PRIVILEGED AND CONFIDENTIAL. THE INFORMATION CONTAINED IN THIS MATERIAL IS PRIVILEGED AND CONFIDENTIAL, AND IS INTENDED ONLY FOR THE USE OF THE INDIVIDUAL TO WHOM IT IS ADDRESSED AND OTHERS WHO HAVE BEEN SPECIFICALLY AUTHORIZED TO RECEIVE IT. IF YOU ARE NOT THE INTENDED RECIPIENT, YOU ARE HEREBY NOTIFIED THAT ANY DISSEMINATION, DISTRIBUTION OR COPYING OF THIS MATERIAL IS STRICTLY PROHIBITED. IF YOU HAVE RECEIVED THIS MATERIAL IN ERROR, PLEASE DESTROY IT IMMEDIATELY.

February, 2nd 2015

Knowledge Sharing

Session Number 7th

||

Agenda

DCR Definition

DCR Reasons

DCR Counters

DCR Parameters

Activity Carried for DCR improvement

POST Impact

||

DCR-Retainibility

Retainablity is defined as the ability of user to retain its requested service once connected for the desired duration.

Major Factors which affecting the retainablity -

Mobility Inter/Intra - frequency Handover (Soft/Softer) Inter Radio access Technology Handover(IRAT HO)

Coverage Radio Connection supervision (RCS) Radio Link control(RLC)

||

DCR-Retainibility

Congestion Control Verify CE usage & HW allocation. Failure due to lack of DL power & codes.

Others Transport network problem Hardware faults. UE Problem. Cell downtime.

||

DCR-Approches

Retainibility

Missing Nbr Soft Handover Uplink Synch IRAT Congestion Others

Add suggested Neighbors with WNCS/DriveTest

Analysis existing Nbr With 3G-3G radio link attempts, distance & location.

Analysis Cell coverage DT

Check RBS HW alarm & NBR cell also.

Check RL Add attempt failure.

Check cell availability .

Verify SC clashes

PRACH Delay check cell overshooting

Investigating UE Tx pwr by WMRR.

Check cell RSSI- (pmr- 4 OSS commend)

Check GSM coverage area

Check resources availability (TAVAACC for 2G)

Failure due to lack of DL pwr & codes.

Verify CE Usage

& HW allocation

Transport issue. Hardware fault .UE problem. Cell downtime.

||

DCR-Retainibility

Counters for DCR

| © TEOCO PROPRIETARY AND CONFIDENTIAL | | 7

Drops due to Missing Neighbor

Based on WNCS analysis Nbr Addition done which decreases the No. of drop due to missing Nbr

||

Drops due to Missing Neighbor

As per WNCS result potential neighbors were added in network.(Approx 2000+) One way neighbors also added in network.(Approx 800+) 30-Dec onwards missing neighbor count reduced.

1-De

c

2-De

c

3-De

c

4-De

c

5-De

c

6-De

c

7-De

c

8-De

c

9-De

c

10-D

ec

11-D

ec

12-D

ec

13-D

ec

14-D

ec

15-D

ec

16-D

ec

17-D

ec

18-D

ec

19-D

ec

20-D

ec

21-D

ec

22-D

ec

23-D

ec

24-D

ec

25-D

ec

26-D

ec

27-D

ec

28-D

ec

29-D

ec

30-D

ec

31-D

ec

1-Ja

n

2-Ja

n

3-Ja

n

4-Ja

n

5-Ja

n

6-Ja

n

7-Ja

n

8-Ja

n

9-Ja

n

10-J

an

0

100

200

300

400

500

600

700

CRE04 DRE01 DRE03

Nbr Addition done

WNCS _Network

||

WNCS-WCDMA Neighbouring Cell Support

Deletion required

Addtion required

Limitation : You can schedule only300 Cell across 5 RNC in WNCS.

||

Drops due to Soft handover

Nbr Addition done

Check all service affecting alarm. Check Cell availability-check administrative state(0= LOCKED & UNLOCKED = 1) Verify SC clashes.

||

Drops due to Soft handover

Nbr Addition & DL code adjustment done on 6th Jan

dlCodeAdm :Admission limit based on downlink channelization code tree usage. 80% default: Ideally it should not be more than 85 %

||

Alarm

For every Top offender of KPI we need to check few alarms.

