Adaptive HandOver Trial-E402 & E404 Madina.pdf

M

Adaptive Handover Trial Madinah BSCs E402 & E404

Authors: Shahzad Farooq & Hasham M Qureshi

[email protected]

Version: 0.3

Status: Final Report

Last update: April 26, 2006

Motorola–Mobily Confidential Page 1 of 17 4/26/2006

mailto:[email protected]

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


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


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


⇒ 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


15000

65000

115000

165000

215000

265000

315000

365000

415000



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



Sum of Downlink Quality

Date

BSC

Adaptive Handover

feature implemented


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



Sum of OHOA_Downlink_Quality

Date

BSC


UL QUALITY HANDOVERS (%age)

⇒ Following graph shows significant decrease in UL Quality HOs for both the BSCs

0

2

4

6

8

10

12



Average of Uplink Quality

Date

BSC

Adaptive Handover

feature implemented


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



Sum of OHOA_Uplink_Quality

Date

BSC


MEAN TIME BETWEEN HANDOVERS

⇒ Mean Time between Handovers have increase from ~ 65 to ~ 100 in both BSCs.

0

20

40

60

80

100

120



Average of Mean Time Between HOs (s)

Date

BSC



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


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



Sum of Handover Success Rate

Date

BSC

Adaptive Handover

feature implemented


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



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


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


0

50000

100000

150000

200000

250000

300000

350000

400000

450000


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



Sum of Drop Call Rate

Date

BSC

Adaptive Handover

feature implemented


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


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-


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


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.


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


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-


Documents

Adaptive HandOver Trial-E402 & E404 Madina.pdf