Communication device, control method thereof, and program

Abstract

To allow more efficient use of a time division duplex (TDD) communication system.SOLUTION: A communication device operating as a base station in a TDD communication system comprises: communication means that performs communication by using a TDD pattern; storage means that stores a plurality of TDD patterns; determination means that determines the TDD pattern used by the communication means; and acquisition means that acquires the type of a network slice used by a terminal connected to the base station. The plurality of TDD patterns include a synchronous TDD pattern matching a TDD pattern used by a predetermined base station, and a sub-synchronous TDD pattern obtained by replacing the timing of at least one downlink included in the synchronous TDD pattern with the timing of an uplink. The determination means determines the TDD pattern based on the type acquired by the acquisition means and the plurality of TDD patterns.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to the operation of a base station in a time division duplex (TDD) communications system. [Background technology]

[0002] Base stations (carrier network base stations) in time division duplex (TDD) communication systems built by public telecommunications carriers (carriers) synchronize and operate the TDD patterns of each base station to prevent interference with neighboring base stations. A TDD pattern is a pattern that specifies the uplink / downlink timing within the TDD slots operated by each base station.

[0003] Meanwhile, in recent years, efforts are being made to institutionalize local 5G and regional BWA (Broadband Wireless Access) systems that enable operators other than public carriers to build and operate cellular communication networks. However, base stations installed by operators other than carriers (local network base stations) may implement communication patterns that differ from those of carrier network base stations, which primarily focus on high-speed downlink communication, such as low-latency communication and high-speed uplink communication. In such cases, the TDD UL / DL patterns between local network base stations and carrier network base stations will not match. Therefore, when geographically adjacent carrier network base stations and local network base stations operate in adjacent frequency bands, the mismatch in TDD patterns may cause interference and degrade performance.

[0004] Therefore, the introduction of a quasi-synchronous TDD pattern to prevent interference between carrier network base stations and adjacent local network base stations is being considered (Patent Document 1). A quasi-synchronous TDD pattern is one in which some downlink subframes in the TDD pattern of a specific base station (synchronized base station) in synchronous operation are replaced with uplink subframes (Fig. 1). Fig. 1 shows the types of multiple subframes (slots) included in one radio frame. "D" indicates downlink (from base station to terminal), "U" indicates uplink (from terminal to base station), and "S" indicates a special slot that includes a switching period from D to U. When a local network base station uses such a quasi-synchronous TDD pattern, it is possible to at least prevent the local network base station from interfering with the carrier network base station. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-188388 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above study of quasi-synchronous TDD patterns assumes that synchronized base stations in a carrier network use fixed TDD patterns, and does not consider cases where synchronized base stations change their TDD patterns. Furthermore, if a synchronized base station changes its TDD pattern, interference will occur with other base stations that did not occur during synchronous operation. Therefore, there is a problem in that it is difficult for a synchronized base station to change its TDD pattern.

[0007] The present invention has been made in view of the above problems, and aims to provide a technique that enables more efficient operation of a TDD communication system. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, a communication device according to the present invention has the following configuration: That is, a communication device operating as a base station in a time division duplex (TDD) communication system, A communication means for communicating using a TDD pattern that defines downlink / uplink timing; a storage means for storing a plurality of TDD patterns; determining means for determining a TDD pattern to be used by said communication means; The base station uses Should An acquisition means for acquiring a type of network slice; Equipped with the plurality of TDD patterns include a synchronous TDD pattern that matches a TDD pattern used by a predetermined base station, and a quasi-synchronous TDD pattern in which at least one downlink timing included in the synchronous TDD pattern is replaced with an uplink timing; The determining means determines a TDD pattern to be used by the communication means based on the type acquired by the acquiring means and the plurality of TDD patterns. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a technique that enables more efficient operation of a TDD communication system. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a quasi-synchronous TDD pattern. [Figure 2] FIG. 2 is a block diagram showing the hardware configuration of a base station device. [Figure 3] FIG. 2 is a block diagram showing software functions of the base station device in the first embodiment. [Figure 4] FIG. 10 is a diagram illustrating an example of a TDD pattern correspondence table. [Figure 5] FIG. 10 is a diagram illustrating an example of a terminal list. [Figure 6] FIG. 1 is a diagram illustrating an overall configuration of a network in a first embodiment. [Figure 7] 4 is an operational flowchart of a TDD pattern setting process in the first embodiment. [Figure 8] FIG. 3 is a diagram showing an operation sequence in the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating an example of determining an operational TDD pattern. [Figure 10] FIG. 11 is a block diagram showing software functions of a base station device in a second embodiment. [Figure 11] FIG. 10 is a diagram showing the overall configuration of a network in a second embodiment. [Figure 12] 10 is an operational flowchart of a TDD pattern setting process in the second embodiment. [Figure 13] FIG. 10 is a diagram showing an operation sequence in the second embodiment. [Figure 14] FIG. 1 is a diagram showing a plurality of TDD patterns that serve as operational TDD patterns. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0012] (First embodiment) A first embodiment of the device according to the present invention will be described below by taking as an example a base station device, which is a communication device that operates as a base station in a time division duplex communication system (TDD communication system).

