owo205030 wcdma ran13 call drop kpi and relative counters issue 1.00

WCDMA RAN Call Drop KPI and Relative Counters

Confidential Information of Huawei. No Spreading Without Permission

The scenario for “User inactivity”:

If a user with PS service has no data transmission after a certain timer expires (this

timer is set by RNC), RNC can send signaling IU RELEASE REQUEST to CN to release

the service. This is not considered as call drop.

The scenario for “UE generated signaling connection release”

Some type of UE can release signaling connection automatically be sending

signaling SIGNALLING CONNECTION RELEASE INDICATION to RNC, then RNC will

send signaling IU RELEASE REQUEST to CN to release the service. This is not

considered as call drop neither.


P-4 Confidential Information of Huawei. No Spreading Without Permission



CDR: call drop ratio



VP: video phone



Why

VS.HSDPA.H2D.Succ+VS.HSDPA.H2F.Succ+VS.HSDPA.HHO.H2D.SuccOutIntraFreq

+VS.HSDPA.HHO.H2D.SuccOutInterFreq is added in the denominator to calculate the

HSDPA service drop ratio?

If one user switch from HS-DSCH to other channel types due to some reason

(mobility e.g.), it should be consider as a normal HS-DSCH release (refer to second

item in Notes).



VS.HSDPA.RAB.AbnormRel

Number of HSDPA RABs abnormal released for cell

VS.HSDPA.RAB.NormRel

Number of HSDPA RABs normal released for cell

VS.HSDPA.H2D.Succ

Number of successful handovers from HS-DSCH to DCH for cell

VS.HSDPA.H2F.Succ

Number of successful handovers from HS-DSCH to CCH for cell

VS.HSDPA.HHO.H2D.SuccOutIntraFreq

Number of successful Intra-Frequency H2D hard handovers for cell

VS.HSDPA.HHO.H2D.SuccOutInterFreq

Number of successful Inter-Frequency H2D hard handovers for cell

UE RNC

RB Reconfiguration

RB Reconfiguration Complete

Counter VS.HSDPA.H2D.Succ /

VS.HSDPA.H2F.Succ /

VS.HSDPA.HHO.H2D.SuccOutIntraFreq /

S.HSDPA.HHO.H2D.SuccOutInterFreq is added by

1 in the corresponding scenarios.

· Cpounter VS.HSDPA.H2D.Succ / VS.HSDPA.H2F.Succ is triggered in H2D / H2F channel switch.

· Counter VS.HSDPA.HHO.H2D.SuccOutIntraFreq / S.HSDPA.HHO.H2D.SuccOutInterFreq is triggered in H2D

inter-frequencty / intra-frequency hard handover.

· H2D / H2F Channel switch and H2D hard handover are both completed by RB Reconfiguration procedure.



Why

VS.HSUPA.E2D.Succ+VS.HSUPA.E2F.Succ+VS.HSUPA.HHO.E2D.SuccOutIntraFreq+

VS.HSUPA.HHO.E2D.SuccOutInterFreq is added in the denominator to calculate the

HSUPA service drop ratio?

If one user switch from E-DCH to other channel types due to some reason (mobility

e.g.), it should be consider as a normal E-DCH release (refer to second item in

Notes).



VS.HSUPA.RAB.AbnormRel

Number of HSUPA RABs abnormal released for cell

VS.HSUPA.RAB.NormRel

Number of HSUPA RABs normal released for cell

VS.HSUPA.E2D.Succ

Number of successful handovers from E-DCH to DCH for cell

VS.HSUPA.E2F.Succ

Number of successful handovers from E-DCH to CCH for cell

VS.HSUPA.HHO.E2D.SuccOutIntraFreq

Number of successful Intra-Frequency E2D hard handovers for cell

VS.HSUPA.HHO.E2D.SuccOutInterFreq

Number of successful Inter-Frequency E2D hard handovers for cell

If the call drop ratio is high, we need to find the reason. Some counters can indicate the

reason of call drop.



Normally RF (radio frequency) problem is the main reason of call drop in real network such

as bad coverage or handover failure.



VS.RAB.AbnormRel.CS.IuAAL2

Number of CS RABs Abnormally Released for Cell Due to Iu Interface AAL2 Link Failure

This counter is triggered when RNC finds the AAL2 path is abnormal. Maybe it is the

problem of Iu-CS transmission.

VS.RAB.AbnormRel.CS.RF

Number of CS RABs Abnormally Released Due to RF for Cell

Some RF problems will trigger this counter such as bad coverage, handover failure,

interference and etc. Normally RF problem is the main reason of call drop in real network.

