JP7802523B2 - Distributed antenna system, communication device, sleep control method and program - Google Patents

Description

Embodiments of the present invention relate to a distributed antenna system, a communication device, a sleep control method, and a program.

One type of wireless communication system is the Distributed Antenna System (DAS). A DAS distributes communication signals sent and received by base stations of a wide-area mobile communication network to multiple antennas distributed indoors, for example, to extend the communication area of the network to indoor locations such as buildings or basements where radio waves have difficulty reaching the network.

A DAS, for example, comprises a master station connected to a base station of a mobile communications network, multiple slave stations distributed indoors and connected to the master station via relay devices, and antennas connected to these slave stations. Wired communication media with low transmission loss, such as coaxial cable or optical cable, are used for the connections between the base station and master station, between the master station and each slave station, and between the slave station and the antenna.

In general, in DAS, slave station devices are always in operation, whether they are communicating with a wireless terminal or in standby mode. This means that power consumption by slave station devices in standby mode tends to be high.

On the other hand, some mobile communications systems are equipped with functions to reduce the power consumption of communications devices used in base stations and other components of a mobile communications network. For example, Patent Document 1 describes a technology in which, in a system in which multiple small cell base stations are deployed within a macrocell to compensate for local bandwidth shortages in the macrocell base station, an optical terminal device sets the optical terminal device and the small cell base stations connected to it into a sleep state based on wireless terminal information managed by the macrocell base station in order to reduce the power consumption of the multiple small cell base stations.

However, the technology described in Patent Document 1 uses wireless terminal information managed by the macrocell base station to set the optical terminal equipment and small cell base stations into a sleep state. Therefore, while sleep control is possible for the entire system, it is difficult to perform sleep control for each small cell base station according to its usage status.

Japanese Patent Application Laid-Open No. 2018-207457

The problem this invention aims to solve is to provide technology that achieves appropriate sleep control according to the usage status of slave station equipment.

According to an embodiment, the spatial antenna system includes one or more slave station devices each having at least one transceiver unit configured to transmit and receive wireless signals to and from a wireless terminal via an antenna, and a master station device configured to transmit and receive the wireless signals to and from the slave station devices directly or via a relay device. The slave station devices each include a determination unit configured to determine a transmission/reception state of the wireless signals by the transceiver unit and notify the master station device of determination information representing the determination result. The master station device includes a control unit configured to control the slave station devices based on the determination information to set the transceiver units to an operable mode when the wireless signals are being transmitted and received, and to set at least some of the transceiver units to a sleep mode when the wireless signals are not being transmitted or received. The control unit includes a determination processing unit that determines, based on the information representing the transmission and reception state, whether a reception quality index is lower than a first threshold, or whether the reception quality index is equal to or higher than the first threshold and lower than a second threshold, a first control processing unit that sets a first receiving function unit of the transceiver unit to a sleep mode when it is determined that the reception quality index is equal to or higher than the first threshold and lower than the second threshold, and a second control processing unit that sets both the first receiving function unit and a second receiving function unit of the transceiver unit to a sleep mode when it is determined that the reception quality index is lower than the first threshold. The first control processing unit performs a first process that stops a calibration operation of a digital-to-analog converter provided in the transceiver unit and a characteristic compensation operation of a transmission power amplifier. When it is determined that the index of reception quality is lower than the first threshold, the second control processing unit, in addition to the first processing, further performs a second processing of stopping the supply of an operating clock to the baseband processing unit and the digital/analog converter provided in the transceiver unit and the supply of operating power to the transmission power amplifier.

FIG. 1 is a block diagram showing an example of the configuration of a distributed antenna system according to a first embodiment of the present invention. FIG. 2 is a block diagram showing an example of the configuration of a slave station device of the distributed antenna system shown in FIG. 1 . 3 is a block diagram showing an example of the functional configuration of a control unit of the slave station device shown in FIG. 2 ; FIG. 2 is a block diagram showing an example of the configuration of a master station device of the distributed antenna system shown in FIG. 1 . FIG. 5 is a block diagram showing an example of the functional configuration of a control unit of the master station device shown in FIG. 4 . 4 is a flowchart showing an example of a processing procedure and processing content of a control process executed by a control unit of a slave station device shown in FIG. 3 . 5 is a flowchart showing an example of a processing procedure and processing content of a control process executed by a control unit of the parent station device shown in FIG. 4 . 3 is a block diagram showing an example of a sleep operation performed on a transmission/reception unit in the slave station device shown in FIG. 2; 2 is a diagram illustrating an example of a state in which a normal operation mode is set for a slave station device in the distributed antenna system illustrated in FIG. 1 . 2 is a diagram illustrating an example of a state in which a sleep mode is set in a slave station device in the distributed antenna system illustrated in FIG. 1; FIG. 2 is a diagram illustrating an example of a state in which all slave station devices are set to a normal operation mode in the distributed antenna system illustrated in FIG. 1 . 2 is a diagram illustrating an example of a state in which some of the slave station devices are set to a forced sleep mode and other parts of the slave station devices are set to a sleep mode in the distributed antenna system illustrated in FIG. 1 . FIG. 10 is a block diagram showing an example of a state in which a receiving function unit operates in a normal operation mode in a slave station device according to a second embodiment of the present invention; FIG. 10 is a block diagram showing an example of a state in which some functions of a receiving function unit are set in a sleep mode in a slave station device according to a second embodiment of the present invention;

The following describes a distributed antenna system according to an embodiment, as well as the communication devices, sleep control methods, and programs used in the system, with reference to the drawings.

[First embodiment]
(Configuration example)
(1) System FIG. 1 is a block diagram showing an example of the configuration of a distributed antenna system 100 according to the first embodiment.

The distributed antenna system 100 comprises a master unit (MU) 1, a hub unit (HUB) 2 that functions as a relay unit, multiple slave units (RUs) 3-1 to 3-m, and multiple antennas 4-1 to 4-m connected to the slave units 3-1 to 3-m. Optical cables are used to connect the master unit 1 and the hub unit 2, and between the hub unit 2 and each of the slave units 3-1 to 3-m. Note that the master unit 1 may be connected directly to some of the slave units 3 without going through the hub unit 2.

The master station device 1 is connected, for example, via a coaxial cable, to a base station device BS of a mobile communications system that covers a wide area, such as outdoors. The master station device 1 then transmits and receives radio signals to and from the base station device BS. The master station device 1 converts the radio signals received from the base station device BS into downstream (downlink) digital transmission signals and transmits them to the slave station devices 3-1 to 3-m directly or via the hub station device 2. The master station device 1 also converts upstream (uplink) digital transmission signals transmitted from the slave station devices 3-1 to 3-m directly or via the hub station device 2 into radio signals and transmits them to the base station device BS.

