An electronic device comprising: at least one communication processor; and an application processor configured to transmit data to be transmitted through first cellular communication and/or second cellular communication to the at least one communication processor, wherein the at least one communication processor comprises: a packet data convergence protocol, "PDCP," configured to support a split bearer for transmitting split data generated by splitting the data to a first node corresponding to the first cellular communication and a second node corresponding to the second cellular communication; a first radio layer control, "RLC," configured to split first data received from the PDCP and transmit the split first data to a first media access control, "MAC," corresponding to the first cellular communication; and a second RLC configured to split second data received from the PDCP and transmit the split second data to a second MAC corresponding to the second cellular communication, wherein the PDCP is configured to: split data received from the application processor into data units having a preset size, identify a data processing rate of the first RLC and a data processing rate of the second RLC, and distribute the data units to the first RLC and the second RLC, based on the data processing rate of the first RLC and the data processing rate of the second RLC, characterised in that the device further comprises a PDCP sequence number allocation unit configured to: assign a small sequence number to the data unit to be transmitted to an RLC having a faster data processing rate on the basis of the data processing rate of the first RLC and the data processing rate of the second RLC. at least one communication processor; and an application processor configured to transmit data to be transmitted through first cellular communication and/or second cellular communication to the at least one communication processor, wherein the at least one communication processor comprises: a packet data convergence protocol, "PDCP," configured to support a split bearer for transmitting split data generated by splitting the data to a first node corresponding to the first cellular communication and a second node corresponding to the second cellular communication; a first radio layer control, "RLC," configured to split first data received from the PDCP and transmit the split first data to a first media access control, "MAC," corresponding to the first cellular communication; and a second RLC configured to split second data received from the PDCP and transmit the split second data to a second MAC corresponding to the second cellular communication, wherein the PDCP is configured to: split data received from the application processor into data units having a preset size, identify a data processing rate of the first RLC and a data processing rate of the second RLC, and distribute the data units to the first RLC and the second RLC, based on the data processing rate of the first RLC and the data processing rate of the second RLC, a packet data convergence protocol, "PDCP," configured to support a split bearer for transmitting split data generated by splitting the data to a first node corresponding to the first cellular communication and a second node corresponding to the second cellular communication; a first radio layer control, "RLC," configured to split first data received from the PDCP and transmit the split first data to a first media access control, "MAC," corresponding to the first cellular communication; and a second RLC configured to split second data received from the PDCP and transmit the split second data to a second MAC corresponding to the second cellular communication, wherein the PDCP is configured to: split data received from the application processor into data units having a preset size, identify a data processing rate of the first RLC and a data processing rate of the second RLC, and distribute the data units to the first RLC and the second RLC, based on the data processing rate of the first RLC and the data processing rate of the second RLC, split data received from the application processor into data units having a preset size, identify a data processing rate of the first RLC and a data processing rate of the second RLC, and distribute the data units to the first RLC and the second RLC, based on the data processing rate of the first RLC and the data processing rate of the second RLC, characterised in that the device further comprises a PDCP sequence number allocation unit configured to: assign a small sequence number to the data unit to be transmitted to an RLC having a faster data processing rate on the basis of the data processing rate of the first RLC and the data processing rate of the second RLC.