Optical access system for mobile communication

Abstract

The present disclosure relates to an optical access system for mobile communication. The optical access system is characterized by comprising: a master station device for a mobile base which has a baseband processing function corresponding to mobile communication and transmits and receives an optical signal via a high-order optical fiber network; a plurality of slave station devices for the mobile base which transmits and receives the optical signal to and from the master station device via any of a plurality of low-order optical fiber networks, has a radio wave transmission / reception function corresponding to the mobile communication, and start / stop according to an instruction; a plurality of optical switches that connects / disconnects the high-order optical fiber network and any of the plurality of low-order optical fiber networks according to an instruction; a base station control device that instructs the slave station device to start / stop; and an optical access control device that instructs the plurality of optical switches to connect / disconnect the high-order optical fiber network and any of the plurality of low-order optical fiber networks according to connection / disconnection information from the base station control device.

Description

Optical access system for mobile communications

[0001] The present disclosure relates to an optical access system applied to a base station for mobile communications.

[0002] Mobile communication networks have become an important social infrastructure that supports people's daily lives and industry. With the expansion of 5G capacity and coverage area, the rollout of 6G is expected in the future. Due to the limited radio frequency bandwidth, the use of millimeter wave bands above 30 GHz is being considered for the expansion of 5G capacity and the rollout of 6G. Because millimeter wave radio waves have high linearity and little diffraction, it is expected that a large number of mobile base stations will be required to expand the service area.

[0003] Current mobile base stations consist of a master station, which is centrally installed in a data center or the like and controls the slave station devices and connects them to the core network, and slave station devices, which are installed near antennas in various locations and communicate with terminals via radio waves (see, for example, Non-Patent Document 1).

[0004] If a large number of mobile base stations are installed in this configuration, the number of master and slave stations will increase, raising concerns about increased costs and a lack of installation space. Therefore, a technology to reduce the resource usage of master stations is needed. Prior art has developed a technology that shares a master station and accommodates up to 12 slave stations in a single master station (see, for example, Non-Patent Document 1).

[0005] Furthermore, the installation of a large number of slave station devices will increase the power consumption of the entire mobile communication network. From the perspective of achieving carbon neutrality, technology to reduce the power consumption of slave station devices is necessary. Prior art has developed a technology that switches mobile base stations near wireless terminals between active and sleep states based on the wireless terminal's positioning information (see, for example, Non-Patent Document 2). This technology makes it possible to flexibly operate mobile base stations intermittently according to the timing of passing automobiles and trains, thereby reducing the power consumption of slave station devices.

[0006] Furthermore, as the number of remote station equipment increases, the amount of optical fiber used to connect the master station equipment and remote station equipment also increases. Installing additional optical fiber for optical access requires safety risk management, such as working at height, and the time required for installation increases, so technology for efficiently utilizing optical fiber resources is also required.

[0007] https: / / journal.ntt.co.jp / article / 6936https: / / group.ntt / jp / newsrelease / 2023 / 03 / 31 / 230331a.html

[0008] In Prior Art Document 1, although the resources of the master station device can be reduced, the slave station devices are assumed to be constantly running, and power consumption of the slave station devices cannot be reduced.

[0009] In Prior Art Document 2, power consumption is reduced by putting slave station equipment into a sleep state as needed, but the sleep control only stops some of the functions of the slave station equipment, so the reduction in power consumption of the slave station equipment is limited.

[0010] None of the prior art technologies can simultaneously achieve resource reduction in the master station device and power consumption reduction in the slave station device, nor can they achieve efficient use of optical fiber resources.

[0011] An object of the present disclosure is to realize efficient use of optical fiber resources in an optical access system for mobile communications by reducing the power consumption of a slave station device while reducing the resource consumption of a master station device.

[0012] To achieve the above object, in the optical access system for mobile communications according to the present disclosure, a plurality of slave station devices share a master station device. The master station device and any of the slave station devices can be connected or disconnected, and the slave station devices can be started or stopped as needed. Furthermore, the optical fiber network has a two-stage configuration, and the first stage is shared by switching connections using an optical switch.

[0013] Specifically, the present disclosure provides an optical access system for mobile communications, comprising: a base station device for a mobile base station, which has a baseband processing function corresponding to mobile communications and transmits and receives optical signals via an upper optical fiber network; a plurality of slave station devices for the mobile base station, which transmit and receive the optical signals with the base station device via one of a plurality of lower optical fiber networks, have a function of transmitting and receiving radio waves corresponding to mobile communications, and are activated and stopped in response to instructions; a plurality of optical switches, which connect and disconnect the upper optical fiber network and one of the plurality of lower optical fiber networks in response to instructions; a base station control device that instructs the slave station devices to start and stop; and an optical access control device that instructs the plurality of optical switches to connect and disconnect the upper optical fiber network and one of the plurality of lower optical fiber networks in response to connection and disconnection information from the base station control device.

