Communication device, control method of the communication device, and program

Abstract

To set an appropriate priority order for data transmitted by each communication device even when a plurality of communication devices transmit data of the same category.SOLUTION: A communication device is a communication device capable of communicating with an access point using an orthogonal frequency division multiple access (OFDMA). The communication device includes: an acquisition part that acquires an operation state related to data in another communication device that transmits data of the same category to the access point; a determination part that determines a priority related to transmission of the data of the own communication device to the access point according to an operation state in the other communication device and the operation state related to the data in the own communication device; and a granting part that grants priority information indicating the determined priority to the data transmitted to the access point.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a communication device, a control method for a communication device, and a program. [Background technology]

[0002] In wireless communications, in order to make effective use of limited frequency bands, techniques such as multiplexing in various dimensions, including time, frequency, power, code, and space, are used. In wireless LANs (Local Area Networks), attempts are being made to expand communication capacity by using multi-level modulation methods, channel bonding, and MIMO (Multiple-Input and Multiple-Output).

[0003] The Institute of Electrical and Electronics Engineers (IEEE) is currently working on standardizing the IEEE802.11ax standard as a highly efficient next-generation wireless LAN standard. The IEEE802.11ax standard allows frequency bands to be allocated in smaller sizes than the conventional 20 MHz, allowing multiple terminals to use wireless resources simultaneously. Such wireless resource allocation is achieved using Orthogonal Frequency Division Multiple Access (OFDMA). This is done using the IEEE 802.11n Multiple Access (IEEE 802.11n) protocol.

[0004] Patent Document 1 proposes a method for the IEEE802.11ax standard in which access category information of transmission data held by multiple terminals is acquired and wireless resources are preferentially allocated to terminals holding data of a high-priority access category. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-036093 Summary of the Invention [Problem to be solved by the invention]

[0006] In a system in which multiple terminals communicate with a single access point (AP) and transmit data of the same category, each terminal assigns an access category according to the type of data being transmitted. As a result, the access category of data transmitted by multiple terminals becomes the same, and the above method cannot determine the priority of transmitted data between terminals. For example, consider a case in which multiple terminals within a wireless LAN transmit video footage from each terminal via an access point to a distribution device on an external network, and the distribution device then uses the video footage for live streaming.

[0007] In this case, according to the method proposed in Patent Document 1, the access category of the video data transmitted by each terminal is AC_VI. In live streaming using video captured by multiple terminals, there is a need to stream video with as little interruption as possible by increasing the priority of the transmission data held by the terminal transmitting the video data currently being used for streaming. However, the method proposed in Patent Document 1 has the problem that it is not possible to determine the priority between video data with the same access category.

[0008] The present invention has been made in view of the above-mentioned problems, and provides a technique for setting appropriate priorities for data transmitted by each communication device even when multiple communication devices transmit data of the same category. [Means for solving the problem]

[0009] The communication device of the present invention is a communication device capable of communicating with an access point using orthogonal frequency division multiple access (OFDMA), and is characterized by having an acquisition unit that acquires an operating state related to the data in other communication devices that transmit data of the same category to the access point, a determination unit that determines a priority for transmitting the data of the communication device to the access point based on the operating state in the other communication devices and the operating state related to the data in the communication device itself, and an assignment unit that assigns priority information indicating the determined priority to the data transmitted to the access point. [Effects of the Invention]

[0010] According to the present invention, even when a plurality of communication devices transmit data of the same category, it is possible to set an appropriate priority for the data transmitted by each communication device. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a communication system according to a first embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a communication device according to a first embodiment. [Figure 3] FIG. 1 is a diagram illustrating an example of the configuration of a distribution device according to a first embodiment. [Figure 4] FIG. 1 is a diagram showing an example of the configuration of an access point according to a first embodiment; [Figure 5] Diagram illustrating multi-user (MU) uplink (UL) communication [Figure 6] A diagram showing an example of the trigger frame configuration [Figure 7] Diagram showing an example of UL data frame or BSR configuration [Figure 8] 1 is a flowchart showing a wireless resource allocation process in the first embodiment; [Figure 9] FIG. 1 is a diagram showing a flow from the start to the end of live distribution in the first embodiment. [Figure 10]1 is a flowchart showing a priority determination process executed by an STA according to the first embodiment; [Figure 11] FIG. 10 is a diagram showing the flow from the start to the end of live distribution in Example 2. [Figure 12] 10 is a flowchart showing a priority determination process executed by an STA according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the embodiments described below are examples of means for realizing the present invention, and may be modified or changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions. Furthermore, the embodiments may be combined as appropriate.

[0013] (First embodiment) 1 shows an example of a network configuration for multi-camera live streaming in a communication system according to this embodiment. A wireless LAN (Local Area Network) 100 is configured with two communication devices, stations (STA) 102 and 103, and one access point (AP) 101. Note that STA 102 and STA 103 are assumed to be HE (High Efficiency) STAs capable of communication compliant with the IEEE 802.11ax standard.

[0014] In the IEEE 802.11ax standard, for example, a 20 MHz bandwidth is divided into nine blocks, each with 26 non-overlapping subcarriers (tones) on the frequency axis, and radio resources are allocated to terminals in block units. This allocation unit block is called a Resource Unit (RU), and the size of the RU can be determined based on the frequency bandwidth and the number of communication devices to which the radio resources are allocated. The size of the RU is expressed in units of the number of tones, and for example, 26, 52, 106, 242, 484, 996, and 2 × 996 are available, but in a 20 MHz bandwidth, values ​​of 242 or less are available. When allocating the entire 20 MHz bandwidth to one terminal, a maximum of 242 tones can be allocated.

[0015] In this embodiment, the number of APs and STAs constituting the communication system 1 is merely an example. For example, one or three or more STAs may exist within the wireless LAN 100, or two or more APs may exist. Furthermore, in the following description, each STA is assumed to be a HE STA. However, one of the STAs may not be compliant with the IEEE 802.11ax standard, but may perform communication in accordance with another IEEE 802.11 standard series. This embodiment is not limited to communication systems having STAs performing communication in accordance with the IEEE 802.11ax standard, but may also be applied to other IEEE 802.11 standard series or any other communication system having similar features to the IEEE 802.11ax standard. Furthermore, in this embodiment, it is assumed that authentication between the AP and each STA has been successful, and that data can be transmitted and received between them.

[0016] 1, STA102 and STA103 use OFDMA (orthogonal frequency division multiple access) to perform UL (uplink) MU (multi-user) communication with AP 101, receiving data transmitted in parallel from each STA. Note that the uplink is an upward link for transmitting data from STA102 and STA103 to AP 101.

[0017] STA102 and STA103 each hold video data to be transmitted. Each video data has a transmission priority defined by an access category (AC). Here, "AC" is an acronym for access category, where VO stands for Voice, VI for Video, BE for Best Effort, and BK for Background. AC_VO has the highest priority, followed by AC_VI, AC_BE, and AC_BK in decreasing order. Note that this order of priority is merely an example, and may be changed as appropriate. Furthermore, it is assumed that the access category includes any of video, still images, and audio, but access categories indicating other types of data may also be adopted.

[0018] Furthermore, AP101 determines the order of allocation of radio resources, i.e., RUs, to each STA based on the AC of the video data to be transmitted held by each STA. That is, AP101 acquires information on the AC of the data to be transmitted held by each STA, and allocates RUs to each STA based on the acquired information so that high-priority transmission data is transmitted to AP101 first. STAs holding high-priority transmission data are preferentially allocated RUs, so that transmission data with higher priority can arrive at AP101 first.

[0019] AP101 is connected to the distribution device 104 via a network 105 different from the wireless LAN 100. The network 105 is assumed to be the Internet as an example, but various networks may be adopted. In the multi-camera live distribution by the distribution device 104, the videos captured by the STAs 102 and 103 are transmitted as video data from each STA to the AP101. The AP101 transmits the video data received from the STAs 102 and 103 to the distribution device 104 via the network 105. The distribution device 104 performs live distribution using the video data received from the AP101. Further, the distribution device 104 changes the shooting settings for each STA, or transmits a tally signal notifying the STA that is the transmission source of the video data used for the live distribution that the video data is being used in real time. The tally signal is a signal transmitted to the communication device that has transmitted the data related to the live distribution when an external device capable of communicating with the access point performs live distribution of data.

