mpcs la lte ho parameters trial. overview a study on the effect of handover parameters on the...

Mpcs lalte ho parameters trial

Overview• A study on the effect of handover parameters on the network performance

will be done in a trial cluster (part of Cerritos)

• The parameter change to be implemented as an iterative process with each drive and the results to be compared to analyze the effect of the parameters

• Following parameters to be changedA3offset;hysteresisA3; filtercoefficientEutranRsrp;sMeasure; timetotriggerA3

Review: LTE HO• Evaluates if one or more intra frequency cell is better than current serving

cell

• UE receives measurement configuration in RRC Connection Reconfiguration

• No measurement list sent to UE (UE search for all 504 physical cell id and reports the cell(s) fulfilling the event criteria).

• UE Event Trigger controlled by:– Filtering (How much averaging is done before event evaluation)– Offset (How much better in dB)– Time to trigger (For how long)

Main Trigger Parameters• sMeasure = 0 { -140..-44, 0 } [dBm]

Controlling if the UE is required to perform measurements.Disabled if set to “0” (used only RSRP is the trigger)

• a3offset = 30 { -150..150 } [0.1 dB]Offset value for EventA3, added to serving cell

• hysteresisA3 = 10 { 0..150 } [0.1 dB]Hysteresis value for eventA3, added to neighbor cell

• timeToTriggerA3 = 40 { 0, 40, 64, 80, 100, 128, 160, 256, 320, 480, 512,640, 1024, 1280, 2560, 5120 } [ms]Time after Event A3 is fulfilled when UE starts to send Measurement reports

• triggerQuantityA3 = RSRP [RSRP,RSRQ]The quantity that triggers the event

• cellIndividualOffsetEUtranOffset value specific to a neighbor relation

Handover Filtering• To avoid that the measurement reporting is triggered by fast fading, the

measurement configuration contains filter coefficient for the UE to use

• filterCoefficientEUtraRsrp = 9{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19 }Filter coefficient for RSRP measurements

• filterCoefficientEUtraRsrq = 11{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19 }Filter coefficient for RSRQ measurements

Event A3: A neighbour cell(b) becomes offset better than serving cell(a)

Drive InfoTest Parameter

Drive Details

Date Started Time Started Date Finished Time Finished

Baseline - 12/17/2010 21:15:00 12/13/2010 00:30:00

Offset1 a3offset=10 12/23/2010 21:00:00 12/23/2010 23:15:00

Offset2 a3offset=20 12/27/2010 20:30:00 12/27/2010 23:00:00

Offset3 a3offset=30 12/28/2010 23:15:00 12/28/2010 01:45:00

Hyst1 hysteresisA3=30 12/29/2010 20:00:00 12/29/2010 22:15:00




TTT1 timeToTriggerA3=80 01/05/2011 20:30:00 01/05/2011 22:45:00



FC1 filterCoefficientEUtraRsrp=7 01/12/2011 23:00:00 02/13/2011 01:00:00




SM1 sMeasure=-70 01/15/2011 19:45:00 01/15/2011 22:15:00

SM2 sMeasure=-80 01/17/2011 20:30:00 01/17/2011 22:45:00

BL2 Baseline2 01/18/2011 20:00:00 01/18/2011 22:30:00

BL3 Baseline3 01/19/2011 20:30:00 01/19/2011 23:00:00




SM3 sMeasure=-90 01/25/2011 19:00:00 01/25/2011 21:15:00

Baseline Baseline 01/25/2011 21:30:00 01/26/2011 01:00:00

TTT4 timeToTrigger=640 01/26/2011 01:15:00 01/26/2011 03:00:00

Trial Cluster – Drive Route

Baseline Test Cases

MO Parameter Baseline BL2 BL3

UeMeasControl sMeasure 0 0 -80

UeMeasControl filterCoefficientEUtraRsrp 9 5 4

ReportConfigEUtraBestCell hysteresisA3 50 30 0

ReportConfigEUtraBestCell timeToTriggerA3 40 40 480

ReportConfigEUtraBestCell a3offset 0 10 40

Baseline Baseline 2 Baseline 3 Cell Availability 100% 100% 100% Retainability (Session Failure Rate) 0% 26% 0% Integrity DL Throughput Mean (kbps) 2636.85 2482.42 2511.49 Integrity DL Throughput Max (kbps) 3664.32 3600.96 3738.24 Mobility (Handover Success Rate) 100% 100% 100%FTP DL session starts 14 19 14FTP DL session ends 14 14 14EUTRAN Intra-frequency Handover Failed events 0 0 0EUTRAN Intra-frequency Handover (success) events 192 322 161

Baseline Test Cases (contd)

Handover Measurement Info (Source-to-Target)

Baseline

5.5 5.3

6.7

2.8

1.6

4.0

0

1

2

3

4

5

6

7

8

Baseline Baseline 2 Baseline 3

Average Delta RSRP (dBm) Average Delta RSRQ (dB)

• Baseline2 drive demonstrated the highest number of handovers and the smallest delta in RSRP/RSRQ.

