WO2022244373A1

WO2022244373A1 - Base station, communication control device, communication method, and communication control method

Info

Publication number: WO2022244373A1
Application number: PCT/JP2022/008484
Authority: WO
Inventors: 裕昭高野; 啓文葛西; 寛斗栗木; 隆志臼居; 智彰松村
Original assignee: ソニーグループ株式会社
Priority date: 2021-05-20
Filing date: 2022-03-01
Publication date: 2022-11-24

Abstract

[Problem] To realize high-quality communication between a base station and a communication device. [Solution] This base station comprises: a transmission unit for transmitting a request for use of a target beam, the request for use including identification information to identify the target beam; and a reception unit for receiving a response transmitted in response to the request for use, the response including information relating to whether the target beam can be used.

Description

BASE STATION, COMMUNICATION CONTROL DEVICE, COMMUNICATION METHOD, AND COMMUNICATION CONTROL METHOD

The present disclosure relates to base stations, communication control devices, communication methods, and communication control methods.

A service called local 5G or private 5G is known as a cellular communication service that is performed in limited areas such as factories, offices, studios, hospitals, and universities. This service is sometimes called a non-public network. By limiting the service area to a local area, there is an advantage that customized cellular service can be provided. As with many use cases, there may be important communications to protect within the local area. For example, in the case of a factory, there are devices that should not cause a communication failure due to the production line of the factory. In the case of hospitals, the communication used for surgery must not cause communication failure. In the case of a university, when classes are distributed online, the communication should be protected with priority over other communication. In this way, in communications in a local area, there is a use for wanting to protect specific very important communications.

Wi-Fi communication and communication based on standards such as 802.11a, b, g, n, and ac have been used for local area communication. Communication such as Wi-Fi has the advantage of good performance, but since the access point does not have a scheduler that adjusts resources among different users, LBT (Listen Before Talk) is a contention-based method based on carrier sense. In a way the traffic between users is multiplexed. User packets collide frequently. Therefore, when there are a plurality of users, there is a demand to use cellular communication even in local areas because cellular communication can maintain quality.

　5G base stations can perform beamforming. In beamforming, a desired beam is determined between a base station and a terminal by a procedure called beam management, and data is transmitted using that beam. In beamforming, interference control is performed so that beams provided by adjacent base stations do not interfere with each other. However, interference control may become difficult due to various factors such as the positional relationship between the base station and the terminal, the direction and beam width of the beam generated by the base station, and the like. Since very important communications exist in local area communications, communications that maintain quality are required even when beamforming is used.

The present disclosure provides a base station, a communication control device, a communication method, and a communication control method that realize high-quality communication between the base station and communication devices.

The base station of the present disclosure includes a transmission unit that transmits a request to use the target beam, including identification information that identifies the target beam, and information on whether or not to use the target beam, which is transmitted in response to the use request. and a receiving unit that receives a response including:

The communication control device of the present disclosure includes a receiving unit that receives a request to use the target beam, which includes identification information that identifies the target beam, and information about interference that each of the one or more beams gives to the first communication device, a controller for determining whether or not the target beam can be used based on corresponding data held in association with identification information for identifying the beam; and information about whether or not the target beam can be used based on the determination of the controller. and a transmission unit that transmits a response.

The communication method of the present disclosure transmits a request for using the target beam, which includes identification information for identifying the target beam, and transmits a response including information regarding whether or not to use the target beam, which is transmitted in response to the use request. receive.

The communication control method of the present disclosure receives a request to use the target beam, which includes identification information that identifies the target beam, and transmits information about interference each of the one or more beams gives to the first communication device. Use of the target beam is determined based on the corresponding data held in association with the identified identification information, and a response including information on whether the target beam can be used is transmitted based on the determination of the control unit.

FIG. 4 is a sequence diagram showing an example of beam management procedures; FIG. 4 is a diagram schematically showing beam sweeping performed in a beam management procedure; FIG. 4 is a diagram showing an example in which tilting between a base station and a terminal is large; FIG. 4 is a diagram showing an example in which tilting between a base station and a terminal is small; A diagram schematically showing the measurement of L1-SINR. Partial figure from 3GPP Rel16 38.214 Section 5.2.1. A diagram schematically showing the measurement of L1-SINR. An excerpt of the report configuration in Rel16 TS38.331 Section 6.3.2. Diagram extracting resource configuration from Rel16 TS38.331 Section 6.3.2. 1 is a diagram schematically showing an example of a communication system according to an embodiment of the present disclosure; FIG. 1 is a block diagram showing an example of a base station according to an embodiment of the present disclosure; FIG. 1 is a block diagram showing an example of a beam coordinator according to an embodiment of the present disclosure; FIG. FIG. 4 is a diagram showing an example of beam transmission from a start time specified by a base station in a beam request; FIG. 4 is a diagram showing an example in which a base station uses beams periodically; FIG. 4 is a diagram showing an example in which a base station uses a beam only once; FIG. 2 is a sequence diagram showing an example of overall procedures of the communication system according to the embodiment; 9 is a flowchart showing an example of operations of a beam coordinator and a plurality of base stations according to the second embodiment; 10 is a flow chart showing an example of operations of a beam coordinator and a plurality of base stations according to the third embodiment;

Embodiments of the present disclosure will be described below with reference to the drawings. In one or more of the embodiments presented in this disclosure, the elements included in each embodiment may be combined with each other and the combined result also forms part of the embodiments presented in this disclosure.

The technical background of this embodiment will be described below.
First, we will explain the beamforming performed in local 5G and its problems.

As explained in the background technology section, communication using beams (e.g., reference signals with directivity (e.g., CSI-RS)) can be achieved by performing a procedure called beam management between 5G base stations and terminals. can be done with the terminal. Hereinafter, the term "beam" may also mean a directional reference signal (e.g., CSI-RS) or simply a reference signal (e.g., CSI-RS). Additionally or alternatively, a beam (a directional reference signal) may refer to a directional SSB (SS/PBCH block) or simply SSB. SSB is an information block containing Synchronization Signal (Primary Synchronization Signal and Secondary Synchronization Signal) and Physical Broadcast Channel.

FIG. 1 is a sequence diagram showing an example of beam management procedures. FIG. 2 is a diagram schematically showing beam sweeping performed in a beam management procedure.

In FIG. 1, the base station 1000 sequentially transmits a plurality of beams by beam sweeping (S101), and receives a beam measurement result report (for example, a measurement report including a desired beam to be used) from the terminal 2000 (S102). ). The base station 1000 transmits a reference signal for communication quality measurement with the desired beam to the terminal 2000 (S103). The base station 1000 receives a report indicating beam channel quality (communication quality) from the terminal 2000 (S104). The base station 1000 determines parameters such as modulation scheme and coding scheme based on the channel quality, and transmits downlink data (user data) to the terminal 2000 using the determined beam (S105).

In outdoor public networks, beams provided by adjacent base stations with partially overlapping cells (coverage) are controlled so that they do not interfere with each other. In a public network, a base station is installed at a high position, and the angle (tilting) at which a terminal is looked down from the base station is large. Therefore, interference with adjacent cells can be controlled to be small.

FIG. 3 shows an example in which the tilting between the base station 1000A and the terminal 2000A and the tilting between the base station 1000B adjacent to the base station 1000A and the terminal 2000B are large.

On the other hand, in networks in local areas, it may not be possible to secure the installation height for the base station to be installed.

FIG. 4 shows an example in which the tilting between the base station 1000A and the terminal 2000A and the tilting between the base station 1000B adjacent to the base station 1000A and the terminal 2000B are small.

When the tilting is small as in Fig. 4, interference between adjacent cells may increase. For example, when a beam is used for communication between a base station and a terminal, not only the distance between the base station and the terminal but also the direction of the beam affects the amount of interference to the terminal. When a narrow beam width beam is used, the energy is not dispersed, so the signal of the beam may reach other distant terminals beyond the terminal. The direction of the beam, rather than the distance from the base station, has a greater bearing on whether or not interference occurs, making interference control difficult. Reducing interference by such beams is important.

Conventionally, in order to use different resources (frequency and time resources specified by frequency and time) between adjacent base stations, information on which resource to use was exchanged via the X2 (Xn) interface. Even with the same resources, if beams that do not cause interference are used, adjacent base stations can simultaneously use these beams to communicate with terminals in each cell. Therefore, beam coordination (beam adjustment) between base stations becomes important.

[Information that the base station acquires from the terminal, information on beams that the base station can acquire]
An example of information that the base station can obtain as a report from the terminal in beam sweeping (S101) shown in FIG. 1 is shown below. The base station can selectively obtain the information shown in Table 1 from the terminal. A desired beam is a beam that the terminal desires to use.

Each piece of information in Table 1 will be explained below.

First, L1-RSRP (Layer 1-Reference Signal Received Power) will be explained.
FIG. 5 schematically shows the measurement of L1-RSRP. A plurality of resources (frequency/time resources) for channel measurement are set from the base station to the terminal. The configured resources correspond to NZP (Non-Zero Power) CSI-RS resources for channel measurement in FIG. The base station uses the set resources to transmit reference signals with different beams. The terminal monitors a plurality of resources and measures received power to detect the resource from which the beam with the highest received power is transmitted. The terminal reports information identifying the detected resource to the base station together with the received power of the beam. The information specifying the detected resource is, for example, CRI (CSI-RS Reference Identification), and the received power of the beam is, for example, RSRP (Reference Signal Received Power). CRI and RSRP are information for notifying the base station which beam is desirable for the terminal (desired beam). The L1-RSRP report is a mechanism for identifying a desired beam on the base station side, and is not a mechanism for identifying an interfering beam.

Next, we will explain L1-SINR. In the 3GPP Rel16 MIMO work item, the amount of interference between the desired beam for the terminal and the beam from the interfering source measured while the terminal is receiving the desired beam is reported to the base station as desired beam power vs. interference beam power, called L1-SINR. reportedly can be reported.

Figure 6 is an excerpt from 3GPP Rel16 38.214 Section 5.2.1. A measurement of L1-SINR is described.

Fig. 7 schematically shows the measurement of L1-SINR. A base station transmits multiple different beams with resources for channel measurement. Channel measurement resources correspond to NZP (Non-Zero Power) CSI-RS resources for channel measurement in FIG. The terminal identifies the resource from which the beam (desired beam) with the highest received power is transmitted. The terminal uses the beam (receive beam) used to receive the desired beam to receive multiple different beams transmitted from the base station using resources for interference measurement, and measures the amount of interference with the desired beam (SINR). do. Resources for interference measurement correspond to NZP CSI-RS resources for interference measurement or interference measurement resource (IMR) in FIG. The IMR is a resource in which a base station guarantees no signals from its own station, and is a window for monitoring interference signals from other base stations. When measuring the SINR, the terminal uses the same receiving beam as when receiving the desired beam from the base station to receive the beam (interference beam) transmitted by the resource for interference measurement. The terminal calculates SINR (Signal to Interference and Noise Ratio) from the received power of the desired beam (desired power) and the received power of the interference beam (interference power). The terminal reports the CRI indicating the resource on which the desired beam is transmitted to the base station together with the calculated SINR (L1-SINR). If there are multiple interference measurement resources, the SINR to be reported is, for example, a representative value (minimum value, maximum value, etc.) of the measured SINRs.

