Wireless communication device, wireless communication system, and resource control method

Abstract

A wireless communication device according to the present invention comprises: a plurality of cell resources for controlling communication with a terminal in a cell formed by a plurality of antennas; a control unit for acquiring a required cell resource amount, controlling, on the basis of the acquired cell resource amount, switching of connection between the antennas and the cell resources so as to aggregate the cell resources to which the antennas are connected, and setting, to a sleep state or a stop state, the cell resources to which the antennas are no longer connected due to the switching; and a switching unit for executing the switching of the connection between the antennas and the cell resources in accordance with the control by the control unit.

Description

Wireless communication device, wireless communication system, and resource control method

[0001] The present invention relates to a wireless communication device, a wireless communication system, and a resource control method.

[0002] Wireless communication systems such as the fifth-generation mobile communication system (5G) use the millimeter wave band, which is a high-frequency band. To achieve even higher speeds and larger capacities in wireless communication, future wireless systems such as the sixth-generation mobile communication system (6G) are expected to use even higher frequency bands. This will enable even wider bandwidths to be secured. Generally, high-frequency bands have the properties of large propagation loss and high directivity. Therefore, with the aim of covering communication areas and improving communication connectivity, distributed antenna systems are being studied (see, for example, Non-Patent Document 1).

[0003] Fig. 10 is a diagram showing an example of a base station configuration of a conventional general wireless communication system. As shown in Fig. 10, a wireless communication system 6a, which is a conventional wireless communication system, includes a BBU (Base Band Unit) 7, a plurality of RRHs (Remote Radio Heads) 8, and a plurality of UEs (User Equipment) 9. The BBU 7 and the plurality of RRHs (Remote Radio Heads) 8 that are distributed in a distributed manner constitute a base station. The UEs 9 are, for example, mobile terminals such as smartphones.

[0004] The BBU 7 is a baseband device (control unit) that performs digital signal processing of information transmitted and received during communication with the UE 9. The BBU 7 performs processing of layers higher than the physical layer. The BBU 7 and the RRH 8 are connected by an optical fiber cable, and digital signals are transmitted between them.

[0005] The RRHs 8 are installed away from the BBUs 7 and are radio devices (antenna units) that transmit and receive radio signals to and from the UEs 9. The RRHs 8 perform RF (Radio Frequency) processing and the like. The RRHs 8 may also perform some physical layer processing. An antenna 80 is connected to each of the RRHs 8. The RRHs 8 and the antennas 80 are connected by coaxial cables, and radio signals are transmitted between them. The antennas 80 may be connected to extend from the RRHs 8 in this manner, or may be integrated with the RRHs 8.

[0006] 10 shows three RRHs 8 (RRHs 8-1 to 8-3) as an example. As shown in FIG. 10, RRH 8-1 covers the range of Cell #1, RRH 8-2 covers the range of Cell #2, and RRH 8-3 covers the range of Cell #3. RRHs 8-1 to 8-3 can transmit and receive radio signals to and from UEs 9 present in the cells they cover.

[0007] Fig. 11 is a diagram showing an example of a base station configuration of a conventional general distributed antenna system. As shown in Fig. 11, a wireless communication system 6b, which is a conventional distributed antenna system, includes a BBU 7, a plurality of RRHs 8, and a plurality of UEs 9. A plurality of antennas 80 are connected to each of the RRHs 8.

[0008] 11 shows, as an example, three RRHs (RRHs 8-1 to 8-3). Also, as an example, in FIG. 11, four antennas 80 are connected to each of the RRHs 8-1 to 8-3. As shown in FIG. 11, the RRH 8-1 covers the range of Cell #1, the RRH 8-2 covers the range of Cell #2, and the RRH 8-3 covers the range of Cell #3. The RRHs 8-1 to 8-3 can transmit and receive radio signals to and from UEs 9 present in the cells they cover using a plurality of antennas 80 (distributed antennas).

[0009] In this way, the wireless communication system 6b, which is a distributed antenna system, extends multiple antennas 80 from the RRH 8 and covers the same cell with the multiple antennas 80. This allows the wireless communication system 6b to further expand its communication area. Furthermore, the wireless communication system 6b can perform MIMO (Multi-Input Multi-Output) transmission by coordinating the multiple antennas 80. This allows the wireless communication system 6b to further expand its communication capacity.

[0010] Fig. 12 is a diagram showing another example of a base station configuration of a conventional general distributed antenna system. As shown in Fig. 12, a wireless communication system 6c, which is a conventional distributed antenna system, includes a BBU 7, a plurality of RRHs 8, and a plurality of UEs 9. An antenna 80 is connected to each of the RRHs 8.

[0011] 12 shows three RRHs (RRHs 8-1 to 8-3) as an example. As shown in FIG. 12, all three RRHs (RRHs 8-1 to 8-3) cover the range of Cell #1. RRHs 8-1 to 8-3 can transmit and receive radio signals to and from UEs 9 present in the same cell (within the range of Cell #1) using antennas 80 connected to each of them. In this way, it is also possible to configure a system in which multiple pairs of RRHs 8 and antennas 80 are used to cover the range of the same cell.

[0012] "White Paper: 5G Advancements and 6G," Version 5.0, NTT DOCOMO, Inc., November 2022. Kodai Ito et al., "Efficient Accommodation of Diverse High-Frequency Band Wireless Systems Using Analog RoF," NTT Technical Journal, Vol. 32, No. 3, Nippon Telegraph and Telephone Corporation, pp. 15-17, March 2020.

[0013] However, in the case of the base station configuration of the conventional wireless communication system shown in Figures 10 to 12, the antenna covering each cell is fixed and determined in advance when the antenna is installed. Therefore, in areas or time periods with low traffic volume or areas or time periods with a small number of connected users, there is a high probability of excess cell resources (cell resources with low utilization rates). Since the excess cell resources still consume power, there has been a problem in the past that power may be wasted in the base station device.

[0014] In view of the above circumstances, an object of the present invention is to provide a wireless communication device, a wireless communication system, and a resource control method that can reduce the power consumption of a wireless communication base station while maintaining communication quality.

[0015] One aspect of the present invention is a wireless communication device comprising: a plurality of cell resources that control communication with terminals within a cell formed by a plurality of antennas; a control unit that acquires a required amount of cell resources, controls switching of the connection between the antenna and the cell resources so as to aggregate the cell resources to which the antenna is connected based on the acquired amount of cell resources, and places the cell resources to which the antenna is no longer connected due to the switching into a sleep state or a stopped state; and a switching unit that performs switching of the connection between the antenna and the cell resources in accordance with control by the control unit.

