uetr presentation 200812104

UETR Analysis

Table of Content

1. What is UETR?2. Interfaces in UTRAN3. Signalling Protocols4. UETR File location & File format5. UETR Messages and Measurements

RF Indicators: RSCP, Ec/Io, Tx Power, BLER, SIR, SIRerror

6. Call Flows1. CS (Voice & Video) Call Establishment

1. UETR Call Flow CS Voice2. UETR Call Flow CS Video

2. HSDPA Call Establishment & Primary Cell Change1. UETR Call Flow HSDPA

3. UETR Call Flow multi-RAB4. RANAP Iu Releases

7. Call Failure analysis8. Tipps and Tricks – UETR Analysis methodologyAPPENDIX

UTRAN Measurement mapping

1. What is the UETR ?

• UETR = User Equipment Traffic Recording• UETR is a performance recording tool.• UETR is a message flow of inter-node events (using signalling protocols)

and measurements for a specific UE (identified by its IMSI) that the RNC records.

• Only dedicated events with UE identifier is filtered and recorded in UETR. • Events occurring before the internal UE identity has been assigned are not

recorded.• UETR is initiated and configured in the OSS. (imsi, start/end time,…)• Events are recorded in 15min ROP. (UETR file size is 15min)

2. Interfaces in UTRANThe UTRAN network elements are connected by 4 Interfaces internally or

externally to each other:

• Iu interface is external interface that connects the RNC to the Core Network(CN)

• Uu is also external, connecting the Node B with the User Equipment (UE).

• Iub is an internal interface connecting the RNC with the Node B. • Iur interface which is an internal interface most cases connects two RNCs with

each other.

UETR signailling messages are transmitted via these interfaces using the different Signalling Prtocols.

2. Interfaces & Signalling Protocols

UE NodeB CNsRNC dRNC

NBAP

RANAP

RNSAP

NAS

RRC

Uu Iu-PS/Iu-CSIub Iu-PS/Iu-CS

Iur

3. Signalling Protocols in UETR 1/2The following Signalling Protocols can be found in UETR:

• RRC

The RRC (Radio Resource Control) handles the Layer 3 control signalling between the UE and RNC and performs functions for

– connection establishment and release, – broadcast of system information, – Radio Bearer establishment/reconfiguration and releases, – RRC Connection mobility procedures, – paging notification and release, – outer loop power control.

• NBAP

NBAP (Node B Application Part) is the signalling protocol responsible for the

control of the NodeB by the RNC. NBAP is carried over Iub.

3. Signalling Protocols in UETR 2/2• RNSAP

RNSAP (Radio Network Subsystem Application Part) is a signalling protocol

responsible for communications between RNCs. It is carried on the Iur interface

and provides functionality for

– SHO

– network configuration relocation.

• RANAP

RANAP (Radio Access Network Application Part) is a signaling protocol between

the Core Network (CN) and the RNC. RANAP is carried over Iu-interface. RANAP is

used for the following tasks:

– Relocation

– Radio Access Bearer Management

– Paging

– Transport of signalling between a UE and the Core Network (non-access stratum signalling)

• NAS

NAS (Non Access Stratum) is a functional layer running between the UE (User Equipment) and the CN (Core Network) and supports traffic and signalling messages between the CN and UE.

4. UETR file location

• Where the UETR files are stored?• Path to the UETR files.• How to find the requested UETR file?• How UETR GUI looks like?

4. UETR file location 1/4

UETR files are located in the Sonar Server : http://10.200.26.56

Select the Traffic Recording Analysis (UETR/CTR) menu

4. UETR files location 2/4

Select the UETR menu

4. UETR files location 3/4Select the relevant IMSI from the POP-UP list

To see earlier files than visible in the “File” window click on “Earlier Files”

Select the RNC where the IMSI has been traced

Select the Start/End Dates of the UE trace

After all setting done click on “Perform Filter”

After UETR files have been filtered outDouble click on the UETR file name to open it.

