Communication control device, communication control method, and computer program

Abstract

[Problem] To achieve lower power consumption by appropriately setting priority periods for transmitting data. [Solution] A communication control device according to the present disclosure comprises a control unit that controls a communication unit that communicates with a wireless communication device. The control unit performs control of: acquiring, via the communication unit, first information that is transmitted from the wireless communication device and indicates a first period as a priority period during which transmission of data of a specific type is prioritized; acquiring, via the communication unit, second information that is transmitted from the wireless communication device and is for setting the priority period to a second period that is shorter than the first period; and setting the priority period to the second period on the basis of the first information and the second information.

Description

Communication control device, communication control method, and computer program

[0001] The present disclosure relates to a communication control device, a communication control method, and a computer program.

[0002] In recent years, the practical application of next-generation applications such as VR (Virtual Reality), AR (Augmented Reality), and XR (Extended Reality / Cross Reality) has been increasing year by year. Currently, the most common use case is a wired connection between a console, which generates video information, and a head-mounted display (HMD), which displays the video information. However, wireless kit products that eliminate the need for a wired cable between the console and HMD are also commercially available. It is predicted that the trend toward completely wireless communication between the two will accelerate in the future. Furthermore, systems in which a rendering server resides on a local network or in the cloud, and the generated video information is transmitted to the HMD via a wireless local area network (LAN) access point (AP) are also expected to become more common.

[0003] Requirements for wireless HMDs include low-latency transmission of video information and low power consumption of HMDs. One method for addressing both of these issues is Restricted TWT (R-TWT), adopted in the IEEE802.11be standard. By using R-TWT, it is possible to prevent interruptions from surrounding devices by temporarily halting data transmission during periods when low-latency traffic transmission is required. Furthermore, the HMD device can enter sleep mode outside of this period. Therefore, it is expected that low-latency transmission and low power consumption can be achieved.

[0004] IEEE802.11-22 / 0304r0, “Restricted TWT SP Early Termination”

[0005] However, because this function sets periodic slots at intervals of about 10 ms as the occupancy period for data transmission at beacon intervals of 100 to 200 ms, if the arrival time of video information, for example, fluctuates, the video information cannot be received at the slot timing, causing transmission delays. Setting a longer slot time increases the chances of receiving video information even if the arrival time is delayed, but it also reduces the time the HMD device can transition to sleep mode, which is likely to impair the low power consumption effect.

[0006] In order to solve the above-mentioned problems, the present disclosure aims to reduce power consumption by appropriately setting a priority period for transmitting data.

[0007] The communication control device of the present disclosure includes a control unit that controls a communication unit that communicates with a wireless communication device, and the control unit acquires, via the communication unit, first information transmitted from the wireless communication device that indicates a first period as a priority period during which transmission of a specific type of data is prioritized, acquires, via the communication unit, second information transmitted from the wireless communication device for setting the priority period to a second period that is shorter than the first period, and performs control to set the priority period to the second period based on the first information and the second information.

[0008] 1 is a diagram showing an example of a system configuration in a first embodiment of the present disclosure. FIG. 1 is a block diagram of an AP in the present disclosure. FIG. 2 is a block diagram of an STA in the present disclosure. FIG. 3 is a diagram for explaining an overview of R-TWT (Restricted Target Wake Time). FIG. 4 is a diagram for explaining the problems of R-TWT explained in FIG. 5. FIG. 6 is an overall sequence diagram of this embodiment. FIG. 7 is a diagram showing an example configuration of a Capability Element used in the Association Phase. FIG. 8 is a diagram showing an example configuration of a TWT Element used in the Data Tx Phase. FIG. 9 is a diagram showing an example configuration of TWT Adjustment Info. FIG. 10 is a diagram showing an example configuration of a TWT Change Frame. FIG. 11 is a flowchart of an example operation of an AP. FIG. 12 is a flowchart of an example operation of an STA. FIG. 13 is a diagram showing a first example sequence in the first embodiment. FIG. 14 is a diagram showing a second example sequence in the first embodiment. FIG. 15 is a diagram showing a third example sequence in the first embodiment. FIG. 16 is a diagram showing an example system architecture according to a second embodiment. FIG. 17 is a block diagram of an example of a Rendering Device in the second embodiment. FIG. 18 is a diagram showing a first example sequence in the second embodiment. FIG. 19 is a diagram showing a second example sequence in the second embodiment. FIG. 20 is a diagram showing a third example sequence in the second embodiment. FIG. 21 is a block diagram of an example configuration of an AP in the third embodiment. FIG. 22 is a block diagram of an example configuration of an STA in the third embodiment. A block diagram showing an example of the hardware configuration of a computer that executes a series of processes according to the present disclosure using a program. A block diagram showing an example of the schematic configuration of a smartphone to which the technology of the present disclosure is applied. A block diagram showing an example of the schematic configuration of an in-vehicle device to which the technology of the present disclosure is applied. A block diagram showing an example of the schematic configuration of a wireless AP to which the technology of the present disclosure is applied.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] First Embodiment FIG. 1 shows an example of a system configuration according to a first embodiment of the present disclosure.

[0011] The system in FIG. 1 includes one AP device (Access Point, base station) 100 and three STA devices (STAtion, child devices) 1, 2, and 3. The system also includes a Rendering Server 300 (data generation device) connected to the AP device 100 via a wired backhaul (communications network). All three STA devices 1 to 3 are wirelessly connected to the AP 100, forming a BSS (Basic Service Set) that exchanges information wirelessly with the AP 100. Hereinafter, the AP device 100 will be referred to as AP100, and the STA devices 1 to 3 will be referred to as STA1 to STA3. In this embodiment, STA1 to STA3 have the following features.

[0012] STA1 is a device (commonly known as a Head Mount Display: HMD) that executes VR / AR / XR applications and can be worn on the user's head. STA1 feeds back its own position information, which changes according to the user's movements, to Rendering Server 300, and acquires and displays video information generated by Rendering Server 300 according to the position information. STA1 has the capability to execute the functions of the present disclosure, which will be described later. Rendering Server 300 is a data generation device that generates data such as video information and distributes the generated data. STA2 is a general communication device (such as a smartphone) that performs Internet communication via AP 100. STA2 has the capability to execute the functions of the present disclosure, which will be described later. STA3 is a general communication device that performs Internet communication via AP 100. STA2 does not have the capability to execute the functions of the present disclosure, which will be described later.

[0013] The present disclosure is not limited to the system configuration shown in FIG. 1 . For example, the number of STAs may be three or more. STA 1 does not have to be a device worn by a user as shown in the figure, but may be a general communication device. Furthermore, the rendering server 300 may be located on the cloud side.

[0014] 2 is a block diagram of an AP 100 according to the present disclosure. The AP 100 mainly includes a wireless communication unit 110, a control unit 130, a storage unit 140, an antenna 150, and a backhaul communication unit 160. In addition to the operations described in this embodiment, the AP 100 may also operate as a wireless LAN base station conforming to the IEEE 802.11 standard, such as IEEE 802.11a / b / g / n / ac / ax / be / bn. For example, the AP 100 may operate based on CSMA / CA (Carrier Sense Multiple Access with Carrier Avoidance) as its access method, and may also transmit beacon signals at regular intervals (periodically).

[0015] The wireless communication unit 110 performs wireless communication with STAs, which are other connected wireless communication devices (devices having a wireless communication unit). The wireless communication unit 110 includes a communication control unit 111, a communication storage unit 112, a data processing unit 121, a signal processing unit 122, a wireless interface unit 123, and an amplifier unit 124. The communication unit of the base station according to this embodiment at least partially includes the functions performed by at least one of the wireless communication unit 110 and the backhaul communication unit 160.

[0016] The communication control unit 111 controls the operation of each unit and the transmission of information between each unit, and also passes control information and management information to the data processing unit 121 to be notified to other wireless communication devices.

[0017] The communication storage unit 112 stores information used by the communication control unit 111. The communication storage unit 112 also stores data (or data packets) to be transmitted and received data (or data packets). A transmission buffer that stores data to be transmitted is included in the communication storage unit 112.

[0018] During transmission, the data processing unit 121 manages the sequence of information to be transmitted. The information to be transmitted includes data stored in the communication storage unit 112 and control information and management information received from the communication control unit 111. The data processing unit 121 performs encryption processing and the like on the information to be transmitted, then adds a MAC (Media Access Control) header and an error detection code to generate a frame. The data processing unit 121 may also perform processing to concatenate multiple frames. During reception, the data processing unit 121 performs processing to deconcatenate, analyze, and detect errors in the MAC headers of received frames. The data processing unit 121 also performs reordering processing in response to a retransmission request. The frame type may be any of a data frame, management frame, and control frame.

[0019] During transmission, the signal processing unit 122 performs encoding, interleaving, modulation, etc. on frames, and adds a physical header to generate a symbol stream. During reception, the signal processing unit 122 analyzes the physical header and performs demodulation, deinterleaving, decoding, etc. on the symbol stream to generate a frame. The signal processing unit 122 also estimates complex channel characteristics and performs spatial separation processing as necessary.

[0020] During transmission, the wireless interface unit 123 performs digital-to-analog signal conversion, filtering, up-conversion, and phase control on the symbol stream to generate a transmission signal. During reception, the wireless interface unit 123 performs down-conversion, filtering, and analog-to-digital signal conversion on the received signal to generate a symbol stream.

[0021] The amplifier 124 amplifies a signal input from the wireless interface 123 or the antenna 150. A part of the amplifier 124 may be a component outside the communication unit. Alternatively, a part of the amplifier 124 may be included in the wireless interface 123.

[0022] Although an example of a SISO (Single-Input Single-Output) configuration in which one pair of amplifier 124 and antenna 150 is provided is shown here, a configuration that enables MIMO (Multi-Input Multi-Output) transmission and reception processing by using multiple pairs of antenna 150 and amplifier 124 is also possible. Also, a configuration having multiple pairs of wireless interface units, signal processing units, data processing units, etc. is also possible so that multiple links or multiple frequency channels can operate in parallel. Details of this will be described in the explanation of the third embodiment.

[0023] Although the wireless communication unit 110 is shown in the figure as being configured as a single IC, the IC configuration is not limited to this. For example, the wireless interface unit may be configured as a separate IC.

[0024] The control unit 130 controls the wireless communication unit 110 and the communication control unit 111. The control unit 130 may also perform part of the operations of the communication control unit 111. The communication control unit 111 and the control unit 130 may also be configured as a single block.

