Communication control device and communication control method

Abstract

[Problem] To provide a communication control device and a communication control method capable of flexibly setting a priority transmission period for transmitting target data. [Solution] A communication control device according to the present disclosure is provided with a control unit that controls communication with a target wireless communication device, wherein the control unit performs control for: setting a plurality of priority transmission periods, which are candidates for a period for preferentially transmitting target data within a reception expected period, which is a continuous time, to the target wireless communication device to which the target data is to be transmitted; and transmitting priority transmission period information, indicating the plurality of priority transmission periods, to the target wireless communication device.

Description

Communication control device and communication control method

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

[0002] There is a growing demand for next-generation XR (Extended Reality / Cross Reality) services with high Quality of Experience (QoE) on a variety of small devices over wireless local area networks (LANs), and requirements for wireless communication latency, reliability, power consumption, etc. are becoming stricter.

[0003] The IEEE 802.11ax standard, which corresponds to Wi-Fi 6, includes a feature called Target Wake Time (TWT) to achieve power savings. This feature specifies a wake-up time for terminals with periodic traffic data and limits the number of terminals that can transmit at a specific time. This reduces the number of channel access conflicts between terminals and also achieves power savings by transitioning terminals to a doze state when there is no traffic data to transmit or receive. In the IEEE 802.11be standard, which corresponds to Wi-Fi 7, a feature called Restricted Target Wake Time (R-TWT) is proposed in the following non-patent document 1, which further reduces latency by setting a priority transmission period (R-TWT SP (Service Period)) for specific traffic data in addition to TWT.

[0004] In use cases such as Extended Reality (XR), due to the limitations of XR devices, heavy processing loads such as rendering may be performed using external computing resources such as servers. In such cases, server processing time varies depending on factors such as server load, encoding method, and network transmission delay. This results in significant frame arrival jitter, which is a significant fluctuation in the frame arrival interval, on the wireless network side. XR requires low latency, high reliability, and low power consumption. To apply R-TWT to meet these requirements, the R-TWT SP must be set long to account for frame arrival jitter. However, setting a long R-TWT SP may increase power consumption and reduce communication efficiency with other devices. On the other hand, setting a short R-TWT SP may not meet the requirements for low latency and high reliability.

[0005] Non-Patent Document 2 below proposes a technology ("early termination") that can shorten the R-TWT SP by generating a termination event, which indicates the end of the R-TWT SP, when the transmission of traffic data is completed during the R-TWT SP. However, due to the nature of frame arrival jitter in XR, the probability that the transmission and reception of traffic data can be completed earlier than expected is low, and the effect of early termination is limited.

[0006] IEEE 802.11-20 / 1046r14IEEE 802.11-22 / 0304r0

[0007] In order to solve the above-mentioned problems, the present disclosure provides a communication control device and a communication control method that are capable of flexibly setting a prioritized transmission period for transmitting target data.

[0008] The communication control device of the present disclosure includes a control unit that controls communication with a target wireless communication device, and the control unit controls the target wireless communication device to which target data is to be transmitted by setting, for the target wireless communication device, multiple priority transmission periods that are candidates for periods during which the target data is to be preferentially transmitted within a reception expected period, which is a continuous period of time, and transmitting priority transmission period information indicating the multiple priority transmission periods to the target wireless communication device.

[0009] 1 is a diagram showing an example of the configuration of a communication system according to the present disclosure. FIG. 1 is a diagram showing an example of the configuration of a wireless communication device in an AP according to the present disclosure. FIG. 2 is a diagram showing an example of the configuration of a wireless communication device in a STA according to the present disclosure. FIG. 2 is a diagram showing an overview of R-TWT operation. A flowchart of R-TWT membership setup. A diagram for explaining issues when R-TWT is applied to XR. A diagram showing R-TWT operation when early termination is applied. A diagram showing an example of setting multiple divided prioritized transmission periods (R-TWT SPs) for the same traffic data transmitted by an AP to an XR device. A flowchart of an example of AP operation in a Semi R-TWT SP. A flowchart of an example of XR device operation as a PS STA in a Semi R-TWT SP. An example of setting multiple R-TWT SPs within an expected traffic generation period is shown. An example of a format for transmitting information on multiple R-TWT SPs in a single R-TWT Parameter Set field is shown. A flowchart of R-TWT membership setup according to the present disclosure. A flowchart of operation for changing the method by which an AP broadcasts R-TWT parameters depending on the capabilities of STAs in a cell. A block diagram showing an example of the configuration of hardware for a computer that executes a series of processes according to the present disclosure by a program. 1 is a block diagram showing an example of a schematic configuration of a smartphone to which the technology of the present disclosure is applied, a block diagram showing an example of a schematic configuration of an in-vehicle device to which the technology of the present disclosure is applied, and a block diagram showing an example of a schematic configuration of a wireless AP to which the technology of the present disclosure is applied.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The following description will focus on the main components of the present disclosure, but components and functions that are not shown or described may exist. The following description does not exclude components and functions that are not shown or described.

[0011] FIG. 1 shows an example of the configuration of a communication system according to the present disclosure. The communication system of FIG. 1 includes one AP (Access Point, base station) 100, one XR device 300, and multiple STAs (STAtions, child devices) 200. The XR device 300 and the multiple STAs 200 are connected to the same AP 100 via a wireless network, which is a first communication network. Furthermore, in this system, a server 400 is connected to the AP 100 via a wired or wireless backhaul, which is a second communication network. The server 400 is a data generating device that generates data such as video information and distributes the generated data. Here, it is assumed that the AP 100 receives data addressed to the XR device 300 from the server 400 and transmits the received data to the XR device 300 with low latency. The data transmitted to the XR device 300 is also referred to as traffic data or target data. In other words, it is assumed that communication between the AP 100 and the XR device 300 is DL (Downlink) communication, in which traffic data is transmitted from the AP 100 to the XR device 300. On the other hand, the communication between the AP 100 and the STA 200 is assumed to be UL (Uplink) communication in which traffic data is transmitted from the STA 200 to the AP 100 .

[0012] Note that the communication system of the present disclosure is not limited to the system configuration shown in Fig. 1. For example, the XR device 300 may be another type of STA. Also, there may be multiple APs.

[0013] 2A shows a configuration example of a wireless communication device (communication device) 1000 included in the AP 100 according to the present disclosure. 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 and their successor standards. For example, the AP 100 may operate based on CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) as an access method, and may transmit a beacon signal at regular time intervals (periodically).

[0014] The wireless communication device 1000 includes a wireless communication unit 110 , an information storage device 120 , a control unit 130 , an LLC processing unit 140 , an upper layer 150 , and a backhaul communication unit 160 .

[0015] The wireless communication unit 110 is equipped with multiple antennas 116A and 116B. In this example, there are two antennas, but the number of antennas may be other than one or three.

[0016] The RF switches 115A and 115B are provided between the antennas 116A and 116B and the RF units 114A and 114B, and switch the connection destination of the antennas 116A and 116B between transmission and reception. That is, the RF switches 115A and 115B connect the antennas 116A and 116B to the transmission systems included in the RF units 114A and 114B, respectively, during transmission, and connect the antennas 116A and 116B to the reception systems included in the RF units 114A and 114B, respectively, during reception.

[0017] During transmission, the RF units 114A and 114B perform digital-to-analog signal conversion, filtering, frequency conversion (up-conversion) using a local oscillator, signal amplification, etc. During reception, they perform frequency conversion (down-conversion), filtering, analog-to-digital signal conversion, etc. on the received signal.

[0018] The signal processing unit (PHY layer) 113 performs baseband signal processing. For example, during transmission, it performs scrambling, interleaving, encoding, modulation, etc. to generate the digital signal and sends it to the RF units 114A and 114B. During reception, it performs demodulation, decoding, deinterleaving, descrambling, etc. on the digital signal and sends the processed signal to the MAC processing unit 112.

[0019] The MAC processing unit 112 corresponds to a MAC (Media Access Control) sublayer, and performs channel access control, signal multiplexing control, etc. The MAC processing unit 112 also adds a MAC header and a FCS (Frame Check Sequence) when transmitting, and separates the MAC header and the FCS when receiving.

[0020] The communication control unit 111 controls the RF switches 115A and 115B, the RF units 114A and 114B, the signal processing unit 113, and the MAC processing unit 112 so that they perform the above-mentioned operations.

[0021] The LLC processing unit 140 corresponds to an LLC (Logical Link Control) sublayer and includes a data processing unit 141 and a data control unit 142. The data processing unit 141 performs data framing (packetization of data) or extracts data from packets to be passed to a higher layer. The data control unit 142 performs flow control and error control.

[0022] The information storage device 120 holds information used by the communication control unit 111. The information storage device 120 includes a buffer that stores data received from the upper layer 150 and data received by the wireless communication unit 110.

[0023] The upper layer 150 is a layer above the network layer.

[0024] The control unit 130 controls the wireless communication unit 110, the communication control unit 111, and the LLC processing unit 140. Furthermore, the control unit 130 controls the doze state and awake state of each of these blocks during power saving. In this specification, the doze state may also be referred to as a sleep state. Furthermore, the control unit 130 may perform part of the operations of the communication control unit 111, or the communication control unit 111 may perform part of the operations of the control unit 130. Furthermore, the communication control unit 111 and the control unit 130 may be configured as a single block. The communication control unit 111 and the control unit 130 control operations related to R-TWT and Divided R-TWT according to the present disclosure, which will be described later.

[0025] The backhaul communication unit 160 is a communication unit that communicates with other devices via a backhaul network. The other devices include, for example, the server 400. The backhaul communication unit 160 decodes packets acquired 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 server 400 is performed via the backhaul communication unit 160, but communication via the wireless communication unit 110 is also possible.

[0026] The communication control device in the AP of the present disclosure may be realized in hardware by one or more integrated circuits including at least one of the control unit 130 and the communication control unit 111, or may be realized in software by having a processor execute a program that implements the functions of at least one of the control unit 130 and the communication control unit 111. The communication control device in the AP 100 includes a control unit that controls the wireless communication unit 110 that communicates with multiple STAs (wireless communication devices), and this control unit corresponds to at least one of the control unit 130 and the communication control unit 111.

[0027] 2B shows an example configuration of a wireless communication device (communication device) 2000 included in the STA 200 according to the present disclosure. The XR device 300 also includes a wireless communication device 2000 having the same configuration as that shown in FIG.

[0028] The wireless communication device 2000 includes a wireless communication unit 210 , an information storage device 220 , a control unit 230 , an LLC processing unit 240 , and an upper layer 250 .

[0029] The wireless communication unit 210 is equipped with multiple antennas 216A and 216B. In this example, there are two antennas, but the number of antennas may be other than one or three.