Considering the above-described L1-SINR measurement and L1-SINR reporting to the base station from the viewpoint of implementation, when the base station sets one resource for interference measurement, for the beam used by the terminal (desired beam) , the interference situation of the beams transmitted on the resources for interference measurement (eg, whether the amount of interference is high or low, in other words, whether there is unacceptable interference). That is, when the base station receives a report indicating that the SINR is large, the base station can know that the amount of interference is low with respect to the beam used by the terminal (desired beam) with the beam transmitted using the resource for interference measurement. . Also, when the base station receives a report indicating that the SINR is small, it can know that the beam transmitted using the resources for interference measurement has a large amount of interference. In other words, a base station that supports 3GPP Rel16 can indirectly acquire information on beams with high and low interference with respect to a desired beam.

Next, CQI (Channel Quality Indication) will be explained using FIG. 7 above. The base station can configure multiple resources for channel measurement. Channel measurement resources correspond to NZP (Non-Zero Power) CSI-RS resources for channel measurement in FIG. Also, it is possible to configure a plurality of resources for measuring interference (or measuring the amount of interference). The resource for interference measurement corresponds to NZP CSI-RS resources for interference measurement or interference measurement resource in FIG. The IMR is a resource in which a base station guarantees no signals from its own station, and is a window for monitoring interference signals from other base stations. Using the resources configured as described above, the terminal designates, by CRI, the resource that transmits the beam with the highest received power (desired beam) among the sources for channel measurement, and uses the desired beam. , the modulation scheme and coding rate (code rate) required for receiving downlink data on the terminal side are specified by CQI (number assigned to a combination of modulation scheme and coding rate). The terminal reports CRI and CQI to the base station. The higher the CQI value (number), the higher the quality of the channel and the higher the quality of the channel. Therefore, by checking the CQI value, the base station can know the state of interference with the desired beam (for example, whether the amount of interference is high or low, in other words, whether there is unacceptable interference).

[Regarding the configuration of the conventional beam report]
Figure 8 shows an excerpt of the report configuration in Rel16 TS38.331 Section 6.3.2. Based on the report configuration, the terminal monitors (measures the received power) multiple resources set by frequency and time, and the settings for reporting the monitoring results are sent from the base station to the terminal in advance. (ie, the terminal configures itself using the configuration information element by sending an RRC message including the configuration information element from the base station to the terminal in advance). More details are as follows.

In the Cell ID, which frequency band (Component Carrier) resource configuration (Resource Configuration) is to be monitored is set.

The Resource Configuration ID for channel measurement indicates which resource configuration to monitor to obtain the received power of the candidate beam (candidate beam) to be used with the terminal.

The Resource Configuration ID for interference measurement indicates which resource configuration to monitor to obtain information (RSRP, SINR or CQI) on interference by interference beams.

　Resource configuration for Report indicates which Uplink Resource to use to report to the base station.

In Report Quantity, CRI-SINR (CRI and SINR), CRI-SINR (CRI and SINR), or CRI-CQI (CRI and CQI) is selectively set as the content to be reported to the base station. For example, CRI-SINR means reporting a resource ID in which a desired beam desired by a terminal among candidate beams is transmitted, and an amount of interference (SINR) between the desired beam and an interference beam. When multiple interfering beams are transmitted, it is conceivable to report representative values (minimum value, average value, maximum value, etc.) of multiple SINRs or all of multiple SINRs.

The format of the Resource Configuration ID is the same for channel measurement and interference measurement, but different resources are specified for both measurements.

Fig. 9 shows an excerpt of the resource configuration settings in Rel16 TS38.331 Section 6.3.2. As mentioned above, the same format is used for both channel and interference measurements.

The Reference Signal Resource Set List contains multiple RS Resource Sets (Reference Signal Resource Sets) composed of multiple DL RS (Downlink Reference Signal) resources. That is, the list includes a set of resources to which reference signals are transmitted.

The BWP ID indicates which BWP (Bandwidth Part) to use. In other words, it indicates to which BWP the above resource or resource set belongs. A BWP is each part obtained by dividing a component carrier, which is a frequency band, into partial frequency domains.

　Based on the settings shown in Figs. 8 and 9, the terminal calculates RSRP, SINR or CQI and reports the calculated value to the base station together with the CRI. Note that this report is intended to report the RSRP, SINR, or CQI of the interference beam for the desired beam, and is not intended to report information identifying the interference beam to the base station.

In addition, in the report configuration described in FIGS. 8 and 9, after monitoring a plurality of reference signals (Reference Signals) arranged in one BWP in one frequency band (Component Carrier), the desired reference signal ( The information of the resource on which the RS) was transmitted (e.g., the resource on which the desired beam was transmitted, the identifier of the reference signal corresponding to the desired beam (e.g., CRI)) is reported along with the SINR. It was not done by monitoring reference signals (RS) placed in multiple cells (Component Carriers) or multiple BWPs.

[Possible implementation with conventional 3GPP standard]
For a beam (beam 1) transmitted from a base station to a specific terminal, information on a beam with a large amount of interference (beam 2) and information on a beam with a small amount of interference (beam 3) are acquired. is possible. If the transmission sources of beams 1 to 3 are included in a plurality of small base stations that can be controlled by this base station, the information on beams 1 to 3 can be obtained by the base station, Under control, it is possible to coordinate the use of beams 1-3. In other words, adjustment between beams is possible if it can be regarded as processing within the control of one base station.

However, if the transmission sources of beams 1 to 3 belong to independent and separate base stations, it is difficult to coordinate the measurements described above among the base stations. In other words, the conventional method based on the 3GPP standard does not allow measuring the amount of beam interference between base stations operated by different operators or between base stations that belong to the same operator but are controlled differently. Coordinating the setting of resources between base stations itself is difficult.

For example, in FIG. 7 described above, assume that a base station (assumed to be base station A) sets resources for channel measurement for determining a desired beam. In this case, it is difficult to configure resources for interference measurement in another base station B belonging to the same operator as base station A or in base station C belonging to another operator. After coordinating resource settings for two base stations (base station A and base station B, or base station A and base station C), the two base stations coordinate the timing of sending signals from each resource. because it must. If the operators are the same, the hurdles for implementation will be lower, but whether or not base station B can set up such interlocking with base station A depends on the implementation of base station B. . Therefore, such interlocked setting is not always possible.

[Beam coordination between base stations according to the present disclosure (beam adjustment)]
The present disclosure provides methods that effectively enable coordination of beam usage between base stations. A beam coordinator, which is a communication control device that controls multiple base stations, collects information on the amount of interference of other beams with respect to the beam used for the terminal (for example, information on beam groups with large amounts of interference), A coordinator coordinates beam usage among base stations.

According to the present disclosure, for example, it is possible for a base station to notify a beam coordinator of information about a beam that the base station wants to use, and for the beam coordinator to determine whether or not the beam can be used by the base station. As an example, if a beam that a base station wants to use affects a beam used by a specific terminal (for example, another terminal belonging to another base station), the beam coordinator refuses to use that beam. to protect the communication of a specific terminal.

It should be noted that a method of specifying a beam with a large amount of interference among the beams desired by the terminal can be considered, using an approach completely different from the method of having the coordinator acquire information on a beam group with a large amount of interference. Specifically, when a beam is transmitted from a base station using the location information of the base station and the terminal, it is virtually determined whether the beam interferes with the terminal by considering the propagation characteristics of the channel. calculate. In this case, it is considered possible for the coordinator to acquire the location information of the base station and the terminal itself, but from this location information, the beam characteristics of the base station and the beam of the terminal (receiving beam) can be accurately determined. It is difficult to grasp. In other words, since the beam characteristics (beam width, gain, direction, etc.) on the base station side basically depend on the implementation, it is difficult to grasp the beam characteristics without actual measurements. . In addition, since the beam characteristics on the terminal side are related not only to the position of the terminal but also to the direction of the terminal, it is difficult to grasp the beam characteristics on the terminal side without actually performing measurements. Therefore, it is difficult to accurately calculate the amount of beam interference with respect to the desired beam of the terminal by virtual calculation from the location information of the base station and the terminal.

(First embodiment)
FIG. 10 is a diagram schematically illustrating an example of a communication system according to an embodiment of the present disclosure; The communication system in FIG. 10 includes

base stations

101 and 102, a terminal 201 (communication device), and a beam coordinator 301 (communication control device). A terminal 201 is a communication device within a cell (coverage) operated by the base station 101 . The

base stations

101 and 102 are connected to each other by wire or wirelessly, and can transmit and receive information using a predetermined interface such as the X2 interface.

Base stations

101 and 102 are connected to beam coordinator 301 . Beam coordinator 301 controls a plurality of base stations including

base stations

101 and 102 . Although two base stations are shown in FIG. 10, three or more base stations may be arranged so that information can be transmitted and received between them. Although one terminal is shown in FIG. 10, two or more terminals (communication devices) may be arranged. The beam coordinator 301 is connected to a core network (not shown), and is connected to a packet data network (PDN) (not shown) via the core network.

Base stations

101 and 102 may be directly connected to the core network without going through beam coordinator 301 .

Note that the beam coordinator described above or later may be one of a plurality of core network nodes in the core network to which the base station is connected, or one of the plurality of core network nodes in the core network. , may be realized by a combination of several. Additionally or alternatively, the beam coordinator (or communication, control or processing by it) described above or below may be performed by one or more base stations. For example, another base station notified of information on a beam to be used may make the decision itself as to whether or not the beam can be used. Alternatively, the base station itself, which has information on the beam it wishes to use, may determine whether or not the beam can be used, and transmit to the other base stations a notification denying the use of the beam by other base stations. The communication of these information (notifications) may be over X2, Xn or F1 interfaces.

The communication system in FIG. 10 is, for example, a cellular communication system such as W-CDMA (Wideband Code Division Multiple Access), cdma2000 (Code Division Multiple Access 2000), LTE, and NR. "LTE" shall include LTEA (LTE-Advanced), LTE-A Pro (LTE-Advanced Pro), and EUTRA (Evolved Universal Terrestrial Radio Access). "NR" shall include NRAT (New Radio Access Technology) and FEUTRA (Further EUTRA). In this embodiment, it is assumed that the communication system is an NR cellular communication system. The core network is NR's core network (5G Core (5GC)), which includes AMF (Access and Mobility Management Function), SMF (Session Management Function), UPF (User Plane Function), PCF (Policy Control Function) and UDM (Unified Data Management).

NR is the radio access technology (RAT) of the next generation (5th generation) of LTE. NR is a radio access technology that can support various use cases including eMBB (Enhanced Mobile Broadband), mMTC (Massive Machine Type Communications) and URLLC (Ultra-Reliable and Low Latency Communications).

A communication system according to the present disclosure is not limited to a cellular communication system. For example, the communication system may be other wireless communication systems such as a wireless LAN (Local Area Network) system, a television broadcasting system, an aircraft radio system, a space radio communication system, and the like.

The

base stations

101 and 102 are communication devices that operate cells and provide wireless services to one or more terminals located within the coverage of the cells. A cell may be operated according to any radio communication scheme, such as NR. A

base station

101, 102 may be configured to manage multiple cells. In this example, the

base stations

101 and 102 are 5G base stations and correspond to gNBs.