[0025] The control unit according to this embodiment at least partially includes the functions of at least one of the communication control unit 111 and the control unit 130. The control unit controls the wireless communication unit 110, which communicates with multiple STAs (wireless communication devices), and transmits first information indicating a first period as a priority period for transmitting a specific type of data (e.g., a specified type) to the multiple STAs. The control unit also controls the transmission of second information to at least one target wireless communication device (e.g., STA1) among the multiple STAs, for setting the priority period to a second period shorter than the first period. The control unit also controls information communication related to the setting of the first period and the second period, communication within the first period and the second period, and communication outside the first period and the second period. Details of the control performed by the control unit will be described later in the sequences (see Figures 13 to 15) and operation flow (see Figure 11) of this disclosure.

[0026] The storage unit 140 holds information used by the control unit 130 and the wireless communication unit 110. The storage unit 140 may also perform part of the operations of the communication storage unit 112. The storage unit 140 and the communication storage unit 112 may be configured as a single block.

[0027] The backhaul communication unit 160 communicates with other devices via a backhaul network, which is a wired or wireless communication network. The other devices include the Rendering Server 300. The backhaul communication unit 160 decodes packets received from the backhaul network and passes them to the wireless communication unit 110 via the control unit 130. The format of the packets passed here may be one in which the IP header remains intact (access point mode) or one in which the IP header has been decoded and removed by the backhaul communication unit 160 (router mode). In this embodiment, communication with the Rendering Server 300 is performed via the backhaul communication unit 160, but communication via the wireless communication unit 110 is also possible.

[0028] FIG. 3 is a block diagram of STA 200 according to the present disclosure. STA 200 corresponds to STAs 1 and 2 in FIG. 1. STA 3 may have a similar configuration to STAs 1 and 2, but does not include the functions related to the present disclosure. STA 200 mainly includes a wireless communication unit 210, a control unit 230, a storage unit 240, and an antenna 250. In addition to the operations described in this embodiment, STA 200 may also operate as a wireless LAN station conforming to the IEEE 802.11 standard, such as IEEE 802.11a / b / g / n / ac / ax / be / bn. For example, STA 200 may operate based on CSMA / CA (Carrier Sense Multiple Access with Carrier Avoidance) as its access method.

[0029] The wireless communication unit 210 performs processing for wireless communication with the AP 100 or other STAs, which are other wireless communication devices (devices having a wireless communication unit) connected thereto. The wireless communication unit 210 includes a communication control unit 211, a communication storage unit 212, a data processing unit 221, a signal processing unit 222, a wireless interface unit 223, and an amplifier unit 224.

[0030] The communication control unit 211 controls the operation of each unit and the transmission of information between each unit. The communication control unit 211 also passes control information and management information to the data processing unit 221, which are to be notified to other wireless communication devices.

[0031] The communication storage unit 212 stores information used by the communication control unit 211. The communication storage unit 212 also stores data (or data packets) to be transmitted and received data (or data packets). A transmission buffer that stores data to be transmitted is included in the communication storage unit 212.

[0032] During transmission, the data processing unit 221 manages the sequence of information to be transmitted. The information to be transmitted includes data stored in the communication storage unit 212 and control information and management information received from the communication control unit 211. The data processing unit 221 performs encryption processing and the like on the information to be transmitted, then adds a MAC (Media Access Control) header and an error detection code to generate a frame. The data processing unit 221 may also perform processing to concatenate multiple frames. During reception, the data processing unit 221 performs processing to deconcatenate, analyze, and detect errors in the MAC headers of received frames. The data processing unit 221 also performs reordering processing in response to a retransmission request. The frame type may be any of a data frame, management frame, and control frame.

[0033] During transmission, the signal processing unit 222 performs encoding, interleaving, modulation, etc. on frames, and adds a physical header to generate a symbol stream. During reception, the signal processing unit 222 analyzes the physical header and performs demodulation, deinterleaving, decoding, etc. on the symbol stream to generate a frame. The signal processing unit 222 also estimates complex channel characteristics and performs spatial separation processing as necessary.

[0034] During transmission, the wireless interface unit 223 performs digital-to-analog signal conversion, filtering, up-conversion, and phase control on the symbol stream to generate a transmission signal. During reception, the wireless interface unit 223 performs down-conversion, filtering, and analog-to-digital signal conversion on the received signal to generate a symbol stream.

[0035] The amplifier 224 amplifies a signal input from the wireless interface 223 or the antenna 250. A part of the amplifier 224 may be a component outside the communication unit. Also, a part of the amplifier 224 may be included in the wireless interface 223.

[0036] Although an example of a SISO configuration in which one pair of amplifier 224 and antenna 250 is provided has been shown here, a configuration that enables MIMO transmission and reception processing by using multiple pairs of antenna 250 and amplifier 224 is also possible. Also, a configuration having multiple pairs of wireless interface units, signal processing units, data processing units, etc. is also possible so that multiple links or multiple frequency channels can operate in parallel. Details of this will be described in the explanation of the third embodiment.

[0037] Although the wireless communication unit 210 is shown in the figure as being configured as a single IC, the IC configuration is not limited to this. For example, the wireless interface unit may be configured as a separate IC.

[0038] The control unit 230 controls the wireless communication unit 210 and the communication control unit 211. The control unit 230 may also perform part of the operations of the communication control unit 211. The communication control unit 211 and the control unit 230 may also be configured as a single block.

[0039] The control unit according to this embodiment controls the wireless communication unit 210, which communicates with the AP 100 (wireless communication unit device), and acquires first information from the AP 100 via the wireless communication unit 210, indicating a first period as a priority period for transmitting data of a specific type (e.g., a specified type), and controls the setting of the first period. The control unit also acquires second information via the wireless communication unit 210 for setting a second period shorter than the first period, and controls the change of the priority period from the first period to the second period based on the second information and the first information. The control unit also controls information communication related to the setting of the first period and the second period, communication within the first period and the second period, and communication outside the first period and the second period. The priority period for transmitting data may be an exclusive period during which data transmission is exclusively performed (during which other devices are not permitted to send or receive data), or a period during which data transmission can be performed before other devices (during which other devices are permitted to send or receive data, but only after the device itself has finished sending or receiving data). In this embodiment, the priority period is assumed to be an exclusive period, but is not limited thereto. Details of the control by this control unit will be described later in the sequences (see FIGS. 13 to 15) and operation flow (see FIG. 11) of this disclosure.

[0040] The storage unit 240 holds information used by the control unit 230 and the wireless communication unit 210. The storage unit 240 may also perform part of the operations of the communication storage unit 212. The storage unit 240 and the communication storage unit 212 may be configured as a single block.

[0041] 4 is a diagram for explaining an overview of R-TWT (Restricted Target Wake Time) as a related technique. R-TWT (Restricted Target Wake Time) will be explained using FIG. 4.

[0042] R-TWT is a function that achieves low-latency transmission without interrupting the transmission of latency-sensitive traffic by setting a service period (SP)—an exclusive period for transmitting latency-sensitive traffic—as R-TWT SP 401 throughout the entire BSS. For example, if STA2 or STA3 starts an uplink transmission just before AP 100 transmits picture data to STA1, AP 100 must wait until the transmission ends, resulting in a delay in the transmission of the picture data. Furthermore, because STA1 does not know when the picture data from AP 100 will arrive, STA1 constantly scans channels to attempt to detect a received signal, resulting in a certain amount of power consumption even outside of communication periods. Furthermore, when either STA2 or STA3 starts an uplink transmission to AP 100, STA1 begins receiving processing even if the signal is not addressed to it, which raises concerns about increased power consumption.

[0043] Therefore, as shown in Figure 4, AP 100 can set R-TWT SP 401 for video information (Picture Data) transmission in advance, thereby halting uplink transmissions of STA2 and STA3 during this period. This prevents interruptions and reduces the transmission delay of video information (Picture Data) to STA1. Furthermore, STA1 can enter low power consumption mode (i.e., turn off at least some RF / PHY / MAC functions) outside of this R-TWT SP 401, i.e., transition to Doze state 402, thereby reducing power consumption outside of communication. In this way, utilizing scheduling technology within the BSS makes it possible to address both the low-latency transmission required for applications such as VR / AR / XR and low power consumption on the HMD side.

[0044] Information regarding the R-TWT SP is included in a beacon signal broadcast by AP 100, and an operation in which R-TWT SPs having the same period length are set at regular intervals during the beacon interval is considered to be a common method.

[0045] R-TWT is a feature currently being defined in IEEE802.11be and is expected to be implemented as part of Wi-Fi 7. However, depending on the usage environment, it is anticipated that legacy devices that predate Wi-Fi 7 may exist. In this case, for example, a method is being considered in which the TWT function, the predecessor of R-TWT, is used in conjunction with R-TWT for Wi-Fi 6 (IEEE802.11ax)-compatible devices, and the Quiet function is used in conjunction with R-TWT for older Wi-Fi devices, thereby stopping transmission initiation during the R-TWT SP period for legacy devices as well. WLAN scheduling technology must also take into account the existence of such legacy devices.

[0046] FIG. 5 is a diagram for explaining the problem with the R-TWT described with reference to FIG.

[0047] 4, it is assumed that the video information (Picture Data) arrives at a fixed time interval from the Rendering Server 300 to the AP 100, so there is basically no problem using an R-TWT SP that has a fixed period length and is set at fixed intervals. In fact, in applications such as VR / AR / XR, video information (Picture Data) is generated at a fixed cycle determined by the refresh rate.

[0048] However, the arrival time of picture data may not be constant. For example, jitter occurs due to various factors, such as the processing load on the Rendering Server 300, delays on the backhaul side, and the processing load on the AP's upper layer (processing unit). In this case, if the R-TWT SP is not set to a slightly longer value to take the jitter into account, the picture data cannot be received within the R-TWT SP.

[0049] Therefore, Non-Patent Document 1 proposes a method of setting a longer R-TWT SP 403 and terminating the R-TWT SP early if the transmission of video information (Picture Data) to STA1 is completed early. However, conversely, if the video information (Picture Data) arrives at AP 100 later than expected, STA1 must attempt signal detection by channel scanning for a long time 404A, 404B, which is likely to undermine the low power consumption effect on STA1 (HMD side). Furthermore, STA2 and STA3 must also suspend their own transmissions for a long time, which may reduce effective throughput.

[0050] (Summary of the Solution of the Present Disclosure) In view of the above, the AP 100 is provided with a function that can adjust or change at least one of the start time and duration (start time / duration) for each R-TWT SP (occupancy period for data transmission). Existing standards offer a similar function, "flexible TWT," which flexibly sets the TWT by transmitting a TWT information frame, as defined in IEEE 802.11ax. However, "flexible TWT" only supports individual TWT, which sets an individual SP for each STA, and does not support broadcast TWT like R-TWT. To achieve similar functional flexibility with broadcast TWT, the impact on all STAs within the BSS must be considered, and in particular, the SP must be adjusted to take into account compatibility with terminals prior to IEEE 802.11be (Wi-Fi 7).

