- This topic has 29 replies, 1 voice, and was last updated 9 years, 11 months ago by BOUBA.
11th April 2010 at 06:33 #62022AliAsgherGuest
But dear Pix,
Why are you talking about Rxlevel Sub? These are the measurements taken from TEMS, for which I think that it is CODED in TEMS that when DTX is off, RXlev Full only matters and Rxlev Sub is not calculated. Which is why TEMS is displaying -126 only. Have you seen the snap I uploaded?
P.S. Where are you located in S-E Asia by the way?
Regards11th April 2010 at 11:41 #62023pixGuest
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.
pix12th April 2010 at 07:02 #62024AliAsgherGuest
I forgot about RNO measurements. If this is it then something must be wrong in measuring Rxlevel Sub with DTX off. I will try to get some more DT logs in this regard.
Thanks again, your posts are a great source of learning.12th April 2010 at 12:05 #62025lilyGuest
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.
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!
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.13th April 2010 at 04:06 #62026AliAsgherGuest
Haha. Many Hmm-mmss there. And many more to come I guess 🙂14th April 2010 at 21:13 #62027lilyGuest
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 🙂
Best regards, Lily27th August 2010 at 00:45 #62028riyazGuest
please can u tell me about concept of frequency hoping and types of frequency hopings.
i want to know how can we asign MAIO AND HSN FOR 4+4+4 CONFIGRATION31st August 2010 at 05:42 #62029ManiaGuest
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 discussion31st August 2010 at 15:40 #62030pixGuest
amazing idea ! however, in alu, this problem was always taken into account (at least since B6) : a TRX hopping on only one frequency is considered as ‘not hopping’
(i just checked it, and the B6 document says :
If the channel is hopping only on the BCCH frequency (after a transmitter failure), it is considered as a non-
hopping channel and it is concerned by the non frequency hopping case. )1st September 2010 at 05:29 #62031ManiaGuest
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.8th September 2010 at 09:20 #62032HARENDRA KUMAR RAJPUTGuest
DL HANDOVER IN CELL DEPENDS ON THE AMR FR AND AMR HR,IF THE INTRACELL HYANDOVER TAKEN PLACE FROM AMR FR TO AMR HR THEN THIS HANDOVER OCCUR DUE TO CAPACITY REASON OF THE CELL AND IF THE HANDOVER TAKES PLACE FROM AMR HR TO AMR FR THEN HANDOVER DUE TO QUALITY REASON.AND IF THE MS DOES NOT DECODE THE SACCH BLOCK COMES FROM THE BTS AT EVERY 480ms THEN RLT DECREASE BY ONE, IF RLT GOES TO 0 THEN HANDOVER NOT TAKES PLACE EITHER INTRACELL OR INTER CELL HANDOVER.8th December 2010 at 13:00 #62033WHY RX-LEVEL SUB(DBM) IN DEDICGuest
WHY WE ARE TAKING RX-LEVEL SUB(DBM) IN DEDICATED MODE?19th December 2010 at 12:17 #62034SaeedGuest
I am also getting same -125dBm in drive test…Can anyone tell me what to do.20th December 2010 at 03:35 #62035LSGuest
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, LS17th November 2011 at 23:59 #62036BOUBAGuest
pls i’ll so grateful if any one can explain the situation below :
during Drive test it’s shown that’s RxLev sub=-124 and ping pong phenomenas is followed and MS can’t camp or continues call in the same cell so after checking alarms on this cell we’ve found that’s this site suffer from radio link prompt alarm somtimes apears in trx0 and diapear quickly secondelly apear in trx2 and disapear also quickly so if anyone can help us by telling us which cause is probable for radio link prompt alarm and the abnormal value of Rxlev sub
thanks in advance