Transmission Protection For Wireless Communications

• US 20110194644A1
• Filed: 02/10/2011
• Published: 08/11/2011
• Est. Priority Date: 02/10/2010
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Liu, Yong, Ramamurthy, Harish, Banerjea, Raja
• Granted Patent: US 8,532,221 B2
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04W 72/121 for groups of terminals or users
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Systems and techniques relating to wireless communications are described. A described technique includes identifying devices to receive spatially steered data frames during a transmission opportunity (TXOP), the data frames being included in a multi-user frame; transmitting, during the TXOP, request to send (RTS) information to the identified devices; receiving clear to send (CTS) responses from the identified devices; determining a bandwidth configuration for the multi-user frame based on the CTS responses; and transmitting, during the TXOP, the multi-user frame to the identified devices in accordance with the bandwidth configuration. The bandwidth configuration can indicate one or more frequency bands that are available during at least a portion of the TXOP.

Claims

1. A method, comprising:

identifying devices to receive spatially steered data frames during a transmission opportunity (TXOP), the data frames being included in a multi-user frame;

transmitting, during the TXOP, request to send (RTS) information to the identified devices;

receiving clear to send (CTS) responses from the identified devices;

determining a bandwidth configuration for the multi-user frame based on the CTS responses, the bandwidth configuration indicating one or more frequency bands that are available during at least a portion of the TXOP; and

transmitting, during the TXOP, the multi-user frame to the identified devices in accordance with the bandwidth configuration.

2. The method of claim 1, wherein

transmitting the RTS information comprises transmitting a first RTS frame to a first device of the identified devices,

receiving the CTS responses comprises receiving, after transmitting the first RTS frame, a first CTS frame,

transmitting the RTS information comprises transmitting, based on receiving the first CTS frame, a second RTS frame to a second device of the identified devices, and

receiving the CTS responses comprises receiving, after transmitting the second RTS frame, a second CTS frame.

3. The method of claim 2, wherein

a first bandwidth configuration indicated by the first CTS frame is equal to or less than a bandwidth configuration indicated by the first RTS frame, the first bandwidth configuration being based on an available bandwidth at the first device,

a second bandwidth configuration indicated by the second CTS frame is equal to or less than a bandwidth configuration indicated by the second RTS frame, the second bandwidth configuration being based on an available bandwidth at the second device, and

determining the bandwidth configuration for the multi-user frame comprises selecting a smallest bandwidth configuration indicated by the CTS responses.

4. The method of claim 3, further comprising:

selecting the bandwidth configuration indicated by the second RTS frame to be less than or equal to the bandwidth configuration indicated by the first CTS frame.

5. The method of claim 2, wherein transmitting the second RTS frame comprises transmitting the second RTS frame responsive to an expiration of a timer, wherein the timer is configured based on i) receiving the first CTS frame and ii) an interframe space (IFS) parameter, and wherein the second device is configured to determine an availability of two or more channels during a duration of the timer.

6. The method of claim 2, wherein transmitting the second RTS frame comprises transmitting the second RTS frame responsive to an expiration of a timer, wherein the timer is configured based on i) receiving the first CTS frame and ii) a short interframe space (SIFS) parameter, and wherein the second CTS frame indicates the same bandwidth configuration as indicated by the second RTS frame.

7. The method of claim 1, wherein

the multi-user frame comprises i) data belonging to a primary access category and ii) data belonging to a secondary access category,

identifying the devices comprises identifying a primary device of the devices that will receive data belonging to the primary access category, and

transmitting the RTS information comprises transmitting an initial RTS frame to the primary device.

8. The method of claim 1, wherein transmitting the RTS information comprises transmitting a multi-user RTS (MU-RTS) frame to cause the identified devices to transmit the CTS responses.

9. The method of claim 8, wherein receiving the CTS responses comprises receiving, during a response period associated with the MU-RTS frame, CTS frames via respective spatial wireless communication channels.

10. The method of claim 1, wherein the CTS responses comprise an indication of one or more valid frequency bands available for transmission, the one or more frequency bands providing an aggregate bandwidth of 20 MHz, 40 MHz, 80 MHz, or 160 MHz.

11. An apparatus, comprising:

circuitry to access a wireless communication interface; and

processor electronics configured to

identify devices to receive spatially steered data frames during a transmission opportunity (TXOP), the data frames being included in a multi-user frame;

transmit, during the TXOP, request to send (RTS) information to the identified devices;

receive clear to send (CTS) responses from the identified devices;

determine a bandwidth configuration for the multi-user frame based on the CTS responses, the bandwidth configuration indicating one or more frequency bands that are available during at least a portion of the TXOP; and

control, during the TXOP, a transmission of the multi-user frame via the wireless communication interface to the identified devices in accordance with the bandwidth configuration.

