Communication device, communication method, and program

Abstract

To allow a communication device to recognize group identification information for a plurality of other communication devices to transmit in coordination with each other.SOLUTION: A communication device includes first receiving means for receiving from the outside a first wireless frame including first group identification information in a PHY preamble for identifying a group for a plurality of other communication devices to transmit in coordination with each other, and processing means for processing the first wireless frame.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a communication control technique in a wireless LAN. [Background technology]

[0002] In recent years, with the increase in the amount of data being communicated, the development of communication technologies such as wireless LANs (Local Area Networks) is progressing. The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known as the main communication standard for wireless LANs. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax / be (Patent Document 1).

[0003] For example, the IEEE802.11be standard considers Multi-Link communication, in which one AP (Access Point) establishes multiple links with one STA (Station) via multiple different frequency channels and communicates in parallel. Note that the two or more links may be selected from the same frequency band (2.4GHz, 3.6GHz, 4.9GHz, 5GHz, or 6GHz), or each may be selected from a different frequency band. APs and STAs that support Multi-Link are called AP MLD (Multi-Link Device) and STA MLD, respectively.

[0004] In addition, methods are being considered for improving usability using Multi-AP communication in the successor standard to IEEE802.11be.

[0005] For example, there is distributed MIMO technology, which is based on a technology called MIMO (multi-user multi-output), which uses multiple transmitting and receiving antennas at the same time and on the same channel. In distributed MIMO, in an environment where multiple APs and multiple STAs exist, the APs form groups to share information about the communication status and the status of each AP, and data is sent from the AP to the STAs at the same time. By cooperatively transmitting from multiple APs, the number of spatial streams can be increased compared to the case of a single AP, and this is expected to improve throughput.

[0006] Another example is a technology called cooperative beamforming. When an AP transmits data to a STA in a basic service set (BSS), it uses an antenna pattern that provides high antenna gain in the direction of the STA to which the data is to be transmitted, and low antenna gain in the direction of STAs in the BSS of other APs. By setting antenna patterns, adjusting transmission power, and scheduling between multiple APs based on environmental information such as the location of the STA, interference between BSSs can be reduced.

[0007] Another example is a technology in which a plurality of APs transmit data to a STA at different timings by time division, thereby improving the reception quality at the STA by taking advantage of the effects of time diversity and space diversity.

[0008] This type of communication technology, in which multiple APs form a group and operate cooperatively, is called Multi-AP communication, and the APs are classified into a single CoordinatorAP that manages all the APs, and CoordinatedAPs that operate under the management of the CoordinatorAP. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2018-50133 A Summary of the Invention [Problem to be solved by the invention]

[0010] It may be useful for a communication device to recognize group identification information for multiple other communication devices to transmit in cooperation. For example, in multi-AP communication, multiple APs form a group and transmit data to one STA in cooperation. However, there has been no mechanism for a communication device to recognize group identification information for multiple other communication devices to transmit in cooperation.

[0011] The present invention provides a technique for a communication device to recognize group identification information for cooperative transmission by a number of other communication devices. [Means for solving the problem]

[0012] A communication device according to one embodiment of the present invention is characterized in that it comprises a first receiving means for receiving from an external device a first wireless frame including first group identification information in a PHY preamble for identifying a group for a plurality of other communication devices to transmit in cooperation with each other, and a processing means for processing the first wireless frame. Effect of the Invention

[0013] According to the present invention, a communication device can recognize group identification information for a plurality of other communication devices to transmit in cooperation with each other. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing an example of a network configuration according to the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of a communication device according to the present invention. [Diagram 3] FIG. 2 is a diagram illustrating an example of a functional configuration of a communication device according to the present invention. [Figure 4] FIG. 4 is a sequence diagram showing an example of processing of a communication device according to the present invention. [Diagram 5]FIG. 2 is a diagram illustrating an example of a radio frame structure. [Figure 6] FIG. 2 is a flow chart illustrating an example of processing of communication devices 102 to 104 in the present invention. [Figure 7] FIG. 2 is a flow chart illustrating an example of processing of communication devices 105 to 107 in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0016] (Network Configuration) 1 shows an example of the configuration of a wireless communication network according to this embodiment. This wireless communication network includes access points (communication device 102, communication device 103, communication device 104, hereinafter AP102, AP103, AP104) and terminals (communication device 105, communication device 106, communication device 107, hereinafter STA105, STA106, STA107). Hereinafter, when a specific device is not being referred to, the access points may be referred to as "AP" and the stations as "STA" without a reference number.

