[0001]
　The present disclosure relates to a communication device, a communication method, and a program.
Background technology
[0002]
　Wireless access method and wireless network for cellular mobile communication (hereinafter, "Long Term Evolution (LTE)", "LTE-Advanced (LTE-A)", "LTE-Advanced Pro (LTE-A Pro)", "New Radio ( NR)”, “New Radio Access Technology (NRAT)”, “Evolved Universal Terrestrial Radio Access (EUTRA)”, or “Further EUTRA (FEUTRA)”) is a 3rd Generation Partnership Project: 3GPP). In the following description, LTE includes LTE-A, LTE-A Pro, and EUTRA, and NR includes NRAT and FEUTRA. In LTE and NR, a base station device (base station) is also called an eNodeB (evolved NodeB), and a terminal device (mobile station, mobile station device, terminal) is also called a UE (User Equipment). LTE and NR are cellular communication systems in which a plurality of areas covered by a base station device are arranged in a cell shape. A single base station device may manage a plurality of cells.
[0003]
　In the fifth generation (5G) mobile communication system following LTE/LTE-A, a technique of using a directional beam for communication between a base station and a terminal device is being studied. By using such a technique, communication between the base station and the terminal device can be spatially multiplexed in addition to being multiplexed in time and frequency.
[0004]
　As a procedure for determining a more suitable beam to be used for communication between the base station and the terminal device, for example, various beam candidates are provided to the terminal device from the base station, and the terminal device provides the beam to the base station. , Information about each beam is reported. With such a procedure, the base station can specify a more suitable beam based on the information about each beam reported from the terminal device.
Prior art documents
Non-patent literature
[0005]
Non-Patent Document 1: MediaTek Inc., “Discussion on Beam Recovery Mechanism” R1-1716214, 3GPP TSG RAN WG1 Meeting NR#3, Nagoya, Japan, 18th-21th September 2017
Summary of the invention
Problems to be Solved by the Invention
[0006]
　On the other hand, while communication is being performed using the determined beam, an obstacle such as a person or vehicle is interposed between the base station and the terminal device, and the beam is blocked by the obstacle. As a result, it may be difficult to continue communication between the base station and the terminal device. Such blocking of the beam by the obstacle is also referred to as “blocking”. In addition, the quality of the beam being used may deteriorate due to interference from other beams. In such a case, it may be necessary to recover the communication between the base station and the terminal device. For example, Non-Patent Document 1 discloses an example of beam management in a case where communication between a base station and a terminal device is restored due to blocking or deterioration of beam quality.
[0007]
　However, when the communication between the base station and the terminal device is restored due to blocking or deterioration of beam quality, it may be necessary to newly search for a more suitable beam. The procedure of re-searching for this beam may take a relatively long time, and in such a case, it may be difficult to quickly restore communication between the base station and the terminal device. To be done.
[0008]
　Therefore, the present disclosure proposes a technique that enables communication between the base station and the terminal device to be restored in a more preferable manner.
Means for solving the problems
[0009]
　According to the present disclosure, for a communication unit that performs wireless communication and a base station, in place of a plurality of beams, a first beam that is preferentially used in the wireless communication with the base station is replaced. And a notification unit that notifies information about the available second beam.
[0010]
　Further, according to the present disclosure, instead of the communication unit that performs wireless communication and the terminal device, the first beam that is preferentially used in the wireless communication between the terminal device and the plurality of beams is used. A communication, comprising: an acquisition unit that acquires information about a usable second beam, and a control unit that controls the wireless communication with the terminal device based on the acquired information about the second beam. A device is provided.
[0011]
　Further, according to the present disclosure, a computer performs wireless communication, and a first base station among a plurality of beams, which is used preferentially in the wireless communication with the base station. Notifying information about a second beam that can be used in place of the beam is provided.
[0012]
　Further, according to the present disclosure, a computer performs wireless communication, and a terminal device selects a first beam that is preferentially used in the wireless communication with the terminal device from among a plurality of beams. Communication including acquiring information about a second beam that can be used instead, and controlling the wireless communication with the terminal device based on the acquired information about the second beam. A method is provided.
[0013]
　Further, according to the present disclosure, a computer is used to perform wireless communication, and a base station is used to preferentially use a plurality of beams in the wireless communication with the base station. A program is provided for performing notification of information regarding a second beam that can be used instead of the beam, and execution of the information.
[0014]
　Further, according to the present disclosure, performing wireless communication with a computer, and selecting from a terminal device a first beam that is preferentially used in the wireless communication with the terminal device among a plurality of beams. And acquiring information about a second beam that can be used instead, and controlling the wireless communication with the terminal device based on the acquired information about the second beam. The program is provided.
Effect of the invention
[0015]
　As described above, according to the present disclosure, there is provided a technique that enables communication between a base station and a terminal device to be restored in a more preferable manner.
[0016]
　Note that the above effects are not necessarily limited, and in addition to or in place of the above effects, any of the effects shown in this specification, or other effects that can be grasped from this specification. May be played.
Brief description of the drawings
[0017]
FIG. 1 is an explanatory diagram for describing an example of a schematic configuration of a system according to an embodiment of the present disclosure.
FIG. 2 is a block diagram showing an example of a configuration of a base station according to the same embodiment.
FIG. 3 is a block diagram showing an example of a configuration of a terminal device according to the same embodiment.
FIG. 4 is an example of a base station in the case where all antenna weights are configured by a digital unit in beamforming.
FIG. 5 is an example of a base station in the case of including a phase shifter of an analog unit in beamforming.
FIG. 6 is an explanatory diagram showing an example of beam sweeping using Rough Beam.
FIG. 7 is an explanatory diagram showing an example of beam sweeping using Accurate Beam.
FIG. 8 is an explanatory diagram showing an example of beam sweeping using Rough Beam.
FIG. 9 is an explanatory diagram showing an example in which Accuate Beams are bundled to form a Rough Beam.
FIG. 10 is an explanatory diagram showing an example in which a plurality of base stations exist around a terminal.
FIG. 11 is an explanatory diagram showing an example of DL beam sweeping procedures performed by a base station and a terminal.
FIG. 12 is a sequence diagram showing an example of a series of processing flows of the communication system according to the embodiment.
FIG. 13 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 1.
FIG. 14 is an explanatory diagram for explaining an outline of a communication system according to modification 2.
FIG. 15 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 2.
FIG. 16 is an explanatory diagram for explaining an example of a blocking situation.
FIG. 17 is an explanatory diagram for explaining another example of a blocking situation.
FIG. 18 is an explanatory diagram illustrating an example of a beam selected according to a blocking situation.
FIG. 19 is an explanatory diagram illustrating an example of a beam selected according to a blocking situation.
FIG. 20 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 3.
FIG. 21 is an explanatory diagram illustrating an overview of a partial band in 5G.
FIG. 22 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to modification 4.
FIG. 23 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 5.
FIG. 24 is a sequence diagram showing an example of a flow of a series of processes of a communication system according to modification 6.
FIG. 25 is a block diagram showing a first example of a schematic configuration of an eNB.
FIG. 26 is a block diagram showing a second example of a schematic configuration of an eNB.
FIG. 27 is a block diagram showing an example of a schematic configuration of a smartphone.
FIG. 28 is a block diagram showing an example of a schematic configuration of a car navigation device.
MODE FOR CARRYING OUT THE INVENTION
[0018]
　Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, and duplicate description will be omitted.
[0019]
　The description will be given in the following order.
　1. Configuration example
　　1.1. Example of system configuration
　　1.2. Configuration example of base station
　　1.3. Configuration example of the terminal device
　2. History
　3. Technical features
　4. Application example
　　4.1. Application example regarding base station>
　　4.2. Applications for the terminal device
　5. Conclusion
[0020]
　<<1. Configuration example>>
　　<1.1. Example of System Configuration>
　First, an example of a schematic configuration of a system 1 according to an embodiment of the present disclosure will be described with reference to FIG. 1. FIG. 1 is an explanatory diagram for describing an example of a schematic configuration of a system 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the system 1 includes a wireless communication device 100 and a terminal device 200. Here, the terminal device 200 is also called a user. The user may also be referred to as a UE. The wireless communication device 100C is also called UE-Relay. The UE herein may be a UE defined in LTE or LTE-A, and the UE-Relay may be a Prose UE to Network Relay discussed in 3GPP, and more generally communicates. It may mean a device.
[0021]
　　(1) Wireless Communication Device 100 The
　wireless communication device 100 is a device that provides wireless communication services to devices under its control. For example, the wireless communication device 100A is a base station of a cellular system (or mobile communication system). The base station 100A performs wireless communication with a device (for example, the terminal device 200A) located inside the cell 10A of the base station 100A. For example, the base station 100A transmits a downlink signal to the terminal device 200A and receives an uplink signal from the terminal device 200A.
[0022]
　The base station 100A is logically connected to another base station by, for example, an X2 interface, and can transmit/receive control information and the like. Further, the base station 100A is logically connected to a so-called core network (not shown) by, for example, the S1 interface, and can transmit/receive control information and the like. Communication between these devices can be physically relayed by various devices.
[0023]
　Here, the wireless communication device 100A shown in FIG. 1 is a macrocell base station, and the cell 10A is a macrocell. On the other hand, the wireless communication devices 100B and 100C are master devices that operate the small cells 10B and 10C, respectively. As an example, the master device 100B is a small cell base station that is fixedly installed. The small cell base station 100B establishes a wireless backhaul link with the macrocell base station 100A and an access link with one or more terminal devices (for example, the terminal device 200B) in the small cell 10B. The wireless communication device 100B may be a relay node defined by 3GPP. The master device 100C is a dynamic AP (access point). The dynamic AP 100C is a mobile device that dynamically operates the small cell 10C. The dynamic AP 100C establishes a wireless backhaul link with the macrocell base station 100A and an access link with one or more terminal devices (for example, the terminal device 200C) in the small cell 10C. The dynamic AP 100C may be, for example, a terminal device equipped with hardware or software operable as a base station or a wireless access point. The small cell 10C in this case is a dynamically formed local network (Localized Network/Virtual Cell).
[0024]
　The cell 10A is, for example, an arbitrary wireless communication system such as LTE, LTE-A (LTE-Advanced), LTE-ADVANCED PRO, GSM (registered trademark), UMTS, W-CDMA, CDMA2000, WiMAX, WiMAX2 or IEEE802.16. May be operated according to.
[0025]
　The small cell is a concept that can include various types of cells (for example, femtocells, nanocells, picocells, and microcells) smaller than the macrocell and arranged to overlap or not overlap with the macrocell. In one example, the small cell is operated by a dedicated base station. In another example, the small cell is operated by a terminal serving as a master device temporarily operating as a small cell base station. So-called relay nodes can also be considered as a form of small cell base station. A wireless communication device that functions as a master station of a relay node is also called a donor base station. The donor base station may mean a DeNB in ​​LTE, and more generally a master station of a relay node.
[0026]
　　(2) Terminal device 200 The
　terminal device 200 can communicate in a cellular system (or mobile communication system). The terminal device 200 performs wireless communication with a wireless communication device of a cellular system (for example, the base station 100A, the master device 100B or 100C). For example, the terminal device 200A receives the downlink signal from the base station 100A and transmits the uplink signal to the base station 100A.
[0027]
　Further, the terminal device 200 is not limited to a so-called UE, and for example, a so-called low cost terminal (Low cost UE) such as an MTC terminal, an eMTC (Enhanced MTC) terminal, and an NB-IoT terminal may be applied. ..
[0028]
　　(3) Supplement Although
　the schematic configuration of the system 1 has been described above, the present technology is not limited to the example illustrated in FIG. 1. For example, as a configuration of the system 1, a configuration not including a master device, SCE (Small Cell Enhancement), HetNet (Heterogeneous Network), MTC network, or the like can be adopted. As another example of the configuration of the system 1, a master device may be connected to a small cell and a cell may be constructed under the control of the small cell.
[0029]
　　<1.2. Configuration Example of Base Station>
　Next, the configuration of the base station 100 according to an embodiment of the present disclosure will be described with reference to FIG. FIG. 2 is a block diagram showing an example of the configuration of the base station 100 according to an embodiment of the present disclosure. Referring to FIG. 2, the base station 100 includes an antenna unit 110, a wireless communication unit 120, a network communication unit 130, a storage unit 140, and a processing unit 150.
[0030]
　(1) Antenna unit 110 The
　antenna unit 110 radiates the signal output from the wireless communication unit 120 as a radio wave into space. The antenna unit 110 also converts radio waves in space into a signal and outputs the signal to the wireless communication unit 120.
[0031]
　(2) Wireless communication unit 120 The
　wireless communication unit 120 transmits and receives signals. For example, the wireless communication unit 120 transmits a downlink signal to the terminal device and receives an uplink signal from the terminal device.
[0032]
　(3) Network communication unit 130 The
　network communication unit 130 transmits and receives information. For example, the network communication unit 130 transmits information to other nodes and receives information from other nodes. For example, the other node includes another base station and a core network node.
