Communication equipment and communication methods

Abstract

To provide a communication device for performing multi-link operation by synchronous transmission.SOLUTION: A communication device includes: a communication unit that performs communication by a plurality of links; and a control unit that controls communication operation by the communication unit. The control unit performs control so as to transmit a signal including information related to a period in which data transmission is performed by the plurality of links. The information related to the period includes at least one piece of information of start time of the period, a time length of the period, and a link that performs transmission in the period. The control unit controls description of the information related to the start time of the period and the time length of the period so that the periods overlap in each link used for the data transmission.SELECTED DRAWING: Figure 5

Description

Technical Field

[0005] ,

[0004] , , , ,

[0003]

[0001] The technology disclosed in this specification (hereinafter referred to as "the present disclosure") relates to a communication device and a communication method for performing wireless communication by bundling a plurality of links.

Background Art

[0002] In recent years, data traffic in wireless communication, such as VR (Virtual Reality) and 8K video transmission, has been increasing. In order to accommodate such traffic, improvement in throughput is required in a wireless LAN (Local Area Network). Currently, as a technology useful for improving throughput, the standardization of multi-link operation (MLO) for communicating by bundling a plurality of links is underway.

[0003] MLO can be roughly classified into two types: an asynchronous transmission method in which each link operates independently for communication, and a synchronous transmission method in which the transmission timings are completely aligned between links. In MLO, since the channels between links are close and leakage occurs, it may be difficult to receive on one link while transmitting on another link. In this case, according to the synchronous transmission method that aligns the transmission timings among a plurality of links, simultaneous transmission and reception between links do not occur, and the effect of MLO can be obtained.

[0004] When implementing MLO by synchronous transmission, it is required that all the links used can transmit simultaneously, or in other words, each link becomes idle simultaneously. However, terminals that do not support MLO, such as legacy terminals, perform a transmission operation using only one link independently of other links. Therefore, the time during which all of the plurality of links are in an idle state and synchronous transmission can be implemented is limited, and the effect of improving throughput by MLO cannot be expected.

[0005] Furthermore, IEEE 802.11ax standardizes the setting of a Quiet Time Period (QTP). This is an operation that sets a period during which a terminal suppresses transmission from other terminals within the Basic Service Set (BSS) in order to prioritize a particular communication method. In QTP operation, first, a terminal that wants to communicate using a certain method sends a QTP request to the access point, and the access point sends a QTP response back to that terminal. Next, when the start time of the period during which transmission from other terminals is suppressed, as indicated in the QTP request and QTP response, the access point sends a QTP Setup to surrounding terminals. Terminals other than the source of the QTP request suppress transmission for a period corresponding to the Duration stated in that frame when they receive the QTP Setup. This prevents communication other than communication between terminals from occurring. However, in order to suppress terminal transmission on each link in order to implement MLO, it is necessary to send QTP Setups simultaneously across multiple links at the start time. Since there is a technical challenge in that simultaneous transmission across multiple links is not possible in the first place, it is not possible to achieve MLO by synchronous transmission using QTP operation. Furthermore, a wireless LAN system has been proposed that indicates that the transmission of a frame containing a silence element and a silence channel element will silence the second subchannel during the silence period, and that it will also indicate the conditions and duration under which the first subchannel may be used (see Patent Document 1). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2014-522196 [Overview of the project] [Problems that the invention aims to solve]

[0007] The purpose of this disclosure is to provide a communication device and communication method that perform MLO by synchronous transmission. [Means for solving the problem]

[0008] This disclosure has been made in consideration of the above issues, and its first aspect is: A communication unit that communicates using multiple links, A control unit that controls the communication operation by the communication unit, It is equipped with, The control unit controls the transmission of a signal containing information about the period during which data transmission is performed on the plurality of links. It is a communication device.

[0009] The information relating to the period includes at least one of the following: the start time of the period, the duration of the period, and the links used for transmission during the period. The control unit controls the description of the information relating to the start time and duration of the period so that the periods overlap across each link used for data transmission.

[0010] Furthermore, the second aspect of this disclosure is, A communication method for communication devices that communicate using multiple links, The steps include setting a period for which data transmission will be performed across the aforementioned multiple links, The steps include transmitting a signal containing information about the aforementioned period, This is a communication method that has [a certain characteristic].

[0011] Furthermore, the third aspect of this disclosure is, A communication unit that communicates using at least one of multiple links, A control unit that controls the communication operation by the communication unit, It is equipped with, The control unit receives a signal containing information about the period during which data transmission is performed on the plurality of links on at least one of the plurality of links, and controls the link that received the signal containing information about the period to suppress transmission. It is a communication device.

[0012] The information regarding the period includes at least one of the start time of the period, the duration of the period, and the information of at least one link for which transmission is carried out during the period. Then, the control unit controls so as to suppress transmission in the link that has received the signal based on the start time of the period and the duration of the period described in the signal.

[0013] Furthermore, a fourth aspect of the present disclosure is A communication method of a communication device that communicates via a plurality of links, comprising: Receiving, via at least one of the plurality of links, a signal including information regarding a period during which data transmission is carried out via the plurality of links; Suppressing transmission in the link that has received the signal including the information regarding the period; and a communication method having these steps.

Advantages of the Invention

[0014] According to the present disclosure, it is possible to provide a communication device and a communication method that perform MLO by synchronous transmission.

[0015] Note that the effects described in this specification are merely examples, and the effects brought about by the present disclosure are not limited thereto. Further, the present disclosure may have additional effects other than the above effects.

