JP5637476B2 - Base station apparatus and control method for base station apparatus - Google Patents

Description

  The present invention relates to a base station apparatus and a base station apparatus control method, and more particularly to a base station apparatus and a base station apparatus control method for reducing power consumption.

  Conventionally, a method for reducing the power consumption of a radio base station has been proposed. In the future, with the spread of many base station devices in a narrower range than before, including the home environment, the need to reduce the power of the base station devices will increase.

  As a method for reducing the power consumption of the radio base station, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 10-145842), the power consumption is reduced by changing the zone configuration of the radio base station according to the communication traffic state of the system. A method is described that reduces and prevents the occurrence of an incommunicable area by changing the zone configuration.

JP-A-10-145842

  However, the method of Patent Document 1 requires a control station that controls the base station as a constituent element, which increases costs. In this method, the installation status of the base station is managed by a database, but the database must be updated when the installation status of the base station changes.

  Therefore, an object of the present invention is to provide a base station apparatus and a base station apparatus control method capable of reducing power consumption without providing a control station and a database for managing the installation status of the base station. It is.

  In order to solve the above-described problem, a base station apparatus of the present invention includes a notification unit for reporting information representing the traffic of the own apparatus, and information representing the traffic of another base station apparatus broadcasted by another base station apparatus. A receiving unit for receiving, and a control unit for stopping a part of functions of the own device based on information representing traffic of the other base station device broadcast from another base station device.

  Preferably, when the number of other base station apparatuses whose traffic is equal to or less than a threshold is equal to or greater than a predetermined value, the control unit stops some functions of the own apparatus.

  Preferably, the base station device further includes a measurement unit that measures the received electric field strength of a signal transmitted from another base station device, and the control unit further includes the base station device based on the traffic and the received electric field strength. Stop some functions.

  Preferably, when the number of other base station apparatuses whose received electric field strength is equal to or greater than the first threshold and whose traffic is equal to or less than the second threshold is equal to or greater than a predetermined value, Stop the function.

  Preferably, the base station apparatus further includes a reception response vector calculation unit that calculates a reception response vector of a signal transmitted from another base station apparatus, and reception response vectors of signals from a plurality of other base station apparatuses. A correlation value calculation unit that calculates correlation values for the two pairs, and the control unit further stops some functions of the own device based on the traffic and the correlation value.

  Preferably, the control unit receives reception response vectors of all the base station devices that satisfy the condition when the number of base station devices that satisfy the condition that the traffic is equal to or less than the first threshold is equal to or more than the first predetermined value. When the number of pairs that are equal to or smaller than the second threshold among the correlation values of all possible pairs created from the above is equal to or larger than the second predetermined value, some functions of the own device are stopped.

  Preferably, the base station device further includes a measurement unit that measures the received electric field strength of a signal transmitted from another base station device, and calculates a reception response vector of the signal transmitted from the other base station device. And a correlation value calculation unit that calculates correlation values for two pairs of reception response vectors of signals from a plurality of other base station apparatuses, and the control unit further receives traffic and reception Based on the electric field strength and the correlation value, some functions of the device itself are stopped.

  Preferably, the control unit satisfies the condition when the number of base station apparatuses satisfying the condition that the traffic is equal to or less than the first threshold and the received electric field strength is equal to or greater than the second threshold is equal to or greater than the first predetermined value. If all the possible pairs created from the reception response vectors of all base station apparatuses satisfying the condition are equal to or greater than the second predetermined value among the correlation values, Stop some functions of the device.

  Preferably, the control unit stops the transmission process of the own device as the stop of some functions of the own device.

  The base station apparatus control method according to the present invention includes a step of notifying information representing the traffic of the own apparatus, a step of receiving information representing the traffic of another base station apparatus broadcast from another base station apparatus, and the like. And a step of stopping a part of the function of the own device based on information representing the traffic of the other base station device broadcast from the base station device.

  According to the base station apparatus and base station apparatus control method of the present invention, it is possible to reduce power consumption without providing a control station and a database for managing the installation status of the base station.

It is a figure showing the example of arrangement | positioning of the several radio base station of embodiment of this invention. It is a figure showing the structure of the wireless base station of the 1st Embodiment of this invention. It is a flowchart showing the control procedure of the radio base station of the 1st Embodiment of this invention. It is a figure showing the structure of the wireless base station of the 2nd Embodiment of this invention. It is a flowchart showing the control procedure of the radio base station of the 2nd Embodiment of this invention. It is a flowchart showing the control procedure of the radio base station of the modification of the 2nd Embodiment of this invention. It is a figure showing the structure of the wireless base station of the 3rd Embodiment of this invention. It is a flowchart showing the control procedure of the radio base station of the 3rd Embodiment of this invention. It is a figure showing the structure of the wireless base station of the 4th Embodiment of this invention. It is a flowchart showing the control procedure of the radio base station of the 4th Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
(Radio base station arrangement example)
FIG. 1 is a diagram illustrating an arrangement example of a plurality of radio base stations according to an embodiment of the present invention.