[0017] Each of the APs 102 to 104 and the STAs 105 to 107 is configured to be capable of communicating wireless frames that comply with the successor standard to the IEEE802.11be standard, which targets a maximum transmission speed of 46.08 Gbps and is a successor standard that targets a maximum transmission speed of 90 Gbps to 100 Gbps or more. IEEE is an abbreviation for the Institute of Electrical and Electronics Engineers.

[0018] The main features of this successor standard to 802.11be are support for highly reliable and low latency communication and AP cooperation. In light of the above, in this embodiment, the successor standard to IEEE802.11be, which targets a maximum transmission speed of 90Gbps to 100Gbps, is also called IEEE802.11UHR (Ultra High Reliability). In addition, a wireless frame communicated under the successor standard is also called UHR PPDU. PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation for Physical Layer Convergence Protocol.

[0019] The names IEEE802.11UHR and UHR standards are given for convenience in consideration of the goals to be achieved by the successor standards and the features that are the main features of the standards, and may be different names when the standards are completed. However, it should be noted that this specification and the appended claims are essentially applicable to all successor standards that are successors to the 802.11be standard and that can support the function of multiple APs cooperating to perform data communication with STAs.

[0020] Each communication device can communicate at frequencies of 2.4 Hz band, 3.6 GHz band, 5 GHz band, 6 GHz band, 45 GHz band, and 60 GHz band called millimeter wave. The frequency band used by each communication device is not limited to these, and a different frequency band such as the Sub 1 GHz band may be used. In addition, the APs 102 to 104 and the STAs 105 to 107 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidth used by each communication device is not limited to these, and a different bandwidth such as 240 MHz and 4 MHz may be used.

[0021] The APs 102 to 104 and the STAs 105 to 107 can realize multi-user (MU) communication, which multiplexes signals from multiple users, by performing OFDMA communication conforming to the IEEE802.11 standard. OFDMA stands for Orthogonal Frequency Division Multiple Access. In OFDMA communication, a portion of the divided frequency band (RU, Resource Unit) is assigned to each STA so that they do not overlap, and the carrier waves of each STA are orthogonal. Therefore, the AP can communicate with multiple STAs in parallel within a specified bandwidth.

[0022] Although each communication device is described as being compatible with the IEEE802.11UHR standard, it may also be compatible with a legacy standard that is a standard that precedes the IEEE802.11UHR standard. Specifically, each communication device may be compatible with at least one of the IEEE802.11a / b / g / n / ac / ax / be standards. In addition to the IEEE802.11 series standards, it may also be compatible with other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA. Note that UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, and the like. It may also be compatible with a communication standard for wired communication such as wired LAN. Specific examples of the APs 102 to 104 include, but are not limited to, wireless LAN routers and personal computers (PCs). The APs 102 to 104 may be information processing devices such as wireless chips capable of performing wireless communication conforming to the IEEE802.11 UHR standard. Specific examples of the STAs 105 to 107 include, but are not limited to, cameras, tablets, smartphones, PCs, mobile phones, video cameras, and headsets. The STAs 105 to 107 may be information processing devices such as wireless chips capable of performing wireless communication conforming to the IEEE802.11 UHR standard.

[0023] 1 shows a wireless communication network including three APs and three STAs as an example, but the number of these communication devices may be two or less, or may be four or more. In FIG. 1, the communication range of the network formed by APs 102 to 104 is shown by a circle 101. This communication range may cover a wider range, or may cover only a narrower range.

[0024] In this embodiment, each of the APs 102 to 104 establishes a BSS, and the BSS Color of each BSS is different. BSS Color is an abbreviation for Basic Service Set Color, and is an ID for identifying a BSS. Also, the SSID indicated by the APs 102 to 104 in each BSS is all the same. Note that SSID is an abbreviation for Service Set Identifier, and is an identifier for identifying an access point.

