Airtel_badagry_ran Optimisation Report August&September

AIRTEL/ERICSSON

GSM/WCDMA RAN OPTIMIZATION REPORT

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AIRTEL Ericsson

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RAN Tuning Engineer

Document Number:

Prepared By: xxxxxxxxxxx 1(42) 2023-04-18

Approved By: © Ericsson. Commercial in confidence

AIRTELGSM/ WCDMA RAN Optimization Report

1 Methodology

In this report, the performance of the GSM and WCDMA radio access network (RAN) is described in terms of accessibility, retain-ability and coverage, using Ericsson quality metrics and classifications. By giving an unbiased picture of the GSM and WCDMA RAN performance, Ericsson’s quality process provides a valuable aid for tuning the radio access network.

© Ericsson. Commercial in confidence 2(42)


2 EVENTS STATISTICS

Accessibility:

MS1/WCDMA MS2/GSM MS3/ IRAT

Events PRE-DT POST-DT PRE-DT POST-DT PRE-DT POST-DT

Call Attempt 88 89 218 242 220 187

Call Setup 73 81 184 218 185 168

Call Established 73 81 184 218 185 168

Blocked Call 15 8 11 24 3 12

Blocked Call Rate (%) 17.045 8.99 5.046 9.917 1.364 6.42

Call Setup Success Rate (%) 82.955 91.01 94.954 90.082 98.636 90.00Retain-ability:


Events PRE-DT POST-DT PRE-DT POST-DT PRE-DT POST-DT

Call Established 73 81 184 218 185 168

Dropped call 9 5 4 1 4 0

Call End 64 76 180 217 181 168

Call Drop Rate (%) 12.329 6.172 2.174 0.459 2.162 0.00

Handover Statistics


EventsPRE-DT

POST-DT Events

PRE-DT POST-DT Events

PRE-DT

POST-DT

Radio Link Addition

273 378 Hand Over Attempts 547 471

Cell Reselection to UTRAN(Success/Failure) 9/0 9/ 0

Radio Link Removal

252 341Hand Over Failure 2 2

Cell Reselection from UTRAN(Success/Failure) 2/0 1/ 0

Radio Link Replacement 226

239 Hand Over Success Rate 99.634 99.58

Handover from UTRAN(Success/Failure) 9/3 8/ 2

Soft Hand-Over Procedure Complete

704 879Handover to UTRAN(Success/ Failure)



3 WCDMA RAN ANALYSISThe following section of the report contains a description of each problem area/ region showing the WCDMA coverage, quality and CPICH Pilot/ Active Set Number of members in the area.

The values and ranges for CPICH RSCP, Ec/No and Pilot Pollution levels are shown in the figure 3 below.

Figure 3: Colour schemes for map thematic



3.1 PLOTS OF CPICH RSCP, Ec/No and PILOT POLLUTION3.1.1 CPICH PLOTS

PRE-DT: MS1: Serving CPICH RSCP POST-DT: MS1: Serving CPICH RSCP



PRE-DT: MS1: SAN CPICH RSCP Distribution Histogram

POST-DT: MS1: SAN CPICH RSCP Distribution Histogram



PRE-DT: MS1: Serving CPICH EcNo

POST-DT: MS1: Serving CPICH EcNo



PRE-DT: MS1: SAN CPICH Ec/No Distribution Histogram

POST-DT: MS1: SAN CPICH Ec/No Distribution Histogram



PRE-DT: MS1: Total Polluter/ Active Sets Size

POST-DT: MS1: Total Polluter/ Active Sets Size



PRE-DT: MS1: SAN No of Members

POST-DT: MS1: SAN No of Members



PRE-DT: MS1: UETx Power

POST-DT: MS1: UETx Power



PRE-DT: MS1: UE Tx Power

POST-DT: MS1: UE Tx Power



3.1.2 REGION 1Figures a), b) and c) below show the situation encountered during the drive test regarding CPICH Ec/No, CPICH RSCP, and Pilot Pollution respectively:

a) PA1 CPICH Ec/No

b) PA1 CPICH RSCP


A

B

C

D


c) PA1 PILOT POLLUTION



Below are recommendations to help improve coverage in the area:

Observations/ Recommendations

A Poor downlink coverage in the area was due to the distance traveled from serving WCDMA cell: LG1403J.No coverage was observed after.Deploying a new Node B in this area should boost WCDMA coverage in the area.