  Referring to FIG. 1, radio base stations A to D are arranged. The zone of the radio base station A overlaps with the zones of the other radio base stations B to D. Therefore, in such an arrangement, when there is little night traffic, the wireless terminal can communicate with other wireless base stations even if transmission from the wireless base station A is stopped.

  In the following description, the radio base station of the present embodiment will be described as a PHS (Personal Handy-phone System) radio base station.

[First Embodiment]
The present embodiment relates to a radio base station that stops the function of its own device based on traffic at another radio base station.

(Configuration of radio base station)
FIG. 2 is a diagram illustrating the configuration of the radio base station according to the first embodiment of this invention.

  With reference to FIG. 2, the radio base station includes antennas 4, 5, 6, 7, a reception unit 8, a traffic information acquisition unit 12, a traffic information notification unit 18, and a control unit 22.

  The traffic information notification unit 18 transmits traffic information using a BCCH (broadcasting control channel). The BCCH is a control channel for the radio base station to transfer information for location registration, information on the channel structure, system information, and the like to the radio terminal. The traffic information notification unit 18 describes the traffic information in the option part of this BCCH. For example, Erlang can be used as the traffic information. The traffic information notification unit 18 recalculates Erlang every several tens of minutes and updates the optional part of the traffic information.

  The transmission unit 10 transmits signals to the wireless terminal and other wireless base stations. The transmission unit 10 performs an adaptive transmission process on the transmission signal. The transmission unit 10 includes an upper converter, a power amplifier, and the like, converts a transmission signal to a high frequency, amplifies the transmission signal to a transmission output level, and outputs the amplified signal to a corresponding antenna.

  The receiving unit 8 receives signals from the wireless terminal and other wireless base stations. The receiving unit 8 includes a low noise amplifier, a down converter, and the like, converts a signal received by a corresponding antenna from a high frequency to a low frequency, and amplifies it. The receiving unit 8 performs adaptive reception processing on signals from a plurality of antennas.

  The traffic information acquisition unit 12 acquires traffic information (erlang) from the BCCH transmitted from the other radio base station received by the reception unit 8.

  When the number of radio base stations whose traffic (Erlang) indicated by the acquired traffic information is equal to or less than the threshold A is equal to or greater than the predetermined value N1, the control unit 22 notifies the transmission unit 10 and the traffic information notification unit 18. To stop the transmission process. This is because when there are a large number of radio base stations with low traffic, the radio terminal can communicate with radio base stations with low traffic even if the own device stops transmission. is there.

  After the transmission unit 10 and the traffic information notification unit 18 stop the transmission process, the control unit 22 determines that the number of radio base stations whose traffic (Erlang) indicated by the acquired traffic information is equal to or less than the threshold value A is N1 or more. If not, the transmission unit 10 and the traffic information notification unit 18 are instructed to resume transmission processing.

(Operation)
FIG. 3 is a flowchart showing a control procedure of the radio base station according to the first embodiment of this invention.

  First, the traffic information acquisition unit 12 acquires traffic information transmitted from a plurality of other radio base stations (step S101).

  Next, when the number of radio base stations whose traffic indicated by the traffic information is equal to or less than the threshold A is equal to or greater than the predetermined value N1 (YES in step S102), the control unit 22 transmits the traffic information to the transmission unit 10 and the traffic information notification. The unit 18 is instructed to stop the transmission process (step S103).

  After the transmission process is stopped, the traffic information acquisition unit 12 further acquires traffic information transmitted from a plurality of other radio base stations (step S104).

  Next, when the number of wireless base stations whose traffic indicated by the traffic information is equal to or less than the threshold A is equal to or greater than the predetermined value N1 (YES in step S105), the control unit 22 transmits the traffic information to the transmission unit 10 and the traffic information notification. The transmission process by the unit 18 remains stopped, and the process returns to step S104.

  Next, when the number of radio base stations whose traffic indicated by the traffic information is equal to or less than the threshold A is not equal to or greater than the predetermined value N1 (NO in step S105), the control unit 22 transmits the transmission unit 10 and the traffic information notification unit. 18 is instructed to resume the transmission process (step S106).

  As described above, according to the present embodiment, when there are a large number of wireless base stations with low traffic, the transmission processing of the own device is stopped, so a database for managing the installation status of the control station and the base station is established. Power consumption can be reduced without provision.

