Feedback for multicast transmissions while in an inactive or idle mode

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

receiving, from a base station, one or more configurations for the UE to use, while in an inactive mode or an idle mode, to provide feedback associated with multicast transmissions from the base station;

monitoring, while in the inactive mode or the idle mode, a set of time frequency resources configured for the multicast transmissions from the base station;

transmitting, while in the inactive mode or the idle mode, one or more multicast feedback messages in accordance with the one or more configurations based at least in part on the monitoring; and

transmitting a reception status report that indicates a ratio of a quantity of received physical control channels for the multicast transmissions to a total quantity of physical control channels for the multicast transmissions scheduled over a set of monitoring occasions, the reception status report being transmitted on a set of uplink resources associated with the ratio.

2. The method of claim 1 , further comprising determining a set of random access channel resources available for multicast feedback based at least in part on a resource allocation indicated by the one or more configurations, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages via the set of random access channel resources.

3. The method of claim 1 , further comprising:

determining a set of random access channel preambles available for multicast feedback based at least in part on a resource allocation indicated by the one or more configurations; and

selecting a preamble of the set of random access channel preambles, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using the selected preamble.

4. The method of claim 3 , further comprising receiving a multicast message over the set of time frequency resources based at least in part on the monitoring, wherein selecting the preamble of the set of random access channel preambles comprises selecting the preamble based at least in part on a channel quality metric associated with the received multicast message.

5. The method of claim 1 , further comprising:

receiving a multicast message over the set of time frequency resources based at least in part on the monitoring;

transmitting channel quality information associated with the received multicast message, wherein the channel quality information comprises one or more of reference signal received power, beam direction, beam width, geographical location, or altitude and azimuth values associated with one or more beams; and

determining time frequency resources for multicast feedback based at least in part on the channel quality information, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages via the determined time frequency resources.

6. The method of claim 1 , further comprising determining a resource pool available for multicast feedback based at least in part on the one or more configurations, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using a subset of time frequency resources of the resource pool.

7. The method of claim 1 , further comprising determining a set of physical uplink control channel resources available for multicast feedback based at least in part on the one or more configurations, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using a subset of the physical uplink control channel resources.

8. The method of claim 7 , further comprising:

determining an uplink control format for the one or more multicast feedback messages; and

padding a payload of the one or more multicast feedback messages based at least in part on a size associated with the uplink control format.

9. The method of claim 1 , further comprising receiving a timing advance command from the base station, the timing advance command indicating a timing advance for the UE to use while in the inactive mode or the idle mode, wherein the timing advance command corresponds to first set of values for one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE.

10. The method of claim 9 , further comprising receiving a second timing advance command from the base station, the second timing advance command indicating a second timing advance for the UE to use while in the inactive mode or the idle mode, wherein the second timing advance command corresponds to second set of values for one or more channel metrics associated with the UE and associated with one or more cells including the serving cell for the UE.

11. The method of claim 10 , further comprising measuring a set of channel metrics of the one or more cells including the serving cell, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using the timing advance based at least in part on the set of channel metrics satisfying the first set of values or using the second timing advance based at least in part on the set of channel metrics satisfying the second set of values.

12. The method of claim 10 , wherein the one or more channel metrics comprise one or more of a reference signal received power, a relative delay between the serving cell and one or more other cells, or a positioning range of the UE.

13. The method of claim 10 , further comprising receiving one or more of the timing advance command or the second timing advance command in the one or more configurations, the one or more configurations indicating a set of uplink resources for multicast feedback, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using the set of uplink resources.

14. The method of claim 9 , further comprising receiving a set of neural network parameters in the timing advance command from the base station, wherein the set of neural network parameters indicate the timing advance.

15. The method of claim 1 , further comprising:

receiving, at the UE while in a connected mode, a neural network model and a set of neural network parameters from the base station, the neural network model and the set of neural network parameters being associated with a neural network for a timing advance;

receiving one or more neural network parameters from the base station; and

determining the timing advance based at least in part on the neural network model, the set of neural network parameters, and the one or more neural network parameters, wherein transmitting the one or more multicast feedback messages comprises transmitting, by the UE while in the inactive mode or the idle mode, the one or more multicast feedback messages based at least in part on the timing advance.

16. The method of claim 1 , further comprising:

receiving a broadcast message from the base station indicating a counting duration for a service of the multicast transmissions supported by the base station; and

transmitting a service request message over the counting duration requesting the service of the multicast transmissions supported by the base station based at least in part on an identifier of the UE.

