RxLevel = – 125 dBm

ali,

i used to be based in m’sia, but now i’m back in my native country (the one with the red wine, the smelly cheese and the nano-president).

tems MS (and all MS, btw) are measuring both Full and Sub. And both are reported in the Meas. Reports. I think we both agree about this, don’t we ? 🙂

So let me rephrase : there are still 2 unanswered questions :
1/ why BBH w/ HSN0 is impacting so badly the RXLEV SUB. I guess it has to do with some periodic weird thing happening on the SACCH/0 ?
Lily : what is your value of PWRC ?

2/ why can lily see it in NPO ?
The RMS should show the Full RxLev, not the Sub RxLev (as long as DTX = 0, the Sub is useless).

Thanks for the image of the TEMS, I forgot about it.

Cheers
pix

Good day, dear Pix and Ali!

Thanks a lot that you are still in this question 🙂 I appreciate it very much and absolutely agree with Ali 🙂

All in order 🙂

Dear Pix, in previous post you asked about DL HO in cell. – No, I would say that HO distribution in these cell is normal – HO cause 12 (PBGT) dominates as usual 🙂
I think it’s ok – if DTX is OFF than only Full values are used to calculate AV_RXLEV_DL_HO, so no HOs due to low level. Correct me please, if I’m mistaken.

PWRC is set to 1, i.e. BCCH is not included in measurements.

The question about RSM is even more interesting than the first one …
The pictures from NPO before and after HSN change are really visual, I mean the difference is really signi-i-i-ficant. I can share some examples 🙂
As far as positive results from HSN change was confirmed both by drive test and by changes in RMS data we can assert that before we saw (somehow) in RMS reports those RxLevSub values (which were bad, i.e. = -126 dBm). Correct me, please, if this conclusion isn’t correct. But it’s BCCH-trx and DTX should be OFF, so no sub-values mustn’t been taken into account. Being sure about it, I checked indicator RMS_meas_with_DTX_DL_total (by trxs), expecting to see a zero value for BCCH-trx.
It doesn’t equal to 0… The average percentage of measurement with DTX in DL on BCCH-trx was ~ 4-5% (for other similar cells it is even higher). Hm-m-m….
So there is a question: Is DTX feature off on BCCH-trx or only on BCCH carrier?
But at once – another inconsistency: in our network DOWNLINK_DTX_HR = 0 and DOWNLINK_DTX_HR_AMR= 0 and it’s mandatory rule.
So in any case, our bad RxLevSub values in HR shouldn’t be counted.
Hm-m-m…

So, there are even more questions here (at least for me) 🙂 I’ve collect more than 50 logs with such problem and going to check them – maybe I haven’t noticed something … maybe – even important 🙂

Once more – thank you, Pix and Ali!

Best regards,
Lily

P.S. About DTM – 🙂 We have some problems with Gs on Alcatel MSC now… it doesn’t want to work correctly …to work at all 🙂
Siemens MSC turned out to be much more pliable 🙂 Thread #4984 was also very useful.

Good evening, Ali!

🙂 You have good intuition 🙂

Yes, too many peaces from this puzzle are absent now … so seeing the whole picture is still impossible…

Just some observations (after looking up all logs I have with this problem):
– it happens not only on 0 subchannel, twice I saw it on subchannel 1
– it happens not only on MAIO 0 subchannel, several times I saw it on MAIO 1
The statements, which stayed irrefutable:
– it’s always BBH
– it’s always HSN = 0
– and it’s usually TS 5 or 6 or 7…

I think it’s time to left this problem… for some time at least… One day all missing peaces will be found (maybe even accidentally) and the mystery will be solved 🙂

Good night!

Best regards, Lily

Hi Lilly, Ali, Pix and m121,
Just read the whole ordeal and enjoyed every word of it..:) thanks for the wonderful investigation.
By the way have you ppl checked the PWRC value ( or PWCR for Siemens ” These guys surely forgot that GSM / ETSI were made for standardization” :))and Lilly/m121 do these cells where this happens have only one radio i.e (BCCH only) or the other radio is down at that time.
As as per the theory (dont know about exact Alcatel Algorithm) if PWRC is set and system is set to ignore BCCH measurements then if a TRX gets down then frequency redefinition process takes place and the MS is set to hop on only one frequency the BCCH and since it is set to discard measurements of BCCH then issues can arrise. (such issues did occur in previous versions of some vendors) like HO and Power control process not taking place from that cell as all measurements were discarded.
Just a very wild card, but I just liked to open it for discussion

Yeah Pix,
I was expecting this reply as I too have checked this in field in Alcatel and Handovers and Power Control keep working there irrespective of the value of PWRC.

WHY WE ARE TAKING RX-LEVEL SUB(DBM) IN DEDICATED MODE?

Obviously, my friend, you have frequency hopping activated. And your HSN is obviously = 0.

Just change your HSN from 0 to something else – everithing will be great!

BR, LS