BASE STATION, RADIO COMMUNICATION SYSTEM, BASE STATION CONTROL METHOD, RADIO COMMUNICATION METHOD, AND CONTROL PROGRAM

• US 20110207500A1
• Filed: 09/15/2009
• Published: 08/25/2011
• Est. Priority Date: 10/27/2008
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ariyoshi, Masayuki, Hamabe, Kojiro, Muraoka, Kazushi, Nakamura, Toshifumi
• Granted Patent: US 9,155,099 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

[Problems] Because it is not possible to reduce sufficiently the number of base stations that starts uselessly in spite of being in light traffic state, it is not possible to lower interference between adjacent cells and power consumption sufficiently.

[Measures] A base station receives a transmission signal from a mobile station to other base station, and starts transmission of a control signal with predetermined power depending on a reception condition of the transmission signal.

Claims

1. A base station characterized by receiving a transmission signal from a mobile station to other base station, and starting transmission of a control signal with predetermined power depending on a reception condition of the transmission signal.

2. The base station according to claim 1, further comprising:

a decision unit which receives the transmission signal from said mobile station to said other base station and decides a reception condition of the transmission signal; and

a transmission unit which starts transmission of the control signal with predetermined power based on a decision result of said decision unit.

3. The base station according to claim 2, wherein

said decision unit measures a received power of the transmission signal from said mobile station to said other base station in upstream band and compares the received power with a predetermined threshold value.

4. The base station according to claim 2, wherein

said decision unit detects an outgoing call from said mobile station to said other base station.

5. The base station according to claim 2, wherein

said decision unit decides whether the transmission signal from said mobile station to said other base station is included in signals which are received by said base station using radio resources allocation information that said other base station is using.

6. The base station according to claim 2, further comprising:

a reception unit which receives predetermined information concerning the other base station, wherein

said decision unit controls decision processing based on said predetermined information.

7. The base station according to claim 6, wherein

said decision unit changes decision criteria in the decision processing based on said predetermined information.

8. The base station according to claim 6, wherein

said decision unit changes at least one of a period to carry out the decision processing and a cycle of the period, based on said predetermined information.

9. The base station according to claim 6, wherein

said predetermined information is load information of said other base station.

10. The base station according to claim 2, further comprising:

suspension unit which suspends transmission of said control signal depending on a predetermined condition after transmission of said control signal is started.

11. The base station according to claim 10, wherein

said suspension unit suspends transmission of said control signal, when a condition, as said predetermined condition, that a mobile station which communicates with said base station does not exist is satisfied.

12. The base station according to claim 10, wherein

said suspension means unit suspends transmission of said control signal, when received power of the transmission signal from the mobile station to other base station in upstream band which is measured by said base station is lower than a threshold value, as said predetermined condition.

13. The base station according to claim 11, wherein

said suspension unit lowers output of said control signal step by step.

14. The base station according to claim 10, wherein

said suspension unit does not suspend output of said control signal completely but holds said control signal at a predetermined value.

15. A radio communications system comprising:

a first base station;

a second base station; and

at least one mobile station which can communicate with said first base station and said second base station, wherein

said second base station receives a transmission signal from said mobile station to said first base station, and starts transmission of a control signal with predetermined power depending on a reception condition of the transmission signal concerned.

16. The radio communications system according to claim 15, wherein

said second base station includes decision unit for receiving the transmission signal from said mobile station to said first base station and deciding a reception condition of the transmission signal;

and transmission unit for starting transmission of a control signal with predetermined power based on a decision result by said decision unit.

17. The radio communications system according to claim 16, wherein

said decision unit measures received power of the transmission signal from said mobile station to said first base station in upstream band and compares the received power with a predetermined threshold value.

18. The radio communications system according to claim 16, wherein

said decision unit detects an outgoing call of said mobile station to said first base station.

19. The radio communications system according to claim 16, wherein

said decision unit judges whether the transmission signal of said mobile station is included in signals which are received by said second base station using radio resources allocation information that said first base station is using.

20. The radio communications system according to claim 16, wherein

said second base station further includes reception unit which receives predetermined information concerning said first base station and said decision unit controls decision processing based on said predetermined information.

21. The radio communications system according to claim 20, wherein

said decision unit changes decision criteria in the decision processing based on said predetermined information.

22. The radio communications system according to claim 20, wherein

said decision unit changes at least one of a period to carry out the decision processing and a cycle of the period, based on said predetermined information.

23. A control method of a base station comprising:

receiving a transmission signal from a mobile station to other base station; and

starting transmission of a control signal with predetermined power depending on a reception condition of the transmission signal.

24. The control method of a base station according to claim 23, wherein

said base station measures received power of the transmission signal from said mobile station to said other base station in upstream band, compares the received power with a predetermined threshold value, and starts transmission of the control signal with predetermined power depending on the comparison result.

25. The control method of a base station according to claim 23, wherein said base station detects an outgoing call from said mobile station to said other base station, and starts transmission of the control signal with predetermined power depending on the detection result.

26. The control method of a base station according to claim 23, wherein said base station decides whether the transmission signal of said mobile station is included in signals which are received by said base station using radio resources allocation information that said other base station is using, and starts transmission of the control signal with predetermined power depending on the decision result.

27. A radio communications method of a radio communications system including a first base station, a second base station, and at least one of mobile station which can communicate with said first base station and said second base station, comprising:

receiving a transmission signal from said mobile station to said first base station in said second base station; and

starting transmission of a control signal with predetermined power depending on a reception condition of the transmission signal.

28. The radio communications method according to claim 27, wherein

said second base station measures received power from said mobile station to said first base station in upstream band, compares the received power with a predetermined threshold value, and starts transmission of a control signal with predetermined power depending on the comparison result.

29. The radio communications method according to claim 27, wherein

said second base station detects an outgoing call from said mobile station to said first base station, and starts transmission of the control signal with predetermined power depending on the detection result.

30. The radio communications method according to claim 27, wherein

said second base station decides whether the transmission signal of said mobile station is included in signals which are received by said second base station using radio resources allocation information which said first base station is using, and starts transmission of the control signal with predetermined power depending on the decision result.

31. A control program characterized by making a base station execute processing to receive a transmission signal from a mobile station to other base station, and to start transmission of a control signal with predetermined power depending on a reception condition of the transmission signal.

32. A mobile station which is able to communicate with a first base station and a second base station, characterized by transmitting a transmission signal to said first base station, and receiving a control signal transmitted from said second base station with predetermined power depending on a reception condition of the transmission signal in said second base station.