Control plane data transmission
A session management function (SMF) receives a first message from an access and mobility management function (AMF). The first message indicates a request to configure a first session for a wireless device via the SMF and the AMF. The first message comprises: a first identifier of the first session; and a parameter indicating data transfer over control plane. the SMF selects a user plane function (UPF) based on the first message. The SMF sends a second message to the UPF to indicate a request to configure a second session between the SMF and the UPF. The second message comprises: a second identifier of the second session; and the parameter indicating data transfer over control plane. The SMF receives uplink data from the AMF via the first session and sends the uplink data to the UPF via the second session.
1. A method comprising:
receiving, by a session management function (SMF) from an access and mobility management function (AMF), a first message indicating a request to configure a first session for a wireless device, the first message comprising:
a first identifier of the first session; and
a cellular internet-of-things (IoT) optimization indication parameter indicating transfer of uplink data for cellular IoT over a control plane;
selecting, by the SMF and based on the first message, a user plane function (UPF);
sending, by the SMF to the UPF, a second message indicating a request to configure a second session between the SMF and the UPF, the second message comprising a second identifier of the second session;
receiving, by the SMF from the AMF, the uplink data for cellular IoT via the first session; and
sending, by the SMF to the UPF, the uplink data for cellular IoT via the second session.
2. The method of claim 1 , wherein the first message comprises at least one of:
an identifier of the SMF; and
an address of the SMF.
3. The method of claim 1 , wherein the first message comprises at least one of:
an identifier of the AMF; and
an address of the AMF.
4. The method of claim 1 , wherein the second message comprises at least one of:
an identifier of the SMF; and
an address of the SMF.
5. The method of claim 1 , wherein the second message comprises at least one of:
an identifier of the UPF; and
an address of the UPF.
6. The method of claim 1 , further comprising:
selecting, by the SMF, the UPF, based on a capability requirement; and
determining an identifier of the UPF.
7. The method of claim 1 , further comprising:
receiving by the SMF from the UPF, a second response message indicating an acceptance for configuration of the second session; and
sending by the SMF to the AMF, a first response message indicating an acceptance for configuration of the first session.
8. The method of claim 1 , further comprising:
receiving, by the SMF from the UPF, a first acknowledgment message indicating receipt of the uplink data via the second session; and
sending by the SMF to the AMF, a second acknowledgment message indicating receipt of the uplink data via the first session.
9. The method of claim 1 , further comprising receiving by the AMF from the wireless device, a first non-access stratum (NAS) message indicating a request for data transmission over the control plane.
10. The method of claim 9 , wherein the first NAS message comprises the uplink data.
11. The method of claim 1 , further comprising:
receiving, by the SMF from the UPF, a third message indicating a request to configure a third session for transmission of downlink data, the third message comprising an identifier of the third session; and
sending, by the SMF to the AMF a fourth message indicating a request to configure a fourth session for transmission of the downlink data, the fourth message comprising an identifier of the fourth session.
12. The method of claim 11 , further comprising:
receiving, by the SMF from the UPF, the downlink data; and
sending, by the SMF to the AMF, the downlink data.
13. The method of claim 12 , further comprising:
receiving, by the SMF from the UPF, a downlink data notification;
sending, by the SMF to the AMF, the downlink data notification; and
sending, by the AMF to a base station and in response to receiving the downlink data notification, a paging request for the wireless device.
14. The method of claim 12 , further comprising sending by the AMF to the wireless device, the downlink data via a non access stratum (NAS) message.
15. The method of claim 11 , wherein the identifier of the third session is the identifier of the second session.
16. The method of claim 11 , wherein the identifier of the fourth session is the identifier of the first session.
17. The method of claim 1 , further comprising:
receiving, by the AMF from the wireless device, a request to establish a non-access stratum (NAS) connection via a base station, the request indicating that the NAS connection is for data transmission over the control plane.
18. The method of claim 17 , further comprising receiving, by the AMF from the wireless device, a NAS message comprising:
uplink data; and
an indicator for data transmission over the control plane.
19. The method of claim 1 , further comprising receiving by the SMF from the wireless device, a second NAS message indicating a request for data transmission over the control plane.
20. The method of claim 19 , wherein the second NAS message comprises the uplink data.