[0013] <Device configuration and system configuration> 2 is a block diagram showing the hardware configuration of the base station device 201. The base station device 201 includes a control unit 202, a storage unit 203, a wireless communication unit 204, and an antenna control unit 205.

[0014] The control unit 202 controls the entire device by executing a control program stored in the storage unit 203. The storage unit 203 stores the control program executed by the control unit 202 and various information (a plurality of given TDD patterns available for use, connected terminal information, network slice information, etc.). The various operations described below are performed by the control unit 202 executing the control program stored in the storage unit 203.

[0015] The wireless communication unit 204 performs cellular network communication such as LTE or 5G that conforms to the 3GPP (3rd Generation Partnership Project) standard. The antenna control unit 205 controls an antenna for wireless communication performed by the wireless communication unit 204.

[0016] 3 is a block diagram showing software functions of the base station device in the first embodiment. The communication device functions 301 include a signal receiving unit 302, a signal transmitting unit 303, a data storage unit 304, a connection control unit 305, a network slice control unit 306, and a TDD pattern determination unit 307.

[0017] The signal receiving unit 302 and the signal transmitting unit 303 perform cellular network communication such as LTE or 5G compliant with the 3GPP standard with the terminal device. The data storage unit 304 stores and holds software programs and information such as a TDD pattern correspondence table and a terminal list, which will be described later.

[0018] 4 is a diagram showing an example of a TDD pattern correspondence table. The TDD pattern correspondence table is stored in the data storage unit 304. The TDD pattern correspondence table shows correspondence between service type values ​​corresponding to each of multiple network slice service types available in the base station and associated TDD patterns.

[0019] FIG. 5 is a diagram showing an example of a terminal list. The terminal list is stored in the data storage unit 304. The terminal list associates identification information of a terminal currently connected to a base station with the service type value of the network slice used by the terminal. Here, IMSI (International Mobile Subscriber Identity) is used as information for identifying a terminal within the network. IMSI is a number stored in a SIM (Subscriber Identity Module) for identifying a subscriber. However, other information may be used as long as it can uniquely identify a terminal.

[0020] The connection control unit 305 performs processing related to connection and disconnection of the terminal to the cellular network, such as RRC (Radio Resource Control) message communication, which is performed between the terminal and the core network function.

[0021] The network slice control unit 306 manages information about the network slice used by a terminal connected to a base station using the terminal list (FIG. 5) stored in the data storage unit 304. For example, when a terminal connects to a base station, the network slice control unit 306, upon receiving a connection notification from the connection control unit 305, registers the identification information of the connected terminal and the service type value of the network slice used by the connected terminal in the terminal list. In addition, when the connected terminal disconnects from the base station, the network slice control unit 306, upon receiving a disconnection notification from the connection control unit 305, deletes information about the disconnected connected terminal from the terminal list.

[0022] When a terminal is connected, the TDD pattern determination section 307 determines an operating TDD pattern in a TDD pattern setting process described later, and notifies the connection control section of the terminal of the determined TDD pattern.

[0023] 6 is a diagram showing the overall configuration of a network in the first embodiment. In this embodiment, a base station 602 is arranged in the service area (communication range) of a carrier network 601 as equipment constituting the carrier network 601. Furthermore, the service area of ​​a local network 603 exists within the communication range of the carrier network 601. In the service area of ​​the local network 603, a base station 604 is arranged as equipment constituting the local network 603. A terminal 605 is a terminal that can connect to the carrier network 602 to communicate, and possesses subscriber information (IMSI) required for connecting to the carrier network 602.

[0024] The carrier network 603 can use the slice service type services shown in Fig. 4. The base station 602 stores a TDD pattern correspondence table (Fig. 4) in the data storage unit 304. It is also assumed that when the terminal 605 connects to the carrier network 602, it will use the highly reliable, low latency communication (URLLC) service (service type value is "2") that uses a quasi-synchronous TDD pattern.

[0025] It is assumed that the carrier network 601 established by the base station 602 and the local network 603 established by the base station 604 operate in adjacent frequency bands. For example, the carrier network 601 uses radio waves in the 4.5 GHz band, and the local network 603 uses radio waves in the 4.6 GHz band.

[0026] <Device Operation> 7 is an operational flowchart of the TDD pattern setting process in the first embodiment. The TDD pattern setting process is performed by the base station 602, and is started by the connection control unit 305 when the terminal connects to the base station 602. The TDD pattern setting process is realized by the control unit 202 reading and executing a computer program stored in the storage unit 203.

