Communication device and communication method

Abstract

A communication device includes: a MAC control circuit, i.e., a media access control circuit, for performing transmission and reception control of control frames and data frames for communication with other communication devices; and a radio circuit, which uses a transmission antenna and a reception antenna to perform wireless communication of the control frames and the data frames. When the radio circuit receives, from the other communication device, a sector scan frame (i.e., an SSW frame) in the control frame that includes an OCB response subfield (i.e., a response subfield outside the context of a basic service set), the MAC control circuit determines whether to perform data communication between the communication device and the other communication device according to the OCB response subfield.

Description

Technical Field

[0001] The present invention relates to a communication device and a communication method. Background Art

[0002] There has been research on a method of performing high-speed and low-latency communication using a wide frequency band at a carrier frequency of 10 GHz or higher. For example, for a high-frequency band of 10 GHz or higher, in order to take advantage of the fact that the antenna can be miniaturized due to the short wavelength, and in addition, in order to avoid large propagation losses and extend the communication distance, there has been research on a beamforming technique using an antenna with high directivity and electrically controllable directivity.

[0003] As a millimeter-wave wireless LAN (Local Area Network) communication standard using the 60 GHz band, there is the IEEE (Institute of Electrical and Electronics Engineers) 802.11ad-2012 standard (Non-Patent Document 1). In the IEEE 802.11ad-2012 standard, a beamforming protocol is specified.

[0004] Prior Art Documents

[0005] Non-Patent Documents

[0006] Non-Patent Document 1: IEEE802.11ad-2012

[0007] Non-Patent Document 2: IEEE1609.3-2016 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The IEEE 802.11ad-2012 standard specifies the following wireless communication method, which assumes fixed wireless devices and wireless devices moving at approximately the walking speed of a person, and does not assume being mounted on a high-speed moving body such as a car or a train and performing millimeter-wave communication.

[0010] Non-limiting embodiments of the present invention contribute to providing a communication device and a communication method that can be mounted on a high-speed moving body and perform millimeter-wave communication.

[0011] Solutions to the Problems

[0012] A communication device according to one embodiment of the present invention includes: a MAC control circuit, i.e., a media access control circuit, for controlling the transmission and reception of control frames and data frames for communication with other communication devices; and a radio circuit, which uses a transmitting antenna and a receiving antenna to perform wireless communication of the control frames and the data frames. When the radio circuit receives from the other communication device a sector scan frame, i.e., an SSW frame, in the control frame that includes an OCB response subfield, i.e., a response subfield outside the context of the basic service set, the MAC control circuit determines whether to perform data communication between the communication device and the other communication device based on the OCB response subfield.

[0013] It should be noted that these general or specific embodiments can be implemented by a system, a device, a method, an integrated circuit, a computer program, or a recording medium, or can be implemented by any combination of a system, a device, a method, an integrated circuit, a computer program, and a recording medium.

[0014] Advantages of the Invention

[0015] According to one embodiment of the present invention, it is possible to be mounted on a high-speed moving body and perform millimeter-wave communication.

[0016] More advantages and effects of one embodiment of the present invention will be clarified in the description and the drawings. These advantages and / or effects are provided by several embodiments and the features described in the description and the drawings respectively, but it is not necessary to provide all of them in order to obtain one or more of the same features. Description of the Drawings

[0017] Figure 1A FIG. is an example of a system configuration of a V2X (Vehicle to Everything) communication system according to Embodiment 1.

[0018] Figure 1B FIG. is an example of a wireless link between communication devices in the V2X communication system according to Embodiment 1.

[0019] Figure 2 FIG. is an example of the structure of a communication device according to the IEEE802.11ad standard.

[0020] Figure 3A FIG. is an example of a process of establishing a communication link by a communication device according to the IEEE802.11ad standard.

[0021] Figure 3B FIG. is another example of a process of establishing a communication link by a communication device according to the IEEE802.11ad standard.

[0022] Figure 3CIt is a diagram showing another example of the process of establishing a communication link between communication devices based on the IEEE802.11ad standard.

[0023] Figure 4 It is a diagram showing an example of the structure of the communication device of Embodiment 1.

[0024] Figure 5 It is a diagram showing another example of the process of the communication device of Embodiment 1 establishing a communication link.

[0025] Figure 6A It is a diagram showing an example of the process of the communication device of Embodiment 1 establishing a communication link.

[0026] Figure 6B It is a diagram showing another example of the process of the communication device of Embodiment 1 establishing a communication link.

[0027] Figure 6C It is a diagram showing another example of the process of the communication device of Embodiment 1 establishing a communication link.

[0028] Figure 6D It is a diagram showing another example of the process of the communication device of Embodiment 1 establishing a communication link.

[0029] Figure 6E It is a diagram showing Figures 6A to 6D the wireless link established through the application process.

[0030] Figure 7A It is a diagram showing an example of the format of the DMG beacon frame of Embodiment 1.

[0031] Figure 7B It is a diagram showing an example of the values and descriptions of the BSS (Basic Service Set) type subfield of Embodiment 1.

[0032] Figure 8A It is a diagram showing an example of the format of the SSW frame of Embodiment 1.

[0033] Figure 8B It is a diagram showing an example of the format of the short SSW packet payload of Embodiment 1.

[0034] Figure 9 It is a flowchart showing an example of the process of the communication device of Embodiment 1 performing millimeter-wave communication.

[0035] Figure 10 It is a timing diagram explaining an example of the process of the communication device of Embodiment 1 performing millimeter-wave communication.

[0036] Figure 11It is a flowchart showing an example of the operation of a communication device according to a modification of Embodiment 1.

[0037] Figure 12A It is a diagram showing an example of the format of a DMG beacon frame according to a modification of Embodiment 1.

[0038] Figure 12B It is a diagram showing an example of the format of an SSW feedback element according to a modification of Embodiment 1.

[0039] Figure 13 It is a timing diagram showing an example of the process of a communication device performing millimeter-wave communication according to a modification of Embodiment 1.

[0040] Figure 14 It is a diagram showing an example of the structure of a communication device according to Embodiment 2.

[0041] Figure 15 It is a flowchart showing an example of the process of a communication device performing millimeter-wave communication according to Embodiment 2.

[0042] Figure 16 It is a diagram showing an example of the format of a WSA frame according to Embodiment 2.

[0043] Figure 17 It is a diagram showing an example of the format of a channel information (Channel Info) section according to Embodiment 2.

[0044] Figure 18 It is a diagram showing an example of the format of an SSW frame according to Embodiment 2.

[0045] Figure 19 It is a timing diagram showing an example of the process of a communication device performing millimeter-wave communication according to Embodiment 2. Detailed Embodiments

[0046] Hereinafter, embodiments of the present invention will be described in detail with appropriate reference to the accompanying drawings. However, sometimes overly detailed descriptions will be omitted. For example, sometimes the detailed description of well-known matters or the repeated description of substantially the same structures will be omitted. This is to avoid making the following description unnecessarily long and to make it easy for those skilled in the art to understand.

[0047] In addition, the purpose of providing the accompanying drawings and the following description is to enable those skilled in the art to fully understand the present invention, and there is no intention of limiting the subject matter described in the claims thereby.

[0048] In addition, in the respective drawings, the same reference numerals are attached to common structural elements. In addition, when distinguishing and describing elements of the same type, reference numerals are used as in "vehicle 10A" and "vehicle 10B", and when not distinguishing and describing elements of the same type, reference numerals are sometimes used as in "vehicle 10" with a common number among the reference numerals. In addition, "vehicle" may also be referred to as "mobile body" or "mobility".

[0049] (Embodiment 1)

[0050] Figure 1A FIG. is an example of the system configuration of a V2X (Vehicle to Everything) communication system 1.

[0051] In the communication system 1, vehicles 10 (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i, 10j, 10k, 10m) each include a communication device 100 (100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100m). In addition, pedestrians 20 (20a, 20b, 20c) each include a communication device 100 (100n, 100p, 100q). In addition, roadside devices 30 (30a, 30b) each include a communication device 100 (100r, 100s).

[0052] In addition, the vehicle 10, the pedestrian 20, and the roadside device 30 may each include a plurality of communication devices 100.

[0053] The communication device 100 has a communication function based on the millimeter-wave communication method. It may be based on the IEEE802.11ad standard, the IEEE802.11-2016 standard, the IEEE802.11ay standard (draft), the IEEE802.11bd standard (draft), the IEEE802.15.3c standard, the IEEE802.15.3e standard, or the 3GPP NR (New Radio) method.

[0054] Figure 1B FIG. is an example of the wireless link between communication devices in the V2X communication system of Embodiment 1. Figure 1BThis shows an example of a wireless link between communication devices 100 in communication system 1. The dashed arrows between communication devices 100 respectively represent wireless links. As an example, communication device 100a has wireless links with communication devices 100b, 100e, and 100r, and can communicate with each other, but for example, sometimes it does not have a wireless link with communication device 100c. For example, sometimes due to the large distance between communication devices 100 or the presence of obstacles such as other vehicles between the communication devices, there is no link between communication devices 100. As Figure 1B shown, for communication system 1 that performs V2X communication, there is one or more wireless links between each of the multiple communication devices 100. In addition, when vehicle 10 and pedestrian 20 move, the presence or absence or quality of the wireless links between each of the multiple communication devices 100 will change.

[0055] Figure 2 This is a diagram showing an example of the structure of a communication device according to the IEEE802.11ad standard. Figure 2 This shows the structure of communication device 100. Communication device 100 includes antenna 101, radio circuit 102, MAC (Media Access Control) control circuit 103, host CPU (Central Processing Unit) 104, and peripheral devices 105. In addition, host CPU 104 and MAC control circuit 10a can also be collectively referred to as the control circuit.

[0056] Antenna 101 can include one or more antenna elements. In addition, antenna 101 can also be, for example, a phased array antenna or an array antenna. A transmitting antenna and a receiving antenna can be provided separately, or the same antenna can be used for both transmission and reception. Antenna 101 can also have a function of switching the antenna directivity (for example, called "beam steering function", "beamforming function"). The process of selecting the directivity for communicating with a communication device at the communication destination with good quality is called "beamforming training".

[0057] Radio circuit 102 includes an RF (Radio Frequency) circuit and a PHY (PHYsical layer) control circuit, and controls the transmission and reception of packets specified by standards such as IEEE802.11ad. Sometimes radio circuit 102 is called a "transceiver".