[0016] Still other objects, features, and advantages of the present disclosure will become apparent from more detailed descriptions based on the embodiments described below and the accompanying drawings.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a diagram showing a configuration example of a communication system 100. [Figure 2] FIG. 2 is a diagram showing an example of channel selection between a first link (link1) and a second link (link2). [Figure 3] >FIG. 3 is a diagram showing an example of channel selection between a first link (link1) and a second link (link2). [Figure 4] Figure 4 is a diagram showing a configuration example of the communication device 200. [Figure 5] Figure 5 is a diagram showing an example of a communication sequence (first operation example) for performing MLO. [Figure 6] Figure 6 is a diagram showing an example of the format of the MLP Setup frame. [Figure 7] Figure 7 is a diagram showing an example of the format of the MLP Request frame. [Figure 8] Figure 8 is a diagram showing an example of the format of the MLP End frame. [Figure 9] Figure 9 is a diagram showing an example of the format of the MLP Advertisement frame. [Figure 10] Figure 10 is a diagram showing an example of the format of the MLP Advertisement Response frame. [Figure 11] Figure 11 is a diagram showing an example of a communication sequence (modified example of the first operation example) for performing MLO. [Figure 12] Figure 12 is a flowchart showing the processing procedure executed when the communication device (MLD) operating as an AP performs MLO. [Figure 13] Figure 13 is a flowchart showing the processing procedure executed by the communication device (MLD) operating as a STA when MLO is performed. [Figure 14] Figure 14 is a diagram showing an example of a communication sequence (second operation example) for performing MLO. [Figure 15] Figure 15 is a diagram showing an example of a communication sequence (second operation example) for performing MLO.

Mode for Carrying Out the Invention

[0018] Hereinafter, the present disclosure will be described in the following order while referring to the drawings. A. Overview B. System Configuration C. Device Configuration [[ID=5{0]] D. Operation Example 1 E. Frame Format F. Modified version of Operation Example 1 G. Operation of communication equipment H. Example of Operation 2 I. Effects

[0019] A. Overview In this disclosure, a terminal that wants to perform a synchronous transmission method MLO (hereinafter also simply referred to as "multilink transmission"), or a terminal that receives a request from such a terminal, sends a signal (MLP Setup frame) to surrounding terminals on multiple links before the start of the Multi-link Period (MLP) during which the MLO is performed, in order to suppress transmission by each terminal during the MLP. The MLP Setup frames sent on each link are sent at different timings and notify the time (offset) from the sending timing to the start timing of the MLP and the length of the MLP. A terminal that receives an MLP Setup frame suppresses transmission for the specified period. For conventional (legacy) terminals that do not support this disclosure, the Duration of the MLP Setup frame is set to match the length of the MLP.

[0020] Therefore, a terminal attempting to perform multilink transmission sends an MLP Setup frame on each link to notify the time until the MLP starts and the length of the MLP. When an MLP arrives, it suppresses transmissions by surrounding terminals, making it easier to gain an opportunity to perform multilink transmission.

[0021] B. System Configuration Figure 1 schematically shows an example configuration of a communication system 100 to which this disclosure applies. The illustrated communication system 100 consists of an access point (AP) 110 and a terminal (STA) 120. The terminal 120 is not an access point, i.e., it is a non-AP. In the communication system 100, a first link and a second link are available, and the access point 110 and the terminal 120 are connected via the first link and the second link.

[0022] Both the access point 110 and the terminal 120 are Multi-link Devices (MLDs) that perform MLO using the first link (link1) and the second link (link2), i.e., AP MLD and non-AP MLD, respectively. In the following, when simply referring to "multi-link operation" or MLO, unless otherwise specified, it refers to MLO by synchronous transmission.

[0023] In the example shown in Figure 1, access point 110 contains two access points: AP1-1 operating on the first link and AP1-2 operating on the second link. Similarly, terminal 120 contains two terminals: non-AP STA1-1 operating on the first link and non-AP STA1-2 operating on the second link. However, the number of access points and terminals contained in access point 110 and terminal 120 is not limited to two; there may be three or more. That is, the number of links connecting access point 110 and terminal 120 is not limited to two; they may be connected through three or more links. Furthermore, for the sake of simplicity, Figure 1 only depicts one access point and one terminal within the communication system 100, but multiple access points and terminals may be connected. Also, a single communication device may contain one or more access points (AP MLDs) and one or more terminals (non-AP MLDs).

[0024] The MLD management entity is an entity that manages the operations within access point 110 and terminal 120, which are MLDs, respectively. Furthermore, MAC-SAP to LLC is a Service Access Point that provides MAC layer services to the LLC (Logical Link Control) layer, which is a higher layer than the MAC (Media Access Control) layer.

[0025] In this specification, a "link" refers to a wireless transmission path that enables data transmission between two communication devices. Each link is selected from a plurality of independent wireless transmission paths (channels), for example, divided by frequency domain. Figures 2 and 3 show two examples of channel selection for the first link (link1) and the second link (link2) used in the communication system 100. In each figure, band A and band B are, respectively, one of the bands such as the 2.4GHz band, 5GHz band, 6GHz band, and 920GHz band. Bands A and B may be unlicensed bands that do not require a radio station license, for example, and their use may be permitted through database access such as SAS (Spectrum Access System).

[0026] Band A and Band B each contain multiple channels. In the examples shown in Figures 2 and 3, Band A consists of 6 channels and Band B consists of 5 channels. MLDs such as access points 110 and terminals 120 operating in the communication system 100 select channels from Band A and Band B to be used for the first link (link1) and the second link (link2). In the example shown in Figure 2, channels for the first link (link1) and the second link (link2) are selected from Band A. In the example shown in Figure 3, channels for the first link (link1) are selected from Band A, and channels for the second link (link2) are selected from Band B.

[0027] C. Equipment configuration Figure 4 shows an example configuration of a communication device 200 that can operate as an access point 110 and a terminal 120. The communication device 200 is a device, or MLD, that performs multilink operation using a first link (link1) and a second link (link2).

[0028] The illustrated communication device 200 consists of a control unit 210, a power supply unit 220, a plurality of (two in the illustrated example) communication units 230-1 and 230-2, an antenna unit 240-1 corresponding to communication unit 230-1, and an antenna unit 240-2 corresponding to communication unit 230-2.

[0029] The combination of communication unit 230-1 and antenna unit 240-1, and the combination of communication unit 230-2 and antenna unit 240-2, are installed for each bandwidth used by the communication device 200. In the example shown in Figure 4, data communication is performed using the first link (link1) by the combination of communication unit 230-1 and antenna unit 240-1, and data communication is performed using the second link (link2) by the combination of communication unit 230-2 and antenna unit 240-2. Therefore, if the communication device 200 uses three or more bandwidths, additional combinations of communication units and antenna units (not shown) will be installed. Communication units 230-1 and 230-2 may control and exchange information with each other.