[0030] The RF switches 215A and 215B are provided between the antennas 216A and 216B and the RF units 214A and 214B, and switch the connection destination of the antennas 216A and 216B between transmission and reception. That is, the RF switches 215A and 215B connect the antennas 216A and 216B to the transmission systems included in the RF units 214A and 214B, respectively, during transmission, and connect the antennas 216A and 216B to the reception systems included in the RF units 214A and 214B, respectively, during reception.

[0031] During transmission, the RF units 214A and 214B perform digital-to-analog signal conversion, filtering, frequency conversion (up-conversion) using a local oscillator, signal amplification, etc. During reception, they perform frequency conversion (down-conversion), filtering, analog-to-digital signal conversion, etc. on the received signal.

[0032] The signal processing unit (PHY layer) 213 performs baseband signal processing. For example, during transmission, it performs scrambling, interleaving, encoding, modulation, etc. to generate the digital signal and sends it to the RF units 214A and 214B. During reception, it performs demodulation, decoding, deinterleaving, descrambling, etc. on the digital signal and sends the processed signal to the MAC processing unit 212.

[0033] The MAC processing unit 212 corresponds to a MAC (Media Access Control) sublayer, and performs channel access control, signal multiplexing control, etc. The MAC processing unit 212 also adds a MAC header and a FCS (Frame Check Sequence) when transmitting, and separates the MAC header and the FCS when receiving.

[0034] The communication control unit 211 controls the RF switches 215A and 215B, the RF units 214A and 214B, the signal processing unit 213, and the MAC processing unit 212 so that they perform the above operations.

[0035] The LLC processing unit 240 corresponds to an LLC (Logical Link Control) sublayer and includes a data processing unit 241 and a data control unit 242. The data processing unit 241 performs data framing (packetization of data) or extraction of data from packets to be passed to a higher layer. The data control unit 242 performs flow control and error control.

[0036] The information storage device 220 holds information used by the communication control unit 211. The information storage device 220 includes a buffer that stores data received from the upper layer 250 and data received by the wireless communication unit 210.

[0037] The upper layer 250 is a layer above the network layer.

[0038] The control unit 230 controls the wireless communication unit 210, the communication control unit 211, and the LLC processing unit 240. Furthermore, the control unit 230 controls the doze state and awake state of each of these blocks during power saving. In this specification, the doze state may also be referred to as a sleep state. Furthermore, the control unit 230 may perform part of the operations of the communication control unit 211, or the communication control unit 211 may perform part of the operations of the control unit 230. Furthermore, the communication control unit 211 and the control unit 230 may be configured as a single block. The communication control unit 211 and the control unit 230 control operations related to R-TWT and Divided R-TWT according to the present disclosure, which will be described later.

[0039] The communication control device in the STA (including when the STA is an XR device) of the present disclosure may be realized in hardware by one or more integrated circuits including at least one of the control unit 230 and the communication control unit 211, or may be realized in software by having a processor execute a program that realizes the functions of at least one of the control unit 230 and the communication control unit 211.The communication control device in the STA 200 has a control unit that controls the wireless communication unit 210 that communicates with the AP 100 (wireless communication device), and this control unit corresponds to at least one of the control unit 230 and the communication control unit 211.

[0040] Note that the block diagram of Figure 2 shows a case where both AP 100 and STA 200 have a minimum configuration, but for example, at least one of AP 100 and STA 200 may have a Multi-Link Device (MLD) configuration that is expected to be standardized in IEEE 802.11be.

[0041] Figure 3 shows an overview of R-TWT operation. The example in Figure 3 shows one AP and two STAs (STA1 and STA2). Both STA1 and STA2 are assumed to be STAs capable of receiving R-TWT scheduling parameters (R-TWT parameters). Also, assume that STA1 is about to start R-TWT operation, while STA2 is already configured and operating with R-TWT. Here, we assume that, with regard to communications between the AP and STA1 and STA2, STA1 transmits traffic data requiring low latency via the downlink, while STA2 transmits traffic data requiring low latency via the uplink to the AP.

[0042] The operation of R-TWT is roughly composed of the following three steps: Step S1: R-TWT membership setup in which the STA becomes a member of R-TWT. Step S2: R-TWT SP announcement in which the AP transmits R-TWT schedule information. Step S3: The terminal wakes up, and transmission of the target data, traffic data requiring low latency (low latency traffic data or high priority traffic data), is performed within the R-TWT SP.

[0043] (Step S1: R-TWT membership setup where STA becomes a member of R-TWT) First, STA1 transmits an R-TWT request signal 401 to the AP to become a member of R-TWT. The AP, having received the R-TWT request signal, transmits an R-TWT response signal 402 to STA1. A frame including a TWT element is used as each of the R-TWT request signal and the R-TWT response signal. Examples of such frames include a Beacon, Association request, Association response, TWT setup, Probe request, Probe response, and Action frame. Furthermore, when transmitting the R-TWT request signal, STA1 can also specify an R-TWT parameter, which is a parameter related to the R-TWT SP that is being requested to be set. The R-TWT parameter is included in the TWT element.

[0044] More specifically, the R-TWT parameters represent the duration of the R-TWT SP (Nominal Minimum TWT Wake Duration), the period (TWT Wake Interval), the R-TWT SP start time (Target Wake Time), the channel to be used (TWT Channel), low-latency traffic data information, etc.

[0045] FIG. 4 shows a flowchart of the R-TWT membership setup.

[0046] STA1 determines whether to specify R-TWT parameters on its own side (S11). If it does not specify R-TWT parameters, it transmits an R-TWT request signal to the AP (S12), which includes a TWT element in which Request is set in the TWT Setup Command subfield in the Request Type field (see FIG. 11, which will be described later).

[0047] If the TWT Setup Command subfield is set to "Request," the AP determines whether STA1 has sufficient resources to set up the R-TWT (S13). The resources may be, for example, a frequency band or a frequency channel. However, the resources may also include time resources and spatial resources.

[0048] If it is determined that there are insufficient resources, the AP transmits an R-TWT response signal including a TWT element with the TWT Setup Command subfield set to Reject to STA1 (S14).If there are sufficient resources, the AP specifies R-TWT parameters and transmits an R-TWT response signal including a TWT element with the TWT Setup Command subfield set to Accept to STA1 (S15).

[0049] On the other hand, if STA1 specifies an R-TWT parameter, STA1 specifies the R-TWT parameter and transmits an R-TWT request signal to the AP including a TWT element with the TWT Setup Command subfield set to "Suggest" or "Demand." More specifically, if STA1 requests that setup be performed only using the R-TWT parameter specified by STA1, it transmits an R-TWT request signal to the AP including a TWT element with the TWT Setup Command subfield set to "Demand" (S17). If STA1 allows the possibility of setup being performed using R-TWT parameters other than those specified by STA1, it transmits an R-TWT request signal to the AP including a TWT element with the TWT Setup Command subfield set to "Suggest" (S21).

[0050] If Demand is set in the TWT Setup Command subfield, the AP that receives the R-TWT request signal determines whether it is possible to configure the R-TWT using the R-TWT parameters specified by STA1, i.e., whether it accepts the R-TWT parameters specified by STA1 (S18). If the AP accepts the R-TWT parameters from STA1, it transmits an R-TWT response signal to STA1 that includes a TWT element with Accept set in the TWT Setup Command subfield (S19). If the AP does not accept the R-TWT parameters from STA1, i.e., if it is not possible to configure the R-TWT using the R-TWT parameters specified by STA1, it transmits an R-TWT response signal to STA1 that includes a TWT element with Reject set in the TWT Setup Command subfield (S20).

[0051] If "Suggest" is set in the TWT Setup Command subfield, the AP that receives the R-TWT request signal determines whether or not it is possible to set the R-TWT with the R-TWT parameters specified by STA1 (S22). If the R-TWT can be set, the AP transmits an R-TWT response signal to STA1 that includes a TWT element with the TWT Setup Command subfield set to "Accept" (S23). If the R-TWT cannot be set, the AP determines whether or not to force STA1 to specify (forcefully accept) R-TWT parameters that can be set by the AP (S24).

[0052] If the AP does not forcibly specify the R-TWT parameters, it specifies R-TWT parameters that are different from the R-TWT parameters specified by STA1 but are likely to be accepted by STA1, and transmits an R-TWT response signal including a TWT element with the TWT Setup Command subfield set to Alternate (S25). STA1, having received the R-TWT response signal, determines newly requested R-TWT parameters with reference to the R-TWT parameters specified by the AP, and transmits an R-TWT request signal including a TWT element specifying the newly determined R-TWT parameters (S26). In this case, the newly requested R-TWT parameters may be those specified by the AP, or may be those other than those specified by the AP.

[0053] When the AP forcibly specifies the R-TWT parameters, the AP determines new R-TWT parameters that can be set by the AP, specifies the determined R-TWT parameters, and transmits an R-TWT response signal including a TWT element with "Dictate" set in the TWT Setup Command subfield to STA1 (S27). STA1, having received the R-TWT response signal with "Dictate" set in the TWT Setup Command subfield, transmits an R-TWT request signal including the R-TWT parameters specified by the AP in the TWT element (S28). When the AP receives from STA1 an R-TWT request signal including the R-TWT parameters specified by the AP in the TWT element, the AP accepts the request from STA1 and transmits an R-TWT response signal including a TWT element with "Accept" set in the TWT Setup Command subfield (S29).

[0054] When STA1 receives from the AP an R-TWT response signal including a TWT element with Accept set in the TWT Setup Command subfield, the R-TWT membership setup is completed.

[0055] In the example of Figure 3, the AP receives a request from STA1 and allows STA1 to join the R-TWT membership, but it is also possible to specify R-TWT parameters to STA1 and allow STA1 to join the R-TWT membership without receiving a request from STA1.

[0056] If STA1 has successfully become a member of the R-TWT by completing the setup, and if the STA is a power save (PS) STA (PS STA), it transitions to doze state 403 (see Figure 3) until the next TBTT (Target Beacon Transmission Time).

[0057] (Step S2: R-TWT SP announcement transmitting R-TWT schedule information) When the next TBTT arrives, STA1 transitions to the awake state again and receives a Beacon frame 404, which is a Beacon signal broadcast from the AP. This Beacon frame 404 includes a TWT element, which includes information regarding the schedules of R-TWT, Broadcast TWT (B-TWT), and Individual TWT. After receiving the Beacon signal, the PS STA (STA1) transitions to a doze state 405 until the next SP (Service Period).

