Uplink eul fach

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Enhanced Uplink for FACH

USER DESCRIPTION

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Copyright

© Ericsson AB 2012-2015. 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 Information 2

1.2 Benefits 3

1.3 Additional Information 3

2 Feature Description 5

2.1 Network Requirements 5

2.2 Technical Description 5

3 Parameters 11

3.1 Introduced Parameters 11

3.2 Affected Parameters 12

4 Network Impact 13

4.1 Subscriber Capacity 13

4.2 Network Performance 13

4.3 Hardware 13

4.4 Inter-Node Interface 14

4.5 Other Network Elements 14

5 Associated Features and Affected Functions 15

5.1 Prerequisite Features 15

5.2 Affected Features 15

5.3 Related Features 15

5.4 Affected System Functions 16

6 Performance 17

6.1 KPIs 17

6.2 Counters 17

6.3 Events 19

7 Operation and Maintenance 21

7.1 Activating the Feature 21

7.2 Deactivating the Feature 22

7.3 Engineering Guidelines 22

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Introduction

1 Introduction

This document describes the Enhanced Uplink for FACH feature and its mainbenefits and impacts in the WCDMA RAN. The Enhanced Uplink for FACHfeature is also referred to as EUL-FACH.

Enhanced Uplink for FACH is a 3GPP optional feature for Rel-8 and later UserEquipments (UEs).

Enhanced Uplink for FACH introduces the use of the E-DCH transport channelinstead of the message part of the RACH transport channel in Idle Mode,URA_PCH and CELL_FACH state. This feature is used together with the HighSpeed Downlink for FACH feature, which implies that the HS-DSCH transportchannel is used for downlink (DL) in CELL_FACH state.

Figure 1 shows the transport channels used for DL and uplink (UL) for a UE inCELL_FACH state in R99 and the ones used when the High Speed Downlinkfor FACH feature is supported by both the UE and the cell, in contrast with thetransport channels used by a UE in CELL_FACH state when the EnhancedUplink for FACH feature is also supported.

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a)

In R99

FACH

RACH

High Speed Downlink for FACHis supported by the cell and the UE (but not Enhanced Uplink for FACH)

b)

HS-DSCH

RACH

Enhanced Uplink for FACHis supported by the cell and the UE

HS-DSCH

c)

E-DCH

Figure 1 Transport channels for UE in Idle Mode, URA_PCH or CELL_FACHstate.

1.1 Basic Information

This section describes the basic characteristics of the feature.

Feature identity:FAJ 121 1652, Enhanced Uplink for FACH

Release: Introduced in release W12.1

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Introduction

Dependencies

This feature requires the following RAN features to be active:

• Enhanced Uplink Introduction Package, FAJ 121 1023

• Improved Layer 2 UL, FAJ 121 1516

• High Speed Downlink for FACH, FAJ 121 1537

This feature affects the following RAN features:

• If Enhanced Uplink for FACH, FAJ 121 1652 is activated, High SpeedDownlink for FACH improves its efficiency, for link adaptation, with theChannel Quality Information (CQI) delivered by the UE at EUL-FACHaccesses. This improves the capacity of HS-DSCH.

• If Enhanced Uplink for FACH, FAJ 121 1652 is activated, the UEs usingBattery Efficiency for High Speed FACH have their response timesimproved since DL transmissions are allowed during the periods when theUE uses a common E-DCH.

1.2 Benefits

This section describes the benefits of this feature.

The Enhanced Uplink for FACH feature provides the following benefits:

• Improved end-user experience in CELL_FACH state by providing fasterpacket delivery for applications with low to medium data requirements, forexample, social media applications.

• Faster transition from CELL_FACH state to CELL_DCH state.

• Higher UL bandwidth for UEs in CELL_FACH state.

• Reduction of channel switching between CELL_FACH state andCELL_DCH state owing to the improved UL capacity in CELL_FACH state,and the resulting decrease in the amount of load due to channel switching.

1.3 Additional Information

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

• Physical Layer Procedures. TS 25.214.

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Feature Description

2 Feature Description

This section describes the Enhanced Uplink for FACH feature in more detail,including network configuration requirements and operation flows.

2.1 Network Requirements

The following must be fulfilled at feature activation:

• The license key for FAJ 121 1652, Enhanced Uplink for FACH is installed.

The feature requires that the UEs are Enhanced Uplink for FACH-capable.Support for Enhanced Uplink for FACH is optional for 3GPP Rel-8 and later.

2.2 Technical Description

This section provides the technical description of the feature.

