UPF based transmission of user data for selective activation to selective activation candidate nodes
Described herein is a User Plane Function, UPF, network node, configured for data forwarding for selective activation of a Secondary Cell Group, SCG, for serving a User Equipment, UE, the UPF network node comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the UPF network node at least to: receive an indication message for starting data forwarding; and execute data forwarding on the basis of the received indication message.
1 . A User Plane Function (UPF) network node, configured for data forwarding for selective activation of a Secondary Cell Group (SCG) for serving a User Equipment (UE) the UPF network node comprising:
at least one processor, and
at least one memory storing instructions that, when executed by the at least one processor, cause the UPF network node at least to:
receive an indication message for starting data forwarding; and
execute data forwarding on the basis of the received indication message,
wherein the indication message indicates, for selective activation of a Target Primary SCG Cell (Target PSCell), for serving the UE, a candidate list comprising Candidate PSCells and Candidate Secondary Nodes (Candidate SNs), wherein the indication message further indicates a Source Secondary Node (Source SN) and the UPF network node is further caused to:
execute data forwarding directly towards the Candidate SNs and the Source SN.
2 . The UPF network node according to claim 1 , wherein the indication message indicates, for each SN of the candidate list, a Protocol Data Unit, (PDU) session related to the each SN.
3 . The UPF network node according to claim 1 , wherein the UPF network node is caused to execute data forwarding before the UE moves to a Candidate PSCell that is selected from the candidate list as the Target PSCell.
4 . The UPF network node according to claim 1 , wherein the UPF network note is caused to transmit a confirmation message for starting data forwarding, wherein the confirmation message comprises, for each SN of the candidate list, a Tunnel Endpoint Identity (TEID) of a GPRS Tunnelling Protocol (GTP) tunnel established for transmitting Protocol Data Unit (PDU) session packets related to the each SN.
5 . The UPF network node according to claim 1 , wherein the UPF network node is caused to execute data forwarding after the UE moves to a Candidate PSCell that is selected from the candidate list as the Target PSCell.
6 . A Source Master Node (Source MN) configured for data forwarding for selective activation of a Secondary Cell Group (SCG) for serving a User Equipment (UE) the Source MN node comprising:
at least one processor, and
at least one memory storing instructions that, when executed by the at least one processor, cause the Source MN at least to:
transmit, to a User Plane Function (UPF) network node, an indication message for starting data forwarding,
wherein the indication message indicates, for selective activation of a Target Primary SCG Cells (Target PSCell) for serving the UE, a candidate list comprising Candidate PSCells and Candidate Secondary Nodes (Candidate SNs), wherein the indication message further indicates a Source Secondary Node (Source SN).
7 . The Source MN according to claim 6 , wherein the indication message indicates, for each SN of the candidate list, a Protocol Data Unit (PDU) session related to the each SN.
8 . The Source MN according to claim 6 , wherein the Source MN is further caused to:
transmit a Sequence Number Status message to a Candidate SN that is selected from the candidate list as the Target SN for serving the UE, the Sequence Number Status message indicating a last sequence number of the last Protocol Data Unit, PDU session packet sent towards the UE before the UE moves to the Target PSCell.
9 . The Source MN according to claim 8 , wherein the Sequence Number Status message comprises a Tunnel Endpoint Identity (TEID) of a GPRS Tunneling Protocol (GTP) tunnel established for a corresponding PDU session, for which the last PDU Session packet with the last sequence number is received, and the Source MN is further caused to:
map the TEID of the GTP tunnel for the corresponding PDU session to a TEID of the Target SN.
10 . The Source MN according to claim 6 , wherein the Source MN is caused to transmit the indication message for starting data forwarding to the UPF network node via an Access and Mobility Management Function (AMF) network node.
11 . The Source MN according to claim 6 , wherein the Source MN is further caused to: before sending the indication message and on the basis of latency requirements of the UE, determine that data forwarding is to be carried out.
12 . A Source Secondary Node (Source SN) configured for data forwarding for selective activation of a Secondary Cell Group (SCG) for serving a User Equipment (UE) the Source SN comprising:
at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the Source SN at least to:
transmit, to a User Plane Function (UPF) network element, an indication message for starting data forwarding,
wherein the indication message indicates, for selective activation of a Target Primary SCG Cells (Target PSCell) for serving the UE, a candidate list comprising Candidate PSCells and Candidate Secondary Nodes (Candidate SNs) wherein the indication message further indicates the Source SN.
13 . The Source SN according to claim 12 , wherein the indication message indicates, for each SN of the candidate list, a Protocol Data Unit (PDU) session related to the each SN.
14 . The Source SN according to claim 12 , wherein the Source SN is further caused to:
transmit, to the Source MN, a Sequence Number Status message indicating a last sequence number of the PDU session packet sent towards the UE before the UE moves to the Target PSCell.
15 . The Source SN according to claim 12 , wherein the Source SN is further caused to: before sending the indication message and on the basis of latency requirements of the UE, determine that data forwarding is to be carried out.