[Bol LeTan]

Hi, all.

I have the problem as blow, I hope i will have your support to solve root cause:
– Extended cell service the sea area, now their quality are very low (CSSR low and CDR hight. The analysis of counter on BSC shows that low quality in extend cell due to radio (call_drop_radio and RTCH_assign_unsucess_rate very hight) and i don’t see interference between extended cell and neighbor cell. Therefor i identified low quality in extended cell due to cell covered too far.
– I tried to calculate distribution of number of measurement report for which the value of timing advance in the TA band (RMS_Timingadvance_sample = V_ROUND( RMS50a * RMS50b //254), Through which assessment distribution of voice traffic with the actual distance. But i don’t sure my opinion is correct.
Pls,let me know your opinion for this problem.
Thanks.

[pix]

hi bol,

Checking out the timing advance is a good idea. Do you have a NPO ? It should be rather easy to do then.

The interference on the sea may be coming from cells located 200km away. It might be coming from another country !
Check out the RXLEV and the RXQUAL distributions per TIMING ADVANCE. That will give you a good indication of the radio quality in your “outer” trx.
Or more simply, check out TRX indicators -> KPI on the outer TRX will perfecctly reflect the qos in the outer trx.

To overcome interferences:
either, use dummy neighbours to detect clean frequencies
or, apply a “wideband” SFH.

regards
pix

[Bol LeTan]

Hi Pix.
Thank you for your interest in my problem.
– Unfortunately, i don’t have support from NPO. I calculated based on counters RMS50a and RMS50b in formula RMS_Timingadvance_sample = V_ROUND( RMS50a * RMS50b //254).
– Because format in forum don’t allow me show my opinion, pls send me your email so i could discuss with you more about this issue.
thanks you very much.

[Bol LeTan]

Hi Pix and All.
I see counter RMS50a is a matrix (10), therefor RMS_Timingadvance_sample = V_ROUND( RMS50a * RMS50b //254)would also be a matrix (10).
And TOA value Band (BTS TA) support by NPO tool include 10 sub band ([0.0,7.0[ [7.0,13.0[ [13.0,19.0[ [19.0,25.0[ [25.0,31.0[ [31.0,37.0[ [37.0,43.0[ [43.0,49.0[ [49.0,55.0[ [55.0,63.0] )

I think each value in matrix RMS_Timingadvance_sample
is the sample measured report corresponding to each sub band of TOA value Band (BTS TA). Through which assessment distribution of voice traffic with the actual distance : Distance_i = (Subband_i) * 533m.
My calculate as above is applied with INNER cell. But i don’t sure it be applied with OUTER cell (with each sub band additional a offset 60bit and we don’t review case MS in overlap zone).

I hope i will have your support this problem?
thanks!!

[pix]

hi Bol,

so far everything you said makes perfect sense.

the vector with 10 values does relate to the 10 TA intervals :

([0.0,7.0[ [7.0,13.0[ [13.0,19.0[ [19.0,25.0[ [25.0,31.0[ [31.0,37.0[ [37.0,43.0[ [43.0,49.0[ [49.0,55.0[ [55.0,63.0] )

The way you compute and interpret the vector is the same for the inner zone and the outer zone.
the only difference is that the intervals for the outer cell are offset by 63 TA (= 63*550m)

For example, the first interval is now, for the outer cell only:
[63.0,70.0[

Please share the results of your computation 🙂

regards
pix

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