[0058] (Step S3: STA Awakes and Executes Transmission of Low-Latency Traffic Data in R-TWT SP) When the R-TWT SP begins, the PS STA (STA1) transitions to the awake state and begins transmitting data (low-latency traffic data) specified by the R-TWT TID (Traffic ID) from the AP to STA1. Note that all STAs must suspend transmission once when the R-TWT SP begins. When the R-TWT SP duration (R-TWT SP duration) expires or if the aforementioned early termination is applied, the R-TWT SP ends, and the PS STA (STA1) can transition to the doze state 406 until the next R-TWT SP. Note that in the R-TWT SP, the STA may not only receive data from the AP, but also transmit data. Like STA1, STA2 transitions to the awake state when the R-TWT SP begins. STA2 transmits uplink data to the AP in the R-TWT SP.

[0059] (Issues When R-TWT is Applied to XR) Figure 5 is a diagram illustrating the issues that arise when R-TWT is applied to XR devices. An environment is assumed in which an AP, an XR device, and multiple STAs (STA1, STA2) exist. Next-generation XR devices are often battery-powered or require physical contact, placing strict power consumption requirements on the XR device. Furthermore, due to the demand for miniaturization and diversification, XR devices may have limited computing resources. Therefore, the server 400 performs high-load processing such as rendering. As a result, XR device traffic suffers from significant frame arrival jitter. R-TWT requires that R-TWT parameters be determined in advance. Because wireless LANs manage traffic based on the time it takes for data to arrive on the wireless LAN, a long R-TWT SP must be set to achieve low-latency, highly reliable transmission of XR device traffic data when significant frame arrival jitter occurs. As a result, the R-TWT SPs 410 and 411 assigned to XR devices become larger, as shown in Figure 5. This reduces the time resources available for STA1 and STA2 to transmit without overlapping with the R-TWT SPs 410 and 411. Furthermore, the awake time of the XR device increases, limiting the effect of low power consumption of the R-TWT. This reduces the efficiency of the system.

[0060] (Early Termination) As mentioned above, early termination is a technology that shortens the R-TWT SP by generating a termination event when traffic can be transmitted earlier than expected in the R-TWT.

[0061] FIG. 6 shows the operation of R-TWT when early termination is applied. After traffic data transmission from the AP to the STA (EHT STA) is completed, the STA or AP transmits a signal 421 for a termination event 420. Examples of transmission methods for the signal 421 that trigger the termination event 420 include the STA transmitting a QoS Data frame with the EOSP subfield set to 1, a QoS Null frame, or a signal with the More Data field set to 0. Transmitting the signal 421 for the termination event 420 forcibly terminates the R-TWT SP. In other words, the period 423 after these frames or signals in the R-TWT SP is released. During this period 423, the STA can acquire channel access rights using CSMA / CA. In this case, the STA may transition to a doze state. However, due to the nature of frame arrival jitter assumed in XR, the probability of traffic occurring earlier than expected is low, and the effectiveness of this method is limited.

[0062] (Summary of the Present Disclosure) In consideration of these issues, the present disclosure proposes a method of setting multiple candidate periods, called prioritized transmission periods (R-TWT SPs), distributed within a traffic generation expected period (reception expected period), which is a continuous period during which target data (hereinafter also referred to as identical traffic data) is expected to be received from the server 400, as candidate periods for preferentially transmitting the target data to STAs. In other words, in the R-TWT described with reference to FIGS. 3 and 4, the entire traffic generation expected period during which the same traffic data is expected to be received is set as an R-TWT SP, and the STA is awake within the R-TWT SP. However, in the present disclosure, multiple R-TWT SPs are set intermittently or distributed within the traffic generation expected period. In other words, the period during which the target data can be preferentially transmitted is divided into multiple periods. Each of these divided periods constitutes a prioritized transmission period (R-TWT SP) in the present disclosure. Because the total length of these multiple prioritized transmission periods set within the expected traffic generation period is shorter than the expected traffic generation period, the total length of the multiple prioritized transmission periods (R-TWT SPs) in the present disclosure is shorter than the total length of the R-TWT SPs when the entire expected traffic generation period in Figure 3 is set as the R-TWT SP. In this disclosure, an R-TWT that sets multiple divided R-TWT SPs for the same traffic data in this way is called a divided R-TWT, or an R-TWT according to the present disclosure. Below, we will explain what is necessary to realize divided R-TWT.

[0063] (1) Guaranteeing worst-case traffic transmission delays. The time displayed on an XR device's display is determined by the refresh rate and is a fixed interval. Therefore, if the transmission delay exceeds the required value even slightly, the image frame cannot be updated until the next image frame update time, significantly increasing the wireless transmission delay. Therefore, it is necessary to determine the placement of multiple R-TWT SPs (multiple priority transmission periods) within the traffic reception expected period to guarantee the worst-case delay time.

[0064] (2) Transmitting information on multiple periodic priority transmission periods (R-TWT SPs) in a single R-TWT parameter set field. In the R-TWT shown in Figure 3, a single R-TWT parameter set field can only convey information on a single periodic R-TWT SP. Therefore, to configure multiple R-TWT SPs using the TWT shown in Figure 3, multiple R-TWT parameter set fields must be configured within the TWT element. However, this method increases the frame length and makes it difficult to manage multiple R-TWT SPs collectively. To manage multiple periodic R-TWT SPs more efficiently, a method is needed that allows multiple periodic R-TWT SPs to be configured or managed collectively in a single R-TWT parameter set field. To achieve this, a process must be performed during membership that explicitly indicates that multiple R-TWTs will be configured for the same traffic data.

[0065] (3) Changing the method of notifying information about multiple periodic prioritized transmission periods (R-TWT SPs) depending on the capabilities of each STA (terminal) within the AP's cell. Some terminals within a cell may not be able to receive (recognize) the TWT element newly defined in this disclosure. In this case, it is not possible to notify all terminals of information about multiple divided periodic R-TWT SPs configured for the same traffic data. Even if there is a STA that cannot receive the TWT element according to this disclosure, a mechanism is needed to enable STAs that have multiple divided periodic R-TWT SPs configured to transmit traffic data with priority.

[0066] Below, we will explain an example of an operation and an example of a frame configuration for setting multiple divided R-TWT SPs for the same traffic data (i.e., setting multiple R-TWT SPs in a distributed manner within the expected traffic reception period), which is a feature of the present disclosure, while satisfying the requirements (1) to (3) above.

[0067] (Example of setting multiple divided R-TWT SPs for the same traffic data) FIG. 7 shows an example of setting multiple divided R-TWT SPs for the same traffic data that the AP 100 transmits to the XR device 300.

[0068] In the example of FIG. 7 , the AP 100 periodically sets the expected traffic generation period (expected reception period) T1, which is the period during which data addressed to the XR device is expected to be received from the server 400, based on, for example, information about the XR device 300's app (e.g., required transmission rate information, refresh rate, XR device motion / control information, etc.). In this example, the set period P1 for period T1 is the average traffic reception period during which data from the server 400 is received by the AP 100 via backhaul communication, and is a period that covers the frame arrival jitter range. The AP 100 sets two R-TWT SPs 431 and 432 with an interval between them within each period T1. In this example, period T1 is divided into two intervals of equal length, and R-TWT SPs of the same length are set so that they include the end time of each interval. The number of R-TWT SPs set is not limited to two and may be three or more. Furthermore, the lengths of the R-TWT SPs do not have to be the same.

[0069] The AP 100 treats periods within period T1 other than the set R-TWT SPs 431 and 432 as Semi-R-TWT SPs. In the example of FIG. 7 , in period T1, Semi-R-TWT SP 441 precedes R-TWT SP 431, and Semi-R-TWT SP 442 occurs between R-TWT SPs 431 and 432. The AP 100 covers the frame arrival jitter range with R-TWT SPs 431 and 432 and Semi-R-TWT SPs 441 and 442. The XR device 300 recognizes R-TWT SPs 431 and 432 as periods during which the XR device 300 can transmit with priority, but Semi-R-TWT SPs 441 and 442 are periods managed by the AP 100 and do not necessarily need to be explicitly recognized by the XR device 300 as Semi-R-TWT SPs. The Semi-R-TWT SP corresponds to a non-priority transmission period for the XR device 300. An example of the operation of the AP 100 in the Semi R-TWT SP will be described with reference to FIG.

[0070] 8 shows a flowchart of an example of the operation of the AP 100 in a Semi-R-TWT SP. This operation is controlled by the communication control unit 111 or the control unit 130 of the AP 100. In this example, it is assumed that the STA performing the R-TWT operation (here, the XR device 300) is a PS STA. The operation of the AP 100 in a Semi-R-TWT SP changes depending on the data transmission / reception status with the XR device 300 in the R-TWT SP immediately preceding the Semi-R-TWT SP. Note that the example of FIG. 8 assumes that no R-TWT SP that allows transmission of traffic data other than Divided R-TWT in the Semi-R-TWT SP is assigned to any STA.

[0071] First, the AP 100 determines whether traffic data is being transmitted in the immediately preceding R-TWT SP (whether traffic data transmission has started) (S51). In FIG. 7, the R-TWT SP immediately preceding the Semi-R-TWT SP 442 is the R-TWT SP 431. The Semi-R-TWT SP 441 is the period at the start of period T1, and there is no immediately preceding R-TWT SP. If traffic data is not being transmitted in the immediately preceding R-TWT SP, the AP 100 can communicate with other STAs during the Semi-R-TWT SP (S52). Here, other STAs refer to STAs other than the XR device, and in the example of FIG. 5, refer to terminals such as STA1 and STA2. Furthermore, if the XR device 300 is not a PS STA, it is assumed that the XR device 300 is in an awake state during the Semi-R-TWT SP, and therefore traffic data can also be transmitted to the XR device 300. In other words, if the XR device 300 is in an awake state, it can communicate with the AP 100 during the Semi-R-TWT SP. Alternatively, for example, it is possible to allocate a Broadcast TWT SP to terminals other than the XR device 300, such as STA1 and STA2, during a Semi R-TWT SP.

[0072] If traffic data transmission is being performed in the immediately preceding R-TWT SP in step S51, it is determined whether transmission of the traffic data (traffic data specified by the R-TWT TID) has been completed within that R-TWT SP (S53). If traffic data transmission has been completed, the AP 100 can communicate with other terminals (other STAs) in that Semi-R-TWT SP (S54). In this case, if the XR device 300 is not a PS STA, the AP 100 can also transmit traffic data to the XR device 300. In other words, if the XR device 300 is in an awake state, it can communicate with the AP 100 during the Semi-R-TWT SP.

[0073] If the traffic data transmission is not complete, the AP 100 extends the R-TWT SP and continues transmitting the traffic data specified by the R-TWT TID (S55). For example, if the traffic data transmission is started in the R-TWT SP 431 and the transmission is not complete at the end of the R-TWT SP 431, the traffic data transmission is continued in the Semi R-TWT SP 442 following the R-TWT SP 431. In the case of downlink (DL) communication of traffic data, if the receiving terminal (here, the XR device 300) is in an awake state, the R-TWT SP can be extended to continue transmitting the traffic data. Note that in the case of the R-TWT SP 432, there is no Semi R-TWT SP following the R-TWT SP 432, but even in this case, the traffic data transmission may be allowed to continue.