[0027] In S701, the connection control unit 305 refers to the terminal list and the TDD pattern correspondence table stored in the data storage unit 304, and checks whether or not there is a terminal using a slice service that uses a quasi-synchronous TDD pattern.

[0028] If there is a terminal using a slice service that uses a quasi-synchronous TDD pattern (Yes in S701), the connection control unit 305 ends the processing, and the base station continues operation using the quasi-synchronous TDD pattern. On the other hand, if there is no terminal using a slice service that uses a quasi-synchronous TDD pattern (No in S701), the connection control unit 305 instructs the TDD pattern determination unit 307 to determine an operating TDD pattern. Note that when instructing the TDD pattern determination unit 307, the connection control unit 305 also notifies the TDD pattern determination unit 307 of the service type value used by the connected terminal. Note that the connection control unit 305 acquires the service type value used by the connected terminal by referencing the NSSAI value in the RRC Connection Complete message received from the terminal when the terminal is connected. The NSSAI is network slice selection auxiliary information.

[0029] In S702, upon receiving an instruction from the connection control unit 305, the TDD pattern determination unit 307 checks the TDD pattern of the network slice used by the connecting terminal. Specifically, the TDD pattern determination unit 307 checks the TDD pattern of the network slice used by the connecting terminal by referring to the TDD pattern correspondence table based on the service type value notified from the connection control unit 305. If the TDD pattern of the network slice is a quasi-synchronous TDD pattern, proceed to S703, and if the TDD pattern of the network slice is a synchronous TDD pattern, proceed to S704.

[0030] In S703, TDD pattern determination section 307 determines the operating TDD pattern to be a "quasi-synchronous TDD pattern" and notifies connection control section 305 of the result. On the other hand, in S704, TDD pattern determination section 307 determines the operating TDD pattern to be a "synchronous TDD pattern" and notifies connection control section 305 of the result.

[0031] In S705, upon receiving notification from TDD pattern determination unit 307, connection control unit 305 sets the determined operating TDD pattern in wireless communication unit 204 (signal transmission unit 302, signal reception unit 303). After notifying the currently connected terminal of the set TDD pattern, wireless communication unit 204 changes its operation to the set TDD pattern.

[0032] In S706, the connection control unit 305 transmits a connection notification to the network slice control unit 306 and updates the contents of the terminal list, and then ends the process.

[0033] 8 is a diagram showing an operation sequence in the first embodiment. Specifically, it shows a sequence of processing operations performed when a terminal 605 currently connected to a carrier network 601 connects to a base station 602.

[0034] The terminal 605 establishes an RRC connection with the base station 602 (F801). After that, the terminal 605 transmits an RRC Connection Complete message including a service type value (e.g., NSSAI) of the network slice to be used to the base station 602 (F802).

[0035] Upon receiving the message, the base station 602 starts the TDD pattern setting process (FIG. 7). Here, because the terminal 605 uses the URLLC service (service type value is "2"), the base station 602 determines the operating TDD pattern to be the "quasi-synchronous TDD pattern" (F803).

[0036] The base station 602 notifies the terminal 605 of the determined TDD pattern (F804). After that, the base station 602 switches the operating TDD pattern to the "quasi-synchronous TDD pattern" (F805).

[0037] Through the above procedure, the base station 602 can change the TDD pattern to a "synchronous TDD pattern" or a "quasi-synchronous TDD pattern" depending on the network slice used by the terminal 605. This allows the base station 602 to use a TDD pattern suitable for its service without interfering with other base stations.

[0038] In this embodiment, the terminal 605 uses URLLC as a slice service, but the "quasi-synchronous TDD pattern" may be set when using other slice services. For example, a "high-speed uplink service" that provides a higher uplink speed than the high-speed, large-capacity (eMBB) slice service may be defined, and the "quasi-synchronous TDD pattern" may be set when using this service.

[0039] In the TDD pattern setting process (FIG. 7), the base station has been described as setting the operating TDD pattern to either a "synchronous TDD pattern" or a "quasi-synchronous TDD pattern." However, a TDD pattern other than the above may also be set. For example, the base station may determine another operating TDD pattern based on the synchronous TDD pattern and the quasi-synchronous TDD pattern.

[0040] Figure 9 shows an example of how an operating TDD pattern is determined. First, the base station defines the section with the same subframe type between the stored "synchronous TDD pattern" and "quasi-synchronous TDD pattern" as a "synchronous section," and defines the section with a different subframe type as an "asynchronous section." The base station then arbitrarily sets the subframe type of the "asynchronous section" as the operating TDD pattern.

[0041] By using the operating TDD pattern set as described above, a synchronized base station can use a TDD pattern suitable for the service while avoiding interference with other synchronized base stations and avoiding interference from quasi-synchronized base stations.