[0020] Next, a configuration example of the AP101, STAs 102 and 103, and the distribution device 104, and an example of the process executed in the communication system 1 will be described in detail.

[0021] <Configuration of STA> FIG. 2 is a block diagram showing a configuration example of the STAs 102 and 103 according to the present embodiment. Here, it is assumed that the STAs 102 and 103 are digital cameras as an example of communication devices, but the communication devices are not limited thereto. For example, the STAs 102 and 103 may be information processing devices such as personal computers, mobile phones, smartphones, tablet devices, and digital video cameras. Further, instead of the control unit 201 described below controlling the operations of each part of the STAs 102 and 103, a plurality of hardware may share the processing to control the operations of each part of the STAs 102 and 103. The control unit 201 is realized by, for example, a CPU (Central Processing Unit), and expands the program stored in the non-volatile memory 203 into the working memory 204 to execute the processes described below.

[0022] 2, STA102 has a control unit 201, an imaging unit 202, a nonvolatile memory 203, a working memory 204, a display unit 205, an operation unit 206, a recording unit 207, and a communication unit 208. Note that STA103 also has similar components, and the description of each unit of STA102 also applies to the corresponding unit of STA103.

[0023] The imaging unit 202 is composed of, for example, an optical lens unit, an optical system that controls the aperture, zoom, focus, and the like, and an imaging element that converts light (image) traveling through the optical lens unit into an electrical video signal. A complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD) may be used as the imaging element. Under the control of the control unit 201, the imaging unit 202 converts subject light focused by a lens of the imaging unit 202 into an electrical signal using the imaging element, performs noise reduction processing, and outputs the resulting digital data as image data or video data. The data output from the imaging unit 202 is recorded in the recording unit 207 or transmitted to the AP 101 via the communication unit 208.

[0024] The nonvolatile memory 203 is a nonvolatile memory that can be electrically erased and recorded, and stores programs and the like executed by the control unit 201. The working memory 204 is used as a buffer memory that temporarily stores image and video data captured by the imaging unit 202, an image display memory for the display unit 205, a working area for the control unit 201, and the like.

[0025] The display unit 205 displays a viewfinder image when shooting in the STA 102, displays shot images or videos, displays text for interactive operations, and turns on a tally lamp to indicate that video data is being recorded. Here, the display unit 205 also controls the lighting of a tally lamp in accordance with information indicating the distribution status of live streaming, such as a tally signal received from the AP 101 via the communication unit 208. Note that the display unit 205 does not necessarily have to be included in the STA 102, and may be configured as an external display unit.

[0026] The operation unit 206 is used by the user to receive instructions from the user to the STA 102. The operation unit 206 includes, for example, a power button used by the user to instruct the STA 102 to power on / off, a release switch used to instruct the STA 102 to take a picture, and a playback button used to instruct the STA 102 to play back a captured image or video. The operation unit 206 also includes a button for starting communication with an external device such as the distribution device 104 via the communication unit 208, which will be described later. The operation unit 206 also includes a touch panel that constitutes the display unit 205.

[0027] The recording unit 207 records image data and video data output from the imaging unit 202. The recording unit 207 may be configured to be detachable from the STA 102, or may be built into the STA 102. In other words, the STA 102 only needs to have a means for accessing the recording unit 207.

[0028] The communication unit 208 is an interface for connecting to an external device such as the AP 101. The STA 102 of this embodiment transmits and receives data to and from the external device via the communication unit 208. For example, the communication unit 208 transmits video data generated by the imaging unit 202 to the external device. The communication unit 208 also receives, from the external device, control signals for changing settings such as the resolution and bit rate of the video captured by the STA 102 and information indicating the distribution status of the live distribution by the distribution device 104. Based on the various information received from the communication unit 208, the control unit 201 changes various settings related to the shooting of the STA 102 and controls the display unit 205 to turn on and off a tally lamp.

[0029] In this embodiment, the communication unit 208 has an interface for communication via a wireless LAN conforming to the IEEE802.11 standard series. The control unit 201 controls the communication unit 208 to achieve wireless communication with an external device. The communication method in this embodiment is not limited to a wireless communication method, and may include, for example, an existing wired communication method.

[0030] <Configuration of Distribution Device 104> FIG. 3 is a block diagram showing an example configuration of a distribution device 104 according to this embodiment. Note that the configuration of the distribution device 104 shown here is merely an example, and information processing devices such as personal computers, mobile phones, smartphones, and tablet devices may also be used. Alternatively, the distribution device 104 may be a combination of live distribution devices such as an IP decoder and a switcher. As shown in FIG. 3, the distribution device 104 includes a control unit 301, a video input unit 302, a video output unit 303, a non-volatile memory 304, a working memory 305, a display unit 306, an operation unit 307, and a communication unit 308.

[0031] The control unit 301 controls each unit of the distribution device 104 according to a program described below. The control unit 301 also generates distribution video to be used in live distribution by superimposing other video, captions, etc. on the video data received from the AP 101. The control unit 301 also transmits a tally signal notifying the STA that the video data being used for live distribution is being distributed, and information indicating the distribution status of the live distribution, via the communication unit 308.

[0032] Video input unit 302 acquires video data transmitted from each STA via communication unit 308, decodes the video data as necessary, and sends a video signal to control unit 301. Video input unit 302 may also be configured to have an interface for video input such as an HDMI (registered trademark) terminal or an SDI terminal, so that it can not only receive video data from the network via communication unit 308, but also acquire a video signal via the interface.

[0033] The video output unit 303 encodes the video data for live distribution generated by the control unit 301 as necessary and outputs the encoded data to the communication unit 308. The video output unit 303 may also be configured to have an interface for video input such as an HDMI (registered trademark) terminal or an SDI terminal, so that it can not only transmit video data to the Internet via the communication unit 308, but also output video data via the interface.

[0034] The nonvolatile memory 304 is an electrically erasable and recordable nonvolatile memory, and stores programs executed by the control unit 301. The working memory 305 is used as an image display memory for the display unit 306, a working area for the control unit 301, etc.

[0035] The display unit 306 displays video using the video data generated by the control unit 301. The display unit 306 also displays a UI for controlling the generation of video data used for live distribution, and a display for the STAs 102 and 103 connected to the network via the communication unit 308. The UI for instructing the shooting settings is also displayed. Note that the display unit 306 does not necessarily have to be possessed by the distribution device 104. As long as the distribution device 300 can be connected to the display unit 306 inside or outside the device and the display of the display unit 306 is controlled by the control unit 301, various configurations may be adopted.

[0036] The operation unit 307 is an input unit used by the user of the distribution device 104 to give instructions to the distribution device 104. The operation unit 307 is, for example, a power button for the user to instruct ON / OFF of the power of the distribution device 104, switches and faders used to switch the video displayed on the distribution device 104, dials for adjusting effects superimposed on the video, and the like. Further, the operation unit 307 may be a touch panel displayed on the display unit 306 or an external device such as a mouse or a keyboard.

[0037] The communication unit 308 communicates with the AP101 via a network to receive video data from the STA102 and STA103, transmit a signal for performing shooting settings to the STA102 and STA103, or transmit a tally signal indicating the distribution status of the live distribution. Further, when the distribution device 104 performs a live distribution using the video data received from the STA102 and STA103, the communication unit 308 transmits the video data decoded by the video output unit 303. In the present embodiment, the communication method of the communication unit 308 is not limited to a wireless communication method, and for example, an existing wired communication method may be adopted.

[0038] <Configuration of AP101> FIG. 4 is a block diagram showing a functional configuration example of the AP101. As shown in FIG. 4, the AP101 includes a wireless LAN control unit 401, a Trigger frame control unit 402, a received frame analysis unit 403, a UI control unit 404, a storage unit 405, and a bandwidth distribution unit 406.

[0039] The wireless LAN control unit 401 executes control for transmitting and receiving wireless signals to and from the STA 102, the STA 103, and the broadcasting device 104. The wireless LAN control unit 401 can be realized by, for example, a program for controlling a baseband circuit, an RF (Radio Frequency) circuit, and an antenna for the wireless LAN.

