defined in 3GPP Release 8 or later.

4.3.1.4 Operation and Maintenance

4.3.1.4.1 Data Preparation

Table 4-15 and Table 4-16 describe the parameters used for function activation
and optimization, respectively.

Table 4-15 Parameters used for activation

Parameter Name Parameter ID Option Setting Notes

AC barring CellAcBar.AcBarringInf None Set this parameter

information oCfgInd to CFG.
configure indicator

AcBar algorithms CellAlgoSwitch.AcBar ACBAR_S Select this option.

switch AlgoSwitch WITCH_DY
NAMIC

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Option Setting Notes

Ac Bar Algorithm CellAlgoSwitch.AcBar DYNAMIC_ Select this option.

Switch for Dynamic AlgoforDynSwitch FOR_MO

AC barring for CellAcBar.AcBarringFo None Set this parameter

mobile data rMoDataCfgInd to CFG.
configure indicator

AC barring for CellAcBar.AcBarringFo None Set this parameter

mobile signal rMoSigCfgInd to CFG.
configure indicator

Table 4-16 Parameters used for optimization

Parameter Name Parameter ID Setting Notes

Dynamic AC Barring CellDynAcBarAlgo- Set this parameter

Control Statistic Para.DynAcBarStatPeriod to its
Period recommended
value.

Dynamic AC Barring CellDynAcBarAlgo- Set this parameter

Control Trigger Para.DynAcBarTriggerThd to its
Threshold recommended
value.

Dynamic AC Barring CellDynAcBarAlgo- Set this parameter

Control Cancel Para.DynAcBarCancelThd to its
Threshold recommended
value.

RRC Reject Rate CellDynAcBarAlgo- Set this parameter

Congestion Trigger Para.RrcRejectCongTriggerThld to its
Thld recommended
value.

MO Trigger CellDynAcBarAlgo- Set this parameter

Condition Satisfied Para.MoTriggerCondSatiPeriods to its
Periods recommended
value.

MO Cancel CellDynAcBarAlgo- Set this parameter

Condition Satisfied Para.MoCancelCondSatiPeriods to its
Periods recommended
value.

MO Factor Initial CellDynAcBarAlgo- Set this parameter

Value Para.MoFactorInitialValue to its
recommended
value.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Setting Notes

MO Factor CellDynAcBarAlgo- Set this parameter

Adjusting Step Para.MoFactorAdjStep to its
recommended
value.

MO Factor CellDynAcBarAlgo- Set this parameter

Retreating Step Para.MoFactorRetreatStep to its
recommended
value.

UE-Number-based CellDynAcBarAlgo- Set this parameter

Congestion Thld Para.UeNumCongThld to its
recommended
value.

Ue-Number-based CellDynAcBarAlgo- Set this parameter

Congestion Clear Para.UeNumCongClearThld to its
Thld recommended
value.

Dynamic AC Barring eNodeBFlowCtrlPara.DynAcBarPoli Set this parameter

Policy Mode cyMode to its
recommended
value.

CPU Load Threshold eNodeBFlowCtrlPara.CpuLoadThd Set this parameter

to its
recommended
value.

4.3.1.4.2 Using MML Commands

Activation Command Examples

//Enabling intelligent access class control for MO data and MO signaling with the access probability factors
for MO data and MO signaling set to 95% and the average access barring duration set to 4s
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch=ACBAR_SWITCH_DYNAMIC,
AcBarAlgoforDynSwitch=DYNAMIC_FOR_MO-1;
MOD CELLACBAR: LocalCellId=0, AcBarringInfoCfgInd=CFG, AcBarringForMoDataCfgInd=CFG,
AcBarringForMoSigCfgInd=CFG, AcBarringFactorForCall=P95, AcBarringFactorForSig=P95,
AcBarTimeForCall=ACCESS_BARRING_TIME_S4, AcBarTimeForSig=ACCESS_BARRING_TIME_S4;

Optimization Command Examples

//Setting parameters related to intelligent access class control with the DynAcBarTriggerThd parameter set
to 100, DynAcBarCancelThd parameter set to 80, DynAcBarStatPeriod parameter set to 20,
MoTriggerCondSatiPeriods parameter set to 2, MoCancelCondSatiPeriods parameter set to 1,
MoFactorInitialValue parameter set to 95, MoFactorAdjStep parameter set to 1, MoFactorRetreatStep
parameter set to 0, RrcRejectCongTriggerThld parameter set to 100, and UeNumCongThld parameter set
to 0 (that is, this parameter does not take effect)
MOD CELLDYNACBARALGOPARA: LocalCellId=0, DynAcBarTriggerThd=100, DynAcBarCancelThd=80,
DynAcBarStatPeriod=20, MoTriggerCondSatiPeriods=2, MoCancelCondSatiPeriods=1,
MoFactorInitialValue=P95, MoFactorAdjStep=1, MoFactorRetreatStep=0, RrcRejectCongTriggerThld=100,
UeNumCongThld=0;
MOD ENODEBFLOWCTRLPARA: DynAcBarPolicyMode=FLOWCONTROL;

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Deactivation Command Examples

//Disabling the access barring function
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch=ACBAR_SWITCH_DISABLE;

4.3.1.4.3 Using the MAE-Deployment

For detailed operations, see Feature Configuration Using the MAE-Deployment.

