RAU during CSFB

[fahmi]

Dear experts,

Do we have RAU in 3G systematically during CSFB from LTE ?

Could you explain different scenarios ?

BR,
Fahmi

[dennielone]

Dear fahmi,

Yes. If have data to transfer before CSFB, UE should do RAU during CSFB procedure.
I live network, RAU during CSFB may break out CSFB procedure. for example, RAU reject with GPRS no allow in this PLMN and so on.

Thanks
Dennielone