阅读说明：本技术 无线通信设备、控制设备和控制方法 (Wireless communication apparatus, control apparatus, and control method ) 是由 仲山隆 于 2018-04-18 设计创作，主要内容包括：【问题】以更合适的方式使用定向波束来实现无线通信。【方案】一种无线通信设备,包括：一个或多个天线元件,每个被配置为能够控制定向波束的方向并使用该定向波束执行无线通信；检测单元,检测所述一个或多个天线元件中的至少任何一个天线元件的姿势；和控制单元,将能够经由一个或多个天线元件中的任何一个接收至少从基站使用定向波束发送的至少一个无线信号的状态设置为基准状态,并根据从基准状态的姿势变化控制使用定向光束与基站的无线通信。(The use of directional beams to enable wireless communications in a more suitable manner. [ solution ] A wireless communication apparatus comprising: one or more antenna elements each configured to be capable of controlling a direction of a directional beam and performing wireless communication using the directional beam; a detection unit that detects a posture of at least any one of the one or more antenna elements; and a control unit that sets, as a reference state, a state capable of receiving at least one wireless signal transmitted using a directional beam at least from the base station via any one of the one or more antenna elements, and controls wireless communication with the base station using the directional beam according to a change in posture from the reference state.)

1. A wireless communication device, comprising:

one or more antenna elements configured to be able to control a direction of a directional beam and perform wireless communication using the directional beam;

a detection unit that detects a posture of at least any one of the one or more antenna elements; and

a control unit that sets, as a reference state, a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam via any one of the one or more antenna elements, and controls wireless communication with the base station using the directional beam according to a change in posture from the reference state.

2. The wireless communication device according to claim 1, wherein a plurality of antenna elements that perform wireless communication using directional beams that face directions different from each other are provided as the one or more antenna elements, and

the control unit selectively switches an antenna element for wireless communication with the base station among the plurality of antenna elements in accordance with a change in the posture of at least any one of the plurality of antenna elements.

3. The wireless communication apparatus according to claim 2, wherein, in a case where the control unit has switched an antenna element for wireless communication with a base station among a plurality of antenna elements, the control unit controls the direction of a directional beam formed by the antenna element in accordance with a state of wireless communication with the base station after switching.

4. The wireless communication device of claim 1, wherein the control unit controls the direction of the directional beam formed by the antenna element according to a change in the attitude of at least any one of the one or more antenna elements.

5. The wireless communication device of claim 1, wherein at least a portion of one or more antenna elements are configured as movable antenna elements, and

the control unit controls a direction of a directional beam formed by the movable antenna element by controlling at least one of a position or an attitude of the movable antenna element according to a change in the attitude of at least any one of the one or more antennas.

6. The wireless communication device according to claim 1, wherein the reference state is a state in which a reception power of a wireless signal transmitted from the base station using a directional beam is equal to or greater than a threshold value.

7. The wireless communication device according to claim 1, wherein the reference state is a state in which a signal block transmitted from the base station for each directional beam using a synchronization signal and a control signal as one unit can be received.

8. The wireless communication device according to claim 1, wherein the control unit sets the reference state when an initial access procedure to the base station is performed.

9. The wireless communication apparatus according to claim 8, wherein the control unit sets the reference state after a transmission timing of a preamble to the base station in the procedure.

10. The wireless communication device according to claim 1, wherein the control unit sets the reference state when performing a procedure for establishing or resuming communication with the base station using a directional beam.

11. The wireless communication apparatus according to claim 10, wherein the control unit sets the reference state after timing at which a directional beam for communication with the base station is selected by the base station among directional beams respectively formed toward a plurality of directions in the procedure.

12. The wireless communication apparatus according to claim 1, wherein the control unit detects a change in the posture from the reference state based on a detection result of the posture by the detection unit using a predetermined event as a trigger.

13. The wireless communication device of claim 12, wherein the event is an event that is notified if a deviation occurs between a directional beam formed by the antenna element and a directional beam formed by the base station.

14. The wireless communication apparatus according to claim 1, wherein the control unit detects a change in the posture with respect to the reference state by monitoring a detection result of the posture by the detection unit.

15. A control device, comprising:

an acquisition unit that acquires a detection result of a posture of at least one of one or more antenna elements configured to be able to control a direction of a directional beam and perform wireless communication using the directional beam; and

a control unit that sets, as a reference state, a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam, and controls wireless communication with the base station using the directional beam according to a change in the posture from the reference state.

16. A computer-implemented control method comprising:

acquiring a detection result of a posture of at least any one of one or more antenna elements configured to be capable of controlling a direction of a directional beam and performing wireless communication using the directional beam; and

setting a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam as a reference state, and controlling wireless communication with the base station using the directional beam according to a change in the posture from the reference state.

Technical Field

The present disclosure relates to a wireless communication apparatus, a control apparatus, and a control method.

Background

In a mobile communication system based on a communication standard called Long Term Evolution (LTE)/LTE-advanced (LTE-a), radio signals having a frequency of an ultra high frequency of about 700MHz to 3.5GHz are mainly used for communication.

In addition, in communication using an ultra high frequency in the communication standard as described above, by adopting a so-called Multiple Input Multiple Output (MIMO) technique, it is possible to further improve communication performance using reflected waves in addition to direct waves so that signals can be transmitted and received even in a fading environment. Since a plurality of antennas are used in MIMO, various methods of arranging a plurality of antennas in a more appropriate manner for mobile communication terminal devices such as smart phones and the like have also been studied.

Further, in recent years, various studies have been made on a fifth generation (5G) mobile communication system following LTE/LTE-a. For example, in a 5G mobile communication system, communication using a radio signal having a frequency called a millimeter wave such as 28GHz or 39GHz (hereinafter also simply referred to as "millimeter wave") has been studied. In general, millimeter waves have relatively large spatial attenuation, so that in the case where millimeter waves are used for communication, there is a tendency to demand antennas having high gain. In order to fulfill such a requirement, research has been conducted on using a directional beam for communication between a base station and a terminal device by forming the directional beam using a so-called beam forming technique. For example, non-patent document 1 discloses, in particular, as a content of research on communication using millimeter waves, a research on using a beam forming technique in a 5G mobile communication system.

CITATION LIST

Non-patent document

Non-patent document 1: satoshi Suyama et al, "5G Multi-antenna technology", NTT DOCOMO technical journal, Vol.23, No. 4, 2016, pages 30-39

Disclosure of Invention

Problems to be solved by the invention

Meanwhile, in the case of forming a directional beam by a beamforming technique, the beam width is limited, and communication via beams different from each other is thus spatially separated. Therefore, in the case where a directional beam from the terminal device toward the base station is directed in a direction different from the base station in accordance with a change in the posture of the terminal device, communication between the terminal device and the base station is restricted, and a case where communication is disconnected can be assumed.

Accordingly, the present disclosure proposes a technique capable of achieving wireless communication using directional beams in a more appropriate manner.

Solution to the problem

According to the present disclosure, there is provided a wireless communication apparatus including: one or more antenna elements configured to be able to control a direction of a directional beam and perform wireless communication using the directional beam; a detection unit that detects a posture of at least any one of the one or more antenna elements; and a control unit that sets, as a reference state, a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam via any one of the one or more antenna elements, and controls wireless communication with the base station using the directional beam according to a change in posture from the reference state.

Further, according to the present disclosure, there is provided a control apparatus including: an acquisition unit that acquires a detection result of a posture of at least any one of one or more antenna elements configured to be able to control a direction of a directional beam and perform wireless communication using the directional beam; and a control unit that sets, as a reference state, a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam, and controls wireless communication with the base station using the directional beam according to a change in posture from the reference state.

Further, according to the present disclosure, there is provided a computer-performed control method including: acquiring a detection result of a posture of at least any one of one or more antenna elements configured to be capable of controlling a direction of a directional beam and performing wireless communication using the directional beam; and setting a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam as a reference state, and controlling wireless communication with the base station using the directional beam according to a change in the posture with respect to the reference state.

ADVANTAGEOUS EFFECTS OF INVENTION

As described above, according to the present disclosure, a technique capable of achieving wireless communication using a directional beam in a more appropriate manner is provided.

Note that the above-described effects are not necessarily restrictive, and any effect set forth in this specification or other effects that can be grasped from this specification may be achieved together with or instead of the above-described effects.

Drawings

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.

Fig. 2 is a block diagram showing an example of the configuration of a base station according to the embodiment.

Fig. 3 is a block diagram showing a configuration example of a terminal device according to the embodiment.

Fig. 4 is a diagram showing an example of a system configuration of a mobile communication system assumed in non-standalone (NSA).

Fig. 5 is an explanatory diagram for describing an overview of an example of the cell layout design in the fifth generation (5G).

Fig. 6 is an explanatory diagram for describing an overview of the initial access procedure.

Fig. 7 is a diagram showing an example of a schematic structure of an SS block.

Fig. 8 is an explanatory diagram for describing an overview in which a base station notifies a terminal device in a cell of a new radio master information block (NR-MIB).

Fig. 9 is a diagram schematically illustrating quasi co-location (QCL) and Remaining Minimum System Information (RMSI) of an SS block.

Fig. 10 is a schematic sequence diagram showing the flow of a 4-step Random Access Channel (RACH) procedure.

Fig. 11 is an explanatory diagram for describing an overview of the 4-step RACH procedure.

Fig. 12 is a diagram showing an overview of an idea of mapping from an SS block to a RACH transmission occasion (RO).

Fig. 13 is a diagram illustrating an overview of another idea of mapping of SS blocks to ROs.

Fig. 14 is an explanatory diagram for describing a series of flows of the 4-step RACH.

Fig. 15 is an explanatory diagram for describing an overview of the beam management process.

Fig. 16 is an explanatory diagram for describing an overview of a procedure related to data transmission and reception between a base station and a terminal device in a connected mode.

Fig. 17 is an explanatory diagram for describing an overview of procedures related to data transmission and reception between a base station and a terminal device in a connected mode.

Fig. 18 is an explanatory diagram for describing an example of the case of the beam direction change of the BPL.

Fig. 19 is an explanatory diagram for describing another example of the case of the beam direction change of the BPL.

Fig. 20 is an explanatory diagram for describing a basic principle according to the technique of the present disclosure.

Fig. 21 is an explanatory diagram for describing a basic principle of the technique according to the present disclosure.

Fig. 22 is an explanatory diagram for describing a basic principle of the technique according to the present disclosure.

Fig. 23 is a flowchart showing an example of a process flow relating to control of communication with a base station by a terminal device according to the embodiment.

Fig. 24 is a flowchart showing another example of a process flow relating to control of communication with a base station by a terminal device according to the embodiment.

Fig. 25 is a flowchart showing an example of a processing flow relating to control of communication with a base station by a terminal device according to the embodiment.

Fig. 26 is a diagram showing an example of a state transition diagram until a terminal device transitions to a Radio Resource Control (RRC) connected state in NSA.

Fig. 27 is a diagram showing an example of a state transition diagram until the terminal device transitions to the RRC connected state in the SA.

Fig. 28 is a schematic sequence diagram showing a processing flow of Contention Free Random Access (CFRA).

Fig. 29 is a functional block diagram showing a configuration example of a hardware configuration of an information processing apparatus configuring a system according to an embodiment of the present disclosure.

Fig. 30 is an explanatory diagram for describing an application example of the communication apparatus according to the embodiment.

Fig. 31 is an explanatory diagram for describing an application example of the communication apparatus according to the embodiment.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configuration will be denoted by the same reference numerals, and overlapping description will be omitted.

Note that the description will be given in the following order.

1. Example of configuration

1.1 example of System configuration

1.2 configuration example of base station

1.3 configuration example of terminal device

2. Overview of communications assuming the use of millimeter waves

3. Technical problem

4. Characteristic of the technology

4.1 basic principle

4.2, treatment

4.3, modification

5. Hardware configuration

6. Application example

6.1, application example 1: application example of another communication device

6.2, application example 2: examples of applications of communication based on other communication standards

7. End up

< <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 apparatus 100 and a terminal apparatus 200. Here, the terminal device 200 is also referred to as a user. The user may also be referred to as a User Equipment (UE). The wireless communication device 100C is also referred to as a UE relay. The UE herein may be a UE defined in Long Term Evolution (LTE) or LTE-advanced (LTE-a), and the UE relay may be a Prose UE for network relay discussed in the third generation partnership project (3GPP), and may more generally represent a communication device.

