A wireless transmit/receive unit (WTRU) is configured to receive at least one serving grant and at least one non-scheduled grant. The at least one serving grant is a grant for scheduled data transmission. The at least one non-scheduled grant is a grant for non-scheduled data transmission. The WTRU is configured to determine supported enhanced dedicated channel transport format combinations (E-TFCs) within a E-TFC set (E-TFCS) based on a remaining transmit power for enhanced uplink (EU) transmission. The WTRU is configured to limit medium access control for dedicated channel (MAC-d) flow data multiplexed into a medium access control for enhanced uplink (MAC-e) protocol data unit (PDU) to a largest E-TFC size that is smaller than a size of MAC-d flow data allowed by the received serving and non-scheduled grants and available for transmission.