1. TS 23.402**): Non-Roaming Reference Architecture for non-3GPP Accesses
HSS
Wx*
**) Colouring of non-3GPP accesses and red arrows (incl. text in red) added for this presentation S4
S6a
2G/3G SGSN
PCRF S3
Rx+
MME S7
S11
S1-MME
SGi
Operator’s IP Services
(e.g. IMS, PSS, MIHF etc.)
S10
Serving SAE Gateway
PDN SAE Gateway
EUTRAN S5
S1-U
S6c
S2b
Wm*
3GPP AAA
Server
ePDG
S2c
S2a
HPLMN
Wn*
Trusted/Untrusted*
Non-3GPP IP Access
or 3GPP Access
Trusted
Non-3GPP IP Access
Non-3GPP Networks
Untrusted
Non-3GPP IP Access
Wa*
Ta* UE
* Untrusted non-3GPP access requires ePDG in the data path
Handovers (Discovery and Selection of non-3GPP Access is needed before)

2. An example of a possible extension to HO Message Flow using 802
An example of a possible extension to HO Message Flow using concepts
Untrusted
non-3GPP
IP Access