3 RAN Performance Tuning NOKIA

RAN Performance Tuning Reunanen Jussi 18.03.2004

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Introduction • The call performance is divided into 7 sections starting from the initial cell search all the way to call release • In each section: • relevant counters for performance evaluation and trouble shooting • parameters for performance improvement • are presented

UE is powered up Cell search

Cell Selection and Cell Reselection RRC Connection Establishment

RAB Establishment Handovers; SHO, ISHO, IFHO RRC Active Releases

RAB Active Releases

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Idle Mode Performance


• DL Scrambling code info is needed for cell search procedure & frame syncronization • Each cell has own DL primary scramling code (cell identification) • Codes are divided to Primary and secondary Scrambling codes • Each cell is allocated one and only one primary scrambling code. The primary CCPCH, primary CPICH, PICH, AICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling code. • The total number DL primary scrambling codes is 512, subdivided into 64 groups each of 8 primary scrambling codes • Each Primary Scrambling code could have up to 15 secondary scrambling codes

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• The allocation of DL Scrambling code in neighbouring cells is possible in two ways: • Random code planning approach: Use any of the 512 codes • Use of 64 SC groups i.e. allocating SC groups cell by cell • Which ever planning approach is used, large enough separation (reuse 64) between two cells using the same scrambling code must be guaranteed • The best code planning strategy depends on the UE algorithm •

However the cell search performance difference between the two primary SC methods is negligible

• Cell search performance gain decreases when the number of neighbours are increased

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UE is powered up

Idle Mode Performance C256,0

Cell search

Scrambling Code

CPICH BCH C256,1

∑ ∑

All channels CSF,n

P-SCH S-SCH

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When searching cells: The UE measures the impulse response first by using the P-SCH , which is unique in the whole system.

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!

By finding a delay, which produces a local maximum correlation with this code, the UE gets slot and symbol synchronisation with a base station/sector (matched filter).

!

The correlation peaks of different cells appear with different delays. This is achieved by offsets in the transmission time of the search symbols and partly by different propagation delays.

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After the UE gets the slot/symbol synchronisation it can use the S-SCH to find the frame synchronisation and to identify the code group to which the cell's scrambling code belongs to.

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!

This is required at least in the initial power on.

!

The 2nd Synchronisation channel's code changes from slot to slot in a sequence which has a period of 15 slots (i.e. 1 frame). There are 64 sequences chosen each defining a code group for the actual scrambling code of the cell.

!

By solving this sequence the UE gets the frame synchronisation with the BS and identifies the code group from which the scrambling code of the BS has been taken.

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UE knows the scrambling codes of each scrambling code group and finally after finding the right code, which is given on P-CPICH UE can start decoding the BCH.

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!

If the UE has a neighbour list available the search procedure may be different.

!

The cell is found when its primary scrambling code has been identified.

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UE is powered up

Idle Mode Performance 2560 Chips

256 Chips

CP

CP

CP

Cs1

Cs2

Cs15

Slot 0

Slot 1

10 ms Frame Cp = Primary Synchronisation Code Cs = Secondary Synchronisation Code 9

Cell search

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Slot 14


64 Different combination

Sequence of length 15

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Matrix made by 16 different codes

5th row matches with the secondary SCH channel

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Idle Mode Performance Total number of Scrambling Code 64 x 8 = 512

8 Different Codes

64 Different group

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5th row, the Cell Scrambling code is within that group


Cell Selection and Cell Reselection

• The UE should always be connected to the best cell: highest CPICH RSCP and Ec/No to avoid several consecutive RRC Connection Request • The more RRC Connection Requests are sent by the UE the worse is the call setup delay cumulative distribution function

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• The UE should always be connected to the best cell: highest CPICH RSCP and Ec/No to avoid several consecutive RRC Connection Request • Call setup failure performance gets worse by the decreasing CPICH RSCP & Ec/No

CPICH RSCP

CPICH Ec/No Recommended area

Calls setups very successful Calls setups ok Calls setups difficult Calls setups failures QqualMin = -20dB

QqualMin+Sintrasearch+ Qhyst2= -16dB + 4dB = -12dB QqualMin+Sintrasearch =-20dB + 4dB = -16dB

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Idle Mode Performance Initial Initialcell cellselection/Stored selection/StoredInformation Information Cell Selection to find suitable Cell Selection to find suitablecell cell

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UE scans all RF channels in UTRA band of the selected PLMN or stored info is used

Suitable Suitablecell cellisischecked checkedwith withS-criteria S-criteria

Both level & quality should be checked.

After Aftercamped campednormally normallyto tosuitable suitablecell cell re-selection process can start re-selection process can start

UE measures the cells from neighboring list of the own cell

Cell Cellare areprioritized prioritizedwith withH-criteria H-criteriainincase case HCS is used HCS is used

If HCS is not used R-criteria is used directly

Cells Cellsare areranked rankedwith withRR-Criteria Criteriafor for highest highestHCS HCSprio prio(not (notfor forfast fastmoving movingUE) UE)

Ranking is starting from Highest HCS priorities & cells passing the H-criteria For fast moving UEs ranking starts from lowest HCS priorities

Cell Cellre-selection re-selectionto toHighest HighestRRisisdone donefor for all the cells that fulfill S-criteria all the cells that fulfill S-criteria

After this cell will be selected by the UE and it will be checked if the cell will be suitable to camp on

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Idle Mode Performance HCS in use:

HCS not in use:

Serving cell+ measured neighboring cells

Serving + measured neighboring cells

S-Criteria OK Fast MS

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Cells with Lower HCS Priority than in Serving cell

Cells with Highest HCS Priorities & H>0

Best R

Best R

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S-Criteria OK If No Cell with H>0 accept all neighbors

Best R

Idle Mode Performance • The cell selection criteria S are defined as:

• The cell selection criterion S for a suitable cell is fulfilled when:


Squal = Qqualmeas – QqualMin Srxlev = Qrxlevmeas – QrxlevMin - Pcompensation

Squal > 0 AND Srxlev > 0

• Where: Name

Description

Unit

Squal

Cell Selection quality value. Not applicable for GSM or TDD cells.

dB

Srxlev

Cell Selection Rx level value.

dB

Qqualmeas

Measured cell quality value, it is expressed in CPICH Ec/No. Not applicable for GSM or TDD cellls.

dB

Qrxlevmeas

Measured cell Rx level. For FDD cells it CPICH RSCP, for GSM cells RxLEV and for TDD cell P-CCPCH RSCP

dBm

QqualMin

The minimum required quality level in the cell (Ec/N0). Parameter is part of SIB 3

dB

Range

-24 ..0

Default

-20

1dB step QrxlevMin

The minimum required RX level in the cell (RSCP). Parameter is part of SIB 3

dBm

-115 .. -25

-115

2dBm step

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Pcompensation

max(UEtxPowerMaxPRACH – P_MAX,0)

dB

UEtxPowerMaxPRACH

Defines the maximum transmission power level a UE can use on PRACH. Parameter is part of SIB 3

dBm

P_MAX

Maximum RF output power of the UE

dBm

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-50 .. 33

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Idle Mode Performance First ranking of all the cells based on CPICH RSCP (WCDMA) and RSSI (GSM)

R - criteria

Rs = CPICH RSCP/GSM RSSI + Qhyst1 Rn= CPICH_RSCP(n) or RXLEV(n) - Qoffset1 temp_offset1_during_penalty Penalty & temp_offset1 is used in case HCS is used and neighbour is having same priority.

Yes

Cell re-selection to GSM

Temp offset2 is used only in case HCS is used and neighbour is having same priority 17

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Rn higher in GSM cell


Serving WCDMA cell calculation, with hysteresis parameter Neighbour WCDMA or GSM cell calculation with offset parameter

No

Second ranking only for WCDMA cells based on CPICH Ec/No Rs = CPICH Ec/No + Qhyst2 Rn= CPICH Ec/No -Qoffset2 temp_offset2_during_penalty Cell re-selection to WCDMA cell of highest R value



• Parameters Sintrasearch, Sintersearch and SsearchRAT are compared with Squal (CPICH Ec/No Qqualmin) in S-criteria for cell re-selection Region

Condition

Neighbour cells to be measured

1

Squal > Sintrasearch

None

2

Sintersearch < Squal ≤ Sintrasearch

Intra-frequency cells

3

SsearchRATm < Squal ≤ Sintersearch

Intra- and inter-frequency cells

4

Squal ≤ SsearchRATm

Intra-, inter-frequency and inter-RAT cells

Sintrasearch

4

3

2

1 WCDMA CELL

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Sintersearch

?

