Communication device and communication method

Abstract

Provided is a communication device that transmits a common response signal containing data acquisition success probability information for a plurality of links.　The communication device, which engages in wireless communication by using the plurality of links, is provided with: a common data processing unit that comprises a cached common storage unit for storing the probability of successfully acquiring packets received through the plurality of links, and that subjects, to common data processing, the packets received through the various links; and a control unit that controls the transmission of response signals in response to received packets. The control unit generates, on the basis of the acquisition success probability information held by the common storage unit, a common response signal including the acquisition success probability information received through the plurality of links.

Description

Technical Field

[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 multi-link operation.

Background Art

[0002] In order to cope with the recent increase in data traffic, an increase in data capacity and an improvement in peak throughput in a wireless local area network (LAN) are required. As one solution, multi-link operation (MLO) that performs communication using a plurality of frequency bands simultaneously (see, for example, Patent Document 1) has attracted attention and is expected to be standardized in IEEE802.11be, which is the next-generation standard of IEEE802.11.

[0003] In addition, an automatic repeat-request (ARQ) technique is known to achieve high reliability of data communication. That is, the data receiver returns a response signal including information on whether the reception of the received data was successful, and the data transmitter retransmits the data based on the information on whether the reception was successful extracted from the response signal. Usually, when a communication terminal attempts to send a response signal on a certain link, it is assumed that the response signal is generated in the MAC (Media Access Control) block corresponding to the link in the communication terminal, and the response signal includes only information on whether the reception of the data received on the corresponding link was successful (in other words, information on whether the reception of the data on other links was successful is not included). In such an assumption, for example, when the data transmitter fails to receive the response signal on a certain link, even if the data receiver has successfully received the data, the data transmitter determines that the data was not correctly received and retransmits the data that the data receiver has already acquired, resulting in waste.

[0004] Therefore, as an ARQ method in MLO, a method called Common Block Ack has been proposed (see, for example, Non-Patent Document 1). In this method, the data receiver transmits a Common Block Ack, which is a response signal including the acquisition success / failure information of the data received on other links in addition to the acquisition success / failure information of the data received on the same link, to the data transmitter side. Therefore, even if the data transmitter fails to receive the response signal on a certain link, if it has successfully received the response signal on other links, it can obtain the acquisition success / failure information of the data transmitted on the link where the response signal reception has failed, and can prevent unnecessary retransmission.

[0005] In MLO, the transmitter may distribute and transmit the data of the same traffic to multiple links. According to the Common Block Ack method, the receiver transmits a response signal summarizing the acquisition success / failure information of the data in one Block Ack Session. Therefore, even if the transmitter fails to receive an individual response signal including the individual acquisition success / failure information for each link, if it has successfully received the common response signal summarizing the acquisition success / failure information for the entire Block Ack Session, it can prevent unnecessary retransmission. Here, the Block Ack Session consists of a combination of the transmitter (transmitter address) and the traffic (Traffic Identifier: TID). In this specification, the combination of the transmitter and the TID will also be referred to as "transmitter information".

[0006] Generally, on the data receiver side, a memory called a "scoreboard" is used to store the data acquisition success / failure information. In Non-Patent Document 1, a Common Scoreboard is used to store the data acquisition success / failure information for each link in order to generate a Common Block Ack. However, in the proposal described in Non-Patent Document 1, it is assumed that the Common Scoreboard manages the data acquisition success / failure information in a "Full-state type" that allocates a fixed memory area for each Block Ack Session (i.e., for each combination of a sender and a traffic identifier (TID)). Since it is necessary to implement a memory with a large storage capacity and high cost, there is a concern that the implementation difficulty will increase.

[0007] On the other hand, it is mainstream to use a "Partial-state type" scoreboard to store the data acquisition success / failure information for each link. The Partial-state type scoreboard is a cache-type small-capacity memory that temporarily stores at most the data acquisition success / failure information for one Block Ack Session. That is, in the Partial-state type scoreboard, a fixed memory area is not allocated for each Block Ack Session as in the Full-state type, and it will be overwritten if another Block Ack Session starts on the corresponding link.

[0008] If the above-mentioned Common Scoreboard is also managed in a Partial-state type instead of a Full-state type, the storage capacity can be reduced and the implementation difficulty can be alleviated. However, in the Partial-state type, only the storage of the data acquisition success / failure information for at most one Block Ack Session is guaranteed. For this reason, if the update timing and conditions are not defined, there may be a problem that the Common Scoreboard is overwritten with information from another session and thus a Common Block Ack cannot be generated.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Non-Patent Document

[0010]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0011] An object of the present disclosure is to provide a communication device and a communication method for transmitting a common response signal including data acquisition success / failure information of a plurality of links.