[0016] Another aspect of the present invention is a wireless communication system having a plurality of wireless communication devices, a control unit, and a switching unit, wherein the wireless communication devices are provided with cell resources that control communication with terminals within a cell formed by a plurality of antennas, the control unit acquires a required amount of cell resources, controls switching of the connection between the antenna and the cell resources so as to aggregate the cell resources to which the antenna is connected based on the acquired amount of cell resources, and controls the wireless communication device having the cell resource to which the antenna is no longer connected due to the switching to a sleep state or a stopped state, and the switching unit performs switching of the connection between the antenna and the cell resources in accordance with control by the control unit.

[0017] Another aspect of the present invention is a resource control method having a control step of controlling communication with a terminal within a cell formed by a plurality of antennas using a plurality of cell resources; an acquisition step of acquiring a required amount of cell resources; a switching control step of controlling switching of a connection between the antenna and the cell resources so as to aggregate the cell resources to which the antenna is connected based on the acquired amount of cell resources; a switching step of executing switching of a connection between the antenna and the cell resources in accordance with the control in the switching control step; and a state control step of putting the cell resources to which the antenna is no longer connected due to the switching into a sleep state or a stopped state.

[0018] Another aspect of the present invention is a resource control method for a wireless communication system having a plurality of wireless communication devices, a control unit, and a switching unit, the resource control method comprising: a control step in which the wireless communication device controls communication with a terminal within a cell formed by a plurality of antennas using cell resources; an acquisition step in which the control unit acquires a required amount of cell resources; a switching control step in which the control unit controls switching of the connection between the antenna and the cell resources so as to aggregate the cell resources to which the antenna is connected based on the acquired amount of cell resources; a switching step in which the switching unit switches the connection between the antenna and the cell resources in accordance with control by the control unit; and a state control step in which the control unit switches the wireless communication device having the cell resource to which the antenna is no longer connected due to the switching into a sleep state or a stopped state.

[0019] According to the present invention, it is possible to reduce the power consumption of a wireless communication base station while maintaining communication quality.

[0020] FIG. 1 is an overall configuration diagram of a wireless communication system 1a in a first embodiment of the present invention. FIG. 1 is an overall configuration diagram of the wireless communication system 1a in the first embodiment of the present invention. FIG. 2 is a block diagram showing a functional configuration of a base station device in the first embodiment of the present invention. FIG. 3 is an overall configuration diagram of a wireless communication system 1b in a second embodiment of the present invention. FIG. 4 is an overall configuration diagram of a wireless communication system 1b in the second embodiment of the present invention. FIG. 5 is a block diagram showing a functional configuration of a base station device in the second embodiment of the present invention. FIG. 6 is a flowchart showing an example of operation in connection switching processing of a central station 2 in an embodiment of the present invention. FIG. 7 is a flowchart showing another example of operation in connection switching processing of a central station 2 in an embodiment of the present invention. FIG. 8 is a diagram showing an example of a base station configuration of a conventional general wireless communication system. FIG. 9 is a diagram showing an example of a base station configuration of a conventional general distributed antenna system. FIG. 10 is a diagram showing another example of a base station configuration of a conventional general distributed antenna system.

[0021] Hereinafter, a wireless communication device, a wireless communication system, and a resource control method according to embodiments of the present invention will be described. Note that each embodiment described below is merely one form of the present invention, and the application of the present invention is not limited to the embodiments described below. Note that in the wireless communication systems of the embodiments described below, components having the same functions are assigned the same reference numerals, and repeated explanations of the functions may be omitted.

[0022] <First embodiment> A first embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a diagram showing the overall configuration of a wireless communication system 1a according to the first embodiment of the present invention. As shown in Fig. 1, the wireless communication system 1a includes a central station 2, a switch 3 (SW), multiple antennas 4, and multiple UEs 5.

[0023] The wireless communication system 1a is a distributed antenna system in which functions are concentrated in a central station 2 and a plurality of antennas 4 are extended. The central station 2 is connected to each of the plurality of antennas 4 via a switch 3. The central station 2 shown in Fig. 1 can cover the range of Cell #1, the range of Cell #2, and the range of Cell #3 using the plurality of antennas 4. The central station 2 can transmit and receive wireless signals to and from UEs 9 present in each cell using the plurality of antennas 4 (distributed antennas).

[0024] In this way, the wireless communication system 1a, which is a distributed antenna system, extends multiple antennas 80 from the central station 2 and covers the ranges of multiple cells with multiple antennas 4 (distributed antennas). This allows the wireless communication system 1a to further expand its communication area. Furthermore, the wireless communication system 1a may also perform MIMO transmission by coordinating the multiple antennas 4. This allows the wireless communication system 1a to further expand its communication capacity.

[0025] The wireless communication system 1a in this embodiment uses analog RoF (Radio over Fiber) technology, similar to the high-frequency band wireless system described in Non-Patent Document 2, for example. This makes it possible to aggregate functions in the central station 2, including functions such as those possessed by the RRH 8 of the conventional wireless communication system shown in Figures 10 to 12. However, the technology used to aggregate functions in the central station 2 is not limited to analog RoF, and other technologies may also be used.

[0026] Below, we will explain the technology of consolidating functions in a central station using analog RoF. To further expand wireless transmission capacity, it is generally effective to use high-frequency radio waves such as millimeter waves and sub-terahertz waves, which can ensure a wide bandwidth. Millimeter waves are radio waves with very short wavelengths of 1 to 10 mm and frequencies of 30 to 300 GHz. Sub-terahertz waves are radio waves with wavelengths of 30 μm to 3 mm and frequencies of 100 GHz to 1 THz.

[0027] However, since the propagation distance of radio waves becomes shorter as the frequency increases, wireless communication systems using high frequency bands must install wireless base stations at high densities to cover a wide area. Furthermore, traditionally, a wireless base station had to be installed for each wireless communication system. Therefore, as wireless communication systems using high frequency bands become more diverse to meet diversifying needs, a huge number of wireless base stations will be installed. Therefore, with the aim of reducing the number of wireless base stations and reducing operational load, studies are underway to develop system configurations that enable wireless base stations to be shared by multiple wireless communication systems.

[0028] RoF is a technology for transmitting the waveform information of a radio signal over optical fiber. Analog RoF is a technology for intensity-modulating an optical signal with a radio signal and transmitting the radio-shaped optical signal over optical fiber. With analog RoF, the original radio signal can be extracted simply by O / E (Optical-to-Electrical) conversion of the transmitted optical signal. In other words, while digital RoF converts the waveform into a digital signal before transmitting it over optical fiber, analog RoF transmits the waveform directly as an analog signal over optical fiber. Therefore, unlike digital RoF, analog RoF does not require A / D (Analogue-to-Digital) conversion or D / A (Digital-to-Analogue) conversion. This has the advantage of requiring a narrower optical transmission bandwidth.