SsearchRAT



R Qmeas (CPICH Ec/No)

Rn > Rs => Cell re-selection Serving Cell

Qoffset2

Rs Qhyst2

Neighbor Cell Rn

Qoffset2 and Qhyst2 define the total margin that neighbour cell quality needs to be higher than serving cell quality

Sintersearch SsearchRAT t

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• Best performance can be found by tuning the following parameters and maximising the CSSR and minimising the number of consecutive RRC Connection Requests sent by the UE • Cell reselection triggering time (e.g. Treselection = 0s) • Reselection takes place immediately when the UE notices that there is difference between the cells’ Ec/No values (in worst case scenario there can be up to 3dB + Qhyst difference based on the measurement accuracy requirement before the UE performs cell reselection) • Cell reselection hysteresis 2 (e.g. Qhyst2 = 4dB) • This will add 4dB hysteresis to the neighboring cell evaluation (target for the cell reselection) • Note that Qhyst1 is used only in case the cell selection and re-selection quality measure is set to CPICH RSCP (default is CPICH Ec/No so Qhyst 1 is not used in intra-FDD reselection) • Cell Re-selection Quality Offset 2 (e.g. AdjsQoffset2 = 0dB) • This parameter is used in the cell re-selection and ranking between WCDMA cells. The value of this parameter is subtracted from the measured CPICH Ec/No of the neighbor cell before the UE compares the quality measure with the cell re-selection/ ranking criteria • S intrasearch (e.g. Sintrasearch = 4dB) • This parameter is used by the UE to calculate the threshold (CPICH Ec/No) to start intra frequency (SHO) measurements (Sintrasearch above QqualMin value) • Minimum required quality level in the cell (e.g. QqualMin = -20dB) 20

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• New set Case : Sintrasearch = 12 dB, Treselection = 0 sec and Qhyst2 =0 dB All Call Attempts: New -2

CPICH Ec/No [dB]

-4 -6 -8 -10 -12 -14 -16 -18

• Between location area borders it might be good to have some hysteresis between the adjacent LA cells -> Qhyst2 = 2dB or 4dB 21

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Connection Establishment UE - RAN UE

Node B [RACH] RRC:RRC Connection Request

RNC

RRC Connection Establishment

• The power level for sending of the RRC Connection Request –message is set/calculated by the UE

• Uplink open loop PC take place at the random access procedure: NBAP: RL Setup Response • UE measures the received power of the CPICH ALCAP:ERQ which reported back in "measured results on ALCAP:ECF RACH" IE in: initial direct transfer (UTRAN must [FACH] RRC: RRC Connection Setup extract this IE from the NAS message), cell update L1 Synchronisation / ura update, measurement report (UL traffic NBAP: Synchronisation Indication volume measurement report), RRC connection [DCH] RRC: RRC Connection Setup Complete request, uplink direct transfer (UTRAN must extract this IE from the NAS message) • Transmission power of CPICH (SIB5&6), total received uplink power at BS (SIB7) and a parameter value PRACHRequiredReceivedCI are sent from BS in system information broadcast messages (SIB5&6) • Based on this information UE calculates the transmission power of the first preamble of PRACH ptx NBAP: RL Setup Request

• ptx = CPICHtransmissionPower-RSCP(CPICH)+RSSI(BS)+"constant value“ where the "constant value" is the value of the RNC parameter PRACHRequiredReceivedCI 22

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RNC

Node B [RACH] RRC:RRC Connection Request NBAP: RL Setup Request NBAP: RL Setup Response ALCAP:ERQ ALCAP:ECF [FACH] RRC: RRC Connection Setup

• If no acquisition indicator is received UE raises the transmission power by PowerRampStepPRACHpreamble which is a broadcast parameter • This procedure is repeated until acquisition indicator is received, after which UE sends the RACH message at power which offset by PowerOffsetLastPreamblePRACHmessage from the last preamble L1 ACK / AICH

• PRACH_preamble_retrans parameter determines how many times PRACH preamble can be sent (without AICH response) within one preamble ramping cycle (SIB5&6)

Downlink BS

• RACH_tx_Max defines how many times the PRACH pre-amble ramping cycle procedure can be repeated before UE MAC reports a failure on RACH transmission to higher layers (SIB 5&6)

P2 Uplink P1 MS Preamble Preamble 1 2

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Not detected

Message part

Connection Establishment UE - RAN


• Some of the early UEs are not capable of performing Open Loop PC accurately i.e. they have problems in RRC Connection Establishment • The UE cannot detect the SIB7 UL interference level correctly or cannot measure the CPICH RSCP accurately enough • The situation can be corrected by increasing the parameter value PRACH_preamble_retrans or RACH_tx_Max • Increasing the parameter values should be made with extra care as increasing the maximum UE TX power on RACH increases the UL load is as well • In case of problematic site which does not answer to PRACH at all due to BTS problems; increasing the power on RACH increases the UL interference on the surrounding sites

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Connection Establishment UE - RAN UE Tx Power [dBm] -40 -35 -30 -25 -20 -15 -10 -5 0 5

10 15 20 25 -40 -60 -70 -80 -90

RSCP [dBm]

-50

-100 -110 -120 30

10 0 -30

-25

-20

-15

-10

-5

0 -10 -20 -30 -40

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CPICH Ec/No [dBm] [dB]

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UE Tx Power [dBm]

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• For failed calls the UE Tx vs. CPICH Ec/No and CPICH RSCP should be investigated in order to see possible DL coverage or open loop PC problems •In case CPICH RSCP is low but UE Tx Power is low •There is possibility that UE open loop PC is not working correctly •Or the CPICH Tx power is pretty low and there is DL coverage problems •Or the SCCPCH power offset to CPICH power is set wrongly – too big offset •In case CPICH Ec/No is low but the UE Tx power is low then there could be some problem in DL quality - provided that the CPICH RSCP is ok •Some high DL loading in the cell •Pilot pollution on that area

Connection Establishment UE - RAN -30

CPICH Ec/No [dB] -20 -15 -10

-25

-5

• From CPICH Ec/No vs. CPICH RSCP it can be seen that only a few call failures are having relatively good CPICH RSCP but still pretty poor CPICH Ec/No: •indicating possibility of Pilot Pollution •Indicating possibility of relatively high DL load • Those cells in case they constantly do have this kind of phenomena should be investigated more

0

-60 -70 -80 -90 -100

CPICH RSCP [dBm]

-40 -50


-110 -120

RSCP and RSSI (dBm)

Pilot pollution area/poor dominance area

-20 -40 -60

• For possible pilot pollution investigation the amount of SCs and their strength can be plotted -5 from the drive test data and possible the cells -10 causing the pilot pollution can be identified and -15 dominance optimisation can be done -20 0

-25 -80

-30 -35

-100

-40 -120 -45 -140

ANT1_RSSI SC174 RSCP SC69 Ec/No 26

-50

Data No.

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SC97 RSCP SC180 RSCP SC174 Ec/No

SC106 RSCP SC97 Ec/No SC180 Ec/No

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SC103 RSCP SC106 Ec/No

SC69 RSCP SC103 Ec/No

Ec/No (dB)

Plot of RSCP and Ec/No vs Data No. in problem Area 0



RNC

Node B [RACH] RRC:RRC Connection Request NBAP: RL Setup Request

Timer T300 is started

Start TX/RX NBAP: RL Setup Response ALCAP:ERQ ALCAP:ECF [FACH] RRC: RRC Connection Setup

Start TX/RX L1 Synchronisation NBAP: Synchronisation Indication

NBAP:RL Setup Request

RNC sends RRC Connection Setup -message

1

S UE sends RRC Connection Request message

BTS Starts sending DPCCH: Pilot and TPC & Starts UL synchronization procedure

BTS sends: NBAP RADIO LINK SETUP RESPONSE message

UE start sending DPCCH for UL sync purposes (pilot) after DL frame sync is established

[DCH] RRC: RRC Connection Setup Complete

• When the UE has established the frame synchronization to the downlink DPCH, it starts the transmission of the uplink DPCH • The DPDCH is transmitted only when there are Transport Blocks received from the UE L2

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RNC



Start TX/RX

• When a physical dedicated channel establishment is initiated by the UE, the UE starts a timer T312 and wait for layer 1 to indicate N312 "in sync" indications • On receiving N312 "in sync" indications, the physical channel is considered established and the timer T312 is stopped and reset • On the BTS side after receiving synchronisation indicators the BTS sends NBAP: SYNCHRONIZATION INDICATION – message to RNC after which the closed loop and outer loop PC start to control the powers

L1 Synchronisation NBAP: Synchronisation Indication [DCH] RRC: RRC Connection Setup Complete

N_INSYNC_IND indicators on L1

Timer T312 started

1 UE initiates physical dedicated channel establishment before sending e.g. RRC Connection Setup Complete –message on DPDCH

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Other cases HHO, FACH=>DCHstate transitions RAN_c_pe.PPT / 18-03-2004 / JRe

“in sync” indicators on L1

N312 L1 “in sync” indicators

L1 Synchronization established BTS sends NBAP: SYNCHRONIZATION IDICATION -message

RNC receives RRC Connection Setup Complete –message ->

Timer T312 stopped L1 Synchronization established

RRC Connection Setup Complete –message SENT



• In case UE is not able to establish synchronization within timer T312 it stops TX on the DCH • In case BTS is not able to establish synchronization it does not send NBAP:Synchronization Indication –message to RNC • The BTS tries to establish synchronization until RNC sends NBAP:Radio Link Deletion -message UE

RNC



Start TX/RX L1 Synchronisation

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• Longer time (T312 high and high N312) the UE has to establish the L1 synchronization the higher probability successful physical channel establishment is and better call set up success rate • However longer the time for L1 synch the longer is call setup time • During the test it was noted that setting N312 to 2 or 4 (between 1 and 2 there is notable difference) does not have any significant effect on the call set up success rate

100% 90% 80% 70% 60% 50% 40% 30% 20% 10%

Percentile MOC call setup delay @5 sec Percentile MTC call setup delay @5 sec

N312 =1 30

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N312 =4

N312 =2

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17/03/03

07/03/03

06/03/03

01/03/03

15/02/03

12/02/03

10/02/03

05/02/03

01/02/03

28/01/03

25/01/03

24/01/03

22/01/03

20/01/03

18/01/03

16/01/03

0% 14/01/03

MOC / MTC call setup delay 5 sec Percentile

AMR performance

• But the effect on the call set up time is significant and therefore N312 value of 2 was selected to be used



• Way to improve RRC Connection success rate •

Improve the UE idle mode behavior by making the intra-frequency measurements earlier and cell reselection more aggressive • Adjust the T312 and N312 values

• RRC Connection Success rate can be low due to: • •

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UE changing cell during RRC Connection Setup phase (cell A -> cell B) RRC Connection Setup –message is not heard by the UE

RAN_c_pe.PPT / 18-03-2004 / JRe


RNC

BTS RRC: Connection Request


CN

Correctly Received message RRC Connection Setup Starts Triggers: 1001C0 RRC Connection Attempt

