JP2009278580A - Base station device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base station device reducing a trouble to another wireless communication terminal, caused by transmitting a switching wave for communicating with a narrow-area base station from a specific wireless communication terminal for communicating with both a wide-area base station and the narrow-area base station, while the specific wireless communication terminal communicates with the wide-area base station. <P>SOLUTION: In the base station device constituting a femtocell base station 11 covering a femtocell area 31 inside a public network area 30, communication with a specific wireless communication terminal 20a communicable with both a wide-area base station 10 and the femtocell base station 11 is performed, the switching wave is transmitted for switching to enable the wireless communication terminal 20a to communicate with the femtocell base station 11, the frequency channel necessary for transmitting the switching wave is specified, the switching wave constituted of the specified frequency channel is transmitted in a cycle based on timing of a monitor slot and after the lapse of a fixed time from the transmission of the switching wave, the transmission of the switching wave is stopped. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a base station apparatus that communicates with a wireless communication terminal within a specific area.

  In recent years, a communication system called a femtocell has been proposed in a wireless communication system, and the femtocell enables communication of a wireless communication terminal in a local service area that is narrower than a service area of a public network. is there.

  A service area (hereinafter referred to as a femtocell area) in which a base station that implements a femtocell (hereinafter referred to as a femtocell base station) can communicate is basically a service area (in which a base station of a public network can communicate with ( (Hereinafter referred to as the public network area). A specific wireless communication terminal can communicate with either base station by switching between the frequency used in the public network area and the frequency used in the femtocell area.

  When the femtocell base station is installed for personal use or for commercial purposes, only a wireless communication terminal capable of communicating with either of the above base stations (hereinafter referred to as a femtocell usable terminal) can communicate with the femtocell base station. And can receive special services within the femtocell area. A wireless communication terminal that is not a femtocell usable terminal cannot communicate with a femtocell base station in a femtocell area and cannot receive a special service.

  Normally, a femtocell-enabled terminal has a scan list that includes information for identifying frequencies and systems for scanning femtocell base stations. An example of the scan list is shown in FIG. In the scan list of FIG. 9, information (frequency channel, system ID, network ID) registered in scan order 1 is information about femtocells, and information registered in scan orders 2, 3 is related to public networks. Information.

  When the wireless communication terminal is turned on, at the end of a call, or when the system is lost, the base station is scanned according to the scan order and connected to the found base station. According to the scan list of FIG. 9, information registered in the scan order 1 is first set in the femtocell usable terminal. The femtocell usable terminal finds the femtocell base station, and the system ID and the like are set. If it matches the registered one, it can connect to the femtocell base station and wait. If the femtocell base station is not found, or if the system ID or the like does not match the registered one, the information registered in the scan order 2 is set in the femtocell usable terminal, and the femtocell The cell-usable terminal attempts to connect to a public network base station.

  If the femtocell-enabled terminal is communicating with a public network base station and is present in the femtocell area, the connection is switched from the public network base station to the femtocell base station in order to communicate with the femtocell base station. A conventional method will be described below.

  A conventional wireless communication system based on the description in Patent Document 1 is shown in FIG. The wireless communication system shown in FIG. 8 includes a wide area base station 10 of a public network for mobile phones, a femtocell base station 9 installed in a public network area 30 capable of communicating with the wide area base station 10, and a public network. The wireless communication terminals 20a, 20b, and 20c are portable devices that can be used. In addition, when distinguishing each radio | wireless communication terminal, it describes as radio | wireless communication terminal 20a, 20b, 20c, and when not distinguishing each radio | wireless communication terminal, it describes as the radio | wireless communication terminal 20. FIG.

  Of the wireless communication terminals 20a, 20b, and 20c, the wireless communication terminal 20a is a femtocell usable terminal. The radio communication terminals 20 b and 20 c are terminals that cannot be used in the femtocell base station 9. In the wireless communication terminals 20b and 20c, a scan list for connecting only through the public network is set.

  In addition, the femtocell base station 9 detects radio waves of the wide area base station 10 of the public network that can be received in the femtocell area 31 and interferes with a channel having the same frequency as the frequency used by the wide area base station 10. Is radiating. Further, the femtocell base station 9 provides a service on a frequency channel that is not used by the wide area base station 10.

  The radio communication terminal 20 c is in the service area of the wide area base station 10 and outside the service area of the femtocell base station 9. In this case, the radio communication terminal 20c can receive the radio wave of the wide area base station 10 without error without being affected by the interference wave radiated from the femtocell base station 9.

