Methods and systems are provided that support the transmission of transport blocks over carrier bundles and bandwidth part (BWP) bundles. These carrier bundles and BWP bundles include physical resources from multiple carriers, the multiple carriers being a proper subset of the carriers configured for a user equipment (UE). A base station transmits an indication to the UE identifying one or more carrier bundles and/or BWP bundles. Each carrier bundle and BWP bundle supports the transmission of a respective transport block over a given duration, and is associated with a respective hybrid automatic repeat request (HARQ) entity.