Also, the

base stations

101 and 102 may be referred to as a combination of gNB CU (Central Unit) and gNB DU (Distributed Unit) or any of these. In this embodiment, the

base stations

101 and 102 may be configured to be able to wirelessly communicate with other base stations. For example, when a plurality of

base stations

101 and 102 are eNBs or a combination of eNBs and gNBs, the devices may be connected via an X2 interface. Also, when the plurality of

base stations

101 and 102 are eNBs or a combination of eNBs and gNBs, the devices may be connected by an Xn interface. Also, when a plurality of

base stations

101 and 102 are a combination of gNB CU and gNB DU, the devices may be connected via an F1 interface. All or at least some of the messages/information described below may be communicated between multiple base stations 101, 102 (eg, via X2, Xn, F1 interfaces).

Furthermore, the

base stations

101 and 102 may consist of a set of multiple physical or logical devices. For example, in this embodiment, the

base stations

101 and 102 may be classified into a plurality of devices of BBU (Baseband Unit) and RU (Radio Unit), and interpreted as an aggregate of these plurality of devices. Additionally or alternatively, the

base stations

101, 102 may be either or both BBUs and RUs in embodiments of the present disclosure. The BBU and RU may be connected by a predetermined interface (e.g. eCPRI). Additionally or alternatively, the RU may be referred to as RRU (Remote Radio Unit) or RD (Radio DoT). Additionally or alternatively, an RU may correspond to a gNB DU as described above or below. Additionally or alternatively, a BBU may correspond to a gNB CU as described above or below. Additionally or alternatively, the RU may be a unit integrally formed with the antenna. The antennas possessed by the base stations 101 and 102 (for example, antennas formed integrally with the RU) may adopt an Advanced Antenna System and support MIMO (for example, FD-MIMO) and beamforming. In the Advanced Antenna System, the antennas of the base stations 101 and 102 (for example, antennas integrally formed with the RU) have, for example, 64 transmitting antenna ports and 64 receiving antenna ports. may be provided. When the

base stations

101 and 102 support beamforming, the

base stations

101 and 102 transmit signals by performing beam sweeping, for example, in the circumferential and radial directions of the cell. The direction of beam sweeping is not limited to the horizontal direction, and may be any direction in the vertical direction or a combination of the horizontal and vertical directions. That is, when multiple antenna elements of an antenna that performs beamforming are arranged in the horizontal direction and the vertical direction with respect to the antenna plane, the antenna settings (e.g., antenna tilt angle, distance between antenna elements (elements), wavelength , phase offset, and reference transmission power), the beam can be directed and controlled in the horizontal and vertical directions.

The terminal 201 is a communication device that wirelessly communicates with other devices. The terminal 201 is, for example, a sensor or camera device having a communication function, a mobile phone, a smart device (smartphone or tablet), a PDA (Personal Digital Assistant), or a personal computer. The terminal 201 may be a head-mounted display, VR goggles, or the like that has a function of wirelessly transmitting and receiving data. A terminal 201 is a 5G terminal and corresponds to a UE.

Note that if the communication system of the present embodiment is an NR cellular communication system, the communication system may be applied not only to 5G NR Standalone, but also to 3GPP 5G NR Non-Standalone.

A cell provided by

base stations

101 and 102 is called a serving cell. Serving cells include PCell (Primary Cell) and SCell (Secondary Cell). Dual Connectivity (e.g. EUTRA-EUTRA Dual Connectivity, EUTRA-NR Dual Connectivity (ENDC), EUTRA-NR Dual Connectivity with 5GC, NR-EUTRA Dual Connectivity (NEDC), NR-NR Dual Connectivity) to UE (e.g. Terminal 201) If provided, the PCell and zero or more SCell(s) provided by the MN (Master Node) are called a Master Cell Group. Furthermore, the Serving cell may include a PS Cell (Primary Secondary Cell or Primary SCG Cell). That is, when Dual Connectivity is provided to the UE, the PSCell and zero or more SCell(s) provided by the SN (Secondary Node) are called a Secondary Cell Group (SCG). Unless a special setting (e.g., PUCCH on SCell) is made, the physical uplink control channel (PUCCH) is transmitted on PCell and PSCell, but not on SCell. Radio Link Failure is also detected in PCell and PSCell, but not detected in SCell (it does not have to be detected). In this way, PCell and PSCell have special roles in Serving Cell(s), so they are also called Special Cells (SpCells). One cell may be associated with one Downlink Component Carrier and one Uplink Component Carrier. Also, the system bandwidth corresponding to one cell may be divided into a plurality of bandwidth parts (Bandwidth Parts). In this case, one or more Bandwidth Parts may be set for the UE, and one Bandwidth Part may be used for the UE as an Active BWP. Also, the radio resources (for example, frequency band, numerology (subcarrier spacing), slot format (Slot configuration)) that can be used by the terminal device 10 may differ for each cell, each component carrier, or each BWP.

That is, the

base stations

101 and 102 may be MN or SN of NR-NR DC as 3GPP 5G NR Standalone, ENDC as 3GPP 5G NR Non-Standalone, ENDC with 5GC, or gNB (en -gNB).

<Configuration of base station>
FIG. 11 is a block diagram illustrating an example of a base station 101 according to embodiments of the present disclosure. Base station 101 includes antenna 110 , radio communication section 120 , network communication section 130 , storage section 140 and control section 150 . The block diagram of base station 102 is also the same as that of base station 101 .

The wireless communication unit 120, the network communication unit 130, and the control unit 150 are, for example, a CPU (Central Processing Unit), a processor (hardware processor) such as an MPU (Micro-Processing Unit), an ASIC (Application Specific Integrated Circuit), or an FPGA. (Field-Programmable Gate Array) or other integrated circuits. The storage unit 140 is realized by any recording medium such as memory, hard disk device, optical disk, or magnetic recording device. The memory may be volatile memory or non-volatile memory.

The antenna 110 radiates the signal output by the wireless communication unit 120 into space as radio waves. Antenna 110 also converts radio waves in space into a signal and outputs the signal to wireless communication section 120 . The antenna 110 has multiple antenna elements and is capable of forming a beam. Antenna 110 may be configured to form multiple beams simultaneously.

The wireless communication unit 120 transmits and receives signals. A signal contains data or information. The wireless communication unit 120 includes a signal transmission unit 121 that transmits signals and a signal reception unit 122 that receives signals. For example, the signal transmitter 121 transmits downlink signals to the terminal 201 and the signal receiver 122 receives uplink signals from the terminal 201 . The radio communication unit 120 can form one or more beams (transmission beams) by the antenna 110 in sequence or simultaneously, and beam transmit a signal to the terminal 201 . A transmit beam is formed based on a transmit beam filter, which is sometimes also called a transmit spatial filter (TX spatial filter). Signal transmission by the signal transmission unit 121 includes both beam transmission and non-beam transmission (omni transmission).

The network communication unit 130 transmits and receives information by wire or wirelessly. For example, network communication unit 130 transmits information to other nodes and receives information from other nodes. Other nodes include, for example, at least one of other base stations (such as base station 102), beam coordinator 301, and core network nodes. The network communication unit 130 may have one or more antennas if it is configured to perform wireless communication. This antenna may be shared with antenna 110 .

The storage unit 140 temporarily or permanently stores programs and data for operating the base station 101 .

The control unit 150 includes a receiving unit 152 and a transmitting unit 151. The receiving section 152 receives data or information from the terminal 201 via the wireless communication section 120 or the signal receiving section 122 . The transmitting section 151 transmits data or information to the terminal 201 via the wireless communication section 120 or the signal transmitting section 121 . The receiver 152 also receives data or information from the beam coordinator 301 or the base station 102 via the network communication unit 130 . The transmitter 151 transmits data or information to the beam coordinator 301 or base station 102 via the network communication unit 130 .

The control unit 150 controls the operation of the entire base station 101 and provides various functions of the base station 101 .

When using a beam for transmission to a terminal, the control unit 150 transmits a beam use request (beam request) to the beam coordinator 301 (communication control device) that controls a plurality of base stations. The control unit 150 includes identification information (beam ID) for identifying a target beam (target beam) in a beam use request (beam request). The identification information (beam ID) that identifies the beam may be an identifier that can be globally identified by itself, or cell ID, base station ID, TRP (Transmission Reception Point) ID or BWP ID, A combination of at least one and a beam ID may be included in a beam use request (beam request). The control unit 150 receives a response including information regarding whether or not the beam can be used, which is transmitted in response to the use request from the beam coordinator 301 . If use of the beam is permitted in the response, the control unit 150 determines that the requested beam can be used. If the response does not permit the use of the beam, the control unit 150 determines that the beam cannot be used. In this case, the control unit 150 may transmit a use request to the beam coordinator 301 with another beam as the target beam.

Here, the control unit 150 may include in the beam request a condition regarding at least one of the beam usage time and frequency (beam usage condition).

The beam usage conditions may include, by way of example, at least one of the following.
・Conditions regarding the start time of beam use ・Conditions regarding the length of time that beams are used ・Conditions regarding the number of times beams are used ・Conditions regarding the period of beam use ・Conditions regarding subframes or slots in which beams are used conditions for channel quality

Since the control unit 150 requests the use of a plurality of beams, the beam request may include identification information for identifying each of the plurality of beams, and may further include usage conditions for each of the plurality of beams. In this case, the response from the beam coordinator 301 includes information on whether or not each of the beams can be used. The control unit 150 determines whether use is permitted for each of a plurality of beams, and determines that only the permitted beams can be used for transmission to the terminal.

If the controller 150 wishes to use multiple beams simultaneously, it may include identification information for identifying each of the multiple beams and information requesting simultaneous use of the multiple beams in the beam request. In this case, beam usage conditions may be common to a plurality of beams, or may be defined separately for each beam. The response from the beam coordinator 301 includes information on whether or not multiple beams can be used simultaneously. The control unit 150 can transmit downlink data to the terminal using multiple beams simultaneously if simultaneous use is permitted.

The control unit 150 may include information regarding the importance or priority of the beam in the beam request. As a result, for example, the beam coordinator 301 can flexibly determine whether or not to use a beam according to the importance or priority of the beam. For example, at least some of the conditions of use may be restricted to permit use of the beam if all of the conditions of use are not met.

If the control unit 150 does not receive a response from the beam coordinator 301 within a certain period of time after transmitting the beam request, the control unit 150 may transmit a cancel message for canceling the use request to the beam coordinator 301 . This makes it possible to reliably inform the beam coordinator 301 that the requested beam is not being used by the base station, regardless of the reason why the response is not received. For example, when the response transmitted from the beam coordinator 301 is lost due to congestion in the network, the beam coordinator 301 can be notified that the permitted beam is not being used. After transmitting the cancel message, the control unit 150 may transmit the beam request again.