[0074] FIG. 9 shows a flowchart of an example of the operation of the XR device 300, which is a PS STA in a Semi R-TWT SP.

[0075] Similar to the operation of the AP 100, the XR device 300 determines whether traffic data is being received in the immediately preceding R-TWT SP (whether reception of traffic data has started) (S61). If traffic data is not being received, the XR device 300 transitions to a doze state during the Semi R-TWT SP (S62) to reduce power consumption. Note that the XR device 300 does not need to recognize the Semi R-TWT SP; it is sufficient if it recognizes that it is not an R-TWT SP. However, a configuration in which the XR device 300 recognizes the Semi R-TWT SP is not excluded.

[0076] If traffic data is being received in the immediately preceding R-TWT SP, the XR device 300 determines whether the reception of the traffic data has been completed in that R-TWT SP (S63). If the reception of the traffic data has been completed, the XR device 300 transitions to the doze state (S64).

[0077] If reception of the traffic data is not complete, the XR device 300 continues receiving the traffic data (S65). Note that if the XR device 300 is not a PS STA (if the Responder PM Mode in the Control field of the TWT element is 0), the XR device 300 does not need to transition to the doze state. In this case, the XR device can communicate with the AP 100 by acquiring channel access rights even during Semi R-TWT SP.

[0078] The Semi R-TWT SP may be set as an R-TWT SP for transmitting information such as Motion / Control from the XR device 300 to the AP 100. In addition, it is also possible to further shorten the R-TWT SP by applying early termination to the Divided R-TWT disclosed herein.

[0079] The following describes in detail how to set the R-TWT SP and Semi R-TWT SP.

[0080] (The R-TWT SP is set to meet the worst-case delay time.) The AP 100 manages traffic data based on the time from when the traffic data arrives from the server 400. When a traffic data packet arrives at the AP 100, if the AP does not start transmitting the packet, the requested delay time will not be met, which is the transmission start deadline. If the AP 100 transmits the packet by the transmission start deadline, the traffic data can be transmitted to the XR 300 by the requested delay time. The requested delay time corresponds to the latest time by which the traffic data must arrive at the XR 300 (the worst-case delay time). The transmission start deadline is the requested delay time minus the traffic data transmission time and overhead time (such as the exchange of trigger frames). The time from the packet reception time to this transmission start deadline corresponds to the allowable delay time. For these reasons, the R-TWT SP must start before the transmission start deadline. In other words, multiple R-TWT SPs must be set within the expected traffic reception period so that the time length from any time within the expected traffic reception period to the start time of the immediately following R-TWT SP is less than or equal to the above-mentioned allowable delay time.

[0081] (The timing t when traffic data arrives the latest during the traffic generation expected period T1. END (See FIG. 7.) The R-TWT SP is set so that it includes the timing t at which traffic data arrives latest during the traffic generation expected period T1. END When Semi R-TWT SP is set to , the length of the traffic generation expected period T1 is set to a length that takes into account the frame arrival jitter, so normally, t END Therefore, the timing t ENDIf the Semi-R-TWT SP is set to include the traffic data received by the Semi-R-TWT SP, there is a possibility that the traffic data cannot be transmitted within the required delay time, and low-delay transmission cannot be achieved. For example, if the XR device 300 is a PS STA, traffic cannot be transmitted until the R-TWT SP in the next traffic generation expected period, which increases the delay time. Therefore, at the end of the traffic generation expected period T1, the R-TWT SP is set instead of the Semi-R-TWT SP, and the traffic data arrival timing t is set to the latest timing. END Arrange them so that they include

[0082] (Allocation of R-TWT SP and Semi-R-TWT SP) The maximum duration of a Semi-R-TWT SP must not exceed the allowable delay time, which is the time from the packet reception time to the transmission start deadline. Another constraint is that the minimum length of an R-TWT SP must be 256 μs. However, 16 bits are allocated to the duration setting of an R-TWT SP, allowing for flexibility in the allocation of R-TWT SPs and Semi-R-TWT SPs within period T1. If the duration of an R-TWT SP is predetermined, the optimal allocation is to allocate the R-TWT SP so that the probability of traffic data occurrence (probability of traffic data arrival) within the R-TWT SP is maximized or quasi-maximized. For example, one of multiple R-TWT SPs may be set at a position that includes the time during the expected traffic reception period when traffic data is most likely to be received or is greater than or equal to a threshold.

[0083] 10(A) to 10(C) show three examples of (Divided) R-TWT SP allocation. The average frame period P2 is not limited to a specific value, but is, for example, 11 ms (frame rate 90 fps). Comparing the allocation example of FIG. 10(A) with the allocation example of FIG. 10(B), the total period length of the R-TWT SP within each expected traffic generation period T2 is shorter in FIG. 10(B). Therefore, while FIG. 10(A), in which most of the expected traffic generation period is set to R-TWT SP, can achieve lower latency transmission than FIG. 10(B), it can be said that FIG. 10(B) is a more efficient allocation in terms of time resource allocation to other terminals and low power consumption. On the other hand, if the distribution of frame arrival jitter is a truncated normal distribution, the time t max The probability of traffic data occurrence is maximized in (A) and (B). Therefore, if the total duration of the R-TWT SPs within each expected traffic occurrence period T2 is the same in Figures 10(B) and 10(C), the allocation example in Figure 10(C) has a higher probability of traffic data occurring within the R-TWT SPs, and can be said to be a more efficient allocation than the allocation example in Figure 10(B). The ideal allocation of R-TWT SPs and Semi-R-TWT SPs is one in which the total duration of the R-TWT SPs is as short as possible and the probability of traffic data occurring within the R-TWT SPs is high. From this perspective, of the allocation examples in Figures 10(A) to 10(C), Figure 10(C) can be said to be the most efficient allocation example in terms of time resource allocation to other terminals and low power consumption.

[0084] (Problem during membership setup to set up multiple divided R-TWT SPs for the same traffic data) For a STA to join R-TWT, it must receive a signal from the AP that includes a TWT element with Accept set in the TWT Setup Command subfield. We will consider the problem when a STA sends an R-TWT participation request to the AP.

[0085] When a STA that wants to participate in R-TWT sends a signal containing a TWT element with the TWT Setup Command subfield set to Request, the STA does not specify the R-TWT parameters; the AP sets the R-TWT parameters (see Figure 4). Even if the STA wants to specify whether to use Divided R-TWT during implementation, the STA cannot communicate its intention to use Divided R-TWT to the AP in Figure 4, and the AP may return a response specifying R-TWT parameters that are different from the desired R-TWT parameters. Similarly, when a STA that wants to participate in R-TWT sends a signal containing a TWT element with the TWT Setup Command subfield set to Suggest or Demand, even if the STA wishes to use Divided R-TWT, the AP may not communicate its intention to use Divided R-TWT to the AP in Figure 4, and the AP may return a response specifying undesired R-TWT parameters. 4, multiple R-TWT parameters can be included in a TWT element and transmitted, so that a divided R-TWT configuration can be essentially achieved by transmitting a TWT element including multiple R-TWT parameters from a STA. However, even in this case, only some of the multiple R-TWT parameters may be accepted by the AP, and the rest may be rejected. In this case, the STA may need to tear down the accepted R-TWT parameters and transmit the multiple R-TWT parameters again.

[0086] To solve these problems, we introduce a method to explicitly indicate the desire to configure Divided R-TWT. Furthermore, R-TWT is intended for use with periodic traffic, and current R-TWTs can only transmit information for one R-TWT SP within one R-TWT Parameter Set field. This disclosure introduces a new R-TWT Parameter Set field that enables the collective management of information for multiple R-TWT SPs (multiple divided R-TWT SPs) for the same traffic data.

[0087] (Example of format of R-TWT Parameter Set field that transmits information on multiple R-TWT SPs for the same traffic data in one R-TWT Parameter Set field) Figure 11 shows an example of the format of a MAC frame including an R-TWT Parameter Set field that transmits information on multiple R-TWT SPs for the same traffic data in one R-TWT Parameter Set field.

[0088] The R-TWT Parameter Set field is included in the TWT Parameter Information within the TWT element. If it is not an Individual TWT, the TWT Parameter Information can include multiple R-TWT Parameter Sets / Broadcast TWT Parameter Sets.

[0089] Signals that include TWT elements include management frames such as beacon, association request, association response, probe request, and probe response, as well as action frames such as TWT setup and TWT teardown.

[0090] The Common R-TWT Parameter Set field in the R-TWT Parameter Set field in FIG. 11 is composed of Request Type, Target Wake Time, Nominal Minimum TWT Wake Duration, TWT Wake Interval Mantissa, Broadcast TWT Info, and Restricted TWT Traffic Info.

[0091] In this disclosure, to allocate multiple periodic R-TWT SPs to the same traffic data, four subfields are defined in the R-TWT Parameter Set field: Extended SP Number, Broadcast TWT ID Info, Target Wake Time, and Wake Duration (Nominal Minimum TWT Wake Duration). One or more of Broadcast TWT ID Info, Target Wake Time, and Wake Duration (Nominal Minimum TWT Wake Duration) can be set as a set. These fields correspond to the Additional R-TWT Parameter Set field in FIG. 11.

[0092] The Extended SP Number subfield indicates the number of R-TWT SPs (division number) set for the same traffic data. In the example of Fig. 11, one octet is newly assigned to the Extended SP Number subfield, but it is also possible to use the reserved part of the Traffic Info Control field in the Restricted TWT Traffic Info.

[0093] Broadcast TWT ID Info is assigned to each R-TWT SP to uniquely manage it. For example, Broadcast TWT ID Info consists of a 3-bit Reserved field and a 5-bit Broadcast TWT ID. Each time the number of R-TWT SPs increases by one, a set of three subfields, Broadcast TWT ID Info, TWT Wake Time, and Wake Duration, is added. The added sets of Broadcast TWT ID Info, Target Wake Time, and Wake Duration are sorted in ascending order of Target Wake Time. For each R-TWT SP, the values ​​of the information other than these three subfields are the same as the fields other than Broadcast TWT ID Info, Target Wake Time, and Wake Duration in the Common R-TWT parameter set.

[0094] Broadcast TWT ID Info, Target Wake Time, and Wake Duration correspond to the second field, which stores information specific to multiple R-TWT SPs, while Request Type, TWT Wake Interval Mantissa, and the like correspond to the first field, which stores information common to multiple R-TWT SPs. In other words, a TWT element according to the present disclosure can be said to have a single R-TWT Parameter Set field that includes a first field that stores common information among multiple R-TWT SPs (priority transmission periods) and multiple second fields that store information specific to the multiple R-TWT SPs (priority transmission periods). A conventional TWT element can be said to have multiple R-TWT Parameter Set fields (third fields) that can store only one piece of information for each of multiple priority transmission periods. A frame format including a first field and multiple second fields is referred to as a first format, and a frame format including multiple third fields is referred to as a second format.