4. UETR – Message Flow 4/4UETR File Information

UETR – saving file

UETR – saving file

5. UETR File Format

• What is the UETR file format in the Sonar User Interface?

• Message Types• Message Directions• Message End Points

5. UETR File Format

UE NodeB RNC CN

5. Signalling protocol messages -RANAP

RANAPRANAP (Radio Access Network Application Part) is a signaling

protocol between the Core Network (CN) and the RNC. RANAP is carried over Iu-interface. RANAP is

RNC CN

5. Signalling protocol messages -NBAPNBAP

NBAP (Node B Application Part) is the signalling protocol responsible for the control of the NodeB by the RNC. NBAP is carried over Iub.

NodeB RNC

5. Signalling protocol messages -RRC

UE RNC

RRCThe RRC (Radio Resource Control) handles the Layer 3 control signalling between the UE and RNC

5. Signalling protocol messages -RNSAP

SRNC DRCN

RNSAPRNSAP (Radio Network Subsystem Application Part) is a signalling protocol responsible for communications between RNCs. It is carried on the Iur interface

5. Signalling protocol messages - NAS

UE CN

NASNAS (Non Access Stratum) is a functional layer between the UE and the CN and supports traffic and signalling messages between the CN and UE.

5. Signalling protocol messages -measurements

Internal RNC measurements

5. UETR messages

• What kind of information the messages carry?• How can be seen more details?• UETR file structure• What kind of measurements are recorded?• Mapping of measurement values

5. UETR File structure• Header : Administrative information about the file. • Recording : Scope of the recording. • Protocol : The name and version of the protocol (RRC, NBAP, RANAP, RNSAP). • Connection : Indicates that a UE has been added to, or removed from the scanner. • Body: Details of inter-node events, RNC-internal events and measurement results.• Footer : Administrative information about the time of normal termination of the

ROP file. • Error: Contains the time and cause of an abnormal termination of a recording. The

error record replaces the footer record if the file is terminated abnormally.

5. UETR Event Message Example

Event Message Header

Event Message Body

Parameter Value (Mapped)(For Mapping details refer to Appendix A )

Measured Parameter

Message details

5. Event Message Header EVENT : 234 = ID number of the EventHour: 22 Minute: 15 Second: 06 Millisecond: 140 = TimeStamp of the eventEvent_ID: 8 = ID of the event (eg.: Active Set Update = eventID: 0)RncModuleId: 4 = Identity of the RNC module from which the event is reported.UeContextId: 847 = Initial UE context (internal identifier) number.C_ID_1: 40331 = Cell identity of the first cell in the active setRNC_ID_1: 1006 = Identity of the controlling RNC (CRNC) for the first cell in the active set.C_ID_2: EVENT_VALUE_INVALID = Cell identity of the 2nd cell in the active setRNC_ID_2: EVENT_VALUE_INVALID = ID of the controlRNC (CRNC) for the 2nd cell in the active set.C_ID_3: EVENT_VALUE_INVALID = Cell identity of the 3rd cell in the active setRNC_ID_3: EVENT_VALUE_INVALID = ID of the controlling RNC (CRNC) for the 3rd cell in the active set.C_ID_4: EVENT_VALUE_INVALID = Cell identity of the 4th cell in the active setRNC_ID_4: EVENT_VALUE_INVALID = ID of the controlling RNC (CRNC) for the 4th cell in the active set.Direction: RECEIVED = Direction of the recorded event, measurement (Received / Sent)ProtocolID: 0 = RRC=0 / NBAP=1 / RANAP=2 / RNSAP= 4PDU-type: Type of the PDU Message length: Length of the messageCoded Message:

5. UETR – Message Details

5. UETR Event Measurements

The UETR Measurements can be grouped into:• NBAP measurements• UE measurements• RNC measurements

The following chapters present only measurements which can be found in the UETR records.

5. NBAP Measurements - SIRSIR

• Uplink Signal-to-Interference Ratio (SIR) per radio link set (RL-Set), measured on Dedicated Physical Control Channel (DPCCH) after radio link combination in the Node B.