Baseline Test Cases (contd)PRE-HANDOVER SINR CDF (%)

Baseline

0

10

20

30

40

50

60

70

80

90

100

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41

SINR

Pe

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Baseline Baseline2 Baseline3

• Baseline drive demonstrated the best SINR performance.

A3offset Test Cases

MO Parameter Baseline Offset1 Offset2 Offset3 Offset4

UeMeasControl sMeasure 0 0 0 0 0

UeMeasControl filterCoefficientEUtraRsrp 9 9 9 9 9

ReportConfigEUtraBestCell hysteresisA3 50 50 50 50 50

ReportConfigEUtraBestCell timeToTriggerA3 40 40 40 40 40

ReportConfigEUtraBestCell a3offset 0 10 20 30 40

Baseline (0) a3offset=10 a3offset=20 a3offset=30 a3offset=40 Cell Availability 100% 100% 100% 100% 100% Retainability (Session Failure Rate) 0% 0% 0% 0% 0% Integrity DL Throughput Mean (kbps) 2636.85 2365 2509.72 2415.835 2564.95 Integrity DL Throughput Max (kbps) 3664.32 3632 3696 3674.88 3653.76 Mobility (Handover Success Rate) 100% 100% 99.23% 100% 100%FTP DL session starts 14 13 13 14 18FTP DL session ends 14 13 13 13 17EUTRAN Intra-frequency Handover Failed events 0 0 1 0 0EUTRAN Intra-frequency Handover (success) events 192 161 129 118 99

A3offset Test Cases (contd)


a3Offset

5.56.6

7.48.2

9.0

2.83.4

4.24.9 5.2

0

2

4

6

8

10

Baseline (0) a3Offset=10 a3Offset=20 a3Offset=30 a3Offset=40


• There was a clear decrease in the number of handovers and an increase in the RSRP/RSRQ delta as went from a3offset=0 to a3offset=40.

• This is expected as the sum of hysteresisA3 and a3offset increases.Notice, as expected, Delta RSRP ~ hysteresisA3+a3offset.

A3offset Test Cases (contd)PRE-HANDOVER SINR CDF (%)

a3Offset

0

10

20

30

40

50

60

70

80

90

100

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41

SINR

Pe

rce

nta

ge

Baseline (0) a3Offset=10 a3Offset=20 a3Offset=30 a3Offset=40

• Baseline (smallest offset) demonstrated the best SINR performance.

HysteresisA3 Test CasesMO Parameter Hyst0 Hyst1 Hyst2

Baseline Hyst3 Hyst4 Hyst5

UeMeasControl sMeasure 0 0 0 0 0 0 0

UeMeasControl filterCoefficientEUtraRsrp 9 9 9 9 9 9 9

ReportConfigEUtraBestCell hysteresisA3 20 30 40 50 60 70 80

ReportConfigEUtraBestCell timeToTriggerA3 40 40 40 40 40 40 40

ReportConfigEUtraBestCell a3offset 0 0 0 0 0 0 0

hysteresisA3=20 hysteresisA3=30 hysteresisA3=40 Baseline (50) hysteresisA3=60 hysteresisA3=70 hysteresisA3=80

Cell Availability 100% 100% 100% 100% 100% 100% 100% Retainability (Session Failure Rate) 19% 0% 0% 0% 0% 0% 0% Integrity DL Throughput Mean (kbps) 2545.26 2380.99 2418.08 2636.85 2464.73 2275.54 2548.9 Integrity DL Throughput Max (kbps) 3706.56 3590.4 3664.32 3664.32 3442.56 3643.2 3632.64 Mobility (Handover Success Rate) 100% 100% 100% 100% 100% 100% 100%FTP DL session starts 16 13 14 14 13 12 14FTP DL session ends 13 13 14 14 13 12 14EUTRAN Intra-frequency Handover Failed events 0 1 0 0 0 0 0EUTRAN Intra-frequency Handover (success) events 417 337 224 192 131 140 121