RRC Connection Setup phase

RRC Setup Complete Ratio [%] 100*[Sum(1001C1)/Sum(1001C0)]

Resource Reservation in RNC, BTS, Transmission RRC: RRC Connection Request Setup RRC Connection setup completed Triggers: 1001C1 RRC Con Setup Compl

RRC Setup and Access Complete Ratio [%] 100*[Sum(1001C8)/Sum(1001C0)]

RRC Connection Access phase RNC waits reply from UE

RRC: RRC Connection Completed RRC Connection Access completed Triggers: 1001C8 RRC Con Acc Comp

RRC: Initial Direct Transfer

Special Reason: RRC Connection Active Release Due to Triggers: 1001C13 SRNC Relocation 1001C14 Pre-emption

RANAP: Initial UE Message

RRC Drop Ratio [%]

RRC Connection Active phase

100-100*[Sum(1001C12+1001C13 +1001C14)/Sum(1001C8)]

UE-CN Signaling

RANAP: Iu Release Command RRC Connection Active completed Triggers: 1001C12 RRC Con Active Comp

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RNC

BTS RRC: Connection Request


CN

Failure Case: RRC Connection Setup fails Due to Triggers: 1001C2 Handover control 1001C3 Admission control 1001C4 BTS 1001C5 Transmission network 1001C6 RNC internal reason 1001C7 Frozen BTS





RRC: RRC Connection Completed

Failure Case: RRC Connection Access fails Due to Triggers: 1001C9 L1 synchronization in BTS 1001C10 UU interface 1001C11 RNC internal reason

RRC Connection Access completed Triggers: 1001C8 RRC Con Acc Comp



RRC Connection Active phase UE-CN Signaling


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Failure Case: RRC Connection Active fails Due to Triggers: 1001C15 Iu interface 1001C16 Radio interface 1001C17 BTS 1001C18 Iur interface 1001C19 Ciphering failure 1001C20 Integrity check 1001C21 RNC internal reason Special Reason: RRC Connection Active Release Due to Triggers: 1001C13 SRNC Relocation 1001C14 Pre-emption


RNC

BTS

CN

RRC: Connection Request Correctly Received message Triggers: 1001C0 RRC Connection Attempt




RRC: RRC Connection Completed RRC Connection Access completed Triggers: 1001C8 RRC Con Acc Comp





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RRC Connection Establishment RRC Connection Setup due to Cause Triggers: 1001C22 MOC conv call att 1001C24 MOC stream call att 1001C26 MOC interac call att 1001C28 MOC backgr call att 1001C30 MOC subscribed call att 1001C32 MTC conv call att 1001C34 MTC stream call att 1001C36 MTC interac call att 1001C38 MTC backgr call att 1001C40 Emergency call att 1001C42 Inter RAT cell reselection 1001C44 Inter RAT cell chng ord 1001C46 Registration attempt 1001C48 Detach attempt 1001C50 MOC high prior signaling 1001C52 MTC high prior signaling 1001C54 MOC low prior signaling 1001C56 MTC high prior signaling 1001C58 Call re establishment att 1001C60 Terminating cause unknown Failures by RRC Connection Setup Causes Triggers: 1001C23 MOC conv call failure 1001C25 MOC stream call failure 1001C27 MOC interac call failure 1001C29 MOC backgr call failure 1001C31 MOC subscribed call fail 1001C33 MTC conv call failure 1001C35 MTC stream call failure 1001C37 MTC interac call failure 1001C39 MTC backgr call failure 1001C41 Emergency call failure 1001C43 Inter RAT cell reselec fail 1001C45 Inter RAT cell chng ord fail 1001C47 Registration attempt fai 1001C49 Detach attempt failure 1001C51 MOC high prior sig failure 1001C53 MTC high prior sig failure 1001C55 MOC low prior sig failure 1001C57 MTC high prior sig failure 1001C59 Call re establishment fail 1001C61 Terminating cause unknown failure


RNC


AC to check to accept or reject RRC Connection Request [FACH] RRC:RRC Connection Reject : Cause Unspecified

DCH allocation rejection triggers: M1001C3 RRC Connection Setup Failure due to Admission Control

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Correctly Received message RRC Connection Request Triggers: 1001C0 RRC Connection Attempt M1002C3 DCH Requests for RRC Connection in SRNC M1002C0 DCH Request for Signaling Link in SRNC – includes SHO

In case the UL load (measured PrxTotal) exceeds PrxTraget + PrxOffset or Prx_nc exceeds PrxTarget Counter M1002C1 DCH Request for Signaling Link Reject in UL in SRNC


RNC


AC to check to accept or reject RRC Connection Request [FACH] RRC:RRC Connection Reject : Cause Unspecified

DCH allocation rejection triggers: M1001C3 RRC Connection Setup Failure due to Admission Control

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Correctly Received message RRC Connection Request Triggers: 1001C0 RRC Connection Attempt M1002C3 DCH Requests for RRC Connection in SRNC M1002C0 DCH Request for Signaling Link in SRNC – includes SHO

In case the DL load (measured PtxTotal) exceeds PtxTraget + PtxOffset or Ptx_nc exceeds the PtxTarget Counter M1002C2 DCH Request for Signaling Link Reject in DL in SRNC


Node B

RNC

[RACH] RRC:RRC Connection Request AC to check to accept or reject RRC Connection Request NBAP: RL Setup Request Start TX/RX NBAP: RL Setup Failure


Correctly Received message RRC Connection Request Triggers: 1001C0 RRC Connection Attempt M1002C0 DCH Request for Signaling Link in SRNC M1002C3 DCH Requests for RRC Connection in SRNC Successful AC decision triggers: M1002C7 DCH Allocation for Signaling Link 3.4kbps in SRNC M1005C0 Radio Link Setup Attempt for First Radio Link

[FACH] RRC:RRC Connection Reject : Cause Unspecified

RL allocation rejection triggers: M1001C4 RRC Connection Setup Failure due to BTS Reasons

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M1005C13 Radio Link Setup Failure for First Radio Link due to Not Enough Resources M1005C15 Radio Link Setup Failure for First Radio Link due to BTS General Reason


Node B

RNC


[RACH] RRC:RRC Connection Request AC to check to accept or reject RRC Connection Request NBAP: RL Setup Request Start TX/RX NBAP: RL Setup Response ALCAP:ERQ ALCAP:ECF


M1002C0 DCH Request for Signaling Link in SRNC M1002C3 DCH Requests for RRC Connection in SRNC Successful AC decision triggers: M1002C7 DCH Allocation for Signaling Link 3.4kbps in SRNC M1005C0 Radio Link Setup Attempt for First Radio Link M1005C5 Radio Link Setup Success for First Radio Link

[FACH] RRC:RRC Connection Reject : Cause Unspecified

Failure in AAL2 connection setups triggers RRC Connection Reject message and: M1001C5 RRC Connection Setup Failure due to Transmission

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Node B


RNC

[RACH] RRC:RRC Connection Request AC to check to accept or reject RRC Connection Request NBAP: RL Setup Request Start TX/RX

Sent RRC Connection Setup –message triggers: M1001C1 RRC Connection Setup Complete

NBAP: RL Setup Failure ALCAP:ERQ ALCAP:ECF [FACH] RRC: RRC Connection Setup Start TX/RX L1 Synchronisation NBAP: Synchronisation Indication

Failure in receiving the RRC Connection Setup Complete 1) And missing NBAP Synchronisation Indication: M1001C9 RRC Connection Access Failure due to Radio Interface Synchronisation is updated 2) NBAP Synchronisation Indication is received : M1001C10 RRC Connection Failure due to Uu Interface

[DCH] RRC: RRC Connection Setup Complete

Received RRC Connection Setup Complete – message triggers: M1001C8 RRC Connection Access Complete

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RAB Establishment UE

Node B

RAB Establishment MGW

RNC

RRC Connection Establishment Initial Direct Transfer (CM Service Request)

SCCP: Connection Request SCCP: Connection Confirm Location Reporting Control Common ID Security Mode Command

Security Mode Complete Setup Call Proceeding Facility RAB Assignment Request Radio Link Reconfigure Prepare Radio Link Reconfigure Ready AAL2SIG:ERQ AAL2SIG:ECF FP: Downlink Sync FP: Uplink Sync AAL2SIG:ERQ AAL2SIG:ECF Radio Link Reconfiguration Commit Radio Bearer Setup Radio Bearer Setup Complete RAB Assignment Response Alerting Connect Connect Acknowledge Call Established

40

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RAB Establishment BTS

UE

RNC

RAB Establishment

CN

RANAP: RAB Assignment Request

RAB Setup phase

Resource Reservation in RNC, BTS, Transmission

RAB Setup Complete Ratio [%]

100*[Sum(1001C73…79)/Sum(1001C66…72)]

RRC: Radio Bearer Setup

RAB Setup and Access Complete Ratio [%]

RAB Connection Access phase RNC waits reply from UE

100*[Sum(1001C115..121)/Sum(1001C66…72)]

RRC: Radio Bearer Setup Completed RANAP: RAB Assignment Response

RANAP: RAB Assignment Request, with IE: RAB Release RRC: Radio Bearer Release RRC: Radio Bearer Reconfiguration Complete RANAP: RAB Assignment Response

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RAB Drop Ratio [%]

100-100*[Sum(1001C136…142+1001C143+ 1001C144+1001C151…154+1001C167…172) /Sum(1001C115…121)]


UE

RNC

RAB Establishment

CN


RANAP: RAB Assignment Request

RAB Setup phase

Resource Reservation in RNC, BTS, Transmission RRC: Radio Bearer Setup

RAB Setup starts Depending on RAB Type Triggers: 1001C66 RAB setup att for CS Voice 1001C67 RAB setup att for CS Data conv class 1001C68 RAB setup att for CS Data stream class 1001C69 RAB setup att for PS Data conv class 1001C70 RAB setup att for PS Data stream class 1001C71 RAB setup att for PS Data intera class 1001C72 RAB setup att for PS Data backgr class