[Second Embodiment]
The present embodiment relates to a radio base station that stops the function of its own device based on the traffic at another radio base station and the received electric field strength of a signal from the other radio base station.

(Configuration of radio base station)
FIG. 4 is a diagram illustrating the configuration of a radio base station according to the second embodiment of this invention.

  Referring to FIG. 4, this wireless base station is different from the wireless base station according to the first embodiment in FIG. 2 as follows.

  This radio base station includes a received electric field strength measurement unit 14 that is not included in the radio base station of the first embodiment. Furthermore, the function of the control unit 42 of this radio base station is different from the control unit 22 of the radio base station of the first embodiment.

  The received electric field strength measuring unit 14 measures the received electric field strength of signals transmitted from other wireless base stations received by the receiving unit 8.

  When the traffic (Erlang) indicated by the traffic information is equal to or less than the threshold A and the number of radio base stations whose received electric field strength is equal to or greater than the threshold B is equal to or greater than the predetermined value N2, the control unit 42 And instructs the traffic information notification unit 18 to stop the transmission process. This is because when there are many radio base stations with low traffic and high received electric field strength, even if the own device stops transmission, the radio terminal has less traffic and the received electric field. This is because communication with a wireless base station having high strength is possible. By adding the condition that the received electric field strength is high, it is possible to prevent transmission from stopping when other wireless base stations are not in close proximity, so that the wireless terminal does not find the wireless base station of the communication partner. You can avoid the situation.

  After the transmission unit 10 and the traffic information notification unit 18 stop the transmission process, the control unit 42 is a radio base station in which the traffic (Erlang) indicated by the traffic information is equal to or lower than the threshold A and the received electric field strength is equal to or higher than the threshold B. Is not equal to or greater than the predetermined value N2, the transmission unit 10 and the traffic information notification unit 18 are instructed to resume transmission processing.

(Operation)
FIG. 5 is a flowchart showing a control procedure of the radio base station according to the second embodiment of this invention.

  First, the traffic information acquisition unit 12 acquires traffic information transmitted from a plurality of other radio base stations (step S201).

  Next, the received electric field strength measurement unit 14 measures the received electric field strength of signals transmitted from other wireless base stations (step S202).

  Next, when the traffic indicated by the traffic information is equal to or less than the threshold A and the number of radio base stations whose received electric field strength is equal to or greater than the threshold B is equal to or greater than the predetermined value N2 (in step S203). YES), the transmission unit 10 and the traffic information notification unit 18 are instructed to stop the transmission process (step S204).

  After the transmission process is stopped, the traffic information acquisition unit 12 further acquires traffic information transmitted from a plurality of other radio base stations (step S205).

  Further, the received electric field strength measurement unit 14 measures the received electric field strength of signals transmitted from other wireless base stations (step S206).

  Next, when the traffic indicated by the traffic information is equal to or less than the threshold A and the number of radio base stations whose received electric field strength is equal to or greater than the threshold B is equal to or greater than the predetermined value N2 (in step S207). YES), the transmission processing by the transmission unit 10 and the traffic information notification unit 18 remains stopped, and the process returns to step S205.

  Next, when the traffic indicated by the traffic information is equal to or less than the threshold A and the number of radio base stations whose received electric field strength is equal to or greater than the threshold B is not equal to or greater than the predetermined value N2 (NO in step S207). ) Instruct the transmission unit 10 and the traffic information notification unit 18 to resume the transmission process (step S208).

  As described above, according to the present embodiment, when there are a large number of radio base stations with low traffic and high received electric field strength, transmission of the own device is stopped, so that the installation status of the control station and the base station The power consumption can be reduced without providing a database for managing

[Modification of Second Embodiment]
(Operation)
FIG. 6 is a flowchart showing a control procedure of the radio base station according to the modification of the second embodiment of the present invention.

  First, the traffic information acquisition unit 12 acquires traffic information transmitted from a plurality of other radio base stations (step S301).

  Next, the received electric field strength measuring unit 14 measures the received electric field strength of signals transmitted from other wireless base stations (step S302).

  Next, when the number of radio base stations that satisfy the condition that the received electric field strength is equal to or greater than the threshold value B is equal to or greater than the predetermined value N3 (YES in step S303), the control unit 42 selects all radio base stations that satisfy this condition. For the station, when the traffic indicated by the traffic information is equal to or less than the threshold A (YES in step S304), the transmission unit 10 and the traffic information notification unit 18 are instructed to stop the transmission process (step S305). .

  After the transmission process is stopped, the traffic information acquisition unit 12 further acquires traffic information transmitted from another plurality of radio base stations (step S306).

