Issue with RAB Setup success Rate

[no_1'sfasterthanradiowave]

Hi All,

Please for your comments if anyone has seen the following issue:

High number of AMR RAB setup failures exist in all cells of a RNC during an hour of big demand /such as New Years Eve /. Oddly enough all cells are with similar success rate of about 75% during that hour.
Failures are under "Requested max bit rate not available" in the RNC and "VS.RAB.FailEstCS.Unsp" on cell level but no blocking at all in Uu or elsewhere!!

Thanks in advance!

[mon3em]

if the failures are occurred for all cells , the bottleneck must be @ upper level .... not a cell level.
So ... try to investigate your RNC for any kind of bottlenecks , licenses, ....etc

[eritelecom]

Check the CAC parameters.

[sala70vic]

Hi All,

Please for your comments if anyone has seen the following issue:

High number of AMR RAB setup failures exist in all cells of a RNC during an hour of big demand /such as New Years Eve /. Oddly enough all cells are with similar success rate of about 75% during that hour.
Failures are under "Requested max bit rate not available" in the RNC and "VS.RAB.FailEstCS.Unsp" on cell level but no blocking at all in Uu or elsewhere!!

Thanks in advance!

Hi,

failure "Request Max Bit rate is not avilable" is in RAB assignment response message, please check the RAB profile in RAB assignment request message came from core network in order to have full picture, thanks.
regards,

[no_1'sfasterthanradiowave]

Thank u guys for your replies...what I have so far is that, yes it is an admission issue and scarce resource is Iu-CS. Will come back if more is revealed.

[coolashishsaxena]

Hi All,

HOW to improve IRAT-PS for cells which are having good IRAT CS.
anything on parameter setttings. we cannot change 2D and 2F event it should remain constant.

thanks in advance

[a19997104]

Hi All,

HOW to improve IRAT-PS for cells which are having good IRAT CS.
anything on parameter setttings. we cannot change 2D and 2F event it should remain constant.

thanks in advance

changing from periodic to event based helps a lot..

[kaizzer545]

As well it was mentionated, you can check bottle neck, remember its proportional when increase traffic, try to check links of Iu-Cs

[nimopaul]

Hi All,

HOW to improve IRAT-PS for cells which are having good IRAT CS.
anything on parameter setttings. we cannot change 2D and 2F event it should remain constant.

thanks in advance

Which is your UTRAN vendor?
You can keep Event 2D/2F as constant, it is for Inter freq. Your aim is to improve PS i-RAT right? So better tune thresholds for 1E/1F.

You can look at the i-RAT HO event reason count (RSCP or EcNo). There will be counters for that. For eg: if you have more no: of PS-iRAT HO events on RSCP, then, tune the 1E/1F RSCP thresholds.

More clarity can be given based on your vendor.

R's
Nimo

[jvalant]

Which is your UTRAN vendor?
You can keep Event 2D/2F as constant, it is for Inter freq. Your aim is to improve PS i-RAT right? So better tune thresholds for 1E/1F.

You can look at the i-RAT HO event reason count (RSCP or EcNo). There will be counters for that. For eg: if you have more no: of PS-iRAT HO events on RSCP, then, tune the 1E/1F RSCP thresholds.

More clarity can be given based on your vendor.

R's
Nimo

Vendor is E///
Can you tell me counter??

Thanks