[0058] The MAC control circuit 103 controls the transmission and reception of MAC frames (control frames) defined by the IEEE 802.11ad standard, for example. In addition, the MAC control circuit 103 controls the radio circuit 102, for example, controlling the process of discovering a communication device as the communication destination (also referred to as "discovery" or "scanning"), the beamforming training process, and the RTS / CTS (Request to Send / Clear to Send) process.

[0059] The host CPU 104 controls the MAC control circuit 103, for example, by executing a device driver and a Supplicant software. In addition, it executes an OS (Operating System) or application software.

[0060] The peripheral device 105 may also include, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), a network expansion device such as an Ethernet (registered trademark) controller / Ethernet board, which are connected to the host CPU 104 and used by the host CPU 104 to execute software, and peripheral devices utilized by the application software of GNSS (Global Navigation Satellite System).

[0061] Next, a method for establishing a communication link among the communication devices 100a, 100b, 100c, 100d, and 100e according to the IEEE 802.11ad standard will be described. Figure 3A This is a diagram showing an example of the process of establishing a communication link for a communication device according to the IEEE 802.11ad standard. Figure 3B This is a diagram showing another example of the process of establishing a communication link for a communication device according to the IEEE 802.11ad standard. Figure 3C This is a diagram showing another example of the process of establishing a communication link between communication devices according to the IEEE 802.11ad standard.

[0062] In Figure 3A the communication device 100a transmits a plurality of DMG (Directional MultiGigabit) beacon frames with the value of the discovery mode (DM: Discovery Mode) subfield set to 1 (flagged) while changing the antenna directivity of the antenna 101. In addition, the communication device 100d transmits a plurality of DMG (Directional MultiGigabit) beacon frames while changing the antenna directivity of the antenna 101.

[0063] In Figure 3BIn the case where communication devices 100b and 100c respond to the DMG beacon frame sent by communication device 100a, communication device 100a performs an association process with communication devices 100b and 100c and starts PBSS (Personal Basic Service Set) 1001a. Communication device 100a becomes the PCP (PBSS Control Point) and schedules PBSS 1001a.

[0064] While changing the antenna directivity of antenna 101, communication device 100b sends multiple DMG beacon frames in which the value of the discovery mode subfield is set to 1, and in the case where communication device 100c responds, it recognizes that communication device 100c has joined PBSS 1001a.

[0065] Communication devices 100a, 100b, and 100c respectively determine whether data communication is possible or beamforming training can be performed according to the scheduling information notified by communication device 100a, and communicate with each other with communication devices 100 that have joined PBSS 1001a.

[0066] Similarly, communication device 100d sends multiple DMG beacon frames in which the value of the discovery mode subfield is set to 1, and in the case where the responding communication device 100e has not joined any PBSS, it starts PBSS 1001b with communication device 100d as the PCP and communicates with each other with communication device 100 (100e) that has joined PBSS 1001b.

[0067] In addition, in Figure 3B Communication devices 100a and 100d that have sent DMG beacons are selected as the PCP, but other communication devices 100 can also be selected as the PCP. As an example, it can also be that communication device 100b or communication device 100c is the PCP of PBSS 1001a, and in addition, it can also be that communication device 100e is the PCP of PBSS 1001b.

[0068] In Figure 3C It can also be that in the case where vehicle 10d (not shown) equipped with communication device 100d moves and approaches within the communication circle between communication devices 100b and 100c, communication devices 100b and 100c will respond to the DMG beacon sent by communication device 100d, but since communication devices 100b and 100c have joined PBSS 1001a, they do not join PBSS 1001b. In this case, it is difficult for communication devices 100b and 100c to communicate with each other with communication device 100d.

[0069] Figure 4 This is a diagram showing another example of the structure of a communication device. Figure 4 This shows the structure of a communication device 200 that enables communication between communication devices 100b, 100c, and 100d under the same conditions as Figure 3C This shows an example of the structure of a communication device 200 that enables communication between communication devices 100b, 100c, and 100d under the same conditions as Figure 4 The communication device 200 includes a plurality of MAC control circuits 103. As an example,

[0070] The MAC control circuits 103a and 103b can be formed by setting two Figure 2 MAC control circuits 103. Alternatively, as another example, the MAC control circuits 103a and 103b can be formed by using software with functions equivalent to those of two MAC control circuits 103 in a single circuit. For example, the following structure can be adopted: by improving the processing performance of the CPU (not shown), DSP (Digital Signal Processor: not shown), FPGA (Field Programmable Gate Array: not shown), and ASIC (Application Specific Integrated Circuit) included in the Figure 2 MAC control circuit 103, the functions equivalent to those of the two MAC control circuits 103a and 103b can be emulated using software.

[0071] Figure 5 This is a diagram showing another example of the process by which the communication device in Embodiment 1 establishes a communication link. Figure 5 This shows a state where communication devices 200 (200a, 200b, 200c, 200d, 200e) Figure 3C similarly form PBSS1001a (communication device 200a is the PCP, and communication devices 200b and 200c join) and PBSS1001b (communication device 200d is the PCP, and communication device 200e joins), and communication device 200d is close to communication devices 200b and 200c.

[0072] Each of communication devices 200b and 200c is controlled by the MAC control circuit 103a to join PBSS1001a and performs communication control based on the scheduling information from communication device 200a, which is the PCP. In addition, the fact that communication devices 200b and 200c perform communication control based on the scheduling information from communication device 200a, which is the PCP, is referred to as communication devices 200b and 200c being synchronized with communication device 200a.

[0073] Communication devices 200b and 200c can also, when approaching communication device 200d, perform an association process with communication device 200d using another MAC control circuit 103b and join PBSS 1001b. That is, communication device 200 can join multiple PBSSs corresponding to the number of MAC control circuits 103 it has.

[0074] However, the number of PBSSs that communication device 200 can join is limited by the number of MAC control circuits 103 it has. For example, in Figure 5 when communication device 200f (not shown), which is the PCP of PBSS 1001c (not shown), approaches communication device 200b, since communication device 200b has already joined two PBSSs, it is difficult to further join PBSS 1001c to communicate with communication device 200f.

[0075] In addition, since communication device 200 has multiple MAC control circuits 103a and 103b, or uses a circuit that improves the Figure 2 processing performance of MAC control circuit 103, the circuit scale increases and the power consumption increases.

[0076] Next, a method for communication devices to communicate with surrounding communication devices without increasing the circuit scale in a V2X communication system will be described.

[0077] Figure 6A It is a diagram showing an example of the process of a communication device in Embodiment 1 establishing a communication link. Figure 6B It is a diagram showing another example of the process of a communication device in Embodiment 1 establishing a communication link. Figure 6C It is a diagram showing another example of the process of a communication device in Embodiment 1 establishing a communication link. Figure 6D It is a diagram showing another example of the process of a communication device in Embodiment 1 establishing a communication link. Figures 6A to 6E It shows a method for communication devices 300 (300a, 300b, 300c, 300d, 300e) to communicate with each other. The structure of communication device 300 is the same as that of Figure 2 the communication device 100 in Figures 3A to 3C However, the MAC control circuit 103 and the host CPU 104 in communication device 300 perform different operations using a different control method.

[0078] In Figure 6AIn this case, communication devices 300a and 300d transmit a plurality of DMG beacon frames in which the value of the OCB mode subfield (Outside the Context of a BSS: not joined to a BSS) is set to 1 (flagged) while changing the antenna directivity of antenna 101. The OCB mode subfield contains a value indicating whether communication device 300 communicates with each other without joining a BSS. In addition, when the value of the OCB mode subfield is 1, it indicates that communication device 300 transmits a data frame without association. Further, it is also possible that communication devices 300d and 300e transmit with the value of the discovery mode subfield set to 1 in addition to the OCB mode subfield.

[0079] Figure 7A FIG. is an example of the format of the DMG beacon frame of Embodiment 1. Figure 7A Represents the format of the DMG beacon frame. The DMG beacon frame includes a Frame Control field, a Duration field, a BSSID field, a Frame Body field, and an FCS field.

[0080] The Frame Control field contains information indicating the type of the frame and indicates that it is a DMG beacon frame. When communication device 300 transmits a plurality of DMG beacon frames, the Duration field indicates the time until the transmission of the plurality of DMG beacons ends.

[0081] The BSSID (Basic Service Set Identifier) represents the identification number of the BSS. When communication device 300 communicates in the OCB mode, the value of the BSSID field is set to a value representing a wildcard (all bits are 1).

[0082] The Frame Body contains a plurality of fields (described later). The FCS (Frame Check Sequence) contains an error detection code (as an example, CRC: Cyclic Redundancy Check code).

[0083] The Frame Body contains a Timestamp field, a Sector Sweep field, a Beacon Interval field, a Beacon Interval Control field, and a DMG Parameters field. In addition, one or more non-essential fields (referred to as "Optional fields") may be newly added.

[0084] The timestamp field contains information for time synchronization between communication devices.

[0085] When the communication device 300 changes the antenna directivity of the antenna 101 while transmitting a plurality of DMG beacon frames, the sector scan field contains directivity-related information such as a sector number or an antenna array number. Other communication devices that receive the DMG beacon frame include the sector number and the antenna array number included in the DMG beacon frame with the best reception quality in an SSW frame (described later) and notify the communication device 300. Thereby, the communication device 300 can select the best sector number and antenna array number (i.e., the best directivity) and transmit a data frame.

[0086] The beacon interval field contains a current CC (CC Present) subfield, a discovery mode subfield, a next beacon subfield, a current ATI (ATI (Access Terminal Identifier) Present) subfield, an A-BFT (Association Beamforming Training) length (Length) subfield, an FSS subfield, an is responder TXSS (IsResponderTXSS (Transmit Sector Scan)) subfield, a next (Next) A-BFT subfield, a fragmented TXSS subfield, a TXSS span subfield, an N BIs A-BFT (N BIs A-BFT) subfield, an A-BFT count subfield, an N A-BFT in Ant subfield, a PCP association ready subfield, and a reserved bit.

[0087] The communication device 300 sets the value of the discovery mode subfield to 1. Thereby, the communication device 300 indicates that the transmitted DMG beacon does not notify the synchronization information of the BSS.

[0088] The description of the following fields is omitted (refer to Non-Patent Document 1): the next beacon subfield, the current ATI subfield, the A-BFT length subfield, the FSS subfield, the is responder TXSS subfield, the next A-BFT subfield, the fragmented TXSS subfield, the TXSS span subfield, the N BIs A-BFT subfield, the A-BFT count subfield, the N A-BFT in Ant subfield, the PCP association ready subfield, and the reserved bit.

