Base station, transmission power control method for base station, processing apparatus, storage medium storing program, and communication system
A base station 1 includes a radio communication unit 11 and a power ratio control unit 15 . The radio communication unit 11 is capable of forming a serving HS-DSCH cell (primary cell) and a secondary-serving HS-DSCH cell (secondary cell), and transmitting a physical channel for data transmission in each of the primary and secondary cells. The power ratio control unit 15 is adapted, when a predetermined condition is satisfied, to control the radio communication unit 11 so as to lower the transmission power of secondary cell in comparison to the transmission power of the primary cell. In this way, the interference to a nearby cell caused by the base station 1 is suppressed.
1. A base station comprising:
radio communication unit being capable of forming a first cell and at least one second cell that is dependently formed under condition of the formation of the first cell by using a frequency channel different from that of the first cell, and for transmitting a physical channel for data transmission in each of the first cell and the at least one second cell; and
power ratio control unit being adapted, when a predetermined condition is satisfied, to control the radio communication unit so as to lower a transmission power of at least one cell included in the at least one second cell in comparison to transmission power of the first cell
wherein the predetermined condition relates to a penetration loss amount of a radio signal that passes through a structure and reaches an installation place of the base station, and
the power ratio control unit changes a transmission power ratio between the at least one cell and the first cell according to the penetration loss amount.
2. The base station according to claim 1 , wherein
the predetermined condition relates to a use status by a nearby base station of a frequency channel allocated to the at least one cell, and
when the use status exceeds a predetermined criterion, the power ratio control unit directs to lower the transmission power of the at least one cell.
3. The base station according to claim 2 , wherein the power ratio control unit estimates the use status by the nearby base station based on a received power of a signal wirelessly transmitted from the nearby base station.
4. The base station according to claim 1 , wherein
the predetermined condition relates to a use status by a nearby base station of a frequency channel allocated to the at least one cell, and
the power ratio control unit changes a transmission power ratio between the at least one cell and the first cell according to the use status.
5. The base station according to claim 1 , wherein
when an estimated value of the penetration loss amount is lower than a predetermined value, the power ratio control unit directs to lower the transmission power of the at least one cell.
6. The base station according to claim 1 , further comprising receiving unit being capable of receiving the radio signal,
wherein the power ratio control unit stores a reference value of a received power of the radio signal obtained on the ground outdoor in advance, and estimates the penetration loss amount based on a difference between the reference value and a received power level of the radio signal.
7. The base station according to claim 1 , wherein the power ratio control unit controls the transmission power of the at least one cell such that a leakage power of the at least one cell leaking to outside of the structure becomes substantially constant.
8. The base station according to claim 1 , wherein
the predetermined condition relates to a transmission data amount of the base station, and
when the transmission data amount is smaller than a predetermined value, the power ratio control unit directs to lower the transmission power of the at least one cell.
9. The base station according to claim 1 , wherein
the predetermined condition relates to a transmission data amount of the base station, and
the power ratio control unit changes a transmission power ratio between the at least one cell and the first cell according to the transmission data amount.
10. The base station according to claim 1 , wherein when the transmission power of the at least one cell is to be lowered, the power ratio control unit directs to stop data transmission using the physical channel for data transmission in the at least one cell.
11. The base station according to claim 10 , wherein when the data transmission using the physical channel for data transmission in the at least one cell is to be resumed, the power ratio control unit directs to increase the transmission power of the at least one cell a predetermined time before the resumption of the transmission.
12. The base station according to claim 10 , wherein when the data transmission using the physical channel for data transmission in the at least one cell is resumed, the power ratio control unit uses a frequency channel different from a frequency channel that is used for the at least one cell before the transmission stop.
13. The base station according to claim 1 , wherein the at least one cell is connected by only a mobile station that has already connected to the first cell.
14. The base station according to claim 1 , wherein the first cell and the at least one second cell are formed by using mutually different radio communication schemes.
15. The base station according to claim 1 , wherein a radio communication scheme used for each of the first cell and the at least one second cell is one of W-CDMA, mobile WiMAX, and LTE (Long Term Evolution).
