adaptive handover trial-e402 & e404 madina.pdf
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M
Adaptive Handover Trial Madinah BSCs E402 & E404
Authors: Shahzad Farooq & Hasham M Qureshi
s.farooq.mot@mobily.com.sa
Version: 0.3
Status: Final Report
Last update: April 26, 2006
Motorola–Mobily Confidential Page 1 of 17 4/26/2006
Abstract
The purpose of this document is to provide the impact on Madina BSC 401 & 403 performance and quality after changing AMR lower quality thresholds for Handover and Power Control algorithms.
Revision History
Date of Issue Issue Author/Editor Description of Changes
22-Apr-06 Version
0.1 Hashaam Qureshi Initial Document Created
26-Apr-06 Version
0.2 Hashaam Qureshi Included SQI plots, FER graphs, Executive summary
26-Apr-06 Version
0.3 Shahzad Farooq Minor Additions & Corrections, Report formatting
List of Reviewers Date of review Issue List of Reviewers
24-Apr-06 Version
0.1 Shahzad Farooq
26-Apr-06 Version
0.2 Shahzad Farooq & Mohamed El-Sayed
26-Apr-06 Version
0.3 Mohamed El-Sayed
Motorola–Mobily Confidential Page 2 of 17 4/26/2006
Table of Contents
INTRODUCTION ................................................................................................................................... 4 EXECUTIVE SUMMARY ...................................................................................................................... 4 KPIS-COMPARISON ........................................................................................................................... 5
POWER BUDGET HANDOVERS (%AGE)........................................................................................ 5 POWER BUDGET HANDOVER ATTEMPTS.................................................................................... 5 DL QUALITY HANDOVERS (%AGE) ................................................................................................ 6 DL QUALITY HANDOVERS ATTEMPTS.......................................................................................... 7 UL QUALITY HANDOVERS (%AGE) ................................................................................................ 7 UL QUALITY HANDOVERS ATTEMPTS .......................................................................................... 8 MEAN TIME BETWEEN HANDOVERS ............................................................................................ 8 HOS PER CALL .......................................................................................................................................... 9 HANDOVER SUCCESS RATE............................................................................................................ 9 HANDOVER FAILURE RATE ............................................................................................................ 10 DROP CALL RATE .............................................................................................................................. 11
BER STATS............................................................................................................................................. 12 DOWNLINK- BER............................................................................................................................... 12 UPLINK- BER....................................................................................................................................... 12
FER DISTRIBUTION ......................................................................................................................... 13 DRIVETEST COMPARISON............................................................................................................ 14
RXQUAL PLOT BEFORE ADAPTIVE HANDOVERS IMPLEMENTATION .............................. 14 RXQUAL PLOT AFTER ADAPTIVE HANDOVERS IMPLEMENTATION ................................. 14 RXQUAL DISTRIBUTION................................................................................................................. 15
Marginal Degradation-Possible Reasons & Recommendations................................... 15 SQI PLOT BEFORE ADAPTIVE HANDOVERS IMPLEMENTATION ....................................... 16 AFTER ADAPTIVE HANDOVERS IMPLEMENTATION .............................................................. 16 SQI DISTRIBUTION.......................................................................................................................... 17
CONCLUSION ....................................................................................................................................... 17
Motorola–Mobily Confidential Page 3 of 17 4/26/2006
INTRODUCTION
Adaptive handovers were implemented in Madina BSCs E402 & E404 Implementation Time: 01:00 AM on 13-April-2006 Parameter Changes: Pls find the details in following table
Note: AMR lower quality thresholds are already set 4 & 5 for Power Control and Handover algorithms respectively.
