Communication device and control method for the same

Abstract

To make it possible to change a data transmission mode even while data transmission is in progress.SOLUTION: A communication device for performing wireless communication has notification means for notifying an opposing communication device of mode information regarding a data transmission mode used for communication with the opposing communication device. The notification means notifies the opposing communication device of the mode information after a setup process for multilink communication between the communication device and the opposing communication device is completed and before the multilink communication is cut off.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a control technology for data transmission modes in wireless communication.

Background Art

[0002] As a WLAN communication standard established by IEEE (Institute of Electrical and Electronics Engineers), the IEEE 802.11 series standards are known. Note that WLAN is an abbreviation for Wireless Local Area Network. For example, the currently utilized latest standard, the IEEE 802.11ax standard (hereinafter referred to as 11ax), has been established. In 11ax, by using orthogonal frequency division multiple access (OFDMA), in addition to a high peak throughput of up to 9.6 gigabits per second (Gbps), it enables the improvement of communication speed under congested situations (Patent Document 1). Furthermore, for further improvement of throughput and improvement of frequency utilization efficiency, the formulation of the IEEE 802.11be standard (hereinafter referred to as the 11be standard) is being considered. In the 11be standard, the standardization of multi-link communication in which one access point (AP) constructs a plurality of wireless links with one station (STA) is being considered.

[0003] In multi-link communication, the AP is called AP_MLD (Multi-Link Device), and the STA is called Non-AP_MLD. In the 11be standard characterized by this multi-link, a plurality of data transmission modes are defined in the data communication between MLDs composed of a plurality of APs / STAs.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] However, while 11be specifies how to set the data transmission mode when establishing a wireless link, it does not specify how to change the mode while data transmission is in progress after association. Therefore, if you want to switch to a different data transmission mode, you need to reconnect the wireless link and reset the data transmission mode. In other words, it is not possible to quickly change the data transmission mode while data transmission is in progress.

[0006] This invention has been made in view of these problems, and aims to provide a technology that allows the data transmission mode to be changed even while data transmission is in progress. [Means for solving the problem]

[0007] To solve the above-mentioned problems, the communication device according to the present invention has the following configuration. That is, the communication device that performs wireless communication is It has a notification means for notifying the opposing communication device of mode information regarding the data transmission mode used for communication with the opposing communication device, The notification means notifies the opposing communication device of the mode information after the setup process for multilink communication between the communication device and the opposing communication device is completed and before the multilink communication is disconnected. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a technology that allows the data transmission mode to be changed even while data transmission is in progress. [Brief explanation of the drawing]

[0009] [Figure 1] This diagram shows the network configuration. [Figure 2] This is a diagram showing the hardware configuration of the communication device. [Figure 3]This is a diagram showing the functional configuration of a communication device. [Figure 4] This is a flowchart showing the processing on the Initiator side. [Figure 5] This is a flowchart showing the processing on the Respondor side. [Figure 6] This is a diagram showing an example of the MAC frame format. [Figure 7] This is a diagram showing an example of the HT Control field. [Figure 8] This is a diagram showing an example of the A-Control field. [Figure 9] This is a diagram showing an example of the Control List field. [Figure 10] This is a diagram showing an example of the OM Control Information subfield. [Figure 11] This is a diagram showing an example of the EHT_OM Control subfield. [Figure 12] This is a diagram explaining the method of specifying the number of received streams. [Figure 13] This is a diagram explaining the method of specifying the number of transmitted streams. [Figure 14] This is a diagram showing an example of using the reserved area of the EHT_OM Control field. [Figure 15] This is a diagram showing an example of the EHT_OM Control field and the unused area. [Figure 16] This is a diagram showing an example of using the reserved area and the unused area of the EHT_OM Control field. [Figure 17] This is a diagram explaining the frame exchange in the STR mode. [Figure 18] This is a diagram explaining the frame exchange in the EMLSR mode. [Figure 19] This is a diagram explaining the frame exchange in the EMLMR mode only on the DL side.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential for the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and redundant explanations are omitted.

[0011] (First Embodiment) As a first embodiment of the communication device according to the present invention, a communication device 102 that operates as an access point (AP) of a wireless LAN will be described below as an example.

[0012] <Device Configuration and Network Configuration> FIG. 1 is a diagram showing the configuration of a network including the communication device 102. As described above, the communication device 102 operates as an AP having a role of constructing the network 101. Also, the communication device 103 operates as a station (STA) having a role of participating in the network 101 and operates as a counter communication device regarding the communication device 102. Note that the network 101 is a wireless network. In FIG. 1, a network composed of one AP and one STA is shown, but the number of APs and STAs is not limited to this.

[0013] In this embodiment, when the communication device 102 constructs a plurality of networks, it is assumed that the BSSIDs of all the networks are the same. Note that BSSID is an abbreviation for Basic Service Set Identifier and is an identifier for identifying a network. Also, it is assumed that the SSIDs indicated by the communication device 102 in each network are also all common. Note that SSID is an abbreviation for Service Set Identifier and is an identifier for identifying an access point. In this embodiment, the communication device 102 uses one SSID even when establishing a plurality of connections.

[0014] Communication devices 102 and 103 are compliant with the 11be standard (also known as the EHT standard) and can perform wireless communication compliant with the 11be standard via network 101. EHT stands for Extremely High Throughput. Each communication device can communicate in the 2.4GHz, 5GHz, and 6GHz frequency bands. The frequency band used by each communication device is not limited to these, and different frequency bands, such as the 60GHz band, may be used. In addition, each communication device can communicate using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, and 320MHz.