RAB Connection Access phase RNC waits reply from UE

RRC: Radio Bearer Setup Completed RANAP: RAB Assignment Response

RAB Active phase

User Plane Data Transfer

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RAB Access Completed Triggers: 1001C115 RAB setup acc comp for CS Voice 1001C116 RAB setup acc comp for CS Data conv class 1001C117 RAB setup acc comp for CS Data stream class 1001C118 RAB setup acc comp for PS Data conv class 1001C119 RAB setup acc comp for PS Data stream class 1001C120 RAB setup acc comp for PS Data intera class 1001C121 RAB setup acc comp for PS Data backgr class RAN_c_pe.PPT / 18-03-2004 / JRe

Failure Case: CS RAB Access for Voice fails Due to Triggers: 1001C122 UE 1001C123 RNC internal Note: Each RAB type has identical failure counters

Failure Case: CS RAB Setup for Voice fails Due to Triggers: 1001C80 Admission control 1001C81 BTS 1001C82 Transmission network 1001C83 RNC internal reason 1001C84 Frozen BTS Note: Each RAB type has identical failure counters RAB Setup Completed Depending on RAB Type Triggers: 1001C73 RAB setup comp for CS Voice 1001C74 RAB setup comp for CS Data conv class 1001C75 RAB setup comp for CS Data stream class 1001C76 RAB setup comp for PS Data conv class 1001C77 RAB setup comp for PS Data stream class 1001C78 RAB setup comp for PS Data intera class 1001C79 RAB setup comp for PS Data backgr class


UE

RNC

RAB Establishment

CN

RAB Active phase

Special Reason: RAB Active Release Due to Triggers: 1001C143 SRNC Relocation for CS Voice 1001C144 Pre-emption for CS Voice For all types of RABs

User Plane Data Transfer RANAP: RAB Assignment Request, with IE: RAB reconfiguration

RAB Reconfiguration

Resource Reconfigured in RNC, BTS, Transmission

RAB Reconfiguration Attempt Triggers: 1001C197 RAB reconf Att For all types of RABs

RRC: Radio Bearer Reconfiguration RRC: Radio Bearer Reconfiguration Complete RANAP: RAB Assignment Response

RANAP: RAB Assignment Request, with IE: RAB Release

RAB Reconfiguration Failure Triggers: 1001C198 RAB reconf Fail For all types of RABs

RRC: Radio Bearer Release RRC: Radio Bearer Reconfiguration Complete RANAP: RAB Assignment Response

RAB Release

Resource Released in RNC, BTS, Transmission

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RAB Active Completed Depending on RAB Type Triggers: 1001C136 RAB Act Comp for CS Voice 1001C137 RAB Act Comp for CS Data conv class 1001C138 RAB Act Comp for CS Data stream class 1001C139 RAB Act Comp for PS Data conv class 1001C140 RAB Act Comp for PS Data stream class 1001C141 RAB Act Comp for PS Data intera class 1001C142 RAB Act Comp for PS Data backgr class


Node B

RNC

MGW

RANAP: RAB Assignment Request Triggers: M1003C8 RAB ASS REQ BY CN 1001C66 RAB setup att for CS Voice… 1001C72 RAB setup att for PS Data backgr class

RANAP: RAB Assignment Request AC to check to accept or reject RAB Assignment Request

RAB Establishment

M1002C12 RT DCH REQ FOR CS VOICE CALL IN SRNC – includes SHO M1002C15 RT DCH INIT REQ FOR CS VOICE CALL IN SRNC M1002C16 RT DCH DHO REQ FOR CS VOICE CALL IN SRNC

Same separately for: CS Conversational class CS Streaming class PS Conversational class PS Streaming class PS Interactive class PS Background class

In case the UL load (measured PrxTotal) exceeds PrxTraget + PrxOffset or Prx_nc + ∆ Prx_nc exceeds PrxTarget Counter M1002C13 RT DCH REQ FOR CS VOICE CALL REJECT IN UL IN SRNC is updated – includes SHO

RANAP: RAB Assignment Response

power max planned power

In case the RAB assignment fails due to AC, counters: M1003C13 RAB ASS NONSUCC DUE TO RN LAYER CAUSE and M1001C80 CS RAB SETUP FAIL DUE TO AC are updated 44

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∆ Prx_nc

?

max planned load

load

RAB Establishment

RAB Establishment

• Parameters to change in order to decrease the AC rejection of RAB (or RRC) connection. • Each BTS measures the total received interference power (PrxTotal)

45

•

BTS uses Alpha Trimmed Averaging Window to calculate Prx_Total values

•

BTS reports the PrxTotal results to the RNC by using RADIO RESOURCE INDICATION message every RRIindicationPeriod

•

RNC calculates simple arithmetic mean to obtain averaged PrxTotal values

•

WinAcRabSetupUl is a BTS parameter that defines the size of the load measurement averaging window used in RNC (AC) to average PrxTotal results

•

Sliding averaging window provides new av PrxTotal value every RRI period

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RAB Establishment

RAB Establishment

• Frame mean of Prx_total is pre-calculated using arithmetic mean of the slot values (15 slots) • Averaged frames are sorted based on PrxMeasAveWindow frames • Filtered values are calculated by taking arithmetic frame mean values which are between ALPHA and (1-APLHA) defined by PrxAlpha • N x α lowest and highest measurements removed • N x (1- 2α) measurements remain Prx

• PrxMeasAveWindow = 10 & PrxAlpha = 0.2 • Frame averages are calculated for 10 frames • 2 max. & 2 min. values excluded : 6 values remaining • Final average Prx_total is calculated on the 6 values

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Av. Frame measurements

RAB Establishment

RAB Establishment

RADIO RESOURCE INDICATION (RRI) message Prx Total is reported to the RNC for LC, AC and PS usage, on every RRIindicationperiod (200 ms)

The BTS is measuring: Prx Total

BTS uses ALPHA TRIMMED MEAN FILTER

PrxAlpha PrxMeasAvWindow

BTS sends the LASTEST averaged measurement result to RNC every RRI period

Prx

… Frame measurements

RRIx RRIx+1RRIx+2 RRIx+n Sliding window average result on every RRI period

WinAcRabSetupUI

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RNC is calculating a sliding window averaged value over the values given by RRI messages

1 m Prx_total = ⋅ ∑Pr x _Totaln+ j m j=1

RAB Establishment

RAB Establishment

• Parameter Name: PrxTarget (Prx_target = PrxTarget+PrxNoise) • Description: An uplink RT RAB is not admitted if the estimated non-controllable power exceeds this threshold

• Default value: 4 dB The default value is coming from the UL load i.e. 10*LOG(1-η) where η is the loading in %.

UL interference power

Prx_target_BS Prx_target

Marginal load area

Planned load area

The 4dB default value corresponds to 60% loading value

The value of the PrxTarget is relative to the system noise; it gives an upper threshold for the noise rise (the ratio of the total received uplink power to system noise) => Prx_target = PrxTarget+PrxNoise 48

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Load

RAB Establishment Load < PrxTarget

RAB Establishment

Load => PrxTarget

Load => PrxTarget

PrxTarget set too high (compared to dimensioning) -> cell shrinks and there is coverage hole -> RAB establishment fails due to not enough power from UE

PrxTarget set too low (compared to dimensioning) -> RAB establishment requests are denied by AC even though there is "enough" coverage in UL

• In case the value is set too low Admission control can reject RT RAB establishments due to UL load threshold exceeded too early. • On the other hand in case the value is set too high (higher than used in dimensioning) then the AC will admit new users beyond the planned UL load limit -> cell breathing will cause coverage holes. 49

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RAB Establishment

RAB Establishment

• Parameter Name: PrxOffset (Prx_target_BS = PrxTarget + PrxOffset + PrxNoise) • Description: The target value of the total received power (PrxTarget) can be exceeded by the value of this parameter before the cell is considered to be overloaded in uplink • Default value: 1 dB The default value of this and PrxTarget gives the total noise rise as 4dB + 1dB = 5dB which corresponds to 68% load

PrxTarget + PrxOffset [dB] should be set according to dimensioning e.g. in case in dimensioning the UL load has been set to be 50% (including RT and NRT services) then the PrxTarget + PrxOffset [dB] should be set to 3dB 50

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RAB Establishment

RAB Establishment

• Parameters to change in order to decrease the AC rejection of RAB (or RRC) connection. • Together with the DL admission decision equation the maximum allowed DL transmission power per connection limits the coverage (and capacity) of certain user (using certain service) • The maximum DL transmission power per connection is determined by the parameter CPICHToRefRABOffset C pichTo Re fRabOffset and the formula below

PtxPrimaryCPICH Ptx ,CPICH Ptx ,max =

Ptx ,CPICH ρ ⋅ RI max ⋅ ρ ref ⋅ RI ref C pichtorefRabOffset

The formula for the maximum link power is defined so that the CPICH coverage and the service coverage are ALWAYS the same

CPICH coverage

=

Service Coverage 51

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RAB Establishment

RAB Establishment

• Parameters to change in order to decrease the AC rejection of RAB (or RRC) connection. • Ptx_target = max planned DL tx power • Set by RNP parameter PtxTarget • When the NC cell load exceeds the target limit, AC rejects RAB requests that would mean immediate DL load increase (i.e. RT RABs)

• Ptx_target_BS = DL overload threshold above which BTS starts its load control actions to prevent overload • RNC also performs preventive actions; AC rejects all RAB requests if this limit is reached • Ptx_target_BS is defined by the RNP parameters PtxOffset + PtxTarget 52

