# US 2021/0345205 A1 · User equipment, source access node, target access node, and methods in a wireless communications network for handling data packets in a handover > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0345205 A1 - Document ID: US20210345205A1 - Status: Published application - Kind: A1 - Application number: 17/286,546 - Filed: 2019-10-29 - Published: 2021-11-04 - Earliest claimed: 2018-11-01 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Claes-Göran PERSSON; Paul SCHLIWA-BERTLING; Johan Rune; Pontus WALLENTIN; Pradeepa RAMACHANDRA - Web page: https://patentgrep.com/patent/US20210345205A1 ## CPC - H04W 36/0011: {for data sessions of end-to-end connection} - H04W 36/0235: {by transmitting sequence numbers, e.g. SN status transfer} - H04W 36/0033: {with transfer of context information} - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method performed by a target access node for handling data packets in a handover of a User Equipment, UE, from a source cell served by a source access node, to a target cell, served by the target access node in a wireless communications network is provided. The target access node receives a status report of last received data packet in the UE from the source access node. The target access node performs a data packet duplication check based on the information comprised in the status report. The target access node then sends to the UE, only data packets which have not already been received by the UE from the source access node, based on the outcome of the duplication check. ## Claims ### Claim 1 A method performed by a target access node for handling data packets in a handover of a User Equipment, UE, from a source cell served by a source access node, to a target cell served by the target access node, in a wireless communications network, the method comprising: receiving a status report of last received data packet in the UE from the source access node; performing a data packet duplication check based on the information comprised in the status report; and sending to the UE, only data packets which have not already been received by the UE from the source access node, based on the outcome of the duplication check. ### Claim 2 (depends on 1) The method according to claim 1, further comprising: receiving a handover request message from a source access node serving the source cell, which Handover request message comprises an enhanced make-before-break, MBB, indicator; and based on the enhanced MBB indicator reserving, UL resources for a status report of last received data packet in the UE from the source access node. ### Claim 3 (canceled) ### Claim 4 (canceled) ### Claim 5 A method performed by a User Equipment, UE, for assisting a target access node to handling data packets in a handover from a source cell, served by a source access node, to a target cell served by a target access node in a wireless communications network, the method comprising: when the handover is decided, transmitting to the target access node, a status report of the last received data packet from the source access node, which status report assists the target access node to perform a data packet duplication check to avoid sending data packets to the UE in the target cell that was already sent in the source cell. ### Claim 6 (depends on 5) The method according to claim 5, further comprising: receiving a handover command from the source access node, wherein the handover command comprises an indicator instructing the UE to send to the target access node a status report of the last received data packet from the source access node. ### Claim 7 (depends on 5) The method according to claim 5, wherein the status report of the last received data packet from the source access node is transmitted as a response to a received indicator in the received handover command from the source access node. ### Claim 8 (depends on 5) The method according to claim 5, wherein the status report of the last received data packet from the source access node is transmitted one of during and immediately after a random access procedure in the target cell. ### Claim 9 (depends on 8) The method according to claim 8, wherein the status report of the last received data packet from the source access node, is comprised in any one out of: a MAC uplink control PDU and an RRC message. ### Claim 10 (depends on 5) The method according to claim 5, wherein the status report of the last received data packet from the source access node comprises the PDCP SN of the last PDCP packet received from the source access node. ### Claim at position 11 -15. (canceled) ### Claim 16 A target access node for handling data packets in a handover of a User Equipment, UE, from a source cell served by a source access node, to a target cell served by the target access node in a wireless communications network, the target access node being configured to: receive a status report of last received data packet in the UE from the source access node; perform a data packet duplication check based on the information comprised in the status report; and send to the UE, only data packets which have not already been received by the UE from the source access node, based on the outcome of the duplication check. ### Claim 17 (depends on 16) The target access node according to claim 16, further being configured to: receive a handover request message from the source access node, which Handover request message comprises an enhanced make-before-break, MBB, indicator; and based on the enhanced MBB indicator reserve UL resources for a status report of last received data packet in the UE from the source access node. ### Claim 18 A User Equipment, UE, for assisting a target access node to handling data packets in a handover from a source cell served by a source access node, to a target cell served by a target access node in a wireless communications network, the UE being configured to: when the handover is decided, transmit, to the target access node, a status report of the last received data packet from the source access node, which status report is adapted to assist the target access node to perform a data packet duplication check to avoid sending data packets to the UE in the target cell that was already sent in the source cell. ### Claim 19 (depends on 18) The UE according to claim 18, being configured to: receive a handover command from the source access node, wherein the handover command includes an indicator instructing the UE to send to the target access node a status report of the last received data packet from the source access node. ### Claim 20 (depends on 18) The UE according to claim 18, wherein the status report of the last received data packet from the source access node is adapted to be transmitted as a response to a received indicator in the received handover command from the source access node. ### Claim 21 (depends on 18) The UE (120) according to claim 18, wherein the status report of the last received data packet from the source access node is adapted to be transmitted one of during and immediately after a random access procedure in the target cell. ### Claim 22 (depends on 21) The UE according to claim 21, wherein the status report of the last received data packet from the source access node is comprised in any one out of: a MAC uplink control PDU and an RRC message. ### Claim 23 (depends on 18) The UE according to claim 18, wherein the status report of the last received data packet from the source access node is adapted to comprise the PDCP SN of the last PDCP packet received from the source access node. ### Claim 24 (canceled) ### Claim 25 (depends on 6) The method according to claim 6, wherein the status report of the last received data packet from the source access node is transmitted as a response to a received indicator in the received handover command from the source access node. ### Claim 26 (depends on 6) The method according to claim 6, wherein the status report of the last received data packet from the source access node is one of transmitted during and immediately after a random access procedure in the target cell. ### Claim 27 (depends on 26) The method according to claim 26, wherein the status report of the last received data packet from the source access node, is comprised in any one out of: a MAC uplink control PDU and an RRC message. ### Claim 28 (depends on 6) The method according to claim 6, wherein the status report of the last received data packet from the source access node comprises the PDCP SN of the last PDCP packet received from the source access node.