[0051] Therefore, the present disclosure provides a method for performing flexible R-TWT adjustment by using the following features as an example, although the features of the present disclosure are not limited to the following.

[0052] AP 100 notifies the R-TWT SP using the TWT Element as a rough SP, "Rough R-TWT SP" (first period), and then notifies the R-TWT SP as an "Accurate R-TWT SP" (second period) obtained by adjusting the "Rough R-TWT SP" to an accurate SP. The "Accurate R-TWT SP" (second period) may be shorter than the "Rough R-TWT SP" (first period), and the "Accurate R-TWT SP" (second period) may be a part of the "Rough R-TWT SP" (first period). STAs that have the ability (adjustment function) to adjust this "Rough R-TWT SP" to the "Accurate R-TWT SP" are called "SP Adjustment-capable STAs," and STAs that do not support this adjustment function are called "SP Adjustment-incapable STAs." In the present disclosure, STA1 and STA2 correspond to "SP Adjustment-capable STAs," and STA3 corresponds to an "SP Adjustment-incapable STA."

[0053] - STAs that support SP Adjustment will be able to adjust their SP based on the above method, and STAs that do not support SP Adjustment will use the Rough R-TWT SP as the R-TWT SP and perform R-TWT operation in accordance with the 802.11be standard.

[0054] - If a STA that does not support SP Adjustment exists in the BSS, the "Accurate R-TWT SP" must be set within the "Rough R-TWT SP" period.

[0055] The SP adjustment method differs depending on the type of jitter (time lag or fluctuation) in the arrival time of the video information.

[0056] - If there is a correlation in the jitter of the arrival time (for example, the jitter is constant and the arrival time of the next video information can be predicted with a certain degree of accuracy), AP100 delays the start time of the Rough R-TWT SP little by little (for example, by a fixed amount of time) and sets the delayed Rough R-TWT SP as the Accurate R-TWT SP.

[0057] - If there is no correlation in the jitter of arrival times (for example, the jitter varies greatly and the arrival time of video information cannot be predicted), AP 100 sets Accurate R-TWT SP by notifying the STA of Accurate R-TWT SP in a frame before the start time of Rough R-TWT SP.

[0058] Hereinafter, based on the system configuration shown in FIG. 1, details of an embodiment having the R-TWT SP adjustment function according to the present disclosure will be described.

[0059] 6 is a sequence diagram of the entire embodiment, which mainly includes an Association Phase S110 and a Data Tx Phase S120 following the Association Phase.

[0060] In Association Phase S110, authentication and connection processing is performed between AP 100 and STAs 1 to 3. In this phase, capability information regarding whether "SP Adjustment" is supported or not is exchanged between AP 100 and each STA. Details will be explained later with reference to FIG. 7.

[0061] In Data Tx Phase S120, data is transmitted between the AP 100 and each STA. In this phase, the AP 100 uses a Beacon signal to set a "Rough R-TWT SP" for each STA, and then performs R-TWT operation by having SP Adjustment-compatible STAs reset their SP from "Rough R-TWT SP" to "Accurate R-TWT SP." Details will be explained later using Figure 8 and subsequent figures.

[0062] FIG. 7 shows an example of the configuration of a Capability Element used in the Association Phase S110. This Element includes flag information for "SP Adjustment Support" in the MAC Capabilities Information of the Capability Element used for each version of the IEEE 802.11 standard (e.g., HT / HE / EHT). This flag information corresponds to Capability information indicating support for "SP Adjustment." Note that "xxx" in the figure is set to the version name of the supported standard. For example, for the 11bn-equivalent standard, "xxx" is expected to be "UHR (Ultra High Reliability)." Support for "SP Adjustment" means having the ability to adjust or change "Rough R-TWT SP" (first period) to "Accurate R-TWT SP" (second period).

[0063] Fig. 8 shows an example of the configuration of a TWT Element used in the Data Tx Phase S120. This is based on the TWT Element described in IEEE802.11be D3.0, and newly includes "TWT Adjustment Info". Whether or not TWT Adjustment Info is included in this Element can be determined by checking the "Broadcast TWT ID" field in Broadcast TWT Info. Details will be given later. Details of "TWT Adjustment Info" will be given later in Fig. 9. Here, the other fields will be explained below.

[0064] ・Target Wake Interval Exponent of Request Type: Exponent information used to calculate the interval between successive R-TWT SPs

[0065] ・Target Wake Time: Time information used to set the period until the start of the first R-TWT SP

[0066] Nominal Minimum TWT Wake Duration: Time information used to set the R-TWT SP period.

[0067] TWT Wake Interval Mantissa: Base information used to calculate the interval between successive R-TWT SPs

[0068] Broadcast TWT ID of Broadcast TWT Info: Identifier information for this TWT process. If the most significant bit of the 5-bit identification information (Broadcast TWT ID) is "1", it means that "TWT Adjustment Info" follows, i.e., R-TWT Adjustment is to be performed.

[0069] One, all, or any combination of the above-mentioned Target Wake Interval Exponent, Target Wake Time, Nominal Minimum TWT Wake Duration, and TWT Wake Interval Mantissa corresponds to an example of first information that instructs the setting of a first period (e.g., R-TWT SP).

[0070] Restricted TWT Traffic Info: Information specifying the type of traffic. For example, a traffic ID between 0 and 7 can be specified. The type of traffic specified here corresponds to, for example, a specific type of data, or data requiring low-latency transmission.

[0071] The TWT Adjustment Info included in the TWT Element will be described with reference to FIG.

[0072] Fig. 9 shows an example of the structure of TWT Adjustment Info. Note that TWT Adjustment Info does not necessarily have to be included in a TWT Element, and may be notified to STAs as a separate Element (in that case, additional information for linking with a TWT Element, such as a Broadcast TWT ID, is required). Note that the structure of TWT Adjustment Info is not limited to the structure shown in Fig. 9, and it is sufficient if at least part of the information shown in Fig. 9 is included. Each field of the TWT Adjustment Info in Fig. 9 will be explained below.

[0073] Jitter Type: Accurate Information about the jitter of the R-TWT SP start time. "0" means that the jitter is predictable, and "1" means that the jitter is unpredictable. However, the meanings of "0" and "1" may be reversed. A predictable jitter means that the time available to acquire video information from the Rendering Server 300 is predictable (in other words, the time available to transmit the acquired video information is predictable). An unpredictable jitter means that the time available to acquire video information from the Rendering Server 300 is unpredictable (in other words, the time available to transmit the acquired video information is unpredictable).

[0074] Target Wake Time Offset Value: This is time information used when adjusting the Accurate R-TWT SP start time (time information indicating how much the Accurate R-TWT SP start time is shifted from the start time of the corresponding R-TWT SP), and corresponds to the reference offset value. It is used when the Jitter Type is "0" (predictable). This reference offset value is cumulatively added to the offset value applied to the previous R-TWT SP (see FIG. 13, described later). As a result, when R-TWT SPs are placed periodically at intervals in the time direction, the offset value of the Accurate R-TWT SP corresponding to the R-TWT SP (the deviation from the start time of the R-TWT SP) increases as the time direction advances.

[0075] Default Accurate R-TWT Wake Duration: Default duration information indicating the default duration of the Accurate R-TWT SP. Used when Jitter Type is "0" (predictable). This default duration information corresponds to the duration information starting from the time indicated by the offset value above.

[0076] TWT Change Frame Timing Control Info: Information about the contents of the following TWT Change Frame Timing field. Used when Jitter Type is "1" (unpredictable). If TWT Change Frame Timing Control Info is "0", the TWT Change Frame Timing field indicates information about the timing of TWT Change Frame transmission. This information can be absolute time, or information about how far in advance the frame is to be transmitted from the Rough R-TWT SP start time (time going back from the Rough R-TWT SP start time). If TWT Change Frame Timing Control Info is "1", the TWT Change Frame Timing field indicates information identifying another R-TWT SP (for example, an R-TWT SP after the next R-TWT SP) that is the target of transmitting the TWT Change Frame.

[0077] TWT Change Frame Timing: Information about the transmission timing of the TWT Change Frame. If TWT Change Frame Timing Control Info is "0", TWT Change Frame Timing contains time information. If TWT Change Frame Timing Control Info is "1", TWT Change Frame Timing contains the TWT ID (or information that can identify the R-TWT SP).

[0078] At least one of the above-mentioned Target Wake Time Offset Value and Default Accurate R-TWT Wake Duration corresponds to an example of first information that instructs the setting of the second period (e.g., Accurate R-TWT SP).

[0079] The TWT Change Frame will be described with reference to FIG.

[0080] Fig. 10 shows an example of the structure of a TWT Change Frame. Here, the structure is based on the Action frame of IEEE802.11, but the structure of the TWT Change Frame is not limited to that shown in Fig. 10, and it is sufficient if it contains at least some of the information shown in Fig. 10. Each field of the TWT Change Frame in Fig. 10 will be explained below.

[0081] Type: Information for identifying whether this frame is an "SP adjustment request from AP to STA" or an "SP adjustment request from STA to AP." In this embodiment, only the former is used. The latter is used in the second embodiment, which will be described later.

[0082] Broadcast TWT ID: Information to identify the R-TWT process that this frame is for (R-TWT process identifier information)

[0083] Next TWT SP: Information indicating whether to apply to the next R-TWT SP. For example, if it is "0", it indicates that it will be applied from the next R-TWT SP, and if it is "1" or greater, it indicates which R-TWT SP from the next R-TWT SP it will be applied to.

[0084] Accurate Target Wake Time: Accurate R-TWT SP start time information. This can be absolute time or relative time (adjusted time) based on some starting time. Examples of starting time include the transmission timing of this frame or the start time of Rough R-TWT SP.

[0085] Accurate TWT Wake Duration: Accurate R-TWT SP duration information

[0086] FIG. 11 is a flowchart showing an example of the operation of the AP 100.

[0087] First, the AP 100 checks the jitter (arrival time jitter) of the time it takes for video information (picture data) from the Rendering Server 300 to arrive at the AP 100 (S210). The AP 100 may estimate the arrival time jitter through learning using AI (Artificial Intelligence) or ML (Machine Learning), or may obtain information about the arrival time jitter from the Rendering Server 300 or another external device.

[0088] The AP 100 determines whether the arrival time jitter is below a threshold, and if so, determines that the arrival time jitter is small and negligible, or that there is no jitter (YES in S220). In this case, the AP 100 transmits a Beacon signal containing a TWT element in the format of the TWE element shown in FIG. 8 that does not include the optional TWT Adjustment Info (S230). That is, the AP 100 transmits a Beacon signal containing the TWT element according to the conventional R-TWT processing. After this, the AP 100 transmits the specified traffic, i.e., the video information (Picture Data) received from the Rendering Server 300, according to the R-TWT SP set in the TWT element.