[0029] By using analog RoF, the functions of a conventional wireless base station can be separated into a central station (signal processing unit) and a base station (antenna unit). Conventional wireless base stations generally have the following functions: an antenna, an amplifier, an E / O converter, an O / E converter, and a signal processing unit. In contrast, by using analog RoF to consolidate the signal processing unit function in the central station, the functions of the base station can be simplified. This allows for the base station to be made smaller and consume less power.

[0030] Furthermore, by consolidating the signal processing functions that depend on the wireless communication system in the central station, the base station can be configured to have only common functions that are not dependent on the wireless communication system. This makes it possible to share the base station with multiple wireless communication systems as long as the frequency range supported by the antenna and amplifier is within the range. Furthermore, since the installation and renewal of wireless communication systems can be handled solely by operations on the central station side, it becomes possible to efficiently deploy and operate wireless communication systems. This reduces the number of wireless base stations required and operational costs.

[0031] 1 , the central station 2 is connected to the switch 3. The switch 3 may be provided outside the central station 2 as described above, or may be provided inside the central station 2. When the switch 3 is provided outside the central station 2, it may be located at a location distant from the central station 2.

[0032] The central station 2 has a plurality of cell resources for performing processing of wireless communication with UEs 5 present in a plurality of cells covered by the central station 2. The cell resources here refer to hardware that controls the cells, such as cards or boards. Note that the cell resources may also include software.

[0033] The central station 2 can arbitrarily switch the antenna 4 connected to each cell resource by switching the connection of the switch 3 .

[0034] Furthermore, the central station 2 controls the switching of connections between cell resources and antennas 4 based on index values ​​that represent, for example, the current traffic situation and the number of connected users of each cell. The central station 2 activates cell resources (e.g., cards, boards, etc.) that satisfy the processing capacity required for all areas covered by the central station 2. The central station 2 connects the activated cell resources to the antennas 4 by switching the connection using the switch 3. Meanwhile, the central station 2 puts surplus (unnecessary) cell resources (e.g., cards, boards, etc.) into a sleep state or a stopped state because the processing capacity exceeds the capacity required for all areas covered by the central station 2. This reduces unnecessary power consumption.

[0035] For example, as shown in Fig. 1, it is assumed that the aggregation station 2 has three cell resources (Cell #1, Cell #2, and Cell #1-3). Also, as shown in Fig. 1, it is assumed that the areas covered by the aggregation station 2 are the area covered by the four antennas 4 in the upper left of the top row, the area covered by the four antennas 4 in the center of the bottom row, and the area covered by the four antennas 4 in the upper right of the top row.

[0036] Figure 1 shows that of the four antennas 4 covering the area on the top left, two are connected to the cell resources of Cell #1 (covering the two small areas at the top within that area), one is connected to the cell resources of Cell #2 (covering the small area at the bottom left within that area), and one is connected to the cell resources of Cell #3 (covering the small area at the bottom right within that area). Figure 1 also shows that the four antennas 4 covering the area in the bottom center are all connected to the cell resources of Cell #2. Figure 1 also shows that the four antennas 4 covering the area on the top right are all connected to the cell resources of Cell #3.

[0037] The central station 2 periodically acquires index values ​​that indicate, for example, the current traffic situation in each area, the number of connected users, etc. The central station 2 controls switching of connections between cell resources and antennas 4 based on the acquired index values.

[0038] Here, for example, it is assumed that the area covered by the cell resources of Cell #2 has a low level of traffic and a low number of connected users. As shown in Fig. 1, the area covered by the cell resources of Cell #2 before switching the connection between the cell resources and antenna 4 is the small area at the bottom left of the area at the top left and all (four) small areas in the area at the bottom center. The central station 2 switches the antenna 4 to which the cell resources of Cell #2 are connected so that cell resources other than Cell #2 are connected to the antenna 4.

[0039] Fig. 2 is a diagram showing the overall configuration of a wireless communication system 1a according to a first embodiment of the present invention. While Fig. 1 shows a state before connection switching by the wireless communication system 1a, Fig. 2 shows a state after connection switching.

[0040] As shown in Figure 2, due to the connection switching, the antenna 4 that was connected to the cell resources of Cell #2 in Figure 1 is switched to connect to another cell resource. Specifically, the antenna 4 covering the small area at the bottom left of the area on the top left has been switched to connect to the cell resources of Cell #1. Furthermore, the three antennas 4 covering the small areas at the top left, bottom left, and bottom right of the area in the center of the bottom have been switched to connect to the cell resources of Cell #1. Furthermore, the antennas 4 covering the small areas at the top right of the area in the center of the bottom have been switched to connect to the cell resources of Cell #3.

[0041] In this way, based on the fact that the traffic and number of connected users in the area covered by the cell resources of Cell #2 are low, the central station 2 switches the cell resources covering that area to cell resources other than Cell #2. Then, the central station 2 puts the cell resources of Cell #2, which are no longer used in any area, into a sleep state or a stopped state. This reduces unnecessary power consumption.

[0042] [Functional Configuration of Base Station Apparatus] The functional configuration of the base station apparatus will be described below. Fig. 3 is a block diagram showing the functional configuration of the base station apparatus according to the first embodiment of the present invention.

[0043] As shown in Fig. 3, the base station device includes a wireless communication device 2, a connection switching unit 3, and a plurality of antennas 4. The wireless communication device 2 is a device corresponding to the central station 2 in Figs. 1 and 2, and the connection switching unit 3 is a device corresponding to the SW3 in Figs. 1 and 2.

[0044] The connection switching unit 3 may be provided inside the wireless communication device 2. The wireless communication device 2 and the connection switching unit 3 may be installed close to each other or may be installed far apart.

[0045] As shown in FIG. 3, the wireless communication device 2 (central station 2) includes a transmission unit 21, a signal processing unit 22, a control unit 23, a beam control unit 24, and a transmission / reception unit 25.

[0046] The transmission unit 21 is connected to a network (not shown) and performs signal transmission with a higher-level device (not shown), etc. The signal processing unit 22 performs signal processing related to wireless communication.

[0047] The control unit 23 performs communication control for each UE 5, such as allocating communication resources. The control unit 23 also periodically acquires index values ​​that represent the current traffic situation in each area and the number of connected users, for example. The control unit 23 controls the switching of the connection between the cell resource and the antenna 4 based on the acquired index values. The control unit 23 outputs a control signal to the connection switching unit 3 to instruct the switching of the connection between the antenna 4 and the cell resource. The control unit 23 puts cell resources (e.g., cards and boards) that are no longer in use due to the connection switching into a sleep state or a stopped state.