<Configuration of Beam Coordinator 301 (Communication Control Device)>
FIG. 12 is a block diagram illustrating an example beam coordinator 301 according to an embodiment of the present disclosure. The beam coordinator 301 comprises a network communication section 330 , a storage section 340 and a control section 350 . The beam coordinator 301, the network communication unit 330, and the control unit 350 include, for example, a CPU (Central Processing Unit), a processor (hardware processor) such as an MPU (Micro-Processing Unit), an ASIC (Application Specific Integrated Circuit), and an FPGA (Field - Programmable Gate Array) and other integrated circuits. The storage unit 340 is implemented by any recording medium such as a memory, hard disk device, optical disk, or magnetic recording device. The memory may be volatile memory or non-volatile memory.

The network communication unit 330 transmits and receives information or data by wire or wirelessly. For example, the network communication unit 330 transmits information or data to other nodes and receives information or data from other nodes. Other nodes include, for example, base station 101, base station 102, core network nodes. The network communication unit 330 may be provided with one or more antennas if it is configured to communicate wirelessly.

The storage unit 340 temporarily or permanently stores programs and various data for the operation of the beam coordinator 301 .

The control unit 350 includes a receiving unit 352 and a transmitting unit 351. The receiving unit 352 receives signals including data or information from the

base stations

101 and 102 via the network communication unit 330 . The transmission unit 351 transmits signals including data or information to the

base stations

101 and 102 via the network communication unit 330 . The receiver 352 also receives signals including data or information from the beam coordinator 301 , the base station 101 or the base station 102 via the network communication unit 330 . The transmitter 351 transmits a signal including data or information to the beam coordinator 301, base station 101 or base station 102 via the network communication unit 130. FIG.

The control unit 350 controls the operation of the entire beam coordinator 301 and provides various functions of the beam coordinator 301 . A control unit 350 controls a plurality of base stations (base stations 101 and 102). In particular, the controller 350 controls or manages beam usage by multiple base stations.

The control unit 350 receives a request to use the target beam (target beam) from the base station. The usage request includes a beam ID that identifies the beam as identification information that identifies the beam.

The control unit 350 manages, in the storage unit 340 for each terminal, correspondence data (interference database) that holds information about interference given to the terminal (first communication device) by one or more beams in association with the beam ID. That is, the storage unit 340 stores correspondence data (interference database) for each terminal.

In addition, the control unit 350 manages, in the storage unit 340, a usage management database that holds the usage conditions of the permitted beams in association with beam IDs when beam usage is permitted for each terminal. That is, the usage management database is stored in the storage unit 340. FIG.

The control unit 350 determines whether or not to use the beam (target beam) requested in the use request based on the interference database and use management database for each other terminal. Based on the determination result, the control unit 350 transmits a response including information regarding whether or not the beam can be used to the base station that transmitted the use request.

Here, the usage request from the base station may include a condition (first condition) regarding at least one of the time and frequency at which the requested beam (target beam) is used. Specific examples of the conditions are as described above.

Based on the usage management database, the control unit 350 checks whether there is another beam that uses the same resource (frequency/time resource) as the requested beam. If no such other beam exists, allow the beam to be used. That is, the control unit 350 determines that the frequency included in the first condition at least partially matches the frequency of the beam used by another terminal, and the time included in the first condition If the condition that the beam being used by the terminal at least partly coincides with the time it is used (second condition) is not met, then use of the beam is permitted. In other words, if the beam and frequency of another terminal are different, the use of the beam is permitted even if the usage time of the beam of the other terminal is the same, and even if the beam and frequency of the other terminal are the same. , the use of the beam may be permitted if the use time differs from that of other terminals.

On the other hand, when the second condition is satisfied, the information about the interference that the requested beam gives to the other terminal is specified. Specifically, the control unit 350 identifies information about the interference that the requested beam gives to the other terminal based on the interference database of the other terminal using the other beam. If the interference due to the identified information is acceptable (for example, if the amount of interference is low, or if the amount of interference is less than a threshold), use of the beam is allowed. If the interference is unacceptable, do not allow the beam to be used.

The control unit 350 instructs each of the plurality of base stations to measure the interference given to the terminal (first communication device) by one or more beams that can be transmitted from the base station. You may send instruction information to do. Terminals to be measured may be limited to specific terminals. Examples of specific terminals include terminals that have an important function or role, or fixedly installed terminals that do not move. Details will be described in a second embodiment or a third embodiment, which will be described later.

The control unit 350 acquires from the base station information about interference given to the terminal by a beam transmitted from the base station in association with identification information (beam ID, etc.) that identifies the beam. The control unit 350 stores the acquired information on interference and the beam ID in the interference database of the terminal. The instruction information instructing to measure the interference is, for example, information instructing the terminal to measure the received power of the beam (for example, RSRP).

The control unit 350 transmits instruction information for instructing one of the plurality of base stations to transmit a beam for measuring interference to the terminal, and a plurality of base stations other than the one base station. Indication information may be transmitted to the base stations instructing them not to transmit signals during at least a portion of the period of beam transmission by the one base station. Details will be described in a third embodiment described later.

The control unit 350 transmits instruction information for instructing transmission of beams for interference measurement to base stations other than the base station (first base station) to which the terminal belongs. Furthermore, the control unit 350 transmits instruction information instructing the base station (first base station) to which the terminal belongs to transmit a beam for quality measurement to the terminal. Furthermore, the control unit 350 performs the quality measurement when the terminal receives the beam for interference measurement from the other base station and the beam for quality measurement is received by the terminal using the same resource. and transmitting instruction information instructing acquisition of information on interference with the beam for use (information on quality of the beam for quality measurement). The control unit 350 acquires information on interference with the beam for quality measurement (information on quality of the beam for quality measurement) from the base station (first base station) to which the terminal belongs. The control unit 350 acquires the acquired information as information on interference given to the terminal by beams from other base stations, associates the acquired information with identification information (beam ID) that identifies the beam, and stores it in the interference database. Store. That is, the interference database is generated by associating the acquired information on interference with the identification information (beam ID) for identifying the beam. The information on the interference with the beam for quality measurement (information on the quality of the beam for quality measurement) includes, for example, SINR or CQI. The details of the description described in this paragraph will be described later in the second embodiment.

The present embodiment will be described in more detail below using specific examples.

[Example 1]
In specific example 1, the beam request transmitted from the base station to the beam coordinator 301 includes a base station ID (Base station ID), a terminal ID (UE ID), a beam ID, and beam usage conditions (or usage requirements). Include. Information included in the beam request is not limited to this. As described above, in addition to or instead of the base station ID, at least one of a cell ID, a transmission reception point (TRP) ID, or a BWP ID may be included in the beam request together with the beam ID. The beam coordinator 301 determines whether or not the base station identified by the base station ID can use the beam identified by the beam ID for transmission to the terminal identified by the terminal ID, based on the beam usage conditions. to decide. The beam usage conditions include conditions related to the time (time resources) in which the beams are used, conditions related to frequencies (frequency resources) in which the beams are used, and the like.

Table 2 shows an example of usage conditions included in the beam request according to the specific example 1.

FIG. 13 shows an example in which the base station starts using resources for beam transmission (starts beam transmission) after k [ms] after transmitting a beam request to the beam coordinator 301 at time t. The value of k may be fixed in the system. The value of k may differ from system to system. The value of k may depend on the time it takes beam coordinator 301 to process a beam resource availability decision. The value of k is, for example, a value within the range of about 1ms to 1000ms.

FIG. 14 shows an example in which the base station periodically uses the beam after starting using the beam in the example of FIG. A base station that starts using a beam uses the beam for a period of time T every period R. Since the repetition number N is 3, the base station can use the beam up to 3 times.

FIG. 15 shows an example in which the base station uses the beam only once in the example of FIG.

FIG. 16 is a sequence diagram showing an example of the overall procedure of the communication system according to this embodiment. Under the control of the beam coordinator 301, the base station 102 transmits a beam (interference beam) including a reference signal for interference measurement using one or a plurality of resources (frequency/time resources) for the terminal 201 belonging to the base station 101. (S201).

The base station 102 receives report information (beam report) including information (for example, RSRP) on interference measured by the terminal 201 from the terminal 201 (S202).

The base station 102 transmits to the beam coordinator 301 interference report information including information about the interference of the interference beams in association with information specifying the interference beams (eg, beam ID) (S303).

The interference report information includes, for example, a base station ID (base station 101 ID), a terminal ID (terminal 201 ID), an interference beam ID (interference beam ID), and information about interference. Note that the base station 102 may detect interference beams with large interference (for example, RSRP is greater than a threshold) and transmit interference report information to the beam coordinator 301 only for the detected interference beams.

The beam coordinator 301 associates the base station ID, the interference beam ID, and information about interference with the interference database for the terminal corresponding to the terminal ID, and stores them in the interference database.

Details of an example of the operations of S201 to S203 described above (referred to as interference measurement example 1) will be described in a third embodiment described later.

The beam coordinator 301 may determine in advance the resources for the base station 102 to transmit interference beams, and transmit information on the determined resources to the base station 102 . Alternatively, the base station 102 can determine the resources on which to transmit the interfering beams.

The configuration (direction, width, gain, etc.) of the interference beams transmitted from the base station 102 may be determined arbitrarily by the base station 102, or the beam coordinator 301 determines and instructs the determined configuration. The instructional information may be sent to base station 102 . For example, all or part of a plurality of transmittable beam candidates may be determined as interference beams by the base station 102, or interference beams may be randomly determined from these candidates. Alternatively, the base station 102 may acquire the location information of the terminal 201 from the beam coordinator 301 or the base station 101, and determine one or more interference beams to be transmitted based on the acquired location information of the terminal 201. .

The method (S201 to S203) for the beam coordinator 301 to acquire information about the interference of interference beams is not limited to the above example (interference measurement example 1). For example, the following example (referred to as Interference Measurement Example 2) may be used.

The base station 101 sequentially transmits a plurality of beams using a plurality of resources to the terminal 201 by beam sweeping, and causes the terminal 201 to select or determine a desired beam (see S101 in FIG. 1). Under the control of the beam coordinator 301, the base station 102 transmits a beam (interference beam) including a reference signal for interference measurement using one or a plurality of resources (frequency/time resources) for the terminal 201 belonging to the base station 101. (S201). As a beam (reception beam) for receiving the interference beam, the terminal 201 uses the same reception beam as the reception beam used for receiving the above-described desired beam. However, the reception beam for receiving the interference beam at the terminal 201 may be determined by other methods. For example, the terminal 201 selects a reception beam (reception filter) with the highest quality (for example, received power) for each interference beam from a plurality of candidate beams (candidate filters), and uses the selected reception beam (candidate filter). Interfering beams may be received. Terminal 201 measures the interference caused by the interference beam with respect to the desired beam, and obtains information about the interference (for example, SINP or CQI).

The base station 101 receives report information (beam report) including information (for example, SINP or CQI) on interference measured by the terminal 201 from the terminal 201 (S202). The base station 101 transmits to the beam coordinator 301 interference report information including information about the interference of the interference beams in association with information identifying the interference beams (for example, beam ID) (S303). Note that the base station 101 may detect interference beams with large interference (for example, SINP or CQI is above a threshold) and transmit interference report information to the beam coordinator 301 only for the detected interference beams.

