The Tx wireless device (e.g., Tx UE1) may transmit a transport block, via a PSSCH, to the plurality of Rx wireless devices (e.g., Rx UE1, Rx UE2, Rx UE3, Rx UE4, Rx UE5, and Rx UE6) in a groupcast communication. The Tx wireless device (e.g., Tx UE1) may transmit the transport block with a number of repetition transmissions to the plurality of Rx wireless devices in a groupcast communication. The Tx wireless device (e.g., Tx UE1) may transmit a media access control element (MAC CE) activating one or more of the plurality of repetition values of the PSSCH to each of the plurality of Rx wireless devices. The Tx wireless device (e.g., Tx UE1) may transmit a physical sidelink control channel (PSCCH) comprising a sidelink control information (SCI) scheduling the transport block to the plurality of Rx wireless devices (e.g., Rx UE1, Rx UE2, Rx UE3, Rx UE4, Rx UE5, and Rx UE6). The SCI may indicate the number of the repetition transmissions. In an example, the number of the repetition transmissions may be one of the one or more of the plurality of repetition values of the PSSCH (e.g., indicated by the one or more RRC messages). The number of the repetition transmissions may comprise transmission and retransmissions of the transport block. A Rx wireless device (e.g., Rx UE2) may receive, from the Tx wireless device (e.g., Tx UE1), the SCI indicating one of the one or more of the plurality of repetition values of the PSSCH (e.g., activated by the MAC CE). The Rx wireless device (e.g., Rx UE2) may determine, based on the repetition threshold and the one of the one or more of the plurality of repetition values, whether to transmit a positive/negative acknowledgment for the transport block scheduled by the SCI. The Rx wireless device (e.g., Rx UE2) may determine, based on the repetition threshold and the one of the one or more of the plurality of repetition values, to transmit a positive/negative acknowledgment for the transport block scheduled by the SCI. In an example, the Rx wireless device (e.g., Rx UE2) may determine to transmit a positive/negative acknowledgment for the transport block scheduled by the SCI in response to the one of the one or more of the plurality of repetition values being equal to the repetition threshold. In an example, the Rx wireless device (e.g., Rx UE2) may determine to transmit a positive/negative acknowledgment for the transport block scheduled by the SCI in response to the one of the one or more of the plurality of repetition values being less than the repetition threshold. The Rx wireless device (e.g., Rx UE2) may determine, based on the repetition threshold and the one of the one or more of the plurality of repetition values, not to transmit a positive/negative acknowledgment for the transport block scheduled by the SCI. In an example, the Rx wireless device (e.g., Rx UE2) may determine not to transmit a positive/negative acknowledgment for the transport block scheduled by the SCI in response to the one of the one or more of the plurality of repetition values being greater than the repetition threshold. The Rx wireless device (e.g., Rx UE2) may detect the transport block scheduled by the SCI. Base on the detecting the transport block, the Rx wireless device (e.g., Rx UE2) may transmit the positive/negative acknowledgment to the Tx wireless device (e.g., Tx UE1) in response to the Rx wireless device determining to transmit the positive/negative acknowledgment for the transport block. The Rx wireless device (e.g., Rx UE2) may transmit the positive/negative acknowledgment (e.g., ACK or NACK) to the Tx wireless device (e.g., Tx UE1) via a physical sidelink feedback channel (PSFCH) in response to the Rx wireless device determining to transmit the positive/negative acknowledgment for the transport block. The PSFCH may comprise an association with the PSSCH used to transmit the transport block of the Tx wireless device (e.g., Tx UE1). The configuration parameters may indicate the association between the PSSCH and the PSFCH. The Rx wireless device (e.g., Rx UE2) may determine, based on the association, the PSFCH in response to receiving the PSSCH. In an example, the PSFCH may use the same frequency resources as the PSSCH. In an example, the PSFCH may use a portion of frequency resources of the PSSCH. In an example, the PSFCH may use frequency resources without overlapping with the PSSCH. In an example, the Rx wireless device (e.g., Rx UE2) may transmit a transport block via the PSFCH in response to the Rx wireless device determining not to transmit the positive/negative acknowledgment for the transport block. Each of the plurality of repetition values of the PSSCH may indicate a plurality of repetition transmissions of the PSSCH. The plurality of repetition transmissions may comprise transmission and retransmissions of the PSSCH. In an example, the transmission and retransmissions of the PSSCH may comprise transmission and retransmissions of the PSSCH with a same or different redundancy versions of channel coding. The Tx wireless device (e.g., Tx UE1) may transmit the PSCCH comprising the SCI to the Rx wireless device (e.g., Rx UE2). The SCI may indicate the same or different redundancy versions of channel coding for the plurality of repetition transmissions. The Rx wireless device (e.g., Rx UE2) may receive the PSCCH comprising the SCI via a reception resource pool. The reception resource pool may comprise continuous or noncontinuous resources in frequency domain. The reception resource pool may comprise continuous or noncontinuous resources in time domain. The reception resource pool may comprise a reception periodicity in sidelink. The Rx wireless device may receive the reception resource pool according to the reception periodicity in sidelink. In an example, the base station may configure the reception periodicity of the reception resource pool to the Rx wireless device (e.g., Rx UE2). In an example, the Tx wireless device (e.g., Tx UE1) may configure the reception periodicity of the reception resource pool to the Rx wireless device (e.g., Rx UE2).