HysteresisA3 Test Cases (contd)


hysteresis

3.0

3.9

4.85.5

6.6

7.58.2

1.01.6

2.22.8

3.54.2

4.9

0

1

2

3

4

5

6

7

8

9

hysteresisA3=20 hysteresisA3=30 hysteresisA3=40 Baseline (50) hysteresisA3=60 hysteresisA3=70 hysteresisA3=80


• There was a clear decrease in the number of handovers and an increase in the RSRP/RSRQ delta as went from hysteresisA3=20 to hysteresisA3=80.

• This is expected as the sum of hysteresisA3 and a3offset increases.Notice, as expected, Delta RSRP ~ hysteresisA3+a3offset.

HysteresisA3 Test Cases (contd)PRE-HANDOVER SINR CDF (%)

Hysteresis

0

10

20

30

40

50

60

70

80

90

100

-10 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

SINR

Pe

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hysteresisA3=20 hysteresisA3=30 hysteresisA3=40 Baseline (50)

hysteresisA3=60 hysteresisA3=70 hysteresisA3=80

• hysteresisA3=20 (smallest hysteresis) demonstrated the best SINR performance.

TimeToTriggerA3 Test CasesMO Parameter TTT0 Baseline TTT1 TTT2 TTT3 TTT4

UeMeasControl sMeasure 0 0 0 0 0 0

UeMeasControl filterCoefficientEUtraRsrp 9 9 9 9 9 9

ReportConfigEUtraBestCell hysteresisA3 50 50 50 50 50 50

ReportConfigEUtraBestCell timeToTriggerA3 0 40 80 160 320 640

ReportConfigEUtraBestCell a3offset 0 0 0 0 0 0

timeToTriggerA3= 0 Baseline (40) timeToTriggerA3= 80 timeToTriggerA3= 160 timeToTriggerA3= 320 timeToTriggerA3= 640

Cell Availability 100% 100% 100% 100% 100% 100% Retainability (Session Failure Rate) 0% 0% 0% 0% 0% 0% Integrity DL Throughput Mean (kbps) 2618.28 2636.85 2487.26 2461.05 2461.72 2654.53 Integrity DL Throughput Max (kbps) 3633.24 3664.32 3600.96 3696 3653.22 3674.88 Mobility (Handover Success Rate) 100% 100% 100% 100% 100% 100%FTP DL session starts 13 14 13 13 13 13FTP DL session ends 13 14 13 13 13 13EUTRAN Intra-frequency Handover Failed events 0 0 0 0 0 0EUTRAN Intra-frequency Handover (success) events 187 192 197 186 171 120

TimeToTriggerA3 Test Cases (contd)


timeToTriggerA3

5.3 5.5 5.9 6.2 6.4 6.7

2.7 2.83.2 3.3

3.9 4.3

0

1

2

3

4

5

6

7

8

timeToTriggerA3=0 Baseline (40) timeToTriggerA3=80 timeToTriggerA3=160 timeToTriggerA3=320 timeToTriggerA3=640


• Number of handovers decreased and RSRP/RSRQ delta increased with the increasing timeToTrigger. This is as expected.

TimeToTriggerA3 Test Cases (contd)PRE-HANDOVER SINR CDF (%)

timeToTriggerA3

0

10

20

30

40

50

60

70

80

90

100

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41

SINR

Pe

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nta

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timeToTriggerA3=0 Baseline (40) timeToTriggerA3=80

timeToTriggerA3=160 timeToTriggerA3=320 timeToTriggerA3=640

• timeToTriggerA3=0 and Baseline(40) demonstrated the best SINR performance.

