Methods for power-efficient transfer of small data in radio resource control connected lite mode

1. A method for wireless communication at a user equipment (UE), comprising:

transmitting, to a network device during a connection establishment procedure, a UE message in a random access procedure message, the UE message comprising an indication of support for a plurality of connected modes, wherein the plurality of connected modes comprises a first connected mode, wherein the first connected mode comprises a radio resource control connected mode free of acknowledgment feedback messaging;

receiving, based at least in part on the UE message, a configuration message from the network device configuring resources for the UE to use while operating in the first connected mode, wherein the configuration message is based at least in part on an association between the first connected mode and a small data transmission at the UE, the small data transmission satisfying a threshold data size; and

performing a grantless communication with the network device while operating in the first connected mode and using the configured resources, the grantless communication comprising the small data transmission, wherein the UE refrains from applying a feedback procedure for the small data transmission based at least in part on the radio resource control connected mode being free of the acknowledgment feedback messaging and the small data transmission satisfying the threshold data size.

2. The method of claim 1 , wherein the first connected mode is associated with grantless resource scheduling and free of at least one of a configured control channel, or mobility management, or channel performance measurement and reporting, or a combination thereof.

3. The method of claim 2 , wherein the configured control channel comprises at least one of a physical downlink control channel (PDCCH), or a physical uplink control channel (PUCCH), or a combination thereof.

4. The method of claim 1 , further comprising:

configuring the UE message to identify the first connected mode as a preferred connected mode of the UE.

5. The method of claim 1 , further comprising:

refraining from performing reference signal transmissions in conjunction with performing the grantless communication with the network device based at least in part on the UE operating in the first connected mode.

6. The method of claim 1 , further comprising:

determining, at a first protocol layer of the UE, that the grantless communication has failed in a second protocol layer of the UE; and

performing, at the first protocol layer of the UE, a retransmission of the grantless communication with the network device.

7. The method of claim 1 , further comprising:

determining that at least one of a mobility of the UE is below a first threshold, or that the UE has an amount of data below a second threshold, or a combination thereof; and

refraining from performing mobility management while operating in the first connected mode and based at least in part on the determining.

8. The method of claim 1 , further comprising:

transitioning from the first connected mode to a second connected mode based at least in part on expiry of a radio resource control (RRC) connection lease, or expiry of a data inactivity timer, or upon receipt of a signal indicating for the UE to transition from the first connected mode to the second connected mode, or a combination thereof.

9. The method of claim 1 , wherein the UE message is transmitted as part of a random access channel (RACH) message A (msgA), or a RACH message 3 (msg3), or a UE assistance information message, or a combination thereof.

10. The method of claim 1 , wherein the grantless communication comprises uplink communication, downlink communication, or a combination thereof.

11. The method of claim 1 , wherein:

the first connected mode comprises a radio resource control (RRC) inactive mode; and

the plurality of connected modes comprises an RRC connected mode, an RRC connected lite mode, the RRC inactive mode, and an RRC idle mode.

12. The method of claim 1 , wherein the configured resources comprise at least one of a semi-persistent scheduling (SPS) resources for grantless downlink communications, or a configured grant (CG) for grantless uplink communications, or a combination thereof.

13. The method of claim 1 , wherein the UE message comprises an RRC resume message of a RACH msg3.

14. The method of claim 1 , further comprising:

transmitting, to the network device, information for scheduling subsequent data transmissions comprising one or more of a buffer status report, a preferred beam index, a beam measurement report, a power headroom report, a mobility state, or a combination thereof, wherein the information for scheduling the subsequent data transmissions is transmitted in one of a RACH msg3 or a RACH message 5 (msg5).

15. The method of claim 1 , wherein one or more parameters associated with the configured resources are received in a Release-Config message.

16. A method for wireless communication at a network device, comprising:

receiving, from a user equipment (UE) during a connection establishment procedure, a UE message in a random access procedure message, the UE message comprising an indication of support for a plurality of connected modes, wherein the plurality of connected modes comprises a first connected mode, wherein the first connected mode comprises a radio resource control connected mode free of acknowledgment feedback messaging;

transmitting, based at least in part on the UE message, a configuration message to the UE configuring resources for the UE to use while operating in the first connected mode, wherein the configuration message is based at least in part on an association between the first connected mode and a small data transmission at the UE, the small data transmission satisfying a threshold data size; and

performing a grantless communication with the UE while operating in the first connected mode and using the configured resources, the grantless communication comprising the small data transmission, wherein the network device refrains from applying a feedback procedure for the small data transmission based at least in part on the radio resource control connected mode being free of the acknowledgment feedback messaging and the small data transmission satisfying the threshold data size.

