iption Profile Repository) database. 3) The PCRF responds to Wi-Fi access with the DIAMETER message CCA (Credit-Control-Answer) containing the rules to apply to the default bearer. 4) Wi-Fi access transmits to the PGW entity the PBU extension containing the following parameters: MN-NAI, Lifetime, Access Technology Type, APN, GRE key for downlink traffic, Charging Characteristics and Additional Parameters. 5) The PGW entity sends the PCRF entity the CCR DIAMETER message to obtain the default bearer characteristics. 6) The PCRF entity responds to the PGW entity with the CCA DIAMETER message containing the rules to apply to the default bearer (filter parameter, charging mode). 7) The PGW entity sends the AAA server the DIAMETER message AAR (Authenticate and Authorize Request) to communicate its identity and the access point name for the connection. 8) The AAA server sends the HSS entity the DIAMETER message SAR (Server-Assignment Request) to transfer the information received from the PGW entity. 9) The HSS entity responds to the AAA server with the DIAMETER message SAA (Server-Assignment-Answer) that contains the mobile profile: - the access point name (APN); - QoS (Quality of Service) characteristics for each default bearer to be established. 10) The AAA server responds to the PGW entity with the DIAMETER message AAA (Authenticate and Authorize Answer) containing the information received from the HSS entity. 154 Wi-Fi Integration to the 4G Mobile Network The PGW will use the mobile profile received from the AAA server if these parameters were not provided by the PCRF. 11) The PGW entity responds to the Wi-Fi access point with the PBA extension containing the following parameters: MN NAI, Lifetime, UE Address Info, GRE key for uplink traffic, Charging ID and Additional Parameters. 12) Wi-Fi access responds to the mobile with the ICMPv6 message Router Advertisement containing the mobile configuration parameters (IPv6 prefix, IP address of the DNS server). 8.1.3.2. Untrusted Wi-Fi access The LMA and MAG functions are 