Downlink OFDMA for service sets with mixed client types

• US 9,363,048 B2
• Filed: 09/19/2013
• Issued: 06/07/2016
• Est. Priority Date: 03/10/2010
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Hart, Brian D.
• Primary Examiner(s): GREY, CHRISTOPHER P
• Application Number:
  US14/031,472
• Publication Number:
  US 20140016607A1
• Time in Patent Office: 992 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0028 Variable division signaling therefor H04L5/0092
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0087 when data requirements change
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Techniques are provided herein to allow a wireless network access point (AP) to more fully use its bandwidth in order to leverage the different bandwidth capabilities of different types of wireless client devices that the AP serves. The AP generates control parameters for usage of a plurality of channels in a bandwidth during a downlink transmission interval. The control parameters comprise information indicating channel assignments that result in multiple downlink transmissions that at least partially overlap in time to different wireless client devices according to their respective bandwidth capabilities. The AP transmits the control parameters in a control frame in advance of the downlink transmission interval on each of the plurality of channels in the bandwidth.

Claims

1. A method comprising:

at a wireless access point that serves at least first and second wireless devices having lower and higher bandwidth capabilities, respectively;

generating control parameters including information that;

assigns first and second non-overlapping channel bandwidths for first and second downlink transmissions to the first and second wireless devices, respectively; and

indicates timing for an acknowledgement to be sent from the first device and after which an acknowledgement from the second device is to be sent;

transmitting a first downlink transmission to the first device over the first channel bandwidth at a lower data rate during a first time interval;

transmitting a second downlink transmission to the second device over the second channel bandwidth at a higher data rate during a second time interval that partially overlaps with and ends at or before the first time interval; and

transmitting a false acknowledgement message that does not acknowledge anything over the second bandwidth after the second time interval and during the first time interval.

2. The method of claim 1, wherein the wireless access point serves the first device having the lower bandwidth capability and one or more second devices having the higher bandwidth capability, and the generating includes generating control parameters including information to indicate that acknowledgement messages are to be sent from the one or more higher bandwidth second devices in sequence after the acknowledgment from the lower bandwidth first device.

3. The method of claim 2, further comprising, at the wireless access point, receiving acknowledgements from the lower bandwidth first device and the one or more higher bandwidth second devices over the first channel bandwidth assigned to the lower bandwidth first device.

4. The method of claim 3, wherein:

the generating includes generating the control parameters to include information that assigns one or more second non-overlapping channel bandwidths that do not overlap with the first channel bandwidth for downlink transmissions to the one or more higher bandwidth second devices.

5. The method of claim 1, wherein:

the generating includes generating control parameters including information to assign the second channel bandwidth to the higher bandwidth second device as multiple contiguous channels selected from a set of available channels and bonded together; and

the transmitting the false acknowledgement includes transmitting the false acknowledgement over the multiple contiguous channels bonded together.

6. The method of claim 1, wherein the transmitting a second downlink transmission including transmitting a physical layer convergence protocol (PLCP) header in the downlink transmission including a field to identify channels selected from among a set of channels and assigned to the second device, the field including bits encoded so that three bits represents a bandwidth of 80 MHz and five bits represents a bandwidth of 160 MHz.

7. The method of claim 1, further comprising, at the wireless access point, determining the respective bandwidth capabilities of the different devices, wherein the determining includes determining the lower bandwidth first device is a legacy device that operates in accordance with one of an IEEE 802.11a and 802.11n standards and the higher bandwidth device operates in accordance with an IEEE 802.11ac standard.

8. The method of claim 1, further comprising polling at least one of the at least first and second devices for acknowledgements and receiving at least one polled acknowledgements from the at least one of the first and second polled devices.

9. An apparatus comprising:

at least one transmitter and a receiver respectively configured to transmit wireless signals to and receive signals from different wireless devices having different respective bandwidth capabilities; and

a controller configured to be coupled to the at least one transmitter and the receiver, wherein the controller is configured to;

generate control parameters based on the different bandwidth capabilities, the control parameters including information that;

assigns first and second non-overlapping channel bandwidths for first and second downlink transmissions to first and second devices having lower and higher bandwidth capabilities, respectively; and

indicates timing for an acknowledgement to be sent from the first device and after which an acknowledgement from the second device is to be sent;

cause the at least one transmitter to transmit a first downlink transmission to the first device over the first channel bandwidth at a lower data rate during a first time interval;

cause the at least one transmitter to transmit a second downlink transmission to the second device over the second channel bandwidth at a higher data rate during a second time interval that partially overlaps with and ends at or before the first time interval; and

cause the at least one transmitter to transmit a false acknowledgement message that does not acknowledge anything over the second bandwidth after the second time interval and during the first time interval.

