- This topic has 12 replies, 1 voice, and was last updated 15 years ago by TUFAIL.
11th July 2007 at 12:15 #48148BhanuGuest
In My network(Motorola System)I am facing one problem. In idle mode at BSC border, Ms tries to make location update but T3126 expires and MS goes in No service mode then it select the cell. can anyone tell me the solution to this problem.12th July 2007 at 19:27 #48149bo2k10Guest
I’m not too familiar with Moto systems, but check hyst value if one exists for LAC updates; in E/// systems its called CRH and too high a value can lead to poor RF conditions (Poor C/I) when cell borders are stretched in both directions due to this or similar parameter.12th July 2007 at 19:48 #48150bo2k10Guest
or rather to use more correct terminology, cell re-selection is delayed due to such a hysteresis value ( LAC update hysteresis parameters are used to delay and avoid too many LAC updates and keep SDCCH traffic down) its a compromise between saving SD resources and maintaining clean cell borders.12th July 2007 at 20:07 #48151PixGuest
yes, that sounds probable. cell reselect hysteresis, or maybe cell reselect offset (or both) are set at a too high value.
but in this case, when finally camping on the new cell, in the new LAC, (which means for the MS : “need to send a new LU message”) the location update shouldn’t suffer from a problem : the new cell should have a much better level than the previous one. So the LU should be fine ? It is worth checking it out anyway.
Also, check SDCCH congestion in the cell, check the LU/call ratio, and check the radio conditions.14th July 2007 at 05:39 #48152bhanuGuest
thanks i will check that,we gave soft reset to that site and now the problem is solved.
As per trend of 7 days the sdcch traffic was good(no congestion) and all LAC update hysteresis is at default value.
well pix radio condition is bit poor,rx level is -80dBm to -85dBm.
But thank u all for ur valuable advices.I will keep them in mind for future.14th July 2007 at 08:33 #48153pixGuest
a rule of thumb : any sudden degradation of KPI can be fixed by soft reset or HW change…
you didn’t told us that the problem happened suddenly… 🙂15th July 2007 at 09:43 #48154BhanuGuest
But there wasnt any abnormal rise in blocking or congestion.
I have one more query, in One Of our BSC we are having uplink quality problem, especially in busy hours, we checked all E1’s.
Can u suggest something. we r getting complaints from last 4 days only.So u can say that it is sudden.15th July 2007 at 18:19 #48155PixGuest
I don’t know about this… what do you mean by “UL Quality” ? Is this a problem of call drop, voice quality, or handover ?
If it happens on all the cells of the BSC, that is clearly a hardware problem, certainly from a board in the BSC or in the TC. Or yes, as you mention, an interface link. Any alarm in the O&M ?16th July 2007 at 15:50 #48156bhanuGuest
I m talking abt uplink voice quality, and problem is not in whole of the bsc, but it happens randomly in busy hours in different sites. There is no alarm in O&M.
I suspect it is some H/W problem, we have told BSS guys to check all cards.17th July 2007 at 06:18 #48157PixGuest
How do you measure the poor UL voice quality ? Is that a counter, or do you perfrm traces ?
If it’s random over many BTS during busy hour, your assumption should be right. I would too check the BSC-TC-MSC part.
Regards,17th July 2007 at 13:01 #48158BhanuGuest
There is one Tool COP tool of motorola in our OMCR for tracing calls. We found it from there.17th July 2007 at 19:12 #48159PixGuest
But UL is between the BTS and the BSC, no ? And your tool is collecting data that comes from the BSC… so it can’t be A/Ater interface.
And the TCUC board are statically allocated per cell, isn’t t-it ? So the “random” -ness of the problem is quite intriguing …
Can’t it be simply UL interference ? Did you see an increase in the number of handovers due to UL poor quality or UL high interference ?
Is it possible to give us the distribution of the UL RXQUAL per UL RXLEV bands, before and after the problem ?
Just proposing ways to anlyze the problem, can’t know for sure 🙂
regards,18th July 2007 at 12:30 #48160TUFAILGuest
HOW MUCH IS HOSR FOR THAT CELL OR CELLS.