Wireless communication device

1. A wireless communication device communicating with a plurality of other wireless communication devices comprising:

controlling circuitry configured to select, from among the other wireless communication devices, first wireless communication devices for inquiring whether to have data for uplink multiuser multiplexing transmission and determine parameter information of a contention window used in CSMA/CA (carrier sense multiple access/collision avoidance) for the first wireless communication devices on basis of a number of the first wireless communication devices;

a transmitter configured to transmit a first frame to the first wireless communication devices, wherein the first frame includes information to specify the first wireless communication devices and the parameter information, and the first frame instructs the first wireless communication devices to use the contention window based on the parameter information for acquisition of a transmission right for transmission of a response frame for the first frame; and

a receiver configured to sequentially receive second frames transmitted based on the acquired transmission right from the first wireless communication devices in a single user manner wherein the second frames are response frames for the first frame and the transmission right is acquired under carrier sensing during a backoff time determined based on a value selected randomly from the contention window,

wherein the controlling circuitry is configured to select second wireless communication devices for execution of uplink multiuser multiplexing transmission from among the first wireless communication devices which have transmitted the second frame.

2. The wireless communication device according to claim 1 , wherein the parameter information defines a range of random numbers as the contention window, and

the controlling circuitry is configured to determine the parameter information so as to increase the range of random numbers as the number of first wireless communication devices increases.

3. The wireless communication device according to claim 1 , wherein the controlling circuitry is configured to determine the parameter information on basis of a number of wireless communication devices supporting an uplink multiuser multiplexing scheme among the first wireless communication devices.

4. The wireless communication device according to claim 1 , wherein the controlling circuitry is configured to determine the parameter information on basis of a number of wireless communication devices that are not transited into a low power consumption mode among the first wireless communication devices.

5. The wireless communication device according to claim 1 , wherein the transmitter is configured to transmit a fourth frame including information to specify the second wireless communication devices, and

the receiver is configured to receive fifth frames transmitted in the uplink multiuser multiplexing from the second wireless communication devices a predetermined time after the fourth frame is transmitted.

6. The wireless communication device according to claim 5 , wherein the transmitter is configured to transmit the fourth frame when a predetermined condition is satisfied after the first frame is transmitted.

7. The wireless communication device according to claim 6 , wherein the transmitter is configured to transmit the fourth frame when at least any one of following cases is established as the predetermined condition: a case where a predetermined time limit reaches after the first frame is transmitted; a case where response frames are received from a predetermined number of wireless communication devices of the wireless communication devices specified in the fourth frame after the first frame is transmitted; and a case where response frames are received from all of the first wireless communication devices specified in the first frame.

8. The wireless communication device according to claim 1 , wherein the receiver is configured to receive a sixth frame from one of the other wireless communication devices,

the controlling circuitry is configured to select, when the sixth frame is received from the first wireless communication devices from among wireless communication devices other than one of the other wireless communication devices; and

select, the second wireless communication devices from among the one of the other wireless communication devices and the first wireless communication devices which have transmitted the response frames.

9. The wireless communication device according to claim 1 , further comprising at least one antenna.

10. A wireless communication device communicating with a plurality of other wireless communication devices, comprising:

controlling circuitry configured to select, from among the other wireless communication devices, first wireless communication devices for inquiring whether to have data for uplink multiuser multiplexing transmission and determine parameter information of a contention window used in CSMA/CA (carrier sense multiple access/collision avoidance) for the first wireless communication devices on a basis of a number of the first wireless communication devices;

a transmitter configured to transmit a first frame to the first wireless communication devices, wherein the first frame includes information to specify the first wireless communication devices and the parameter information, and the first frame instructs the first wireless communication devices to use the contention window based on the parameter information for acquisition of transmission right for transmission of a response frame for the first frame; and

a receiver configured to sequentially receive second frames transmitted based on the acquired transmission right from the first wireless communication devices in a single user manner, wherein the second frames are response frames for the first frame and

include identification of whether the first wireless communication devices have the data for uplink multiuser multiplexing transmission,

wherein

the controlling circuitry is configured to specify wireless communication devices having the data for uplink multiuser multiplexing transmission from among the first wireless communication devices based on the received second frames and to select second wireless communication devices for execution of the uplink multiuser multiplexing transmission from among the specified wireless communication devices.

11. A wireless communication device comprising:

a receiver configured to receive a first frame including information to specify one or more wireless communication devices from a base station; and

controlling circuitry configured to determine parameter information of a contention window used in CSMA/CA based on a number of the wireless communication devices specified in the first frame and perform carrier sensing during a backoff time determined based on a value selected randomly from the contention window specified by the parameter information; and

a transmitter configured to transmit a response frame for the first frame in a single user manner in accordance with a transmission right acquired when a result of the carrier sensing is idle.

12. The wireless communication device according to claim 11 , wherein the parameter information defines a range of random numbers as the contention window.

13. The wireless communication device according to claim 11 , wherein the transmitter is configured to transmit the response frame, for the first frame when the first frame includes information to specify the wireless communication device and when the wireless communication device has data for uplink multiuser multiplexing transmission.

14. The wireless communication device according to claim 13 , wherein the response frame for the first frame includes information for specifying whether the wireless communication device has the data for uplink multiuser multiplexing transmission.

15. The wireless communication device according to claim 11 , further comprising at least one antenna.