  When the radio communication terminal 20a that can be used in the femtocell base station 9 is located in the femtocell area 31 as shown in FIG. The radio wave from the wide area base station 10 cannot be received, and communication with the wide area base station 10 becomes impossible.

Since the wireless communication terminal 20a has the scan list shown in FIG. 9, when communication with the wide area base station 10 becomes impossible, the frequency channel from the head of the scan list is searched to search for a usable system. Scan. As a result of this scan, the radio communication terminal 20a receives radio waves from the femtocell base station 9, confirms that the femtocell base station 9 is usable, and then enters the standby state. As described above, the wireless communication system disclosed in Patent Document 1 switches the connection with the base station so as to reliably wait for a femtocell usable terminal in the femtocell area.
Japanese Patent No. 38049797

  However, in the above-described conventional wireless communication system, since the femtocell base station 9 radiates an interference wave so that the femtocell base station 9 does not communicate with the wide area base station 10 in the femtocell area 31, the wireless communication in the femtocell area 31 is performed. There is a possibility that the terminal 20b cannot receive the radio waves of the wide area base station 10 correctly. Furthermore, since the wireless communication terminal 20b is not set to be usable in the femtocell base station 9, it cannot wait on the femtocell base station 9, and is in the public network area 30. It becomes impossible to communicate.

  Therefore, the present invention has been made to solve the conventional problems, and when a specific wireless communication terminal capable of communicating with both the wide area base station and the narrow area base station is communicating with the wide area base station, It is an object of the present invention to provide a base station apparatus that can reduce problems with other wireless communication terminals caused by transmission of a switching wave for allowing a specific wireless communication terminal to communicate with a narrow base station.

  The base station apparatus of the present invention is a base station apparatus that constitutes a narrow base station that can communicate in a narrow area within a wide area that can communicate with the wide area base station. A communication unit that communicates with a specific wireless communication terminal capable of communicating with both, and when the specific wireless communication terminal communicates with the wide area base station, the specific wireless communication terminal communicates with the narrow area base station. A switching wave transmitter for transmitting a switching wave for switching so as to perform communication, a frequency channel necessary for transmission of the switching wave based on communication information regarding the specific wireless communication terminal output from the wide area base station, and A control unit that identifies the timing of the monitoring slot, wherein the switching wave transmission unit is configured to switch the switching wave configured by the frequency channel specified by the control unit based on the timing of the monitoring slot. Sends the period, and has a structure to stop transmission of the switching wave from transmission The sections Kawanami after a predetermined time.

  With this configuration, transmission is performed at a period based on the timing of the monitoring slot of a specific wireless communication terminal, and the transmission of the switching wave is stopped after a certain time from transmitting the switching wave, thereby affecting other wireless communication terminals. Since the possibility of giving is reduced, problems with other wireless communication terminals caused by transmission of the switching wave can be reduced.

  Further, in the base station apparatus of the present invention, the control unit includes a frequency channel necessary for transmitting the switching wave based on the communication information acquired from a server that manages the wide area base station and the narrow area base station, and The monitor slot timing is calculated.

  Whereas the conventional base station apparatus directly receives the radio wave transmitted by the wide area base station and obtains the frequency of the radio wave, the base station apparatus of the present invention is based on the communication information acquired from the server. Compared with the conventional method of calculating the frequency of radio waves used by other stations to calculate the frequency channel and monitoring slot timing required for switching wave transmission, the switching channel frequency channel and monitoring slot are more accurate. Timing can be specified.

  The base station apparatus of the present invention has a configuration in which the period is a period that is a multiple of the timing of the monitoring slot.

  With this configuration, the transmission interval of the switching wave is set to a period that is a multiple of the timing of the monitoring slot, so that the transmission interval of the switching wave is somewhat increased, which affects a wireless communication terminal that is not a specific wireless communication terminal in a narrow area. Can not be.

  Further, in the base station apparatus of the present invention, when the control unit detects that the specific wireless communication terminal is communicating with the wide area base station, the switching wave transmission unit is configured to have a frequency specified by the control unit. When the control unit detects that the specific wireless communication terminal is not communicating with the wide area base station, the switching wave transmission unit is identified by the control unit. The transmission of the switching wave configured by the frequency channel is stopped.

