Huawei NRT ISHO Success rate

[kyokuman]

Hi,

I have quite bad ISHO NRT success rate from 3G to 2G.

I am checking this counters and values are quite high :
Number of Timeouts of Waiting for IU RELEASE COMMAND Messages During Outgoing Inter-RAT PS Handovers Initiated by the RNC (Cell)

Do you know which timer is related to it? When does it start and expire?

I imagine it start when RNC sends CCO request to Ue.
And expire if RNC doesnt receive Iu release command from CN.

However, I couldnt find the timer itself. Which parameter is it?

Thanks for your help

[kyokuman]

Hi,

Anybody having any idea? any impression to share please?

Thanks

[agenov]

Hi,

I have quite bad ISHO NRT success rate from 3G to 2G.

I am checking this counters and values are quite high :
Number of Timeouts of Waiting for IU RELEASE COMMAND Messages During Outgoing Inter-RAT PS Handovers Initiated by the RNC (Cell)

Do you know which timer is related to it? When does it start and expire?

I imagine it start when RNC sends CCO request to Ue.
And expire if RNC doesnt receive Iu release command from CN.

However, I couldnt find the timer itself. Which parameter is it?

Thanks for your help

Under SET USTATETIMER you may see all timers related.

BR
Alex

[kyokuman]

Yes but 1 timer should start when RNC sends CCO request to Ue.

None of them describes such scenario...

[boring]

well i had a close look and i think there is no such timer in Huawei's documentation

i strongly suspect that they have a rather long hard-coded supervising timer (e.g. 30 sec or more)

[agenov]

No, you are not right. CHeck again - Number of Timeouts of Waiting for IU RELEASE COMMAND Messages During Outgoing Inter-RAT PS Handovers Initiated by the RNC (Cell).

Or in another words, after the RNC sends request for Iu release of course it needs to receive a command from CN. After particular timer expiration the RNC will release the connection by itself. So the RNC is the one initiating the release and waiting for command that is not received within particular time.

BR
Alex

[boring]

you need to be careful. the RNC does not send any iu release request for PS ISHO. signalling goes like this:

RNC --> UE: CCO from UTRAN
(UE synchs with GPRS)
CN --> RNC: Iu release command

so after sending the CCO message the RNC starts its internal timer which stops only if it receives the Iu release command

is it clear?

[kyokuman]

Yes it is correct. As I mentionned from beginning.

And if timer expires, RNC sends Iu Release REQUEST to CN.

Still wondering about which timer they mention here. Could it be RRCIuRELCMDTimer ?

[agenov]

you need to be careful. the RNC does not send any iu release request for PS ISHO. signalling goes like this:

RNC --> UE: CCO from UTRAN
(UE synchs with GPRS)
CN --> RNC: Iu release command

so after sending the CCO message the RNC starts its internal timer which stops only if it receives the Iu release command

is it clear?

This is true and like that. I just gave an example of normal release Iu release. Of course for Inter RAT is like you said and is similar procedure...

BR
Alex

[boring]

Yes it is correct. As I mentionned from beginning.

And if timer expires, RNC sends Iu Release REQUEST to CN.

Still wondering about which timer they mention here. Could it be RRCIuRELCMDTimer ?

i couldn't find this timer. any more info about this?
which section describes it?