[0014] Specifically, the present disclosure relates to an optical access system for mobile communications, comprising: a mobile base station having a baseband processing function corresponding to mobile communications and transmitting and receiving optical signals via an upper optical fiber network; a plurality of mobile base station devices that transmit and receive the optical signals to and from the mobile base station via one of a plurality of lower optical fiber networks, have a radio wave transmission and reception function corresponding to mobile communications, and are activated and deactivated depending on whether or not an optical signal is detected from the mobile base station; a plurality of optical switches that connect and disconnect the upper optical fiber network to one of the plurality of lower optical fiber networks in response to an instruction; and an optical access control device that instructs the plurality of optical switches to connect and disconnect the upper optical fiber network to one of the plurality of lower optical fiber networks.

[0015] Specifically, the present disclosure provides an optical access system for mobile communications, comprising: a base station device for a mobile base station, having a baseband processing function corresponding to mobile communications and transmitting and receiving optical signals via an upper optical fiber network; a plurality of slave station devices for the mobile base station, which transmit and receive the optical signals to and from the base station device via one of a plurality of lower optical fiber networks, have a function of transmitting and receiving radio waves corresponding to mobile communications, and are activated and stopped in response to instructions; a plurality of optical switches, which detect optical signals from the slave station devices and connect and disconnect the upper optical fiber network and one of the plurality of lower optical fiber networks in response to instructions; a base station control device that instructs the slave station devices to start and stop; and an optical access control device that monitors the detection of optical signals in the optical switches, and instructs the plurality of optical switches to connect and disconnect the upper optical fiber network and one of the plurality of lower optical fiber networks depending on whether or not an optical signal is detected.

[0016] Specifically, the present disclosure provides an optical access system for mobile communications, comprising: a base station device for a mobile base station, which has a baseband processing function corresponding to mobile communications and transmits and receives optical signals via an upper optical fiber network; a plurality of sub-station devices for the mobile base station, which transmit and receive the optical signals with the base station device via one of a plurality of lower optical fiber networks, have a function of transmitting and receiving radio waves corresponding to mobile communications, and are activated and stopped in response to instructions; a plurality of optical switches that connect and disconnect the upper optical fiber network and one of the plurality of lower optical fiber networks depending on whether or not an optical signal is detected from the sub-station devices; and a base station control device that instructs the sub-station devices to start and stop.

[0017] The device disclosed herein, for example, a base station control device or an optical access control device, can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network. The program disclosed herein is a program for causing a computer to realize each function of the device disclosed herein, and a program for causing a computer to execute each procedure of the method executed by the device disclosed herein.

[0018] The above disclosures can be combined as much as possible.

[0019] The present disclosure makes it possible to reduce the resources of a master station device and the power consumption of a slave station device in an optical access system for mobile communications, thereby realizing efficient use of optical fiber resources.

[0020] 1 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 2 is a configuration example of an optical switch according to the present disclosure; FIG. 3 is a configuration example of a local station device according to the present disclosure; FIG. 4 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 5 is a configuration example of an optical switch according to the present disclosure; FIG. 6 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 7 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 8 is a configuration example of a local station device according to the present disclosure; FIG. 9 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 10 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 11 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 12 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 13 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 14 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 15 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 16 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 17 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 18 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 19 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 20 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 21 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 22 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 23 is a configuration example of an optical access system for mobile communications according to the present disclosure; FIG. 24 is a

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0022] (Embodiment 1) An example of the configuration of an optical access system for mobile communications according to the present disclosure is shown in Fig. 1. The optical access system for mobile communications according to the present embodiment includes a base station device 11 for a mobile base station, which has a baseband processing function corresponding to mobile communications and transmits and receives optical signals to and from a slave station device 12 via an upper optical fiber network 16, a plurality of slave station devices 12 for a mobile base station, which transmit and receive optical signals to and from the base station device 11 via one of a plurality of lower optical fiber networks 17, have a radio wave transmission and reception function corresponding to mobile communications, and are activated and stopped in response to instructions from a base station controller 14, a plurality of optical switches (optical SW) 13 which connect and disconnect the upper optical fiber network 16 and one of the plurality of lower optical fiber networks 17 in response to instructions from an optical access controller (optical AC controller) 15, a base station controller 14 which transmits information of the slave station device 12 to be activated and stopped to the base station device 11, remotely instructs the slave station device 12 to activate and stop, and transmits connection and disconnection information between the base station device 11 and the slave station device 12 to the optical access controller 15, and and an optical access control device (optical AC control device) 15 that remotely instructs the plurality of optical switches 13 to connect or disconnect to or from either an upper optical fiber network 16 or a plurality of lower optical fiber networks 17 based on connection / disconnection information from a base station control device 14.

