Feature State Dynamic QoS Modification

Dynamic QoS Modification

USER DESCRIPTION

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Copyright

© Ericsson AB 2012. All rights reserved. No part of this document may bereproduced in any form without the written permission of the copyright owner.

Disclaimer

The contents of this document are subject to revision without notice due tocontinued progress in methodology, design and manufacturing. Ericsson shallhave no liability for any error or damage of any kind resulting from the useof this document.

Trademark List

All trademarks mentioned herein are the property of their respective owners.These are shown in the document Trademark Information.

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Contents

Contents

1 Introduction 1

1.1 Basic Characteristics 1

1.2 Benefits 2

1.3 Further Information 2

2 Feature Operation 3

2.1 Network Requirements 3

2.2 Feature Operation Sequence Diagram 3

2.3 Process steps 4

3 Parameters 7

3.1 Introduced Parameters 7

3.2 Affected Parameters 7

4 Network Impact 9

5 Associated Features and Affected Functions 11

5.1 Prerequisite Features 11

5.2 Affected Features 11

5.3 Related Features 11

5.4 Affected System Functions 11

6 Performance 13

6.1 KPI 13

6.2 Counters 13

6.3 Events 13

7 O&M Information 15

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Introduction

1 Introduction

This document describes the Dynamic QoS Modification feature and its mainbenefits and impacts in the LTE RAN.

The information in this document reflects the feature at the time of its release.

The Dynamic QoS Modification feature provides the possibility to modify theQuality of Service (QoS) profile, as defined by 3GPP, for an already establishedbearer. The Mobility Management Entity (MME) provides a QoS profile whilstthe definition of QoS Class Indicator (QCI) is given by configurable parametersin RBS.

The QoS profile for a bearer consists of the following parameters:

• QCI is handled in RBS as a reference to a set of configurable attributes, forexample, priority and packet delay budget for a bearer. It also determineswhich bearers are categorized as Guaranteed Bit Rate (GBR) and whichare categorized as non-GBR bearers. It is further described in Quality ofService

• Allocation and Retention Priority (ARP) specifies the relative importancecompared to other E-UTRAN Radio Access Bearers (E-RABs) for allocationand retention of the E-RAB.

• GBR defines the minimum bit rate which can be expected to be madeavailable to the GBR-bearer when required. GBR exist in an Uplink (UL)and a Downlink (DL) component.

• Maximum Bit Rate (MBR) defines the maximum bit rate that can beexpected to be made available to the GBR-bearer when required. MBRexists in an UL and a DL component.

1.1 Basic Characteristics

Feature identity:FAJ 121 1749, Dynamic QoS Modification

Replaces: N/A

Dependencies

This feature requires the following RAN features to be active:

• No prerequisite features are required.

This feature affects the following RAN features:

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• No features are affected.

1.2 Benefits

The Dynamic QoS Modification feature allows Evolved Packet Core (EPC)to dynamically modify the QoS profile for a Data Radio Bearer (DRB) andtherefore change the end-user experience of an application.

1.3 Further Information

Further information about related topics can be found in the followingdocumentation:

• End-user Bitrate Shaping

• Dynamic GBR Admission Control

• Scheduler

• QoS-Aware Scheduler

• Differentiated Admission Control

• TCP Optimization

• 3GPP TS 36.413

• 3GPP TS 36.331

• 3GPP TS 23.203

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Feature Operation

2 Feature Operation

This section describes the Dynamic QoS Modification feature in more detail,including network configuration requirements and operation flows. Eachparameter possible to modify is described together with its affect on RBSfeatures and functions.

2.1 Network Requirements

The following network configuration prerequisites must be fulfilled at featureactivation:

• The Dynamic QoS Modification feature license must be present. TheDynamicQoSModification MO holds the licensing parameters for thefeature.

Details on the process required to load and activate a license can be found inLicense Management

2.2 Feature Operation Sequence Diagram

The Dynamic QoS Modification feature is activated by MME using the S1APE-RAB Modify procedure. Depending on what Information Element (IE)must be modified, the feature might involve the User Equipment (UE) in themodification procedure using the RRC Connection Reconfiguration procedure.The E-RAB Modify Response contains the outcome of the modification requestper E-RAB. If the outcome is unsuccessful the result also includes a causevalue indicating the reason for the failure. Figure 1 shows the E-RAB ModifyProcedure sequence diagram.