[0025] In this example, it is assumed that the AP103 and AP104 can receive a signal transmitted by the AP102, and that the AP102 can receive a signal transmitted by the AP103 and AP104. However, the connection form is not particularly limited, and the AP102 and the AP103 and AP104 may be connected by wire or wirelessly. The AP103 and AP104 may or may not be able to transmit and receive signals to and from each other. The AP102 to AP104 are capable of Multi-AP communication of IEEE802.11UHR. That is, it is assumed that the AP102 to AP104 support a configuration in which multiple APs communicate with one common STA in cooperation as specified by IEEE802.11UHR. For example, the STA105 can transmit and receive wireless frames in parallel with the AP103 and AP104 that operate in cooperation with each other. The STA105 may be configured to have, for example, multiple wireless LAN controllers and to be able to transmit and receive wireless frames between multiple APs using different wireless channels. The STA105 may also have one physical controller capable of processing multiple frames received in parallel via multiple wireless channels. That is, the STA105 has a configuration that allows it to logically process multiple wireless communications in parallel using one or more physical control devices.

[0026] Here, APs such as AP103 and AP104 that are controlled by the CoordinatorAP and directly transmit and receive signals with each STA are called CoordinatedAPs. Also, an AP that can transmit and receive wireless frames with each STA at least indirectly by issuing instructions to AP103 and AP104, such as AP102, is called CoordinatorAP. The CoordinatorAP is sometimes called Sharing AP because it shares wireless medium resources with other APs and performs cooperative operations. Similarly, the CoordinatedAP is sometimes called Shared AP. Note that the CoordinatorAP may directly transmit and receive signals with the STA105. For example, the AP102 may operate as both the CoordinatorAP and the CoordinatedAP. In this case, for example, the AP102 may transmit and receive wireless frames between itself and the STA105 by issuing instructions to the AP103 or AP104 to transmit and receive wireless frames with the STA. Note that when the CoordinatorAP transmits wireless frames from the CoordinatedAP, the CoordinatorAP may transmit data to be transmitted to the CoordinatedAP. However, the present invention is not limited to this, and the CoordinatedAP may directly acquire data to be transmitted from the Internet, for example. The CoordinatedAP may receive data from the STA from the CoordinatedAP, but the CoordinatedAP may forward the data received from the STA to the other device of the STA without forwarding it to the CoordinatorAP.

[0027] Any AP in the same network can operate as a Coordinator AP, and it may be determined by some criteria which AP will operate as the Coordinator AP. The Coordinator AP may not operate as an AP such as transmitting Beacon frames, but may only perform the role of the Coordinator AP, such as sending instructions to each AP. Each AP may have multiple wireless LAN control units and operate as multiple Coordinated APs. The Coordinator AP may be realized as a logical function, and one physical AP may operate as one or more Coordinated APs while operating as a Coordinator AP.

[0028] (AP / STA configuration) 2 shows an example of the hardware configuration of the APs 102 to 104 in this embodiment. The APs 102 to 104 each include a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207. Note that there may be multiple antennas.

[0029] The storage unit 201 is composed of one or more memories such as a ROM and a RAM, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. As the storage unit 201, in addition to memories such as ROM and RAM, storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs may be used. Furthermore, the storage unit 201 may include multiple memories.

[0030] The control unit 202 is configured with one or more processors such as a CPU or MPU, and controls the entire AP 100 by executing a computer program stored in the storage unit 201. The control unit 202 may control the entire APs 102 to 104 in cooperation with the computer program stored in the storage unit 201 and an OS (Operating System). The control unit 202 generates data and signals (wireless frames) to be transmitted in communication with other communication devices. The CPU stands for Central Processing Unit, and the MPU stands for Micro Processing Unit. The control unit 202 may include multiple processors such as multi-core processors, and the entire AP 100 may be controlled by the multiple processors.

[0031] Furthermore, the control unit 202 controls the functional unit 203 to execute predetermined processes such as wireless communication, image capture, printing, and projection. The functional unit 203 is hardware for the APs 102 to 104 to execute predetermined processes. If the functional unit is a printer, it prints image data acquired via the communication unit 206. If the functional unit is a scanner, it transmits image data generated by scanning with the scanner to an external device via the communication unit 206. If the functional unit is a camera, it transmits image data captured by the camera to an external device via the communication unit 206.

[0032] The input unit 204 receives various operations from the user and is configured with, for example, a touch panel, hard keys, buttons, and the like.

[0033] The output unit 205 performs various outputs to the user via a monitor screen or a speaker. Here, the output by the output unit 205 may be a display on a monitor screen, a voice output by a speaker, a vibration output, or the like. Note that both the input unit 204 and the output unit 205 may be realized by one module, such as a touch panel. Also, the input unit 204 and the output unit 205 may be integrated with the APs 102 to 104, or may be separate from them.

