Method and apparatus for supporting uplink protocol changes

1. A wireless transmit/receive unit (WTRU) for performing a medium access control (MAC) reset, comprising:

a processor configured to:

process a MAC-e/es reset indicator in response to a MAC protocol change to an enhanced MAC e/es with Uplink (UL) Layer 2 (L2) improvements or from the enhanced MAC e/es; and

in response to processing the MAC-e/es reset indicator, flush a hybrid automatic repeat request (HARQ) process, and discard a segment stored in a segmentation entity when enhanced MAC-e/es is configured;

wherein the UL L2 improvements comprise an ability to communicate RLC PDUs of flexible sizes utilizing an adaptation layer between MAC-e/es and the enhanced MAC-e/es, and wherein a header in the enhanced MAC-e/es comprises a segmentation description field indicating whether a first and last part of the enhanced MAC-e/es are segments or full PDU's and a length indication field indicating a number of bytes of each segment.

2. The WTRU of claim 1 , wherein the processor is configured to receive the MAC-e/es reset indicator via radio resource controller (RRC) signaling.

3. The WTRU of claim 1 , wherein the MAC-e/es reset indicator included in an RRC reconfiguration message.

4. The WTRU of claim 1 , wherein the MAC-e/es reset indicator included in an active set update message.

5. The WTRU of claim 1 , wherein the segmentation entity is configured to store MAC packet data unit (PDU) segments.

6. A method for performing a medium access control (MAC) reset, the method comprising:

processing a MAC-e/es reset indicator in response to a MAC protocol change to an enhanced MAC e/es or from the enhanced MAC e/es;

in response to processing the MAC-e/es reset indicator, flushing a hybrid automatic repeat request (HARQ) process; and

discarding a segment, when enhanced MAC-e/es is configured

wherein the enhanced MAC-e/es include UL Layer 2 (L2) improvements which comprise an ability to communicate RLC PDUs of flexible sizes utilizing an adaptation layer between MAC-e/es and the enhanced MAC-e/es, and wherein a header in the enhanced MAC-e/es comprises a segmentation description field indicating whether a first and last part of the enhanced MAC-e/es are segments or full PDU's and a length indication field indicating a number of bytes of each segment.

7. The method of claim 6 , further comprising setting a state variable to zero for logical channels mapped to an enhanced dedicated channel (E-DCH).

8. The method of claim 6 , further comprising:

notifying a radio link controller (RLC) of a failed RLC packet data unit (PDU);

discarding the failed RLC PDU;

retransmitting the failed RLC PDU; and

discarding the RLC PDU after transmission.

9. The method of claim 6 , further comprising notifying the RLC of PDUs present in a HARQ buffer.

10. The method of claim 6 , wherein the MAC-e/es reset indicator is received in at least one of an RRC reconfiguration message or an active set update message.

11. A wireless transmit/receive unit (WTRU) supporting uplink (UL) protocol changes, comprising:

a processor configured to:

receive a medium access control (MAC) protocol change indicator indicating a change from MAC-e/es to enhanced MAC-e/es with UL L2 improvements or from enhanced MAC-e/es with UL Layer 2 (L2) improvements to MAC-e/es;

in response to the MAC protocol change indicator, verify a MAC reset indicator is set to true; and

perform a MAC e/es reset; and

wherein the UL L2 improvements comprise an ability to communicate RLC PDUs of flexible sizes utilizing an adaptation layer between MAC-e/es and the enhanced MAC-e/es, and wherein a header in the enhanced MAC-e/es comprises a segmentation description field indicating whether a first and last part of the enhanced MAC-e/es are segments or full PDU's and

a length indication field indicating a number of bytes of each segment.

12. The WTRU of claim 11 , wherein the processor is further configured to receive the MAC reset indicator via radio resource controller (RRC) signaling.

13. The WTRU of claim 11 , wherein the processor is further configured to set a state variable to zero for logical channels mapped to an enhanced dedicated channel (E-DCH).

14. The WTRU of claim 11 , wherein the processor is further configured to discard a segment in a segmentation entity when an enhanced MAC protocol is configured.

15. A method for supporting uplink (UL) protocol changes, comprising:

processing a medium access control (MAC) protocol change from MAC-es/e to enhanced MAC-e/es with UL Layer 2 (L2) improvements or from the enhanced MAC-e/es with UL L2 improvements to MAC-e/es;

verifying a MAC reset indicator is set to true; and

performing a MAC e/es reset;

wherein the UL L2 improvements comprise an ability to communicate RLC PDUs of flexible sizes utilizing an adaptation layer between MAC-e/es and the enhanced MAC-e/es, and wherein a header in the enhanced MAC-e/es comprises a segmentation description field indicating whether a first and last part of the enhanced MAC-e/es are segments or full PDU's and a length indication field indicating a number of bytes of each segment.

16. The method of claim 15 , wherein the MAC reset indicator is received via radio resource controller (RRC) signaling.

17. The method of claim 15 , further comprising setting a state variable to zero for logical channels mapped to an enhanced dedicated channel (E-DCH).

18. The method of claim 15 , further comprising discarding a segment indicating the length of each enhanced MAC-e/es SDU stored in a segmentation entity when an enhanced MAC protocol is configured.