4.3.1.4.4 Activation Verification

If the values of counters listed in Table 4-17 are not 0, this function has taken
effect.

Table 4-17 Counters related to intelligent access class control

Counter ID Counter Name

1526729499 L.Dyn.ACBar.Trigger.Num

1526729500 L.Dyn.ACBar.Cancel.Num

If the value of the CellAlgoSwitch.AcBarAlgoSwitch parameter is changed from

ACBAR_SWITCH_DYNAMIC to ACBAR_SWITCH_STATIC or
ACBAR_SWITCH_DISABLE when this function is triggered and still effective, the
values of counters listed in Table 4-17 will be slightly different from those in
scenarios without the change.

4.3.1.4.5 Network Monitoring

● Check whether the eNodeB reports EVT-29252 Cell Intelligent Access Class
Control. If the eNodeB reports this event, intelligent access class control has
been triggered. This event is cleared when intelligent access class control
stops.
● When intelligent access class control is triggered:
– Monitor the counters in Table 4-18. If the number of RRC connection
request discards or rejections due to flow control decreases, intelligent
access class control has taken effect.

Table 4-18 Number of times the RRC Connection Request message is

discarded due to flow control and number of times the eNodeB sends an
RRC Connection Reject message to the UE due to flow control

Counter ID Counter Name

1526728489 L.RRC.ConnReq.Msg.disc.FlowCtrl

1526728490 L.RRC.SetupFail.Rej.FlowCtrl

The decreased number of RRC connection request discards or rejections

depends on the proportion of UEs that support intelligent access class

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

control, access probability factor, and access barring duration. The more
congested the cell is and the higher the proportion of UEs that support
AC control, the more significant the gains provided by intelligent access
class control.
– Monitor the counters listed in Table 4-19. Observe the number of times
intelligent access class control parameters are adjusted and the duration
of intelligent access class control.

Table 4-19 Number of times intelligent access class control parameters

are adjusted and duration of intelligent access class control

Counter ID Counter Name

1526729501 L.Dyn.ACBar.Adjust.Num

1526729502 L.Dyn.ACBar.Control.Dur

● Monitor counters listed in Table 4-20. Observe the distribution of the access
probability factor delivered for intelligent access class control, the average
barring ratio, and the maximum barring ratio.

Table 4-20 Counters related to the access probability factor

Counter ID Counter Name

1526747693 L.Dyn.ACBarFactor.Num.P00

1526747694 L.Dyn.ACBarFactor.Num.P05

1526747695 L.Dyn.ACBarFactor.Num.P10

1526747696 L.Dyn.ACBarFactor.Num.P15

1526747697 L.Dyn.ACBarFactor.Num.P20

1526747698 L.Dyn.ACBarFactor.Num.P25

1526747699 L.Dyn.ACBarFactor.Num.P30

1526747700 L.Dyn.ACBarFactor.Num.P40

1526747701 L.Dyn.ACBarFactor.Num.P50

1526747702 L.Dyn.ACBarFactor.Num.P60

1526747703 L.Dyn.ACBarFactor.Num.P70

1526747704 L.Dyn.ACBarFactor.Num.P75

1526747705 L.Dyn.ACBarFactor.Num.P80

1526747706 L.Dyn.ACBarFactor.Num.P85

1526747707 L.Dyn.ACBarFactor.Num.P90

1526747708 L.Dyn.ACBarFactor.Num.P95

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Counter ID Counter Name

1526747709 L.Dyn.ACBarFactor.Avg

1526747710 L.Dyn.ACBarFactor.Min

4.3.2 Dynamic SSAC

4.3.2.1 Principles
The eNodeB dynamically determines whether to adjust and deliver settings of AC
control parameters in a cell based on the cell disaster and congestion states.
This function takes effect when both of the following conditions apply:
● The CellAlgoSwitch.AcBarAlgoSwitch parameter is set to
ACBAR_SWITCH_DYNAMIC.
● The DYNAMIC_FOR_SSAC option of the
CellAlgoSwitch.AcBarAlgoforDynSwitch parameter is selected.
If intelligent access class control cannot be enabled, ensure that the
DYNAMIC_FOR_MO option of the CellAlgoSwitch.AcBarAlgoforDynSwitch
parameter is deselected.