[0034] The communication unit 206 controls wireless communication conforming to the IEEE802.11UHR standard. The communication unit 206 may also control wireless communication conforming to other IEEE802.11 series standards in addition to the IEEE802.11UHR standard, and control wired communication such as a wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals generated by the control unit 202 for wireless communication.

[0035] If the APs 102 to 104 are compatible with the NFC standard, Bluetooth standard, etc. in addition to the IEEE802.11UHR standard, they may control wireless communication in compliance with these communication standards. If the AP 100 can perform wireless communication in compliance with a plurality of communication standards, it may be configured to have a communication unit and an antenna compatible with each communication standard. The APs 102 to 104 communicate data such as image data, document data, and video data with each STA via the communication unit 206. The antenna 207 may be configured as a separate unit from the communication unit 206, or may be configured as a single module together with the communication unit 206.

[0036] The antenna 207 is an antenna capable of communication in the 2.4 GHz band, the 5 GHz band, the 6 GHz band, the 45 GHz band, and the 60 GHz band. In this embodiment, the APs 102 to 104 have two antennas, but may have three antennas. Alternatively, each of the APs 102 to 104 may have a different antenna for each frequency band. Furthermore, when the APs 102 to 104 have a plurality of antennas, each of the APs 102 to 104 may have a communication unit 206 corresponding to each antenna.

[0037] The STAs 105 to 107 have the same hardware configuration as the APs 102 to 104.

[0038] 3 is a block diagram showing the functional configuration of APs 102 to 104 and STAs 105 to 107 in this embodiment, which is realized, for example, by one or more processors executing programs stored in one or more memories.

[0039] The APs 102 to 104 and the STAs 105 to 107 are each composed of a MultiAP communication control unit 301 , a group identification information processing unit 302 , a BSS Color processing unit 303 , a wireless frame generation unit 304 , and a wireless frame processing unit 305 .

[0040] The Multi-AP communication control unit 301 is a functional unit that performs group formation processing for the APs 102 to 104 to perform Multi-AP communication, addition and deletion processing of participating APs, sharing processing of network information related to Multi-AP communication, and controls communication between APs. The Multi-AP communication control unit 301 also performs control for the STAs 105 to 107 to establish connections for Multi-AP communication.

[0041] The group identification information processing unit 302 is a functional unit for extracting group identification information shared after the APs 102-104 perform group formation processing for Multi-AP communication, and for managing the group identification information of wireless frames to be transmitted. The group identification information processing unit 302 is also a functional unit for managing group identification information acquired from the connected AP when the STAs 105-107 establish a connection for participating in Multi-AP communication, and for determining whether to process or discard the wireless frame based on the group identification information included in the wireless frame received from the AP in the Multi-AP communication.

[0042] The BSS Color processing unit 303 is a functional unit that sets a BSS Color associated with the BSS established by each of the APs 102 to 104. The BSS Color processing unit 303 is also a functional unit that acquires the BSS Color contained in the wireless frame received by the STAs 105 to 107, and determines whether to process or discard the received wireless frame when Multi-AP communication is not being performed.

[0043] The wireless frame generator 304 is a functional unit that generates wireless frames for wireless frame exchange when communicating with a connected STA or another AP. The APs 102 to 104 add a BSS Color to the wireless frames they generate, and add group identification information to the wireless frames they generate when performing Multi-AP communication.

[0044] The wireless frame processing unit 305 transmits wireless frames including Beacon frames and data frames generated by the wireless frame generating unit 304, and receives wireless frames from a partner device.

[0045] (Processing flow) Next, several embodiments will be described, including the flow of the processes executed by the AP / STA and sequences in the wireless communication system.

[0046] Example 1 FIG. 4 is a sequence diagram showing an example of a process in which the AP 102 operates as a Coordinator AP, and the APs 103 and 104, which are Coordinated APs, transmit data to the STA 105 in cooperation with each other.

[0047] In this process, first, among AP102 to AP104, it is determined which AP operates in the role of CoordinatorAP (and which AP operates in the role of CoordinatedAP) (S401). For example, AP102, AP103, and AP104 exchange parameters as APs and compare the parameters to determine the AP that operates as the CoordinatorAP. In this process example, it is determined that AP102 operates as the CoordinatorAP, and AP103 and AP104 operate as the CoordinatedAP. Thereafter, AP102 operating as the CoordinatorAP notifies AP103 and AP104 operating as the CoordinatedAP of network information such as group identification information, SSID, and BSSID of the multiple APs. Then, AP103 and AP104 receive the notified network information (S402). In addition, if the roles of CoordinatorAP and CoordinatedAP are determined in advance, part of the process of S401 and S402 may be omitted.

