5.6.1.2.2 UE is using 5GS services with control plane CIoT 5GS optimization

The UE shall send a CONTROL PLANE SERVICE REQUEST message, start T3517 and enter the state 5GMM-SERVICE-REQUEST-INITIATED.

For case a), and case b) in clause 5.6.1.1, the Control plane service type of the CONTROL PLANE SERVICE REQUEST message shall indicate "mobile terminating request". If:

• the UE only has uplink CIoT user data or SMS to be sent, the UE shall:
• if the data size is not more than 254 octets and there is no other optional IE to be included in the message:
• for sending CIoT user data, set the Data type field to "control plane user data", include the PDU session ID, data, and Downlink data expected (DDX) (if available), in the CIoT small data container IE; and
• for sending SMS, set the Data type field to "SMS", include SMS in the CIoT small data container IE; and
• otherwise if the data size is more than 254 octets or there are other optional IEs to be included in the message:
• for sending CIoT user data, set the Payload container type IE to "CIoT user data container", include the PDU session ID in the PDU session ID IE and include data in the Payload container IE as described in clause 5.4.5.2.2; and
• for sending SMS, set the Payload container type IE to "SMS" and include data in the Payload container IE as described in clause 5.4.5.2.2; and
• the paging request or the notification includes an indication for non-3GPP access type, the UE has at least one PDU session that is not associated with control plane only indication, the Allowed PDU session status IE shall be included in the CONTROL PLANE SERVICE REQUEST message. If the UE is in a non-allowed area or the UE is not in an allowed area, the UE shall set the Allowed PDU session status IE as specified in clause 5.3.5.2. If the UE has PDU session(s) over non-3GPP access where:
• the associated S-NSSAI(s) are included in the allowed NSSAI for 3GPP access or the partially allowed NSSAI for 3GPP access and the current TAI is in the list of TAs for which the S-NSSAI is allowed; and
• the UE is currently located inside the NS-AoS of the S-NSSAI, if the S-NSSAI location validity information is available,

the UE shall indicate the PDU session(s) for which the UE allows the user-plane resources to be re-established over 3GPP access in the Allowed PDU session status IE; otherwise, the UE shall not indicate any PDU session(s) in the Allowed PDU session status IE.

NOTE 1: The term DDX used in the present document corresponds to the term NAS RAI used in 3GPP TS 23.502 [9].

For case c), and case d), when the UE is located outside the LADN service area, the UE shall not perform the service request procedure to send CIoT user data via the control plane for a PDU session for LADN.

For case c), and case d) if the UE has pending CIoT user data that is to be sent via the control plane in clause 5.6.1.1, the UE shall set the Control plane service type of the CONTROL PLANE SERVICE REQUEST message to "mobile originating request". If the UE has only uplink CIoT user data, SMS or location services message to be sent, the UE shall:

• if the data size is not more than 254 octets, there is no other optional IE to be included in the CONTROL PLANE SERVICE REQUEST message, and the data being sent is:
• CIoT user data, set the Data type field to "control plane user data", include the PDU session ID, data, and Downlink data expected (DDX) (if available), in the CIoT small data container IE;
• location services message, set the Data type field to "Location services message container" and Downlink data expected (DDX), if available, in the CIoT small data container IE, and:
• if routing information is provided by upper layers:

A) set the length of additional information field in the CIoT small data container IE to the length of routing information provided by upper layer location services application (see clause 9.11.3.18B), and set the additional information field in the CIoT small data container IE to the routing information provided by upper layer location services application (see clause 9.11.3.18B); or

B) otherwise set the length of additional information field in the CIoT small data container IE to zero. In this case the Additional information field of the CIoT small data container IE shall not be included; and

• set the Data contents field of the CIoT small data container IE to the location services message payload; or
• SMS, set the Data type field to "SMS", include SMS in the CIoT small data container IE; or
• otherwise if the data size is more than 254 octets or there are other optional IEs to be included in the CONTROL PLANE SERVICE REQUEST message, and the data being sent is:
• CIoT user data, set the Payload container type IE to "CIoT user data container", include the PDU session ID in the PDU session ID IE and include data in the Payload container IE as described in clause 5.4.5.2.2;
• location services message, set the Payload container type IE to "Location services message container", include data in the Payload container IE as described in clause 5.4.5.2.2. If the upper layer location services application provides the routing information set the Additional information IE to the routing information as described in clause 5.4.5.2.2; or
• SMS, set the Payload container type IE to "SMS" and include data in the Payload container IE as described in clause 5.4.5.2.2.

