Radio interface failure

[javierinfante]

Hello:
In my network suddenly since three days ago we have found an increase in the number of BSC/RNC call releases with cause Radio interface failure.
I haven't found any alarm or indicator, I didnt find any parameter modification in the BSC/RNC database, have anyone found a similar situation?, any help, suggestion is welcome.

best regards

[Kirill Kucherov]

hello! have almost the same situation, but within only 1 cell (2nd cell of the same sector and other sectors are ok)
the failures are common for a single subscriber, but in other cells (even in the same sector) he does not experience these problems.
There are RANAP Iu Release due to radio connection with UE lost or failureon the radio interface procedure.
I see that sometimes (not regularly) UE does not reply on some msgs from BSC6900 (Huawei) - common o RRC release procerure - and when RL is Deleted by NodeB UE sends RRC CELL Update with the causes RLC unrecoverable error or radio link failure. BSC does not reply on these msgs.

he almost the only one subscriber on the cell. no interference, good ec/no, RSCP, all resources are sufficient. and agai - other users on this cell do not experience problems and at the same time this user on other cells (even within the same sector) does not experience problems as well.

???

[samuraial]

Well if it is only one subscriber maybe it is the UE problem or sim problem.

Regards.

[Kirill Kucherov]

Well if it is only one subscriber maybe it is the UE problem or sim problem.

Regards.

well, it could be if he has the same problem on other cells, but no - he does not, even on this cell not every time his terminal is connecting he experience the problem but very often: if suppose that he is the only subscriber on the cell than i could say that he experience cssr of 60% in avarage on this cell

[samuraial]

What about the place this failures happened? radio conditions??? What about doing a trace this no for a day and see??

Regards.

[Kirill Kucherov]

What about the place this failures happened? radio conditions??? What about doing a trace this no for a day and see??

Regards.

done! radio conditions are good.
UE/cell traces are done - I've written the main idea of them in my first post. if you need to know something specific from them please specify.

thnks

[samuraial]

Well didn't read it good before but seems that you already gave the answer yourself IMO.
You have only one UE having this problem.(others not as it seems)
We had some problems too thats why i am saying as we have problems with only 1 no that had similar like yours and solved it by changing the SIM card.(my experience)



I see that sometimes (not regularly) UE does not reply on some msgs from BSC6900 (Huawei) - common o RRC release procerure - and when RL is Deleted by NodeB UE sends RRC CELL Update with the causes RLC unrecoverable error or radio link failure

Regards

[Kirill Kucherov]

ok. thanks. i could suppose everything because there is no full explanation for any of idea I have...

but for sim - if its is true could you explain why he is ok in other cells? same NodeB / same frequency / or same sector?

[samuraial]

The only idea that makes sense it is the place he is staying, but you said the radio conditions are ok so that falls down.
And btw if you find the solution, post it here made me really curious.

Regards.

[Kirill Kucherov]

yes, EcNo is -6dB and RSCP is -85 dBm... when he awakes from unhearing and sends Measurement report i saw the worst levels of -12dB of EcNo and -92 dBm of RSCP.
and probably he lives in the house on which antennas are install because I see him in all 3 sectors (however, mainly in 1st)
and he has iPad3 Rel.8 btw, but problem does not connected with Fast Dormancy :-)

ok, i'll do if succeed