Csfb & VoLTE

Security Level: confdential

CSFB: Circuit Switched FallBack

www.huawei.com

Made by: MARRAHA by: MARRAHA Mehdi

HUAWEI TECHNOLOGIES TECHNOLOGI ES Co., Ltd.

HUAWEI Confdential

2. 3.

Requires changes in the MSC with the introduction of SGs interface

&a)ed on te ca+ailitie) o- Ue) and netor/), t(e -olloin! 'ec(ani)') are availale -or ana eN& to +er-or' CS %allac/ to UT*AN0GE*AN.

CS%& 'ec(ani) ') %la)( CS%&

*edirectio n

System Information B(oc,s!

+rocedure) 4a)ed on SI&)5 &a)ic *edirection

it( SI& )/i++in!

En(anced 4SI tunnelin!5

Call reliaility +oor in ca)e o- %la)( CS%&

etter in ca)e o*edirection

"oice oer IP can e im'(emented in t+o +ays:

S)"CC Procedure

%+o ste' 'rocess of S)"CC from $%& to 24534