  Further, the received electric field strength measurement unit 14 measures the received electric field strength of signals transmitted from other wireless base stations (step S307).

  Next, when the number of radio base stations satisfying the condition that the received electric field strength is equal to or greater than the threshold value B is not equal to or greater than the predetermined value N3 (NO in step S308), the control unit 42 and the traffic information notifying unit 18 is instructed to resume the transmission process (step S310).

  In addition, when the number of radio base stations that satisfy the condition that the received electric field strength is equal to or greater than the threshold value B is equal to or greater than the predetermined value N3 (YES in step S308), the control unit 42 determines all radio base stations that satisfy the condition. If the traffic indicated by the traffic information is not equal to or less than the threshold A (NO in step S309), the transmission unit 10 and the traffic information notification unit 18 are instructed to stop the transmission process (step S310).

  As described above, also in this modification, as in the second embodiment, when there are a large number of radio base stations with low traffic and high received electric field strength, transmission of the own device is stopped. In addition, it is possible to reduce power consumption without providing a database for managing the installation status of base stations.

[Third Embodiment]
The present embodiment relates to a radio base station that stops the function of its own device based on the correlation value between traffic at other radio base stations and reception response vectors of signals from other radio base stations.

(Configuration of radio base station)
FIG. 7 is a diagram illustrating the configuration of a radio base station according to the third embodiment of the present invention.

  Referring to FIG. 7, this radio base station is different from the radio base station according to the first embodiment in FIG. 2 as follows.

  This radio base station includes a reception response vector calculation unit 16 and a correlation value calculation unit 20 that are not included in the radio base station of the first embodiment. Further, the function of the control unit 62 of this radio base station is different from the control unit 22 of the radio base station of the first embodiment.

  The reception response vector acquisition unit calculates reception response vectors of signals from other radio base stations received by the reception unit 8.

  Here, it is assumed that the receiving unit 8 has received signals from three radio base stations, that is, the radio base station # 1, the radio base station # 2, and the radio base station # 3, and receives signals from these radio base stations. A method for calculating the response vector will be described.

  The reception response vector H1 of the radio base station # 1, the reception response vector H2 of the radio base station # 2, and the reception response vector H3 of the radio base station # 3 are expressed by the following equations.

H1 = [h11, h21, h31, h41]
H2 = [h12, h22, h32, h42]
H3 = [h13, h23, h33, h43]
On the other hand, the signals respectively received by the four antennas 4 to 7 are X1 (t), X2 (t), X3 (t), and X4 (t), and the radio base station # 1, the radio base station # 2, If the received signals of the radio base station # 3 are S1 (t), S2 (t), and S3 (t), the received signals of the respective antennas are expressed by the following equations.

X1 (t) = h11 · S1 (t) + h12 · S2 (t) + h13 · S3 (t) + N1 (t)
X2 (t) = h21 · S1 (t) + h22 · S2 (t) + h23 · S3 (t) + N2 (t)
X3 (t) = h31 · S1 (t) + h32 · S2 (t) + h33 · S3 (t) + N3 (t)
X4 (t) = h41 · S1 (t) + h42 · S2 (t) + h43 · S3 (t) + N4 (t)
Here, N1 (t), N2 (t), N3 (t), and N4 (t) are noise components.

For example, the reception response vector of the reception signal from the radio base station # 1 is each of the reception signals X1 (t), X2 (t), X3 (t), X4 (t) of the four antennas 4-7, By averaging the product of the complex conjugate S1 ^* (t) of the signal S1 (t) obtained by re-modulating the reception signal of the radio base station # 1 obtained by the adaptive array processing after successful reception, for a certain period of time, By taking the ensemble average E, the following equation is obtained.

E [X1 (t) · S1 ^* (t)] = E [h11 · S1 (t) · S1 ^* (t) + h12 · S2 (t) · S1 ^* (t) + h13 · S3 (t) · S1 ^* ( t) + N1 (t) · S1 ^* (t)] (1)
E [X2 (t) · S1 ^* (t)] = E [h21 · S1 (t) · S1 ^* (t) + h22 · S2 (t) · S1 ^* (t) + h23 · S3 (t) · S1 ^* ( t) + N2 (t) · S1 ^* (t)] (2)
E [X3 (t) · S1 ^* (t)] = E [h31 · S1 (t) · S1 ^* (t) + h32 · S2 (t) · S1 ^* (t) + h33 · S3 (t) · S1 ^* ( t) + N3 (t) · S1 ^* (t)] (3)
E [X4 (t) · S1 ^* (t)] = E [h41 · S1 (t) · S1 ^* (t) + h42 · S2 (t) · S1 ^* (t) + h43 · S3 (t) · S1 ^* ( t) + N4 (t) · S1 ^* (t)] (4)
Here, the ensemble average of the received signal S1 (t) and its complex conjugate S1 ^* (t) is E [S1 (t) · S1 ^* (t)] = 1. The ensemble average of the time-series random noise component Nn (t) and the complex conjugate S1 ^* (t) of the received signal S1 (t) is E [Nn (t) · S1 ^* (t)] = 0.