[0015] Communication devices 102 and 103 can implement multi-user (MU) communication by multiplexing signals from multiple users by performing orthogonal frequency division multiple access (OFDMA) communication compliant with the 11be standard. In OFDMA communication, one or more resource units (RUs) are assigned to each STA so as not to overlap, and the carrier waves assigned to each STA are configured to be orthogonal. Therefore, an AP can communicate with multiple STAs in parallel.

[0016] Furthermore, communication devices 102 and 103 perform multilink communication by establishing links and communicating via multiple frequency channels. Here, frequency channels refer to frequency channels defined in the IEEE 802.11 series standards. The IEEE 802.11 series standards define multiple frequency channels in each frequency band: the 2.4 GHz band, the 5 GHz band, and the 6 GHz band. In addition, the IEEE 802.11 series standards define the bandwidth of each frequency channel as 20 MHz. However, by channel bonding with adjacent frequency channels, it is possible to utilize a bandwidth of 40 MHz or more in a single frequency channel.

[0017] For example, communication device 102 can establish a first link 104 via a first frequency channel in the 2.4GHz band and a second link 105 via a second frequency channel in the 5GHz band with communication device 103, and communicate via both links. In this case, communication device 102 maintains the second link 105 via the second frequency channel in parallel with the first link 104 via the first frequency channel. In this way, communication device 102 can improve the throughput of communication with communication device 103 by establishing links via multiple frequency channels with communication device 103.

[0018] Furthermore, communication devices 102 and 103 may establish multiple links in different frequency bands in multilink communication. For example, communication devices 102 and 103 may establish a first link 104 in the 2.4GHz band, a second link 105 in the 5GHz band, and a third link 106 in the 6GHz band. Alternatively, links may be established via multiple different channels included in the same frequency band. For example, a first link 104 may be established via channel 1 in the 2.4GHz band, and a second link 105 may be established via channel 5 in the 2.4GHz band. Moreover, links with the same frequency band and links with different frequency bands may be mixed. For example, communication devices 102 and 103 may establish a first link 104 via channel 1 in the 2.4GHz band, a second link 105 via channel 5 in the 2.4GHz band, and a third link 106 via channel 36 in the 5GHz band. By establishing multiple connections with communication device 103 in different frequency bands, communication device 102 can communicate with communication device 103 on other bands even when one band is congested, thereby preventing a decrease in throughput during communication with communication device 103.

[0019] In multilink communication, the multiple links established by communication devices 102 and 103 only need to have at least different frequency channels. Furthermore, in multilink communication, the channel spacing between the frequency channels of the multiple links established by communication devices 102 and 103 only needs to be greater than 20 MHz. In this embodiment, communication devices 102 and 103 establish a first link 104 and a second link 105, but they may establish three or more links.

[0020] When performing multilink communication, communication devices 102 and 103 divide a single piece of data and transmit it to the other device via multiple links. Alternatively, communication devices 102 and 103 may transmit the same data via each of the multiple links, so that communication via one link serves as a backup for communication via the other link. Specifically, suppose communication device 102 transmits the same data to communication device 103 via a first link via a first frequency channel and a second link via a second frequency channel. In this case, even if an error occurs in communication via the first link, for example, communication device 103 can receive the data transmitted from communication device 102 because the same data is being transmitted via the second link. Alternatively, communication devices 102 and 103 may use different links depending on the type of frame or data being communicated. For example, communication device 102 may transmit management frames via the first link and data frames containing data via the second link.

[0021] Specifically, the management framework refers to the Beacon framework, the Probe_Request framework / Response framework, and the Association_Request framework / Response framework. In addition to these frameworks, the Disassociation framework, Authentication framework, De-Authentication framework, and Action framework are also referred to as management frameworks.

[0022] A Beacon frame is a frame that broadcasts network information. A Probe_Request frame is a frame that requests network information, and a Probe_Response frame is the response, providing the network information. An Association_Request frame is a frame that requests a connection, and an Association_Response frame is the response, indicating whether the connection is approved or an error occurs.

[0023] A Disassociation frame is a frame that disconnects a connection. An Authentication frame is a frame that authenticates the other device, and a De-Authentication frame is a frame that interrupts the authentication of the other device and disconnects the connection.

[0024] An Action frame is a frame used to perform additional functions other than those described above. Communication devices 102 and 103 send and receive management frames compliant with the IEEE 802.11 series standard. Alternatively, when communication device 102 transmits data related to an captured image, for example, metadata such as the date, parameters at the time of capture (aperture value and shutter speed), and location information may be transmitted via the first link, and pixel information may be transmitted via the second link.

[0025] Furthermore, communication devices 102 and 103 may perform MIMO (Multiple-Input And Multiple-Output) communication. In this case, communication devices 102 and 103 have multiple antennas, and one of them sends different signals from each antenna using the same frequency channel. The receiving side simultaneously receives all signals arriving from multiple streams using multiple antennas, separates the signals from each stream, and decodes them. By performing MIMO communication in this way, communication devices 102 and 103 can communicate more data in the same amount of time compared to when MIMO communication is not performed. In addition, when performing multilink communication, communication devices 102 and 103 may perform MIMO communication on some links.