Every alarm provided the following information. Event Type: Indicates type of events. Communication alarm Processing error alarm Environmental alarm Quality of service alarm. Equipment alarm

Perceived Severity: indicates the relative level of urgency Critical Major Minor Warning

||

Alarm

Few commands for checking Daily alarms.• alt(Current alarms)• ala(Current Alarms with details).• lh ru fui get vswr(get VSWR )• Lgo(Opererational history of nodeB  

||

Drops due to UL Synch

For the UL synch drop issue need to check the overshooting cell(HIGH PRACH) If high PRACH observed need to optimize these cell(Physical/parameter).

As per WMRR we can see that High UE Tx pwr observed.

||

Drops due to UL Synch

pmx –m 24 prach prop –a (with the help OSS command we can check the propagation dealy in nodeB)

||

Recommendation: Cell having high PRACH. Need to optimize first.. Missing 3G-2G neighbor can added further, if any.

PRACH Analysis:

||

Drops due to UL Synch

rlFailure: Guard period before sending RL Failure.

Unit: 0.1 s, ranges :0..255,default: 10nOutSyncInd:Number of frames to be considered for

out-of-sync detection. ranges :1..256,default: 10

CR implemented

||

Drops due to UL Synch

nOutSyncInd parameters tuning done for top contributor for UL drop on 6 th Jan post implementation drop decreases.

||

Drops due to UL Synch

nOutSyncInd parameters tuning done for top contributor for UL drop on 6 th Jan post implementation drop decreases.

minpwr RL changes done for 37 Cells on 12th JAN

minPwrRl parameters tuning done for top contributor for UL drop on 12th Jan post implementation drop decreases.

minPwrRl : Minimum power per radio link. Default: -150 dBm.

||

IRAT-Drop IRAT (inter Radio access technology) handover and cell change allow 3G Voice & data services WCDMA RAN to GSM transition to maintain the connection with the UE between coverage area to prevent drop calls• Main causes for IRAT drop:

• Wrong Definition (BCCH/BSIC/LAC) • Missing 2G relation.• Non Availability of 2G resources.• Poor 2G coverage.

||

Congestion Control

Congestion control algorithms has the ability to drop calls when cell congestion is detected.

Congestion mainly comes due to resources crunch in the nodeB/network,so need to augmented the recourses as per planning guidelines. As we can observed from below graph there is few cases only in the network where drop due to congestion.

||

Drop due to others reason In second phase of DCR optimization drop due to others reason will take in consideration. The percentage of drops due to reasons other than Mobility, Congestion Control or Coverage can be

calculated using the formula:

100* (pmNoSystemRabReleaseSpeech-pmNoSysRelSpeechSoHo-pmNoSysRelSpeechULSynch-pmNoOfTermSpeechCong) =

(pmNoNormalRabReleaseSpeech+pmNoSystemRabReleaseSpeech)

||

UE Related ProblemsSome terminal related problems (non-UTRAN) could be present especially in the data cards or new generation mobiles affecting retainability for PS services. Sometimes application layer errors cause the terminal restarting or freezing, and the connection is released. These types of failures are normally seen as coveragedrops although it may be worth while analyzing these drops based on IMEI and finding the associated UE type.

Transport NetworkThe drops due to problems in the TN occur especially in mobility, since it is not possible to add the cell belonging to the site with TN issues in the active set.These drops are more similar to coverage drops due to interference from the target cell that cannot be added.To investigate Transport Network issues, subscription profiles should be set up to collect a range of transport network counters that may be used to confirm that there is congestion in this area. Sometimes the problems can be due to wrong TN configuration. In these cases, a review of the TN design would be needed to solveproblems in TN.

Hardware IssueIn order to detect HW faults that are causing low retainability performances, it is very important to look at alarms in the node. After a first analysis has been made by the alarms, it could be useful to put specific traces in the node.

