ar20000331 airtelsierraleone gsm weeklyreport week40 2010 (1)

7/28/2019 AR20000331 AirtelSierraLeone GSM WeeklyReport Week40 2010 (1)

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Document confidentiel - Aucune copie, partielle ou complte, ne peut tre faite sans lautorisation crite et pralable dAstelliaConfidential document - Partial or global copy cannot be made without prior and written authorization of Astellia

Customer: Airtel Sierra Leone

Order acknowledgement: AR20000331

ASTELLIA SERVICESWEEKLY REPORT GSM (W40)

YEAR 2010

QOS AND NETWORK PERFORMANCE

FOR AIRTEL SIERRA LEONE


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ASTELLIA SERVICESWEEKLY REPORT GSM

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Model: Audit Report GSM - Release: RA AR20000331_AirtelSierraLeone_GSM_WeeklyReport_Week40_2010.doc

Written by

Name Khaled Ounifi

Company Astellia

Job title Telecom Engineer

Date October, 13rd

2010Signature

RecipientsAIRTEL SIERRA LEONE

Salwa S KAMARA

Victor JONAH

Amjad M. KAMARA

Gibrilla KAMARA

Lovemore MOYO

Melvine J. S. TEMPLE

Mamadu BAH Arnold Warren NOTTIDGE

Alieu KAMARA

Mohamed JALLOH

Princetta SILLAH

Kadiatu M. BANGURA

Desmond BUCK

Sylvanus Redwood-Sawyerr

ASTELLIA

AIRTEL Support Team

Release

Release Date Author SubjectA 13/10/10 K.Ounifi Original VersionA 13/10/10 M.Camara Review


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SUMMARY

1. ABSTRACT.................................................................................................................................................42. MAIN POINTS/ISSUES ..............................................................................................................................53.

OVERVIEW NETWORK LEVEL .............................................................................................................6

3.1. CALL SETUP INEFFICIENCY..........................................................................................................6

3.1.1. ORIGINATING CALLS...............................................................................................................63.1.2. TERMINATING CALLS ..............................................................................................................7

3.2. CALL DROP......................................................................................................................................83.3. TRAFFIC...........................................................................................................................................93.4. HANDOVERS.................................................................................................................................10

3.4.1. OUTGOING HANDOVERS .......................................................................................................103.4.2. INCOMING HANDOVERS ........................................................................................................113.4.3. PING-PONG HANDOVERS......................................................................................................123.4.4. INTER BSCHANDOVERS ......................................................................................................13

3.5. LOCATION UPDATE EFFICIENCY ...............................................................................................143.6. PAGING EFFICIENCY....................................................................................................................153.7.

SMS PERFORMANCES.................................................................................................................16

3.7.1. OUTGOING SMS..................................................................................................................163.7.2. INCOMING SMS....................................................................................................................17

4. ANALYSIS & TOP/WORST LISTS ..........................................................................................................184.1. CALL SETUP..................................................................................................................................18

4.1.1. ORIGINATING CALLS:DETAILS OF INEFFICIENCY ....................................................................184.1.2. ORIGINATING CALLS:WORST BSCS .....................................................................................214.1.3. ORIGINATING CALLS:WORST CELLS.....................................................................................224.1.4. TERMINATING CALLS:DETAILS OF INEFFICIENCY ...................................................................244.1.5. TERMINATING CALLS:WORST BSCS ....................................................................................254.1.6. TERMINATING CALLS:WORST CELLS ....................................................................................26

4.2. CALL DROP....................................................................................................................................274.2.1. DETAILS OF INEFFICIENCY ....................................................................................................274.2.2.

