UPLINK TRANSMISSION RATE IN A WIRELESS COMMUNICATION DEVICE

• US 20150296059A1
• Filed: 04/11/2014
• Published: 10/15/2015
• Est. Priority Date: 04/11/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Karri, Sai Sravan Bharadwaj, Rawat, Naveen
• Granted Patent: US 9,491,269 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 1/1858 Transmission or retransmission of more than one copy of acknowledgement message
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 80/02 Data link layer protocols

Abstract

A method for improving uplink transmission rate in a wireless communication device is provided. The wireless communication device can include a first logical layer and a second logical layer. The method can include the wireless communication device decoding, at the first logical layer, a first acknowledgement status of a transmitted data unit. The method can further include the wireless communication device determining, at the first logical layer, a second acknowledgement status of the data unit, which can be an acknowledgement status of the data unit at the second logical layer. The method can additionally include the wireless communication device determining, at the first logical layer, whether to retransmit the data unit based at least in part on both the first acknowledgement status of the data unit and the second acknowledgement status of the data unit.

Claims

1. A method for improving uplink transmission rate in a wireless communication device comprising a media access control (MAC) layer and a radio link control (RLC) layer, the method comprising the wireless communication device:

transmitting a data unit on an uplink to a Long Term Evolution (LTE) network;

decoding, at the MAC layer, an acknowledgement status of the data unit received to the wireless communication device on a physical hybrid automatic repeat request indicator channel (PHICH);

determining, at the MAC layer, an acknowledgement status of the data unit at the RLC layer, wherein the acknowledgement status of the data unit at the RLC layer is received to the wireless communication device on a physical downlink shared channel (PDSCH); and

determining, at the MAC layer, whether to perform hybrid automatic repeat request (HARQ) retransmission of the data unit based at least in part on both the acknowledgement status of the data unit decoded at the MAC layer and the acknowledgement status of the data unit at the RLC layer.

2. The method of claim 1, wherein the acknowledgement status decoded at the MAC layer is an acknowledgement (ACK), and wherein determining whether to perform HARQ retransmission of the data unit comprises the MAC layer:

determining to perform HARQ retransmission of the data unit in an instance in which the acknowledgement status of the data unit at the RLC layer is a negative-acknowledgement (NACK); and

determining not to perform HARQ retransmission of the data unit in an instance in which the acknowledgement status of the data unit at the RLC layer is also an ACK.

3. The method of claim 2, wherein the method further comprises the wireless communication device, in response to decoding the ACK at the MAC layer:

initiating transmission of a next data unit on the uplink prior to the MAC layer determining the acknowledgement status of the data unit at the RLC layer.

4. The method of claim 2, wherein the method further comprises the wireless communication device waiting to initiate transmission of a next data unit on the uplink at least until after determining whether to perform HARQ retransmission of the data unit.

5. The method of claim 1, wherein the acknowledgement status decoded at the MAC layer is a negative-acknowledgement (NACK), and wherein determining whether to perform HARQ retransmission of the data unit comprises the MAC layer:

determining to perform HARQ retransmission of the data unit in an instance in which the acknowledgement status of the data unit at the RLC layer is also a NACK; and

determining not to perform HARQ retransmission of the data unit in an instance in which the acknowledgement status of the data unit at the RLC layer is an acknowledgement (ACK).

6. The method of claim 5, wherein the method further comprises the wireless communication device, in response to decoding the NACK at the MAC layer:

initiating HARQ retransmission of the data unit at the MAC layer prior to determining the acknowledgement status of the data unit at the RLC layer;

completing HARQ retransmission of the data unit in an instance in which the acknowledgement status of the data unit at the RLC layer is also a NACK; and

terminating HARQ retransmission of the data unit in an instance in which the acknowledgement status of the data unit at the RLC layer is an acknowledgement (ACK).

7. The method of claim 1, wherein determining the acknowledgement status of the data unit at the RLC layer comprises the MAC layer:

determining a sequence identifier of a most recent transmitted data unit acknowledged at the RLC layer; and

determining whether the sequence identifier of the most recent transmitted data unit acknowledged at the RLC layer corresponds to a sequence identifier of the data unit.

8. The method of claim 1, wherein determining the acknowledgement status of the data unit at the RLC layer comprises the MAC layer:

polling the RLC layer to determine the acknowledgement status of the data unit at the RLC layer; and

receiving a polling response from the RLC layer, the polling response indicating the acknowledgement status of the data unit at the RLC layer.

