CS Drop Huawei

[kyokuman]

Hi,

Anybody of you have experience with Drops due to Signalling SRB Reset with Huawei ?

I have sudden increase of drops for that reason only.

Thanks for your help!

[boring]

Hi,
this counter keeps track of SRB RLC resets.

depending on the network parameters, the RF cause of CS AMR drops typically appears as ULSync drops or SRB RLC resets.

now if you didn't have these kind of problems until recentrly, you should look to either some parameter changes in the background (Huawei do this all the time as far as i know) or a recent software upgrade.

this issue is across your network or localised to certain cells?

[kyokuman]

Hi and thanks for answer.

It is a small cluster that has just been swapped to huawei.

Everything was ok, until few days ago, sudden increase of drops due to SRB.

Traffic went a bit up at the same time, so I'm a bit confused. However, I don't think it is traffic increase related.

I would rather bet on a modification from Huawei that I'm not aware of.

But, any chance I could optimize this behavior?

By the way, other subject, they implemented SRB over HSUPA and PS drops increased. They haven't proposed any solution for that. Any idea?

[boring]

ok it is good at least that this happens only to one cluster...

for this cluster how the UlSync counter behaved during this period? what i mean is that did you have a reduction of drops due to UlSync?

and eventually, how the sum of drop rate due to UlSync and SRBreset looks like? if this is pretty much constant then there is no much room for improvement (i will explain the mechanism if you are interested)

and for your last question, i don't have much information on HSUPA over SRB. i wonder if this is due to some unsopported configuration of some UE? not sure here...

br

[kyokuman]

Hi !

It is just a cluster but this cluster is the pilot for the rest of the swap :)

UL sync have same behavior than before (I mean same amount of drops)
So the amount of drops increased only on signqlling SRB.

I have an idea of the mechanism but you can comment if you want.

Regarding PS drops, the degradation is due to SRB over HSUPA implementation. And the reason of drops is again SRB signalling.
Huawei has no solution until now.

Thanks again

[balachandrun]

PS call drop due to srb reset may happen if SRB over HSPA is activated

[agenov]

Hi and thanks for answer.

It is a small cluster that has just been swapped to huawei.

Everything was ok, until few days ago, sudden increase of drops due to SRB.

Traffic went a bit up at the same time, so I'm a bit confused. However, I don't think it is traffic increase related.

I would rather bet on a modification from Huawei that I'm not aware of.

But, any chance I could optimize this behavior?

By the way, other subject, they implemented SRB over HSUPA and PS drops increased. They haven't proposed any solution for that. Any idea?


If you have nastar (or another tool reading CHRs :) ) you may see what radio conditions were ,to check RRC request radio conditions (IOS trace), to check whethere there is only one or few contributors and trace them via LMT. Usually this reset is related to bad radio conditions but could be something else... It is good to check the other KPIs as well like BLER, RTWP, mobility and etc. It is difficult to say just like that what might be the problem.


BR

[blueee]

Hi Agenov,

Using Nastar on CHR data, i can only see the best cell RF environment, is it possible to see the details on the other active set ?

[Junio]

Hi all ,
I need a doc about troubleshooting call drop for HSUPA and HSDPA.
Thank you for help.