A transmission opportunity (TO) allows a transmitting device, such as a base station to transmit up to a pre-determined TO duration. For new radio (NR), subcarrier spacing (SCS) is no longer fixed. This may limit a TO duration for a UE to a small portion of the allowed TO duration, for new radio (NR), a transport block (TB) takes up one slot. A method, apparatus, and computer-readable medium are disclosed extend a TB over more than one slot to maximize utilization of a TO duration, for improved resource utilization and service quality. A method, apparatus, and computer-readable medium implemented by a communication device are disclosed to receive a signaling message, to configure a flexible transport block (TB) to extend the TB over more than one slot. Then the communication device may receive a portion of the flexible TB, based on the received signaling message.