  With this configuration, since the specific radio communication terminal exists in the wide area, that is, only when the specific radio communication terminal is communicating with the wide area base station, the switching wave is transmitted, so the power consumption of the base station apparatus is reduced. Can be saved.

  Further, in the base station apparatus of the present invention, when the communication unit detects that the specific wireless communication terminal is waiting in the narrow area base station, the switching wave transmission unit is specified by the control unit. The switching wave composed of the frequency channels is not transmitted.

  With this configuration, when a specific wireless communication terminal is waiting at a narrow base station, a switching wave is not transmitted, so that it is possible to prevent a communication problem with respect to the specific wireless communication terminal that is waiting.

  In the present invention, when a specific wireless communication terminal capable of communicating with both the wide area base station and the narrow area base station is communicating with the wide area base station, the specific wireless communication terminal allows the specific wireless communication terminal to communicate with the narrow area base station. It is an object of the present invention to provide a base station apparatus that can reduce problems with other wireless communication terminals caused by transmission of switching waves.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of a communication system using a femtocell according to the present embodiment. The communication system shown in FIG. 1 includes a wide area base station 10 and a femtocell base station 11 of a public network using a CDMA system. The femtocell base station 11 is connected to a femtocell usable terminal in a femtocell area 31. Communication is possible. The femtocell area 31 is in the public network area 30 in which the wireless communication terminal 20 can communicate with the wide area base station 10.

  Further, the communication system shown in FIG. 1 includes a gateway 40 that connects the network 60 to which the wide area base station 10 is connected and the Internet 61, and an OAM (Operation And Maintenance) server 50.

  The OAM server 50 manages the femtocell base station 11 and also has information regarding the wide area base station 10. The OAM server 50 includes femtocell information related to the femtocell base station 11 to be managed, information about frequency channels used by the wide area base station 10 to be managed and the radio communication terminal 20, and information about a monitoring slot to be described later. Communication information including is registered.

  The femtocell information includes, for example, a system ID, a frequency channel to be used, an ID of a femtocell usable terminal, and the like. The femtocell base station 11 acquires the femtocell information registered in the OAM server 50 via the Internet 61.

  Further, the OAM server 50 detects the wireless communication terminal 20 existing in the public network area 30 by receiving information representing the ID of the wireless communication terminal 20 communicating with the wide area base station 10 from the wide area base station 10. It is like that.

  The wireless communication terminal 20 is, for example, a mobile terminal using a CDMA system, can communicate with the wide area base station 10, and can perform a call or data communication with the other communication device. In addition, when distinguishing each radio | wireless communication terminal 20, it describes as radio | wireless communication terminals 20a and 20b etc., and when not distinguishing each radio | wireless communication terminal, it describes as the radio | wireless communication terminal 20. FIG.

  The wireless communication terminal 20a is a femtocell usable terminal, and the ID of the wireless communication terminal 20a is set in femtocell information managed by the OAM server 50. The radio communication terminal 20 b and the radio communication terminal 20 c illustrated in FIG. 6 are terminals that cannot be used in the femtocell base station 11.

  The radio communication terminal 20 a has a scan list including information for identifying frequency channels and systems for scanning the femtocell base station 11. An example of the scan list is shown in FIG. In the scan list of FIG. 9, information registered in scan order 1 is information related to femtocells, and information registered in scan orders 2 and 3 is information related to public networks. The wireless communication terminals 20b and 20c are set with a scan list for connection only through the public network.

  FIG. 2 is a configuration diagram of a paging channel transmitted from a base station using the CDMA system to a wireless communication terminal, and is a diagram for explaining an operation during standby in the CDMA system.

  A base station using the CDMA system divides the paging channel into units of 80 ms slots and transmits them to the radio communication terminal 20. Each waiting wireless communication terminal 20 determines the timing of a monitoring slot having a predetermined time (1.28 × 2 ^ n seconds in FIG. 2) based on an identification number unique to the terminal. For example, the monitoring slot 200 and the monitoring slot 201 illustrated in FIG. 2 indicate the monitoring slots of the paging channel of the radio communication terminals 20a and 20b.

  N is a parameter called a slot cycle index, which is designated by a base station using the CDMA system. For example, in the wide area base station 10, if n is 2, the terminal receives the paging channel of its own monitoring slot at a cycle of 5.12 seconds. Note that n is not limited to 2.

  When there is an incoming call to the radio communication terminal 20, the wide area base station 10 transmits a message notifying the radio communication terminal 20 of the incoming call or a message for performing control at the timing of the monitoring slot.