4.3.2.1.1 Overall Procedure

Figure 4-4 shows how this function works.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Figure 4-4 Process of dynamic SSAC

In the preceding figure, the CellAcBar.AcBarForMVoiceCfgInd and

CellAcBar.AcBarForMVideoCfgInd parameters specify the access barring
configuration indicators for MMTel voice and MMTel video, respectively.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.3.2.1.2 Triggering of Dynamic SSAC

The eNodeB periodically checks whether a cell is congested and in the disaster
state. The period is specified by the CellDynAcBarAlgoPara.DynAcBarStatPeriod
parameter. When the number of consecutive periods during which a cell is
congested and in the disaster state reaches the
CellDynAcBarAlgoPara.SsacTriggerCondSatiPeriods parameter, dynamic SSAC is
triggered.
● Cell disaster state checking
– The cell enters a disaster state when it receives an earthquake and
tsunami warning system (ETWS) primary notification (PN) or CMAS
message configured by the
CellDynAcBarAlgoPara.DisasterReferenceInd parameter for the cell.
– The disaster state duration is specified by the
CellDynAcBarAlgoPara.DisasterDuration parameter. The cell exits the
disaster state when this duration ends.
The timer specified by the CellDynAcBarAlgoPara.DisasterDuration
parameter is independent of the
CellDynAcBarAlgoPara.DisasterReferenceInd parameter. The timer starts
when the cell receives a disaster notification message.
● Cell congestion checking
For details about how the eNodeB determines whether a cell is congested or
recovers from congestion, see 4.3.1.1.2 Triggering of Intelligent Access Class
Control.

4.3.2.1.3 Entry to Dynamic SSAC

If dynamic SSAC is not triggered in a cell in the previous period, set the access
probability factor for MMTel voice or MMTel video to P95 (that is, 95%).
The eNodeB delivers settings of AC control parameters in SIB2 after dynamic SSAC
is triggered to dynamically adjust the access probability factor for MMTel voice or
MMTel video (specified by the CellAcBar.AcBarFactorForMVoice or
CellAcBar.AcBarFactorForMVideo parameter). For details about the adjustment
mechanism, see Figure 4-3.
If dynamic SSAC is triggered in the cell in the previous period and the cell does not
exit dynamic SSAC:
● When the cell is congested and in a disaster state, and conditions for exit
from dynamic SSAC are not met
The eNodeB adjusts the step based on the
CellDynAcBarAlgoPara.SsacFactorAdjStep parameter to gradually reduce
the access probability factor of the cell and increase the proportion of barred
UEs.
The minimum access probability factor is P05 (that is, 5%) to ensure that
some UEs can access the cell. If the cell is still congested even with an access
probability factor of P05 (that is, 5%), P05 (that is, 5%) is retained until the
cell recovers from congestion.
● When the cell is not in the congestion and disaster states at the same time
but the number of consecutive periods during which the cell recovers from
congestion or a disaster does not reach the
CellDynAcBarAlgoPara.SsacCancelCondSatiPeriods parameter

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

The eNodeB rolls back the step based on the

CellDynAcBarAlgoPara.SsacFactorRetreatStep parameter value to gradually
roll back the access probability factor for MMTel voice or MMTel video.
During adjustment, AC barring durations (specified by the
CellAcBar.AcBarTimeForMVoice and CellAcBar.AcBarTimeForMVideo
parameters) are the same as the duration configured for static AC control.

4.3.2.1.4 Exit from Dynamic SSAC

The eNodeB sends SIB2 without the settings of AC control parameters for MMTel
voice or video to cancel AC control if both of the following conditions apply:
● The cell is not in congestion and disaster states at the same time.
● The number of consecutive periods during which the cell recovers from the
congestion or disaster state reaches the value of the
CellDynAcBarAlgoPara.SsacCancelCondSatiPeriods parameter.

4.3.2.2 Network Analysis

4.3.2.2.1 Benefits
This function is recommended only at special events where a large number of UEs
initiate MMTel voice or video services, for example, at holiday celebration,
concerts, sporting events, earthquakes, or tsunamis. This is because this function
has an impact on access experience. If UE access is barred, the perceived access
delay increases.
This function:
● Controls UE access for MMTel voice or video services to prevent network
congestion and ensure that UEs originating data services can promptly access
the disaster bulletin information on the network.
● Performs dynamic AC control based on the disaster state and cell congestion
state without manual intervention.

4.3.2.2.2 Impacts

Network Impacts
This function has the following network impacts:
● If this function is enabled when the CPU resource is sufficient (for example,
when the eNodeBFlowCtrlPara.DynAcBarPolicyMode parameter is set to
CPULOAD and the eNodeBFlowCtrlPara.CpuLoadThd parameter is set to a
value less than 80), a large number of UEs are barred from accessing the
network, affecting access experience. In addition, the BHCA specifications of
the base station may fail to be reached.
● If the RRC connection setup success rate decreases because of flow control on
the main control board or BBPs, dynamic SSAC prevents some UEs from
accessing the cell. This function relieves cell congestion, increasing the RRC
connection setup success rate. The increase in the RRC connection setup
success rate depends on the cell congestion level, AC control parameter
settings, and proportion of UEs that support AC control on the network. If UE
access is barred, the access experience will be affected.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Function Impacts
None

4.3.2.3 Requirements

4.3.2.3.1 Licenses

Feature ID Feature Name Model Sales Unit

LOFD-008002 Dynamic Service- LT1S0DSSAC00 Per Cell

specific Access Control

4.3.2.3.2 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 Function Reference Description
Name Switch

FDD System None Idle Mode AC control parameters are

information Managemen broadcast in SIB2.
broadcast t
FDD Earthquake None ETWS This function is required if
and Tsunami the CellDynAcBarAlgo-
Warning Para.DisasterReferenceInd
System parameter is set to
(ETWS) ETWS_PN or
ETWS_PN_TEST.