(1) Wireless communication device 100

The wireless communication apparatus 100 is an apparatus that provides a wireless communication service to a lower-level apparatus. The wireless communication apparatus 100A is, for example, a base station of a cellular system (or a mobile communication system). The base station 100A performs wireless communication with a device (for example, the terminal device 200A) located within the cell 10A of the base station 100A. For example, the base station 100A transmits a downlink signal to the terminal apparatus 200A and receives an uplink signal from the terminal apparatus 200A.

The base station 100A is logically connected to another base station through, for example, an X2 interface, and can transmit and receive control information and the like to and from the other base station. Further, the base station 100A is logically connected to a so-called core network (not shown) through, for example, an S1 interface, and can transmit and receive control information and the like to and from the core network. Note that communications between these devices may be physically relayed through various devices.

Here, the wireless communication apparatus 100A shown in fig. 1 is a macrocell base station, and the cell 10A is a macrocell. On the other hand, the wireless communication apparatuses 100B and 100C are master apparatuses that operate the small cells 10B and 10C, respectively. As an example, the master device 100B is a fixedly installed small cell base station. The small cell base station 100B establishes a radio backhaul link with the macro cell base station 100A and establishes an access link with one or more terminal devices (e.g., terminal device 200B) in the small cell 10B. Note that the wireless communication device 100B may be a relay node defined in 3 GPP. The master device 100C is a dynamic Access Point (AP). The dynamic AP100C is a mobile device that dynamically operates the small cell 10C. The dynamic AP100C establishes a radio backhaul link with the macrocell base station 100A and an access link with one or more terminal devices (e.g., terminal device 200C) in the small cell 10C. The dynamic AP100C may be, for example, a terminal device installed with hardware or software that may serve as a base station or wireless access point. In this case, the small cell 10C is a dynamically formed local area network (localized network/virtual cell).

The cell 10A may operate according to a wireless communication scheme such as LTE, LTE-A, LTE-Advanced Pro, global system for mobile communications (GSM) (registered trademark), Universal Mobile Telecommunications System (UMTS), wideband code division multiple access (W-CDMA), CDMA2000, Worldwide Interoperability for Microwave Access (WiMAX), WiMAX2, IEEE 802.16, and the like.

Note that the small cell is a concept that may include various types of cells (e.g., femto cells, nano cells, pico cells, micro cells, etc.) that are arranged to overlap with or not overlap with and are smaller than the macro cell. In a certain example, the small cell is operated by a private base station. In another example, a small cell is operated by having a terminal that is the primary device temporarily operate as a small cell base station. So-called relay nodes can also be considered in the form of small cell base stations. The wireless communication device acting as a master station of the relay node is also referred to as a donor base station. A donor base station may refer to a DeNB in LTE and, more generally, may refer to a primary station of a relay node.

(2) Terminal device 200

The terminal device 200 may perform communication in a cellular system (or mobile communication system). The terminal device 200 performs wireless communication with a wireless communication device (e.g., the base station 100A or the master device 100B or 100C) of the cellular system. For example, the terminal apparatus 200A receives a downlink signal from the base station 100A and transmits an uplink signal to the base station 100A.

Further, the terminal apparatus 200 is not limited to so-called UE, and may be, for example, so-called low-cost UE such as Machine Type Communication (MTC) terminal, enhanced MTC (emtc) terminal, narrowband internet of things (NB-IoT) terminal, and the like.

(3) Supplement

The schematic configuration of the system 1 has been described above, but the present technology is not limited to the example shown in fig. 1. For example, a configuration that does not include a master, a Small Cell Enhancement (SCE), a heterogeneous network (HetNet), an MTC network, or the like may be employed as the configuration of the system 1. Further, as another example of the configuration of the system 1, a master device may be connected to a small cell to construct a cell under the small cell.

<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. 2. Fig. 2 is a block diagram illustrating 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 communication control unit 150.

(1) Antenna unit 110

The antenna unit 110 radiates a signal output from the wireless communication unit 120 into a space as radio waves. Further, the antenna unit 110 converts radio waves in the space into a signal and outputs the signal to the wireless communication unit 120.

(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.

(3) Network communication unit 130

The network communication unit 130 transmits and receives information. For example, the network communication unit 130 transmits and receives information to and from another node. The further node comprises, for example, a further base station and a core network node.

Note that, as described above, in the system 1 according to the present embodiment, the terminal device can function as a relay terminal to relay communication between the remote terminal and the base station. In this case, for example, the wireless communication device 100C corresponding to the relay terminal may not include the network communication unit 130.

(4) Memory cell 140

The storage unit 140 temporarily or permanently stores programs and various data for operating the base station 100.

(5) Communication control unit 150

The communication control unit 150 controls communication with another device (for example, the terminal device 200) via a wireless communication path by controlling the operation of the wireless communication unit 120. As a specific example, the communication control unit 150 may generate a transmission signal by modulating data as a transmission target based on a predetermined modulation scheme, and cause the wireless communication unit 120 to transmit the transmission signal to the terminal device 200 in the cell. Further, as another example, the communication control unit 150 may acquire a reception result of a signal from the terminal device 200 (i.e., a reception signal) from the wireless communication unit 120 and demodulate data transmitted from the terminal device 200 by performing predetermined demodulation processing on the reception signal.

Further, the communication control unit 150 may control communication with another base station 100 or each entity configuring a core network by controlling the operation of the network communication unit 130.

Note that the configuration of the base station 100 described above with reference to fig. 2 is merely an example, and the functional configuration of the base station 100 is not necessarily limited. As a specific example, a part in each configuration of the base station 100 may be provided outside the base station 100. Further, each function of the base station 100 may be realized by a plurality of devices operating in cooperation with each other.

<1.3, configuration example of terminal device >

Next, an example of the configuration of the terminal device 200 according to an embodiment of the present disclosure will be described with reference to fig. 3. Fig. 3 is a block diagram showing a configuration example 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 detection unit 230, a storage unit 240, and a communication control unit 250.

(1) Antenna unit 210

The antenna unit 210 radiates a signal output from the wireless communication unit 220 into space as radio waves. Further, the antenna unit 210 converts radio waves in the space into a signal and outputs the signal to the wireless communication unit 220. Note that the antenna unit 210 may include a plurality of antenna elements. Therefore, in the following description, each antenna element is also referred to as an "antenna element 210".

(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 a base station and transmits an uplink signal to the base station.

Further, as described above, in the system 1 according to the present embodiment, the terminal device can function as a relay terminal to relay communication between the remote terminal and the base station. In this case, for example, the wireless communication unit 220 in the terminal device 200C serving as a remote terminal can transmit and receive a sidelink signal to and from the relay terminal.

(3) Detector 230

The detection unit 230 includes various sensors such as an acceleration sensor, a gyro sensor, and the like, and detects a change in the posture of the terminal device 200. The detection unit 230 may notify the communication control unit 250 of information according to the detection result of the posture change of the terminal device 200.

(4) Memory cell 240

The storage unit 240 temporarily or permanently stores programs and various data for operating the terminal device 200.

(5) Communication control unit 250

The communication control unit 250 controls communication with another device (e.g., the base station 100) via a wireless communication path by controlling the operation of the wireless communication unit 220. As a specific example, the communication control unit 250 may generate a transmission signal by modulating data as a transmission target based on a predetermined modulation scheme, and cause the wireless communication unit 220 to transmit the transmission signal to the base station 100. Further, as another example, the communication control unit 250 may acquire a reception result of a signal from the base station 100 (i.e., a reception signal) from the wireless communication unit 220 and demodulate data transmitted from the base station 100 by performing a predetermined demodulation process on the reception signal.

Note that the configuration of the terminal device 200 described above with reference to fig. 3 is merely an example, and the functional configuration of the terminal device 200 is not necessarily limited. As a specific example, a part in each configuration of the terminal device 200 may be provided outside the terminal device 200. As a more specific example, the antenna unit 210, the wireless communication unit 220, the detection unit 230, and the storage unit 240 shown in fig. 3 may also be externally attached to the terminal device 200. Note that in this case, a device on the side including the communication control unit 250 corresponds to an example of "control device". Further, each function of the terminal apparatus 200 may be realized by a plurality of apparatuses operating in cooperation with each other.

<2, communication overview assuming the use of millimeter waves >)

In recent years, various studies have been made on a fifth generation (5G) mobile communication system succeeding LTE/LTE-a, and introduction of a Radio Access Technology (RAT) also called New Radio (NR) and different from LTE as a next generation radio access manner has also been studied.

Furthermore, with the introduction of NR, research has also been conducted on a standard called non-independent (NSA) that is assumed to be used in conjunction with existing LTE networks. For example, fig. 4 is a diagram showing an example of a system configuration of a mobile communication system assumed in NSA. As shown in fig. 4, in NSA, C-plane (control information) transmission and reception are performed between macrocell base station 100A and terminal apparatus 200 using existing LTE as an anchor point. Further, transmission and reception of U-plane (user data) is performed between the small cell base station 100B and the terminal apparatus 200 through NR. With such a configuration, it becomes possible to realize transmission and reception of U-play with higher throughput. Further, the Evolved Packet Core (EPC)190 controls the 5G Radio Access Network (RAN) via the S1 interface.

In particular, in a 5G mobile communication system, communication using a radio signal having a frequency called a millimeter wave such as 28GHz or 39GHz (hereinafter also simply referred to as "millimeter wave") has been studied. Further, the millimeter wave has a relatively large spatial attenuation, so that in the case where the millimeter wave is used for communication, there is a tendency to require an antenna having a high gain. In order to achieve such a request, in a 5G mobile communication system, it has been studied to use a directional beam for communication between a base station and a terminal device by forming the directional beam by a so-called beam forming technique. By using such a technique, for example, communication between the base station and the terminal device is time-multiplexed and frequency-multiplexed, but may also be spatially multiplexed. With such a configuration, in the 5G mobile communication system, the number of users capable of simultaneously performing end-to-end communication at a very high data rate can be increased, and the cell capacity is significantly increased. Accordingly, it has been desired to implement enhanced mobile broadband (eMBB) for services.

(cell layout design overview)

Here, an overview of an example of the cell layout design in 5G will be described with reference to fig. 5. Fig. 5 is an explanatory diagram for describing an overview of an example of the cell layout design in 5G. In the example shown in fig. 5, an existing cell 10A based on the LTE standard is used as a coverage cell, and small cells 10B #1 to 10B #3 capable of communicating using millimeter waves overlap with each other in the cell 10A to form a heterogeneous network (HetNet). Note that the small cells 10B #1 to 10B #3 respectively refer to small cells formed by the small cell base stations 100B #1 to 100B # 3. Based on such a configuration, transmission and reception of U-play (user data) are performed between each small cell base station 100B #1 to 100B #3 and each terminal apparatus 200#1 to 200#3 located in the small cells 10B #1 to 10B #3, respectively. Therefore, it becomes possible to further improve throughput relating to transmission and reception of U-plane (user data).

(initial Access overview)

Next, an overview of the Initial Access (IA) procedure in 5G for which a standardized specification is being prepared will be described.

For example, fig. 6 is an explanatory diagram for describing an overview of the initial access procedure. As shown in fig. 6, when the terminal apparatus 200 is activated according to power-on or the like, the terminal apparatus 200 establishes communication with the base station 100 by performing an initial access procedure, and then performs transmission of user data to the base station 100 and reception of user data from the base station 100. Further, in the initial access procedure, processes of cell search and selection, system information receiver, and random access are mainly performed in this order.

In 5G, in order to reduce power consumption on the network side and compensate for path loss in the millimeter wave, a beam-forming technique is used to reduce the beam width, and then beam scanning of a Downlink (DL) signal is performed in a cell. According to this characteristic, in 5G, as in LTE, Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), and Physical Broadcast Channels (PBCH) for performing cell search and cell selection, and specific reference signals (CRS) for Channel Estimation (CE) are not always transmitted in an on manner from the base station (eNB) side in each cell.

In 5G, PSS, SSS and PBCH are organized and transmitted into OFDM4 symbols as SS blocks. For example, fig. 7 is a diagram showing an example of a schematic structure of an SS block.