2.2.1 Main Description

When Enhanced Uplink for FACH is activated in a cell, information forsupporting the replacement of the message part of the RACH transport channelby the E-DCH transport channel in Idle Mode, URA_PCH and CELL_FACHstate is broadcast in the System Information Block (SIB) on the BroadcastCommon Channel (BCCH). The EUL-FACH broadcast information includes thecommon E-DCH parameters and the random-access preamble signatures. AnEnhanced Uplink for FACH-capable UE is able to understand the EUL-FACHinformation in the SIB.

The RBS manages two types of resources, common E-DCH and hardware(HW) decoders. The common E-DCH resources consist of a configurationcomprising F-DPCH and E-HICH signature in DL and by DPCCH, HS-DPCCH,E-DPCCH and E-DPDCH in UL. A HW decoder is defined as the required HWto provide the use of a common E-DCH. The necessary HW decoders arestatically allocated and pooled for each Baseband (BB) pool in one ReceiverModule (RXM).

Extended Acquisition Indicator (E-AI) allows for the configuration of 32 commonE-DCH resources in a cell. Any of these resources can be allocated to UE,irrespective of which preamble signature (configured for EUL-FACH) the UEselects.

The random-access preamble signatures for EUL-FACH users are a subsetof the 16 random-access signatures available in a cell, while the remainingsignatures are used for R99 RACH access. The network identifies the

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random-access type, R99 RACH or EUL-FACH, according to the signaturereceived.

For acquiring a common E-DCH, the preamble ramping procedure on therandom-access is the same as for R99 RACH, except that only the dedicatedsignatures configured for EUL-FACH are used. For the message part there is adifference, instead of sending one Protocol Data Unit (PDU) for each accessas for R99 RACH, the UE starts sending consecutive 10 ms TransmissionTime Intervals (TTIs) E-DCH frames. There is no rate regulation for commonE-DCH, but the initial granted rate defined for each cell by the parametereulFachInitialRate is kept during the entire access time.

Figure 2 shows the random-access procedure and the data transmission forR99 RACH and EUL-FACH users. First, the UE performs preamble ramping,1 in Figure 2. As soon as the RBS properly detects the preamble, it sendsan Acquisition Indicator (AI) and an E-AI on the AICH, 2 in Figure 2. Then,EUL-FACH users transmit continuously on common E-DCH, 3b in Figure 2, incontrast to R99 RACH, 3a in Figure 2.

AICH

1

2 3a Legacy UEs

3b EUL_FACH capable UEs

E-DCH

PRACH20 ms

10 ms

Figure 2 Data transmission for R99 RACH and EUL-FACH users.

3GPP introduces a synchronization establishment procedure of Authenticationand Authorization (AA) in Physical Layer Procedures, TS 25.214. Afterreception of a positive Acquisition Indicator (AI), EUL-FACH users start a newAA procedure, which provides faster synchronization time.

By default, for EUL-FACH users, the initial power setting in the preambleramping is based on the dynamic UL interference level broadcast in SIB type 7(SIB7), as for release 99 design.

Once a common E-DCH is acquired, the inner-loop power control algorithmsfor the different channels is performed as in release 99 design. The outer-looppower control on the DPCCH is not performed, since the holding time for acommon E-DCH is expected to be short. Instead of setting the target SIR byusing the outer-loop power control, the target SIR defined by the parameterulSirTarget is used for inner-loop power control.

When the Enhanced Uplink for FACH feature is activated, there is CQIreporting. The CQI report is carried on HS-DPCCH and is sent only in

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Feature Description

dedicated signalling and user data traffic transmissions. This CQI knowledgemakes it possible to improve the HSDPA scheduler efficiency in comparisonto the activation of only the High Speed Downlink for FACH feature, since inthat case CQI reports are not sent.

For more information about power control, refer to Power Control. For moreinformation about CQI, refer to HSDPA User Plane.

2.2.2 Data Transmissions

2.2.2.1 User identification

An Enhanced Radio Network Temporary Identity (E-RNTI) is required fortransmitting on a common E-DCH. An E-RNTI is assigned to an EUL-FACH UEwhenever the UE is in CELL_FACH state and is allocated or deallocated whenthe UE changes the cell or changes RRC state from CELL_FACH.

The E-RNTI is also used for collision resolution on DTCH and DCCHtransmissions. A collision occurs when two UEs accidentally gain accessto the network using the same signature in the same access slot and acommon E-DCH is granted to both. For collision resolution, the UE attachesthe E-RNTI to each transmission during the initial phase by means of aspecial MAC-i header. Once a transmission is successfully decoded, theRBS sends an Absolute Grant (AG) with the UE E-RNTI. This acknowledgesthat the UE successfully acquires the C-EDCH. The UEs stop sendingdata if they do not receive an AG within the time defined by the parametermaxCollisionResTime. The parameter maxCollisionResTime isbroadcast in SIB type 5 (SIB5).

