Medium access control layer architecture for supporting enhanced uplink

A wireless transmit/receive unit (WTRU) comprising:

• circuitry configured to transmit a request for uplink resources, wherein the request for uplink resources is a request to transmit data over an enhanced dedicated channel (E-DCH);
• circuitry configured to receive an uplink scheduling grant in response to the request for uplink resources;
• circuitry configured to multiplex data from medium access control for dedicated channel (MAC-d) flows into a medium access control for enhanced uplink (MAC-e) protocol data unit (PDU);
• circuitry configured to select a transport format combination (TFC) for transmission of the MAC-e PDU, wherein the TFC selection is at least based on the uplink scheduling grant, a maximum allowed transmit power, and logical channel priority;
• circuitry configured to transmit the MAC-e PDU over the E-DCH using an identified hybrid automatic repeat request (H-ARQ) process;
• circuitry configured to receive feedback information in response to the transmitted MAC-e PDU;
• circuitry configured to retransmit the MAC-e PDU using the identified H-ARQ process on a condition that the feedback information indicates a negative acknowledgment (NACK) of the MAC-e PDU transmission;
• and
• circuitry configured to transmit an updated request for uplink resources.