17. The method of claim 16 , wherein the first connected mode is associated with grantless resource scheduling and free of at least one of a configured control channel, or mobility management, or channel performance measurement and reporting, or a combination thereof.

18. The method of claim 17 , wherein the configured control channel comprises at least one of a physical downlink control channel (PDCCH), or a physical uplink control channel (PUCCH), or a combination thereof.

19. The method of claim 16 , further comprising:

determining that the UE message identifies the first connected mode as a preferred connected mode for the UE.

20. The method of claim 16 , further comprising:

performing the grantless communication with the UE free of reference signal transmissions by the UE based at least in part on the UE operating in the first connected mode.

21. The method of claim 16 , further comprising:

determining that at least one of a mobility of the UE is below a first threshold, or that the UE has an amount of data below a second threshold, or a combination thereof; and

refraining from performing mobility management for the UE while the UE is operating in the first connected mode and based at least in part on the determining.

22. The method of claim 16 , further comprising:

transitioning the UE from the first connected mode to a second connected mode based at least in part on expiry of a radio resource control (RRC) connection lease, or expiry of a data inactivity timer, or upon receipt of a signal indicating for the UE to transition from the first connected mode to the second connected mode, or a combination thereof.

23. The method of claim 16 , wherein the UE message is transmitted as part of a random access channel (RACH) message A (msgA), or a RACH message 3 (msg3), or a UE assistance information message, or a combination thereof.

24. The method of claim 16 , wherein:

the first connected mode comprises a radio resource control (RRC) inactive mode; and

the plurality of connected modes comprises an RRC connected mode, an RRC connected lite mode, the RRC inactive mode, and an RRC idle mode.

25. The method of claim 16 , wherein the configured resources comprise at least one of a semi-persistent scheduling (SPS) resources for grantless downlink communications, or a configured grant (CG) for grantless uplink communications, or a combination thereof.

26. The method of claim 16 , wherein the UE message comprises an RRC resume message of a RACH msg3.

27. The method of claim 16 , further comprising:

receiving, from the UE, information for scheduling subsequent data transmissions comprising one or more of a buffer status report, a preferred beam index, a beam measurement report, a power headroom report, a mobility state, or a combination thereof, wherein the information for scheduling the subsequent data transmissions is transmitted in one of a RACH msg3 or a RACH message 5 (msg5).

28. The method of claim 16 , wherein one or more parameters associated with the configured resources are received in a Release-Config message.

29. An apparatus for wireless communication at a user equipment (UE), comprising:

at least one processor; and

one or more memories coupled with the at least one processor, the one or more memories storing instructions for the at least one processor to cause the UE to:

transmit, to a network device during a connection establishment procedure, a UE message in a random access procedure message, the UE message comprising an indication of support for a plurality of connected modes, wherein the plurality of connected modes comprises a first connected mode, wherein the first connected mode comprises a radio resource control connected mode free of acknowledgment feedback messaging;

receive, based at least in part on the UE message, a configuration message from the network device configuring resources for the UE to use while operating in the first connected mode, wherein the configuration message is based at least in part on an association between the first connected mode and a small data transmission at the UE, the small data transmission satisfying a threshold data size; and

perform a grantless communication with the network device while operating in the first connected mode and using the configured resources, the grantless communication comprising the small data transmission, wherein the UE refrains from applying a feedback procedure for the small data transmission based at least in part on the radio resource control connected mode being free of the acknowledgment feedback messaging and the small data transmission satisfying the threshold data size.

30. An apparatus for wireless communication at a network device, comprising:

at least one processor; and

one or more memories coupled with the at least one processor, the one or more memories storing instructions for the at least one processor to cause the network device to:

receive, from a user equipment (UE) during a connection establishment procedure, a UE message in a random access procedure message, the UE message comprising an indication of support for a plurality of connected modes, wherein the plurality of connected modes comprises a first connected mode, wherein the first connected mode comprises a radio resource control connected mode free of acknowledgment feedback messaging;

transmit, based at least in part on the UE message, a configuration message to the UE configuring resources for the UE to use while operating in the first connected mode, wherein the configuration message is based at least in part on an association between the first connected mode and a small data transmission at the UE, the small data transmission satisfying a threshold data size; and

perform a grantless communication with the UE while operating in the first connected mode and using the configured resources, the grantless communication comprising the small data transmission, wherein the network device refrains from applying a feedback procedure for the small data transmission based at least in part on the radio resource control connected mode being free of the acknowledgment feedback messaging and the small data transmission satisfying the threshold data size.