A user equipment of a communication system includes a first communication circuit configured to operably receive ANDSF rule set and RAN rule transmitted from a communication station; a second communication circuit; and a control circuit configured to operably: select a target ANDSF rule out of the ANDSF rule set; determine whether the user equipment fulfills all validity conditions of the target ANDSF rule; select a target access network out of a prioritized network list defined by the target ANDSF rule if all validity conditions of the target ANDSF rule are fulfilled; determine whether the target access network fulfills all validity conditions of the RAN rule if the target access network is present; and control the second communication circuit to steer traffic specified in the target ANDSF rule or traffic specified in the RAN rule to a target access point of the target access network.