[0030] Since communication unit 230-1 and communication unit 230-2, and antenna unit 240-1 and antenna unit 240-2 have the same configuration, they will be referred to as communication unit 230 and antenna unit 240 respectively for simplification below.

[0031] The communication unit 230 is composed of a processor and circuits, such as a microprocessor, and includes a memory unit 238, a wireless control unit 231, a data processing unit 232, a modulation / demodulation unit 233, a signal processing unit 234, a channel estimation unit 235, a plurality of wireless interface (IF) units 236-1, ..., 236-N arranged in parallel, and amplifier units 237-1, ..., 237-N connected in series to each wireless interface unit 236-1, ..., 236-N (where N is an integer of 2 or more). Each amplifier unit 237-1, ..., 237-N is connected to the respective antenna elements that constitute the antenna unit 240 corresponding to the communication unit 230.

[0032] One or more sets of the series-connected wireless interface unit 236, amplifier unit 237, and antenna element in the antenna unit 240 may constitute a component of the communication unit 230. Furthermore, each wireless interface unit 236-1, ..., 236-N may contain the functions of its corresponding amplifier unit 237-1, ..., 237-N.

[0033] The memory unit 238 temporarily stores data input from the upper layer of the communication protocol (e.g., transmission data) and provides it to the data processing unit 232. The memory unit 238 also temporarily stores data received from the data processing unit 232 (e.g., reception data) and provides it to the upper layer of the communication protocol. In other words, the memory unit 238 is used as a transmission queue and a reception queue.

[0034] Furthermore, part or all of the memory unit 238 may be located outside the communication unit 230. Also, a memory unit 238-1 located in one communication unit 230-1 may be shared with other communication units 230-2, or a memory unit 238 located outside the communication unit 230 may be shared by multiple communication units 230-1, 230-2, ...

[0035] The data processing unit 232, upon receiving data from a higher layer of its own communication protocol during transmission, generates a packet for wireless transmission from that data, and further performs processing such as adding a header for media access control (MAC) and adding error detection codes, before providing the processed data to the modulation / demodulation unit 233. Furthermore, upon receiving input from the modulation / demodulation unit 233, the data processing unit 232 performs processing such as analyzing the MAC header, detecting packet errors, and reordering packets, before providing the processed data to its own protocol's higher layer.

[0036] The wireless control unit 231 controls the transfer of information between the various parts of the communication device 200. The wireless control unit 231 also sets parameters in the modulation / demodulation unit 233 and the signal processing unit 234, schedules packets in the data processing unit 232, and sets parameters and controls the transmission power of the wireless interface unit 236 and the amplifier unit 237.

[0037] During transmission, the modulation / demodulation unit 233 performs encoding, interleaving, and modulation processing on the input data from the data processing unit 232 based on the encoding and modulation scheme set by the radio control unit 231, generating a data symbol stream and providing it to the signal processing unit 234. During reception, the modulation / demodulation unit 233 performs demodulation, deinterleaving, and decoding processing on the input symbol stream from the signal processing unit 234, in the opposite direction to that during transmission, and provides the data to the data processing unit 232 or the radio control unit 231.

[0038] During transmission, the signal processing unit 234 performs signal processing on the input from the modulation / demodulation unit 233 as needed to enable spatial separation, and provides one or more transmitted symbol streams to the respective wireless interface units 236-1, ... During reception, the signal processing unit 234 performs signal processing on the received symbol streams input from the respective wireless interface units 236-1, ..., performs spatial resolution of the streams as needed, and provides them to the modulation / demodulation unit 233.

[0039] The channel estimation unit 235 calculates complex channel gain information for the propagation path from the preamble portion and the training signal portion of the input signals from each of the wireless interface units 236-1, ... . The calculated complex channel gain information is used for demodulation processing in the modulation / demodulation unit 233 and spatial processing in the signal processing unit 234 via the wireless control unit 231.

[0040] During transmission, the wireless interface unit 236 converts the input from the signal processing unit 234 into an analog signal, filters it, upconverts it to the carrier frequency, and performs phase control before sending it to the corresponding amplifier unit 237 or antenna unit 240. During reception, the wireless interface unit 236 performs the opposite processing on the input from the corresponding amplifier unit 237 or antenna unit 240, such as downconversion, filtering, and conversion to a digital signal, before providing the data to the signal processing unit 234 and the channel estimation unit 235.

[0041] During transmission, the amplifier unit 237 amplifies the analog signal input from the wireless interface unit 236 to a predetermined power level and sends it to the corresponding antenna element in the antenna unit 240. During reception, the amplifier unit 237 amplifies the signal input from the corresponding antenna element in the antenna unit 240 to a predetermined power level with low noise and outputs it to the wireless interface unit 236.

[0042] Furthermore, at least one of the functions of the amplifier unit 237, either during transmission or during reception, may be incorporated into the wireless interface unit 236. Also, at least one of the functions of the amplifier unit 237, either during transmission or during reception, may be a component other than the communication unit 230.

[0043] A single set of wireless interface unit 236 and amplifier unit 237 constitutes one RF (Radio Frequency) branch. Each RF branch is capable of transmitting and receiving on one band. In the example device configuration shown in Figure 4, the communication unit 230 has N RF branches.

[0044] The control unit 210 is composed of a processor and circuits, such as a microprocessor, and controls the wireless control unit 231 and the power supply unit 220. Furthermore, the control unit 210 may perform at least some of the operations of the wireless control unit 231 as described above, instead of the wireless control unit 231. In particular, in this embodiment, the control unit 210 and the wireless control unit 231 control the operation of each part in order to realize the operations described in each embodiment later.

[0045] The power supply unit 220 consists of a battery power supply or a fixed power supply and supplies power for driving the communication device 200.

[0046] The control unit 210 and the communication unit 230 can be combined and configured using one or more LSIs (Large Scale Integration).

[0047] Furthermore, when the communication device 200 is in standby mode, the communication unit 230 may be configured to transition to a standby or sleep state (or a state in which at least some functions are disabled) in order to reduce power consumption. In the example device configuration shown in Figure 4, the communication unit 230 has N RF branches, but it may also be configured so that each RF branch can transition to a standby or sleep state.

