[ActiveCell.Selection]

Hello all,

AMR actived on BSC, after implementation there is TCH Drops increased and RX Qual degraded. Could you investigate below thresholds please and any suggestion for changing any threshold?
Vendor-Nokia ,2G

-Codecs
AMR RADIO LINK TIMEOUT…………………..(ARLT)… 40 SACCH FRAMES

AMR FR CODEC MODE SET……………………(FRC)… 12.2 7.40 5.90 4.75 kbit/s
AMR FR START MODE……………………….(FRS)… 00
AMR FR INITIAL CODEC MODE INDICATOR (ICMI)…(FRI)… 0
AMR FR THRESHOLD 1………………………(FRT1).. 9.0 dB
AMR FR THRESHOLD 2………………………(FRT2).. 12.0 dB
AMR FR THRESHOLD 3………………………(FRT3).. 16.0 dB
AMR FR HYSTERESIS 1……………………..(FRH1).. 1.0 dB
AMR FR HYSTERESIS 2……………………..(FRH2).. 1.0 dB
AMR FR HYSTERESIS 3……………………..(FRH3).. 1.0 dB

AMR HR CODEC MODE SET……………………(HRC)… 7.40 5.90 4.75 kbit/s
AMR HR START MODE……………………….(HRS)… 00
AMR HR INITIAL CODEC MODE INDICATOR (ICMI)…(HRI)… 0
AMR HR THRESHOLD 1………………………(HRT1).. 14.0 dB
AMR HR THRESHOLD 2………………………(HRT2).. 17.0 dB
AMR HR THRESHOLD 3………………………(HRT3).. 0.0 dB
AMR HR HYSTERESIS 1……………………..(HRH1).. 1.0 dB
AMR HR HYSTERESIS 2……………………..(HRH2).. 1.0 dB
AMR HR HYSTERESIS 3……………………..(HRH3).. 0.0 dB

-HO Pars
THRESHOLD DL RX QUAL AMR FR …………… 6.4% – 12.8%
THRESHOLD UL RX QUAL AMR FR …………… 6.4% – 12.8%
INTRA HO THRESHOLD RX QUAL AMR FR ……… 1.6% – 3.2%
THRESHOLD DL RX QUAL AMR HR …………… 1.6% – 3.2%
THRESHOLD UL RX QUAL AMR HR …………… 1.6% – 3.2%
INTRA HO THRESHOLD RX QUAL AMR HR ……… 6.4% – 12.8%

-PC Pars

PC UPPER THRESHOLDS DL RX QUAL AMR FR .. 0.8% – 1.6%
PC UPPER THRESHOLDS UL RX QUAL AMR FR .. 0.8% – 1.6%
PC LOWER THRESHOLDS DL RX QUAL AMR FR .. 1.6% – 3.2%
PC LOWER THRESHOLDS UL RX QUAL AMR FR .. 1.6% – 3.2%

PC UPPER THRESHOLDS DL RX QUAL AMR HR .. < 0.2% PC UPPER THRESHOLDS UL RX QUAL AMR HR .. < 0.2% PC LOWER THRESHOLDS DL RX QUAL AMR HR .. 0.4% - 0.8% PC LOWER THRESHOLDS UL RX QUAL AMR HR .. 0.4% - 0.8% Thanks in advance, BR

[Pix]

First you need to investigate what are the AMR codecs used by the MS, and see for which codec there are call drops.

And also the HO split : after AMR activation, new HO causes are enabled (intracell mostly) –> how much do they occur, are they replacing some of the HO quality that occured before activation ?

About parameter values, I can’t help. If you’re using default values, then you need to spend time analyzing the QoS before tuning them.

[Author]

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