[0089] If the arrival time jitter is greater than the threshold, the AP 100 determines whether the arrival time jitter is predictable (correlated) (S240). For example, if the arrival time is expected to be delayed by a certain amount each time, it is determined to be predictable. If the delay time is expected to vary greatly, it is determined to be unpredictable. If it is determined to be predictable (correlated), the AP 100 broadcasts a Beacon signal containing R-TWT SP Adjustment Info with Jitter Type set to "0" in the TWT Element to its subordinate STAs (S250). The operation of step S250 corresponds, for example, to a second operation, which is an operation of transmitting a third frame containing first information indicating a first period as a priority period for preferentially transmitting data and second information for setting a second period shorter than the first period. The AP 100 then adjusts the start time / period length of the Rough R-TWT SP to set an Accurate R-TWT SP. That is, for each SP, the start time is cumulatively increased by the offset value to set an Accurate R-TWT SP. The duration of each period is the same as the Default Accurate R-TWT Wake Duration. The specified traffic (Picture Data) is transmitted using the specified Accurate R-TWT SP.

[0090] If the AP 100 determines that the arrival time jitter is unpredictable (uncorrelated), it broadcasts a Beacon signal containing R-TWT SP Adjustment Info with Jitter Type set to "1" in the TWT Element to its subordinate STAs (S260). Then, it broadcasts a TWT Change Frame at the timing specified in the TWT Change Frame Timing field of the R-TWT SP Adjustment Info (S270). The AP 100 then transmits the specified traffic (picture data) within the Accurate R-TWT SP set by adjusting the start time / duration of the Rough R-TWT SP. Steps S260 and S270 correspond to a first operation, which is an operation of transmitting a first frame containing first information indicating a first period as a priority period for preferentially transmitting data, and transmitting a second frame containing second information for setting a second period shorter than the first period after transmitting the first frame. In this way, the AP 100 selectively executes the first operation and the above-described second operation depending on the determination result in step S250.

[0091] Note that the signal containing the TWT Element is not limited to a beacon signal, and may be contained in other broadcast signals.

[0092] FIG. 12 shows a flowchart of an example of the operation of the STA.

[0093] When a STA acquires a TWT Element from a Beacon signal received from the AP 100 (S310), it first checks the Broadcast TWT ID field of the Broadcast TWT Info. If the most significant bit of this field is "0" (NO in S340), or if the STA does not support SP Adjustment (NO in S320) (i.e., if the STA does not have the capability to interpret this field and cannot check it), the STA performs scheduling control using the R-TWT SP set in the TWT Element according to conventional R-TWT processing (S320, S330).

[0094] The scheduling control referred to here includes the following: - Always end its own uplink transmission before the start time of the R-TWT SP. - Do not start transmission of any traffic other than the designated traffic during the R-TWT SP period. - If no traffic transmission is performed outside the R-TWT SP period and no data is acquired from the AP 100, it is permissible to transition to low power consumption (Doze) mode (however, prior negotiation with the AP 100 is required).

[0095] If the STA is an SP Adjustment-compatible STA and the most significant bit of this field is "1" (YES in S340), the STA checks the TWT Adjustment Info in the TWT Element. If the Jitter Type in the TWT Adjustment Info is "0" (the SP start time is predictable) (YES in S350), the STA sets an Accurate R-TWT SP by delaying the start time of the R-TWT SP (Rough R-TWT SP) set in this Element by the "Target Wake Time Offset Value" and performs scheduling control (S380). At this time, the duration of the Accurate R-TWT SP is obtained from the Default Accurate R-TWT Wake Duration in the TWT Adjustment Info.

[0096] If Jitter Type is "1" (arrival time jitter is unpredictable), the STA attempts to receive the TWT Change Frame transmitted from the AP 100 at the timing specified in the TWT Change Frame Timing field of the TWT Adjustment Info (S360). At this time, if the STA is operating in low power consumption (Doze) mode outside of the R-TWT SP, it must return to the Wake state once at the transmission timing of this frame. If the STA successfully receives this frame, it adjusts the R-TWT SP based on the information stored in this frame to set the Accurate R-TWT SP and performs scheduling control using the Accurate R-TWT SP (S370). If reception of this frame fails, the STA performs scheduling control using the Rough R-TWT SP (S330).

[0097] Note that this flowchart is an example, and for example, the STA may transmit an Ack in response to successful reception of the TWT Change Frame. Alternatively, the STA may transmit a retransmission request to the AP 100 in response to unsuccessful reception of the TWT Change Frame.

[0098] Examples of sequences in this disclosure will be described below as Examples 1 to 3.

[0099] 13 shows a first example of a sequence in the first embodiment, where the Jitter Type is "0" (SP start time or arrival time jitter is predictable).

[0100] First, the AP 100 broadcasts a Beacon signal including a TWT Element (S410). The Beacon signal transmitted in step S410 corresponds to an example of a third frame including first information related to the setting of the first period and second information related to the setting of the second period.

[0101] STA1, STA2, and STA3, which obtain the TWT Element from the Beacon signal, determine the period from the time of receiving the Beacon signal that continues for the TWT Wake Duration (this information is obtained from the Nominal Minimum TWT Wake Duration) after the time stored in the Target Wake Time field as the first R-TWT SP (S420A). Subsequent R-TWT SPs are set periodically at every TWT Wake Interval (this information is obtained from the TWT Wake Interval Mantissa and TWT Wake Interval Exponent) (S420B, S430C). At this time, STA1 and STA2, which support SP Adjustment, treat this R-TWT SP as a "Rough R-TWT SP," while STA3, which does not support SP Adjustment, treats it as a conventional R-TWT SP.

[0102] Next, AP 100 and the SP Adjustment-compatible STAs STA1 and STA2 configure an "Accurate R-TWT SP" (S430A, S430B, S430C). The Accurate R-TWT SP is configured using the Target Wake Time Offset Value and Default Accurate R-TWT Wake Duration in the TWT Adjustment Info field within the Element. Specifically, AP 100, STA1, and STA2 configure (adjust) the start time of the nth "Accurate R-TWT SP" (n is an integer greater than or equal to 1) counting from the transmission of the Beacon signal (AP 100) / reception of the Beacon signal (STA) to be delayed from the start time of the Rough R-TWT SP by Target Wake Time Offset Value * (n - 1) (see "Start Time offset × 1" and "Start Time offset × 2" in the figure). In other words, the offset value increases each time the Rough R-TWT SP advances in the time direction. In addition, AP 100 and STA1 and STA2 set the value of Default Accurate R-TWT Wake Duration as the duration of Accurate R-TWT SP. AP 100 and STA1 and STA2 perform scheduling control based on the Accurate R-TWT SP set in this way.

[0103] The AP 100 receives video information from the Rendering Server 300 (S440A, S440B, S440C) and transmits it to the STA 1 within the Accurate R-TWT SP, and the STA 1 receives and displays the video information from the AP 100 within the same SP (S450A, S450B, S450C).

[0104] STA1 can also save power consumption by transitioning to low power consumption mode (Doze state) during times other than "Accurate R-TWT SP" (S460A, S460B, S460C). STA1 is in the Wake state when not in the Doze state, and transitioning to the Doze state means transitioning from Wake to Doze state. In other words, STA1 may be in the Wake state during the Accurate R-TWT SP, and in the Doze state for at least a portion of the period other than the Accurate R-TWT SP. STA2 can also transition to the low power consumption mode during times other than the "Accurate R-TWT SP".

[0105] 14 shows a second example of a sequence in the first embodiment, where Jitter Type is "1" (SP start time unpredictable) and time information is specified by TWT Change Frame Timing.

[0106] AP 100 broadcasts a Beacon signal including a TWT Element (S510). The Beacon signal transmitted in step S510 corresponds to a first frame including first information related to the setting of a first period. STA1, STA2, and STA3 acquire the TWT Element from the Beacon signal and set the R-TWT SP ("Rough R-TWT SP" for SP Adjustment-compatible STAs) in the same procedure as in the sequence of FIG. 13 (S520A, S520B).

[0107] The AP 100 then broadcasts a TWT Change Frame at the timing (TWT Change Frame Timing) specified by the TWT Element (S570A, S570B). The TWT Change Frame corresponds to a second frame containing second information related to the setting of a second period. The AP 100 and the SP Adjustment-compatible STAs STA1 and STA2 use the information contained in the TWT Change Frame to set an "Accurate R-TWT SP" for each SP (S530A, S530B) and perform scheduling control based on this SP. The start time of the set Accurate R-TWT SP is the timing indicated by the Accurate Target Wake Time, or the Accurate Target Wake Time after the TWT Change Frame is transmitted (in the case of the AP 100) or received (in the case of the STA), and the period length is the Accurate TWT Wake Duration.

[0108] The AP 100 receives video information from the Rendering Server 300 (S540A, S540B) and transmits it to the STA 1 within the Accurate R-TWT SP, and the STA 1 receives and displays the video information from the AP 100 within the same SP (S550A, S550B).

[0109] STA1 can also save power consumption by transitioning to a low power consumption mode (Doze state) outside of this Accurate R-TWT SP (S560A, S560B, S560C, S560D). When transitioning to Doze state, STA1 transitions to the Wake state as appropriate for the time required to perform necessary operations, such as transitioning to the Wake state when a TWT Change frame is received. On the other hand, for STA3, which does not support SP Adjustment, scheduling control is performed based on the normal R-TWT SP (which is the same period as the "Rough R-TWT SP" for SP Adjustment-compatible STAs).

[0110] 15 shows a third example of a sequence in the first embodiment, where the Jitter Type is "1" (SP start time or arrival time is unpredictable) and the TWT ID is specified in the TWT Change Frame Timing.

[0111] AP 100 broadcasts a Beacon signal including a TWT Element (S610). STA1, STA2, and STA3 acquire the TWT Element from the Beacon signal and set the R-TWT SP ("Rough R-TWT SP" for SP Adjustment-compatible STAs) in the same manner as in the first or second example of the sequence (S620A, S620B).

[0112] Thereafter, the AP 100 broadcasts a TWT Change Frame within the R-TWT SP for uplink transmission of STA1 set in step S620A (S670). Before transmitting the TWT Change Frame, the AP 100 may transmit a trigger frame to STA1 (S680) and receive a response frame including STA1's location information, etc., as an uplink frame from STA1 (S690).

[0113] AP 100 and STA1 and STA2, which are SP Adjustment compatible STAs, use the information included in the TWT Change Frame to set an Accurate R-TWT SP for each SP (S630), and perform scheduling control based on the set SP.

[0114] The AP 100 receives video information from the Rendering Server 300 (S640) and transmits it to the STA 1 within the Accurate R-TWT SP, and the STA 1 receives and displays the video information from the AP 100 within the SP (S650).