2.2.2.2 Termination

EUL-FACH access is terminated in different ways, depending on thetransmission. Figure 3 gives a timing overview for the common E-DCHresources release scenarios.

After the AI is transmitted, EUL-FACH access is considered failed if there is noUL synchronization, as shown in 1 in Figure 3. When the RBS achieves ULsynchronization and data is not correctly decoded because of unsuccessfulcollision resolution or limited coverage, the access is considered failed and theHW resources are deallocated, as shown in 2 in Figure 3.

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First expected DPCCH frame

DPCCH

E-DPDCH

Delay of E-DPDCH after starting DPCCH

First expected E-DPDCH frame

1. Release due to lack of synchronization

2. Release due to no data correctly decoded

3a. Release due to holding time exceeds maxCcchTime

3b. Release due to holding time exceeds

4. Release due to triggering an upswitch

Upswitch to CELL_DCH

eulFachMaxDcchDtchTime

Figure 3 Timing overview for the common E-DCH resources releasescenarios.

For CCCH and DCCH/DTCH transmissions, the resources are implicitlyreleased when the UE finishes the transmission by sending a SchedulingInformation (SI) with buffer status zero to the RBS. The resources areexplicitly released if the holding time exceeds the time configured by theparameter maxCcchTime for CCCH transmissions, 3a in Figure 3, andeulFachMaxDcchDtchTime for DCCH/DTCH transmissions, 3b in Figure 3.

Also, the common E-DCH resources are released and the HW resourcesare deallocated when the UE performs upswitching to CELL_DCH state, 4in Figure 3.

2.2.3 Configuration Information

• The number of preamble signatures to be used for EUL-FACH in a cell isdefined by the parameter numPreambleSignatures.

• The number of common E-DCH resources in the cell that are shared by allEUL-FACH users is defined with the parameter cEdchResourcesEai.

• Enhanced Uplink for FACH introduces an alternative static setting for the ULinterference level broadcast in SIB5 so that the UE does not have to readSIB7 to update the expired values. For using the default configuration in theinitial power setting for the preamble ramping, that is, using the dynamicUL interference level, the parameter initInterferenceUl is set to 0.Alternatively, the static UL interference level is used and is defined by theparameter initInterferenceUl, if it is set to a value different than 0.

• For EUL-FACH users, a HW decoder consists of the UL CEs needed toreceive the E-DCH at the data rate defined by eulFachInitialRate

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Feature Description

and the DL CEs needed to transmit the F-DPCH. The RBS parametereulFachMinAllocation sets the number of pooled static HW resourcesfor EUL-FACH, for each BB Pool. A pooling concept is used to lower CEconsumption, which means that the statically allocated HW decoders forEUL-FACH are shared between all cells in the BB pool.

• The eulFachInitialRate is set in the RBS and is communicated tothe RNC as a Serving Grant at feature activation through NBAP: PhysicalShared Channel Reconfiguration Response. The Serving Grant is thenbroadcast through SIB5. The parameter eulFachInitialRate is definedfor each cell and changes in its value are applied after deactivating andactivating the feature.

• The Enhanced Uplink for FACH feature introduces the possibility of settingthe initial power for transmissions on F-DPCH and UL DPCCH, to securethe initial synchronization. The parameter initFdpchPower is used forF-DPCH and initDpcchPower is used for UL DPCCH.

• The Enhanced Uplink for FACH feature has a configurable power offsetfor CQI on HS-DPCCH, which is used only for EUL-FACH transmissions,defined by the parameter deltaCqi.

• For EUL-FACH users, two different Iub common flows are set upfor carrying the data in the Transport Network (TN), the first forsignalling data and the second for user data traffic. As for CELL_DCHusers, the mapping between SPI and TN QoS attributes is defined byTnlHspaQosClassProfile, for both signalling data and user datatraffic flows. The common flow for signalling data has Scheduling PriorityIndicator (SPI) 15, which means that it has absolute priority. The commonflow for user data traffic has configurable SPI defined by the parametereulFachSpi. The parameter eulFachSpi defines the SPI for the userdata traffic common flow and influences its TN QoS attributes.

Note: For more information on TnlHspaQosClassProfile, refer toFigure 9 in QoS configuration.

• A different threshold for triggering event 4a can be used forEUL-FACH users. This threshold is set by the parameterulRlcBufUpswitchEulFach and is broadcast in SIB type 12 (SIB12).

For more information about channel switching, refer to Channel Switching.