• NodeB measures the Pilot Bit power of DPCCH and calculates the Signal-to –Interference ratio (SIR) per RL-set. This is compared to SIRtarget and based on the result TPC sent to UE (increase/decrease TxPwr).

• Range: [-11..20] dB by step of 0.5 dB• The optimal value for the SIR is around 3-6 dB.• High SIR value indicates the presence high UL Interference.• Low SIR triggers PC algorithm to order changing UeTxPwr for higher value ->

Increase of UL Interference.Example message:

5. NBAP Measurements - SIRerrorSIR ERROR

• SIRerror = SIR - SIRtarget. • SIRerror shows the gap between the assigned SIRtarget and measured SIR.

Value of SIRerror per connection shows how well the SRNC is able to adjust UE Tx Pwr, which shows the accuracy of Power Control.

• SIR should follow the SIRtarget -> SIRerror should present 0 value.• SIRerror measured on Dedicated Physical Control Channel (DPCCH) after

radio link combination in the Node B and reported for all RL-Sets relating to the UE connections being recorded.

• Range: [-31..31] dB by step of 0.5 dB• (SIRtarget is adjusted by UL outer-loop power control algorithm and used

for closed-loop PC. ) Example message:

5. NBAP Measurements – Tx Power

• TRANSMITTED CODE POWER• Transmitted code power is the transmitted power measured on the pilot

bits of one channelization code on one scrambling code on one Dedicated Physical Channel (DPCH).

• One average value is reported for all DPCHs relating to the UE connections.• This is the power allocated per connection. Based on this measurement

DL load of UE per connection can be estimated.• Range: [-10..46] dBm by step of 0.5 dB• The higher TCP value indicates worse RF conditions and higher DL-code Pwr

load since pilot channel has to transmit with higher power. Example message:

5. UE Measurement Report

UE performs various measurements. The measurements are sent in the MR – Measurement Report.The measurements are started by sending the RRC message: MEASUREMENT CONTROL to a UE, specifying: measurement quantity, measurement id and reporting period.

UE measurements: DL TRANSPORT CHANNEL BLERUE Tx POWER DL CPICH Ec/No DL CPICH RSCP

5. UE Measurement Report - BLERDOWNLINK TRANSPORT CHANNEL BLER• (BLER = Block Error Rate)• BLER is estimation of Transport Channel Block Error Rate in DL DCH, based on

evaluating CRC on each Trabsport Block after Radio Link combination.• BLER is long-time average block error rate calculated from transport blocks.• Range: [0…1] by setp of 0.065• The lower BLER value indicates better Transport Channel quality. • There is NO BLER measurement in HSDPA.

Measurement Control message defines which MR will report the UE Tx Pwr and which one The DL-Transport Ch. BLER. (for more details see Slide of

MeasurementControl)

message measurementReport : { measurementIdentity 7, measuredResults qualityMeasuredResults : { blerMeasurementResultsList { { transportChannelIdentity 31, dl-TransportChannelBLER 0 } }, modeSpecificInfo fdd : NULL } }

Message details

5. UE Measurement Report - DL CPICH Ec/No

DL CPICH Ec/No • CPICH_Ec/No is the received energy per chip divided by the power density

in the band. Measurement is performed on the Primary CPICH (P-CPICH).• In more simple : Ec/No = P-CPICH_RSCP / UTRA_Carrier_RSSI• DL CPICH Ec/No (Ec/Io) is the DL quality indicator of the P-CPICH.• DL CPICH Ec/No measurement is used for cell selection and re-selection

procedure, active set update, handover triggers, downlink power setting.• Range: [-24..0] dB by step of 1 dB. (see mapping in Appendix)• The higher the Ec/No the better the P-CPICH quality.• DL CPICH Ec/No > -8dB the connection considered good.• DL CPICH Ec/No < -14dB triggers CM and Inter-RAT HO/CC.• Measurement values are in MR (measID=1): (for details go to next slide)