Further, within one cell, various information on the payload data of the PBCH of one SS block is provided to the terminal device side in notification as a new radio master information block (NR-MIB). For example, fig. 8 is an explanatory diagram for describing an overview of notifying the NR-MIB by the base station to the terminal apparatus in the cell. Similar to LTE, examples of information provided in the notification as the NR-MIB may include a minimum required System Frame Number (SFN) in an initial access procedure, an SS burst setup period (i.e., a period in which a set of SS blocks is transmitted), scheduling information of Remaining Minimum System Information (RMSI) carrying remaining system information NR-SIB1, and the like. Furthermore, it has been agreed during standardization that SS blocks and RMSIs can be assumed to be (spatially) quasi co-located (QCL).

Note that QCL corresponds to the case where the long-term propagation path characteristics are the same between different Antenna Ports (APs). The long-term propagation path characteristics refer to delay spread, doppler shift, average gain, average delay, and the like, and a case in which some or all of the doppler spread, doppler shift, average gain, average delay, and the like are identical to each other is assumed as QCL. QCLs correspond to cases where the quasi-geographic relationships are identical to each other, but are not necessarily limited to cases where they are physically close to each other. Further, the definition of QCL up to 4G has been described above, but in the definition of QCL in 5G, in addition to the above-described characteristics of QCL defined in Rel-11 of LTE-a, the angular domain characteristics indicating the spatial beam direction are further increased. The angular domain characteristic indicating the beam direction is defined as QCL type D: spatial Rx in the standardized specification, a beam can be considered (spatially) quasi co-located (QCL) meaning that beams can be received from the same spatial direction.

Meanwhile, the payload size of the NR-PBCH in the SS block is limited to a small bit capacity, which is greater than 40 bits and does not exceed 72 bits. Therefore, similar to LTE, it is necessary to receive the RMSI carrying the NR-SIB1 in 5G, which is the remaining system information needed to perform the initial access procedure.

Currently, RMSI is being discussed in 3GPP, but at present, almost agreed that RMSI linked to one SS block in one cell has only one-to-one association. Note that in the case of broadband operation, it has been agreed that multiple SS blocks may be sent in multiple bandwidth parts (BWPs), but in that case, it has been determined that many-to-one support of RMSI linking with multiple SS blocks depends on support on the network side.

The RMSI basically includes a new radio physical downlink shared channel (NR-PDSCH) carrying message data and a control resource set (CORESET) carrying resource information for the RMSI. Information on the CORESET carrying resource information for RMSI is provided in the notification of the NR-MIB to the terminal device side about payload data of NR-PBCH. Further, the CORESET is configured by a new radio physical downlink control channel (NR-PDCCH), through which the terminal device side will monitor, and set the CORESET to a Common Search Space (CSS) or a UE-specific search space (USS).

Further, in 5G, a consensus has been reached in 3GPP that setting information of Random Access (RA) in an initial access procedure is included in RMSI. Furthermore, it has been agreed that, similar to LTE, a 4-step RACH procedure is employed as an initial access procedure. That is, the threshold information of the SS block to be selected in the case where the terminal device (UE) side transmits the Msg1 (physical random access channel (PRACH) preamble) and the Tx transmission power information of the base station (gNB) side are transmitted by the RMSI. Path Loss (PL) estimation may be performed by Reference Signal Received Power (RSRP) measurement or selecting the best SS block in the serving cell in Msg1 transmission or the RACH resource corresponding to the SS block based on the SS blocks that meet this threshold.

Further, as described above, COREST and RMSI linked with one SS block in the serving cell are Frequency Division Multiplexed (FDM) and (spatially) quasi co-located (QCL). For example, fig. 9 is a diagram schematically illustrating quasi co-location (QCL) of an SS block and an RMSI.

The terminal device side can simultaneously receive the frequency division multiplexed COREST and RMSI by receiving the SS block transmitted using the broadband from the base station side using the broadband. Therefore, as described above, the terminal device side can select the best SS block in the Msg1 transmission, or derive the initial value of open-loop Uplink (UL) power control from the path loss estimate. Furthermore, the terminal device side may also know subcarrier spacing (SCS) information of the PRACH or information about the step size of the power increase in the PRACH at the same time.

(four-step RACH procedure)

Next, the flow of the 4-step RACH procedure will be described with respect to a characteristic part in the case where the 4-step RACH procedure is applied in 5G. For example, fig. 10 is a schematic sequence diagram showing the flow of the 4-step RACH procedure. Further, fig. 11 is an explanatory diagram for describing an overview of the 4-step RACH procedure, and shows information flow between the base station and the terminal device in each procedure.

As shown in fig. 10 and 11, in the 4-step RACH procedure, the terminal device sequentially performs the following four procedures.

Msg1(PRACH preamble) transmission

Msg2 (random access response (RAR)) reception

Msg3 (radio resource control (RRC) connection request) Send

Msg4(RRC connection setup) reception

Further, in addition to the above four procedures, the terminal device may transmit Msg5(RRC connection setup complete) indicating completion of the initial access procedure to the base station after receiving Msg 4.

In general, it is desirable that the terminal device side completes the initial access procedure and transitions to the connected mode as soon as possible. In particular, as described above, in 5G, beamforming is performed to compensate for path loss due to the use of millimeter waves. In this case, it becomes important for the terminal device side to finish the initial access procedure performed using the wide beam and to switch to the connection mode as soon as possible, in order to stably maintain the Beam Pear Link (BPL) state through beam synchronization. From such a background, in 5G, a mechanism for making the delay caused by beam scanning for establishing BPL as small as possible by using the above-described assumption of (spatial) QCL has been studied.

Information for performing the initial access procedure (4-step RACH) has been obtained assuming that the terminal device side has 2 to 4 antenna arrays/subsets related to the UE capability. This is due to the fact that, as described above, the terminal apparatus side can simultaneously receive core and RMSI of Frequency Division Multiplexing (FDM) by receiving an SS block transmitted using a wide beam from the base station (gNB) side using a quasi-omni wide beam on each antenna array/subset.

Next, each procedure of the 4-step RACH will be described below focusing on the processing in 5G.

(1) Msg1(PRACH preamble) transmission

In 3GPP, RACH transmission occasion (RO) is defined as a time-frequency (T-F) resource for transmitting PRACH Msg1 using a set PRACH preamble format in a Tx beam in one specific direction. As an idea of mapping from selecting SS blocks to be received to ROs, two candidates of one-to-one and many-to-one have been studied. For example, fig. 12 is a diagram showing an overview of the idea of mapping from SS blocks to ROs, and shows an example of one-to-one mapping from SS blocks to ROs. Further, fig. 13 is a diagram showing an overview of another idea of mapping from SS blocks to ROs, and shows an example of many-to-one mapping from SS blocks to ROs. The terminal device side sends Msg1 using information obtained by the RO.

(2) Msg2 (random access response (RAR)) reception

In 3GPP, almost a consensus has been reached: the terminal device side can assume that PDCCH demodulation reference signal (DMRS) and PDSCH DMRS carrying Msg2(RAR) are quasi co-located with SS blocks (QCLs) associated with RO and Msg1 previously sent by the terminal device side.

(3) Msg3 (radio resource control (RRC) connection request) send

In 3GPP, almost a consensus has been reached: the "base station side can assume that the usch dmrs of Msg3 transmitted by the terminal device side is quasi co-located (QCL) with the previously transmitted Msg 1".

(4) Msg4(RRC connection setup) reception

In 3GPP, almost a consensus has been reached: "in case there is no beam report in Msg3 of RACH, the terminal device side can assume that PDCCH DMRS and PDSCH DMRS carrying Msg4 are quasi co-located (QCL) with SS blocks related to Msg1 and RO previously sent by the terminal device side.

Further, fig. 14 is an explanatory diagram for describing a series of flows of the 4-step RACH, and schematically shows a relationship between the base station and the terminal device in each procedure. In fig. 14, reference numerals B101 and B103 schematically represent beams used by the base station 100 to transmit and receive information to and from the terminal apparatus 200 in the cell. Specifically, the beam B101 indicates a so-called wide beam which makes the beam width relatively wide, and is used for transmission of an SS block, COREST (NR-PDCCH), or the like. Further, the beam B103 indicates a so-called narrow beam that makes the beam width relatively narrow, and is used for transmission of RMSI (NR-PDSCH) or the like. Further, reference numeral B111 schematically denotes a beam used by the terminal apparatus 200 to transmit and receive information to and from the base station 100. In the example shown in fig. 14, the beam B111 is formed as a wide beam.

As shown in fig. 14, in the initial access procedure performed after the terminal device side completes the search and selection of the best SS block in the serving cell, the transmission and reception of each of Msg1 to Msg4 are performed assuming that beam synchronization with the SS block has been performed and the BPL state is maintained. By this control, the initial access procedure can be completed quickly.

In order to complete the initial access procedure including the random access procedure as described above more quickly, it can also be assumed that the terminal device side performs the initial access procedure using a wide beam. Therefore, in a series of procedures called a beam optimization (BR) operation, narrowing of a beam used by the terminal device side for communication with the base station is performed, but the BR operation may be performed after the terminal device side switches to the RRC connected mode, for example. On the other hand, according to vendor-side implementations in the specifications of 3GPP, no beam optimization (BR) operation is currently specifically defined. Therefore, even in the initial access procedure, for example, the P2 procedure and the P3 procedure of the beam optimization (BR) operation in the Msg2 can be simultaneously performed on the terminal device side. That is, it can be said that the terminal device side performs beam optimization (BR) operations of the P2 procedure and the P3 procedure, and BPL states of narrow beams can be overlapped and performed in an initial access procedure before the terminal device side switches to the RRC connected mode. Note that the details of this case will be described separately later.

(Beam management)

Next, a Beam Management (BM) procedure in 5G will be described specifically for a procedure of narrowing a beam used by the base station and the terminal device for communication therebetween. For example, fig. 15 is an explanatory diagram for describing an overview of the beam management process. In 3GPP, as described above, the operation of Beam Management (BM) represented by the P1, P2, and P3 procedures is defined as a procedure for narrowing a beam. Beam optimization (BR) between the base station and the terminal device is performed through P1, P2, and P3 procedures.

The P1 procedure is defined by beam selection and beam reselection. In the P1 procedure, basically, an operation of beam alignment is assumed at the time of initial access using a wide beam having a relatively wide beam width.

The P2 procedure is defined by Tx beam optimization. In the P2 process, the following operations are assumed: beam optimization (BR) is performed on a Downlink (DL) Tx beam on the base station side, and positioning is performed between a narrow beam on the base station side and a beam on the terminal device side whose beam width is further narrowed (beam correspondence).

The P3 procedure is defined by Rx beam optimization. In the P3 process, the following operations are assumed: the DL Rx beam on the terminal device side is beam optimized (BR) and positioned (beam mapped) between the narrow beam on the base station side and the narrow beam on the terminal device side whose beam width is further narrowed.

(operating in connected mode)

Next, the operation in the connected mode will be described mainly focusing on the operation of the hypothetical (spatial) QCL. For example, fig. 16 and 17 are explanatory diagrams for describing an overview of procedures related to data transmission and reception between a base station and a terminal device in a connected mode. Specifically, fig. 16 shows an example of a procedure in the case where the terminal device receives DL data transmitted from the base station. Further, fig. 17 shows an example of a procedure in the case where the terminal device transmits UL data to the base station.

As described above, beam optimization (BR) in Beam Management (BM) typified by the P1, P2, and P3 procedures is generally performed after the terminal device side switches to the RRC connected mode.

In 5G, it has been agreed that the terminal device side can assume that a Reference Signal (RS) of DL corresponding to a Transmission Configuration Indication (TCI) state of N bits on Downlink Control Information (DCI) is quasi-co-located (QCL) with respect to NR-PDSCH (spatially). In addition, in order to reduce latency and additional signaling at the time of beam switching, it has been studied to transmit NR-PDCCH (control signal) and NR-PDSCH (data signal) in the same beam. In 3GPP, it has been discussed that aperiodic channel state information reference signals (CSI-RS) for Beam Management (BM) are assumed to be RS with respect to DL quasi co-location (QCL) of NR-PDSCH and NR-PDCCH.

As described above, in case of (spatially) quasi co-location (QCL) in TCI state of N bits on DCI by the aperiodic CSI-RS for Beam Management (BM), beam scanning is performed using the aperiodic CSI-RS by the above-described P2 process. Then, beam optimization (BR) is performed to select an optimal beam for the aperiodic CSI-RS. When the P2 procedure is completed, the terminal device side transmits a beam report indicating the best beam resource of the CSI-RS for Beam Management (BM) to the base station side.