[0042] As described above, according to the first embodiment, a synchronized base station changes the operating TDD pattern depending on the network slice used by a terminal. By setting the operating TDD pattern based on the synchronous TDD pattern and the quasi-synchronous TDD pattern, a synchronized base station can use a more efficient TDD pattern without interfering with other synchronized base stations and without being interfered with by quasi-synchronous base stations.

[0043] (Second embodiment) In the first embodiment, a case has been described in which the base station 602 of the carrier network switches the TDD pattern depending on the network slice used by the connected terminal 605. However, when the base station 602 switches the TDD pattern for operation, it is conceivable that the base station 604 of the local network also switches the TDD pattern for operation. In such a case, depending on the selected TDD pattern, the base station 604 may cause interference to the base station 602.

[0044] For example, consider the case where base station 602 has set the quasi-synchronous TDD pattern shown in Figure 1, and base station 604 has selected the synchronous TDD pattern shown in Figure 1. In this case, in the TDD pattern of base station 602, slots with subframe numbers 8, 9, 18, and 19 are "U" frames. In contrast, the corresponding slots in base station 604 are set to "D" frames. If communication is performed in this state, there is a possibility that radio waves from base station 604 will cause interference to base station 602 in these slots.

[0045] The base station 604 of the local network is to implement measures independently at the base station 604 so as not to cause interference to the base station 602 of the carrier network. Therefore, in the second embodiment, a mode will be described in which the base station 604 of the local network sets a TDD pattern so as not to cause interference to the base station 602 of the carrier network.

[0046] <Device configuration and system configuration> The block diagram of the hardware configuration of the local base station 604 is the same as the block diagram shown in Figure 2, so detailed description will be omitted. In addition to the description of Figure 2, the antenna control unit 205 of this embodiment is configured to be able to communicate with other base stations operating in a frequency band adjacent to the frequency band of the cell established by the local base station. Accordingly, the antenna is also configured to be able to communicate in an adjacent frequency band. Note that a single RF circuit may be configured to cover both the frequency band of the local base station and the adjacent frequency band, or an RF circuit may be provided for each frequency band.

[0047] Fig. 10 is a block diagram showing software functions of a base station device in the first embodiment. The communication device function 1001 includes a signal receiving unit 1002, a signal transmitting unit 1003, a data storage unit 1004, a connection control unit 1005, a network slice control unit 1006, a TDD pattern determination unit 1007, and a TDD pattern acquisition unit 1008. The signal receiving unit 1002 to the TDD pattern determination unit 1007 are equivalent blocks to the signal receiving unit 302 to the TDD pattern determination unit 307 shown in Fig. 3, and therefore a description thereof will be omitted. The TDD pattern acquisition unit 1008 acquires the TDD pattern of a neighboring base station. More specifically, it performs an acquisition process of "TDD patterns of other base stations operating in neighboring frequency bands" used to determine a TDD pattern in the TDD pattern determination unit 1007. Details of the acquisition process will be described later with reference to Figs. 12 and 13.

[0048] 11 is a diagram showing the overall configuration of a network in the second embodiment. In this embodiment, in addition to the configuration in FIG. 6, a terminal 1101 that connects to the local network 603 and performs communication is included. The terminal 1101 possesses subscriber information (IMSI) required for connecting to the local network 603.

[0049] In this embodiment, the local network 603 can also use the slice service type services shown in Fig. 4, and the base station 604 of the local network 603 stores the TDD pattern correspondence table of Fig. 4 in the data storage unit 304. Note that the TDD pattern does not need to be the same slice service type as that of the carrier network 601. The local network 603 may use its own slice service type, but in the following explanation, the slice service type of Fig. 4 will be used for simplicity.

[0050] In this embodiment, the TDD pattern shown in the "TDD pattern" section of Figure 4 is a "preferred TDD pattern" that has priority for use. If the "preferred TDD pattern" is determined to be unavailable as a result of the TDD pattern determination process described below, another TDD pattern will be used. Details will be described later with reference to Figure 12.

[0051] Furthermore, it is assumed that the terminal 1101 uses the eMBB service (service type value is "1") that uses a quasi-synchronous TDD pattern when connected to the local network 602. Note that the synchronous TDD pattern and quasi-synchronous TDD pattern used in this embodiment are those shown in Figs. 1 and 9.

[0052] <Device Operation> 12 is an operational flowchart of the TDD pattern setting process in the second embodiment. The TDD pattern setting process is performed by the base station 604 of the local network 603, and is started by the connection control unit 305 when the terminal connects to the base station 604. The TDD pattern setting process is realized by the control unit 202 reading and executing a computer program stored in the storage unit 203.

[0053] After processing starts, connection control section 1005 instructs TDD pattern determination section 1007 to determine an operating TDD pattern. When instructing TDD pattern determination section 1007, connection control section 1005 also notifies TDD pattern determination section 1007 of the service type value used by the connected terminal. Connection control section 1005 also acquires the service type value used by the connected terminal by referencing the NSSAI value in the RRC Connection Complete message received from the terminal when the terminal is connected.