[0033]
　Note that, as described above, in the system 1 according to the present embodiment, the terminal device may operate as a relay terminal and relay communication between the remote terminal and the base station. In such a case, for example, the wireless communication device 100C corresponding to the relay terminal may not include the network communication unit 130.
[0034]
　(4) Storage Unit 140 The
　storage unit 140 temporarily or permanently stores a program and various data for the operation of the base station 100.
[0035]
　(5) Processing Unit 150 The
　processing unit 150 provides various functions of the base station 100. The processing unit 150 includes a communication control unit 151, an information acquisition unit 153, and a notification unit 155. It should be noted that the processing unit 150 may further include components other than these components. That is, the processing unit 150 can perform operations other than the operations of these components.
[0036]
　The operations of the communication control unit 151, the information acquisition unit 153, and the notification unit 155 will be described in detail later.
[0037]
　　<1.3. Example Configuration of Terminal Device>
　Next, an example configuration of the terminal device 200 according to the embodiment of the present disclosure will be described with reference to FIG. FIG. 3 is a block diagram showing an example of the configuration of the terminal device 200 according to the embodiment of the present disclosure. As shown in FIG. 3, the terminal device 200 includes an antenna unit 210, a wireless communication unit 220, a storage unit 230, and a processing unit 240.
[0038]
　(1) Antenna part 210 The
　antenna part 210 radiates the signal output from the wireless communication part 220 to space as a radio wave. The antenna unit 210 also converts radio waves in space into a signal and outputs the signal to the wireless communication unit 220.
[0039]
　(2) Wireless communication unit 220 The
　wireless communication unit 220 transmits and receives signals. For example, the wireless communication unit 220 receives a downlink signal from the base station and transmits an uplink signal to the base station.
[0040]
　Further, as described above, in the system 1 according to the present embodiment, the terminal device may operate as a relay terminal and relay communication between the remote terminal and the base station. In such a case, for example, the wireless communication unit 220 in the terminal device 200C that operates as a remote terminal may send and receive a side link signal with the relay terminal.
[0041]
　(3) Storage unit 230 The
　storage unit 230 temporarily or permanently stores a program and various data for the operation of the terminal device 200.
[0042]
　(4) Processing Unit 240 The
　processing unit 240 provides various functions of the terminal device 200. For example, the processing unit 240 includes a communication control unit 241, an information acquisition unit 243, a selection unit 245, and a notification unit 247. It should be noted that the processing unit 240 may further include components other than these components. That is, the processing unit 240 can perform operations other than the operations of these components.
[0043]
　The operations of the communication control unit 241, the information acquisition unit 243, the selection unit 245, and the notification unit 247 will be described in detail later.
[0044]
　<<2. Background>
　Next, in describing the embodiments of the present disclosure in detail, first, the background of the embodiments of the present disclosure will be described.
[0045]
　　(Codebook based beam) In
　a future wireless communication system (5G), which is being studied in 3GPP, a mechanism can be adopted in which a beam emitted from a base station is changed steplessly and a beam following a terminal device is recreated. Unlikely. This is because the calculation cost of recreating a new beam is incurred. In FD-MIMO of 3GPP Rel13, the method of wake-up from a base station in all directions and selecting and providing the necessary beam for the terminal device from the pre-made beams Has been adopted. Such a beam is called codebook based beam forming. If a beam is prepared in 1 degree increments of 360 degrees in the horizontal direction, 360 types of beams are required. When the beams are to be overlapped with each other by half, it is sufficient to prepare 720 beams, which is twice that, as a codebook based beam in the horizontal direction. Furthermore, when preparing the beams so that the beams are overlapped with each other by 180 degrees in the vertical direction and the beams overlap with each other by half, the horizontal direction is 0 degrees, and 180 degrees from -90 degrees to +90 degrees are prepared with 360 beams. You can do it.
[0046]
　　(Necessity of beam association) A
　base station can be equipped with a very large number of antenna elements such as 256 (frequency band is 30 GHz) and 1000 (frequency band is 70 GHz). As described above, as the number of antenna elements increases, it becomes possible to form a very sharp beam when performing beam forming processing using the antenna. For example, it becomes possible for the base station to provide the terminal device with a very sharp beam having a full width at half maximum (indicating how often the level at which the gain drops by 3 dB occurs more than once) is 1 degree or less.
[0047]
　In order to communicate between the base station and the terminal device, it is necessary to determine what kind of beam is used in the base station. In the case of downlink (DL) communication, it is necessary to determine the DL beam provided from the base station. Further, in the case of uplink (UL) communication, it is necessary for the base station to determine the UL beam to be used at the time of reception. The latter UL beam means that the base station does not transmit radio waves, but the directivity of the antenna for the base station to receive radio waves is a beam.
[0048]
　　(Beam sweeping) By sweeping a
　plurality of beam candidates from a base station (beam sweeping), a terminal device observing a beam candidate can determine which beam the base station uses to easily receive the beam. You can decide. On the other hand, when the terminal device transmits an RS (Reference Signal) of UL and the base station receives the RS while beam-sweeping, the base station may determine an optimum reception beam for receiving a signal from the terminal device. it can.
[0049]
　　(Resource for Performing Beamforming)
　FIG. 4 is an example of a base station in the case where all antenna weights are configured by digital units in beamforming. In this way, the case where all the weights of the antenna in beamforming are configured by the digital part is called a full digital antenna architecture. In the case of full digital, when performing Tx Sweeping (transmission sweeping), different resources are required by the number of beams. On the other hand, when performing Rx Sweeping (reception sweeping), it is possible to simultaneously receive all beams within one resource. Therefore, the fully digital antenna architecture can reduce resources during reception sweeping. That is, when performing full digital reception sweeping at the base station, the terminal device only needs to transmit an RS (Resource Signal) of UL for one resource, so that power consumption is low. The resource here means an orthogonal resource using frequency or time. For example, the LTE Resource Block and Resource element correspond to the resources mentioned here.
[0050]
　FIG. 5 is an example of a base station in the case of including the phase shifter of the analog unit in beamforming. When it is realized by including the phase shifter of the analog part in beamforming, it is called a hybrid antenna architecture of digital and analog. The hybrid digital/analog antenna architecture of FIG. 5 is advantageous in terms of cost because the hardware of the digital unit is reduced. However, in this hybrid antenna architecture, the Phase Shifter connected to the antenna can only express the beam in one direction, so both transmit and receive sweeping require resources for the number of beams. This means that the terminal device needs to transmit the UL RS to all the resources corresponding to the number of beams for the reception sweeping of the base station. That is, the power consumption of the terminal device becomes significant.
[0051]
　Considering the actual usage situation, it is assumed that the hybrid architecture shown in FIG. 5 is used, which is a drawback of the hybrid architecture, that is, different beams require different frequency or time resources. How to overcome is important.
[0052]
　　(Efficiency of beam sweeping) If the
　beam is prepared in 1 degree increments in the horizontal 360 degree direction, beam sweeping may be performed using 360 resources and the beams may be evaluated one by one. It takes time, requires a lot of resources, and consumes a lot of power in the terminal device. Therefore, the base station makes a rough beam of 10 degrees (Rough Beam), finds the optimum resolution from the beam of 10 degrees using 36 resources, and then within the range of 10 degrees. A technique is conceivable in which a beam sweeping using a fine beam (Accurate Beam) with a step of 1 degree is performed to find an optimum beam. In this case, the base station can determine the optimum beam by using 36+10=46 resources, so that the resources can be greatly reduced from 360 to 46. FIG. 6 is an explanatory diagram showing an example of beam sweeping using Rough Beam. FIG. 7 is an explanatory diagram showing an example of beam sweeping using Accurate Beam. The base station may bundle a plurality of Accurate Beams and use the Accurate Beams at the same time to treat them as a Rough beam. In that case, for example, a plurality of adjacent Accuate Beams (for example, three) are used at the same time to be used as a Rough beam. The base station may provide a bundle of three Accurate Beams as shown in FIG. 9 to make the Rough Beam shown in FIG. By transmitting the three beams in FIG. 9 at the same time and at the same frequency, it is possible to realize the provision of the Rough beam as in FIG.
[0053]
　　(Beam Sweeping from Multiple Base Stations) When
　there are multiple base stations around the terminal device, it is necessary to determine the transmit and receive beams of the multiple base stations for the terminal device. FIG. 10 is an explanatory diagram showing an example in which a plurality of base stations exist around the terminal device. In the example shown in FIG. 10, the optimum beam for the terminal device 200 is beam B100-1 at base station 100-1, beam B100-2 at base station 100-2, and beam B100-3 at base station 100-3. is there. Based on the information from the terminal device 200, the optimum beam is finally determined by the base station closest to the terminal device 200 among the plurality of base stations 100-1 to 100-3, or the main beam. It is conceivable that a different base station decides and gives instructions to other base stations. In this case, a certain base station needs to determine the transmission beam and the reception beam of a plurality of base stations, which means that the load on the terminal device increases.
[0054]
　　(Channel Reciprocity)
　Channel Reciprocity means that the UL channel and the DL channel between the base station and the terminal device are the same. In a TDD (Time Division Duplex) system, UL and DL use the same frequency band, so that UL and DL Channel Reciprocity basically hold. However, by performing an operation called calibration so that TX/RX of the analog part of the base station and the analog part of the terminal device have the same characteristics, it is necessary to ensure that Reciprocity is established in both the analog part of the terminal device and the spatial channel. is there.
[0055]
　When this Channel Reciprocity is satisfied, when the terminal device selects the DL beam of the base station, the terminal device transmits the beam number to the base station, so that the UL beam that the base station should use is the operation of reception sweeping. Can be determined without. The combination of the Rough beam and the Accurate beam described in the above (Efficiency of beam sweeping) is as follows.
[0056]
　(DL Beam Sweeping Procedure)
　FIG. 11 is an explanatory diagram showing an example of a DL beam sweeping procedure by the base station 100 and the terminal device 200. First, the base station performs transmission sweeping using Rough beam on the terminal device (step S101). This transmission sweeping is performed by a sweeping pattern unique to the base station 100. In other words, transmission sweeping is also called Base Station-specific or Cell Specific.
[0057]
　The terminal device 200 reports the number of the Rough beam desired for the terminal device 200 to the base station 100 (step S103). When determining the desired Rough beam, the terminal device 200 determines, for example, based on whether the beam has the highest received power.
[0058]
　Upon receiving the report of the Rough beam number from the terminal device 200, the base station 100 performs transmission sweeping using the Accurate Beam corresponding to the Rough beam (step S105). The transmission sweeping at this time may be a sweeping pattern specific to the terminal device 200 specially prepared for the terminal device 200. Alternatively, the sweeping pattern is prepared in common to all the terminal devices 200, but the base station 100 may notify which part is monitored for each terminal device 200. In the former case, the transmission sweeping pattern itself is unique to the terminal device 200 (UE Specific). In the latter case, it can be said that the setting of the transmission sweeping pattern is unique to the terminal device 200 (UE Specific).
[0059]
　The terminal device 200 reports to the base station 100 the number of the Accurate beam that is desirable for the terminal device 200 (step S107). The terminal device 200 may determine the desirable Accurate beam, for example, depending on whether the beam has the highest received power.
[0060]
　Upon receiving the Accurate beam number report from the terminal device 200, the base station 100 transmits DL user data for the terminal device 200 using the Accurate beam (step S109). Then, when the Channel Reciprocity is secured, the base station 100 receives the user data of UL from the terminal device 200 by using the same Accurate beam as the Accurate beam at the time of transmission for reception from the terminal device 200. (Step S111).
[0061]
　The beam setting method may be appropriately changed according to the system application conditions and use cases. As a specific example, the Rough beam may be commonly set for the cell or the base station and shared by a plurality of terminal devices. In this case, each terminal device may monitor the Rough beam. The Accurate beam may be customized and provided for each terminal device. Further, as another example, a common Accurate beam may be provided to a plurality of terminal devices. In this case, by designating which beam is to be monitored for each terminal device, it is possible to provide a required beam for each terminal device.
[0062]
　　(CSI (Channel State Information) acquisition) When the
　above beam sweeping procedure is completed, the optimum transmission beam on the base station side to be used between the base station and the terminal device can be determined. DL CQI acquisition is to grasp the channel quality and interference situation when using the determined transmission beam. DL CQI acquisition is a feedback using UL, which is what is called a CQI (Channel Quality Indicator) feedback, which is what modulation method or coding rate the terminal device wants to use for DL ​​data transmission as a base station. It is necessary to notify the base station from. In order to perform this feedback, the base station transmits the DL reference signal to the terminal device side for DL ​​CSI acquisition, the DL reference signal for DL ​​CSI acquisition is received, and the channel condition is evaluated. To do. By this means, the terminal device can determine a desired CQI (combination of modulation scheme and individual coding rate).
[0063]
　As described above, first, the desired transmission beam on the base station side is determined by the beam sweeping procedure, the CQI is determined on the terminal device side in the CSI acquisition procedure, and the CQI is determined from the terminal device by CSI feedback. It is necessary to notify the base station.
