Resource request for uplink transmission

1. A method for informing an access point of a wireless local area network (WLAN) that a client station has data to transmit to the access point, the method comprising:

generating, at the client station, a media access control (MAC) data unit (MPDU) that includes a MAC header, wherein the MAC header includes a control field that indicates an amount of data queued at the client station for transmission to the access point, wherein the control field includes i) a first subfield that specifies a scale factor, and ii) a second subfield that specifies a base value, and wherein multiplying the specified base value by the specified scale factor indicates the amount of data queued at the client station.

2. The method of claim 1 , wherein:

the method further comprises: generating, at the client station, the control field of the MAC header to include a third subfield that indicates a first category of traffic, among a plurality of categories of traffic, queued at the client station for transmission to the access point; and

multiplying the specified base value by the specified scale factor indicates the amount of data in the first category of traffic queued at the client station.

3. The method of claim 2 , wherein:

the base value is a first base value corresponding to the first category of traffic;

the method further comprises:

generating, at the client station, the control field of the MAC header to further indicate a group of categories of traffic, from among a plurality of categories of traffic, queued at the client station for transmission to the access point, and

generating, at the client station, the control field of the MAC header to further include a fourth subfield that specifies a second base value that corresponds to the group of categories of traffic; and

multiplying the specified second base value by the specified scale factor indicates the amount of data in the group of categories of traffic queued at the client station.

4. The method of claim 3 , wherein generating the control field of the MAC header to further indicate the group of categories of traffic comprises generating the control field of the MAC header to include a bitmap, wherein bits of the bitmap correspond to respective categories of traffic.

5. The method of claim 1 , wherein:

the base value is in units of bytes.

6. The method of claim 1 , wherein:

a communication protocol defines multiple variants of the control field with respective different formats; and

the method further comprises: generating, at the client station, the control field of the MAC header to include information specifying one variant from among the multiple variants.

7. The method of claim 1 , wherein:

the MPDU is a first MPDU;

the method further comprises:

receiving, at the client station, a second MPDU from the access point, and

generating, at the client station, the first MPDU to include acknowledgment information regarding the second MPDU; and

transmitting the first MPDU to the access point is responsive to receiving the second MPDU from the access point.

8. The method of claim 1 , wherein:

the method further comprises: receiving, at the client station, a sync frame from the access point;

the sync frame is configured to prompt the client station to transmit information regarding the amount of data queued at the client station for transmission to the access point; and

generating and transmitting the MPDU are responsive to receiving the sync frame from the access point.

9. The method of claim 8 , wherein:

the sync frame is configured to prompt multiple client stations to transmit, as part of an uplink multi-user (UL MU) transmission, respective information regarding amounts of data queued at the multiple client stations for transmission to the access point; and

the client station transmits the MPDU as part of the UL MU transmission by the multiple client stations.

10. A communication device, comprising:

a network interface device associated with a client station of a wireless local area network (WLAN), wherein the network interface device includes one or more integrated circuits (ICs) configured to:

generate a media access control (MAC) data unit (MPDU) that includes a MAC header, wherein the MAC header includes a control field that indicates an amount of data queued at the client station for transmission to the access point, wherein the control field includes i) a first subfield that specifies a scale factor,

transmit the MPDU to the access point to inform the access point of the amount of data queued at the client station for transmission to the access point;

wherein the one or more ICs are further configured to generate the control field of the MAC header to include a second subfield that indicates a first category of traffic, among a plurality of categories of traffic, queued at the client station for transmission to the access point; and

multiplying a specified base value by the specified scale factor indicates the amount of data in the first category of traffic queued at the client station.

11. The communication device of claim 10 , wherein:

the specified base value is a first base value corresponding to the first category of traffic;

the one or more ICs are further configured to:

generate the control field of the MAC header to further indicate a group of categories of traffic, from among a plurality of categories of traffic, queued at the client station for transmission to the access point, and

generate the control field of the MAC header to further include a third subfield that specifies a second base value that corresponds to the group of categories of traffic; and

multiplying the specified second base value by the specified scale factor indicates the amount of data in the group of categories of traffic queued at the client station.

12. The communication device of claim 11 , wherein the one or more ICs are further configured to generate the control field of the MAC header to further indicate the group of categories of traffic at least by generating the control field of the MAC header to include a bitmap, wherein bits of the bitmap correspond to respective categories of traffic.

13. The communication device of claim 10 , wherein: the specified base value is in units of bytes.

14. The communication device of claim 10 , wherein:

a communication protocol defines multiple variants of the control field with respective different formats; and

the one or more ICs are further configured to generate the control field of the MAC header to include information specifying one variant from among the multiple variants.

15. The communication device of claim 10 , wherein:

the MPDU is a first MPDU;

the one or more ICs are further configured to:

receive a second MPDU from the access point,

generate the first MPDU to include acknowledgment information regarding the second MPDU, and

transmit the first MPDU to the access point in response to receiving the second MPDU from the access point.

16. The communication device of claim 10 , wherein the one or more ICs are further configured to:

receive a sync frame from the access point, wherein the sync frame is configured to prompt the client station to transmit information regarding the amount of data queued at the client station for transmission to the access point; and

generate and transmit the MPDU in response to receiving the sync frame from the access point.

17. The communication device of claim 16 , wherein:

the sync frame is configured to prompt multiple client stations to transmit, as part of an uplink multi-user (UL MU) transmission, respective information regarding amounts of data queued at the multiple client stations for transmission to the access point; and

the one or more ICs are further configured to transmit the MPDU as part of the UL MU transmission by the multiple client stations.