[0048] The beam control unit 24 controls the beam formed by the antenna 4. The transmission / reception unit 25 controls at least one of the phase and amplitude of the signal to control beam forming by the antenna 4. The beam control unit 24 also performs processing related to the transmission and reception of signals by the antenna 4.

[0049] The functional configuration of the wireless communication device 2 is not limited to the configuration shown in FIG. 3, and may be configured such that functional units such as the signal processing unit 22 and the beam control unit 24 are separated as separate devices, for example, as in the CU (Central Unit), DU (Distributed Unit), and RU (Radio Unit) in 5G NR (New Radio).

[0050] The connection switching unit 3 (SW3) connects the wireless communication device 2 (central station 2) to each of the multiple antennas 4, which are distributed antennas. The connection switching unit 3 can arbitrarily switch the connection relationship between the antennas 4 and cell resources. The connection switching unit 3 performs the switching based on a control signal output from the control unit 23 of the wireless communication device 2, which instructs switching of the connection between the antennas 4 (distributed antennas) and cell resources (e.g., cards, boards, etc.).

[0051] As described above, the wireless communication system 1a in the first embodiment of the present invention has a configuration in which the connection relationship between cell resources (e.g., hardware that controls each cell) and antenna 4 (distributed antenna) can be switched in a distributed antenna system.

[0052] This allows the wireless communication system 1a to change the allocation of cell resources for each antenna 4. The wireless communication system 1a actively aggregates cell resources for executing processing and control according to the amount of cell resources required. The wireless communication system 1a is characterized by being able to reduce power consumption by putting unused cell resources that have been aggregated into a sleep state (inactive state) or a suspended state.

[0053] With these features, the wireless communication system 1a according to the first embodiment of the present invention can actively reduce excess cell resources in a central station that accommodates multiple cells, particularly in a base station of a distributed antenna system that can control cell resources on a distributed antenna basis. This allows the wireless communication system 1a to reduce power consumption in the central station (of the base station), which consumes particularly large amounts of power.

[0054] <Second Embodiment> A second embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 4 is a diagram showing the overall configuration of a wireless communication system 1b according to the second embodiment of the present invention. As shown in Fig. 4, the wireless communication system 1b includes a plurality of central stations 2, a switch 3 (SW), a plurality of antennas 4, and a plurality of UEs 5.

[0055] The wireless communication system 1b is a distributed antenna system in which functions are concentrated in each of a plurality of central stations 2 and a plurality of antennas 4 are extended. The plurality of central stations 2 are each connected to a plurality of antennas 4 via a single switch 3. Each of the plurality of central stations 2 shown in Fig. 4 can cover the range of Cell #1 and the range of Cell #2 using the plurality of antennas 4. Each of the plurality of central stations 2 can transmit and receive wireless signals to and from UEs 9 present in each cell using the plurality of antennas 4 (distributed antennas).

[0056] In this way, the wireless communication system 1b, which is a distributed antenna system, extends multiple antennas 80 from multiple central stations 2 and covers the ranges of multiple cells with multiple antennas 4 (distributed antennas). This allows the wireless communication system 1b to further expand its communication area. Furthermore, the wireless communication system 1b may also perform MIMO transmission by coordinating the multiple antennas 4. This allows the wireless communication system 1b to further expand its communication capacity.

[0057] Like the wireless communication system 1a in the first embodiment described above, the wireless communication system 1b in the second embodiment uses analog RoF (Radio over Fiber) technology. This makes it possible to aggregate functions in each of the multiple central stations 2, including functions such as those possessed by the remote radio heads 8 in the conventional wireless communication systems shown in Figures 10 to 12. However, the technology used to aggregate functions in the central station 2 is not limited to analog RoF, and other technologies may also be used.

[0058] As shown in Fig. 4, each of the multiple central stations 2 is connected to a switch 3. Each of the multiple central stations 2 has cell resources for processing wireless communications with UEs 5 present in the cell covered by the central station 2. As mentioned above, the cell resources here refer to hardware that controls the cell, such as a card or board. Note that the cell resources may also include software.

[0059] The central station 2 can arbitrarily switch the antenna 4 connected to each cell resource by switching the connection of the switch 3. For example, one predetermined central station 2 among a plurality of central stations 2 controls the switching of the connection of the switch 3. For example, while two central stations 2 (central station 2-1 and central station 2-2) are shown in FIG. 4, central station 2-1 may control the switching of the connection of the switch 3. Note that a configuration may also be adopted in which a device that controls the switching of the connection of the switch 3 is provided separately as an external device.

[0060] In the configuration of the wireless communication system 1b illustrated in Fig. 4, one central station 2 is configured to have only one cell resource. That is, in this embodiment, each central station 2 is configured to have one cell resource. As shown in Fig. 4, the central station 2-1 has the cell resource of Cell #1, and the central station 2-2 has the cell resource of Cell #2. Therefore, in this embodiment, arbitrarily switching the antennas 4 connected to each cell resource is synonymous with arbitrarily switching the antennas 4 connected to each central station 2.

[0061] Furthermore, the central station 2, which controls the switching of the connection of the switch 3, controls the switching of the connection between the cell resources and the antenna 4, for example, based on index values ​​that indicate the current traffic situation and the number of connected users of each cell. The central station 2, which controls the switching of the connection of the switch 3, activates cell resources (e.g., cards, boards, etc.) that satisfy the processing capacity required for all areas covered by the wireless communication system 1b including the central station 2 itself. The central station 2 connects the activated cell resources to the antenna 4 by switching the connection using the switch 3.

[0062] On the other hand, since the processing capacity of the central station 2 exceeds the processing capacity required for all areas covered by the wireless communication system 1b including the central station 2 itself, the central station 2 puts surplus (unnecessary) cell resources (e.g., cards, boards, etc.) into a sleep state or a stopped state. This reduces unnecessary power consumption. As described above, in this embodiment, each central station 2 is configured to have one cell resource, so not only do the surplus cell resources go into a sleep state or a stopped state, but the central station 2 itself that has the surplus cell resources goes into a sleep state or a stopped state.

[0063] For example, as shown in Fig. 4, the aggregation station 2-1 has cell resources for Cell #1, and the aggregation station 2-2 has cell resources for Cell #2. Also, as shown in Fig. 4, the area covered by the cell resources for Cell #1 in the aggregation station 2-1 is the area covered by the four antennas 4 in the upper row, and the area covered by the cell resources for Cell #2 in the aggregation station 2-2 is the area covered by the four antennas 4 in the lower row.

[0064] Figure 4 shows that all four antennas 4 covering four small areas within the upper area are connected to the cell resources of Cell #1, and all four antennas 4 covering four small areas within the lower area are connected to the cell resources of Cell #2.