[0048] The AP 103 transmits a Beacon frame according to the notified information. The Beacon frame includes information indicating that the Multi-AP communication is possible for the connected STA. The AP here includes a logical AP, and one AP may include two logical APs, for example, an AP that operates in the 2.4 GHz band and an AP that operates in the 5 GHz band. That is, data transmission and reception by multiple APs may include data transmission and reception by one physical AP that can operate as multiple logical APs. The AP 103, for example, adds a Multi-AP Information Element to a Beacon frame and transmits the information including group identification information, SSID, BSSID, operating wireless channel, etc. of multiple APs used by multiple Coordinated APs that can operate in cooperation. The method and configuration of storing these pieces of information are not limited to this, and the AP 103 may store similar information in a similar format and transmit it. The information indicating that the Multi-AP communication is possible for the connected STA may be included in a Probe Response frame or other wireless frames. When the STA105 receives the Beacon frame, it performs a connection process with at least one of the multiple Coordinated APs based on the information included in the Beacon frame (S403). The connection process here includes processes such as authentication and association defined in the IEEE802.11 standard series. For example, the STA105 adds a Multi-AP Information Element to an Association Request frame to be transmitted, indicating a request for Multi-AP communication. The AP103 that receives the Association Request frame transmits an Association Response frame as a response. Note that the Association Response frame may include group identification information of multiple APs that perform Multi-AP communication with the connected STA. When the AP103 is in a connected state where a connection is established with the STA105, it notifies the CoordinatorAP that it has become connected to the STA together with the connection parameters (S404).At this time, when one physical AP is connected to each STA as two logical APs, it may notify the CoordinatorAP of the fact. In FIG. 4, only AP103 is connected to STA105, but AP104 may also transmit a Beacon frame to connect to STA105 and notify the CoordinatorAP (AP102) of the connection state. However, this is not limited to the above, and for example, the STA may be connected to only one of the multiple CoordinatedAPs. In this case, for example, a wireless frame transmitted from another CoordinatedAP that is not connected may be treated by the STA as a wireless frame from the connected CoordinatedAP. In addition, even if the STA is connected to only one of the multiple CoordinatedAPs, it may be possible to recognize that the CoordinatedAPs that send the wireless frames from each CoordinatedAP are different. In this embodiment, by decoding the PHY preamble of the wireless frame, it is possible to recognize that signals are being transmitted from multiple Coordinated APs (that a Multi-AP Coordination system is being configured) based on the group identification information of the multiple APs.

[0049] The CoordinatorAP manages the connection parameters of the CoordinatedAP that is connected to the STA, and determines transmission parameters based on the information, and allocates the subsequent transmission data. The information of the transmission parameters determined by the CoordinatorAP is notified to the CoordinatedAP, and the AP103 and AP104 set their own transmission parameters based on the notified information (S405). The connection parameters may include information on the transmission rate and error rate of each connection. For example, the CoordinatorAP may allocate a lot of transmission data to a CoordinatedAP having a connection with a high transmission rate, and allocate a small amount of transmission data to a CoordinatedAP having a connection with a low transmission rate. This allows data transmission from each CoordinatedAP to the STA to be performed efficiently. The connection parameters may be updated by each CoordinatedAP at regular intervals to reflect the current connection status, and may be notified to the CoordinatorAP. After that, when the CoordinatedAP receives transmission data from the CoordinatorAP to the STA (S410), it transmits the data to the STA (S412). At this time, the PHY preamble of the wireless frame of the data transmitted by each of AP103 and AP104 contains the group identification information of the multiple APs set to the same value. STA105 compares the group identification information of the multiple APs for performing Multi-AP communication for STA105 acquired from AP103 with which the connection was established with the group identification information of the multiple APs contained in the PHY preamble of the wireless frame received in S412, and processes the received wireless frame if they match, and discards the received wireless frame if they do not match. Therefore, even if the BSS Color value of the wireless frame received from AP104 is different from the BSS Color value of AP103, the wireless frame received from AP104 at STA105 is processed without being discarded.