VS.RAB.AbnormRel.CS.OM

Number of CS RAB Release Requests for Cell Due to O&M Intervention

If RAB is release by O&M intervention (For example RAB is released by MML command),

this counter will be triggered. Normally this is not the main reason of call drop in real

network.

VS.RAB.AbnormRel.CS.Preempt

Number of CS RAB Release Attempts for Cell Due to RAB Preemption

During access control procedure if system resource is limited and preemption function is

enabled, a user with higher priority can preempt a user with lower priority. Then this

counter will be triggered.

VS.RAB.AbnormRel.CS.UTRANgen

Number of CS RAB Abnormal Releases Triggered by RNC for Cell Due to UTRAN Cause

If RAB is released because of UTRAN problem, this counter will be triggered. If this counter

has high value, more detailed information need to be collected and analyzed.

VS.RAB.AbnormRel.CS.OLC

Number of CS Domain RABs Released Due to Congestion for Cell

If the system load is very high and over load control function is enabled, RNC can release

some RAB to reduce the load. Then this counter will be triggered.



Normally RF problem is the main reason of call drop. More sub counters can be used to

analyze the detailed RF reason of call drop. To find the exact reason maybe more detailed

information such as drive test result and signaling trace result need to be collected.

VS.RAB.AbnormRel.CS.RF.ULSync

If NodeB loses the UL synchronization of the UE during service, the RAB will be

released and this counter will be triggered. Bad coverage or missing neighboring

cell configuration can triggered this counter.

VS.RAB.AbnormRel.CS.RF.UuNoReply

If UE can not respond to the signaling from RNC during service, the RAB will be

release and this counter will be triggered. Bad coverage can trigger this counter.

VS.RAB.AbnormRel.CS.RF.SRBReset

If RNC sends signaling to UE repeat but UE can not send a ACK response, RNC will

reset RLC layer. Then call drop will happen and this counter will be triggered. Bad

coverage or interference can trigger this counter.



VS.RAB.AbnormRel.PS.GTPULoss

Number of PS RABs Abnormally Released for Cell Due to GTPU Failure

This counter is triggered when RNC finds the GTPU in Iu-PS user plane is abnormal.

Maybe it is the problem of Iu-PS transmission.

VS.RAB.AbnormRel.PS.RF

Number of PS RABs Abnormally Released Due to RF for Cell

Some RF problems will trigger this counter such as bad coverage, handover failure,

interference and etc. Normally RF problem is the main reason of call drop in real

network.

VS.RAB.AbnormRel.PS.OM

Number of PS RAB Release Requests for Cell Due to O&M Intervention

If RAB is release by O&M intervention (For example RAB is released by MML

command), this counter will be triggered. Normally this is not the main reason of

call drop in real network.

VS.RAB.AbnormRel.PS.Preempt

Number of PS RAB Release Attempts for Cell Due to RAB Preemption

During access control procedure if system resource is limited and preemption

function is enabled, a user with higher priority can preempt a user with lower

priority. Then this counter will be triggered.

VS.RAB.AbnormRel.PS.OLC

Number of PS Domain RABs Released Due to Congestion for Cell

If the system load is very high and over load control function is enabled, RNC can

release some RAB to reduce the load. Then this counter will be triggered.



Normally RF problem is the main reason of call drop. More sub counters can be used to

analyze the detailed RF reason of call drop. To find the exact reason maybe more detailed

information such as drive test result and signaling trace result need to be collected.

VS.RAB.AbnormRel.PS.RF.ULSync

If NodeB loses the UL synchronization of the UE during service, the RAB will be

released and this counter will be triggered. Bad coverage or missing neighboring

cell configuration can triggered this counter.

VS.RAB.AbnormRel.PS.RF.UuNoReply

If UE can not respond to the signaling from RNC during service, the RAB will be

release and this counter will be triggered. Bad coverage can trigger this counter.

VS.RAB.AbnormRel.PS.RF.SRBReset

If RNC sends signaling to UE repeat but UE can not send a ACK response, RNC will



VS.RAB.AbnormRel.PS.RF.TRBReset

If RNC sends PS data to UE repeat but UE can not send a ACK response, RNC will





The table shows the result of CS call drop of Top 10 cells in one month. It is from a real

network.

In the example we can see that most of the CS call drops in the network are caused by RF

problems.



The table shows the result of PS call drop of Top 10 cells in one month. It is from a real

network.

In the example we can see that most of the PS call drops in the network are caused by RF

problems.



owo205030 wcdma ran13 call drop kpi and relative counters issue 1.00

Documents

drop kpi

permission wcdma

drop ratio wcdma

relative counters p

permission vp

permission cdr

video phone wcdma

iu release request