Method and apparatus for enhancing discontinuous reception in wireless systems

• US 9,066,350 B2
• Filed: 06/18/2012
• Issued: 06/23/2015
• Est. Priority Date: 10/27/2006
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Wang, Jin, Somasundaram, Shankar, Sammour, Mohammed, Chandra, Arty
• Primary Examiner(s): TRAN, PHUC H
• Application Number:
  US13/526,104
• Publication Number:
  US 20130148521A1
• Time in Patent Office: 1,100 Days
• Field of Search: 370/311, 370/350, 455/574
• US Class Current: 1/1
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 76/20 Manipulation of established connections
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of discontinuous reception (DRX) in a wireless transmit receive unit (WTRU) includes the WTRU receiving DRX setting information over a radio resource control (RRC) signal, and the WTRU receiving DRX activation information over medium access control (MAC) signal.

Claims

1. A method implemented by a wireless transmit receive unit (WTRU) for performing discontinuous reception (DRX) while in an RRC_CONNECTED state, the method comprising:

the WTRU receiving DRX setting information from an evolved Node-B (eNB) via a radio resource control (RRC) message, the DRX setting information indicating a length of a minimum active period, wherein the minimum active period corresponds to a minimum amount of time during which the WTRU is active at a beginning of a given DRX cycle;

the WTRU monitoring for reception of Layer 1 control signaling from the eNB during the minimum active period of a first DRX cycle, wherein the Layer 1 control signaling indicates whether data is to be transmitted to the WTRU;

the WTRU receiving a data indication message during the minimum active period of the first DRX cycle, the data indication message indicating that downlink data is to be transmitted to the WTRU;

the WTRU remaining in an awake state beyond the minimum active period of the first DRX cycle based on receiving the data indication message;

while awake, the WTRU receiving a DRX activation medium access control (MAC) message; and

the WTRU resuming DRX operation in response to receiving the DRX activation MAC message.

2. The method of claim 1, wherein the data indication signal is received via Layer 1 control signaling.

3. The method of claim 1, further comprising the WTRU receiving the downlink data after staying awake in response to receiving the data indication message.

4. The method of claim 3, wherein the downlink data is received from the eNB on a shared data channel.

5. The method of claim 1, wherein the WTRU interprets lack of receipt of the Layer 1 control signaling during the minimum active period of the first DRX cycle as an indication that the WTRU may go to sleep at an end of the minimum active period of the first DRX cycle.

6. The method of claim 5, further comprising the WTRU waking up at the start of a subsequent DRX cycle to monitor for reception of subsequent Layer 1 control signaling.

7. The method of claim 6, further comprising the WTRU determining that the subsequent Layer 1 control signaling was not received during a minimum active period of the subsequent DRX cycle.

8. The method of claim 7, further comprising the WTRU going to sleep until a beginning of a next DRX cycle based on determining that the subsequent Layer 1 control signaling was not received during the minimum active period of the subsequent DRX cycle.

9. The method of claim 8, wherein the trigger for sending the DRX activation MAC message to the WTRU is the eNB determining that there are currently no more packets that need to be transmitted to the WTRU.

10. The method of claim 1, wherein the DRX setting information further indicates a DRX cycle periodicity.

11. The method of claim 1, further comprising the WTRU receiving a periodic allocation for a thin channel, wherein transmission using the periodic allocation of the thin channel are configured to coincide with active periods of DRX cycles.

12. A base station for facilitating discontinuous reception (DRX) at a wireless transmit receive unit (WTRU), the base station comprising a processor configured, at least in part, to:

send DRX setting information to the WTRU using a radio resource control (RRC) message, the DRX setting information indicating a length of a minimum active period, wherein the minimum active period corresponds to a minimum amount of time during which the WTRU is active at a beginning of given DRX cycle;

send a data indication signal to the WTRU using Layer 1 control signaling, wherein the Layer 1 control signaling is used to indicate whether or not the eNB will transmit download data to the WTRU during the given DRX cycle;

send the downlink data to the WTRU after transmitting the data indication signal; and

send a DRX activation medium access control (MAC) message to the WTRU, wherein the DRX activation MAC message indicates that the WTRU is to resume DRX.