The interference report information includes, for example, a base station ID (base station 101 ID), a terminal ID (terminal 201 ID), an interference beam ID (interference beam ID), and information about interference. The beam coordinator 301 associates a base station ID, an interference beam ID, and information about interference with an interference database for a terminal corresponding to the terminal ID, and stores them in the interference database. Details of an example of the operations of S201 to S203 (interference measurement example 2) will be described later in a second embodiment.

In the above description of S201 to S203, the information about the interference beam transmitted from the base station 102 is obtained in association with the information (beam ID, etc.) specifying the interference beam. Similarly, for the interference beams transmitted from the base station 101 as well, the beam coordinator 301 may acquire information about interference in association with information (beam ID) specifying the interference beams. Similarly, for terminals other than terminal 201, beam coordinator 301 associates information about interference in the terminal with information (beam ID) specifying the interference beam for interference beams transmitted from

base stations

101 and 102, respectively. can be obtained.

After that, when the base station 101 receives a beam communication request from the terminal 201 , the base station 101 determines the desired beam to be used for transmission to the terminal 201 . Therefore, the base station 101 configures a plurality of resources and transmits a plurality of beams including reference signals in each of the configured resources by beam sweeping (S204). The terminal 201 measures the received power of a plurality of beams transmitted from the base station 101 and selects one or more desired beams (desired beams).

The terminal 201 transmits report information (beam report) including information specifying the selected beam and information indicating the received power of the selected beam, etc. to the base station 101 (S305). The information that identifies the beam is, for example, CRI (CSI-RS Resource identification) that identifies a resource transmitted by the beam or a reference signal transmitted by the beam. Also, the received power of the beam is, for example, RSRP (Reference Signal Received Power).

The base station 101 selects one or more beams to be used for transmitting downlink data to the terminal 201 from among the beams reported in the beam report as desired beams. For example, the base station 101 selects a beam with the highest received power or a beam with received power greater than or equal to a threshold. The base station 101 determines beam usage conditions (conditions regarding frequency and time for using the beam) for the selected beam. Any method for determining the conditions of use may be determined. The base station 101 transmits a beam request (beam use request) including the beam ID of the selected beam, the terminal ID of the terminal 201, the base station ID of the base station 101, and beam use conditions to the beam coordinator 301 (S206). ). Beam coordinator 301 receives beam requests.

The beam coordinator 301 keeps track of the usage status of beams in multiple base stations (including the base stations 101 and 102) in the usage management database. That is, information on beams that have been permitted by the beam coordinator 301 in the past and are currently in use are held in the use management database. The beam information includes beam IDs, base station IDs, terminal IDs, beam usage conditions (information on frequencies and times permitted to be used).

The beam coordinator 301 determines whether or not the beam requested to be used by the base station 101 (requested beam) can be used based on the beam usage conditions included in the beam request. That is, beam coordinator 301 first determines whether or not the beam is being used by another terminal at the frequency at which the use of the beam is requested and the time at which use of the beam is requested, based on the use management database. do.

Specifically, for example, the beam coordinator 301 selects beams in use by other terminals whose frequency is the same (or partially overlaps) and whose usage time at least partially overlaps with the requested beam in the usage management database. Determine if the beam ID is retained. Note that other terminals may belong to either the cell of base station 101 or the cell of base station 102 .

The beam coordinator 301 decides to allow the base station 101 to use the requested beam if the beam ID of the beam is not held in the usage management database.

On the other hand, if the beam ID of the beam being used by the other terminal is held in the usage management database, it is determined whether the beam ID of the beam requested to be used is held in the interference database. When the beam ID of the beam requested to be used is held, further, whether the beam requested to be used is held as an interference beam that gives strong interference to the terminal 201 is determined based on information on interference related to the beam ID. to decide.

The beam coordinator 301 decides to permit the use of the requested beam if the beam ID of the requested beam is not held in the interference database. The beam coordinator 301 decides to allow the use of the requested beam if the beam ID of the requested beam is held in the interference database and the interference of the beam is weak. The beam coordinator 301 decides not to permit the use of the requested beam if the beam ID of the requested beam is held in the interference database and the interference of the beam is strong. Thus, beam coordinator 301 does not allow the use of a requested beam when there is a beam in use that causes strong interference to other terminals.

When the beam coordinator 301 permits the use of the requested beam, the beam coordinator 301 transmits to the base station 101 a response including information indicating permission to use the requested beam (that is, OK to use the requested beam) (S307). The information indicating permission to use the requested beam includes, for example, the beam ID of the requested beam and at least one of the ID of the base station 101 and the ID of the terminal 201 .

On the other hand, if the beam coordinator 301 does not permit the use of the requested beam, it transmits a response including information indicating that the requested beam cannot be used (that is, the use of the requested beam is NG) to the base station 101 (S307). The information indicating that the requested beam cannot be used includes, for example, the beam ID of the requested beam and at least one of the ID of the base station 101 and the ID of the terminal 201 .

When the base station 101 receives a response including information indicating permission to use the requested beam from the beam coordinator 301, the base station 101 transmits downlink data to the terminal 201 using the requested beam at the frequency and time requested in the beam request (S308). . On the other hand, when the base station 101 receives a response including information indicating that the requested beam cannot be used from the beam coordinator 301, the base station 101 does not transmit downlink data using the requested beam. In this case, the base station 101 may select another beam as the requested beam based on the beam report received in step S305 and transmit the side beam request. Alternatively, the process may return to step S304 and start again from beam sweeping.

[Example 2]
In specific example 2, the beam request sent to the beam coordinator 301 includes IDs of multiple requested beams. The beam request also includes information about whether or not each of the plurality of requested beams may be used simultaneously with other requested beams among the plurality of requested beams.

Between the base station and one terminal, communication may be performed using one beam, or two or more beams may be used at the same time. Even when one beam is used for communication, one beam may be selected from three beams and switched to another beam as time passes. This is because beams that can be used simultaneously with other terminals (beams that can be used with resources of the same frequency and time) change according to beam use scheduling of other terminals. If there are a plurality of beams that one terminal may use, simply requesting beam coordinator 301 for permission to use one beam cannot handle beam switching. In this specific example 2, the beam request according to specific example 1 includes the IDs of the plurality of requested beams, and the possibility of using each of the plurality of requested beams at the same time as other requested beams among the plurality of requested beams. Include information about whether there is

Table 3 shows an example of information about multiple requested beams to include in a beam request.

In the example of Table 3, 6 requested beams are selected for one terminal, and information about the 6 requested beams is included in the beam request. Each requested beam is represented by a set of a base station ID (number uniquely assigned to the base station) and a number (beam ID) uniquely assigned to the beam in the base station.

The base station ID is 2 in all rows of Table 3. Since the (2,3) beam, the (2,15) beam, and the (2,31) beam can be used simultaneously, there is a possibility that these three beams will be used at the same time. Of these three beams, two or three beams can be used simultaneously. Of course, it is possible that only one of the three is used. A beam marked as "none" for simultaneous use will not be used at the same time as other beams, but may be switched over as time passes.

Based on the information in Table 3, the beam coordinator 301 determines whether or not the simultaneous use "none" beam can be used alone. Also, for beams with simultaneous use "yes", it is determined whether or not they can be used simultaneously. For example, it is determined whether three beams (2,3), (2,15), and (2,31) can be used simultaneously. Whether or not a plurality of beams can be used simultaneously can be determined by determining whether all three beams can be used. In step S107, the beam coordinator 301 transmits to the base station 101 a response including information on whether or not each beam can be used simultaneously and information about whether or not each beam can be used simultaneously, and information about whether or not a plurality of beams can be used simultaneously. Just do it.

The base station 101 receives the response from the beam coordinator 301. Based on the information included in the received response, the base station 101 selects one or more beams to be used for transmission to the terminal 201, and transmits downlink data using the selected beams. The base station 101 may switch beams to be used between beams determined to be usable over time. For example, the base station 101 may switch the beam to be used when the transmission data error rate or its average exceeds a threshold, or may switch the beam to be used at regular intervals.

[Example 3]
In specific example 3, the beam request sent to the beam coordinator 301 includes information about the importance or priority of the requested beam. This allows the beam coordinator 301 to more flexibly determine whether or not the requested beam can be used (adjust beam usage with other terminals).

When the base station determines whether or not to use the beam that the base station requests the beam coordinator 301 to use with the terminal, the beam coordinator 301 needs to consider the interference relationship between the requested beam and other beams.

Specifically, as interference relation 1, the requested beam interferes with a terminal belonging to another base station already using the beam, in other words, the requested beam interferes with the communication of a terminal belonging to another base station. There is a relationship that can cause quality loss. In this case, the requested beam corresponds to the beam causing interference to the other terminal, and the other terminal corresponds to the terminal receiving the interference.

As interference relationship 2, the beam already in use by another terminal interferes with the terminal using the requested beam when the use of the requested beam is permitted. There is a relationship that can cause degradation of communications for terminals using beams. In this case, the beam already in use by another terminal corresponds to the interfering beam, and the terminal that uses the requested beam when the use of the requested beam is permitted corresponds to the terminal receiving interference.

Table 4 shows the combination of the presence/absence of interference relationship 1 and the presence/absence of interference relationship 2. The presence or absence of relationship 1 and the presence or absence of relationship 2 can be easily determined by comparing RSRP, SINR, or CQI with a threshold using the method described above.

Table 5 shows an example of information to be included in a beam request according to Specific Example 3. The beam request includes a base station ID and a beam ID as information specifying the requested beam, and further includes information regarding priority or importance. As in Example 1, usage conditions regarding frequency and time may also be included in the beam request. Also, other indicators such as CQI or RSRP may be used instead of SINR.

The QoS Level ID may be set in the base station in advance by the operator in association with the terminal ID (IMSI, SUPI, etc.) of the terminal. Alternatively, the base station may determine the QoS Level ID based on the QoS assigned when setting up a dedicated bearer for the terminal. A dedicated bearer is a logical path for transmitting data.

A specific example in which the beam coordinator 301 determines whether the requested beam can be used will be shown below. When permitting the use of the requested beam, it is assumed that the usage conditions regarding frequency and time are satisfied, as in the first specific example. The following determination example is just an example, and other determination examples are possible as long as priority or importance is used.

An example of determination in the case of combination 1 of the interference relationship is shown. Interference relationship combination 1 corresponds to the case where the SINR of the terminal using (receiving) the requested beam is SINR V or more, and the SINR of the terminal of the beam being used by another terminal is also SINR V or more. Note that the SINR V of both terminals may be the same value or different values. In this case, beam coordinator 301 may authorize the use of the requested beam.

An example of determination in the case of combination 2 of the interference relationship is shown. Interference relationship combination 2 corresponds to the case where the SINR of the terminal that uses (receives) the requested beam is less than the SINR V of the requested beam, but the SINR of the other terminals is SINR V or more. In this case, the beam coordinator 301 may permit use of the requested beam when the priority (QoS Level ID) of the requested beam is equal to or greater than the threshold.

An example of judgment in the case of combination 3 of the interference relationship is shown. Interference relationship combination 3 corresponds to the case where the SINR of the terminal using (receiving) the requested beam is SINR V or more, but the SINR of the terminals of other beams in use is also less than SINR V. In this case, the beam coordinator 301 may permit use of the requested beam when the priority (QoS Level ID) of the requested beam is greater than or equal to the threshold. However, the condition may be that the SINR of a terminal on another beam in use is equal to or greater than a threshold value (less than the SINR V of the beam in question). Alternatively, it may additionally/alternatively require that the priority of the requested beam is higher or higher than the priority of other beams in use. The SINR threshold may be changed according to priority. For example, the higher the priority, the smaller the threshold may be.