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Parameters

3 Parameters

This section describes parameters introduced by the Enhanced Uplink forFACH feature and parameters affected by activating the feature.

3.1 Introduced Parameters

Table 1 describes the parameters introduced by the feature.

Table 1 Introduced Parameters

Parameter Description

RBS parameters

licenseStateEulFach

(read-only)

Indicates the license state for the Enhanced Uplink for FACHfeature.

featureStateEulFach Defines the feature state for the Enhanced Uplink for FACHfeature.

eulFachMinAllocation Defines the number of pooled static HW resources for EUL-FACH,for each BB Pool.

eulFachInitialRate Defines the initial granted rate (RLC) to EUL-FACH users.

eulFachMaxDcchDtchTime Defines the maximum number of TTIs that a user is allowed totransmit on C-EDCH for DCCH and DTCH transmissions.

RNC parameters

EulFach.operationalState

(read-only)

Indicates the operational state of the EUL-FACH resources inthe cell.

EulFach.administrativeState Defines the administrative state of the EUL-FACH resources inthe cell.

EulFach.availabilityStatus

(read-only)

Indicates the availability status of the EUL-FACH resources inthe cell.

initInterferenceUl Defines the UL interference to be used by EUL-FACH users forinitial power settings in preamble ramping. Setting it to 0 disablesthe parameter, that is, the parameter is not included in SIB5.

numPreambleSignatures Defines the number of signatures to be used for EUL-FACH ina cell.

cEdchResourcesEai Defines the number of C-EDCH resources to be used forEUL-FACH in a cell.

maxCollisionResTime For EUL-FACH users, it defines the maximum time that a usercan transmit E-DPDCH without receiving an absolute grant forresolving collision resolution phase.

maxCcchTime Defines the maximum time during which a user is allowed totransmit E-DPCCH for CCCH transmissions.

ulSirTarget Defines the Sir target to be applied to E-DCH for EUL-FACHusers.

ulRlcBufUpswitchEulFach Provides the UL RLC buffer threshold for upswitching fromCELL_FACH to CELL_DCH for EUL-FACH users.

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initFdpchPower Provides the initial power for F-DPCH for EUL-FACH users,relative to primary CPICH power.

initDpcchPower Provides the power offset for DPCCH referred to the power of thelast preamble for EUL-FACH users.

deltaCqi Defines the power offset for CQI report messages on HS-DPCCHfor UE Connections using EUL-FACH.

eulFachSpi Points to the instance of the TnlQosClass, under this profile,that contains the QoS settings for EUL-FACH user data over Iub.

eulFachEnabled Enables or disables EUL-FACH feature on RNC level. When thisparameter is activated, EUL-FACH is activated in all cells thatfulfill the activation requirements.

eulFachCapable

(read-only)

Indicates whether the cell is EUL-FACH-capable or not asreported by the RBS. This, however, does not mean thatEUL-FACH is active in the cell.

eAiCapable

(read-only)

Indicates whether the RBS has reported that the cell is E-AIcapable.

3.2 Affected Parameters

Table 2 describes the parameters affected by this feature.

Table 2 Affected Parameters


Rach::preambleSignatures Preamble signatures for PRACH. For details onthe dependency between this parameter and theintroduced parameter numPreambleSignatures,see Section 7.3 on page 22.

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Network Impact

4 Network Impact

This section describes how the Enhanced Uplink for FACH feature impactsthe network functions and capabilities.

4.1 Subscriber Capacity

This section provides information on the impact of the feature on subscribercapacity.

EUL-FACH-capable UEs can stay longer in CELL_FACH state thannon-EUL-FACH-capable users, depending on the channel switching parametersetting, which can increase the number of users in the cell.

4.2 Network Performance

This section provides information on the impact of the feature on networkperformance.

The RNC processor load can be reduced by having potentially less channelswitches between CELL_FACH state and CELL_DCH state, depending on thesetting of the channel switching threshold.

This feature improves efficiency of UL transmissions for UEs in CELL_FACH,which implicitly decreases the number of upswitches to CELL_DCH state,depending on the channel switching threshold.

The introduction of faster access times can itself trigger a larger traffic volumesince the end users have less waiting time.

As the 16 random-access signatures available in a cell are split betweenEUL-FACH and R99 RACH, the number of signatures available for R99 RACHis reduced, since the EUL-FACH signatures are seen by the other CELL_FACHusers as not available.

EUL-FACH does not support soft or softer handover procedures.

When deactivating EUL-FACH in a cell, all EUL-FACH users are released.3GPP compliant UEs can read SIB5 with the new parameters in all other RRCstates and Idle Mode seamlessly.