Slave station devices 3-1 to 3-m transmit and receive radio signals to and from wireless terminals MT1 to MTn via antennas 4-1 to 4-m. Slave station devices 3-1 to 3-m convert radio signals received from the wireless terminals MT1 to MTn into upstream digital transmission signals and transmit them to the master station device 1 directly or via the hub station device 2. Slave station devices 3-1 to 3-m also convert downstream digital transmission signals transmitted from the master station device 1 directly or via the hub station device 2 into radio signals and transmit them to the wireless terminals MT from antennas 4-1 to 4-m.

The distributed antenna system 100 includes a management terminal 7 used by a system administrator or the like. The management terminal 7 is connected to the master station device 1 via a network NW, such as a LAN (Local Area Network), and a router 6, and transmits and receives control data to and from the master station device 1.

(2) Equipment (2-1) Slave station equipment 3-1 to 3-m
2 is a block diagram showing an example of the configuration of communication devices used as slave station equipment 3-1 to 3-m. Note that, since the slave station equipment 3-1 to 3-m all have the same configuration, only the slave station equipment 3-1 will be described here as an example, and the description of the other slave station equipment 3-2 to 3-m will be omitted.

Slave station equipment 3-1 includes a slave station control unit 30, multiple transceiver units 31-3k each corresponding to a band, an uplink processing unit 35, a downlink processing unit 36, a transmission interface (hereinafter referred to as I/F) unit 37, and a power and clock supply unit 38.

The slave station control unit 30 includes a hardware processor, such as a central processing unit (CPU), a program storage unit, a data storage unit, and an input/output interface unit. The slave station control unit 30 performs various predetermined signal processing and control processes by having the hardware processor execute middleware such as an operating system (OS) and application programs stored in the program storage unit. The hardware processor may also be configured using a programmable logic device (PLD) or field programmable gate array (FPGA).

The transceiver units 31-3k each include an analog-to-digital converter (ADC) 321-32k, a digital-to-analog converter (DAC) 331-33k, and an antenna I/F unit 341-34k.

The antenna I/F units 341 to 34k each have, for example, a transmission power amplifier (PA) and a low-noise amplifier for reception, and transmit and receive radio signals to and from the wireless terminals MT1 to MTn via the antennas 4-11 to 4-1k.

The ADCs 321 to 32k convert the radio signals of each band received by the antenna I/F units 341 to 34k into upstream digital radio signals, and output the converted upstream digital radio signals to the slave station control unit 30.

The slave station control unit 30 performs predetermined baseband signal processing on each of the upstream digital radio signals output from the ADCs 321-32k to convert them into baseband upstream transmission signals. The slave station control unit 30 then outputs these upstream transmission signals, along with the control signals generated by the slave station control unit 30, to the uplink processing unit 35.

The uplink processing unit 35 multiplexes the upstream transmission signal and control signal output from the slave station control unit 30 to generate an upstream multiplexed transmission signal, and sends the generated upstream multiplexed transmission signal to the transmission I/F unit 37. The transmission I/F unit 37 converts the upstream multiplexed transmission signal output from the uplink processing unit 35 into an optical signal and transmits it to the master station equipment 1 directly or via the hub station equipment 2.

In addition, the transmission I/F unit 37 receives downstream multiplexed transmission signals consisting of optical signals transmitted from the hub station device 2 or the parent station device 1, converts them into electrical signals, and then outputs them to the downlink processing unit 36.

The downlink processing unit 36 separates the downstream multiplexed transmission signal output from the transmission I/F unit 37 into multiple transmission signals and control signals for each band, and inputs the separated transmission signals and control signals for each band to the slave station control unit 30.

The slave station control unit 30 performs the specified baseband signal processing on the downstream transmission signals of each band output from the downlink processing unit 36, converting them into downstream digital transmission signals, and then outputs them to the corresponding transceiver units 31 to 3k.

The transceiver units 31-3k convert the downstream digital transmission signals output from the slave station control unit 30 into analog signals using DACs 331-33k, and input the converted analog downstream transmission signals to antenna I/F units 341-34k. The antenna I/F units 341-34k convert the analog downstream transmission signals into wireless signals and transmit the converted wireless signals from antennas 4-1-4-m to wireless terminals MT1-MTn.

The power and clock supply unit 38 generates an operating power output VC based on the main power output supplied from the system power supply unit BT and supplies it to each unit within the slave station equipment 3-1. The power and clock supply unit 38 also supplies an operating clock CK generated by the clock generation circuit to each unit within the slave station equipment 3-1.

Incidentally, the slave station control unit 30 has a function for realizing the sleep control according to the first embodiment in addition to the baseband signal processing function.
FIG. 3 is a block diagram showing the functional configuration for realizing the sleep control.

The slave station control unit 30 has the functions for implementing sleep control: a reception level detection processing unit 301, a reception level detection signal transmission processing unit 302, and a power supply/clock control processing unit 303.

The reception level detection processing unit 301 detects the reception level (e.g., received field strength indicator (RSSI)) for each transceiver unit 32-3k, i.e., for each band, based on the radio signals received by the antenna I/F units 341-34k, and notifies the reception level detection signal transmission processing unit 302 of the detected value.

The reception level detection signal transmission processing unit 302 generates a reception level detection signal that includes the detection value notified by the reception level detection processing unit 301 and the identification ID of the band to be detected. The reception level detection signal transmission processing unit 302 then outputs the generated reception level detection signal to the uplink processing unit 35 as one of the control signals.

The power supply and clock control processing unit 303 receives an operation mode control signal transmitted from the parent station equipment 1 via the downlink processing unit 36. Then, in accordance with the received operation mode control signal, the power supply and clock control processing unit 303 performs processing to issue instructions to the power supply and clock supply unit 38 to control the supply of the operating power output VC and the operating clock CK to the transmission/reception units 31 to 3k in the child station equipment 3-1.
(2-2) Master station device 1
FIG. 4 is a block diagram showing an example of the configuration of a communication device used as the master station device 1 according to the first embodiment.

The master station device 1 includes a master station control unit 10, a transmission I/F unit 11, an uplink processing unit 12, a downlink processing unit 13, a DAC 14, an ADC 15, and a wireless I/F unit 16.

