3GPP 24.501 v20.0.0 — the document's own text
9.11.3.18B CIoT small data container
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
This information element is used to encapsulate the CIoT user data, SMS, or location services message with a size that is not more than 254 octets between the UE and the AMF when the UE is using control plane CIoT 5GS optimization. The CIoT small data container information element is coded as shown in figure 9.11.3.18B.1, figure 9.11.3.18B.2, figure 9.11.3.18B.3, figure 9.11.3.18B.4 and table 9.11.3.18B.1.
The CIoT small data container is a type 4 information element with a minimum length of 4 octets and a maximum length of 257 octets.
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
|---|---|---|---|---|---|---|---|---|
| CIoT small data container IEI | octet 1 | |||||||
| Length of CIoT small data container contents | octet 2 | |||||||
| octet 3 | ||||||||
| CIoT small data container contents | ||||||||
| octet 257 |
Figure 9.11.3.18B.1: CIoT small data container information element
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
|---|---|---|---|---|---|---|---|---|
| Data type | DDX | PDU session identity | octet 3 | |||||
| Data contents | octet 4octet 257 |
Figure 9.11.3.18B.2: CIoT small data container contents for Data type "Control plane user data"
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
|---|---|---|---|---|---|---|---|---|
| Data type | DDX | 0Spare | 0Spare | 0Spare | octet 3 | |||
| Length of additional information | octet 4 | |||||||
| Additional information | octet 5*octet m* | |||||||
| Data contents | octet m+1octet n |
Figure 9.11.3.18B.3: CIoT small data container contents for Data type "Location services message container"
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
|---|---|---|---|---|---|---|---|---|
| Data type | Spare | octet 3 | ||||||
| Data contents | octet 4octet n |
Figure 9.11.3.18B.4: CIoT small data container contents for Data type "SMS"
Table 9.11.3.18B.1: CIoT small data container information element
| CIoT small data container contents (octet 3 to octet 257) | ||||
|---|---|---|---|---|
| These octets include user data to be delivered between UE and AMF. | ||||
| Data type (octet 3, bits 6 to 8)Bits | ||||
| 8 | 7 | 6 | ||
| 0 | 0 | 0 | Control plane user data | |
| 0 | 0 | 1 | SMS | |
| 0 | 1 | 0 | Location services message container | |
| All other values are spare. If received they shall be ignored. | ||||
| When the Data type is "Control plane user data ", the PDU session identity and Downlink data expected (DDX) fields are encoded as follows: | ||||
| PDU session identity (octet 3, bits 1 to 4)Bit | ||||
| 3 | 2 | 1 | ||
| 0 | 0 | 0 | No PDU session identity assigned | |
| 0 | 0 | 1 | PDU session identity value 1 | |
| 0 | 1 | 0 | PDU session identity value 2 | |
| 0 | 1 | 1 | PDU session identity value 3 | |
| 1 | 0 | 0 | PDU session identity value 4 | |
| 1 | 0 | 1 | PDU session identity value 5 | |
| 1 | 1 | 0 | PDU session identity value 6 | |
| 1 | 1 | 1 | PDU session identity value 7 | |
| Downlink data expected (DDX) (octet 3, bits 5 to 6) | ||||
| Bits | ||||
| 5 | 4 | |||
| 0 | 0 | No information available | ||
| 0 | 1 | No further uplink and no further downlink data transmission subsequent to the uplink data transmission is expected | ||
| 1 | 0 | Only a single downlink data transmission and no further uplink data transmission subsequent to the uplink data transmission is expected | ||
| 1 | 1 | reserved | ||
| NOTE: The DDX field is only used in the UE to network direction. | ||||
| Data contents (octet 4 to octet 257)This field contains the control plane user data. | ||||
| When the Data type is "SMS", Bits 1 to 5 of octet 3 are spare and shall be coded as zero. | ||||
| Data contents (octet 4 to octet 257)This field contains an SMS message.When the Data type is "Location services message container":Downlink data expected (DDX) (octet 3, bits 5 to 4)This field is encoded as described above for the case when the Data type is "Control plane user data".Bits 3 to 1 of octet 3 are spare and shall be encoded as zero.Length of Additional information (octet 4) (see NOTE)Indicates the length, in octets, of the Additional information field.Additional information (octets 5 to m)Contains additional information if provided by the upper layer location services application.Data contents (octets m+1 to n)Contains the location services message payload. | ||||
| NOTE: The Length of Additional information shall be set to zero if the upper layer location service application does not provide routing information. |