Download - KPI improvment in 3G
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8/13/2019 KPI improvment in 3G
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8/13/2019 KPI improvment in 3G
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Call set-up
failure
The PrxTotal level is significantly higher than
expected in no/low load conditions.
In case of MHA is used in BTS check MHA an
cables loss parameters, otherwise PrxTotal
value will be too high.
Call dropMHA settings should be checked, see more
in reference [7]
(If MHA parameter is set to ON, Cable loss
parameter is used, Cable loss = Real MHA ga
= Feeder loss parameter)
Call set-up
failureCall drop
Set parameters so that reselection process w
start earlier:
Qqualmin, Sintrasearch and Qhyst2 as per
latest recommendation [8]
Use smaller value N312 (2, recommendation
4).
Use Actix for checking the call set-up delay (L
messages).
Use call set-up time optimisation feature
Dynamic setting of ActivationTimeOffset
(possible in RAN1.5.2 ED2) enables 200 to
500ms reduction for set up delay.
Dropped
call
SHO to wrong cell
will cause drop call.
Overshooting cell come temporarily into
active set and forces a suitable serving cell to
be dropped out. Later RSCP suddenly drops
in the wrong cell and causes a dropped call
because there is no neighbour defined.
Pan away overshooting cell if it is too close to
the serving cell, otherwise apply down tilting a
well.
Use cell individual offset (negative value)
parameter to balance the DL and UL coverag
Check traffic direction of in-car UEs to decide
which cell requires offsets.
Use cell individual offset (positive value)
parameter to balance the DL and UL coverag
Note: Cell individual offsets are not taken into
account when calculating the added cell Tx
power.
Use cell individual offset (positive value)
parameter to balance the DL and UL coverag
Note: Cell individual offsets are not taken into
account when calculating the added cell Tx
power.
Delete unnecessary neighbours.
Improve dominance.
Dropped
call
Round the corner
effect
The call drops due to too rapid CPICH
coverage degradation for Cell A, and
therefore there is not enough time for SHO.
Dropped
call/SHO
failure
Too many
neighbours
n area t e num er o com ne
neighbouring cells become more than 31.
HO list is created using RNC algorithm in the
final sta e some of the nei hbours will
Dropped
call
Cell suffering from
UL interference = DL
(CPICH) coverage
much bigger than ULcoverage
As the UE Tx power is not enough for target
cell synchronisation, the SHO fails which will
cause call drop later.
Dropped
call
DL CPICH coverage
< UL coverage
Cell with lower CPICH power than the
surrounding is having too good UL
performance, as this cells UL cannot be
used efficiently due to SHO is decided upon
DL (CPICH Ec/No).
Cell set-up
failure
Bad RRC connection
set-up success rate
due to slow Ue cell
reselection
RRC connection set-up complete message
not heard by BTS.
Long call
set-up
ime
Long time interval for
sync between RNC
and BTS before
connection
The value of Parameter N312 is too high:
maximum number of in sync indications
received from L1 during the establishment of
a physical channel
High PrxToatal due
to wrong MHA
settings
High Prxtotal due to
Installation problems
The PrxTotal level is significantly higher than
expected in no/low load conditions.
Check the antenna installation as the last
alternative in high PrxNoise case.