A transmitting sidelink device assigns a transport block (TB) to a logical hybrid automatic repeat request (HARQ) entity, maps the TB to an carrier, transmits the TB to a receiving sidelink device, the TB is associated with a first sidelink control information (SCI) that cross-references the TB to an identifier of the logical HARQ entity, maps the TB to a different carrier, and retransmits the TB on the different carrier, the retransmitted TB is associated with a second SCI that cross-references the TB to the identifier of the logical HARQ entity. A receiving sidelink device receives the TB and SCI, maps the TB to the identified logical HARQ entity, detects the retransmission, and maps the retransmission to the identified logical HARQ entity. A transmitting sidelink device generates packets in advance and transmits one of the generated packets when required.