For case a), and case b) in clause 5.6.1.1, if the UE has pending user data that is to be sent via the user plane, the UE shall set the Control plane service type of the CONTROL PLANE SERVICE REQUEST message to "mobile terminating request". The UE shall include the Uplink data status IE in the CONTROL PLANE SERVICE REQUEST message to indicate which PDU session(s) have pending user data to be sent via user-plane resources.

For case c) in clause 5.6.1.1, if the UE is in WB-N1 mode and the CONTROL PLANE SERVICE REQUEST message is triggered by a request for emergency services from the upper layer, the UE shall set the Control plane service type of the CONTROL PLANE SERVICE REQUEST message to "emergency services".

For cases d) and k), if the UE has pending user data that is to be sent via the user plane in clause 5.6.1.1:

• and if there exists an emergency PDU session which is indicated in the Uplink data status IE, the UE shall set the Control plane service type of the CONTROL PLANE SERVICE REQUEST message to "emergency services"; or
• otherwise, the UE shall set the Control plane service type to "mobile originating request".

The UE shall include the Uplink data status IE in the CONTROL PLANE SERVICE REQUEST message to indicate which PDU session(s) have pending user data to be sent via user-plane resources or are associated with active multicast MBS session(s).

NOTE 2: For a UE in NB-N1 mode, the Uplink data status IE cannot be used to request the establishment of user-plane resources such that there will be user-plane resources established for a number of PDU sessions that exceeds the UE's maximum number of supported user-plane resources.

For case h) in clause 5.6.1.1, if the UE is in WB-N1 mode and the UE does not have any PDU session that is associated with control plane only indication, the UE shall send a CONTROL PLANE SERVICE REQUEST message with the Control plane service type set to "emergency services fallback" and without an Uplink data status IE.

For case i) in clause 5.6.1.1, the Control plane service type of the CONTROL PLANE SERVICE REQUEST message shall indicate "mobile originating request". If the pending message is an UL NAS TRANSPORT message with the Payload container type IE set to:

• "SMS", "Location services message container", or "CIoT user data container", the UE shall send the CONTROL PLANE SERVICE REQUEST and include the SMS, location services message, or CIoT user data as described in this clause; or
• otherwise, the UE shall send the CONTROL PLANE SERVICE REQUEST:
• without including the CIoT small data container IE and without including the NAS message container IE if the UE has no other optional IE to be sent; or
• with the NAS message container IE if the UE has an optional IE to be sent as described in this clause.

For case j) in clause 5.6.1.1, the Control plane service type of the CONTROL PLANE SERVICE REQUEST message shall indicate "mobile originating request". The UE shall include the Uplink data status IE in the CONTROL PLANE SERVICE REQUEST message indicating the PDU session(s) for which user-plane resources were active prior to receiving the fallback indication, if any.

For cases o) and p) in clause 5.6.1.1, the UE shall not include the Uplink data status IE and the Allowed PDU session status IE in the CONTROL PLANE SERVICE REQUEST message. Further,

• for case o) in clause 5.6.1.1, the UE shall set Request type to "NAS signalling connection release" in the UE request type IE and Control plane service type to "mobile originating request";
• for case p) in clause 5.6.1.1, the UE shall set Request type to "Rejection of paging" in the UE request type IE and Control plane service type to "mobile terminating request"; and

may include its paging restriction preferences in the Paging restriction IE in the CONTROL PLANE SERVICE REQUEST message.

For case m) in clause 5.6.1.1, the Control plane service type of the CONTROL PLANE SERVICE REQUEST message shall indicate "mobile originating request". The UE shall not include the Paging restriction IE in the CONTROL PLANE SERVICE REQUEST message. The UE may include the UE request type IE and set Request type to "NAS signalling connection release" to remove the paging restriction and request the release of the NAS signalling connection at the same time. If the UE requests the release of the NAS signalling connection, the UE shall not include the Uplink data status IE in the SERVICE REQUEST message. For all cases, if the UE includes the Uplink data status IE and the UE is located outside the LADN service area of a PDU session, the UE shall not include the PDU session for LADN in the Uplink data status IE.

If the UE is in a non-allowed area or the UE is not in an allowed area, the UE shall apply the restrictions for the inclusion of the Uplink data status IE specified in clause 5.3.5.2.

The UE may include the PDU session status IE in the CONTROL PLANE SERVICE REQUEST message to indicate which PDU session(s) associated with the access type the CONTROL PLANE SERVICE REQUEST message is sent over are active in the UE.