Cell DowntimeIn case maintenance operations are performed in the network, connections are released suddenly in the node where they are executed.From the counters it is possible to detect these issues looking at the counter ‘pmCellDowntimeMan’ that measures the length of time (in seconds) during which a cell is unavailable for service because of Administration state being set to manual lock. This means that Administration state of the cell and/or channel =locked, regardless of the operational state of the cell or channel.If the downtime is due to network faults, then the counter ‘pmCellDowntimeAuto’ is stepped. This counters measures the length of time (in seconds) during which a cell is unavailable for service because, due to a fault, the system has set a cell or channel state to disable. This means that cell and/or channel Operation state = Disabled and the cell and/or channel Administration state = unlocked.

||

Cell DowntimeIn case maintenance operations are performed in the network, connections are released suddenly in the node where they are executed.From the counters it is possible to detect these issues looking at the counter ‘pmCellDowntimeMan’ that measures the length of time (in seconds) during which a cell is unavailable for service because of Administration state being set to manual lock. This means that Administration state of the cell and/or channel =locked, regardless of the operational state of the cell or channel.If the downtime is due to network faults, then the counter ‘pmCellDowntimeAuto’ is stepped. This counters measures the length of time (in seconds) during which a cell is unavailable for service because, due to a fault, the system has set a cell or channel state to disable. This means that cell and/or channel Operation state = Disabled and the cell and/or channel Administration state = unlocked.

1-De

c

2-De

c

3-De

c

4-De

c

5-De

c

6-De

c

7-De

c

8-De

c

9-De

c

10-D

ec

11-D

ec

12-D

ec

13-D

ec

14-D

ec

15-D

ec

16-D

ec

17-D

ec

18-D

ec

19-D

ec

20-D

ec

21-D

ec

22-D

ec

23-D

ec

24-D

ec

25-D

ec

26-D

ec

27-D

ec

28-D

ec

29-D

ec

30-D

ec

31-D

ec

1-Ja

n

2-Ja

n

3-Ja

n

4-Ja

n

5-Ja

n

6-Ja

n

7-Ja

n

8-Ja

n

9-Ja

n

10-J

an

0.5

5.5

10.5

15.5

20.5

25.5

30.5

35.5

40.5

45.5

CRE04 DRE01 DRE03

Total Down Time (Hour)

||

Mobile drop distribution by drop reasons

As per GPEH analysis in CRE04 below are the drop categories along with ranking based on % Contribution.

Note: 18-Dec Data taken in consideration.

CN HHO - Relocation

Failed

Downlink Drop

IRAT - CS Drop

Iu - Iuc Rate Con-trol Pro-cedure Failure

MC IRAT Missing Neighbor

O&M - Cell Lock

Indication

RCS - Other (HW)

RCS - Un-recover-

able Error

Soft Han-dover -

Addition

Soft Han-dover -

Deletion

Soft Han-dover -

Replace-ment

Undefined Uplink Drop

% con-tribu-tor

0.000509770603228

547

0.117077315208156

0.18249787595582

0.066949872557349

2

0.000339847068819

031

0.018011894647408

7

0.012574341546304

2

0.024978759558198

8

0.098045879354290

6

0.089549702633814

8

0.016482582837723

0.007476635514018

69

0.245199660152931

0.120305862361937

2.50%

7.50%

12.50%

17.50%

22.50%

27.50%

Drop Categories %

(%)

1

2

5

4 3

67

GPEH Analysis

108

911 1214

13

||

Mobile Vendor Count of Vendor Mobile Vendor Count of VendorAG-TEL 2 Maximus 2Amoi 1 Micromax 15Apple 44 Moral 2Axiom 2 Motorola 105Bangla 1 N/A 2875BenQ 1 NGM Italia 1

Billion Well Holdings 1 Nokia 1337Blackberry 19 Pantech 1

Chi Mei Communications Systems 1 Quartel Infotech 21Concox 1 Samsung 1120

Edison Communication 28 SB Tel Enterprise 23Emitac 1 Senseit 1

E-Smart 4 Sierra Wireless 24Gfive 1 Sony 10

Gionee 3 Sony Ericsson 64Hisense 1 Strong Rising Electronics 1

HTC 13 Symphony 74Huawei 32 TCT Mobile 4

Intex 1 Tec Sync 2Kingstar Fast Track Corporation 1 Tec Sync Electronics 1

Kingtak (HK) Communication Equipment 1 Vodafone-TCT 1Konka 1 Walton Plaza 16Lava 2 Zhongtian 1

Lenovo 1 ZTE 4LG 15 ZTS 2

Drop distribution by UE

As per GPEH analysis in CRE04 below are the Drop distribution by UE.

1

3

2

Majorly with Unidentified IMEI marked with RED.

© TEOCO PROPRIETARY AND CONFIDENTIAL