Multi access packet/protocol data unit session

1. A method comprising:

receiving, by a session management function (SMF) from a user plane function (UPF), a data notification message for a multi access (MA) packet data unit (PDU) session associated with multiple tunnels between multiple access network types and a PDU session anchor; and

sending, by the SMF to an access and mobility management function (AMF), a first request to activate user plane resources of an access network type from among the multiple access network types of the MA PDU session, wherein the first request comprises an indication of the access network type, from among the multiple access network types.

2. The method of claim 1 , further comprising receiving, by the SMF from the AMF, a second request to establish the MA PDU session.

3. The method of claim 2 , further comprising sending, by the SMF to a network repository function (NRF), a third request for discovery of one or more UPFs that support access traffic steering, switching and splitting (ATSSS) for the MA PDU session, the third request comprising an ATSSS capability indicator.

4. The method of claim 3 , further comprising receiving, by the SMF from the NRF and based on the third request, an identifier of the UPF from among the one or more UPFs that support ATSSS for the MA PDU session.

5. The method of claim 4 , further comprising sending, by the SMF to the UPF, a fourth request to establish the MA PDU session.

6. The method of claim 1 , further comprising sending, by the SMF to the UPF, a packet detection rule (PDR) comprising packet detection information, wherein the packet detection information comprises an access network information for the MA PDU session.

7. The method of claim 6 , wherein the SMF sends to the UPF the PDR in response to receiving an access traffic steering, switching and splitting (ATSSS) rule from a policy and charging control function node.

8. The method of claim 1 , wherein the data notification message comprises:

access information associated with the MA PDU session, wherein the access information comprises the access network type; and

an identifier of a session between the SMF and the UPF associated with the MA PDU session.

9. The method of claim 8 , further comprising determining by the SMF to activate the MA PDU session based on the data notification message.

10. The method of claim 9 , wherein the first request to activate the user plane resources is sent by the SMF to the AMF in response to the determining.

11. The method of claim 1 , wherein the MA PDU session comprises one or more PDU sessions associated with one or more access network types.

12. The method of claim 1 , wherein the multiple access network types comprise:

a third generation partnership project (3GPP) access network; and

a non-3GPP access network.

13. A session management function (SMF) comprising:

one or more processors; and

memory storing instructions that, when executed by the one or more processors, cause the SMF to:

receive, from a user plane function (UPF), a data notification message for a multi access (MA) packet data unit (PDU) session associated with multiple tunnels between multiple access network types and a PDU session anchor; and

send, to an access and mobility management function (AMF), a first request to activate user plane resources of an access network type from among the multiple access network types of the MA PDU session, wherein the first request comprises an indication of the access network type, from among the multiple access network types.

14. The SMF of claim 13 , wherein the instructions further cause the SMF to receive, from the AMF, a second request to establish the MA PDU session.

15. The SMF of claim 14 , wherein the instructions further cause the SMF to send, to a network repository function (NRF), a third request for discovery of one or more UPFs that support access traffic steering, switching and splitting (ATSSS) for the MA PDU session, the third request comprising an ATSSS capability indicator.

16. The SMF of claim 15 , wherein the instructions further cause the SMF to receive, from the NRF and based on the third request, an identifier of the UPF from among the one or more UPFs that support ATSSS for the MA PDU session.

17. The SMF of claim 16 , wherein the instructions further cause the SMF to send, to the UPF, a fourth request to establish the MA PDU session.

18. The SMF of claim 13 , wherein the instructions further cause the SMF to send, to the UPF, a packet detection rule (PDR) comprising packet detection information, wherein the packet detection information comprises an access network information for the MA PDU session.

19. The SMF of claim 18 , wherein the PDR is sent in response to receiving an access traffic steering, switching and splitting (ATSSS) rule from a policy and charging control function node.

20. A system, comprising:

a session management function (SMF) comprising:

one or more processors; and

memory storing instructions that, when executed by the one or more processors of the SMF, cause the SMF to:

receive, from a user plane function (UPF), a data notification message for a multi access (MA) packet data unit (PDU) session associated with multiple tunnels between multiple access network types and a PDU session anchor; and

send, to an access and mobility management function (AMF), a first request to activate user plane resources of an access network type from among the multiple access network types of the MA PDU session, wherein the first request comprises an indication of the access network type, from among the multiple access network types.