1. Mpcs la lte ho parameters trial

2. 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 changed
A3offset;
hysteresisA3;
filtercoefficientEutranRsrp;
sMeasure;
timetotriggerA3

3. 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)

4. Main Trigger Parameters
sMeasure = 0 { , 0 } [dBm]
Controlling if the UE is required to perform measurements.
Disabled if set to “0” (used only RSRP is the trigger)
a3offset = 30 { } [0.1 dB]
Offset value for EventA3, added to serving cell
hysteresisA3 = 10 { } [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
cellIndividualOffsetEUtran
Offset value specific to a neighbor relation

5. 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

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

7. Drive Info Test 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
23:15:00
Offset2
a3offset=20
12/27/2010
20:30:00
23:00:00
Offset3
a3offset=30
12/28/2010
01:45:00
Hyst1
hysteresisA3=30
12/29/2010
20:00:00
22:15:00
Hyst2
hysteresisA3=40
12/30/2010
22:30:00
Hyst3
hysteresisA3=60
12/31/2010
01:30:00
Hyst4
hysteresisA3=70
01/03/2011
20:15:00
01/03/2010
TTT1
timeToTriggerA3=80
01/05/2011
22:45:00
TTT2
timeToTriggerA3=160
01/06/2011
00:45:00
TTT3
timeToTriggerA3=320
01/12/2011
FC1
filterCoefficientEUtraRsrp=7
02/13/2011
01:00:00
FC2
filterCoefficientEUtraRsrp=5
01/13/2011
FC3
filterCoefficientEUtraRsrp=13
01/14/2011
FC4
filterCoefficientEUtraRsrp=11
SM1
sMeasure=-70
01/15/2011
19:45:00
SM2
sMeasure=-80
01/17/2011
BL2
Baseline2
01/18/2011
BL3
Baseline3
01/19/2011
Hyst0
hysteresisA3=20
01/20/2011
Hyst5
hysteresisA3=80
01/21/2011
20:45:00
23:30:00
TTT0
timeToTriggerA3=0
01/25/2011
02:45:00
SM3
sMeasure=-90
19:00:00
21:30:00
01/26/2011
TTT4
timeToTrigger=640
01:15:00
03:00:00

8. Trial Cluster – Drive Route

9. Baseline Test Cases MO Parameter Baseline BL2 BL3 UeMeasControl
sMeasure
-80
filterCoefficientEUtraRsrp 9 5 4
ReportConfigEUtraBestCell
hysteresisA3 50 30
timeToTriggerA3 40
480
a3offset 10
Baseline
Baseline 2
Baseline 3
Cell Availability
100%
Retainability (Session Failure Rate) 0%
26%
Integrity DL Throughput Mean (kbps)
Integrity DL Throughput Max (kbps)
Mobility (Handover Success Rate)
FTP DL session starts 14 19
FTP DL session ends
EUTRAN Intra-frequency Handover Failed events
EUTRAN Intra-frequency Handover (success) events
192
322
161

10. Baseline Test Cases (contd)
Baseline2 drive demonstrated the highest number of handovers and the smallest delta in RSRP/RSRQ.

11. Baseline Test Cases (contd)
Baseline drive demonstrated the best SINR performance.

12. A3offset Test Cases MO Parameter Baseline Offset1 Offset2 Offset3
UeMeasControl
sMeasure
filterCoefficientEUtraRsrp 9
ReportConfigEUtraBestCell
hysteresisA3 50
timeToTriggerA3 40
a3offset 10 20 30
Baseline (0)
a3offset=10
a3offset=20
a3offset=30
a3offset=40
Cell Availability
100%
Retainability (Session Failure Rate) 0%
Integrity DL Throughput Mean (kbps)
2365
Integrity DL Throughput Max (kbps)
3632
3696
Mobility (Handover Success Rate)
99.23%
FTP DL session starts 14 13 18
FTP DL session ends 17
EUTRAN Intra-frequency Handover Failed events 1
EUTRAN Intra-frequency Handover (success) events
192
161
129
118 99