  Further, the radio communication terminal 20 turns on the power of the receiver before receiving the monitoring slot in order to receive the monitoring slot, so that reception is possible on the frequency channel transmitting the paging channel. Next, when there is no message addressed to itself in the monitoring slot, the wireless communication terminal 20 turns off the power of the receiver so that power is not consumed until the next monitoring slot. As described above, the wireless communication terminal 20 reduces power consumption by turning off the power supply for operating the reception function while not receiving the paging channel.

  FIG. 3 shows a block diagram of a base station apparatus constituting the femtocell base station of the present embodiment. In FIG. 3, the femtocell base station 11 controls a base station unit 100 (communication unit) that performs communication with a femtocell-usable terminal, a switching wave transmission unit 101 that transmits a switching wave, which will be described later, and transmission of the switching wave. A control unit 102 is included. For example, these members are constituted by an integrated circuit or the like.

  The base station unit 100 has, in addition to a control unit composed of an antenna, a CPU, a ROM, and a RAM, a unit that realizes the function of a femtocell base station using a CDMA system such as a transmitter and a receiver for wireless communication. Yes. The base station unit 100 also has a communication interface and the like, and is configured to be able to communicate with the OAM server 50 via the gateway 40.

  The switching wave transmission unit 101 has an antenna different from the antenna installed in the base station unit 100, and when the femtocell usable terminal is communicating with the wide area base station 10, the femtocell usable terminal is the femtocell base station. 11 is transmitted so as to be switched so as to communicate with the terminal 11.

  The control unit 102 uses the frequency channel used by the femtocell-usable terminal in the public network area 30 and the timing of the monitoring slot of the femtocell-usable terminal to determine the frequency channel and switching wave transmission timing necessary for transmitting the switching wave. Is to identify.

  For example, the control unit 102 is configured to calculate a frequency channel necessary for transmitting a switching wave to the femtocell usable terminal from the information regarding the frequency channel received from the OAM server 50. In the present embodiment, the frequency channel used by the femtocell usable terminal in the public network area 30 is the same as the frequency channel of the switching wave.

  For example, the control unit 102 calculates the timing of the monitoring slot of the femtocell usable terminal from the information regarding the monitoring slot received from the OAM server 50. Note that the control unit 102 calculates the timing of the frequency channel and the monitoring slot of the femtocell-usable terminal necessary for transmission of the switching wave from information set by a network administrator or the like instead of information received from the OAM server 50. You may do it.

  Here, the transmission time of the switching wave will be described. FIG. 4 is a diagram for explaining the timing for generating the switching wave. The timing at which the wireless communication terminal 20 monitors the paging channel with respect to the time axis and the transmission time of the switching wave are shown.

  Timing 300 is the timing at which the femtocell-usable terminal monitors the paging channel in the public network area 30, and is the timing of the same monitoring slot as the period described in FIG. Since the femtocell-enabled terminal receives the monitoring slot at timing 300, the control unit 102 causes the switching wave transmission unit 101 to transmit a switching wave almost simultaneously with any of the timings 300.

  The transmission time 301 is the time from the start of transmission of the switching wave to the end of transmission. When the femtocell usable terminal is communicating with the wide area base station 10, the femtocell usable terminal communicates with the femtocell base station 11. Is the time required to switch. In the present embodiment, the transmission time 301 is a time necessary for determining that the radio communication terminal 20 has lost the base station.

  In the CDMA system, when the wireless communication terminal is not receiving a correct paging channel message for a defined transmission time T30m (for example, 3 seconds) while monitoring the paging channel, it is determined that the wireless communication terminal has lost (the base station has been lost). Is stipulated. For example, when the femtocell usable terminal after the loss scans the frequency channel according to the scan list illustrated in FIG. 9 and finds the femtocell base station 11, the femtocell base station 11 is connected.

  As described above, the switching wave transmission unit 101 starts transmission of the switching wave almost simultaneously with the reception timing of the monitoring slot of the femtocell-usable terminal at the timing 300 and can determine that the femtocell-usable terminal has been lost. For example, the transmission of the switching wave is stopped when the time of T30 m elapses. The transmission time T30m is variable and is not limited to 3 seconds.

  In the CDMA system, a plurality of frequency channels used for standby can be prepared, and one base station can also use a plurality of standby frequency channels. In this case, the terminal using the CDMA scheme determines a frequency channel to be awaited from the information unique to the terminal from the frequency channel list received from the base station, similarly to the determination of the monitoring slot timing. If it is different from the current frequency channel, it switches to that frequency channel and waits.