B Poor measured CPICH RSCP in the area was due to the distance transversed from the Node B(4.90km)LG1766 was off air during the drive.Bringing LG1766 on-air will help to improve WCDMA coverage in the area

3 Poor or limited downlink coverage observed in the area was to the distance(4.19km) from the serving node B. LG22597&LG0208 were suspected to be either off-air or malfuntioning.



4



3.1.3 REGION 2Figures a), b) and c) below show the situation encountered during the drive test regarding CPICH Ec/No, CPICH RSCP, and Pilot Pollution respectively:



a) PA2 CPICH Ec/Io

b) PA2 CPICH RSCP


PA2a

A


\c) PA2 PILOT POLLUTION



Below are recommendations to help improve coverage in the area:

Observation/ Recommendations

A -Poor downlink coverage within a 500m radius from LG0461.-UE Tx power also excessively high in the area.

-check LG0461H/J for possible hardware problems-reduce antenna tilt on LG0461H/J by 2deg each to improve distant coverage.

Cell Name

Setting Changes

Region Affected Label Priority & Reason Comments

Elect. Tilt

old new

LG0461H 0 -2 R1 C High(Poor Distant Coverage)

LG0461J 0 -2 R1 C High(Poor Distant Coverage)



4 GSM RAN ANALYSISThe following section of the report contains a description of each problem area showing the received signal level, quality and summarizing the situation.The values and ranges for RxLev Sub dBm and RxQual Sub are shown in the figure 3 below.

Figure 3: Colour schemes for map thematic



4.1 PLOTS OF Rxlev and RxQual 4.1.1 RxLev Sub (dBm)

PRE-DT: RxLevSub (dBm): MS2

POST-DT: RxLevSub (dBm): MS2As evident in the plot above; there isn’t any severe coverage problem as all recorded rxlev counts are < -80dBm.



PRE-DT: RxLevSub (dBm) Distribution Histogram

POST-DT: RxLevSub (dBm) Distribution Histogram



3.1.2 RxQual Sub

PRE-DT: RxQual Sub:MS2

POST-DT: RxQual Sub:MS2



PRE DT: RxQual Sub Distribution Histogram

POST DT: RxQual Sub Distribution Histogram



3.1.3 FER_SUB

PRE-DT: FER_SUB: MS2

POST-DT: FER_SUB: MS2



PRE DT: FER_SUB Distribution Histogram

POST DT: FER_SUB Distribution Histogram



3.1.4 C/I WORST

PRE DT:C/I WORST: MS2

POST DT:C/I WORST: MS2



PRE DT: C/I WORST Distribution Histogram

POST DT: C/I WORST Distribution Histogram

3.1.5 SQI



PRE DT: SQI: MS2

POST DT: SQI: MS2



PRE-DT: SQI: MS2

POST-DT: SQI: MS2



2.1.3 REGION 1

Figures a) and b) below shows the map of the received signal level and quality during the course of the drive test for Region1.

a)R1 RxQual

b) R1 RxLev


A

B


Below are recommendations to help improve the received signal quality in the region:

Observations/Recommendations

A Poor coverage in the area was due to Terrain/Vegetation covered in the area which increase signal attenuation within a kilometer radius from GSM site: LG0483.-reduce antenna tilt on LG0483C by 2deg to improve coverage in the interest area.

B The poor coverage was due to the distant from the serving celland it was observed in the coverage area of LG2000.The site is suspected to be having alarms/hardware issues.

_Resolving hardware issues will help to improve coverage in the area.

Cell Name

Setting Changes

Region Affected

LabelPriority & Reason Comments

Elect. Tilt

old new

LG0483C 0 -2 R1 B Medium(Poor Coverage)



4.1.2 REGION 2Figures a) and b) below shows the map of the received signal level and quality during the course of the drive test for Region 2.

a) R2 Rx_qual

b) R2 RxLev


A


Below are recommendations to help improve received signal quality:

Observations/RecommendationsA

-LG2102 was also off-air during the DT exercise.-resolving power/hardware issues on this site(LG2102) should improve GSM coverage in this area.