[0040] The wireless LAN control unit 401 executes wireless LAN communication control in accordance with, for example, the IEEE 802.11 standard series, and performs wireless communication in accordance with the IEEE 802.11 standard series between the STAs 102 and 103. The trigger frame control unit 402 performs control for transmitting a trigger frame to a successfully authenticated STA via the wireless LAN control unit 401. When the successfully authenticated STA receives a trigger frame from the AP 101, it transmits an uplink (UL) frame to the AP 101 in response to the frame.

[0041] When AP 101 receives a UL frame transmitted from a STA via wireless LAN control unit 401, received frame analysis unit 403 interprets the contents of the received UL frame. For example, if the received UL frame contains AC information, received frame analysis unit 403 analyzes the UL frame to obtain the AC information, and identifies which AC's video data the STA that transmitted the UL frame holds.

[0042] The bandwidth allocating unit 406 determines the width of the frequency band to be allocated for data transmission of each STA, the center frequency of the frequency band, and the time for allocating the frequency band, based on the information acquired by the received frame analyzing unit 403. In other words, the bandwidth allocating unit 406 determines the timing and frequency range of radio resources to be allocated to each STA.

[0043] The Trigger frame control unit 402 notifies each STA of the information indicating the allocation determined by the bandwidth distribution unit 406 using a Trigger frame. As a result, each STA transmits a UL frame according to the notified allocation.

[0044] The UI control unit 404 is realized by a program that controls hardware related to a user interface such as a touch panel or buttons for receiving operations on the AP 101 by the user of the AP 101. Note that the UI control unit 404 also has a function for presenting information related to the live distribution of video data to the user, such as displaying images or outputting audio. The storage unit 405 is composed of a ROM, a RAM, etc. that store programs and data executed by the AP 101.

[0045] <OFDMA Communication> Next, an example of the flow of multi-user (MU) communication using a UL frame in the communication system 1 will be described while referring to FIG. 5.

[0046] In step S501, the AP 101 transmits a Buffer Status Report Request (BSR Request) to the STA 102 and the STA 103 by the Trigger frame control unit 402. FIG. 6 shows a configuration example of the frame of the Buffer Status Report Request transmitted to the STA 102 and the STA 103. As shown in FIG. 6, the frame of the BSR Request has a Frame Control field 601, a Duration field 602, a RA field 603, a TA field 604, and a Common Info field 605. Further, the frame of the BSR Request has User Info fields 606-1 to 606-k (k is a positive integer), a Padding field 607, and an FCS field 608. Note that hereinafter, descriptions of fields not related to the processing in the communication system 1 in the present embodiment will be omitted.

[0047] The Frame Control field 601 is a field having a value indicating that the frame is, for example, an IEEE802.11ax Trigger frame. The Common Info field 605 is a field indicating information common to multiple terminals that are destinations of the Trigger frame. The User Info fields 606-1 to 606-k are fields indicating individual information for the destination of the Trigger frame. The Common Info field 605 includes a Trigger Type subfield 611 and a UL Length subfield 612.

[0048] The Trigger Type subfield 611 is used to specify the type of trigger. For example, for the BSR Request sent in step S501, the value of the Trigger Type subfield 611 is set to 4. The UL Length subfield 612 indicates the length of the HE TB PPDU specified by the AP 101, which is the sender of the trigger frame, when the STA 102 and STA 103 respond to the trigger frame. The HE TB PPDU is a High Efficiency Trigger Based PLCP Protocol PLCP is an abbreviation for Data Unit. PLCP is an abbreviation for Physical Layer Convergence Protocol. User Info fields 606-1 to 606-k include an AID subfield 621 and an RU Allocation subfield 622. These subfields will be described later.

[0049] Returning to Fig. 5, in step S502, STA102 and STA103 transmit a Buffer Status Report (BSP). Fig. 7 shows an example of the structure of a UL frame transmitted as a BSP. As shown in Fig. 7, the BSP frame is The BSP frame has a Control field 701, a Duration field 702, an Address1 field 703, an Address2 field 704, and an Address3 field 705. Furthermore, the BSP frame has a Sequence Control field 706, an Address4 field 707, and a QoS Control field 708. Furthermore, the BSP frame has an HT Control field 709, a Frame Body field 710, and an FCS field 711. Note that, in the following, description of fields that are not related to processing in the communication system 1 in this embodiment will be omitted.

[0050] The Frame Control field 701 indicates the type of BSP frame. The Frame Control field 701 includes a Type subfield 721 and a SubType subfield 722. For example, the values ​​of the Type subfield 721 and the SubType subfield 722 in the Frame Control field 701 are set to "11" and "00," respectively. This indicates that the frame being transmitted is a QoS Null frame.

[0051] The TID subfield 731 included in the QoS Control field 708 indicates the AC of the video data to be transmitted that is held by the source STA, and the Queue Size subfield 732 indicates the size of the video data. The value indicated in the Queue Size subfield 732 is the size of the video data of the AC indicated in the TID subfield 731 that is buffered by the STA.

[0052] The value stored in the Queue Size subfield 732 increases by 1 for every 256 octets of the size (amount of data) of the video data to be transmitted, and is expressed by rounding up. For example, if the size of the video data to be transmitted is 255 octets or less, the value stored in the Queue Size subfield 732 is "1." If the size of the video data to be transmitted is 256 to 511 octets, the value stored in the Queue Size subfield 732 is "2."

[0053] In step S503, upon receiving a BSR from STA102 and STA103, AP101 transmits a Trigger frame to STA102 and STA103 to prompt the transmission of UL data, based on the information contained in the received frame. The frame transmitted to STA102 and STA103 here is configured in the format shown in FIG. 6, for example. At this time, "0" is stored in the Trigger Type subfield 611. A value corresponding to a communication period common to all STAs is stored in the UL Length subfield 612, and this value specifies the amount of data that each STA can transmit.

[0054] When the value of the Trigger Type subfield 611 is "0," User Info fields 606-1 to 606-k are added to the frame in FIG. 6. In the User Info fields 606-1 to 606-k, an AID subfield 621 specifies an STA, respectively. An RU Allocation subfield 622 specifies the RU and tone size to be allocated to the specified STA. The tone size is a value indicating the width of the frequency band that can be allocated to each STA. For example, a 20 MHz bandwidth is divided into nine frequency bands, each with a tone size of 26, and frequency resources are allocated in units of these divided blocks. On the other hand, it is also possible to allocate frequency resources to one STA in units of a single block with a tone size of 242, without dividing the 20 MHz bandwidth. Note that tone sizes can also be allocated in the same manner as above, even in the case of a 40 MHz or 80 MHz bandwidth.

[0055] In step S504, STA102 and STA103 receive a trigger frame from AP 101. Then, STA102 and STA103 transmit a UL data frame of a size that falls within the range of the data amount specified by the UL Length subfield 612 of the received trigger frame to AP 101. In step S505, upon receiving a PPDU from STA102 and STA103, AP 101 transmits a multi-block acknowledgment (multi-BA) to STA102 and STA103 as a receipt confirmation.

[0056] In the above, the STAs 102 and 103 may transmit a BSR to the AP 101 at any timing. That is, the STAs 102 and 103 may include information to be notified by the BSR in the UL Data frame they transmit to the AP 101. The AP 101 may also obtain data equivalent to the BSR based on the UL Data frame received from each STA. For example, a frame complying with QoS is transmitted with data stored in the Frame Body field 710 in the format shown in FIG. 7. Here, the QoS Control field 708 indicates the TID corresponding to the data stored in the Frame Body and the Queue Size held by the STA. The AP 101 can obtain the values ​​stored in the TID subfield 731 and the Queue Size subfield 732 of the QoS Control field 708 as information obtained by the BSR.

[0057] Furthermore, BSR information may be transmitted using other fields in the UL Data frame. For example, BSR information can be transmitted using the HT Control field 709 in Fig. 7. For example, the value of the Version subfield 741 in the HT Control field 709 indicates that the frame is an IEEE802.11ax frame. Furthermore, setting the value of the Control ID subfield 742 in the HT Control field 709 to "3", for example, indicates that the type of control is BSR Control.

