Hello Everyone.
We are having a problem on the Customer network, possibly caused by a terminal where there is a sudden increase in MOS attempts and this ends up impacting RRC Accessibility.
It does not establish an ERAB and therefore it is not possible to identify which type of terminal.
Several actions were taken and none were effective in resolving it, and as soon as the error appears, it disappears without leaving any indication of the reason.
Has anyone ever experienced this type of behavior on the Network where they operate?
OEM Ericsson.
MOS: Mobile Originating Signaling.
Does signalling attempts also increases?
Exactly.
The indicator of failures is it Attempts-Success.
The main Reason for is on increase Attempts…and low success.
Is this happening on NEW site or sudden increases on OLD site?
Because I’m facing issue related to signaling…
Did you perform SSV testing on the site?
Is the interference within acceptable thresholds?
Did you check the network change logs? Many times it happens that someone changes some parameters and does not notify…
Yes, and no problem was detected on SSV Activity.
No interference was detected.
No change related on this behavior, this issues occurs on several sites on the network.
Mmm… OperationalState of the termpointtomme?
Rsaroz
September 12, 2024, 12:37pm
10
RenatoLourenco:
We are having a problem on the Customer network, possibly caused by a terminal where there is a sudden increase in MOS attempts and this ends up impacting RRC Accessibility.
It does not establish an ERAB and therefore it is not possible to identify which type of terminal.
Check Base Station or Core network capacity.
Check RRC and eRAB threshold as per guideline.
Enabled and operable.
This behavior occurs in sites with Low / Medium Traffic.
The CORE Network does not received any ERAB request, this fail stop on RRC procedures.
Consistency check to see if there are any parameters outside your baseline.
Check packet loss counters.
Could be something transmission.
No Problem with CC in this sites.
No problem de Pkt Loss and no problem IP Reassembling Fail Rate…
This problem is probably caused by a terminal, since it does not establish an ERAB, failure occurs in the RRC stage…
RenatoLourenco:
This behavior occurs in sites with Low / Medium Traffic.
The CORE Network does not received any ERAB request, this fail stop on RRC procedures.
It cannot do TAU so it keeps trying.
What is the cellradius for this cell?
I do not mean TA values but cellradius parameter.
If cellradius is 1 km it is a problem.
Give it a try with 20 km and let us know how it goes…
Thanks Guys, but it doesn’t make much sense in my understanding…
The problem is not in the RA process, and Timing Advanced is low.
RenatoLourenco:
We are having a problem on the Customer network, possibly caused by a terminal where there is a sudden increase in MOS attempts and this ends up impacting RRC Accessibility.
It does not establish an ERAB and therefore it is not possible to identify which type of terminal.
Most probably terminal issue,
You still can get this device info.
Supposing this device fails in 4G RRC phase so it will try camping in legacy one (3G or 2G) and successes.
From your tracing tool (preferred E2E one) you can check 3G excessive attach requests or TAC update on your particular site or RNC during timestamp and you will get it.
Actually nothing to do from your side, just you proof it and escalate it to vendor device team.
Is MT access and Mo data is fine?
Exactly what we suspect here. (Thanks for your contribution)
However we were unable to identify any terminal.
MT is OK.
When I posted this observation in this forum, the intention was to find out if this behavior appears on any other network.
This behavior has occurred on the Brazilian and Mexican networks.
Does it happen on other networks on other continents?
The idea is to find someone who has identified a terminal with these failures.
Yes occured and we got it.
