Small data transfer over configured grants for asynchronous non-orthogonal multiple access

1. A method for wireless communications performed by a user equipment (UE), comprising:

obtaining, from a base station (BS), parameters and a grant of transmission resources for asynchronous non-orthogonal multiple access (A-NOMA) transmissions based on a multiple access (MA) signature of the UE;

obtaining data for transmission to the BS; and

transmitting the data in an A-NOMA transmission via the transmission resources according to the parameters while the UE is in a radio resource control (RRC) Inactive mode, wherein transmitting the data in the A-NOMA comprises indicating in the A-NOMA transmission that the data is a first part of a small data transfer (SDT).

2. The method of claim 1 , wherein obtaining the grant and the parameters comprises:

receiving the grant and the parameters in a release configuration (Release-Config) message that orders the UE to enter the RRC Inactive mode.

3. The method of claim 1 , wherein obtaining the grant and the parameters comprises:

receiving a range for a first parameter of the parameters in a system information (SI) broadcast from the BS; and

determining the first parameter from the range based on the MA signature of the UE.

4. The method of claim 3 , further comprising:

selecting the MA signature from a pool of MA signatures in the SI broadcast.

5. The method of claim 4 , wherein selecting the MA signature comprises selecting the MA signature from the pool based on at least one of a globally unique identifier (GUID) of the UE, a cell radio network temporary identifier (C-RNTI) of the UE, or a Resume-ID assigned to the UE by the BS.

6. The method of claim 3 , further comprising:

generating the MA signature based on an identifier (ID) of the UE, wherein the ID comprises at least one of a globally unique identifier (GUID) of the UE, a cell radio network temporary identifier (C-RNTI) of the UE, or a Resume-ID assigned to the UE by the BS.

7. The method of claim 1 , further comprising:

determining, based on an estimated latency for transmitting the data, to not perform a random access channel (RACH) procedure.

8. The method of claim 1 , wherein transmitting the data via the A-NOMA transmission comprises scrambling the transmission based on a cell radio network temporary identifier (C-RNTI) of the UE.

9. The method of claim 1 , further comprising:

receiving, from the BS and in response to the A-NOMA transmission, an order to enter an RRC connected mode;

entering the RRC connected mode; and

transmitting a second part of the SDT to the BS after entering the RRC connected mode.

10. The method of claim 1 , further comprising:

receiving, in response to the A-NOMA transmission, a dynamic uplink (UL) grant from the BS; and

transmitting a second part of the SDT via transmission resources of the dynamic UL grant while the UE is in the RRC Inactive mode.

11. The method of claim 1 , further comprising:

determining, based on the UE not receiving a response from the BS, to transmit a second part of the SDT via another A-NOMA transmission.

12. A method for wireless communications performed by a base station (BS), comprising:

transmitting, to a user equipment (UE), parameters and a grant of transmission resources for asynchronous non-orthogonal multiple access (A-NOMA) transmissions based on a multiple access (MA) signature of the UE; and

receiving data in an A-NOMA transmission via the transmission resources according to the parameters from the UE that is in a radio resource control (RRC) Inactive mode, wherein receiving data in an A-NOMA transmission comprises receiving an indication in the A-NOMA transmission that the data is a first part of a small data transfer (SDT).

13. The method of claim 12 , wherein transmitting the grant and the parameters comprises:

transmitting the grant and the parameters in a release configuration (Release-Config) message that orders the UE to enter the RRC Inactive mode.

14. The method of claim 12 , wherein:

transmitting the grant and the parameters comprises:

transmitting a range for a first parameter of the parameters in a system information (SI) broadcast; and

receiving the data comprises:

determining the first parameter from the range based on the MA signature of the UE.

15. The method of claim 14 , further comprising:

transmitting a pool of MA signatures in the SI broadcast.

16. The method of claim 14 , further comprising:

determining the MA signature based on an identifier (ID) of the UE, wherein the ID comprises at least one of a globally unique identifier (GUID) of the UE, a cell radio network temporary identifier (C-RNTI) of the UE, or a Resume-ID assigned to the UE by the BS.