  Therefore, the above equations (1) to (4) are expressed as the following equations (5) to (8), respectively.

E [X1 (t) · S1 ^* (t)] = h11 + h12 · E [S2 (t) · S1 ^* (t)] + h13 · E [S3 (t) · S1 ^* (t)] (5)
E [X2 (t) · S1 ^* (t)] = h21 + h22 · E [S2 (t) · S1 ^* (t)] + h23 · E [S3 (t) · S1 ^* (t)] (6)
E [X3 (t) · S1 ^* (t)] = h31 + h32 · E [S2 (t) · S1 ^* (t)] + h23 · E [S3 (t) · S1 ^* (t)] (7)
E [X4 (t) · S1 ^* (t)] = h41 + h42 · E [S2 (t) · S1 ^* (t)] + h43 · E [S3 (t) · S1 ^* (t)] (8)
Here, the complex conjugate S1 ^* (t) of the received signal S2 (t) of the radio base station # 2 and the modulated signal of the radio base station # 1 is obtained by taking a long time average (over a large number of data symbols). Ensemble average E [S2 (t) · S1 ^* (t)] and the received signal S3 (t) of radio base station # 3 and the complex conjugate S1 ^* (t) of the modulated signal of radio base station # 1 The ensemble average E [S3 (t) · S1 ^* (t)] can be made zero.

  Thereby, the reception response vector H1 = [h11, h21, h31, h41] of the radio base station # 1 is obtained as in the following equations (9) to (12).

h11 = E [X1 (t) · S1 ^* (t)] (9)
h21 = E [X2 (t) · S1 ^* (t)] (10)
h31 = E [X3 (t) · S1 ^* (t)] (11)
h41 = E [X4 (t) · S1 ^* (t)] (12)
Similarly, the reception response vector H2 = [h12, h22, h32, h42] of the radio base station # 2 is obtained as in the following equations (13) to (16).

h12 = E [X1 (t) · S2 ^* (t)] (13)
h22 = E [X2 (t) · S2 ^* (t)] (14)
h32 = E [X3 (t) · S2 ^* (t)] (15)
h42 = E [X4 (t) · S2 ^* (t)] (16)
Similarly, the reception response vector H3 = [h13, h23, h33, h43] of the radio base station # 3 is obtained as in the following equations (17) to (20).

h13 = E [X1 (t) · S3 ^* (t)] (17)
h23 = E [X2 (t) · S3 ^* (t)] (18)
h33 = E [X3 (t) · S3 ^* (t)] (19)
h43 = E [X4 (t) · S3 ^* (t)] (20)
By the way, in the PHS, a timing for receiving a signal (control channel including BCCH) from the radio base station # 1, a timing for receiving a signal (control channel including BCCH) from the radio base station # 2, and a radio base station The timing for receiving a signal from # 3 (control channel including BCCH) is different.

  Therefore, the timing for receiving a signal from the radio base station # 1 is t1, the timing for receiving a signal from the radio base station # 2 is t2, and the timing for receiving a signal from the radio base station # 3 is t3. In equations (9) to (12), H1 is calculated when t is t1, and in equations (13) to (16), H2 is calculated when t is t2, and equations (17) to (20) are calculated. ), H3 when t is t3 may be calculated.

  The correlation value calculation unit 20 creates all possible pairs from all the calculated reception response vectors, and calculates a correlation value between the paired reception response vectors. Correlation value calculation unit 20 calculates correlation value Co12 from the pair of reception response vectors H1 and H2. The correlation value calculation unit 20 calculates a correlation value Co13 from the pair of reception response vectors H1 and H3. The correlation value calculation unit 20 calculates a correlation value Co23 from the pair of reception response vectors H2 and H3.

Co12 = (H1 · H2) / (| H1 || H2 |) (21)
Co13 = (H1 · H3) / (| H1 || H3 |) (22)
Co23 = (H2 · H3) / (| H2 || H3 |) (23)
When the number of radio base stations that satisfy the condition that the traffic indicated by the traffic information is less than or equal to the threshold A is equal to or greater than the predetermined value N4, the control unit 62 receives reception responses of all radio base stations that satisfy the condition. When all the possible pairs created from the vectors have a correlation value equal to or less than the threshold value D and the number of pairs is equal to or greater than the predetermined value N5, the transmission processing is stopped for the transmission unit 10 and the traffic information notification unit 18 To instruct. This is because, when the correlation value of the reception response vector of the signal from the radio base station with low traffic is small, even if the own device stops transmission, the radio terminal This is because communication with a station is possible. By adding the condition that the correlation value of the reception response vector is small, the transmission is stopped when other radio base stations are concentrated in a specific direction and there are no other radio base stations in the other direction. Therefore, it is possible to avoid the situation where the wireless terminal does not find the wireless base station of the communication partner.

