e being initiated by the PGW entity or the AAA server. Table 1.3 summarizes the DIAMETER messages exchanged on the S6b interface. Messages Comments PGW entity request to register and retrieve Authenticate and Authorize Request (AAR) the mobile profile AAA server response containing mobile Authenticate and Authorize Answer (AAA) profile AAA server request for mobile Re-Auth-Request (RAR) authentication renewal Re-Auth-Answer (RAA) PGW response to RAR request PGW request for termination of mobile Session Termination Request (STR) session Session Termination Answer (STA) AAA server response to STR request AAA server request for termination of Abort-Session-Request (ASR) mobile session Abort-Session-Answer (ASA) PGW response to ASR request Request of the PGW entity used for the EAP- Diameter-EAP-Request (DER) AKA authentication procedure for the DSMIPv6 mechanism AAA server response used for the EAP-AKA Diameter-EAP-Answer (DEA) authentication procedure Table 1.3. DIAMETER messages on the S6b interface Architecture Based on Wi-Fi Access The SWm interface is used for the mutual authentication procedure of the mobile and the AAA server, which is implemented during the establishment of the SWu tunnel. The SWm interface is used by the ePDG entity to retrieve the subscriber's profile and the PMIPv6 and GTPv2 mechanism information. The SWm interface can also be used to transmit to the ePDG entity, the IP address or the FQDN of the PGW entity. The SWm interface is used for terminating the mobile session, the procedure being initiated by the ePDG entity or the AAA server. Table 1.4 summarizes the DIAMETER messages exchanged on the SWm interface. Messages Comments Authenticate and Authorize Request Request from the ePDG entity to register itself (AAR) and retrieve the mobile profile Authenticate and Authorize Answer AAA server response containing mobile profile (AAA) AAA server request for mobile authentication Re-Auth-Request (RAR) renewal Re-Auth-Answer (RAA) Response of the ePDG entity to the RAR request Request from ePDG 