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DL transmission power

Ptx_target_BS Ptx_target

Marginal load area

Planned load area

Load


Node B

RNC

RAB Establishment

MGW

RANAP: RAB Assignment Request Triggers: M1003C8 RAB ASS REQ BY CN 1001C66 RAB setup att for CS Voice… 1001C72 RAB setup att for PS Data backgr class

RANAP: RAB Assignment Request AC to check to accept or reject RAB Assignment Request

Same separately for: CS Conversational class CS Streaming class PS Conversational class PS Streaming class PS Interactive class PS Background class

M1002C12 RT DCH REQ FOR CS VOICE CALL IN SRNC – includes SHO M1002C15 RT DCH INIT REQ FOR CS VOICE CALL IN SRNC M1002C16 RT DCH DHO REQ FOR CS VOICE CALL IN SRNC

In case the DL load (measured PtxTotal) exceeds PtxTraget + PtxOffset or Ptx_nc + ∆ Ptx_nc exceeds PtxTarget Counter M1002C14 RT DCH REQ FOR CS VOICE CALL REJECT IN DL IN SRNC is updated – includes SHO M1002C17 RT DCH DHO REQ FOR CS VOICE CALL REJECT IN SRNC – includes SHO only


In case the RAB assignment fails due to AC, counters: M1003C13 RAB ASS NONSUCC DUE TO RN LAYER CAUSE and M1001C80 CS RAB SETUP FAIL DUE TO AC are updated 53

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∆Ptx _ nc = ∆Ptx + Ptx ,inactive

∆Ptx = Ptx ,max = RI max,eff ⋅ Ptx ,ref RI max,eff =

ρ ⋅ RI max ρ ref ⋅ RI ref

Ptx ,ref =

Ptx ,CPICH C pichTo Re fRabOffset


Node B

RNC

MGW

RANAP: RAB Assignment Request AC to check to accept or reject RAB Assignment Request NBAP: RL Reconfiguration Prepare NBAP: RL Reconfiguration Ready Same separately for: CS Conversational class CS Streaming class ALCAP:ERQ PS Conversational class PS Streaming class ALCAP:ECF PS Interactive class PS Background class NBAP: RL Reconfiguration Commit [DCH] RRC: Radio Bearer Setup [DCH] RRC: Radio Bearer Setup Complete RANAP: RAB Assignment Response

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RAB Establishment

RANAP: RAB Assignment Request Triggers: M1003C8 RAB ASS REQ BY CN 1001C66 RAB setup att for CS Voice… 1001C72 RAB setup att for PS Data backgr class M1002C12 RT DCH REQ FOR CS VOICE CALL IN SRNC – includes SHO M1002C15 RT DCH INIT REQ FOR CS VOICE CALL IN SRNC M1002C16 RT DCH DHO REQ FOR CS VOICE CALL IN SRNC

In case successful AC (UL and DL) counter M1002C18 -M1002C33 RT DCH ALLO FOR AMR x.xx KBPS IN yL IN SRNC For different bitrates and separately for UL and DL, includes SHO as well


Node B

RNC

MGW

RANAP: RAB Assignment Request AC to check to accept or reject RAB Assignment Request NBAP: RL Reconfiguration Prepare NBAP: RL Reconfiguration Failure


In case the RAB assignment fails due to AC, counters: M1003C13 RAB ASS NONSUCC DUE TO RN LAYER CAUSE and M1001C81 CS RAB SETUP FAIL DUE TO BTS are updated 55

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RAB Establishment

When RNC starts existing RL modification procedure (to modify the RL set up for SRB) counter: M1005C79 RL RECONF PREP SYNCH FOR DCH MOD ON SRNC In case there is a failure to setup RL with the BTS one of the failure cause counters is updated: M1005C96 RL RECONF PREP SYNCH FOR DCH MOD FAIL ON SRNC DUE TO O&M INTERV M1005C97 RL RECONF PREP SYNCH FOR DCH MOD FAIL ON SRNC DUE TO ALREADY ACTIV M1005C98 RL RECONF PREP SYNCH FOR DCH MOD FAIL ON SRNC DUE TO HW RES NOT AVAIL M1005C99 RL RECONF PREP SYNCH FOR DCH MOD FAIL ON SRNC DUE TO NOT ENOUGH RES M1005C100 RL RECONF PREP SYNCH FOR DCH MOD FAIL ON SRNC DUE TO BTS NOT RESP M1005C101 RL RECONF PREP SYNCH FOR DCH MOD FAIL ON SRNC DUE TO BTS GEN REA


Node B

RNC

MGW

RANAP: RAB Assignment Request AC to check to accept or reject RAB Assignment Request NBAP: RL Reconfiguration Prepare NBAP: RL Reconfiguration Ready ALCAP:ERQ ALCAP:ECF NBAP: RL Reconfiguration Cancel


In case the RAB assignment fails due to AC, counters: M1003C13 RAB ASS NONSUCC DUE TO RN LAYER CAUSE and M1001C81 CS RAB SETUP FAIL DUE TO BTS are updated 56

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RAB Establishment

When RNC starts existing RL modification procedure (to modify the RL set up for SRB) counter: M1005C79 RL RECONF PREP SYNCH FOR DCH MOD ON SRNC In case of Successful RL Reconfiguration counter: M1005C85 RL RECONF PREP SYNCH FOR DCH MOD ON SRNC READY, is updated In case the AAL2 connection setup fails , counters: M1003C14 RAB ASS NONSUCC DUE TO TR LAYER CAUSE and M1001C82 CS RAB SETUP FAIL DUE TO TRANSM are updated In case the AAL2 connection setup fails , NBAP RL Reconfiguration Cancel message is sent and counter: M1005C128 RL RECONF CANC SYNCH ON SRNC DUE TO TRANSMISSION SETUP FAIL is updated


Node B

RNC

RAB Establishment

MGW

RANAP: RAB Assignment Request AC to check to accept or reject RAB Assignment Request NBAP: RL Reconfiguration Prepare NBAP: RL Reconfiguration Ready ALCAP:ERQ ALCAP:ECF NBAP: RL Reconfiguration Commit [DCH] RRC: Radio Bearer Setup


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Successful AAL2 setup leads to NBAP: RL Reconfiguration Commit message being sent to the BTS and counter M1005C126 RL RECONF COMM SYNCH ON SRNC – includes modifications & additions After successful RL Reconfiguration Commit the RNC tells the UE about the new DCH by sending RRC: Radio Bearer Setup message. Counter: M1006C28 RADIO BEARER SETUP is updated

THIS IS THE END OF RAB SETUP PHASE and STARTING POINT OF RAB ACCESS PHASE In case there is no RRC: Radio Bearer Setup Complete message received from the UE either counter M1001C122 RAB SETUP ACC FAIL FOR CS VOICE CALL DUE TO UE (UE failing to support new configuration) or M1001C123 RAB SETUP ACC FAIL FOR CS VOICE CALL DUE TO RNC INTERNAL is updated (the RB Setup Complete message is lost)


Node B

RNC

RAB Establishment

MGW

RANAP: RAB Assignment Request AC to check to accept or reject RAB Assignment Request NBAP: RL Reconfiguration Prepare NBAP: RL Reconfiguration Ready ALCAP:ERQ ALCAP:ECF NBAP: RL Reconfiguration Commit [DCH] RRC: Radio Bearer Setup [DCH] RRC: Radio Bearer Setup Complete RANAP: RAB Assignment Response

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In case of successful RAB Assignment counters: M1003C11 RAB ASS SUCC and M1001C115 RAB SETUP ACC COMP FOR CS VOICE CALL are updated

THIS IS THE END OF RAB ACCESS PHASE

Handovers BTS

UE

RNC

RRC: Measurement Report (e1a / e1c) Decision to set up new RL NBAP: Radio Link Setup Request – for Soft Handover NBAP: Radio Link Addition Request – for Softer Handover Start TX/RX NBAP: Radio Link Setup Response

Handovers; SHO, ISHO, IFHO

Received message RRC: Measurement Report (e1A). Triggers for RT: M1007C10 CELL ADDITION REQUEST ON SHO FOR RT TRAFFIC Received message RRC: Measurement Report (e1B). Triggers for RT: M1007C11 CELL DELETION REQUEST ON SHO FOR RT TRAFFIC Received message RRC: Measurement Report (e1C). Triggers for RT: M1007C12 CELL REPLACEMENT REQUEST ON SHO FOR RT TRAFFIC Received message RRC: Measurement Report (e1A). Triggers for NRT: M1007C27 CELL ADDITION REQUEST ON SHO FOR NRT TRAFFIC Received message RRC: Measurement Report (e1B). Triggers for NRT: M1007C28 CELL DELETION REQUEST ON SHO FOR NRT TRAFFIC Received message RRC: Measurement Report (e1C). Triggers for NRT: M1007C29 CELL REPLACEMENT REQUEST ON SHO FOR NRT TRAFFIC

NBAP: Radio Link Addition Response ALCAP:ERQ ALCAP:ECF

For each cell already in AS the above counters are updated i.e. in this case 2 cells

RRC: Active Set Update B

RRC: Active Set Update Complete A

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At first (UE in point A) AS includes 2 cells Then UE moves to point B and reports e1A to add “blue” cell

Handovers BTS

UE

RNC

RRC: Measurement Report (e1a / e1c) Decision to set up new RL NBAP: Radio Link Setup Request Start TX/RX UL Synchronisation Procedure starts ALCAP:ERQ ALCAP:ECF RRC: Active Set Update UE Synchronisation Procedure starts: According to Synchronization Procedure B

RRC: Active Set Update Complete

In case BTS responses back to RNC by NBAP: RL Setup Response/RL Addition Response M1005C6: RL SETUP SUCC FOR SHO ON SRNC M1005C8:RL SETUP SUCC FOR SHO ON DRNC M1005C44: RL BRANCH ADD SUCC FOR SHO ON SRNC M1005C45: RL BRANCH ADD SUCC FOR SHO ON SRNC 60