16. A base station comprising:
radio communication unit being capable of forming a first cell and a least one second cell that is dependently formed under condition of the formation of the first cell by using a frequency channel different from that of the first cell, and for transmitting a physical channel for data transmission in each of the first cell, and the at least one second cell; and
power ratio control unit being adapted, when a predetermined condition is satisfied, to control the radio communication unit so as to lower a transmission power of a least one cell included in the at least one second cell in comparison to a transmission power of the first cell,
wherein a transmission power ratio between the at least one cell and the first cell is supplied from an external apparatus connected through a communication network.
17. A base station comprising:
radio communication unit being capable of forming a first cell and a least one second cell that is dependently formed under condition of the formation of the first cell by using a frequency channel different from that of the first cell, and for transmitting a physical channel for data transmission in each of the first cell and the at least one second cell; and
power ratio control unit being adapted, when a predetermined condition is satisfied, to control the radio communication unit so as to lower a transmission power of a least one cell included in the at least one second cell in comparison to a transmission power of the first cell, wherein
the base station is a base station supporting dual-cell HSDPA (DC-HSDPA) in which High Speed Downlink Packet Access (HSDPA) is simultaneously provided in both of the two cells,
the physical channel for data transmission is High Speed Physical Downlink Common Channel (HS-PDSCH),
the first cell is a serving HS-DSCH cell, and
the at least one cell is a secondary-serving HS-DSCH cell.
18. A transmission power control method for a base station, the base station being capable of forming a first cell and at least one second cell that is dependently formed under condition of the formation of the first cell by using a frequency channel different from that of the first cell, and transmitting a physical channel for data transmission in each of the first cell and the at least one second cell,
the method comprising:
determining satisfaction of a predetermined condition; and
performing, when the predetermined condition is satisfied, transmission power control so as to lower a transmission power of at least one cell included in the at least one second cell in comparison to the transmission power of the first cell, wherein
the predetermined condition relates to a penetration loss amount of a radio signal that passes through a structure and reaches an installation place of the base station, and
the transmission power control includes changing a transmission power ratio between the at least one cell and the first cell according to the penetration loss amount.
19. The method according to claim 1 , wherein
the predetermined condition relates to a use status by a nearby base station of a frequency channel allocated to the at least one cell, and
the transmission power control includes directing to lower the transmission power of the at least one cell when the use status exceeds a predetermined criterion.
20. The method according to claim 18 , wherein
the predetermined condition relates to a penetration loss amount of a radio signal that passes through a structure and reaches an installation place of the base station, and
the transmission power control includes directing to lower the transmission power of the at least one cell when an estimated value of the penetration loss amount is lower than a predetermined value
21. The method according to claim 18 , further comprising estimating the penetration loss amount based on a difference between a reference value of a received power of the radio signal obtained on the ground outdoor and a received power level of the radio signal.
22. The method according to claim 18 , wherein
the predetermined condition relates to a transmission data amount of the base station, and
the transmission power control includes changing a transmission power ratio between the at least one cell and the first cell according to the transmission data amount.
23. The method according to claim 18 , wherein the transmission power control includes directing to lower the transmission power of the at least one cell by stopping data transmission using the physical channel for data transmission in the at least one cell.
24. The method according to claim 23 , further comprising resuming the data transmission using the physical channel for data transmission in the at least one cell using a frequency channel different from a frequency channel that is used for the at least one cell before the transmission stop.
25. A processing apparatus for abuse station apparatus, the base station apparatus being capable of forming a first cell and at least one second cell that is dependently formed under condition of the formation of the first cell by using a frequency channel different from that of the first cell, and transmitting a physical channel for data transmission in each of the first cell and the at least one second cell,
the processing apparatus comprising a control unit being adapted to:
determine satisfaction of a predetermined condition; and
perform, when the predetermined condition is satisfied, transmission power control so as to lower a transmission power of at least one cell included in the at least one second cell in comparison to the transmission power of the first cell, wherein
the predetermined condition relates to a penetration loss amount of a radio signal that passes through a structure and reaches an installation place of the base station apparatus, and
the transmission power control includes changing a transmission power ratio between the at least one cell and the first cell according to the penetration loss amount.