FDD Commercial None CMAS This function is required if

Mobile Alert the CellDynAcBarAlgo-
System Para.DisasterReferenceInd
parameter is set to CMAS.

Mutually Exclusive Functions

None

4.3.2.3.3 Hardware

Base Station Models

No requirements

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Boards
No requirements

RF Modules
No requirements

4.3.2.3.4 Others
UEs must support AC barring control defined in 3GPP Release 9 or later.

4.3.2.4 Operation and Maintenance

4.3.2.4.1 Data Preparation

Table 4-21 and Table 4-22 describe the parameters used for function activation
and optimization, respectively.

Table 4-21 Parameters used for activation

Parameter Name Parameter ID Option Setting Notes

AC barring CellAcBar.AcBarring None Set this parameter

information InfoCfgInd to CFG.
configure indicator

AcBar algorithms CellAlgoSwitch.AcB ACBAR_SWITC Select this option.

switch arAlgoSwitch H_DYNAMIC

Ac Bar Algorithm CellAlgoSwitch.AcB DYNAMIC_FO Select this option.

Switch for Dynamic arAlgoforDynSwitch R_SSAC
AC barring for CellAcBar.AcBarFor None Set this parameter
MMTEL voice MVoiceCfgInd to CFG.
configure indicator

AC barring for CellAcBar.AcBarFor None Set this parameter

MMTEL video MVideoCfgInd to CFG.
configure indicator

Table 4-22 Parameters used for optimization

Parameter Name Parameter ID Setting Notes

Dynamic AC CellDynAcBarAlgo- Set this parameter

Barring Control Para.DynAcBarStatPeriod to its
Statistic Period recommended
value.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Setting Notes

Dynamic AC CellDynAcBarAlgo- Set this parameter

Barring Control Para.DynAcBarTriggerThd to its
Trigger Threshold recommended
value.

Dynamic AC CellDynAcBarAlgo- Set this parameter

Barring Control Para.DynAcBarCancelThd to its
Cancel Threshold recommended
value.

Disaster Reference CellDynAcBarAlgo- Set this parameter

Indication Para.DisasterReferenceInd to its
recommended
value.

Disaster Duration CellDynAcBarAlgo- Set this parameter

Para.DisasterDuration to its
recommended
value.

Ssac Trigger CellDynAcBarAlgo- Set this parameter

Condition Satisfied Para.SsacTriggerCondSatiPeriods to its
Periods recommended
value.

Ssac Cancel CellDynAcBarAlgo- Set this parameter

Condition Satisfied Para.SsacCancelCondSatiPeriods to its
Periods recommended
value.

SSAC Factor CellDynAcBarAlgo- Set this parameter

Adjusting Step Para.SsacFactorAdjStep to its
recommended
value.

SSAC Factor CellDynAcBarAlgo- Set this parameter

Retreating Step Para.SsacFactorRetreatStep to its
recommended
value.

UE-Number-based CellDynAcBarAlgo- Set this parameter

Congestion Thld Para.UeNumCongThld to its
recommended
value.

Ue-Number-based CellDynAcBarAlgo- Set this parameter

Congestion Clear Para.UeNumCongClearThld to its
Thld recommended
value.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Parameter Name Parameter ID Setting Notes

Dynamic AC eNodeBFlowCtrlPara.DynAcBarPoli Set this parameter

Barring Policy Mode cyMode to its
recommended
value.

CPU Load eNodeBFlowCtrlPara.CpuLoadThd Set this parameter

Threshold to its
recommended
value.

4.3.2.4.2 Using MML Commands

Activation Command Examples

//Enabling dynamic SSAC for MMTel voice and video with the access probability factors for MMTel voice
and MMTel video set to 95% and the average access barring duration set to 4s
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch=ACBAR_SWITCH_DYNAMIC,
AcBarAlgoforDynSwitch=DYNAMIC_FOR_SSAC-1;
MOD CELLACBAR: LocalCellId=0, AcBarringInfoCfgInd=CFG, AcBarForMVoiceCfgInd=CFG,
AcBarForMVideoCfgInd=CFG, AcBarFactorForMVoice=P95, AcBarFactorForMVideo=P95,
AcBarTimeForMVoice=ACCESS_BARRING_TIME_S4, AcBarTimeForMVideo=ACCESS_BARRING_TIME_S4;