[0054] In S1201, the TDD pattern determination unit 1007 confirms the TDD pattern of the network slice used by the connecting terminal after receiving an instruction from the connection control unit 1005. Specifically, the TDD pattern determination unit 1007 confirms the TDD pattern of the network slice used by the connecting terminal by referring to the TDD pattern correspondence table based on the service type value notified from the connection control unit 1005.

[0055] In S1202, TDD pattern determination unit 1007 instructs TDD pattern acquisition unit 1008 to acquire the TDD pattern of a base station operating in an adjacent frequency band. After receiving the instruction from TDD pattern determination unit 1007, TDD pattern acquisition unit 1008 first performs processing to determine whether or not a base station operating in an adjacent frequency band exists. If a base station operating in an adjacent frequency band exists, the process proceeds to S1203. If no base station operating in an adjacent frequency band exists, the process proceeds to S1206.

[0056] Whether or not there is another base station operating in an adjacent frequency band is determined by whether or not a signal broadcast by another base station is received in an adjacent frequency band to the frequency band of the cell established by the base station itself. Whether or not there is another base station in an adjacent frequency band is not limited to this. Information may be obtained via a device on the network side, or by requesting the connected terminal to collect and notify information about adjacent base stations.

[0057] Here, the adjacent frequency band is an adjacent frequency band in which the base station itself may cause interference to other base stations, and whether or not a frequency band causes interference is stored in advance as a specified frequency band in a storage unit. Alternatively, radio waves from other base stations may be received, and the degree of interference may be calculated based on the radio wave strength of the own device, and if it is determined that the frequency band causes interference, the corresponding frequency band may be included in the adjacent frequency bands.

[0058] Furthermore, a determination may be made as to whether or not a base station operating in an adjacent frequency band is a carrier network. If it is a carrier network, it is determined that a base station operating in an adjacent frequency band exists. If it is not a carrier network, it is determined that no base station operating in an adjacent frequency band exists. Whether or not it is a carrier network is determined by receiving a broadcast signal transmitted from another base station and using a PLMNID (Public Land Mobile Network Identifier) ​​included in the broadcast signal. However, the method of determining whether or not it is a carrier network is not limited to this.

[0059] In S1203, the TDD pattern acquisition unit 1008 performs a process to acquire the TDD pattern of another base station operating in an adjacent frequency band. For example, the TDD pattern can be acquired from information included in an SIB (System Information Block) broadcast by another base station operating in an adjacent frequency band. There are several types of SIBs, and the TDD pattern can be acquired from an information element called "TDD UL / DL Configuration" included in SIB1 (System Information Block Type 1). However, the method for acquiring the TDD pattern is not limited to this. The information can be acquired via a device on the network side, or by requesting the connected terminal to collect and notify information about adjacent base stations. Alternatively, a signal for exchanging TDD patterns between base stations can be defined, and the TDD pattern can be acquired based on this signal.

[0060] In this embodiment, it is assumed that TDD pattern acquisition unit 1008 acquires the TDD pattern of base station 602 of the carrier network. TDD pattern acquisition unit 1008 sends the acquired TDD pattern to TDD pattern determination unit 1007. After receiving the TDD pattern from TDD pattern acquisition unit 1008, TDD pattern determination unit 1007 proceeds to S1204. Note that if a TDD pattern cannot be acquired, TDD pattern determination unit 1007 may determine not to use a TDD pattern that may cause interference to the carrier network, but to use another TDD pattern.

[0061] In S1204, TDD pattern determination unit 1007 determines whether a preferred TDD pattern is available for the slice service used by the connected terminal. Whether a preferred TDD pattern is available is determined based on the TDD patterns of base stations in adjacent frequency bands collected in S1203 and the TDD pattern correspondence table (FIG. 4). If it is determined that the preferred TDD pattern is available, proceed to S1026. If it is determined that the preferred TDD pattern is unavailable, proceed to S1205.

[0062] For example, in this embodiment, the access terminal 1101 uses the eMBB service (service type value is "1") and tentatively selects the "synchronous TDD pattern," which is the preferred TDD pattern. In contrast, the TDD pattern of the base station in the adjacent frequency band is the TDD pattern of the base station 602 in the carrier network, which is the "quasi-synchronous TDD pattern." In this case, if the base station 604 in the local network selects the "synchronous TDD pattern," which is the preferred TDD pattern, interference will occur in the subframes in the asynchronous interval with the base station 602 in the carrier network. Therefore, the TDD pattern determination unit 1007 determines that the preferred TDD pattern cannot be used in the base station 604 in the local network. In contrast, if the TDD pattern of the base station in the adjacent frequency band is the "synchronous TDD pattern," it is determined that the synchronous TDD pattern, which is the preferred TDD pattern, can be used.