[0058] The Control Information subfield 743 also has an ACI Bitmap subfield 751 and a Delta ID subfield 752. The Control Information subfield 743 also has an ACI High subfield 753 and a Scaling Factor subfield 754. The Control Information subfield 743 also has a Queue Size High subfield 755 and a Queue Size All subfield 756.

[0059] The ACI Bitmap subfield 751 indicates all ACs of data held by the STA that is the source of the frame. The Delta ID subfield 752 indicates the total number of TIDs of data held by the STA that is the source of the frame. The ACI High subfield 753 indicates the AC with the largest Queue Size. The Scaling Factor subfield 754 indicates the scale of the Queue Size, which determines the order indicated by the next Queue Size.

[0060] The Queue Size High subfield 755 indicates the Queue Size value of the AC with the largest Queue Size among the data of each AC held by the STA. Also, the Queue Size All subfield 756 indicates the combined Queue Size value of all data of each AC held by the STA. In this way, the STA can notify the AP 101 of the amount of data held for each AC.

[0061] Next, an example of the process of allocating wireless resources to STA 102 and STA 103 by AP 101 will be described. In the embodiment described below, AP 101 determines the priority according to the AC of the data held by multiple STAs, and allocates RUs to STAs in descending order of priority. This allows AP 101 to preferentially receive data of high-priority ACs from STA 102 and STA 103.

[0062] 8 shows an example of a flowchart of the processing executed by AP 101 when performing MU-UL communication between STA 102 and STA 103. Note that the processing of this flowchart starts when AP 101 performs MU-UL communication, and is not executed while performing single-user communication. However, this is not limiting, and AP 101 may perform processing such as periodically receiving a BSR even when not performing MU-UL communication.

[0063] First, in step S801, the wireless LAN control unit 401 of the AP 101 transmits a BSR request to the STAs 102 and 103 as a trigger for receiving a BSR from the STAs 102 and 103. The frame transmitted at this time is, for example, a frame indicating that it is a BSR request according to the format shown in FIG. 6 as described above. Then, in step S802, the STAs 102 and 103 that have received the BSR request transmit a BSR to the AP 101. The BSR frame received by the AP 101 is a frame configured according to the format shown in FIG. 7 as described above. Next, in step S803, the received frame analysis unit 403 of the AP 101 acquires, from the received BSR, information indicating the ACs of the video data to be transmitted that each STA holds and the queue size for each AC. The bandwidth allocation unit 406 allocates wireless resources to each STA based on the information acquired from the BSR.

[0064] In the following description, N (a positive integer) is the group number, the tone size allocated to each STA is 26, and the RU index takes a value from 1 to the maximum value. The RU index is information that specifies the RU to be allocated, and a different RU is associated with each RU index value. The maximum value of the RU index is the number of RUs that can be allocated per transmission opportunity; for example, when the tone size is 26 in a 20 MHz bandwidth, the maximum value of the RU index is 9. The group indicated by N refers to a group of STAs to which radio resources are allocated at the same timing. In other words, two STAs belonging to different Ns perform UL communication at different times. In step S804, prior to allocating radio resources, AP101 initializes the group number N to 0 and the RU index to 1, respectively.

[0065] In step S805, the bandwidth allocating unit 406 of AP 101 determines whether allocation of RUs to STAs for all groups has been completed. If the bandwidth allocating unit 406 determines that allocation of RUs to STAs for all groups has not been completed (S805: NO), the processing proceeds to step S806. If the bandwidth allocating unit 406 determines that allocation of RUs to STAs for all groups has been completed (S805: YES), the processing proceeds to step S812.

[0066] In step S806, the bandwidth allocator 406 assigns the smallest allocable RU index to a STA that has not been assigned an RU and that holds video data of the AC with the highest priority. Therefore, for example, when N=0, an RU with RU index=1 is assigned to the STA.

[0067] In step S806, if there are multiple STAs holding video data of the same AC, the RU idex may be allocated to one of these STAs. The RU indexes may be assigned to the STAs in order. Alternatively, the bandwidth allocating unit 406 may acquire information about the IP addresses of the STAs from each STA, and assign the RU indexes to the STAs in order according to the order of the IP addresses. Alternatively, the bandwidth allocating unit 406 may acquire information about management numbers assigned to each STA by the AP 101 for management purposes, and assign the RU indexes to the STAs in order according to the management numbers. Alternatively, the bandwidth allocating unit 406 may assign the RU indexes to the STAs in order according to the size of the video data transmitted by each STA. Alternatively, the bandwidth allocating unit 406 may store history information indicating the time when an RU index was assigned to each STA in the storage unit 405, and assign the RU indexes to the STAs in order according to the longest elapsed time since the last assignment.

[0068] In step S807, the bandwidth allocating unit 406 increments the RU index to be allocated to the STA next. For example, if an RU with RU index=1 is allocated to the STA in step S806, the bandwidth allocating unit 406 sets RU index=2.

[0069] Next, in step S808, the bandwidth allocating unit 406 determines whether or not there are any STAs remaining that have not been assigned an RU index. If the bandwidth allocating unit 406 determines that there are any STAs remaining that have not been assigned an RU index (S808: YES), the process proceeds to step S809. If the bandwidth allocating unit 406 determines that there are no STAs remaining that have not been assigned an RU index (S808: NO), the process proceeds to step S810.

[0070] In step S809, the bandwidth allocating unit 406 determines whether the value of the RU index incremented in step S807 has exceeded the maximum value. If the bandwidth allocating unit 406 determines that the value of the RU index has exceeded the maximum value (S809: YES), the process proceeds to step S810. If the bandwidth allocating unit 406 determines that the value of the RU index has not exceeded the maximum value (S809: NO), the process returns to step S806, and the above process is executed again.

[0071] As an example, when RU index=2, the maximum value (9 when a 20 MHz bandwidth is used) is not exceeded, so the bandwidth allocating unit 406 returns the process from step S809 to step S806. Then, in step S806, the bandwidth allocating unit 406 allocates an RU index to the STA that holds the video data to be transmitted by the AC with the highest priority, among the STAs for which RU allocation has not been completed (the remaining STAs).

[0072] In this way, while there are STAs to which no RU has been assigned, different RU indices are assigned in order to those STAs. Then, when the bandwidth allocating unit 406 determines in step S809 that the RU index has exceeded the maximum value, it terminates the allocation of RUs to STAs in the current group. Also, even if there are no STAs to which no RU has been assigned when RU allocation is possible, the bandwidth allocating unit 406 proceeds from step S808 to step S810, thereby terminating the allocation of RUs to STAs in the current group.

[0073] Next, in step S810, the bandwidth allocating unit 406 identifies a communication period for each of one or more STAs to which an RU is assigned in the current group, based on the Queue Size. Then, the bandwidth allocating unit 406 determines a communication period common to all STAs in this group according to the identified communication period. For example, the bandwidth allocating unit 406 identifies, for each of one or more STAs, the communication period until data of the size (amount of data) indicated by the Queue Size is received, and sets the longest communication period among the identified communication periods as the communication period common to all STAs. This allows the AP 101 to easily receive data from the STAs. When reception fails, instead of waiting for reception of low-priority data, radio resources are allocated for retransmission of the high-priority data that failed to be received, thereby encouraging the STA to retransmit the data. As a result, the AP 101 and ultimately the distribution device 104 can efficiently and reliably receive video data of high-priority ACs. As such, according to this embodiment, by preferentially allocating RUs to STAs that hold video data of high-priority ACs, the AP 101 can more reliably receive data of high-priority ACs.

[0074] It is also assumed that while AP 101 receives BSR from STA 102 and STA 103 and is processing MULTILUB communication, new video data to be transmitted may be generated in one of the STAs. In this case, the Queue Size value indicated by the received BSR and the Queue Size value indicated by the QoS Control field in the received data frame are used as the Queue Size value. Therefore, when the AP 101 determines that the Queue Size value indicated by the BSR and the Queue Size value indicated by the received data frame are different, the AP 101 may perform the RU allocation process again.