WORST BSCS .....................................................................................................................28

4.2.3. WORST CELLS .....................................................................................................................29

4.3. TRAFFIC.........................................................................................................................................304.3.1. WORST BSCS:TCHCONGESTION .......................................................................................304.3.2. WORST CELLS:TCHCONGESTION (>0.5%TCH CONGESTION RATE)....................................31 4.3.3. WORST BSC:CICUSE RATE...............................................................................................32

4.4. HANDOVERS.................................................................................................................................334.4.1. BSCLEVEL: HO CAUSES DISTRIBUTION...............................................................................334.4.2. INTER BSCHANDOVERS EFFICIENCY....................................................................................35

4.5. LOCATION UPDATE......................................................................................................................364.5.1. DETAILS OF INEFFICIENCY ....................................................................................................364.5.2. WORST CELL LIST................................................................................................................38

4.6. PAGING..........................................................................................................................................394.6.1.

LACLEVEL:PAGING EFFICIENCY ........................................................................................39

4.7. SMS PERFORMANCES.................................................................................................................40

4.7.1. DETAILS OF INEFFICIENCY FOR ORIGINATING SMS................................................................404.7.2. SMSCENTER PERFORMANCES ............................................................................................42

5. CONCLUSION..........................................................................................................................................43


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1. ABSTRACT

In the context of ASTELLIA Services dedicated to AIRTEL SIERRA LEONE, GSM reports will be supplied

each week.

This report provides Performances and Quality of Service trends of AIRTEL SIERRA LEONE GSMnetwork. The Key Performances Indicators provided are based on 24H captures.

The analyzed period is from October, 04th

to October, 11th

(Week 40)

Here is the current topology of AIRTEL SIERRA LEONE GSM Network:

The dashboards allow comparing AIRTEL SIERRA LEONEs QoS and Performances during one month.They provide trends from each day of the month. They include most of indicators described below:

Call Setup

Traffic

Call Drop

Handover

Location Update

SMS

Paging

All these indicators and trends will be provided at network, BSC and cells Level, except for paging asindicators are given per LAC.

FTBSC01_300

(200)Ericsson

BOMGW01Ericsson

FTMGW01Ericsson

BOBSC01_300

(210)Ericsson

MSS1 in Freetown(300)

Ericsson

MSS2 in Freetown(330)

Ericsson


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2. MAIN POINTS/ISSUES

Topic Network Elements Problems Astellia recomme

Call Setup SHENGE3_1_1083TRX issue when switching from

SDCCH to TCH.Perform a soft reset of the TRX. Block the T

Call Setup BLAMA3_200_533TRX issue when switching from


Call Setup SERABU2_300_1072TRX issue when switching from


Call Setup PENDUM1_200_211TRX issue when switching from


Call Setup BO51_200_1211 Lack of radio resource Check the TRX statu

Call Setup MOKANJ2_300_482 Lack of radio resource Check the TRX statu

Call Setup BOJON2_200_312 Lack of radio resource Check the TRX statu

Call Drop SERABU2_300_1072 Loss of radio link Check the global rad

Call Drop YELE2_200_1592 Loss of radio link Check the global rad

Call Drop KONADE2_300_1222 Loss of radio link Check the global rad

Traffic MOKANJ2_300_482 TCH congestion Check TRX status

Traffic BO51_200_1211 TCH congestion Check TRX status

Traffic MASING2_200_942 TCH congestion Check TRX status

Traffic RUTILE1_300_491 TCH congestion Check TRX status


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3. OVERVIEW NETWORK LEVEL

3.1. CALL SETUP INEFFICIENCY

3.1.1. ORIGINATING CALLS

NSS and BSS inefficiencies are still stable.More details about this, is provided in the analysis part of the report in chapter 4.1.1.


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3.1.2. TERMINATING CALLS

..The same behavor is appearing for terminating calls, where the average BSS/NSS inefficiency rises to ~4%.Main causes are provided in chapter 4.1.4.


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3.2. CALL DROP

BSS/NSS inefficiency is improvedDetails on drops causes are available in chapter 4.2.1


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3.3. TRAFFIC

At network level, the TCH congestion rate is good since few weeks, with an average value of < 0.5%. As well, the direct retList of more impacted cells are available in chapter 4.3.2.