[0063] As another example, the case where the access terminal 1101 uses an uplink high-speed service (service type value is "101") will be described. First, the "quasi-synchronous TDD pattern," which is the preferred TDD pattern for the uplink high-speed service, is tentatively selected. In this case, regardless of whether the TDD pattern of the carrier network, which is a base station in an adjacent frequency band, is a "synchronous TDD pattern" or a "quasi-synchronous TDD pattern," when the base station 604 uses the quasi-synchronous TDD pattern, it will not cause interference to the base station 602. Therefore, the TDD pattern determination unit 1007 determines that the "quasi-synchronous TDD pattern," which is the preferred TDD pattern, is available for the base station 604 of the local network.

[0064] As mentioned above, there are cases where it is known that the preferred TDD pattern of the service type value of the connecting terminal will not cause interference (independent of the TDD pattern of a base station operating in an adjacent frequency band). In such cases, the process of acquiring a TDD pattern operating in an adjacent frequency band (S1202 to S1203) may be skipped and the preferred TDD pattern may be determined to be usable. An example of a case where it is known that there will be no interference is when a TDD pattern in which all asynchronous sections are "U" is used.

[0065] In S1205, the TDD pattern determination unit 1007 determines that a "TDD pattern other than the preferred TDD pattern" will be used as the operating TDD pattern for the base station 604. In this embodiment, a "quasi-synchronous TDD pattern" is determined to be used as the other TDD pattern. Note that although this embodiment describes a case where there is one synchronous TDD pattern and one quasi-synchronous TDD pattern, this is not limiting. In other words, there may be multiple synchronous TDD patterns and / or multiple quasi-synchronous TDD patterns. In such a case, in S1205, a TDD pattern that does not interfere with the TDD patterns of base stations operating in adjacent frequency bands is selected. Once the TDD pattern is determined in S1205, the process proceeds to S1207.

[0066] In S1206, the TDD pattern determination unit 1007 determines to use the "preferred TDD pattern" as the operating TDD pattern of the own base station, and notifies the connection control unit 305 of the result.

[0067] In S1207, upon receiving notification from TDD pattern determination unit 1007, connection control unit 1005 sets the determined operating TDD pattern in wireless communication unit 204 (signal transmission unit 1002, signal reception unit 1003). After notifying the currently connected terminal of the set TDD pattern, wireless communication unit 204 changes its operation to the set TDD pattern.

[0068] In S1208, the connection control unit 1005 transmits a connection notification to the network slice control unit 306 and updates the contents of the terminal list, and then ends the process.

[0069] 13 is a diagram showing an operation sequence in the second embodiment. Specifically, it shows a sequence of processing operations performed when a terminal 1101 connecting to a local network connects to a base station 604 of the local network.

[0070] The terminal 1101 establishes an RRC connection with the base station 604 (F1301). After that, the terminal 1101 transmits an RRC Connection Complete message including a service type value (e.g., NSSAI) of the network slice to be used to the base station 604 (F1302).

[0071] The base station 604 that received the message starts the TDD pattern setting process (FIG. 12). Here, the base station 604 acquires the service type value of the slice service (eMBB) used by the terminal 1101 and acquires the corresponding preferred TDD pattern (F1303). The base station 604 also performs a reception process for the SIB (F1304) broadcast by the base station 602.

[0072] The base station 604 compares the preferred TDD pattern for the slice service used by the terminal 1101 with the TDD pattern included in the SIB, and determines the operating TDD pattern to be the "quasi-synchronous TDD pattern" (F1305).

[0073] The base station 604 notifies the terminal 1101 of the determined TDD pattern (F1306). After that, the base station 604 switches the operating TDD pattern to the "quasi-synchronous TDD pattern" (F1307).

[0074] Through the above procedure, the base station 604 can change the TDD pattern to a "synchronous TDD pattern" or a "quasi-synchronous TDD pattern" depending on the network slice used by the terminal 605 and the TDD pattern being operated by the base station 602. This allows the base station 604 to use a TDD pattern suitable for the service without interfering with the carrier network base stations.

[0075] In this embodiment, the case where the terminal 1101 uses eMBB as a slice service has been described, but the "quasi-synchronous TDD pattern" may be set when using other slice services.

[0076] In addition, for simplicity of explanation, this embodiment has been described assuming that there is no currently connected terminal at the base station 604, but it can also be applied to a case where there is already a connected terminal, as in the first embodiment. In this case, the TDD pattern to be used is determined based on the slice service value of the currently connected terminal, the slice service value of the terminal to be newly connected, and the TDD pattern of the carrier network base station.

[0077] Furthermore, although the present embodiment has been described with reference to a case where there is one base station operating in an adjacent frequency band, the present invention is not limited to this. For example, the present invention can be applied to a case where there are multiple base stations operating in adjacent frequency bands. In this case, the TDD patterns of the multiple base stations are acquired, and a TDD pattern that does not interfere with each base station is determined.