The parent station control unit 10 includes a hardware processor such as a central processing unit (CPU), a program storage unit, a data storage unit, and an input/output interface unit. The parent station control unit 10 performs various predetermined signal processing and control processes by having the hardware processor execute middleware such as an OS and application programs stored in the program storage unit. The hardware processor may also be configured using a PLD, FPGA, or the like.

The transmission I/F unit 11 receives upstream multiplexed transmission signals consisting of optical signals transmitted from the slave station devices 3-1 to 3-m directly or via the hub station device 2, converts them into electrical signals, and then outputs them to the uplink processing unit 12.

The uplink processing unit 12 separates the upstream multiplexed transmission signals output from the slave station devices 3-1 to 3-m into transmission signals and control signals, and inputs the separated transmission signals and control signals to the master station control unit 10.

The parent station control unit 10 performs predetermined baseband signal processing on the input upstream transmission signal and then outputs it to the DAC 14. The DAC 14 converts the upstream transmission signal output from the parent station control unit 10 into an analog signal and outputs the converted analog upstream transmission signal to the wireless I/F unit 16. The wireless I/F unit 16 converts the analog upstream transmission signal into a wireless signal and transmits it to the base station device BS.

The wireless I/F unit 16 receives downstream wireless signals transmitted from the base station device BS and outputs them to the ADC 15. The ADC 15 converts the downstream wireless signals into digital wireless signals and inputs the converted downstream digital wireless signals to the parent station control unit 10.

The parent station control unit 10 performs predetermined baseband signal processing on the downstream digital radio signal input from the ADC 15 to convert it into a baseband downstream transmission signal. The parent station control unit 10 then outputs the baseband downstream transmission signal to the downlink processing unit 13 along with a control signal generated by the parent station control unit 10.

The downlink processing unit 13 multiplexes a control signal onto the downlink transmission signal to generate a downlink multiplexed transmission signal, and outputs the generated downlink multiplexed transmission signal to the transmission I/F unit 11. The transmission I/F unit 11 transmits the downlink multiplexed transmission signal to the slave station equipment 3-1 to 3-m directly or via the hub station equipment 2.

In addition to the baseband signal processing function described above, the master station control unit 10 also has the function of controlling the operation modes of the slave station devices 3-1 to 3-m according to the first embodiment. Figure 5 is a block diagram showing the functional configuration for realizing the above operation mode control.

The parent station control unit 10 has the following functions for implementing the sleep control: a reception level detection signal reception processing unit 101, an operation mode setting control processing unit 102, an operation mode control signal transmission processing unit 103, and a setting information storage unit 104.

The setting information storage unit 104 is used to store the operation mode controllable period, which specifies the period during which switching control of the operation modes of the slave station devices 3-1 to 3-m is possible, the forced sleep setting period, which specifies the period during which the operation mode of the slave station devices 3-1 to 3-m is forcibly set to sleep mode, and the threshold value TH1 for determining the reception level.

The reception level detection signal reception processing unit 101 receives reception level detection signals sent as control signals from the slave station devices 3-1 to 3-m. The reception level detection signal reception processing unit 101 then performs processing to extract the reception level detection values of each transmitting/receiving unit from each received reception level detection signal.

For each of the slave station devices 3-1 to 3-m, the operation mode setting control processing unit 102 compares the reception level detection value of each transceiver unit with a judgment threshold value TH1 pre-stored in the setting information storage unit 104, and performs processing to set the operation mode for each transceiver unit based on the judgment result. There are two operation modes: a "normal operation mode," in which both transmission and reception are performed, and a "sleep operation mode," in which reception is stopped and only transmission is performed. The operation mode setting control processing unit 102 sets one of these operation modes.

In addition, when the operation mode setting control processing unit 102 performs operation mode setting control based on the determination result of the reception level detection value, it compares the current time measured by a timer (not shown) with the operation mode controllable period and forced sleep setting period pre-stored in the setting information storage unit 104, and performs the operation mode setting control while further taking this determination result into consideration. An example of this operation will be described in the operation example section.

The operation mode control signal transmission processing unit 103 receives the operation mode setting results from the operation mode setting control processing unit 102 and generates an operation mode control signal that specifies the operation mode for each transceiver unit of each slave station device 3-1 to 3-m. The operation mode control signal transmission processing unit 103 then outputs the generated operation mode control signal to the downlink processing unit 13.

(Example of operation)
Next, we will explain an example of the operation of the slave station devices 3-1 to 3-m and the master station device 1 of the distributed antenna system 100 configured as described above. Note that, while the explanation here takes as an example a case where the master station device 1 controls the operating mode of the slave station device 3-1, the same applies to the other slave station devices 3-2 to 3-m.

(1) Detection of Reception Level in the Slave Station Equipment 3-1 FIG. 6 is a flowchart showing an example of the processing procedure and processing contents of the sleep control executed by the slave station control unit 30 of the slave station equipment 3-1.

During system operation, the slave station control unit 30 of slave station device 3-1, under the control of the reception level detection processing unit 301, first selects one band in step S11. Then, in step S12, the reception level detection processing unit 301 determines whether the current time is a period for reception level detection or a period for operating mode control. If this determination determines that the current time is a period for reception level detection, the reception level detection processing unit 301 proceeds to step S13 and detects the reception level (RSSI value) of the wireless signal received by the transceiver unit corresponding to the selected band.

The reception level detection processing unit 301 then performs the above reception level detection process sequentially for all bands provided by the slave station device 3-1.

Once the reception level detection process for all bands has been completed, the slave station control unit 30 then, under the control of the reception level detection signal transmission processing unit 302, generates a reception level detection signal in step S14 that includes the reception level detection value obtained for each band and the identification ID of each band that was the detection target. The reception level detection signal transmission processing unit 302 then transmits the generated reception level detection signal to the master station device 1.

(2) Operation Mode Setting Control by the Master Station Equipment 1 The master station control unit 10 of the master station equipment 1 executes processing related to setting control of the operation mode for each band for the slave station equipment 3-1 to 3-m as follows.

Prior to executing the above-mentioned operation mode setting control process, for example, a system administrator operates the management terminal 7 to initially register the operation mode controllable period, forced sleep setting period, and reception level determination threshold TH1 for each of the slave station devices 3-1 to 3-m in the setting information storage unit 104 provided in the master station control unit 10 of the master station device 1.

Figure 7 is a flowchart showing an example of the processing procedure and processing content of the operation mode setting control executed by the parent station control unit 10.