Means for Solving the Problems

[0012] The present disclosure has been made in consideration of the above problems, and a first aspect thereof is a communication device that performs wireless communication using a plurality of links, having a cache-type common storage unit that stores the acquisition success / failure of packets received on a plurality of links, and a common data processing unit that performs common data processing on the packets received on each link, a control unit that controls the transmission of a response signal for the received packet, and comprising the control unit generates a common response signal including the acquisition success / failure information received on the plurality of links based on the acquisition success / failure information held by the common storage unit, which is a communication device.

[0013] The communication device according to the first aspect further includes an individual storage unit that stores the acquisition success / failure information of the packets received on individual links, and an individual data processing unit that performs individual data processing on the packets received on individual links.

[0014] The control unit performs an update process on the common storage unit based on the acquisition success / failure information regarding the same sender information stored in the common storage unit and the individual storage unit. That is, when the individual storage unit stores acquisition success / failure information regarding the same sender information as the common storage unit, the control unit performs an update process on the common storage unit based on the acquisition success / failure information regarding the same sender information stored in the individual storage unit.

[0015] Alternatively, the control unit performs an update process on the individual storage unit based on the acquisition success / failure information regarding the same sender information stored in the common storage unit and the individual storage unit.

[0016] Further, a second aspect of the present disclosure is a communication method for performing wireless communication using a plurality of links, a common data processing step of performing common data processing on the packets received on each link, using a cache-type common storage unit that stores the acquisition success / failure of the packets received on the plurality of links, a control step of controlling the transmission of a response signal for the received packet, and having In the control step, a common response signal including the acquisition success / failure information received on the plurality of links is generated based on the acquisition success / failure information held by the common storage unit. It is a communication method.

[0017] Further, a third aspect of the present disclosure is a communication unit that performs wireless communication using a plurality of links, a control unit that controls the wireless communication operation in the communication unit, and comprising When transmitting a data signal on the plurality of links, the control unit notifies whether there is a request for a common response signal including acquisition success / failure information regarding the reception of the data signal on the plurality of links. It is a communication device.

[0018] Further, a fourth aspect of the present disclosure is a communication method for performing wireless communication using a plurality of links, notifying whether there is a request for a common response signal including acquisition success / failure information regarding reception of data signals in the plurality of links, and transmitting a data signal; receiving a response signal; and a communication method comprising the same. [Effect of the Invention]

[0019] According to the present disclosure, it is possible to provide a communication device and a communication method that transmit a common response signal using a cache-type common storage unit that stores acquisition success / failure information of packets received on a plurality of links.

[0020] 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.

[0021] Still other objects, features, and advantages of the present disclosure will become apparent from more detailed descriptions based on embodiments described later and the accompanying drawings. [Brief Description of the Drawings]

[0022]

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Embodiments for Carrying Out the Invention

[0023] Hereinafter, the technology according to the present disclosure will be described in the following order with reference to the drawings. A. System Configuration B. Device Configuration C. Functional Configuration Example of MLD D. Regarding Common Block Ack E. First Embodiment E-1. Overall Sequence E-2. Block Ack Setup Phase E-3. Data Transmission Phase E-4. Block Ack Request Phase E-5. Operation Example F. Second Embodiment G. Effects

[0024] A. System Configuration Figure 1 schematically shows a configuration example of a communication system corresponding to MLO to which the present disclosure is applied. The illustrated communication system is composed of one base station or access point (AP) and two slave devices STA (STAtion) 1 and STA2 connected to the AP. In Figure 1, only two STAs are drawn for simplicity of the drawing, but it is also assumed that three or more STAs are connected to one AP.

[0025] For data communication between the AP, STA1, and STA2, two links, Link1 and Link2, are available. The AP, STA1, and STA2 are all communication devices corresponding to MLO. A communication device corresponding to MLO is hereinafter also referred to as an MLD (Multi Link Device).

[0026] Note that the "link" referred to in this specification is a wireless transmission path capable of transmitting data between two communication devices. Each individual link is selected from a plurality of independent wireless transmission paths (channels) divided, for example, in the frequency domain. The two links used in the communication system shown in FIG. 1 each use a channel selected from a plurality of channels included in any one of frequency bands such as the 2.4 GHz band, 5 GHz band, 6 GHz band, 920 MHz band, etc. The two links used in the communication system shown in FIG. 1 may be two channels selected from the same frequency band or two channels selected from different frequency bands. Also, the frequency band including the channel selected by at least one of the two links used in the communication system shown in FIG. 1 may be a frequency band (unlicensed band) permitted for use by database access such as SAS (Spectrum Access System).