[0078] Figure 14 shows multiple TDD patterns that can be used as operational TDD patterns. For example, suppose that the TDD pattern of a first carrier network base station is a "synchronous TDD pattern," and the TDD pattern of a second carrier network base station is "quasi-synchronous TDD pattern 1." Furthermore, suppose that there is also an available quasi-synchronous TDD pattern, "quasi-synchronous TDD pattern 2."

[0079] In this case, if a slice service that prioritizes downlink communication (such as the above-mentioned "high-speed uplink service") is specified in the access terminal, the local network base station is set to "quasi-synchronous TDD pattern 2" as the preferred TDD pattern. In this case, the preferred TDD pattern is used as the operating TDD pattern.

[0080] On the other hand, if a slice service that prioritizes downlink communication (such as the aforementioned "eMBB") is specified in the connecting terminal, the "synchronous TDD pattern" is set as the preferred TDD pattern in the local network base station. In this case, if the "synchronous TDD pattern" is selected as the operating TDD pattern, interference will occur in slots of subframe numbers 8 and 9 with the "quasi-synchronous TDD pattern 1" of the second carrier network base station. Therefore, in this case, the "synchronous TDD pattern" is used as the operating TDD pattern of the local network base station.

[0081] As in the first embodiment, the base station may set a TDD pattern in which the subframe type of the asynchronous interval is arbitrarily set as the operating TDD pattern. It may also be a TDD pattern that is not set in the storage unit 203. For example, a new quasi-synchronous TDD pattern that does not interfere with base stations operating in adjacent frequency bands may be generated and used as the operating TDD pattern.

[0082] As described above, according to the second embodiment, the local network base station changes the operating TDD pattern depending on the network slice used by the terminal. The local network base station sets the operating TDD pattern based on the network slice used by the connecting terminal and the TDD pattern currently being operated by the carrier network base station. This allows the local network base station to use a more efficient TDD pattern without interfering with the carrier network base station.

[0083] (Variation) In the above-described embodiment, the TDD pattern is determined by the base station device, but the present invention is not limited to this. The functions of the network slice control unit and the TDD pattern determination unit shown in Figures 3 and 10 may be provided in a control device that controls the base station device. The control device may then perform each determination process and control the base station device based on the determination results.

[0084] (Other Examples) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0085] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0086] 201 communication device; 202 control unit; 203 memory unit; 204 wireless communication unit; 205 antenna control unit; 301 communication device function; 302 signal transmission unit; 303 signal reception unit; 304 data storage unit; 305 connection control unit; 306 network slice control unit; 307 TDD pattern determination unit

Claims

1. 1. A communication device operating as a base station in a time division duplex (TDD) communication system, comprising: a communication means for communicating using a TDD pattern that defines uplink / downlink timing; a storage means for storing a plurality of TDD patterns; a determining means for determining a TDD pattern to be used by the communication means; An acquisition means for acquiring a type of network slice to be used by a terminal connected to the base station; Equipped with the plurality of TDD patterns include a synchronous TDD pattern that matches a TDD pattern used by a predetermined base station, and a quasi-synchronous TDD pattern in which at least one downlink timing included in the synchronous TDD pattern is replaced with an uplink timing; The determining means determines a TDD pattern to be used by the communication means based on the type acquired by the acquiring means and the plurality of TDD patterns. A communication device comprising:

2. The plurality of TDD patterns are associated with different network slice types.

2. The communication device according to claim 1.

3. The determining means selects the quasi-synchronous TDD pattern included in the plurality of TDD patterns when the type acquired by the acquiring means indicates highly reliable and low latency communication (URLLC).

3. The communication device according to claim 1 or 2.

4. The determining means selects the synchronous TDD pattern included in the plurality of TDD patterns when the type acquired by the acquiring means indicates high speed and large capacity (eMBB).

4. The communication device according to claim 1, wherein the communication device is a communication device.

5. The determining means determines a new TDD pattern obtained by arbitrarily changing the uplink and downlink in the asynchronous section where the synchronous TDD pattern and the quasi-synchronous TDD pattern do not match with the synchronous TDD pattern as the TDD pattern to be used by the communication means.

5. The communication device according to claim 1, wherein the communication device is a communication device.

6. the communication device operates as a base station operated by a public communication carrier; The predetermined base station is a base station operated by a public communication carrier.

6. The communication device according to claim 1, wherein the communication device is a communication device.

7. The communication device further includes a pattern acquisition means for acquiring a TDD pattern used by a second base station that establishes a cell in a second frequency band adjacent to the first frequency band of the cell established by the communication device, The determining means determines a TDD pattern to be used by the communication means based on the TDD pattern acquired by the pattern acquiring means.

3. The communication device according to claim 1 or 2.

8. The pattern acquisition means acquires the TDD pattern used by the second base station by receiving a notification signal broadcast by the second base station.