[0026] Although communication devices 102 and 103 are stated to be compliant with the 11be standard, they may also be compliant with at least one of the standards prior to the 11be standard (IEEE 802.11a / b / g / n / ac / ax). In addition to the IEEE 802.11 series standards, they may also be compliant with other communication standards such as Bluetooth®, NFC, UWB, Zigbee, and MBOA. UWB stands for Ultra Wide Band, MBOA stands for Multi Band OFDM Alliance, OFDM stands for Orthogonal Frequency Division Multiplexing, and NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, Winet, etc. They may also be compliant with wired communication standards such as wired LAN.

[0027] Specific examples of the communication device 102 include, but are not limited to, wireless LAN routers and PCs. The communication device 102 can be any communication device capable of performing multilink communication with other communication devices. Alternatively, the communication device 102 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with the 11be standard. Note that the information processing device such as a wireless chip has an antenna for transmitting the generated signals.

[0028] Specific examples of the communication device 103 include, but are not limited to, cameras, tablets, smartphones, PCs, mobile phones, and video cameras. The communication device 103 can be any communication device capable of performing multilink communication with other communication devices. Alternatively, the communication device 103 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with the 11be standard.

[0029] Figure 2 shows the hardware configuration of the communication device 102. The communication device 102 includes 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. The communication device 103 has the same hardware configuration as the communication device 102.

[0030] The memory unit 201 is composed of one or more memories such as ROM and RAM, and stores various information such as computer programs for performing various operations described later, and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. In addition to memories such as ROM and RAM, the memory unit 201 may also use 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. Furthermore, the memory unit 201 may have multiple memories.

[0031] The control unit 202 is composed of one or more processors, such as a CPU and an MPU, and controls the entire communication device 102 by executing a computer program stored in the memory unit 201. The control unit 202 may also control the entire communication device 102 in cooperation with the computer program stored in the memory unit 201 and the operating system (OS). Furthermore, the control unit 202 generates data and signals (wireless frames) to be transmitted in communication with other communication devices. Note that CPU stands for Central Processing Unit, and MPU stands for Micro Processing Unit. Alternatively, the control unit 202 may have multiple processors, such as a multi-core processor, and control the entire communication device 102 using multiple processors.

[0032] Furthermore, the control unit 202 controls the functional unit 203 to perform predetermined processes such as wireless communication, imaging, printing, and projection. The functional unit 203 is the hardware that enables the communication device 102 to perform predetermined processes.

[0033] The input unit 204 receives various operations from the user. The output unit 205 provides various outputs to the user via a monitor screen or speaker. Here, the output from the output unit 205 may be a display on the monitor screen, audio output via a speaker, vibration output, etc. The input unit 204 and the output unit 205 may be implemented in a single module, such as a touch panel. The input unit 204 and the output unit 205 may be integrated with the communication device 102, or they may be separate units.

[0034] The communication unit 206 controls wireless communication compliant with the 11be standard. In addition to the 11be standard, the communication unit 206 may also control wireless communication compliant with other IEEE 802.11 series standards, or wired communication such as wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. If the communication device 102 supports the NFC standard, Bluetooth standard, etc., in addition to the 11be standard, it may also control wireless communication compliant with these communication standards. Furthermore, if the communication device 102 can perform wireless communication compliant with multiple communication standards, it may be configured to have separate communication units and antennas corresponding to each communication standard. The communication device 102 communicates data such as image data, document data, and video data with the communication device 103 via the communication unit 206. The antenna 207 may be configured separately from the communication unit 206, or it may be configured as a single module together with the communication unit 206.

[0035] Antenna 207 is an antenna capable of communication in the 2.4GHz, 5GHz, and 6GHz bands. In this embodiment, the communication device 102 is assumed to have one antenna, but it may have different antennas for each frequency band. Also, if the communication device 102 has multiple antennas, it may have a communication unit 206 corresponding to each antenna.

[0036] Figure 3 shows the functional configuration of the communication device 102. The communication device 102 consists of a link connection unit 301, a MAC frame generation unit 302, a data transmission / reception unit 303, a data transmission mode determination unit 304, a data transmission mode setting unit 305, and a communication application 306. The functional configuration of the communication device 103 is similar.

[0037] The link connection section 301 is a block that performs connection processing to establish one or more links for data communication between the communication device 102 and the communication device 103. Specifically, the connection processing consists of Authentication processing, Association processing, and 4-Way-Hand-Shake (4WHS) processing. Upon completion of the 4WHS processing, a PTK, which is the encryption key for unicast communication, and a GTK, which is the encryption key for broadcast / multicast communication, are generated in the communication device 102 and the communication device 103, respectively. When connecting with the communication device 103, multiple links may be connected in advance, or another link may be connected later while communication is in progress on a predetermined link.

[0038] The communication application 306 determines and selects the data transmission mode according to the characteristics of the application being used. If it is necessary to switch the current transmission mode, it requests the data transmission mode determination unit 304 to switch the data transmission mode. Requests to switch the data transmission mode arise due to congestion in the frequency band used for multilink communication, changes in radio wave conditions, or power-saving operation of battery-powered communication devices. The data transmission mode determination unit 304 also selects either the initial value of the data transmission mode or the previous transmission mode when data transmission is resumed. Furthermore, while data transmission is in progress, it checks the information elements contained in the frame exchange packets with the opposing communication device to determine whether a change in the data transmission mode is required. "Data transmission in progress" means being in State 3 / 4 according to the IEEE 802.11 standard. At this time, the appropriateness of switching the data transmission mode according to the capabilities of the equipment requested by the opposing communication device may be determined. Furthermore, the data transmission mode setting unit 305, based on the results of its judgment regarding the change request described above, sets the data transmission mode to be implemented in subsequent frame exchanges, such as setting the data transmission mode to be common to both uplink (UL) and downlink (DL) or to be set individually for each. Here, UL means data transmission from STA to AP, and DL means data transmission from AP to STA.