[0023] 1, instructions from the base station controller 14 or the optical access controller 15, or information to the base station controller 14 or the optical access controller 15, as indicated by arrows or dashed lines, are transmitted and received not via the upper optical fiber network 16 or the lower optical fiber network 17 that transmit and receive optical signals, but via a separate line, for example, a mobile communication line or a dedicated line. This also applies to the following embodiments.

[0024] The master station 11 superimposes communication baseband information onto an optical signal and transmits the superimposed information to the slave station 12. The slave station 12 modulates the communication baseband information superimposed on the optical signal from the master station 11, transmits it from an antenna, demodulates the signal received from the antenna, superimposes the communication baseband information onto an optical signal, and transmits the optical signal to the master station 11. An antenna (not shown) for mobile communication is installed near the slave station 12. The master station 11 processes the communication baseband information superimposed on the optical signal from the slave station 12.

[0025] The optical access control device 15 may monitor the status of the upper optical fiber network 16 and the lower optical fiber network 17 by causing the optical switch 13 to detect optical signals from the parent station device 11 and the child station device 12 .

[0026] The optical fiber network is composed of an upper optical fiber network 16 represented by a double line in Fig. 1 and multiple lower optical fiber networks 17 represented by double lines. An optical switch 13 switches between the upper optical fiber network 16 and one of the multiple lower optical fiber networks 17, and connects or disconnects transmission and reception of optical signals between a master station device 11 and one of multiple slave station devices 12. In Fig. 1, the optical fiber network is composed of a two-stage loop topology consisting of an upper optical fiber loop as the upper optical fiber network and a lower optical fiber loop as the lower optical fiber network, but is not limited to a two-stage loop topology. A two-stage tree topology, a two-stage star topology, or a two-stage bus topology may also be used. The same applies to the following embodiments.

[0027] Since the upper optical fiber network 16 and the master station equipment 11 are shared by each slave station equipment 12, resources of the master station equipment can be reduced and optical fiber resources can be used efficiently.

[0028] An example of the configuration of an optical switch applied to an optical fiber network with a two-stage loop topology is shown in Figure 2. In Figure 2, the optical fiber network is composed of an upper optical fiber loop as an upper optical fiber network 16 and a lower optical fiber loop as a lower optical fiber network 17. When the optical switch 13 disconnects the upper optical fiber loop from the lower optical fiber loop, it connects port A and port B within the optical switch 13 as shown in Figure 2A. The connection between port C and port D is arbitrary. When the optical switch 13 connects between the upper optical fiber loop and the lower optical fiber loop, it connects port A and port D, and port B and port C within the optical switch 13 as shown in Figure 2B. When the optical switch 13 connects between the upper optical fiber loop and the lower optical fiber loop, it may also connect port A and port C, and port B and port D within the optical switch 13 as shown in Figure 2C. The same applies to the optical switches described below.

[0029] In the case of a two-stage tree topology or a two-stage star topology, a 1:N changeover switch according to the number of branches N is applied to the branching points, and in the case of a two-stage bus topology, a 1:2 changeover switch is applied to each branching point.

[0030] An example of the configuration of a slave station equipment is shown in Figure 3. The slave station equipment 12 includes a transceiver unit having an optical transceiver for transmitting and receiving optical signals to and from the master station equipment 11, a slave station power control device that starts and stops the slave station equipment 12 in response to instructions from the base station controller 14, a power supply that supplies power to each unit of the slave station equipment under the control of the slave station power control device, and a modulation / demodulation circuit (not shown). The slave station power control device is constantly powered in order to receive instructions from the base station controller 14. Upon receiving a start instruction from the base station controller 14, the slave station power control device causes the power supply to start supplying power to each unit of the slave station equipment. Upon receiving a stop instruction from the base station controller 14, the slave station power control device causes the power supply to stop supplying power to each unit of the slave station equipment.

[0031] 4 shows another example of the configuration of an optical access system for mobile communications in which multiple slave station devices are installed in the area where the lower optical fiber network 17 is installed. When multiple slave station devices, for example, #C1, #C2, and #C3, exist in the area where the lower optical fiber network 17 is installed, multiple lower optical fiber networks 17 accommodating the slave station devices are placed under the optical switch 13. Multiple upper optical fiber networks 16 are placed under the control of the master station 11 so as to be connected to the lower optical fiber networks 17. The master station 11 has optical input / output ports 01, 02, and 03 so as to be connected to the multiple upper optical fiber networks 16. To improve reliability, the master station 11 may be configured as a dual system, such as a master station (001) and a master station (002).