That is, in step S21, the master station control unit 10 of the master station device 1, under the control of the reception level detection signal reception processing unit 101, monitors the transmission of reception level detection signals from each of the slave station devices 3-1 to 3-m. For example, if a reception level detection signal is sent from slave station device 3-1, the reception level detection signal reception processing unit 101 receives that reception level detection signal. The reception level detection signal reception processing unit 101 also performs similar reception processing on reception level detection signals sent from the other slave station devices 3-2 to 3-m.

When the above-mentioned reception level detection signal is received from the slave station equipment 3-1 to 3-m, the master station control unit 10, under the control of the operation mode setting control processing unit 102, executes the following operation mode setting control for the slave station equipment 3-1 to 3-m. Note that in this explanation, the slave station equipment 3-1 is the control target.

That is, in step S22, the operation mode setting control processing unit 102 first determines whether an operation mode controllable period corresponding to the slave station equipment 3-1 is registered in the setting information storage unit 104. If the result of this determination is that an operation mode controllable period is not registered, the operation mode setting control processing unit 102 ends processing without performing operation mode setting control.

On the other hand, suppose that an operation mode controllable period has been registered in the setting information storage unit 104 for the slave station equipment 3-1. In this case, in step S23, the operation mode setting control processing unit 102 determines whether the current time measured by a timer (not shown) is within the operation mode controllable period. If this determination determines that the current time is outside the operation mode controllable period, the operation mode setting control processing unit 102 terminates processing without performing operation mode setting control.

In contrast, let us assume that the current time is within the operation mode control period. In this case, the operation mode setting control processing unit 102 then determines in step S24 whether the current time is within the forced sleep setting period stored in the setting information storage unit 104. If the result of this determination is that the current time is outside the forced sleep setting period, the operation mode setting control processing unit 102 proceeds to step S25. Note that forced sleep setting control when the current time is within the forced sleep setting period will be described later.

In step S25, the operating mode setting control processing unit 102 compares the detection values of the reception level detection signals for each band from the slave station device 3-1 received in step S21 with the threshold value TH1 stored in the setting information storage unit 104, and determines whether the detection values of the reception levels have been below the threshold value TH1 for a predetermined period of time or more.

If, as a result of this determination, there is a band for which the detected reception level has been below threshold value TH1 for a predetermined period of time or longer, the operation mode setting control processing unit 102 proceeds to step S26 and sets the operation mode of that band to "sleep operation mode." Note that, for bands for which the detected reception level has remained above threshold value TH1 for a predetermined period of time or longer, the operation mode setting control processing unit 102 maintains the operation mode of that band in "normal operation mode" in step S27.

After completing the operation mode setting process, the parent station control unit 10 then generates an operation mode control signal containing operation mode setting information for each band of the child station equipment 3-1 under the control of the operation mode control signal transmission processing unit 103 in step S28. The operation mode control signal transmission processing unit 103 then outputs the generated operation mode control signal to the downlink processing unit 13. As a result, the operation mode control signal is transmitted from the downlink processing unit 13 to the child station equipment 3-1.

The same series of operation mode setting control and operation mode control signal transmission processes are performed for the other slave station devices 3-2 to 3-m.

(3) Operation Mode Control in Slave Station Equipment 3-1 When the current time falls within the operation mode control period, the slave station control unit 30 of the slave station equipment 3-1 receives, in step S15, an operation mode control signal transmitted from the master station equipment 1 under the control of the power supply and clock control processing unit 303. Subsequently, in step S16, the power supply and clock control processing unit 303 generates a power supply and clock control signal based on the received operation mode control signal and supplies the generated signal to the power supply and clock supply unit 38.

For example, the power supply and clock control processing unit 303 generates a control signal to maintain the supply of the operating power output VC and operating clock CK to the transceiver unit corresponding to the band whose operating mode is set to "normal operating mode" in accordance with the operating mode setting information for each band contained in the operating mode control signal, and supplies this to the power supply and clock supply unit 38.

On the other hand, for transceiver units corresponding to bands whose operating mode is set to "sleep operating mode," the power supply and clock control processing unit 303 generates a control signal to control the supply of the operating power output VC and operating clock CK to correspond to the sleep state, and supplies this to the power supply and clock supply unit 38.

The power supply and clock supply unit 38 controls the supply of operating power output VC and operating clock CK individually to each transceiver unit 31-3k in accordance with the control signal provided.

For example, consider the case where, of the transceiver units 31 to 3k, transceiver unit 31 is set to "sleep operation mode." Figure 8 shows an example of the configuration of the transceiver unit 31 and the downlink system block of the slave station control unit 30. As shown in Figure 8, the downlink system block of slave station equipment 3-1 includes a transmission power amplifier 3411 provided in the antenna I/F unit 341, a DAC 331, and a downlink baseband processing unit 39 within the slave station control unit 30. The downlink baseband processing unit 39 includes, for example, a quadrature modulation processing function.

When the power supply and clock supply unit 38 sets the downlink system block to "sleep operation mode," it stops supplying the operating power output VC to the transmission power amplifier 3410 and stops supplying the operating clock CK to the DAC 331 and the downlink baseband processing unit 39 in the slave station control unit 30. As a result, the transceiver unit 31 of the slave station equipment 3-1 and the downlink system block in the slave station control unit 30 enter sleep operation, thereby reducing power consumption.

In addition, the operating power output VC and operating clock CK are supplied to the transmitting/receiving unit and the downlink system block within the slave station control unit 30 for which "normal operation mode" has been specified by the power supply/clock control processing unit 303, and normal operation is maintained.

The above-described operation mode control process is performed in the same way for each band in the other slave station devices 3-2 to 3-m.

An example of the above-mentioned operation mode control will be explained using Figures 9 and 10. Figure 9 shows an example of the operating state of the slave station equipment 3-1 to 3-2 before operation mode control is performed, while Figure 10 shows an example of the operating state of the slave station equipment 3-1 to 3-2 after operation mode control is performed.

In the state shown in Figure 9, wireless terminals MT1, MT2, and MT3 communicate using bands B1, B2, and B3 of slave station equipment 3-1, respectively, and wireless terminals MT4 and MT5 communicate using bands B4 and B5 of slave station equipment 3-2.

Suppose that wireless terminals MT1 to MT5 subsequently end communications, and another wireless terminal MTi begins communications using band B1 of slave station device 3-1. In this case, the series of operating mode controls described above are performed, so that only the block corresponding to band B1 of slave station device 3-1 remains in "normal operating mode," as shown in Figure 10, while all blocks corresponding to the other bands of slave station devices 3-1 and 3-2 are set to "sleep operating mode."

As a result, power consumption in the slave station equipment 3-1 to 3-m is reduced compared to when the slave station equipment 3-1 to 3-m are always fixed to operate in "normal operation mode."