9. The method of claim 8, wherein polling the RLC layer comprises periodically polling the RLC layer for an indication of a most recent transmitted data unit acknowledged at the RLC layer.

10. The method of claim 8, wherein polling the RLC layer comprises polling the RLC layer in response to receiving the acknowledgement status of the data unit decoded at the MAC layer.

11. The method of claim 8, wherein polling the RLC layer comprises one of:

polling the RLC layer for an acknowledgement status of a sequence identifier of the data unit;

or

polling the RLC layer for a sequence identifier of a most recent transmitted data unit acknowledged at the RLC layer.

12. A wireless communication device comprising:

a wireless communication interface configured to send signals to and receive signals from a wireless network; and

processing circuitry coupled with the wireless communication interface, wherein the processing circuitry is configured to cause the wireless communication device to at least;

implement a first logical layer and a second logical laver, wherein the second logical layer is a higher layer on a protocol stack than the first logical layer;

transmit a data unit on an uplink;

decode, at the first logical layer, a first acknowledgement status of the data unit;

determine, at the first logical layer, a second acknowledgement status of the data unit, wherein the second acknowledgement status of the data unit is an acknowledgement status of the data unit at the second logical layer; and

determine, at the first logical layer, whether to retransmit the data unit based at least in part on both the first acknowledgement status of the data unit and the second acknowledgement status of the data unit.

13. The wireless communication device of claim 12, wherein the first logical layer is a media access control (MAC) layer, and wherein the second logical layer is a radio link control (RLC) layer.

14. The wireless communication device of claim 12, wherein:

the first acknowledgement status of the data unit is received to the wireless communication device on a physical hybrid automatic repeat request indicator channel (PHICH); and

the second acknowledgement status of the data unit is received to the wireless communication device on a physical downlink shared channel (PDSCH).

15. The wireless communication device of claim 12, wherein the processing circuitry is further configured to cause the wireless communication device to determine whether to retransmit the data unit at least in part by causing the wireless communication device to determine whether to perform hybrid automatic repeat request (HARQ) retransmission of the data unit.

16. The wireless communication device of claim 12, wherein:

in an instance in which the first acknowledgement status of the data unit is an acknowledgement (ACK), the processing circuitry is further configured to cause the wireless communication device to determine whether to retransmit the data unit at least in part by causing the wireless communication device to;

determine, at the first logical layer, to retransmit the data unit in an instance in which the second acknowledgement status of the data unit is a negative-acknowledgement (NACK); and

determine, at the first logical layer, not to retransmit the data unit in an instance in which the second acknowledgement status of the data unit is also an ACK; and

in an instance in which the first acknowledgement status of the data unit is a NACK, the processing circuitry is further configured to cause the wireless communication device to determining whether to retransmit the data unit at least in part by causing the wireless communication device to;

determine, at the first logical layer, to retransmit the data unit in an instance in which the second acknowledgement status of the data unit is also a NACK; and

determine, at the first logical layer, not to retransmit the data unit in an instance in which the second acknowledgement status of the data unit is an ACK.

17. The wireless communication device of claim 12, wherein the processing circuitry is further configured to cause the wireless communication device to determine, at the first logical layer, the second acknowledgement status of the data unit at least in part by causing the wireless communication device to cause the first logical layer to:

poll the second logical layer to determine the second acknowledgement status of the data unit; and

receive a polling response from the second logical layer, the polling response indicating the second acknowledgement status of the data unit.

18. A non-transitory computer readable storage medium having computer program code stored thereon, the computer program code comprising program code, which, when executed by one or more processors implemented on a wireless communication device configured to implement a first logical layer and a second logical layer, is configured to cause the wireless communication device to perform a method comprising:

determining, at the first logical layer, an acknowledgement status of a data unit transmitted on an uplink, wherein the acknowledgement status of the data unit is an acknowledgement status of the data unit at the second logical layer; and

determining, at the first logical layer, whether to retransmit the data unit based at least in part on the acknowledgement status of the data unit.

19. The non-transitory computer readable storage medium of claim 18, wherein the first logical layer is a media access control (MAC) layer, and wherein the second logical layer is a radio link control (RLC) layer.

20. The non-transitory computer readable storage medium of claim 19, wherein:

the acknowledgement status of the data unit is received to the wireless communication device on a physical downlink shared channel (PDSCH); and

determining whether to retransmit the data unit comprises determining whether to perform hybrid automatic repeat request (HARQ) retransmission of the data unit.