[0039] The MAC frame generation unit 302 is a block that generates MAC frames included in various management frames such as Authentication Request and Association Request, as well as data frames. The data transmission / reception unit 303 transmits wireless frames containing MAC frames generated by the MAC frame generation unit 302 and receives wireless frames from the receiving device.

[0040] <Explanation of data transmission modes and mode selection methods> The 11be standard specifies the following data transmission modes for data communication between MLDs composed of multiple AP / STAs. • NSTR (Non-Simultaneous Transmit and Receive): A transmission mode in which transmission and reception are performed using only one of multiple wireless links. STR (Simultaneous Transmit and Receive): A transmission mode that uses multiple wireless links to transmit and receive data simultaneously. • EMLSR (Enhanced Multi-Link Single Radio): A transmission mode in which the MLD selects the optimal single frequency and uses that single frequency across multiple radio links. • ELMMR (Enhanced multi-link multi-radio): A transmission mode that concentrates multiple spatial streams onto a single wireless link.

[0041] In the current 11ax standard, one of the measures to improve throughput is the standardization of a function called OMI (Operating mode indication) to change the number of transmit and receive streams, transmit and receive bandwidth, etc., after association. This OMI is used between AP / STA via a QoS Data / QoS Null frame or Action frame that includes an OM Control Information subfield composed of data transmission information. Furthermore, in the 11be standard currently under development, it is being considered to achieve frequency bandwidth expansion and other improvements by combining the OM Control Information subfield of the 11ax standard with the 11be standard's unique EHT_OM (Extreme High Throughput Operating mode).

[0042] In the first embodiment, a portion of the EHT_OM field is further extended. Specifically, information elements are set in the reserved area 1104 and unused area 1501 of the EHT_OM field 1100, which are described below. This makes it possible to quickly switch the data transmission mode while data transmission is in progress.

[0043] Figure 6 shows an example of the MAC frame format 600. Communication devices 102 and 103 use the HT Control field 601 to notify the data transmission mode.

[0044] Figure 7 shows an example of the HT Control field 601. When notifying EHT_OM, the values ​​of Bit0 (VHT: Very High Throughput) and Bit1 (HE) of the HE (High Efficiency) Variant 701 are set to "1" each. This HE Variant 701 includes the A-Control field 702.

[0045] Figure 8 shows an example of the A-Control field 702. The A-Control field 702 includes the Control List field 801.

[0046] Figure 9 shows an example of a Control List field 801. The Control List field 801 includes a Control ID field 901 and a Control Information field 902.

[0047] Table 1 shows an example of the correspondence between the field value (4 bits) stored in the Control ID field 901 and the type of the corresponding Control Information field 902 (maximum 26 bits).

[0048] [Table 1]

[0049] In this embodiment, the Operating mode (OLM) field value "1" and the EHT Operating mode (EHT_OM) field value "7" of the Control List field 801 are used to notify the data transmission mode.

[0050] Figure 10 shows an example of the OM Control Information subfield 1000. The OM Control Information subfield includes the RxNSS subfield 1001, Channel Width subfield 1002, UL MU Disable subfield 1003, TxNSTS subfield 1004, ER SU Disable subfield 1005, DL MU MiMO Resound Recommendation subfield 1006, and UL MU Data Disable subfield 1007.

[0051] Figure 11 shows an example of the EHT_OM Control subfield. The EHT_OM Control subfield includes, from the beginning, the RxNSS Extension subfield 1101, the Channel Width Extension subfield 1102, the TxNSS Extension subfield 1103, and the Reserved subfield (reserved area) 1104.

[0052] Figure 12 illustrates how to specify the number of received streams. Specifically, it shows an example of how an Initiator can notify a Respondor of the number of received spatial streams.

[0053] The number of received spatial streams is determined using the RxNSS subfield 1001 in the OM Control Information subfield and the RxNSS Extension subfield 1101 in the EHT_OM Control subfield. Specifically, the number of spatial streams in 11be is displayed by combining the settings of each field, and the details are shown in Indication of Nss1201.

[0054] Figure 13 illustrates how to specify the number of transmission streams. Specifically, it shows an example of how an Initiator can notify a Respondor of the number of spatial transmission streams.

[0055] The number of spatial streams transmitted is determined using the TxNSS subfield 1004 of the OM Control Information subfield and the TxNSS Extension subfield 1103 within the EHT_OM Control subfield. Specifically, the number of spatial streams for 11be is displayed by combining the settings of each field, and the details are shown in Indication of Nss1301.

[0056] Figure 15 shows an example of the EHT_OM Control field and unused area. Specifically, it shows the unused area 1501 (4-bit padding) that can be expanded when the OLM and EHT_OM control subfield 1100 are used in the A-control field 702.

[0057] To notify the data transmission mode, the Operating mode (OLM) field value "1" and the EHT Operating mode (EHT_OM) field value "7" of the Control List field 801 are used. In this case, the number of unused bits in the A-control field 702, which has a maximum bit count of 30 bits, is 4 bits (=30-16-10), since 16 bits (=4+12) are used for OLM and 10 bits (=4+6) are used for EHT_OM.