[0050] Such parallel transmission of data from multiple CoordinatedAPs to one STA can be performed, for example, by transmitting a trigger frame for triggering transmission from the CoordinatedAP to the CoordinatedAP after the CoordinatorAP notifies the CoordinatedAP of data to be transmitted. That is, the CoordinatedAP transmits data to the STAs all at once based on receiving a trigger frame from the CoordinatedAP when the data to be transmitted is ready. When the CoordinatedAP transmits data to the CoordinatedAP, information instructing the transmission timing of the data may be notified to the CoordinatedAP together with the data to be transmitted. In this case, multiple CoordinatedAPs can transmit data to the STAs in parallel by transmitting the data to be transmitted at the indicated transmission timing.

[0051] On the other hand, when the CoordinatedAP receives data from the STA, it transmits the received data to the CoordinatorAP. Note that the order of data transmission and reception is only an example, and data may be transmitted and received in a manner other than that shown in the figure, such as receiving data from the STA before transmitting data to the STA.

[0052] (Radio frame structure) FIG. 5 shows an example of a PPDU (Physical Layer (PHY) Protocol Data Unit) defined in the IEEE 802.11 UHR standard that is transmitted in the present invention.

[0053] The UHR PPDU includes the fields of a Short Training Field (STF), a Long Training Field (LTF), and a Signal Field (SIG). As shown in FIG. 5, the head of the PPDU includes an L (Legacy)-STF 501, an L-LTF 502, and an L-SIG 503 for ensuring backward compatibility with the IEEE802.11a / b / g / n / ax standards. The L-LTF is placed immediately after the L-STF, and the LSIG is placed immediately after the L-LTF. The configuration of FIG. 5 further includes an RL-SIG (Repeated L-SIG, RL-SIG 504) placed immediately after the L-SIG. In the RL-SIG, the contents of the L-SIG are repeatedly transmitted. The RL-SIG allows the receiver to recognize that the PPDU is compliant with the IEEE802.11ax standard or later, and may be omitted in the IEEE802.11UHR in some cases. Also, instead of the RL-SIG, a field may be provided to enable the receiver to recognize that the PPDU is an IEEE802.11UHR PPDU. The fields of the PPDU do not necessarily have to be arranged in the order shown in Fig. 5, and may include new fields not shown in Fig. 5.

[0054] L-STF501 is used for detecting PHY frame signals, automatic gain control (AGC) and timing detection. L-LTF502 is used for highly accurate frequency and time synchronization and for acquiring channel state information (CSI). L-SIG503 is used to transmit control information including data transmission rate and PHY frame length information. Legacy devices that comply with the IEEE802.11a / b / g / n / ax / be standards can decode the various legacy fields listed above.

[0055] The UHR PPDU further includes a U-SIG (Universal SIG, U-SIG505) field that is located immediately after the RL-SIG and contains information common to IEEE802.11be and later standards.

[0056] The UHR PPDU further includes a UHR-SIG (UHR-SIG 506) for transmitting control information for the UHR. Each PPDU also has an STF for the UHR (UHR-STF 507) and an LTF for the UHR (UHR-LTF 508). Each PPDU has a data field 509 and a packet extention field 510 after these control fields. The fields from the L-STF to the UHR-LTF of the UHR PPDU are called the PHY preamble.

[0057] 5 shows an example of a PPDU that can ensure backward compatibility, but when backward compatibility does not need to be ensured, for example, the legacy field may be omitted. In this case, for example, UHR-STF and UHR-LTF are used instead of L-STF and L-LTF to establish synchronization. In this case, the UHR-STF after the UHR-SIG and one of the multiple UHR-LTFs may be omitted.

[0058] The U-SIG 506 included in the UHR PPDU includes U-SIG1 and U-SIG2 required for receiving the PPDU, as shown in Table 1 below.

[0059] [Table 1]

[0060] In Table 1, the group identification information of multiple APs is indicated in the Multi-AP Group ID field of B20-B22. In this case, by setting all the bits of the Multi-AP Group ID field to 1, it is possible to indicate that the Multi-AP communication is not performed, and the group identification information may be indicated by other values. In this embodiment, 3 bits are used in the Multi-AP Group ID field, but the number of bits less than 3 bits or the number of bits more than 3 bits may be used. The Multi-AP Group ID field is determined when determining the roles between multiple APs, and is shared as network information between multiple APs. Each AP performing the Multi-AP communication transmits a wireless frame including a PHY preamble in which the value of the Multi-AP Group ID field is set to the same value. In this embodiment, the Multi-AP Group ID field is provided in U-SIG1, but it may be provided in another SIG, such as U-SIG2 or UHR-SIG.