[0064]
　　(Beam Recovery) In the
　present disclosure, beam recovery (Beam Recovery) is to find and use a new beam because the beam between the base station and the terminal device cannot be used for some reason. The reasons why Beam Recovery is required are as follows.
[0065]
　(Reason 1) Blocking
　This is because a beam from the base station does not reach due to an obstacle such as a car or a person entering between the base station and the terminal device, and control signals and user data are transmitted between the base station and the terminal device. It is in a state where communication between them becomes difficult.
[0066]
　(Reason 2) Interference
　This is a state in which signals from other base stations and other terminal devices cause interference, making it difficult to transmit and receive a target signal between the base station and the terminal device.
[0067]
　Blocking is the complete loss of signal, and it is difficult to hope for the same beam to return to communication unless the obstacle, a car or a person, is present. Even if the frequency at which the base station is transmitting data is slightly changed, it is likely that it will be difficult to transmit and receive the beam using the direction of the obstacle in all the neighboring frequency bands. Even in the time direction, there is a high possibility that communication will be difficult for several seconds until the obstacle is not present.
[0068]
　On the other hand, interference does not always occur in all time and frequency resources. Therefore, interference does not occur due to another base station or another terminal device stopping transmission. In LTE, control signals and user data are provided by one beam. On the other hand, in 5G, since it is possible to transmit and receive control signals and user data by using a plurality of beams, it is necessary to improve the resistance to interference in consideration of this characteristic.
[0069]
　On the other hand, in the blocking method, the base station is basically required to change the beam. In changing the beam, there is an urgent need for a return, i.e. the identification of a new beam. This is because, depending on the application, it is assumed that beam communication is used for vehicle control, drone control, remote medical device control, etc. that require continuous low-delay communication.
[0070]
　(Target of
　recovery ) There are various possible targets for recovery. The possible targets for recovery are listed below.
[0071]
(1) PDCCH (Physical Downlink Control Channel) The
　PDCCH is a channel through which a downlink control signal is transmitted, and has higher importance than user data. Therefore, it is desirable to quickly recover from the situation where the terminal device cannot receive the control signal.
[0072]
(2) PDSCH (Physical Downlink Shard Channel)
　PDSCH is a channel for transmitting downlink user data. In many cases, the user data itself cannot be received by the terminal device. For example, the terminal device may temporarily be unable to receive the user data due to interference. Normally, when the terminal device cannot receive the user data, the terminal device returns NACK to the base station to notify that the data cannot be received, and has the same data retransmitted.
[0073]
(3) PUCCH (Physical Uplink Control Channel)
　PUSCH is a channel transmitted by an Uplink control signal, and is as important as a Downlink control signal.
[0074]
(4) PUSCH (Physical Uplink Shared Channel)
　PDSCH is a channel through which Uplink user data is transmitted.
[0075]
(5) Beam This
　is a beam used between the base station and the terminal device. The base station determines a beam, and then uses the beam to perform transmission and reception of Uplink and Downlink. Therefore, when the used beam itself is no longer usable, the base station needs to immediately find a new suitable beam. After all, the beam should be the first to be restored. This is because it is difficult to restore only the PDCCH without restoring the beam. That is, it can be said that beam restoration is the most important of the five mentioned above.
[0076]
　(
　Environment for recovering ) As an environment for recovering, basically, there are many cases where a base station provides a plurality of beams. This is because if there is another beam when blocking occurs, there are few situations in which communication between the base station and the terminal device is completely interrupted. However, the base station is not always able to use a plurality of beams, and a case may be assumed in which communication is performed using only one beam. In such cases, the base station needs to find a new suitable beam immediately.
[0077]
　In view of the above situation, the present disclosure proposes an example of a technique capable of promptly recovering communication between a base station and a terminal device even when blocking, beam quality deterioration, or the like occurs. Specifically, the present disclosure proposes an example of a technique that enables a new beam link to be quickly found in a beam recovery procedure.
[0078]
　<<3. Technical Features>> The technical features of the
　communication system according to an embodiment of the present disclosure will be described below.
[0079]
　　(Basic configuration) When
　a DL beam (Downlink beam) in use between a base station and a terminal device is lost due to blocking, it is necessary to find a new DL beam. In the method in which the base station performs beam sweeping again and then the terminal device finds a more suitable beam and feeds it back to the base station, it may take time for beam sweeping. Therefore, it may be difficult to quickly find a new beam by such a method.
[0080]
　On the other hand, in the beam report for the normal beam sweeping, in addition to the candidate of the beam (optimal beam) that the terminal device wants to use for communication with the base station, the candidate of the beam for backup is reported. Therefore, it is possible to provide redundancy in beam selection. However, if only K (K is an integer equal to or greater than 2) beams are reported, the base station determines that the beam mainly used for communication with the terminal device (that is, the terminal device communicates with the base station It is difficult to distinguish between the beam that is desired to be used for communication) and the beam notified for backup.
[0081]
　In view of such a situation, in the system according to the embodiment of the present disclosure, the terminal device 200 specifies and reports a backup beam when performing beam reporting to the base station 100. In other words, the terminal device 200 reports the backup beam separately from the beam candidates desired to be used for communication with the base station. The backup beam corresponds to, for example, a beam that can be used in place of a beam that is preferentially used for communication between the base station 100 and the terminal device 200 (for example, a beam that the terminal device wants to use). .. The method of designating the backup beam is not particularly limited. That is, the backup beam may be explicitly (Explicit) specified or implicitly (Implicit) specified.
[0082]
　Here, with reference to FIG. 12, an example of a flow of a series of processes of the communication system according to the present embodiment, particularly an example of a flow of processes related to beam reporting from the terminal device 200 to the base station 100 will be described. FIG. 12 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to this embodiment.
[0083]
　As illustrated in FIG. 12, the base station 100 (notification unit 155) notifies the terminal device 200 located within its own communication range (within the cell) of information regarding the setting of beam sweeping (S201). In addition, the base station 100 (notification unit 155) notifies the terminal device 200 of information regarding the setting of beam reporting (S203). Then, the base station 100 (communication control unit 151) performs beam sweeping (S205). Specifically, the base station 100 emits a beam in a time division manner in each of a plurality of directions.
[0084]
　The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam that the base station 100 transmits in each of a plurality of directions in a time division manner. The terminal device 200 (selection unit 245) measures the quality of each beam (for example, RSRP: Reference Signal Received Power), and according to the measurement result, the beam used preferentially for communication with the base station 100 (hereinafter, beam). , "Main beam") and a backup beam (hereinafter also referred to as "backup beam") that can be used instead of the beam. Then, the terminal device 200 (notifying unit 247) notifies the base station 100 of information regarding the selected main beam (that is, the beam that the terminal device 200 wants to use) and the backup beam, respectively, to the base station 100 (that is, the beam). Beam reporting). As a specific example, the terminal device 200 associates, with the IDs of the selected main beam and backup beam, information corresponding to the measurement result of the beam quality (for example, RSRP measurement result), The ID may be notified to the base station 100 (S207). In this description, it is assumed that the beam associated with ID1 is selected as the main beam and the beam associated with ID2 is selected as the backup beam.
[0085]
　The base station 100 (information acquisition unit 243) acquires from the terminal device 200 a notification (report) regarding the main beam and backup beam selected by the terminal device 200. The base station 100 (communication control unit 151) registers ID2 as the ID of the backup beam based on the notification from the terminal device 200 (S209). Then, the base station 100 (communication control unit 151) transmits the user data to the terminal device 200 using the beam associated with ID1 (S211).
[0086]
　Regarding the beam registered as the backup beam (that is, the beam associated with ID2), the communication between the base station 100 and the terminal device 200 using the main beam (that is, the beam associated with ID1) is performed. When it becomes difficult, it is used for the communication instead of the beam. This allows the base station 100 to continue communication using the registered backup beam without performing beam sweeping again, even when communication with the main beam becomes difficult. The main beam corresponds to an example of “first beam”, and the backup beam corresponds to an example of “second beam”.
[0087]
　The basic configuration of the communication system according to the present embodiment has been described above with reference to FIG.
[0088]
　　(Modification 1)
　Next, a modification of the communication system according to an embodiment of the present disclosure will be described. Note that, hereinafter, this modified example is also referred to as “modified example 1”.
[0089]
　In this modification, an example will be described in which the base station 100 instructs the terminal device 200 to perform a report regarding a backup beam. Specifically, when the terminal device 200 receives an instruction from the base station 100, the terminal device 200 notifies (reports) information regarding the backup beam to the base station 100. For example, FIG. 13 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to the first modification. Specifically, FIG. 13 illustrates an example of a case where the base station 100 selectively controls whether or not to notify the terminal device 200 of information regarding a backup beam based on timer control. ..
[0090]
　As shown in FIG. 13, the base station 100 (notifying unit 155) notifies the terminal device 200 located within its communication range (within the cell) of the information regarding the setting of beam sweeping (S251). In addition, the base station 100 (notifying unit 155) notifies the terminal device 200 of the information regarding the setting of the beam reporting and the information regarding the setting of the reporting of the backup beam, respectively (S253). Then, the base station 100 (communication control unit 151) performs beam sweeping (S255). Specifically, the base station 100 emits a beam in a time division manner in each of a plurality of directions.
[0091]
　The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam that the base station 100 transmits in each of a plurality of directions in a time division manner. The terminal device 200 (selection unit 245) measures the quality (for example, RSRP) of each beam, and selects the main beam and the backup beam according to the measurement result. Then, the terminal device 200 associates the IDs of the selected main beam and backup beam with information corresponding to the measurement result of the quality of the beam (for example, RSRP measurement result), and then uses the ID as a base. Notify the station 100 (S257). In this description, it is assumed that the beam associated with ID1 is selected as the main beam and the beam associated with ID2 is selected as the backup beam.
[0092]
　The base station 100 (information acquisition unit 243) acquires from the terminal device 200 a notification (report) regarding the main beam and backup beam selected by the terminal device 200. Based on the notification from the terminal device 200, the base station 100 (communication control unit 151) registers ID2 as the ID of the backup beam and starts the timer (S259). Then, the base station 100 (communication control unit 151) transmits the user data to the terminal device 200 using the beam associated with ID1 (S261).
[0093]
　Next, the operation before the expiration date of the timer elapses will be described. The base station 100 (notification unit 155) notifies the terminal device 200 of information regarding the setting of beam reporting. At this time, the base station 100 does not notify the terminal device 200 of the information regarding the backup beam reporting setting (S263). Then, the base station 100 (communication control unit 151) performs beam sweeping (S265).
[0094]
　The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam that the base station 100 transmits in each of a plurality of directions in a time division manner. The terminal device 200 (selection unit 245) measures the quality (for example, RSRP) of each beam, and selects the main beam according to the measurement result. At this time, the terminal device 200 does not select the backup beam based on the information notified from the base station 100. Then, the terminal device 200 (notification unit 247) associates the selected main beam ID with information corresponding to the measurement result of the quality of the beam (for example, RSRP measurement result), and then assigns the ID. Notify the base station 100 (S267)
[0095]
　Subsequently, as indicated by reference numeral S269, it is assumed that the expiration date of the timer has passed. In this case, the base station 100 (notification unit 155) notifies the terminal device 200 of the information regarding the setting of the beam reporting and the information regarding the setting of the backup beam reporting, respectively (S271). Then, the base station 100 (communication control unit 151) performs beam sweeping (S273).
[0096]
　The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam that the base station 100 transmits in each of a plurality of directions in a time division manner. The terminal device 200 (selection unit 245) measures the quality (for example, RSRP) of each beam and selects the main beam and the backup beam according to the measurement result. Then, the terminal device 200 associates the IDs of the selected main beam and backup beam with information corresponding to the measurement result of the quality of the beam (for example, RSRP measurement result), and then uses the ID as a base. Notify the station 100 (S275).
[0097]
　By the control as described above, when the base station 100 registers the backup beam based on the report from the terminal device 200, the base station 100 determines that the backup beam is valid for a certain period by the timer control. Then, when the expiration date of the timer has passed, the base station 100 causes the terminal device 200 to newly report the backup beam, and then newly registers the backup beam. That is, the base station 100 controls the terminal device 200 not to request the report regarding the backup beam during the period when the backup beam is effective. By such control, the frequency of reporting the backup beam is suppressed, and the UL overhead due to the report can be reduced as compared with the case where the report of the backup beam is performed every time beam sweeping is performed. Become.
[0098]
　The communication system according to Modification 1 has been described above with reference to FIG.
[0099]
　　(Modification 2)
　Next, another modification of the communication system according to an embodiment of the present disclosure will be described. Note that, hereinafter, this modification will also be referred to as “modification 2”.
[0100]
　As described above, in the communication system according to the present embodiment, when the terminal device 200 performs the beam reporting to the base station 100, the backup beam is also reported. In this modification, the terminal device 200 sets a beam group including one or more backup beams (hereinafter, also referred to as “backup beam group”), and reports the beam group to the base station 100.