Further, on the terminal device side, Rx beam scanning is performed through the P3 procedure, and after determining the optimal Rx beam resource, a new DCI field of N bits is signaled to the base station.

Using aperiodic CSI-RS for Beam Management (BM), NR-PDSCH and NR-PDCCH in case of terminal device side transition to RRC connected mode are quasi co-located (QCL). Accordingly, the operations of the P2 and P3 processes are performed using aperiodic CSI-RS in order to establish BPL.

As described above, even in the RRC connected mode, the reception of both the NR-PDSCH and the NR-PDCCH is performed under the assumption that the BPL state is maintained, similar to the initial access procedure. Specifically, regarding the NR-PDSCH and NR-PDCCH, the BPL state can be maintained assuming that beam synchronization has been performed with the (spatially) quasi-co-located (QCL) aperiodic CSI-RS for Beam Management (BM), and only beam narrowing is required by using the P1, P2, and P3 procedures. That is, in the RRC connected mode, even when both NR-PDSCH and NR-PDCCH are received on the terminal device side, the assumption of having (spatial) QCL for RS of DL from the base station side is considered as a mechanism to maintain the BPL state.

<3, technical problem >)

Next, a technical problem of the system according to the embodiment of the present disclosure will be described.

In the random access procedure at the time of initial access in 5G, after the search and selection of the best SS block in the serving cell are completed, (spatial) QCL is performed as described above under the assumption that the BPL state between the base station and the terminal device is maintained. Therefore, the delay due to the beam scanning for establishing the BPL can be made as small as possible.

Meanwhile, a case where the beam direction of the BPL is changed due to sudden rotation of the terminal device or the like can be assumed. Specifically, in the case where unexpected sudden rotation or the like occurs on the terminal device side during the initial access procedure, the BPL state acquired at the point in time when the search and selection of the optimal SS block at the time of initial access have been completed may not be maintained.

For example, fig. 18 is an explanatory diagram for describing an example of a case where the beam direction of the BPL is changed, and shows an example of a case where the beam direction is changed at the time of initial access. Specifically, fig. 18 schematically shows a case where the terminal apparatus 200 in the BPL state with the base station 100#1 is suddenly rotated. Reference numeral 200' schematically represents the state of the terminal device 200 after rotation.

In fig. 18, reference numeral B151 schematically denotes a directional beam formed by the base station 100# 1. Further, reference numeral B161 schematically denotes a directional beam formed by the terminal apparatus 200 before rotation. That is, in the example shown in fig. 18, the terminal apparatus 200 before rotation is in the BPL state with the base station 100# 1. More specifically, the beam B161 formed by the terminal apparatus 200 before rotation and the beam B151 formed by the base station 100#1 establish BPL with each other.

On the other hand, according to the rotation of the terminal apparatus 200, the direction in which the beam B161 formed by the terminal apparatus 200 is directed also changes. For example, reference numeral B161 'schematically denotes a directional beam formed by the terminal device 200' after rotation. Further, reference numeral B171 schematically denotes a directional beam formed by the base station 100# 2. That is, in the example shown in fig. 18, the beam B161 'formed by the terminal device 200' after rotation is directed to a direction in which BPL can be established with the beam B171 formed by the base station 100# 2.

For example, in the case where rotation of the terminal apparatus 200 as shown in fig. 18 occurs at the time of initial access, the BPL state between the base station 100#1 and the terminal apparatus 200 acquired at the time point when the search and selection of the optimal SS block have been completed at the time of initial access is not maintained. Thus, for example, a case may be assumed in which the Msg1 in the random access procedure is transmitted to another base station 100#2, instead of the base station 100#1 that was originally in the BPL state with the terminal device 200. Such a case does not satisfy the above-described condition regarding the assumption of the (spatial) QCL at the initial access, so that a delay is generated in the random access procedure, and in addition, it can also assume the possibility that the subsequent RRC connection may be affected. In particular, it is generally assumed that the mobile device is driven by a battery. Under such an assumption, for example, in a terminal device in which four millimeter wave antenna arrays/sub-modules are installed, it is assumed that the initial access procedure is repeated a plurality of times due to a delay in the random access procedure. In this case, for example, influences such as a reduction in battery life, an increase in processing load due to the continued occurrence of another re-process, and the like can be assumed.

Further, in the connection mode, it is difficult to maintain the BPL state between the base station and the terminal device, assuming that the beam direction of the BPL changes due to sudden rotation of the terminal device or the like.

For example, fig. 19 is an explanatory diagram for describing another example of the case of the beam direction change of the BPL, and shows an example of the case of the beam direction change in the connected mode. Specifically, the left diagram of fig. 19 shows a case where a BPL state is established between the base station 100 and the terminal apparatus 200. More specifically, reference numeral B201 schematically denotes a directional beam formed by the base station 100. Reference numeral B203 schematically denotes a directional beam formed by the terminal apparatus 200. That is, in the left diagram of fig. 19, the beam B201 formed by the base station 100 and the beam B203 formed by the terminal apparatus 200 establish a BPL with each other. In this case, for example, NR-PDCCH and NR-PDSCH transmitted from the base station 100, aperiodic CSI-RS for Beam Management (BM), and the like are received by the terminal apparatus 200.

On the other hand, the right diagram of fig. 19 schematically shows a case where the terminal device 200 is suddenly rotated. Reference numeral 200' schematically represents the state of the terminal device 200 after rotation. Further, reference numeral B203 'schematically denotes a directional beam formed by the terminal device 200' after the rotation.

In the right diagram of fig. 19, the beam B203 formed by the terminal apparatus 200' after the rotation is directed to a different direction from the base station 100, so that it becomes difficult to maintain the BPL state between the base station 100 and the terminal apparatus 200. In this case, an event called a beam failure occurs first, and if the state continues, an event of call disconnection due to Radio Link Failure (RLF) occurs. That is, it is also possible to assume a case where call disconnection frequently occurs according to the rotation of the terminal apparatus 200. Such a case does not satisfy the above-described condition regarding the hypothetical (spatial) QCL in the connected mode, and thus a subsequent RRC reconnection procedure, etc. is required. Therefore, it can be assumed that the possibility of achieving stable communication in the connected mode may be affected. As described above, in the case where an RRC reconnection procedure or the like is required, the terminal apparatus side may need to repeatedly perform an initial access procedure including the above-described random access procedure from the beginning. As described above, the above operation may have an influence such as shortening of the battery life on the terminal device side as a mobile device, an increase in processing load due to continuation of an additional re-process, and the like.

In view of the circumstances as described above, the present disclosure proposes a technique capable of achieving wireless communication using a directional beam in a more appropriate manner. Specifically, the present disclosure proposes a technique capable of further reducing the frequency at which communication between a base station and a terminal device is restricted even in a case where the direction of a directional beam formed by the terminal device changes according to the rotation of the terminal device or the like.

<4, technical characteristics >, and

hereinafter, technical features of a system according to an embodiment of the present disclosure will be described.

<4.1, basic principles >

First, the basic principle of the technique according to the present disclosure will be described. In the system according to the present disclosure, the terminal device is configured to be able to detect the attitude of the housing of the terminal device or the antenna element supported by the housing by various sensors such as a gyro sensor. In this configuration, in the case where the direction of the directional beam changes in accordance with a change in posture, the terminal device recognizes the change in posture based on the detection result of the above-described sensor, and controls communication with the base station using the directional beam in accordance with the change in posture.

For example, fig. 20 is an explanatory diagram for describing a basic principle according to the technique of the present disclosure. In the example shown in fig. 20, the terminal device 200 includes a plurality of antenna elements that perform wireless communication using directional beams directed in directions different from each other. In fig. 20, reference numeral B211 schematically denotes a directional beam formed by the base station 100. Further, reference numeral B213 schematically denotes a directional beam formed by the antenna element 210A among the plurality of antenna elements 210 included in the terminal apparatus 200. Further, reference symbol B215 schematically represents a directional beam formed by another antenna element 210B different from the antenna element 210A among the plurality of antenna elements 210 included in the terminal apparatus 200. In this configuration, the directional beam formed by at least any one of the plurality of antenna elements establishes BPL with the directional beam formed by the base station 100.

The upper diagram of fig. 20 schematically shows a case where a BPL state is established between the base station 100 and the terminal apparatus 200. That is, in the upper diagram of fig. 20, the beam B211 formed by the base station 100 and the beam B213 formed by the antenna element 210A of the terminal apparatus 200 establish BPL with each other.

On the other hand, the lower diagram of fig. 20 schematically shows a state in which the terminal apparatus 200 has been rotated from the state shown in the upper diagram of fig. 20. That is, in the lower diagram of fig. 20, according to the rotation of the terminal apparatus 200, the beam B213 formed by the antenna element 210A is directed to a direction different from the direction in which the base station 100 is located. That is, in the lower diagram of fig. 20, it becomes difficult to maintain the BPL by the beam B211 formed by the base station 100 and the beam B213 formed by the antenna element 210A of the terminal apparatus 200.

Meanwhile, in the lower diagram of fig. 20, according to the rotation of the terminal apparatus 200, a beam B215 formed by another antenna element 210B different from the antenna element 210A is directed to the direction in which the base station 100 is located.

Therefore, the terminal device 200 (communication control unit 250) according to the embodiment of the present disclosure detects a change in the posture of the terminal device 200, that is, the rotational direction or the amount of rotation of the terminal device 200, based on the detection result of the acceleration, the angular velocity, or the like of the detection unit 230 (e.g., a gyro sensor or the like).

Specifically, for example, as shown in the upper diagram of fig. 20, in the case where the BPL state is established between the terminal apparatus 200 and the base station 100 as the reference state, the terminal apparatus 200 sets the posture of the terminal apparatus 200 (in other words, the posture of each antenna element 210). As a more specific example, in a case where the initial access procedure is focused, on the terminal device 200 side, the best SS block that satisfies the threshold condition in the serving cell is selected by performing beam scanning on all subsets of the plurality of antenna elements 210. Further, in the subsequent random access procedure, the (spatial) QCL is performed on the assumption that beam synchronization with the selected SS block described above has been assumed and the BPL state is maintained. Therefore, for example, the fact that beam synchronization with the SS block has been performed may be considered as a point of time when decoding of PBCH in the SS block having Reference Signal Received Power (RSRP) satisfying a threshold condition set from the network side within the cell or decoding of CORESET and RMSI having a (spatial) QCL relationship with the SS block as described above has been completed, and the posture of the terminal device 200 at that point of time may be set to the reference state.

By the control as described above, even in the case where the posture of the terminal apparatus 200 changes due to sudden rotation or the like, the terminal apparatus 200 can detect the change in posture (i.e., the rotation direction and the rotation amount) from the reference state based on the detection result of the detection unit 230. As a specific example, in the case of the example shown in the lower diagram of fig. 20, based on the detection result of the detection unit 230, the terminal apparatus 200 can recognize that the beam B215 formed by the antenna element 210B is directed to the direction in which the base station 100 is located.

Then, the terminal apparatus 200 selectively switches the antenna element 210 for wireless communication with the base station 100 according to the detection result of the posture change of the terminal apparatus 200. Specifically, in the case of the example shown in the lower diagram of fig. 20, the terminal apparatus 200 switches the antenna element 210 for wireless communication with the base station 100 from the antenna element 210A to the antenna element 210B according to the recognition result of the posture after the terminal apparatus 200 is rotated. Based on such control, even in a case where it is difficult to maintain the BPL state with the base station 100 using the beam B213, the terminal apparatus 200 quickly reestablishes the BPL state with the base station 100 using the beam B215 formed by the antenna element 210B.

With the control as described above, for example, even in the case where the posture of the terminal apparatus 200 changes due to sudden rotation or the like during initial access, a beam from the terminal apparatus 200 is guided to the base station 100 according to the assumed conditions on the (spatial) QCL. Therefore, in the case where the posture of the terminal apparatus 200 is changed, it becomes possible to immediately re-establish the BPL state between the terminal apparatus 200 and the base station 100, and thus it becomes possible to quickly complete the initial access procedure.