[0075] In the example of Figure 8 above, AP 101 receives data frames from STAs after RU allocation to the STAs in one group is completed, but the timing of receiving data frames is not limited to this. For example, AP 101 may execute reception processing of data frames from STAs when RU allocation to the STAs in one group is completed (when proceeding to step S811 in Figure 8). In this way, by combining the reception processing of data frames when allocation for one group is completed with the reallocation processing, it is possible to flexibly allocate RUs while keeping processing time short.

[0076] Furthermore, although the above example assumes that the tone size is fixed at 26, the tone size is not limited to this. For example, RUs may be allocated to STA102 and STA103 with a tone size of 52. In this case, if a 20 MHz bandwidth is used, the maximum number of STAs that can be allocated to one group is four. Therefore, AP101 may change the tone size depending on the number of STAs communicating with AP101 and / or the number of STAs holding video data to be transmitted. For example, if AP101 determines that the number of STAs holding video data to be transmitted is eight, AP101 may set the tone size to 52, and if it determines that the number of STAs holding video data to be transmitted has reached nine, AP101 may change the tone size to 26. This allows each STA to transmit more data to AP101 in a single transmission opportunity while efficiently using the bandwidth.

[0077] Also, in the above example, AP101 does not execute other processes until the RU allocation for all STAs and the reception of data frames are completed. However, AP101 may execute other processes during this period. For example, AP101 may transmit and receive another frame during this period. Also, when the reception of data frames from a group including STAs that hold video data of AC_VO and AC_VI by the AC is completed and the reception of data frames from other groups is not completed, AP101 may transmit a BSR Request to each STA. Thereby, AP101 can identify STAs that hold video data with a higher priority of the AC than AC_BE, and can perform transmission and reception of video data by the identified STAs with higher priority than other STAs.

[0078] Although the embodiments have been described using terms related to the IEEE802.11ax standard, these are for facilitating the understanding of the present invention and are not for limiting the technical scope of the present invention. That is, the above method may be applied not only to the IEEE802.11ax standard but also to its successor standards and other IEEE802.11 standard series, and may also be applied to wireless communication standards other than the IEEE802.11 standard series. That is, a communication device that acquires information indicating the priority of transmission of video data held by each STA and allocates wireless resources to each STA according to the priority may be adopted in a wireless communication system compliant with any standard.

[0079] <Determination of AC for Video Data Based on STA's Operating State> Below, two examples (embodiments 1 and 2) of a process for determining an AC to be assigned to transmission data based on the operating status shared by STA102 and STA103 in the network configuration of multi-camera live streaming in the communication system 1 illustrated in FIG. 1 are shown. STA102 and STA103 transmit data of the same category to AP101. Data of the same category is data with the same AC in communication conforming to the IEEE802.11 standard series, such as video data, for example. STA102 and STA103 then determine a priority for the transmission of video data from AP101 based on the operating status related to the video data in their own communication devices and the operating status related to the video data in the other STAs. STA102 and STA103 then determine an AC for the video data based on the determined priority. The AC determined here is used as priority information indicating the priority.

[0080] In the first embodiment, the STAs 102 and 103 determine the priority of data transmission for their own devices based on information indicating the distribution status of live distribution transmitted from the distribution device 104. The STAs 102 and 103 then assign ACs to the transmission data so that the ACs of video data transmitted by high-priority STAs to the AP 101 have a higher priority than the ACs of video data transmitted by low-priority STAs. In the second embodiment, the STAs 102 and 103 determine the priority based on the video data they transmit to the AP 10 and the shooting settings of their own devices. The STAs 102 and 103 then assign ACs to the transmission data so that the ACs of video data transmitted by high-priority STAs to the AP 101 have a higher priority than the ACs of video data transmitted by low-priority STAs.

[0081] For convenience, the methods for determining the priority of transmission data are shown separately in Example 1 and Example 2, but the priority may be determined by combining the processes in the examples. It is also assumed that STA 102 and STA 103 within wireless LAN 100 have the function of transmitting video data used for multi-camera live streaming by streaming device 104 to streaming device 104 and that the IP addresses of each STA are recognized. This can be achieved by a user presetting information in each STA, but it may also be achieved by acquiring information about each STA using broadcast communication to devices within wireless LAN 100.

[0082] In the following example, in the case of live streaming in which one of STA102 and STA103 transmits video data, each STA transmits the video data with the AC set to AC_VI. Furthermore, in the case of multi-camera live streaming in which multiple STAs, i.e., STA102 and STA103, transmit video data, each STA transmits the video data with the AC of the video data of a lower priority STA set to AC_BE, which has a lower priority than AC_VI. However, the determination of priority is not limited to this. For example, STA102 and STA103 may assign a high-priority AC_VO to the AC of the video data of a higher priority STA, or may assign a combination of three or more types of ACs by determining the priority numerically. Furthermore, in the following description, the same reference numerals are used for configurations and processes similar to those of the first embodiment, and detailed description thereof will be omitted.

[0083] Example 1 In the first embodiment, the STAs 102 and 103 receive live broadcasts from the broadcasting device 104. The priority is determined based on information indicating the usage status of the video data. In this embodiment, a tally signal transmitted from the distribution device 104 to the STAs 102 and 103 is used as information indicating the usage status of the video data in live distribution. The tally signal is a signal transmitted to the STAs 102 and 103 that transmit the video data used to generate the video to be distributed in the live distribution performed by the distribution device 104. The tally signal may be transmitted to no STA or may be transmitted to multiple STAs.

[0084] 9 shows an example of the flow of processing executed by each device from the start to the end of live streaming by the streaming device 104 in the first embodiment. For convenience, the AP 101 is omitted from FIG. 9, but communication between the STAs 102 and 103 and between the STAs 102 and 103 and the streaming device 104 is performed via the AP 101.

[0085] In step S901, the control unit 201 of the STA 103 activates the live streaming function, for example, in response to an input from the operation unit 206. Next, in step S902, the control unit 201 of the STA 103 sends a link request to the STA 102 to check the operating status, based on the information about the STA 102 preset in the STA 103. At this time, if the live streaming function of the STA 102 has not been activated, no response is returned from the STA 102 to the STA 103. If transmission of video data to the distribution device 104 starts in this state, only the STA 103 transmits video data to the distribution device 104 within the wireless LAN 100. Therefore, in this case, the control units 201 of the STAs 102 and 103 do not perform processes such as sharing the reception status of the tally signal, determining priority, and changing the AC, which will be described later in steps S907 to S911 and steps S913 to S917.

[0086] Although not shown in FIG. 9 , when a response is returned from STA102 to STA103 in step S903, a link for operating as multi-camera live streaming is established between STA102 and STA103. Alternatively, if the live streaming function is activated in STA102 at a stage after step S903 and a link request is sent to STA103, a link is similarly established. With the link between STA102 and STA103 established, in step S904, the streaming device 104 requests STA102 and STA103 to start transmitting video data. In step S905, upon receiving the request, the control units 201 of STA102 and STA103 start transmitting video data to the streaming device 104. At this time, the AC of the video data transmitted from STA102 and STA103 to AP 101 is AC_VI.

[0087] After STA102 and STA103 start transmitting video data in step S905, in step S906, the control unit 301 of the distribution device 104 transmits a tally signal to the STAs depending on the usage status of the video data in live streaming. Here, as an example, it is assumed that the distribution device 104 performs live streaming using video data transmitted from STA102. At this time, the control unit 301 of the distribution device 104 transmits a tally signal to STA102 notifying STA102 that the video data transmitted by STA102 will be used in live streaming. In step S907, upon receiving the tally signal from the distribution device 104, the control unit 201 of STA102 notifies STA103, with which a link has been established, that it has started receiving the tally signal. The control unit 201 of STA103, as an operating status acquisition unit for a communication device, acquires information on the reception status of the tally signal from STA102. Then, in step S908, the control unit 201 of STA103 returns a response to the transmission of the tally signal from STA102 to STA102.