[0101]
　For example, FIG. 14 is an explanatory diagram for describing the outline of the communication system according to the second modification. In the example shown in FIG. 14, backup beam groups B101 to B103 are set. Specifically, the backup beam group B101 is set to include the backup beams B101-1 to B101-3. The backup beam group B102 is set to include the backup beams B102-1 and B102-2. The backup beam group B103 is set so as to include the backup beams B103-1 to B103-3.
[0102]
　It is desirable that the backup beam groups have low correlation with each other, and that the beams included in the other group can be used as backups of the beams included in the one group. Further, it is preferable that the plurality of beams included in the same group have the same characteristics. Further, the base station can recognize that the beams belonging to different backup groups have a relationship in which they can be used as backups. Therefore, it is not necessary to explicitly indicate that the beams belong to different backup groups as backup. Of course, it may be specified that the beams belong to different backup groups as backup.
[0103]
　As a method of classifying each beam into a backup group, for example, there is a method of classifying each of a plurality of beams into a group according to the arrival direction of each beam when viewed from the terminal device 200. In this case, the terminal device 200 classifies each beam according to the direction in which the beam reaches itself (that is, the arrival direction of the beam) based on the reception result of each beam, and each of the beams is classified according to the classification result. The beams may be grouped.
[0104]
　Further, as another example, there is a method of classifying each of the plurality of beams into groups according to the direction in which the base station 100 transmits each beam (radiation direction). In this case, the terminal device 200 transmits information regarding the direction in which each beam is transmitted (for example, information indicating how different the direction in which each beam is transmitted, etc.) or between the beams transmitted from the base station 100. Information such as the correlation value of is preferably acquired in advance from the base station 100. This allows the terminal device 200 to determine a backup beam for each received beam, depending on the direction in which the beam is transmitted from the base station 100 when viewed from the base station 100. That is, the terminal device 200 can also report, for each of the determined backup beams, the measurement result (for example, RSRP) of the quality of the beam to the base station 100. Also, the terminal device 200 may classify each beam according to the direction in which the beam is transmitted from the base station 100, and group each beam according to the classification result.
[0105]
　Here, with reference to FIG. 15, an example of a flow of a series of processes of the communication system according to the second modification, particularly an example of a process flow of beam reporting from the terminal device 200 to the base station 100 will be described. FIG. 15 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 2.
[0106]
　As shown in FIG. 15, the base station 100 (notification unit 155) notifies the terminal device 200 located within its communication range (within the cell) of the information regarding the setting of the beam sweeping (S301). In addition, the base station 100 (notifying unit 155) notifies the terminal device 200 of information regarding the setting of beam reporting (S303). Then, the base station 100 (communication control unit 151) performs beam sweeping (S305). Specifically, the base station 100 emits a beam in a time division manner in each of a plurality of directions.
[0107]
　The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam that the base station 100 transmits in each of a plurality of directions in a time division manner. The terminal device 200 (selection unit 245) selects a beam used as a main beam or a backup beam based on the reception result of each beam, and allocates each selected beam to a beam group. Then, the terminal device 200 (notifying unit 247) notifies the base station 100 of information on the set beam group (for example, the beam group ID) in association with the beam report (S307). In this description, it is assumed that beam groups 1 to 3 are set.
[0108]
　The base station 100 (information acquisition unit 243) acquires from the terminal device 200 a notification (beam report) associated with the information about the beam group set by the terminal device 200. The base station 100 (communication control unit 151) selects, for example, a beam belonging to any one of the beam groups set by the terminal device 200 as a main beam based on the notification from the terminal device 200, Beams belonging to other beam groups are registered as backup beams. In this description, it is assumed that the beam belonging to the beam group 3 is selected as the main beam and the beams belonging to the beam groups 1 and 2 are registered as the backup beams (S309). Then, the base station 100 (communication control unit 151) transmits the user data to the terminal device 200 using the beam belonging to the beam group 3 (that is, the beam selected as the main beam) (S311).
[0109]
　When a backup beam group is set according to the direction in which the base station 100 transmits each beam, beams belonging to the same beam group arrive from different directions when viewed from the terminal device 200. It may appear as a beam. Similarly, when a backup beam group is set according to the arrival direction of each beam to the terminal device 200, the beams belonging to the same beam group are transmitted in different directions when viewed from the base station 100. It may be seen as a broken beam.
[0110]
　Further, when a beam group is set, only some of the one or more beams included in the beam group (for example, beams having better characteristics) may be used for communication. In this case, for example, at the time of switching to backup, beam sweeping is performed in the backup beam group to be switched, so that some of the beams belonging to the backup beam group are selected as backup beams. May be done. In this case, since the range in which beam sweeping is performed is limited to the range of the backup beam group, it is possible to reduce the time required for processing as compared to the case where beam sweeping is performed for the entire target. Becomes
[0111]
　The communication system according to Modification 2 has been described above with reference to FIGS. 14 and 15.
[0112]
　　(Modification 3)
　Next, another modification of the communication system according to an embodiment of the present disclosure will be described. Note that, hereinafter, this modification will also be referred to as “modification 3”. In this modification, an example of control according to the blocking situation will be described.
[0113]
　First, an example of a blocking situation will be described with reference to FIGS. 16 and 17. As described above, in blocking, an obstacle (Obstacle) such as a person, a vehicle, or a building is interposed between the base station 100 and the terminal device 200, and the obstacle causes a gap between the base station 100 and the terminal device 200. Occurs when the communication (in other words, the beam) is blocked. On the other hand, the blocking situation differs depending on the positional relationship between the base station 100, the terminal device 200, and the obstacle.
[0114]
　For example, FIG. 16 is an explanatory diagram for describing an example of a blocking situation. In the example shown in FIG. 16, an obstacle 310 is located near the terminal device 200, and the obstacle 310 blocks the beam from the base station 100. In addition, FIG. 17 is an explanatory diagram for describing another example of the blocking situation. In the example shown in FIG. 17, an obstacle 310 is located near the base station 100, and the obstacle 310 blocks the beam from the base station 100. In each case shown in FIGS. 16 and 17, the beam to be held as a backup candidate is different.
[0115]
　For example, as shown in FIG. 16, when the obstacle 310 is located near the terminal device 200, use a beam that arrives from a direction different from the direction in which the obstacle 310 is located when viewed from the terminal device 200. Is important. For example, FIG. 18 is an explanatory diagram for describing an example of a beam selected according to a blocking situation, and an example of a case where an obstacle 310 is located near the terminal device 200 as illustrated in FIG. Showing. Specifically, FIG. 18 illustrates an example of a beam that is reflected by a reflector 330 such as a building and arrives at the terminal device 200 from a direction different from the direction in which the obstacle 310 is located. ..
[0116]
　On the other hand, as shown in FIG. 17, when the obstacle 310 is located in the vicinity of the base station 100, the obstacle 310 is transmitted in a direction different from the direction in which the obstacle 310 is located when viewed from the base station 100. It is important to use the beam that reaches the device 200. For example, FIG. 19 is an explanatory diagram for describing an example of a beam selected according to a blocking situation, and an example of a case where an obstacle 310 is located near the base station 100 as illustrated in FIG. Showing. Specifically, in FIG. 19, the terminal device is transmitted from the base station 100 to the base station 100 in a direction different from the direction in which the obstacle 310 is located, and is reflected by a reflector 330 such as a building. An example of a beam reaching 200 is shown.
[0117]
　In view of the above situation, for example, when the beam is blocked in the vicinity of the terminal device 200, the backup beam has a different direction from the beam used before as seen from the terminal device 200. It is desirable to select candidates for beams coming from. It should be noted that the beam selected at this time has a possibility that the direction in which it is transmitted from the base station 100 is significantly different from the beam used before, and may not be significantly different from the beam used before. , Both can be envisaged. This is because this is the viewpoint from the terminal device 200 side.
[0118]
　In such a case, for example, first, based on the reception beam forming (beam forming) on ​​the terminal device 200 side, the reception beam forming on the terminal device 200 side for receiving a more suitable beam is specified. Then, when the backup beam is determined, when reception beamforming on the terminal device 200 side in a direction different from the specified reception beamforming on the terminal device 200 side is used, reception can be performed with larger reception power. The beam from the base station 100 may be specified. In this case, the terminal device 200 may report the specified beam to the base station 100 as a backup beam (back up beams from UE perspective) from the viewpoint of the terminal device 200. The report on the backup beam from the viewpoint of the terminal device 200 corresponds to an example of “first information”.
[0119]
　When a beam is blocked in the vicinity of the base station 100, a candidate beam to be transmitted in a different direction from the beam used before is selected as the backup beam from the perspective of the base station 100. It is desirable to do. Note that the beam selected at this time has a possibility that the direction of arrival at the terminal device 200 is significantly different from the beam used before, and the possibility that it is not significantly different from the beam used before, Both can be envisioned. This is because this is from the viewpoint of the base station 100 side.
[0120]
　In such a case, for example, the terminal device 200 first identifies a more suitable beam from among the beams transmitted by the beam sweeping by the base station 100. Then, when the backup beam is determined, a beam that can be received with a larger reception power may be identified from the identified beam and the beam having a lower correlation from the viewpoint of the base station 100 side. In this case, the terminal device 200 side determines whether or not the correlation between the beams transmitted from the base station 100 (that is, the correlation between the beams from the viewpoint of the base station 100 side) is low. A mechanism is needed. Therefore, for example, the base station 100 starts beam sweeping on information such as the direction of each beam transmitted from the base station 100, the weight of the antenna used for the beam, and the correlation value between the transmitted beams. It is preferable to notify the terminal device 200 in advance (Base station beam information). As a result, the terminal device 200 can select a beam candidate to be transmitted in a different direction from the beam used before, as viewed from the base station 100. In this case, the terminal device 200 may report the identified beam to the base station 100 as a backup beam (back up beam from base station perspective) from the viewpoint of the base station 100. The report on the backup beam from the viewpoint of the base station 100 corresponds to an example of “second information”.
[0121]
　The backup beam report may be, for example, a backup beam (back up beam from base station perspective) when blocking occurs near the base station 100 and a backup beam (blocking beam when blocking occurs near the terminal device 200 ( Both the back up beams from UE perspective) may be notified to the base station 100.
[0122]
　In addition, when blocking occurs, the terminal device 200 may make a request for beam recovery to the base station 100 (blocking notification). At this time, it may be assumed that it is difficult for the base station 100 to determine whether blocking has occurred near the base station 100 or near the terminal device 200. Therefore, for example, the base station 100 transmits backup beams from the viewpoints of the base station 100 and the terminal device 200 registered as backups to the terminal device 200, and issues a report according to the evaluation result of the beam. You may acquire from the terminal device 200. In this case, for example, the base station 100 may use a beam having a better evaluation result from the terminal device 200 to restore communication with the terminal device 200. Of course, the above is only an example, and the operation related to beam restoration is not necessarily limited. As a specific example, if the base station 100 can recognize the positional relationship between the base station 100, the terminal device 200, and the obstacle, of the base station 100 and the terminal device 200 according to the recognition result. A backup beam according to at least one of the viewpoints may be used to restore communication.
[0123]
　Here, with reference to FIG. 20, an example of a flow of a series of processes of the communication system according to Modification 3 will be described, particularly focusing on a process flow regarding beam reporting from the terminal device 200 to the base station 100. .. FIG. 20 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 3.
[0124]
　As shown in FIG. 20, the base station 100 (notification unit 155) notifies the terminal device 200 located within its communication range (within the cell) of the information regarding the setting of beam sweeping (S351). In addition, the base station 100 (notification unit 155) notifies the terminal device 200 of information about each beam (Base station beam information) transmitted from the base station 100 (S353). In addition, the base station 100 (notification unit 155) notifies the terminal device 200 of information regarding the setting of beam reporting (S355). Then, the base station 100 (communication control unit 151) performs beam sweeping (S357). Specifically, the base station 100 emits a beam in a time division manner in each of a plurality of directions.
[0125]
　The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam that the base station 100 transmits in each of a plurality of directions in a time division manner. The terminal device 200 (selection unit 245) selects a beam (that is, a main beam) to be used with priority for transmission of user data based on the reception result of each beam, and outputs information regarding the selected beam to a beam report. The base station 100 is associated and notified (S359). Further, the terminal device 200 specifies a backup beam (back up beams from UE perspective) from the perspective of the terminal device 200, and notifies the base station 100 of information regarding the beam in association with the beam report (S361). In addition, the terminal device 200 identifies a backup beam from the perspective of the base station 100 (back up beams from base station perspective), and notifies the base station 100 of information relating to the beam in association with the beam report (S363).
[0126]
　The base station 100 (information acquisition unit 243) uses the backup beam (back up beams from UE perspective) from the viewpoint of the terminal device 200 and the base station 100 based on the information (beam report) notified from the terminal device 200. And a back up beam from a base station perspective is registered (S365). In addition, the base station 100 (communication control unit 151) transmits user data to the terminal device 200, for example, using the beam selected as the main beam based on the information notified from the terminal device 200 (S367). ..
