Flexible DTX and DRX in a wireless communication system

• US 8,169,957 B2
• Filed: 02/01/2008
• Issued: 05/01/2012
• Est. Priority Date: 02/05/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Damnjanovic, Aleksandar
• Primary Examiner(s): CHRISS, ANDREW W
• Application Number:
  US12/024,849
• Publication Number:
  US 20080186892A1
• Time in Patent Office: 1,551 Days
• Field of Search: 370/328
• US Class Current: 370/329
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A data traffic responsive battery-saving approach for a wireless user equipment (UE) device such as an data packet capable cellphone incorporates flexible discontinuous transmission and reception (DTX-DRX) when in Long Term Evolution (LTE) active mode as dictated by an evolved radio access network (RAN) such as an evolved base node (eNode B). A UE device requests are made on unsynchronized random access channel (RACH). Lengthening a duration of DRX and reducing requirements for synchronization uplink transmissions results in power savings of up to 75%, as well as creating opportunities for reducing interference and for allocating additional time slots for data. This power savings is compatible with other downlink scheduling proposals, with control channel-less Voice-over-IP (VoIP), and need not target those UE devices in bad radio conditions. Legacy UE devices that can interact with the eNode B by being capable of radio resource control (RRC) signaling continue to be compatible.

Claims

1. A method for reducing power consumption by varying user equipment discontinuous communication of reception on a downlink channel or transmission on an uplink channel with a base node, comprising:

specifying on a downlink channel a changed interval for discontinuous communication scheduling for a user equipment;

participating in communication with the user equipment following the changed interval at a nominal interval automatically reverted to by the user equipment; and

commanding extended microsleep in response to a low data rate downlink data transmission allowing the user equipment to enter extended microsleep.

2. The method of claim 1, wherein the changed interval is a longer interval than a nominal discontinuous reception cycle.

3. The method of claim 2, wherein the changed interval is a multiple of the nominal discontinuous reception cycle.

4. The method of claim 3, wherein discontinuous transmission by the user equipment is changed in alignment with discontinuous reception.

5. The method of claim 1, in which commanding extended microsleep comprises commanding extended microsleep upon decoding a data transmission without receiving a redundant retransmission;

and

the method further comprising sending an interleaved sequence of hybrid automatic repeat request downlink transmissions and retransmission to the user equipment.

6. The method of claim 1, further comprising recognizing ongoing nominal DRX by monitoring radio resource control (RRC) signaling from a user equipment that is not configured for flexible DRX.

7. The method of claim 1, further comprising transmitting the flexible DRX interval to the user equipment over a physical downlink control channel (PDCCH).

8. The method of claim 1, further comprising defining a flexible DRX interval in terms of an upload reference signal interval and offset for paging indication channel (PICH) interval and Physical uplink control channel (PUCCH) interval.

9. The method of claim 1, further comprising performing open loop power control on downlink transmission to the user equipment, the user equipment infrequently reporting channel quality indications during flexible DRX.

10. A computer program product for reducing power consumption by varying user equipment discontinuous communication of reception on a downlink channel or transmission on an uplink channel with a base node, comprising:

a non-transitory computer-readable medium, comprising;

a first set of codes configured to cause a computer to specify on a downlink channel a changed interval for a discontinuous communication scheduling for a user equipment;

a second set of codes configured to

cause the computer to participate in communication with the user equipment following the changed interval at a nominal interval automatically reverted to by the user equipment; and

a third set of codes configured to command extended microsleep in response to a low data rate downlink data transmission allowing the user equipment to enter extended microsleep.

11. A method for reducing power consumption by varying user equipment discontinuous communication of reception on a downlink channel or transmission on an uplink channel with a base node, comprising:

receiving on a downlink channel a changed interval for a discontinuous communication scheduling for a user equipment;

automatically reverting to a nominal communication interval following the changed interval; and

receiving a command for extended microsleep in response to a low data rate downlink data transmission.

12. The method of claim 11, wherein the changed interval is a longer interval than a nominal discontinuous reception cycle.

13. The method of claim 12, wherein the changed interval is a multiple of the nominal discontinuous reception cycle.

14. The method of claim 13, wherein discontinuous transmission by the user equipment is changed in alignment with discontinuous reception.

15. The method of claim 11, further comprising:

receiving an interleaved sequence of hybrid automatic repeat request downlink transmissions and retransmission by the user equipment; and

entering extended microsleep upon decoding a data transmission without receiving a redundant retransmission.

16. The method of claim 11, further comprising utilizing radio resource control (RRC) signaling to indicate noncompliance with the commanded changed interval when not configured for flexible DRX.

17. The method of claim 11, further comprising receiving the flexible DRX interval to the user equipment over a physical downlink control channel (PDCCH).

18. The method of claim 11, further comprising receiving a definition for a flexible DRX interval in terms of an upload reference signal interval and offset for paging indication channel (PICH) interval and Physical uplink control channel (PUCCH) interval.

19. The method of claim 11, further comprising receiving open loop power control on downlink transmission to the user equipment, the user equipment infrequently reporting channel quality indications during flexible DRX.

20. A computer program product for reducing power consumption by varying user equipment discontinuous communication of reception on a downlink channel or transmission on an uplink channel with a base node, comprising:

a non-transitory computer-readable medium, comprising;

a first set of codes configured to cause a computer to receive on a downlink channel a changed interval for a discontinuous communication scheduling for a user equipment;

a second set of codes configured to

cause the computer to automatically reverting to a nominal communication interval following the changed interval; and

a third set of codes configured to receive a command for extended microsleep in response to a low data rate downlink data transmission.