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NBAP: Synchronization Indication

NBAP: Radio Link Setup Response


Number of DCH requests for Diversity HO (SHO) for voice calls in SRNC M1002C16 RT DCH DHO REQ FOR CS VOICE CALL IN SRNC Number of DCH requests for a CS Voice Call rejected by the SRNC for reasons caused by radio resources in the target cell of diversity handover M1002C17 RT DCH DHO REQ FOR CS VOICE CALL REJECT IN SRNC Number of DCH requests for a transparent CS Data Call with conversational class due to diversity handover in the SRNC M1002C58 RT DCH DHO REQ FOR CS DATA CALL CONV CLASS IN SRNC Number of DCH requests for a transparent CS Data Call (on SRNC side) rejected for reasons caused by radio resources in the target cell of diversity handover M1002C59 RT DCH DHO REQ FOR CS DATA CALL CONV CLASS REJECT IN SRNC SRNC A total number of DCH requests for a nontransparent CS Data Call with streaming class due to diversity handover in the SRNC M1002C60 RT DCH DHO REQ FOR CS DATA CALL STREAM CLASS IN Number of DCH requests for a nontransparent CS Data Call with streaming class (SRNC side) rejected for reasons caused by radio resources in the target cell of diversity handover M1002C61RT DCH DHO REQ FOR CS DATA CALL STREAM CLASS REJECT IN SRNC

SAME FOR DRNC!

In case of RNC sends to BTS NBAP: RL Setup Request/RL Addition Request M1005C1: RL SETUP ATT FOR SHO ON SRNC M1005C3:RL SETUP ATT FOR SHO ON DRNC M1005C42: RL BRANCH ADD ATT FOR SHO ON SRNC M1005C43: RL BRANCH ADD ATT FOR SHO ON DRNC

Handovers BTS

UE

RNC

RRC: Measurement Report (e1a / e1c) Decision to set up new RL NBAP: Radio Link Setup Request Start TX/RX NBAP: Radio Link Setup Response ALCAP:ERQ ALCAP:ECF


Received message RRC: Active Set Update Complete. Triggers: M1007C15 SUCCESSFUL ACTIVE SET UPDATES ON SHO FOR RT TRAFFIC Received message RRC: Active Set Update Complete. Triggers: M1007C32 SUCCESSFUL ACTIVE SET UPDATES ON SHO FOR NRT TRAFFIC Received message RRC: Active Set Update Failure. Triggers: M1007C16 UNSUCCESSFUL ACTIVE SET UPDATES ON SHO FOR RT TRAFFIC Received message RRC: Active Set Update Failure. Triggers: M1007C33 UNSUCCESSFUL ACTIVE SET UPDATES ON SHO FOR NRT TRAFFIC

RRC: Active Set Update RRC: Active Set Update Complete RRC: Active Set Update Failure

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For each cell in the AS the above counter(s) are updated (including the cell to be deleted from AS in case of e1B)

Handovers UE is in Spot A i.e. not in soft handover -> AS size = 1

A

1

B

2

UE in Spot B sends Measurement report indicating e1A to add cell 2 -> M1007C10 CELL ADDITION REQUEST ON SHO FOR RT TRAFFIC is updated in cell 1

UE


BTS

RNC

RRC: Measurement Report (e1a / e1c) Decision to set up new RL NBAP: Radio Link Setup Request UL Synchronisation Procedure starts NBAP: Radio Link Setup Response

Start TX/RX

ALCAP:ERQ ALCAP:ECF

RNC Makes AC/RM for the SHO – updates M1002C16 RT DCH DHO REQ FOR CS VOICE CALL IN SRNC counter in cell 2 RNC sends NBAP: RL Setup Request to BTS – updates M1005C1: RL SETUP ATT FOR SHO ON SRNC counter in cell 2

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BTS receives the NBAP; RL Setup Request, if RL Setup Is successful, starts TX/RX and UL Synchronization procedure and sends NBAP: RL Setup Response to RNC

Handovers UE

RNC Sends RRC: Active Set Update –message to the UE


BTS

RNC


Start TX/RX

1

B

2

ALCAP:ERQ ALCAP:ECF RRC: Active Set Update

UE Synchronisation Procedure starts: After receiving RRC: Active Set Update from RNC According to Synchronization Procedure B the UE checks the Update message and if ok UE RRC: Active Set Update Complete starts Synchronization Procedure B and and sends RRC: Active Set Update Complete message without waiting for the completion of the When receiving RRC: Active Set Update Physical Layer synchronization procedure B Complete, the RNC updates M1007C15 (according to 25.214/25.331) SUCCESSFUL ACTIVE SET UPDATES ON SHO FOR

RT TRAFFIC or M1007C32 SUCCESSFUL ACTIVE SET UPDATES ON SHO FOR NRT TRAFFIC counter. Counter updated for cell 1.

63

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Handovers


• The Active Set Update success rate can be calculated as: Active Set Update Success Ratio ( RT ) = 100 *

sum ( Successful Active Set Updates On SHO For RT Traffic ( M 1007 C15)) % sum ( Successful Active Set Updates On SHO For RT Traffic ( M 1007 C15) + Unsuccessf ul Active Set Updates On SHO For RT Traffic ( M 1007 C16))

Active Set Update Success Ratio ( NRT ) = 100 *

sum ( Successful Active Set Updates On SHO For NRT Traffic ( M 1007 C 32 )) % sum ( Successful Active Set Updates On SHO For NRT Traffic ( M 1007 C 32 ) + Unsuccessf ul Active Set Updates On SHO For NRT Traffic ( M 1007 C 33)) UE

BTS

RNC


Start TX/RX

ALCAP:ERQ ALCAP:ECF

1 RRC: Active Set Update

UE Synchronisation Procedure starts: According to Synchronization Procedure B

RRC: Active Set Update Complete 64

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Handovers


• In case also RL Setup Procedure and AC decision are needed to be included then the SHO Success Rate could be counted as: • •

(M1007C15)/(M1007C10 + M1007C11 + M1007C12) – for RT traffic (M1007C32)/(M1007C27 + M1007C28 + M1007C29) – for NRT traffic

• SUCCESSFUL ACTIVE SET UPDATES ON SHO FOR RT TRAFFIC (M1007C15) divided by ADDITION/DELETION/REPLACEMENT REQUEST ON SHO FOR RT TRAFFIC (M1007C10 + M1007C11 + M1007C12) • Then in case the SHO Success Rate formula 1 and 2 are giving different results the problem spot can be identified by analysing: •

Iub Radio Link Set up & Addition success rate (either combined as below or separately)

Radio Link Set Up / Addition Success ( SHO ) = M1005C42 + M1005C43 + M1005C1 + M1005C3 100 * % M1005C44 + M1005C45 + M1005C6 + M1005C8 •

UE

BTS

RNC

RRC: Measurement Report (e1a / e1c) Decision to set up new RL

And separate failure reasons can be identified based on M1005C16 – M1005C21, M1005C28 – M1005C33, M1005C46 – M1005C57 and M1005C58 – M1005C65

NBAP: Radio Link Setup Request UL Synchronisation Procedure starts NBAP: Radio Link Setup Response

Start TX/RX

ALCAP:ERQ ALCAP:ECF RRC: Active Set Update

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UE Synchronisation Procedure starts: According to Synchronization Procedure B


Handovers


• Then in case the SHO Success Rate formula 1 and 2 are giving different results the problem spot can be identified by analysing: •

DCH allocation success rate for SHO purposes

DCH Allocation Success ( SHO ) = M 1002 C17 + M 1002 C 59 + M 1002 C 61 + M 1002 C103 + M 1002 C105 + M 1002 C107 + M 1002 C109    ⋅ 100 % 1 − M1002C16 + M1002C58 + M1002C60 + M1002C102 + M1002C104 + M1002C106 + M1002C108  

• Where nominator is stating the number of DCH allocation requests in the target cell for Diversity Handover (SHO) for RT traffic classes (Speech+Conversational CS data + Streaming CS Data) and NRT traffic classes (Conversational PS data + Streaming PS data + Interactive PS data + Background PS data) • Where denominator is the allocation rejections due to lack of radio resources in target cell

UE

BTS

RNC


Start TX/RX

ALCAP:ERQ ALCAP:ECF RRC: Active Set Update UE Synchronisation Procedure starts: According to Synchronization Procedure B


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Handovers


• RL SETUP ATT FOR SHO ON SRNC (M1005C1) • •

A number of radio link setup attempts for soft HO on SRNC side UPDATED when a common NBAP signaling entity sends a RADIO_LINK_SETUP_REQUEST message to a BTS

• RL SETUP ATT FOR SHO ON DRNC (M1005C3) • •

A number of radio link setup attempts for soft HO on DRNC side UPDATED when a common NBAP signaling entity sends a RADIO_LINK_SETUP_REQUEST message to a BTS

• RL SETUP SUCC FOR SHO ON SRNC (M1005C6) • •

A number of radio link setup successes for SHO (=first RL) UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_RESPONSE message from a BTS

• RL SETUP SUCC FOR SHO ON DRNC (M1005C8) • •

A number of radio link setup successes for SHO (=first RL) UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_RESPONSE message from a BTS

• RL SETUP FAIL FOR SHO ON SRNC DUE TO O&M INTERV (M1005C16) • •

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A number of radio link setup failures for soft HO on SRNC side due to O&M intervention UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• RL SETUP FAIL FOR SHO ON SRNC DUE TO ALREADY ACTIV (M1005C17) • •

A number of radio link setup failures for soft HO on SRNC side due to a context that is already activated UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

• RL SETUP FAIL FOR SHO ON SRNC DUE TO HW RES NOT AVAIL (M1005C18) • •

A number of radio link setup failures for soft HO on SRNC side caused by the fact that there are no available HW resources UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