[0048] D. Example of Operation 1 Section D describes a first operational example of a communication device (MLD) that performs MLO using the first and second links. Specifically, the communication device (MLD) sends MLP Setup frames on multiple links before the MLP start timing, notifying surrounding terminals of the time (offset) from the transmission timing of the MLP Setup frames to the start timing of the MLP and the length of the MLP, so that they suppress transmission during the specified period. The operation of the communication device (MLD) performing MLO by putting both the first and second links into an idle state to facilitate MLO by synchronous transmission is described below.

[0049] Figure 5 shows an example of a communication sequence demonstrating this operation. However, Figure 5 assumes a communication system in which a first link (link1) and a second link (link2) are available, and one terminal (STA MLD) operates under one access point (AP MLD1). AP MLD1 includes AP1-1 operating on the first link and AP1-2 operating on the second link. Similarly, STA MLD1 includes STA1-1 operating on the first link and STA1-2 operating on the second link.

[0050] In Figure 5, the horizontal axis represents time, showing the communication activity over time on the first and second links of the access point and each terminal. The solid rectangular blocks represent transmitted frames, the solid vertical arrows indicate frame transmission to the destination, and the dotted rectangular blocks represent received frames.

[0051] First, AP1-1 of AP MLD1 sends an MLP Setup frame on the first link (link1) at time T1, prior to the MLP start timing. AP1-2 of AP MLD1, unlike time T1, sends an MLP Setup frame on the second link (link2) at time T2, prior to the MLP start timing. Although not shown in the diagram, AP1-1 and AP1-2 each complete a backoff period of waiting for a random latency on the first link (link1) and second link (link2), respectively, and then send the MLP Setup frame after acquiring a period of channel occupancy (e.g., TXOP).

[0052] The MLP Setup frame is sent to suppress transmission from each terminal during the MLP period. It is desirable that the MLP Setup frame be received by surrounding OBSS (Overlapping BSS) terminals as well. Therefore, the MLP Setup frame is sent as a "01" control frame, one of the three classes defined in IEEE 802.11.

[0053] The MLP Setup frame contains information about the MLP. This information includes, for example, the link to set up the MLP, the time to start the MLP (the offset between the transmission of the frame and the start time of the MLP), and the duration and number of MLP sessions. However, details about the MLP Setup frame will be discussed later.

[0054] The AP may send an MLP Setup frame on each link performing MLO in response to receiving an MLP Request frame from a subordinate STA requesting MLP configuration. However, in Figure 5, for the sake of simplifying the diagram, the exchange of MLP Request frames between STA MLD1 and AP MLD1 is omitted. The STA sends an MLP Request frame to the connected AP, for example, when there is more than a certain amount of data in its transmit buffer, or when there are packets that cannot meet latency or throughput requirements without multilink transmission. The AP MLD and STA MLD may exchange Capacity information indicating whether or not they support MLP configuration in advance, such as during association.

[0055] The MLP Setup frame sent by AP1-1 at time T1 contains information about the offset to time T3 when the MLP will start, and the duration of the MLP, which corresponds to the time from time T3 to time T5. Therefore, when STA1-1 of STA MLD1 receives the MLP Setup frame from AP1-1, it suppresses transmission for a period corresponding to the duration from time T3 to time T5. As a result, the first link (link1) remains idle for the period from time T3 to time T5.

[0056] Furthermore, the MLP Setup frame sent by AP1-2 at time T2 contains information about the offset to time T4, when the MLP will start, and the duration of the MLP, which corresponds to the time from time T4 to time T6. Therefore, when STA1-2 of STA MLD1 receives the MLP Setup frame from AP1-2, it suppresses transmission for a period corresponding to the duration from time T4 to time T6. As a result, the second link (link2) remains idle for the period from time T4 to time T6.

[0057] AP MLD1 controls the start time and duration of the MLP specified in the MLP Setup frame transmitted on each link, such that the MLP start time T3 on the first link (link1) is earlier than the MLP end time T6 on the second link (link2), and the MLP start time T4 on the second link (link2) is earlier than the MLP end time T5 on the first link (link1).

[0058] AP MLD1 can configure MLP for a period (period T in Figure 5) from the latest of the MLP start times for the first link (link1) and the second link (link2) to the earliest of the MLP end times for the first link (link1) and the second link (link2). During this period, AP MLD1 (or any STA MLD under AP MLD1 that sent an MLP Request frame) can prioritize multilink transmission.

[0059] When STA MLD1 receives an MLP Setup frame from AP MLD1, it suppresses transmission for the period specified by the Duration information, starting from the time specified by the offset information of that frame. However, STA MLD1 may transmit if it is requested to transmit, such as by receiving a trigger frame from AP MLD1.

[0060] Furthermore, if the transmit power can be set such that the received power at AP MLD1 when STA MLD1 transmits a signal on each link is below a first threshold, STA MLD1 may set the transmit power and then transmit. The first threshold is, for example, a preamble detection threshold. In this case, AP MLD1 may include information about the transmit power in the MLP Setup frame so that STA MLD1, upon receiving the MLP Setup frame, can calculate the received power at AP1-1 and AP1-2 when it transmits a signal.

[0061] To prevent legacy terminals that cannot correctly decode MLP Setup frames from transmitting during the MLP, AP MLD1 may send an MLP Setup frame with the MLP duration specified in the Duration / ID field at the start of the MLP.

[0062] Additionally, AP MLD1 (or the subordinate STA MLD that requested MLP configuration from AP MLD1) may send an MLP END frame to cancel the MLP configured on surrounding terminals if it is no longer necessary to perform multilink transmissions during MLP, or if it becomes impossible to configure MLP for the same period on each link.

[0063] E. Frame Format Section E describes the format of the main frames used in the first operational example of MLO. Figures 6-8 show example formats for the MLP Setup frame, MLP Request frame, and MLP End frame, respectively. The information contained in the fields of each frame is described below.

[0064] The Category field contains information indicating the category of the frame in question. For example, it may contain information indicating that it is a Public Action frame.

[0065] The Public Action field contains information indicating that the frame in question is a Public Action frame related to MLP configuration.

[0066] The Dialog Token field is used to link a frame to its corresponding MLP Request frame, MLP Setup frame, and MLP End frame by including the same value in each frame.