[0065] The central station 2 (for example, central station 2-1) that controls the switching of the connection of the switch 3 periodically acquires index values ​​that indicate the current traffic situation in each area, the number of connected users, etc. The central station 2 that controls the switching of the connection of the switch 3 controls the switching of the connection between the cell resource and the antenna 4 based on the acquired index values.

[0066] Here, for example, it is assumed that the area covered by the cell resources of Cell #2 has a low level of traffic and a low number of connected users. As shown in Fig. 4 , the area covered by the cell resources of Cell #2 before switching the connection between the cell resources and antenna 4 is all (four) small areas within the area in the lower row. The central station 2, which controls the connection switching of the switch 3, switches the antenna 4 to which the cell resources of Cell #2 are connected so that a cell resource other than Cell #2 (i.e., the cell resource of Cell #1 in the case of Fig. 4 ) is connected to the antenna 4.

[0067] Fig. 5 is a diagram showing the overall configuration of a wireless communication system 1b according to a second embodiment of the present invention. While Fig. 4 shows the state before connection switching by the wireless communication system 1b, Fig. 5 shows the state after connection switching.

[0068] As shown in Fig. 5, due to the connection switching, the antenna 4 connected to the cell resource of Cell #2 (aggregation station 2-2) in Fig. 4 is switched to be connected to another cell resource (i.e., the cell resource of Cell #1). Specifically, the antennas 4 covering all (four) small areas in the area in the lower row are switched to be connected to the cell resource of Cell #1 (aggregation station 2-1).

[0069] In this way, the aggregation station 2 (e.g., aggregation station 2-1) that controls the switching of the connection of the switch 3 switches the cell resource covering the area to a cell resource other than Cell #2 (i.e., the cell resource of Cell #1) based on the fact that the traffic and the number of connected users in the area covered by the cell resource of Cell #2 are low.

[0070] Then, the central station 2 that controls the switching of the connection of the switch 3 puts the cell resource of Cell #2, which is no longer used in any area, into a sleep state or a stopped state. As described above, in this embodiment, each central station 2 is configured to have one cell resource, so not only does it put the surplus cell resource into a sleep state or a stopped state, but it also puts the central station 2 that has the surplus cell resource (i.e., central station 2-2) itself into a sleep state or a stopped state. This reduces unnecessary power consumption.

[0071] [Functional Configuration of Base Station Apparatus] The functional configuration of the base station apparatus will be described below. Fig. 6 is a block diagram showing the functional configuration of the base station apparatus according to the second embodiment of the present invention.

[0072] As shown in Fig. 6, the base station device includes a plurality of wireless communication devices 2 (wireless communication devices 2-1 and 2-1 in Fig. 6), a connection switching unit 3, and a plurality of antennas 4. The wireless communication devices 2 are devices corresponding to the central station 2 in Figs. 4 and 5 described above, and the connection switching unit 3 is a device corresponding to the SW3 in Figs. 4 and 5 described above.

[0073] The wireless communication device 2-1, the wireless communication device 2-2, and the connection switching unit 3 may be installed close to each other, or may be installed far away from each other.

[0074] As shown in FIG. 6, the wireless communication device 2-1 (central station 2-1) includes a transmission unit 21, a signal processing unit 22, a control unit 23, a beam control unit 24, and a transmission / reception unit 25.

[0075] The transmission unit 21 is connected to a network (not shown) and performs signal transmission with a higher-level device (not shown), etc. The signal processing unit 22 performs signal processing related to wireless communication.

[0076] The control unit 23 performs communication control for each UE 5, such as allocating communication resources. The control unit 23 also periodically acquires index values ​​that represent the current traffic situation in each area, the number of connected users, and the like. The control unit 23 controls the switching of the connection between the cell resource and the antenna 4 based on the acquired index values. The control unit 23 outputs a control signal to the connection switching unit 3 to instruct the switching of the connection between the antenna 4 and the cell resource. The control unit 23 places the cell resource (e.g., card, board, etc.) that is no longer in use due to the connection switching, or the other wireless communication device 2 (i.e., wireless communication device 2-2) itself, into a sleep state or a stopped state.

[0077] The beam control unit 24 controls the beam formed by the antenna 4. The transmission / reception unit 25 controls at least one of the phase and amplitude of the signal to control beam forming by the antenna 4. The beam control unit 24 also performs processing related to the transmission and reception of signals by the antenna 4.

[0078] The functional configuration of the wireless communication device 2-1 is not limited to the configuration shown in FIG. 6, and may be configured such that functional units such as the signal processing unit 22 and the beam control unit 24 are separated into separate devices, for example, as in the CU (Central Unit), DU (Distributed Unit), and RU (Radio Unit) in 5G NR (New Radio).

[0079] The configuration of the wireless communication device 2-2 (aggregate station 2-2) is the same as the configuration of the wireless communication device 2-1 (aggregate station 2-1) except for the configuration of the control unit 23. The configuration of the control unit 23 of the wireless communication device 2-2 differs from the configuration of the wireless communication device 2-1 in that the control unit 23 does not execute the process of controlling the switching of the connection between the cell resource and the antenna 4 using the switch 3.

[0080] The control unit 23 of the wireless communication device 2-2 may transmit to the control unit 23 of the wireless communication device 2-1 information required for the control unit 23 of the wireless communication device 2-1 to control switching of the connection between the cell resource and the antenna 4 using the switch 3. Here, the information required for controlling switching of the connection between the cell resource and the antenna 4 is, for example, index values ​​representing the current traffic situation and the number of connected users in the area covered by the cell resource of Cell #2 provided in the wireless communication device 2-2.

[0081] Furthermore, the control unit 23 of the wireless communication device 2-2 puts the cell resources of Cell #2 included in the wireless communication device 2-2 or the wireless communication device itself into a sleep state or a suspended state in response to an instruction from the wireless communication device 2-1.

[0082] The connection switching unit 3 (SW3) connects each of the multiple wireless communication devices 2 (central stations 2) to multiple antennas 4, which are distributed antennas. The connection switching unit 3 can arbitrarily switch the connection relationship between the antennas 4 and cell resources. The connection switching unit 3 controls the connection of the switch 3 based on a control signal output from the control unit 23 of the wireless communication device 2 (e.g., wireless communication device 2-1) that instructs switching of the connection between the antennas 4 (distributed antennas) and the cell resources (e.g., cards, boards, etc.).

[0083] As described above, the wireless communication system 1b in the second embodiment of the present invention has a configuration in which the connection relationship between cell resources (e.g., hardware that controls each cell) and antenna 4 (distributed antenna) can be switched in a distributed antenna system.