[0061] Next, the flow of the process executed by the AP and the STA as described above will be explained with reference to FIG. 6 and FIG.

[0062] 6 is a flow chart showing an example of processing executed in an AP. This processing is executed when an AP transmits a wireless frame. In S601, the AP determines whether the wireless frame to be transmitted is a wireless frame for multi-AP communication, and if it is a wireless frame for multi-AP communication, in S602, it sets group identification information of the multiple APs in a predetermined field of the PHY preamble of the wireless frame, and transmits the wireless frame in S603. The group identification information of the multiple APs is determined when roles are determined between the multiple APs, and is shared as network information between the multiple APs. If the wireless frame to be transmitted by the AP is not a wireless frame for multi-AP communication, the AP does not set group identification information of the multiple APs in a predetermined field of the PHY preamble of the wireless frame, or sets information indicating that the group identification information of the multiple APs is not included in the predetermined field of the PHY preamble, and transmits the wireless frame in S603.

[0063] FIG. 7 is a flow chart showing an example of a process executed by the STA. This process is executed when the STA receives a wireless frame from an external source. The STA determines whether or not group identification information of multiple APs is included from a predetermined field of the PHY preamble of the wireless frame received in S701. If the group identification information of multiple APs is not included, the STA determines that multi-AP communication is not being performed, and checks the value of the BSS Color field of the wireless frame in S702. If the value matches the BSS Color of the AP to which the STA is connected, the STA decodes the data field of the wireless frame in S704 and performs processing according to the contents of the data field, and if the value does not match the BSS Color of the AP to which the STA is connected, the STA discards the wireless frame in S703. If the group identification information of multiple APs is included in the wireless frame received in S701, the STA determines that multi-AP communication is being performed, and determines whether the group identification information of multiple APs acquired in S705 matches the group identification information of multiple APs received from the AP to which the STA is connected (S706). The group identification information of the multiple APs obtained from the AP to which the connection is made may be obtained from an information element included in a Beacon frame, a Probe Response frame, an Association Response frame, or other management frames, or may be obtained from information included in a PHY preamble included in other wireless frames. For example, it may be obtained from information included in a PHY preamble of a data frame, not a management frame. If the group identification information of the multiple APs for the STA notified by the AP to which the connection is made matches, the STA decodes the data field of the wireless frame received in S707 and performs processing according to the contents of the data field. If the group identification information of the multiple APs for the STA to which the connection is made does not match, the STA discards the wireless frame in S703. For example, when the STA105 receives group identification information for Multi-AP communication for STA106 and STA107, the group identification information is different from the group identification information received from the AP to which the connection is made, so the STA discards the wireless frame.

[0064] As described above, in the wireless frame structure of the PPDU (UHR PPDU) used in the IEEE802.11 UHR standard, the AP transmitting data can transmit group identification information of multiple APs when performing Multi-AP communication to the STA. In this way, the communication device can recognize group identification information for multiple other communication devices to transmit in cooperation. As a result, the STA can compare the group identification information of multiple APs notified by the AP to which the STA has established a connection and determine whether to process or discard the received wireless frame. As a result, for example, when performing Multi-AP communication, even if the BSS Color of the received wireless frame differs from the BSS Color of the AP to which the STA is connected, the wireless frame can be appropriately processed without being discarded. Also, when a wireless frame that does not perform Multi-AP communication is received as in the standards before IEEE802.11be, the wireless frame can be appropriately processed based on the BSS Color.

[0065] In addition to the APs 102 to 104 and the STAs 105 to 107 which are communication devices, the present invention can also be implemented by an information processing device (for example, a wireless chip) that generates the above-mentioned PHY preamble.

[0066] Example 2 In the second embodiment, an example will be shown in which a different format is used for the U-SIG field included in the UHR PPDU.

[0067] The U-SIG field included in the UHR PPDU includes U-SIG1 and U-SIG2 required for receiving the PPDU, as shown in Table 2 below.