[0067] The Multi-link Period element field includes the following fields: Element ID, Length, Element ID Extension, and Control.

[0068] The Element ID field and Element ID Extension field contain information indicating that it is a Multi-link Period element.

[0069] The Control field contains information that distinguishes whether the frame in question is an MLP Request frame, an MLP Setup frame, or an MLP End frame.

[0070] The Multi-link Period content field in the MLP Setup frame and MLP Request frame is the Multi-link Period Offset field, Multi-link Period Duration field, Multi-link Period Count field, Multi-link Road This includes each field in the Link ID. Additionally, the Multi-link Period content field in the MLP Setup frame further includes the Status Code.

[0071] The Status Code contains information about the outcome of the MLP configuration requested by the Multi-link Request frame (such as whether the configuration was allowed or denied).

[0072] The Multi-link Period Offset field contains information about the time when the MLP (Multi-link Program) should start. The start time may be expressed as an absolute time, or as relative time information from a reference point to the start of the MLP. The reference point may be, for example, the Target Beacon Transmission Time (TBTT). The relative time information may be expressed in granularity, for example, Time Units (TU, 1024 microseconds).

[0073] The Multi-link Period Duration field contains information indicating the length of the MLP. The length information is described in granularity, for example, in units of 32 microseconds.

[0074] The Multi-link Period Count field contains information indicating how many times the MLP Setup frame has been sent. The process of sending an MLP Setup frame multiple times will be explained later.

[0075] The Multi-link Period Link ID field contains information about the link that configures the MLP.

[0076] A communication device (MLD) performing MLO may operate to configure MLP if it receives an MLP Setup frame on at least one of the links it is using, regardless of whether it has received MLP Setup frames on other links. Alternatively, the communication device (MLD) performing MLO may operate to configure MLP only if it has received MLP Setup frames on all links specified in the Multi-link Period Link ID field of the MLP Setup frame. The AP may instruct its subordinate STAs on which method to configure MLP using an MLP Setup frame or other means, or it may be set during the exchange of capability information regarding MLP configuration during association.

[0077] An AP may negotiate with surrounding APs regarding the Multi-link Period setting. In this case, the AP notifies surrounding APs by sending an MLP Advertisement frame about the MLPs it has already configured for its subordinate STAs by sending an MLP Setup frame, as well as information about MLPs for which it has not yet sent an MLP Setup frame but plans to configure them in the future.

[0078] An AP that receives an MLP Advertisement frame from another AP sends back an MLP Advertisement Response frame indicating whether it accepts each of the MLP settings described in the received frame. Negotiation of MLP settings may be performed per link, or a single link may negotiate the settings for all links.

[0079] Figure 9 shows the format of the MLP Advertisement frame. Fields common to the frame formats shown in Figures 6 to 8 are not explained here.

[0080] The "Number of Reported MLP Reservations" field indicates the number of MLPs that the AP that sent the frame has already configured on its subordinate STAs by sending an MLP Setup frame.

[0081] The "Number of Pending MLP Reservations" field indicates the number of MLPs that the AP that sent the frame plans to configure under its STAs by sending MLP Setup frames in the future.

[0082] The Active MLP Reservations field contains information about the start time and duration of each MLP that the AP that sent the frame has already configured on its subordinate STAs by sending an MLP Setup frame.

[0083] The Pending MLP Reservations field contains information about the start time and duration of each MLP that the AP that sent the frame plans to set up on its subordinate STAs in the future.

[0084] The Active MLP Reservations and Pending MLP Reservations fields may also notify information regarding the start time and duration of each MLP, for example, through the TXOP (Transmission Opportunity) Reservation field already defined in the standard. The TXOP Reservation field contains the following fields: Duration, Service Interval, and Start Time. The Duration field contains the duration information of the MLP. The Service Interval field contains information about the time interval since the previous MLP was set up. The START Time field contains information about the time to start the MLP. The MLP start time information may be expressed as an absolute time, similar to the MLP setup frame, or as relative time information from a reference point such as TBTT.

[0085] Figure 10 shows an example of the MLP Advertisement Response frame format. When an AP receives an MLP Advertisement frame from a surrounding AP, it sends back an MLP Advertisement Response frame. Fields common to the frame formats shown in Figures 6 to 8 are not explained here.

[0086] The Status Code field contains information indicating whether the settings for each MLP described in the received MLP Advertisement frame are acceptable.

[0087] The Schedule Conflict field is only available if you do not want to allow the MLP configuration, and it contains information indicating which MLP listed in the MLP Advertisement frame is not allowed.

[0088] The Alternate Schedule field is also provided only if MLP configuration is not allowed, and it contains information about the start time and duration of an MLP that can be configured in place of the MLP indicated in the Schedule Conflict field. The Alternate Schedule field may also be described using the TXOP Reservation field, similar to the Active MLP Reservations field in the MLP Advertisement frame.

[0089] F. Modified version of Operation Example 1 Figure 11 shows an example of a communication sequence in the first operation example where the MLP start time of the second link is set later than the MLP end time of the first link. Similar to the operation example in Figure 5, Figure 11 assumes a communication system where one terminal (STA MLD) operates under one access point (AP MLD1). AP MLD1 includes AP1-1 operating on the first link and AP1-2 operating on the second link. Similarly, STA MLD1 includes STA1-1 operating on the first link and STA1-2 operating on the second link. The horizontal axis represents time, showing the communication operation of the access point and each terminal on the first and second links over time. Solid rectangular blocks represent transmitted frames, vertical solid arrows indicate frame transmission to the destination, and dotted rectangular blocks represent untransmitted frames and received frames.

[0090] First, AP1-1 of AP MLD1 transmits an MLP Setup frame on the first link (link1) at time T11, prior to the MLP start time. Then, STA1-1 of STA MLD1, based on the information regarding the MLP start time and duration contained in the MLP Setup frame received from AP1-1, suppresses transmission for a period corresponding to the Duration until time T15 when time T13 arrives.

[0091] On the other hand, if AP1-2 of AP MLD1 fails to send an MLP Setup frame on the second link (link2) within a certain time after AP1-1 sends an MLP Setup frame on the first link (link1), even if an MLP Setup frame is sent on the second link (link2), the MLP start time on the second link (link2) will be later than the MLP end time T15 on the first link (link1). In such a case, it becomes impossible to set a time for both the first link (link1) and the second link (link2) to be idle simultaneously.