[0032] As the optical switch 13, a plurality of optical switches having the configuration shown in FIG. 2 may be arranged according to the number of slave station equipment 12, and the optical switches having the configuration shown in FIG. 2 may be operated independently. The optical switch having the configuration shown in FIG. 2 connects and disconnects a specific upper optical fiber network 16 and a specific lower optical fiber network 17. Another optical switch configuration is shown in FIG. 5. In FIG. 5, the optical fiber network is composed of an upper optical fiber loop as the upper optical fiber network 16 and a lower optical fiber loop as the lower optical fiber network 17. The optical switch having the configuration shown in FIG. 5 may connect and disconnect any upper optical fiber loop and any lower optical fiber loop. The optical switch having the configuration shown in FIG. 5 provides greater flexibility in the connection between the master station equipment 11 and the slave station equipment 12 than when a plurality of optical switches having the configuration shown in FIG. 2 are arranged.

[0033] 6 and 7 show the flow of the optical access system for mobile communications according to the present embodiment shown in FIG. 1 . FIG. 6 shows the start flow of mobile communications. S11: The base station control device establishes a connection between the master station and the slave station, and transmits slave station information to the master station (not shown). S12: The base station control device transmits slave station activation information to the slave station to which the connection is to be established, and transmits connection information between the master station and the slave station to the optical access control device. S13: The slave station to which the connection is to be established receives the slave station activation information from the base station control device. S14: The slave station to which the connection is to be established turns on its power. S15: The optical access control device receives connection information between the master station and the slave station from the base station control device. S16: The optical access control device instructs the optical switch to which the connection is to be established to connect the upper optical fiber network and the lower optical fiber network. S17: The instructed optical switch connects the upper optical fiber network and the lower optical fiber network. S18: The slave station to which the connection is to be established starts transmitting and receiving optical signals to the master station, thereby starting mobile communications.

[0034] 6, the optical access control device receives connection information between the master station device and the slave station device from the base station control device and accesses a database containing the following information: (1) Relationship between the master station device and the upper optical fiber network to which the master station device belongs (2) Relationship between the slave station device and the lower optical fiber network to which the slave station device belongs (3) Optical switches that connect / disconnect the upper optical fiber network to which the master station device belongs and the lower optical fiber network to which the slave station device belongs The optical access control device searches the database for an optical switch to be set up for connection, and instructs the optical switch to be set up for connection to connect the upper optical fiber network and the lower optical fiber network in S16.

[0035] The base station control device may access the database and transmit connection information of the optical switch for which connection is to be set up, instead of transmitting connection information between the master station device and the slave station device to the optical access control device in S12. In S15, the optical access control device receives the connection information of the optical switch for which connection is to be set up, and in S16, the optical access control device instructs the optical switch for which connection is to be set up to connect the upper optical fiber network and the lower optical fiber network.

[0036] The master station device 11 may be always activated, or may be activated after receiving "activating slave station information" from the base station control device 14 in S11. The same applies to the following embodiments.

[0037] 7 shows the termination flow of mobile communication. S21: The base station controller sets a disconnection between the master station device and the slave station device, and transmits slave station information to the master station device (not shown). S22: The base station controller transmits slave station device shutdown information to the slave station device for which the disconnection is to be set, and transmits disconnection information between the master station device and the slave station device to the optical access controller. S23: The slave station device for which the disconnection is to be set receives the slave station device shutdown information from the base station controller. S24: The slave station device for which the disconnection is to be set stops its power supply. S25: The optical access controller receives the disconnection information of the master station device and the slave station device from the base station controller. S26: The optical access controller instructs the optical switch for which the disconnection is to be set to disconnect to disconnect the upper optical fiber network from the lower optical fiber network. S27: The instructed optical switch disconnects the upper optical fiber network from the lower optical fiber network. S28: The slave station device for which the disconnection is to be set to disconnect stops transmitting and receiving optical signals to and from the master station device, and stops mobile communication. If the power supply of the slave station device is cut off first in S24, the slave station device will stop mobile communication first.

[0038] In S25 of FIG. 7, the optical access control device receives disconnection information about the parent station device and the child station device from the base station control device, accesses the database described above to search for the optical switch to be set for disconnection, and in S26 instructs the optical switch to be set for disconnection to disconnect the upper optical fiber network and the lower optical fiber network.