5. UE Measurement Report - DL CPICH RSCP

DL CPICH RSCP• DL CPICH RSCP is the Received Signal Code Power on one channelization code. Measured on the bits of the Primary CPICH.• DL CPICH RSCP measurement can be used for cell selection and reselection for handover preparation for power control and for

path loss calculation.• Measurement values are in MR (measID=1):

• which is initiated by MeasurementControl :

• Range: [-115..-25] dBm by step of 1 dB (see for mapping Appendix A)

• The higher DL CPICH RSCP value indicates better RF conditions.

Mapped Values

MR (measID=1) message details

5. UE Measurement Report – DL CPICH RSCP & Ec/Io Mapping

Mapped Values

To convert the reported Ec/Io and RSCP values use following equations:

Ec/Io = -24 dB + (Ec/IoREPORTED / 2)

RSCP = -115 dBm + RSCPREPORTED

In the previous example:

The UE reports for PSC 359… Ec/Io = -24+31/2 = -8.5 dB RSCP = -115+38 = -77 dBm

5. UE Measurement Report – UE Tx Power

UE Tx POWER • The UE transmitted power is the total power transmitted by the UE on

one carrier.• UE Tx power measurement is used for power management and handover

preparation.• Range: [-50..33] dBm by step of 1 dB.• The lower the UE Tx power the lower the UL Interference since UE is not

ordered by PC algorithm to use high power.

Measurement Control message defines which MR will report the UE Tx Pwr and which one The DL-Transport Ch. BLER. (for more details see Slide 31)

5. Measurement ControlEach MR has its own function:

•qualityMeasuredResults (measID=7) [ e.g.: dl-TransportChannelBLER ]•ue-InternalMeasuredResults (measID=8) [ e.g.: ue-TransmittedPower ]•intraFreqMeasuredResultsList (measID=1) or (measID=6) [e.g.: ev1a / e1b …]

Measurement Control allocates the MR functions to the measurementReports

6. Call flows

Call flow presented:• Call Setup• RAB allocation• Radio Bearer Reconfiguration• Active Set Update• Compressed Mode• Inter-RAT HO• Call Release

6.4.1. UETR Call Flow CS-Speech (UE Originated) 1/12

Call Setup Phase

NAS – Setup message indicates the Service type and other details of the call requested by the UE.

NBAP – Dedicated Measurement Init. Req.RL unique ID allocation in RBS (RBS.CCID)

NBAP – Dedicated Measurement Init. Req.RL unique ID allocation in RNC (RNC.CCID)

RRC - Measurement Control define the functions of the MRs.

RANAP – RAB assignment Req.

RB Setup on “cs-domain”

The UETR recording starts with (RRC) Security Mode Complete message, this is the first message after UE has a unique ID allocated.

6.4.1. UETR Call Flow CS-Speech 2/11

SecurityModeComplete (RRC) is the first dedicated message of the call (CS/PS) in UETR file. This is the response to SecurityModeCommand (RANAP) to allocate unique ID for the UE.The CCID (communicationContext ID) uniquely identifies the RL during the entire call in the ControlRNC. (This procedure is used also to trigger of ciphering or to command the change of the cipher key.)RNC.CCID= Identifies the RL during the whole communication within the controlRNCRBS.CCID= Identifies the RL in the NodeB (RBS)

The Measurement Control messages define the functions of the MRs (which one is for the UE Tx Pwr and which one the DL Transport BLER, which one is for RL-addition/deletion (ev1a/ev1b….) (More info of MCs in slide 31)

Direct Transfer messages (RANAP) carry UE-CN signalling messages (like MM or CC messages).


Dedicated Measurement Initial Request (NBAP) procedure is used by a CRNC to request the initiation of measurements on dedicated resources in a NodeB.