Note that an example of a case where the terminal device 200 supports four antenna elements 210 capable of performing wireless communication using millimeter waves so as to point in different directions from each other has been described in the example shown in fig. 20, but the configuration of the terminal device 200 is not necessarily limited. That is, as long as two or more of the plurality of antenna elements 210 are supported to face directions different from each other, the configuration of the terminal apparatus 200 (more specifically, the number of antenna elements 210 or the position supporting each antenna element 210) is not particularly limited. Note that, in the present embodiment, it is desirable that each of the plurality of antenna elements 210 supported by the terminal device 200 can configure a quasi-omni antenna pattern similar to LTE by performing beam scanning.

Next, an example of a case where the direction of a directional beam (particularly, a narrow beam) formed by each antenna element 210 is controlled according to the rotation of the terminal device 200 will be described. Note that in this specification, an example of beam control according to a change in the posture of the terminal device 200 will be mainly described, focusing mainly on a case where communication is performed using a narrow beam as in the connected mode.

For example, fig. 21 is an explanatory diagram for describing a basic principle according to the technique of the present disclosure, and shows an example of a case where the direction of a directional beam formed by each antenna element 210 is controlled. In fig. 21, reference numeral B211 schematically denotes a directional beam formed by the base station 100. Further, reference numerals B221 and B223 schematically represent directional beams (narrow beams) respectively formed in mutually different directions by the antenna element 210A.

For example, the upper diagram of fig. 21 schematically shows a case where the BPL state is established between the base station 100 and the terminal apparatus 200. That is, in the upper diagram of fig. 20, the beam B211 formed by the base station and the beam B221 formed by the antenna element 210A of the terminal apparatus 200 establish BPL with each other.

On the other hand, the lower diagram of fig. 21 schematically shows a state in which the terminal apparatus 200 has been rotated from the state shown in the upper diagram of fig. 21. That is, in the lower diagram of fig. 21, according to the rotation of the terminal apparatus 200, the beam B221 formed by the antenna element 210A is directed in a direction different from the direction in which the base station 100 is located. That is, in the lower diagram of fig. 20, it becomes difficult to maintain the BPL by the beam B211 formed by the base station 100 and the beam B221 formed by the antenna element 210A of the terminal apparatus 200.

Meanwhile, in the lower diagram of fig. 21, even after the terminal apparatus 200 is rotated, the base station 100 is located in a range in which the antenna element 210A can generate a directional beam (narrow beam) (in other words, in a beam scanning range). Specifically, among the beams generated by the antenna element 210A, the beam B223 formed in a direction different from the beam B221 is directed to the direction in which the base station 100 is located.

Therefore, in this case, the terminal device 200 (communication control unit 250) can reestablish the BPL state with the base station 100 by controlling the direction of the beam formed by the antenna element 210A.

Specifically, the terminal apparatus 200 sets the posture of the terminal apparatus 200 (in other words, the posture of each antenna element 210) in the case where the BPL state is established between the terminal apparatus 200 and the base station 100 as a reference state, as shown in the upper diagram of fig. 21. Further, the terminal apparatus 200 detects a change in the posture of the terminal apparatus 200, that is, the rotational direction or the amount of rotation of the terminal apparatus 200, based on the detection result of the acceleration, the angular velocity, or the like by the detection unit 230 (for example, a gyro sensor or the like). Therefore, even in the case where the posture of the terminal apparatus 200 changes due to sudden rotation or the like, the terminal apparatus 200 can detect the change in posture (i.e., the rotation direction and the rotation amount) from the above-described reference state based on the detection result of the detection unit 230. As a specific example, in the case of the example shown in the lower diagram of fig. 21, the terminal apparatus 200 can recognize the direction in which the beam B223 formed by the antenna element 210A is directed to the base station 100 based on the detection result of the detection unit 230.

Note that, while operating in the connected mode, the terminal device 200 performs reception of both the NR-PDSCH and the NR-PDCCH on the assumption that the BPL state is maintained, using the antenna element 210 selected in the initial access procedure. Specifically, regarding NR-PDSCH and NR-PDCCH, and assuming that beam synchronization with an aperiodic CSI-RS for Beam Management (BM) has been taken, the aperiodic CSI-RS is (spatially) quasi co-located (QCL) and has maintained a BPL state by performing beam narrowing by P1, P2, and P3 processes. That is, since reception is performed based on the (spatial) QCL on the assumption that beam synchronization with the optimal beam of the aperiodic CSI-RS for Beam Management (BM) described above has been taken and the BPL state has been maintained, the fact that beam synchronization with the aperiodic CSI-RS for Beam Management (BM) has been taken can be considered as a point of time at which signaling is performed in a new DCI field of N bits as an example, and the posture of the terminal apparatus 200 at that point of time can be set to the reference state.

Then, the terminal apparatus 200 controls the direction of the directional beam formed by the antenna element 210A according to the detection result of the posture change of the terminal apparatus 200. Specifically, in the case of the example shown in the lower diagram of fig. 21, the terminal apparatus 200 switches the beam used for wireless communication with the base station 100 from the beam B221 to the beam B223 according to the recognition result of the posture of the terminal apparatus 200 after rotation. Based on such control, even in a case where it becomes difficult to maintain the BPL state with the base station 100 using the beam B221, the terminal apparatus 200 can quickly reestablish the BPL state with the base station 100 using the beam B223.

Note that even when narrow beam communication is used, in a case where the attitude of the terminal apparatus 200 changes significantly due to sudden rotation or the like, it may be difficult to reestablish the BPL state between the terminal apparatus 200 and the base station 100 using the antenna element 210 similar to before the change. For example, fig. 22 is an explanatory diagram for describing a basic principle according to the technique of the present disclosure, and illustrates an example of beam steering according to a change in the posture of the terminal device 200 at the time of communication using a narrow beam. In fig. 22, reference numeral B211 schematically denotes a directional beam formed by the base station 100. Further, reference numeral B221 schematically denotes a directional beam (narrow beam) formed by the antenna element 210A among the plurality of antenna elements 210 included in the terminal device 200. Further, reference numeral B225 schematically denotes a directional beam (narrow beam) formed by another antenna element 210B different from the antenna element 210A among the plurality of antenna elements 210 included in the terminal device 200.

The upper diagram of fig. 22 schematically shows a case where the BPL state is established between the base station 100 and the terminal apparatus 200. That is, in the upper diagram of fig. 22, the beam B211 formed by the base station 100 and the beam B221 formed by the antenna element 210A of the terminal apparatus 200 establish BPL with each other.

On the other hand, the lower diagram of fig. 22 schematically shows a state in which the terminal apparatus 200 has been rotated from the state shown in the upper diagram of fig. 22. That is, in the lower diagram of fig. 22, the base station 100 is located outside the range in which the antenna element 210A can generate a directional beam (narrow beam) (in other words, outside the range in which the beam is scanned) in accordance with the rotation of the terminal device 200. That is, in the lower diagram of fig. 22, it becomes difficult to maintain the BPL by the beam B211 formed by the base station 100 and the beam (for example, the beam B221) formed by the antenna element 210A of the terminal apparatus 200.

On the other hand, in the lower diagram of fig. 22, the base station 100 is located in a range in which the other antenna element 210B different from the antenna element 210A can generate a directional beam (narrow beam) according to the rotation of the terminal device 200. Specifically, beam B225 of the beams generated by antenna element 210B points in the direction in which base station 100 is located.

Therefore, in this case, the terminal apparatus 200 (communication control unit 250) switches the antenna element 210 for wireless communication with the base station 100 from the antenna element 210A to the antenna element 210B according to the detection result of the change in the posture of the terminal apparatus 200. Further, the terminal device 200 controls the direction of the directional beam formed by the antenna element 210B according to the detection result of the above-described attitude change. In the lower diagram of fig. 22, the beam B225 corresponds to a beam whose direction has been controlled by the terminal apparatus 200. Based on such control, even in a case where it becomes difficult to maintain the BPL state with the base station 100 using the beam B221, the terminal apparatus 200 quickly reestablishes the BPL state with the base station 100 using the beam B223 formed by the antenna element 210B.

With the control as described above, for example, even in the case where the posture of the terminal apparatus 200 changes due to sudden rotation or the like at the time of operation in the connected mode, the beam from the terminal apparatus 200 is directed to the base station 100 according to the condition related to the assumption of the (spatial) QCL. Therefore, even in the case where the posture of the terminal apparatus 200 changes, the terminal apparatus 200 can immediately re-establish the BPL state with the base station 100. Therefore, for example, even if a beam failure occurs due to a change in the posture of the terminal apparatus 200 caused by a sudden rotation or the like, the terminal apparatus 200 can reestablish the BPL state with the base station 100 before a call disconnection due to the RLF occurs. Further, ideally, even if the posture of the terminal apparatus 200 changes due to sudden rotation or the like, the terminal apparatus 200 is able to re-establish the BPL state with the base station 100 before the beam failure occurs.

Note that the examples described with reference to fig. 20 to 22 are merely examples, and do not necessarily limit operations related to control of communication with the base station 100 using a directional beam according to a change in the posture of the terminal device 200 by the terminal device 200 according to the present embodiment.

For example, if the reference state is set to a state in which at least a radio signal transmitted from the base station using a directional beam can be received via any of the above-described one or more antenna elements, the condition for setting the reference state can be appropriately changed. As a specific example, if the terminal device 200 is in a state where the received power (e.g., RSRP) of a radio signal transmitted from the base station 100 using a directional beam is equal to or greater than a threshold, the terminal device 200 may set a reference state at any timing based on the detection result of the posture at that timing. Further, as another example, if the terminal apparatus 200 is in a state in which it can receive a signal block for each directional beam, such as the above-described SS block, transmitted from the base station 100 using the synchronization signal and the control signal as one unit, the terminal apparatus 200 can set the reference state at any timing based on the detection result of the posture at that timing.

Further, the opportunity of the terminal apparatus 200 to detect the posture change of the terminal apparatus 200 is not particularly limited. As a specific example, the terminal apparatus 200 may detect a change in the posture of the terminal apparatus 200 from a reference state set in advance by sequentially monitoring the detection result of the detection unit 230 at each predetermined timing. With such control, the terminal device 200 can also detect a change in the posture of the terminal device 200 in real time. Further, as another example, the terminal apparatus 200 may detect a change in the posture of the terminal apparatus 200 by using a predetermined event as a trigger to acquire a detection result by the detection unit 230. As a more specific example, the terminal apparatus 200 may detect a change in the posture of the terminal apparatus 200 from a reference state set previously using the occurrence of a beam failure as a trigger.

Hereinabove, the basic principle of the technique according to the present disclosure has been described with reference to fig. 20 to 22.

<4.2, treatment >

Next, an example of processing related to controlling communication with the base station 100 by the terminal apparatus 200 according to the present embodiment will be described.

(procedure in initial Access)

First, an example of processing related to controlling communication with the base station 100 by the terminal device 200 according to the present embodiment will be described with a focus on the initial access procedure. Note that in this specification, a process flow focusing on an initial access procedure in non-standalone (NSA) assumed to be used with an existing LTE network and a process flow focusing on an initial access procedure in Standalone (SA) operable only on an NR network will be described separately.

First, with reference to fig. 23, an example of a process flow related to controlling communication with the base station 100 by the terminal device 200 will be described with a focus on an initial access procedure in NSA. Fig. 23 is a diagram illustrating an example of a process flow related to controlling communication with the base station 100 by the terminal device 200 according to the present embodiment, and illustrates an initial access procedure in NSA.

In case of NSA, the terminal device 200 side is connected to a network based on the LTE standard as an anchor point. Therefore, in this case, the terminal apparatus 200 acquires information required for cell selection at the time of initial access to the NR network from the C-plane transmitted via the LTE network (S101).

Next, the terminal apparatus 200 performs search and selection of an optimal SS block in the serving cell based on the above-obtained information, establishes synchronization with the NR cell, and performs identification of the serving cell by detecting the NR cell ID (S103).

Next, when performing the identification of the serving cell, the terminal apparatus 200 acquires information required for the random access procedure from CORESET and RMSI Frequency Division Multiplexing (FDM) within a (spatially) quasi-co-located (QCL) beam (S105). Further, it may be assumed that the BPL state has been established between the base station 100 and the terminal apparatus 200 at a point of time when information required for the random access procedure is obtained. Therefore, the terminal apparatus 200 sets the posture of the terminal apparatus 200 at this time (in other words, the posture of each antenna element 210) to the reference state. Specifically, the terminal device 200 holds information corresponding to the detection result of the detection unit 230 in layer 1 as a reference value of the BPL state (S107). Note that, as described above, the terminal apparatus 200 may set the reference state when the random access procedure is performed. That is, in the initial access procedure, the terminal apparatus 200 may set the reference state at least after the transmission timing of the MSG1(PRACH preamble).

