6 wcdma ran12 call drop kpi and relative counters issue 1.01

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.


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


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CDR: call drop ratio


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VP: video phone


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Why

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

Freq+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).


Counters


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.


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Why

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

Freq+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).


Counters


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


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

the reason of call drop.


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

such as bad coverage or handover failure.


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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.


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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.


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VS.RAB.AbnormRel.PS.GTUPLoss

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.


Counters


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,



VS.RAB.AbnormRel.PS.RF.TRBReset

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




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The table shows the result of CS call drop of Top 10 cells in one day. 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.


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The table shows the result of PS call drop of Top 10 cells in one day. 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.


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6 wcdma ran12 call drop kpi and relative counters issue 1.01

Documents

drop kpi

drop ratiowcdma

relative countersp

permission wcdma

permission vp

permission cdr

iu release request

ps service