Dedicated Measurement Initial Response (NBAP) is the response to Dedicated Measurement Init Req. with the RNC.CCID (see previous slide) The RNC.CCID the unique ID of the RL in the RNC. Lost RL ID due to any synch.Failure can be found here (this is the first appearance of the RL ID.)

DL Direct Transfer (RRC) procedure is used in both downlink and uplink to carry all higher layer (NAS) messages over the radio interface. It can also be used to establish and release signalling connections.

RAB Assignment Request (RANAP) is sent by CN to RNC to request Establishment, Modification or Release of one or more RABS to the same UE.

RadioLinkReconfigurationPrepare (NBAP) procedure is used to prepare a new configuration of all Radio Links related to one UE-UTRAN connection within a Node B.

Radio Bearer Setup (RRC) is the procedure to establish new radio bearer(s).


Alerting – Connect Phase

RB reconfiguration Phase RB Reconfiguration for the negotiated QoS Bearer.

6.4.1.UETR Call Flow CS-Speech 5/12

Radio Bearer Reconfiguration (RRC) procedure is to reconfigure RB parameters (SRB /TRB) or the signalling link to reflect the changes in QoS.

Alerting (NAS)This is higher Layer signalling message on NAS.

Connect (NAS) This is higher Layer signalling message on NAS.


1

2

6

3

4

5


Meaurement Report (measID=1) assigned by Measurement Control presents cpich-Ec-N0 and cpich-RSCP measurements of the measured PSCs.In case of measured result is above/below e1a or e1b criteria -> RL addition or removal is initiated. (ASU is initiated during e1a/e1b/e1c/e1d events)

RadioLinkAdditionRequest (NBAP) is used for establishing the necessary resources in the Node B for one or more additional RLs towards a UE when there is already a Node B communication context for this UE in the NodeB.This message includes the Initial DL Transm. Pwr and DL Channelization Pwr too.

RadioLinkDeletionRequest (NBAP) is used for deleting RL resources in the Node BActiveSetUpdate (RRC) procedure is to update the active set of the connection

between the UE and UTRAN. The UE keeps on using the old RLs while allocating the new RLs. At Hard HO case the ActiveSetUpdate message has to contain additional “physical CH information elements”: frequency info, UL-RR, DL-RR and other optional parameters for the target phyCH configuration.


Compressed Mode 1

Phy.Ch.Reconfiguration for entering into

Compressed Mode.

Measurement Control message to start measurements on Inter-RAT cells (set-up 2G cell list)


Compressed Mode 2

RNC sends Iu-Release Request (RANAP) to CN due to Connection Relocation.

When Iu-Release succefully done the RRC connection is still open for sending IRAT events.


Compressed Mode 3

After Iu-Release UE sends e2d event messages to the RNC on RRC.

In this case IRAT-HO succesfully has been done -> Connection released in UTRAN and the call continous in 2G. (event3a will be sent for HO execution phase)

IRAT-HO preparation+


• Compressed Mode is initiated to preform UE measurements on Inter-Frequency or Inter-RAT cells.

• Compressed Mode is triggered by e2d event (UTRAN EcNo or RSCP is bellow of the e2d threshold (individual thersholds for EcNo and RSCP) + histeresys/2 during “timeToTrigger2d” timer.

• Compressed mode is stopped by e2f event when measured EcNo or RSCP is above e2f criteria during “timeToTrigger2f” timer.

• If the connection is using HS-DSCH then a reconfiguration attempt to DCH is triggered first (Physical Channel reconfiuration). When the connection has been moved to DCH the IRAT HO attempt (event e3a) can proceed.


Call Release Phase

The normal call release initiated by Iu-release request (RANAP) with cause code: “normal release”


Iu-ReleaseRequest (cause:radioNetwork/release-due-to-UE-generated-signalling-connection-release) (RANAP) is sent by the RNC to CN request for release of Iu connection.The Request contains the Release Cause as well.

Iu-ReleaseCommand (cause:radioNetwork/release-due-to-UE-generated-signalling-connection-release) (RANAP) is sent by CN to order the RNC to release all resources related to Iu connection.