[0039] The base station control device may access the database and transmit disconnection information of the optical switch to be set for disconnection instead of transmitting disconnection information of the master station device and slave station device to the optical access control device in S22. In S25, the optical access control device receives the disconnection information of the optical switch to be set for disconnection, and in S26, the optical access control device instructs the optical switch to be set for disconnection to disconnect the upper optical fiber network and the lower optical fiber network.

[0040] The slave station equipment that has stopped mobile communication enters a sleep state, except for at least the slave station power control device, so that power consumption of the slave station equipment can be reduced.

[0041] Therefore, in the optical access system for mobile communications of this embodiment, it is possible to reduce the resources of the master station device while also reducing the power consumption of the slave station device, thereby realizing efficient use of optical fiber resources.

[0042] Second Embodiment FIG. 8 shows a configuration example of an optical access system for mobile communications according to the present disclosure. The optical access system for mobile communications of this embodiment includes a base station device 11 for a mobile base station, which has a baseband processing function corresponding to mobile communications and transmits and receives optical signals to and from a slave station device 12 via an upper optical fiber network 16; a plurality of slave station devices 12 for the mobile base station, which transmit and receive optical signals to and from the base station device 11 via one of a plurality of lower optical fiber networks 17, have a radio wave transmission and reception function corresponding to mobile communications, and are activated or deactivated depending on whether or not an optical signal from the base station device 11 is detected; a plurality of optical switches (optical SW) 13 that connect or disconnect the upper optical fiber network 16 and one of the plurality of lower optical fiber networks 17 in response to instructions from an optical access control device (optical AC control device) 15; a base station control device 14 that transmits information about the slave station device 12 to be activated or deactivated to the base station device 11, and transmits connection and disconnection information between the base station device 11 and the slave station devices 12 to the optical access control device 15; and the optical access control device 15 that remotely instructs the plurality of optical switches 13 to connect or disconnect the upper optical fiber network 16 and one of the plurality of lower optical fiber networks 17 in response to the connection and disconnection information from the base station control device 14.

[0043] An example of the configuration of a slave station equipment is shown in Figure 9. The slave station equipment 12 includes a transceiver unit with an optical transceiver that transmits and receives optical signals to and from the master station equipment 11, a slave station power control device that starts and stops the slave station equipment 12 in response to instructions from the master station equipment 11, a power supply that supplies power to each unit of the slave station equipment under the control of the slave station power control device, a modulation / demodulation circuit, etc. (not shown). The O / E converter and slave station power control device are constantly powered in order to receive optical signals from the master station equipment 11.

[0044] The slave station equipment 12 is activated or deactivated depending on whether or not an optical signal from the master station equipment 11 is detected. To this end, the master station equipment 11 transmits an optical signal with a wavelength different from that of the optical signal on which the main signal is superimposed, thereby activating the slave station equipment 12. The slave station equipment 12 uses a WDM coupler to separate the optical signal with a wavelength different from that of the optical signal on which the main signal is superimposed, and performs optical-to-electrical conversion with an O / E converter to extract a startup signal. When the O / E converter receives the startup signal, the slave station power supply control device causes the power supply to start supplying power to each unit of the slave station equipment. When the startup signal stops, the slave station power supply control device causes the power supply to stop supplying power to each unit of the slave station equipment.

[0045] Another example of the configuration of a slave station device is shown in Figure 10. The master station device 11 transmits an optical signal on which a main signal is superimposed, and activates the slave station device 12. The slave station device 12 uses an optical branching circuit to branch the optical signal on which the main signal is superimposed, and an O / E converter performs optical-to-electrical conversion to extract a start signal. When the O / E converter receives the start signal, the slave station power supply control device causes the power supply to start supplying power to each unit of the slave station device. When the start signal stops, the slave station power supply control device causes the power supply to stop supplying power to each unit of the slave station device.

[0046] 11 and 12 show the flow of the optical access system for mobile communications according to this embodiment shown in FIG. 8 . FIG. 11 shows the start flow of mobile communications. S31: The base station control device sets up a connection between the master station and the slave station, and transmits slave station information to the master station (not shown). S32: The base station control device transmits connection information between the master station and the slave station to the optical access control device. S33: The optical access control device receives connection information between the master station and the slave station from the base station control device. S34: The optical access control device instructs the optical switch that is to set up the connection to connect the upper optical fiber network and the lower optical fiber network. S35: The instructed optical switch connects the upper optical fiber network and the lower optical fiber network. S36: The slave station that is to be started up detects an optical signal from the master station. S37: The slave station that is to be started up turns on its power. S38: The slave station that is to be started up transmits and receives optical signals to and from the master station, and starts mobile communications.