Optimization Command Examples

//Setting parameters related to dynamic SSAC with the DynAcBarTriggerThd parameter set to 100,
DynAcBarCancelThd parameter set to 80, DynAcBarStatPeriod parameter set to 20,
SsacTriggerCondSatiPeriods parameter set to 2, SsacCancelCondSatiPeriods parameter set to 1,
DisasterReferenceInd parameter set to ETWS_PN, DisasterDuration parameter set to 60,
SsacFactorAdjStep parameter set to 1, SsacFactorRetreatStep parameter set to 0, DynAcBarPolicyMode
parameter set to FLOWCONTROL, and UeNumCongThld parameter set to 0 (that is, this parameter does
not take effect)
MOD CELLDYNACBARALGOPARA: LocalCellId=0, DynAcBarTriggerThd=100, DynAcBarCancelThd=80,
DynAcBarStatPeriod=20, SsacTriggerCondSatiPeriods=2, SsacCancelCondSatiPeriods=1,
DisasterReferenceInd=ETWS_PN-1, DisasterDuration=60, SsacFactorAdjStep=1, SsacFactorRetreatStep=0,
UeNumCongThld=0;
MOD ENODEBFLOWCTRLPARA: DynAcBarPolicyMode=FLOWCONTROL;

Deactivation Command Examples

//Disabling the access barring function
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch= ACBAR_SWITCH_DISABLE;

4.3.2.4.3 Using the MAE-Deployment

For detailed operations, see Feature Configuration Using the MAE-Deployment.

4.3.2.4.4 Activation Verification

If the values of counters listed in Table 4-23 are not 0, this function has taken
effect.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Table 4-23 Counters related to activation verification of dynamic SSAC

Counter ID Counter Name

1526736656 L.SSAC.Dyn.ACBar.Trigger.Num

1526736658 L.SSAC.Dyn.ACBar.Cancel.Num

If the value of the CellAlgoSwitch.AcBarAlgoSwitch parameter is changed from

ACBAR_SWITCH_DYNAMIC to ACBAR_SWITCH_STATIC or
ACBAR_SWITCH_DISABLE when this function is triggered and still effective, the
values of counters listed in Table 4-23 will be slightly different from those in
scenarios without the change.

4.3.2.4.5 Network Monitoring

When this function is triggered:
● Monitor the counters in Table 4-24. If the number of RRC connection request
discards or rejections due to flow control decreases, dynamic SSAC has taken
effect.

Table 4-24 Counters related to network monitoring for dynamic SSAC

Counter ID Counter Name

1526728489 L.RRC.ConnReq.Msg.disc.FlowCtrl

1526728490 L.RRC.SetupFail.Rej.FlowCtrl

The decreased number of RRC connection request discards or rejections

depends on the proportion of UEs that support dynamic SSAC, the access
probability factor, and the access barring duration. If a cell is seriously
congested because a large number of UEs simultaneously initiate access for
MMTel voice and video and the proportion of UEs that support dynamic SSAC
is high, dynamic SSAC can achieve high gains.
● Monitor the counters listed in Table 4-25. Observe the number of times
dynamic SSAC parameters are adjusted and the duration of dynamic SSAC.

Table 4-25 Number of times dynamic SSAC parameters are adjusted and
duration of dynamic SSAC
Counter ID Counter Name

1526736657 L.SSAC.Dyn.ACBar.Adjust.Num

1526736659 L.SSAC.Dyn.ACBar.Control.Dur

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.4 Operator-specific AC Control

4.4.1 Principles

Operator-specific Cell Reservation

If a cell needs to be reserved for a specified operator, UEs of AC 11 or AC 15 and
running in the HPLMN/EHPLMN use this cell as a candidate cell during cell
selection or reselection. However, UEs of other ACs consider this cell as a barred
cell during cell selection or reselection. This function is controlled by the
CellOp.CellReservedForOp parameter.

● If the CellOp.CellReservedForOp parameter is set to

CELL_NOT_RESERVED_FOR_OP for a cell, the cell is not reserved for a
specified operator. In this case, all UEs can use this cell as a candidate cell
during cell selection or reselection.
● If the CellOp.CellReservedForOp parameter is set to
CELL_RESERVED_FOR_OP for a cell, the cell is reserved for a specified
operator.
● If the CellOp.CellReservedForOp parameter is set to
CELL_DYNAMIC_RESERVED_FOR_OP, the cell is reserved for a specified
operator when dynamic AC control is triggered and the reservation is canceled
after the cell exits from dynamic AC control.

AC Control Specific to Primary and Secondary Operators

If access barring information needs to be broadcast specific to operators, the
CellAcBar.AcBarringInfoCfgInd parameter can be set to OPERATOR_BASED_CFG.

When the CellAcBar.AcBarringInfoCfgInd parameter is set to

OPERATOR_BASED_CFG:

● If the CellAlgoSwitch.AcBarAlgoSwitch parameter is set to

ACBAR_SWITCH_STATIC, AC control does not apply to the primary operator
and static AC control applies to secondary operators.
● If the CellAlgoSwitch.AcBarAlgoSwitch parameter is set to
ACBAR_SWITCH_DYNAMIC, dynamic AC control applies to the primary
operator and static AC control applies to secondary operators. In this case, the
ac-BarringFactor value of the primary operator is not less than that of any
secondary operator.
NOTE

For details about the primary and secondary operators, see RAN Sharing.