Iu-ReleaseComplete (RANAP) is sent by the RNC as the response to CN Iu Release Command.

6.4.2. UETR Call Flow CS-Video Call

• Call flow for CS-Video Call Mobile Originated• Which message the UETR scanning starts with?• What is the main difference from CS-Voice call?• What kind of information are transferred in Call

Setup?

6.4.2. UETR Call Flow CS-Video Call 1/3Call Setup Phase

NAS – Setup message indicates the Service type and other details of the call requested by the UE.


NBAP – Dedicated Measurement Init. Req.RL unique ID allocation in RNC (RNC.CCID)


RANAP – RAB assignment Req.

The UETR recording starts with (RRC) Security Mode Complete message, this is the first message after UE has a unique ID allocated.

RB Setup on “cs-domain”

6.4.2. UETR Call Flow CS-Video Call 2/3

The message flow of MOC CS-Video Call is very similar to CS-Speech call. For message details please refer to Call Flow of MOC CS-Speech Call slides.

The differences between CS-Speech and CS-Video Calls is during call setup:• Setup (NAS) message • RAB assignment• RB Setup

Other messages (CM, ASU,…) are same to CS-Speech Call flow, thus no details can be found here on this matter.

CS-voice call

CS-video call

6.4.2. UETR Call Flow CS-Video Call 3/3

Call Release Phase

There is no difference in the Call Release Phase between CS-voice and CS-video Call

6.6.1. UETR call flow HSDPA Call

• Which message the UETR scanning starts with?• What kind of messages can be seen?• What kind of information they carry?• Differences in Call Setup phase.• RB Reconfiguration.• Phy Channel Reconfiguration.• Active Set Update. (Intra/Inter-NodeB, Inter-

RNC)

6.6.1. UETR call flow HSDPA Call 1/8

Call Setup Phase

RB-Setup on “ps-domain”

PDP Contxt Req.

PDP Contxt Active.

HS-DSCH RB allocation

The UETR recording starts with (RRC) Security Mode Complete message, this is the first message after UE has aunique ID allocated.




• During PS call setup UE requests PDP Context Activation in NAS message while in CS (voice/video) setup the UE request is a call Setup (NAS).

• RAB assignment allocates different RAB type (64/HS, 384/HS, 64/64,…)• RB Setup allocates different type of RB (64kbps, 128kbps, 384kbps, HS)

PS-call

CS-voice call

• Why there are differences between CS and PS Call Flow messages?

• What are the differences?• Which RB type is used for PS call?• What are the differences between PS-R99 and

HS call flow?


Example: Radio Bearer Reconfiguration from Cell-DCH to Cell-FACH for Cell Update due to Cell Reselection

RB Reconfiguration from Cell-DCH to Cell-FACH

Cell Update due to Cell Reselection on Cell-FACH

RB Reconfig. from Cell-FACH to Cell-DCH

RB Reconfiguration


Physical Channel Reconfiguration is done in HSDPA for:

• Cell Change procedure (intra/inter-NodeB)• Upswitch/Downswitch due to RF conditions:• Upswitch/Downswitch due to Throughput:• Crossing RNC border:• IRAT-HO/CC:


Physical Channel Reconfiguration

Cell Change after Active Set Update

Active Set UpdateCell Change after Active Set Update – Intra-NodeB C.C.


Physical Channel Reconfiguration – Inter-NodeB C.C.

Cell Change (e1d)

Cell Change based on e1d (no ASU)

event 1d

6.6.1. UETR call flow HSDPA Call 7/8Physical Channel Reconfiguration

Reconfiguration over Iur – Inter-RNC C.C.

Phy Ch Reconfiguration From HS-DSCH to DCH due to RL addition from DRNC

Active Set Update : Add RL from DRNC

Phy Ch Reconfiguration: Best Server Cell Change in AS.=> DRNC cell became best.

Active Set Update event in DRNC

There is NO Phy Reconfiguration for Upswitch to HS-DSCH in DRNC!


