AMR Unpacking Parameter Fine Tunning Final Presentation

AMR Unpacking Parameter Tuning

Feb 8th 2012

Presentation Name | Prepared by: Hassan Atique/Adeeb Shahzad| Date | (4)

› Feature Description:

The “AMR unpacking optimization” (BSS21120) feature provides new AMR quality and

level based handover parameters to avoid unnecessary unpacking in intra-cell AMR FR/HR handovers.

When the field strength drops rapidly, the quality of service also drops typically. This triggers AMR unpacking handovers. If the field strength drop is high, quality is degraded. The mobile cannot decode handover assignments and handover is not performed. Also, when the MS moves round a corner, its own RX level is not changed, but the interference becomes stronger. This can cause drops to “bad” quality levels in the MS. In a “bad” quality level, SACCH decoding in the MS fails, and hence the MS cannot identify any handover assignments.

Normally, the radio-link time-out timer controls the time for which the mobile can be unreachable, before the TCH is deactivated and the call is regarded as a dropped call. This can be e.g. 16 seconds. When a handover starts using a fixed 6 seconds timer to control handover success, and if the MS does not answer during this time with either a successful or a non-successful handover, then the BSC deactivates the target and source channels. This is considered as a drop. Without an intra-cell handover start, the MS could still have about 10 seconds to get out of the bad coverage.

When RX quality on the AMR HR channel is below the unpacking threshold, but RX level conditions are good, it is reasonable to perform an intra-cell HO to a better HR channel in the cell. This is achieved by preventing AMR unpacking handover when the RX level is high enough.

Due to this feature, the HO algorithm prevents AMR unpacking and interference-based intra-cell handovers, when the RX level and/or RX quality conditions are very bad. Also, unnecessary AMR unpacking handovers are avoided when the RX level is good. With this, the dropped call rate can be reduced.

AMR Unpacking Optimization(DCR)


› Benefits:

This feature saves capital expense and improves network quality by reducing the rate of dropped calls.

› Parameter Description:

AMR UnPacking Optimization(DCR)

Parameter Name Parameter Description

IHRH

With this parameter you define the threshold level of the signal quality downlink and uplink measurements for triggering the intra-cell handover process for an AMR HR call in order to switch it to an AMR FR call.NOTE: MML managed object class: HOCNetAct managed object class: BTS

ULLAMR

This parameter defines the limit for averaged uplink and downlink signal level. If averaged uplink or downlink signal level is better than this parameter then the quality based intra cell handovers are not allowed.

LLLAMR

This parameter defines the limit for averaged uplink and downlink signal level. If averaged uplink or downlink signal level is worse than this parameter then the quality based intra cell handovers are not allowed.

LQLAMR

This parameter defines the limit of the averaged uplink and downlink signal quality. If averaged uplink or downlink signal quality is worse than this parameter then the quality based intra cell handovers are not allowed. NOTE: MML range: 0...7, default 7


AMR UnPacking Optimization(DCR)

Observations:

After Activating AMR Unpacking Optimization DCR we have a significant improvement in DCR around 30%. After using the Parameter Set 1 DCR was further improved by 37.5%. After Implementing parameter set 2 we observe little degradation around 5% and after implementing parameter set 3 we observe improvement in SDR around 40%

IHRH ULLAMR LLLAMR LQLAMR QDR QURImplementation

DateDefault Parameter

Set 4 -47 -100 7 - - 27-Dec-11

Parameter Set 1 6 -50 -95 6 - - 30-Dec-12

Parameter Set 2 5 -50 -95 6 - - 7-Jan-12

Parameter Set 3 6 -50 -95 6 5 5 17-Jan-12


AMR UnPacking Optimization(CSSR)

Observations:

There is no impact of AMR Unpacking Feature on CSSR.



Set 4 -47 -100 7 - - 27-Dec-11





AMR Unpacking Optimization(HOSR)

HOSR was degraded due to T6542X that was resolved on 1st Jan after that HOSR was degraded on T1269X due to PMAX Removal on T1269X. These 2 issues degraded HOSR. AMR unpacking has no effect on HOSR.

T6542XC T1269XB1 2



Set 4 -47 -100 7 - - 27-Dec-11




Ashura Holidays


AMR Unpacking Optimization(SD_TCH_Blocking)

Observations:

There is no impact of AMR Unpacking Optimization on SD and TCH blocking.



Set 4 -47 -100 7 - - 27-Dec-11





AMR Unpacking Optimization(TCH_MHT)

Observations:

There is a significant improvement in TCH Mean holding time as number of HO are reduced it mean the call is sustaining per TSL that result in improved user perception in the field.



Set 4 -47 -100 7 - - 27-Dec-11





AMR Unpacking Optimization(DCS Utilization)

Observations:

After implementing Parameter set 1 DCS utilization is improved it means we are utilizing resources more effectively. This is due to the increased HR share on DCS band which have minimum impact on user as generally DCS band is better then GSM band.



Set 4 -47 -100 7 - - 27-Dec-11





AMR Unpacking Optimization(DL Quality)

Observations:

The DL quality is improved after implementing Parameter Set 1, 2 and 3. Which mean the subscriber perception is improving.



Set 4 -47 -100 7 - - 27-Dec-11





Conclusion The main Aim of AMR Unpacking was to improve DCR which was achieved. DCR was improved by

33% by using default parameter Set.

When parameter fine tune was done DCR was improved up to 40% by using Parameter Set 3 on BSC level, DL Quality and DCS Utilization are also improved .

So after doing the Benchmarking it is Recommended to roll out parameter Set 3 on network.

IHRH ULLAMR LLLAMR LQLAMR QDR QUR Implementation Date

Default Parameter Set 4 -47 -100 7 - - 27-Dec-11




AMR Unpacking Parameter Fine Tunning Final Presentation

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