4.4.2 Network Analysis

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.4.2.1 Benefits

Operator-specific Cell Reservation

If a cell is reserved for a specified operator, UEs of AC 0 to AC 9 or those of AC 12
to AC 14 cannot reselect to the cell. This greatly reduces the cell load.

AC Control Specific to Primary and Secondary Operators

● If AC control is not performed for the primary operator and static AC control
applies to secondary operators, refer to 4.2.2.1 Benefits for details about the
benefits.
● If dynamic AC control is performed for the primary operator and static AC
control applies to secondary operators, refer to 4.3.1.2.1 Benefits or 4.3.2.2.1
Benefits for details about the benefits.

4.4.2.2 Impacts

Network Impacts
When a cell is reserved for a specified operator, the values of the following
performance counters may change:

● Decrease in the board CPU usage

● Decrease in the number of RRC connection setup requests
● Decrease in the number of initial context setup requests
● Decrease in the random access requests
● Possible increase in the RRC connection setup success rate
● Possible decrease in the cell throughput
● Decrease in the air resource usage for cell

For AC control specific to primary and secondary operators:

● If AC control is not performed for the primary operator and static AC control
applies to secondary operators, there is no impact on the network.
● If dynamic AC control is performed for the primary operator and static AC
control applies to secondary operators, refer to 4.3.1.2.2 Impacts or 4.3.2.2.2
Impacts for details about the impact.

Function Impacts
None

4.4.3 Requirements

4.4.3.1 Licenses
There are no license requirements.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.4.3.2 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 Function Reference Description
Name Switch

FDD System None Idle Mode AC control parameters

information Managem are broadcast in SIB2.
broadcast ent

Mutually Exclusive Functions

None

4.4.3.3 Hardware

Base Station Models

No requirements

Boards
No requirements

RF Modules
No requirements

4.4.3.4 Others
For AC control specific to primary and secondary operators, UEs must support the
AC control mechanisms defined in 3GPP Release 12 or later.

4.4.4 Operation and Maintenance

4.4.4.1 Data Preparation

Table 4-27 describes the parameters used for function activation.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Table 4-26 Parameters used for activating operator-specific cell reservation

Parameter Name Parameter ID Setting Notes

Cell reserved for CellOp.CellReservedFo ● If a cell does not need to be

operator rOp reserved for a specified
operator, set this parameter
to
CELL_NOT_RESERVED_FOR_
OP.
● If a cell needs to be reserved
for a specified operator, set
this parameter to
CELL_RESERVED_FOR_OP.
● If a cell needs to be reserved
for a specified operator when
dynamic AC control is
triggered, set this parameter
to
CELL_DYNAMIC_RESERVED_
FOR_OP.

Table 4-27 Parameters used for activating AC control specific to primary and
secondary operators
Parameter Name Parameter ID Setting Notes

AC barring information CellAcBar.AcBarringI Set this parameter to

configure indicator nfoCfgInd OPERATOR_BASED_C
FG.

AcBar algorithms switch CellAlgoSwitch.AcBar If AC control is not

AlgoSwitch performed for the
primary operator and
static AC control
applies to secondary
operators, set this
parameter to
ACBAR_SWITCH_STA
TIC.
If dynamic AC control
is performed for the
primary operator and
static AC control
applies to secondary
operators, set this
parameter to
ACBAR_SWITCH_DYN
AMIC.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.4.4.2 Using MML Commands

Activation Command Examples

//Operations required when a cell does not need to be reserved for a specified operator
MOD CELLOP: LocalCellId=0, TrackingAreaId=1, CellReservedForOp=CELL_NOT_RESERVED_FOR_OP;
//Operations required when AC control is not performed for the primary operator and static AC control
applies to secondary operators
MOD CELLACBAR: LocalCellId=0, AcBarringInfoCfgInd=OPERATOR_BASED_CFG;
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch=ACBAR_SWITCH_STATIC;
//Operations required when dynamic AC control is performed for the primary operator and static AC control
applies to secondary operators
MOD CELLACBAR: LocalCellId=0, AcBarringInfoCfgInd=OPERATOR_BASED_CFG;
MOD CELLALGOSWITCH: LocalCellId=0, AcBarAlgoSwitch= ACBAR_SWITCH_DYNAMIC;

Deactivation Command Examples

//Disabling the access barring function
MOD CELLACBAR: LocalCellId=0, AcBarringInfoCfgInd=NOT_CFG;

4.4.4.3 Using the MAE-Deployment

For detailed operations, see Feature Configuration Using the MAE-Deployment.