[0058] Figure 16 shows an example of using multiple bits within the Reserved subfield and Padding of the EHT_OM Control field. Specifically, it uses 5 bits in the A-control field (3 bits in reserved area 1104 and 2 bits in unused area 1501). In other words, the bit sequence in reserved area 1104 is extended by adding one or more bits from unused area 1501 (4 bits). Here, we show an example where the first 2 bits (bit 6 (B6) 1601, bit 7 (B7) 1602) are used and the remaining 2 bits are configured as a reserved area.

[0059] Bit 6 (B6) 1601 indicates whether the communication device 103 supports the data transmission mode for the uplink radio link of the packet data transmitted to the communication device 102. Also, bit 7 (B7) 1602 indicates whether the communication device 102 supports the data transmission mode for the downlink radio link of the packet data transmitted to the communication device 103. As an example, when the bit fields in bits 3 (B3) to bits 7 (B7) are set to "0" "0" "1" "0" "1", it notifies that the data transmission mode for the downlink radio link is the EMLMR data transmission mode (DL-EMLMR).

[0060] <Operation of the device> Hereinafter, the processing of the communication device 102 and the communication device 103 when switching the data transmission mode from "NSTR" to "STR", "EMLSR", and "EMLMR" in the initial multi-link communication setting will be described. Specifically, after the setup process of multi-link communication is performed with the data transmission mode being NSTR between the communication devices 102 and 103, the operation when the communication device 102 operates as the Initiator and the communication device 103 operates as the Respondor will be described.

[0061] <Example of operation on the Initiator side> FIG. 4 is a flowchart showing the processing on the Initiator side. Specifically, it shows the processing of the communication device 102 that has become the side (Initiator) to initiate the change notification of the data transmission mode.

[0062] <In the case of switching to the initial value (for example, NSTR mode)> In S401, when the communication device 102 performs data transmission processing in response to a data transmission request from, for example, the communication application 306, it checks the switching state of the past data transmission mode. If it is to resume data transmission after switching the data transmission mode, it proceeds to S410.

[0063] In S410, the communication device 102 determines whether to use a given initial value (e.g., NSTR mode) set during wireless link setup as the data transmission mode when restarting. Here, it determines to use the initial value and proceeds to S411.

[0064] In S411, the communication device 102 resets the information related to the NSTR data transmission mode to predetermined information elements (first reset mode). Then, the process proceeds to S408. The predetermined information elements are the OM Control subfield 1000 and the EHT_OM Control subfield 1100, and the details of the information elements related to switching to NSTR mode are described below.

[0065] The information elements in the OM Control field 1000 are set such that RxNSS1001, which indicates the number of spatial streams received, is "0", and RxNSS Extension1101 in the EHT_OM Control subfield 1100 is set to "0". Similarly, TxNSS1004, which indicates the number of spatial streams transmitted, is "0", and TxNSS Extension1103 in the EHT_OM Control subfield 1100 is set to "0". These information elements are interpreted by the Respondor-side communication device 103 as indicating that the number of spatial streams received (Indication of Nss number 1201) is 1, and the number of spatial streams transmitted (Indication of Nss number 1301) is 1.

[0066] In S408, the communication device 102 sets the information elements of the reserved area 1104 and unused area 1501 of the EHT_OM field 1100. Specifically, as shown in Figure 16, the values ​​"0", "0", "0", "0", "0" are set in the bit field for bits 3 (B3) to 7 (B7).

[0067] In S409, the communication device 102 transmits a data packet containing a MAC frame 600 with information elements regarding the data transmission mode to the communication device 103.

[0068] <If the mode used during the previous data transmission (e.g., STR mode) is continued> In S401, the communication device 102 determines that data transmission has resumed after switching the data transmission mode and proceeds to S410.

[0069] In S410, the communication device 102 determines whether to use the initial value (e.g., NSTR mode) set during wireless link setup as the data transmission mode when restarting. Here, it determines to use the mode used during the previous data transmission (e.g., STR mode for both UL and DL) and proceeds to S412.

[0070] In S412, the communication device 102 resets the information related to the STR data transmission mode to predetermined information elements (second reset mode). Then, the process proceeds to S408. The predetermined information elements are the OM Control subfield 1000 and the EHT_OM Control subfield 1100, and the details of the information elements related to switching to STR mode are described below.

[0071] The information elements in the OM Control field 1000 are set such that RxNSS1001, which indicates the number of spatial streams received, is "0", and RxNSS Extension1101 in the EHT_OM Control subfield 1100 is set to "0". Similarly, TxNSS1004, which indicates the number of spatial streams transmitted, is "0", and TxNSS Extension1103 in the EHT_OM Control subfield 1100 is set to "0". These information elements are interpreted by the Respondor-side communication device 103 as indicating that the number of spatial streams received (Indication of Nss number 1201) is 1, and the number of spatial streams transmitted (Indication of Nss number 1301) is 1.

[0072] In S408, the communication device 102 sets the information elements of the reserved area 1104 and unused area 1501 of the EHT_OM field 1100. Specifically, as shown in Figure 16, the values ​​"1", "0", "0", "1", and "1" are set in the bit field for bits 3 (B3) to 7 (B7).

[0073] In S409, the communication device 102 transmits a data packet containing a MAC frame 600 with information elements regarding the data transmission mode to the communication device 103.

[0074] <When a new data transmission mode switch occurs> In S401, the communication device 102 determines that it has not yet performed the data transmission mode switching process (it is not data restart), and proceeds to S402.