[0127]
　Next, it is assumed that blocking occurs, and the terminal device 200 (notification unit 247) makes a request for beam recovery (Blocking notification/beam recovery request) to the base station 100 (S369).
[0128]
　The base station 100 (communication control unit 151) registers a backup beam (back up beams from UE perspective) from the viewpoint of the terminal device 200 and a backup beam (viewpoint from the base station 100) registered as a backup. Back up beams from base station perspective) are transmitted to the terminal device 200 (S371, S373). The terminal device 200 (communication control unit 241) receives the backup beams from the viewpoints of the terminal device 200 and the base station 100, which are transmitted from the base station 100. Then, the terminal device 200 (notifying unit 247) reports on both the backup beams from the viewpoints of the terminal device 200 and the base station 100 (S375). Thereby, the base station 100 can restore communication with the terminal device 200 by using a more preferable beam among the backup beams from the viewpoints of the terminal device 200 and the base station 100, respectively.
[0129]
　Since normal beam sweeping requires time for processing, it is desirable to search for a beam that can be used for restoration (for example, a beam of good quality) from the registered backup beams as much as possible. However, if there is no suitable beam among the registered backup beams, the base station 100 may search again for a beam that can be used for restoration by normal beam sweeping. This operation is not limited to this modification, but is also the same for the above-described embodiment and other modifications.
[0130]
　The communication system according to Modification 3 has been described above with reference to FIGS. 16 to 20.
[0131]
　　(Modification 4)
　Next, another modification of the communication system according to an embodiment of the present disclosure will be described. Note that, hereinafter, this modification will also be referred to as “modification 4”. In this modification, an example of control assuming use of a partial frequency band will be described. In the following description, the “frequency band” will also be simply referred to as the “band”.
[0132]
　First, the outline of the “partial band” will be described with reference to FIG. FIG. 21 is an explanatory diagram for describing an overview of a partial band in 5G. As shown in FIG. 21, in 5G, a plurality of partial bands (band width part) are prepared in one component carrier. These partial bands may be used for a variety of purposes, such as being used for high speed downloads or for carrying low latency traffic. Also, separate partial bands may be used, each with different subcarrier spacing. As a specific example, bands having different subcarrier intervals for each feature may be used. Examples of subcarrier intervals include, for example, 15 kHz, 30 kHz, 60 kHz, and the like. Also, different neurology may be applied to each partial band.
[0133]
　When partial bands are used, basically beam sweeping is performed for each band. For example, in the example shown in FIG. 21, partial band 1 and partial band 2 are set as partial bands. In this case, beam sweeping at normal time is performed for both partial band 1 and partial band 2. Also, the backup beam may be set for each of the partial band 1 and the partial band 2, and in this case, both the partial band 1 and the partial band 2 are transmitted from the terminal device 200 to the base station 100. About backup beam information (report) will be notified. On the base station 100 side, backup beams are registered for each of partial band 1 and partial band 2 in response to the notification from the terminal device 200.
[0134]
　Further, when a request for beam recovery (Beam recovery request) is made from the terminal device 200 to the base station 100, the base station 100 is a backup beam corresponding to each of partial band 1 and partial band 2. May be time-division multiplexed or frequency-multiplexed and transmitted to the terminal device 200. At this time, the base station 100 may transmit the backup beam corresponding to each of the multiplexed partial band 1 and partial band 2 as one configuration. Accordingly, the terminal device 200 can simultaneously evaluate the backup beams corresponding to the partial band 1 and the partial band 2, for example, and can shorten the time required for beam restoration.
[0135]
　Here, with reference to FIG. 22, an example of the flow of a series of processes of the communication system according to Modification 4 will be described, particularly focusing on the flow of processes related to beam reporting from the terminal device 200 to the base station 100. .. FIG. 22 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 4. In the example shown in FIG. 22, it is assumed that partial band 1 and partial band 2 are set as partial bands, as shown in FIG.
[0136]
　As shown in FIG. 22, the base station 100 (notifying unit 155) notifies the terminal device 200 located within its communication range (within the cell) of the information regarding the setting of the beam sweeping (S401). Further, the base station 100 (notification unit 155) notifies the terminal device 200 of information regarding the setting of the beam reporting and the setting of the backup beam reporting (S403).
[0137]
　Subsequently, the base station 100 (communication control unit 151) performs beam sweeping. At this time, the base station 100 individually performs beam sweeping on each of partial band 1 and partial band 2.
[0138]
　Specifically, first, the base station 100 (communication control unit 151) performs beam sweeping on partial band 1 (S405). The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam transmitted by the base station 100 in each of a plurality of directions in time division using the partial band 1. .. The terminal device 200 (selection unit 245) performs notification of information about the main beam (Beam report) and notification of information about the backup beam (Backup beam report) for partial band 1 based on the reception result of each beam. (S407).
[0139]
　Next, the base station 100 (communication control unit 151) performs beam sweeping on partial band 2 (S409). The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam transmitted by the base station 100 in each of a plurality of directions in a time division manner using the partial band 2. .. The terminal device 200 (selection unit 245) performs notification of information regarding the main beam (Beam report) and notification of information regarding the backup beam (Backup beam report) for partial band 2 based on the reception result of each beam. (S411).
[0140]
　The base station 100 (information acquisition unit 243) registers a backup beam for each of partial band 1 and partial band 2 based on the information notified from the terminal device 200 for each of partial band 1 and partial band 2 (S413).
[0141]
　Subsequently, it is assumed that blocking occurs, and the terminal device 200 (notification unit 247) makes a request for beam recovery (Blocking notification/beam recovery request) to the base station 100 (S415).
[0142]
　The base station 100 (communication control unit 151) transmits, to the terminal device 200, a backup beam corresponding to partial band 1 and a backup beam corresponding to partial band 2, which are registered as backups (S417). , S419). At this time, the base station 100 may transmit the backup beams corresponding to each of the partial band 1 and the partial band 2 as one configuration by time-division-multiplexing or frequency-division-multiplexing as described above. The terminal device 200 (communication control unit 241) receives the backup beams corresponding to the partial band 1 and the partial band 2 transmitted from the base station 100. Then, the terminal device 200 (notifying unit 247) reports on both backup beams corresponding to partial band 1 and partial band 2 (S421). Accordingly, the base station 100 can restore communication with the terminal device 200 by using a more suitable beam for each of the partial band 1 and the partial band 2.
[0143]
　Then, for the partial band 1, the base station 100 transmits the user data to the terminal device 200 by using the backup beam corresponding to the partial band 1 (S423). Similarly, for the partial band 2, the base station 100 uses the backup beam corresponding to the partial band 2 to transmit the user data to the terminal device 200 (S425).
[0144]
　In the example illustrated in FIG. 22, the case where recovery is required for both partial band 1 and partial band 2 has been described. On the other hand, a situation in which only one of partial band 1 and partial band 2 is restored may be assumed. For example, when only the partial band 1 is restored, the terminal device 200 may notify the base station 100 of a request for restoration of only the partial band 1 by a beam recovery request (Beam recovery request). .. Further, in this case, the base station 100 may execute the process related to beam restoration only for partial band 1 in response to a request from the terminal device 200.
[0145]
　Further, in the above description, the description is made by focusing on the processing for each partial band, but it is also possible to replace the partial band with a component carrier and execute the above processing. That is, it is possible to register a backup beam for each component carrier and restore the communication between the base station 100 and the terminal device 200 for each component carrier by using the registered backup beam.
[0146]
　The communication system according to Modification 4 has been described above with reference to FIGS. 21 and 22.
[0147]
　　(Modification 5)
　Next, another modification of the communication system according to an embodiment of the present disclosure will be described. Note that, hereinafter, this modification will also be referred to as “modification 5”.
[0148]
　In the above-described modified example, after the backup beam is registered for each partial band, the communication between the base station 100 and the terminal device 200 is restored by using the backup beam corresponding to each partial band. An example of the case of performing (that is, performing beam recovery) has been described. In this modification, priority is set between partial bands (or between backup beams for each band), and beams are restored in accordance with the priority, so that communication with higher priority is performed. An example of a technique that makes it possible to shorten the time required for beam restoration for a band in which the beam is being performed will be described.
[0149]
　Specifically, in the communication system according to the present modification, when a message related to beam recovery (Beam recovery) includes information regarding a plurality of partial bands (for example, partial bands), which band Decide in advance whether to use the backup beam first. The priority may be notified from the base station 100 to the terminal device 200, for example. Further, as another example, the priority may be defined in advance by a standard or the like. In addition, as another example, the terminal device 200 may notify the base station 100 of information regarding a desired priority. The priority may be set between bands or between backup beams registered for each band.
[0150]
　Here, with reference to FIG. 23, an example of a series of processing flows of the communication system according to Modification 5 will be described, particularly focusing on the processing flow related to beam reporting from the terminal device 200 to the base station 100. .. FIG. 23 is a sequence diagram showing an example of the flow of a series of processes of the communication system according to Modification 5. Note that in the example shown in FIG. 23, as shown in FIG. 21, partial band 1 and partial band 2 are set as partial bands.
[0151]
　First, the base station 100 and the terminal device 200 execute a procedure related to backup beam registration, as indicated by reference numerals S451 to S463. The processing indicated by reference numerals S451 to S463 is substantially the same as the processing indicated by reference numerals S401 to S413 in the example shown in FIG. 22, and thus detailed description thereof will be omitted.
[0152]
　In addition, the terminal device 200 (notifying unit 247) notifies the base station 100 of a request for setting the priority between partial bands for beam restoration (S465). The base station 100 (notification unit 155) notifies the request from the terminal device 200 of information regarding the priority set between the partial bands (S467). Note that in the example shown in FIG. 23, it is assumed that a priority higher than that of partial band 1 is set for partial band 2. Specifically, the highest priority (1st prioritization) is set for partial band 2, and the next highest priority (2nd prioritization) is set for partial band 1. To do.
[0153]
　Next, it is assumed that blocking occurs, and the terminal device 200 (notification unit 247) makes a request for beam recovery (Blocking notification/beam recovery request) to the base station 100 (S469).
[0154]
　First, the base station 100 restores the beam for the partial band 2 in which the highest priority (1st prioritization) is set. Specifically, the base station 100 (communication control unit 151) transmits a backup beam corresponding to partial band 2 to the terminal device 200 (S471). The terminal device 200 (communication control unit 241) receives the backup beam corresponding to partial band 2 transmitted from the base station 100. In addition, the terminal device 200 (notification unit 247) reports the backup beam corresponding to partial band 2 (S473). This allows the base station 100 to restore communication with the terminal device 200 by using a more suitable beam for partial band 2. Then, for the partial band 2, the base station 100 uses the backup beam corresponding to the partial band 2 to transmit the user data to the terminal device 200 (S475).
[0155]
　Next, the base station 100 restores the beam for the partial band 1 in which the second highest priority (2nd prioritization) of the partial band 2 is set. Specifically, the base station 100 (communication control unit 151) transmits a backup beam corresponding to partial band 1 to the terminal device 200 (S477). The terminal device 200 (communication control unit 241) receives the backup beam corresponding to partial band 1 transmitted from the base station 100. In addition, the terminal device 200 (notification unit 247) reports the backup beam corresponding to partial band 1 (S479). This allows the base station 100 to restore communication with the terminal device 200 by using a more suitable beam for partial band 1. Then, for the partial band 1, the base station 100 transmits the user data to the terminal device 200 using the backup beam corresponding to the partial band 1 (S481).
[0156]
　As described above, when the request for beam restoration is notified from the terminal device 200, the base station 100 preferentially restores a beam with a higher priority band. As a result, it becomes possible to further shorten the recovery time of communication in which a higher priority is set.
[0157]
　Note that beam restoration may be performed only for some of two or more bands out of a plurality of partial bands for which backup beams are registered. In this case, for example, of the two or more bands for which the beam restoration is requested, the band for which the higher priority is set may be controlled so that the beam restoration is given priority.
[0158]
　The communication system according to Modification 5 has been described above with reference to FIG.
[0159]
　　(Modification 6)
　Next, another modification of the communication system according to an embodiment of the present disclosure will be described. Note that, hereinafter, this modification will also be referred to as “modification 6”.
[0160]
　In Modifications 5 and 6 described above, an example in which the backup beam is registered for each partial band has been described. On the other hand, in the present modification, by registering a backup beam commonly among a plurality of partial bands, signaling at the time of backup beam registration and beam restoration is reduced, and as a result, throughput is improved. We propose an example of possible technology.
[0161]
　Specifically, it is more desirable that CSI Acquisition be performed separately for each partial band. This is because the channel characteristics may differ for each partial band. On the other hand, regarding the procedure for searching for a more suitable beam in the beam management procedure, there is often no significant difference in the beams used in each partial band. This is because the beam forming used in 5G forms a beam by concentrating energy in a specific direction. Therefore, if the frequency is slightly different, a large change occurs in the direction in which the beam is directed. Because there is no. From these characteristics, for example, even if a beam that is suitable for each partial band is selected in normal times, a common beam is registered for beams for beam recovery in an emergency. It may be assumed that it should be kept.