Then, the terminal apparatus 200 monitors a change in the posture of the terminal apparatus 200 based on, for example, the detection result of the detection unit 230 (e.g., a gyro sensor or the like), and in the case where the posture is changed due to sudden rotation or the like, controls communication with the base station 100 using directional beams (S109). As a specific example, the terminal apparatus 200 controls the direction of a directional beam used for communication with the base station 100 according to the rotation direction or the rotation amount of the terminal apparatus 200. Further, at this time, the terminal apparatus 200 may switch the antenna element 210 for forming a directional beam according to the rotation direction or the rotation amount of the terminal apparatus 200.

By the control as described above, even in the case where the posture of the terminal apparatus 200 changes due to sudden rotation or the like, the terminal apparatus 200 can immediately re-establish the BPL state with the base station 100, making it difficult to maintain the BPL state with the base station 100.

In the above, an example of a process flow related to controlling communication with the base station 100 by the terminal device 200 has been described with reference to fig. 23 with a view to the initial access procedure in NSA.

Next, an example of a flow of processing related to control of communication with the base station 100 by the terminal device 200 will be described with emphasis on an initial access procedure in SA with reference to fig. 24. Fig. 24 is a flowchart illustrating another example of a processing flow related to controlling communication with the base station 100 by the terminal device 200 according to the present embodiment, and illustrates an initial access procedure in SA.

In case of SA, the terminal device 200 uses information related to initial access, such as SCS, corresponding to the carrier frequency determined in the specification. That is, the terminal apparatus 200 performs search and selection of an optimal SS block in the serving cell based on the above information, establishes synchronization with the NR cell, and performs identification of the serving cell by detecting the NR cell ID (S131).

Next, when performing the identification of the serving cell, the terminal apparatus 200 acquires information required for the random access procedure from CORESET and RMSI Frequency Division Multiplexing (FDM) within a (spatially) quasi-co-located (QCL) beam (S133). Further, it may be assumed that the BPL state has been established between the base station 100 and the terminal apparatus 200 at a point of time when information required for the random access procedure is obtained. Therefore, the terminal apparatus 200 sets the posture of the terminal apparatus 200 at this time (in other words, the posture of each antenna element 210) to the reference state. Specifically, the terminal device 200 holds information corresponding to the detection result of the detection unit 230 in layer 1 as a reference value of the BPL state (S135).

Then, the terminal apparatus 200 monitors a change in the posture of the terminal apparatus 200 based on, for example, the detection result of the detection unit 230 (e.g., a gyro sensor or the like), and in the case where the posture is changed due to sudden rotation or the like, controls communication with the base station 100 using directional beams (S137). As a specific example, the terminal apparatus 200 controls the direction of a directional beam used for communication with the base station 100 according to the rotation direction or the rotation amount of the terminal apparatus 200. Further, at this time, the terminal apparatus 200 may switch the antenna element 210 for forming a directional beam according to the rotation direction or the rotation amount of the terminal apparatus 200.

With the control as described above, in the case where the posture of the terminal apparatus 200 changes, it becomes possible to immediately re-establish the BPL state between the terminal apparatus 200 and the base station 100, and thus it becomes possible to quickly complete the initial access procedure.

In the above, an example of a process flow related to controlling communication with the base station 100 by the terminal device 200 has been described with reference to fig. 24 focusing on the initial access procedure in the SA.

(processing flow in connection mode)

Next, an example of processing related to controlling communication with the base station 100 by the terminal device 200 according to the present embodiment will be described with a focus on control in a case where communication using a narrow beam is performed in the connected mode. For example, fig. 25 is a flowchart showing an example of a flow of processing related to controlling communication with the base station 100 by the terminal device 200 according to the present embodiment, and shows an example of control in a case where communication using a narrow beam is performed in a connected mode for communication. Note that in NSA and SA, the sequence of initial access differs from each other with respect to the transition of each state until the terminal device becomes a connected state, but description will be made on the assumption that a similar sequence other than the initial access sequence is applied. That is, the processing flow shown in fig. 25 is common to NSA and SA.

As shown in fig. 25, when the terminal apparatus 200 transitions to the RRC connected mode, the terminal apparatus 200 performs beam scanning using a narrow beam in a Beam Management (BM) procedure, particularly, P2 and P3 procedures. At this time, the terminal apparatus 200 performs the above beam scanning using an aperiodic CSI-RS applying Beam Management (BM) with respect to NR-PDSCH and NR-PDCCH (spatial) quasi co-located (QCL) within the serving cell, for example, in a TCI state of N bits on DCI. Then, the terminal apparatus 200 performs beam optimization (BR) to select an optimal beam of the aperiodic CSI-RS (S151). Note that the P2 process and the P3 process may be simultaneously performed on aperiodic beams of CSI-RS for Beam Management (BM) in order to reduce delay and additional signaling at beam switching.

When the establishment of the BPL state in the narrow beam between the base station 100 and the terminal apparatus 200 is completed according to the above-described procedure, the terminal apparatus 200 signals information on the optimal Rx beam resource in a new DCI field of N bits (S153). Further, at a point of time when signaling of information on the optimal Rx beam resource for a new DCI field of N bits is performed, it may be assumed that a BPL state has been established between the base station 100 and the terminal apparatus 200. Therefore, the terminal apparatus 200 sets the posture of the terminal apparatus 200 at this time (in other words, the posture of each antenna element 210) as a reference state. Specifically, the terminal device 200 holds information corresponding to the detection result of the detection unit 230 in layer 1 as a reference value of the BPL state (S155).

Thereafter, the terminal device 200 monitors a change in the posture of the terminal device 200 based on, for example, the detection result of the detection unit 230 (e.g., a gyro sensor or the like), and in the case where the posture is changed due to sudden rotation or the like, controls communication with the base station 100 using directional beams (S137). As a specific example, the terminal apparatus 200 controls the direction of a directional beam used for communication with the base station 100 according to the rotation direction or the rotation amount of the terminal apparatus 200. Further, at this time, the terminal apparatus 200 may switch the antenna element 210 for forming a directional beam according to the rotation direction or the rotation amount of the terminal apparatus 200. This control continues until the connection mode is released, for example.

By the control as described above, the terminal apparatus 200 can stably receive the DL channel signals of both the NR-PDSCH and the NR-PDCCH in the serving cell.

Note that, for reference, fig. 26 and 27 show examples of state transition diagrams until the terminal device transitions to the RRC connected state in 5G for each of NSA and SA. Fig. 26 is a diagram showing an example of a state transition diagram before a terminal device transitions to an RRC connected state in NSA. Further, fig. 27 is a diagram showing an example of a state transition diagram before the terminal device transitions to the RRC connected state in the SA. As can be seen from a comparison between fig. 26 and 27, in NSA and SA, state transitions are substantially identical to each other except that initial access procedures are different from each other.

Above, an example of processing related to controlling communication with the base station 100 by the terminal apparatus 200 according to the present embodiment has been described.

<4.3, modification >

Next, a modification of the system according to the present embodiment will be described.

(variation 1: example of execution timing of Beam Management (BM) procedure)

First, as modification 1, an example of execution timing of a Beam Management (BM) procedure will be described. The initial access and Beam Management (BM) procedures have been described separately above. Meanwhile, as described above, in the 3GPP specification, the execution timing of the Beam Management (BM) procedure is defined depending on the implementation. Thus, for example, an initial access procedure and a Beam Management (BM) procedure may be performed in parallel.

As a specific example, when the Msg2 is received in the initial access procedure, the terminal device 200 may perform the P2 and P3 procedures in parallel in a Beam Management (BM) procedure. That is, the terminal device 200 may perform establishment of the BPL state through the narrow beam according to the beam optimization (BR) in the P2 and P3 processes at the initial access before the transition to the connected mode. In this case, for example, the setting of the reference state as the operation in the connection mode can be performed by a method similar to the above-described example. In other words, in the Beam Management (BM) process, if the process is a process from the P1 process, the posture at this time can be set as the reference state.

With the control as described above of the modification of the present embodiment, for example, even in the case where the terminal apparatus 200 is suddenly rotated, the terminal apparatus 200 can quickly complete the random access procedure in the initial access while maintaining the BPL state with the base station 100 through the narrow beam.

(modification 2: correction of Beam Direction)

Next, as modification 2, control of the beam direction after the BPL state is reestablished will be described. As described above, the terminal apparatus 200 according to the present embodiment promptly re-establishes the BPL state with the base station 100 based on the detection result of the posture change of the terminal apparatus 200 by using the detection result of the posture change of the terminal apparatus 200 even in the case where it becomes difficult to maintain the BPL state with the base station 100 due to the rotation of the terminal apparatus 200 or the like. Meanwhile, the direction of the directional beam (narrow beam) after the control based on the detection result of the detection unit 230 such as the gyro sensor or the like may deviate from the direction in which the BPL state with the base station 100 can be re-established due to another factor such as an obstacle, the movement of the terminal device 200, or the like. In this case, the terminal device 200 may re-correct the direction of the narrow beam after the control based on the detection result of the change in the posture of the terminal device 200 from the reference position. Note that in the following description, for convenience, the narrow beam after being controlled based on the detection result of the change in the posture of the terminal device 200 from the reference position is also simply referred to as "narrow beam after being controlled according to the change in the posture". Further, the narrow beam before being controlled based on the detection result of the change in the posture of the terminal device 200 from the reference position is also simply referred to as "narrow beam before posture change".

For example, the terminal device 200 may designate a more appropriate direction of the narrow beam again by scanning the narrow beam again around the direction of the narrow beam after the control according to the change of the posture. Based on such control, the terminal device 200 can search for the direction of the narrow beam by scanning the narrow beam again, where, for example, the reception power level indicated by RSRP is equal to the reception power level of the BPL state before the posture change.

Further, as another example, when scanning the narrow beam again, the terminal apparatus 200 may scan the narrow beams in a predetermined order after the control according to the change of the posture, without being limited to the direction of the narrow beams. As a specific example, when scanning the narrow beam again, the terminal device 200 may designate a more appropriate direction of the narrow beam again by scanning a range in which the antenna element 210 for communicating with the base station 100 can generate the narrow beam from one end portion to the other end portion in a predetermined direction.

Further, the terminal device 200 may determine whether to designate the narrow beam again by sweeping the narrow beam again as described above based on a predetermined condition. As a specific example, the terminal device 200 may determine whether to designate a narrow beam again by scanning the narrow beam again according to a communication state with the base station 100 using the narrow beam after control based on a detection result of a posture change of the terminal device 200.

As a more specific example, the terminal device 200 may determine whether to designate a narrow beam again according to whether or not the communication quality (e.g., the received power level indicated by RSRP) in communicating with the base station 100 using a narrow beam after the control according to the posture change is equal to the communication quality of the BPL state before the posture change.

Further, as another example, the terminal device 200 may determine whether to designate a narrow beam again according to whether or not the communication quality in communication with the base station 100 using the narrow beam after the control according to the change of the posture satisfies a required communication rate (e.g., MCS, level, or the like).

Further, as another example, the terminal device 200 may determine whether to designate a narrow beam again according to whether or not a communication quality (e.g., a received power level indicated by RSRP) in communication with the base station 100 using a narrow beam after the control according to the posture change is equal to or greater than a predetermined threshold. In this case, for example, if the communication quality of communication with the base station 100 using the narrow beam after the control according to the posture change is equal to or greater than the threshold value predetermined from the network side, the terminal device 200 may perform control so as not to designate the narrow beam again even if the communication quality has deteriorated compared with the BPL state before the posture change.

By the above control, the terminal device 200 can reestablish the BPL state with the base station 100 in a more appropriate manner according to each situation.

(variation 3: control example in communication Using polarization)

Next, as modification 3, an example of a method of applying the technique according to the present disclosure to communication using polarization will be described. In the above-described embodiments, in order to allow easier understanding of the features of the technique according to the present disclosure, the description has been provided focusing on the change of the two-dimensional posture of the terminal device 200. Meanwhile, by using the detection result of the detection unit 230 such as a gyro sensor, it is possible to detect a change in the three-dimensional posture of the terminal device 200. Further, in 5G, introduction of polarization Multiple Input Multiple Output (MIMO) or polarization diversity using two orthogonal polarized waves has been studied. In consideration of this, the terminal device 200 may reestablish the BPL state with the base station 100 in consideration of the skew of the polarization plane, for example, by detecting a change in the three-dimensional posture of the terminal device 200.