[0095] (Example of a method for notifying an intention to apply Divided R-TWT) The following methods are examples of a method for explicitly notifying an intention to apply Divided R-TWT. The notification can be made either by the STA or the AP. [1] Use the Extended SP Number (set the value of the Extended SP Number to 0, set Request in the TWT Setup Command subfield, etc.) [2] Add a new Broadcast TWT Recommendation (in the Request Type field) [3] Add a new Element ID [4] Add a new Capabilities element

[0096] Divided R-TWT guarantees worst-case latency by setting multiple divided R-TWT SPs taking into account the grace period before transmission begins. However, if data is received outside of an R-TWT SP, transmission must wait until the next R-TWT SP, which increases the average latency. On the other hand, the advantage is that the total length of R-TWT SPs within the expected traffic reception period can be shortened, thereby achieving low power consumption and increasing the time resources allocated to other terminals. Therefore, whether to use Divided R-TWT is decided by the application user, or by the AP or STA. Specific examples are shown below.

[0097] (Example of how an AP determines whether or not to apply Divided R-TWT) Examples of how an AP can make a determination include the following: [1] When the AP determines that the frame arrival jitter in the traffic is large [2] When the application user changes the settings on the AP side (such as setting low power consumption mode) [3] When the AP determines that there are many STAs connected to the AP (for example, above a threshold value).

[0098] (Example of how a STA determines whether or not to apply Divided R-TWT) Examples of how a STA can make this determination include the following: [1] When the STA is a device dedicated to XR applications [2] When a setting change is requested after receiving an arbitrary or specified signal from the AP Specific cases in which a terminal requests the application of Divided R-TWT include the following: Unless a cross-layer architecture is used or all traffic data arriving from the network is decoded, the AP cannot determine the application of the traffic data arriving from the network or server. For this reason, the STA may determine the type of application, i.e., the type of data being transmitted, and send a request for Divided R-TWT configuration based on the results of this determination. For example, if the data type is a specified data type such as XR data, a request for Divided R-TWT configuration is sent.

[0099] 12 shows a flowchart of an example of the operation of R-TWT membership setup when the R-TWT parameter set field (see FIG. 11) according to the present disclosure is applied. The operation of this flowchart is controlled by a control unit in the AP 100 (the communication control unit 111 or the control unit 130 in the AP 100), and also by a control unit in the STA (assumed to be the XR 300 here) (the communication control unit 211 or the control unit 230 in the XR device 300). Descriptions similar to those in FIG. 4 above will be omitted or simplified as appropriate.

[0100] First, the STA (here, assumed to be the XR 300) determines whether to specify R-TWT parameters (S101). For example, if the STA obtains TWT SP information from a beacon and determines that resources are available, it may decide to specify the R-TWT parameters itself. If the STA does not specify R-TWT parameters, it sets the TWT Setup Command subfield to Request and the Extended SP Number field to 0, and transmits an R-TWT request signal to the AP 100 (S102). Setting the Extended SP Number field to 0 notifies the AP 100 that it wishes to apply Divided R-TWT. This R-TWT request signal corresponds to a request signal requesting that the AP 100 determine parameter values ​​for multiple preferred transmission periods (R-TWT SPs). If it wishes to apply conventional R-TWT instead of Divided R-TWT, it sets the Extended SP Number field to a predetermined value (e.g., 1). In addition to using the Extended SP Number field, other methods described above may also be used to notify the desire to apply Divided R-TWT. That is, a method of adding a Broadcast TWT Recommendation field or a method of changing the Element ID from the conventional R-TWT may be used.

[0101] The AP 100 determines whether the STA has sufficient resources to set up the Divided R-TWT (S103). If it determines that there are insufficient resources, the AP 100 transmits to the STA an R-TWT response signal including a TWT element with Reject set in the TWT Setup Command subfield (S104). If there are sufficient resources, the AP 100 transmits to the STA a response signal including a TWT element with Accept set in the TWT Setup Command subfield, setting the R-TWT parameters for each divided R-TWT SP, and setting the value of the Extended SP Number subfield to 1 or greater (S105). The value of the Extended SP Number subfield is N-1, where N is the number of R-TWT SPs (or the number of divisions). Information about the first R-TWT SP in terms of time among the N R-TWT SPs is set in the Common R-TWT Parameter Set field in FIG. 11, and information about the second and subsequent R-TWT SPs is set in the Additional R-TWT Parameter Set field in FIG. 11 for the number of R-TWT SPs from the second onwards. As described above, information common to all N R-TWT SPs is set in the Common R-TWT Parameter Set field (e.g., Request type field, TWT Wake Interval Mantissa field).

[0102] When the STA specifies R-TWT parameters for each divided R-TWT SP, if the STA requests that setup be performed only using the R-TWT parameters specified by the STA, the STA sets the TWT Setup Command subfield to Demand and sets the value of the Extended SP Number subfield to 1 or greater according to the desired number of R-TWT SPs (number of divisions). Then, the STA sets the R-TWT parameters for each R-TWT SP. An R-TWT request signal including TWT elements based on these settings is transmitted to the AP 100 (S107). This R-TWT request signal corresponds to a request signal including information specifying parameter values ​​for multiple preferred transmission periods (R-TWT SPs) for which setup is requested. On the other hand, if the STA allows the possibility of setup using R-TWT parameters other than those specified by the STA for at least one of the R-TWT SPs, the STA sets the TWT Setup Command subfield to Suggest, sets the value of the Extended SP Number subfield to 1 or greater according to the desired number of divisions, and then sets the R-TWT parameters for each divided R-TWT SP. An R-TWT request signal including TWT elements based on these settings is transmitted to the AP 100 (S111).

[0103] If Demand is set in the TWT Setup Command subfield, the AP 100 that receives the R-TWT request signal determines whether it is possible to set all the R-TWT parameters for each R-TWT SP (S108). Only if it is possible to set the R-TWT parameters for all of the R-TWT SPs, does the AP 100 transmit an R-TWT response signal to the STA, including a TWT element with Accept set in the TWT Setup Command subfield (S109). If it is not possible to set the R-TWT parameters for at least one of the R-TWT SPs, the AP 100 transmits an R-TWT response signal to the STA, including a TWT element with Reject set in the TWT Setup Command subfield (S110). If it is not possible to set the R-TWT parameters for at least one of the R-TWT SPs, the AP 100 determines whether to forcibly assign to the STA the R-TWT parameters that can be set by the AP 100 for each R-TWT SP (S114).

[0104] If the AP 100 does not forcibly specify R-TWT parameters for each R-TWT SP, it determines R-TWT parameters for at least one R-TWT SP that are different from those specified by the STA but are likely to be acceptable. Since the AP 100 has the discretion to allocate R-TWT SPs, it may determine a value for the number of R-TWT SPs (division number) that differs from the STA's preference. The AP 100 then transmits an R-TWT response signal specifying the determined R-TWT parameters for each R-TWT SP and including a TWT element with the TWT Setup Command subfield set to Alternate (S118). The STA that receives the R-TWT response signal determines newly requested R-TWT parameters by referring to the R-TWT parameters specified by the AP 100 for each R-TWT SP. The STA then transmits an R-TWT request signal specifying the newly determined R-TWT parameters for each R-TWT SP (S119). At this time, the R-TWT parameters newly requested for each R-TWT SP may be those specified by the AP 100 or may be those other than those specified by the AP 100 .

[0105] When the AP forcibly specifies the R-TWT parameters for each R-TWT SP, the AP determines new configurable R-TWT parameters. Then, the AP transmits an R-TWT response signal to the STA, specifying the determined R-TWT parameters for each R-TWT SP and including a TWT element with Dictate set in the TWT Setup Command subfield (S115). Upon receiving the R-TWT response signal with Dictate set in the TWT Setup Command subfield, the STA transmits an R-TWT request signal including the R-TWT parameters specified by the AP 100 for each R-TWT SP (S116). When the AP 100 receives an R-TWT request signal including the R-TWT parameters specified by the AP 100 for each R-TWT SP, the AP 100 accepts the request from the STA and transmits an R-TWT response signal including a TWT element with Accept set in the TWT Setup Command subfield (S117).

[0106] As described above, AP 100 collectively manages and determines the R-TWT parameters for each R-TWT SP.

[0107] (AP100 changes the method of notifying information of multiple R-TWT SPs by referring to the capabilities of STAs in the cell) Figure 13 is a flowchart of the operation of AP100 to change the method of broadcasting information of multiple R-TWT SPs (R-TWT parameters) depending on the capabilities of STAs in the cell.

[0108] 13, we will explain the application of Divided R-TWT, which takes into account the presence of STAs in a cell that cannot receive (interpret) the R-TWT parameters. In R-TWT, one or more R-TWT SPs are configured to prioritize transmission of low-latency traffic data. However, in order for a specific STA to prioritize transmission or reception of low-latency traffic data using the configured R-TWT SP, all STAs in the cell must be able to recognize the R-TWT SP.

[0109] First, it is determined whether all STAs in the cell can receive (interpret) the R-TWT Parameter Set field (see FIG. 11 ) for Divided R-TWT (S121). If all STAs can receive it, the R-TWT Parameter Set field according to the present disclosure is used to broadcast information about each R-TWT SP (R-TWT parameter) (S122). Because the R-TWT parameters in the R-TWT Parameter Set field format according to the present disclosure include information about multiple R-TWT SPs divided for the same traffic data, the number of transmission bits can be reduced compared to conventional R-TWT, in which multiple R-TWT parameters representing information about multiple R-TWT SPs are transmitted together in a TWT element.

[0110] An STA that can receive the R-TWT parameter set field (see FIG. 11 ) according to the present disclosure corresponds to a first wireless communication device that can interpret the above-described first format (the format of the R-TWT parameter set field including the first and second fields in FIG. 11 ). Information on each R-TWT SP transmitted to the first wireless communication device corresponds to a first signal that includes information on each R-TWT SP (priority transmission period) transmitted in the first format.

[0111] Next, if at least some of the STAs in the cell cannot receive the R-TWT parameter set field according to the present disclosure, it is determined whether all STAs in the cell can receive (interpret) conventional R-TWT parameters (S123). Whether conventional R-TWT parameters can be received can be determined by using dot11RestrictedTWTOptionImplemented in the EHT Capabilities element. If all STAs in the cell can receive (interpret) conventional R-TWT parameters, information on multiple R-TWT SPs for the same traffic data is notified by broadcasting a TWT element containing multiple R-TWT parameters for the same traffic data (S124). The TWT element is designed to include multiple R-TWT parameter set fields. However, unlike the R-TWT parameter set field format according to the present disclosure, the conventional R-TWT parameter set field must be repeated the same number of times as the number of R-TWT SPs, which increases the number of transmission bits. Furthermore, it is difficult to associate and centrally manage multiple R-TWT SPs.

