Control congestion For HSDPA cells

My target is to control congestion For the HSDPA cells with limited radio resources on
ZTE RAN , i have BPK “CE” hardware resource limitation
Is there any parameters or features can help?

“Channel switch of interactive services and background services over HSDPA to RACH/FACH”
// This feature I always want try on ZTE RAN, but don’t found the result, like in Nokia we successfully implement it.
Any body have experience to implement in ZTE RAN?

I get some ideas but not working for me:

  1. Forced release of resources according to priority.
    // This I think will lose users serverice , it is not my target result.

  2. Adjustment of total HSDPA power (when the total power available to HSDPA is
    adjusted by RNC dynamically).
    // This feature I aready try. But no change, the feature need change NodeB & RNC side.

  3. Adjustment of code resources for HSDPA.
    // already set 1/8/14.

  4. DCH downgrade for the Rel99 services.
    // R99 Max speed limit 64k.

  5. Channel switc h of interact ive services and background services over HSDPA to
    RACH/FACH.

RACH and FACH channels have low capacity like 32Kb/sec on FACh for example .
You can’t offload much HSDPA traffic to those channels.