26. The processing apparatus according to claim 25 , wherein
the predetermined condition relates to a use status by a nearby base station of a frequency channel allocated to the at least one cell, and
when the use status exceeds a predetermined criterion, the control unit directs to lower the transmission power of the at least one cell.
27. The processing apparatus according to claim 25 , wherein
when an estimated value of the penetration loss amount is lower than a predetermined value, the control unit directs to lower the transmission power of the at least one cell.
28. The processing apparatus according to claim 25 , wherein the control unit estimates the penetration loss amount based on a difference between a reference value of a received power of the radio signal obtained on the ground outdoor and a received power level of the radio signal.
29. The processing apparatus according to claim 25 , wherein
the predetermined condition relates to a transmission data amount of the base station, and
when the transmission data amount is smaller than a predetermined value, the control unit directs to lower the transmission power of the at least one cell.
30. A non-transitory storage medium storing a program that causes a computer to perform control processing relating to a base station apparatus, the base station apparatus being capable of forming a first cell and at least one second cell that is dependently formed under condition of the formation of the first cell by using a frequency channel different from that of the first cell, and transmitting a physical channel for data transmission in each of the first cell and the at least one second cell,
the control processing comprising:
determining satisfaction of a predetermined condition; and
performing, when the predetermined condition is satisfied, transmission power control so as to lower a transmission power of at least one cell included in the at least one second cell in comparison to the transmission power of the first cell, wherein
the predetermined condition relates to a penetration loss amount of a radio signal that passes through a structure and reaches an installation place of the base station apparatus, and
the transmission power control includes changing a transmission power ratio between the at least one cell and the first cell according to the penetration loss amount.
31. The non-transitory storage medium storing a program according to claim 30 , wherein
the predetermined condition relates to a use status of a frequency channel allocated to the at least one cell by a nearby base station, and
the transmission power control includes directing to lower the transmission power of the at least one cell when the use status exceeds a predetermined criterion.
32. The non-transitory storage medium storing a program according to claim 30 , wherein
the transmission power control includes directing to lower the transmission power of the at least one cell when an estimated value of the penetration loss amount is lower than a predetermined value.
33. The non-transitory storage medium storing a program according to claim 30 , wherein the control processing further comprises estimating the penetration loss amount based on a difference between a reference value of a received power of the radio signal obtained on the ground outdoor and a received power level of the radio signal.
34. The non-transitory storage medium storing a program according to claim 30 , wherein
the predetermined condition relates to a transmission data amount of the base station, and
the transmission power control includes changing a transmission power ratio between the at least one cell and the first cell according to the transmission data amount.
35. A communication system comprising:
a base station apparatus being capable of forming a first cell and at least one second cell that is dependently formed under condition of the formation of the first cell by using a frequency channel different from that of the first cell, and transmitting a physical channel for data transmission in each of the first cell and the at least one second cell; and
a mobile station being capable of simultaneously receiving the physical channels for data transmission, each of which is transmitted in a respective one of the first cell and the at least one second cell,
wherein, when a predetermined condition is satisfied, the base station apparatus lowers a transmission power of at least one cell included in the at least one second cell in comparison to the transmission power of the first cell, wherein
the predetermined condition relates to a penetration loss amount of a radio signal that passes through a structure and reaches installation place of the base station apparatus, and
the base station apparatus changes a transmission power ratio between the at least one cell and the first cell according to the penetration loss amount.
36. The communication system according to claim 35 , wherein
the predetermined condition relates to a use status by a nearby base station of a frequency channel allocated to the at least one cell, and
when the use status exceeds a predetermined criterion, the base station apparatus lowers the transmission power of the at least one cell.
37. The communication system according to claim 35 , wherein
the predetermined condition relates to a use status by a nearby base station of a frequency channel allocated to the at least one cell, and
the base station apparatus changes a transmission power ratio between the at least one cell and the first cell according to the use status.