4.2 EVENTS DISTRIBUTION PLOTS

4.2.1 MS1/MS2/MS3: DROPS & BLOCKS

MS1/MS2/MS3: HANDOVER EVENTS



5 Analysis5.1.1 GSM CALL DROP ANALYSIS

Observations/Recommendations1 Drop type: No service

BCCH ARFCN: 112 BSIC: 1-2 CGI: 621 20 131 22214

-The drop call was due to poor received signal quality from the serving cell (LG2214B).The cell is approximately at a distance of 4.82km from point of the drop.

2 Drop type: No service BCCH ARFCN: 109 BSIC: 4-5 CGI: 621 20 131 12259

A link failure is suspected to be responsible for the drop call._A trace on the A-bis interface can help to provide a logical reason for the drop.

5.1.2 GSM BLOCKED CALL ANALYSIS

Observations/Recommendations1 Block Type:

No Traffic Channel Assignment

Non-availability of Traffic Channels (CM Service Reject) lead to the multiple failed call setups on LG0432B as shown in the highlighted area on the plot.



2 Block Type: No Traffic Channel Assignment

Non-availability of Traffic Channels due to TCH congestion on serving cell OG0082C led to the failed call setup.

3 Block Type: No Alerting or connect

Non- availability of radio resources at Call Initiation led to the failed call setup on LG0461B.


Non-availability of Traffic Channels due to TCH congestion on serving cell LG0208B led to the call block.


Non-availability of Traffic Channels due to TCH congestion on serving cell LG02438B led to the blocked call

5.1.3 WCDMA CALL DROP ANALYSIS



Observations/Recommendations

1 Drop type: No serviceUARFCN: 10712 AS: 133-The dropped call was due to the poor downlink coverage experienced in the area.LG0382 close to the point of the drop was off-air during the time of the drive.-Bringing LG0382 on air will improve the coverage and eventually prevent drop call in the area.

2 Drop type: No service UARFCN: 10712 AS: 64-80- Poor coverage was responsible for the dropped calls in the area.-Improving WCDMA coverage in the area should improve the call retain-ability in the area.LG0461 should be checked for any hardware issues.

3 Drop type: No service UARFCN: 10712 AS: 94 -Poor coverage was responsible for the dropped calls in the area.-Improving WCDMA coverage in the area by increasing electrical uptilt on LG0485H by 2deg. should improve the call retain-ability in the area



4 Drop type: No service UARFCN: 10712 AS: 94 _Dropped call as a result of poor downlink coverage in the area._Improved coverage will also help reduce drop call re- occurrence in the area.

5 Drop type: No service UARFCN: 10712 AS: 54-4_Poor coverage responsible for the dropped call in the area._Improving the coverage in the area as suggested in the coverage analysis should reduce DCR in the area.



5.1.4 WCDMA BLOCKED CALL ANALYSIS

Observations/Recommendations1 Block type: T-303 expiry, no MM connection

available._ The multiple Call block in the area was due to the limited WCDMA coverage in the area.

2 Block type: T-303 expiry, no MM connection available._ The multiple blocked calls were due to non-availability or limited of WCDMA coverage in the area.

3Block type: T-303 expiry, no MM connection available._ The repeated blocked calls were due to non-availability of WCDMA coverage in the area.



5.1.5 INTER-RAT HANDOVER FAILURE ANALYSIS

Observations/Recommendations1

The Handover from UTRAN failures (3) all occurred in the same area between WCDMA on LG0461J and GSM onLG1671C.

Handover from UTRAN Failure(UL-DCCH)InterRAT HO-FailureCause:Physical channel failure

-Check LG1671 for channel/hardware problems

2

3


Airtel_badagry_ran Optimisation Report August&September

Documents

cpich plots

plots of cpich rscp

wcdma coverage

wcdma radio access network

wcdma cell

radio link removal252341hand

radio link replacement

problem area region