[0089] The DMG parameter field includes a BSS type sub-field, a CBAP (CBAP (Contention-Based Access Period) Only) sub-field, a CBAP Source sub-field, a DMG Privacy sub-field, an ECAPC (Extended Centralized Access Point or Personal Service Set Control Point Cluster) Policy Enforced sub-field, an OCB mode sub-field, and reserved bits.

[0090] Figure 7B FIG. is an example of the value and description of the BSS type sub-field indicating Embodiment 1. Figure 7B Indicates the value and description of the BSS type sub-field. When the AP responds to the DMG beacon frame sent by the communication device 300, the value of the BSS type sub-field is set to 3. When the PCP responds to the DMG beacon frame sent by the communication device 300, the value of the BSS type sub-field is set to 2. As an example, in Figure 3C , the communication device 100b can also send a DMG beacon frame to discover the communication device 100d (not shown). At this time, since the communication device 100b sets the value of the BSS type sub-field of the DMG beacon frame to 2, it is responded to by the communication device 100d as the PCP.

[0091] The communication device 300 sets the value of the BSS type field to 1 or 0 so that other communication devices send an SSW frame with the value of the OCB Response sub-field (described later) set to 1 to respond to the DMG beacon frame. The communication device 300 sets the value of the BSS type sub-field to 0 when communicating with other communication devices corresponding to the OCB mode and / or connecting to an existing AP or PCP.

[0092] In the OCB mode, the communication device 300 does not use an AP or PCP and does not schedule communication opportunities. Therefore, Figure 7A the value of the CBAP Only field is set to 1.

[0093] The communication device 300 sets the value of the OCB mode sub-field to 1 to use the OCB mode. The OCB mode sub-field is a newly added field using the reserved bits in the IEEE802.11ad standard. That is, communication devices (communication devices 100, 200) that do not support the OCB mode corresponding to the IEEE802.11ad standard will ignore the OCB mode sub-field. When the value shown in the BSS type is consistent with the roles assumed by the communication devices 100, 200, the communication devices 100, 200 respond to the DMG beacon frame.

[0094] In addition, the OCB mode sub-field may not be included in the DMG parameter field, but may be included in the beacon interval control field or other fields. Alternatively, an OCB parameter (for example, not shown) field may be newly added as an optional field of the DMG beacon frame. If the OCB parameter field exists in the DMG beacon frame, it indicates support for the OCB mode; if the OCB parameter field does not exist, it indicates non-support for the OCB mode.

[0095] When the communication device 300 has sent Figure 7A the DMG beacon frame, it may receive responses from the communication devices 100 and 200 corresponding to the OCB mode and those not corresponding to the OCB mode. It is possible that when the communication device 300 receives a response from a communication device not corresponding to the OCB mode, it sends a probe request frame and performs the active scanning process described in the IEEE 802.11ad standard. That is, the communication device 300 can communicate with the communication devices corresponding to the OCB mode and those not corresponding to the OCB mode.

[0096] Descriptions of other sub-fields of the DMG parameter field (only the CBAP sub-field, CBAP source sub-field, DMG privacy sub-field, ECAPC policy enforcement sub-field, reserved bits) are omitted (refer to Non-Patent Document 1).

[0097] In Figure 6B when the communication devices 300b and 300c receive Figure 7A the DMG beacon frame from the communication device 300a, they send an SSW (Sector Sweep) frame as a response (described later, refer to FIG. 8). In Figure 6B it is possible that the communication device 300a has not started the PBSS, the communication devices 300b and 300c have not performed the association process with the communication device 300a, but the communication device 300a communicates with the communication device 300b, and it is also possible that the communication device 300a communicates with the communication device 300c. In addition, use Figure 10 to describe in detail the process until the combination of the communication device 300a and the communication device 300b and the combination of the communication device 300a and the communication device 300c communicate with each other as described later in Figure 6B .

[0098] In addition, in Figure 6B the communication devices 300d and 300e also communicate with each other without starting the PBSS and without performing the association process.

[0099] Use Figure 6CA method for the communication device 300d to communicate with the communication devices 300b and 300c when the communication device 300d is close to the communication devices 300b and 300c is described.

[0100] The communication device 300d sets the value of the OCB mode subfield of the DMG beacon frame to 1, and while changing the antenna directivity of the antenna 101, transmits the DMG beacon frame multiple times. When the communication devices 300b and 300c receive the Figure 7A DMG beacon frame, they send an SSW frame as a response. It can be that although the communication device 300d has not started PBSS and the communication devices 300b and 300c have not performed an association process with the communication device 300d, the communication device 300d communicates with the communication device 300b, and also, the communication device 300d can communicate with the communication device 300c. Figure 7A That is,

[0101] Namely, Figure 6C the process of the communication device 300d communicating with the communication devices 300b and 300c in Figure 6A is the same as the process of the communication device 300a communicating with the communication devices 300b and 300c in

[0102] In addition, in Figure 6D the communication device 300e can also communicate with Figure 6C the communication device 300d in the same way, using the Figure 7A DMG beacon frame to communicate with the communication devices 300b and 300c.

[0103] Figure 6E represents a wireless link established by applying the process of Figures 6A to 6D . Different from Figure 3C , for the group of the communication device 300b and the communication device 300d, the group of the communication device 300c and the communication device 300d, the group of the communication device 300b and the communication device 300e, and the group of the communication device 300c and the communication device 300e, a wireless link can be established. Therefore, the communication device 300 using the Figure 7A DMG beacon frame can communicate with more communication devices. In addition, different from the Figure 4 communication device 200, the communication device 300 does not require multiple MAC control circuits 103, so the circuit scale is small and the power consumption is low.

[0104] Figure 8AThis is a diagram showing an example of the format of the SSW frame in Embodiment 1. The SSW frame includes a Frame Control field, a Duration field, an RA (Receiver Address) field, a TA (Transmitter Address) field, an SSW field, an SSW Feedback field, and an FCS field.

[0105] The Frame Control field contains information indicating the type of the frame and also contains information indicating that it is an SSW frame. The Duration field indicates the time until the completion of SLS (Sector Level Sweep, a form of beamforming training). The RA field and the TA field respectively contain the MAC addresses of the communication devices that receive and transmit the SSW frame. The SSW field contains information required for SLS such as sector numbers and antenna array numbers.

[0106] The SSW Feedback field contains a Sector Select subfield, a DMG Antenna Select subfield, an SNR (Signal Noise Ratio) Report subfield, a Poll Required subfield, an OCB Response subfield, Reserved bits, an Unsolicited RSS Enabled subfield, and an EDMG (Enhanced Directional Multi-Gigabit) Extension Flag subfield.

[0107] The OCB Response subfield indicates that the communication device 300 sends a data frame without association (referred to as the "OCB mode"). The communication device 300 sends an SSW frame with the value of the OCB mode subfield set to 1 when it receives a DMG beacon frame with the value of the OCB mode subfield set to 1 from another communication device.

[0108] The name of the OCB Response subfield may also be other subfield names such as OCB Mode subfield, OCBSupported.

[0109] Descriptions of the other subfields of the SSW Feedback field (Sector Select subfield, DMG Antenna Select subfield, SNR Report subfield, Poll Required subfield, Reserved bits, Unsolicited RSS Enabled subfield, EDMG Extension Flag subfield) are omitted (refer to Non-Patent Document 1).

[0110] The communication device 300 may also send a short SSW packet instead of Figure 8A the SSW frame. Figure 8B FIG. is an example of the format of the short SSW packet payload showing Embodiment 1.

[0111] The short SSW packet includes a Packet type field, a Direction field, an OCB response field, a Source AID field, a Destination AID field, a CDOWN field, an RF Chain ID field, a short SSW feedback field, and an FCS field.

[0112] The OCB response subfield indicates that the communication device 300 supports the OCB mode. When the communication device 300 receives a DMG beacon frame in which the value of the OCB mode subfield is set to 1 from another communication device, it sends a short SSW packet in which the value of the OCB response field is set to 1.

[0113] Descriptions of other fields of the short SSW packet (packet type field, direction field, source AID field, destination AID field, CDOWN field, RF chain ID field, short SSW feedback field, FCS field) are omitted (see Non-Patent Document 1).

[0114] Figure 9 FIG. is a flowchart showing an example of the process of millimeter-wave communication performed by the communication device according to Embodiment 1. Figure 9 It shows the process of communication between the communication device 300a and the communication device 300b.

[0115] (Step S1001) The communication device 300a receives a scan start instruction (not shown) and starts the operation of step S1001. The communication device 300a sets the values of the discovery mode subfield and the OCB mode subfield of the Figure 7A DMG beacon frame to 1 and transmits it. The communication device 300a may also transmit a plurality of DMG beacon frames while changing the antenna directivity of the antenna 101.

[0116] (Step S1003) When an SSW frame is received in A-BFT, the communication device 300a proceeds to step S1004 (step S1003 is "Yes"). When no SSW frame is received, the communication device 300a returns to step S1001 (step S1003 is "No").

[0117] (Step S1004) When step S1003 is "Yes", the communication device 300a sends an SSW feedback frame to the transmission source of the SSW frame (as an example, assume it is the communication device 300b).

[0118] (Step S1005) The communication device 300a determines whether the scanning is completed. When it is determined that the scanning is completed, it proceeds to Step S1006 (Step S1005 is "Yes"). It can be that when a predetermined scanning time has elapsed since the start of the scanning in Step S1001, the communication device 300a determines that the scanning is completed. It can be that the scanning time is included in the scanning start instruction in Step S1001, and is notified to the MAC control circuit 103 by the host CPU 104, for example. When the scanning is not completed, the communication device 300a returns to Step S1001 (Step S1005 is "No").

[0119] Based on the allowable delay time, the scanning time is determined. Thus, the communication device 300a can communicate with more communication devices within the allowable delay time. As an example, the scanning time is 200 milliseconds or more and less than 300 milliseconds.

[0120] It can be that when at least one SSW frame with the value of the OCB mode subfield being 1 is received, regardless of whether the scanning time has elapsed, the communication device 300a determines as "Yes" in Step S1005. That is, the order of Step S1005 and Step 1006 (described later) can also be swapped. Thus, the communication device 300a can use less delay time to discover other communication devices 300b corresponding to the OCB mode and capable of communicating with the communication device 300a, and start communication.

[0121] (Step S1006) When at least one SSW frame with the value of the OCB mode subfield being 1 is received, the communication device 300a proceeds to Step S1007 (Step S1006 is "Yes"). When Step S1006 is "No", the communication device 300a ends the process.

