An electronic device comprising: at least one communication processor (212, 214); 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 (212, 214), wherein the at least one communication processor (212, 214) 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 process first data received from the PDCP and transmit the processed first data to a first media access control, MAC, corresponding to the first cellular communication; and a second RLC configured to process second data received from the PDCP and transmit the processed second data to a second MAC corresponding to the second cellular communication, wherein the PDCP is configured to: receive data to be transmitted through the first cellular communication and/or the second cellular communication from the application processor, transmit the data to at least one of the first RLC or the second RLC, characterized in that the PDCP is configured to stop transmitting the data to the at least one of the first RLC or the second RLC receiving the data, based on a result of comparison that a size of data temporarily stored in the at least one of the first RLC or the second RLC receiving the data is larger than a first configuration value, and in that the PDCP is configured to determine the first configuration value based on a size of successfully transmitted data per unit time through the first cellular communication or the second cellular communication and further based on a maximum time during which a PDCP of a receiving side waits for reception of the data. at least one communication processor (212, 214); 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 (212, 214), wherein the at least one communication processor (212, 214) 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 process first data received from the PDCP and transmit the processed first data to a first media access control, MAC, corresponding to the first cellular communication; and a second RLC configured to process second data received from the PDCP and transmit the processed second data to a second MAC corresponding to the second cellular communication, 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 process first data received from the PDCP and transmit the processed first data to a first media access control, MAC, corresponding to the first cellular communication; and a second RLC configured to process second data received from the PDCP and transmit the processed second data to a second MAC corresponding to the second cellular communication, wherein the PDCP is configured to: receive data to be transmitted through the first cellular communication and/or the second cellular communication from the application processor, transmit the data to at least one of the first RLC or the second RLC, characterized in that the PDCP is configured to stop transmitting the data to the at least one of the first RLC or the second RLC receiving the data, based on a result of comparison that a size of data temporarily stored in the at least one of the first RLC or the second RLC receiving the data is larger than a first configuration value, and in that the PDCP is configured to determine the first configuration value based on a size of successfully transmitted data per unit time through the first cellular communication or the second cellular communication and further based on a maximum time during which a PDCP of a receiving side waits for reception of the data. receive data to be transmitted through the first cellular communication and/or the second cellular communication from the application processor, transmit the data to at least one of the first RLC or the second RLC, characterized in that the PDCP is configured to stop transmitting the data to the at least one of the first RLC or the second RLC receiving the data, based on a result of comparison that a size of data temporarily stored in the at least one of the first RLC or the second RLC receiving the data is larger than a first configuration value, and in that the PDCP is configured to determine the first configuration value based on a size of successfully transmitted data per unit time through the first cellular communication or the second cellular communication and further based on a maximum time during which a PDCP of a receiving side waits for reception of the data.