[0027] B. Device Configuration FIG. 2 shows an example of the internal configuration of the communication device 200. The communication device 200 is a communication device corresponding to MLO, and is assumed to operate as an AP or STA1, STA2 in the communication system shown in FIG. 1. The communication device 200 mainly includes a communication unit 210, a control unit 220, a storage unit 230, and an antenna 240. Also, the communication unit 210 includes a communication control unit 211, a communication storage unit 212, a data processing unit including a common data processing unit 213 and an individual data processing unit 214, a signal processing unit 215, a wireless interface (IF) unit 216, and an amplification unit 217.

[0028] The individual data processing unit 214, the signal processing unit 215, the radio interface (IF) unit 216, the amplification unit 217, and the antenna 240 are provided for each link. The communication device 200 is assumed to perform MLO using two links, Link1 and Link2. For example, the individual data processing unit 214-1, the signal processing unit 215-1, the radio interface unit 216-1, the amplification unit 217-1, and the antenna 240-1 are regarded as one individual communication set for transmission and reception processing in Link1, and the individual data processing unit 214-2, the signal processing unit 215-2, the radio interface unit 216-2, the amplification unit 217-2, and the antenna 240-2 are regarded as another individual communication set for transmission and reception processing in Link2.

[0029] The communication control unit 211 controls the operations of each part in the communication unit 210 and the information transmission between each part. Also, the communication control unit 211 performs control to transfer the control information and management information to be notified to other communication devices to the data processing units (the common data processing unit 213, the individual data processing unit 214-1, and the individual data processing unit 214-2).

[0030] The communication storage unit 212 holds the information used by the communication control unit 211. Also, the communication storage unit 212 holds the data transmitted by the communication device 200 and the data received by the communication device 200.

[0031] The data processing unit consists of the common data processing unit 213 and the individual data processing unit 214. Also, the individual data processing unit 214 consists of the individual data processing unit 214-1 and the individual data processing unit 214-2 for each link.

[0032] When transmitting, the common data processing unit 213 performs sequence management of the data held in the communication storage unit 212 and the control information and management information received from the communication control unit 211, performs encryption processing and the like to generate data units, and allocates them to the individual data processing units 214-1 and 214-2. Also, when receiving, the common data processing unit 213 performs decoding processing and reordering processing of the data units.

[0033] In the present disclosure, when applying the Common Block Ack method, the common data processing unit 213 performs data processing for transmitting a Common Block Ack that summarizes the data acquisition success / failure information for each Block Ack Session, that is, for each sender information, using a Partial-state type or cache type Common Scoreboard. Details thereof will be described later.

[0034] When transmitting, the individual data processing units 214-1 and 214-2 perform a channel access operation based on carrier sense in the corresponding link, addition of a MAC header and an error detection code to the data to be transmitted, and concatenation processing of a plurality of data units. Also, when receiving, the individual data processing units 214-1 and 214-2 perform a MAC header concatenation release process, analysis and error detection of the received data unit, and a retransmission request operation.

[0035] Note that the operations of the common data processing unit 213 and the individual data processing units 214-1 and 214-2 are not limited to the above, and for example, one may perform the operations of the other.

[0036] When transmitting, the signal processing units 215-1 and 215-1-2 perform encoding, interleaving, modulation, etc. on the data unit, add a physical header, and generate a symbol stream. Also, when receiving, the signal processing units 215-1 and 215-2 analyze the physical header, perform demodulation, deinterleaving, decoding, etc. on the symbol stream, and generate a data unit. Also, the signal processing units 215-1 and 215-2 perform estimation of complex channel characteristics and spatial separation processing as necessary.

[0037] The wireless interface units 216-1 and 216-2 perform digital-to-analog signal conversion, filtering, up-conversion, and phase control on the symbol stream during transmission to generate a transmission signal. Also, the wireless interface units 216-1 and 216-2 perform down-conversion, filtering, and analog-to-digital signal conversion on the received signal during reception to generate a symbol stream.