FilterCoefficientEutraRSRP Test Cases

MO Parameter FC0 FC2 FC1 Baseline FC4 FC3

UeMeasControl sMeasure 0 0 0 0 0 0

UeMeasControl filterCoefficientEUtraRsrp 3 5 7 9 11 13

ReportConfigEUtraBestCell hysteresisA3 50 50 50 50 50 50

ReportConfigEUtraBestCell timeToTriggerA3 40 40 40 40 40 40

ReportConfigEUtraBestCell a3offset 0 0 0 0 0 0

filterCoefficientEUtraRsrp=3


filterCoefficientEUtraRsrp=7 Baseline (9)



Cell Availability 100% 100% 100% 100% 100% 100% Retainability (Session Failure Rate) 0% 0% 0% 0% 0% 0% Integrity DL Throughput Mean (kbps) 2661.5 2549.69 2423.83 2636.85 2553.79 2540.09 Integrity DL Throughput Max (kbps) 3706.56 3600.96 3590.4 3664.32 3706.56 3759.36 Mobility (Handover Success Rate) 100% 100% 100% 100% 99.38% 100.00%FTP DL session starts 13 13 13 14 13 13FTP DL session ends 13 13 13 14 13 13EUTRAN Intra-frequency Handover Failed events 0 0 0 0 1 0EUTRAN Intra-frequency Handover (success) events 269 262 214 192 161 141

FilterCoefficientEutraRSRP Test Cases (contd)


filterCoefficientEUtraRsrp

6.0 6.0 5.8 5.5 5.5 5.4

2.0 2.22.6 2.8

3.84.4

0

1

2

3

4

5

6

7

filterCoefficientEUtraRsrp=3 filterCoefficientEUtraRsrp=5 filterCoefficientEUtraRsrp=7 Baseline (9) f ilterCoefficientEUtraRsrp=11 filterCoefficientEUtraRsrp=13


• Number of handovers decreased and RSRP/RSRQ delta increased with the increasing filterCoefficientEUtraRsrp.

• This is as expected as the number of measurement samples analyzed for each handover increases.

FilterCoefficientEutraRSRP Test Cases (contd)PRE-HANDOVER SINR CDF (%)

filterCoefficientEUtraRsrp

0

10

20

30

40

50

60

70

80

90

100

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41

SINR

Pe

rce

nta

ge

filterCoefficientEUtraRsrp=3 filterCoefficientEUtraRsrp=5 filterCoefficientEUtraRsrp=7

Baseline(9) filterCoefficientEUtraRsrp=11 filterCoefficientEUtraRsrp=13

• Baseline gave the best SINR performance.

sMeasure test cases

MO Parameter Baseline SM1 SM2 SM3

UeMeasControl sMeasure 0 -70 -80 -90

UeMeasControl filterCoefficientEUtraRsrp 9 9 9 9

ReportConfigEUtraBestCell hysteresisA3 50 50 50 50

ReportConfigEUtraBestCell timeToTriggerA3 40 40 40 40

ReportConfigEUtraBestCell a3offset 0 0 0 0

Baseline (0) sMeasure=-70 sMeasure=-80 sMeasure=-90 Cell Availability 100% 100% 100% 100% Retainability (Session Failure Rate) 0% 0% 0% 0% Integrity DL Throughput Mean (kbps) 2636.85 2251.63 2496.11 2603.72 Integrity DL Throughput Max (kbps) 3664.32 3812.16 3643.2 3590.4 Mobility (Handover Success Rate) 100% 100% 100% 99.5%FTP DL session starts 14 14 13 13FTP DL session ends 14 14 13 13EUTRAN Intra-frequency Handover Failed events 0 0 0 1EUTRAN Intra-frequency Handover (success) events 192 188 204 193

sMeasure test cases (contd)


sMeasure

5.5 5.7 5.9 5.8

2.83.3 3.2 3.1

0

1

2

3

4

5

6

7

Baseline (0) sMeasure=-70 sMeasure=-80 sMeasure=-90


• No apparent trend was observed between these drives.

sMeasure test cases (contd)PRE-HANDOVER SINR CDF (%)

sMeasure

0

10

20

30

40

50

60

70

80

90

100

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41

SINR

Pe

rce

nta

ge

Baseline (0) sMeasure=-70 sMeasure=-80 sMeasure=-90

• The effect of sMeasure parameter on the network is inconclusive in regards to the performed drives.

Summary• Tested parameters for the most part resulted in the expected behavior:

– Number of Handover events.– RSRP/RSRQ delta upon Handover.– Pre-handover SINR performance.

• Part of the unexpected behavior can be attributed to the variation in drive test setup between some of the drives.

• The effect of sMeasure parameter on the network is inconclusive at this point. It will be further analyzed during the testing on DAS nodes.

• Current Baseline is pretty suitable to the network at this early stage of operation. It is recommended that optimization, when performed, be performed on a case by case basis.

THANK YOU

mpcs la lte ho parameters trial. overview a study on the effect of handover parameters on the...

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