The present disclosure relates to a system and method to consider a data request and based thereon, select an access network that ensures battery life in a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-generation (4G) communication system such as long term evolution (LTE). An operating method of a terminal is provided that determines whether a data request occurs, then estimates a requested data amount when the data request occurs, and selects an access network, based on the estimated data amount. A terminal is also provided that includes a transceiver and at least one processor that exchanges communications with a server or base station and in doing so, determines whether a data request occurs, estimates a requested data amount when the data request occurs, and selects an access network, based on the estimated data amount.