Cell re-selection problem from 2G->LTE

Hi Experts,


System : E// Equipment,


GSM : G11B


We just have activated selection priority (idle) mode and parameters are set to get priority in following order.


FDD - LTE RATPRIO (2)
UTRAN RATPRIO (1)
GSM RATPRIO (0)


But reselctions occur from GSM->UTRAN->LTE. UE is not attempting to GSM->LTE reselection. We have even disabled GSM->UTRAN reselections by aggressive parameter settings. But still no reselections from GSM->LTE.


In SysInfo2Q we can see following parameters.

3G CCN ACTIVE : (0) CCN towards 3G cells is disabled in the cell
PriorityAndEutranParametersDescriptionStruct
GERAN_PRIORITY : 0
THRESH_Priority_Search : 15
THRESH_GSM_Low : 0
H_PRIO : 0
T_Reselection : 0
UTRAN_Start : 1
UTRAN_Stop : 1
UtranPriorityParameters :
[0 ] :
RepeatedUtranPriorityParametersStruct
UTRAN_FREQUENCY_INDEX :
[0 ] : 0
[1 ] : 1
UTRAN_PRIORITY : 1
THRESH_UTRAN_high : 4

EutranParametersDescriptionStruct
EUTRAN_CCN_ACTIVE : 0
EUTRAN_Start : 1
EUTRAN_Stop : 0
EutranMeasurementParameterDescription
Qsearch_C_EUTRAN_Initial : 15
EUTRAN_REP_QUANT : 0
EUTRAN_MULTIRAT_REPORTING : 0
GprsEutranMeasurementParameterDescription
Qsearch_P_EUTRAN : 15
EUTRAN_REP_QUANT : 0
EUTRAN_MULTIRAT_REPORTING : 0
EutranNeighborCells :
[0 ] :
RepeatedEutranNeighborCellsStruct
Channels :
[0 ] :
EARFCN : 1924
MeasurementBandwidth : 0
EUTRAN_PRIORITY : 2
THRESH_EUTRAN_high : 15
EutranNotAllowedCells :
EutranPcidToTaMapping :


BR//
Hasnain

I noticed your MeasurementBandwidth is set to 0 for EUTRAN. This should indiciate how many Resource Blocks you are using for LTE. I cannot say if this is the root cause of the issue but you should correct it anyway.

Dear Wolverine,

I will correct it now.
With current investigation, I have observed that 2G->LTE reselection works fine when I delete 3G neighbours from 2G cells. But once the 3 UTRAN FDDs are added in neighbor list of 2G cells, reselections go from 2G->UTRAN.

Somehow the Priority list is not working.
FDD - LTE RATPRIO (2)
UTRAN RATPRIO (1)
GSM PRIOCR (0)

I also cannot see E-UTRAN_QRXLEVMIN in your extract above.

Is this being broadcasted?

IN parameter settings, I can see in parameters that QRXLEVMINE=0(-140dB).

do you have adjacency TAC defined in 2G? if there is, TAC might be incorrect going to target LTE site/cell.

Quote:

---

Originally Posted by Hasnain

Hi Experts,


System : E// Equipment,


GSM : G11B


We just have activated selection priority (idle) mode and parameters are set to get priority in following order.


FDD - LTE RATPRIO (2)
UTRAN RATPRIO (1)
GSM RATPRIO (0)


But reselctions occur from GSM->UTRAN->LTE. UE is not attempting to GSM->LTE reselection. We have even disabled GSM->UTRAN reselections by aggressive parameter settings. But still no reselections from GSM->LTE.


In SysInfo2Q we can see following parameters.

3G CCN ACTIVE : (0) CCN towards 3G cells is disabled in the cell
PriorityAndEutranParametersDescriptionStruct
GERAN_PRIORITY : 0
THRESH_Priority_Search : 15
THRESH_GSM_Low : 0
H_PRIO : 0
T_Reselection : 0
UTRAN_Start : 1
UTRAN_Stop : 1
UtranPriorityParameters :
[0 ] :
RepeatedUtranPriorityParametersStruct
UTRAN_FREQUENCY_INDEX :
[0 ] : 0
[1 ] : 1
UTRAN_PRIORITY : 1
THRESH_UTRAN_high : 4

EutranParametersDescriptionStruct
EUTRAN_CCN_ACTIVE : 0
EUTRAN_Start : 1
EUTRAN_Stop : 0
EutranMeasurementParameterDescription
Qsearch_C_EUTRAN_Initial : 15
EUTRAN_REP_QUANT : 0
EUTRAN_MULTIRAT_REPORTING : 0
GprsEutranMeasurementParameterDescription
Qsearch_P_EUTRAN : 15
EUTRAN_REP_QUANT : 0
EUTRAN_MULTIRAT_REPORTING : 0
EutranNeighborCells :
[0 ] :
RepeatedEutranNeighborCellsStruct
Channels :
[0 ] :
EARFCN : 1924
MeasurementBandwidth : 0
EUTRAN_PRIORITY : 2
THRESH_EUTRAN_high : 15
EutranNotAllowedCells :
EutranPcidToTaMapping :


BR//
Hasnain

---

Hi Hasnaian,

I attach a few slides related to your issue. Recommended param settings work in Nsn.

Hope it helps

I am looking forward to your feedback

br,

I remember having a similar issue in e******* due to gsm prio set to 0.
Try gsm 1, umts 2 and lte 3 (or similar)
Let us know if you sorted out the issue

Quote:

---

Originally Posted by incoincov

Hi Hasnaian,

I attach a few slides related to your issue. Recommended param settings work in Nsn.

Hope it helps

I am looking forward to your feedback

br,

---

@incoincov

@NSN equipment: you also need to consider setting pMaxOwncell to "23" (internal value) so your
pcompensation will be zero "0"

otherwise, your computation for idle mode settings specially in LTE -> Lower absolute priority layer
Involves:
Qrxlevmin
Pcompensation (pMaxOwnCell - pMax from UE)
Qrxlevminoffset usually is "0"

ps: thanks for the slide anyway, will verify as well my settings.

br/Anita

hello incoincov,
do you have logfiles with sib2quater message? tnx


br/anita

Quote:

---

Originally Posted by incoincov

Hi Hasnaian,

I attach a few slides related to your issue. Recommended param settings work in Nsn.

Hope it helps

I am looking forward to your feedback

br,

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