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3.4. HANDOVERS

3.4.1. OUTGOING HANDOVERS

Main causes of outgoing handovers are still Better Cell(BC) and Uplink Quality(ULQ), which is a normal comportment:

o BC is the expected cause of handover: HO is triggered when a second cell has better signal than the first.o ULQ is here mainly used for intracell HO: handovers are made between the different frequencies of a same sector


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3.4.2. INCOMING HANDOVERS

Same causes for incoming handovers. Causes distribution is stable as well.


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3.4.3. PING-PONG HANDOVERS


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3.4.4. INTER BSCHANDOVERS

Inter-BSC handovers efficiencies are good and stable at network level. However there are still some cell couples with a vDetails on this point are provided in chapter 4.4.2


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3.5. LOCATION UPDATE EFFICIENCY

Over the past week, the NSS/BSS inefficiency for LU has been quite stable. On October 09th, we note a small increase of r

number.Details on rejection causes are provided in chapter 4.5.1


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3.6. PAGING EFFICIENCY

Paging efficiency has strongly decreased since the 10/09/10 and its still very low, as LAC 200 issue has been handled few


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3.7. SMS PERFORMANCES

3.7.1. OUTGOING SMS

Originating SMS efficiency is very low: around 40%.Refer to the section 4.7.1 Details of Inefficiency for Originating SMS to check failure causes.


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3.7.2. INCOMING SMS

Incoming SMS efficiency is quite good and stable.


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4. ANALYSIS & TOP/WORST LISTS

4.1. CALL SETUP

4.1.1. ORIGINATING CALLS:DETAILS OF INEFFICIENCY

Inefficiency causes are mostly related to user behaviour and/or radio issues.Refer to the table below for main inefficiency causes.


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1. CM Service Abort(light green bar):The release comes from thesubscriber. This means that the user hung up before the ringing phaseand before the sent of Setup message.

No needed actions from your side

2. DISC_M Normal Clearing(dark green bar): The release comes fromthe subscriber. This means that the user hung up before the ringingphase but after the sent of Setup message.

No needed actions from your side


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3. DISC_F- Unassigned Number (UN)(brown bar): This message can besent because dialled number is not assigned.

Because the Disconnect message is sent by the MSC, this failure is countedas NSS inefficiency while it is in fact related to user behaviour.

Reject calls with wrong number format with a Disconnectmessage with cause Invalid Number Format. Then, associated

failures will not affect the NSS inefficiency rate.

4. DISC_F Nu(pink bar): Disconnect message sent by the MSC with causeNormal Unspecified, with 2 possible causes.

Disc_F-Nu / state OC_ASS_FAI: This iDisc_F-Nu / state OC_PROC: These fa

Refer to 4.1.3 and 4.1.6 (Originatiidentify impacted cells.

5. Clear Request Radio Interface Message Failure(dark blue bar).

This is mainly representative of radio is

Refer to 4.1.3 and 4.1.6 (Originatiidentify impacted cells.


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4.1.2. ORIGINATING CALLS:WORST BSCS

MOC inefficiency causes distribution is more or less the same on both of the BSC with mainly user causes (green bars: MSS brown bars: )


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4.1.3. ORIGINATING CALLS:WORST CELLS

This graph shows cells with highest inefficiency rates. According to further studies, impacted cells are showed in the table n


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1. DISC_F Nu( bar): Disconnect message sent by the MSCwith cause Normal Unspecified. This failure occurs in twodifferent final states:

- after an assignment Failure message:o

OC_ASS_FAIstate

- after Call Proceeding message:o OC_PROCstate

Disc_F-Nu/state OC_ASS_FAI:This week, the only cell that may be impacted by t

BSC Cell CI

FTBSC1_200 SHENGE3_1_1083 10

BOBSC1_210 BLAMA3_200_533 5

FTBSC1_200 SERABU2_300_1072 10

BOBSC1_210 PENDUM1_200_211 2

- TRX issue when switching from SDCCsetting and their capabilities. Reset

equipment if the pro

Disc_F-Nu /state OC_PROC:

This week, the only cell that may be impacted by t

BSC Cell CI

FTBSC1_200 KUKUNA3_300_753 7

FTBSC1_200 GBALAM1_300_1241 12

BOBSC1_210 MALEMA3_200_1433 14

BOBSC1_210 MALEMA2_200_1432 14

- Change the configuration at MSC level incases with cause Invalid Num

- Check of links towards international

(congestion, hardw


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4.1.4. TERMINATING CALLS:DETAILS OF INEFFICIENCY

...

Main causes of inefficiency are: CLCMD Call Controland DISC_F- Normal Clearing, meaning releases coming from sub


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4.1.5. TERMINATING CALLS:WORST BSCS

Main causes of inefficiency are: CLCMD Call Controland DISC_F- Normal Clearing, meaning releases coming from sub


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4.1.6. TERMINATING CALLS:WORST CELLS

BO51_200_1211, MOKANJ2_300_482 and BOJON2_200_312 are impacted by TCH congestion (ASSFAI No Radavailability and traffic dimensioning in these cells.SERABU2_300_1072 and CANDY1_200_1101 are impacted by radio problems (CLREQ RIF+RIMF) =>Check hardwarservice (azimuth, tilt and antenna height)


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4.2. CALL DROP

4.2.1. DETAILS OF INEFFICIENCY

At a network level, the detected increase of NSS+BSS drops rate highly impacting statistics. The main cause is Radio Inradio issues on coverage cells. Main impacted cells are listed below (in chapter 4.2.3)


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4.2.2. WORST BSCS

The 2 BSCs {BOBSC1_210 and FTBSC1_200} are impacted by radio issues (Clear request RIF + RIMF, dark blue barin the next page.


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4.2.3. WORST CELLS

Since September, 26th

to October 3rd

, the drop rate had increased on every cell. All drops are due to an error on th[Message] Failure). An improvement has been happened since October 4

th. But, call drops are not stable.

Do you see any explanation causing this global behaviour?The call drops rate should be followed in order to return to same values before deg


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4.3. TRAFFIC

4.3.1. WORST BSCS:TCHCONGESTION

Good TCH congestion rate at BSC level


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4.3.2. WORST CELLS:TCHCONGESTION (>0.5%TCH CONGESTION RATE)

Several cells are suffering from TCH congestion => Check resources availability of TRXs (there is no hardware probleneeding supplementary resources.


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4.3.3. WORST BSC:CICUSE RATE

..


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4.4. HANDOVERS

4.4.1. BSCLEVEL: HO CAUSES DISTRIBUTION

..

The main causes of outgoing handovers are Better Cell (BC) and Uplink Quality (ULQ). Description of major causes is de


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Better Cell HO is triggered when a second cell has a better signal than the first cell (HO margin parameter).site having sectors with dual-band configuration

ULQ it generally indicates radio interferences. In case of intracell HO, it might indicate a site having sectors w

codec (FRHR) DLQ it generally indicates radio interferences.

DLS signal strength on the downlink: the power signal of the BTS isnt sufficient to maintain the call.

ULS signal strength on the uplink: the power signal of the mobile isnt sufficient: check the link balance to adapt

O_M Operation & Maintenance: an operation is ongoing (software update, etc)

DR Directed Retry: when the traffic is more important than a certain level, a HO is triggered to a cell having less

D a HO is triggered when a mobile is identified as too far from the serving cell.