[0092] If AP MLD1 determines that it cannot set a time for both the first link (link1) and the second link (link2) to be idle simultaneously because it cannot send an MLP Setup frame on the second link (link2) by a certain time, AP1-2 will refrain from sending an MLP Setup frame on the second link (link2). Furthermore, AP1-1 may send an MLP End frame indicating that the MLP has been canceled on the first link (link1) to prevent surrounding terminals from unnecessarily suppressing transmissions based solely on the MLP Setup frame (i.e., even though MLO is not performed). In the example shown in Figure 11, AP1-1 sends the MLP End frame before the MLP start time T13 specified in the MLP Setup frame.

[0093] When STA1-1 receives an MLP End frame from AP1-1 and detects that the MLP has been canceled, it can transmit data frames (DATA) and perform other actions without suppressing transmission during the Duration period from time T13 to time T15.

[0094] Alternatively, AP MLD1 may control AP1-2 to send an MLP Setup frame on the second link (link2) instead of canceling the MLP. In this case, AP1-1 sends an MLP Setup frame on the first link (link1) containing appropriate information about the start time and duration of the MLP on the first link (link1) so that surrounding terminals on the first link (link1) also suppress transmission during the Duration set on the second link (link2) by this MLP Setup frame.

[0095] G. Operation of communication equipment Section G describes the operation of the communication device (MLD) to realize the first example of operation related to the MLO described above.

[0096] Figure 12 shows a flowchart illustrating the processing steps performed by a communication device (MLD) operating as an AP when configuring an MLP. However, it is assumed that the communication device (MLD) has the configuration shown in Figure 4.

[0097] First, the AP sends an MLP Advertisement frame (or receives an MLP Advertisement frame from a surrounding AP) to negotiate the Multi-link Period setting with the surrounding APs (step S1201). The surrounding APs that receive the MLP Advertisement frame will send back an MLP Advertisement Response frame.

[0098] Here, we assume that AP has negotiated with surrounding APs and decided to configure MLP using the first and second links.

[0099] Then, once the AP acquires transmission rights on the first link, it sends an MLP Setup frame on the first link (step S1202).

[0100] Next, once the AP acquires transmission rights on the second link, it sends an MLP Setup frame on the second link at this point to check whether MLP setup is possible. Specifically, the AP checks whether it can control the start time and duration of the MLP to be specified in the MLP Setup frame sent on the second link so that the MLP start time on the second link (corresponding to time T4 in Figure 5) is earlier than the MLP end time on the first link (corresponding to time T5 in Figure 5) (step S1203).

[0101] If it is possible to set the MLP start time on the second link to be earlier than the MLP end time on the first link (Yes in step S1203), then the AP will also send an MLP Setup frame on the second link (step S 1204), and this process will be terminated.

[0102] On the other hand, if the MLP start time on the second link cannot be set to be earlier than the MLP end time on the first link, and the MLP cannot be configured, the AP will also send an MLP End frame on the first link. Cancel MLP (Step S1205) This process is terminated.

[0103] Figure 13 shows a flowchart illustrating the processing steps performed by a communication device (MLD) operating as a STA (a device that suppresses transmission in order for peripheral terminals to perform MLO). However, it is assumed that the communication device (MLD) has the configuration shown in Figure 4.

[0104] When the STA receives an MLP Setup frame from the connected AP on the first link (step S1301), and then receives an MLP Setup frame on the second link (step S1302), it starts suppressing transmission on the first and second links based on the MLP start time and duration described in the MLP Setup frames received on each link (step S1303).

[0105] Subsequently, when the MLP termination time arrives based on the contents of the MLP Setup frame received on the first link (Yes in step S1304), the STA releases the transmission suppression on the first link (step S1305).

[0106] Furthermore, when the MLP termination time arrives based on the contents of the MLP Setup frame received on the second link (Yes in step S1306), the STA releases the transmission suppression on the second link (step S1307) and terminates this process.

[0107] The operation of the communication device (MLD) shown in Figures 12 and 13 can be realized as follows (1) to (4).

[0108] (1) An AP MLD that supports MLP is called an MLP AP MLD and sets the MLP Support field of the EHT (Extreme High Throughput) Capabilities element it sends to 1. If the AP MLD does not support MLP, it sets the MLP Support field to 0.

[0109] (2) Non-AP MLDs that support MLP are called MLP non-AP MLDs and set the MLP Support field of the EHT Capabilities element they send to 1. If a non-AP MLD does not support MLP, set the MLP Support field to 0.

[0110] (3) An MLP non-AP MLD may request the connected MLP AP MLD to configure the MLP. An MLP non-AP MLD requesting MLP configuration may send an MLP Request frame indicating that it is an MLP Request subtype in the Control field of the Multi-link Period element. An MLP AP MLD requesting MLP configuration will send an MLP Setup frame indicating that it is an MLP Setup subtype in the Control field of the Multi-link Period element. The MLP Setup frame indicates the MLP start time, duration, and link ID (see Figure 6).

[0111] (4) When an MLP AP MLD or MLP non-AP MLD determines that it is setting up an MLP, it stops decrementing the backoff counter from the start time of the MLP and resumes decrementing the backoff counter when the MLP ends.

[0112] H. Example of Operation 2 Section H describes a second operational example of a communication device (MLD) that performs MLO using the first and second links. Before the start timing of MLP, the communication device (MLD) sends MLP Setup frames on multiple links to notify the surrounding terminals of the time (offset) from the transmission timing of the MLP Setup frames to the start timing of the MLP and the length of the MLP, thereby suppressing transmission for the specified period. In this operational example, the AP sends MLP Setup frames multiple times on each link to more reliably set the MLP on surrounding terminals. At this time, the AP can set the MLP for a period in which transmission suppression is set on surrounding terminals in common across all links by all MLP Setup frames sent on each link, and can prioritize multilink transmission.