12. The apparatus of claim 11, wherein the processor electronics are configured to

transmit a first RTS frame to a first device of the identified devices, the RTS information including the first RTS frame,

receive a first CTS frame in response to the first RTS frame, the CTS responses including the first CTS frame,

transmit, responsive to receiving the first CTS frame, a second RTS frame to a second device of the identified devices, the RTS information including the second RTS frame, and

receive a second CTS frame in response to the second RTS frame, the CTS responses including the second CTS frame.

13. The apparatus of claim 12, wherein

a first bandwidth configuration indicated by the first CTS frame is equal to or less than a bandwidth configuration indicated by the first RTS frame, the first bandwidth configuration being based on an available bandwidth at the first device,

a second bandwidth configuration indicated by the second CTS frame is equal to or less than a bandwidth configuration indicated by the second RTS frame, the second bandwidth configuration being based on an available bandwidth at the second device, and

the processor electronics are configured to determine the bandwidth configuration for the multi-user frame based on selecting a smallest bandwidth configuration indicated by the CTS responses.

14. The apparatus of claim 13, wherein the processor electronics are configured to select the bandwidth configuration indicated by the second RTS frame to be less than or equal to the bandwidth configuration indicated by the first CTS frame.

15. The apparatus of claim 12, wherein transmitting the second RTS frame is responsive to an expiration of a timer, wherein the timer is configured based on i) receiving the first CTS frame and ii) an interframe space (IFS) parameter, and wherein the second device is configured to determine an availability of two or more channels during a duration of the timer.

16. The apparatus of claim 12, wherein transmitting the second RTS frame is responsive to an expiration of a timer, wherein the timer is configured based on i) receiving the first CTS frame and ii) a short interframe space (SIFS) parameter, and wherein the second CTS frame indicates the same bandwidth configuration as indicated by the second RTS frame.

17. The apparatus of claim 16, wherein

the multi-user frame comprises i) data belonging to a primary access category and ii) data belonging to a secondary access category,

the processor electronics are configured to identify a primary device of the devices that will receive data belonging to the primary access category, and

transmitting the RTS information comprises transmitting an initial RTS frame to the primary device.

18. The apparatus of claim 11, wherein transmitting the RTS information comprises transmitting a multi-user RTS (MU-RTS) frame to cause the identified devices to transmit the CTS responses.

19. The apparatus of claim 18, wherein receiving the CTS responses comprises receiving, during a response period associated with the MU-RTS frame, CTS frames via respective spatial wireless communication channels.

20. The apparatus of claim 11, wherein the CTS responses comprise an indication of one or more valid frequency bands available for transmission, the one or more frequency bands providing an aggregate bandwidth of 20 MHz, 40 MHz, 80 MHz, or 160 MHz.

21. A system comprising:

processor electronics configured to

identify devices to receive spatially steered data frames during a transmission opportunity (TXOP), the data frames being included in a multi-user frame;

transmit, during the TXOP, request to send (RTS) information to the identified devices;

receive clear to send (CTS) responses from the identified devices;

determine a bandwidth configuration for the multi-user frame based on the CTS responses, the bandwidth configuration indicating one or more frequency bands that are available during at least a portion of the TXOP; and

circuitry to transmit, during the TXOP, the multi-user frame to the identified devices in accordance with the bandwidth configuration.

22. The system of claim 21, wherein the processor electronics are configured to

transmit a first RTS frame to a first device of the identified devices, the RTS information including the first RTS frame,

receive a first CTS frame in response to the first RTS frame, the CTS responses including the first CTS frame,

transmit, responsive to receiving the first CTS frame, a second RTS frame to a second device of the identified devices, the RTS information including the second RTS frame, and

receive a second CTS frame in response to the second RTS frame, the CTS responses including the second CTS frame.

23. The system of claim 22, wherein

a first bandwidth configuration indicated by the first CTS frame is equal to or less than a bandwidth configuration indicated by the first RTS frame, the first bandwidth configuration being based on an available bandwidth at the first device,

a second bandwidth configuration indicated by the second CTS frame is equal to or less than a bandwidth configuration indicated by the second RTS frame, the second bandwidth configuration being based on an available bandwidth at the second device, and

the processor electronics are configured to determine the bandwidth configuration for the multi-user frame based on selecting a smallest bandwidth configuration indicated by the CTS responses.