Method and apparatus for enhancing discontinuous reception in wireless systems

1. A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:

the WTRU receiving a radio resource control (RRC) message comprising discontinuous reception (DRX) configuration information, the DRX configuration information comprising a first set of DRX parameters and a second set of DRX parameters, the first set of DRX parameters comprising an indication of a DRX cycle periodicity and an indication of a length of a first DRX minimum active period, the second set of DRX parameters comprising an indication of a length of a second DRX minimum active period;

the WTRU applying the first set of DRX parameters and monitoring for a data indication signal in accordance with the first DRX minimum active period, wherein the first DRX minimum active period corresponds to a period at a beginning of a DRX cycle that the WTRU monitors for a data indication signal when applying the first set of DRX parameters, and the WTRU stays awake beyond the first DRX minimum active period if a data indication signal is received during the first DRX minimum active period; and

the WTRU applying the second set of DRX parameters and monitoring for a data indication signal in accordance with the second DRX minimum active period, wherein the second DRX minimum active period corresponds to a period at a beginning of a DRX cycle that the WTRU monitors for a data indication signal when applying the second set of DRX parameters, and the WTRU stays awake beyond the second DRX minimum active period if a data indication signal is received during the second DRX minimum active period.

2. The method of claim 1 , wherein the first set of DRX parameters further comprises an indication of a DRX active period start position.

3. The method of claim 1 , wherein a DRX active period of is of variable length depending on an amount of data transmissions sent to the WTRU, a minimum length of the DRX active period corresponds to the length of the first DRX minimum active period when applying the first set of DRX parameters, and the minimum length of the DRX active period corresponds to the length of the second DRX minimum active period when applying the second set of DRX parameters.

4. The method of claim 1 , wherein a medium access control (MAC) message is used to explicitly signal an end of a DRX active period.

5. The method of claim 1 , wherein monitoring for a data indication signal comprises monitoring for a control channel transmission that comprises a data indication signal.

6. The method of claim 1 , wherein the WTRU goes to sleep at an end of the first DRX minimum active period based on the WTRU not receiving any data indication signals during the first DRX minimum active period when applying the first set of DRX parameters.

7. The method of claim 6 , wherein the WTRU goes to sleep at an end of the second DRX minimum active period based on the WTRU not receiving any data indication signals during the second DRX minimum active period when applying the second set of DRX parameters.

8. The method of claim 6 , wherein the WTRU going to sleep comprises the WTRU stopping monitoring for control channel transmission comprising a data indication signal.

9. The method of claim 1 , wherein the first set of DRX parameters corresponds to a first DRX profile, the second set of DRX parameters corresponds to a second DRX profile.

10. The method of claim 1 , wherein a received medium access control (MAC) message indicates whether to apply the first set of DRX parameters corresponding to a first DRX profile or the second set of DRX parameters corresponding to a second DRX profile.

11. A wireless transmit/receive unit (WTRU) comprising a processor and memory, the WTRU configured to:

receive a radio resource control (RRC) message comprising discontinuous reception (DRX) configuration information, the DRX configuration information comprising a first set of DRX parameters and a second set of DRX parameters, the first set of DRX parameters comprising an indication of a DRX cycle periodicity and an indication of a length of a first DRX minimum active period, the second set of DRX parameters comprising an indication of a length of a second DRX minimum active period;

apply the first set of DRX parameters and monitor for a data indication signal in accordance with the first DRX minimum active period, wherein the first DRX minimum active period corresponds to a period at a beginning of a DRX cycle that the WTRU is configured to monitor for a data indication signal when applying the first set of DRX parameters, and the WTRU is configured to stay awake beyond the first DRX minimum active period if a data indication signal is received during the first DRX minimum active period; and

apply the second set of DRX parameters and monitor for a data indication signal in accordance with the second DRX minimum active period, wherein the second DRX minimum active period corresponds to a period at a beginning of a DRX cycle that the WTRU is configured to monitor for a data indication signal when applying the second set of DRX parameters, and the WTRU is configured to stay awake beyond the second DRX minimum active period if a data indication signal is received during the second DRX minimum active period.

12. The WTRU of claim 11 , wherein a DRX active period of is of variable length depending on an amount of data transmissions sent to the WTRU, a minimum length of the DRX active period corresponds to the length of the first DRX minimum active period when applying the first set of DRX parameters, and the minimum length of the DRX active period corresponds to the length of the second DRX minimum active period when applying the second set of DRX parameters.

13. The WTRU of claim 11 , wherein when applying the first set of DRX parameters the WTRU is configured to go to sleep at an end of the first DRX minimum active period based on no data indication signal being received during the first DRX minimum active period, and when applying the second set of DRX parameters the WTRU is configured to go to sleep at an end of the second DRX minimum active period based on no data indication signal being received during the second DRX minimum active period.

14. The WTRU of claim 13 , wherein the WTRU being configured to go to sleep comprises the WTRU being configured to stop monitoring for a control channel transmission comprising a data indication signal.

15. The WTRU of claim 11 , wherein the first set of DRX parameters corresponds to a first DRX profile, the second set of DRX parameters corresponds to a second DRX profile.

16. The method of claim 11 , wherein the WTRU is configured to:

receive a first medium access control (MAC) message; and

apply the second set of DRX parameters based on the first MAC message;

receive a second MAC message; and

stop applying the second set of DRX parameters based on the second MAC message.

17. A base station comprising a processor and memory, the base station configured to:

send a radio resource control (RRC) message to a wireless transmit/receive unit (WTRU), the RRC message comprising discontinuous reception (DRX) configuration information, the DRX configuration information comprising a first set of DRX parameters and a second set of DRX parameters, the first set of DRX parameters comprising an indication of a DRX cycle periodicity and an indication of a length of a first DRX minimum active period, the second set of DRX parameters comprising an indication of a length of a second DRX minimum active period;

send a data indication signal to the WTRU in accordance with the first DRX minimum active period when the WTRU is applying the first set of DRX parameters, wherein the first DRX minimum active period corresponds to a period at a beginning of a DRX cycle when a data indication signal can be sent to the WTRU when the WTRU is applying the first set of DRX parameters, and sending a data indication signal to the WTRU during the first DRX minimum active period indicates that the WTRU is to stay awake beyond the first DRX minimum active period; and

send a data indication signal to the WTRU in accordance with the second DRX minimum active period when the WTRU is applying the second set of DRX parameters, wherein the second DRX minimum active period corresponds to a period at a beginning of a DRX cycle when a data indication signal can be sent to the WTRU when the WTRU is applying the second set of DRX parameters, and sending a data indication signal to the WTRU during the second DRX minimum active period indicates that the WTRU is to stay awake beyond the second DRX minimum active period.

18. The base station of claim 17 , wherein the first set of DRX parameters further comprises an indication of a DRX active period start position.

19. The base station of claim 17 , wherein a data indication signal is sent to the WTRU in a control channel transmission.

20. The base station of claim 17 , wherein the base station is configured to:

send a first medium access control (MAC) message to the WTRU, the first MAC message indicating that the WTRU is to apply the second set of DRX parameters; and

send a second MAC message to the WTRU, the second MAC message indicating that the WTRU is to stop applying the second set of DRX parameters.