[0084] This allows the wireless communication system 1b to change the allocation of cell resources for each antenna 4. The wireless communication system 1a actively aggregates cell resources for performing processing and control according to the amount of cell resources required. The wireless communication system 1a is characterized in that it can significantly reduce power consumption by putting unused cell resources that have been aggregated into a sleep state (inactive state) or a stopped state, or by putting the central station 2 (wireless communication device 2) that includes the cell resources into a sleep state (inactive state) or a stopped state.

[0085] With these features, the wireless communication system 1b according to the second embodiment of the present invention can actively reduce excess cell resources in an aggregate station that accommodates multiple cells, or the aggregate station itself, particularly in a base station of a distributed antenna system that can control cell resources on a distributed antenna basis. This allows the wireless communication system 1b to reduce power consumption in the aggregate station (of the base station), which consumes particularly large amounts of power.

[0086] The following describes an example of an execution method and execution timing of a process in which the control unit 23 of the wireless communication device 2 controls switching of the connection between the cell resource and the antenna 4 using the switch 3. The execution conditions and execution timing described below are applicable to both the wireless communication system 1a in the first embodiment described above and the wireless communication system 1b in the second embodiment described above.

[0087] (First Example of Means for Executing Connection Switching) Hereinafter, a description will be given of a first example of means for executing connection switching between cell resources and antennas 4. In the wireless communication system 1a in the first embodiment and the wireless communication system 1b in the second embodiment described above, the connection between cell resources and antennas 4 is switched based on index values ​​that represent, for example, the current traffic situation of each cell and the number of connected users.

[0088] The switching of the connection between the cell resources and the antenna 4 may be performed, for example, on the condition that the amount of required cell resources falls below a predetermined threshold. The wireless communication device 2, for example, periodically calculates the amount of required cell resources. The central station 2 compares the calculated amount of required cell resources with the predetermined threshold, and switches the connection between the cell resources and the antenna 4 when the amount of required cell resources falls below the predetermined threshold. Hereinafter, the first example will be described in more detail, assuming the configuration of the wireless communication system 1b in the second embodiment described above as an example.

[0089] First, let Xn (n=1, 2, ..., N) be the amount of required cell resources required in N cells accommodated in the central station 2. The value of Xn is determined based on, for example, an index value related to the accommodation of UE 5 in each cell.

[0090] The index value related to the accommodation of UEs 5 referred to here is, for example, the number of UEs 5 in an RRC (Radio Resource Control Connected) state (communicating state), the traffic volume, or the average throughput value. Note that a single index value itself may be used as the value of Xn, or a value calculated based on multiple index values ​​may be used. Note that, when an index value that can be obtained or calculated for each antenna 4 is used, the value of Xn may be determined for each antenna 4. Note that the value of Xn may be the value itself obtained at a fixed time interval, or may be a statistical value calculated from time to time based on calculations such as a time average.

[0091] The central station 2 compares, for example, ΣXn, which is the total amount of required cell resources for each cell, with a predetermined threshold T. The central station 2 switches the connection between the cell resources and the antenna 4 when the following formula (1) is satisfied:

[0092] ΣXn≦T (1)

[0093] The threshold T may be set to, for example, a multiple of the upper limit of the number of UEs 5 in an RRC connected state per cell. Alternatively, the threshold T may be set to, for example, a multiple of the upper limit of the amount of traffic buffered per cell. Alternatively, the threshold T may be set to, for example, a multiple of the upper limit of the throughput per cell.

[0094] When switching the connection between the cell resources and the antennas 4, the central station 2, for example, assigns antennas 4 to each cell resource so that as many cell resources (e.g., cards and boards) of the central station 2 as possible can be put into a sleep state or a stopped state, thereby aggregating the antennas 4 into a smaller number of specific cell resources. Alternatively, when switching the connection between the cell resources and the antennas 4, the central station 2, for example, assigns antennas 4 to each cell resource so that as many central stations 2 themselves as possible can be put into a sleep state or a stopped state, thereby aggregating the antennas 4 into a smaller number of specific central stations 2.

[0095] 7 is a flowchart showing an example of operation of the central station 2 in the connection switching process according to an embodiment of the present invention. First, the central station 2 determines a threshold T for the total amount of required cell resources for all cells accommodated in the wireless communication system (step S01). Next, the central station 2 acquires or calculates and collects the value of the amount of required cell resources Xn for each cell accommodated in the wireless communication system (step S02). The central station 2 adds up the collected values ​​of the amount of required cell resources Xn for each cell and calculates the value ΣXn, which is the total value.

[0096] Next, the central station 2 compares the total amount of required cell resources ΣXn with a threshold value T (step S03). If the total amount of required cell resources ΣXn is greater than the threshold value T (step S03: No), the central station 2 does not switch the connection between the cell resources and the antenna 4, and waits until the next time to collect the value of the amount of required cell resources Xn for each cell (return to step S02).

[0097] If the total value ΣXn of the required cell resource amounts is equal to or less than the threshold T (step S03, Yes), the central station 2 identifies the cell m that is the cell with the smallest amount of cell resource among the collected values ​​of the required cell resource amounts Xn (step S04).

[0098] Next, the central station 2 switches the connection so that the connection destinations of the antenna 4 covering the identified cell m are equally allocated to cell resources other than the cell resource accommodating the cell m (step S05). As a result, the cell resource accommodating the cell m is not used for the connection switching, and it becomes possible to put the cell resource (or the central station 2 itself including the cell resource) into a sleep state or a stopped state.

[0099] If the cell resource and the connection between the antenna 4 are immediately switched when the condition that the total value ΣXn of the required cell resource amounts of each cell is equal to or less than the threshold T is satisfied, then depending on the frequency of calculation of the required cell resource amounts, switching may occur frequently when ΣXn is a value close to the threshold T. For this reason, for example, a configuration may be adopted in which a timer is started when the above condition is satisfied, and switching is performed if the above condition continues to be satisfied until the timer expires.

[0100] The central station 2 waits until the next timing for collecting the value of the amount of required cell resource Xn of each cell (return to step S02). The above is the operation of the central station 2 in the connection switching process shown in the flowchart of FIG.

[0101] The operation in the connection switching process of the central station 2 may be the following operation shown in Fig. 8. In the connection switching process shown in Fig. 7 described above, the connection destination of the antenna 4 configuring the cell requiring the smallest amount of cell resources is switched to cell resources other than the cell resources to which it was previously connected in an equal allocation manner, whereas in the connection switching process shown in Fig. 8, the connection destination of the antenna 4 configuring the cell requiring the smallest amount of cell resources is switched to the cell resource requiring the second smallest amount of cell resources. In other words, the connection switching is performed so that the antenna 4 covering the cell requiring the smallest amount of cell resources and the antenna 4 covering the cell requiring the second smallest amount of cell resources are aggregated and connected to a single cell resource, making it possible to leave one of the cell resources unused.