[0115] STA1 can also save power consumption by transitioning to low power consumption mode (Doze) during times other than this Accurate R-TWT SP (S660A, S660B). On the other hand, for STA3, which is an STA that does not support SP Adjustment, scheduling control is performed based on the normal R-TWT SP (the same period as the "Rough R-TWT SP" for an SP Adjustment-compatible STA).

[0116] In a situation where the Jitter Type is “1” as shown in the second or third example of the sequence above, i.e., the arrival time of picture data cannot be predicted and varies for each SP, there are several possible specific methods for setting an accurate R-TWT SP by adjusting the R-TWT SP.

[0117] First, as the simplest example, there is a method in which the AP 100 transmits a TWT Change Frame immediately before the start of a Rough R-TWT SP. For example, the AP 100 sets an Accurate R-TWT SP by transmitting a TWT Change Frame immediately before the start of a Rough R-TWT SP, even if the exact arrival time of video information (Picture Data) from the Rendering Server 300 is unknown. The start time of the Accurate R-TWT SP may be set to coincide with the start time of the Rough R-TWT SP, or the start time of the Accurate R-TWT SP may be set to a time delayed from the start time of the Rough R-TWT SP, taking into account at least the overhead time required for transmission when video information is received in the shortest time possible. Alternatively, if at least the length of time during which video information does not arrive is known, the start time of the Accurate R-TWT SP may be set to a time delayed from the start time of the Rough R-TWT SP by an amount corresponding to that length of time. If video information (Picture Data) arrives before the start of the Accurate R-TWT SP, the AP 100 may perform transmission at the Accurate R-TWT SP start time. If there is time remaining after transmitting the video information, the AP 100 may terminate the Accurate R-TWT SP midway.

[0118] The start time and end time of the Accurate R-TWT SP may be made to match the start time and end time of the Rough R-TWT SP (i.e., the Accurate R-TWT SP and the Rough R-TWT SP may be made to match). In this case, as in the above, the AP 100 may terminate the Accurate R-TWT SP / Rough R-TWT SP midway if there is time remaining after transmitting the video information.

[0119] If picture data has not arrived from the Rendering Server 300 immediately before the start of the Accurate R-TWT SP or a certain time before, the AP 100 can delay the start of the Accurate R-TWT SP, which is expected to have a certain effect.

[0120] It is also possible to omit setting the Accurate R-TWT SP. For example, if the AP 100 receives picture data before the start of the Rough R-TWT SP, it transmits at the Rough R-TWT SP start time, and if there is time remaining after transmission, it terminates the R-TWT SP. If picture data has not arrived from the Rendering Server 300 immediately before the start of the Rough R-TWT SP or a certain amount of time before, the AP 100 can delay the start of the R-TWT SP. This can be expected to have a certain effect.

[0121] Alternatively, the AP 100 may obtain information regarding the arrival time of picture data from the Rendering Server 300 or another external device for each transmission of picture data. For example, when the Rendering Server 300 obtains location information from the STA 1, it calculates a rough estimate of the time when picture data generation is complete based on the amount of change in the image included in the generated picture data or the load of compression processing, and notifies the AP 100 of this estimate. The AP 100 estimates the time when picture data will arrive based on the notified estimate of the time when picture data will arrive and determines the Accurate R-TWT SP from the estimated time when picture data will arrive. At this time, in order to set the Accurate R-TWT SP while taking backhaul delays into account, the AP 100 instructs the Rendering Server 300 to add a timestamp to the packet notifying the estimated time when picture data generation is complete. The AP 100 uses the timestamp added to the stamp of the received packet as the transmission time of the packet, and determines the difference between the transmission time and the reception time of the packet as the backhaul delay.The arrival time of the video information is estimated based on this backhaul delay and the estimated generation completion time, and the Accurate R-TWT SP is determined.The details of the supported standards and protocols for the frames exchanged between the AP 100 and the Rendering Server 300 are not limited to any particular ones.

[0122] As described above, according to this embodiment, the AP 100 can flexibly set an R-TWT SP that takes into account the arrival time jitter of video information (picture data). In other words, by setting a longer R-TWT SP as the Rough R-TWT SP and flexibly setting a shorter Accurate R-TWT SP within the Rough R-TWT SP while taking into account the arrival time jitter, it is possible to efficiently use the time outside the Accurate R-TWT SP, even within the Rough R-TWT SP, by transitioning to low power consumption mode or transmitting data other than low-latency traffic. In other words, even within the Rough R-TWT SP, there is no need to wait outside the Accurate R-TWT SP, enabling efficient operation and achieving both low latency and low power consumption. In this case, with regard to a STA that does not support SP Adjustment (STA3 in this embodiment), interrupts from STAs that do not support SP Adjustment can be prevented when transmitting video information to STA1. However, there is a concern that efficiency may decrease because scheduling control is performed using a longer R-TWT SP for STAs that do not support SP Adjustment. Therefore, for example, AP 100 may introduce a mechanism to eliminate at least some of the unfairness for STA 3 by actively inducing uplink transmission from STA 3 during times other than the Accurate R-TWT SP within the Rough R-TWT SP, or during times other than the Rough R-TWT SP.

[0123] In the first embodiment described above, the first period is set as the priority period based on the first information, and then the priority period is adjusted from the first period to the second period based on the second information. However, it is also possible to omit setting the first period and set the second period directly from the first information and the second information. This reduces the amount or frequency of information transmitted and received between STA1 and STA2, enabling the second period to be set efficiently.

[0124] Second Embodiment FIG. 16 shows an example of a system architecture according to the second embodiment. In the first embodiment, the rendering server 300 and STA1 communicate via the AP 100. In the second embodiment, however, the rendering device 500 and STA1 communicate directly, with the AP 100, STA2, and STA3 located nearby. The rendering device 500 has a wireless control unit (STAx) for communicating with the AP 100 and STA1. STA1, STA2, and STA3 are assumed to be the same as in the first embodiment (see FIG. 1). That is, STA1 is an HMD, and STA2 is a general communication device such as a smartphone, each of which has the capability to execute the functions of the present disclosure. STA3 is a general communication device that communicates over the Internet via the AP 100, but does not have the capability to execute the functions of the present disclosure.

[0125] As in the first embodiment, by using R-TWT in the transmission of video information (Picture Data) from the Rendering Device 500 to STA1, low-latency transmission and low power consumption are achieved while preventing interruptions by other communications. STAx and STA1 are connected to the AP 100. STAx and STA1 are configured to enable P2P communication using TDLS (Tunneled Direct Link Setup) in accordance with the IEEE 802.11 standard. As in the first embodiment, the STAs under the AP 100 reference the TWT Element broadcast from the AP 100, set the R-TWT SP, and perform scheduling control.

[0126] The major difference from the first embodiment is that it is the Rendering Device 500 or the STAx, rather than the AP 100, that knows the information regarding the arrival time of the picture data (the type of jitter and the generation or arrival time of each piece of picture data). Therefore, the AP 100 must determine a method for adjusting the R-TWT SP (Rough R-TWT SP) to an Accurate R-TWT SP and the start time / duration length of the Accurate R-TWT SP based on the information from the STAx of the Rendering Device 500.

[0127] 17 is a block diagram of an example of a rendering device 500 according to the second embodiment. The rendering device 500 mainly includes a wireless communication unit 310, a control unit 330, a storage unit 340, an antenna 350, and an image generation unit 360.

[0128] The wireless communication unit 310 performs processing for wireless communication with the AP 100 or other STAs, which are other connected wireless communication devices (devices having a wireless communication unit). The wireless communication unit 310 includes a communication control unit 311, a communication storage unit 312, a data processing unit 321, a signal processing unit 322, a wireless interface unit 323, and an amplifier unit 324.

[0129] The video generation unit 360 generates video information to be transmitted to the STA 2 based on information acquired from the control unit 330. The main processes are rendering and compression. While this embodiment mainly deals with video information, the present disclosure is not limited to this, and other types of information may be generated by an application.

[0130] Other configurations and operations are omitted because they are the same as the elements with the same names in the STA block diagram of Figure 3. Note that the rendering device 500 may have multiple wireless communication units for communicating with both the AP 100 and the STA 1. Alternatively, the rendering device 500 may use a multi-link configuration within a single wireless communication unit, with different connection destinations (AP 100 and STA 1) for each link.

[0131] 18 shows a first example of a sequence in the second embodiment, where Jitter Type is "1" (SP start time or arrival time jitter is predictable).

[0132] The difference from the first example of the sequence of the first embodiment (see FIG. 13 ) is that, in order to negotiate SP Adjustment beforehand between the AP 100 and STAx, TWT Elements are included in the Association frame and ReAssociation frame, respectively, and information is exchanged. The request / response / rejection related to this negotiation are already defined in IEEE 802.11-2020 and can be specified in the Request Type field of FIG. 8 . STAx enters arrival time jitter information related to picture data into a field (e.g., the Jitter Type field) in the TWT Adjustment Info field of FIG. 9 and transmits a request signal to the AP 100 requesting the setting of Rough R-TWT SP and Accurate R-TWT SP (S710). The AP 100 then transmits a response signal indicating OK or NG (S720). This request signal includes a first request signal requesting the setting of Rough R-TWT SP and a second request signal requesting the setting of Accurate R-TWT SP. This exchange may be repeated multiple times. The subsequent sequence is the same as in FIG. 13 except that the entity that transmits video information to STA1 is STAx rather than AP 100, so the same reference numerals are used for equivalent sequences and a description thereof will be omitted.

[0133] 19 shows a second example of a sequence in the second embodiment, where Jitter Type is "1" (SP start time or arrival time jitter is unpredictable) and time information is specified by TWT Change Frame Timing.

[0134] Similar to the sequence of FIG. 18 , this sequence differs from the second example of the sequence of the first embodiment (see FIG. 14 ) in that the AP 100 and STAx negotiate the Rough R-TWT SP setting beforehand (S810, S820). While step S710 of FIG. 18 transmitted request signals (corresponding to both the first and second request signals) requesting the setting of the Rough R-TWT SP and the Accurate R-TWT SP, step S810 of this sequence transmits a request signal (first request signal) requesting the setting of the Rough R-TWT SP. After this, STAx transmits a TWT Change Request frame (S830). The TWT Change Request frame corresponds to the second request signal requesting the setting of the Accurate R-TWT SP. The TWT Change Request frame is defined and used by setting a predetermined value (a value identifying an SP adjustment request from the STA to the AP or a value indicating that it is a TWT Change Request frame) in the Type field of the TWT Change Frame of FIG. 10 . The TWT Change Request frame contains the contents of the TWT Change Frame to be broadcast by the AP 100. The TWT Change Request frame only needs to be notified before the transmission timing indicated by the TWT Change Frame Timing of the TWT Element. The AP 100 may use a Trigger frame (not shown) to induce STAx to transmit a TWT Change Request frame, or STAx may transmit the TWT Change Request frame when it acquires the right to transmit by carrier sensing based on CSMA / CA. The other sequences are the same as those in FIG. 14 except that the entity that transmits video information to STA1 is STAx rather than AP 100. Therefore, the same reference numerals are used for sequences equivalent to those in FIG. 14, and a description thereof will be omitted.