[0122] (Step S1007) The communication device 300a performs SLS (sector-level scanning, a form of beamforming training) with the communication device 300b (the communication device that sent the SSW frame with the value of the OCB mode subfield being 1), and performs training on the transmit antenna and the receive antenna. Thus, the communication devices 300a and 300b can select the directivities of the transmit antenna and the receive antenna in a manner that improves the communication quality, and thereby can improve the data rate.

[0123] The communication device 300a can also execute BRP (Beam Refinement Protocol) in Step S1007. BRP is a method of more precisely controlling the directivity of the antenna 101 to improve the communication quality.

[0124] (Step S1008) When the SLS in step S1007 by the communication device 300a is not successfully completed (step S1008 is "No"), it returns to step S1007. Alternatively, when the SLS in step S1007 by the communication device 300a is not successfully completed, step S1007 can be repeated multiple times. If it still cannot be successfully completed after that, it returns to step S1001.

[0125] Reasons for the unsuccessful completion of SLS include the following situations: for example, the distance between the communication devices 300a and 300b increases due to the movement of the vehicle or pedestrian carrying the communication devices 300a and 300b, or it is difficult to establish a wireless link because an obstacle (as an example, another vehicle) enters between the communication device 300a and the communication device 300b. In this case, by returning to step S1001 and executing the process, the communication device 300a may discover other communicable communication devices, or reconnect with the communication device 300b after the obstacle moves.

[0126] When the SLS in step S1007 by the communication device 300a is successfully completed (step S1008 is "Yes"), it proceeds to step S1009.

[0127] (Step S1009) The communication device 300a sets the antenna 101 to the directivity selected in step S1007 and transmits a data frame.

[0128] (Step S1010) Alternatively, when the link quality deteriorates, for example, when the received power or the S / N (Signal to Noise) ratio decreases, or when the packet error rate increases, the communication device 300a returns to step S1007 to perform SLS with the communication device 300b (step S1010 is "Yes"). On the other hand, when the link quality does not deteriorate, the communication device 300a proceeds to step S1011 (step S1010 is "No"). Additionally, alternatively, regardless of the link quality, when a fixed time has elapsed, the communication device 300a returns to step S1007 to perform SLS.

[0129] (Step S1011) When the specified time (BeaconInterval: beacon interval) has elapsed since the DMG beacon frame started being transmitted in step S1001 (step S1011 is "Yes"), the communication device 300a returns to step S1001 to transmit the DMG beacon frame. The purpose is to discover communication devices that have approached the communication device 300a during the specified time and start communication. On the other hand, when the specified time has not elapsed, the communication device 300a returns to step S1009 to transmit a data frame (step S1011 is "No").

[0130] Alternatively, whenever step S1001 is performed, within a range greater than 10 TU (Time Unit: 1 TU is 1.024 milliseconds) and less than 200 TU, the communication device 300a randomly determines the time (beacon interval) for repeatedly performing step S1001.

[0131] The communication device 300a can also change the time interval for performing SLS according to the moving speed of the vehicle 10a or the pedestrian 20a equipped with the communication device 300a. When the moving speed of the vehicle 10a or the pedestrian 20a is fast, the wireless link can be maintained at high quality by shortening the time interval for performing SLS. When the moving speed of the vehicle 10a or the pedestrian 20a is slow or stopped, the data rate drop caused by the overhead of SLS or the interference to other communication devices can be reduced by extending the time interval for performing SLS.

[0132] It can be that when the communication device 300a operates in the OCB mode, that is, when the communication device 300a sets the value of the OCB mode subfield of the Figure 7A DMG beacon frame to 1 and transmits it, and receives the SSW frame of FIG. 8 in which the value of the OCB response subfield is set to 1 from the communication device 300b, the communication device 300a shortens the time interval for performing SLS with the communication device 300b.

[0133] In addition, it can be that when the communication device 100a does not operate in the OCB mode, that is, when receiving the SSW frame with the value of the OCB response subfield being 0 from the communication device 100b, the communication device 100a extends the time interval for performing SLS with the communication device 100b.

[0134] Thus, when the communication device 300b supporting the OCB mode is mounted on a vehicle, the wireless link can be maintained at high quality by shortening the time interval for performing SLS. When the communication device 100b that does not support the OCB mode is mounted on a non-mobile device, such as a base station or an access point, the data rate drop caused by the overhead of SLS or the interference to other communication devices can be reduced by extending the time interval for performing SLS.

[0135] In Figure 1B the situation where there are multiple wireless links between multiple communication devices as shown, the communication device 300 mounted on the vehicle 10, the pedestrian 20, and the moving entity can, by using the OCB mode, Figures 6A to 6EAs shown, the wireless link is flexibly changed corresponding to the movement of the communication device. In addition, although the communication device 300 mounted on the roadside device 30 does not move, by using the OCB mode, it can communicate with the communication devices 300 mounted on the vehicle 10 and the pedestrian 20 using a single mode (OCB mode), thereby simplifying the MAC control.

[0136] On the other hand, when the mobile communication device 300 communicates with a non-mobile base station or access point and directly communicates with other mobile communication devices 300, by not using the OCB mode but performing association, functions such as scheduling can be applied, and thus, communication can be performed efficiently.

[0137] In addition, it can also be that when at least one SSW frame with the value of the OCB response subfield being 0 is received in step S1002 (as an example, the transmission source is set to the communication device 100b), after the communication device 300a sends an SSW feedback frame in step S1004, it receives a probe request frame, or sends a probe request frame, and after the scanning ends, starts the association process with the communication device 100b.

[0138] For example, when an SSW frame with the value of the OCB response subfield being 0 is received in step S1006 (step S1006 is "no"), the communication device 300a ends Figure 9 the process, and through Figures 3A to 3C the process, starts or joins the process of PBSS specified in the IEEE802.11ad standard. When an SSW frame with the value of the OCB response subfield being 1 is received in step S1006 (step S1006 is "yes"), the communication device 300a can, through the process after step S1007 of Figure 9 as Figures 6A to 6E shown, establish multiple wireless links.

[0139] Therefore, the communication device 300 can communicate with each communication device in a situation where communication devices 300 that support the OCB mode and IEEE802.11ad-based communication devices that do not support the OCB mode are mixed.

[0140] In addition, in step S1007, the communication device 300 performs SLS, but may also perform a BRP (Beam Refinement Protocol) process. When the communication devices 300a and 300b have established a wireless link through the processes of steps S1001 to S1006, the communication device 300 performs BRP instead of SLS, whereby beamforming with low latency and high precision can be performed. On the other hand, when it is determined in step S1010 that the wireless link has been disconnected, or when it is assumed that the S / N ratio is low and the probability of successful BRP is low, the communication device 300 performs SLS as described above, whereby the probability of successful beamforming can be increased.

[0141] Figure 10 is a timing chart showing an example of the process of the communication device of Embodiment 1 performing millimeter-wave communication. Using Figure 10 explains the process of the communication device (STA: STAtion) 300d communicating with the communication devices 300b and 300c (see Figure 6C ). In Figure 10 , as an example, "MAC" represents the operation of the MAC control circuit 103. As an example, "higher layer entities" represents the operation of the host CPU 104. In addition, the "higher layer entities" may also be software such as an SME (Station Management Entity: terminal management unit), a requester, a driver, or an OS, for example.

[0142] Regarding the MAC, an interface specification called "MLME (MAC Layer Management Entity) SAP (Service Access Point)" is defined. The MLME SAP may also include the definition of primitives prefixed with MLME- and is used to control the MAC (MAC control circuit 103). In addition, regarding the MAC, an interface specification called "MAC SAP" is defined. The MAC SAP may also include the definition of primitives prefixed with MAC- and is used to control data transmission and reception in the MAC (MAC control circuit 103).

[0143] In addition, the interface specifications and primitives of the MLME SAP and the MAC SAP are defined for convenience, and the signals exchanged between the MAC control circuit 103 and the host CPU 104 depend on the implementation. Examples of the signals exchanged between the MAC control circuit 103 and the host CPU 104 include PCI Express (Peripheral Component Interconnect Express) signals, USB (Universal Serial Bus) signals, serial communication signals, and function calls. In addition, a part of the higher layer entity can also be implemented as a part of the MAC control circuit 103. In this case, the interface specifications and primitives of the MLME SAP and the MAC SAP become internal signals of the MAC control circuit 103.

[0144] Therefore, the interface specifications and primitives of the MLME SAP and the MAC SAP do not limit the operation of the communication device 300, but are used to describe the content and transmission / reception order of a series of frames exchanged between the communication device 300d and the communication device 300b.

[0145] (Step S1100) In Figure 10 the MLME-SCAN.request issued by the higher layer entity to the MAC means an indication to start scanning. The MAC control circuit 103 of the communication device 300d starts the Figure 9 process from step S1001 on the occasion of MLME-SCAN.request.

[0146] The MAC of the communication device 300d transmits a DMG beacon frame in which the value of the discovery mode subfield is set to 1 and the value of the OCB mode subfield is set to 1 (corresponding to Figure 9 step S1001). The communication devices 300b and 300c respectively receive the DMG beacon frame.

[0147] The MACs of the communication devices 300b and 300c transmit an SSW frame in which the OCB response field is set to 1 as a response to the DMG beacon frame (corresponding to Figure 9 step S1003). In addition, the communication devices 300b and 300c can also perform transmission in a time slot in which the transmission timing of the SSW frame is randomly selected based on the A-BFT (Associated Beamforming Training) method described in the IEEE802.11ad standard, thereby avoiding competition between the transmission of the communication device 300b and the transmission of the communication device 300c.

[0148] When the communication device 300d receives the SSW frames from the communication devices 300b and 300c, it transmits an SSW feedback frame (corresponding to Figure 9step 1004).

[0149] When the MAC of communication device 300d has passed the scanning time, it completes the scanning and issues an MLME-SCAN.confirm primitive to the higher layer entity. The MLME-SCAN.confirm primitive contains the MAC addresses of the transmitting source communication devices 300b and 300c that received the SSW frame in step S1002, link quality information, and information indicating whether each of the communication devices 300b and 300c supports the OCB mode. As an example of the concretization of the MLME-SCAN.confirm primitive, the MAC control circuit 103 notifies the host CPU 104 of the information contained in the MLME-SCAN.confirm as scanning report information.