EXECUTIVE SUMMARY
⇒ Power Budget handovers have increased from ~78% to ~91.4% and from ~ 89.4% to ~ 96.6 in BSC E402 and E404 respectively
⇒ Downlink quality handovers have decreased from ~11.8% to ~3.6% and from ~6.33% to 2% in BSC E402 and E404 respectively
⇒ Uplink Quality handovers have decreased from ~9.93% to ~4.9% and from ~4.09% to 1.34% in BSC E402 and E404 respectively
⇒ Reduction of ~ 165000 and ~ 140000 handover attempts per day in BSC E402 and E404 respectively
⇒ Ho-per-call reduced from ~0.65 to ~0.45 ⇒ Mean time between handovers have increased from ~65s to ~100s in
both BSCs ⇒ DCR remains unaffected for both the BSCs ⇒ Handover Success Rate has observed a slight degradation(~98.6% to
~98.2%) in BSC E404
Motorola–Mobily Confidential Page 4 of 17 4/26/2006
⇒ Slight degradation in HFR has been observed. This is because HO Lost
MS reduces in the multiples of 10 while HO Attempts have decreased significantly (~165000 and 140000 in BSC E402 and E404 respectively). Since HO Attempts is in the denominator of HFR formula, therefore, HFR has increased. This is not a true degradation
⇒ There hasn’t been any significant change in the DL_BER & UL_BER ⇒ Drive test comparison doesn’t reveal any major change in RxQual & FER
while there is slight degradation observed in SQI ⇒ Rxqual & SQI distributions show marginal degradation. Fine tuning of
cumulative areas and/or AMR lower quality thresholds recommended
KPIS-COMPARISON
POWER BUDGET HANDOVERS (%age)
⇒ Following graph shows significant improvement in PBGT handovers for both the BSCs. PBGT HOs also known as better cell handover
60
65
70
75
80
85
90
95
100
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of Power Budget
Date
BSC
Adaptive Handover
feature implemented
POWER BUDGET HANDOVER ATTEMPTS
⇒ Following graph shows that there has been a decrease of almost 100,000 power budget handover attempts per day for both the BSCs
Motorola–Mobily Confidential Page 5 of 17 4/26/2006
15000
65000
115000
165000
215000
265000
315000
365000
415000
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Average of OHOA_Power_Budget
Date
BSC
Adaptive HO implemented
DL QUALITY HANDOVERS (%age)
⇒ Following graph shows significant decrease in DL Quality HOs for both the BSCs
0
2
4
6
8
10
12
14
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of Downlink Quality
Date
BSC
Adaptive Handover
feature implemented
Motorola–Mobily Confidential Page 6 of 17 4/26/2006
DL QUALITY HANDOVERS ATTEMPTS
⇒ Following graphs show a decrease of almost 35000 and 25000 downlink handover attempts/day in BSC E402 & E404 respectively
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of OHOA_Downlink_Quality
Date
BSC
Adaptive HO implemented
UL QUALITY HANDOVERS (%age)
⇒ Following graph shows significant decrease in UL Quality HOs for both the BSCs
0
2
4
6
8
10
12
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Average of Uplink Quality
Date
BSC
Adaptive Handover
feature implemented
Motorola–Mobily Confidential Page 7 of 17 4/26/2006
UL QUALITY HANDOVERS ATTEMPTS
⇒ Following graphs show a decrease of almost ~30000 and 10000 Uplink handover attempts per day in BSC E402 & E404 respectively
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of OHOA_Uplink_Quality
Date
BSC
Adaptive HO implemented
MEAN TIME BETWEEN HANDOVERS
⇒ Mean Time between Handovers have increase from ~ 65 to ~ 100 in both BSCs.