An example of judgment in the case of interference relationship combination 4 is shown. Interference relationship combination 4 corresponds to the case where the SINR of the terminal using (receiving) the requested beam is less than SINR V, and the SINR of the terminals of the other beams in use is also less than SINR V. In this case, beam coordinator 301 may not allow the requested beam to be used. Alternatively, beam coordinator 301 compares the priority of the requested beam (assumed to be priority A1) and the priority of the beam being used by another base station (assumed to be priority A2), and priority A1 is given priority. Use of the request beam may be permitted if the degree is greater than A2. However, at least one of the SINR of the terminal when using the requested beam and the SINR of the terminal using other beams in use may be a threshold value (less than SINR V) or more. The threshold may be changed according to priority. For example, the higher the priority, the smaller the threshold may be.

[Handling of beams for terminals that do not convey information about beam interference in advance]
As described in the description of steps S201 to S203 in FIG. 16 above, the base station first receives information about the amount of interference (for example, RSRP, SINR, CQI, or presence or absence of interference) for one or more interference beams from each terminal. etc.). Then, based on the acquired information, the base station notifies the coordinator 301 of information on each detected interference beam for each terminal.

However, there may be terminals that do not perform this procedure. For example, a terminal moving at high speed may not report information on interference to the network side (base station) because the interference situation fluctuates rapidly. When receiving a beam request from a base station requesting use of a beam for such a terminal, beam coordinator 301 lowers the priority of the beam requested in the beam request regardless of the value of QoS Level ID in Table 5. It may be considered a value (eg lowest value or predetermined value). If the requested beam is a beam that gives unacceptable (or large) interference to other terminals (for example, if the SINR of the other terminal is smaller than SINR V or a separately defined threshold), the beam coordinator 301 of the requested beam use should not be allowed. Even if there is another beam that gives a large interference to the terminal related to the requested beam, if the information about the interference by the other beam does not exist for the terminal, the requested beam gives a large interference to the other terminal ( The requested beam may be permitted to be used unless the beam is obtained with an amount of interference equal to or greater than the threshold.

[Example 4]
In specific example 4, the beam request received from the base station by the beam coordinator 301 is permitted to use the beam by restricting at least part of the usage conditions.

The beam coordinator 301 conditionally (restricts at least part of the usage conditions) of the requested beams requested by the base station even if the usage conditions included in the beam request are not satisfied. use may be permitted. It cannot be said that it is efficient in terms of the system if it is determined uniformly that the beam cannot be used when the conditions for using the requested beam are not satisfied. For example, in the specific example 3 described above, if the SINR value (=V) expected for the requested beam is included in the beam request, and if the SINR lower than V is acceptable, the use of the requested beam may be permitted. obtain. Further, in the above-described specific example 1, if the number of repetitions of the period is 10, the use of the requested beam may be permitted if the number of repetitions is 8. In such a case, the beam coordinator 301 restricts at least some of the usage conditions (with usage restrictions) so that the SINR becomes a low value or the number of iterations becomes 8, and the beam coordinator 301 responds to the request Allow use of beams. The beam coordinator 301 transmits a response including information indicating permission to use the requested beam to the base station, including usage restriction information (restricted usage conditions).

Table 6 shows an example in which the beam request from the base station in the above-described specific example 1 is permitted with usage restrictions.

Table 7 shows an example of granting a beam request from the base station in specific example 3 described above with use restrictions.

[Example 5]
Specific example 5 describes the operation of the base station when the beam request sent from the base station to the beam coordinator 301 does not receive a response including information on availability from the beam coordinator 301 .

Even if a beam request is sent from the base station to the beam coordinator 301, there may be cases where a response regarding whether or not the beam request can be used is not immediately returned due to network failure (eg, congestion).

For example, suppose that the beam request includes a request to transmit the beam from time t+k as a usage condition. In other words, suppose that a request is made to start using the beam k [ms] after the time t when the beam request is sent. In this case, if a response including usage permission information arrives after time t+k or just before time t+k, the base station will not be ready for transmission in time.

Therefore, if the base station does not receive a response including information on availability of use by time t-h (h is a positive real number), it transmits a message to the beam coordinator 301 notifying of cancellation of the beam request. The base station then sends another beam request again. The reason for transmitting the cancellation message is that the reason why the base station does not receive the response by time t-h is unknown, so it is clear to the beam coordinator 301 that the base station is not using the beam requested in the beam request. It is for For example, when beam coordinator 301 transmits a response but the response does not reach the base station, beam coordinator 301 may erroneously recognize that the base station is using the requested beam.

As described above, this embodiment enables beam coordination across multiple base stations. Therefore, beam interference in the terminal can be suppressed, and communication throughput between the terminal and the base station can be improved.

(Second embodiment)
In steps S201 to S203 in FIG. 16 in the first embodiment, the base station acquires information (SINR, CQI, etc.) on interference by interference beams from the terminal, and information on interference of each interference beam (for example, information on strong interference beams). ) to the beam coordinator 301 . Details and variations of this operation will be described in the second embodiment.

A beam coordinator 301 (control unit 350) synchronizes a plurality of base stations (base station 101 and base station 102 in the example of FIG. 10). The function of beam coordinator 301 may be stored as base station control software in any one of a plurality of base stations. Especially between base stations with the same PLMN (Public Land Mobile Network), synchronization control is normally performed by the base station controller. Beam coordinator 301 may be a device independent of multiple base stations.

FIG. 17 is a flowchart for explaining an example of operations of the beam coordinator 301, base station 101, and base station 102 according to the second embodiment.

The beam coordinator 301 selects a target terminal from a plurality of terminals belonging to each of a plurality of base stations (S301). A part or all of the plurality of terminals may be selected in turn, or a specific terminal may be selected as the target terminal. As examples of specific terminals, terminals that do not move (eg, terminals that are fixedly installed), terminals that have important functions or roles, terminals that do not move and have important functions or roles, etc. may be selected. A specific example of a terminal having an important function or role is a terminal that performs important control such as stopping a production line in a factory when the communication quality of the terminal deteriorates due to beam interference. Another specific example is a terminal that controls medical equipment for surgery. Selection of target terminals can be performed not only by the beam coordinator 301 but also by the base station. In this case, the base station may notify the beam coordinator 301 of the selected terminal information (terminal ID, etc.). In the following description, it is assumed that terminal 201 (see FIG. 10) belonging to the cell of base station 101 is selected.

The base station 101 communicates with the terminal 201 using the desired beam. As an example of how to determine the desired beam, there is a method in which the base station 101 sequentially transmits a plurality of beams using a plurality of resources to the terminal 201 by beam sweeping, and selects the beam with the highest quality as the desired beam. The beam with the highest quality is, for example, the beam with the highest received power (RSRP) or above a threshold. The terminal 201 uses, for example, a beam (reception filter) with the highest reception power of the desired beam as a reception beam (reception filter) for receiving the desired beam. As another method, a plurality of reception beam (reception filter) candidates may be prepared, and a reception beam (reception filter) may be selected from among these plurality of candidates.

The beam coordinator 301 selects a base station as an interference source from a plurality of base stations (S302), and stops radio signal transmission operations by other base stations than the base station 101 and the selected base station. As a method of selecting the base station that is the source of interference, for example, base stations included in a range of distance where the terminal can communicate may be selected in order. Alternatively, base stations in the local area may be selected in order. Assume here that the base station 102 is selected as the base station that is the source of interference. It is also possible to select the base station 101 as an interference source.

The beam coordinator 301 determines multiple resources (resources defined by frequency and time) for transmitting multiple interference beams to the terminal 201 for the base station selected as the interference source (S302). The frequencies of the plurality of resources are the same frequencies as the desired beam resources used between the base station 101 and the terminal 201 . It is possible to make the resource time for transmitting the interference beam different from or the same as the resource time for transmitting the desired beam. The beam coordinator 301 transmits information specifying the determined plurality of resources to the base station 101 (S302).

Under the control of the beam coordinator 301, the base station 101 transmits setting information for causing the terminal 201 to measure an interference beam transmitted from the base station 102 and report information on interference with the desired beam (S303). ). The report configuration information may be included in RRC messages (e.g., RRCSetupmessage, RRCReconfigurationmessage) and transmitted from the base station 101 to the terminal 201 . The configuration information may include information identifying resources on which interfering beams are transmitted. Information may be included that indicates the order of resources on which the interfering beams are transmitted. If the interfering beam is transmitted on different resources than the desired beam, terminal 201 may calculate the SINR or CQI assuming that the interfering beam is received at the same time as the desired beam.

The beam coordinator 301 transmits information instructing the base station 102 selected as the interference source to transmit one of the plurality of interference beams using one of the plurality of resources determined above. (S304). For example, the beam coordinator 301 selects a beam from a plurality of beam candidates (each beam ID is assigned) that can be transmitted from the base station 102, and instructs the base station 102 to transmit the selected beam using the beam ID. . Selection of interfering beams may be performed at the base station 102 . In this case, the base station 102 may notify the beam coordinator 301 of the beam ID of the interference beam to be transmitted using the designated resource.

Based on the information instructed by the beam coordinator 301, the base station 102 transmits interference beams using the resources instructed by the beam coordinator 301 (S304).

The base station 101 receives report information (beam report) including information (for example, SINR or CQI) on the interference amount of interference beams from the terminal 201 (S305). A resource for uplink transmission of the beam report by the terminal 201 may be configured in the terminal 201 in advance by configuration information. Alternatively, other methods (e.g., DCI (Downlink Control Information), MAC Control Element) may be used to indicate the reporting resource to terminal 201 . Additionally or alternatively, the resource for transmitting the beam report from the terminal 201 is specified in advance by the base station 101 to the terminal 201 in the configuration information, and the report is triggered by other methods (e.g., DCI (Downlink Control Information), MAC (Control Element) to instruct the terminal 201. These measurement methods and reporting methods may also be applied to other embodiments described above or below. The base station 101 transmits information about the received interference amount together with the ID (Base Station ID) of the base station 101 and the ID (UE ID) of the terminal 201 as interference report information to the beam coordinator 301 (S305). The information about the interference transmitted from the terminal 201 may be associated with the ID of the resource on which the interfering beam was received. In this case, the base station 101 includes the ID of the resource in the interference report information transmitted to the beam coordinator 301. you can

When the beam coordinator 301 receives the interference report information from the base station 101, the beam coordinator 301 associates the ID of the base station that transmitted the interference beam, the ID of the beam for which the interference was measured, and the information about the interference, and determines the interference for the terminal. Store in database. When the interference database is shared by a plurality of terminals, the IDs of the terminals are also stored in the interference database. The information on interference stored in the interference database may be the SINR or CQI value itself reported from base station 101, or may be a class (for example, large, medium, or small) classified according to the value of information on interference.