4.4.4.4 Activation Verification

Operator-specific Cell Reservation

If a cell is not reserved for a specified operator, check the Uu interface tracing
result on the MAE-Access and observe that the value of the
cellReservedForOperatorUse IE for the specified operator in SIB1 is notReserved.
If a cell is reserved for a specified operator or the cell is reserved for a specified
operator when dynamic AC control is triggered, check the Uu interface tracing
result on the MAE-Access and observe that the value of the
cellReservedForOperatorUse IE for the specified operator in SIB1 is reserved, as
shown in Figure 4-5.

Figure 4-5 SIB1 message tracing result

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

AC Control Specific to Primary and Secondary Operators

If dynamic AC control is performed for the primary operator and static AC control
applies to secondary operators, check the Uu interface tracing result on the MAE-
Access and observe that the value of ac-BarringFactor for the primary operator in
SIB2 is not less than that for secondary operators.

4.4.4.5 Network Monitoring

None

4.5 AC Bar Skipping

4.5.1 Principles
When the network is congested due to simultaneous network access of a large
number of UEs, intelligent access class control is triggered to allow voice UEs to
preferentially access the network during the AC control, improving the voice UE
experience.
Voice UEs include:
● UEs that initiate MMTel voice services
● UEs that initiate MMTel video services
● UEs that send SMSs
This function is controlled by the AcBarForVoLTEPreferSwitch option of the
CellAlgoSwitch.VoLTESwitch parameter.
Figure 4-6 shows how this function works.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

Figure 4-6 AC bar skipping process

The AC bar skipping configuration indicators in the preceding figure are

configured using the parameters listed in Table 4-28.

Table 4-28 AC bar skipping configuration indicators

AC Bar Skipping Parameter

Configuration Indicator

MMTEL voice bar skipping MMTELVoicePreferCfgInd option of the

configure indicator CellAcBar.VoLTEPreferCfgInd parameter

MMTEL video bar skipping MMTELVideoPreferCfgInd option of the

configure indicator CellAcBar.VoLTEPreferCfgInd parameter

SMS voice bar skipping SMSPreferCfgInd option of the

configure indicator CellAcBar.VoLTEPreferCfgInd parameter

4.5.2 Network Analysis

4.5.2.1 Benefits
When the network is congested and AC control is triggered, this function allows
more UEs that originate MMTel voice, MMTel video, or SMS services to access the
network, improving access experience of such UEs.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.5.2.2 Impacts

Network Impacts
None

Function Impacts
None

4.5.3 Requirements

4.5.3.1 Licenses
There are no license requirements.

4.5.3.2 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 Function Reference Description
Name Switch

FDD System None Idle Mode AC control parameters

information Managemen are broadcast in SIB2.
broadcast t

Mutually Exclusive Functions

None

4.5.3.3 Hardware

Base Station Models

No requirements

Boards
No requirements

RF Modules
No requirements

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.5.3.4 Others
UEs must support AC bar skipping defined in 3GPP Release 12 or later.

4.5.4 Operation and Maintenance

4.5.4.1 Data Preparation

Table 4-29 describes the parameters used for function activation.

Table 4-29 Parameters used for activation

Parameter Parameter ID Option Setting Notes

Name

VoLTE Switch CellAlgoSwitch.VoLTESwitc AcBarForVoLT Select this

h EPreferSwitch option.

VoLTE CellAcBar.VoLTEPreferCfgIn None Set this

Preference d parameter
Configuration based on site
Indication conditions.

4.5.4.2 Using MML Commands

Activation Command Examples

//Enabling the AC bar skipping function
MOD CELLALGOSWITCH: LocalCellId=0, VoLTESwitch=AcBarForVoLTEPreferSwitch-1;
//Setting parameters related to AC bar skipping with the MMTELVoicePreferCfgInd,
MMTELVideoPreferCfgInd, and SMSPreferCfgInd options selected
MOD CELLACBAR: LocalCellId=0,
VoLTEPreferCfgInd=MMTELVoicePreferCfgInd-1&MMTELVideoPreferCfgInd-1&SMSPreferCfgInd-1;

Deactivation Command Examples

//Disabling the AC bar skipping function
MOD CELLALGOSWITCH: LocalCellId=0, VoLTESwitch=AcBarForVoLTEPreferSwitch-0;

4.5.4.3 Using the MAE-Deployment

For detailed operations, see Feature Configuration Using the MAE-Deployment.

4.5.4.4 Activation Verification

On the MAE, observe whether settings of the following IEs related to AC bar
skipping are included in SIB2 traced over the Uu interface.
● ac-BarringSkipForMMTELVoice-r12
● ac-BarringSkipForMMTELVideo-r12
● ac-BarringSkipForSMS-r12
If yes, this function has taken effect.

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Access Class Control Feature Parameter Description 4 eNodeB AC Control

4.5.4.5 Network Monitoring

None

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Access Class Control Feature Parameter Description 5 UE AC Control

5 UE AC Control

UEs perform access decision after receiving settings of AC control parameters from
the eNodeB, as shown in Figure 5-1.

