Medium access control layer architecture for supporting enhanced uplink

1. A Node-B that communicates with a wireless transmit/receive unit (WTRU) over an enhanced uplink channel, the Node-B comprising:

a receiver configured to receive a scheduling request from a WTRU;

a processor configured to determine a scheduling grant based at least on the scheduling request, wherein the scheduling grant specifies an amount by which a current amount of uplink resources is increased or decreased;

a transmitter configured to transmit the scheduling grant to the WTRU;

the processor configured to demultiplex a received medium access control for enhanced uplink (MAC-e) protocol data unit (PDU), from the WTRU, into medium access control for dedicated channel (MAC-d) PDUs, wherein the received MAC-e PDU includes data based on network controlled allowed combinations of MAC-d flows; and

the transmitter configured to send a transmission feedback in response to the received MAC-e PDU, wherein the Node-B supports a plurality of hybrid automatic repeat request (H-ARQ) processes, wherein the H-ARQ processes are synchronized between the Node-B and the WTRU.

2. The Node-B of claim 1 wherein the scheduling grant is an absolute grant, which provides an absolute limitation of the maximum amount of uplink resources that the WTRU may use.

3. The Node-B of claim 1 wherein the scheduling request includes information regarding a volume of enhanced uplink data.

4. The Node-B of claim 1 wherein the Node-B comprises a MAC-e entity.

5. The Node-B of claim 4 wherein there is one MAC-e entity in the Node-B for each WTRU that transmits data over an enhanced uplink channel to the Node-B.

6. The Node-B of claim 1 wherein the Node-B manages enhanced uplink resources between WTRUs in a cell.

7. A method implemented by a Node-B, wherein the Node-B communicates with a wireless transmit/receive unit (WTRU) over an enhanced uplink channel, comprising:

receiving a scheduling request from a WTRU;

determining a scheduling grant based at least on the scheduling request, wherein the scheduling grant specifies an amount by which a current amount of uplink resources is increased or decreased;

transmitting the scheduling grant to the WTRU;

demultiplexing a received medium access control for enhanced uplink (MAC-e) protocol data unit (PDU), from the WTRU, into medium access control for dedicated channel (MAC-d) PDUs, wherein the received MAC-e PDU includes data based on network controlled allowed combination of MAC-d flows;

generating a transmission feedback in response to the received MAC-e PDU; and

transmitting the transmission feedback to the WTRU, wherein the Node-B supports a plurality of hybrid automatic repeat request (H-ARQ) processes, wherein the H-ARQ processes are synchronized between the Node-B and the WTRU.

8. The method of claim 7 wherein the scheduling grant is an absolute grant, which provides an absolute limitation of the maximum amount of uplink resources that the WTRU may use.

9. The method of claim 7 wherein the scheduling request includes information regarding a volume of enhanced uplink data.

10. The method of claim 7 wherein the Node-B comprises a MAC-e entity.

11. The method of claim 10 wherein the MAC-e entity comprises a controller, a demultiplexer, and a H-ARQ entity.

12. The method of claim 11 wherein there is one MAC-e entity in the Node-B for each WTRU that transmits data over an enhanced uplink channel to the Node-B.

13. The method of claim 7 wherein the Node-B comprises a scheduler and the scheduler manages enhanced uplink resources between WTRUs in a cell.