[0135] 20 shows a third example of a sequence in the second embodiment, in which the Jitter Type is "1" (SP start time or arrival time jitter is unpredictable) and the TWT ID is specified in the TWT Change Frame Timing.

[0136] As with the sequence in Figure 19, AP 100 and STAx negotiate in advance regarding the Rough R-TWT SP setting (S910, S920), and STAx then transmits a TWT Change Request frame (S930), which is different from the third example sequence of the first embodiment (see Figure 15). In step S010 of this sequence, a request signal (first request signal) requesting the setting of a Rough R-TWT SP is transmitted. The TWT Change Request frame transmitted in step S930 corresponds to a second request signal requesting the setting of an Accurate R-TWT SP. The rest of the sequence is the same as in Figure 19 except that the entity transmitting video information to STA1 is STAx rather than AP 100. Therefore, the same reference numerals are used for sequences equivalent to those in Figure 19, and a description thereof will be omitted.

[0137] (Third Embodiment) In the first and second embodiments, it was assumed that the AP 100 and the STA 200 each have only one set of a data processing unit, a signal processing unit, a wireless interface unit, an amplifier unit, and an antenna 150, and perform single-link communication. As another configuration example, as described in the explanation of the first embodiment, multiple sets of these may be provided, and the AP 100 and the STA 200 may have a configuration (multi-link configuration) in which they perform wireless communication using multiple links (Multi Link Operation: MLO). An AP having a multi-link configuration may be called an MLD (Multi Link Device: ML) AP, and a STA having a multi-link configuration may be called an MLD STA. Of STA1 to STA3, STA1 (the target wireless communication device) may be an MLD STA, and STA2 and STA3 may be STAs that are not MLD STAs. All of STA1 to STA3 may be MLD STAs.

[0138] Fig. 21 is a block diagram of an AP 100 having a multi-link configuration. The wireless communication unit 110 of the AP 100 in Fig. 21 includes multiple sets of a data processing unit 121, a signal processing unit 122, a wireless interface unit 123, an amplifier unit 124, and an antenna 150, each set being referred to as an AP entity. In the example shown in the figure, AP entities 11 and 12 are provided. AP entities 11 and 12 independently perform processing below the MAC layer related to the AP, and establish separate links with STA 200 to communicate.

[0139] Fig. 22 is a block diagram of a STA 200 having a multi-link configuration. The wireless communication unit 210 of the STA 200 in Fig. 22 includes multiple sets of a data processing unit 221, a signal processing unit 222, a wireless interface unit 223, an amplifier unit 224, and an antenna 250, and each set is called an STA entity. In the example shown in the figure, STA entity 21 and STA entity 22 are provided.

[0140] An AP entity 11 of the AP 100 is connected to a STA entity 21 of the STA 200 via a first link among multiple links and performs processing related to the first link, and an AP entity 12 of the AP 100 is connected to a STA entity 22 of the STA 200 via a second link among multiple links and performs processing related to the second link. With this configuration, the AP 100 and the STA 200 can communicate using multiple links simultaneously or in parallel. The AP 100 only needs to connect to a STA that is not an MLD STA via one of the first link and the second link (the first link in this example).

[0141] For example, the links for information transmitted and received between the AP 100 and the STA 200 described in the first embodiment may be different for each type of information. For example, first information indicating a first period as a priority period for preferentially transmitting data may be transmitted and received via the first link, and second information for setting a second period shorter than the first period may be transmitted and received via the second link. Alternatively, one of the first information and the second information may be transmitted and received via the first link or the second link, and the other of the first information and the second information may be transmitted and received via both the first link and the second link. Both the first information and the second information may be transmitted and received via both the first link and the second link. Transmitting and receiving via both the first link and the second link can increase the likelihood that the information will be correctly received by the STA. Furthermore, the link with the higher communication quality from the first link or the second link may be selected and used to transmit the first information or the second information. This allows the STA to more reliably receive the first information and the second information.

[0142] Like the AP 100 and the STA 200, the rendering device 300 in the second embodiment may also have a multi-link configuration. In this case, the block diagram may be similar to that shown in FIG. 21 or 22. The rendering device 300 in the multi-link configuration may communicate with the STA 200 (STA1) using one of multiple links and communicate with the AP 100 using another link. The rendering device 300 in the multi-link configuration may determine the link to use depending on the type of information to be transmitted or received, and transmit or receive information via the determined link.

[0143] <Example of Computer Configuration> The above-described series of processes can be executed by hardware or software. When the series of processes is executed by software, the program constituting the software is installed from a program recording medium into a computer incorporated in dedicated hardware, or into a general-purpose personal computer, etc.

[0144] FIG. 23 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processes by a program.

[0145] A CPU (Central Processing Unit) 801 , a ROM (Read Only Memory) 802 , and a RAM (Random Access Memory) 803 are interconnected by a bus 804 .

[0146] An input / output interface 805 is also connected to the bus 804. An input unit 806 including a keyboard, a mouse, etc., and an output unit 807 including a display, a speaker, etc. are connected to the input / output interface 805. In addition, a storage unit 808 including a hard disk, a nonvolatile memory, etc., a communication unit 809 including a network interface, etc., and a drive 810 that drives removable media 811 are also connected to the input / output interface 805.

[0147] In a computer configured as described above, the CPU 801 performs the above-described series of processes by, for example, loading a program stored in the storage unit 808 into the RAM 803 via the input / output interface 805 and the bus 804 and executing it.

[0148] The program executed by the CPU 801 is provided, for example, by being recorded on a removable medium 811 or via a wired or wireless transmission medium such as a local area network, the Internet, or digital broadcasting, and is installed in the storage unit 808.

[0149] The program executed by the computer may be a program that processes in chronological order according to the order described in this specification, or may be a program that processes in parallel or at the required timing, such as when called.

[0150] <Application Examples> The present technology can be applied to various products. For example, the base station (wireless communication device) 100 in FIG. 2 , the terminal device (wireless communication device) 200 in FIG. 3 , and the rendering device 300 (wireless communication device) in FIG. 17 may be realized as a mobile terminal such as a smartphone, a tablet PC (Personal Computer), a notebook PC, a portable game terminal, or a digital camera, a fixed terminal such as a television receiver, a printer, a digital scanner, or a network storage, or an in-vehicle terminal such as a car navigation device. Furthermore, the base station (wireless communication device) 100, the terminal device (wireless communication device) 200, and the rendering device 300 (wireless communication device) may be realized as an M2M (Machine-to-Machine Communication) terminal such as a smart meter, a vending machine, a remote monitoring device, or a POS (Point of Sale) terminal. Furthermore, the base station (wireless communication device) 100, the terminal device (wireless communication device) 200, and the rendering device 300 (wireless communication device) may be a wireless communication module (e.g., an integrated circuit module configured on a single die) mounted on these terminals.

[0151] On the other hand, for example, the base station (wireless communication device) 100, the terminal device (wireless communication device) 200, and the rendering device 300 (wireless communication device) may be realized as a wireless LAN AP (wireless base station) with or without a router function. The base station (wireless communication device) 100, the terminal device (wireless communication device) 200, and the rendering device 300 (wireless communication device) may also be realized as a mobile wireless LAN router. Furthermore, the base station (wireless communication device) 100, the terminal device (wireless communication device) 200, and the rendering device 300 (wireless communication device) may be a wireless communication module (for example, an integrated circuit module configured on a single die) mounted on these devices.

[0152] <Configuration Example of Smartphone> FIG. 24 is a block diagram showing a schematic configuration example of a smartphone to which the present technology is applied.

[0153] The smartphone 900 includes a processor 901, a memory 902, a storage 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, and a display device 910. The smartphone 900 also includes a speaker 911, a wireless communication interface 913, an antenna switch 914, an antenna 915, a bus 917, a battery 918, and an auxiliary controller 919.

[0154] The processor 901 may be, for example, a CPU or a SoC (System on Chip), and limits the functions of the application layer and other layers of the smartphone 900.

[0155] The memory 902 includes RAM and ROM, and stores programs and data executed by the processor 901 .

[0156] The storage 903 includes a storage medium such as a semiconductor memory or a hard disk.

[0157] The external connection interface 904 is an interface for connecting an external device such as a memory card or a USB (Universal Serial Bus) device to the smartphone 900 .

[0158] The camera 906 has an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), and generates a captured image.

[0159] The sensor 907 includes a group of sensors such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor.

[0160] The microphone 908 converts the sound input to the smartphone 900 into an audio signal.

[0161] The input device 909 includes, for example, a touch sensor that detects a touch on the screen of the display device 910, a keypad, a keyboard, a button, or a switch, and accepts operations or information input from the user.

[0162] The display device 910 has a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays an output image of the smartphone 900. The speaker 911 converts an audio signal output from the smartphone 900 into audio.

[0163] The wireless communication interface 913 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11ac, 11ad, 11ax, 11ay, 11be, and 11bn, and performs wireless communication.

[0164] The wireless communication interface 913 communicates with other devices via a wireless LAN AP in infrastructure mode, and directly with other devices in ad hoc mode or a direct communication mode such as Wi-Fi Direct.

[0165] Unlike ad hoc mode, in Wi-Fi Direct, one of the two terminals acts as an AP, but communication is carried out directly between the terminals.

[0166] The wireless communication interface 913 typically includes a baseband processor, an RF (Radio Frequency) circuit, a power amplifier, etc. The wireless communication interface 913 may be a one-chip module that integrates a memory that stores a communication control program, a processor that executes the program, and related circuits.

[0167] The wireless communication interface 913 may support other types of wireless communication methods, such as a short-range wireless communication method, a proximity wireless communication method, or a cellular communication method, in addition to a wireless LAN method.

[0168] The antenna switch 914 switches the connection destination of the antenna 915 between multiple circuits (for example, circuits for different wireless communication methods) included in the wireless communication interface 913 .

[0169] The antenna 915 has a single or multiple antenna elements (for example, multiple antenna elements constituting a MIMO (Multiple Input Multiple Output) antenna) and is used for transmitting and receiving wireless signals via the wireless communication interface 913.

[0170] 24 , the smartphone 900 may include multiple antennas (for example, an antenna for wireless LAN and an antenna for a close-proximity wireless communication system). In this case, the antenna switch 914 may be omitted from the configuration of the smartphone 900.