8. The communication device according to claim 7,

9. a determining means for determining whether the two designated TDD patterns cause interference in communication; the determining means, when the type acquired by the acquiring means indicates URLLC, tentatively selecting the quasi-synchronous TDD pattern included in the plurality of TDD patterns; the determining means determines whether or not the quasi-synchronous TDD pattern and the TDD pattern acquired by the pattern acquiring means cause interference in communication; The determining means determines the quasi-synchronous TDD pattern as the TDD pattern to be used by the communication means when the determining means determines that the quasi-synchronous TDD pattern will not cause interference.

9. The communication device according to claim 7 or 8.

10. a determining means for determining whether the two designated TDD patterns cause interference in communication; the determining means, when the type acquired by the acquiring means indicates eMBB, tentatively selecting the synchronous TDD pattern included in the plurality of TDD patterns; the determining means determines whether or not the synchronized TDD pattern and the TDD pattern acquired by the pattern acquiring means cause interference in communication; The determining means determines the synchronous TDD pattern as the TDD pattern to be used by the communication means when the determining means determines that the synchronous TDD pattern will not cause interference.

9. The communication device according to claim 7 or 8.

11. the communication device operates as a base station operated by a carrier other than a public communication carrier; The predetermined base station is a base station operated by a public communication carrier.

11. A communication device according to any one of claims 7 to 10.

12. A method for providing a communication device with base station functionality in a time division duplex (TDD) communication system, comprising: An acquisition step of acquiring a type of network slice to be used by a terminal connected to the communication device; a determining step of determining a TDD pattern to be used by the communication device for TDD communication based on the type acquired in the acquiring step and a plurality of given TDD patterns; Including, The plurality of TDD patterns include a synchronous TDD pattern that matches a TDD pattern used by a predetermined base station, and a quasi-synchronous TDD pattern in which at least one downlink timing included in the synchronous TDD pattern is replaced with an uplink timing. A method characterized by:

13. The plurality of TDD patterns are each associated with a different type of network slice.

13. The method of claim 12.

14. In the determining step, when the type acquired in the acquiring step indicates highly reliable and low latency communication (URLLC), the quasi-synchronous TDD pattern included in the plurality of TDD patterns is selected.

14. The method according to claim 12 or 13.

15. In the determining step, when the type acquired in the acquiring step indicates high speed large capacity (eMBB), the synchronous TDD pattern included in the plurality of TDD patterns is selected.

15. The method according to any one of claims 12 to 14.

16. In the determination step, a new TDD pattern obtained by arbitrarily changing the uplink and downlink in an asynchronous section where the synchronous TDD pattern does not match the quasi-synchronous TDD pattern is determined as the TDD pattern to be used by the communication device.

16. The method according to any one of claims 12 to 15.

17. The communication device operates as a base station operated by a public communication carrier; The predetermined base station is a base station operated by a public communication carrier.

17. The method according to any one of claims 12 to 16.

18. The method further includes a pattern acquisition step of acquiring a TDD pattern used by a second base station that establishes a cell in a second frequency band adjacent to the first frequency band of the cell established by the communication device; In the determining step, a TDD pattern to be used by the communication device is determined based on the TDD pattern acquired in the pattern acquiring step.

14. The method according to claim 12 or 13.

19. In the pattern acquisition step, a TDD pattern used by the second base station is acquired by receiving a notification signal transmitted by the second base station.

20. The method of claim 18.

20. The method further includes a determination step of determining whether the two designated TDD patterns cause interference in communication; In the determining step, when the type acquired in the acquiring step indicates URLLC, the quasi-synchronous TDD pattern included in the plurality of TDD patterns is tentatively selected; the determining step determines whether the quasi-synchronous TDD pattern and the TDD pattern acquired in the pattern acquiring step cause interference in communication; In the determining step, the quasi-synchronous TDD pattern is determined as the TDD pattern to be used by the communication device if it is determined in the determining step that the quasi-synchronous TDD pattern will not cause interference.

20. The method of claim 18 or 19.

21. The method further includes a determination step of determining whether the two designated TDD patterns cause interference in communication; In the determining step, when the type acquired in the acquiring step indicates eMBB, the synchronous TDD pattern included in the plurality of TDD patterns is tentatively selected; In the determining step, it is determined whether or not the synchronized TDD pattern and the TDD pattern acquired in the pattern acquiring step cause interference in communication; In the determining step, the synchronous TDD pattern is determined as the TDD pattern to be used by the communication device if it is determined in the determining step that the synchronous TDD pattern will not cause interference.

20. The method of claim 18 or 19.

22. The communication device operates as a base station operated by a carrier other than a public communication carrier; The predetermined base station is a base station operated by a public communication carrier.

22. The method according to any one of claims 18 to 21.

23. A program for causing a computer to execute the method according to any one of claims 12 to 22.

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