  After the transmission unit 10 and the traffic information notification unit 18 stop the transmission process, the control unit 62 does not have the number of radio base stations satisfying the condition that the traffic indicated by the traffic information is equal to or less than the threshold A equal to or greater than the predetermined value N4. In this case, the transmission unit 10 and the traffic information notification unit 18 are instructed to resume transmission processing.

  In addition, after the transmission unit 10 and the traffic information notification unit 18 stop the transmission process, the control unit 62 determines that the number of wireless base stations that satisfy the condition that the traffic indicated by the traffic information is equal to or less than the threshold value A is N4. If all the possible pairs created from the reception response vectors of all the radio base stations satisfying this condition in the case of the above are the correlation values, the number of pairs that are less than or equal to the threshold value D is not greater than or equal to the predetermined value N5 Instructs the transmission unit 10 and the traffic information notification unit 18 to resume the transmission process.

(Operation)
FIG. 8 is a flowchart showing a control procedure of the radio base station according to the third embodiment of the present invention.

  First, the traffic information acquisition unit 12 acquires traffic information transmitted from a plurality of other radio base stations (step S401).

  Next, when the number of radio base stations satisfying the condition that the traffic indicated by the traffic information is equal to or less than the threshold value A is equal to or greater than the predetermined value N4 (YES in step S402), The reception response vectors of all radio base stations that satisfy this condition are calculated (step S403).

  Next, the correlation value calculation unit 20 creates all possible pairs from all the calculated reception response vectors, and calculates correlation values between the paired reception response vectors. Thereby, a correlation value for each pair is obtained for a plurality of pairs (step S404).

  When the number of pairs whose correlation value is equal to or less than the threshold value D is equal to or greater than the predetermined value N5 (YES in step S405), the control unit 62 stops the transmission process for the transmission unit 10 and the traffic information notification unit 18. (Step S405).

  After the transmission process is stopped, the traffic information acquisition unit 12 further acquires traffic information transmitted from a plurality of other radio base stations (step S407).

  Next, when the number of wireless base stations satisfying the condition that the traffic indicated by the traffic information is equal to or less than the threshold A is equal to or greater than the predetermined value N4 (YES in step S408), The reception response vectors of all wireless base stations that satisfy this condition are calculated (step S409).

  On the other hand, when the number of wireless base stations that satisfy the condition that the traffic indicated by the traffic information is equal to or less than the threshold A is not equal to or greater than the predetermined value N4 (NO in step S408), the control unit 62 The information notification unit 18 is instructed to resume the transmission process (step S412).

  Next, the correlation value calculation unit 20 creates all possible pairs from all the calculated reception response vectors, and calculates correlation values between the paired reception response vectors. Thereby, a correlation value for each pair is obtained for a plurality of pairs (step S410).

  When the number of pairs whose correlation value is equal to or less than the threshold value D is equal to or greater than the predetermined value N5 (YES in step S411), the control unit 62 keeps the transmission processing by the transmission unit 10 and the traffic information notification unit 18 stopped. And return to step S407. The predetermined value N5 may be, for example, the number of all bears.

  Next, when the number of pairs whose correlation value is equal to or less than the threshold value D is not equal to or greater than the predetermined value N5 (NO in step S411), the control unit 62 performs transmission processing on the transmission unit 10 and the traffic information notification unit 18. An instruction is given to resume (step S412).

  As described above, according to the present embodiment, when the correlation value of the reception response vector of the signal from the radio base station with low traffic is small, the transmission of the own device is stopped, so that the control station and the base station It is possible to reduce power consumption without providing a database for managing the installation status of the system.

[Fourth Embodiment]
This embodiment is based on the traffic of other radio base stations, the received electric field strength of signals from other radio base stations, and the reception response vector of signals from other radio base stations. The present invention relates to a radio base station that stops communication.

(Configuration of radio base station)
FIG. 9 is a diagram illustrating the configuration of a radio base station according to the fourth embodiment of the present invention.

  Referring to FIG. 9, this wireless base station is different from the wireless base station according to the first embodiment in FIG. 2 as follows.