4.3 Hardware

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

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This feature requires the DUW hardware to be installed.

4.4 Inter-Node Interface

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

The following interfaces are affected when the feature is activated:

• Uu interface

• Iub interface

4.5 Other Network Elements

No feature specific information is identified.

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Associated Features and Affected Functions

5 Associated Features and AffectedFunctions

This section describes how the Enhanced Uplink for FACH feature affectsother features and functions.

5.1 Prerequisite Features

Table 3 lists prerequisite features to the Enhanced Uplink for FACH feature,that is, they must be active prior to introducing the Enhanced Uplink for FACHfeature.

Table 3 Prerequisite Features

Feature Description

Enhanced Uplink Introduction Package,

FAJ 121 1023

This feature provides a group of functions that improve thesystem capabilities to handle UL packet-switched data.

Improved Layer 2 UL,

FAJ 121 1516

This feature enables a configurable RLC PDU size andsupports MAC-i/is on a single carrier.

High Speed Downlink for FACH,

FAJ 121 1537

This feature introduces the replacement of the DL FACHtransport channel by the HS-DSCH transport channel if the UEand the network or cell have the appropriate support.

5.2 Affected Features

Table 4 lists features that are affected by the Enhanced Uplink for FACH feature.

Table 4 Affected Features

Feature Description

�-Coverage,

FAJ 121 1679

If the FAJ 121 1652: Enhanced Uplink for FACH featureis activated, the FAJ 121 1679: �-Coverage feature is notsupported.

Transmit Diversity,

FAJ 121 1128

If the FAJ 121 1128: Transmit Diversity feature is activated,the FAJ 121 1652: Enhanced Uplink for FACH feature is notsupported.

5.3 Related Features

Table 5 lists features that are related to the Enhanced Uplink for FACH feature.

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Table 5 Related Features

Feature Description

Configurable transport bearer QoSclass,

FAJ 121 966

The activation of this feature makes it possible to influence the TNQoS attributes for the user data traffic flow by using the parametereulFachSpi, otherwise the preconfigured values are used.

5.4 Affected System Functions

Table 6 lists functions affected by the Enhanced Uplink for FACH feature.

Table 6 Affected System Functions

Function Description

Synchronization If the FAJ 121 1652: Enhanced Uplink for FACH feature is activated, the newprocedure AA is used for EUL-FACH users.

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Performance

6 Performance

This section describes performance indicators, counters, and events associatedwith the Enhanced Uplink for FACH feature.

6.1 KPIs

Table 7 lists the main Key Performance Indicators (KPIs) associated with theEnhanced Uplink for FACH feature.

Table 7 KPIs

KPI Description

PintEulFach_U_User Gives the average number of PS Interactive EUL-FACH users perUtranCell.

For more information about KPIs, refer to Radio Network KPI.

6.2 Counters

Table 8 lists the counters associated with the Enhanced Uplink for FACHfeature.

Table 8 Counters

Counter Description

RBS counters

pmNegativeMessagesEulFach Indicates the number of negative Acquisition Indicator (AI)messages sent on the Acquisition Indicator Channel (AICH) forEUL-FACH-assigned signatures.

pmPositiveMessagesEulFach Indicates the number of positive Acquisition Indicator (AI)messages sent on the Acquisition Indicator Channel (AICH) forEUL-FACH-assigned signatures.

pmAccessIntensityRach Indicates the number of RACH accesses during a samplingperiod.

pmAccessIntensityEulFach Indicates the number of EUL-FACH accesses during a samplingperiod.

pmLCEdch Provides the C-EDCH Uu load estimate in a cell. Includesa component from E-DPDCH, E-DPCCH and DPCCH forEUL-FACH users in the cell, but not from the HS-DPCCH.

pmUlSynchTimeFromCEdch Indicates the synchronization time between DL TX resourceassignment (when AAL2 or IP connection is established overIub) and achievement of UL synchronization for RL, whichbelongs to the first RLS. The counter applies to EUL-FACH usersupswitching from CELL_FACH to CELL_DCH and seamlessupswitch is performed.

pmFirstDecodedFrameEulFach Indicates the frame number when E-DPDCH data is first correctlydecoded.