[0112] An STA that cannot receive the R-TWT parameter set field according to the present disclosure (see FIG. 11 ) but can receive a conventional R-TWT parameter set field corresponds to a second wireless communication device that cannot interpret the first format (the format of the R-TWT parameter set field including the first and second fields in FIG. 11 ) but can interpret the second format (the conventional R-TWT parameter set field format). Information on each R-TWT SP transmitted to the second wireless communication device corresponds to a second signal that includes information on each R-TWT SP (priority transmission period) transmitted in the second format.

[0113] Finally, if there is a STA in the cell that cannot receive conventional R-TWT parameters, it is determined whether the STA that can receive (interpret) conventional R-TWT parameters can receive (interpret) the R-TWT Parameter Set field format according to the present disclosure (S125).

[0114] If there are STAs in a cell that cannot receive conventional R-TWT parameters, and STAs that can receive conventional R-TWT parameters can receive the R-TWT parameter set field according to the present disclosure, the R-TWT parameters are broadcast using the R-TWT parameter set field according to the present disclosure to STAs that can receive the R-TWT parameter set field according to the present disclosure. On the other hand, for STAs that cannot receive conventional R-TWT parameters, a quiet element is broadcast to set a quiet interval so that the STAs do not transmit to the R-TWT SP (step S126). The quiet interval is used for channel measurement, etc., and STAs cannot transmit traffic data during the quiet interval. EHT STAs, which are IEEE 802.11be or later STAs, are capable of transmitting data during the quiet interval regardless of rules, and therefore can transmit data during the R-TWT SP. Since multiple quiet elements can be included in a beacon frame, they can be set to overlap with the R-TWT SP of a non-periodic divided R-TWT (overlapping quiet interval). However, the specification requires that the length of the overlapping quiet interval must be 1 TU (Time Unit). Therefore, by setting each divided R-TWT SP to 1 TU, STAs that cannot receive conventional R-TWT parameters can be prevented from transmitting to the R-TWT SP.

[0115] An STA that cannot receive conventional R-TWT parameters corresponds to a third wireless communication device that cannot interpret either the first format (the format of the R-TWT Parameter Set field in FIG. 11 ) or the second format (the format of the conventional R-TWT Parameter Set field), and the Quiet element transmitted to the third wireless communication device corresponds to a third signal that prohibits transmission in each divided R-TWT SP (priority transmission period).

[0116] On the other hand, if there are STAs in the cell that cannot receive conventional R-TWT parameters and STAs that can receive conventional R-TWT parameters cannot receive the R-TWT Parameter Set field format according to the present disclosure, a Quiet element is transmitted to the STAs that cannot receive conventional R-TWT parameters (S127). A TWT element including multiple R-TWT parameters for the same traffic data is transmitted to STAs that can receive conventional R-TWT parameters (S127). However, even if there are STAs in the cell that cannot receive the R-TWT Parameter Set field according to the present disclosure, because R-TWT membership is a process performed between the AP and the STA that makes the R-TWT setup request, it is possible to explicitly configure Divided R-TWT using the R-TWT Parameter Set field according to the present disclosure, thereby enabling efficient R-TWT setup.

[0117] 11, a Broadcast ID is assigned to each of the divided R-TWT SPs, making it possible to manage each R-TWT SP uniquely. Therefore, when broadcasting a TWT element containing multiple R-TWT parameters in an environment where STAs exist that can only receive conventional R-TWT parameters, it becomes possible to transmit or notify information about the multiple R-TWT SPs in a manner that distinguishes them from one another using the multiple R-TWT parameters.

[0118] As described above, according to the present disclosure, flexible R-TWT SP configuration is possible by setting multiple prioritized transmission periods (R-TWT SPs) for the same traffic data. For example, the total duration of R-TWT SPs within the expected traffic generation period (expected reception period) can be shortened while ensuring worst-case latency, thereby reducing the power consumption of STAs. Furthermore, within the expected traffic generation period, adjacent R-TWT SPs can be defined as semi-R-TWT SPs, thereby increasing the time resources available for transmission by a STA or other STAs within the semi-R-TWT SP. For example, R-TWT configuration can be performed for uplink (UL) signals such as motion / control information, or TWT configuration can be performed for traffic data that does not require low-latency transmission. Furthermore, applying early termination can substantially further shorten the total duration of R-TWT SPs within the expected traffic generation period.

[0119] Furthermore, according to the present disclosure, by transmitting information on multiple divided prioritized transmission periods (R-TWT SPs) for the same traffic data in a single R-TWT Parameter Set field, it is possible to manage information on multiple R-TWT SPs collectively. This reduces the number of transmission bits during R-TWT membership setup and R-TWT parameter broadcasting, thereby improving efficiency. Furthermore, it is possible for either the STA or the AP to explicitly indicate that divided R-TWT will be performed on the same traffic data, making it possible to configure the desired number or arrangement pattern of R-TWT SPs.

[0120] Furthermore, according to the present disclosure, by changing the method of notifying information about the prioritized transmission period (R-TWT SP) depending on the capability of each STA (terminal) within a cell, it becomes possible for Divided R-TWT to operate even if there is an STA that cannot receive at least one of the R-TWT parameters in the format according to the present disclosure (see FIG. 11 ) and the R-TWT parameters in the conventional format.

[0121] <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.

[0122] FIG. 14 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.

[0123] 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 .

[0124] 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. Information related to the present technology, for example, information related to the R-TWT parameter set field (particularly, the additional R-TWT parameter set field), may be output or displayed from the output unit 807. Information related to the present technology, for example, information related to the R-TWT parameter set field (particularly, the additional R-TWT parameter set field), may be input from the input unit 806, and confirmation or a response to the information output or displayed on the output unit 807 may be input. In addition, a storage unit 808 including a hard disk, nonvolatile memory, etc., a communication unit 809 including a network interface, etc., and a drive 810 that drives removable media 811 are connected to the input / output interface 805.

[0125] In the computer configured as 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 the program. For example, the CPU 801 may execute processing programs corresponding to the flowcharts of Figures 4, 8, 9, 12, and 13 of the present technology.

[0126] 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.

[0127] 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.

[0128] <Application Examples> The present technology can be applied to various products. For example, the wireless communication devices 1000 and 2000 (APs or STAs) may be realized as mobile devices such as smartphones, tablet PCs (Personal Computers), notebook PCs, portable game consoles, or digital cameras; fixed devices such as television sets, projectors, printers, digital scanners, or network storage; or in-vehicle devices such as car navigation systems and drive recorders. The wireless communication devices 1000 and 2000 (APs or STAs) may also be realized as machine-to-machine communication (M2M) terminals, such as smart meters, vending machines, remote monitoring devices, or point-of-sale (POS) terminals, or Internet of Things (IoT) terminals. The wireless communication devices 1000 and 2000 (APs or STAs) may also be realized as terminals requiring low latency and high reliability, such as extended reality / cross reality (XR) devices. Furthermore, the wireless communication devices 1000 and 2000 (AP or STA) may be wireless communication modules (for example, integrated circuit modules configured on a single die) mounted on these terminals.

[0129] On the other hand, for example, the wireless communication devices 1000 and 2000 (APs or STAs) may be realized as wireless LAN APs (wireless base stations) with or without router functionality. The wireless communication devices 1000 and 2000 (APs or STAs) may also be realized as mobile wireless LAN routers. The wireless communication devices 1000 and 2000 (APs or STAs) may also be realized as cellular communication base stations and femtocells. Furthermore, the wireless communication devices 1000 and 2000 (APs or STAs) may be wireless communication modules (e.g., integrated circuit modules configured on a single die) mounted on these devices.

[0130] <Configuration example of smartphone> Fig. 15 is a block diagram showing a schematic configuration example of a smartphone 900 to which the present technology is applied. Fig. 15 is described as a configuration example of the smartphone 900, but the present technology is not limited to this, and may be a configuration example of the various devices and functions described above.

[0131] 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. The smartphone 900 may include all or some of the above.

[0132] The processor 901 may be, for example, a CPU or a SoC (System on Chip), and controls the functions of the application layer and other layers of the smartphone 900.

[0133] The memory 902 includes RAM and ROM, and stores programs and data executed by the processor 901 .

[0134] The storage 903 includes a storage medium such as a semiconductor memory or a hard disk.

[0135] 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 .

[0136] 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.

[0137] The sensor 907 includes a group of sensors such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor.

[0138] The microphone 908 converts the sound input to the smartphone 900 into an audio signal.

[0139] 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.

[0140] The display device 910 has a screen such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, or a quantum dot (QD) display, and displays the output image of the smartphone 900.

[0141] The speaker 911 converts the audio signal output from the smartphone 900 into sound.

[0142] The wireless communication interface 913 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11ac, 11ad, 11ax, 11ay, 11be, 11bn, and successor standards thereof, and performs wireless communication.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] The wireless communication interface 913 may support other types of wireless communication methods in addition to the wireless LAN method, such as a short-range wireless communication method such as Bluetooth, a proximity wireless communication method such as NFC, or a 3GPP cellular communication method such as 2G, 3G, 4G, 5G, and 6G. The wireless communication interface 913 may be a one-chip module that supports multiple wireless communication methods, or may be a combination of modules that support some of the wireless communication methods.

[0147] The antenna switch 914 switches the connection destination of the antenna 915 between multiple circuits included in the wireless communication interface 913 (for example, circuits for different wireless communication methods, or transmission system circuits and reception system circuits).

[0148] The antenna 915 has a single or multiple antenna elements (e.g., multiple antenna elements constituting a MIMO (Multiple Input Multiple Output) antenna, or multiple antenna elements constituting an array antenna) and is used for transmitting and receiving radio signals via the wireless communication interface 913.

[0149] 15 , the smartphone 900 may include multiple antennas (for example, a wireless LAN antenna, a proximity wireless communication antenna, and a cellular communication antenna). In this case, the antenna switch 914 may be omitted from the configuration of the smartphone 900.

[0150] 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.

[0151] The battery 918 supplies power to each block of the smartphone 900 shown in FIG. 15 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. The battery 918 may also be charged via the external connection interface 904. The battery 918 may also have a function that allows reading of information regarding the remaining amount of power, the cumulative power-on time, or the cumulative amount of power supply, and the processor 901, the wireless communication interface 913, or the auxiliary controller 919 may control any of the functions of the above-described embodiments based on the information read from the battery 918.

