Method and user equipment for performing network selection and traffic routing

A user equipment (UE) for performing network selection and traffic routing, comprising:

• a transceiver;
• and
• a processor controlling the transceiver,
• wherein the processor includes an access stratum (AS) layer and a non-access stratum (NAS) layer and controls the NAS layer to perform the following NAS layer procedures, and
• the NAS layer procedures include:
• receiving, from a mobility management entity (MME), first information on wireless local area network (WLAN) offloadability for a first public data network (PDN) connection, and information on a capability of the first PDN connection to support a network-based IP flow mobility (NBIFOM);
• determining that conflict exists between the first information and the information on the capability to support the NBIFOM when the first information includes information representing that an offloading to a WLAN is not possible and the information on the capability of the first PDN to support the NBIFOM includes information related to mobility to the WLAN;
• when the conflict is determined to exist, transmitting, to a PDN gateway (P-GW), a message for notifying a suspension of the NBIFOM;
• and
• receiving a second information on WLAN offloadability for a second PDN connection and the information on the capability of the second PDN to support the NBIFOM from the MME,
• determining whether the conflict is resolved based on the second information and the information on the capability of the second PDN to support the NBIFOM;
• and
• determining whether to resume the NBIFOM based on the determining of whether the conflict is resolved.