[0075] In S402, the data transmission mode determination unit 304 of the communication device 102 checks whether there is a request from the communication application 306 to change the data transmission mode. If there is no request from the communication application 306, the process proceeds to S401. If a request to change the data transmission mode is generated, the process proceeds to S403.

[0076] In S403, the data transmission mode determination unit 304 determines the data transmission mode to be used by the communication device 102 from that point onward, based on the data transmission mode currently in operation. If a switch to NSTR is requested, the process proceeds to S407. If a switch to a data transmission mode other than NSTR is requested, the process proceeds to S404.

[0077] In S404, the data transmission mode determination unit 304 checks whether a setting change has been requested for UL / DL individually. If it is not a request for an individual UL / DL change (i.e., it is common to both UL and DL), the process proceeds to S405; if it is a request for an individual UL / DL change, the process proceeds to S406.

[0078] In S405, the data transmission mode setting unit 305 sets data transmission mode information to predetermined information elements for application to multilink communication between communication devices. Then, the process proceeds to S408. Here, we will explain the case where the EMLSR mode is set for both UL and DL in the respective subfields using the predetermined information elements OM Control subfield 1000 and EHT_OM Control subfield 1100.

[0079] The information elements in the OM Control field 1000 are set such that RxNSS1001, which indicates the number of spatial streams received, is "0", and RxNSS Extension1101 in the EHT_OM Control subfield 1100 is set to "0". Similarly, TxNSS1004, which indicates the number of spatial streams transmitted, is "0", and TxNSS Extension1103 in the EHT_OM Control subfield 1100 is set to "0". These information elements are interpreted by the Respondor-side communication device 103 as indicating that the number of spatial streams received (Indication of Nss number 1201) is 1, and the number of spatial streams transmitted (Indication of Nss number 1301) is 1.

[0080] In S406, the communication device 102, for example, if there is a request for a change on the DL side, sets ELMMR communication on the DL side as information for the data transmission mode. Then proceed to S408. The setting information for each subfield using the OM Control subfield 1000 and the EHT_OM Control subfield 1100 when changing the data transmission mode to ELMMR communication at this time will be explained in detail.

[0081] The information elements in the OM Control field 1000 are set such that RxNSS1001, which indicates the number of spatial streams received, is set to "1", and RxNSS Extension1101 in the EHT_OM Control subfield 1100 is set to "0". Similarly, TxNSS1004, which indicates the number of spatial streams transmitted, is set to "1", and TxNSS Extension1103 in the EHT_OM Control subfield 1100 is set to "0". These information elements are interpreted by the Respondor-side communication device 103 as indicating that the number of spatial streams received (Indication of Nss 1201) and the number of spatial streams transmitted (Indication of Nss 1301) are both at most 2.

[0082] In S407, the data transmission mode setting unit 305 sets NSTR communication as data transmission mode information to be applied to multiple wireless links established by communication devices 102 and 103. The specific information elements to be set are the same as in S411, so no explanation is given.

[0083] In S408, if the process has proceeded from S405, the communication device 102 sets the information elements of the reserved area 1104 and unused area 1501 of the EHT_OM field 1100. Specifically, as shown in Figure 16, the values ​​"0", "1", "0", "1", and "1" are set in the bit field for bits 3 (B3) to 7 (B7).

[0084] On the other hand, if the process proceeds from S406, the communication device 102 sets the information elements of the EHT_OM field 1100 and the subsequent extended unused area 1501. Specifically, as shown in Figure 16, the values ​​"0", "0", "1", "0", and "1" are set in the bit field for bits 3 (B3) to 7 (B7).

[0085] Regarding the specific information element settings when proceeding from S407, the explanation is omitted as it is the same as when proceeding from S411 as described above.

[0086] In S409, the communication device 102 transmits a data packet including a MAC frame 600 in which an information element regarding the data transmission mode is set, to the communication device 103.

[0087] <Operation example on the Respondor side> FIG. 5 is a flowchart showing the processing on the Respondor side. Specifically, it shows the processing of the communication device 103 which has become the side (Respondor) that receives the notification of the change in the data transmission mode. That is, it shows the processing when receiving a data packet including a MAC frame 600 in which an information element regarding the data transmission mode is set.

[0088] In S501, the communication device 103 receives a data packet from the communication device 102. In S502, the communication device 103 checks the information elements of the OM Control subfield 1000 and the EHT_OM Control subfield 1100 in the received MAC frame 600.

[0089] In S503, the data transmission mode determination unit 304 of the communication device 103 determines whether there is a change (switch) in the data transmission mode. Here, when the information elements of OM and EHT_OM are not included, it is determined that there is no change in the data transmission mode and the process proceeds to S505. On the other hand, when the information elements of OM and EHT_OM are included, it is determined that there is a request for a change in the data transmission mode and the process proceeds to S504.

[0090] In S504, the data transmission mode determination unit 304 performs a detailed check of the information element settings. Specifically, it checks whether the change request is specific to UL / DL. For example, if bits 3 (B3) to 7 (B7) of the bit information elements in the reserved area 1104 and the unused area 1501 are "1", "0", "0", "1", "1", the data transmission mode is determined to be common to UL / DL (STR mode), and the process proceeds to S507. Alternatively, if the bit information elements (bits 3 (B3) to 7 (B7)) in the reserved area 1104 and the unused area 1501 are "0", "1", "0", "1", "1", the data transmission mode is determined to be common to UL / DL (EMLSR mode), and the process proceeds to S507. On the other hand, if the bit information elements (bits 3 (B3) to 7 (B7)) of the reserved area 1104 and the unused area 1501 are "0", "0", "1", "0", "1", the data transmission mode is determined to be UL / DL individual (EMLSR mode only on the DL side), and the process proceeds to S506.