[0088] In step S909, the control unit 201 of the STA 103 performs a process of determining the priority of the video data that the STA 103 transmits to the AP 101. In step S910, upon receiving the response from the STA 103 in step S908, the control unit 201 of the STA 102 performs a process of determining the priority of the video data that the STA 102 transmits to the AP 101. The control unit 201 of A102 and STA103 is a decision unit that decides the priority of transmitting data of the communication device to the access point according to the operating states of other communication devices and the operating states related to data in the communication device itself.

[0089] Here, a process executed by the control units 201 of the STAs 102 and 103 to determine the priority of video data that the STAs transmit to the AP 101 will be described. The control unit 201 of each STA determines the AC of the video data that the STAs transmit to the AP 101 based on the operating status of the STAs themselves, i.e., whether or not the STAs themselves and other STAs are receiving a tally signal. An example of a flowchart of the AC determination process executed by the control units 201 of the STAs 102 and 103 is shown in FIG.

[0090] In step S1001, the control units 201 of the STA102 and STA103 determine whether or not the respective devices are receiving a tally signal. If the control units 201 of the STA102 and STA103 determine that the respective devices are receiving a tally signal (S1001: YES), the control units 201 determine that the priority of the video data that the respective devices are transmitting to the AP 101 is high, and the process proceeds to step S1004. In step S104, the control units 201 of the STA102 and STA103 determine that the AC for the video data that the respective devices are transmitting to the AP 101 is AC_VI.

[0091] If the control units 201 of STA102 and STA103 determine that their own devices have not received a tally signal (S1001: NO), the process proceeds to step S1002. In step S1002, the control units 201 of STA102 and STA103 determine whether or not another STA other than their own devices is receiving a tally signal. If the control units 201 of STA102 and STA103 determine that another STA is receiving a tally signal (S1002: YES), the control units 201 of STA102 and STA103 determine that the priority of the video data that their own devices transmit to AP 101 is low, and the process proceeds to step S1003. In step S1003, the control units 201 of STA102 and STA103 determine the AC for the video data that their own devices transmit to AP 101 to be AC_BE. Furthermore, if the control units 201 of the STAs 102 and 103 determine that the other STAs have not received the tally signal either (S1002: NO), the process proceeds to step S1004. In step S104, the control units 201 of the STAs 102 and 103 determine the AC for the video data that they transmit to the AP 101 to be AC_VI. Note that in the embodiment of FIG. 10, the AC for the video data that they transmit to the AP 101 is not changed for the STAs that are receiving the tally signal. Therefore, the STAs that are receiving the tally signal can omit the priority determination process shown in FIG. 10 as necessary.

[0092] 9, once the AC of the video data is determined by the priority determination process in each STA in steps S909 and S910, control units 201 of STA102 and STA103 assign the determined AC to the video data in step S911. Then, control units 201 of STA102 and STA103 start transmitting the video data to AP 101. Here, control units 201 of STA102 and STA103 are assigning units that assign priority information indicating the determined priority to data to be transmitted to the access point.

[0093] Then, when the control unit 301 of the distribution device 104 finishes using the video data transmitted by the STA 102 for live distribution, in step S912, it notifies the STA 102 of the end of transmission of the tally signal. In step S913, when the control unit 201 of the STA 102 receives the notification of the end of transmission of the tally signal from the distribution device 104, it notifies the STA 103, with which the link is established, of the end of reception of the tally signal. In step S914, the control unit 201 of the STA 103 returns a response to the notification received in step S913 to the STA 102. Then, in step S915, the control unit 201 of the STA 103 performs processing to determine the priority of the video data that the STA 103 transmits to the AP 101. Furthermore, in step S916, when the control unit 201 of the STA 102 receives the response from the STA 103 in step S914, it performs processing to determine the priority of the video data that the STA 102 transmits to the AP 101. As a result, the control units 201 of the STAs 102 and 103 determine the AC of each video data to be AC_VI.

[0094] Next, in step S917, the control units 201 of STA102 and STA103 start transmitting the video data to which the ACs determined in steps S915 and S916 have been assigned. Thereafter, the control units 201 of STA102 and STA103 notify and respond to the reception status of the tally signal between the STAs, determine the priority, and determine the AC for the video data in response to the tally signal transmitted from the broadcasting device 104. Then, in step S918, the control unit 301 of the broadcasting device 104 transmits a request to STA102 and STA103 to stop transmitting the video data. Then, in step S919, the control units 201 of STA102 and STA103 stop transmitting the video data to the broadcasting device 104.

[0095] In this embodiment, the distributing device 104 continues to transmit a tally signal to the STAs from the start to the end of the use of video data for live streaming, but the transmission format of the tally signal is not limited to this. For example, the distributing device 104 may transmit a tally signal to the STAs at the start and end of the use of video data for live streaming. In this case, the STAs 102 and 103 determine that they are receiving a tally signal from the distributing device 104 during the period from when they receive a tally signal notifying the start of use of video data to when they receive a tally signal notifying the end of use. Alternatively, the distributing device 104 may transmit a tally signal at a specific interval to the STAs transmitting the video data used for live streaming. In this case, the STAs 102 and 103 may determine that they are receiving a tally signal while they are receiving a tally signal at that interval, and determine that they are not receiving a tally signal while they are not receiving a tally signal for a period longer than that interval.

[0096] <Example 2> In the second embodiment, the STAs 102 and 103 in the wireless LAN 100 determine the priority based on parameters set for each STA, such as the specifications of the video data to be transmitted to the AP 101 and / or the imaging conditions for acquiring the video data. The parameters for determining the priority of the transmission of the video data may be input by a user operating the operation unit 206 of the STAs 102 and 103, or may be acquired via the communication unit 208 from another device, such as the distribution device 104 or a communication terminal (not shown).

[0097] In this embodiment, parameters used to determine the priority of video data include parameters such as the "bit rate," "resolution," and "frame rate" of the video data transmitted by the STA, as well as a "delivery priority" that can be arbitrarily set by the user for the video data. However, the parameters used to determine the priority of video data are not limited to these. For example, various parameters indicating the operating status of the STA, such as whether or not the video data is compressed, the focal length of the lens of the STA's imaging unit, and whether or not the tally signal in the first embodiment is being received, may be used as parameters used to determine the priority of video data. Note that the "delivery priority" is a parameter that can be set to either "high" or "low," and can be set in advance by the user depending on the role of each STA in multi-camera live streaming, or can be changed in real time depending on the scene of the video being streamed.

[0098] FIG. 11 shows an example of the flow of processing executed by each device from the start to the end of live streaming by the streaming device 104 in this embodiment. For convenience, the AP 101 is omitted from FIG. 11, but communication between the STAs 102 and 103, and communication between the STAs 102 and 103 and the streaming device 104, is performed via the AP 101. In addition, as a prerequisite for this embodiment, it is assumed that the above parameters for the STAs 102 and 103 are all "bit rate: 9 Mbps," "resolution: 1920 × 1080," "frame rate: 59.94 fps," and "streaming priority: low."

[0099] The process from the activation of the live distribution function of the STA 103 in step S1101 to the start of transmission of video data from the STA 103 to the distribution device 104 in step S1105 is the same as steps S901 to S905 in the first embodiment, and therefore detailed description thereof will be omitted.

[0100] Next, in step S1106, the user operates operation unit 206 of STA 103 to set "delivery priority," a parameter related to determining the priority of video data, to "high." Then, in step S1107, control unit 201 of STA 103 notifies STA 102, with which a link was established in step S1103, that the priority setting has been changed and of the changed parameter (in this case, "high"). In step S1108, control unit 201 of STA 102 returns a response to the notification from STA 103 in step S1107 to STA 103.

[0101] In step S1109, the control unit 201 of the STA 103 performs processing to determine the priority of the video data that the STA 103 transmits to the AP 101. In addition, in step S1110, upon receiving the response from the STA 103 in step S1108, the control unit 201 of the STA 102 performs processing to determine the priority of the video data that the STA 102 transmits to the AP 101.

[0102] Next, a process for determining the priority of video data that the STAs themselves transmit to the AP 101, which is executed by the control units 201 of the STAs 102 and 103 in this embodiment, will be described. Each STA determines the AC of the video data that it transmits to the AP 101, depending on the contents of the above parameters of the STAs itself and the other STAs. An example of a flowchart of the AC determination process executed by the STAs 102 and 103 is shown in FIG.

