Analysis Report on the Call Drop Rate Increased Issue in STC After Upgrade

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Analysis report on the Call DropRate increased issue in STCafter upgraded from eRAN3.0 toeRAN6.0SPC3!

"ssue 0#

Date 0#3$0%$'

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Issue 01 (2013-05-29) Huawei Proprietary and Confidential

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&nalysis report on the Call 'rop ate in"reased issue in !C after

upgraded fro* e&+3#0 to e&+,#0PC23 &.out !his 'o"u*ent

About This Document

Trouble Ticket Number iCare/ -+567

Prepared By u iang (e*ployee I'/00133,5)4ue 4uing(e*ployee I'/ 0022553,)

Approved By hi 6hi7ue (e*ployee I'/ 0010,2)

Approval Date 2013-05-291



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upgraded fro* e&+3#0 to e&+,#0PC23 Contents

Contents

About This Document....................................................................... ii

1 Basic Information..........................................................................1

Problem Description......................................................................

! Problem Analysis..........................................................................!

3#1 !he "ause of Call 'rop######################################################################################################################################3

" #oot Cause...................................................................................$

% Corrective Action..........................................................................&

5#1 olution##############################################################################################################################################################



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upgraded fro* e&+3#0 to e&+,#0PC23 3 Pro.le* &nalysis

1 Basic InformationProduct Name 'ersion

'83900 %! !'' :10000,C00PC23



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Problem DescriptionIn !C of audi &ra.ia$ !he Call 'rop ate in"rease fro* 0#2; to 0#5; after upgrade fro*e&+3#0 to e&+,#0PC23$ the root "ause needs to e7plain#



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! Problem Analysis!.1 The cause of Call Drop

1# !he the upgrade was at the

red line#

2# ?ro* the


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3# !he e+8 logs re"orded that A didnBt support !'' .and during handoer#

# ?ro* the tra"e of the DCall 'rop AE$ we "an only see 8and3 (?'') in"luded in the

ACapa.ilityInfor*ation whi"h indi"ated that the A only support 8and3 and doesnFtsupport !'' 8and#

&nd the release was after the CG&GP!$ handoer wasnBt perfor*ed#

In ean,#0PC23$ a new fun"tion was added to "he"= the a.nor*al A# 8efore the

e+8 perfor* a handoer$ the e+8 will "he"= if the A support the 8and of the target

"ell# If not$ the A wasnBt allowed to handoer$ and "all drop would happen#

?'' 8andLT& (andNumber

plink89H):

;ownlink89H):

2idth of (and 89H): ;uple$ "pacing 89H): (and += -++= > -+5= 7= += +?=

- +*= > ++= +?= > += 7= = -=

? +5+= > +5* +=* >+= 5* * -=

6 +5+= > +5** -++= > -+** 6* 6== ?**

* -6 > 6 7 > 6 -* 6* -=

@@@

-? -=== > -=-= -+= > --== -= += +7=

-6 +7-*.* > +77=.* +*-* > +** ?6 >+=+.* +?*.*

-* +*= > ++* +?= > +* 7* = +*

!'' 8andLT& (andNumber

Allocation 89H): 2idth of (and 89H):

?? +== > +-= -=



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LT& (andNumber

Allocation 89H): 2idth of (and 89H):

?6 -=+= > -=-* +*

?* +*= > ++= 7=

?7 +?= > += 7=

?5 ++= > +?= -=

? -*5= > -7-= *=

? += > +-= 6=

6= -?== > -6== +==

6+ -67 > -7= +6

6- ?6== > ?7== -==

6? ?7== > ?== -==

5# !he des"ription in 3,#331 of 3PP agree*ent#

!he agree*ent defined that the A should in"lude the supported .ands infor*ation in

the UECapabilityInformation *essage after re"eption the UECapabilityEnquiry.

?ro* the tra"e of the nor*al A$ we "an see 8and0 (!'') was in"luded in

upported8and%istA!&$ so handoer "an perfor* su""essfully#



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Conclusion/ !he Call 'rop was due to so*e a.nor*al A didnBt report the !'' 8andCapa.ility and the e+8 in ean,#0PC23 enhan"ed to "he"= the a.nor*al A#

" #oot Causeo*e a.nor*al A in !C didnBt report !'' 8and in UECapabilityInformation $ and in

ean,#0PC23$ a new fun"tion was added to "he"= the a.nor*al A$ .efore the e+8 perfor* a

handoer$ the e+8 will "he"= if the A support the 8and of the target "ell# If not$ the A wasnBt

allowed to handoer$ and "all drop happened#



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% Corrective Action%.1 (olution

!he A should in"lude the supported !'' 8and in UECapabilityInformation and send the

*essage to the e+8#

Huawei e+8 will .e "o*pati.le with the a.nor*al A in '83900 %! !''

:10000,C00PCJ10# &nd e+8 will allow this a.nor*al A handoer su""essfully$ the

'83900 %! !'' :10000,C00PCJ10 will release at 201#0,#15#



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Analysis Report on the Call Drop Rate Increased Issue in STC After Upgrade