[0091] In S505, the communication device 103 continues in the current data transmission mode.

[0092] In S506, the data transmission mode setting unit 305 sets the data transmission mode used for data frame exchange with the communication device 102 to ELMMR mode only on the DL side.

[0093] In S507, the data transmission mode setting unit 305 sets the data transmission mode to be used for data frame exchange with the communication device 102. That is, it sets it to the UL / DL common mode (STR mode or EMLSR mode) determined in S503 and S504.

[0094] After any of steps S505 to S507, communication device 103 (Non-AP_MLD) performs frame exchange of data packets in the multilink established with communication device 102 (AP_MLD).

[0095] <Example of operation after switching data transmission modes> Referring to Figures 17 to 19, the communication between communication device 102 and communication device 103 after the data transmission mode switch will be explained.

[0096] Figure 17 illustrates frame exchange in STR mode. For example, it describes the communication operation after switching the data transmission mode to STR during multilink data transmission established in "NSTR" between communication device 102 and communication device 103.

[0097] Specifically, this describes the operation of simultaneously transmitting and receiving data frames on two wireless links, Link1 and Link2 (each with one spatial stream for transmission and reception).

[0098] Figure 18 illustrates frame exchange in EMLSR mode. For example, it describes the communication operation after switching the data transmission mode to EMLSR during multilink data transmission established in "NSTR" between communication device 102 and communication device 103.

[0099] Specifically, Non-AP_MLD configures 2x2 Tx / Rx modules to 1x1 each for different radio links in each channel frequency band (2.4 / 5GHz) and starts monitoring incoming packets for both channel frequency bands. Before actually transmitting data frames, AP_MLD sends a control frame (RTS or MU-RTS) on the idle channel of the pre-configured channels to indicate which channel will be used for data transmission. Upon receiving the control frame, Non-AP_MLD responds with a CTS, switches the corresponding radio link to 2x2, and AP_MLD switches one of the radio links used for frame exchange to 2x2 and transmits data following the CTS. In EMLSR communication, the above operations are repeated to select the optimal channel frequency band for frame exchange between Non-AP_MLD and AP_MLD and exchange data packets.

[0100] Figure 19 illustrates frame exchange when only the DL side is in EMLMR mode. For example, it describes the communication operation after switching the DL side's data transmission mode to EMLMR during multilink data transmission established in "NSTR" between communication device 102 and communication device 103.

[0101] Specifically, this describes a series of steps in which, after switching the data transmission mode, AP_MLD of communication device 102 transmits a data frame to Non-AP_MLD of communication device 103 in ELMMR mode on Link 1, with the spatial stream set to 2.

[0102] First, AP_MLD sends an RTS frame containing the information necessary for ELMR operation. This RTS frame initiates ELMR operation on Non-AP_MLD. Upon receiving the RTS frame, if Non-AP_MLD is able to perform ELMR operation, it sends a CTS frame in response to the RTS frame, notifying AP that it is able to receive a data frame with spatial stream 2.

[0103] Furthermore, Non-AP_MLD moves the receiving function from Link2 to Link1, setting the spatial stream count for Link1 to 2 and the spatial stream count for Link2 to 0. After Link1 has finished transmitting CTS frames, Non-AP_MLD starts transmitting with a spatial stream count of 2, so the transfer (switching) of the receiving function is completed by then.

[0104] AP_MLD, after receiving the CTS frame, transmits a data frame with a spatial stream count of 2. Non-AP_MLD, after completing the reception of the data frame with a spatial stream count of 2, returns the receiving functions concentrated on Link1 to Link2. As a result, Non-AP_MLD returns to the state it was in before the frame exchange sequence began.

[0105] As described above, according to the first embodiment, information elements are set in the reserved area 1104 and the unused area 1501 of the EHT_OM field 1100. This makes it possible to quickly switch the data transmission mode without performing a reconnection process, even when data transmission is in progress.

[0106] For example, if the efficiency of frequency band usage deteriorates while using the STR or EMLSR data transmission mode, and you want to expand to another frequency band, you can switch to EMLMR without performing a reconnection process. Also, if the efficiency of usage of one frequency band deteriorates while using the EMLMR data transmission mode and you want to reduce the frequency band used, you can switch to STR or EMLSR without performing a reconnection process.

[0107] The above description explained the switching of data transmission modes from NSTR to STR / EMSMR / EMSMR. However, the order and mode types can be set arbitrarily. Also, in the above description, the communication device 102 operating as AP was described as the Initiator and the communication device 103 operating as STA was described as the Respondor, but the order can also be reversed.

[0108] (modified version) In the first embodiment described above, a change in the data transmission mode was notified by setting information elements in the reserved area 1104 and the unused area 1501 (Figure 16). However, a change in the data transmission mode may also be notified by setting information elements in other fields.