[0103] As shown in Figure 12, in the priority determination process in this embodiment, the video data in the device itself and other STAs is determined in the order of "delivery priority," "bit rate," "resolution," and "frame rate," but the order of determination is not limited to this.

[0104] In step S1201, the control units 201 of the STAs 102 and 103 determine the delivery priority of their own devices. If the control units 201 of the STAs 102 and 103 determine that the delivery priority of their own devices is set to "high" (S1201: "high"), they determine that the priority of the video data that their own devices transmit to the AP 101 is higher than that of the other STAs. Then, the control units 201 of the STAs 102 and 103 proceed to step S1207. Then, in step S1207, the control units 201 of the STAs 102 and 103 leave the AC of the video data to be transmitted to the AP 101 as AC_VI. On the other hand, if the control units 201 of the STAs 102 and 103 determine that the delivery priority of their own devices is set to "low" (S1201: "low"), they proceed to step S1202. Then, in step S1202, the control units 201 of the STAs 102 and 103 determine the delivery priorities of the other STAs.

[0105] In step S1202, the control units 201 of STA102 and STA103 determine whether there are other STAs whose delivery priority is set to "high." For example, the control units 201 of STA102 and STA103 determine that there are other STAs whose delivery priority is set to "high" (S1202: "high" exists). In this case, the control units 201 of STA102 and STA103 determine that the priority of the video data that they transmit to AP 101 is low, and proceed to step S1206. In step S1206, the control units 201 of STA102 and STA103 set the AC of the video data to be transmitted to AP 101 to AC_BE.

[0106] On the other hand, for example, the control unit 201 of the STA 102 and the STA 103 sets the delivery priority to "high." If the other STAs have the same bit rate as the STA102 or STA103, the control unit 201 of the STA102 or STA103 determines that there are no other STAs for which the delivery priority is set, i.e., the delivery priority of all the other STAs is "low" (S1202: all "low"). In this case, the control unit 201 of the STA102 or STA103 proceeds to step S1203. In step S1203, the control unit 201 of the STA102 or STA103 determines the bit rate of the video data to be transmitted in the own device and the other STAs. In determining the bit rate in step S1203, the control unit 201 of the STA102 or STA103 compares the bit rate of the video data in the own device and the other STAs. For example, the control unit 201 of the STA102 or STA103 determines that there is an STA that holds video data with a higher bit rate than the bit rate of the video data transmitted by the own device (S1203: "own STA<other STA"). In this case, the control unit 201 of the STA102 or STA103 determines that the priority of the video data to be transmitted by the own device is low, and proceeds to step S1206.

[0107] Also, for example, control units 201 of STA102 and STA103 determine that the bit rate of the video data transmitted by their own devices is higher than the bit rates of all the video data transmitted by the other STAs (S1203: "own STA > other STAs"). In this case, control units 201 of STA102 and STA103 determine that the priority of the video data transmitted by their own devices is high, and proceed to step S1207. Also, for example, control units 201 of STA102 and STA103 determine that the bit rate of the video data transmitted by their own devices is equal to the bit rate of all the video data transmitted by the other STAs (S1203: "own STA = other STAs"). In this case, control units 201 of STA102 and STA103 proceed to step S1204.

[0108] In determining the resolution in step S1204, the resolution of the video data in the own device is compared with that of the other STAs. For example, control units 201 of STA102 and STA103 determine that there is an STA that holds video data with a higher resolution than the resolution of the video data transmitted by the own device (S1204: "own STA<other STA"). In this case, control units 201 of STA102 and STA103 determine that the priority of the video data transmitted by the own device is low, and proceed to step S1206.

[0109] Also, for example, control units 201 of STA102 and STA103 determine that the resolution of the video data transmitted by their own devices is higher than the resolution of any of the video data transmitted by the other STAs (S1204: "own STA > other STAs"). In this case, control units 201 of STA102 and STA103 determine that the priority of the video data transmitted by their own devices is high, and proceed to step S1207. Also, for example, control units 201 of STA102 and STA103 determine that the resolution of the video data transmitted by their own devices is equal to the resolution of any of the video data transmitted by all the other STAs (S1204: "own STA = other STAs"). In this case, control units 201 of STA102 and STA103 proceed to step S1205.

[0110] In determining the resolution in step S1205, the frame rates of the video data in the own device and other STAs are compared. For example, control units 201 of STA102 and STA103 determine that there is an STA that holds video data with a frame rate higher than the frame rate of the video data transmitted by the own device (S1205: "own STA<other STA"). In this case, control units 201 of STA102 and STA103 determine that the priority of the video data transmitted by the own device is low, and proceed to step S1206.

[0111] Also, for example, control units 201 of STA102 and STA103 determine that the frame rate of the video data transmitted by their own devices is equal to or higher than the frame rate of the video data transmitted by the other STAs (S1205: "own STA≧other STA"). In this case, control units 201 of STA102 and STA103 determine that the priority of the video data transmitted by their own devices is high, and proceed to step S1207.

[0112] As described above, STA102 and STA103 compare video data parameters between themselves and other STAs in the order of bit rate, resolution, and frame rate. As a result, STA102 and STA103 determine the priority of transmitting video data from themselves to AP 101 and decide the AC of the video data to be transmitted by themselves.

[0113] Furthermore, since the above parameters may differ depending on the specifications for transmitting video data from each STA, STA102 and STA103 may compare each parameter with a threshold value in the above comparison process rather than comparing the absolute values ​​of the parameters. For example, assume that the bit rate of video data transmitted by one STA is 8 Mbps and the bit rate of video data transmitted by another STA is 9 Mbps. However, this difference in bit rates is not enough to determine that the STA holding video data with a bit rate of 9 Mbps is the main camera and the STA holding video data with a bit rate of 8 Mbps is the sub-camera in live streaming. Therefore, STA102 and STA103 perform the bit rate determination process in step S1203 above, using, for example, 10 Mbps as the threshold. In this case, for two STAs, if the bit rate of video data in one STA is 10 Mbps or higher and the bit rate of video data in the other STA is less than 10 Mbps, STA102 and STA103 assign higher priority to the former. Furthermore, if the bit rate of the video data in either STA 102 or STA 103 is 10 Mbps or higher, or if the bit rate of the video data in either STA is less than 10 Mbps, then both STAs are considered to have the same bit rate.

[0114] 11, the processing of the communication system 1 in the above example will be described. In the priority determination processing of steps S1109 and S1110, the distribution priority of STA 103 is set to "high," and therefore the distribution priority of STA 102 is determined to be low. As a result, the AC of the video data to be transmitted in STA 103 is determined to be AC_VI, and the AC of the video data to be transmitted in STA 102 is determined to be AC_BE. Then, in step S1111, upon receiving the request in step S905, the control units 201 of STA 102 and STA 103 start transmitting the video data to the distribution device 104.

[0115] Also, in step S1112, the delivery priority is set to "low" in STA 103. Then, in step S1113, control unit 201 of STA 103 notifies STA 102, with which a link was established in step S1103, that the priority setting has been changed and the changed parameter (in this case, "low"). Here, control unit 201 of STA 103 is a notification unit that notifies other communication devices of the operating state of its own communication device when the operating state of its own communication device is changed. In step S1114, control unit 201 of STA 102 returns a response to the notification from STA 103 in step S1113 to STA 103.

[0116] After notifying STA 102 of the operating state, in step S1115, control unit 201 of STA 103 performs processing to determine the priority of the video data that its own device will transmit to AP 101. Furthermore, in step S1116, upon receiving the response from STA 103 in step S1114, control unit 201 of STA 102 performs processing to determine the priority of the video data that its own device will transmit to AP 101. As a result, control units 201 of STA 102 and STA 103 determine the AC of each video data to be AC_VI.