[0102] 8 is a flowchart showing another example of the operation of the central station 2 in the connection switching process according to an embodiment of the present invention. First, the central station 2 determines a threshold T for the total amount of required cell resources for all cells accommodated in the wireless communication system (step S11). Next, the central station 2 acquires or calculates and collects the value of the amount of required cell resources Xn for each cell accommodated in the wireless communication system (step S12). The central station 2 adds up the collected values ​​of the amount of required cell resources Xn for each cell and calculates the value ΣXn, which is the total value.

[0103] Next, the central station 2 compares the total amount of required cell resources ΣXn with a threshold value T (step S13). If the total amount of required cell resources ΣXn is greater than the threshold value T (step S13: No), the central station 2 does not switch the connection between the cell resources and the antenna 4, and waits until the next timing for collecting the value of the amount of required cell resources Xn for each cell (return to step S12).

[0104] If the total value ΣXn of the required cell resource amounts is equal to or less than the threshold value T (step S13, Yes), the aggregation station 2 identifies the cell m having the smallest amount of cell resource and the cell m having the second smallest amount of cell resource from the collected values ​​of the required cell resource amounts Xn (step S14).

[0105] Next, the central station 2 switches the connection destination of the antenna 4 covering the cell m with the smallest amount of cell resources to the cell resource accommodating the cell l with the second smallest amount of cell resources (step S15). As a result, the cell resource accommodating the cell m is not used for the connection switching, and it becomes possible to put the cell resource (or the central station 2 itself that has the cell resource) into a sleep state or a stopped state.

[0106] As described above, if switching of the connection between the cell resources and the antenna 4 is immediately performed when the condition that the total value ΣXn of the amount of required cell resources of each cell is equal to or less than the threshold T is satisfied, depending on the frequency of calculation of the amount of required cell resources, switching may occur frequently when ΣXn is a value close to the threshold T. For this reason, for example, a configuration may be adopted in which a timer is started when the above condition is satisfied, and switching is performed if the above condition continues to be satisfied until the timer expires.

[0107] The central station 2 waits until the next timing for collecting the value of the amount of required cell resource Xn of each cell (return to step S12). The above is the operation of the central station 2 in the connection switching process shown in the flowchart of FIG.

[0108] The operation of the connection switching process of the central station 2 may be the following operation shown in Fig. 9. In the connection switching process shown in Fig. 9 described below, multiple thresholds are set to control the connection switching. Multiple thresholds are set according to the number of cells, for example, Ti (i = 1, 2, ..., N-1, where N is the total number of cells). This makes it possible to provide multiple triggers for switching the connection between the cell resources and the antenna 4. The connection switching process shown in Fig. 9 described below is a modified version of the connection switching process shown in Fig. 7 described above, in which multiple thresholds are set to control the connection switching.

[0109] 9 is a flowchart showing another example of the operation of the connection switching process of the central station 2 in the embodiment of the present invention. First, the central station 2 determines a threshold Ti for the total amount of required cell resources for all cells accommodated in the wireless communication system (step S01). As described above, a plurality of thresholds Ti are set according to the number of cells, for example, Ti (i=1, 2, ..., N-1, where N is the total number of cells).

[0110] Next, the central station 2 acquires or calculates and collects the value of the required cell resource amount Xn of each cell accommodated in the wireless communication system (step S02). The central station 2 adds up the collected values ​​of the required cell resource amount Xn of each cell and calculates the value of the total value ΣXn.

[0111] Next, the central station 2 initializes the value of the variable i (i=1) (step S23), and calculates the threshold value Ti by １ In order from the maximum T Ｎ－１ 9. The process is repeated from Ls to Le shown in FIG.

[0112] The central station 2 compares the total amount of required cell resources ΣXn with the threshold value Ti (step S24). If the total amount of required cell resources ΣXn is greater than the threshold value Ti (step S24: No), the central station 2 does not switch the connection between the cell resources and the antenna 4, but instead adds 1 to the value of variable i (step S25) and performs the comparison process of step S24 again. However, if adding 1 to the value of variable i causes the value of variable i to become N, which is the number of cells, the central station 2 waits until the next time to collect the value of the amount of required cell resources Xn for each cell (return to step S22).

[0113] If the total required cell resource amount ΣXn is equal to or less than the threshold Ti (step S24, Yes), the central station 2 identifies the Ni cells with the smallest required cell resource amount Xn from the collected values. Here, the identified cells are designated as cells mj (j = 1, ..., Ni) (step S26).

[0114] Next, the central station 2 switches the connection so that the connection destinations of the antenna 4 covering the identified cell mj are equally allocated to cell resources other than the cell resource accommodating the cell mj (step S27). As a result, the cell resource accommodating the cell mj is not used for the connection switching, and it becomes possible to put the cell resource (or the central station 2 itself including the cell resource) into a sleep state or a stopped state.

[0115] If the cell resource and the antenna 4 are immediately switched when the condition that the total value ΣXn of the required cell resource amounts of each cell is equal to or less than the threshold Ti is satisfied, switching may occur frequently when ΣXn is a value close to the threshold Ti, depending on the frequency of calculation of the required cell resource amounts. Therefore, for example, a configuration may be adopted in which a timer is started when the above condition is satisfied, and switching is performed if the above condition continues to be satisfied until the timer expires.

[0116] The central station 2 waits until the next timing for collecting the value of the amount of required cell resource Xn of each cell (return to step S22). The above is the operation of the central station 2 in the connection switching process shown in the flowchart of FIG.

[0117] In addition, if it is possible to obtain the value of the cell resource amount for each antenna 4, the obtained cell resource amount value for each antenna 4 may be sorted, and the connection destinations of the antennas 4 may be allocated so that the required cell resource amount is equalized as much as possible (for each cell resource or for each aggregation station 2).

[0118] In addition, taking into consideration interference between antennas 4, etc., the connection between cell resources and antennas 4 may be switched after setting conditions such as combinations of antennas 4 that must be connected to the same cell resource and combinations of antennas 4 that are prohibited from being connected to the same cell resource.

[0119] (Second Example of Means for Executing Connection Switching) The following describes a second example of means for executing connection switching between cell resources and antenna 4. In the first example described above, the connection switching process is executed when the amount of required cell resources falls below a threshold, whereas in the second example described below, the connection switching process is executed when instructed by a user such as a system operator.

[0120] The timing for switching the connection between the cell resource and the antenna 4 may be triggered by a command input by the user or may be triggered by a predetermined periodic interval. The central station 2 switches the connection between the cell resource and the antenna 4, for example, triggered by the above-mentioned point.

