Wireless communication system and wireless station
A station determines the presence/absence of directional beam control in an access point, on the basis of received power measured when data transmitted from the access point are received, and the type of the received data. In accordance with the result of this determination, the station controls transmitting power to transmit data to the access point.
1. A wireless communication system which exchanges data between an access point and plural stations, wherein at least one of said stations comprises:
a received power measurement unit which measures received power when data transmitted from said access point is received;
a received data type detection unit which detects the type of the received data;
a beam gain estimation unit which determines the presence/absence of directional beam control in said access point, on the basis of, the received power measured by said received power measurement unit, and the received data type detected by said received data type detection unit; and
a transmitter power control unit which controls transmitting power for transmitting data to said access point, in accordance with the result of the determination by said beam gain estimation unit.
2. A system according to claim 1 , wherein said received data type detection unit detects whether received data are broadcast frame data or unicast frame data.
3. A system according to claim 1 , wherein said beam gain estimation unit determines that space division multiple access (SDMA) is applicable at said access point, when the level of the directional beam is larger or equal to a predetermined level.
4. A system according to claim 1 , further comprising:
a transmitted power detection unit which detects transmitted power when said access point transmits data.
5. A wireless communication system which exchanges data between an access point and plural stations by CSMA (Carrier Sense Multiple Access), wherein at least one of said stations comprises:
a received power measurement unit which measures received power when data transmitted from said access point is received;
a received data type detection unit which detects the type of the received data;
a beam gain estimation unit which determines the presence/absence of directional beam control in said access point, on the basis of the received power measured by said received power measurement unit, and the received data type detected by said received data type detection unit;
a transmitter power control unit which controls transmitting power for transmitting data to said access point, in accordance with the result of the determination by said beam gain estimation unit; and
a carrier sense control unit which controls the carrier sense level of said station in accordance with the result of the determination by said beam gain estimation unit.
6. A system according to claim 5 , wherein said received data type detection unit detects whether received data are broadcast frame data or unicast frame data.
7. A system according to claim 5 , further comprising:
a transmitted power detection unit which detects transmitted power when said access point transmits data.
8. A wireless communication system which exchanges data between an access point and plural stations, wherein at least one of said stations comprises:
a received power measurement unit which measures the received power of the first data which are broadcast from said access point, and measures the received power of the second data which are unicast from said access point to said station;
a beam gain estimation unit which determines the presence/absence of directional beam control in said access point, on the basis of the first and second received powers measured by said received power measurement unit; and
a transmitting power control unit which controls transmitting power for transmitting data to said access point, when said beam gain estimation unit determines that said access point is performing directional beam control.
9. A system according to claim 8 , wherein when said beam gain estimation unit determines that said access point is performing directional beam control, said transmitting power control unit sets the transmitting power to transmit data to said access point at the minimum necessary power receivable by said access point.
10. A system according to claim 8 , wherein when determining that said access point is performing directional beam control, said beam gain estimation unit further checks whether space division multiple access is applicable at said access point, and when said beam gain estimation unit determines that said access point is performing directional beam control, and that space division multiple access is applicable at said access point, said transmitting power control unit sets the transmitting power to transmit data to said access point at the minimum necessary power receivable by said access point.
11. A system according to claim 8 , further comprising:
a transmitted power detection unit which detects transmitted power when said access point transmits the first data, and detects transmitted power when said access point transmits the second data.
12. A wireless communication system which exchanges data between an access point and plural stations by CSMA (Carrier Sense Multiple Access), wherein at least one of said stations comprises:
a received power measurement unit which measures the received power of the first data which are broadcast from said access point, and measures the received power of the second data which are unicast from said access point to said station;
a beam gain estimation unit which determines the presence/absence of directional beam control in said access point, on the basis of the first and second received powers measured by said received power measurement unit;
a transmitting power control unit which controls transmitting power to transmit data to said access point, when said beam gain estimation unit determines that said access point is performing directional beam control; and
a carrier sense control unit which controls the carrier sense level of said station in accordance with the result of the determination by said beam gain estimation unit.
13. A system according to claim 12 , wherein when said beam gain estimation unit determines that said access point is performing directional beam control, said carrier sense control unit raises the carrier sense level of said station to such an extent that the carrier sense function does not degrade.
14. A system according to claim 12 , wherein
when determining that said access point is performing directional beam control, said beam gain estimation unit further checks whether space division multiple access is applicable at said access point, and
when said beam gain estimation unit determines that said access point is performing directional beam control, and that space division multiple access is applicable at said access point, said carrier sense control unit raises the carrier sense level of said station to such an extent that the carrier sense function does not degrade.
15. A system according to claim 12 , further comprising:
a transmitted power detection unit which detects transmitted power when said access point transmits the first data, and detects transmitted power when said access point transmits the second data.
16. A wireless station which exchanges data with an access point, comprising:
a received power measurement unit which measures the received power of the first data which are broadcast from said access point, and measures the received power of the second data which are unicast from said access point to said station;
a beam gain estimation unit which determines the presence/absence of directional beam control in said access point, on the basis of the first and second received powers measured by said received power measurement unit; and
a transmitting power control unit which controls transmitting power for transmitting data to said access point, when said beam gain estimation unit determines that said access point is performing directional beam control.
17. A station according to claim 16 , wherein when said beam gain estimation unit determines that said access point is performing directional beam control, said transmitting power control unit sets the transmitting power to transmit data to said access point at the minimum necessary power receivable by said access point.
18. A station according to claim 16 , wherein when determining that said access point is performing directional beam control, said beam gain estimation unit further checks whether space division multiple access is applicable at said access point, and
when said beam gain estimation unit determines that said access point is performing directional beam control, and that space division multiple access is applicable at said access point, said transmitting power control unit sets the transmitting power to transmit data to said access point at the minimum necessary power receivable by said access point.
19. A station according to claim 16 , further comprising:
a transmitted power detection unit which detects transmitted power when said access point transmits the first data, and detects transmitted power when said access point transmits the second data.
20. A wireless station which exchanges data with an access point by CSMA (Carrier Sense Multiple Access), comprising:
a received power measurement unit which measures the received power of the first data which are broadcast from said access point, and measures the received power of the second data which are unicast from said access point to said station;
a beam gain estimation unit which determines the presence/absence of directional beam control in said access point, on the basis of the first and second received powers measured by said received power measurement unit, and the first and second transmitted powers detected by said transmitted power detection unit;
a transmitting power control unit which controls transmitting power for transmitting data to said access point, when said beam gain estimation unit determines that said access point is performing directional beam control; and
a carrier sense control unit which controls the carrier sense level of said station in accordance with the result of the determination by said beam gain estimation unit.
21. A wireless station according to claim 20 , further comprising:
a transmitted power detection unit which detects transmitted power when said access point transmits the first data, and detects transmitted power when said access point transmits the second data.