A receiving device includes: a communication unit to receive a plurality of partial data divided from data to be transmitted through two or more connection networks; an information confirming unit to confirm (i) transmission order information and (ii) network transmission order information indicating related to a transmission order assigned to of the specific partial data among the plurality of partial data to be transmitted through a the specific connection network designated among the two or more connection networks; and the control unit to determine whether non-received partial data are lost based on at least one of the transmission order information and the network transmission order information.