  The operation of the femtocell base station apparatus shown in FIG. 3 as described above will be described with reference to the drawings. FIG. 5 is a flowchart illustrating a specific control example of the control unit 102.

  First, the control unit 102 is connected to the OAM server 50 via the base station unit 100, acquires femto cell information from the OAM server 50 (step S1), and the femto cell usable terminal is transferred to the public network area 30 from the femto cell information. Detect that In the present embodiment, the control unit 102 acquires information indicating that the wireless communication terminal 20 a is in the public network area 30.

  Next, the control unit 102 acquires information on the frequency channel list used by the wide area base station 10 of the public network and the timing of the monitoring slot from the OAM server 50 via the base station unit 100 (step S2).

  Next, the control unit 102, based on the information on the femtocell usable terminal and the information acquired from the OAM server 50, the frequency channel necessary for transmitting the switching wave and the transmission timing of the switching wave, that is, the femtocell usable terminal. Calculates the frequency channel waiting for the wide area base station 10 and the timing of intermittent reception (timing of the monitoring slot) (step S3).

  Next, the control unit 102 synchronizes with the slot timing of the public network based on information received by the base station unit 100 in order to obtain the generation timing of the switching wave (step S4).

  Next, the control unit 102 sets a predetermined value in a counter that controls how many times of the monitoring slot period the switching wave is generated (step S5). For example, when a switching wave is transmitted once every 10 cycles, the predetermined value is set to 10, and when the cycle of its own monitoring slot is 5.12 seconds, 1 is set to a cycle of about 51.2 seconds. A switching wave is transmitted every time. The predetermined value is not limited to 10. In this way, by slightly increasing the transmission interval of the switching wave, the wireless communication terminal 20 that is not a femtocell usable terminal in the femtocell area 31 is not affected.

  The predetermined value is preferably set such that the femtocell usable terminal switches to communication with the femtocell base station 11 without affecting the radio communication terminal 20 that is not a femtocell usable terminal.

  Next, the control unit 102 waits for the timing 300 to start transmission of the switching wave, that is, the timing of intermittent reception (step S6). When the timing for intermittent reception comes, the control unit 102 decrements the counter by one (step S7), and determines whether the counter has become 0 (step S8). If the counter is not 0, the process returns to step S6, and the control unit 102 waits until the next intermittent reception timing is reached.

  If the counter is 0, a switching wave is transmitted, but before that, the control unit 102 makes an inquiry to the base station unit 100 to determine whether or not a femtocell usable terminal is already waiting in the femtocell base station 11. (Step S9). If the femtocell base station 11 has already waited, the process returns to step S5.

  If the femtocell usable terminal is not waiting in the femtocell base station 11 in step S9, the control unit 102 transmits a switching wave to the frequency channel in which the femtocell usable terminal calculated in step S3 is waiting. The switching wave transmission unit 101 is started (step S10). At this time, the control unit 102 starts a timer for stopping the switching wave (step S11). Here, the timer is set to a value of T30m, for example.

  The control unit 102 determines whether or not the timer has timed out (step S12). When the timer has timed out, the switching wave transmission unit 101 stops transmission of the switching wave (step S13). Thereafter, the process returns to S5.

  As described above, the femtocell base station apparatus according to the present embodiment transmits a switching wave at a period based on the timing of the monitoring slot of the femtocell usable terminal (in this embodiment, the wireless communication terminal 20a). Since the transmission of the switching wave is stopped after a certain period of time from the transmission of the signal, the possibility of affecting other wireless communication terminals (the wireless communication terminal 20b in this embodiment) in the femtocell area 31 is reduced. Therefore, it is possible to reduce problems with other wireless communication terminals caused by transmission of switching waves.

  Further, as shown in FIG. 6, the radio communication terminals 20b and 20c are terminals that cannot be used in the femtocell base station 11, and are femtocell usable terminals in the public network area 30 including the femtocell base station 11. There may be a case where there is not. In this case, the femtocell base station 11 does not need to output not only switching waves but also pilot signals, synchronization channels, paging channels, and the like necessary for normal base station operations, You may enter save mode.

  The femtocell base station 11 that has shifted to the power save mode periodically inquires of the OAM server 50 whether or not a femtocell usable terminal exists in the public network area 30.