  This radio base station includes a received electric field strength measurement unit 14, a reception response vector calculation unit 16, and a correlation value calculation unit 20 that are not included in the radio base station of the first embodiment. Further, the function of the control unit 82 of the radio base station is different from the control unit 22 of the radio base station of the first embodiment.

The reception electric field strength measurement unit 14 is the same as that described in the second embodiment.
The reception response vector calculation unit 16 is the same as that described in the third embodiment.

The correlation value calculation unit 20 is the same as that described in the third embodiment.
When the traffic indicated by the traffic information is equal to or less than the threshold A and the number of radio base stations satisfying the condition where the received electric field strength is equal to or greater than the threshold B is equal to or greater than the predetermined value N6, the control unit 82 When all the possible pairs created from the reception response vectors of all satisfying radio base stations satisfy the threshold value D among the correlation values, the transmission unit 10 and the traffic Instructs the information notification unit 18 to stop the transmission process. This is because if the correlation value of the reception response vector of the signal from the radio base station with low traffic and high received electric field strength is small, the radio terminal This is because it is possible to communicate with a radio base station with less traffic and high received electric field strength. By adding the condition that the correlation value of the reception response vector is small, the transmission is stopped when other radio base stations are concentrated in a specific direction and there are no other radio base stations in the other direction. Therefore, it is possible to avoid the situation where the wireless terminal does not find the wireless base station of the communication partner.

  After the transmission unit 10 and the traffic information notification unit 18 stop the transmission process, the control unit 82 is a wireless base station that satisfies the condition that the traffic indicated by the traffic information is less than or equal to the threshold A and the received electric field strength is greater than or equal to the threshold B. If the number of stations is not equal to or greater than the predetermined value N6, the transmission unit 10 and the traffic information notification unit 18 are instructed to resume transmission processing.

  In addition, after the transmission unit 10 and the traffic information notification unit 18 stop the transmission process, the control unit 82 satisfies the condition that the traffic indicated by the traffic information is equal to or lower than the threshold A and the received electric field strength is equal to or higher than the threshold B. When the number of radio base stations to be performed is a predetermined value N6 or more, all possible pairs created from reception response vectors of all radio base stations satisfying this condition If the number of pairs is not equal to or greater than the predetermined value N7, the transmission unit 10 and the traffic information notification unit 18 are instructed to resume transmission processing.

(Operation)
FIG. 10 is a flowchart showing a control procedure of the radio base station according to the fourth embodiment of the present invention.

  First, the traffic information acquisition unit 12 acquires traffic information transmitted from a plurality of other radio base stations (step S501).

  Next, the received electric field strength measuring unit 14 measures the received electric field strength of signals transmitted from other wireless base stations (step S502).

  Next, the reception response vector calculation unit 16 determines that the number of radio base stations satisfying the condition that the traffic indicated by the traffic information is equal to or less than the threshold A and the received electric field strength is equal to or greater than the threshold B is equal to or greater than the predetermined value N6. (Step S503: YES), the reception response vectors of all the radio base stations that satisfy this condition are calculated (step S504).

  Next, the correlation value calculation unit 20 creates all possible pairs from all the calculated reception response vectors, and calculates correlation values between the paired reception response vectors. Thereby, a correlation value for each pair is obtained for a plurality of pairs (step S505).

  When the number of pairs whose correlation value is equal to or less than the threshold value D is equal to or greater than the predetermined value N7 (YES in step S506), the control unit 82 stops the transmission process for the transmission unit 10 and the traffic information notification unit 18. (Step S507).

  After the transmission process is stopped, the traffic information acquisition unit 12 further acquires traffic information transmitted from a plurality of other radio base stations (step S508).

  Next, the received electric field strength measurement unit 14 measures the received electric field strength of signals transmitted from other wireless base stations (step S509).

  Next, when the traffic indicated by the traffic information is less than or equal to the threshold A and the number of radio base stations satisfying the condition that the received electric field strength is greater than or equal to the threshold B is not greater than or equal to the predetermined value N6 (step In S510, the transmission unit 10 and the traffic information notification unit 18 are instructed to resume the transmission process (step S514).

  On the other hand, the reception response vector calculation unit 16 determines that the number of radio base stations satisfying the condition that the traffic indicated by the traffic information is equal to or less than the threshold A and the received electric field strength is equal to or greater than the threshold B is equal to or greater than the predetermined value N6. (YES in step S510), the reception response vectors of all radio base stations satisfying this condition are calculated (step S511).

  Next, the correlation value calculation unit 20 creates all possible pairs from all the calculated reception response vectors, and calculates correlation values between the paired reception response vectors. Thereby, a correlation value for each pair is obtained for a plurality of pairs (step S512).