[0113] Figure 14 shows an example of a communication sequence illustrating this operation. However, Figure 14 assumes a communication system where a first link (link1) and a second link (link2) are available, and one terminal (STA MLD) operates under one access point (AP MLD1). AP MLD1 includes AP1-1 operating on the first link and AP1-2 operating on the second link. Similarly, STA MLD1 includes STA1-1 operating on the first link and STA1-2 operating on the second link. The horizontal axis in Figure 14 is the time axis, showing the communication operation over time on the first and second links of the access point and each terminal. The solid rectangular blocks represent transmitted frames, the solid vertical arrows represent frame transmission to the destination, and the dotted rectangular blocks represent received frames.

[0114] First, AP1-1 of AP MLD1 sends the first MLP Setup frame on the first link (link1) at time T1-1, prior to the MLP start timing. The MLP start time and duration information contained in the first MLP Setup frame indicates that the MLP will start at time T1-3 and end at time T1-5. STA1-1 of STA MLD1 successfully receives the first MLP Setup frame and suppresses transmission during the MLP period, from time T1-3 to time T1-5, so the first link (link1) becomes idle.

[0115] Next, AP1-1 of AP MLD1 sends a second MLP Setup frame on the first link (link1) at time T1-7, prior to the MLP start timing. However, STA1-1 of STA MLD1 fails to receive the second MLP Setup frame, and therefore does not suppress transmission with the second MLP Setup frame.

[0116] Furthermore, AP1-2 of AP MLD1 transmits the first MLP Setup frame on the second link (link2) at time T1-2, prior to the MLP start timing. However, STA1-1 of STA MLD1 fails to receive the first transmitted MLP Setup frame, and therefore does not suppress transmission by this MLP Setup frame.

[0117] Next, AP1-2 of AP MLD1 sends a second MLP Setup frame on the second link (link2) at time T1-4, prior to the MLP start timing. The MLP start time and duration information contained in the second MLP Setup frame indicates that the MLP will start at time T1-6 and end at time T1-8. STA1-2 of STA MLD1 successfully receives the second MLP Setup frame and suppresses transmission during the MLP period, from time T1-6 to time T1-8, so the second link (link1) becomes idle.

[0118] AP MLD1 can configure MLP for a period (period T in Figure 14) from the latest of the MLP start times for the first link (link1) and the second link (link2) to the earliest of the MLP end times for the first link (link1) and the second link (link2). During this period, AP MLD1 (or any STA MLD under AP MLD1 that has sent an MLP Request frame) can prioritize multilink transmission.

[0119] In the second operational example, the AP sends multiple MLP Setup frames on each link to ensure that the MLP is more reliably configured on surrounding terminals. However, each MLP Setup frame sent by the AP on a given link may configure a completely different MLP (with no overlapping periods). Figure 15 shows an example of the communication sequence in this case.

[0120] In the communication sequence example shown in Figure 15, AP1-1 of AP MLD1 sends the first MLP Setup frame on the first link (link1) at time T1-1, before the MLP start timing. The MLP start time and duration information contained in the first MLP Setup frame indicates that the MLP starts at time T1-3 and ends at time T1-5. It is also assumed that it takes some time for AP1-1 to send the second MLPSetup frame on the first link (link1), and the MLP start time set by the second MLP Setup frame is T1-9 and the end time is T1-11.

[0121] If the MLP start time T1-9 set in the second MLP Setup frame is later than the MLP end time T1-5 set in the first MLP Setup frame, AP1-1 will stop sending the second MLP Setup frame. This is because sending multiple MLP Setup frames to specify completely non-overlapping Duration periods is pointless, as it does not guarantee that surrounding terminals will reliably configure the MLP.

[0122] AP MLD1 may, for example, assume that the MLP has been correctly configured on surrounding terminals by the first MLP Setup frame on the first link (link1), such as when it has already sent MLP Setup frames more than a certain threshold number of times, and perform MLO during the period of MLP that is assumed to have been configured by MLP Setup frames sent prior to the first MLP Setup frame.

[0123] Alternatively, if there is a terminal that has not correctly received the first MLP Setup frame on the first link (link1), and it is assumed that there is a terminal that will transmit on the first link (link1) during the MLP period specified in the first MLP Setup frame (in the example shown in Figure 15, the period from time T1-3 to time T1-5), AP1-1 may send an MLP End frame on the first link (link1) to cancel the MLP set up by the terminal that correctly received the first MLP Setup frame.

[0124] If the STA has received an MLP Setup frame linked by, for example, a Dialog Token value more than a predetermined number of times, and receives an MLP Setup frame with the same Dialog Token but setting up a completely different MLP, it may not set up the MLP based on the MLP Setup frame, but instead set up the MLP based on previously received MLP Setup frames. If the STA has not received an MLP Setup frame more than a predetermined number of times, it may discard the information of past MLP Setup frames.

[0125] I. Effects The effects of this disclosure are summarized below.

[0126] (1) The communication device (MLD) sends MLP Setup frames on multiple links where MLO is to be implemented. Surrounding terminals configure MLP based on the information contained in the received MLP Setup frames and suppress transmission, making it easier to perform multilink operations via synchronous transmission.

[0127] (2) APs exchange information regarding MLP configuration by sending and receiving MLP Advertisement frames and MLP Advertisement Response frames with surrounding APs. Therefore, MLPs can be efficiently configured among surrounding APs. [Industrial applicability]

[0128] The present disclosure has been described in detail above with reference to specific embodiments. However, it will be obvious that those skilled in the art can modify or substitute these embodiments without departing from the gist of the present disclosure.

[0129] For example, by applying this disclosure to a wireless LAN system compliant with the IEEE 802.11 standard, a communication device (MLD) implementing multilink functionality can easily perform MLO by synchronous transmission, thereby achieving high throughput.

[0130] In short, this disclosure has been explained in the form of examples, and the contents of this specification should not be interpreted restrictively. The claims should be considered in order to determine the gist of this disclosure.

[0131] Furthermore, this disclosure may also take the following form.

[0132] (1) A communication unit that communicates using multiple links, A control unit that controls the communication operation by the communication unit, It is equipped with, The control unit controls the transmission of a signal containing information about the period during which data transmission is performed on the plurality of links. Communication device.

[0133] (2) The information relating to the said period includes at least one of the following: the start time of the said period, the length of the said period, and the links to be transmitted during the said period. The communication device described in (1) above.

