The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services.A communication method operated by a terminal includes receiving, from a base station, control information for configuring the terminal to interwork with a WLAN in a cellular connection state, communicating at least one traffic with a first WLAN based on the control information in the cellular connection state, and communicating the at least one traffic with the first WLAN based on the control information, if the cellular connection state is released. A terminal includes a controller configured to receive, from a base station, control information for configuring the terminal to interwork with a WLAN in a cellular connection state, communicate at least one traffic with a first WLAN based on the control information in the cellular connection state, and communicate the at least one traffic with the first WLAN based on the control information, if the cellular connection state is released.