(variation 4: example of method of detecting posture change)

Next, as modification 4, an example of a method of detecting a posture change of the terminal device 200 will be described. In the above-described embodiments, an example of a case where a change in the attitude of the terminal apparatus 200 (for example, a change in the attitude of the housing of the terminal apparatus 200 or the antenna element supported by the housing) is detected by an acceleration sensor, a gyro sensor, or the like has been described. Meanwhile, the configuration for detecting the posture change of the terminal device 200 and the method of detecting the posture change of the terminal device 200 are not particularly limited as long as the posture change of the terminal device 200 can be detected. As specific examples, an image sensor, an acoustic wave sensor, a distance measurement sensor (e.g., a time-of-flight (TOF) sensor), a pressure sensor, an optical sensor, or the like may be used as a configuration for detecting a change in the attitude of the terminal device 200. Further, a change in the posture of the terminal apparatus 200 may be detected using a technique related to self-position estimation or environment map generation. As a more specific example, an example of a technique of simultaneously performing self-position estimation and environment map generation may include a technique called simultaneous localization and mapping (SLAM).

(variation 5: example of control at recovery time)

Next, as modification 5, an example of a case where the technique according to the present disclosure is applied to the "beam failure recovery process" or the "recovery process from the RLF state" will be described. The "4-step RACH" applied as a random access procedure in the above-described initial access procedure corresponds to contention-based random access (CBRA). On the other hand, contention-free random access (CFRA) is applied to a "beam failure recovery procedure" or a "recovery procedure from an RLF state". CFRA also applies to random access procedures, e.g. at handover.

For example, fig. 28 is a schematic sequence diagram showing the processing flow of the CFRA. Specifically, first, the base station 100 allocates a resource for transmitting the random access preamble to the terminal apparatus 200 (S201). Next, the terminal apparatus 200 performs PRACH transmission of a random access preamble to the base station 100 (S203). Thereafter, PAR (separate signaling on PDSCH) is transmitted from the base station 100 to the terminal device 200 (S205).

Note that in both CBRA and CFRA, due to a change in the posture of the terminal apparatus 200 caused by a sudden rotation or the like, it may be difficult to maintain the BPL state between the base station 100 and the terminal apparatus 200, similar to the random access procedure in the initial access procedure described in the above-described embodiments. Therefore, by applying the technique according to the present disclosure regardless of CBRA or CFRA, even in the case where the posture of the terminal apparatus 200 changes, the BPL state can be immediately re-established between the base station 100 and the terminal apparatus 200, and thus the random access procedure can be quickly completed. That is, in all of the "beam failure recovery procedure", "recovery procedure from RLF state", and "random access procedure at handover in RRC connected state", the above-described effects can be expected by applying the technique according to the present disclosure.

(variation 6: example of Beam steering according to attitude variation)

Next, as modification 6, an example of beam steering according to a change in the posture of the terminal apparatus 200 will be described. As described above, the terminal device 200 according to the present embodiment maintains or reestablishes the BPL state with the base station 100 by controlling the direction in which the directional beam is directed according to the change in posture from the reference state from the terminal device 200. Meanwhile, a configuration or a method for controlling the direction in which the directional beam is directed is not particularly limited as long as the direction in which the directional beam is directed can be controlled.

As a particular example, at least some of the antenna elements 210 may be configured as movable antenna elements whose position or pose may be controlled. In this case, for example, by changing the position or posture of the movable antenna element 210, the direction in which the directional beam is directed can be controlled.

Note that although details will be described later, a device usable as the terminal device 200 is not limited to only a relatively small communication device such as a smartphone or the like, and a relatively large device such as a drone or the like may also be assumed as a device usable as the terminal device 200. Such a device may also be controllably configured such that the position or posture of the movable antenna element 210 is controlled by driving a driving unit such as an actuator or the like, thereby forming a directional beam in a desired direction.

<5, hardware configuration >

Next, an example of a hardware configuration of an information processing apparatus configuring the system according to the embodiment of the present disclosure, such as the above-described base station 100 or terminal apparatus 200, will be described in detail with reference to fig. 29. Fig. 29 is a functional block diagram showing a configuration example of a hardware configuration of an information processing apparatus configuring a system according to an embodiment of the present disclosure.

The information processing apparatus 900 configuring the system according to the present embodiment mainly includes a Central Processing Unit (CPU)901, a Read Only Memory (ROM)902, and a Random Access Memory (RAM) 903. Further, the information processing apparatus 900 includes a host bus 907, a bridge 909, an external bus 911, an interface 913, an input device 915, an output device 917, a storage device 919, a drive 921, a connection port 923, and a communication device 925.

The CPU901 functions as an arithmetic processing device and a control device, and controls all or part of operations in the information processing device 900 according to various programs recorded in the ROM902, the RAM903, the storage device 919, or a removable recording medium 927. The ROM902 stores programs, operation parameters, and the like used by the CPU 901. The RAM903 mainly stores programs used by the CPU901, parameters appropriately changed during program execution, and the like. The CPU901, the ROM902, and the RAM903 are connected to each other through a host bus 907 including a CPU bus and the like. For example, the communication control unit 150 of the base station 100 shown in fig. 2 or the communication control unit 250 of the terminal device 200 shown in fig. 3 may be configured by the CPU 901.

The host bus 907 is connected to the external bus 911 such as a peripheral component interconnect/interface (PCI) bus via the bridge 909. Further, an input device 915, an output device 917, a storage device 919, a drive 921, a connection port 923, and a communication device 925 are connected to the external bus 911 via the interface 913.

The input device 915 is, for example, an operation means operated by a user, such as a mouse, a keyboard, a touch panel, a button, a switch, a lever, a pedal, or the like. Further, the input device 915 may be, for example, a remote control apparatus using infrared rays or other electric waves (so-called remote controller), or may be an externally connected device 929 such as a mobile phone, a Personal Digital Assistant (PDA), or the like corresponding to the operation of the information processing apparatus 900. Further, the input device 915 may include, for example, an input control circuit or the like that generates an input signal according to information input by the user using the above-described operation means and outputs the generated input signal to the CPU 901. The user of the information processing apparatus 900 can input various data to the information processing apparatus 900 or instruct the information processing apparatus 900 to perform processing operations by operating the input apparatus 915.

The output device 917 is a device that can visually or audibly notify the user of the acquired information. Such devices include display devices such as Cathode Ray Tube (CRT) display devices, liquid crystal display devices, plasma display devices, Electroluminescence (EL) display devices, lamps, and the like, and audio output devices such as speakers, headphones, and the like, printer devices, and the like. The output device 917 outputs a result obtained by various processes performed by the information processing apparatus 900, for example. Specifically, the display apparatus displays results obtained by various processes performed by the information processing apparatus 900 through text or images. On the other hand, the audio output device converts an audio signal including reproduced audio data, sound data, and the like into an analog signal and outputs the analog signal.

The storage device 919 is a device for data storage configured as an example of a storage unit of the information processing apparatus 900. The storage device 919 is configured by, for example, a magnetic storage unit device such as a Hard Disk Drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like. The storage device 919 stores programs executed by the CPU901, various data, and the like. For example, the storage unit 140 of the base station 100 shown in fig. 2 or the storage unit 240 of the terminal device 200 shown in fig. 3 may be configured by any one of the storage device 919, the ROM902, and the RAM903, or may be configured by a combination of two or more of the storage device 919, the ROM902, and the RAM 903.

The drive 921 is a reader/writer for a recording medium, and is embedded in the information processing apparatus 900 or externally mounted in the information processing apparatus 900. The drive 921 reads information recorded in a removable recording medium 927 such as a mounted magnetic disk, optical disk, magneto-optical disk, semiconductor memory, or the like, and outputs the read information to the RAM 903. Further, the drive 921 can also write a record to a removable recording medium 927 such as a mounted magnetic disk, optical disk, magneto-optical disk, semiconductor memory, or the like. The removable recording medium 927 is, for example, a Digital Versatile Disc (DVD) medium, a High Definition (HD) -DVD medium, a blu-ray (registered trademark) medium, or the like. Further, the removable recording medium 927 may be a compact flash (registered trademark) (CF), a flash memory, a Secure Digital (SD) memory card, or the like. Further, the removable recording medium 927 may be, for example, an Integrated Circuit (IC) card on which a non-contact type IC chip is mounted, an electronic apparatus, or the like.

The connection port 923 is a port for direct connection to the information processing apparatus 900. Examples of connection ports 923 include a Universal Serial Bus (USB) port, an IEEE1394 port, a Small Computer System Interface (SCSI) port, and the like. Other examples of the connection port 923 include a Recommended Standard (RS) -232C port, an optical audio terminal, a high-definition multimedia interface (HDMI) (registered trademark) port, and the like. By connecting the externally connected device 929 to the connection port 923, the information processing apparatus 900 directly acquires various data from the externally connected device 929, or supplies various data to the externally connected device 929.

The communication device 925 is, for example, a communication interface including a communication device or the like for connecting to a communication network 931. The communication device 925 is, for example, a communication card for wired or wireless Local Area Network (LAN), bluetooth (registered trademark), or Wireless Universal Serial Bus (WUSB), or the like. Further, the communication device 925 may be a router for optical communication, a router for Asymmetric Digital Subscriber Line (ADSL), a modem for various communications, or the like. The communication device 925 can transmit or receive a signal or the like to or from the internet or another communication device according to a predetermined protocol such as a transmission control protocol/internet protocol (TCP/IP). Further, the communication network 931 connected to the communication device 925 includes a network or the like connected in a wired or wireless manner, and may be, for example, the internet, a home LAN, an infrared communication network, a radio wave communication network, a satellite communication network, or the like. For example, the wireless communication unit 120 and the network communication unit 130 of the base station 100 shown in fig. 2 or the wireless communication unit 220 of the terminal device 200 shown in fig. 3 may be configured by the communication device 925.

In the above, an example of a hardware configuration capable of realizing the function of the information processing apparatus 900 configuring the system according to the present embodiment has been described. Each of the above components may be configured using a general-purpose member, or may be configured by hardware dedicated to the function of each component. Therefore, the hardware configuration to be used can be appropriately changed according to the technical level when the present embodiment is executed. Note that although not shown in fig. 29, various configurations corresponding to the information processing apparatus 900 configuring the system are naturally provided.

Note that a computer program for realizing each function of the information processing apparatus 900 configuring the system according to the present embodiment as described above may be created and installed in a Personal Computer (PC) or the like. Further, a computer-readable recording medium storing such a computer program may be provided. The computer-readable recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above-described computer program may be distributed via a network, for example, without using a computer-readable recording medium. Further, the number of computers executing the computer program is not particularly limited. For example, a plurality of computers (e.g., a plurality of servers, etc.) may execute a computer program in cooperation with each other.

<6, application example >

Next, an application example of a communication device such as the terminal device 200 according to an embodiment of the present disclosure will be described.

<6.1, application example 1: application example of another communication apparatus >

First, as application example 1, an example of a case where the technique according to the present disclosure is applied to a device other than a communication terminal such as a smartphone will be described.

In recent years, a technology called internet of things (IoT) that connects various things to a network has attracted attention, assuming that communication can be performed using a device other than a smartphone or a tablet terminal. Therefore, for example, by applying the technique according to the present disclosure to various devices configured to be movable, communication using millimeter waves can also be realized in a more appropriate manner for the various devices.

For example, fig. 30 is an explanatory diagram for describing an application example of the communication device according to the present embodiment, and shows an example of a case where the technique according to the present disclosure is applied to a camera device. Specifically, in the example shown in fig. 30, the antenna device according to the embodiment of the present disclosure is held so as to be located in the vicinity of each of the surfaces 301 and 302 facing different directions from each other in the outer surface of the housing of the camera device 300. For example, reference numeral 311 schematically represents an antenna apparatus according to an embodiment of the present disclosure. With such a configuration, for example, the camera device 300 shown in fig. 30 can transmit or receive a radio signal propagating in, for example, a direction substantially coinciding with the normal line direction of the surfaces 301 and 302 in each of the surfaces 301 and 302. Note that, needless to say, the antenna device 311 may be provided not only on the surfaces 301 and 302 shown in fig. 30 but also on other surfaces.