Call Release Phase Normal Iu-Release process of PS (HS) connection

6.7. UETR Call Flow CS/PS Multi-RAB 1/6

Set-up of CS-RAB

CS-Speech Call is Requested.


CS-RAB allocation

CS-Speech RAB is Requested.

CS-Speech RAB is Set up.

CS-RB Setup

CS-Speech Call Established, Alerting


PS-RAB allocation

PS RAB is Requested.

CS-Speech RAB is Set up.

PS-RB Setup


PS-RAB release

PS RAB disconnect Request from CN via NAS.

PS RAB release Command from CN.

PS-RB release

PS RAB release Complete


CS-RAB release

CS RAB release Request.

CS RAB release Complete

However RadioLinks coud not been Deleted.


Iu-Release Failure

After 7 rrConnectionRelease Requests finally both RLs have been deleted

RadioLinks coud not been Deleted. (synch.Failure)

6.8. Iu-Release Cases

Examples of Iu-Releases:• Normal Release• UE-generated-signalling-release• UE-inactivity• Radio-connection-with-UE-Lost• OM-Intervention

6.8. Iu-Release cause: Normal-release

The Iu-Release Command (RANAP) message contains the cause of the Release. In case of Normal Release (cause: “normal release”)

6.8. Iu-Release cause: UE-generated-signalling-release

This type of Iu-Release is caused by BlackBerry Type UE and is considered as not real dropped connection.

6.8. Iu-Release cause: UE InactivityThis type of Iu-Release is caused by UE inactivity and is considered as not real dropped connection.

The Inactivity Timer (RNC Timer) expires and the corresponding Radio Connections are released. (“downswitchTimer” for R99 or “hsdschInactivityTimer” for HS)When the throughput on both UL and DL is below the “downswitchThreshold”, the timer “downswitchTimer” (DCH/DCH) or the “hsdschInactivityTimer” (DCH/HS or EUL/HS) starts.

6.8. Iu-Release cause: OM-Intervention

This type of Iu-Release is caused by any O&M action in the site or RNC (reset/parameter change which requiers site reset) and is real dropped connection.

To find out more of the casue of the Iu-Release has to open UEH exception log. (see “Tipp & Tricks” slides below)

6.8. Iu-Release cause: Radio Connection with UE Lost

This type of Iu-Release is caused bad RF condition or synchronization failure. This is a real dropped connection. To find out more details of the cause of this Iu-Release the UEH exception logs should be checked. (see “Tipp & Tricks” slides below)

Note possible RL failure indications!

Check also RL quality indicators (CPICH – EcNo / CPICH – RSCP) in (RRC) MR messages (measID=1)

7. Call Failures

• Example of Failure• CS –Voice call• Call Failure Analysis

7. Call Flow – Setup Phase

What type of call has been initiated?

7. Call Flow – Setup Phase

The call is a CS – voice call on 12.2 RAB in cs-domain

7. Call Flow – Iu-release Phase

What type of iu-release appeared?

7. Call Flow – Iu-release Phase

The iu-release cause code: “utran generated reason”

7. Call Flow – Activ Set Update 1.

What type of event appeared?

7. Call Flow – Activ Set Update 1.There is an ASU request after MeasControl to add PSC=359

!


The RF conditions are very bad during the ASU:TxCodePwr=34 (max!)

RLfailureIndicator shows Synch. Problem on all active RLs. which could be resolved finally.


At Start of the ASU Timer ASU is activated.

The RF conditions are very bad during the ASU:TxCodePwr=34 (max!)

RLfailureIndicator shows Synch. Problem on all active RLs. which could be resolved finally.

7. Call Flow – Active Set Update 2.

What kind of failure can be seen?


ASU Timer is running


Very bad RF conditions:txCodePwr=34 /SIRerror=7

The 2nd Rlfailure-SynchFailure could not be solved.