The beam coordinator 301 determines whether all necessary interference beams have been transmitted from the interference source base station, that is, whether it has received interference report information on all interference beams transmitted from the base station 102 (S306). If all the interfering beams have not been transmitted yet, returning to step S304, the beam coordinator 301 transmits information to the base station 102 instructing to transmit another interfering beam on the next resource. Steps S304 and S305 are repeated until the beam coordinator 301 receives the interference report information for all the interference beams. An arbitrary method may be used to select the interference beam in step S304 for each iteration. For example, the beam coordinator 301 may sequentially select all of a plurality of candidate beams, may sequentially select beams at regular azimuth angle intervals, or may select beams randomly. When interference beams are selected not by beam coordinator 301 but by base station 102, beams may be selected in the same manner. In step S302, resources corresponding to the number of beams to be transmitted are determined. Alternatively, a method of determining the number of resources first and transmitting beams (interference beams) corresponding to the number of resources is also possible.

When beam coordinator 301 receives interference report information about all interference beams transmitted from base station 102, it determines whether all base stations have been selected (S307). If there is a base station that has not been selected yet, the process returns to step S302 to select the next base station that will cause interference. The same processing (S302 to S306) is repeated for the selected base station 101, and the beam coordinator 301 receives interference report information on all interference beams transmitted from the base station 101. FIG.

When the processing for all base stations is completed, beam coordinator 301 determines whether or not there are still terminals to be selected (S308). select. Steps S302 to S307 are performed for the selected terminal. If there is no terminal to be selected, the processing of this flowchart is terminated. Note that even a terminal that has already been selected may be selected again if a certain condition is satisfied, such as a certain period of time has elapsed or the terminal has moved.

By the procedure in FIG. 17, information on the amount of interference of beams transmitted from the base station can be individually grasped for each beam. Also, by assigning a beam ID to a beam transmitted from a base station, it becomes possible to distinguish beams between different base stations.

　In the procedure of FIG. 17, as described above, only two base stations are operated, and radio transmission operations by other base stations are stopped. As a related technology, SAS (Spectrum Access System) transmits to the base station only when the warship using military radar is not near the base station in order to protect the incumbent system (the primary system to be protected such as military radar) from interference There is a system for permitting. In the communication system according to the present embodiment, stopping radio transmission operations of base stations other than the two base stations when performing beam interference measurement between base stations means that in this related art, these two base stations to the incumbent system. One of the features of the present embodiment is that when the incumbent system (primary system) is in operation, all but the necessary base stations (two base stations) stop transmitting radio waves.

The operation example in FIG. 17 is an example, and various variations are possible for the content of the operation or the order of the operation. In the operation example of FIG. 17 , after stopping radio transmission operations of base stations other than the two base stations, base station 101 transmits setting information for interference measurement to terminal 201 . After transmitting the setting information for interference measurement to , the operations of the base stations other than the two base stations may be stopped. Also, in the operation example of FIG. 17, the transmission of the interference beams may be performed in the test mode. In this case, interference beams may be transmitted using as many resources as possible.

Table 8 shows an example of the interference database managed by the beam coordinator 301.

The interference database is provided for each terminal selected in step S301 of FIG. 17, as described above. In the example of Table 8, information about the amount of interference is classified into classes (large, medium, and small) indicating the strength of interference. An interfering beam is identified by a base station ID (Base station ID) and a beam ID (beam ID). In addition to or instead of the base station ID, at least one of a cell ID, a TRP (Transmission Reception Point) ID, or a BWP ID may be used to identify an interference beam. For example, (1,10) represents the interfering beam with beam ID=10 transmitted from the base station with base station ID=1. From the interference database, it is possible to grasp for each terminal which beam gives what degree of interference to the terminal. If the uniqueness of the beam ID is guaranteed for each base station, the interference beam may be specified only by the beam ID. When determining the strength (class) of interference when CQI is used as information about the amount of interference, both CQI without and with interference beams are compared to determine the strength of interference ( class) may be determined.

(Third embodiment)
In the third embodiment, as in the second embodiment, detailed operation examples and variations of steps S201 to S203 in FIG. 16 will be described. Descriptions that are the same as those of the second embodiment will be omitted as appropriate.

In the second embodiment described above, it was necessary to synchronize resources among multiple base stations. Although it is easy to synchronize multiple base stations belonging to the same operator, it may be difficult to synchronize between base stations belonging to different operators. In the third embodiment, even if the base station to which the terminal that performs interference measurement belongs and the base station that transmits the interference beam belong to different operators (that is, different PLMNs), information about the amount of interference of the interference beam can be easily obtained. make it available to

FIG. 18 is a flowchart for explaining an example of operations of the beam coordinator 301, base station 101, and base station 102 according to the third embodiment.

The beam coordinator 301 selects a target terminal from a plurality of terminals belonging to a plurality of base stations (S401). An example of terminal selection may be the same as in step S301 of FIG.

The beam coordinator 301 selects one of the plurality of base stations and sets only the selected base station to be able to transmit signals (S402). The beam coordinator 301 stops signal transmission operations of all base stations other than the selected base station (S402). The method of selecting the base station may be the same as in step S302 of FIG.

The selected base station (or beam coordinator 301) determines multiple resources for interfering beam transmission (S403). The selected base station causes the terminal selected in step S401 to measure the interference of the interference beam and report the information on the measured interference (interference amount) based on the determined information of the plurality of resources. setting information is transmitted (at step S403). The configuration information may include information identifying resources on which interfering beams are transmitted.

The selected base station transmits an interference beam including a reference signal (eg NZP CSI-RS) to the terminal on one of the determined resources (S404). The selected base station receives, from the terminal, report information including information (eg, CRI) specifying the resource on which the reference signal was transmitted and received power (eg, RSRO) measured by the terminal (S405). In addition, the base station transmits beams of the same configuration to the terminal using a plurality of resources, and reports information including the highest received power (RSRP) and the information (CRI) identifying the resource where the RSRP beam is transmitted to the base station. You can send it to the station.

Based on the information obtained from the terminal, the selected base station has a PLMN ID (an operator ID), a corresponding base station ID (Base Station ID), a terminal ID (UE ID, such as IMSI, SUPI, etc.), a beam Generate interference report information including ID (Beam ID) and RSRP. A beam ID is an ID given to each beam by the base station. The beam ID may be, but is not limited to, an ID not defined in the 3GPP standard. For example, if the beam is a directional reference signal, the beam ID may be the ID of the reference signal. If the reference signal is CSI-RS, the beam ID may be CRI. If the reference signal is SSB, the beam ID may be SSB Index. The base station transmits the generated interference report information to the beam coordinator 301 (at step S405).

The beam coordinator 301 determines whether all the necessary interference beams have been transmitted from the interference source base station, that is, whether the interference report information regarding all the interference beams transmitted from the selected base station has been received (S406). If all interference beams have not yet been transmitted, return to step S404. Steps S404 and S405 are repeated until all interference beams are transmitted and the beam coordinator 301 receives interference report information for all the interference beams.

The beam coordinator 301 determines whether all base stations have been selected (S407), and if there are base stations that have not been selected yet, similar processing is performed for other base stations (S402 to S406).

The beam coordinator 301 determines whether or not there are still terminals to be selected (S408). If there are still terminals remaining, the process returns to step S401, selects the next target terminal, and performs the step for the selected terminal. The processing of S402 to S407 is performed. If there is no terminal to be selected, the processing of this flowchart is terminated. Note that even a terminal that has already been selected may be selected again if a certain condition is satisfied, such as a certain period of time has elapsed or the terminal has moved.

The operation example in FIG. 18 is an example, and various variations are possible for the content of the operation or the order of the operation. In the operation example of FIG. 18 , after stopping radio transmission operations of base stations other than one selected base station, the selected base station transmits setting information for interference measurement to terminal 201 . After the selected base station transmits interference measurement configuration information to terminal 201, the operations of the base stations other than the selected base station may be stopped. Also, in the operation example of FIG. 18, the transmission of the interference beams may be performed in the test mode. In this case, interference beams may be transmitted using as many resources as possible.

In the procedure of FIG. 18, when the operator of the selected base station is changed from the operator of the base station before selection, by changing the SIM (Subscriber Identity Module Card) of the terminal for each operator, the base station of a different operator It is possible to connect the terminal to Even if the SIM is changed and the SUPI or IMSI of the terminal becomes a different value, if the beam coordinator 301 recognizes the terminal before and after the change as the same terminal, the beams from the base stations belonging to different operators will be different. Information on the amount of interference given to the terminal can be managed for each terminal. While using the same SIM, by rewriting the subscriber file to which base stations belonging to different operators are connected, terminals may be able to connect to different operators with the same SIM.

By the above procedure, the beam coordinator 301 can grasp the information of the beams that can be the source of interference for the selected terminal for each base station.

　In the procedure of FIG. 18, only one base station is operated as described above. Other base stations than one base station cease operation of radio transmission. This corresponds to setting the one base station as an incumbent system (primary system) in the related technology described in the second embodiment. One of the features of this embodiment is that when the incumbent system (primary system) is in operation, radio wave transmission is stopped except for the necessary base stations (one selected base station).

Table 9 shows an example of the interference database managed by the coordinator 301. Table 9 happens to have the same content as Table 8, but it does not have to be the same.

An interference database is provided for each terminal selected in step S401 of FIG. 18, for example. In the example of Table 9, the received signal power (information about the amount of interference) is classified into classes (high, medium, low) indicating signal strength. An interfering beam is identified by a base station ID (Base station ID) and a beam ID (beam ID). In addition to or instead of the base station ID, at least one of a cell ID, a TRP (Transmission Reception Point) ID, or a BWP ID may be used to identify an interference beam. For example, (1,10) represents the interfering beam with beam ID=10 transmitted from the base station with base station ID=1. From the interference database, it is possible to grasp for each terminal which beam gives what degree of interference to the terminal. Since the interference database in Table 9 uses the received power of the signal as information on the amount of interference, the interference database does not necessarily need to be used to grasp the amount of interference of the interference beams. It may be used to select a beam with high intensity (received power) as a desired beam.

In this embodiment, only one base station is selectively operated, so there is no need to operate multiple base stations in cooperation. Since it is sufficient to transmit a beam from one base station and measure the received power of the beam at the terminal, the beam coordinator 301 provides information on the interference power (received power) at the terminal for multiple base stations belonging to different operators, can be obtained easily.

Note that the network side (base station and beam coordinator) does not acquire information on the amount of interference caused by interference beams for terminals other than the terminal for which information on the amount of interference is to be acquired. Therefore, in the first embodiment, which is the basis of this embodiment, the coordinator may not be able to adjust the use of beams so as not to interfere with the communication of other terminals. However, at least for the terminal selected in step S301 or S401, beam transmission that interferes with the terminal can be blocked, so that the function of the terminal controlling important equipment can be effectively protected. . A method of not always using beams that interfere with the terminal is conceivable, but a method of not using beams that interfere with the terminal only while the important equipment to be controlled by the terminal is in use may be used. .

As described above, according to the present embodiment, it is possible to perform cooperative control of beams among a plurality of base stations belonging to different operators, so it is possible to improve the throughput of communication between base stations and terminals.

