Wireless Communications Method, Wireless Control Station, And Wireless Base Station

• US 20090245196A1
• Filed: 06/11/2009
• Published: 10/01/2009
• Est. Priority Date: 12/26/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Iseda, Kohei
• Granted Patent: US 8,204,040 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 72/29 between an access point and the access point controlling device
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

The present invention relates to a wireless communications method, a wireless control station, and a wireless base station. One of the objects of the present invention is to make it possible to allocate the wireless resources to more than one road side device without interference thereamong. Therefore, the allocation information in the communications regions, used by the wireless base stations in their communications with the wireless terminal from the wireless control station, is sent to each of the wireless base stations, and each of the signal base stations performs communications with the wireless terminal by using the communications region in the wireless frame corresponding to the allocation information received from the wide-area control station.

Claims

1. A wireless communications method for use in a wireless communications system that includes a plurality of wireless base stations, a wireless control station and a wireless terminal, the wireless communications method comprising:

on the wireless control station,

sending allocation information of a communications region in a wireless frame used by the each individual wireless base station in communications with the wireless terminal to the wireless base stations and the wireless terminal; and

on the each individual wireless base station,

performing communications with the wireless terminal by using the communications region of the wireless frame according to the allocation information received from the wireless control station.

2. The wireless communications method according to claim 1, wherein the communications region is defined by time and frequency.

3. The wireless communications method according to claim 1,

wherein the wireless control station sends the allocation information, which is included in a header portion that is a part of the wireless frame, to the each individual wireless base station, and

wherein the wireless control station does not send other communications regions than the header part to the each individual wireless base station.

4. The wireless communications method according to claim 1,

wherein the wireless control station holds interference information indicating whether or not interference occurs when the communications regions are overlapped in the wireless frame among the wireless base stations, and

wherein the wireless control station generates allocation information, such that the communications regions are not overlapped in the wireless frame, among the wireless base stations with an occurrence of interference thereamong, based on the interference information.

5. The wireless communications method according to claim 4, wherein the wireless control station generates allocation information, such that a part or all of the communications regions in the wireless frame are overlapped, among the wireless base stations with no occurrence of interference thereamong, based on the interference information.

6. The wireless communications method according to claim 1, wherein the each individual wireless base station holds a connection identifier usable in communications with the wireless terminal, which connection identifier is allocated to the each individual wireless base station respectively,

on the wireless control station,

holding the connection identifier allocated to the each individual wireless base stations respectively;

and

sending one of the connection identifiers, which is included in the allocation information, to the each individual wireless base station, and

on the each individual wireless base station,

receiving allocation information including a connection identifier allocated thereto; and

performing communications with the wireless terminal by using the communications region according to the allocation information.

7. The wireless communications method according to claim 1,

on the each individual wireless base station,

sending transmission data including positional information of the each individual wireless base station, which transmission data is sent by using the communications region, to the wireless terminal,

on the wireless terminal,

recognizing a wireless base station which is a sender of the transmission data based on the positional information.

8. The wireless communications method according to claim 1,

on the wireless control station,

generating allocation information in the communications region of the size according to the amount of data sent by the each individual wireless base station, in the communications region.

9. The wireless communications method according to claim 8, wherein the amount of data takes a fixed value in the each individual wireless base station.

10. The wireless communications method according to claim 8,

on the wireless control station,

obtaining information relating to the amount of data from the each individual wireless base station through a backhaul circuit.

11. The wireless communications method according to claim 4, wherein the interference information is obtained based on one or more than one combination of distances between the individual wireless base stations, transmission power of the each individual wireless base station, a modulation scheme, and a coding ratio.

12. The wireless communications method according to claim 1, wherein the wireless base station is provided for a traffic signal, and the wireless terminal is provided for a vehicle.

13. A wireless control station for use in a wireless communications system that includes a plurality of wireless base stations, a wireless control station and a wireless terminal, the wireless control station comprising:

an allocation information generating unit which generates allocation information of a communications region in a wireless frame used by the each individual wireless base station in its communications with the wireless terminal; and

a transmitting unit which sends the allocation information generated by the allocation information generating unit to the each individual wireless base station and the wireless terminal.

14. The wireless control station according to claim 13, wherein the communications region is defined by time and frequency.

15. The wireless control station according to claim 13,

wherein the wireless control station sends the allocation information, which is included in a header portion that is a part of the wireless frame, to the each individual wireless base station, and

wherein the wireless control station does not send other communications regions than the header part to the each individual wireless base station.

16. The wireless control station according to claim 13, further comprising an interference information holding unit which hold interference information indicating whether or not interference occurs when the communications regions are overlapped in the wireless frame among the wireless base stations, wherein the allocation information generating unit generates allocation information, such that the communications regions are not overlapped in the wireless frame, among the wireless base stations with an occurrence of interference thereamong, based on the interference information held in the interference information holding means.

17. The wireless control station according to claim 16, wherein the allocation information generates unit generating allocation information, such that a part or all of the communications regions in the wireless frame are overlapped, among the wireless base stations with no occurrence of interference thereamong, based on the interference information.

18. The wireless control station according to claim 13, further comprising:

a connection identifier holding unit which holds connection identifiers allocated to the individual wireless base stations respectively, wherein the allocation information generating unit generates the allocation information which includes the connection identifier.

19. The wireless control station according to claim 13, wherein the allocation information generates unit generating allocation information in the communications region of the size according to the amount of data sent, by the each individual wireless base station, in the communications region.

20. The wireless control station according to claim 19, wherein the amount of data takes a fixed value in the each individual wireless base station.

21. The wireless control station according to claim 19, further comprising:

a data amount information obtaining unit which obtains information relating to the amount of data from the each individual wireless base station through a backhaul circuit.

22. The wireless control station according to claim 16, wherein the interference information is obtained based on one or more than one combination of distances between the individual wireless base stations, transmission power of the each individual wireless base station, a modulation scheme, and a coding ratio.

23. A wireless base station for use in a wireless communications system that includes a plurality of wireless base stations, a wireless control station and a wireless terminal, the wireless base station comprising:

an allocation information receiving unit which receives allocation information in a communications region in a wireless frame used in communications with the wireless terminal from the wireless control station; and

a communications unit which performs communications with the wireless terminal by using the communications region in the wireless frame according to the allocation information received by the allocation information receiving unit.

24. The wireless base station according to claim 23, further comprising:

a connection identifier holding unit which holds connection identifiers usable in communications with the wireless terminal, which connection identifier is allocated to the each individual wireless base station respectively,

wherein the allocation information receiving unit receives the allocation information including the connection identifier allocated thereto, and

wherein the communications unit performs communications with the wireless terminal by using the communications region according to the allocation information.

25. The wireless base station according to claim 23, wherein the communications unit sends transmission data including positional information of the wireless base station itself, which transmission data is sent by using the communications region, to the wireless terminal.