[0162]
　Here, with reference to FIG. 24, an example of a series of processing flows of the communication system according to Modification 6 will be described, particularly focusing on the processing flow related to beam reporting from the terminal device 200 to the base station 100. .. FIG. 24 is a sequence diagram showing an example of a flow of a series of processes of the communication system according to Modification 6. Note that, in the example shown in FIG. 24, as shown in FIG. 21, partial band 1 and partial band 2 are set as partial bands.
[0163]
　As shown in FIG. 24, the base station 100 (notification unit 155) notifies the terminal device 200 located within its own communication range (within the cell) of information regarding the setting of beam sweeping (S501). Subsequently, the base station 100 (communication control unit 151) performs beam sweeping. At this time, the base station 100 individually performs beam sweeping on each of partial band 1 and partial band 2.
[0164]
　Specifically, first, the base station 100 (communication control unit 151) performs beam sweeping on partial band 1 (S503). The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam transmitted by the base station 100 in each of a plurality of directions in time division using the partial band 1. .. The terminal device 200 (selection unit 245) notifies the information (Beam report) regarding the main beam for partial band 1 based on the reception result of each beam (S505).
[0165]
　Next, the base station 100 (communication control unit 151) performs beam sweeping on partial band 2 (S507). The terminal device 200 (communication control unit 241) receives, based on the information notified from the base station 100, a beam transmitted by the base station 100 in each of a plurality of directions in a time division manner using the partial band 2. .. The terminal device 200 (selection unit 245) notifies the information (Beam report) about the main beam for partial band 2 based on the reception result of each beam (S509).
[0166]
　In addition, the terminal device 200 (selection unit 245), based on the reception result of each beam transmitted for each of partial band 1 and partial band 2, information regarding a backup beam common to partial band 1 and partial band 2 (Backup beam report). ) Is notified (S511).
[0167]
　The base station 100 (information acquisition unit 243) registers a common backup beam in the partial band 1 and the partial band 2 based on the information commonly notified to the partial band 1 and the partial band 2 from the terminal device 200 (S513). ..
[0168]
　Next, it is assumed that blocking occurs, and the terminal device 200 (notification unit 247) makes a request for beam recovery (Blocking notification/beam recovery request) to the base station 100 (S515).
[0169]
　First, the restoration of the beam of partial band 1 will be described. The base station 100 (communication control unit 151) transmits a backup beam common to partial band 1 and partial band 2 to the terminal device 200 (S517). The terminal device 200 (communication control unit 241) receives the backup beam transmitted from the base station 100 and common to partial band 1 and partial band 2. In addition, the terminal device 200 (notifying unit 247) reports the received backup beam (S473). This allows the base station 100 to restore communication with the terminal device 200 by using a more suitable beam for partial band 1. Then, for the partial band 1, the base station 100 transmits user data to the terminal device 200 by using a backup beam common to the partial band 1 and the partial band 2 (S521).
[0170]
　Next, restoration of the beam of partial band 2 will be described. The base station 100 (communication control unit 151) transmits a backup beam common to partial band 1 and partial band 2 to the terminal device 200 (S523). The terminal device 200 (communication control unit 241) receives the backup beam transmitted from the base station 100 and common to partial band 1 and partial band 2. In addition, the terminal device 200 (notification unit 247) reports the received backup beam (S525). This allows the base station 100 to restore communication with the terminal device 200 by using a more suitable beam for partial band 2. Then, for the base band 100, the base station 100 transmits user data to the terminal device 200 by using a backup beam common to the partial band 1 and the partial band 2 (S527).
[0171]
　As described above, by registering a beam common to a plurality of partial bands as a backup beam, it is possible to register a backup beam at the time of beam restoration when compared to a case of individually registering a backup beam for each band. Signaling can be reduced. Therefore, according to the communication system according to the present modification, it is possible to further improve the throughput of the entire system as compared with the case where backup beams are individually registered for each partial band.
[0172]
　The communication system according to Modification 6 has been described above with reference to FIG.
[0173]
　<<4. Application Examples>>
　The technology according to the present disclosure can be applied to various products. For example, the base station 100 may be implemented as an eNB (evolved Node B) of any type such as a macro eNB or a small eNB. A small eNB may be an eNB that covers a cell smaller than a macro cell, such as a pico eNB, a micro eNB or a home (femto) eNB. Instead, the base station 100 may be realized as another type of base station such as a NodeB or a BTS (Base Transceiver Station). The base station 100 may include a main body (also referred to as a base station device) that controls wireless communication, and one or more RRHs (Remote Radio Heads) arranged in a place different from the main body. In addition, various types of terminals described below may temporarily or semi-permanently execute the base station function to operate as the base station 100. Furthermore, at least a part of the components of the base station 100 may be implemented in a base station device or a module for the base station device.
[0174]
　Further, for example, the terminal device 200 is a mobile terminal such as a smartphone, a tablet PC (Personal Computer), a notebook PC, a portable game terminal, a portable/dongle type mobile router or a digital camera, or an in-vehicle terminal such as a car navigation device. May be realized as. In addition, the terminal device 200 may be realized as a terminal that performs M2M (Machine To Machine) communication (also referred to as an MTC (Machine Type Communication) terminal). Also, the terminal device 200 may be realized as a so-called low-cost terminal such as an MTC terminal, an eMTC terminal, an NB-IoT terminal, or the like. Furthermore, at least a part of the constituent elements of the terminal device 200 may be realized by a module (for example, an integrated circuit module configured by one die) mounted on these terminals.
[0175]
　　<4.1. Application Example Regarding Base Station>
　(First Application Example)
　FIG. 25 is a block diagram showing a first example of a schematic configuration of an eNB to which the technology according to the present disclosure can be applied. The eNB 800 has one or more antennas 810 and a base station device 820. Each antenna 810 and the base station device 820 can be connected to each other via an RF cable.
[0176]
　Each of the antennas 810 has a single or a plurality of antenna elements (for example, a plurality of antenna elements forming a MIMO antenna), and is used for the base station apparatus 820 to transmit and receive radio signals. The eNB 800 has a plurality of antennas 810 as shown in FIG. 25, and the plurality of antennas 810 may correspond to a plurality of frequency bands used by the eNB 800, respectively. Note that FIG. 25 illustrates an example in which the eNB 800 has a plurality of antennas 810, but the eNB 800 may have a single antenna 810.
[0177]
　The base station device 820 includes a controller 821, a memory 822, a network interface 823, and a wireless communication interface 825.
[0178]
　The controller 821 may be, for example, a CPU or a DSP, and operates various functions of the upper layer of the base station device 820. For example, the controller 821 generates a data packet from the data in the signal processed by the wireless communication interface 825, and transfers the generated packet via the network interface 823. The controller 821 may generate a bundled packet by bundling data from a plurality of baseband processors, and may transfer the generated bundled packet. In addition, the controller 821 is a logic that executes control such as radio resource management (Radio Resource Control), radio bearer control (Radio Bearer Control), mobility management (Mobility Management), admission control (Admission Control) or scheduling (Scheduling). It may have a general function. Further, the control may be executed in cooperation with the surrounding eNB or core network node. The memory 822 includes a RAM and a ROM, and stores a program executed by the controller 821 and various control data (for example, a terminal list, transmission power data, scheduling data, etc.).
[0179]
　The network interface 823 is a communication interface for connecting the base station device 820 to the core network 824. Controller 821 may communicate with core network nodes or other eNBs via network interface 823. In that case, the eNB 800 and the core network node or another eNB may be connected to each other by a logical interface (for example, the S1 interface or the X2 interface). The network interface 823 may be a wired communication interface or a wireless communication interface for wireless backhaul. When the network interface 823 is a wireless communication interface, the network interface 823 may use a higher frequency band for wireless communication than the frequency band used by the wireless communication interface 825.
[0180]
　The wireless communication interface 825 supports a cellular communication scheme such as LTE (Long Term Evolution) or LTE-Advanced, and provides a wireless connection to a terminal located in the cell of the eNB 800 via the antenna 810. The wireless communication interface 825 may typically include a baseband (BB) processor 826, an RF circuit 827, and the like. The BB processor 826 may perform, for example, encoding/decoding, modulation/demodulation, and multiplexing/demultiplexing, and each layer (eg, L1, MAC (Medium Access Control), RLC (Radio Link Control), and PDCP). (Packet Data Convergence Protocol). The BB processor 826 may have some or all of the above-described logical functions instead of the controller 821. The BB processor 826 may be a module that includes a memory that stores a communication control program, a processor that executes the program, and a related circuit. The function of the BB processor 826 may be changed by updating the program. Good. Further, the module may be a card or a blade inserted in the slot of the base station device 820, or a chip mounted on the card or the blade. On the other hand, the RF circuit 827 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a wireless signal through the antenna 810.
[0181]
　The wireless communication interface 825 includes a plurality of BB processors 826 as shown in FIG. 25, and the plurality of BB processors 826 may respectively correspond to a plurality of frequency bands used by the eNB 800, for example. The wireless communication interface 825 may include a plurality of RF circuits 827 as shown in FIG. 25, and the plurality of RF circuits 827 may correspond to, for example, a plurality of antenna elements. 25 shows an example in which the wireless communication interface 825 includes a plurality of BB processors 826 and a plurality of RF circuits 827, the wireless communication interface 825 includes a single BB processor 826 or a single RF circuit 827. But it's okay.
[0182]
　In the eNB 800 illustrated in FIG. 25, one or more components (at least one of the communication control unit 151, the information acquisition unit 153, and the notification unit 155) included in the processing unit 150 described with reference to FIG. , May be implemented in the wireless communication interface 825. Alternatively, at least some of these components may be implemented in controller 821. As an example, the eNB 800 includes a module including a part (eg, the BB processor 826) or all of the wireless communication interface 825 and/or the controller 821, and the one or more components may be mounted in the module. Good. In this case, the module stores a program for causing the processor to function as the one or more constituent elements (in other words, a program for causing the processor to execute the operation of the one or more constituent elements). You may run the program. As another example, a program for causing a processor to function as one or more components described above is installed in the eNB 800, and the wireless communication interface 825 (for example, the BB processor 826) and/or the controller 821 executes the program. Good. As described above, the eNB 800, the base station device 820, or the module may be provided as an apparatus including the one or more constituent elements, and a program for causing a processor to function as the one or more constituent elements is provided. May be. A readable recording medium recording the above program may be provided.
[0183]
　Further, in the eNB 800 illustrated in FIG. 25, the wireless communication unit 120 described with reference to FIG. 2 may be mounted in the wireless communication interface 825 (for example, the RF circuit 827). The antenna unit 110 may be mounted on the antenna 810. Further, the network communication unit 130 may be implemented in the controller 821 and/or the network interface 823. The storage unit 140 may be implemented in the memory 822.
[0184]
　(Second Application Example)
　FIG. 26 is a block diagram showing a second example of a schematic configuration of an eNB to which the technology according to the present disclosure can be applied. The eNB 830 has one or more antennas 840, a base station device 850, and an RRH 860. Each antenna 840 and RRH 860 may be connected to each other via an RF cable. Further, the base station device 850 and the RRH 860 can be connected to each other by a high speed line such as an optical fiber cable.
[0185]
　Each of the antennas 840 has a single or a plurality of antenna elements (for example, a plurality of antenna elements forming a MIMO antenna), and is used for transmitting and receiving radio signals by the RRH 860. The eNB 830 may include a plurality of antennas 840 as illustrated in FIG. 26, and the plurality of antennas 840 may correspond to a plurality of frequency bands used by the eNB 830, for example. Note that FIG. 26 shows an example in which the eNB 830 has a plurality of antennas 840, but the eNB 830 may have a single antenna 840.
[0186]
　The base station device 850 includes a controller 851, a memory 852, a network interface 853, a wireless communication interface 855, and a connection interface 857. The controller 851, the memory 852, and the network interface 853 are the same as the controller 821, the memory 822, and the network interface 823 described with reference to FIG.
[0187]
　The wireless communication interface 855 supports a cellular communication scheme such as LTE or LTE-Advanced, and provides a wireless connection to a terminal located in a sector corresponding to the RRH 860 via the RRH 860 and the antenna 840. The wireless communication interface 855 may typically include a BB processor 856 or the like. The BB processor 856 is similar to the BB processor 826 described with reference to FIG. 25, except that the BB processor 856 is connected to the RF circuit 864 of the RRH 860 via the connection interface 857. The wireless communication interface 855 includes a plurality of BB processors 856 as shown in FIG. 25, and the plurality of BB processors 856 may respectively correspond to a plurality of frequency bands used by the eNB 830, for example. Although FIG. 26 shows an example in which the wireless communication interface 855 includes a plurality of BB processors 856, the wireless communication interface 855 may include a single BB processor 856.
