Slide 1Jan-05, 2010
HUAWEI Confidential
Audit Summary
Audit content
12425 NSN 2G cells were audited. 7298 cells were located inside HuaWei RNC boundary.
4371 Huawei 3G cells in 5 RNCs were audited.
Involved parameters
2G IRAT and 3G IRAT idle mode Cell reselection parameters were audited.
Audit Result
*
in idle mode
Related HUAWEI parameters:
Current HUAWEI 3G cells configuration:
Qqualmin and SsearchRAT
Qqualmin=-18 and SsearchRAT=2 are configured for all cells.
IdleQhyst1s
Range[0dB; 2dB]: two kinds of value are used for different cells.
Treselections
Range[1s; 2s]: two kinds of value are used for different cells.
Qoffset1
IDLEQHYST1S
TRESELECTIONS
QQUALMIN
SSEARCHRAT
Qoffset1
2
1
-18
2
0
in idle mode
Related NSN parameters:
meet the requirement of threshold
of searching for 3G cell?
Is RSCP>RLA_C + Qoffset?
Start
End
No
No
No
This page lists current configuration value for each parameter.
qSearchI
Infinity (never): UE never search 3G cells.
fddQOffset
Minus infinity dB [-32dB]: always select a 3G cell if acceptable.
Range[-28dB;-24dB;-16dB;0dB]: 4 kinds of thresholds are used for different cells.
fddQMin
*
qSearchI
fddQOffset
fddQMin
*
These two kinds of configuration are reasonable. And the first series of configuration is recommended from our point of view.
qSearchI
fddQOffset
fddQMin
Statistics of 2G cells in HUAWEI RNC boundary
7298 cells were located inside HUAWEI RNC boundary. Their statistics is shown as below:
241 cells configured with qSearchI= Infinity (never)
274 cells configured with fddQOffset not equal to -32
22 cells configured with fddQMin=-20 dB
1 cell configured with fddQMin=-6 dB
Other cells are configured as per recommendation value.
HUAWEI RNP TEAM
Analysis of the 2G reselection configuration
From the Statistics many cells are not configured as per recommendation. And these configuration may cause some potential problems as below:
When qSearchI= Infinity (never), UE camped in 2G will not reselect to 3G.
When fddQoffset is not configured as -32dB. It is more difficult for UE to reselect to 3G compared to those cells whose fddQoffset=-32dB and UE camped in 2G will use more time to come back to 3G.
When fddQmin is configured with very high threshold like -6dB. It is a very high threshold for UE to reselect to 3G.
When fddQmin is configured with very low threshold like -20dB. It may cause UE do Ping-Pong reselection between 2G and 3G.
HUAWEI RNP TEAM
HUAWEI RNP TEAM
HUAWEI RNP TEAM
Suggestions
To keep UE camping in 3G easily as per strategy, we suggest:
For NSN 2G
Setting qSearchI=Infinity (always) for all cells.
Verify the cells whose fddQoffset and fddQmin are not configured as per recommendation value.
For HUAWEI 3G
We will focus on cell reselection configuration and do audit weekly.
HUAWEI RNP TEAM