10. The apparatus of claim 9, wherein the at least one transmitter is configured to transmit signals to the first device having the lower bandwidth capability and one or more second devices having the lower bandwidth capability, and the controller is configured to generate by generating control parameters including information to indicate that acknowledgement messages are to be sent from the one or more higher bandwidth second devices in sequence after the acknowledgment from the lower bandwidth first device.

11. The apparatus of claim 10, wherein the controller is further configured to receive acknowledgements from the lower bandwidth first device and the one or more higher bandwidth second devices over the first channel bandwidth assigned to the lower bandwidth first device.

12. The apparatus of claim 11, wherein:

the controller is configured to generate by generating the control parameters to include information that assigns one or more second non-overlapping channel bandwidths that do not overlap with the first channel bandwidth for downlink transmissions to the one or more higher bandwidth second devices.

13. The apparatus of claim 9, wherein:

the controller is configured to generate by generating control parameters including information to assign the second channel bandwidth to the higher bandwidth second device as multiple contiguous channels selected from a set of available channels and bonded together; and

the controller is configured to cause the at least one transmitter to transmit by causing the transmitter to transmit the false acknowledgement includes transmitting the false acknowledgement over the multiple contiguous channels bonded together.

14. The apparatus of claim 9, wherein the controller is configured to cause the at least one transmitter to transmit by causing the at least one transmitter to transmit a second downlink transmission including transmitting a physical layer convergence protocol (PLCP) header in the downlink transmission including a field to identify channels selected from among a set of channels and assigned to the second device, the field including bits encoded so that three bits represents a bandwidth of 80 MHz and five bits represents a bandwidth of 160 MHz.

15. The apparatus of claim 9, wherein the controller is further configured to determine the respective bandwidth capabilities of the different devices, wherein the determining includes determining the lower bandwidth first device is a legacy device that operates in accordance with one of an IEEE 802.11a and 802.11n standards and the higher bandwidth device operates in accordance with an IEEE 802.11ac standard.

16. A non-transitory computer readable medium storing instructions that,

when executed by a processor, cause the processor to:

at a wireless access point that serves different wireless devices having different respective bandwidth capabilities, generate control parameters based on the different bandwidth capabilities, the control parameters including information that;

assigns first and second non-overlapping channel bandwidths for first and second downlink transmissions to first and second devices having lower and higher bandwidth capabilities, respectively; and

indicates timing for an acknowledgement to be sent from the first device and after which an acknowledgement from the second device is to be sent;

cause a transmitter to transmit a first downlink transmission to the first device over the first channel bandwidth at a lower data rate during a first time interval; and

cause the transmitter to transmit a second downlink transmission to the second device over the second channel bandwidth at a higher data rate during a second time interval that partially overlaps with and ends at or before the first time interval; and

cause the transmitter to transmit a false acknowledgement message that does not acknowledge anything over the second bandwidth after the second time interval and during the first time interval.

17. The non-transitory computer readable medium of claim 16, wherein the wireless access point serves the first device having the lower bandwidth capability and one or more second devices having the higher bandwidth capability, and the instructions to cause the processor to generate include instructions to cause the processor to generate control parameters including information to indicate that acknowledgement messages are to be sent from the one or more higher bandwidth second devices in sequence after the acknowledgment from the lower bandwidth first device.

18. The non-transitory computer readable medium of claim 17, further comprising instructions to cause the processor to receive acknowledgements from the lower bandwidth first device and the one or more higher bandwidth second devices over the first channel bandwidth assigned to the lower bandwidth first device.

19. The non-transitory computer readable medium of claim 18, wherein:

the instructions to cause the processor to generate include further instructions to cause the processor to generate the control parameters to include information that assigns one or more second non-overlapping channel bandwidths that do not overlap with the first channel bandwidth for downlink transmissions to the one or more higher bandwidth second devices.

20. The non-transitory computer readable medium of claim 16, wherein:

the instructions to cause the processor to generate include instructions to cause the processor to generate control parameters including information to assign the second channel bandwidth to the higher bandwidth second device as multiple contiguous channels selected from a set of available channels and bonded together; and

the instruction to cause the processor to cause the transmitter to transmit the false acknowledgement include instructions to cause the processor to cause the transmitter to transmit the false acknowledgement over the multiple contiguous channels bonded together.