[0152] In the smartphone 900 shown in Fig. 15 , for example, the communication control unit 111 or the control unit 130 in Fig. 2A or the communication control unit 211 or the control unit 230 in Fig. 2B may be implemented in the wireless communication interface 913. For example, processing programs corresponding to the flowcharts in Figs. 3, 8, 9, 12, and 13 may be executed 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.

[0153] The smartphone 900 may operate as a wireless AP (software AP) by having the processor 901 execute an AP function at the application level. The wireless communication interface 913 may also have a wireless AP function. The processor 901 or the wireless communication interface 913 may also have a tethering function that uses a wireless LAN system and a cellular communication system.

[0154] Furthermore, the smartphone 900 may be provided with a biometric authentication unit (fingerprint authentication, palm shape authentication, voice authentication, blood vessel authentication, face authentication, iris authentication, retina authentication). In this case, the wireless communication interface 913 in which the communication control unit 111 or the control unit 130 in Fig. 2A or the communication control unit 211 or the control unit 230 in Fig. 2B is implemented is configured to receive power supply from the same battery 918 as at least one of the display device 910, the speaker 911, and the biometric authentication unit.

[0155] 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 related to the present technology, for example, information related to the R-TWT parameter set field (particularly the additional R-TWT parameter set field), may be output from at least one of the display device 910 and the speaker 911. Furthermore, the input device 909 may be configured to input a confirmation or response to the information output from at least one of the display device 910 and the speaker 911.

[0156] <Configuration example of in-vehicle device> Fig. 16 is a block diagram showing an example of a schematic configuration of an in-vehicle device 920 to which the present technology is applied. Fig. 16 is described as an example of the configuration of the in-vehicle device 920, but the configuration is not limited to this and may be an example of the configuration of the various devices and functions described above.

[0157] 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. The in-vehicle device 920 may be configured to include all or some of the above.

[0158] 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.

[0159] The memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921 .

[0160] 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.

[0161] The sensor 925 includes a group of sensors such as a gyro sensor, a geomagnetic sensor, a millimeter wave radar, a camera (an imaging element such as a CCD or CMOS), and a barometric pressure sensor.

[0162] 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.

[0163] The content player 927 plays content stored on a storage medium (e.g., a CD or DVD) inserted into the storage medium interface 928 or content received via the wireless communication interface 933 .

[0164] The input device 929 includes, for example, a touch sensor, a button, or a switch that detects a touch on the screen of the display device 930, and accepts operations or information input from the user. For example, the input device 929 may be configured to input a confirmation or response to information output from at least one of the display device 930 and the speaker 931.

[0165] The display device 930 has a screen such as an LCD, OLED display, or QD display, and displays images of navigation functions or content being played, as well as information related to the present technology, such as the R-TWT Parameter Set field (especially the Additional R-TWT Parameter Set field).

[0166] The speaker 931 outputs the navigation function, the audio of the content being played, or information related to the present technology, for example, information related to the R-TWT Parameter Set field (particularly the Additional R-TWT Parameter Set field).

[0167] 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.

[0168] The wireless communication interface 933 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, 11be, 11bn, and successor standards thereof, and performs wireless communication.

[0169] The wireless communication interface 933 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.

[0170] 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.

[0171] 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, or related circuits.

[0172] The wireless communication interface 933 may support other types of wireless communication methods in addition to the wireless LAN method, such as a short-range wireless communication method such as Bluetooth, a proximity wireless communication method such as NFC, or a 3GPP cellular communication method such as 2G, 3G, 4G, 5G, and 6G. The wireless communication interface 933 may be a one-chip module that supports multiple wireless communication methods, or may be a combination of modules that support some of the wireless communication methods.

[0173] The antenna switch 934 switches the connection destination of the antenna 935 between multiple circuits included in the wireless communication interface 933 (for example, circuits for different wireless communication methods, or transmission system circuits and reception system circuits).

[0174] The antenna 935 has a single or multiple antenna elements (e.g., multiple antenna elements constituting a MIMO (Multiple Input Multiple Output) antenna, or multiple antenna elements constituting an array antenna) and is used for transmitting and receiving radio signals via the wireless communication interface 933.

[0175] 16, the in-vehicle device 920 may include a plurality of antennas 935 (for example, an antenna for wireless LAN, an antenna for a close-proximity wireless communication system, and an antenna for a cellular communication system). In this case, the antenna switch 934 may be omitted from the configuration of the in-vehicle device 920.

[0176] The battery 938 supplies power to each block of the in-vehicle device 920 shown in Fig. 16 via a power supply line partially indicated by a dashed line in the figure. The battery 938 may also store power supplied from the vehicle side. Alternatively, the in-vehicle device 920 may not be equipped with a battery and may instead use power supplied from the vehicle side via a voltage regulator or a capacitor.

[0177] In the in-vehicle device 920 shown in Fig. 16, for example, the communication control unit 111 or the control unit 130 in Fig. 2A or the communication control unit 211 or the control unit 230 in Fig. 2B may be implemented in the wireless communication interface 933. For example, processing programs corresponding to the flowcharts in Figs. 4, 8, 9, 12, and 13 may be executed in the wireless communication interface 933. Furthermore, at least some of these functions may be implemented in the processor 921.

[0178] 2A or the communication control unit 211 or the control unit 230 in FIG. 2B, and may provide a wireless connection to a terminal owned by a user in the vehicle. For example, the wireless communication interface 933 may connect the in-vehicle device 920 to other peripheral devices, and the in-vehicle device 920 may use CarPlay (registered trademark) or Android Auto (registered trademark). The wireless communication interface 933 may connect the in-vehicle device 920 to other peripheral devices using a short-range wireless communication method, infrastructure mode, or a wireless LAN method using Wi-Fi Direct.

[0179] The in-vehicle device 920 may operate as a wireless AP (software AP) by the processor 921 executing an AP function at the application level. The wireless communication interface 933 may also have a wireless AP function. The processor 921 or the wireless communication interface 933 may also have a tethering function that uses a wireless LAN system and a cellular communication system.

[0180] Furthermore, 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 may generate vehicle-side data such as vehicle speed information, engine rotation speed information, information about the vehicle-side battery, or malfunction information, and output the generated data to the in-vehicle network 941, and the processor 921 or the wireless communication interface 933 may control any of the functions of the above-described embodiments based on the information acquired via the in-vehicle network 941.

[0181] <Configuration example of wireless AP> Fig. 17 is a block diagram showing an example of a schematic configuration of a wireless AP 950 to which the present technology is applied. Fig. 17 is described as an example configuration of the wireless AP 950, but is not limited to this, and may be an example configuration of the various devices and functions described above.

[0182] 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. The wireless AP 950 may include all or some of the above.

[0183] 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).

[0184] 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).

[0185] The input device 954 includes, for example, buttons, switches, etc., and receives operations from the user. For example, the input device 954 may be configured to input a confirmation or response to information output from the display device 955.

[0186] The display device 955 includes an LED lamp or the like and displays the operating status of the wireless AP 950. The display device 955 may display information related to the present technology, such as information related to the R-TWT Parameter Set field (especially the Additional R-TWT Parameter Set field).

[0187] 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 network interface 957 may input and output wireless signals input and output by the wireless communication interface 963 as wired signals, or may input and output wired signals by operating in parallel with or independently of the wireless communication interface 963 inputting and outputting wireless signals. The wired communication network 958 may be a LAN such as Ethernet (registered trademark), or may be a WAN (Wide Area Network).

[0188] The wireless communication interface 963 supports one or more wireless LAN standards, such as IEEE 802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, 11be, 11bn, and their successor standards, and provides wireless connection to nearby terminals as an AP. When the wireless AP 950 is installed in a cellular communication base station or a femtocell, the wireless communication interface 963 may support other types of wireless communication systems, such as 3GPP cellular communication systems such as 2G, 3G, 4G, 5G, and 6G, in addition to the wireless LAN system. The wireless communication interface 963 may be a one-chip module that supports multiple wireless communication systems, or a combination of modules that support some of the wireless communication systems.

[0189] The wireless communication interface 963 typically includes a baseband processor, an RF circuit, a power amplifier, and the like.

[0190] 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, or related circuits.

[0191] The antenna switch 964 switches the connection destination of the antenna 965 between multiple circuits included in the wireless communication interface 963 (for example, circuits for different wireless communication methods, or transmission system circuits and reception system circuits).

[0192] The antenna 965 has a single or multiple antenna elements (for example, multiple antenna elements constituting a MIMO (Multiple Input Multiple Output) antenna, or multiple antenna elements constituting an array antenna) and is used for transmitting and receiving radio signals via the wireless communication interface 963.

[0193] 17, for example, the communication control unit 111 or the control unit 130 in FIG. 2A or the communication control unit 211 or the control unit 230 in FIG. 2B may be implemented in the wireless communication interface 963. For example, processing programs corresponding to the flowcharts in FIGS. 4, 8, 9, 12, and 13 may be executed in the wireless communication interface 963. Furthermore, at least some of these functions may be implemented in the controller 951.

[0194] 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.

[0195] Furthermore, part or all of the communication control device described in the above embodiments may be realized, for example, as a semiconductor chip (IC (Integrated Circuit)) having a wireless communication control function. It may also be realized by a single semiconductor chip equipped with multiple functions, such as a SoC (System on Chip), or by combining multiple semiconductor chips each having a single function, such as a processor. It may also be realized by combining multiple SoCs, or by combining a semiconductor chip with a single function with a SoC. It may also be realized by a semiconductor chip such as an ASIC (Application Specific Integrated Circuit) dedicated to realizing each unit, or by a combination of a general-purpose processor with software or firmware, or by a semiconductor chip such as an FPGA (Field Programmable Gate Array).

[0196] 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.

[0197] 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.

[0198] 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.

[0199] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0200] 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.

[0201] 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.

[0202] 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.

[0203] 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.

[0204] The above-described embodiment shows an example for realizing the present disclosure, and the present disclosure can be implemented in various other forms. For example, various modifications, substitutions, omissions, or combinations thereof are possible without departing from the spirit of the present disclosure. Such modifications, substitutions, omissions, etc. are also included within the scope of the present disclosure, as well as within the scope of the inventions described in the claims and their equivalents.

[0205] Furthermore, the effects of the present disclosure described in this specification are merely examples, and other effects may also be present.