• RL SETUP FAIL FOR SHO ON SRNC DUE TO NOT ENOUGH RES (M1005C19) • •

A number of radio link setup failures for soft HO on SRNC side caused by the fact that there are not enough resources UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

• RL SETUP FAIL FOR SHO ON SRNC DUE TO BTS NOT RESP (M1005C20) • • •

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A number of radio link setup failures for soft HO on SRNC side caused by the fact that the BTS is not responding If the BTS does not respond in the allowed time UPDATED when a common NBAP signaling entity does not receive any response from a BTS to a RADIO_LINK_SETUP message RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• RL SETUP FAIL FOR SHO ON SRNC DUE TO BTS GEN REA (M1005C21) • •

A number of radio link setup failures for soft HO on SRNC side due to a general reason of a BTS UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

• RL SETUP FAIL FOR SHO ON DRNC DUE TO O&M INTERV (M1005C28) • •

A number of radio link setup failures for soft HO on DRNC side due to O&M intervention UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

• RL SETUP FAIL FOR SHO ON DRNC DUE TO ALREADY ACTIV (M1005C29) • •

A number of radio link setup failures for soft HO on DRNC side due to a context that is already activated UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

• RL SETUP FAIL FOR SHO ON DRNC DUE TO HW RES NOT AVAIL (M1005C30) • •

A number of radio link setup failures for soft HO on DRNC side caused by the fact that there are no available HW resources UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

• RL SETUP FAIL FOR SHO ON DRNC DUE TO NOT ENOUGH RES (M1005C31) • •

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A number of radio link setup failures for soft HO on DRNC side caused by the fact that there are not enough resources UPDATED when a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

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RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• RL SETUP FAIL FOR SHO ON DRNC DUE TO BTS NOT RESP (M1005C32) • • •

A number of radio link setup failures for soft HO on DRNC side caused by the fact that the BTS is not responding If the BTS does not respond in the allowed time UPDATED when a common NBAP signaling entity does not receive any response from a BTS to a RADIO_LINK_SETUP message

• RL SETUP FAIL FOR SHO ON DRNC DUE TO BTS GEN REA (M1005C33) • •

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A number of radio link setup failures for soft HO on DRNC side due to a general reason caused by a BTS UPDATED: When a common NBAP signaling entity receives a RADIO_LINK_SETUP_FAILURE message from a BTS

RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers • RL BRANCH ADD FAIL FOR SHO ON SRNC DUE TO O&M INTERV (M1005C46) • •


A number of radio link branch addition failures for softer HO on SRNC side due to O&M intervention UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_ FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON SRNC DUE TO ALREADY ACTIV (M1005C47) • •

A number of radio link branch addition failures for softer HO on SRNC side due to a context that is already activated UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_ FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON SRNC DUE TO HW RES NOT AVAIL (M1005C48) • •

A number of radio link branch addition failures for softer HO on SRNC caused by the fact that there are no resources available UPDATED when a Dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON SRNC DUE TO NOT ENOUGH RES (M1005C49) • •

A number of radio link branch addition failures for softer HO on SRNC side caused by the fact that there are not enough resources UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_ FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON SRNC DUE TO BTS NOT RESP (M1005C50) • • • 71

A number of radio link branch addition failures for softer HO on SRNC side caused by the fact that a BTS is not responding If the BTS does not respond in the allowed time UPDATED when a dedicated NBAP signaling entity does not receive any response from a BTS to a RADIO_LINK_ADDITION_REQUEST message

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RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• RL BRANCH ADD FAIL FOR SHO ON SRNC DUE TO BTS GEN REA (M1005C51) • •

A number of radio link branch addition failures for softer HO on SRNC side due to a general BTS reason UPDATED when a Dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON DRNC DUE TO O&M INTERV (M1005C52) • •

A number of radio link branch addition failures for softer HO on DRNC side due to O&M intervention UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_ FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON DRNC DUE TO ALREADY ACTIV (M1005C53) • •

A number of radio link branch addition failures for softer HO on DRNC side due to a context that is already activated UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_ FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON DRNC DUE TO HW RES NOT AVAIL (M1005C54) • •

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A number of radio link branch addition failures for softer HO on DRNC side due to 'HW resource not available' UPDATED: When a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_FAILURE message from a BTS

RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• RL BRANCH ADD FAIL FOR SHO ON DRNC DUE TO NOT ENOUGH RES (M1005C55) • •

A number of radio link branch addition failures for softer HO on DRNC side due to 'not enough resources' UPDATED: When a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_ FAILURE message from a BTS

• RL BRANCH ADD FAIL FOR SHO ON DRNC DUE TO BTS NOT RESP (M1005C56) • •

A number of radio link branch addition failures for softer HO on DRNC side caused by the fact that a BTS is not responding UPDATED when a dedicated NBAP signaling entity does not receive any response from a BTS to a RADIO_LINK_ADDITION_REQUEST message

• RL BRANCH ADD FAIL FOR SHO ON DRNC DUE TO BTS GEN REA (M1005C57) • •

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A number of radio link branch addition failures for softer HO on DRNC side due to a general BTS reason UPDATED: When a dedicated NBAP signaling entity receives a RADIO_LINK_ADDITION_FAILURE message from a BTS

RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• Also it is very useful to check the synchronization failures for the SHO cases (RL failures due to synchronization) •

•

•

•

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RL FAIL ON SRNC DUE TO INI SYN FAIL (M1005C58) • A number of radio link failures on SRNC side caused by an initial synchronisation failure • If a BTS fails to establish synchronisation at L1 during the allowed time • UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS RL FAIL ON SRNC DUE TO ACT RL SYN FAIL (M1005C59) • A number of radio link failures on SRNC side caused by an active radio link synchronisation failure • If a BTS loses synchronisation on an active RL and is not able to re-establish synchronisation during the allowed time. • UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS RL FAIL ON DRNC DUE TO INI SYN FAIL (M1005C62) • A number of radio link failures on DRNC side caused by an initial synchronisation failure. • If a BTS fails to establish synchronisation at L1 during the allowed time • UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS RL FAILURE ON DRNC DUE TO ACT RL SYN FAIL (M1005C63) • A number of radio link failures on DRNC side caused by an active radio link synchronisation failure • If a BTS loses synchronisation on an active RL and is not able to re-establish synchronisation during the allowed time • UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• RL FAIL ON SRNC DUE TO BTS HW OVERL (M1005C60) • • •

A number of radio link failures on SRNC side caused by a BTS HW overload If a BTS reports on a HW overload. UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS

• RL FAIL ON SRNC DUE TO BTS EQUIP FAIL (M1005C61) • • •

A number of radio link failures on SRNC side due to a BTS equipment failure If a BTS reports on an equipment failure UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS

• RL FAIL ON DRNC DUE TO BTS HW OVERL (M1005C64) • • •

A number of radio link failures on DRNC side caused by a BTS HW overload If a BTS reports on a HW overload UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS

• RL FAIL ON DRNC DUE TO BTS EQUIP FAIL (M1005C65) • • •

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A number of radio link failures on DRNC side caused by a BTS equipment failure If a BTS reports on an equipment failure UPDATED when a dedicated NBAP signaling entity receives a RADIO_LINK_FAILURE message from a BTS

RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers • RL DEL ON SRNC DUE TO INI SYN FAIL (M1005C67) • • • •


When a RADIO_LINK_DELETION_REQUEST message is sent to a BTS. A number of radio link deletions on SRNC side due to an initial synchronisation failure If a BTS fails to establish synchronisation at L1 during the allowed time UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS

• RL DEL ON SRNC DUE TO ACT RL SYN FAIL (M1005C68) • • •

A number of radio link deletions on SRNC side due to an active radio link synchronisation failure If a BTS loses synchronisation on an active RL and is not able to re-establish synchronisation during the allowed time UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS

• RL DEL ON SRNC DUE TO BTS HW OVERL (M1005C69) • • •

A number of radio link deletions on SRNC side due to a BTS HW overload If a BTS reports on a HW overload UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS

• RL DEL ON SRNC DUE TO BTS EQUIP FAIL (M1005C70) • • • 76

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A number of radio link deletions on SRNC side due to a BTS equipment failure If a BTS reports on an equipment failure UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• RL DEL ON DRNC DUE TO INI SYN FAIL (M1005C73) • • •

A number of radio link deletions on DRNC side due to an initial synchronisation failure If a BTS fails to establish synchronisation at L1 during the allowed time UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS

• RL DEL ON DRNC DUE TO ACT RL SYN FAIL (M1005C74) • • •

A number of radio link deletions on DRNC side due to an active radio link synchronisation failure If a BTS loses synchronisation on an active RL and is not able to re-establish synchronisation during the allowed time UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS

• RL DEL ON DRNC DUE TO BTS HW OVERL (M1005C75) • • •

A number of radio link deletions on DRNC side due to BTS HW overload If a BTS reports on a HW overload UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS

• RL DEL ON DRNC DUE TO BTS EQUIP FAIL (M1005C76) • • •

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A number of radio link deletions on DRNC side due to a BTS equipment failure If a BTS reports on an equipment failure UPDATED when a dedicated NBAP signaling entity sends a RADIO_LINK_DELETION_REQUEST message to a BTS RAN_c_pe.PPT / 18-03-2004 / JRe

Handovers


• SHO overhead per cell (does not apply for areas of several cells) can be calculated as: sum (One cell in the active set for RT ( M1007C0) + One cell in the active set for NRT ( M1007C19) ) *1 + sum (Two cell in the active set for RT ( M1007C1) + Two cell in the active set for NRT ( M1007C20) ) * 2 + sum (Three cell in the active set for RT ( M1007C2) + Three cell in the active set for NRT ( M1007C21) ) * 3 − 1) *100 % SHO overhead = ( sum (One cell in the active set for RT ( M1007C0) + One cell in the active set for NRT ( M1007C19) + Two cell in the active set for RT ( M1007C1) + Two cell in the active set for NRT ( M1007C20) + Three cell in the active set for RT ( M1007C2) + Three cell in the active set for NRT ( M1007C21) )