Asymmetric HO (Cells with >100 performed HO)

Neighbour links for cells in the following table may not be declared in the 2 ways. This generally comes from discrepancies

BSC Origin Origin -> Target CI Ho In Ho Out Total Ho %FTBSC1_200 ELECT5_1_135->YOUYI1_1_81 135->81 190 0 190 1

FTBSC1_200 LHILL3_1_53->Cell_1_2032 53->2032 189 0 189 1

FTBSC1_200 KSHELL2_1_252->Cell_1_2031 252->2031 107 0 107 1

You should validate these declarations and check whether they are relevant regarding your network topology


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4.4.2. INTER BSCHANDOVERS EFFICIENCY

Good efficiency for inter-BSC handoversLocation Update


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4.5. LOCATION UPDATE

4.5.1. DETAILS OF INEFFICIENCY

..

This graph provides the main cause of LU reject over the network.These causes are explained below.


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Radio Interface Message Failure:

This is related to radio issues on the coverage cell.

PLMN Not Allowed:

Rejections related to this cause have decreased over the network. But we stillhave a significant proportion of rejection:

Other reject causes (such as LANA or RNAILA Roaming NotAllowed in This Location Area) should be used.

PLMN Not Allowed cause shall be used only for subscribersfrom AIRTEL competitor in Sierra Leone.

See this corresponding table to spot concerned networks.

Main foreign networks with 10

Mobile network Nb

GIN 611-02, Lagui

USA 310-260, T-Mobile

Network Failure: This is related mainly to roamers activities. This cause is sentto the mobile if the MSC cannot service a MS generated request because:

oLink/MAP issues between AIRTEL SLE international GTW and roamer HLRoNon-agreement between AIRTEL SLE and foreign operatorsoSpecific roaming agreements managing outbound roamers from thesenetworks and some roaming steering mechanismso (AIRTEL Sierra Leones competitors being registered in the roamers SIMas a preferred network)

Core team should check the existence of roamingagreement with these networks:

- If so, check MAP routing to these destinations

TOP14 of LU rej(NF) for foreign networ

Mobile network Nb of

ZWE 648-04, Econet

LBR 618-04, Comium Liberia

GBR 234-33, Orange UK

GIN 611-04, Areeba

USA 310-380, ATT

LBR 618-01, Lonestar

ZAF 655-01, Vodacom

USA 310-410, ATT

GIN 611-01, Mobilis

SWE 240-08, Vodafone SE

PHL 515-03, Smart Gold

GBR 234-15, Vodafone UK

GBR 234-10, O2 UK

NGA 621-30, MTN Nigeria


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4.5.2. WORST CELL LIST


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4.6. PAGING

4.6.1. LACLEVEL:PAGING EFFICIENCY

..

Compared to previous weeks, paging efficiency has strongly decreased on LAC 200, affecting the efficiency at network leve

We do recommend Airtel Sierra Leone to check the paging parameters and global radio cond


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4.7. SMS PERFORMANCES

4.7.1. DETAILS OF INEFFICIENCY FOR ORIGINATING SMS

.....

Explanation about main error causes, appearing on your network:


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RFNS (Requested Facility Not Subscribed): this error indicates that the subscriber didnt purchase the desired servsubscribers without credit are also rejected with this cause.

NOO (Network Out of Order): it indicates a failure because of data missing (for example no destination number o

destination number hasnt the correct digit number), system failure (failure from SMS center), lower failure (timer ex

Explanation about others minor cause:

SMTR (Short Message Transfer Rejected): It indicates a delivery failure because of invalid SME (Short Messacenter are wrong.

IMI (Invalid Mandatory Information): it indicates that some IE (Information Element), taking part of the SMS structuexample, a very old mobile with low version software could produce this error or a non compatible mobile (Japanand structure are different from the observed network.


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4.7.2. SMSCENTER PERFORMANCES


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5. CONCLUSION

This report, based on daily GSM captures done during the last 30 days, allows the evaluation of theperformance of the GSM network and the Quality of Service that is delivered to subscribers during theprevious week.

ASTELLIA thanks the teams at AIRTEL SIERRA LEONE for their confidence and their support.

ar20000331 airtelsierraleone gsm weeklyreport week40 2010 (1)

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