17. The method of claim 12 , wherein receiving the data via the A-NOMA transmission comprises determining the UE based on descrambling the A-NOMA transmission based on a cell radio network temporary identifier (C-RNTI) of the UE.

18. The method of claim 12 , further comprising:

determining, based on the indication in the A-NOMA transmission, that the data is the first part of the SDT;

transmitting, to the UE and in response to the A-NOMA transmission, an order to enter an RRC connected mode; and

receiving a second part of the SDT from the UE in the RRC connected mode.

19. The method of claim 12 , further comprising:

determining, based on the indication in the A-NOMA transmission, that the data is the first part of the SDT;

transmitting, in response to the A-NOMA transmission, a dynamic uplink (UL) grant to the UE; and

receiving a second part of the SDT via transmission resources of the dynamic UL grant from the UE in the RRC Inactive mode.

20. The method of claim 12 , further comprising:

determining, based on the indication in the A-NOMA transmission, that the data is the first part of the SDT; and

receiving a second part of the SDT via another A-NOMA transmission.

21. An apparatus for wireless communications, comprising:

a processor configured to:

obtain, from a base station (BS), parameters and a grant of transmission resources for asynchronous non-orthogonal multiple access (A-NOMA) transmissions based on a multiple access (MA) signature of the apparatus;

obtain data for transmission to the BS; and

transmit the data in an A-NOMA transmission via the transmission resources according to the parameters while the apparatus is in a radio resource control (RRC) Inactive mode, wherein, in order to transmit the data in the A-NOMA transmission, the processor is further configured to indicate in the A-NOMA transmission that the data is a first part of a small data transfer (SDT); and

a memory coupled with the processor.

22. The apparatus of claim 21 , wherein the processor is configured to obtain the grant and the parameters by receiving the grant and the parameters in a release configuration (Release-Config) message that orders the apparatus to enter the RRC Inactive mode.

23. The apparatus of claim 21 , wherein the processor is configured to obtain the grant and the parameters by:

receiving a range for a first parameter of the parameters in a system information (SI) broadcast from the BS; and

determining the first parameter from the range based on the MA signature of the apparatus.

24. The apparatus of claim 23 , wherein the processor is further configured to:

select the MA signature from a pool of MA signatures in the SI broadcast.

25. The apparatus of claim 21 , wherein the processor is further configured to:

determine, based on an estimated latency for transmitting the data, to not perform a random access channel (RACH) procedure.

26. The apparatus of claim 21 , wherein the processor is configured to transmit the data via the A-NOMA transmission by scrambling the transmission based on a cell radio network temporary identifier (C-RNTI) of the apparatus.

27. The apparatus of claim 21 , wherein the processor is further configured to:

receive, from the BS and in response to the A-NOMA transmission, an order to enter an RRC connected mode;

enter the RRC connected mode; and

transmit a second part of the SDT to the BS after entering the RRC connected mode.

28. The apparatus of claim 21 , wherein the processor is further configured to:

receive, in response to the A-NOMA transmission, a dynamic uplink (UL) grant from the BS; and

transmit a second part of the SDT via transmission resources of the dynamic UL grant while the apparatus is in the RRC Inactive mode.

29. The apparatus of claim 21 , wherein the processor is further configured to:

determine, based on the apparatus not receiving a response from the BS, to transmit a second part of the SDT via another A-NOMA transmission.

30. An apparatus for wireless communications, comprising:

a processor configured to:

transmit, to a user equipment (UE), parameters and a grant of transmission resources for asynchronous non-orthogonal multiple access (A-NOMA) transmissions based on a multiple access (MA) signature of the UE; and

receive data in an A-NOMA transmission via the transmission resources according to the parameters from the UE that is in a radio resource control (RRC) Inactive mode, wherein, in order to receive the data, the processor is further configured to receive an indication in the A-NOMA transmission that the data is a first part of a small data transfer (SDT); and

a memory coupled with the processor.