L0000571A

UE RBS

RRCConnectionReconfiguration

RRCConnectionReconfigurationComplete

MME

E-RAB MODIFY REQUEST

E-RAB MODIFY RESPONSE

Figure 1 E-RAB Modify Procedure

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2.3 Process steps

This section describes the main process steps for the Dynamic QoSModification feature flow. The section describes in detail what features areinfluenced when modifying a QoS parameter.

2.3.1 Modification impact in eNB

Table 1 gives a description of the Dynamic QoS Modification-related IEs andthe associated feature.

Table 1 Modification Impact

IE in E-RABmodify request

Associated feature

QCI QCI represents a number of configured attributes furtherdescribed in the Quality of Service feature.

ARP ARP modification is related to the bearer pre-emptionfunctionality described in the Differentiated AdmissionControl feature.

GBR An increase of GBR will activate the Dynamic GBRAdmission Control feature.

MBR The sum of MBR for all E-RABs is input to End-user BitrateShaping feature.

NAS If the Non-Access Stratum (NAS) message is present inthe E-RAB modify request signal it is sent to the UE after asuccessful RBS internal E-RAB modification.

2.3.2 Allowed QCI Transitions

Since the QCI value has a considerable impact on the E-RAB behavior,the modification of QCI is governed by certain rules to make sure that anundesirable behavior is avoided. The QCI serves as a reference to attributesstored in the RBS in the Managed Object Module (MOM) table QciTablewhere the parameters rlcSNLength, pdcpSNLength , rlcMode, rohcEnabled,resourceType, aqmMode, and dataFwdPerQciEnabled are included. TheManaged Object Model RBS provide full details of these parameters.

The following rules must be met to allow a QCI modification:

• A QCI modification whereby the resourceType change value from GBR to anon-GBR or vice versa is not allowed.

• A QCI modification whereby the rlcSNLength, pdcpSNLength, or rlcModechange its value is not allowed.

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Feature Operation

• If the ROHC feature is OPERABLE and the UE has capabilities for RobustHeader Compression, it is not allowed to modify the QCI such that thevalue of rohcEnabled would change

• If the IntraLTEHODataFwd feature is OPERABLE, it is not allowed to modifythe QCI such that the value of dataFwdPerQciEnabled would change.

• A QCI modification whereby the aqmMode changes its value so that thePacket Data Convergence Protocol (PDCP) parameter discard timer, asdefined in 3GPP TS 36.331, will change its value is not allowed.

Inability to comply to the rules above leads to modification failure of the E-RABwith the cause set to Not supported QCI value.

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Parameters

3 Parameters

This section describes parameters introduced by the Dynamic QoS Modificationfeature, and parameters affected by activating the feature.

3.1 Introduced Parameters

The implementation of this feature introduces no new parameters.

3.2 Affected Parameters

The implementation of this feature directly affects no parameters.

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Network Impact

4 Network Impact

There is no impact on the network resulting from the implementation of theDynamic QoS Modification feature.

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Associated Features and Affected Functions

5 Associated Features and AffectedFunctions

This section describes how the Dynamic QoS Modification feature affects otherfeatures and functions.

5.1 Prerequisite Features

There are no prerequisite features for this feature.

5.2 Affected Features

This feature affects no other feature.

5.3 Related Features

The related features are described in Table 1.

5.4 Affected System Functions

This feature affects no system functions.

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Performance

6 Performance

This section describes performance indicators, counters, and events associatedwith the Dynamic QoS Modification feature.

6.1 KPI

This feature has no associated Key Performance Indicators (KPIs).

6.2 Counters

Table 2 Counters

Counter Description

pmErabModAttQci Number of E-RAB Modify attempts per QCI

pmErabModSuccQci Number of successful E-RAB Modify attempts per QCI

pmErabModFailLic Number of failed E-RAB Modify attempts due to licensereject

6.3 Events

The important events associated with the Dynamic QoS Modification featureare listed in Table 3.

Table 3 Events

Event Event Parameter Description

INTERNAL_PROC_ERAB_MODIFY

EVENT_PARAM_ERAB_MODIFY_RESULT

EVENT_PARAM_ERAB_QCI

Displays the included parametersin the S1AP signal E-RAB ModifyRequest and also the result of themodification in the S1AP signalE-RAB Modify Response.

INTERNAL_EVENT_ERAB_DATA_INFO

EVENT_PARAM_ERAB_GBR

EVENT_PARAM_ERAB_ARP

The EVENT_PARAM_ERAB_GBRdisplays the GBR value in DLdirection

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O&M Information

7 O&M Information

This section provides Operation and Maintenance (O&M) information for thefeature.

A license is required to activate this feature.

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Documents

Feature State Dynamic QoS Modification