Techniques for handling groupcast feedback communication

A method for wireless communication by a first user equipment (UE), comprising:

• transmitting first control signaling indicating a first mode of groupcast feedback, wherein the first mode is associated with transmission of negative acknowledgment (NACK) feedback and suppression of acknowledgment (ACK) feedback;
• transmitting a plurality of groupcast messages, each of the plurality of groupcast messages comprising a respective transport block;
• receiving one or more NACK feedback messages associated with one or more of the plurality of groupcast messages according to the first mode, wherein each of the one or more NACK feedback messages indicates that reception of at least a portion of the respective transport block was unsuccessful;
• performing one or more retransmissions of the one or more of the plurality of groupcast messages based on the one or more NACK feedback messages;
• and
• transmitting second control signaling indicating a second mode of groupcast feedback based on a metric of the one or more retransmissions exceeding a first threshold, wherein the second mode is associated with monitoring for NACK feedback and ACK feedback.

A first user equipment (UE) for wireless communication, comprising:

• means for transmitting first control signaling indicating a first mode of groupcast feedback, wherein the first mode is associated with transmission of negative acknowledgment (NACK) feedback and suppression of acknowledgment (ACK) feedback;
• means for transmitting a plurality of groupcast messages, each of the plurality of groupcast messages comprising a respective transport block;
• means for receiving one or more NACK feedback messages associated with one or more of the plurality of groupcast messages according to the first mode, wherein each of the one or more NACK feedback messages indicates that reception of at least a portion of the respective transport block was unsuccessful;
• means for performing one or more retransmissions of the one or more of the plurality of groupcast messages based on the one or more NACK feedback messages;
• and
• means for transmitting second control signaling indicating a second mode of groupcast feedback based on a metric of the one or more retransmissions exceeding a first threshold, wherein the second mode is associated with monitoring for NACK feedback and ACK feedback.

A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by one or more processors to:

• transmit first control signaling indicating a first mode of groupcast feedback, wherein the first mode is associated with transmission of negative acknowledgment (NACK) feedback and suppression of acknowledgment (ACK) feedback;
• transmit a plurality of groupcast messages, each of the plurality of groupcast messages comprising a respective transport block;
• receive one or more NACK feedback messages associated with one or more of the plurality of groupcast messages according to the first mode, wherein each of the one or more NACK feedback messages indicates that reception of at least a portion of the respective transport block was unsuccessful;
• perform one or more retransmissions of the one or more of the plurality of groupcast messages based on the one or more NACK feedback messages;
• and
• transmit second control signaling indicating a second mode of groupcast feedback based on a metric of the one or more retransmissions exceeding a first threshold, wherein the second mode is associated with monitoring for NACK feedback and ACK feedback.