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2G /3G Interworking Description
HUAWEI TECHNOLOGIES CO., LTD.
Root cause & Solution
Root cause:
 3G network signal quality (EcNo) degrade due to traffic increased.
 55.2% 3G cell Pilot Power (CPICH) Percentage is less than 10%, Pilot Power setting not proper.
Solution:
 Multi-Sector deployment for high traffic cell ,improving capacity and subscriber experience.---BDCL team
deployment on going.
 Recommend Pilot (CPICH) Power configuration as below:
33dBm Pilot Power configuration for Cells with Power 20W
36dBm Pilot Power configuration for Cells with Power 40W
 Fast WCDMA Reselection feature needs to enable at all 2G cell.(173 cells out of 26834 cells not enabled).
2
180
160
140
120
100
80
60
40
To maintain speed perception
as good as possible during
PS Traffic (TB)
HSDPA User Throughput (kbps)
2800
2400
2000
1600
1200
800
400
0
Throughput (kbps)
HSDPA Traffic Vs. User Throughput
2016-09-01
2016-09-04
2016-09-07
2016-09-10
2016-09-13
2016-09-16
2016-09-19
2016-09-22
2016-09-25
2016-09-28
2016-10-01
2016-10-04
2016-10-07
2016-10-10
2016-10-13
2016-10-16
2016-10-19
2016-10-22
2016-10-25
2016-10-28
2016-10-31
2016-11-03
2016-11-06
2016-11-09
2016-11-12
2016-09-01
2016-09-04
2016-09-07
2016-09-10
2016-09-13
2016-09-16
2016-09-19
2016-09-22
2016-09-25
2016-09-28
2016-10-01
2016-10-04
2016-10-07
2016-10-10
2016-10-13
2016-10-16
2016-10-19
2016-10-22
2016-10-25
2016-10-28
2016-10-31
2016-11-03
2016-11-06
2016-11-09
2016-11-12
2016-11-15
Traffic (TB)
Network KPI Trend
65.00%
RRC Access EcNo <-12 dB Ratio
60.00%
55.00%
50.00%
45.00%
Impact of free internet
promotion
40.00%
1,CN 2G to UMTS change success rate keep normal.
2, In wireless, IRAT RRC cell selection Succ Rate keep stable exclude RNMM01(high bandwidth utilization of Tx ).
3, Network EcNo degrade.(subscriber RRC access network EcNo <-12 dB Ratio increased).
3
Recommendation Parameters
Recommendation
value
Parameter ID
Inter-RAT Cell Reselection
Enable
Yes
Qsearch I
FDD Q Offset
7
0
Meaning
Enable Inter-RAT Cell Reselection
Always searching
always select a cell if acceptable
Idle mode
FDD Qmin
FDD Qmin Offset
FDD RSCP Min
Dedicate mode
7
0
6
CELLSELECTAFTERCALLREL YES
-12
0dB
-102
Select 3G Cell After Call Release
BDCL Network
configuration
Description
This parameter determines whether the
reselection from 2G cells to 3G cells is
allowed.
This parameter indicates the threshold of level
for cell reselection in idle mode.
In idle mode, if the signal level in the service
cell is below (0-7) or above (8-15), the MS
starts to search for 3G cells.
Only when the average receive level of a 3G
cells is FDD Q Offset greater than that of the
current service cell, the 3G cell can become a
candidate cell.0:-∞(always select a cell if
acceptable)
This parameter indicates one of the Ec/Io
threshold of level for the reselection of 3G
cells. Only when the received Ec/Io level of a
3G cell is greater than FDD Qmin, the 3G cell
can be one of the candidate cells for
reselection.
110 cells disabled
ok
ok
ok
0:22926 cells
1:3908 cells(optimization
This parameter specifies one of the thresholds value, the threshold easy
for 3G cell reselection)
of the signal level for 3G cell reselection.
Minimum level threshold of UTRAN cell
reselection. During the cell reselection
decision from a GSM cell to a FDD cell, this
parameter is used to calculate the RSCP
threshold of the target cell.
Fast WCDMA Reselection at 2G CS Call
Release feature
4
ok
172 cells not enabled the
feature
2G Idle mode cell selection to 3G Procedure
UE will start to measure the 3G neighbors when following conditions are
met:
Inter-RAT Cell Reselection Switch is enable.
Q search I: this parameter specifies the level threshold for UE to start to
search for 3G cells
A FDD cell becomes a candidate cell if all the following conditions are met:
1.Receive level of the FDD cell > Average receive level of the current
serving cell + FDD Q offset;
Receive level of the FDD cell > Receive level of any neighboring 2G cell +
FDD Q offset;
2. Ec/No of the FDD cell > FDD Qmin - FDD Qmin Offset;
3. Receive level of the FDD cell > "RSCP Threshold";
If multiple FDD cells meet the preceding conditions, the MS reselects the
cell with the strongest receive level.
UE will start to measure the 3G neighbors when following conditions are
met:
Inter-RAT Cell Reselection Switch is enable.
Q search I: this parameter specifies the level threshold for UE to start to
search for 3G cells
5
Thank You
www.huawei.com
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