[0188]
　The connection interface 857 is an interface for connecting the base station device 850 (radio communication interface 855) to the RRH 860. The connection interface 857 may be a communication module for communication on the high-speed line that connects the base station device 850 (radio communication interface 855) and the RRH 860.
[0189]
　The RRH 860 also includes a connection interface 861 and a wireless communication interface 863.
[0190]
　The connection interface 861 is an interface for connecting the RRH 860 (radio communication interface 863) to the base station device 850. The connection interface 861 may be a communication module for communication on the high speed line.
[0191]
　The wireless communication interface 863 transmits and receives wireless signals via the antenna 840. The wireless communication interface 863 may typically include an RF circuit 864 or the like. The RF circuit 864 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a wireless signal through the antenna 840. The wireless communication interface 863 includes a plurality of RF circuits 864 as shown in FIG. 26, and the plurality of RF circuits 864 may respectively correspond to a plurality of antenna elements, for example. Although FIG. 26 shows an example in which the wireless communication interface 863 includes a plurality of RF circuits 864, the wireless communication interface 863 may include a single RF circuit 864.
[0192]
　In the eNB 830 illustrated in FIG. 26, one or more components (at least one of the communication control unit 151, the information acquisition unit 153, and the notification unit 155) included in the processing unit 150 described with reference to FIG. , Wireless communication interface 855 and/or wireless communication interface 863. Alternatively, at least some of these components may be implemented in controller 851. As an example, the eNB 830 includes a module including a part (eg, the BB processor 856) or all of the wireless communication interface 855 and/or the controller 851, and the one or more components may be mounted in the module. Good. In this case, the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components), You may run the program. As another example, a program for causing a processor to function as the one or more components may be installed in the eNB 830, and the wireless communication interface 855 (for example, the BB processor 856) and/or the controller 851 may execute the program. Good. As described above, the eNB 830, the base station device 850, or the module may be provided as a device including the one or more components, and a program for causing a processor to function as the one or more components is provided. May be. A readable recording medium recording the above program may be provided.
[0193]
　Further, in the eNB 830 illustrated in FIG. 26, for example, the wireless communication unit 120 described with reference to FIG. 2 may be implemented in the wireless communication interface 863 (for example, the RF circuit 864). Further, the antenna unit 110 may be mounted on the antenna 840. Further, the network communication unit 130 may be implemented in the controller 851 and/or the network interface 853. The storage unit 140 may be implemented in the memory 852.
[0194]
　　<4.2. Application Example Regarding Terminal Device>
　(First Application Example)
　FIG. 27 is a block diagram showing an example of a schematic configuration of a smartphone 900 to which the technology according to the present disclosure can be applied. The smartphone 900 includes a processor 901, a memory 902, a storage 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, a display device 910, a speaker 911, a wireless communication interface 912, and one or more antenna switches 915. It comprises one or more antennas 916, a bus 917, a battery 918 and an auxiliary controller 919.
[0195]
　The processor 901 may be, for example, a CPU or a SoC (System on Chip), and controls the functions of the application layer and other layers of the smartphone 900. The memory 902 includes RAM and ROM, and stores programs and data executed by the processor 901. The storage 903 may include a storage medium such as a semiconductor memory or a hard disk. The external connection interface 904 is an interface for connecting an external device such as a memory card or a USB (Universal Serial Bus) device to the smartphone 900.
[0196]
　The camera 906 has, for example, an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and generates a captured image. The sensor 907 may include a sensor group such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor, for example. The microphone 908 converts a voice input to the smartphone 900 into a voice signal. The input device 909 includes, for example, a touch sensor that detects a touch on the screen of the display device 910, a keypad, a keyboard, a button or a switch, and receives an operation or information input from the user. The display device 910 has a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays the output image of the smartphone 900. The speaker 911 converts the audio signal output from the smartphone 900 into audio.
[0197]
　The wireless communication interface 912 supports a cellular communication method such as LTE or LTE-Advanced and executes wireless communication. The wireless communication interface 912 may typically include a BB processor 913, an RF circuit 914, and the like. The BB processor 913 may perform, for example, encoding/decoding, modulation/demodulation, multiplexing/demultiplexing, and the like, and perform various signal processing for wireless communication. On the other hand, the RF circuit 914 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a wireless signal through the antenna 916. The wireless communication interface 912 may be a one-chip module in which the BB processor 913 and the RF circuit 914 are integrated. The wireless communication interface 912 may include a plurality of BB processors 913 and a plurality of RF circuits 914 as shown in FIG. 27. 27 shows an example in which the wireless communication interface 912 includes a plurality of BB processors 913 and a plurality of RF circuits 914, the wireless communication interface 912 includes a single BB processor 913 or a single RF circuit 914. But it's okay.
[0198]
　Further, the wireless communication interface 912 may support other types of wireless communication systems such as a short-range wireless communication system, a close proximity wireless communication system, and a wireless LAN (Local Area Network) system in addition to the cellular communication system, In that case, the BB processor 913 and the RF circuit 914 for each wireless communication system may be included.
[0199]
　Each of the antenna switches 915 switches the connection destination of the antenna 916 among a plurality of circuits (for example, circuits for different wireless communication systems) included in the wireless communication interface 912.
[0200]
　Each of the antennas 916 has a single or a plurality of antenna elements (for example, a plurality of antenna elements forming a MIMO antenna), and is used for transmitting and receiving a radio signal by the radio communication interface 912. The smartphone 900 may have a plurality of antennas 916 as shown in FIG. 27. 27 shows an example in which the smartphone 900 has a plurality of antennas 916, the smartphone 900 may have a single antenna 916.
[0201]
　Furthermore, the smartphone 900 may include an antenna 916 for each wireless communication system. In that case, the antenna switch 915 may be omitted from the configuration of the smartphone 900.
[0202]
　The bus 917 connects the processor 901, the memory 902, the storage 903, the external connection interface 904, the camera 906, the sensor 907, the microphone 908, the input device 909, the display device 910, the speaker 911, the wireless communication interface 912, and the auxiliary controller 919 to each other. .. The battery 918 supplies power to each block of the smartphone 900 shown in FIG. 27 via a power supply line partially shown by a broken line in the figure. The auxiliary controller 919 operates the minimum necessary functions of the smartphone 900 in the sleep mode, for example.
[0203]
　In the smartphone 900 illustrated in FIG. 27, one or more components (the communication control unit 241, the information acquisition unit 243, the selection unit 245, and the notification unit 247 included in the processing unit 240 described with reference to FIG. At least one) may be implemented in the wireless communication interface 912. Alternatively, at least some of these components may be implemented in processor 901 or auxiliary controller 919. As an example, the smartphone 900 includes a module including a part (for example, the BB processor 913) or all of the wireless communication interface 912, the processor 901, and/or the auxiliary controller 919, and the one or more constituent elements in the module. May be implemented. In this case, the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components), You may run the program. As another example, a program for causing a processor to function as the one or more components is installed in the smartphone 900, and the wireless communication interface 912 (for example, the BB processor 913), the processor 901, and/or the auxiliary controller 919 is included in the program. You may run the program. As described above, the smartphone 900 or the module may be provided as the device including the one or more constituent elements, and the program for causing the processor to function as the one or more constituent elements may be provided. A readable recording medium recording the above program may be provided.
[0204]
　Further, in the smartphone 900 shown in FIG. 27, for example, the wireless communication unit 220 described with reference to FIG. 3 may be mounted in the wireless communication interface 912 (for example, the RF circuit 914). The antenna unit 210 may be mounted on the antenna 916. Further, the storage unit 230 may be implemented in the memory 902.
[0205]
　(Second Application Example)
　FIG. 28 is a block diagram showing an example of a schematic configuration of a car navigation device 920 to which the technology according to the present disclosure can be applied. The car navigation device 920 includes a processor 921, a memory 922, a GPS (Global Positioning System) module 924, a sensor 925, a data interface 926, a content player 927, a storage medium interface 928, an input device 929, a display device 930, a speaker 931, and wireless communication. An interface 933, one or more antenna switches 936, one or more antennas 937 and a battery 938 are provided.
[0206]
　The processor 921 may be, for example, a CPU or a SoC, and controls the navigation function and other functions of the car navigation device 920. The memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921.
[0207]
　The GPS module 924 measures the position (eg, latitude, longitude, and altitude) of the car navigation device 920 using GPS signals received from GPS satellites. The sensor 925 may include a sensor group such as a gyro sensor, a geomagnetic sensor, and an atmospheric pressure sensor, for example. The data interface 926 is connected to the in-vehicle network 941 via a terminal (not shown), and acquires data generated on the vehicle side such as vehicle speed data.
[0208]
　The content player 927 plays the content stored in the storage medium (eg, CD or DVD) inserted in the storage medium interface 928. The input device 929 includes, for example, a touch sensor that detects a touch on the screen of the display device 930, a button or a switch, and receives an operation or information input from the user. The display device 930 has a screen such as an LCD or an OLED display, and displays a navigation function or an image of reproduced content. The speaker 931 outputs the navigation function or the sound of the reproduced content.
[0209]
　The wireless communication interface 933 supports a cellular communication method such as LTE or LTE-Advanced and executes wireless communication. The wireless communication interface 933 may typically include a BB processor 934, an RF circuit 935, and the like. The BB processor 934 may perform, for example, encoding/decoding, modulation/demodulation, multiplexing/demultiplexing, and the like, and perform various signal processing for wireless communication. On the other hand, the RF circuit 935 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a wireless signal through the antenna 937. The wireless communication interface 933 may be a one-chip module in which the BB processor 934 and the RF circuit 935 are integrated. The wireless communication interface 933 may include a plurality of BB processors 934 and a plurality of RF circuits 935, as shown in FIG. 28. 28 shows an example in which the wireless communication interface 933 includes a plurality of BB processors 934 and a plurality of RF circuits 935, the wireless communication interface 933 includes a single BB processor 934 or a single RF circuit 935. But it's okay.
[0210]
　Further, the wireless communication interface 933 may support other types of wireless communication systems such as a short-range wireless communication system, a close proximity wireless communication system, and a wireless LAN system in addition to the cellular communication system. A BB processor 934 and an RF circuit 935 for each communication method may be included.
[0211]
　Each of the antenna switches 936 switches a connection destination of the antenna 937 among a plurality of circuits (for example, circuits for different wireless communication systems) included in the wireless communication interface 933.
[0212]
　Each of the antennas 937 has a single or a plurality of antenna elements (for example, a plurality of antenna elements forming a MIMO antenna), and is used for transmitting and receiving radio signals by the radio communication interface 933. The car navigation device 920 may have a plurality of antennas 937 as shown in FIG. Although FIG. 28 shows an example in which the car navigation device 920 has a plurality of antennas 937, the car navigation device 920 may have a single antenna 937.
[0213]
　Further, the car navigation device 920 may include an antenna 937 for each wireless communication system. In that case, the antenna switch 936 may be omitted from the configuration of the car navigation device 920.
[0214]
　The battery 938 supplies electric power to each block of the car navigation device 920 shown in FIG. 28 via a power supply line partially shown by a broken line in the figure. Further, the battery 938 stores electric power supplied from the vehicle side.
[0215]
　In the car navigation device 920 shown in FIG. 28, one or more components (communication control unit 241, information acquisition unit 243, selection unit 245, and notification unit 247 included in the processing unit 240 described with reference to FIG. And/or the like) may be implemented in the wireless communication interface 933. Alternatively, at least some of these components may be implemented in processor 921. As an example, the car navigation device 920 includes a module including a part (for example, the BB processor 934) or all of the wireless communication interface 933 and/or the processor 921, and the one or more components described above are mounted in the module. May be. In this case, the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components), You may run the program. As another example, a program for causing the processor to function as one or more components described above is installed in the car navigation device 920, and the wireless communication interface 933 (eg, BB processor 934) and/or the processor 921 executes the program. You may. As described above, the car navigation device 920 or the module may be provided as the device including the one or more constituent elements, and the program for causing the processor to function as the one or more constituent elements may be provided. Good. A readable recording medium recording the above program may be provided.
[0216]
　Further, in the car navigation device 920 illustrated in FIG. 28, for example, the wireless communication unit 220 described with reference to FIG. 3 may be mounted in the wireless communication interface 933 (for example, the RF circuit 935). The antenna unit 210 may be mounted on the antenna 937. The storage unit 230 may be implemented in the memory 922.
[0217]
　The technology according to the present disclosure may be implemented as an in-vehicle system (or vehicle) 940 including one or more blocks of the car navigation device 920 described above, an in-vehicle network 941, and a vehicle-side module 942. That is, the in-vehicle system (or vehicle) 940 may be provided as an apparatus including at least one of the communication control unit 241, the information acquisition unit 243, the selection unit 245, and the notification unit 247. The vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine speed, or failure information, and outputs the generated data to the vehicle-mounted network 941.