[0117] Next, in step S1117, the control units 201 of the STAs 102 and 103 determine whether or not to transmit the video data to which the AC determined in steps S1115 and S1116 has been assigned. Then, in step S1119, the control units 201 of the STAs 102 and 103 end transmission of the video data to the distribution device 104. Thereafter, in response to the change in distribution priority in the STA 103, the control units 201 of the STAs 102 and 103 notify and respond to the change in distribution priority parameters, determine the priority, and determine the AC of the video data between the STAs. Then, in step S1118, the distribution device 104 transmits a request to stop transmission of the video data to the STAs 102 and 103. Then, in step S1119, the control units 201 of the STAs 102 and 103 end transmission of the video data to the distribution device 104.

[0118] As described in the above examples, the communication system 1 of this embodiment allows a distribution device to perform live distribution using video data transmitted from multiple communication devices, with priority given to data transmission from the communication device that holds the video data being used for distribution. This allows appropriate priorities to be set for the data transmitted by each communication device, even when multiple communication devices transmit data of the same category. As a result, it is expected that the distribution device will be less likely to be unable to receive video data from the communication devices, resulting in an interruption of distribution.

[0119] In the above embodiment, the STAs 102 and 103 assign AC information indicating the determined priority of the video data to the video data. Alternatively or in addition, the control units 201 of the STAs 102 and 103 may transmit the determined AC information to the distribution device 104 in response to a confirmation request for the video data from the distribution device 104. Here, the control units 201 of the STAs 102 and 103 are transmitters that transmit priority information to the access point in response to the confirmation request for the data from the access point. Also, a BSR is an example of a response to a confirmation request for the video data from the distribution device 104.

[0120] The various controls described above may or may not be performed by a single piece of hardware (e.g., a processor or circuit). The entire device may be controlled by multiple pieces of hardware (e.g., multiple processors, multiple circuits, or a combination of one or more processors and one or more circuits) sharing the processing.

[0121] The processor is a processor in the broad sense, and includes both general-purpose processors and dedicated processors. General-purpose processors include, for example, CPUs (Central Processing Units), MPUs (Micro Processing Units), and DSPs (Digital Signal Processors). Dedicated processors Examples of the processor include a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), etc. Examples of the programmable logic device include an FPGA (Field Programmable Gate Array), a CPLD (Complex Programmable Logic Device), etc.

[0122] Although the embodiments of the present invention have been described in detail, the present invention is not limited to these specific embodiments, and various forms within the scope of the gist of the present invention are also included in the present invention. Furthermore, each of the above-described embodiments merely represents one embodiment of the present invention, and each embodiment can be combined as appropriate.

[0123] In the above-described embodiment, the present invention has been described as being applied to a communication device, but the present invention is not limited to this example and can be applied to various communication devices that transmit data used for distribution. The communication device may be an information processing device, an image processing device, a server, a database, or the like.

[0124] <Other embodiments> The present invention provides a program for realizing one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and executes the program on a computer of the system or device. The present invention can be realized by a process in which one or more processors read and execute a program, or by a circuit that performs one or more functions.

[0125] The disclosure of this embodiment includes the following configuration, method, and program. (Configuration 1) 1. A communication device capable of communicating with an access point using Orthogonal Frequency Division Multiple Access (OFDMA), comprising: an acquisition unit that acquires an operation status related to the data in another communication device that transmits data of the same category to the access point; a determination unit that determines a priority for transmission of the data of the communication device to the access point according to the operation state of the other communication device and an operation state related to the data of the communication device; an assigning unit that assigns priority information indicating the determined priority to the data to be transmitted to the access point; A communication device comprising: (Configuration 2) the operating state indicates whether or not an external device capable of communicating with the access point is receiving a tally signal transmitted to a communication device that has transmitted the data related to the live distribution, when the external device is live-distributing the data; The determination unit determines the priority such that transmission of the data by a communication device whose operation state indicates that the tally signal is being received is given priority over transmission of the data by a communication device whose operation state indicates that the tally signal is not being received. 2. The communication device according to configuration 1. (Configuration 3) 3. The communication device according to configuration 1 or 2, further comprising a transmitting unit that transmits the priority information to the access point in response to a confirmation request for the data from the access point. (Configuration 4) the data is video data, the operating state includes any one of a bit rate, a resolution, a frame rate of the video data, and a parameter related to the priority set by a user for the video data; The determination unit determines the priority such that a communication device that transmits the data with a higher bit rate, resolution, frame rate, or any of the parameters is given priority for transmission of the data. 4. The communication device according to any one of configurations 1 to 3. (Configuration 5) a notification unit configured to notify the other communication device of the operation state of the own communication device when the operation state of the own communication device is changed; The determining unit determines the priority after the notifying unit notifies the operating state. 7. The communication device according to any one of configurations 1 to 6. (Configuration 6) 4. The communication device according to configuration 3, wherein the response to the confirmation request regarding the data is a Buffer Status Report in communication conforming to the IEEE 802.11 standard series. (Configuration 7) 7. The communication device according to any one of configurations 1 to 6, wherein the priority information includes an access category of the data in communication conforming to the IEEE 802.11 standard series. (Configuration 8) The same category of data is used in communications conforming to the IEEE802.11 standard series. The data has the same access category, The access category includes any one of video, still image, and audio. 8. The communication device according to any one of configurations 1 to 7. (method) 1. A method for controlling a communication device capable of communicating with an access point using Orthogonal Frequency Division Multiple Access (OFDMA), comprising: obtaining operational states related to the data of other communication devices that transmit data of the same category to the access point; determining a priority for transmitting the data of the communication device to the access point according to the operation state of the other communication device and an operation state related to the data of the communication device; adding priority information indicating the determined priority to the data to be transmitted to the access point; A control method for a communication device comprising: (program) A program for causing a computer to function as each part of the communication device according to any one of configurations 1 to 8. [Explanation of symbols]

[0126] 101 access point, 102, 103 STA, 104 distribution device, 201 control unit

Claims

1. 1. A communications device capable of communicating with an access point using Orthogonal Frequency Division Multiple Access (OFDMA), comprising: an acquisition unit that acquires an operation status related to the data in another communication device that transmits data of the same category to the access point; a determination unit that determines a priority for transmission of the data of the communication device to the access point according to the operation state of the other communication device and an operation state related to the data of the communication device; an assigning unit that assigns priority information indicating the determined priority to the data to be transmitted to the access point; A communication device comprising:

2. the operating state indicates whether or not an external device capable of communicating with the access point is receiving a tally signal transmitted to a communication device that has transmitted the data related to the live distribution, when the external device is live-distributing the data; The determination unit determines the priority such that transmission of the data by a communication device whose operation state indicates that the tally signal is being received is given priority over transmission of the data by a communication device whose operation state indicates that the tally signal is not being received.

2. The communication device according to claim 1.

3. 2. The communication device according to claim 1, further comprising a transmitting unit that transmits the priority information to the access point in response to a confirmation request for the data from the access point.

4. the data is video data, the operating state includes any one of a bit rate, a resolution, a frame rate of the video data, and a parameter related to the priority set by a user for the video data; The determination unit determines the priority such that a communication device that transmits the data with a higher bit rate, resolution, frame rate, or any of the parameters is given priority for transmission of the data.

2. The communication device according to claim 1.

5. a notification unit configured to notify the other communication device of the operation state of the own communication device when the operation state of the own communication device is changed; The determining unit determines the priority after the notifying unit notifies the operating state.

2. The communication device according to claim 1.

6. 4. The communication device according to claim 3, wherein the response to the confirmation request regarding the data is a Buffer Status Report in communication conforming to the IEEE 802.11 standard series.

7. 2. The communication device according to claim 1, wherein the priority information includes an access category of the data in communication conforming to the IEEE 802.11 standard series.

8. The data of the same category is data of the same access category in communication conforming to the IEEE 802.11 standard series, The access category includes any one of video, still image, and audio.

2. The communication device according to claim 1.

9. 1. A method for controlling a communication device capable of communicating with an access point using Orthogonal Frequency Division Multiple Access (OFDMA), comprising: obtaining operational states related to the data of other communication devices that transmit data of the same category to the access point; determining a priority for transmitting the data of the communication device to the access point according to the operation state of the other communication device and an operation state related to the data of the communication device; adding priority information indicating the determined priority to the data to be transmitted to the access point; A control method for a communication device comprising:

10. A program for causing a computer to function as each unit of the communication device according to any one of claims 1 to 8.

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