[0171] The bus 917 connects the processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 913, and auxiliary controller 919 to each other.

[0172] The battery 918 supplies power to each block of the smartphone 900 shown in Fig. 24 via a power supply line partially indicated by a dashed line in the figure. The auxiliary controller 919 operates the minimum necessary functions of the smartphone 900, for example, in sleep mode.

[0173] In the smartphone 900 shown in Fig. 24 , for example, the wireless communication unit 110, the communication control unit 111, and the control unit 130 in Fig. 2 , the wireless communication unit 210, the communication control unit 211, and the control unit 230 in Fig. 3 , and the wireless communication unit 310, the communication control unit 311, and the control unit 330 in Fig. 17 may be implemented in the wireless communication interface 913. Furthermore, at least some of these functions may be implemented in the processor 901 or the auxiliary controller 919.

[0174] The smartphone 900 may operate as a wireless AP (software AP) by the processor 901 executing an AP function at the application level. The wireless communication interface 913 may also have a wireless AP function.

[0175] Furthermore, the smartphone 900 may be provided with a biometric authentication unit (fingerprint authentication, palm geometry authentication, voice authentication, blood vessel authentication, face authentication, iris authentication, retina authentication). In this case, a wireless communication interface 913 in which the wireless communication unit 110, the communication control unit 111, and the control unit 130 in Fig. 2, the wireless communication unit 210, the communication control unit 211, and the control unit 230 in Fig. 3, and the wireless communication unit 310, the communication control unit 311, and the control unit 330 in Fig. 17 are implemented is configured to receive power from the same battery 918 as at least one of the display device 910, the speaker 911, and the biometric authentication unit.

[0176] Furthermore, in the smartphone 900, information is displayed on at least one of the display device 910 and the speaker 911 based on communication with an external device via the wireless communication interface 913. At this time, information relating to the present technology may be output from at least one of the display device 910 and the speaker 911.

[0177] <Configuration Example of In-Vehicle Device> FIG. 25 is a block diagram showing an example of a schematic configuration of an in-vehicle device 920 to which the present technology is applied.

[0178] The in-vehicle device 920 is configured to include a processor 921, a memory 922, a GNSS (Global Navigation Satellite System) module 924, a sensor 925, a data interface 926, a content player 927, and a storage medium interface 928. The in-vehicle device 920 is also configured to include an input device 929, a display device 930, a speaker 931, a wireless communication interface 933, an antenna switch 934, an antenna 935, and a battery 938.

[0179] The processor 921 may be, for example, a CPU or an SoC, and controls the navigation function and other functions of the in-vehicle device 920. The processor 921 can also control the vehicle's driving system, such as the brake, accelerator, or steering, based on information obtained through communication based on the present technology.

[0180] The memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921 .

[0181] The GNSS module 924 measures the position (e.g., latitude, longitude, and altitude) of the in-vehicle device 920 using GNSS signals received from GNSS satellites.

[0182] The sensor 925 includes a group of sensors such as a gyro sensor, a geomagnetic sensor, and an air pressure sensor.

[0183] The data interface 926 is connected to an in-vehicle network 941 via a terminal (not shown), for example, and acquires data generated on the vehicle side, such as in-vehicle data.

[0184] The content player 927 plays content stored on a storage medium (e.g., a CD or DVD) inserted into the storage medium interface 928 .

[0185] The input device 929 includes, for example, a touch sensor that detects a touch on the screen of the display device 930, a button, or a switch, and accepts operations or information input from the user.

[0186] The display device 930 has a screen such as an LCD or OLED display, and displays images of navigation functions or content being played.

[0187] The speaker 931 outputs the audio of the navigation function or the content being played.

[0188] Note that the navigation function and the function of the content player 927 are optional in the in-vehicle device 920. The navigation function and the content player 927 may be removed from the configuration of the in-vehicle device 920.

[0189] The wireless communication interface 933 supports one or more wireless LAN standards such as IEEE 802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, 11be, and 11bn, and performs wireless communication. The wireless communication interface 933 communicates with other devices via a wireless LAN AP in infrastructure mode. The wireless communication interface 933 also communicates directly with other devices in ad hoc mode or a direct communication mode such as Wi-Fi Direct.

[0190] The wireless communication interface 933 typically includes a baseband processor, an RF circuit, a power amplifier, etc. The wireless communication interface 933 may be a one-chip module that integrates a memory that stores a communication control program, a processor that executes the program, and related circuits. In addition to the wireless LAN system, the wireless communication interface 933 may support other types of wireless communication systems, such as a short-range wireless communication system, a proximity wireless communication system, or a cellular communication system.

[0191] The antenna switch 934 switches the connection destination of the antenna 935 among multiple circuits included in the wireless communication interface 933 .

[0192] The antenna 935 has a single or multiple antenna elements and is used for transmitting and receiving radio signals via the wireless communication interface 933 .

[0193] 25, the in-vehicle device 920 may include a plurality of antennas 935. In that case, the antenna switch 934 may be omitted from the configuration of the in-vehicle device 920.

[0194] 25, the battery 938 is connected to the in-vehicle device 920 via a power supply line partially indicated by a dashed line in the figure, and for example, the wireless communication unit 110, communication control unit 111, and control unit 130 in Fig. 2, the wireless communication unit 210, communication control unit 211, and control unit 230 in Fig. 3, and the wireless communication unit 310, communication control unit 311, and control unit 330 in Fig. 17 may be implemented in the wireless communication interface 933. Furthermore, at least some of these functions may be implemented in the processor 921.

[0195] In addition, the wireless communication interface 933 may operate as the above-mentioned base station (wireless communication device) 100, terminal device (wireless communication device) 200, or rendering device (wireless communication device) 300, and provide wireless connection to a terminal owned by a user in a vehicle.

[0196] Moreover, the present technology may be realized as an in-vehicle system (or vehicle) 940 including one or more blocks of the above-described in-vehicle device 920, an in-vehicle network 941, and a vehicle-side module 942. The vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine rotation speed, or failure information, and outputs the generated data to the in-vehicle network 941.

[0197] <Configuration Example of Wireless AP> FIG. 26 is a block diagram showing an example of a schematic configuration of a wireless AP 950 to which the present technology is applied.

[0198] The wireless AP 950 includes a controller 951 , a memory 952 , an input device 954 , a display device 955 , a network interface 957 , a wireless communication interface 963 , an antenna switch 964 , and an antenna 965 .

[0199] The controller 951 may be, for example, a CPU or a DSP (Digital Signal processor) and operates various functions of the IP (Internet Protocol) layer and higher layers of the wireless AP 950 (e.g., access restriction, routing, encryption, firewall, and log management).

[0200] The memory 952 includes RAM and ROM, and stores programs executed by the controller 951 and various control information (for example, a terminal list, a routing table, an encryption key, security settings, and logs).

[0201] The input device 954 includes, for example, buttons and switches, and receives operations from the user.

[0202] The display device 955 includes an LED lamp or the like and displays the operating status of the wireless AP 950 .

[0203] The network interface 957 is a wired communication interface for connecting the wireless AP 950 to a wired communication network 958. The network interface 957 may have multiple connection terminals. The wired communication network 958 may be a LAN such as Ethernet (registered trademark) or a WAN (Wide Area Network).

[0204] The wireless communication interface 963 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, and 11be, and provides wireless connection to nearby terminals as an AP.

[0205] The wireless communication interface 963 typically includes a baseband processor, an RF circuit, a power amplifier, and the like.

[0206] The wireless communication interface 963 may be a one-chip module that integrates a memory that stores a communication control program, a processor that executes the program, and related circuits.

[0207] The antenna switch 964 switches the connection of the antenna 965 between multiple circuits included in the wireless communication interface 963. The antenna 965 has a single or multiple antenna elements and is used for transmitting and receiving wireless signals via the wireless communication interface 963.

[0208] In the wireless AP 950 shown in Fig. 26 , for example, the wireless communication unit 110, the communication control unit 111, and the control unit 130 in Fig. 2 , the wireless communication unit 210, the communication control unit 211, and the control unit 230 in Fig. 3 , and the wireless communication unit 310, the communication control unit 311, and the control unit 330 in Fig. 17 may also be implemented in the wireless communication interface 963. Furthermore, at least some of these functions may be implemented in the controller 951.

[0209] The above-described embodiment shows an example for realizing the present technology, and the matters in the embodiment correspond to the matters specifying the invention in the claims. Similarly, the matters specifying the invention in the claims correspond to the matters in the embodiment of the present technology having the same title. However, the present technology is not limited to the embodiment, and can be realized by applying various modifications to the embodiment without departing from the gist of the present technology.

[0210] Furthermore, the processing procedures described in the above embodiments may be regarded as a method having a series of these procedures, or as a program for causing this computer to execute these procedures or a recording medium for storing the program.

[0211] Examples of the recording medium that can be used include a CD (Compact Disc), an MD (MiniDisc), a DVD (Digital Versatile Disc), a memory card, and a Blu-ray (registered trademark) Disc.

[0212] In this specification, a system refers to a collection of multiple components (devices, modules (components), etc.), regardless of whether all of the components are contained in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device housed in a single housing with multiple modules, are both systems.

[0213] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0214] The embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present technology.

[0215] For example, the present technology can be configured as a cloud computing system in which a single function is shared and processed collaboratively by a plurality of devices via a network.

[0216] Furthermore, each step described in the above flowchart can be executed by one device, or can be shared and executed by a plurality of devices.

[0217] Furthermore, when one step includes multiple processes, the multiple processes included in that one step can be executed by one device or can be shared and executed by multiple devices.