[0047] 11, the optical access control device receives connection information between the master station device and the slave station device from the base station control device and accesses a database containing the following information: (1) Relationship between the master station device and the upper optical fiber network to which the master station device belongs (2) Relationship between the slave station device and the lower optical fiber network to which the slave station device belongs (3) Optical switch that connects / disconnects the upper optical fiber network to which the master station device belongs and the lower optical fiber network to which the slave station device belongs The optical access control device searches the database for an optical switch to be set up for connection, and instructs the optical switch to be set up for connection to connect the upper optical fiber network and the lower optical fiber network in S34.

[0048] The base station control device may access the database and transmit connection information of the optical switch for which connection is to be set up, instead of transmitting connection information between the master station device and the slave station device to the optical access control device in S32. In S33, the optical access control device receives the connection information of the optical switch for which connection is to be set up, and in S34, the optical access control device instructs the optical switch for which connection is to be set up to connect the upper optical fiber network and the lower optical fiber network.

[0049] 12 shows the flow of terminating mobile communications. S41: The base station controller sets disconnection between the master station device and the slave station device, and transmits information about the slave station to be stopped to the master station device (not shown). S42: The base station controller transmits information about disconnection between the master station device and the slave station device to the optical access controller. S43: The optical access controller receives information about disconnection between the master station device and the slave station device from the base station controller. S44: The optical access controller instructs the optical switch that is to be disconnected to disconnect the upper optical fiber network from the lower optical fiber network. S45: The instructed optical switch disconnects the upper optical fiber network from the lower optical fiber network. S46: The slave station device that is to be stopped does not detect an optical signal from the master station device. S47: The slave station device that is to be stopped turns off its power. S48: The slave station device that is to be stopped turns off its transmission and reception of optical signals with the master station device, and ends mobile communications. Note that if the power to the slave station device in S47 is turned off first, the slave station device will stop mobile communications first.

[0050] In S43 of FIG. 12, the optical access control device receives disconnection information about the parent station device and the child station device from the base station control device, accesses the database described above to search for an optical switch to be set for disconnection, and in S44 instructs the optical switch to be set for disconnection to disconnect the upper optical fiber network and the lower optical fiber network.

[0051] The base station control device may access the database and transmit disconnection information of the optical switch to be set for disconnection instead of transmitting disconnection information of the master station device and slave station device to the optical access control device in S42. In S43, the optical access control device receives the disconnection information of the optical switch to be set for disconnection, and in S44, the optical access control device instructs the optical switch to be set for disconnection to disconnect the upper optical fiber network and the lower optical fiber network.

[0052] The slave station equipment that has stopped mobile communication enters a sleep state, except for at least the slave station power control device, so that power consumption of the slave station equipment can be reduced.

[0053] Therefore, in the optical access system for mobile communications of this embodiment, it is possible to reduce the resources of the master station device while also reducing the power consumption of the slave station device, thereby realizing efficient use of optical fiber resources.

[0054] (Embodiment 3) An example of the configuration of an optical access system for mobile communications according to the present disclosure is shown in Figure 13. The optical access system for mobile communications according to this embodiment includes a base station device 11 for a mobile base station, which has a baseband processing function corresponding to mobile communications and transmits and receives optical signals to and from a local station device 12 via an upper optical fiber network 16, a plurality of local station devices 12 for a mobile base station, which transmit and receive optical signals to and from the base station device 11 via one of a plurality of lower optical fiber networks 17, have a radio wave transmission and reception function corresponding to mobile communications, and are activated and stopped according to instructions from a base station controller 14, a plurality of optical switches 13 that detect optical signals from the local station devices 12, notify an optical access controller 15 of detection or non-detection, and connect or disconnect the upper optical fiber network 16 and one of the plurality of lower optical fiber networks 17 according to instructions from the optical access controller 15, a base station controller 14 that transmits information about the local station devices 12 to be activated or stopped to the base station device 11, and remotely instructs the local station devices 12 to activate or stop. and an optical access control device 15 that monitors the detection of an optical signal from the slave station device 12 at the optical switch 13 and remotely instructs the multiple optical switches 13 to connect or disconnect to either the upper optical fiber network 16 or the multiple lower optical fiber networks 17 depending on whether or not an optical signal is detected.

[0055] The optical switch 13 may further detect an optical signal from the parent station device 11 and notify the optical access control device 15 of detection or non-detection. The optical access control device 15 may monitor the optical switch 13 for detection of both an optical signal from the child station device 12 and an optical signal from the parent station device 11, and may remotely instruct the optical switch 13 to connect the parent optical fiber network 16 to any one of the plurality of parent optical fiber networks 17, on the condition that both are detected.