[0218]
　<<5. Conclusion>> As
　described above, in the communication system according to the embodiment of the present disclosure, the terminal device 200 instructs the base station 100 to wirelessly communicate with the base station 100 among a plurality of beams. Information about the second beam (backup beam) that can be used in place of the first beam (that is, the main beam) that is used with priority is notified. In addition, the base station 100 controls wireless communication with the terminal device 200 based on the information regarding the second beam notified from the terminal device 200. As a specific example, the base station 100 registers the second beam in advance and uses the second beam when the wireless communication with the terminal device 200 is interrupted due to blocking or the like. Restore the wireless communication.
[0219]
　With the above-described configuration, according to the communication system according to the present embodiment, even when wireless communication with the terminal device 200 is interrupted due to blocking or the like, the wireless communication is performed without performing beam sweeping again. It will be possible to recover quickly. That is, according to the communication system according to the present embodiment, it is possible to further shorten the time involved in recovery of wireless communication (that is, beam recovery) between the base station 100 and the terminal device 200, and the entire system The effect of improving the throughput can also be expected. Further, according to the communication system according to the present embodiment, it is possible to restore wireless communication between the base station 100 and the terminal device 200 with fewer resources.
[0220]
　Although the preferred embodiments of the present disclosure have been described above in detail with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field of the present disclosure can come up with various changes or modifications within the scope of the technical idea described in the claims. It is understood that the above also naturally belongs to the technical scope of the present disclosure.
[0221]
　Further, the effects described in the present specification are merely illustrative or exemplary, and are not limitative. That is, the technique according to the present disclosure may have other effects that are apparent to those skilled in the art from the description of the present specification, in addition to or instead of the above effects.
[0222]
　The following configurations also belong to the technical scope of the present disclosure.
(1) For
　a communication unit that performs wireless communication and a
　base station, a plurality of beams can be used instead of the first beam that is preferentially used in the wireless communication with the base station. A communication unit that notifies information about the second beam
　.
(2) The
　notification unit notifies the base station of, as the information regarding the second beam, information regarding one or more groups each including one or more of the second beam, to the base station. The communication device described.
(3)
　A selection unit that selects at least a part of the plurality of beams as the second beam according to the correlation with the first beam, and the
　notification unit includes the selected first beam .
　The communication device according to (1) or (2), which notifies the base station of information regarding two beams .
(4) The
　selection unit selects the second beam having a lower correlation with the first beam when receiving the beam transmitted from the base station. Communication device.
(5) In
　the case (3) or (4), the selecting unit selects the second beam having a lower correlation with the first beam when the base station transmits a beam. Communication device.
(6)
　The selecting unit, when the base station transmits a beam based on the information notified from the base station regarding the beam transmitted from the base station, selects the first beam having a lower correlation with the first beam. The communication device according to (5) above, which selects two beams.
(7) The
　notifying unit notifies the base station of information regarding the second beam that is common to a plurality of frequency bands used for the wireless communication with the base station, (1) to (6) The communication device according to any one of 1.
(8) In
　the above (1) to (6), the notifying unit notifies the base station of information regarding the second beam for each of a plurality of frequency bands used for the wireless communication with the base station. The communication device according to any one of claims.
(9)
　The communication device according to (8), wherein the notification unit sets priorities among the plurality of frequency bands and notifies the base station of information regarding the priorities.
(10)
　Each of the plurality of frequency bands is a partial second frequency band to which at least a part of the first frequency band having a wider bandwidth than the frequency band is allocated, (7) to The communication device according to any one of (9).
(11) The
　notifying unit requests the base station to restore the wireless communication with the base station according to the state of the first beam, (1) to (10) The communication device according to claim 1.
(12)
　The communication device according to (11), wherein the request includes information on each of one or more frequency bands used for the wireless communication with the base station.
(13) 　A second beam that can be used in place of the first beam that is preferentially used in the wireless communication
　with the
terminal device from the plurality of beams from the communication unit that performs wireless communication and the terminal device. The 　communication device
　,
which includes: an acquisition unit that acquires information regarding the beam of the second beam; and a control unit that controls the wireless communication with the terminal device based on the acquired information regarding the second beam .
(14)
　A notification unit is provided
　for instructing the terminal device to notify the second beam information, and the acquisition unit is instructed to notify the second beam information to the terminal device.
　The communication device according to (13) above , which acquires the information from the terminal device.
(15) The
　acquisition unit,
　when the terminal device receives the transmitted beam, outputs the first information regarding the second beam having a lower correlation to the first
　beam and the beam to the terminal device. In the case of transmitting, the second information regarding the second beam having a lower correlation with respect to the first beam, and
　from the terminal device,

　The communication device according to (13) or (14) 　, wherein the control unit controls the wireless communication with the terminal device based on the first information and the second information .
(16) At
　least the second beam corresponding to the first information and the second beam corresponding to the second information, in response to a request from the terminal device. The communication device according to (15), which attempts to restore the wireless communication with the terminal device based on either of the above.
(17) The
　acquisition unit acquires, from the terminal device, information regarding the second beam common to a plurality of frequency bands used for the wireless communication with the terminal device, and the
　control unit acquires the acquired information. Any one of the
　above (13) to (16) , which controls the wireless communication with the terminal device using at least any one of a plurality of frequency bands based on the information about the second beam. The communication device according to the item.
(18) The
　acquisition unit acquires, from the terminal device, information regarding the second beam for each of a plurality of frequency bands used for the wireless communication with the terminal device, and the
　control unit sets the frequency band for each frequency band.
　The communication device according to any one of (13) to (16) , which controls the wireless communication with the terminal device based on information about the second beam .
(19)
　The acquisition unit acquires information about the priority set between a plurality of frequency bands used for the wireless communication with the terminal device from the terminal device, the
　control unit based on the information about the priority,
　The communication device according to (18) , which controls the wireless communication with the terminal device.
(20)
　A notification unit configured to notify the terminal device of information regarding priorities set between a plurality of frequency bands used for the wireless communication with the terminal device, the
　control unit including information regarding the priority
　The communication device according to (18) , which controls the wireless communication with the terminal device based on the communication device.
(21) The
　computer
　performs
　wireless communication, and uses a first beam of a plurality of beams for the base station, instead of the first beam used preferentially in the wireless communication with the base station. Signaling information about possible second beams
　.
(22) The
　computer can
　perform wireless communication and can be
　used in place of the first beam of the plurality of beams, which is preferentially used in the wireless communication with the terminal device. Obtaining information about the second beam,
　Controlling the wireless communication with the terminal device based on the acquired information about the second beam
　.
(23) 　Performing wireless communication with a
　computer, and using 　a beam of a plurality of beams for
a
base station instead of the first beam used preferentially in the wireless communication with the base station. A
　program for informing information about possible second beams and for performing.
(24) 　It is possible to perform wireless communication with a
　computer 　and replace the first beam of a plurality of beams that is preferentially used in the wireless communication with the terminal device. A 　program that causes 　acquisition of information about a second beam and control of the wireless communication with the terminal device based on the acquired information about the second beam .

Explanation of symbols
[0223]
　1 system
　100 base station
　110 antenna unit
　120 wireless communication unit
　130 network communication unit
　140 storage unit
　150 processing unit
　151 communication control unit
　153 information acquisition unit
　155 notification unit
　200 terminal device
　210 antenna unit
　220 wireless communication unit
　230 storage unit
　240 processing unit
　241 Communication control unit
　243 Information acquisition unit
　245 Selection unit
　247 Notification unit

claims
[Claim 1]

　Of the plurality of beams, a second beam that can be used in place of the first beam that is preferentially used in the wireless communication between the base station and the 　communication unit that performs wireless communication is used. A
　communication device , comprising: a notification unit that notifies information about a beam .
[Claim 2]
　The communication device according to claim 1, wherein the notification unit notifies the base station of information regarding one or more groups each including one or more of the second beam as information regarding the second beam. ..
[Claim 3]
　A selecting unit for selecting at least a part of the plurality of beams as the second beam according to the correlation with the first beam; and the
　notifying unit , wherein the notifying unit selects the second beam.
　The communication device according to claim 1, wherein the communication device notifies the base station of information related to the information .
[Claim 4]
　The communication device according to claim 3, wherein, when the beam transmitted from the base station is received, the selection unit selects the second beam having a lower correlation with respect to the first beam.
[Claim 5]
　The communication device according to claim 3, wherein the selecting unit selects the second beam having a lower correlation with the first beam when the base station transmits a beam.
[Claim 6]
　The selecting unit, when the base station transmits a beam, based on the information notified from the base station regarding the beam transmitted from the base station, the selecting unit having the lower correlation with the first beam. The communication device according to claim 5, wherein two beams are selected.
[Claim 7]
　The communication device according to claim 1, wherein the notification unit notifies the base station of information regarding the second beam that is common to a plurality of frequency bands used for the wireless communication with the base station.
[Claim 8]
　The communication device according to claim 1, wherein the notification unit notifies the base station of information regarding the second beam for each of a plurality of frequency bands used for the wireless communication with the base station.
[Claim 9]
　The communication device according to claim 8, wherein the notification unit sets priorities among the plurality of frequency bands and notifies the base station of information regarding the priorities.
[Claim 10]
　The communication device according to claim 7, wherein each of the plurality of frequency bands is a partial second frequency band to which at least a part of the first frequency band having a wider bandwidth than the frequency band is assigned. ..
[Claim 11]
　The communication device according to claim 1, wherein the notification unit requests the base station to restore the wireless communication with the base station according to a state of the first beam.
[Claim 12]
　The communication device according to claim 11, wherein the request includes information on each of one or more frequency bands used for the wireless communication with the base station.
[Claim 13]

　Regarding a second beam that can be used in place of the first beam used preferentially in the wireless communication between the terminal and the 　communication unit that performs wireless communication and the terminal device, among the plurality of beams. A
　communication device, comprising: an acquisition unit that acquires information, and a control unit that controls the wireless communication with the terminal device based on the acquired information about the second beam
　.
[Claim 14]
　A notification unit for instructing notification of the information on the second beam to the terminal device is provided, and the
　acquisition unit is provided when the notification of information on the second beam is instructed to the terminal device.
　The communication device according to claim 13 , which acquires the information from the terminal device .
[Claim 15]
　When the
　terminal device receives the transmitted beam , the acquisition unit transmits the first information on the second beam having a lower correlation to the first
　beam and the beam to the terminal device. In this case, the second information on the second beam having a lower correlation with the first beam and the second information are
　acquired from the terminal device, and the
　control unit controls the first information and the second information.
　The communication device according to claim 13 , which controls the wireless communication with the terminal device based on information .
[Claim 16]
　In response to a request from the terminal device, the control unit may provide at least one of the second beam corresponding to the first information and the second beam corresponding to the second information. The communication device according to claim 15, which attempts to restore the wireless communication with the terminal device based on the communication device.
[Claim 17]
　The acquisition unit acquires, from the terminal device, information regarding the second beam common to a plurality of frequency bands used for the wireless communication with the terminal device, and the
　control unit acquires the acquired second beam .
　The communication device according to claim 13 , which controls the wireless communication with the terminal device using at least any one of a plurality of frequency bands based on the information about the beam .
[Claim 18]
　The acquisition unit acquires, from the terminal device, information regarding the second beam for each of a plurality of frequency bands used for the wireless communication with the terminal device, and the
　control unit, for each of the frequency bands, the first
　The communication device according to claim 13, wherein the wireless communication with the terminal device is controlled based on information regarding two beams .
[Claim 19]
　The acquisition unit acquires information about the priority set between a plurality of frequency bands used for the wireless communication with the terminal device from the terminal device, the
　control unit based on the information about the priority,
　The communication device according to claim 18 , which controls the wireless communication with the terminal device.
[Claim 20]
　The terminal unit is provided with a notification unit that notifies the terminal device of information regarding the priority set between a plurality of frequency bands used for the wireless communication with the terminal device, the
　control unit based on the information regarding the priority,
　The communication device according to claim 18 , which controls the wireless communication with a terminal device .
[Claim 21]
　The computer
　performs wireless communication, and,
　among the plurality of beams, a first beam that can be used instead of the first beam that is preferentially used in the wireless communication with the base station. Reporting information about the two beams
　.
[Claim 22]
　The computer
　performs
　wireless communication, and a second beam that can be used from the terminal device in place of the first beam that is preferentially used in the wireless communication with the terminal device among the plurality of beams. A 　communication method, comprising:
　acquiring information about a beam; and controlling the wireless communication with the terminal device based on the acquired information about the second beam
.
[Claim 23]

　Wireless communication to the 　computer, and
　a plurality of beams that can be used for the base station in place of the first beam that is preferentially used in the wireless communication with the base station. A
　program for notifying information about the second beam and executing the information .
[Claim 24]

　Wireless communication is performed 　to the computer, and
　a second beam that can be used in place of the first beam that is preferentially used in the wireless communication with the terminal device from the plurality of beams from the terminal device is used. A 　program that causes
　acquisition of information about a beam and control of the wireless communication with the terminal device based on the acquired information about the second beam
.