(4) Restoring from Sleep Operation Mode to Normal Operation Mode In the sleep operation mode, the slave station control units 30 of the slave station devices 3-1 to 3-m continue the reception level detection process in preparation for access from the wireless terminals MT1 to MTn. The slave station control units 30 then transmit the reception level detection signals obtained by the reception level detection process to the master station device 1.

In response to this, when the master station control unit 10 of the master station device 1 receives the reception level detection signal transmitted from the slave station devices 3-1 to 3-m, it determines in step S25 whether the reception level detection value for each band of each slave station device 3-1 to 3-m has exceeded threshold value TH1. If a band is detected for which the reception level detection value has exceeded threshold value TH1, the process proceeds to step S27, where it changes the operating mode for the corresponding band to "normal operating mode" and transmits that operating mode control signal to the corresponding slave station devices 3-1 to 3-m.

When the slave station control units 30 of the slave station devices 3-1 to 3-m receive the above-mentioned operation mode control signal from the master station device 1, they resume supplying the operating power output VC and the operating clock CK to the transceiver units and downlink blocks of the slave station control units 30 corresponding to the bands designated as the control targets by the operation mode control signal.

(5) Execution of forced sleep control In the parent station control unit 10 of the parent station device 1, the operation mode setting control processing unit 102 determines in step S24 shown in FIG. 7 that the current time is within the forced sleep setting period stored in the setting information storage unit 104.

In this case, the operation mode setting control processing unit 102 proceeds from step S24 to step S26 without determining the operation mode based on the detected reception level. Then, in step S26, the operation mode setting control processing unit 102 outputs a control signal to forcibly set the slave station device to sleep operation mode based on the forced sleep setting period information stored in the setting information storage unit 104.

For example, the forced sleep setting period information is individually set in association with each slave station device 3-1 to 3-m. Therefore, the operation mode setting control processing unit 102 collectively sets the operation mode to "sleep operation mode" for all bands of the slave station devices for which the above-mentioned forced sleep setting period information is set.

In other words, by setting a forced sleep setting period for each slave station device 3-1 to 3-m, it is possible to forcibly set the operating mode of all bands on a slave station basis to sleep operating mode. Figures 11(a), (b) and 12(a), (b) show examples of forced sleep control execution.

This example shows a distributed antenna system in which slave station devices 3-1 to 3-m are distributed across each floor of an office building, and these slave station devices 3-1 to 3-m are grouped together on multiple floors and connected to hub station devices 2, 2, ..., which are then connected to master station device 1.

Figures 11(a) and (b) show the state when all slave station equipment 3-1 to 3-m are set to "normal operation mode." Meanwhile, Figures 12(a) and (b) show the operating state of each slave station equipment 3-1 to 3-m when a "forced sleep period" is set for the slave station equipment on the upper floors, but not for the slave station equipment on the middle and lower floors.

In Figures 11(a), (b) and 12(a), (b), slave station equipment operating in "normal operation mode" is indicated by 3 (on), and slave station equipment set to "forced sleep mode" is indicated by 3 (off). Furthermore, among slave station equipment not set to "forced sleep mode," slave station equipment set to "sleep operation mode" is indicated by 3 (sleep).

As shown in this example, for example, if different tenants occupy the upper, middle, and lower floors, by setting forced sleep setting information for the slave station devices on the corresponding floors according to the working hours of each tenant, it is possible to forcibly set all slave station devices on the upper floors to sleep operating mode during non-working hours, for example. This makes it possible to reduce power consumption even more efficiently.

In addition, typically, slave station equipment on upper floors far from the system power supply unit BT has long power supply paths and large voltage drops. Therefore, constantly supplying the operating power output VC to the slave station equipment on the upper floors reduces the power efficiency of the system. Therefore, a forced sleep period is set for the slave station equipment on the upper floors. This makes it possible to prevent a decrease in the power efficiency of the system. In this case, the slave station equipment on the upper floors will be unable to communicate while the forced sleep period is set. However, in a hierarchical installation environment such as an office building, wireless signals leaking from the middle floors can be received on the upper floors through windows, etc., so wireless communication between the wireless terminals TM1 to TMn can be maintained.

(effect)
As described above, in the first embodiment, the slave station devices 3-1 to 3-m detect the reception level of the radio signal for each band and notify the detection results to the master station device 1. Then, based on the detection results of the reception levels, the master station device 1 determines whether the operation mode for each of the slave station devices 3-1 to 3-m for each band should be the normal operation mode or the sleep operation mode, and based on the determination results, each of the slave station devices 3-1 to 3-m controls the operation mode of the downlink system blocks such as the transceiver units 31 to 3k for each band.

As a result, compared to when the operating mode of the slave station devices 3-1 to 3-m is always fixed to "normal operating mode," it is possible to reduce power consumption in the slave station devices 3-1 to 3-m during periods when wireless communication is not being conducted with the wireless terminals MT1 to MTn.

In addition, in the first embodiment, a forced sleep setting period is set for each slave station equipment 3-1 to 3-m, and during this period, each slave station equipment 3-1 to 3-m is forcibly set to sleep operation mode. As a result, during periods when the slave station equipment 3-1 to 3-m are not actually used, their operation modes are forcibly set to sleep operation mode collectively, making it possible to more effectively reduce system power consumption.

Second Embodiment
In the second embodiment, in addition to the threshold value TH1 used in the first embodiment to determine whether or not the sleep operation mode needs to be set, a threshold value TH2 is set between this threshold value TH1 and the reception level during normal operation as a threshold value for determining the reception level detection value. The threshold value TH2 is used to determine the operation restriction mode. Then, in the second embodiment, when the reception level detection value falls to a value between the threshold values TH2 and TH1, the operation of only the control system of the downlink system blocks of the transceiver units 31 to 3k and the slave station control unit 30 is stopped.

Figure 13 shows an example of the configuration of the downlink system block of the transceiver units 31 to 3k of the slave station devices 3-1 to 3-m and the slave station control unit 30, as well as the control system of the block, in a distributed antenna system according to the second embodiment. Other components of the slave station devices 3-1 to 3-m and the master station device 1 will be explained using Figures 2 to 5.

In Figure 13, the transceiver units 31 to 3k are equipped with a feedback control system consisting of a DAC 331, a transmission power amplifier 341, a branch circuit 411, a level detection circuit 421, and an ADC 431.

