FACH Congestion under RNC with EFD Feature active

[paulus]

Hi guys,

I wonder, how to solve FACH congestion in a cell under RNC which EFD feature active.

2nd SCCPCH already added on the cell,but still congested.

FACHCONG.JPG

Thanks
BR//Paul

[gunpowder]

Dear you can try the following
1] Increase FACH BW but make sure to use the script provided by huawei to avoid State Transition degradation
2] You can use P2D_FACH Congestion switch but if you have big FACH congestion it may lead to excessive P2D attempts
3] if your network is RAN16 version you can use FACH Pool Feature on Cell level but it may increase PS Drop rate

i hope everything is clear paulus

[paulus]

Dear you can try the following
1] Increase FACH BW but make sure to use the script provided by huawei to avoid State Transition degradation
2] You can use P2D_FACH Congestion switch but if you have big FACH congestion it may lead to excessive P2D attempts
3] if your network is RAN16 version you can use FACH Pool Feature on Cell level but it may increase PS Drop rate

i hope everything is clear paulus

Hi Gunpowder,

Thanks for your response. Anyway, for the points you mentioned,

1. How do we know about FACH BW? Is there this value in CFGMML?
2. For P2D_FACH Congestion Switch, do you mean like activating this (Smart P2d) ?

SET UCORRMALGOSWITCH: DraSwitch=DRA_PCH_UE_SMART_P2D_SWITCH-1;
ADD UCELLDCCC: CellId=01,DraSwitch=DRA_PCH_UE_SMART_P2D_SWITCH-1;

3. Yup, our network is alreadyRAn16. Which parameter should I activate? I can't figure out this FACH pool in Hedex

Thanks
BR//Paul

[sabila]

already post at this for the script
http://www.finetopix.com/showthread....highlight=fach

for the fach pool may u can search it at hedex sran 16

[sade]

How long do you allow UE's to stay in CELL_FACH state?
Maybe you can reduce value of:
UUESTATETRANSTIMER\BeF2PStateTransTimer

What's your policy regarding multicarrier? Maybe you have settings which prefer UE's perform PS activities on one carrier and CS (R99) activities on other carrier? (SPGID parameter). In that case FACH capacity will be consumed by UE's switching between carriers

[Vladislav]

Hi Gunpowder,

Thanks for your response. Anyway, for the points you mentioned,

1. How do we know about FACH BW? Is there this value in CFGMML?
2. For P2D_FACH Congestion Switch, do you mean like activating this (Smart P2d) ?

SET UCORRMALGOSWITCH: DraSwitch=DRA_PCH_UE_SMART_P2D_SWITCH-1;
ADD UCELLDCCC: CellId=01,DraSwitch=DRA_PCH_UE_SMART_P2D_SWITCH-1;

3. Yup, our network is alreadyRAn16. Which parameter should I activate? I can't figure out this FACH pool in Hedex

Thanks
BR//Paul

I think he told about URRCTRLSWITCH: OptimizationSwitch=P2D_SWITCH-1;

[Vladislav]

Yes, good suggestions.
For me also the main question is which threshold and timers are used to perform State transition from FACH to CELL_PCH?
Also you can tried to enable PERFENH_FACH_CONG_D2IDLE_SWITCH - but to tell the truth I never tried and cannot estimate the result.

Best regards!