APPARATUS AND METHOD FOR SUPPORTING DATA TRANSMISSION SERVICE OVER MULTIPLE NETWORKS

A transmitting device includes: a communication unit to transmit data through two or more networks including a first network and a second network; and a transmission controller to control the communication unit to transmit the data to the receiving device through the first network, and transmit the data, which is to be transmitted to the receiving device through the first network, to the receiving device in a roundabout way through the second network in response to the data roundabout transmission request state, where the transmission controller identifies whether the receiving device is in the data roundabout transmission request state, based on at least one selected from the group consisting of an available bandwidth, a connection error generation state, a predetermined delay value of receiving the data with respect to the first network.