The branching circuit 411 branches the radio signal output from the transmission power amplifier 341 into two, outputting one to the antennas 4-11 to 4-1k and the other to the level detection circuit 421. The level detection circuit 421 rectifies the radio signal, detects the signal level, and outputs the detection signal. The ADC 431 converts the signal level detection signal into a digital signal and inputs it to the downlink baseband processing unit 39.

In addition to the quadrature modulation processing function, the downlink baseband processing unit 39 also has a calibration processing function that corrects local frequency leakage and quadrature errors during modulation, and a DPD (Digital Pre-Distortion) processing function 391 that compensates for the characteristics of the transmission power amplifier 341.

When the master station control unit 10 of the master station device 1 receives reception level detection signals for each band transmitted from the slave station devices 3-1 to 3-m, the operation mode setting control processing unit 102 compares the reception level detection values included in the reception level detection signals for each band with thresholds TH1 and TH2 for each of the slave station devices 3-1 to 3-m. If the comparison shows that the reception level detection values have fallen below threshold TH1, the operation mode setting control processing unit 102 sets the "sleep operation mode." On the other hand, if the reception level detection values are equal to or greater than threshold TH1 but have fallen below threshold TH2, the operation mode setting control processing unit 102 sets the "restricted operation mode."

Through the above processing, the master station control unit 10 transmits the operating mode setting information set for each band for each slave station device 3-1 to 3-m to each slave station device 3-1 to 3-m under the control of the operating mode control signal transmission processing unit 103.

In response to this, when the slave station control unit 30 of each slave station device 3-1 to 3-m receives the above operation mode control signal, the power supply/clock control processing unit 303 generates a control signal for controlling the supply of operating power and operating clock in accordance with the operation mode setting information for each band included in the above operation mode control signal, as follows, and provides this control signal to the power supply/clock supply unit 38.

In other words, if the operation mode setting information indicates that the operation mode is set to "sleep operation mode," a control signal is generated to set the downlink system blocks of the transceiver unit and slave station control unit 30 to a sleep state, and is provided to the power supply and clock supply unit 38.

In contrast, if the operating mode is set to "operation restriction mode" according to the operating mode setting information, a control signal is generated to stop the operation of the control systems of the downlink system blocks of the transceiver units 31-3k and the slave station control unit 30, and is provided to the power supply and clock supply unit 38.

When the power supply and clock supply unit 38 first receives a control signal to set the unit to sleep mode, it stops supplying the operating power output VC to the transmission power amplifier 3410 and stops supplying the operating clock CK to the DAC 331 and the downlink baseband processing unit 39 in the slave station control unit 30. As a result, the transceiver units 31 to 3k of the slave station equipment 3-1 and the downlink system blocks in the slave station control unit 30 transition to sleep mode.

On the other hand, when a control signal to set the operation restriction mode is received, the power supply and clock supply unit 38 stops supplying the operating power output VC to the level detection circuit 421 in the transceiver units 31 to 3k, and also stops supplying the operating clock CK to the ADC 431 and DPD 391.

As a result, in the transceiver units 31-3k, as shown in Figure 14, downlink radio signal transmission operation is maintained, but the operation of the control system of the downlink system block (the part indicated by the dashed line) is stopped. In other words, some of the operation of the downlink system block is restricted, and power consumption is reduced accordingly.

As described above, according to the second embodiment, when the reception level of the radio signal at the slave station devices 3-1 to 3-m drops, even if the reception level has not yet fallen to the threshold TH1 at which the device transitions to sleep operation mode, but has fallen below threshold TH2, the operation of the control system of the downlink block of the slave station devices 3-1 to 3-m is stopped. This makes it possible to further reduce power consumption at the slave station devices 3-1 to 3-m, thereby further enhancing the power consumption reduction effect of the system.

[Third embodiment]
The third embodiment has a function of calculating the availability of the slave station devices 3-1 to 3-m, and generates warning information or recommendation information to encourage system improvements based on the calculation results, and outputs the generated information to the system administrator.

For example, the slave station control unit 30 of each slave station device 3-1 to 3-m measures the time that each slave station device 3-1 to 3-m operates in normal operation mode and the time that each slave station device 3-1 to 3-m operates in sleep operation mode, and periodically or at a predetermined timing calculates the availability of each slave station device 3-1 to 3-m based on the measured time in each operation mode. Then, information representing the calculated availability is sent to the master station device 1.

Based on the information indicating the availability rates sent from the slave station devices 3-1 to 3-m, the master station device 1 generates warning information or recommendation information to encourage system improvements. For example, if the availability rate of a slave station device falls below threshold TH3, the master station device 1 generates and outputs warning information regarding the usage status of that slave station device.

The master station device 1 also determines, for example, the availability rate of multiple slave station devices located in each area, and based on the results of this determination, generates and outputs recommendation information that encourages the reduction and rearrangement of each slave station device in the area. In this case, the recommendation information may, for example, be a map showing the layout of the slave station devices after rearrangement.

Based on the above alarm information and recommendation information, the system administrator can relocate the slave station equipment 3-1 to 3-m. This makes it possible to eliminate essentially unnecessary slave station equipment and further improve the power efficiency of the system.

In the above explanation, we have taken the example of the parent station equipment 1 generating the alarm information, but the child station equipment 3-1 to 3-m may also be equipped with the function of generating the alarm information. Furthermore, the calculation of the availability of the child station equipment 3-1 to 3-m may be performed collectively by the parent station equipment 1, instead of by the child station equipment 3-1 to 3-m.

[Other embodiments]
(1) In the first embodiment, the slave station control unit 30 performs the detection and determination process for the reception level for each band and the control process for the operation mode for each band in response to the operation mode signal sent from the master station device 1, which are performed alternately in separate operation periods. However, the present invention is not limited to this, and the above control processes may be performed in parallel without separating the operation periods.

(2) In the first and second embodiments, the slave station devices 3-1 to 3-m only detect the reception level of each band and send the detected value to the master station device 1, which then compares the detected reception level value with thresholds TH1 and TH2 to make a judgment. However, this is not limited to this. The slave station devices 3-1 to 3-m may detect and judge the reception level of each band and send the judgment result to the master station device 1, and the master station device 1 may use the judgment result of the received reception level to control the setting of the operating mode.

(3) In the first to third embodiments, an example was described in which the operating mode setting control function was provided in the master station device 1. However, this is not limiting. For example, the reception level detection results detected by each slave station device 3-1 to 3-m may be transferred from the slave station devices 3-1 to 3-m directly or via the master station device 1 to the management terminal 7 shown in FIG. 1, and the operating mode setting control of the slave station devices 3-1 to 3-m may be performed collectively in the management wireless terminal. In this case, the management terminal 7 transmits the operating mode setting control information set by the operating mode setting control to the slave station devices 3-1 to 3-m directly or via the master station device 1, and controls the power and clock supply to the slave station devices 3-1 to 3-m.