[0121] As a means for executing the connection switching, the central station 2 may execute the connection switching so as to establish a connection relationship between the cell resource designated by the user and the antenna 4. Alternatively, the central station 2 may execute the connection switching by identifying a connection relationship that results in the minimum number of connection switchings when averaging the load for each cell resource based on the value of the required cell resource amount Xn.

[0122] Alternatively, the central station 2 may reallocate antennas 4 to the entire cell resources based on the value of the required cell resource amount Xn so as to more evenly distribute the values ​​of Xn for each cell. Alternatively, the central station 2 may allocate antennas 4 to the cell resources in order so as to minimize the number of central stations 2 or cell resources (e.g., cards and boards) required for the total value ΣXn of the required cell resource amounts Xn.

[0123] In addition, if it is possible to obtain the value of the cell resource amount for each antenna 4, the obtained cell resource amount value for each antenna 4 may be sorted, and the connection destinations of the antennas 4 may be allocated so that the required cell resource amount is equalized as much as possible (for each cell resource or for each aggregation station 2).

[0124] In addition, taking into consideration interference between antennas 4, etc., the connection between cell resources and antennas 4 may be switched after setting conditions such as combinations of antennas 4 that must be connected to the same cell resource and combinations of antennas 4 that are prohibited from being connected to the same cell resource.

[0125] The execution means according to the first embodiment and the execution means according to the second embodiment described above may be configured to be executed in combination.

[0126] In the first and second embodiments, the central station 2 may arbitrarily divide time periods into segments and calculate statistical index values ​​by performing calculations such as time averages for each segmented time period.The central station 2 may then determine the connection relationship between the cell resources and the antennas 4 based on index values ​​that differ for each time period, and schedule and operate them.

[0127] According to the above-described embodiment, the wireless communication device includes a plurality of cell resources, a control unit, and a switching unit. For example, the wireless communication device is the central station 2 (wireless communication device 2) of the wireless communication system 1a in the embodiment, the cell resources are Cell #1 to #3 in the embodiment, the control unit is the control unit 23 in the embodiment, and the switching unit is SW3 (connection switching unit 3) in the embodiment.

[0128] Each of the cell resources controls communication with a terminal within a cell formed by a plurality of antennas. For example, the antenna is antenna 4 in the embodiment, and the terminal is UE 5 in the embodiment. The control unit acquires the required cell resource amount, controls switching of the connection between the antenna and the cell resource so as to aggregate the cell resources to which the antenna is connected based on the acquired cell resource amount, and places the cell resource to which the antenna is no longer connected due to the switching in a sleep state or a stopped state. The switching unit switches the connection between the antenna and the cell resource in accordance with the control by the control unit.

[0129] According to the above-described embodiment, the wireless communication system includes a plurality of wireless communication devices, a control unit, and a switching unit. For example, the wireless communication system is the wireless communication system 1b in the embodiment, the wireless communication devices are the central station 2-1 and the central station 2-2 (wireless communication device 2-1 and wireless communication device 2-2) in the embodiment, the control unit is the control unit 23 in the embodiment, and the switching unit is SW3 (connection switching unit 3) in the embodiment.

[0130] The wireless communication device includes cell resources that control communication with terminals within a cell formed by a plurality of antennas. For example, the antenna is antenna 4 in the embodiment, the terminal is UE 5 in the embodiment, and the cell resources are Cell #1 to #2, etc. in the embodiment. The control unit acquires a required amount of cell resources, controls switching of connections between the antennas and the cell resources so as to aggregate the cell resources to which the antennas are connected based on the acquired cell resource amount, and controls placing the wireless communication device, which includes a cell resource to which the antenna is no longer connected due to the switching, into a sleep state or a suspended state. The switching unit switches the connections between the antennas and the cell resources in accordance with the control by the control unit.

[0131] The wireless communication device 2 in the above-described embodiment may be implemented by a computer. In this case, a program for implementing this function may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. Note that the term "computer system" as used herein includes hardware such as an OS and peripheral devices. Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording medium" may also include media that dynamically store programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or telephone lines, or media that store programs for a fixed period of time, such as volatile memory within a computer system that serves as a server or client. The program may be designed to implement only a portion of the above-described functions, or may be capable of implementing the above-described functions in combination with a program already stored in the computer system, or may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0132] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope that do not deviate from the gist of the present invention.

[0133] 1a, 1b... wireless communication system, 2... central station (wireless communication device), 3... switch (connection switching unit), 4... antenna, 5... UE, 21... transmission unit, 22... signal processing unit, 23... control unit, 24... beam control unit, 25... transmission / reception unit

Claims

1. A wireless communication device comprising: a plurality of cell resources that control communication with a terminal within a cell formed by a plurality of antennas; a control unit that acquires a required amount of cell resources, controls switching of the connection between the antenna and the cell resources so as to aggregate the cell resources to which the antenna is connected based on the acquired amount of cell resources, and places the cell resources to which the antenna is no longer connected due to the switching into a sleep state or a stopped state; and a switching unit that switches the connection between the antenna and the cell resources in accordance with the control by the control unit.

2. A wireless communication system having a plurality of wireless communication devices, a control unit, and a switching unit, wherein the wireless communication devices are provided with cell resources that control communication with terminals within a cell formed by a plurality of antennas, the control unit acquires a required amount of cell resources, controls switching of the connection between the antennas and the cell resources so as to aggregate the cell resources to which the antennas are connected based on the acquired amount of cell resources, and controls the wireless communication devices provided with the cell resources to which the antennas are no longer connected due to the switching to enter a sleep state or a stopped state, and the switching unit executes switching of the connection between the antennas and the cell resources in accordance with the control by the control unit.

3. A resource control method comprising: a control step of controlling communication with a terminal in a cell formed by a plurality of antennas using a plurality of cell resources; an acquisition step of acquiring a required cell resource amount; a switching control step of controlling switching of the connection between the antenna and the cell resource so as to aggregate the cell resource to which the antenna is connected based on the acquired cell resource amount; a switching step of executing switching of the connection between the antenna and the cell resource in accordance with the control in the switching control step; and a state control step of putting the cell resource to which the antenna is no longer connected due to the switching into a sleep state or a stopped state.

4. A resource control method for a wireless communication system having a plurality of wireless communication devices, a control unit, and a switching unit, comprising: a control step in which the wireless communication devices control communication with terminals in a cell formed by a plurality of antennas using cell resources; an acquisition step in which the control unit acquires a required cell resource amount; a switching control step in which the control unit controls switching of the connection between the antenna and the cell resource so as to aggregate the cell resource to which the antenna is connected based on the acquired cell resource amount; a switching step in which the switching unit executes switching of the connection between the antenna and the cell resource in accordance with the control by the control unit; and a state control step in which the control unit switches the wireless communication device having the cell resource to which the antenna is no longer connected due to the switching to a sleep state or a stopped state.

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