© Nokia Siemens Networks – Amit Pawar

2G ERICSSON

Sales Cluster Optimization - 2013

© Nokia Siemens Networks – Amit Pawar

• Cluster performance worst in KUTAI BARAT & BANJARMASIN Cluster.• High number of drops are due to T3101 expiry, all BSCtimer are audited values as per

Ericsson default are set. Trial can be proposed to increase the T3101 timer value to reduce SD released. Trial proposed for BSMD2 bsc from samarinda cluster.

SDSR Performance

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0102030405060708090

CCONGS CNDROP CESTIMMASS CNRELCONG SDSRSDSR PERFORMANCE

SD

SR

Co

ntr

ibu

tor

SD

SR

© Nokia Siemens Networks – Amit Pawar

SD BLOCKING- CCONGS

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SD BLOCKING CCONGS

• SD blocking contributor for Low SDSR performance shows Samarinda ULU, Samarinda Utara, Kutai Barat Samarinda 1 and Balikpapan1 are having very high SD blocking.

• For SamarindaUlu and Smarinda Utara, clusters both GSM and DCS cells are having almost same blocking share. Other clusters are having majority of GSM cells with SD blocking.

• SD Blocking can be due to two reasons: 1. Due to unavailability of SD timeslots- SD Addition will be solution. 2. Due to signaling overload- Based on signaling link overload and failure change the SD timeslots location from one channel group to other channel

groups to balance the signaling.

020406080

100120

DCS GSM

SD Blocking- Band level

© Nokia Siemens Networks – Amit Pawar

LAPD Link Analysis

LAPD link status is analysis is checked based on the COVERLOAD and CLINKFAIL counters.

COVERLOAD– It will be incremented if LAPD-Link for TRX is get overloaded due to heavy signaling load.

CLINKFAIL– It will be Incremented if LAPD link is failed due to some hardware issues.

• Based on the LAP-D link data and available SDSR Kpi’s are mapped together to find out the worst links.

• Graph shows the number of cells are having low SDSR due to possile causes of link overload or link failures.

• Possible Solution:1. Change LAP-D signaling timeslots.2. Change TRX mapping from LAP-D timeslots.3. Change Confact value – this may lead to new E1

addition since will require more number of E1 timeslots for signaling.

05

10152025303540

# cells with link overload # cells with link fail

SDSR LAPD LINK ISSUE

D:\Cluster46_2013\CR\Ericsson\SDSR Improv

© Nokia Siemens Networks – Amit Pawar

CNDROP & SD Drop reason distribution

PASIR

BATU LIC

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ASER UTARA

AMUNTAI &

BALA

NGAN

KUTAI BARAT

KUTAI TIM

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BALIKPAPAN 2

BALIKPAPAN 1

BANJARM

ASIN &

MARTAPURA

SAMARIN

DA UTARA

SAMARIN

DA 1

BALIKPAPAN 3

SAMARIN

DA ULU

0

20

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100 'SD DROP LOW SS' 'SD DROP QAULITY' 'SD DROP HIGH TA' 'SD DROP OTHER

SD DROP REASONS

• Drop due to Low signal strength is observed in rural clusters, indicating calls are accepted with in poor radio level. Signal strengths Drop causing due to high coverage area serving.

• Drop due to high TA in some cells were indicated cells are serving with high TA . Total 243 cells are need to checked for physical optimization.• Based on Quality drop reasons 234 cells can be retuned for frequency or SDCCH timeslots can be shuffled based on channel group level quality

measurement.• 118 Cells were found having drop due to other reasons very high (more than 70% of total drop reason). This cells are having issue with the SD

configuration and need to check for the signaling overload since in this cells SDCCH drop reasons due to RF are very low.• Incorrect parameter settings such as high CRO and CRH are also impacting on high SDCCH drop rate.

Action Count of cellsFrequency retune/ SD shifting 234Check Hardware and Signalling Load 118High SS 189High TA Drop 44High TA Drop/ High SS 10Grand Total 595

SD Drop reasons

© Nokia Siemens Networks – Amit Pawar

Action Items

Possible solutions to improve SDSR:• Trial proposed for BSMD2 to increase timer T3101 value from 15 to 30.• SD Addition for cell with low SD capacity.• To avoid SD blocking due to signaling overload SDCCH channels can be shifted to new channel groups based on quality and signaling load.• To improve LAPD signaling:1. Change LAP-D signaling timeslots.2. Change TRX mapping from LAP-D timeslots.3. Change Confact value – this may lead to new E1 addition since will require more number of E1 timeslots for signaling. SD Drop improvement:

© Nokia Siemens Networks – Amit Pawar

THANK YOU…