[0056] The configuration of the slave station device 12 is the same as that of the first embodiment.

[0057] 14 and 15 show the flow of the optical access system for mobile communications according to this embodiment shown in FIG. 13 . FIG. 14 shows the start flow of mobile communications. S51: The base station control device sets up a connection between the master station device and the slave station device, and transmits slave station information to the master station device (not shown). S52: The base station control device transmits activation information to the slave station device. S53: The slave station device to be activated receives the activation information from the base station control device. S54: The slave station device to be activated activates its power supply and transmits an optical signal. S55: The optical switch to be connected detects an optical signal from the slave station device and transmits optical signal detection information to the optical access control device. S56: The optical access control device receives the optical signal detection information from the optical switch and instructs the optical switch that detected the optical signal to connect the upper optical fiber network and the lower optical fiber network. S57: The instructed optical switch connects the upper optical fiber network and the lower optical fiber network. S58: The slave station device to be activated transmits and receives an optical signal to and from the master station device, and starts mobile communications.

[0058] 15 shows the flow of terminating mobile communications. S61: The base station controller sets a disconnection between the master station and the slave station, and transmits slave station information to the master station (not shown). S62: The base station controller transmits shutdown information to the slave station. S63: The slave station that is being set to shutdown receives the shutdown information from the base station controller. S64: The slave station that is being set to shutdown shuts down its power supply and stops transmitting optical signals. S65: The optical switch that is being set to shutdown detects no optical signals from the slave station and transmits optical signal non-detection information to the optical access controller. S66: The optical access controller receives the optical signal non-detection information from the optical switch and instructs the optical switch that is not detecting an optical signal to disconnect the upper optical fiber network from the lower optical fiber network. S67: The instructed optical switch disconnects the upper optical fiber network from the lower optical fiber network. S68: The slave station that is being set to shutdown stops transmitting and receiving optical signals with the master station and terminates mobile communications. If the power supply of the slave station device is cut off first in S64, the slave station device will stop mobile communication first.

[0059] The slave station equipment that has stopped mobile communication enters a sleep state, except for at least the slave station power control device, so that power consumption of the slave station equipment can be reduced.

[0060] Therefore, in the optical access system for mobile communications of this embodiment, it is possible to reduce the resources of the master station device while also reducing the power consumption of the slave station device, thereby realizing efficient use of optical fiber resources.

[0061] (Embodiment 4) An example configuration of an optical access system for mobile communications according to the present disclosure is shown in Fig. 16. The optical access system for mobile communications according to the present embodiment comprises: a base station device 11 for a mobile base station, which has a baseband processing function corresponding to mobile communications and transmits and receives optical signals to and from local station devices 12 via an upper optical fiber network 16; a plurality of local station devices 12 for the mobile base station, which transmit and receive optical signals to and from the base station device 11 via one of a plurality of lower optical fiber networks 17, have a radio wave transmission and reception function corresponding to mobile communications, and are activated and deactivated in response to instructions from a base station controller 14; a plurality of optical switches 13 that detect optical signals from the local station devices 12 and connect or disconnect the upper optical fiber network 16 to one of the plurality of lower optical fiber networks 17 depending on whether or not an optical signal from the local station device is detected; and a base station controller 14 that transmits information about the local station devices 12 to be activated or deactivated to the base station device 11 and remotely instructs the local station devices to activate or deactivate.

[0062] The optical switch 13 may further detect an optical signal from the parent station device 11, monitor both the detection of an optical signal from the child station device 12 and the detection of an optical signal from the parent station device 11, and, upon detection of both, connect the upper optical fiber network 16 to any one of the plurality of lower optical fiber networks 17.

[0063] The configuration of the slave station device 12 is the same as that of the first embodiment.

[0064] The flow of the optical access system for mobile communications of this embodiment shown in Figure 16 is shown in Figures 17 and 18. Figure 16 shows the start flow of mobile communications. S71: The base station control device sets up a connection between the master station device and the slave station device, and transmits slave station information to the master station device (not shown) to activate the slave station device. S72: The base station control device transmits activation information to the slave station device. S73: The slave station device to be activated receives the activation information from the base station control device. S74: The slave station device to be activated activates its power supply and transmits an optical signal. S75: The optical switch to be connected detects an optical signal from the slave station device. S76: The optical switch that detected the optical signal from the slave station device connects the upper optical fiber network and the lower optical fiber network. S77: The slave station device to be activated transmits and receives an optical signal to and from the master station device, and starts mobile communications.

