7/25/2019 61865679 Drop Call Analysis

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Drop Calls on TCH

Drop Calls on TCH

Bad LocatingParameter Setting?

Correct Parameter Setting

Perform

Interference Analysis

Y

N

Check Output Po er

Is Po er !egulationused properly?

Correct po er regulationparameter

Is the Po erBalanced?

Ad"ust output po er

Is #$% &sed? Introduce #$%

Y

N

Is 're(uency)opping used?

Acti*ate 're(uency)opping

Check #ropped call reason

Bad +uality?

Lo SignalStrength?

Perform lo SignalStrength Analysis

$iming Ad*ance? Check site location, $ALI-

Sudden #rop?Check reason for sudden

loss

Other?In*estigate possi.le

)ard are fault

B

N

N

N

Y

Y

Y

Y

Y

Y

Y

Y

N

N

N

N

N

/N#

B

Check Lost )ando*er

-ost dropped callsduring hando*er?

Perform )ando*er Analysis

Check Site Position

#rag on Site?!emo*e site or change

fre(uency

Check B$S /rror Log

)0 'ault?S ap , repair )0

Check link (uality ,synchroni1ation

$ransmission'ault?

Perform link in*estigation

Best ser*er e2ists?

Check -S Pro.lem

Add site

Perform dri*e test

Perform C$! recordings

Perform site sur*ey

Check Antenna installation

Y

Y

Y

Y

N

N

N

N

N

Y

7/25/2019 61865679 Drop Call Analysis

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'rom technical perspecti*e3 dropped call sho the num.er of a.normal disconnection4s during call setup3 S-S3supplementary ser*ice acti*ation or during con*ersation5 $hey are a fe different counters for dropped calls3 i5e5dropped calls due to lo signal strength3 .ad (uality3 too high timing ad*ance and miscellaneous is used to get anindication of the reason for possi.le .ad performance5

'rom a su.scri.er point of *ie 3 dropped calls are those that interrupt an ongoing con*ersation3 i5e5 a call droppedon the $C)5 If the call is dropped on the S#CC) the user simply re6dials again and hopefully succeeds ith the

ne call setup5 'or this analysis e ill focus on the drop call on the $raffic Channel 7$C)85$C) drop call can .e di*ided into a fe categories9

:5 /2cessi*e $iming Ad*ance2. Lo Signal Strength ; &L