Implicit DRX cycle length adjustment control in LTE_active mode
A method for controlling discontinuous reception in a wireless transmit/receive unit includes defining a plurality of DRX levels, wherein each DRX level includes a respective DRX cycle length and transitioning between DRX levels based on a set of criteria. The transitioning may be triggered by implicit rules.
1. A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:
the WTRU receiving a discontinuous reception (DRX) configuration in a radio resource control (RRC) message, the DRX configuration comprising a first DRX cycle length, a second DRX cycle length, and a value for a WTRU timer used to trigger a transition from the first DRX cycle length to the second DRX cycle length, wherein the second DRX cycle length is a multiple of the first DRX cycle length;
the WTRU performing DRX using the second DRX cycle length;
the WTRU receiving a trigger from a base station;
the WTRU performing DRX using the first DRX cycle length based on receiving the trigger;
the WTRU starting the WTRU timer upon beginning DRX operation using the first DRX cycle length;
the WTRU determining that the WTRU timer has expired; and
the WTRU transitioning from the first DRX cycle length to the second DRX cycle length in response to the WTRU determining that the WTRU timer has expired.
2. The method as in claim 1 , wherein the second DRX cycle length is an integer power of two of the first DRX cycle length.
3. The method as in claim 2 , wherein the first and second DRX cycle lengths are selected from a set of DRX cycle lengths given by the equation DRX-cycle-len=L×2 n where n=0, 1, 2, . . . and L is the first DRX cycle length.
4. The method as in claim 1 , wherein the WTRU timer is synchronized with a base station timer.
5. The method as in claim 1 , wherein the WTRU timer is implemented as a counter.
6. The method as in claim 1 , wherein the value of the WTRU timer is signaled as a number of DRX cycles.
7. A wireless transmit/receive unit (WTRU) comprising a processor and memory configured to:
receive a discontinuous reception (DRX) configuration in a radio resource control (RRC) message, the DRX configuration comprising a first DRX cycle length, a second DRX cycle length, and a value for a WTRU timer used to trigger a transition from the first DRX cycle length to the second DRX cycle length;
perform DRX using the second DRX cycle length;
receive a trigger from a base station;
perform DRX using the first DRX cycle length based on receiving the trigger;
start the WTRU timer upon beginning DRX operation using the first DRX cycle length;
determine that the WTRU timer has expired; and
transition from the first DRX cycle length to the second DRX cycle length in response to the expiration of the WTRU timer, wherein the second DRX cycle length is a multiple of the first DRX cycle length.
8. The WTRU as in claim 7 , wherein the second DRX cycle length is an integer power of two of the first DRX cycle length.
9. The WTRU as in claim 8 , wherein the first and second DRX cycle lengths are selected from a set of DRX cycle lengths given by the equation DRX-cycle-len=L×2 n where n=0, 1, 2, . . . and L is the first DRX cycle length.
10. The WTRU as in claim 7 , wherein the WTRU timer is synchronized with a base station timer.
11. The WTRU as in claim 7 , wherein the WTRU timer is implemented as a counter.
12. The WTRU as in claim 7 , wherein the value of the WTRU timer is signaled as a number of DRX cycles.
13. A wireless transmit/receive unit (WTRU) comprising a processor and memory configured to:
receive a discontinuous reception (DRX) configuration in a radio resource control (RRC) message, the DRX configuration comprising a first DRX cycle length, a second DRX cycle length, and a value for a WTRU timer used to trigger a transition from the first DRX cycle length to the second DRX cycle length;
receive a first trigger from a base station, the first trigger indicating that the WTRU should perform DRX using the second DRX cycle length;
perform DRX using the second DRX cycle length based on receiving the first trigger;
receive a second trigger from the base station, the second trigger indicating that the WTRU should perform DRX using the first DRX cycle length;
perform DRX using the first DRX cycle length based on receiving the second trigger;
start the WTRU timer upon beginning DRX operation using the first DRX cycle length;
determine that the WTRU timer has expired; and
transition from the first DRX cycle length to the second DRX cycle length in response to the expiration of the WTRU timer, wherein the second DRX cycle length is a multiple of the first DRX cycle length.
14. The WTRU as in claim 13 , wherein the second DRX cycle length is an integer power of two of the first DRX cycle length.
15. The WTRU as in claim 14 , wherein the first and second DRX cycle lengths are selected from a set of DRX cycle lengths given by the equation DRX-cycle-len=L×2 n where n=0, 1, 2, . . . and L is the first DRX cycle length.
16. The WTRU as in claim 13 , wherein the WTRU timer is synchronized with a base station timer.
17. The WTRU as in claim 13 , wherein the WTRU timer is implemented as a counter.
18. The WTRU as in claim 13 , wherein the value of the WTRU timer is signaled as a number of DRX cycles.
19. The method as in claim 1 , further comprising:
the WTRU receiving a second trigger from the base station, the second trigger indicating that the WTRU should perform DRX using the second DRX cycle length; and
the WTRU performing DRX using the second DRX cycle length based on receiving the second trigger.
20. The WTRU as in claim 7 , wherein the processor and memory are further configured to:
receive a second trigger from the base station, the second trigger indicating that the WTRU should perform DRX using the second DRX cycle length; and
perform DRX using the second DRX cycle length based on receiving the second trigger.