s responds to the mobile with the ICMPv4 message Foreign Agent Advertisement, containing the CoA of the foreign agent. 3) The mobile transmits the Registration Request message containing the following fields: MN-NAI, Lifetime and APN. 4) Wi-Fi access sends the PCRF entity the CCR DIAMETER message containing the mobile profile received from the AAA server during authentication, to obtain authorization to open the default bearer. The PCRF may modify the received parameters if the rules defined for the network and stored in the SPR database are different. 5) The PCRF responds to Wi-Fi access with the CCA DIAMETER message containing the rules to apply to the default bearer. 6) Trusted Wi-Fi access transfers the Registration Request message to the PGW entity. 7) The PGW entity sends the AAR DIAMETER message to the AAA server to retrieve the mobile profile. 8) The AAA server transmits the SAR DIAMETER message to the HSS entity to retrieve the profile of the mobile. 9) The HSS entity responds to the AAA server with the SAA DIAMETER message containing the mobile profile. 10) The AAA server transmits to the PGW entity the AAA DIAMETER message containing the profile of the mobile. 11) The PGW entity sends the PCRF entity the CCR DIAMETER message to obtain the default bearer characteristics. The PCRF can change the value of the aggregate maximum bearer rate (APN-AMBR). 12) The PCRF entity responds to the PGW entity with the CCA DIAMETER message containing the rules to be applied to the default bearer (QoS parameters, filtering parameters, charging mode). 13) The PGW entity sends the AAA server the AAR DIAMETER message to communicate its identity and the access point name for the connection. 164 Wi-Fi Integration to the 4G Mobile Network 14) The AAA server transmits to the HSS entity the SAR DIAMETER message to transfer the information received from the PGW. 15) The HSS entity responds to the AAA server with the SAA DIAMETER message. 16) The AAA server responds to the PGW entity with the AAA DIAMETER message. 17) The PGW ent