17. The method of claim 16 , further comprising receiving, from the base station, a probability indicator for the UE, wherein transmitting the service request message comprises transmitting the message in accordance with the probability indicator.

18. A method for wireless communications at a base station, comprising:

transmitting, to a user equipment (UE), one or more configurations for multicast feedback for use by the UE while in an inactive mode or an idle mode;

transmitting one or more multicast transmissions via a set of time frequency resources configured for multicast communications; and

monitoring, based at least in part on transmitting the one or more multicast transmissions, for one or more multicast feedback messages from the UE in accordance with the one or more configurations; and

receiving a reception status report from the UE that indicates a ratio of a quantity of physical control channels received by the UE for the multicast transmissions to a total quantity of physical control channels for the multicast transmissions scheduled over a set of monitoring occasions, the reception status report being received on a set of uplink resources associated with the ratio.

19. The method of claim 18 , further comprising:

transmitting an indication of a set of random access channel resources available for multicast feedback in the one or more configurations; and

monitoring the set of random access channel resources for the one or more multicast feedback messages.

20. The method of claim 18 , further comprising:

transmitting an indication of a set of random access channel preambles available for multicast feedback in the one or more configurations; and

monitoring for the one or more multicast feedback messages based at least in part on the set of random access channel preambles.

21. The method of claim 18 , further comprising:

receiving, from the UE, channel quality information associated with a multicast channel used for multicast communications with the UE, wherein the channel quality information comprises one or more of reference signal received power, beam direction, beam width, geographical location, or altitude and azimuth values associated with one or more beams;

determining a resource pool for multicast feedback for the UE based at least in part on the channel quality information; and

transmitting an indication of the resource pool in the one or more configurations.

22. The method of claim 21 , further comprising receiving the one or more multicast feedback messages via a subset of time frequency resources of the resource pool based at least in part on the monitoring.

23. The method of claim 18 , further comprising:

transmitting an indication of a set of physical uplink control channel resources available for multicast feedback in the one or more configurations; and

monitoring the set of physical uplink control channel resources for the one or more multicast feedback messages.

24. The method of claim 18 , further comprising transmitting a timing advance command to the UE, the timing advance command indicating a timing advance for the UE to use while in the inactive mode or the idle mode, wherein the timing advance command corresponds to first set of values for one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE.

25. The method of claim 24 , further comprising transmitting a second timing advance command to the UE, the second timing advance command indicating a second timing advance for the UE to use while in the inactive mode or the idle mode, wherein the second timing advance command corresponds to second set of values for one or more channel metrics associated with the UE and associated with one or more cells including the serving cell for the UE.

26. The method of claim 25 , further comprising receiving, based at least in part on the monitoring, the one or more multicast feedback messages according to the timing advance based at least in part on a set of channel metrics at the UE satisfying the first set of values or according to the second timing advance based at least in part on a set of channel metrics at the UE satisfying the second set of values.

27. An apparatus for wireless communications at a user equipment (UE), comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

receive, from a base station, one or more configurations for the UE to use, while in an inactive mode or an idle mode, to provide feedback associated with multicast transmissions from the base station;

monitor, while in the inactive mode or the idle mode, a set of time frequency resources configured for the multicast transmissions from the base station;

transmit, while in the inactive mode or the idle mode, one or more multicast feedback messages in accordance with the one or more configurations based at least in part on the monitoring; and

transmit a reception status report that indicates a ratio of a quantity of received physical control channels for the multicast transmissions to a total quantity of physical control channels for the multicast transmissions scheduled over a set of monitoring occasions, the reception status report being transmitted on a set of uplink resources associated with the ratio.

28. An apparatus for wireless communications at a base station, comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

transmit, to a user equipment (UE), one or more configurations for multicast feedback by the UE in an inactive mode or an idle mode;

transmit one or more multicast transmissions via a set of time frequency resources configured for multicast communications; and

monitor, based at least in part on transmitting the one or more multicast transmissions, for one or more multicast feedback messages from the UE in accordance with the one or more configurations; and

receive a reception status report from the UE that indicates a ratio of a quantity of physical control channels received by the UE for the multicast transmissions to a total quantity of physical control channels for the multicast transmissions scheduled over a set of monitoring occasions, the reception status report being received on a set of uplink resources associated with the ratio.