[0150] At this time, as an example, the requesting party software executed on the host CPU 104 may also display the scanning report information on the display included in the peripheral device 105. In addition, the requesting party software may also perform the determination of step S1006 based on the scanning report information to decide whether to associate with the PBSS or communicate in the OCB mode (steps S1007 to step 1010). Figure 9 step S1006 of, and decide whether to associate with the PBSS or communicate in the OCB mode (steps S1007 to step 1010).

[0151] (Step S1101) The higher layer entity of communication device 300d makes the determination of step S1006. If the result is "yes", it issues an MLME-BF-TRAINING.request primitive to the MAC and starts the SLS with communication device 300b (equivalent to Figure 9 step S1007). The SLS includes the transmission of the SSW frame by communication device 300d (referred to as "ISS: Initiator Sector Scan"), the transmission of the SSW frame by communication device 300b (referred to as "RSS: Responder Sector Sweep"), the transmission of the SSW feedback frame by communication device 300d, and the transmission of the SSW Ack (equivalent to Acknowledgement: Receive Confirmation) frame by communication device 300b.

[0152] When the MAC of communication device 300d has completed the SLS, it issues an MLME-BF-TRAINING.confirm primitive to the higher layer entity. In addition, it is also possible that communication device 300d issues the MLME-BF-TRAINING.confirm primitive regardless of whether the SLS is successful. Information indicating whether the SLS is successful, reception quality, or information of each field contained in the SSW frame may be included in the MLME-BF-TRAINING.confirm primitive and notified to the higher layer entity.

[0153] When the MAC of communication device 300b has completed SLS, it issues the MLME-BF-TRAINING.indicate primitive to the upper layer entity. Additionally, it is also possible that regardless of whether SLS is successful, communication device 300b issues the MLME-BF-TRAINING.indicate primitive. Information indicating whether SLS is successful, reception quality, or information on each field contained in the SSW frame can also be included in the MLME-BF-TRAINING.indicate primitive and notified to the upper layer entity.

[0154] It is possible that when the upper layer entity of communication device 300d has completed SLS with communication device 300b, it issues the MLME-BF-TRAINING.request primitive to the MAC and starts SLS with communication device 300c.

[0155] (Step S1102) The upper layer entity of communication device 300d makes the determination in step S1008 based on the information contained in the MLME-BF-TRAINING.confirm primitive. When the determination result in step S1008 is that SLS has been successful, the upper layer entity issues the MA-UNITDATA.request primitive to the MAC of communication device 300d, requesting execution of data transmission processing. The MA-UNITDATA.request primitive includes the destination address for transmission or the data to be transmitted.

[0156] During the data transmission process, the MAC of communication device 300d transmits an RTS (Request to Send) frame, receives a DMG CTS (Clear to Send) frame, transmits a data frame, and receives an Ack frame (corresponding to Figure 9 step S1008).

[0157] For the transmission of the RTS frame and the data frame, communication device 300d sets the antenna directivity selected by SLS in step S1007 to antenna 101 and then transmits. When communication device 300b receives the RTS frame, it does not know from which communication device the frame is transmitted, so it uses a Quasi-Omni (quasi-omnidirectional) antenna (sets antenna 101 to Quasi-Omni) for reception.

[0158] After communication device 300b transmits the DMG CTS frame, it expects to receive a data frame from communication device 300d, so it sets antenna 101 to the directivity determined by SLS in step S1007 to receive the data frame. Thereby, the quality of the wireless link can be improved and the data rate can be increased.

[0159] In addition, the communication device 300d may also send a DMG CTS to self frame (a DMG CTS frame with the destination set to the address of the communication device 300d) instead of the RTS frame. The communication device 300d may then send a data frame following the DMG CTS to self frame.

[0160] Alternatively, when the communication device 300b receives a DMG CTS to self frame, it does not send a DMG CTS frame. However, since it is assumed that a data frame will be sent from the communication device 300d next, the antenna 101 is set to receive the data frame with the antenna directivity determined by SLS in step S1007.

[0161] The MAC of the communication device 300b issues a MA-UNITDATA.indication primitive to the higher layer entity after sending the Ack frame. The MA-UNITDATA.indication primitive includes the source and destination addresses, the received data (the content of the data frame received from the communication device 300d), and information indicating whether the reception was successful (for example, if there are bit errors in the received data frame, it is set as reception failure).

[0162] When the higher layer entity of the communication device 300b is notified of successful reception using the MA-UNITDATA.indication primitive, it obtains the received data from the MA-UNITDATA.indication primitive and delivers it to the OS or application software.

[0163] When the MAC of the communication device 300d receives an Ack frame, or when the time when it is expected to receive an Ack frame has passed, it issues a MA-UNITDATA.STATUS.indication primitive to the higher layer entity. The MA-UNITDATA.STATUS.indication primitive includes information indicating whether the transmission of the data frame was successful. When the communication device 300d receives an Ack frame, the transmission of the data frame is successful.

[0164] The higher layer entity of the communication device 300d may also, when it receives the MA-UNITDATA.STATUS.indication primitive, newly issue a MA-UNITDATA.request primitive to the MAC to request sending data to the communication device 300c (not shown). Additionally, the communication with the communication device 300b may be repeated.

[0165] Alternatively, when the higher-layer entities of the communication devices 300b and 300c are each notified by the MAC using the MLME-BF-TRAINING.indication primitive that the SLS has been successful, or when the MA-UNITDATA.STATUS.indication primitive or the MA-UNITDATA.indication primitive notifies that data transmission or reception has been completed (not shown), they issue an MA-UNITDATA.request primitive to the MAC to request data transmission to the communication device 300d (not shown).

[0166] In addition, it is not limited to Figure 10 the process. The higher-layer entity of the communication device 300d can also issue an MA-UNITDATA.request primitive to the MAC to request data transmission to the communication device 300b when the SLS between the communication device 300d and the communication device 300b is completed and the MLME-BF-TRAINING.confirm primitive is notified (not shown).

[0167] As described above, the communication device 300 includes a signal supporting the OCB mode in the DMG beacon frame for transmission. When receiving an SSW frame including a signal supporting the OCB mode, it transmits a data frame without association. Therefore, the circuit scale of the MAC control circuit 103 can be reduced, power consumption can be cut, and communication can be performed with multiple moving communication devices.

[0168] (Modification of Embodiment 1)

[0169] In Embodiment 1, the communication device 300 sets the value of the OCB mode subfield to 1 to transmit the DMG beacon frame, receives the SSW frame with the value of the OCB response field being 1, and performs beamforming training, thereby starting communication in the OCB mode. The communication device 500 of this modification, when receiving the DMG beacon frame, does not transmit the SSW frame but includes feedback information in the DMG beacon frame transmitted by the communication device 500. Thus, the communication device 500 can omit the transmission of the SSW frame and reduce interference to other communication devices.

[0170] Figure 11 It is a flowchart showing an example of the operation of the communication device according to the modification of Embodiment 1.

[0171] (Step S2001) The communication device 500 receives a plurality of DMG beacon frames transmitted by other communication devices while changing the directivity (sector) of the antenna. The communication device 500 records the sector number included in the DMG beacon frame with good reception quality (referred to as "optimal sector information"). In the case where a plurality of DMG beacon frames are received from a plurality of transmission sources, the communication device 500 records the optimal sector information for each transmission source.

[0172] (Step S2002) The communication device 500 includes the optimal sector information in the DMG beacon frame and transmits it.

[0173] Figure 12A FIG. is an example of the format of the DMG beacon frame showing a modification of Embodiment 1. Figure 12B FIG. is an example of the format of the SSW feedback element showing a modification of Embodiment 1. Figure 12A Shows the format of the DMG beacon frame transmitted by the communication device 500 in Step S2002. Figure 12A The DMG beacon frame of... includes a DMG beacon sector feedback field in the DMG parameter field. In addition, in the optional field, it includes Figure 12B one or more SSW feedback elements shown in... The description of the fields and sub-fields that are the same as those included in the DMG beacon frame of... is omitted. Figure 7A The DMG beacon sector feedback sub-field includes a bit indicating whether reception of the SSW feedback element is supported.

[0174] The DMG beacon sector feedback sub-field includes a bit indicating whether reception of the SSW feedback element is supported.

[0175] Figure 12B Shows the format of the SSW feedback element. The SSW feedback element includes an Element ID field, a Length field, an Element ID Extension, a Target MAC Address field, and an SSW feedback field.

[0176] The Element ID field and the Element ID Extension field include information for identifying the element type (indicating that it is an SSW feedback element) based on the combination of the values of the Element ID field and the Element ID Extension field.

[0177] The Length field indicates the length (data length) of the element.

[0178] The target MAC address field contains the MAC address of the notification destination indicating the information of the Sector Sweep Feedback field. For example, when the Sector Sweep Feedback field contains the best sector information of the communication device 500b, the MAC address of the communication device 500b is included in the target MAC address field. The communication device 500 can also include the target MAC address field and the Sector Sweep Feedback field in multiple SSW feedback elements respectively, thereby notifying the best sector information to multiple communication devices.

[0179] The format of the Sector Sweep Feedback field is the same as that of Figure 8A the Sector Sweep Feedback field, so the description is omitted.

[0180] (Step S2003) Other communication devices (assumed to be communication device 500b) that receive Figure 12A the DMG beacon frame check whether the MAC address of the communication device 500b is included in the target MAC address field of the SSW feedback element, and when the MAC address is included, send a BRP (Beam Refinement Protocol) frame to the communication device 500 for beamforming training. The communication device 500 can also perform beamforming training on the transmit antenna and receive antenna when receiving the BRP frame.

[0181] The communication device 500b can also send an SSW frame for SLS when the communication device 500 does not respond to the sent BRP frame.

[0182] (Step S2004) When the beamforming training using BRP or SLS is completed in step S2003, the communication device 500 sends and receives data frames.

[0183] Figure 13 is a timing diagram showing an example of the process of a communication device performing millimeter-wave communication in a modification of Embodiment 1. Use Figure 13 to describe in detail the process of communication between the communication device 500a, the communication device 500b, and the communication device 500c using Figure 11 the process.

[0184] The communication device 500a sends multiple DMG beacon frames while changing the antenna directivity of the transmit antenna. It is possible that the communication device 500a sets the value of the DMG beacon sector feedback subfield in the Figure 12A DMG beacon frame to 1 and sends it. The communication devices 500b and 500c receive the DMG beacon frame and record the best sector information (corresponding to step S2001).