[0068] [Table 2]

[0069] In Table 2, the Non Partial Multi-AP Group ID field of B20 indicates whether or not a part of the BSS Color field of B7-B12 is used as group identification information for multiple APs. When the value of Non Partial Multi-AP Group ID is 0, B7-B9 in the BSS Color field are used as group identification information for multiple APs, and B10-B12 are used to identify the BSS. For example, since AP103 and AP104 belong to the same group, B7-B9 in the BSS Color field of the UHT-SIG-A of the UHR PPDU transmitted by AP103 and AP104 are set to the same value, but B10-B12 are set to different values. When the value of Non Partial Multi-AP Group ID is 1, group identification information for multiple APs is not included in part of the BSS Color field, indicating that multi-AP communication is not performed. In this embodiment, the Non Partial Multi-AP Group ID field is provided in U-SIG1, but it may be provided in other SIGs such as U-SIG2 or UHR-SIG.

[0070] Example 3 In the third embodiment, an example will be shown in which yet another format is used for the U-SIG field included in the UHR PPDU.

[0071] The U-SIG field included in the UHR PPDU includes U-SIG1 and U-SIG2 required for receiving the PPDU, as shown in Table 3 below.

[0072] [Table 3]

[0073] In Table 3, as in Table 2, the Non Partial Multi-AP Group ID field B20 indicates whether or not part of the BSS Color field B7-B12 is used as group identification information for multiple APs. When the value of Non Partial Multi-AP Group ID is 0, B7-B9 in the BSS Color field are used as group identification information for multiple APs, and B10-B12 are used to identify the BSS. For example, since AP103 and AP104 belong to the same group, B7-B9 in the BSS Color field of the UHT-SIG-A of the UHR PPDU transmitted by AP103 and AP104 are set to the same value, but B10-B12 are set to different values. When the value of Non Partial Multi-AP Group ID is 1, it indicates that part of the BSS Color field does not include group identification information for multiple APs, and the Multi-AP Group ID field B21-B23 indicates group identification information for multiple APs. At this time, all bits in the Multi-AP Group ID field may be set to 1 to indicate that Multi-AP communication is not performed, and other values ​​may be used to indicate group identification information. In this embodiment, 3 bits are used in the Multi-AP Group ID field, but the number of bits may be less than or more than 3. In this embodiment, the Non Partial Multi-AP Group ID field and the Multi-AP Group ID field are provided in U-SIG1, but they may be provided in other SIGs, such as U-SIG2 or UHR-SIG.

[0074] (Other embodiments) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0075] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0076] 102 AP (Coordinator AP) 103, 104 AP (Coordinated AP) 105-107 STA, 301: Multi-AP communication control unit 302 Group Identification Information Processing Unit 303 BSS Color processing section 304 Wireless frame generation unit 305 Wireless frame processing unit

Claims

1. A communication device for communicating with an access point, Receiving means for receiving a radio frame, the U-SIG1 included in the U-SIG field of the PHY preamble includes a first field indicating a BSS Color for identifying a Basic Service Set (BSS), and a second field indicating identification information for identifying a group of Multi-AP cooperation. A communication device characterized by having the following features.

2. The wireless frame is discarded if the identification information indicated by the second field is different from the identification information of the group to which the communication device belongs, and the wireless frame is further processed if the identification information indicated by the second field matches the identification information of the group to which the communication device belongs, even if the BSS Color indicated by the first field is different from the BSS Color of the BSS to which the communication device belongs. The communication device according to feature 1.

3. The communication device according to claim 1, characterized in that the wireless frame is a wireless frame compliant with the IEEE 802.11 standard.

4. An access point device that forms a group with other access point devices and communicates with a station device, A transmission means for transmitting a radio frame to the station device, the U-SIG1 included in the U-SIG field of the PHY preamble, which includes a first field indicating a BSS Color for identifying a Basic Service Set (BSS), and a second field indicating identification information for identifying a group of Multi-AP cooperation. An access point device characterized by having the following features.

5. A communication method performed by a communication device that communicates with an access point, A receiving step of receiving a radio frame in which the U-SIG1 included in the U-SIG field of the PHY preamble includes a first field indicating a BSS Color for identifying a Basic Service Set (BSS), and a second field indicating identification information for identifying a group of Multi-AP cooperation. A communication method characterized by having the following features.

6. A communication method performed by an access point device that forms a group with other access point devices and communicates with a station device, A transmission step of transmitting a radio frame to the station device, the U-SIG1 included in the U-SIG field of the PHY preamble, which includes a first field indicating a BSS Color for identifying a Basic Service Set (BSS), and a second field indicating identification information for identifying a group of Multi-AP cooperation. A communication method characterized by having the following features.

7. A program for operating a computer as a communication device according to any one of claims 1 to 4.

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