y the ANDSF rules or by the rules provided by the eNB entity, and not by a combination thereof. The only exception is the simultaneous enforcement of the rules provided by the eNB entity and the IARP rules for the access point (APN). 10.2. Mechanisms defined by IEEE and WFA organizations Before associating with an access point, the mobile requires information on the services provided by the Wi-Fi access networks, from GAS (Generic Advertisement Service) frames that are Action-type management frames. The Public Action field, in the byte immediately after the Category field, differentiates the types of Action frames. GAS frames provide transparent transport of a list with ANQP (Access Network Query Protocol) elements to communicate information. The Interworking element in the management frames Beacon or Probe Response indicates that the GAS protocol is supported (Figure 10.9). Network Discovery and Selection Beacon or Probe Response frame Information elements Interworking, Advertisement Protocol, Roaming Consortium GAS Initial Request frame ANQP Query GAS Initial Response frame ANQP information elements Association Authentication Transfer of protected data (confidentiality, integrity) Figure 10.9. GAS/ANQP exchanges The Advertisement Protocol element in the management frames Beacon or Probe Response indicates that the ANQP protocol is supported (Figure 10.9). The mobile transmits a request in a GAS Initial Request frame, and the access point provides the requested information or information on how to receive the response in the GAS Initial Response frame (Figure 10.9). The response to the GAS Initial Request frame is provided in this case in one or more GAS Comeback Response frames. The response to the GAS Initial Request frame shall not be shared between an Initial Response GAS frame and one or more Comeback Response GAS frames. The access point has the information elements or transfers the request from the mobile to an ANQP server. The IEEE (Institute of Electrical and Electronics Engineers) has defined a subset 