COMMUNICATIONS DEVICE AND COMMUNICATION METHOD

1 . A communications device for performing carrier-sense, the communications device comprising:

a reception unit for executing the carrier-sense for reserving a wireless medium;

a control unit for setting a plurality of wireless medium acquisition classes; and

a transmission unit for transmitting a radio signal, wherein:

each of the plurality of wireless medium acquisition classes includes a value indicating at least a data transmission period and an idle period,

each of the plurality of wireless medium acquisition classes are classified based on a length of a fixed frame period including at least the data transmission period and the idle period,

the radio signal includes information indicating a selected wireless medium acquisition class of the plurality of wireless medium classes, and

the radio signal is one of a System Information Block (SIB) and a Physical Downlink Control Channel (PDCCH).

2 . The communications device according to claim 1 , wherein each of the plurality of wireless medium acquisition classes further indicates a value indicating length of a contention period, where the contention period is included in the data transmission period.

3 . The communications device according to claim 2 , wherein:

the contention period is divided by timeslot having a predetermined period,

a random number is generated, where a maximum value of the random number is associated with the contention period,

the random number is decremented based on a result of the carrier-sense during the contention period, and

a length of a period obtained by multiplying the random number by the predetermined period is longer than the contention period.

4 . The communications device according to claim 3 , wherein:

the contention period is set at a start of the data transmission period, and

the random number is continuously decremented after the contention period based on a result of the carrier-sense during the data transmission period.

5 . The communications device according to claim 2 , wherein the contention period is set at a start of the data transmission period.

6 . The communications device according to claim 2 , wherein:

the idle period follows the data transmission period, and

the contention period is in the rear of the data transmission period.

7 . The communications device according to claim 1 , wherein:

the control unit divides the wireless medium into a plurality of frequency bands, and

the transmission unit randomly selects one of the plurality of frequency bands during the data transmission period.

8 . The communications device according to claim 7 , wherein the transmission unit transmits a signal occupying a predetermined bandwidth in the wireless medium at a start of the data transmission period.

9 . The communications device according to claim 8 , wherein the transmission unit generates the signal based on a predetermined rule.

10 . The communication method for performing carrier-sense, comprising:

executing the carrier-sense for reserving a wireless medium;

setting a plurality of wireless medium acquisition classes; and

transmitting a radio signal, wherein:

each of the plurality of wireless medium acquisition classes includes a value indicating at least a data transmission period and an idle period,

each of the plurality of wireless medium acquisition classes are classified based on a length of a fixed frame period including at least the data transmission period and the idle period,

the radio signal includes information indicating a selected wireless medium acquisition class of the plurality of wireless medium classes, and

the radio signal is one of a System Information Block (SIB) and a Physical Downlink Control Channel (PDCCH).

11 . The communication method according to claim 10 , wherein each of the plurality of wireless medium acquisition classes further indicates a value indicating length of a contention period, where the contention period is included in the data transmission period.

12 . The communication method according to claim 11 , wherein:

the contention period is divided by timeslot having a predetermined period,

a random number is generated, where a maximum value of the random number is associated with the contention period,

the random number is decremented based on a result of the carrier-sense during the contention period, and

a length of a period obtained by multiplying the random number by the predetermined period is longer than the contention period.

13 . The communication method according to claim 12 , wherein:

the contention period is set at a start of the data transmission period, and

the random number is continuously decremented after the contention period based on a result of the carrier-sense during the data transmission period.

14 . The communication method according to claim 11 , wherein the contention period is set at a start of the data transmission period.

15 . The communication method according to claim 11 , wherein:

the idle period follows the data transmission period, and

the contention period is in the rear of the data transmission period.

16 . The communication method according to claim 10 , further comprising:

dividing the wireless medium into a plurality of frequency bands, and

randomly selecting one of the plurality of frequency bands during the data transmission period.

17 . The communication method according to claim 16 , further comprising:

transmitting a signal occupying a predetermined bandwidth in the wireless medium at a start of the data transmission period.

18 . The communication method according to claim 17 , further comprising generating the signal based on a predetermined rule.