  When the number of pairs whose correlation value is equal to or less than the threshold value D is not equal to or greater than the predetermined value N7 (NO in step S513), the control unit 82 resumes the transmission process for the transmission unit 10 and the traffic information notification unit 18. (Step S514).

  As described above, according to the present embodiment, when the correlation value of the reception response vector of the signal from the radio base station with low traffic and high received electric field strength is small, the transmission of the own apparatus is stopped. Power consumption can be reduced without providing a database for managing the installation status of the control station and the base station.

(Modification)
The present invention is not limited to the above embodiment, and includes, for example, the following modifications.

(1) Direction of Arrival The direction of arrival of signals from other radio base stations is estimated, and when the directions of arrival are dispersed, the transmission processing of the own device may be stopped.

(2) Threshold In the embodiment of the present invention, the threshold and the predetermined number when stopping the transmission process are set to the same value as the threshold and the predetermined number when restarting the transmission process. However, the present invention is not limited to this. It may be a separate value.

(3) Stop Function In the embodiment of the present invention, the transmission process by the transmission unit and the traffic information notification unit is stopped in order to reduce the power. However, the present invention is not limited to this. It is good also as stopping a part of function of a transmission part and a traffic information alerting | reporting part. Moreover, it is good also as stopping all the functions by turning off a power supply for a fixed time.

(4) Time to calculate reception response vector In this embodiment, since a PHS radio base station is assumed, the timing of receiving a signal (control channel including BCCH) from radio base station # 1, The timing for receiving a signal (control channel including BCCH) from the station # 2 is different from the timing for receiving a signal (control channel including BCCH) from the radio base station # 3. Even if the timing of receiving the signal from the radio base station # 1, the timing of receiving the signal from the radio base station # 2, and the timing of receiving the signal from the radio base station # 3 are the same, spreading It can be separated by a code.

  Therefore, in the case of a CDMA radio base station, the same time t1 can be used for the calculations of equations (9) to (20). That is, in equations (9)-(12), H1 is calculated when t is t1, and in equations (13)-(16), H2 is calculated when t is t1, and equations (17)-( In 20), H3 when t is t1 may be calculated.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  4 to 7 antennas, 8 reception units, 10 transmission units, 12 traffic information acquisition units, 14 reception field strength measurement units, 16 reception response vector calculation units, 19 traffic information notification units, 20 correlation value calculation units, 22, 42, 62 , 82 control unit, AD wireless base station.

Claims (6)

An informing unit for informing information representing traffic of the own device;
A receiving unit for receiving information representing the traffic of the other base station device broadcast from the other base station device;
A reception response vector calculation unit for calculating a reception response vector of a signal transmitted from another base station device;
A correlation value calculation unit for calculating correlation values for two pairs of reception response vectors of signals from a plurality of other base station devices;
Based on said information and the correlation value representing the traffic of the broadcast from another base station apparatus other base station apparatus, base station apparatus provided with a control unit for stopping part of the functions, the own device. The control unit, when the number of base station devices that satisfy the condition that the traffic is equal to or less than a first threshold is equal to or greater than a first predetermined value, the reception response vectors of all base station devices that satisfy the condition If the number of pairs that are equal to or smaller than the second threshold among the correlation values of all possible pairs created from the above is greater than or equal to a second predetermined value, a part of the function of the device is stopped. The base station apparatus according to 1. The base station device further includes:
A measurement unit that measures the received electric field strength of a signal transmitted from another base station device,
The base station apparatus according to claim 1, wherein the control unit further stops a partial function of the own apparatus based on the traffic, the received electric field strength, and the correlation value. In the case where the number of base station apparatuses that satisfy the condition that the traffic is equal to or less than a first threshold and the received electric field strength is equal to or greater than a second threshold is equal to or greater than a first predetermined value, Among the possible correlation values of all the pairs created from the reception response vectors of all base station apparatuses that satisfy the condition, when the number of pairs that are equal to or smaller than the third threshold is equal to or larger than the second predetermined value, The base station apparatus according to claim 3, wherein a part of functions of the own apparatus is stopped. The base station apparatus according to any one of claims 1 to 4, wherein the control unit stops transmission processing of the own apparatus as a stop of a part of functions of the own apparatus. A control method for a base station apparatus,
Informing information representing traffic of the device;
Receiving information representing the traffic of the other base station device broadcast from the other base station device;
Calculating a reception response vector of a signal transmitted from another base station device;
Calculating correlation values for two pairs of reception response vectors of signals from a plurality of other base station devices;
Based on the information and the correlation value representing the traffic of the other base station apparatus which is notified from the other base station apparatus, control method of a base station apparatus and a step of stopping some of the functions of the apparatus .

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