13. The base station of claim 12, wherein the processor is configured to send the DRX activation MAC message to the WTRU based on a determination that the base station does not currently have any remaining packets to be transmitted to the WTRU.

14. The base station of claim 12, wherein the processor is configured to send the downlink data to the WTRU using a shared data channel.

15. The base station of claim 12, wherein the DRX setting information further indicates a DRX cycle periodicity.

16. The base station of claim 12, wherein failure to send the Layer 1 control signaling to the WTRU during the minimum active period indicates that the WTRU may go to sleep at an end of the minimum active period until a start of a subsequent DRX cycle.

17. A wireless transmit receive unit (WTRU) comprising a processor configured, at least in part, to:

receive DRX setting information from the eNB in a radio resource control (RRC) message, the DRX setting information indicating a length of a minimum active period and a DRX cycle periodicity, wherein the minimum active period corresponds to a minimum amount of time during which the WTRU is configured to be active at a beginning of given DRX cycle;

monitor for reception of Layer 1 control signaling from the eNB during the minimum active period of a first DRX cycle, wherein the Layer 1 control signaling indicates whether or not the eNB will transmit download data to the WTRU during the first DRX cycle, and the WTRU is configured to interpret lack of receipt of the Layer 1 control signaling during the minimum active period of the first DRX cycle as an indication that the WTRU may go to sleep at an end of the minimum active period of the first DRX cycle;

receive a data indication message during the minimum active period of the first DRX cycle, the data indication message indicating that downlink data is to be transmitted to the WTRU;

remain in an awake state beyond the minimum active period of the first DRX cycle based on receiving the data indication message;

receive a DRX activation medium access control (MAC) message; and

resume DRX operation in response to receiving the DRX activation MAC message.

18. The WTRU of claim 17, wherein the processor is configured to receive the data indication signal via Layer 1 control signaling.

19. The WTRU of claim 17, wherein the processor is further configured to receive the downlink data on a shared data channel after staying awake in response to receiving the data indication message.

20. The WTRU of claim 17, wherein the processor is configured to awaken the WTRU at the start of a subsequent DRX cycle to monitor for reception of subsequent Layer 1 control signaling.

21. The WTRU of claim 20, wherein the processor is further configured to:

determine that the subsequent Layer 1 control signaling was not received during a minimum active period of the subsequent DRX cycle; and

put the WTRU to sleep until a beginning of a next DRX cycle based on determining that the subsequent Layer 1 control signaling was not received during the minimum active period of the subsequent DRX cycle.

22. The WTRU of claim 17, wherein the processor is further configured to receive a periodic allocation for a thin channel, wherein transmissions using the periodic allocation of the thin channel are configured to coincide with active periods of DRX cycles.

23. A wireless transmit receive unit (WTRU) comprising a processor configured, at least in part, to:

receive DRX setting information from the eNB in a radio resource control (RRC) message, the DRX setting information indicating a length of a minimum active period, wherein the minimum active period corresponds to a minimum amount of time during which the WTRU is configured to be active at a beginning of given DRX cycle;

monitor for reception of Layer 1 control signaling from the eNB during the minimum active period of a first DRX cycle, the Layer 1 control signaling indicating whether downlink data will be transmitted to the WTRU,

receive a data indication message during the minimum active period of the first DRX cycle, the data indication message indicating that downlink data is to be transmitted to the WTRU,

remain in an awake state beyond the minimum active period of the first DRX cycle based on receiving the data indication message,

receive a DRX activation medium access control (MAC) message, and

resume DRX operation in response to receiving the DRX activation MAC message.

24. The WTRU of claim 23, wherein the processor is configured to receive the data indication signal via Layer 1 control signaling.

25. The WTRU of claim 23, wherein the processor is further configured to receive the downlink data on a shared data channel after staying awake in response to receiving the data indication message.

26. The WTRU of claim 23, wherein the WTRU is configured to interpret not receiving the Layer 1 control signaling during the minimum active period of the first DRX cycle as an indication that the WTRU may go to sleep at an end of the minimum active period of the first DRX cycle.