ASU Timer is running


Very bad RF conditions:txCodePwr=34 /SIRerror=7

The ASU request has not received ASU Completed within ASU Timer active.Iu-release requested with cause: utran generated release.

The 2nd Rlfailure-SynchFailure could not be solved.

7. Last MR Report of EcNo/RSCP of Measured Cells

primaryCPICH-Info { primaryScramblingCode 398 }, cpich-Ec-N0 2, cpich-RSCP 0 } }, { primaryCPICH-Info { primaryScramblingCode 353 }, cpich-Ec-N0 2, cpich-RSCP 0 } }, { primaryCPICH-Info { primaryScramblingCode 374 }, cpich-Ec-N0 2, cpich-RSCP 0 } },

Mapped RF quality Indicators:

8. Tips and Tricks

• Time Shift between UETR files and local time.• How to use the message filters?• Missing events.

8. Tips and Tricks 1/4

Time shift in UETR analysis

• Ad-hoc Analysis based on “special request”:– Note that local mexican time has 5 hours earlier than RNC time =

UETR time. (eg.: Dropped event in afternoon 14.30 => have to search UETR file between 19.15-19.30)

• Analysis based on “VIP IMSI - Avance de Fallas” :– The registered Dropped event is in the same timing as UETR events

(there is some minutes variation)

8. Tips and Tricks 2/4Use Filter for finding Iu-Release Event:• Check the exact time of the searched event (in this case Iu-Release)• Filter IMSI and Date for the relevant UETR file. (15min time period)• Apply filter for “RANAP”, “NAS” and “Others” messages. (bottom of the page)• Search for the “Iu-release” event (RANAP).• Find the Abnormal Iu-release cases. (if not found the event go for next/previous file)• Mark the time of the Iu-Release event.• Activate all Protocol Messages again. (click on check boxes) ->Click “Back” to see all

messages and event -> Jump directly to marked Iu-release event -> Find the drop cause.(cont. next page->)

8. Tips and Tricks 3/4• Find the known “Iu-Release” time in the UETR messages.• Go backwards from “Iu-Release Request” (upwards) in the message flow

to find release causes.• Check messages (values) and try to find missing messages, failures.• In case no failure found at first sight than match the call flow to a sample

call flow (in this guideline) and search for differences.• Check if the found difference(s) is/are due to failure or just different call

type/service request.

8. Tips and Tricks 4/4It can happen that some message seems to be missing

in UETR records or in TEMS logfile.Missing event or measurement in UETR records:In case missing event or measurement record is suspected.Check the sample file in this guidelineIf not found similar sample check another UETR file for an example.Check TEMS logfile (Note that timestamp difference [5hours]) for the

missing events or measurements.Compare the time and the events (UETR vs. TEMS)

Missing event or measurement in TEMS:Check UETR files for the missing events or measurement. Compare the time and the events (UETR vs. TEMS)

APPENDIX A.• UTRAN Measurement Mapping.

APPENDIX B.• Call Flows

APPENDIX

CPICH Ec/No measurement report mapping

• The reporting range is for CPICH Ec/No is -24 ...0 dB.

APPENDIX A. – MR Mapping

CPICH RSCP measurement report mapping

• The reporting range is for CPICH RSCP is -120 ...-25 dBm.


UTRA Carrier RSSI

• NOTE: This measurement is for Inter-frequency handover evaluation.

• The reporting range is -100 ...-25 dBm.


GSM carrier RSSI

According to (ETSI 05.08)The reporting range is -110 ...-48 dBm.


Transport channel BLER measurement report mapping

• The Transport channel BLER reporting range is from 0 to 1.


UE Tx Power measurement report mapping

The reporting range is -50 ...+34dBm.


SIR measurement report mapping



SIR Error measurement report mapping



DL Tx Code Power measurement report mapping

The reporting range is -9.5 ...+46.5dBm.


uetr presentation 200812104

Documents

uetr files

uetr gui

requested uetr file

uetr file locationwhere

uetr file size

uetr signailling messages

control signalling

signalling messages