[0206] The present disclosure may also have the following configurations. [Item 1] A communication control device including a control unit that controls communication with a target wireless communication device, wherein the control unit sets, for the target wireless communication device to which target data is to be transmitted, a plurality of prioritized transmission periods that are candidates for periods during which the target data is to be transmitted preferentially within a reception expected period, which is a continuous time, and transmits priority transmission period information indicating the plurality of prioritized transmission periods to the target wireless communication device. [Item 2] The communication control device according to Item 1, wherein the control unit receives the target data from a server, and, if the time at which the target data is received from the server is included in a non-priority period that is a period within the reception expected period other than the plurality of prioritized transmission periods, controls to wait transmission of the target data until before the priority transmission period immediately following the non-priority period starts, and transmits the target data in the priority transmission period immediately following the non-priority period. [Item 3] The communication control device according to Item 2, wherein the control unit sets the plurality of prioritized transmission periods so that the length of time from any time within the non-priority period to the start time of the priority transmission period immediately following the non-priority period is equal to or less than an allowable delay time for the target data. [Item 4] The communication control device according to item 2 or 3, wherein, if transmission of the target data does not end within the prioritized transmission period, the control unit continues transmission of the target data in a non-priority period immediately following the prioritized transmission period. [Item 5] The communication control device according to any one of items 2 to 4, wherein the control unit sets one of the plurality of prioritized transmission periods to a position including an end time of the expected reception period. [Item 6] The communication control device according to any one of items 2 to 5, wherein the control unit sets one of the plurality of prioritized transmission periods to a position including a time within the expected reception period when the possibility of receiving the target data is highest or is equal to or greater than a threshold. [Item 7] The communication control device according to any one of items 2 to 6, wherein, during a non-priority period immediately following a prioritized transmission period in which the target data was not received among the plurality of prioritized transmission periods, the control unit controls communication of information other than the target data with the target wireless communication device, or communication with a wireless communication device other than the target wireless communication device.[Item 8] The control unit performs control to transmit a first signal including the priority transmission period information in a first format to a first wireless communication device that can interpret the first format of the priority transmission period information, and to transmit a second signal including the priority transmission period information in the second format to a second wireless communication device that cannot interpret the first format of the priority transmission period information but can interpret a second format of the priority transmission period information, wherein the first format includes a first field that stores common information among the plurality of priority transmission periods and a plurality of second fields that store information unique to the plurality of priority transmission periods, and the second format includes a plurality of third fields that separately store information about the plurality of priority transmission periods. [Item 9] The communication control device according to item 8, wherein a bit length of the first format is shorter than a bit length of the second format. [Item 10] The communication control device according to item 8 or 9, wherein the control unit performs control to transmit a third signal that prohibits transmission in the plurality of priority transmission periods to a third wireless communication device that cannot interpret either the first format or the second format. [Item 11] The communication control device according to any one of items 1 to 10, wherein the control unit determines the expected reception period based on an average reception cycle and jitter of the target data. [Item 12] The communication control device according to any one of items 1 to 11, comprising: a wireless communication unit that communicates with a plurality of wireless communication devices including the target wireless communication device via a first network; and a receiving unit that receives the target data from a server via a second network different from the first network, wherein the control unit sets the plurality of prioritized transmission periods for the target data received by the receiving unit. [Item 13] A communication control method comprising: controlling communication with a target wireless communication device; setting, for the target wireless communication device to which target data is to be transmitted, a plurality of prioritized transmission periods that are candidates for a period during which the target data is preferentially transmitted within the expected reception period, which is a continuous period of time; and transmitting preferred transmission period information indicating the plurality of prioritized transmission periods to the target wireless communication device.[Item 14] A communication control device comprising: a control unit that controls a wireless communication unit that communicates with a wireless communication device, wherein the control unit receives from the wireless communication device priority transmission period information indicating a plurality of priority transmission periods that are candidates for a period during which target data is preferentially transmitted within a reception expected period that is a continuous time, and controls switching between an awake state and a doze state in the wireless communication unit based on the priority transmission period information. [Item 15] The communication control device according to item 14, wherein the control unit controls the wireless communication unit to the awake state during the reception expected period, and controls the wireless communication unit to the doze state during at least a portion of a period other than the priority transmission period. [Item 16] The communication control device according to item 14 or 15, wherein the control unit controls communication of information other than the target data with the wireless communication device during at least a portion of the period other than the priority transmission period during the reception expected period. [Item 17] The communication control device according to any one of items 14 to 16, wherein the control unit determines whether to request the wireless communication device to set the plurality of preferential transmission periods according to a type of data communicated with the wireless communication device, and when the type of data is a predetermined type, controls to transmit a request signal requesting the wireless communication device to set the plurality of preferential transmission periods, wherein the target data is the predetermined type of data. [Item 18] The communication control device according to item 17, wherein the request signal includes information specifying parameter values ​​of the plurality of preferential transmission periods requested to be set. [Item 19] The communication control device according to item 17 or 18, wherein the request signal includes information requesting the wireless communication device to determine parameter values ​​of the plurality of preferential transmission periods. [Item 20] A communication control method for controlling communication with a wireless communication device, comprising: receiving from the wireless communication device preferential transmission period information indicating a plurality of preferential transmission periods that are candidates for a period during which target data is preferentially transmitted within a reception expected period that is a continuous time; and controlling switching between an awake state and a doze state based on the preferential transmission period information.

[0207] 110, 210 Wireless communication unit 111, 211 Communication control unit 112, 212 MAC processing unit 113, 213 Signal processing unit 114A, 114B, 214A, 214B RF unit 115A, 115B, 215A, 215B RF Switch 116A, 116B, 216A, 216B Antenna 120, 220 Information storage device 130, 230 Control unit 140, 240 LLC processing unit 141, 241 Data processing unit 142, 242 Data control unit 150, 250 Upper layer 300 XR device 400 Server 401 R-TWT request signal 402 R-TWT response signal 403 State 404 Beacon frame 405 Doze state 406 Doze state 410 R-TWT SP 420 termination event 421 signal 423 period 431 R-TWT SP 432 R-TWT SP 441 Semi R-TWT SP 442 Semi R-TWT SP 1000, 2000 Wireless communication device (communication device) 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 920 In-vehicle equipment 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 Battery 940 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 interface958 Wired communication network 963 Wireless communication interface 964 Antenna switch 965 Antenna

Claims

1. A communication control device comprising a control unit that controls communication with a target wireless communication device, wherein the control unit sets, for the target wireless communication device to which target data is to be transmitted, a plurality of priority transmission periods that are candidates for periods during which the target data is to be preferentially transmitted within a reception expected period, which is a continuous period of time, and controls the transmission of priority transmission period information indicating the plurality of priority transmission periods to the target wireless communication device.

2. The communication control device of claim 1, wherein the control unit receives the target data from the server, and if the time at which the target data is received from the server is included in a non-priority period that is a period other than the multiple priority transmission periods within the expected reception period, waits to transmit the target data until before the start of the priority transmission period immediately following the non-priority period, and transmits the target data during the priority transmission period immediately following the non-priority period.

3. The communication control device according to claim 2, wherein the control unit sets the plurality of priority transmission periods so that the length of time from any time within the non-priority period to the start time of the priority transmission period immediately following the non-priority period is equal to or less than the allowable delay time for the target data.

4. The communication control device according to claim 2, wherein, if transmission of the target data does not end within the priority transmission period, the control unit continues transmission of the target data in a non-priority period immediately following the priority transmission period.

5. The communication control device according to claim 2, wherein the control unit sets one of the plurality of priority transmission periods to a position including the end time of the reception expected period.

6. The communication control device according to claim 2, wherein the control unit sets one of the plurality of priority transmission periods at a position including a time within the expected reception period when the probability of receiving the target data is highest or exceeds a threshold.

7. The communication control device according to claim 2, wherein the control unit controls communication with the target wireless communication device of information other than the target data, or communication with a wireless communication device other than the target wireless communication device, during a non-priority period immediately following a priority transmission period among the plurality of priority transmission periods in which the target data was not received.

8. The communication control device according to claim 1, wherein the control unit controls to transmit a first signal including the priority transmission period information in the first format to a first wireless communication device that can interpret the first format of the priority transmission period information, and to transmit a second signal including the priority transmission period information in the second format to a second wireless communication device that cannot interpret the first format of the priority transmission period information but can interpret the second format of the priority transmission period information, wherein the first format includes a first field that stores common information among the plurality of priority transmission period information and a plurality of second fields that store information unique to the plurality of priority transmission periods, and the second format includes a plurality of third fields that separately store information about the plurality of priority transmission periods.

9. The communication control device according to claim 8, wherein the bit length of the first format is shorter than the bit length of the second format.

10. The communication control device according to claim 8, wherein the control unit controls to transmit a third signal that prohibits a third wireless communication device that cannot interpret either the first format or the second format from transmitting during the plurality of priority transmission periods.

11. The communication control device according to claim 1, wherein the control unit determines the expected reception period based on an average reception cycle and jitter of the target data.

12. A communication control device as described in claim 1, comprising: a wireless communication unit that communicates with multiple wireless communication devices including the target wireless communication device via a first network; and a receiving unit that receives the target data from a server via a second network different from the first network, wherein the control unit sets the multiple priority transmission periods for the target data received by the receiving unit.

13. A communication control method that controls communication with a target wireless communication device, sets, for the target wireless communication device to which target data is to be transmitted, a plurality of priority transmission periods that are candidates for periods during which the target data is to be preferentially transmitted within a reception expected period, which is a continuous period of time, and transmits priority transmission period information indicating the plurality of priority transmission periods to the target wireless communication device.

14. A communication control device comprising a control unit that controls a wireless communication unit that communicates with a wireless communication device, wherein the control unit receives from the wireless communication device priority transmission period information indicating a plurality of priority transmission periods that are candidates for periods during which target data is preferentially transmitted within a reception expected period, which is a continuous time, and controls switching between an awake state and a doze state in the wireless communication unit based on the priority transmission period information.

15. The communication control device according to claim 14, wherein the control unit controls the wireless communication unit to the awake state during the priority transmission period in the reception expectation period, and controls the wireless communication unit to the doze state during at least a portion of a period other than the priority transmission period.

16. The communication control device according to claim 14, wherein the control unit controls communication of information other than the target data with the wireless communication device during at least a part of the period other than the priority transmission period in the reception expected period.

17. The communication control device according to claim 14, wherein the control unit determines whether to request the wireless communication device to set the multiple priority transmission periods depending on the type of data to be communicated with the wireless communication device, and when the type of data is a predetermined type, transmits a request signal requesting the wireless communication device to set the multiple priority transmission periods, and the target data is the predetermined type of data.

18. The communication control device according to claim 17, wherein the request signal includes information specifying parameter values ​​of the plurality of preferential transmission periods for which setting is requested.

19. The communication control device according to claim 17, wherein the request signal includes information requesting that the wireless communication device determine values ​​of parameters of the plurality of prioritized transmission periods.

20. A communication control method comprising: controlling communication with a wireless communication device; receiving from the wireless communication device priority transmission period information indicating a plurality of priority transmission periods which are candidates for periods during which target data is preferentially transmitted within a reception expected period, which is a continuous period of time; and controlling switching between an awake state and a doze state based on the priority transmission period information.

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