  As shown in FIG. 7, when the wireless communication terminal 20 a that is a femtocell usable terminal enters the public network area 30, the control unit 102 of the femtocell base station 11 uses the femtocell in the public network area 30. When a response indicating that there is a possible terminal is received from the OAM server 50, the power save mode is canceled, the function as a normal base station is started, and the operation described in the flowchart of FIG. 5 is started.

  Further, when the femtocell base station 11 receives a response from the OAM server 50 that there is no femtocell-usable terminal in the public network area 30 in response to a periodic inquiry to the OAM server 50, the femtocell base station 11 again And the generation of the switching wave is stopped.

  In the present embodiment, the base station unit 100, the switching wave transmission unit 101, and the control unit 102 in the femtocell base station 11 are illustrated, but the control unit 102 may be realized in the control unit of the base station unit 100. The switching wave transmission unit 101 may use the transmitter of the base station unit 100 in a time-sharing manner.

  In addition, in this embodiment, the femtocell base station 11 is described to control transmission of switching waves to the femtocell-usable terminals. However, the femtocell base station 11 transmits switching waves to a plurality of femtocell-usable terminals. Transmission may be controlled.

  In the base station apparatus according to the present invention, when a specific wireless communication terminal capable of communicating with both the wide area base station and the narrow area base station communicates with the wide area base station, the wireless communication terminal communicates with the narrow area base station. Therefore, it is possible to reduce problems with other wireless communication terminals caused by transmission of switching waves for the purpose of making it widely useful as a wireless device.

It is a block diagram of the communication system using the femtocell which concerns on a present Example. 2 is a configuration diagram of a paging channel transmitted from a CDMA base station to a wireless communication terminal. FIG. It is a block diagram of the base station apparatus which comprises the femtocell base station of a present Example. It is a figure for demonstrating the timing which generates a switching wave. It is a flowchart which shows the specific example of control of the control part of a present Example. It is a block diagram of a communication system when a femtocell usable terminal does not exist in a public network area. It is a block diagram of a communication system when a femtocell usable terminal exists in a public network area. It is a block diagram of the communication system using the conventional femtocell. It is a figure which shows the example of a scan list.

Explanation of symbols

9, 11 Femtocell base station 10 Wide area base station 11 Narrow area base station 20 Wireless communication terminal 30 Public network area (wide area)
31 Femtocell area (narrow area)
40 Gateway 50 OAM Server 60 Network 61 Internet 100 Base Station (Communication)
101 switching wave transmission unit 102 control unit 200, 201 monitoring slot 300 timing 301 transmission time (fixed time)

Claims (5)

In a base station apparatus constituting a narrow area base station that can communicate in a narrow area within a wide area that can communicate with a wide area base station,
A communication unit for communicating with a specific wireless communication terminal capable of communicating with both the wide area base station and the narrow area base station;
When the specific wireless communication terminal is communicating with the wide area base station, a switching wave transmission unit that transmits a switching wave for switching the specific wireless communication terminal to communicate with the narrow area base station;
A control unit that identifies a frequency channel and a monitoring slot timing necessary for transmission of the switching wave based on communication information regarding the specific wireless communication terminal output from the wide area base station,
The switching wave transmission unit transmits a switching wave configured by the frequency channel specified by the control unit at a period based on the timing of the monitoring slot, and the switching wave is transmitted after a predetermined time from the transmission of the switching wave. A base station apparatus characterized by stopping wave transmission.   The control unit calculates timing of a frequency channel and a monitoring slot necessary for transmission of the switching wave based on the communication information acquired from a server that manages the wide area base station and the narrow area base station. The base station apparatus according to claim 1.   The base station apparatus according to claim 1, wherein the period is a period that is a multiple of the timing of the monitoring slot. When the control unit detects that the specific wireless communication terminal is communicating with the wide area base station, the switching wave transmission unit transmits a switching wave including the frequency channel specified by the control unit. Start,
When the control unit detects that the specific wireless communication terminal is not communicating with the wide area base station, the switching wave transmission unit transmits a switching wave configured by the frequency channel specified by the control unit. The base station apparatus according to any one of claims 1 to 3, wherein the base station apparatus is stopped.   When the communication unit detects that the specific wireless communication terminal is waiting at the narrow area base station, the switching wave transmission unit transmits a switching wave configured by the frequency channel specified by the control unit. The base station apparatus according to claim 1, wherein the base station apparatus does not transmit.

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