[0109] Figure 14 shows an example where only the reserved area 1104 of the EHT_OM Control field is used. The reserved area 1104 consists of 3 bits, and the bits from the first bit indicate the data transmission mode of STR1401, EMLSR1402, and EMLMR1403. For example, if bits 3 (B3) to 5 (B5) are set to "0", "1", and "0" in the bit field, it indicates that the data transmission mode is EMLSR for a bidirectional wireless link, and if all bits are "0", it indicates NSTR. In other words, in this modified example, by using a common data transmission mode for UL / DL, only the 3 bits from 3 (B3) to 5 (B5) are sufficient. This eliminates the need to use bits in the unused area 1501, making it possible to use the unused area 1501 for other purposes.

[0110] The disclosures herein include the following communication devices, control methods, and programs. (Item 1) A communication device that performs wireless communication, It has a notification means for notifying the opposing communication device of mode information regarding the data transmission mode used for communication with the opposing communication device, The notification means notifies the opposing communication device of the mode information after the setup process for multilink communication between the communication device and the opposing communication device is completed and before the multilink communication is disconnected. A communication device characterized by the following features. (Item 2) The aforementioned communication device and the aforementioned opposing communication device perform wireless communication in accordance with the IEEE 802.11 series standard. The notification means sets the mode information as multiple bits in the A-control field included in the HT Control field of the MAC frame. A communication device as described in item 1, characterized by the features described herein. (Item 3) The aforementioned multiple bits include the three bits in the Reserved subfield within the EHT_OM Control subfield included in the A-Control field. A communication device as described in item 2, characterized by the features described herein. (Item 4) The aforementioned multiple bits further include one or more bits in the unused area of ​​the EHT_OM Control subfield included in the A-Control field. A communication device as described in item 3, characterized by the features described herein. (Item 5) The aforementioned mode information includes information regarding one of the data transmission modes specified in the IEEE 802.11be standard: NSTR, STR, EMLSR, or EMLMR. A communication device as described in any one of items 2 to 4, characterized by the above. (Item 6) The mode information includes information regarding the data transmission mode for the uplink and downlink, respectively. A communication device as described in item 5, characterized by the features described herein. (Item 7) The aforementioned communication device is The system further includes a resetting means for resetting the data transmission mode when resuming data transmission after an interruption. The resetting means includes a first resetting mode for resetting the data transmission mode based on a given initial value, and a second resetting mode for resetting the data transmission mode that was in use before the interruption. A communication device according to any one of items 1 to 6, characterized by the above. (Item 8) The notification means notifies the opposing communication device of the mode information when a request for a change in the data transmission mode used for communication with the opposing communication device occurs. A communication device according to any one of items 1 to 7, characterized by the above. (Item 9) The aforementioned change request arises due to changes in the congestion status of the frequency band used for the multilink communication, changes in radio wave conditions, and / or power-saving operation of the communication device. A communication device as described in item 8, characterized by the features described above. (Item 10) A method for controlling a communication device that performs wireless communication, Processing means for performing the setup process for multilink communication with the opposing communication device, After the setup process by the processing means is completed and before the multilink communication is disconnected, a notification step is made to notify the opposing communication device of mode information relating to the data transmission mode used for communication with the opposing communication device, A control method characterized by including (Item 11) A program to cause a computer having a communication unit that performs wireless communication to function as a communication device as described in any one of items 1 through 9.

[0111] (Other examples) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0112] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of symbols]

[0113] 101 Network; 102 Communication equipment; 103 Communication equipment; 104 First link; 105 Second link; 106 Third link

Claims

1. A communication device for wireless communication, a notification means for notifying the opposite communication device of mode information relating to a data transmission mode used in communication with the opposite communication device, The notifying means notifies the opposite communication device of the mode information after completing a setup process of multilink communication between the communication device and the opposite communication device and before the multilink communication is disconnected. A communication device comprising:

2. the communication device and the opposite communication device perform wireless communication in accordance with the IEEE 802.11 series standard; The notification means sets the mode information as multiple bits in an A-control field included in an HT Control field of a MAC frame.

2. The communication device according to claim 1.

3. The multiple bits include three bits in a Reserved subfield in an EHT_OM Control subfield included in the A-Control field.

3. The communication device according to claim 2.

4. The plurality of bits further includes one or more bits in an unused area of ​​an EHT_OM Control subfield included in the A-Control field.

4. The communication device according to claim 3.

5. The mode information includes information about one of the data transmission modes NSTR, STR, EMLSR, and EMLMR defined in the IEEE 802.11be standard.

3. The communication device according to claim 2.

6. The mode information includes information about a data transmission mode in each of the uplink and the downlink.

6. The communication device according to claim 5.

7. The communication device The data transmission device further includes a resetting means for resetting a data transmission mode when the data transmission is resumed after being interrupted, The resetting means includes a first resetting mode for resetting the data transmission mode based on a given initial value, and a second resetting mode for resetting the data transmission mode used before the interruption.

2. The communication device according to claim 1.

8. The notifying means notifies the opposite communication device of the mode information when a request to change the data transmission mode used for communication with the opposite communication device occurs.

2. The communication device according to claim 1.

9. The change request occurs due to a change in the congestion status of the frequency band used in the multi-link communication, a change in radio wave conditions, and / or a power saving operation of the communication device.

9. The communication device according to claim 8.

10. A control method for a communication device that performs wireless communication, comprising: a processing means for executing a setup process for multi-link communication with an opposite communication device; a notification step of notifying the opposite communication device of mode information regarding a data transmission mode to be used in communication with the opposite communication device after the setup process by the processing means is completed and before the multi-link communication is disconnected; A control method comprising:

11. A program for causing a computer having a communication unit for performing wireless communication to function as the communication device according to any one of claims 1 to 9.

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