Note that the above effects are not necessarily limited, and any of the effects shown in this specification or other effects that can be grasped from this specification can be obtained in addition to or instead of the above effects. may be

It should be noted that the above-described embodiment shows an example for embodying the present disclosure, and the present disclosure can be implemented in various other forms. For example, the present disclosure may be practiced by combining at least some of the above-described several embodiments with other parts. For example, various modifications, substitutions, omissions, or combinations thereof are possible without departing from the gist of the present disclosure. Forms with such modifications, substitutions, omissions, etc. are also included in the scope of the invention described in the claims and their equivalents, as well as being included in the scope of the present disclosure.

For example, in some of the embodiments described above, the beam may be a directional reference signal (e.g., CSI-RS, SSB) or simply a reference signal (e.g., CSI-RS, SSB) as described above. may The beam ID mentioned above may be the CRI or the SSB Index. The processing performed by the beam coordinator described above may be performed by the base station itself or by a core network node.

Also, the effects of the present disclosure described in this specification are merely examples, and other effects may be obtained.

In addition, this disclosure can also take the following configurations.
[Item 1]
a transmission unit that transmits a request to use the target beam, including identification information that identifies the target beam;
a receiving unit that receives a response including information about whether or not the target beam can be used, which is transmitted in response to the use request;
base station with
[Item 2]
The base station according to item 1, wherein the use request includes conditions regarding at least one of time and frequency for using the target beam.
[Item 3]
3. The base station according to item 2, wherein the condition includes a condition regarding start time of use of the target beam.
[Item 4]
4. The base station according to item 2 or 3, wherein the condition includes a condition regarding a length of time for using the target beam.
[Item 5]
The base station according to any one of items 2 to 4, wherein the condition includes a condition regarding the number of times the target beam is used.
[Item 6]
The base station according to item 5, wherein the condition includes a condition regarding a period of using the target beam.
[Item 7]
The base station according to any one of items 2 to 6, wherein the conditions include conditions regarding at least one of subframes and slots using the target beam.
[Item 8]
The base station according to any one of items 2 to 7, wherein the conditions include conditions regarding quality required for the target beam.
[Item 9]
9. The use request according to any one of items 1 to 8, wherein the use request includes identification information for identifying each of the plurality of target beams, and the response includes information regarding whether or not each of the plurality of target beams can be used. base station.
[Item 10]
The base according to any one of items 1 to 9, wherein the use request includes information requesting simultaneous use of the plurality of target beams, and the response includes information regarding whether or not the plurality of target beams can be used simultaneously. station.
[Item 11]
11. The base station according to any one of items 1 to 10, wherein the usage request includes information about importance or priority of the target beam.
[Item 12]
9. The base station according to any one of items 2 to 8, wherein the response includes information indicating that at least part of the conditions are restricted to permit use of the target beam.
[Item 13]
13. The base station according to any one of items 1 to 12, wherein the transmitting unit transmits a cancel message for canceling the usage request when the response is not received within a certain time after the usage request is transmitted. .
[Item 14]
The transmission unit transmits the usage request to a communication control device that controls a plurality of base stations,
14. The base station according to any one of items 1 to 13, wherein the receiving unit receives the response from the communication control device.
[Item 15]
a receiving unit that receives a request to use the target beam, including identification information that identifies the target beam;
a control unit that determines whether or not the target beam can be used based on correspondence data that holds information about interference given to the first communication device by each of the one or more beams in association with identification information that identifies the beam;
a transmission unit configured to transmit a response including information regarding whether or not the target beam can be used based on the determination of the control unit;
A communication controller with
[Item 16]
The control unit specifies interference that the target beam gives to the first communication device based on the corresponding data, determines to permit use of the target beam when the interference is permissible, and determines that the interference is deciding not to authorize the use of said beam of interest if it is unacceptable;
16. A communication control device according to item 15.
[Item 17]
The usage request includes a first condition regarding at least one of time and frequency for using the target beam,
the corresponding data includes information about at least one of the time and frequency at which the beam is used;
The controller controls the frequency included in the first condition to at least partially match the frequency used in the beam, and the time included in the first condition to at least the time in which the beam is used. 17. The communication control device according to item 16, wherein, when a second condition of partial matching is satisfied, interference given by the target beam to the first communication device is identified.
[Item 18]
18. The communication control device according to item 17, wherein the control unit decides to permit use of the target beam when the second condition is not satisfied.
[Item 19]
The control unit
transmitting instruction information to the plurality of base stations for instructing measurement of interference inflicted on the first communication device by one or more beams transmittable from the plurality of base stations with the first communication device; ,
any one of items 15 to 18, obtaining from the plurality of base stations information about interference inflicted on the first communication device by the one or more beams in association with identification information that identifies the one or more beams 1. The communication control device according to item 1.
[Item 20]
20. The communication control device according to item 19, wherein the instruction information is information that instructs the first communication device to measure the received power of the beam.
[Item 21]
The control unit transmits instruction information for instructing one of the plurality of base stations to transmit the beam for measuring the interference to the first communication device, 21. The method according to any one of items 15 to 20, wherein instruction information is transmitted to a base station other than the one base station to instruct not to transmit a signal during a period in which the beam is transmitted by the one base station. communication controller.
[Item 22]
The control unit
transmitting instruction information for instructing transmission of the beam to a base station other than the first base station to which the first communication device belongs;
transmitting instruction information to the first base station to instruct the first communication device to acquire information about interference of the beam received from the other base station;
Obtaining information from the first base station about the interference that the beam imposes on the first communication device;
22. The communication control device according to any one of items 15-21.
[Item 23]
23. The communication control apparatus according to Item 22, wherein the control unit generates the correspondence data by associating the acquired information about the interference with identification information for identifying the beam.
[Item 24]
24. The communication control apparatus according to Item 22 or 23, wherein the information about beam interference includes SINR or CQI.
[Item 25]
transmitting a request to use the target beam, including identification information identifying the target beam;
A communication method for receiving a response including information about whether or not the target beam can be used, which is transmitted in response to the use request.
[Item 26]
receiving a request to use the beam of interest, including identification information identifying the beam of interest;
determining whether or not the target beam can be used based on corresponding data held in association with identification information for identifying the beam, information about interference given to the first communication device by each of the one or more beams;
Transmitting a response including information about whether or not the target beam can be used based on the judgment of the control unit;
Communication control method.

101 base station 102 base station 110 antenna 120 radio communication unit 121 signal transmission unit 122 signal reception unit 130 network communication unit 140 storage unit 150 control unit 151 transmission unit 152 reception unit 201 terminal 301 beam coordinator 330 network communication unit 340 storage unit 350 control Unit 351 Transmitter 352 Receiver 1000 Base station 1000A Base station 1000B Base station 2000 Terminal 2000A Terminal 2000B Terminal

Claims

a transmission unit that transmits a request to use the target beam, including identification information that identifies the target beam;
a receiving unit that receives a response including information about whether or not the target beam can be used, which is transmitted in response to the use request;
base station with
The base station according to claim 1, wherein the use request includes conditions regarding at least one of time and frequency for using the target beam.
The base station according to claim 2, wherein the conditions include a condition regarding start time of use of the target beam.
3. The base station according to claim 2, wherein the condition includes a condition regarding a length of time for using the target beam.
The base station according to Claim 2, wherein the condition includes a condition regarding the number of times the target beam is used.
The base station according to Claim 5, wherein the condition includes a condition regarding a period of using the target beam.
The base station according to Claim 2, wherein the conditions include conditions regarding at least one of subframes and slots using the target beam.
The base station according to claim 2, wherein the conditions include conditions regarding quality required for the target beam.
The base station according to Claim 1, wherein the use request includes identification information for identifying each of the plurality of target beams, and wherein the response includes information regarding whether or not each of the plurality of target beams can be used.
The base station according to claim 1, wherein the use request includes information requesting simultaneous use of the plurality of target beams, and wherein the response includes information regarding whether or not the plurality of target beams can be used simultaneously.
The base station according to Claim 1, wherein the usage request includes information about importance or priority of the target beam.
3. The base station according to claim 2, wherein the response includes information indicating that at least part of the condition is restricted to permit use of the target beam.
The base station according to Claim 1, wherein, if the response is not received within a certain period of time after the transmission of the usage request, the transmission unit transmits a cancel message for canceling the usage request.
The transmission unit transmits the usage request to a communication control device that controls a plurality of base stations,
The base station according to claim 1, wherein the receiving section receives the response from the communication control device.
a receiving unit that receives a request to use the target beam, including identification information that identifies the target beam;
a control unit that determines whether or not the target beam can be used based on correspondence data that holds information about interference given to the first communication device by each of the one or more beams in association with identification information that identifies the beam;
a transmission unit configured to transmit a response including information regarding whether or not the target beam can be used based on the determination of the control unit;
A communication controller with
The control unit specifies interference that the target beam gives to the first communication device based on the corresponding data, determines to permit use of the target beam when the interference is permissible, and determines that the interference is deciding not to authorize the use of said beam of interest if it is unacceptable;
The communication control device according to claim 15.
The usage request includes a first condition regarding at least one of time and frequency for using the target beam,
the corresponding data includes information about at least one of the time and frequency at which the beam is used;
The controller controls the frequency included in the first condition to at least partially match the frequency used in the beam, and the time included in the first condition to at least the time in which the beam is used. 17. The communication control device according to claim 16, wherein if a second condition of partial coincidence is satisfied, the interference caused by the target beam to the first communication device is identified.
The communication control apparatus according to claim 17, wherein the control unit determines to permit use of the target beam when the second condition is not satisfied.
The control unit
transmitting instruction information to the plurality of base stations for instructing measurement of interference inflicted on the first communication device by one or more beams transmittable from the plurality of base stations with the first communication device; ,
16. The communication according to claim 15, wherein information about interference given to the first communication device by the one or more beams is obtained from the plurality of base stations in association with identification information that identifies the one or more beams. Control device.
The communication control apparatus according to claim 19, wherein the instruction information is information instructing measurement of the received power of the beam in the first communication apparatus.
The control unit
transmitting instruction information instructing one of a plurality of base stations to transmit the beam for measuring the interference to the first communication device;
The control unit transmits, to base stations other than the one base station among the plurality of base stations, instruction information instructing not to transmit a signal during a period in which the beam is transmitted by the one base station. The communication control device according to claim 15.
The control unit
transmitting instruction information for instructing transmission of the beam to a base station other than the first base station to which the first communication device belongs;
transmitting instruction information to the first base station to instruct the first communication device to acquire information about interference of the beam received from the other base station;
Obtaining information from the first base station about the interference that the beam imposes on the first communication device;
The communication control device according to claim 15.
The communication control apparatus according to claim 22, wherein the control unit generates the correspondence data by associating the acquired information about the interference with identification information for identifying the beam.
The communication control apparatus according to Claim 22, wherein the information on beam interference includes SINR or CQI.
transmitting a request to use the target beam, including identification information identifying the target beam;
A communication method for receiving a response including information about whether or not the target beam can be used, which is transmitted in response to the use request.
receiving a request to use the beam of interest, including identification information identifying the beam of interest;
determining whether or not the target beam can be used based on corresponding data held in association with identification information for identifying the beam, information about interference given to the first communication device by each of the one or more beams;
Transmitting a response including information regarding whether or not the target beam can be used based on the determination of whether or not the target beam can be used;
Communication control method.