0
20
40
60
80
100
120
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Average of Mean Time Between HOs (s)
Date
BSC
Adaptive HO implemented
Motorola–Mobily Confidential Page 8 of 17 4/26/2006
HOs per call
⇒ Following graph shows significant reduction in HO Per Call for both the BSCs
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
1-Apr-06
2-Apr-06
3-Apr-06
4-Apr-06
5-Apr-06
6-Apr-06
7-Apr-06
8-Apr-06
9-Apr-06
10-Apr-06
11-Apr-06
12-Apr-06
13-Apr-06
14-Apr-06
15-Apr-06
16-Apr-06
17-Apr-06
18-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of HOs Per Call
Date
BSCAdaptive handover
feature implemented
HANDOVER SUCCESS RATE
⇒ Slight degradation in HSR of BSC E404 (from 98.6% to 98.2%) while HSR of BSC 402 remains unaffected
96.8
97
97.2
97.4
97.6
97.8
98
98.2
98.4
98.6
98.8
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of Handover Success Rate
Date
BSC
Adaptive Handover
feature implemented
Motorola–Mobily Confidential Page 9 of 17 4/26/2006
HANDOVER FAILURE RATE
⇒ Slight degradation in Handover Failure Rate has been observed.
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of Handover Failure rate
Date
BSC
Adaptive Handover
feature implemented
⇒ As can be seen from the below graphs the HO lost MS is decreased in the
multiples of 10 while HO Attempts have decreased significantly ( ~ 165000 and 140000 in BSC E402 and E404 respectively ). Since HO Attempts is in the denominator of Handover failure rate formula therefore Handover Failure Rate has increased. Hence this is not a true degradation
0
50000
100000
150000
200000
250000
300000
350000
400000
450000
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402
HO
Atte
mpt
s
0
20
40
60
80
100
120
HO
Los
t MS
HO_Attempts HO_Lost_MS
Adaptive handovers
implemented
Motorola–Mobily Confidential Page 10 of 17 4/26/2006
0
50000
100000
150000
200000
250000
300000
350000
400000
450000
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_04_E404
HO
Atte
mpt
s
0
10
20
30
40
50
60
70
HO
Los
t MS
HO_Attempts HO_Lost_MS
Adaptive Handover
implemented
DROP CALL RATE
⇒ DCR remains unaffected for both the BSCs
0
0.1
0.2
0.3
0.4
0.5
0.6
10-Apr-06 11-Apr-06 12-Apr-06 13-Apr-06 14-Apr-06 15-Apr-06 16-Apr-06 17-Apr-06 18-Apr-06 19-Apr-06
Madina_Bsc_02_E402Madina_Bsc_04_E404
Sum of Drop Call Rate
Date
BSC
Adaptive Handover
feature implemented
Motorola–Mobily Confidential Page 11 of 17 4/26/2006
BER STATS
DOWNLINK- BER ⇒ Following graph shows no degradation in DL BER stats for both the BSCs
DL BER86
.65
2.53
2.53
2.66
2.08
1.58
1.56
0.41
86.5
9
2.55
2.53
2.67
2.10
1.59
1.55
0.41
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
BER_BIN_0 BER_BIN_1 BER_BIN_2 BER_BIN_3 BER_BIN_4 BER_BIN_5 BER_BIN_6 BER_BIN_7
Perc
enta
ge
Madina BSC E402 and E404 12/4/2006 Madina BSC E402 and E404 19-04-2006
UPLINK- BER ⇒ Following graph shows no degradation in UL BER stats for both the BSCs
UL BER
85.7
1
1.85
1.71
1.86
1.44
5.67
1.38
0.37
85.7
9
1.82
1.68
1.82
1.43
5.74
1.37
0.34
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
UL_BER_BIN_0 UL_BER_BIN_1 UL_BER_BIN_2 UL_BER_BIN_3 UL_BER_BIN_4 UL_BER_BIN_5 UL_BER_BIN_6 UL_BER_BIN_7
Perc
enta
ge
Madina BSC E402 and E404 12/4/2006 Madina BSC E402 and E404 19-04-2006
Motorola–Mobily Confidential Page 12 of 17 4/26/2006
FER DISTRIBUTION
⇒ The following comparison doesn’t reveal any change in FER after the Adaptive Handover implementation
