DELAYED AND BUNDLED RETRANSMISSIONS FOR LOW BANDWIDTH APPLICATIONS

• US 20150092645A1
• Filed: 09/26/2014
• Published: 04/02/2015
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Tabet, Tarik, Majjigi, Vinay R., Mujtaba, Syed A., Mucke, Christian W.
• Granted Patent: US 9,615,329 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1825 Adaptation of specific ARQ protocol parameters according to transmission conditions
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1864 ARQ related signaling H04L1/1607 takes precedence
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04W 52/0222 in packet switched networks
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Apparatus and methods are disclosed for performing delayed hybrid automatic repeat request (HARQ) communications in the downlink (DL) to reduce power consumption for a user equipment (UE) during a connected mode discontinuous reception (C-DRX) cycle. An enhanced NodeB can be configured to monitor a physical uplink control channel (PUCCH) for DL HARQ information to determine when the PUCCH contains a negative acknowledgement (NACK) message, and in response to determining that the PUCCH contains a NACK message, the eNodeB can wait until a next C-DRX ON duration to transmit a HARQ DL retransmission. The eNodeB can also determine whether or not to bundle the HARQ DL retransmission in consecutive transmission time intervals, based on a signal to interference plus noise ratio (SINR) associated with the UE.

Claims

1. A method of saving power for a user equipment (UE) communicating via a long term evolution (LTE) network, the method comprising:

at a network base station;

monitoring a control channel for hybrid automatic repeat request (HARQ) information;

receiving a negative acknowledgement (NACK) message from the UE; and

in response to receiving the NACK message, delaying a HARQ retransmission for the UE such that the UE can remain inactive during a sleep mode of operation.

2. The method of claim 1, wherein the sleep mode of operation is an OFF duration of a connected mode discontinuous reception (C-DRX) cycle of the UE.

3. The method of claim 2, wherein the HARQ retransmission is delayed until a subsequent ON duration of the C-DRX cycle of the UE.

4. The method of claim 1, further comprising bundling the HARQ retransmission for the UE within consecutive downlink transmission time intervals (TTIs).

5. The method of claim 4, wherein the bundled HARQ retransmission is communicated to the UE along with a new downlink transmission on a physical downlink shared channel (PDSCH).

6. The method of claim 4, wherein the bundled HARQ retransmission comprises a plurality of HARQ transmissions that employ different modulation and coding schemes (MCSs).

7. The method of claim 1, further comprising determining to bundle the HARQ retransmission based at least in part on one or more signal to interference plus noise ratio (SINR) conditions of the UE, wherein the one or more SINR conditions comprise radio operating conditions that are degraded when the UE is communicating at a periphery of an LTE network cell.

8. The method of claim 1, further comprising:

determining when the UE is communicating low-bandwidth periodic application data;

in response to determining, lowering a block error rate (BLER) target for the UE to reduce or eliminate HARQ retransmissions for the UE while the UE is communicating the low-bandwidth periodic application data.

9. The method of claim 1, wherein the control channel is a physical uplink control channel (PUCCH) and the NACK message is received from the UE on the PUCCH.

10. A mobile device, comprising:

at least one transceiver configurable to communicate via a long term evolution (LTE) network;

one or more processors; and

a storage device storing executable instructions that, when executed by the one or more processors, cause the mobile device to;

identify a downlink transmission from a network base station as erroneous;

transmit a negative acknowledgement (NACK) message as part of a hybrid automatic repeat request (HARQ) communication to the network base station using the at least one transceiver; and

in response to a delayed HARQ retransmission, remain inactive during a sleep mode of operation of the mobile device to conserve power.

11. The mobile device of claim 10, wherein the downlink transmission is identified as erroneous by the mobile device when the mobile device does not receive an expected downlink transmission or when the downlink transmission is received by the mobile device but the received downlink transmission comprises one or more errors.

12. The mobile device of claim 10, wherein the sleep mode of operation is an OFF duration of a connected mode discontinuous reception (C-DRX) cycle of the mobile device.

13. The mobile device of claim 10, wherein execution of the executable instructions further causes the mobile device to receive the delayed HARQ retransmission during a subsequent ON duration of a connected mode discontinuous reception (C-DRX) cycle of the mobile device.

14. The mobile device of claim 10, wherein:

execution of the executable instructions further causes the mobile device to receive the delayed HARQ retransmission after the sleep mode of operation; and

the delayed HARQ retransmission is part of a bundled data transmission that is received by the mobile device within consecutive transmission time intervals (TTIs).

15. The mobile device of claim 14, wherein the bundled data transmission is received by the mobile device on a physical downlink shared channel (PDSCH), and the bundled data transmission further comprises a new downlink transmission.

16. The mobile device of claim 14, wherein the bundled data transmission comprises a plurality of HARQ transmissions that employ different modulation and coding schemes (MCSs).

17. The mobile device of claim 10, wherein the mobile device transmits the NACK message to the network base station on a physical uplink control channel (PUCCH).

18. A non-transitory computer-readable medium storing executable instructions that, when executed by one or more processors of a network base station, cause the network base station to:

monitor a physical uplink control channel (PUCCH) for hybrid automatic repeat request (HARQ) information;

receive a negative acknowledgement (NACK) message from a user equipment (UE) via the PUCCH; and

in response to receiving the NACK message, delay a HARQ retransmission for the UE such that the UE can remain inactive during an OFF duration of a connected mode discontinuous reception (C-DRX) cycle of the UE.

19. The non-transitory computer-readable medium of claim 18, wherein the HARQ retransmission for the UE is delayed until a subsequent ON duration of the C-DRX cycle of the UE.

20. The non-transitory computer-readable medium of claim 18, wherein execution of the executable instructions further causes the network base station to bundle the HARQ retransmission for the UE with a new downlink transmission within consecutive transmission time intervals (TTIs).