# US 11,115,315 B2 · Duplication transmission method and device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,315 B2 - Document ID: US11115315B2 - Status: Granted - Kind: B2 - Application number: 16/650,383 - Filed: 2018-09-19 - Published: 2020-07-16 - Granted: 2021-09-07 - Earliest claimed: 2017-09-27 - Assignees: China Academy of Telecommunications Technology - Applicants: China Academy of Telecommunications Technology - Inventors: Aijuan Liu; Fangli Xu; Jiamin Liu - Web page: https://patentgrep.com/patent/US11115315B2 ## CPC - H04L 1/08: by repeating transmission, e.g. Verdan system {(H04L1/1858 and H04L1/189 take precedence)} - H04L 45/24: Multipath - H04W 80/02: Data link layer protocols - H04W 88/085: {Access point devices with remote components} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A duplication transmission method and device, used for solving the problem in existing technology of a scheme for implementing packet data convergence protocol (PDCP) duplication having yet to be implemented in a central unit/distribute unit (CU/DU) separation scenario. According to the embodiments of the present invention, after determining the need for PDCP duplication transmission on a radio bearer, a CU sends a PDCP data packet transmitted on the radio bearer to a DU and instructs the DU to carry out the PDCP duplication transmission; and the DU sends the PDCP data packet to multiple radio link control (RLC) entities corresponding to the radio bearer so as to carry out the PDCP duplication transmission. Since the CU may instruct the DU to perform the PDCP duplication transmission, the PDCP data packet is subject to duplication transmission in the CU/DU separation scenario, thereby further improving the system performance. ## Claims ### Claim 1 A duplication transmission method, comprising: determining, by a Central Unit, CU, that Packet Data Convergence Protocol, PDCP, duplication transmission needs to be performed on a radio bearer; sending, by the CU, a PDCP data packet to be transmitted on the radio bearer to a Distribute Unit, DU, and instructing the DU to perform the PDCP duplication transmission; wherein sending, by the CU, the PDCP data packet to be transmitted on the radio bearer to the DU, and instructing the DU to perform the PDCP duplication transmission, comprises: if the radio bearer is a Signaling Radio Bearer, SRB, then sending, by the CU, the PDCP data packet to be transmitted on the SRB to the DU through F1 control plane, and instructing the DU to perform the PDCP duplication transmission through an Information Element, IE, in a corresponding F1 interface message; or if the radio bearer is a Data Radio Bearer, DRB, then sending, by the CU, the PDCP data packet to be transmitted on the DRB to the DU through F1 user plane, and instructing the DU to perform the PDCP duplication transmission in a corresponding data packet header of user plane. ### Claim 2 (depends on 1) The method according to claim 1, wherein before the CU sends the PDCP data packet to be transmitted on the radio bearer to the DU and instructs the DU to perform the PDCP duplication transmission, the method further comprises: notifying, by the CU, the DU that the radio bearer supports the PDCP duplication transmission through an F1 interface message, after determining that a radio bearer of a terminal supports PDCP duplication transmission. ### Claim 3 (depends on 2) The method according to claim 2, wherein notifying, by the CU, the DU that the radio bearer supports the PDCP duplication transmission through the F1 interface message, comprises: notifying, by the CU, the DU that the radio bearer supports the PDCP duplication transmission through the F1 interface message during a UE context setup process or a UE context update process of the terminal. ### Claim 4 A duplication transmission method, comprising: receiving, by a DU, a PDCP data packet which is sent by a CU and needs to be transmitted on a radio bearer, and information for instructing to perform PDCP duplication transmission; sending, by the DU, the PDCP data packet to a plurality of Radio Link Control, RLC, entities corresponding to the radio bearer for PDCP duplication transmission; wherein receiving, by the DU, a PDCP data packet which is sent by a CU and needs to be transmitted on a radio bearer, and information instructing the DU to perform PDCP duplication transmission, comprises: if the radio bearer is an SRB, then receiving, by the DU, the PDCP data packet which is sent by the CU and needs to be transmitted on the radio bearer through F1 control plane, and determining the information for instructing to perform PDCP duplication transmission in an Information Element, IE, of a corresponding F1 interface message; or if the radio bearer is a DRB, then receiving, by the DU, the PDCP data packet which is sent by the CU and needs to be transmitted on the radio bearer through F1 user plane, and determining the information for instructing to perform PDCP duplication transmission in a corresponding data packet header of user plane. ### Claim 5 (depends on 4) The method according to claim 4, wherein before the DU receives the PDCP data packet which is sent by the CU and needs to be transmitted on the radio bearer and the information instructing the DU to perform PDCP duplication transmission, the method further comprises: establishing, by the DU, a plurality of RLC entities and logical channels used by the PDCP duplication transmission for the radio bearer after receiving a notification of the CU that the radio bearer supports the PDCP duplication transmission through an F1 interface message. ### Claim 6 (depends on 5) The method according to claim 5, wherein after the DU receives the notification of the CU that the radio bearer supports the PDCP duplication transmission through the F1 interface message, the method further comprises: if the radio bearer is a DRB, then allocating, by the DU, a different Transport Network Layer, TNL, address for each logical channel. ### Claim 7 A duplication transmission device, comprising: a processor, a memory and a transceiver; wherein the memory stores data used by the processor when performing operations, and the transceiver is configured to receive and send data under control of the processor; wherein the processor is configured to read a program in the memory and perform: determining that PDCP duplication transmission needs to be performed on a radio bearer, sending a PDCP data packet to be transmitted on the radio bearer to a DU, and instructing the DU to perform the PDCP duplication transmission; wherein the processor is specifically configured to: if the radio bearer is an SRB, then send a PDCP data packet to be transmitted on the SRB to the DU through F1 control plane, and instruct the DU to perform the PDCP duplication transmission through an Information Element, IE, in a corresponding F1 interface message; or if the radio bearer is a DRB, then send a PDCP data packet transmitted on the DRB to the DU through F1 user plane, and instruct the DU to perform the PDCP duplication transmission in a corresponding data packet header of user plane. ### Claim 8 (depends on 7) The device according to claim 7, wherein the processor is further configured to: notify the DU that the radio bearer supports the PDCP duplication transmission through an F1 interface message after determining that a radio bearer of a terminal supports PDCP duplication transmission; notify the DU that the radio bearer supports the PDCP duplication transmission through an F1 interface message during a UE context setup process or a UE context update process. ### Claim 9 (depends on 4) A duplication transmission device, comprising: a processor, a memory and a transceiver; wherein the memory stores data used by the processor when performing operations, and the transceiver is configured to receive and send data under the control of the processor; wherein the processor is configured to read a program in the memory and perform the method according to claim 4. ### Claim 10 (depends on 9) The device according to claim 9, wherein the processor is further configured to: establish a plurality of RLC entities and logical channels used by the PDCP duplication transmission for the radio bearer after receiving a notification of the CU that the radio bearer supports the PDCP duplication transmission through an F1 interface message; allocate a different TNL address for each logical channel if the radio bearer is a DRB after receiving a notification of the CU that the radio bearer supports the PDCP duplication transmission through an F1 interface message. ### Claim 11 (depends on 4) A non-transitory computer readable storage medium storing a computer program thereon, wherein the program, when executed by a processor, implements the method comprising determining, by a Central Unit, CU, that Packet Data Convergence Protocol, PDCP, duplication transmission needs to be performed on a radio bearer; and sending, by the CU, a PDCP data packet to be transmitted on the radio bearer to a Distribute Unit, DU, and instructing the DU to perform the PDCP duplication transmission, or the method of claim 4.