FER
95.8
3
1.34
0.31
0.18
0.13
0.10
0.08
0.08
0.08 1.86
95.8
4
1.31
0.30
0.17
0.14
0.10
0.08
0.08
0.08 1.89
0.00
20.00
40.00
60.00
80.00
100.00
120.00
FER_BIN0 FER_BIN1 FER_BIN2 FER_BIN3 FER_BIN4 FER_BIN5 FER_BIN6 FER_BIN7 FER_BIN8 FER_BIN9
Perc
enta
ge
BSC E402 and E404 12/4/2006 BSC E402 and E404 19-04-2006
-This Space is left intentionally Blank-
Motorola–Mobily Confidential Page 13 of 17 4/26/2006
DRIVETEST COMPARISON ⇒ Following plots show the DT comparison for Rx Qual. Some areas show
improvements while some shows degradation. Overall no significant degradation can be confirmed by the following plots
RXQUAL PLOT BEFORE ADAPTIVE HANDOVERS IMPLEMENTATION
RXQUAL PLOT AFTER ADAPTIVE HANDOVERS IMPLEMENTATION
Motorola–Mobily Confidential Page 14 of 17 4/26/2006
RXQUAL DISTRIBUTION
⇒ The following comparison shows some degradation in Rx quality after the adaptive handovers implementation
Rx Qual
88.09
7.004.91
85.77
8.02 6.21
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
0 to 3 4 to 5 6 to 7
Perc
enta
ge
Before Adaptive After Adaptive
Marginal Degradation-Possible Reasons & Recommendations To understand one of the possible reasons of this marginal degradation, please see the following adaptive HO algorithm for UL/DL Quality For each measurement report IF (rxqual > quality_threshold) rxqual_Cumulative_Area = rxqual_Cumulative_Area + (rxqual - quality_threshold) ELSE rxqual_Cumulative_Area = 0 IF(hopping_enabled = TRUE AND adap_alt_rxqual_trigger = TRUE) trigger = rxqual_trigger_alt ELSE trigger = rxqual_trigger Handover is triggered if the following is TRUE Rxqual_Cumulative_Area > Trigger
AMR lower quality thresholds are already relaxed to 4 & 5 for PC and HO respectively. Considering the above algorithm this is effectively 6 for adaptive Handovers. We need to fine tune cumulative area or quality thresholds as this might be risky for medium density cities like Madina Munawara Non AMR lower quality thresholds are 3 & 4 for PC and HO respectively. This is effectively 5 for adaptive handovers but considering the algorithm design it triggers the HO early when quality degrading further so it seems to be OK.
Motorola–Mobily Confidential Page 15 of 17 4/26/2006
SQI PLOT BEFORE ADAPTIVE HANDOVERS IMPLEMENTATION ⇒ Following plots show the DT comparison for SQI which doesn’t reveal any
major degradation
AFTER ADAPTIVE HANDOVERS IMPLEMENTATION
Motorola–Mobily Confidential Page 16 of 17 4/26/2006
SQI DISTRIBUTION
⇒ The following comparison shows that % of measurements having SQI=30 have reduced after the implementation of adaptive handovers. The corresponding increase is in SQI=29 and 28 measurements. Reason
SQI distribution
58.9
2
15.6
7
4.12
7.20
1.30
0.60
5.19
4.08
1.62
0.79
0.52
55.9
8
17.7
0
5.38
5.29
1.39
0.88
5.45
4.19
2.07
1.09
0.58
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
30 29 28 27 26 25 20 to 14 15 to 19 10 to 14 5 to 9 0 to 4
Before Adaptive HO After Adaptive HO
Conclusion
⇒ Adaptive Handovers bring overall good impact on network. Marginal degradation is noticed in Rxqual and SQI distributions. Motorola recommends to reduce the cumulative area for quality handovers or lower down the AMR quality thresholds. Details
-THE END-
Motorola–Mobily Confidential Page 17 of 17 4/26/2006
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