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Counter Description

RBS counters

pmNoActive10msFramesEulFach Indicates the number of used 10 ms frames (TTI) in which data isreceived in C-EDCH for all EUL-FACH users.

pmNoActive10msIntervalsEulFach

Provides the total amount of 10 ms intervals in a cell in whichthe transmission of one or more E-DCH frames is detected forEUL-FACH users.

pmSumAckedBitsCellEulFach Indicates the total amount of acknowledged data received afterHARQ process on MAC-i level for all EUL-FACH 10 ms TTI usersin a cell.

pmSumNackedBitsCellEulFach Indicates the total amount of non-acknowledged data receivedafter HARQ process on MAC-i level for all EUL-FACH 10 ms TTIusers in a cell.

pmEulFachHarqTransm Provides the number of HARQ transmissions attempted untilcorrect reception.

pmEulFachHarqTransmFailure Provides the number of HARQ failures for EUL-FACH traffic.

pmNoUsersCEdchEul Indicates the number of simultaneous EUL-FACH users.Increased bin is the number of simultaneous C-EDCH resourcesbeing allocated in the cell at that moment.

pmCEdchReleaseCause Indicates the C-EDCH release cause.

pmBurstLengthEulFach Provides the total number of bits acknowledged (MAC level) inan EUL-FACH access. This counter only applies to DCCH/DTCHtransmissions and not to CCCH transmissions.

RNC Counters

pmSamplesEulFachPsIntRabEst Provides the number of samples recorded within the ResultOutput Period (ROP) for pmSumEulFachPsIntRabEst.

pmSumEulFachPsIntRabEst Provides the addition to this counter of the values that are readperiodically from an internal level counter for the number ofestablished PS RABs in state CELL_FACH for UEs currentlyusing EUL-FACH.

pmEulFachMacisPduTti10DelPsRabs

Indicates the number of MAC-is PDUs, corresponding to the PSRBs with TTI = 10 ms, which are delivered to MAC-d within theROP by the MAC-is reordering function for UEs in CELL_FACHusing EUL-FACH.

pmEulFachMacisPduTti10UndelPsRab

Indicates the number of MAC-is PDUs, corresponding to the PSRBs with TTI = 10 ms, which the MAC-is reordering functioncannot deliver within the ROP. This applies only to Ues inCELL_FACH using EUL-FACH. A MAC-is PDU cannot bedelivered if it has a TSN less than that of a PDU received earlierand is received outside the reception window defined for theMAC-is re-ordering function.

pmEulFachMacisPduTti10DelivSrb

Indicates the number of MAC-is PDUs, corresponding to theSRB with TTI = 10 ms, which are delivered to MAC-d within theROP by the MAC-is reordering function for UEs in CELL_FACHusing EUL-FACH.

pmEulFachMacisPduTti10UndelivSrb

Indicates the number of MAC-is PDUs, corresponding to the SRBwith TTI = 10 ms, which the MAC-is reordering function cannotdeliver within the ROP. This applies only to Ues in CELL_FACHusing EUL-FACH. A MAC-is PDU cannot be delivered if it hasa TSN less than that of a PDU received earlier and is receivedoutside the reception window defined for the MAC-is reorderingfunction.

pmUlTrafficVolumePsIntEulFach

Indicates the payload in the UL for the PS RAB on EUL-FACH.SRB is excluded. Payload traffic volume includes user data,Medium Access Control (MAC) and Radio Link Control (RLC)header information and retransmissions, but not control frames.

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Performance

Counter Description

RBS counters

pmNoCellFachDiscAbnormEulFach

Indicates the number of abnormal disconnections from commonchannels (for example, CELL_FACH state) for EUL-FACH users.

Modified counters: RNC

pmTotNoRrcConnectUeCapability

Indicates the number of times that a UE with certain capabilitiessuccessfully sets up an RRC connection. Expanded for alsoincluding a bin for EUL-FACH capability.

For more information about counters, refer to Managed Object Model RBS andManaged Object Model RNC.

6.3 Events

Enhanced Uplink for FACH is included as a new connection property forGeneral Performance Event Handling (GPEH).

The following event parameters EVENT_PARAM_SOURCE_CONNECTION_PROPERTIES_EXT, EVENT_PARAM_TARGET_CONNECTION_PROPERTIES_EXT andEVENT_PARAM_WANTED_CONNECTION_PROPERTIES_EXT are updated in theRNC to indicate if the source connection, the target connection and the wantedconnection are using Enhanced Uplink for FACH.

For more information about events, refer to General Performance EventHandling RNC.

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Operation and Maintenance

7 Operation and Maintenance

This section provides Operation and Maintenance (O&M) information for theEnhanced Uplink for FACH feature.

7.1 Activating the Feature

7.1.1 Preconditions

The preconditions for activation of FAJ 121 1652: Enhanced Uplink for FACHare:

• The FAJ 121 1023: Enhanced Uplink Introduction Package is activated.

• The FAJ 121 1516: Improved Layer 2 UL is activated.

• The FAJ 121 1537: High speed downlink for FACH is activated.

