RRC_CONNECTION_RELEASE_CCCH

[m2m]

Dear Expert,

When does this message will happen in the system?
What cause that trigger this message to send from system to mobile?
What will happen when mobile detect this message?

BR..
M2M

[zhanglw268]

Dear Expert,

When does this message will happen in the system?
What cause that trigger this message to send from system to mobile?
What will happen when mobile detect this message?

BR..
M2M
RRC CONNECTION RELEASE can be sent by UTRAN at any time.
It can be any reasons, normally it shall be congestion, protocol errors etc.
The Mobile will release all the resources including RABs etc. without argument and sends RRC CONNECTION RELEASE COMPLETE to system.

Hope this helps!

[dave]

It will happen if RRC is mapped to common channel at the time of release. For example:
- Call is setup in CCCH, it happens depending on RRC establishment cause, like SMS. It's configurable on RNC, like Huawei
- Call is in CCCH at release time, i.e. a PS call that goes to cell-FACH state and then releases

Hope it helps

[m2m]

@Zhang

Let's say mobile would like to originate the call
first of all UE send CM_SERVICE_REQUEST follow by RRC_CONNECTION_REQUEST (at this step mobile then change RRC state from idle to Cell FACH)

however during waiting for RRC_CONNECTION_SETUP from UTRAN mobile detect RRC_CONNECTION_RELEASE_CCCH

RESULT in CM_SERVICE_ABORT being sent by UE

What might be the cause of this message?

Thank you in advance

[zhanglw268]

@Zhang

Let's say mobile would like to originate the call
first of all UE send CM_SERVICE_REQUEST follow by RRC_CONNECTION_REQUEST (at this step mobile then change RRC state from idle to Cell FACH)

however during waiting for RRC_CONNECTION_SETUP from UTRAN mobile detect RRC_CONNECTION_RELEASE_CCCH

RESULT in CM_SERVICE_ABORT being sent by UE

What might be the cause of this message?

Thank you in advance

Hi M2M,

The mobile phone user originates a call with dialing number by pressing the "call button", but the mobile phone user changes his/her mind to end the call for certain reasons, for example, incorrect phone number, changed mind etc., you will see CM_SERVICE_ABORT before the "Direct Transfer(Setup)" message from UE is sent to the network, if this is after "SETUP" message, you will see different reason.

Another possible case is that the UTRAN/CN sends RRC CONNECTION RELEASE (can be CCCH or DCCH) to UE before the "Direct Transfer(Setup)", you may see UE generating the same reason CM_SERVICE_ABORT.

From your description, The UE generated the CM_SERVICE_ABORT after the network sent RRC_CONNECTION_RELEASE_CCCH, this is due to UTRAN/CN side problem.

Hope this helps.

[m2m]

Dear Zhang

Thank you for your advise. I also suspect the core problem like u said, so i trace the call at RNC side by trace the IMSI of the mobile. Unfortunately, i don't see any message send from RNC to release the call just the normal protocol operation

rrcConnectionRequest UE->RNC (Tracing at RNC)
RadioLinkSetupRequestFDDMsg NODEB<-RNC (Tracing at RNC)
RadioLinkSetupResponseFDDMsg NODEB->RNC (Tracing at RNC)
rrcConnectionSetup UE<-RNC (Tracing at RNC)
rrcConnectionReleaseCCCH UE<-??? from drivetest log
RadioLinkRestoreIndicationMsg NODEB->RNC (Tracing at RNC)
rrcConnectionSetupComplete UE->RNC (Tracing at RNC)
measurementControl UE<-RNC (Tracing at RNC)
measurementControl UE<-RNC (Tracing at RNC)
initialDirectTransfer UE->RNC (Tracing at RNC)
CM_SERVICE_ABORT UE->UTRAN from drivetest log we sure that we are not order to abort by ourselve
InitialUE_MessageMsg RNC->CN (Tracing at RNC)
uplinkDirectTransfer UE->RNC (Tracing at RNC)
CommonIDMsg RNC<-CN (Tracing at RNC)
SecurityModeCommandMsg RNC<-CN (Tracing at RNC)
securityModeCommand UE<-RNC (Tracing at RNC)
securityModeComplete UE->RNC (Tracing at RNC)
SecurityModeCompleteMsg RNC->CN (Tracing at RNC)
Iu_ReleaseCommandMsg RNC<-CN (Tracing at RNC)
Iu_ReleaseCompleteMsg RNC->CN (Tracing at RNC)
rrcConnectionRelease UE<-RNC (Tracing at RNC)
rrcConnectionReleaseComplete UE->RNC (Tracing at RNC)

Some messages which carry on between RNC and UE are already validated with drivetest log. Do you think this is the protocol error at NodeB?

thank

[zhanglw268]

Hi M2M,

From your message sequence, I didn't see ALCAP and FP message before rrcConnectionSetup was sent, I assume that these messages were not traced.

Have you checked the Iu_ReleaseCommandMsg what's reason CN release the call?

Personally I think that there are 3 possible reasons.

One is UE itself problem, the UE decoded the message wrong and rrcConnectionReleaseCCCH was generated by itself. You can change to another vendor's mobile to see whether you still see same issue.

Another problem is that IuB or NodeB/RNC for some reason really sent the message but you didn't trace them.

Third one is that there is inter-operational issue between UE handset and the UTRAN.

As you have done some basic data collection, I suggest that you have the vendor support team to have a look to see what's the possible problem and the solution.

Regards

Zhanglw268