Under the configuration as described above, based on the technique according to the present disclosure described above, communication with another device (e.g., a base station) using a directional beam is controlled according to a change in the posture of the camera device 300, so that communication using millimeter waves can be achieved in a more appropriate manner.

Further, the technique according to the present disclosure can also be applied to an unmanned aerial vehicle called a drone, and the like. For example, fig. 31 is an explanatory diagram for describing an application example of the communication device according to the present embodiment, and shows an example of a case where the technique according to the present disclosure is applied to a camera device installed in the lower part of a drone. In particular, in the case where the unmanned aerial vehicle flies at a high altitude, it is desirable that the unmanned aerial vehicle be able to transmit or receive radio signals (millimeter waves) that reach the unmanned aerial vehicle from various directions mainly from the underside of the unmanned aerial vehicle. Thus, for example, in the example shown in fig. 31, the antenna device according to the embodiment of the present disclosure is held in the vicinity of each portion facing different directions from each other in the outer surface 401 of the housing of the camera device 400 mounted on the lower portion of the drone. For example, reference numeral 411 schematically represents an antenna apparatus according to an embodiment of the present disclosure. Further, although not shown in fig. 31, the antenna device 411 may be provided not only on the camera device 400 but also on each part of the housing of the drone itself, for example. Also in this case, the antenna device 411 only needs to be arranged, in particular, on the lower side of the housing.

Note that, as shown in fig. 31, in the case where at least a part of the outer surface of the housing of the device as an object is configured as a curved surface (i.e., a curved surface), the antenna device 411 only needs to be held in the vicinity of each of a plurality of local areas where normal directions intersect with each other or where normal directions are skewed from each other between the respective local areas in the curved surface. With such a configuration, the camera device 400 shown in fig. 31 can transmit or receive a radio signal propagating in a direction substantially coinciding with the normal direction of each partial area.

With the configuration as described above, based on the above-described technique according to the present invention, communication with another device (e.g., a base station) using a directional beam is controlled in accordance with a change in the attitude of the drone, so that communication with millimeter waves can be achieved in a more appropriate manner.

Of course, the example described with reference to fig. 30 and 31 is only an example, and the application destination of the technique according to the present disclosure is not particularly limited as long as it is a device that performs communication using millimeter waves. For example, the newly added service area in 5G includes various fields such as an automobile field, an industrial equipment field, a home security field, a smart meter field, and other IoT fields, and technologies according to the present disclosure that can be applied to a communication terminal applied in the various fields. As a more specific example, application examples of the technology according to the present disclosure may include a head-mounted wearable device for implementing Augmented Reality (AR) or Virtual Reality (VR) or various wearable devices used in telemedicine or the like. Further, in recent years, various so-called autonomous robots such as a customer service robot, a pet type robot, a working robot, and the like have also been proposed, and even if such robots have a communication function, and in the case where such robots have a communication function, the technique according to the present disclosure can be applied to such robots. Further, the technology according to the present disclosure may be applied not only to the above-described unmanned aerial vehicle but also to various moving objects, for example, automobiles, motorcycles, bicycles, and the like.

In the above, as application example 1, an example of a case where the technique according to the present disclosure is applied to a device other than a communication terminal such as a smartphone has been described with reference to fig. 30 and 31.

<6.2, application example 2: application example of communication based on other communication standards >

Next, as application example 2, an example of a case where the technique according to the present disclosure is applied to communication other than communication using millimeter waves in 5G will be described, particularly with a view to application of communication based on another communication standard.

Further, in the above, an example of a case where the technique of the present disclosure is applied to communication using millimeter waves between a base station and a terminal device has been described mainly focusing on a 5G wireless communication technique. Meanwhile, the application of the technique according to the present disclosure is not necessarily limited to only communication between a base station and a terminal device or communication using millimeter waves as long as it is communication using a directional beam.

As a specific example, in wireless communication based on the Wi-Fi (registered trademark) standard, the technique according to the present disclosure may be applied to communication based on the IEEE802.11ad standard using the 60GHz band, communication based on the IEEE802.11 ay standard in which standardization work is being performed, and the like.

In the IEEE802.11ad standard and the IEEE802.11 ay standard, similar to the above-described 5G wireless communication technology, the effects of free space reduction, oxygen absorption, rainfall attenuation, and the like are large, and thus a beam forming technology is used. As a specific example, the beamforming process in the IEEE802.11ad standard is largely divided into two steps, namely, Sector Level Scanning (SLS) and beam refinement optimization protocol (BRP).

More specifically, in the SLS, a search for a communication partner is performed and communication is started. The number of sectors in an ANT is defined as a maximum of 64, and the total number of all ANTs is 128. The BRP is suitably performed after the SLS is finished, e.g. after cutting a loop or the like. This operation is similar to the following mechanism: when millimeter wave communication is used in 5G, BPL is established by a wide beam in an IA procedure-based operation, and in Beam Management (BM) in a connected mode, BPL is established by a beam optimization (BR) operation with a narrow beam.

The IEEE802.11 ay standard is currently being developed, but acceleration of data rate is being studied by combining the use of channel bonding techniques or higher order modulation, similar to "continuous" within CA "communication using millimeter waves in 5G.

According to the above feature, the above-described technique according to the present disclosure can also be applied to communication based on the IEEE802.11ad standard or the IEEE802.11 ay standard.

Of course, the techniques according to the present disclosure may also be applied to standards following the various standards described above, assuming communication using directional beams. In particular, in wireless communication using a frequency band exceeding a millimeter wave, the influence of free space reduction, oxygen absorption, rainfall attenuation, and the like is larger than that in communication using a millimeter wave, and therefore it is presumed that the possibility that the beam forming technique will be applied is high.

Hereinabove, as application example 2, an example of a case where the technique according to the present disclosure is applied to communication other than communication using millimeter waves in 5G has been described, particularly with a view to application to communication based on another communication standard.

<7, end >, and

as described above, in the system according to the present embodiment, the terminal device includes one or more antenna elements, a detection unit, and a control unit. The one or more antenna elements are configured to control a direction of a directional beam and perform wireless communication using the directional beam. The detection unit detects a posture of at least one of the one or more antenna elements. The control unit sets a state in which at least a radio signal transmitted from the base station using the directional beam can be received via any of the one or more antenna elements as a reference state, and controls wireless communication with the base station using the directional beam according to the change in the posture from the reference state. More specifically, the control unit selectively switches an antenna element for wireless communication with the base station among a plurality of antenna elements that perform wireless communication using directional beams oriented in different directions from each other, in accordance with a change in the attitude of at least any one of the plurality of antenna elements. Further, the control unit may control the direction of the directional beam formed by the antenna element according to a change in the posture of at least any one of the one or more antenna elements described above.

With the above configuration, for example, even if a beam failure occurs due to a change in the posture of the terminal device caused by a sudden rotation or the like, the terminal device can reestablish the BPL state with the base station before a call disconnection due to RLF occurs. Further, ideally, even if the attitude of the terminal device changes due to sudden rotation or the like, the terminal device can reestablish the BPL state with the base station before the beam failure occurs. That is, according to the system of the present embodiment, it becomes possible to realize wireless communication with a directional beam between a base station and a terminal device in a more appropriate manner. As a result, it is possible to operate only the minimum-required millimeter-wave antenna array/sub-module at all times while maintaining the correct BPL state, and thus it becomes possible to reduce power consumption by turning off other millimeter-wave antenna modules. Therefore, an effect of extending the battery life on the terminal device side as the mobile device can also be expected. Further, some of the millimeter wave antenna arrays/sub-modules are turned off, so that the effect of reducing the processing load can also be expected.

Above, preferred embodiments of the present disclosure have been described in detail with reference to the drawings, but the technical scope of the present disclosure is not limited to such embodiments. It is obvious to those skilled in the art of the present disclosure that various variations or modifications can be conceived within the scope of the technical idea described in the claims, and naturally it is understood that such variations or modifications also fall within the technical scope of the present disclosure.

Further, the effects described in the present specification are merely illustrative or exemplary, and are not restrictive. That is, other effects that are obvious to those skilled in the art from the description of the present specification may be achieved according to the technology of the present disclosure in addition to or instead of the above-described effects.

Note that the following configuration also falls within the technical scope of the present disclosure.

(1) A wireless communication device, comprising:

one or more antenna elements configured to be able to control a direction of a directional beam and perform wireless communication using the directional beam;

a detection unit that detects a posture of at least any one of the one or more antenna elements; and

a control unit that sets, as a reference state, a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam via any one of the one or more antenna elements, and controls wireless communication with the base station using the directional beam according to a change in posture from the reference state.

(2) The wireless communication apparatus according to the above (1), wherein a plurality of antenna elements for performing wireless communication using directional beams directed in different directions from each other are provided as the one or more antenna elements, and

the control unit selectively switches an antenna element for wireless communication with the base station among the plurality of antenna elements in accordance with a change in the posture of at least any one of the plurality of antenna elements.

(3) The wireless communication apparatus according to the above (2), wherein in a case where the control unit has switched an antenna element for wireless communication with a base station among a plurality of antenna elements, the control unit controls the direction of a directional beam formed by the antenna element according to a state of wireless communication with the base station after the switching.

(4) The wireless communication apparatus according to the above (1), wherein the control unit controls the direction of the directional beam formed by the antenna element according to a change in posture of at least any one of the one or more antenna elements.

(5) The wireless communication device according to the above (1), wherein at least part of the one or more antenna elements is configured as a movable antenna element, and

the control unit controls a direction of a directional beam formed by the movable antenna element by controlling at least one of a position or an attitude of the movable antenna element according to a change in the attitude of at least any one of the one or more antennas.

(6) The wireless communication apparatus according to any one of (1) to (5) above, wherein the reference state is a state in which a reception power of a wireless signal transmitted from the base station using a directional beam is equal to or greater than a threshold value.

(7) The wireless communication apparatus according to any one of the above (1) to (5), wherein the reference state is a state in which a signal block transmitted from the base station for each directional beam using a synchronization signal and a control signal as one unit can be received.

(8) The wireless communication apparatus according to any one of the above (1) to (7), wherein the control unit sets the reference state when an initial access procedure to the base station is performed.

(9) The wireless communication apparatus according to the above (8), wherein the control unit sets the reference state after a transmission timing of a preamble to the base station in the procedure.

(10) The wireless communication apparatus according to any one of the above (1) to (7), wherein the control unit sets the reference state when performing a procedure for establishing or resuming communication with the base station using a directional beam.

(11) The wireless communication apparatus according to the above (10), wherein the control unit sets the reference state after timing at which a directional beam for communication with the base station is selected by the base station among directional beams respectively formed toward a plurality of directions in the procedure.

(12) The wireless communication apparatus according to any one of the above (1) to (11), wherein the control unit detects a change in the posture from the reference state based on a detection result of the posture by the detection unit using a predetermined event as a trigger.

(13) The wireless communication device according to the above (12), wherein the event is an event notified when a deviation occurs between a directional beam formed by the antenna element and a directional beam formed by the base station.

(14) The wireless communication apparatus according to any one of the above (1) to (11), wherein the control unit detects a change in the posture with respect to the reference state by monitoring a detection result of the posture by the detection unit.

(15) A control device, comprising:

an acquisition unit that acquires a detection result of a posture of at least one of one or more antenna elements configured to be able to control a direction of a directional beam and perform wireless communication using the directional beam; and

a control unit that sets, as a reference state, a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam, and controls wireless communication with the base station using the directional beam according to a change in the posture from the reference state.

(16) A computer-implemented control method comprising:

acquiring a detection result of a posture of at least any one of one or more antenna elements configured to be capable of controlling a direction of a directional beam and performing wireless communication using the directional beam; and

setting a state capable of receiving at least a wireless signal transmitted from the base station using the directional beam as a reference state, and controlling wireless communication with the base station using the directional beam according to a change in the posture from the reference state.

List of reference numerals

1 System

100 base station

110 antenna unit

120 radio communication unit

130 network communication unit

140 memory cell

150 communication control unit

200 terminal device

210 antenna unit

220 wireless communication unit

230 detection unit

240 storage unit

250 communication control unit