7.1.2 Activating

The feature is activated in a cell by:

• Ordering and installing the FAJ 121 1652: Enhanced Uplink for FACH withlicense key CXC 402 0064.

• Setting the RBS parameter featureStateEulFach = ACTIVATED.

• Setting the RNC parameter eulFachEnabled = TRUE.

• Creating an instance of the EulFach MO under Eul MO representingthe cell where EUL-FACH is activated. For information on the EulFachMO, refer to Cells and Channels.

• Setting the RNC parameter EulFach.AdministrativeState =UNLOCKED.

Note: This step affects all the traffic in the cell, since the cell is temporarilydeactivated when it is set to UNLOCKED .

When Enhanced Uplink for FACH is activated, the following read-onlyparameters can be used for checking several aspects:

• licenseStateEulFach monitors the license validity. licenseStateEulFach = ENABLED if the license is valid.

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• EulFach.operationalState monitors the operational state of theEUL-FACH resources in the cell. EulFach.operationalState =ENABLED if the EUL-FACH resources are operational.

• EulFach.availabilityStatus monitors the availability status ofthe EUL-FACH resources. More than one condition can apply for thisparameter.

• eulFachCapable monitors the EUL-FACH capability of thecell. eulFachCapable=TRUE is set by the RNC if the cell isEUL-FACH-capable.

• eAiCapable monitors the E-AI capability of the cell. The RNC setseAiCapable=TRUE if the RBS reports that it is E-AI capable.

For more information about licenses, refer to Licenses and Hardware ActivationCodes.

7.2 Deactivating the Feature

7.2.1 Preconditions

This feature has no preconditions for deactivating.

7.2.2 Deactivating

The feature FAJ 121 1652: Enhanced Uplink for FACH is deactivated:

• On the cell level, by setting the RBS parameter featureStateEulFach= DEACTIVATED for each cell.

• On the RNC level, by setting the RNC parameter eulFachEnabled =FALSE.

For more information about licenses, refer to Licenses and Hardware ActivationCodes.

7.3 Engineering Guidelines

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

• The cost in terms of UL CEs for EUL-FACH depends on the configured ULrate NodeBFunction::eulFachInitialRate, number of configuredHW decoders NodeBFunction::eulFachMinAllocation and numberof cells in RBS. Page 23 shows mapping from eulFachInitialrate tothe minimum SF. Combining this with used E-DCH CE ladder and numberof cells gives a total reduction of CEs from the licensed CE pool.

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Table 9 Mapping from eulFachInitialrate to Minimum SF

eulFachInitialRate value (kbps) Minimum SF

0-34 SF256 or SF64 or SF32 (same CEcost for SF256, SF64, SF32 in allladders)

35-70 SF16

71-150 SF8

151-689 SF4

690-1376 SF2

For example, the cost is 1 CE for a HW Decoder with 32 kbps. IfeulFachInitialRate is set to a higher value, then the cost increases.Number of HW decoders for EUL-FACH eulFachMinAllocation areconfigured and pooled for each BB pool. To observe the level of HW decoders,use the pmNoUsersCedchEul counter.

• The feature can be tuned to carry more traffic load in CELL_FACH state, bykeeping larger portion of bursty traffic in the CELL_FACH state for eachEUL-FACH UE. Short bursts are handled more efficiently by EUL or HSresources in CELL_FACH state, compared to CELL_DCH state. Thisoffloads NW resources used in the CELL_DCH state and enables theseresources to handle more traffic with continuous data flows instead.

This can be achieved by a combined tuning of the following set ofparameters:

� eulFachInitialrate

� ulRlcBufUpswitchEulFach

� dlRlcBufUpswitchHsFach

� eulFachMaxDcchDtchTime

Handling of larger UL burst can be made by increasing theupswitch threshold parameters, with combination of increasingthe UL rate. This is though under the restriction by the time-outof timer set by eulFachMaxDcchDtchTime. The parametereulFachMaxDcchDtchTime sets a maximum limit for holdingtime of the Common E-DCH resource for transfer of UL data. RBSexplicitly releases the resources (air and HW resources), if length ofUL data transmission exceeds this limit. The recommended value ofeulFachMaxDcchDtchTime is around 200 ms to avoid degradation of RLat mobility and to keep blocking rate low.

The principle is to have about 35-40% margin until time-out of theeulFachMaxDcchDtchTime timer. For UL transfer of data sizesup to ulRlcBufUpswitchEulFach bytes, using maximal UL rate

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eulFachInitialRate. This allows for some margin because of ULE-DCH Harq retransmissions and PDU segmentation due to coverage.