[0134] (3) The control unit controls the transmission of the signal on each link used for data transmission. A communication device as described in either (1) or (2) above.

[0135] (4) The control unit controls the description of information regarding the start time and duration of the period so that the period overlaps in each link used for data transmission. A communication device as described in any of (1) to (3) above.

[0136] (5) In response to receiving a signal requesting the setting of the period, the control unit controls itself to transmit the signal. A communication device as described in any of (1) to (4) above.

[0137] (6) The control unit controls the transmission of a signal to cancel the setting of the period. A communication device as described in any of (1) through (5) above.

[0138] (7) The control unit controls the transmission of a signal to cancel the setting of the period if the period cannot be overlapped on each link used for data transmission. The communication device described in (6) above.

[0139] (8) The control unit controls the transmission of a signal that exchanges information regarding the setting of the period. A communication device as described in any of (1) through (7) above.

[0140] (9) The control unit, in response to receiving the signal to be exchanged, controls to return a signal including whether or not the setting of the period described in the signal to be exchanged is permissible. The communication device described in (8) above.

[0141] (10) A communication method for a communication device that communicates using multiple links, The steps include setting a period for which data transmission will be performed across the aforementioned multiple links, The steps include transmitting a signal containing information about the aforementioned period, A communication method that includes [something].

[0142] (11) A communication unit that communicates on at least one of multiple links, A control unit that controls the communication operation by the communication unit, It is equipped with, The control unit receives a signal containing information about the period during which data transmission is performed on the plurality of links on at least one of the plurality of links, and controls the link that received the signal containing information about the period to suppress transmission. Communication device.

[0143] (12) The information relating to the said period includes at least one of the following: the start time of the said period, the length of the said period, and the links to be transmitted during the said period. The communication device described in (11) above.

[0144] (13) The control unit controls the link that receives the signal to suppress transmission based on the start time of the period and the duration of the period described in the signal. The communication device described in (12) above.

[0145] (14) The control unit controls the transmission of a signal requesting the setting of the period. A communication device as described in any of (11) to (13) above.

[0146] (15) In response to receiving a signal to cancel the setting of the period, the control unit shall not suppress transmission based on a signal containing information about the period. A communication device as described in any of (11) to (14) above.

[0147] (16) A communication method for a communication device that communicates using multiple links, The steps include receiving a signal containing information about the period during which data transmission is performed on the plurality of links on at least one of the plurality of links, A step of suppressing transmission on a link that has received a signal containing information about the aforementioned period, A communication method that includes [something]. [Explanation of Symbols]

[0148] 100...Communication system, 110...Access point, 120...Terminal 200...Communication device, 210...Control unit, 220...Power supply unit 230...Communication Unit, 231...Wireless Control Unit, 232...Data Processing Unit 233... Modulation / Demodulation Unit, 234... Signal Processing Unit, 235... Channel Estimation Unit 236...Wireless interface section, 237...Amplifier section 238...Memory section, 240...Antenna section

Claims

1. It comprises a control unit that controls communication operations via multiple links, The control unit, Period information is generated regarding the period during which data transmission using the aforementioned multiple links is performed. The aforementioned period information is, First information indicating the time to start the aforementioned period, Second information indicating the duration of the aforementioned period, Third information indicating at least one link used for the data transmission during the aforementioned period, Includes, The system controls the first communication device to transmit a signal containing the aforementioned period information. During the period from the time indicated by the first information to the time length indicated by the second information, the link indicated by the third information is controlled to be used for the data transmission. Communication device.

2. The control unit controls the transmission of the signal on each link used for data transmission. The communication device according to claim 1.

3. The control unit sets the first information and the second information so that the periods overlap in each link used for data transmission. The communication device according to claim 1.

4. The control unit controls the transmission of a signal to cancel the setting of the period. The communication device according to claim 1.

5. The control unit controls the transmission of a signal to cancel the setting of the period if the period cannot be overlapped across the links used for data transmission. The communication device according to claim 4.

6. The control unit controls the transmission of a signal that exchanges information regarding the setting of the period. The communication device according to claim 1.

7. The control unit, in response to receiving the signal to be exchanged, controls the unit to return a signal including whether or not the setting of the period described in the signal to be exchanged is permissible. The communication device according to claim 6.

8. The control unit, in response to receiving a signal requesting the setting of the period, controls the unit to transmit a signal containing the period information. The communication device according to claim 1.

9. A communication method for a communication device that controls communication operations via multiple links, The steps include generating period information relating to the period during which data transmission using the aforementioned multiple links is performed, The steps include controlling the first communication device to transmit a signal containing the aforementioned period information, A step of controlling the use of the link indicated by the third information included in the period information for data transmission during a period ranging from the time indicated by the first information included in the period information to the time length indicated by the second information included in the period information, It has, The first piece of information indicates the time when the period begins, The second piece of information indicates the duration of the period, The third piece of information indicates at least one link used for the data transmission during the period. Communication method.

10. It comprises a control unit that controls communication operations via multiple links, The control unit, The system controls the second communication device to receive a signal containing period information relating to the period during which data transmission using the aforementioned multiple links is performed. The aforementioned period information is, First information indicating the time to start the aforementioned period, Second information indicating the duration of the aforementioned period, Third information indicating at least one link used for the data transmission during the aforementioned period, Includes, During the period from the time indicated by the first information to the time length indicated by the second information, the link indicated by the third information is controlled to be used for the data transmission. Communication device.

11. The control unit controls the data transmission not to be performed using a link not indicated by the third information during the period. The communication device according to claim 10.

12. The control unit controls the reception of the signal containing the period information on at least one of the plurality of links. The communication device according to claim 10.

13. The control unit, in response to receiving a signal to cancel the setting of the period, terminates the control based on the period information. The communication device according to claim 10.

14. A communication method for a communication device that controls communication operations via multiple links, The steps include controlling the second communication device to receive a signal containing period information relating to the period during which data transmission using the aforementioned multiple links is performed, A step of controlling the use of the link indicated by the third information included in the period information for data transmission during a period ranging from the time indicated by the first information included in the period information to the time length indicated by the second information included in the period information, It has, The first piece of information indicates the time when the period begins, The second piece of information indicates the duration of the period, The third piece of information indicates at least one link used for the data transmission during the period. Communication method.

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