Optimizing the resource configuration or selection for grant-free contention-based non-orthogonal multiple access (NOMA) transmissions is an effective way to increase network capacity and reduce multi-user interference at the user equipment (UE). In some embodiments, a network node may determine the current traffic load, select multiple access (MA) sequences for the UE based on the determination, and transmit this selection to the UE for subsequent transmissions. In other embodiments, the UE may receive a message with an indication of the traffic load being experienced by the base station that the UE is attempting to connect to, and then may randomly select an MA sequence for subsequent transmissions.