(4) In addition, the configuration, processing functions, processing procedures, processing content, etc. of the communication devices used as slave station devices and master station devices may be configured in ways other than those described in the above embodiments.

Although several embodiments have been described in detail above, the above descriptions are merely illustrative in all respects. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. In other words, specific configurations corresponding to the embodiments may be adopted as appropriate when implementing the present invention.

In short, this invention is not limited to the above-described embodiments, and in the implementation stage, the components can be modified and embodied without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined.
The following is a summary of the scope of claims as originally filed in this application.
[C1]
one or more slave station devices each including at least one transmitting/receiving unit for transmitting and receiving wireless signals to and from a wireless terminal via an antenna;
a master station device that transmits and receives the wireless signal to and from the slave station device directly or via a relay device;
Equipped with
the slave station device includes a determination unit that determines a transmission/reception state of the wireless signal by the transmission/reception unit and notifies the master station device of determination information representing the determination result;
The master station device includes a control unit that controls the slave station device based on the determination information to set the transceiver units to an operable mode when the wireless signal is being transmitted or received, and to set at least a part of the transceiver units to a sleep mode when the wireless signal is not being transmitted or received.
Distributed Antenna System.
[C2]
the determination unit of the slave station device detects an index representing a reception quality of the wireless signal transmitted from the wireless terminal, determines whether the detected index satisfies a preset condition, and notifies the master station device of the determination result as the determination information;
The control unit of the master station device controls the slave station device to set the receiving function unit of the transceiver unit to a sleep mode based on the determination information when the wireless signal is not being transmitted or received.
[C3]
In a distributed antenna system including one or more slave station devices each having at least one transceiver unit for transmitting and receiving wireless signals to and from a wireless terminal via an antenna, and a master station device for transmitting and receiving the wireless signals to and from the slave station devices directly or via a relay device, a communication device used as the master station device or the slave station devices, comprising:
an acquisition unit that acquires information representing a transmission/reception state of the wireless signal by the transmission/reception unit of the slave station device;
a control unit that controls the operation mode of the slave station device based on the acquired information representing the transmission/reception state, so as to set the transmission/reception unit to an operable mode when the wireless signal is being transmitted/received, and to set at least a part of the transmission/reception unit to a sleep mode when the wireless signal is not being transmitted/received;
A communication device comprising:
[C4]
When the slave station device includes a plurality of the transmission/reception units for transmitting and receiving the radio signals,
the acquisition unit acquires information representing the transmission and reception state of the wireless signal for each of the transmission and reception units;
the control unit controls the operation mode for each of the transceiver units based on information representing the transmission/reception state corresponding to the transceiver unit.
The communication device according to C3.
[C5]
a first storage unit that stores control period designation information that designates a controllable period or an uncontrollable period of the operation mode;
the control unit sets at least some of the transmission/reception units of the slave station devices to the sleep mode during the controllable period and during a period when the wireless signal is not being transmitted or received, based on the control period designation information stored in the first storage unit and the information representing the transmission/reception state.
The communication device according to C3.
[C6]
The control unit, in the sleep mode, stops supplying an operating clock to the baseband processing unit and digital/analog converter provided in the transceiver unit, and stops supplying operating power to the transmission power amplifier.
[C7]
The control unit
a determination processing unit that determines whether a reception quality index is lower than a first threshold value, or whether the reception quality index is equal to or higher than the first threshold value and lower than a second threshold value, based on the information representing the transmission and reception state;
a first control processing unit that sets a first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
a second control processing unit that sets a second receiving function unit in addition to the first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is lower than the first threshold value;
The communication device according to C3,
[C8]
the first control processing unit performs a first process of stopping a calibration operation of a digital-to-analog converter and a characteristic compensation operation of a transmission power amplifier included in the transceiver unit when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
When it is determined that the index of reception quality is lower than the first threshold, the second control processing unit performs, in addition to the first processing, a second processing of stopping the supply of an operating clock to the baseband processing unit and the digital/analog converter provided in the transceiver unit and the supply of operating power to the transmission power amplifier.
The communication device according to C7.
[C9]
When a plurality of slave station devices are installed,
a second storage unit that stores forced sleep period designation information that is preset in correspondence with each of the plurality of slave station devices;
The communication device according to C3, wherein the control unit forcibly sets the operation mode of each of the slave station devices to a sleep mode for a period designated by the forced sleep period designation information.
[C10]
When a plurality of slave station devices are installed,
The control unit acquires or calculates, for each of the plurality of slave station devices, information representing an availability rate of the slave station device based on a setting ratio between the operable mode and the sleep mode, and generates and outputs information regarding the suitability of the placement status of the plurality of slave station devices based on the information representing the availability rate.
[C11]
1. A sleep control method executed by one or more slave station devices having at least one transceiver unit for transmitting and receiving wireless signals to and from a wireless terminal via an antenna, or a communication device used as a master station device for transmitting and receiving the wireless signals to and from the slave station devices directly or via a relay device, comprising:
acquiring information representing a transmission/reception state of the wireless signal by the transmission/reception unit of the slave station device;
a step of controlling the operation mode of the slave station device based on the acquired information indicating the transmission/reception state so as to set the transmission/reception units to an operable mode when the wireless signal is being transmitted/received, and to set at least a part of the transmission/reception units to a sleep mode when the wireless signal is not being transmitted/received;
A sleep control method comprising:
[C12]
A computer program that causes a computer to function as the communication device according to any one of C3 to C10.

BS...base station device, MT1 to MTn...wireless terminal, BT...system power supply device, 100...distributed antenna system, 1...master station device, 2...hub station device, 3-1 to 3-m...slave station devices, 7...management wireless terminal, 10...master station control unit, 11...transmission I/F unit, 12...uplink processing unit, 13...downlink processing unit, 14...DAC, 15...ADC, 16...wireless I/F unit, 101...reception level detection signal reception processing unit, 102...operation mode setting control processing unit, 1 03...operation mode control signal transmission processing unit, 104...setting information storage unit, 30...slave station control unit, 31-3k...transmitting/receiving units, 321-32k...ADC, 331-33k...DAC, 341-34k...antenna I/F unit, 35...uplink processing unit, 36...downlink processing unit, 37...transmission I/F unit, 38...power and clock supply unit, 301...receiving level detection processing unit, 302...receiving level detection signal transmission processing unit, 303...power and clock control processing unit.