[0185] The communication device 500c includes the best sector information of the communication device 500a in Figure 12Band sent in the SSW feedback element Figure 12A The DMG beacon frame (equivalent to step S2002). The communication devices 500a and 500b receive the DMG beacon frame, check whether the target MAC address field of the SSW feedback element contains the addresses of the communication devices 500a and 500b, and obtain the optimal sector information.

[0186] The communication device 500a uses the optimal sector information contained in the received DMG beacon frame to set the directivity of the antenna 101 and sends a BRP frame to the communication device 500c. The communication device 500c receives the BRP frame and performs beamforming training with the communication device 500a (equivalent to step S2003).

[0187] In addition, in step S2003, the communication device 500a may also send a Probe Request frame to the communication device 500c, and after receiving a Probe Response frame and obtaining the detailed information (Capability information) of the communication device 500c, send a BRP frame. Thus, based on the information indicating whether the extended function of BRP or the MIMO (Multiple Input Multiple Output) function is supported contained in the detailed information of the communication device 500c, the extended function of BRP or the MIMO function can be used to perform the transceiver of BRP and data frames, thereby being able to shorten the execution time of beamforming training and efficiently perform data communication.

[0188] When the communication devices 500a and 500c complete BRP, they send and receive data frames (equivalent to step S2004).

[0189] Similar to the communication device 500c, the communication device 500b sends a DMG beacon frame in a manner that includes the optimal sector information of the communication device 500a (equivalent to step S2002), performs BRP (equivalent to step S2003), and conducts data communication (equivalent to step S2004).

[0190] In addition, the communication device 500 may also send an SSW frame to perform beamforming training based on SLS (step S4001) when receiving the SSW feedback element (equivalent to step S2002).

[0191] The communication device 500a sends a DMG beacon frame by including the optimal sector information of the communication devices 500b and 500c in the SSW feedback element (equivalent to step S2002).

[0192] The communication device 500b selects, for example, 16 sectors (directivity) based on the received best sector information to transmit 16 SSW frames (step S4001). For example, the communication device 500b may select one sector number included in the best sector information and 15 sectors whose directivity is close to the best sector for transmitting the SSW frames in step S2005.

[0193] When the communication device 500a receives an SSW frame, it sends an SSW feedback frame to the communication device 500b (step S4002). In addition, the communication devices 500a and 500b perform BRP (corresponding to step S2003) and perform data communication (corresponding to step S2004).

[0194] In addition, in step S2002, for the communication device 500 for which a wireless link has been established, the communication device 500a may also omit the transmission of the best sector information. Thereby, the communication device 500a can reduce the data volume of the DMG beacon frame, shorten the delay related to transmission, and reduce the interference to other communication devices 500.

[0195] As an example, since the communication device 500a has established a wireless link with the communication devices 500b and 500c in step S2003, it may also be that the best sector information of the communication devices 500b and 500c is not included in the DMG beacon frame for transmission. In addition, in this case, the communication device 500 may also omit the processes of step S4001 and step S4002.

[0196] In addition, it may also be that the communication device 500 transmits the DMG beacon frame at a predetermined time period. That is, the communication device 500 may also perform step S2001 or step S2002 periodically. It may be that whenever step S2001 or step S2002 is executed, the period (Beacon Interval) is randomly selected within a range of 10 TU or more and less than 200 TU.

[0197] As described above, since the communication device 500 includes the best sector information in the DMG beacon frame for transmission (step S2002), it can establish a wireless link without transmitting and receiving SSW frames and perform BRP. Therefore, it can reduce the delay until the start of transmitting and receiving data frames and can reduce the interference to other communication devices 500 caused by transmitting SSW frames.

[0198] In addition, the communication device 500 reduces the number of transmissions of SSW frames based on the best sector information and performs SLS. Therefore, it can reduce the delay until the start of transmitting and receiving data frames and can reduce the interference to other communication devices 500 caused by transmitting SSW frames.

[0199] (Embodiment 2)

[0200] Figure 14 This is a diagram showing an example of the structure of the communication device 400 according to Embodiment 2. The communication device 400 includes a 60 GHz antenna 101a, a 60 GHz radio circuit 102a, a 60 GHz MAC control circuit 103a, a host CPU 104, peripheral devices 105, a 5.9 GHz antenna 401, a 5.9 GHz radio circuit 402, and a 5.9 GHz MAC control circuit 403. The same reference numerals are assigned to the same structural elements as those of the Figure 2 communication devices 100 and 300, and the description thereof is omitted. In addition, in Figure 14 , in order to distinguish the structural elements in the 60 GHz band from those in the 5.9 GHz band, although the 60 GHz antenna 101a, the 60 GHz radio circuit 102a, and the 60 GHz MAC control circuit 103a have the same operations as Figure 2 the antenna 101, the radio circuit 102, and the MAC control circuit 103, they are labeled as "60 GHz".

[0201] In the 5.9 GHz band, the communication device 400 performs broadcast transmission using an omnidirectional antenna. Thus, low-capacity data can be transmitted to a plurality of communication devices over a wide range (such as Figure 1A such a situation). Since the communication device 400 performs broadcast transmission in the wireless communication in the 5.9 GHz band, it is not necessary to discover the communication device of the transmission destination. In addition, since an omnidirectional antenna is used, beamforming training is not required, and thus the delay until the start of data communication is small. Moreover, since the communication device 400 has a communication function in the 60 GHz band, high-capacity communication can be performed.

[0202] The 5.9 GHz antenna 401 transmits and receives wireless signals in the 5.9 GHz band. The 5.9 GHz antenna 401 can be an omnidirectional antenna. The 5.9 GHz radio circuit 402 transmits and receives wireless signals according to the physical layer of the communication standard in the 5.9 GHz band - for example, the IEEE802.11p standard. The 5.9 GHz MAC control circuit 403 performs MAC control according to the MAC layer of the communication standard in the 5.9 GHz band - for example, the IEEE802.11p standard and the IEEE1609 standard.

[0203] As an example of the standard on which the 5.9 GHz radio circuit 402 is based, IEEE 802.11p is shown, but it can also be other standards, such as IEEE 802.11-2016, DSRC (Dedicated Short Range Communications) standard, LTE-V2X (Long Term Evolution-V2X), C-V2X (Cellular V2X). Additionally, as an example of the frequency band for the 5.9 GHz radio circuit 402 to perform wireless communication, the 5.9 GHz band is shown, but it can also be other frequency bands, such as the 760 MHz band (ARIB STD-T109: Radio Industry Association Standard Specification T109), 2.4 GHz band, 5 GHz band, and 6 GHz band wireless LAN (Wi-Fi or IEEE 802.11).

[0204] As an example of the standard on which the 5.9 GHz MAC control circuit 403 is based, IEEE 802.11p and IEEE 1609 are shown, but it can also be other standards, such as IEEE 802.11-2016, WAVE (Wireless Access in Vehicular Environment) standard, LTE-V2X (Long Term Evolution-V2X), C-V2X (Cellular V2X). Additionally, when the 5.9 GHz radio circuit 402 operates in a frequency band different from 5.9 GHz, such as based on the 760 MHz band (ARIB STD-T109: Radio Industry Association Standard Specification T109), 2.4 GHz band, 5 GHz band, and 6 GHz band wireless LAN (Wi-Fi or IEEE 802.11), the 5.9 GHz MAC control circuit 403 can perform MAC control actions based on the corresponding standard.

[0205] Figure 15 It is a flowchart showing an example of the process of the communication device in Embodiment 2 performing millimeter-wave communication. Figure 15 It shows the process of the communication device 400 communicating in the V2X communication system 1.

[0206] (Step S3001a) The communication device 400 uses 5.9 GHz band wireless to send advertisement information including information related to the channel for communication in the 60 GHz band. The advertisement information can also be included in the WSA (WAVE Service Advertisement) frame described in the IEEE 1609.3-2016 standard (Non-Patent Document 2).

[0207] Figure 16 This is a diagram showing an example of the format of a WSA frame according to Embodiment 2. Figure 16 An example of the format of a WSA frame including information on channels in the 60 GHz band as shown will be described. The WSA frame includes a WSA Version field, a WSA Header Option Indicator field, a WSA Identifier field, a Content Count field, a WAVE Information Element Extension field, a Service Info section, a Channel Info section, and a WAVE Routing Advert. (Advertisement).

[0208] The WSA Version field represents the version information of the WSA frame. The WSA Header Option Indicator field indicates whether the WAVE Information Element Extension field, the Service Info section, the Channel Info section, and the WAVE Routing Advertisement field, which are optional fields, are included in the WSA frame respectively.

[0209] The WSA Identifier field represents the identification information of the WSA frame. The communication device 400 can repeatedly send WSA frames containing the same value, but when sending a WSA frame different from the previous one, a value different from the previous one is set to the WSA Identifier field. In addition, the communication device 400 can also increase the value of the Content Count field while repeatedly sending the same WSA frame as the previous one and then send it.

[0210] The WAVE Information Element Extension field can contain multiple information elements and can also contain information related to services provided by 5.9 GHz communication and 60 GHz communication.

[0211] The Service Info section includes a Service Info Count field, a PSID field, a Channel Index field, a Reserved bit, a Service Info Option Indicator field, and a Service Info WAVE Information Element Extension field.

[0212] The Service Info section can also include multiple sets of fields other than the Service Info Count field. The Service Info Count field indicates how many sets of subsequent fields (from the PSID to the WAVE Information Element Extension field) are included.

[0213] The PSID (Provide Service Identifier) field contains values related to the applications provided by 5.9 GHz communication and 60 GHz communication. The correspondence between the values of the PSID and the content is specified by the IEEE 1609.12 standard.

[0214] The channel index field contains the following value, which indicates which radio channel provides the service from the PSID of the service information section to the service indicated by the WAVE information element extension field. As an example, when the channel information section of the WSA frame (details will be described later) contains 4 sets of channel information and the value of the channel index field is 2, it means that the service is provided in the second channel information represented in the channel information section of the WSA frame.

[0215] The service information option indicator field indicates whether the service information WAVE information element extension field is included as a subsequent field.

[0216] Although the service information WAVE information element extension field contains information related to the provided service in the same way as the aforementioned WAVE information element extension field, it contains information on the service inherent to the channel specified by the channel index field.

[0217] Figure 17 It is a diagram showing an example of the format of the channel information section of Embodiment 2. The channel information section includes a Channel Info Count field, an Operating Class field, a Channel Number field, a Transmit Power Level field, an Adaptable field, a Data Rate field, a Channel Info Option Indicator field, and a Channel Info WAVE information element extension field.

