mpcs la lte ho parameters trial. overview a study on the effect of handover parameters on the...
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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
Hyst2 hysteresisA3=40 12/30/2010 20:30:00 12/30/2010 22:30:00
Hyst3 hysteresisA3=60 12/30/2010 22:30:00 12/31/2010 01:30:00
Hyst4 hysteresisA3=70 01/03/2011 20:15:00 01/03/2010 22:15:00
TTT1 timeToTriggerA3=80 01/05/2011 20:30:00 01/05/2011 22:45:00
TTT2 timeToTriggerA3=160 01/05/2011 22:45:00 01/06/2011 00:45:00
TTT3 timeToTriggerA3=320 01/12/2011 20:00:00 01/12/2011 22:30:00
FC1 filterCoefficientEUtraRsrp=7 01/12/2011 23:00:00 02/13/2011 01:00:00
FC2 filterCoefficientEUtraRsrp=5 01/13/2011 20:00:00 01/13/2011 22:30:00
FC3 filterCoefficientEUtraRsrp=13 01/13/2011 22:45:00 01/14/2011 00:45:00
FC4 filterCoefficientEUtraRsrp=11 01/14/2011 20:15:00 01/14/2011 22:30:00
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
Hyst0 hysteresisA3=20 01/20/2011 20:15:00 01/20/2011 23:15:00
Hyst5 hysteresisA3=80 01/21/2011 20:45:00 01/21/2011 23:30:00
TTT0 timeToTriggerA3=0 01/25/2011 00:30:00 01/25/2011 02:45:00
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
rce
nta
ge
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)
Handover Measurement Info (Source-to-Target)
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
Average Delta RSRP (dBm) Average Delta RSRQ (dB)
• 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)
Handover Measurement Info (Source-to-Target)
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
Average Delta RSRP (dBm) Average Delta RSRQ (dB)
• 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
rce
nta
ge
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)
Handover Measurement Info (Source-to-Target)
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
Average Delta RSRP (dBm) Average Delta RSRQ (dB)
• 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
rce
nta
ge
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=5
filterCoefficientEUtraRsrp=7 Baseline (9)
filterCoefficientEUtraRsrp=11
filterCoefficientEUtraRsrp=13
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)
Handover Measurement Info (Source-to-Target)
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
Average Delta RSRP (dBm) Average Delta RSRQ (dB)
• 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)
Handover Measurement Info (Source-to-Target)
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
Average Delta RSRP (dBm) Average Delta RSRQ (dB)
• 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.
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