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Handovers UE

RNC

BTS1

MSC

Reporting event Ec/No is triggered etc. triggered RRC: MEASUREMENT REPORT (event 1F) Decision to activate inter-RAT measurement. Determination of CM pattern. NBAP: RADIO LINK RECONFIGURATION PREPARE NBAP: RADIO LINK RECONFIGURATION READY NBAP: RADIO LINK RECONFIGURATION COMMIT RRC: TRANSPORT CHANNEL RECONFIGURATION RRC: TRANSPORT CHANNEL RECONFIGURATION COMPLETE NBAP: COMPRESSED MODE COMMAND RRC: MEASUREMENT CONTROL RRC: MEASUREMENT REPORT (GSM RSSI, BCCH ARFCN) RRC:MEASUREMENT REPORT (GSM RSSI, BCCH ARFCN) Handover desicion. BSIC verification required NBAP: COMPRESSED MODE COMMAND (CFN, TGPSI 3)

Handovers; SHO, ISHO, IFHO •M1010 C3 NBR OF STARTED INTER SYST HHO MEAS WITH COM MOD DUE TO UL DCH QUAL FOR RT •M1010 C4 NBR OF STARTED INTER SYST HHO MEAS WITH COM MOD DUE TO UE TX PWR FOR RT •M1010 C5 NBR OF STARTED INTER SYST HHO MEAS WITH COM MOD DUE TO DL DPCH FOR RT •M1010 C6 NBR OF STARTED INTER SYST HHO MEAS WITH COM MOD DUE TO CPICH RSCP FOR RT •M1010 C7 NBR OF STARTED INTER SYST HHO MEAS WITH COM MOD DUE TO CPICH ECNO FOR RT •M1010C18 INTER SYST HHO ATTEMPTS CAUSED BY UL DCH QUAL FOR RT •M1010C22 INTER SYST HHO ATTEMPTS CAUSED BY UE TX PWR FOR RT •M1010C26 INTER SYST HHO ATTEMPTS CAUSED BY DL DPCH PWR FOR RT •M1010C30 INTER SYST HHO ATTEMPTS CAUSED BY CPICH RSCP FOR RT •M1010C34 INTER SYST HHO ATTEMPTS CAUSED BY CPICH ECNO FOR RT

RRC: MEASUREMENT CONTROL (BSIC,CFN,TGPSI 3) RRC: MEASUREMENT REPORT (BSIC, GSM cell index) RANAP: RELOCATION REQUIRED RANAP: RELOCATION COMMAND RRC: HANDOVER FROM UTRAN COMMAND RANAP: IU RELEASE COMMAND NBAP: RADIO LINK DELETION REQUEST NBAP: RADIO LINK DELETION RESPONSE 79

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RANAP: IU RELEASE COMPLETE

•M1009C235 INTER SYST HHO OUT PREP REQ CONTR BY MSC

Handovers UE

RNC

BTS1

MSC


Reporting event Ec/No is triggered etc. triggered RRC: MEASUREMENT REPORT (event 1F) Decision to activate inter-RAT measurement. Determination of CM pattern. NBAP: RADIO LINK RECONFIGURATION PREPARE

•M1009C236 INTER SYST HHO OUT PREP SUCC CONTR BY MSC

NBAP: RADIO LINK RECONFIGURATION READY

•M1006C63 HO FROM UTRAN COM

NBAP: RADIO LINK RECONFIGURATION COMMIT RRC: TRANSPORT CHANNEL RECONFIGURATION RRC: TRANSPORT CHANNEL RECONFIGURATION COMPLETE NBAP: COMPRESSED MODE COMMAND RRC: MEASUREMENT CONTROL RRC: MEASUREMENT REPORT (GSM RSSI, BCCH ARFCN) RRC:MEASUREMENT REPORT (GSM RSSI, BCCH ARFCN) Handover desicion. BSIC verification required NBAP: COMPRESSED MODE COMMAND (CFN, TGPSI 3) RRC: MEASUREMENT CONTROL (BSIC,CFN,TGPSI 3) RRC: MEASUREMENT REPORT (BSIC, GSM cell index) RANAP: RELOCATION REQUIRED RANAP: RELOCATION COMMAND RRC: HANDOVER FROM UTRAN COMMAND RANAP: IU RELEASE COMMAND NBAP: RADIO LINK DELETION REQUEST NBAP: RADIO LINK DELETION RESPONSE 80

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RANAP: IU RELEASE COMPLETE

•M1010C19 SUCCESSFUL INTER SYST HARD HANDOVRS CAUSED BY UL DCH QUAL FOR RT •M1010C22 INTER SYST HHO ATTEMPTS CAUSED BY UE TX PWR FOR RT •M1010C26 INTER SYST HHO ATTEMPTS CAUSED BY DL DPCH PWR FOR RT •M1010C30 INTER SYST HHO ATTEMPTS CAUSED BY CPICH RSCP FOR RT •M1010C34 INTER SYST HHO ATTEMPTS CAUSED BY CPICH ECNO FOR RT

Handovers


Continuous coverage for: GSM900 and GSM1800 and no WCDMA coverage (typically indoor)

GSM1800

GSM900

WCDMA

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Continuous coverage for each layer: GSM900, GSM1800 and WCDMA

RAN_c_pe.PPT / 18-03-2004 / JRe

Continuous coverage for GSM900 and GSM1800 layers. For WCDMA coverage holes exist (even outdoor)

Continuous coverage for GSM900 and GSM1800 layers. Coverage border for WCDMA

Handovers


• UE camps in a 3G cell • If UE moves out of 3G service area (or enters a 3G “hole”) it starts 2G neighbor measurements when CPICH Ec/N0 < Qqualmin + SsearchRAT (-18dB +4dB = -14 dB) • UE reselects to a 2G cell if RXLEV > CPICH RSCP + Qhyst1 and RXLEV > AdjgQrxlevmin RXLEV > CPICH RSCP + 2 dB and RXLEV > -95 dBm • And the above criteria are met for 5 consecutive seconds.

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Handovers


• UE camps in a 2G cell • UE measures 3G neighbors all the time (if neighbors defined) • Threshold to search WCDMA RAN cells (QSRI) = 7 • GPRS Threshold to search WCDMA RAN cells (QSRP) = 7 • When UE enters 3G service area it re-selects to 3G cell if • CPICH RSCP > RXLEV + FDD and b) CPICH Ec/No >= FDM • CPICH RSCP > RXLEV + -Infinity and b) CPICH Ec/No > = -13 dB • CPICH RSCP > -Infinity and b) CPICH Ec/No >= -13 dB • And the above criteria are met for 5 consecutive seconds (3GPP TS 05.08)

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Handovers


Note: No ISHO defined between WCDMA and GSM1800 GSM1800

GSM900

WCDMA

• For every WCDMA Cell, 2-4 outgoing GSM G9 neighbours are to be defined based on the predicted overlapping areas • These GSM neighbours need not necessary be from the same site as the WCDMA cell • During drive test measurements, additional GSM neighbours might need to be added in places where there is no WCDMA coverage 84

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Two-Way neighbor One-Way neighbor

Handovers


• On the 3G coverage border: •

Cell re-selection quantity CPICH Ec/No is not fading so fast outside the real 3G service area

•

This would mean that very many (up to 5th tier) neighbours should be defined

• To avoid excessive number of 2G neighbours, 2G measurements are started already at CPICH Ec/No = -10 dB •

This aggressive set-up would introduce a high inter-RAT ping-ponging risk -> neighbour plan based hysteresis is introduced

If required.

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Handovers


• The number of WCDMA neighbours to be defined for the GSM cells will depend on •

How aggressive we want the UE to re-select back to the WCDMA network and

•

is there any impact on GSM neighbour measurement as more WCDMA neighbours are defined

• A Nokia WCDMA cell may have up-to 32 GSM neighbors defined

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Handovers


• 3G to 2G ISHOs are enabled for • AMR 12.2 conversational class voice calls • Multi-RAB, one AMR voice + one PS data • Possible service downgrade with PS data • Whilst AMR call is on-going the PS data transfer is suspended on 2G side. • 3G to 2G CCO is enabled for • PS domain services • Service downgrade in 2G GPRS

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Handovers


• The triggers for ISHO are: • CPICH Ec/NO, CPICH RSCP • Not enabled: UE Tx Power, UL Quality, DL Quality

CPICH RSCP CPICH Ec/No

Measurement report

RXLEV

HHO CPICH Ecno Threshold = -13 dB (Cancel: -12 dB) HHO CPICH RSCP Threshold = -95 dBm (Cancel: -90 dBm) Note: FMCS group parameters are common for ISHO and IFHO 88

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-95 dBm

Handovers


• To guarantee seamless service and to avoid excessive number of 2G neighbors special settings are required:

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•

Cell re-selection • SSearchRAT = 6 dB (-16 + 6 = -10; start 2G measurements when CPICH Ec/No <-10dB) • AdjgQoffset1 = 0 dB (GSM cell has to be stronger than WCDMA cell) • AdjgQrxlevmin = -95 dBm (minimum criteria for GSM rxlevmin to reselect to) • Pay attention to 2G neighbor definitions.

•

Handovers • HHOEcnoThreshold/Cancel • HHORSCPThreshold/Cancel • AdjqRxlevMinHO

RAN_c_pe.PPT / 18-03-2004 / JRe

-13 dB/-12 dB -95 dBm/ -90 dBm -95 dBm

3 RAN Performance Tuning NOKIA

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