on The procedure for rapid renewal of authentication is described in Figure 7.13. IKE SA INIT server IKE SA INIT IKE AUTH Request DIAMETER AAR EAP Request EAP-Method AKA Reauthentication DIAMETER AAA EAP Request EAP-Method AKA Reauthentication IKE AUTH Response EAP Response EAP-Method AKA Reauthentication IKE AUTH Request EAP Response EAP-Method AKA Reauthentication DIAMETER AAR EAP Success DIAMETER AAA EAP Success IKE AUTH Response IKE AUTH Request IKE AUTH Response Figure 7.13. Procedure for rapid renewal of authentication 146 Wi-Fi Integration to the 4G Mobile Network Steps 1 to 4 are identical to those described for the establishment of the SWu tunnel in Figure 7.12. The identifier for rapid renewal of authentication is transmitted in the IDi block of the first message IKE_AUTH Request. 5) The AAA server initiates the procedure for rapid renewal of authentication with the message EAP Request/EAP-Method AKA Reauthentication. 6) The ePDG entity transmits the message IKE_AUTH Response containing its identity, certificate and signature of the IKE_SA_INIT message in the AUTH block. The message AKA Reauthentication EAP Request/EAP-Method is included to start the EAP procedure on IKEv2. 7) The mobile verifies the signature and responds with the message IKE_AUTH Request and the EAP Response/EAP-Method Reauthentication message containing the mobile seal. 8) The ePDG entity transfers the message EAP Response/EAP-Method Reauthentication to the AAA server. Steps 9 to 12 are identical to steps 13 to 16 described for the establishment of the SWu tunnel in Figure 7.12. The new MSK is generated by the AAA server and passed to the ePDG entity and the mobile. This new key is used to authenticate the first two IKE_SA_INIT messages. S2a/S2b Tunnel Establishment 8.1. PMIPv6 mechanism The PMIPv6 (Proxy Mobile Internet Protocol version 6) mechanism allows a mobile host to keep its original IPv6 address, to maintain its current session or to be reachable when moving, mobility being provided by the network. The mobile node (MN) is a 