[0218] The channel information section may also include multiple sets of information from the operating class field to the channel information WAVE information element extension field (hereinafter referred to as "channel information") except for the channel information count field, and the channel information count field indicates the number of sets.

[0219] As an example, Figure 16 the WSA frame of contains two sets of channel information in the 5.9 GHz band and the 60 GHz band, and the value of the channel information count field is 2.

[0220] The operation class field contains a number for identifying a set of frequency bands or channels specified by the IEEE802.11 standard. As an example, in the case of communication with a channel width of 10 MHz in the 5.9 GHz band in the United States, the value of the operation class field for the 5.9 GHz band channel information is 17. As another example, in the case of communication with a channel width of 2.16 GHz in the 60 GHz band in Japan, the value of the operation class field for the 60 GHz band channel information is 59.

[0221] The channel number field is the channel number within the operation class specified by the IEEE802.11 standard. As an example, in the case of operation class 17 in the United States, the value of the channel number field for the 5.9 GHz band channel information is one of the values from 171 to 184. As another example, in the case of operation class 59 in Japan, the value of the channel number field is one of the values from 1 to 29.

[0222] The transmit power level field contains the value of the transmit power (EIRP: Equivalent Isotropically Radiated Power) in the channel (unit: dBm).

[0223] The adaptive field is used in combination with the data rate field. When the value of the adaptive field is 1, the value of the data rate field represents the minimum data rate when the communication device 400 transmits. When the value of the adaptive field is 0, the communication device 400 transmits at a fixed data rate corresponding to the value of the data rate field.

[0224] In addition, in the IEEE1609.3 standard, the value indicated by the data rate field is from 1 Mbit / s to 63.5 Mbit / s. The value of the data rate field can also be replaced according to the value of the operation class field. For example, it can be understood that in the case where the value of the operation class field is 59 in Japan, etc., which represents the 60 GHz band, the value of the data rate field is replaced by 1000 times the value in the case of the 5.9 GHz band, so that the value represents a range from 1 Gbit / s to 63.5 Gbit / s.

[0225] As another example, in the 60 GHz channel information, the data rate value can be set to represent a value of 63.5 Mbit / s or more, which is the maximum value, and a sub - field representing the data rate in the 60 GHz band channel is included in the channel information option WAVE information element extension field described later.

[0226] The channel information option indicator field indicates whether the channel information contains the channel information WAVE information element extension field.

[0227] The channel information WAVE information element extension field is the same as the aforementioned WAVE information element extension field (refer toFigure 16 ) Similarly, it contains information related to the provided service, but the information it contains is the information of the service inherent in the channel specified by the operation level field and the channel number field.

[0228] When the communication device 400 includes information related to a 60 GHz band channel in the WSA frame for transmission, it Figure 17 includes the DMG information element shown in the channel information WAVE information element extension field for transmission.

[0229] The DMG information element includes a WAVE element ID field, a Primary Channel Number field, a PHY type field, a DMG Beacon Required field, a BTI (Beacon Transmission Interval) SSW feedback field, an Address Included field, Reserved bits, and a MAC address field.

[0230] The WAVE element ID field represents the following identification number, which represents the type of the element (in Figure 17 it is the DMG information element).

[0231] The Primary Channel Number field represents the number of the primary channel in the 60 GHz band.

[0232] The PHY type field represents the wireless communication standard used by the communication device 400 in the 60 GHz band. When the value of the PHY type field is 0, it represents the IEEE 802.11ad standard (DMG: Directional Multi-Gigabit), and when the value of the PHY type field is 1, it represents the IEEE 802.11ay standard (EDMG: Enhanced Directional Multi-Gigabit). Other values from 2 to 7 are reserved for future standards.

[0233] The DMG Beacon Required field indicates whether it is necessary to first receive a DMG beacon frame when the communication device 400 communicates with other communication devices that receive the Figure 16 WSA frame. Details will be described later.

[0234] The BTI SSW feedback field indicates whether the communication device 400 supports the method of using the Figure 11 DMG beacon for SSW feedback.

[0235] The Address Included field indicates whether the MAC address field is included.

[0236] The MAC address field indicates the MAC address used by the communication device 400 in the 60 GHz band. When the value of the field containing the address is 0 (excluding the MAC address field), the communication device 400 uses the MAC address for the 5.9 GHz band contained in the header (not shown) of the WSA frame for the 60 GHz band. In addition, the communication device 400 may use the same MAC address as the 5.9 GHz band in the 60 GHz band, or may use a different MAC address.

[0237] The steps after Figure 15 step S3001b will be described. When another communication device that has received the WSA frame (advertising information) supports operations in the band indicated by the operation class field and supports the communication standard indicated by the PHY type, the other communication device transmits a frame in the primary channel indicated by the primary channel field.

[0238] When the communication device 400 transmits after setting the value of the DMG beacon request field contained in the WSA frame to 0 (step S3001b is "yes"), it receives an SSW frame from another communication device (step S3002). When the communication device 400 transmits after setting the value of the DMG beacon request field contained in the WSA frame to 1 (step S3001b is "no"), it receives a DMG beacon frame from another communication device (step S3012). In addition, when a WSA frame that does not contain channel information for the 60 GHz band is received in step S3001b, an association process to the PBSS / BSS may also be performed.

[0239] After receiving the SSW frame for the ISS in step S3002, the communication device 400 transmits an SSW frame for the RSS as a response (step S3003). After another communication device responds to the SSW frame for the RSS and the communication device 400 receives the SSW feedback frame (step S3004), the communication device 400 transmits an SSW Ack frame to notify another communication device that the SLS has been successful (step S3005).

[0240] Figure 18 is a diagram showing an example of the format of the SSW frame of Embodiment 2. Using Figure 18 the format of the SSW frame transmitted by the communication device 400 in step S3002 will be described. Figure 18 The SSW frame of

[0241] In the case of supporting the OCB mode, in step S3002, the communication device 400 sets the OCB mode subfield to 1 and transmits an SSW frame. In the case of supporting the OCB mode, other communication devices 400 may, in step S3003, set the value of the OCB response subfield of the Figure 8A SSW frame to 1 and transmit it.

[0242] After the communication device 400 receives a DMG beacon frame in step S3012, it transmits an SSW frame for RSS as a response (step S3013). In the case where other communication devices respond to the SSW frame for RSS and the communication device 400 receives an SSW feedback frame from other communication devices (step S3014), SLS is successful.

[0243] The communication device 400 may also, in step S3012, set the value of the OCB mode subfield to 1 and transmit the Figure 7A DMG beacon frame. Other communication devices 400 may also, in step S3013, set the value of the OCB response subfield to 1 and transmit the Figure 8A SSW frame.

[0244] In the case where SLS with other communication devices in step S3005 or step S3014 has been successful, the communication device 400 receives a 60 GHz band data frame from other communication devices. In addition, it may also be that, in step S3006, the communication device 400 transmits a data frame to other communication devices.

[0245] Figure 19 is a timing diagram showing an example of the process of millimeter-wave communication by the communication device of Embodiment 2. Using Figure 19 , the process in which the communication device 400d uses Figure 2 and the method of communicating with a plurality of other communication devices 400b and 400c are described.

[0246] In Figure 19 , as an example, the "higher layer entity" represents the operation of the host CPU 104. In addition, the "higher layer entity" may also be software such as an SME (Station Management Entity: terminal management unit), a requester, a driver, an OS, and software compliant with the IEEE 1609 standard.

[0247] In addition, it is also possible that the communication device 400 causes software compliant with the IEEE 1609 standard to operate on the 60 GHz MAC control circuit 103 and the 5.9 GHz MAC control circuit 403. Additionally, the communication device 400 may also include a MAC control circuit 413 (not shown), which performs general processing carried out by the 60 GHz MAC control circuit 103 and the 5.9 GHz MAC control circuit 403, and executes software compliant with the IEEE 1609 standard in the MAC control circuit 413.

[0248] In Figure 19 this context, "60 GHz MAC" represents the operation of the 60 GHz MAC control circuit 103. Additionally, "5.9 GHz MAC" represents the operation of the 5.9 GHz MAC control circuit 403.

[0249] In Figure 19 the timing diagram, the operations of structural elements other than "higher layer entity", "5.9 GHz MAC", and "60 GHz MAC" (e.g., the operations of the 5.9 GHz radio circuit 402 and the 60 GHz radio circuit 102) are omitted from the description.

[0250] The higher layer entity of the communication device 400d generates Figure 16 , Figure 17 a WSA frame including channel information of the 5.9 GHz band and the 60 GHz band, issues a MA-UNITDATA.request primitive, and requests the 5.9 GHz MAC to transmit the WSA frame.

[0251] The 5.9 GHz MAC of the communication device 400d broadcasts and transmits the WSA frame in 5.9 GHz band wireless communication. Through the broadcast transmission, multiple communication devices can receive the frame data. Therefore, the communication devices 400b and 400c receive the WSA frame (corresponding to step S3001a).

[0252] After receiving the WSA frame, the 5.9 GHz MACs of the communication devices 400b and 400c issue a MA-UNITDATA.indication primitive, and notify each higher layer entity of the notification indicating that the data has been received and the data of the WSA frame.

[0253] Based on the channel information contained in the received WSA frame, the higher layer entities of the communication devices 400b and 400c start 60 GHz band communication. When the value of the DMG beacon request field received by the higher layer entities of the communication devices 400b and 400c is 0, they issue a MLME-BF-TRAINING.request primitive and request each 60 GHz MAC to execute SLS (corresponding to step S3002).

[0254] The higher-layer entities of communication devices 400b and 400c set the parameters of the MLME-BF-TRAINING.request primitive based on the information contained in the primary channel number field of the WSA frame to perform beamforming in the specified primary channel in the 60 GHz band. In addition, the higher-layer entities of communication devices 400b and 400c determine the destination of the SSW frame based on the address field and the MAC address field (if present) of the WSA frame and set it as the parameter of the MLME-BF-TRAINING.request primitive.

[0255] The 60 GHz MACs of communication devices 400b and 400c send the SSW frame (ISS) (corresponding to step S3003), and after receiving the SSW frame (RSS) (corresponding to step S3004), send the SSW feedback frame (corresponding to step S3005) to complete the SLS.

[0256] Alternatively, when receiving the MLME-BF-TRAINING.request primitive, the 60 GHz MACs of communication devices 400b and 400c start sending the SSW frame (ISS) after waiting for a random time so that the transmission of the SSW frame does not compete with each other. Alternatively, the higher-layer entities of communication devices 400b and 400c issue the MLME-BF-TRAINING.request primitive after receiving the WSA frame and waiting for a random time.