[0218] This embodiment may also have the following configuration. [Notes] [Item 1] A communication control device including a control unit that controls a communication unit that communicates with a wireless communication device, wherein the control unit: acquires, via the communication unit, first information transmitted from the wireless communication device, the first information indicating a first period as a priority period during which transmission of a specific type of data is prioritized; acquires, via the communication unit, second information transmitted from the wireless communication device for setting the priority period to a second period that is shorter than the first period; and performs control to set the priority period to the second period based on the first information and the second information. [Item 2] The communication control device according to Item 1, wherein the second period is a part of the first period. [Item 3] The communication control device according to Item 1 or 2, wherein the control unit controls to acquire the first information from a beacon signal received by the communication unit from the wireless communication device. [Item 4] The communication control device according to any one of Items 1 to 3, wherein the control unit transmits capability information to the wireless communication device via the communication unit, the capability information indicating that the control unit has the ability to set the second period, and acquires the second information transmitted from the wireless communication device in accordance with the capability information. [Item 5] The communication control device according to any one of items 1 to 4, wherein the second information includes an offset value from a start time of the first period and a period length starting from the time indicated by the offset value, and the second period is a period from the time indicated by the offset value to the period length. [Item 6] The communication control device according to item 5, wherein the first information indicates a plurality of the first periods arranged at intervals in a time direction, and the second information includes larger values ​​as the offset value of the second period corresponding to the first period as the first information progresses in the time direction. [Item 7] The communication control device according to any one of items 1 to 6, wherein the control unit performs control to be in a Wake state during the second period, and to be in a Doze state during at least a part of a period of the first period other than the second period.[Item 8] The communication control device according to item 7, wherein the control unit acquires the first information from a first frame received by the communication unit, and acquires the second information from a second frame received by the communication unit after receiving the first frame, the first information in the first frame including information regarding timing at which the second frame is to be transmitted, and the control unit performs control to enter a Doze state after acquiring the first information, and then enter a Wake state in accordance with timing at which the second frame is to be transmitted. [Item 9] The communication control device according to any one of items 1 to 8, wherein the control unit transmits a first request signal regarding the first period to the wireless communication device via the communication unit, and transmits a second request signal regarding the second period to the wireless communication device via the communication unit, thereby causing the wireless communication device to transmit the first information and the second information. [Item 10] The communication control device according to any one of items 1 to 9, wherein the priority period is an occupied period for transmission of the specific type of data. [Item 11] The communication control device according to any one of items 1 to 10, wherein the control unit sets the first period as the priority period based on the first information and adjusts the priority period from the first period to the second period based on the second information. [Item 12] The communication control device according to any one of items 1 to 11, wherein the communication unit is connected to the wireless communication device via a first link and a second link, and the control unit receives the first information via one of the first link and the second link and receives the second information via the other of the first link and the second link. [Item 13] The communication control device according to item 13, further comprising a control unit that controls a communication unit that communicates with a plurality of wireless communication devices, wherein the control unit transmits, to the plurality of wireless communication devices, first information indicating a first period as a priority period in which transmission of a specific type of data is prioritized, and transmits, to at least one target wireless communication device among the plurality of wireless communication devices, second information for setting the priority period to a second period shorter than the first period. [Item 14] The communication control device according to item 13, wherein the second occupation period is part of the first occupation period.[Item 15] The communication control device according to item 13 or 14, wherein the control unit controls transmission of a beacon signal including the first information. [Item 16] The communication control device according to any one of items 13 to 15, wherein capability information indicating whether or not the plurality of wireless communication devices have the capability to set the second period is acquired from the plurality of wireless communication devices, and the target wireless communication device is the wireless communication device that has the capability. [Item 17] The communication control device according to any one of items 13 to 16, wherein the second information includes an offset value of a start time of the first period and a period length from the time indicated by the offset value, and the second period is a period from the time indicated by the offset value that has the length of the period length. [Item 18] The communication control device according to item 17, wherein the first information sets a plurality of first periods at intervals in a time direction, and the second information increases the offset value of the second period corresponding to the first period as it progresses in the time direction. [Item 19] The communication control device according to any one of items 13 to 18, wherein the control unit selectively performs either a first operation of transmitting a first frame including the first information and, after transmitting the first frame, transmitting a second frame including the second information, or a second operation of transmitting a third frame including the first information and the second information. [Item 20] The control unit acquires the data from a data generating device that generates the data, and performs control to transmit the acquired data from the communication unit to one of the target wireless communication devices within the second period, wherein the control unit executes the first operation if the time when the data can be acquired is unpredictable before transmitting the first information, and executes the second operation if the time when the data can be acquired is predictable before transmitting the first information. [Item 21] The communication control device according to item 19 or 20, wherein the first information in the first frame includes information regarding the timing at which the second frame will be transmitted. [Item 22] The communication control device according to any one of Items 13 to 21, wherein the control unit controls transmission of the first information and the second information in response to a request signal received from one of the plurality of wireless communication devices.[Item 23] The communication control device according to any one of items 13 to 22, wherein the control unit acquires the data from a data generation device that generates the data and controls transmission of the acquired data from the communication unit to one of the target wireless communication devices within the second period, and the control unit acquires estimated information of a generation completion time of the data from the data generation device and determines the second period based on the estimated information. [Item 24] The communication control device according to item 23, wherein the control unit is connected to the data generation device via a communication network and determines the second period further based on an amount of transmission delay of the communication network. [Item 25] The communication control device according to any one of items 13 to 24, wherein the control unit is connected to the data generation device via a communication network and determines the second period further based on an amount of transmission delay of the communication network. [Item 26] The communication control device according to any one of Items 13 to 25, wherein the communication unit is connected to the plurality of wireless communication devices via one of a first link and a second link, and is connected to at least the target wireless communication device via the other of the first link and the second link, and the control unit transmits the first information via the one link and transmits the second information via the other link. [Item 27] ​​A communication control method comprising: acquiring first information transmitted from a wireless communication device, the first information indicating a first period as a priority period during which transmission of a specific type of data is prioritized; acquiring second information transmitted from the wireless communication device for setting the priority period to a second period shorter than the first period; and setting the priority period to the second period based on the first information and the second information. [Item 28] A computer program causing a computer to execute the steps of: acquiring first information transmitted from a wireless communication device, the first information indicating a first period as a priority period during which transmission of a specific type of data is prioritized; acquiring second information transmitted from the wireless communication device for setting the priority period to a second period that is shorter than the first period; and setting the priority period to the second period based on the first information and the second information.[Item 29] A communication control method for controlling communication with a plurality of wireless communication devices, comprising: transmitting, to the plurality of wireless communication devices, first information indicating a first period as a priority period during which transmission of a specific type of data is prioritized; and transmitting, to at least one target wireless communication device among the plurality of wireless communication devices, second information for setting the priority period to a second period shorter than the first period. [Item 30] A computer program product that causes a computer to execute the steps of: transmitting, to the plurality of wireless communication devices, first information indicating a first period as a priority period during which transmission of a specific type of data is prioritized; and transmitting, to at least one target wireless communication device among the plurality of wireless communication devices, second information for setting the priority period to a second period shorter than the first period.

[0219] 1 to 3, x: STA device 150, 250, 350: Antenna 100 AP device (Access Point, base station, wireless communication device) 110, 210, 310: Wireless communication unit 111, 211, 311: Communication control unit 112, 212, 312: Communication memory unit 121, 221, 321: Data processing unit 122, 222, 322: Signal processing unit 123, 223, 323: Wireless interface unit 124, 224, 324: Amplification unit 130, 230, 330: Control unit 140, 240, 340: Memory unit 160 Backhaul communication unit 200 Terminal device (wireless communication device) 300 Rendering Device (wireless communication device) 360 Image generation unit 500 Backhaul network 804 Bus 805 Input / output interface 806 Input unit 807 Output unit 808 Storage unit 809 Communication unit 810 Drive 811 Removable media 900 Smartphone 901 Processor 902 Memory 903 Storage 904 External connection interface 906 Camera 907 Sensor 908 Microphone 909 Input device 910 Display device 911 Speaker 913 Wireless communication interface 914 Antenna switch 915 Antenna 917 Bus 918 Battery 919 Auxiliary controller 920 In-vehicle device 921 Processor 922 Memory 924 GNSS module 925 Sensor 926 Data interface 927 Content player 928 Storage medium interface 929 Input device 930 Display device 931 Speaker 933 Wireless communication interface 934 Antenna switch 935 Antenna 938 Battery940 In-vehicle system (or vehicle) 941 In-vehicle network 942 Vehicle-side module 951 Controller 952 Memory 954 Input device 955 Display device 957 Network interface 958 Wired communication network 963 Wireless communication interface 964 Antenna switch 965 Antenna

Claims

1. A communication control device comprising a control unit that controls a communication unit that communicates with a wireless communication device, wherein the control unit: acquires, via the communication unit, first information transmitted from the wireless communication device, indicating a first period as a priority period during which transmission of a specific type of data is prioritized; acquires, via the communication unit, second information transmitted from the wireless communication device, for setting the priority period to a second period that is shorter than the first period; and sets the priority period to the second period based on the first information and the second information.

2. The communication control device according to claim 1, wherein the second period is a part of the first period.

3. The communication control device according to claim 1, wherein the control unit performs control to acquire the first information from a beacon signal received by the communication unit from the wireless communication device.

4. A communication control device as described in claim 1, wherein the control unit transmits capability information indicating the ability to set the second period to the wireless communication device via the communication unit, and acquires the second information transmitted from the wireless communication device in response to the capability information.

5. A communication control device as described in claim 1, wherein the second information includes an offset value from a start time of the first period and a period length starting from the time indicated by the offset value, and the second period is a period having a length equal to the period length from the time indicated by the offset value.

6. A communication control device as described in claim 5, wherein the first information indicates a plurality of the first periods spaced apart in the time direction, and the second information includes a larger value as the offset value of the second period corresponding to the first period as it progresses in the time direction.

7. The communication control device according to claim 1, wherein the control unit performs control to enter a Wake state during the second period, and to enter a Doze state during at least a portion of a period other than the second period within the first period.

8. The communication control device according to claim 7, wherein the control unit acquires the first information from a first frame received by the communication unit, and acquires the second information from a second frame received by the communication unit after receiving the first frame, the first information in the first frame including information relating to a timing at which the second frame is to be transmitted, and the control unit performs control such that after acquiring the first information, the control unit goes into a Doze state, and then goes into a Wake state depending on the timing at which the second frame is to be transmitted.

9. The communication control device according to claim 1, wherein the control unit transmits a first request signal regarding the first period to the wireless communication device via the communication unit, and transmits a second request signal regarding the second period to the wireless communication device via the communication unit, thereby causing the wireless communication device to transmit the first information and the second information.

10. The communication control device according to claim 1, wherein the priority period is an exclusive period for transmission of the specific type of data.

11. The communication control device according to claim 1, wherein the control unit sets the first period as the priority period based on the first information, and adjusts the priority period from the first period to the second period based on the second information.

12. A communication control device as described in claim 1, wherein the communication unit is connected to the wireless communication device via a first link and a second link, and the control unit receives the first information via one of the first link and the second link, and receives the second information via the other of the first link and the second link.

13. A communication control method comprising: acquiring first information transmitted from a wireless communication device, the first information indicating a first period as a priority period during which transmission of a specific type of data is prioritized; acquiring second information transmitted from the wireless communication device for setting the priority period to a second period shorter than the first period; and setting the priority period to the second period based on the first information and the second information.

14. A computer program causing a computer to execute the steps of: acquiring first information transmitted from a wireless communication device, the first information indicating a first period as a priority period during which transmission of a specific type of data is prioritized; acquiring second information transmitted from the wireless communication device for setting the priority period to a second period shorter than the first period; and setting the priority period to the second period based on the first information and the second information.

Images