Claims (10)

one or more slave station devices each including at least one transmitting/receiving unit for transmitting and receiving wireless signals to and from a wireless terminal via an antenna;
a master station device that transmits and receives the wireless signal to and from the slave station device directly or via a relay device;
the slave station device includes a determination unit that determines a transmission/reception state of the wireless signal by the transmission/reception unit and notifies the master station device of determination information representing the determination result;
the master station device includes a control unit that controls the slave station device based on the determination information to set the transceiver units to an operable mode when the wireless signal is being transmitted or received, and to set at least a part of the transceiver units to a sleep mode when the wireless signal is not being transmitted or received ,
The control unit
a determination processing unit that determines whether a reception quality index is lower than a first threshold value, or whether the reception quality index is equal to or higher than the first threshold value and lower than a second threshold value, based on the information representing the transmission and reception state;
a first control processing unit that sets a first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
a second control processing unit that sets a second receiving function unit in addition to the first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is lower than the first threshold value;
and
the first control processing unit performs a first process of stopping a calibration operation of a digital-to-analog converter and a characteristic compensation operation of a transmission power amplifier included in the transceiver unit when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
When it is determined that the index of reception quality is lower than the first threshold, the second control processing unit, in addition to the first processing, further performs a second processing of stopping the supply of an operating clock to a baseband processing unit and the digital-to-analog converter provided in the transceiver unit and the supply of operating power to the transmission power amplifier.
Distributed Antenna System. the determination unit of the slave station device detects an index representing a reception quality of the wireless signal transmitted from the wireless terminal, determines whether the detected index satisfies a preset condition, and notifies the master station device of the determination result as the determination information;
2. The distributed antenna system according to claim 1, wherein the control unit of the master station device controls the slave station device to set a receiving function unit of the transceiver unit to a sleep mode based on the determination information when the wireless signal is not being transmitted or received. In a distributed antenna system including one or more slave station devices each having at least one transceiver unit for transmitting and receiving wireless signals to and from a wireless terminal via an antenna, and a master station device for transmitting and receiving the wireless signals to and from the slave station devices directly or via a relay device, a communication device used as the master station device or the slave station devices, comprising:
an acquisition unit that acquires information representing a transmission/reception state of the wireless signal by the transmission/reception unit of the slave station device;
a control unit that controls the operation mode of the slave station device based on the acquired information representing the transmission and reception state, so as to set the transmission and reception units to an operable mode when the wireless signal is being transmitted and received, and to set at least a part of the transmission and reception units to a sleep mode when the wireless signal is not being transmitted or received ,
The control unit
a determination processing unit that determines whether a reception quality index is lower than a first threshold value, or whether the reception quality index is equal to or higher than the first threshold value and lower than a second threshold value, based on the information representing the transmission and reception state;
a first control processing unit that sets a first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
a second control processing unit that sets a second receiving function unit in addition to the first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is lower than the first threshold value;
and
the first control processing unit performs a first process of stopping a calibration operation of a digital-to-analog converter and a characteristic compensation operation of a transmission power amplifier included in the transceiver unit when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
When it is determined that the index of reception quality is lower than the first threshold, the second control processing unit, in addition to the first processing, further performs a second processing of stopping the supply of an operating clock to the baseband processing unit and the digital/analog converter provided in the transceiver unit and the supply of operating power to the transmission power amplifier . When the slave station device includes a plurality of the transmission/reception units for transmitting and receiving the radio signals,
the acquisition unit acquires information representing the transmission and reception state of the wireless signal for each of the transmission and reception units;
the control unit controls the operation mode for each of the transceiver units based on information representing the transmission/reception state corresponding to the transceiver unit.
The communication device according to claim 3 . a first storage unit that stores control period designation information that designates a controllable period or an uncontrollable period of the operation mode;
the control unit sets at least some of the transmission/reception units of the slave station devices to the sleep mode during the controllable period and during a period when the wireless signal is not being transmitted or received, based on the control period designation information stored in the first storage unit and the information indicating the transmission/reception state.
The communication device according to claim 3 . The communication device of claim 3, wherein, in the sleep mode, the control unit stops supplying an operating clock to the baseband processing unit and digital-to-analog converter provided in the transceiver unit, and stops supplying operating power to the transmission power amplifier. When a plurality of slave station devices are installed,
a second storage unit that stores forced sleep period designation information that is preset in correspondence with each of the plurality of slave station devices;
The communication device according to claim 3 , wherein the control unit forcibly sets the operation mode of each of the slave station devices to a sleep mode for a period designated by the forced sleep period designation information. When a plurality of slave station devices are installed,
4. The communication device according to claim 3, wherein the control unit acquires or calculates, for each of the plurality of slave station devices, information representing an availability rate of the slave station device based on a setting ratio between the operable mode and the sleep mode, and generates and outputs information regarding the suitability of the arrangement state of the plurality of slave station devices based on the information representing the availability rate. 1. A sleep control method executed by one or more slave station devices having at least one transceiver unit for transmitting and receiving wireless signals to and from a wireless terminal via an antenna, or a communication device used as a master station device for transmitting and receiving the wireless signals to and from the slave station devices directly or via a relay device, comprising:
acquiring information representing a transmission/reception state of the wireless signal by the transmission/reception unit of the slave station device;
and a step of controlling the operation mode of the slave station device based on the acquired information representing the transmission and reception state so as to set the transmission and reception units to an operable mode when the wireless signal is being transmitted and received, and to set at least a part of the transmission and reception units to a sleep mode when the wireless signal is not being transmitted or received ,
The controlling step comprises:
a determining process step of determining whether a reception quality index is lower than a first threshold value or whether the reception quality index is equal to or higher than the first threshold value and lower than a second threshold value, based on the information representing the transmission and reception state;
a first control process for setting a first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
a second control process for setting a second receiving function unit in addition to the first receiving function unit of the transceiver unit to a sleep mode when it is determined that the index of reception quality is lower than the first threshold value;
and
the first control processing step performs a first process of stopping a calibration operation of a digital-to-analog converter and a characteristic compensation operation of a transmission power amplifier provided in the transceiver unit when it is determined that the index of reception quality is equal to or greater than the first threshold value and lower than the second threshold value;
a second control processing step that, when it is determined that the index of reception quality is lower than the first threshold, further performs, in addition to the first processing, a second processing step of stopping the supply of an operating clock to the baseband processing unit and the digital-to-analog converter provided in the transceiver unit and the supply of operating power to the transmission power amplifier . A computer program that causes a computer to function as the communication device according to any one of claims 3 to 8 .