[0257] After the SLS is completed, the 60 GHz MACs of communication devices 400b and 400c issue the MLME-BF-TRAINING.confirm primitive to notify the higher-layer entities that the beamforming training has been completed. In addition, the 60 GHz MAC of communication device 400d issues the MLME-BF-TRAINING.indication primitive to notify the higher-layer entities to perform beamforming training.

[0258] Data communication can be performed between the communication devices that have completed the beamforming training. For example, in Figure 19 , the higher-layer entity of communication device 400b issues the MA-UNITDATA.request primitive to request the 60 GHz MAC to send data. The 60 GHz MAC of communication device 400b sends an RTS frame, receives a DMG CTS frame, sends a data frame, and receives an ACK frame, thereby completing the data transmission. The 60 GHz MAC of communication device 400b issues the MA-UNITDATA.STATUS.indication primitive to notify the higher-layer entity that the data transmission has been completed.

[0259] The 60GHz MAC of communication device 400d issues the MA-UNITDATA.indication primitive to notify the higher layer entity that data has been received in the 60GHz band.

[0260] In Figure 19 sequence, the communication device 400d does not perform association. Therefore, the latency can be shortened and data transmission to the communication devices 400b and 400c can start earlier. In addition, the communication device 400d includes the 60GHz band channel information, MAC address, and information of the primary channel in the advertisement information and broadcasts it in 5.9GHz. Therefore, it can receive the SSW frame ( Figure 18 ) with a shorter frame length than the DMG beacon frame (refer to Non-Patent Document 1) for beamforming, thereby shortening the latency until the start of data transmission in the 60GHz band.

[0261] As described above, the communication device 400 performs broadcast transmission using an omnidirectional antenna in the 5.9GHz band. Thus, low-capacity data can be transmitted to a wide range of multiple communication devices. Since the communication device 400 performs broadcast transmission in the wireless communication of the 5.9GHz band, there is no need to discover the destination communication device. In addition, since an omnidirectional antenna is used, there is no need for beamforming training. Therefore, the latency until the start of data communication can be reduced. Moreover, since the communication device 400 has a communication function in the 60GHz band, high-capacity communication can be performed.

[0262] In the above embodiment, the expression “... part” used in each component can also be replaced with other expressions such as “... circuitry”, “... device”, “... unit”, or “... module”.

[0263] The embodiments have been described with reference to the drawings, but the present invention is not limited to this example. Those skilled in the art can clearly conceive of various modification examples or correction examples within the scope described in the protection scope of this application. It should be understood that these modification examples or correction examples also belong to the technical scope of the present invention. In addition, the components in the embodiments can be arbitrarily combined without departing from the gist of the present invention.

[0264] The present invention can be implemented by software, hardware, or software in cooperation with hardware. Each functional block used in the description of the above embodiments is partially or wholly implemented as an LSI (Large Scale Integration, large-scale integrated circuit) which is an integrated circuit. Each process described in the above embodiments can also be controlled partially or wholly by one LSI or a combination of LSIs. The LSI can be composed of individual chips, or can be composed of one chip in a manner that includes part or all of the functional blocks. The LSI can also include data input and output. Depending on the degree of integration, the LSI is sometimes referred to as an "IC (Integrated Circuit)", "System LSI", "Super LSI", or "Ultra LSI".

[0265] In addition, the method of integrating into an integrated circuit is not limited to LSI, and can also be implemented by an application-specific circuit, a general-purpose processor, or a special-purpose processor. Additionally, an FPGA (Field Programmable Gate Array), which can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connection or setting of circuit blocks inside the LSI can be used. The present invention can also be implemented as digital processing or analog processing.

[0266] Furthermore, if, with the progress of semiconductor technology or the derivation of other technologies, an integrated circuit technology that replaces the LSI emerges, of course, this technology can also be used to achieve the integration of functional blocks. There is also the possibility of applying biotechnology, etc.

[0267] The present invention can be implemented in all types of devices, equipment, and systems with communication functions (collectively referred to as "communication devices"). Non-limiting examples of communication devices include: telephones (mobile phones, smartphones, etc.), tablet computers, personal computers (PCs) (laptop computers, desktop computers, notebook computers, etc.), cameras (digital cameras, digital video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, e-book readers, remote health / telemedicine (remote healthcare / medical prescription) devices, transportation vehicles or means of transportation with communication functions (automobiles, airplanes, ships, etc.), and combinations of the above various devices.

[0268] The communication device is not limited to portable or mobile devices, but also includes all types of devices, equipment, and systems that are not portable or are fixed. For example, it includes: smart home devices (home appliances, lighting devices, smart meters or gauges, control panels, etc.), vending machines, and all other "Things" that can exist on the IoT (Internet of Things) network.

[0269] Communication includes not only data communication through cellular systems, wireless LAN (Local Area Network) systems, communication satellite systems, etc., but also data communication through combinations of these systems.

[0270] In addition, the communication device also includes devices such as controllers or sensors that are connected or linked to a communication device that executes the communication functions described in the present invention. For example, it includes a controller or sensor that generates a control signal or data signal used by the communication device that executes the communication functions of the communication device.

[0271] In addition, the communication device includes infrastructure devices that communicate with or control the above-mentioned various non-limiting devices, such as base stations, access points, and all other devices, equipment, and systems.

[0272] <Summary of the Present Invention>

[0273] The communication device of the present invention includes: a MAC control circuit, i.e., a media access control control circuit, which performs transmission and reception control of control frames and data frames for communication with other communication devices; and a radio circuit, which uses a transmission antenna and a reception antenna to perform wireless communication of the control frames and the data frames. When the radio circuit receives from the other communication device a sector scan frame, i.e., an SSW frame, in the control frame that includes an OCB response subfield, i.e., a response subfield outside the context of the basic service set, the MAC control circuit determines whether to perform data communication between the communication device and the other communication device based on the OCB response subfield.

[0274] In the communication device of the present invention, when the MAC control circuit determines that data communication is not to be performed between the communication device and the other communication device, the MAC control circuit performs sector-level scanning, i.e., SLS, or beam optimization protocol, i.e., BRP, to control antenna directivity training of the transmission antenna and the reception antenna for the other communication device.

[0275] In the communication device of the present invention, when the MAC control circuit determines that data communication is to be performed between the communication device and the other communication device, the MAC control circuit executes a personal basic service set (PBSS) to control the antenna directivity training of the transmission antenna and the reception antenna for the other communication device.

[0276] In the communication method of the present invention, a reception antenna of a radio circuit of a communication device receives, from another communication device, a sector scan frame (SSW frame) included in a control frame for communication with the other communication device and containing an OCB response subfield, i.e., a subfield for responding outside the context of a basic service set. A MAC control circuit that controls the transmission and reception of the control frame and the data frame determines whether to perform data communication between the communication device and the other communication device based on the OCB response subfield.

[0277] In the communication method of the present invention, when the MAC control circuit determines that data communication is not to be performed between the communication device and the other communication device, the MAC control circuit executes sector-level scanning (SLS) or beam refinement protocol (BRP) to control the training of the transmission antenna and the reception antenna for the other communication device.

[0278] In the communication method of the present invention, when the MAC control circuit determines that data communication is to be performed between the communication device and the other communication device, the MAC control circuit executes a personal basic service set (PBSS) to control the training of the transmission antenna and the reception antenna for the other communication device.

[0279] This application claims priority based on Patent Application 2020-058830 filed with the Japan Patent Office on March 27, 2020. The content of Patent Application 2020-058830 is incorporated herein by reference.

[0280] Industrial Applicability

[0281] The present invention is suitable, for example, for millimeter-wave communication performed on a high-speed moving body.

[0282] Explanation of Reference Numerals

[0283] 10 (10a to 10m) Vehicle

[0284] 100 (100a to 100m), 200, 300, 400, 500 Communication Device

[0285] 30 Roadside Device

[0286] 20 Pedestrian

[0287] 101 Antenna

[0288] 102 Radio circuit

[0289] 103 MAC control circuit

[0290] 104 Host CPU

[0291] 105 Peripheral devices

[0292] 1001 PBSS

[0293] 401 5.9GHz antenna

[0294] 402 5.9GHz radio circuit

[0295] 403 5.9GHz MAC control circuit

Claims

1. A communication device, characterized in that, Including: A MAC control circuit, i.e., a media access control circuit, for controlling the transmission and reception of control frames and data frames for communication with other communication devices; And A radio circuit, using a transmitting antenna and a receiving antenna, for performing wireless communication of the control frame and the data frame, The radio circuit receives, from the other communication device, a sector scan frame, i.e., an SSW frame, in the control frame that includes an OCB response subfield, i.e., a response subfield outside the context of the basic service set. When the value of the OCB response subfield is a first value, the MAC control circuit performs data communication with the other communication device without performing an association process.

2. The communication device according to claim 1, wherein When the value of the OCB response subfield is the first value, the MAC control circuit performs data communication with the other communication device, and after a fixed time, performs sector-level scanning, i.e., SLS, or beam optimization protocol, i.e., BRP, to control the antenna directivity training of the transmitting antenna and the receiving antenna for the other communication device.

3. The communication device according to claim 1 or 2, wherein When the value of the OCB response subfield is a second value, the MAC control circuit determines that an association process is to be performed with the other communication device, and starts a personal basic service set, i.e., PBSS, to control the antenna directivity training of the transmitting antenna and the receiving antenna for the other communication device.

4. A communication method, characterized in that: A receiving antenna of a radio circuit of a communication device receives, from another communication device, a sector scan frame, i.e., an SSW frame, in a control frame for communication with the other communication device, which includes an OCB response subfield, i.e., a response subfield outside the context of the basic service set. When the OCB response subfield is a first value, a MAC control circuit that controls the transmission and reception of the control frame and the data frame performs data communication with the other communication device without performing an association process.

5. The communication method according to claim 4, wherein When the value of the OCB response subfield is the first value, the MAC control circuit performs data communication with the other communication device, and after a fixed time, performs sector-level scanning, i.e., SLS, or beam optimization protocol, i.e., BRP, to control the training of the transmitting antenna and the receiving antenna for the other communication device.

6. The communication method according to claim 4 or 5, wherein When the value of the OCB response subfield is a second value, the MAC control circuit determines that an association process is to be performed with the other communication device, and starts a personal basic service set, i.e., PBSS, to control the training of the transmitting antenna and the receiving antenna for the other communication device.

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