The dimensioning can be made by using the following guiding formula:

eulFachMaxDcchDtchTime = 1.7 x (ulRlcBufUpswitchEulFach/ eulFachInitialRate)

Keeping more traffic in CELL_FACH reduces the NW signalingbetween CELL_FACH and CELL_DCH state, by avoidingunnecessary upswitches. The DL triggered upswitch occursmore often if ulRlcBufUpswitchEulFach is set larger thandlRlcBufUpswitchHsFach and vice versa. Appropriate levels dependson the traffic pattern.

Default parameters setting are based on an initial rate of 34 kbps definedby the parameter eulFachInitialRate.

• If the blocking rate of preamble signatures for EUL-FACHbecomes too high, because of an increasing portion of EUL-FACHcapable UEs, then an increase in the of number of HW decoders(NodeBFunction::eulFachMinAllocation) and/or preamblesignatures (EulFach::numPreambleSignatures) can be required.

The need for an increase to EulFach::numPreambleSignatures canbe determined by checking Prach::pmAccessIntensityRach andPrach::pmAccessIntensityEulFach, and distributing the signaturesbetween R99 RACH and EUL-FACH in the same relation as reflected inthese counters.

Blocking can occur because of shortage of C-EDCH resources or HWdecoders, or both. Shortage of C-EDCH resources can be addressed byallocating more EulFach::cEdchResourcesEai to EUL-FACH.

Blocking rates can be observed by the following KPIs:

PreambleNackRateCEDCH = Aich.pmNegativeMessagesEulFach[0]/ (sum(Aich.pmNegativeMessagesEulFach) + Aich.pmPositiveMessagesEulFach) x 100

PreambleNackRateHW = Aich.pmNegativeMessagesEulFach[1] /(sum(Aich.pmNegativeMessagesEulFach) + Aich.pmPositiveMessagesEulFach) x 100

It is recommended to set the number of remaining signatures for RACH atthe enough high value, to avoid RACH signature collisions.

The blocking rate is also dependant on holding time of CommonE-DCH HW resources and access intensity of EUL-FACH UEs.Minimum number of required EUL-FACH signatures and HW decoderscan be calculated based on holding time and average of accessintensity. Distribution of holding time and access intensity can be

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observed by EdchResources::pmBurstLengthEulFach andAich::pmAccessIntensityEulFach pm counters.

• The RBS rejects the set-up of the number of HW decoders defined byeulFachMinAllocation if at the feature set up there are not enoughCEs to be allocated for EUL-FACH.

• If any problem occurs on the initial synchronization of a UE, for example, tooslow EUL-FACH connection setup, the parameters initFdpchPower andinitDpcchPower can be increased to speed up the initial synchronizationprocess.

• If the parameter ulSirTarget is set to a lower value, it is beneficial to setthe parameter eulFachMaxDcchDtchTime to a higher value to avoidtriggering an explicit release of the common E-DCH resource before theUE finishes its data transmission.

• If the parameter eulFachInitialRate is set to a higher value, theparameter ulSirTarget can be set to a higher value to have the sameBlock Error Rate (BLER).

• There is a dependency between the preamble signatures for RACHconfigured by Rach::preambleSignatures and the signatures forEUL-FACH configured by EulFach::numPreambleSignatures.

The parameter Rach::preambleSignatures is a bit mask where eachbit position represents one signature and determines if the signature isavailable or not. The parameter EulFach::numPreambleSignaturesspecifies how many out of the available signatures set by the parameterRach::preambleSignatures are allocated for EUL-FACH users. Thenumber of available signatures set by Rach::preambleSignaturesneeds to be always larger than EulFach::numPreambleSignatures.

Considering this dependency between the parameters, it is recommendedthat the default setting of Rach::preambleSignatures is kept for theRACH preamble signatures, which means that all 16 signatures are alwaysavailable. It needs to be taken into account that the reconfiguration of theRACH preamble signatures Rach::preambleSignatures in a cell whereEnhanced Uplink for FACH is active can impact the signature allocationsfor EUL-FACH. The change of the signature allocations for EUL-FACHtriggers automatic EUL-FACH channel deactivation and activation.

• Some UE units in the network can be non-3GPP-compliant in terms ofHS-FACH or EUL-FACH handling. It can result in KPI degradation whenthis feature is activated. Refer to the Engineering Guidelines section inHigh Speed Downlink for FACH for information on how to use the DeviceOptimized HS-FACH/EUL-FACH feature to avoid such degradation.

Note: The changes of the parameter values can take effect immediately orwhen the feature is enabled. This condition depends on each parameterand needs be taken into account when setting the parameters.

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Technology

Uplink eul fach