Figure 5-1 Access decision procedures

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Access Class Control Feature Parameter Description 5 UE AC Control

For details about access decision on the access barring information types in the
preceding figure, see the following sections:
● 5.1 Emergency Call Access Decision Procedure
● 5.2 MO Data Access Decision Procedure
● 5.3 MO Signaling Access Decision Procedure
● 5.4 AC Bar Skipping Decision Procedure
● 5.5 MMTel Voice Access Decision Procedure
● 5.6 MMTel Video Access Decision Procedure
● 5.7 CSFB Access Decision Procedure

5.1 Emergency Call Access Decision Procedure

Figure 5-2 shows the access decision making procedure for emergency calls in the
AS.

Figure 5-2 Access decision making procedure for emergency calls

5.2 MO Data Access Decision Procedure

Figure 5-3 shows the access decision making procedure for MO data in the AS.

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Access Class Control Feature Parameter Description 5 UE AC Control

Figure 5-3 Access decision making procedure for MO data

For the AC bar skipping decision procedure, see 5.4 AC Bar Skipping Decision
Procedure.

5.3 MO Signaling Access Decision Procedure

Figure 5-4 shows the access decision making procedure for MO signaling in the
AS.

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Access Class Control Feature Parameter Description 5 UE AC Control

Figure 5-4 Access decision making procedure for MO signaling

For the AC bar skipping decision procedure, see 5.4 AC Bar Skipping Decision
Procedure.

5.4 AC Bar Skipping Decision Procedure

Only UEs that support AC bar skipping defined in 3GPP Release 12 and later can
support this feature.
After receiving access control parameters, the UEs that have initiated MMTel voice
or video services or UEs that have initiated SMS services will not be barred but
preferentially allowed to access the network.
Decisions are made in the AS for the UEs to determine whether to ignore the AC
barring parameters of MMTel voice, MMTel video, and SMS.
Figure 5-5 shows the access decision making procedure that UEs perform after
receiving AC bar skipping parameters.

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Access Class Control Feature Parameter Description 5 UE AC Control

Figure 5-5 AC bar skipping decision making procedure

5.5 MMTel Voice Access Decision Procedure

Figure 5-6 shows the access decision making procedure for MMTel voice services
in the NAS. If the access of a UE running MMTel voice services is allowed in the
NAS and AC control parameters for MO data are available, the UE performs the
access decision procedure again in the AS, as shown in Figure 5-6.

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Access Class Control Feature Parameter Description 5 UE AC Control

Figure 5-6 Access decision making procedure for MMTel voice

5.6 MMTel Video Access Decision Procedure

Figure 5-7 shows the access decision making procedure for MMTel video services
in the NAS. If the access of a UE running MMTel video services is allowed in the
NAS and AC control parameters for MO signaling are available, the UE performs
the access decision procedure again in the AS, as shown in Figure 5-7.

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Access Class Control Feature Parameter Description 5 UE AC Control

Figure 5-7 Access decision making procedure for MMTel video

5.7 CSFB Access Decision Procedure

UEs use the following rules to make access decisions on CSFB:
● If AC control parameters delivered by the eNodeB contain CSFB-related
parameters, these parameters are used.
If access to an E-UTRAN cell is barred during CSFB, the UE selects a GERAN or
UTRAN cell using a cell reselection procedure to originate a call, preventing
user experience from being affected. For details, see section 5.6.1.6 "Abnormal
cases in the UE" in 3GPP TS 24.301 V10.0.0.
● If AC control parameters delivered by the eNodeB do not contain CSFB-
related parameters, AC control parameters for MO data are used.
Figure 5-8 shows the access decision making procedure for CSFB in the AS.

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Access Class Control Feature Parameter Description 5 UE AC Control

Figure 5-8 Access decision making procedure for CSFB

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Access Class Control Feature Parameter Description 6 Parameters

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.
NOTE

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?

Step 1 Open the EXCEL file of parameter reference.

Step 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.

Step 3 Click OK. All parameters related to the feature are displayed.

----End

FAQ 2: How do I find the information about a certain reserved parameter

from the used reserved parameter list?

Step 1 Open the EXCEL file of the used reserved parameter list.

Step 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.

----End

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Access Class Control Feature Parameter Description 7 Counters

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.
NOTE

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?

Step 1 Open the EXCEL file of performance counter reference.

Step 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.
Step 3 Click OK. All counters related to the feature are displayed.

----End

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Access Class Control Feature Parameter Description 8 Glossary

8 Glossary

For the acronyms, abbreviations, terms, and definitions, see Glossary.

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Access Class Control Feature Parameter Description 9 Reference Documents

9 Reference Documents

● 3GPP TS 36.331: "Radio Resource Control (RRC)"

● 3GPP TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet
System (EPS); Stage 3"
● 3GPP TS 22.011: "Service accessibility"
● 3GPP TS 23.122, "Non-Access-Stratum (NAS) functions related to Mobile
Station (MS) in idle mode"
● Flow Control
● CMAS
● ETWS
● Idle Mode Management
● RAN Sharing

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