13. A3offset Test Cases (contd)
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.

14. A3offset Test Cases (contd)
Baseline (smallest offset) demonstrated the best SINR performance.

15. HysteresisA3 Test CasesMO
Parameter
Hyst0
Hyst1
Hyst2
Baseline
Hyst3
Hyst4
Hyst5
UeMeasControl
sMeasure
filterCoefficientEUtraRsrp 9
ReportConfigEUtraBestCell
hysteresisA3 20 30 40 50 60 70 80
timeToTriggerA3
a3offset
hysteresisA3=20
hysteresisA3=30
hysteresisA3=40
Baseline (50)
hysteresisA3=60
hysteresisA3=70
hysteresisA3=80
Cell Availability
100%
Retainability (Session Failure Rate)
19% 0%
Integrity DL Throughput Mean (kbps)
2548.9
Integrity DL Throughput Max (kbps)
3590.4
3643.2
Mobility (Handover Success Rate)
FTP DL session starts 16 13 14 12
FTP DL session ends
EUTRAN Intra-frequency Handover Failed events 1
EUTRAN Intra-frequency Handover (success) events
417
337
224
192
131
140
121

16. HysteresisA3 Test Cases (contd)
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.

17. HysteresisA3 Test Cases (contd)
hysteresisA3=20 (smallest hysteresis) demonstrated the best SINR performance.

18. TimeToTriggerA3 Test CasesMO
Parameter
TTT0
Baseline
TTT1
TTT2
TTT3
TTT4
UeMeasControl
sMeasure
filterCoefficientEUtraRsrp 9
ReportConfigEUtraBestCell
hysteresisA3 50
timeToTriggerA3 40 80
160
320
640
a3offset
timeToTriggerA3= 0
Baseline (40)
timeToTriggerA3= 80
timeToTriggerA3= 160
timeToTriggerA3= 320
timeToTriggerA3= 640
Cell Availability
100%
Retainability (Session Failure Rate) 0%
Integrity DL Throughput Mean (kbps)
Integrity DL Throughput Max (kbps)
3696
Mobility (Handover Success Rate)
FTP DL session starts 13 14
FTP DL session ends
EUTRAN Intra-frequency Handover Failed events
EUTRAN Intra-frequency Handover (success) events
187
192
197
186
171
120

19. TimeToTriggerA3 Test Cases (contd)
Number of handovers decreased and RSRP/RSRQ delta increased with the increasing timeToTrigger. This is as expected.

20. TimeToTriggerA3 Test Cases (contd)
timeToTriggerA3=0 and Baseline(40) demonstrated the best SINR performance.

21. FilterCoefficientEutraRSRP Test CasesMO
Parameter
FC0
FC2
FC1
Baseline
FC4
FC3
UeMeasControl
sMeasure
filterCoefficientEUtraRsrp 3 5 7 9 11 13
ReportConfigEUtraBestCell
hysteresisA3 50
timeToTriggerA3 40
a3offset
filterCoefficientEUtraRsrp=3
filterCoefficientEUtraRsrp=5
filterCoefficientEUtraRsrp=7
Baseline (9)
filterCoefficientEUtraRsrp=11
filterCoefficientEUtraRsrp=13
Cell Availability
100%
Retainability (Session Failure Rate) 0%
Integrity DL Throughput Mean (kbps)
2661.5
Integrity DL Throughput Max (kbps)
3590.4
Mobility (Handover Success Rate)
99.38%
100.00%
FTP DL session starts 13 14
FTP DL session ends
EUTRAN Intra-frequency Handover Failed events 1
EUTRAN Intra-frequency Handover (success) events
269
262
214
192
161
141

22. FilterCoefficientEutraRSRP Test Cases (contd)
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.

23. FilterCoefficientEutraRSRP Test Cases (contd)
Baseline gave the best SINR performance.

24. sMeasure test cases MO Parameter Baseline SM1 SM2 SM3 UeMeasControl
-70
-80
-90
filterCoefficientEUtraRsrp 9
ReportConfigEUtraBestCell
hysteresisA3 50
timeToTriggerA3 40
a3offset
Baseline (0)
sMeasure=-70
sMeasure=-80
sMeasure=-90
Cell Availability
100%
Retainability (Session Failure Rate) 0%
Integrity DL Throughput Mean (kbps)
Integrity DL Throughput Max (kbps)
3643.2
3590.4
Mobility (Handover Success Rate)
99.5%
FTP DL session starts 14 13
FTP DL session ends
EUTRAN Intra-frequency Handover Failed events 1
EUTRAN Intra-frequency Handover (success) events
192
188
204
193

25. sMeasure test cases (contd)
No apparent trend was observed between these drives.

26. sMeasure test cases (contd)
The effect of sMeasure parameter on the network is inconclusive in regards to the performed drives.

27. 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.

28. THANK YOU