[0065] 15 shows the flow of terminating mobile communications. S71: The base station controller disconnects the master station and slave station devices, and transmits slave station information to the master station (not shown). S82: The base station controller transmits shutdown information to the slave station devices. S83: The slave station device that is being shut down receives the shutdown information from the base station controller. S84: The slave station device that is being shut down shuts down its power supply and stops transmitting optical signals. S85: The optical switch that is being shut down detects no optical signals from the slave station device. S86: The optical switch that no longer detects optical signals from the slave station device disconnects the upper optical fiber network from the lower optical fiber network. S87: The slave station device that is being shut down stops transmitting and receiving optical signals with the master station, and terminates mobile communications. Note that if the power supply to the slave station device in S84 is shut down first, the slave station device will shut down its mobile communications first.

[0066] The slave station equipment that has stopped mobile communication enters a sleep state, except for at least the slave station power control device, so that power consumption of the slave station equipment can be reduced.

[0067] Therefore, in the optical access system for mobile communications of this embodiment, it is possible to reduce the resources of the master station device while also reducing the power consumption of the slave station device, thereby realizing efficient use of optical fiber resources.

[0068] As described above, according to the present disclosure, it is possible to provide an optical access system for mobile communications that reduces the resources of the master station device while reducing the power consumption of the slave station device, thereby realizing efficient use of optical fiber resources.

[0069] The optical access system for mobile communications of the present disclosure can be applied to the information and communications industry.

[0070] 11: Master station equipment 12: Slave station equipment 13: Optical switch (optical SW) 14: Base station control device 15: Optical access control device (optical AC control device) 16: Upper optical fiber network 17: Lower optical fiber network

Claims

1. An optical access system for mobile communications comprising: a mobile base station having a baseband processing function corresponding to mobile communications and transmitting and receiving optical signals via an upper optical fiber network; a plurality of mobile base station devices that transmit and receive the optical signals to and from the mobile base station via one of a plurality of lower optical fiber networks, have a radio wave transmission and reception function corresponding to mobile communications, and are activated and stopped in response to instructions; a plurality of optical switches that connect and disconnect the upper optical fiber network and one of the plurality of lower optical fiber networks in response to instructions; a base station controller that instructs the slave station devices to start and stop; and an optical access controller that instructs the plurality of optical switches to connect and disconnect the upper optical fiber network and one of the plurality of lower optical fiber networks in response to connection and disconnection information from the base station controller.

2. An optical access system for mobile communications comprising: a mobile base station having a baseband processing function corresponding to mobile communications and transmitting and receiving optical signals via an upper optical fiber network; a plurality of mobile base station devices that transmit and receive the optical signals to and from the mobile base station via one of a plurality of lower optical fiber networks, have a radio wave transmission and reception function corresponding to mobile communications, and are activated and deactivated depending on whether or not an optical signal is detected from the mobile base station; a plurality of optical switches that connect and disconnect the upper optical fiber network to one of the plurality of lower optical fiber networks in response to instructions; and an optical access control device that instructs the plurality of optical switches to connect and disconnect the upper optical fiber network to one of the plurality of lower optical fiber networks.

3. An optical access system for mobile communications comprising: a mobile base station master station having a baseband processing function corresponding to mobile communications and transmitting and receiving optical signals via an upper optical fiber network; a plurality of mobile base station slave stations which transmit and receive the optical signals to and from said master station station via one of a plurality of lower optical fiber networks, have a radio wave transmission and reception function corresponding to mobile communications, and are activated and stopped in response to instructions; a plurality of optical switches which detect optical signals from said slave station stations and connect or disconnect said upper optical fiber network to one of said plurality of lower optical fiber networks in response to instructions; a base station controller which instructs said slave station stations to activate or stop; and an optical access controller which monitors the detection of optical signals in said optical switches and instructs said plurality of optical switches to connect or disconnect said upper optical fiber network to one of said plurality of lower optical fiber networks depending on whether or not an optical signal is detected.

4. An optical access system for mobile communications comprising: a mobile base station having a baseband processing function corresponding to mobile communications and transmitting and receiving optical signals via an upper optical fiber network; a plurality of mobile base station devices transmitting and receiving the optical signals to and from said mobile base station via one of a plurality of lower optical fiber networks, having a radio wave transmitting and receiving function corresponding to mobile communications, and being activated and stopped in response to instructions; a plurality of optical switches connecting and disconnecting said upper optical fiber network and one of said plurality of lower optical fiber networks depending on whether an optical signal is detected from said mobile station devices; and a base station control device giving instructions to said mobile station devices to start and stop.

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