Subsequent data information for small data transmission

1. A method comprising:

receiving, by a base station central unit from a base station distributed unit, assistance information indicating whether subsequent data is expected for a small data transmission (SDT) procedure of a wireless device; and

transmitting a radio resource control (RRC) release message to the wireless device based on the assistance information.

2. The method of claim 1 , wherein the transmitting the RRC release message is based on determining that the SDT procedure is complete.

3. The method of claim 1 , further comprising determining to transmit the RRC release message based on the assistance information indicating that no subsequent data is expected.

4. The method of claim 1 , further comprising determining that the SDT procedure is complete based on the assistance information indicating that no subsequent data is expected.

5. The method of claim 4 , wherein determining that the SDT procedure is complete based on:

the assistance information indicating that a single transmission or reception of subsequent data is expected; and

the single transmission or reception of subsequent data being received or transmitted.

6. The method of claim 1 , further comprising receiving, by the base station central unit from the wireless device via the base station distributed unit, uplink data associated with the SDT procedure.

7. The method of claim 1 , wherein the assistance information is based on at least one assistance parameter received from the wireless device at the base station distributed unit via at least one medium access control (MAC) control element (CE).

8. The method of claim 1 , further comprising determining to send the RRC release message based on:

the assistance information indicating that a plurality of transmissions or receptions of subsequent data are expected; and

the plurality of transmissions or receptions of subsequent data being received or transmitted.

9. The method of claim 1 , wherein the transmitting the RRC release message is based on a buffer status report of the wireless device.

10. The method of claim 9 , wherein the buffer status report indicates that an amount of the subsequent data is below a threshold data amount.

11. A base station central unit comprising one or more processors and memory storing instructions that, when executed by the one or more processors, cause the base station central unit to perform operations comprising:

receiving, from a base station distributed unit, assistance information indicating whether subsequent data is expected for a small data transmission (SDT) procedure of a wireless device; and

transmitting a radio resource control (RRC) release message to the wireless device based on the assistance information.

12. The base station central unit of claim 11 , wherein the transmitting the RRC release message is based on determining that the SDT procedure is complete.

13. The base station central unit of claim 11 , further comprising determining to transmit the RRC release message based on the assistance information indicating that no subsequent data is expected.

14. The base station central unit of claim 11 , further comprising determining that the SDT procedure is complete based on the assistance information indicating that no subsequent data is expected.

15. The base station central unit of claim 14 , wherein determining that the SDT procedure is complete based on:

the assistance information indicating that a single transmission or reception of subsequent data is expected; and

the single transmission or reception of subsequent data being received or transmitted.

16. The base station central unit of claim 11 , further comprising receiving, by the base station central unit from the wireless device via the base station distributed unit, uplink data associated with the SDT procedure.

17. The base station central unit of claim 11 , wherein the assistance information is based on at least one assistance parameter received from the wireless device at the base station distributed unit via at least one medium access control (MAC) control element (CE).

18. The base station central unit of claim 11 , further comprising determining to send the RRC release message based on:

the assistance information indicating that a plurality of transmissions or receptions of subsequent data are expected; and

the plurality of transmissions or receptions of subsequent data being received or transmitted.

19. The base station central unit of claim 11 , wherein the transmitting the RRC release message is based on a buffer status report of the wireless device.

20. A system, comprising:

a base station distributed unit comprising: one or more processors and memory storing instructions that, when executed by the one or more processors, cause the base station distributed unit to perform operations comprising:

receiving, from a wireless device, one or more parameters indicating subsequent data for a small data transmission (SDT) procedure of the wireless device;

transmitting, to a base station central unit, assistance information indicating whether subsequent data is expected for the SDT procedure;

receiving, from the base station central unit, an radio resource control (RRC) release message; and

transmitting, to the wireless device, the RRC release message; and

the base station central unit, wherein the base station central unit comprises: one or more processors and memory storing instructions that, when executed by the one or more processors, cause the base station central unit to perform operations comprising:

receiving, from the base station distributed unit, the assistance information; and

transmitting the RRC release message to the wireless device based on the assistance information.