Access, collision handling, and resolution for non-orthogonal multiple-access (NOMA) may be used. Fixed or dynamic group demodulation reference signal (DMRS) and multiple-access (MA) signature for NOMA retransmission may be used. A wireless transmit/receive unit (WTRU) may receive MAS information or DMRS information from a network entity. A WTRU may receive indication of the MAS information or DMRS information via a subgrouping-based scheme, a bitmap indication, or a binary threshold. A WTRU may receive an indication of a resource group size from the network entity. Based on the resource group size, the WTRU may determine whether the MAS information or the DMRS information is indicated via the subgrouping-based scheme or via the binary threshold scheme. The WTRU, based on how the MAS information or the DMRS information is indicated, may determine a resource to be used for a NOMA transmission. The WTRU may send the NOMA transmission using the determined resource.