Handover Wi-Fi to 3G

UE

HO decision

SGSN GGSN PDG HA

Attach procedure and PDP Context Activation

GTP Tunnel

Binding Update

Binding Ack

Bearer release

UE SGSN GGSNHLR/HSS

Attach Req (IMSI)

Authentication and Location Update

Attach Res (TMSI)

Activate PDP Context Req (APN)

PDP Context Req (APN)

PDP Context Res (CoA)

Activate PDP Context Res (CoA)

GGSN Selection

GTP Tunnel

UE PDGHLR/HSS

3GPP/AAA

Release Tunnel Req

Release Tunnel Res

Tunnel disconnection report

Update UE Status

Purge procedure