[0038] The amplification units 217-1 and 217-2 amplify the signals input from the wireless interface units 216-1 and 216-2 or the antennas 240-1 and 240-2. A part of the amplification units 217-1 and 217-2 may be components outside the communication unit 210. Also, a part of the amplification units 217-1 and 217-2 may be incorporated in the wireless interface units 216-1 and 216-2.

[0039] The control unit 220 controls the communication unit 210 and the communication control unit 211. Also, the control unit 220 may perform some operations of the communication control unit 211 instead. Also, the communication control unit 211 and the control unit 220 may be configured as one block.

[0040] The storage unit 230 holds information used by the communication unit 210 and the control unit 220. Also, the storage unit 230 may perform some operations of the communication storage unit 212 instead. Also, the storage unit 230 and the communication storage unit 212 may be configured as one block.

[0041] Using the individual data processing unit 214-1, signal processing unit 215-1, wireless interface unit 216-1, amplifier unit 217-1, and antenna 240-1 as one individual communication set, wireless communication is performed on Link1. Also, using the individual data processing unit 214-2, signal processing unit 215-2, wireless interface unit 216-2, amplifier unit 217-2, and antenna 240-2 as another individual communication set, wireless communication is performed on Link2. In FIG. 2, only two individual communication sets are depicted, but three or more sets can be components of the communication device 200, and each individual communication set can be configured to perform wireless communication on its respective link. Also, the storage unit 230 or communication storage unit 212 may be included in each individual communication set.

[0042] A link is a wireless transmission path capable of transmitting data between two communication devices, and each individual link is selected from a plurality of mutually independent wireless transmission paths (channels) divided, for example, in the frequency domain. The links used by each of the above individual communication sets may be two channels selected from the same frequency band or two channels selected from different frequency bands. Also, the individual data processing unit 214 and the signal processing unit 215 may be configured as one set, and two or more sets may be connected to one common wireless interface unit 216.

[0043] The wireless interface unit 216, amplifier unit 217, and antenna 240 may be configured as one set, and two or more sets may be components of the communication device 200.

[0044] The communication unit 210 can also be configured by one or more LSIs (Large Scale Integration).

[0045] The common data processing unit 213 is also referred to as Upper MAC or Higher MAC, and the individual data processing unit 214 is also referred to as Lower MAC. Also, the combination of the individual data processing unit 214 and the signal processing unit 215 is also referred to as an AP entity or a Non-AP entity. Alternatively, the combination of the individual data processing unit 214 and the signal processing unit 215 is also referred to as a MAC entity without distinguishing between AP or Non-AP. The communication control unit 211 is also referred to as an MLD management entity.

[0046] C. Functional Configuration Example of MLD Figure 3 shows a communication device corresponding to MLO, that is, a functional configuration example of MLD. Here, for simplicity, only the functional blocks related to the present disclosure during data reception are shown. In Figure 3, Link1 MAC Entity and Link2 MAC Entity are functional blocks within the individual data processing units 214-1 and 214-2 respectively, and the MLD Entity is a functional block within the common data processing unit 213.

[0047] Link1 MAC Entity, Link2 MAC Entity, and MLD Entity are each assigned a MAC address. The transmission address or reception address of the communication performed via Link1 and Link2 uses the MAC address assigned to the MAC Entity of each link. Also, it is assumed that the MAC address assigned to the MLD Entity is used during Authentication and Block Ack Session establishment.

[0048] Link1 MAC Entity and Link2 MAC Entity each include an A-MPDU (MAC Protocol Data Unit) De-aggregation block, a MAC Header+CRC (Cyclic Redundancy Code) Validation block, and a Link Scoreboard block as functional blocks for performing MAC layer reception processing in the corresponding link.

[0049] The A-MPDU De-aggregation block performs a process of splitting a data signal in which a plurality of packets (data units) are aggregated and transmitted into individual packets.

[0050] The MAC Header + CRC Validation block reads the MAC header of each packet split by the A-MPDU De-aggregation block and checks the CRC of the entire packet. In this block, from the information in the MAC header, the destination of the received packet and the type of the received packet (whether it is a data signal or a control signal) are recognized. Also, in this block, by checking the CRC, it is determined whether the received packet has been correctly acquired. If it is determined in this block that the received packet has been correctly acquired, the information obtained from the payload of that packet is passed to the upper layer. On the other hand, if it is determined in this block that the received packet has not been correctly acquired, the received packet is discarded at this point and no information is passed to the upper layer.

[0051] The Link Scoreboard block stores the information on whether the acquisition of each packet determined in the MPDU Header + CRC Validation block is successful or not in order to generate a Block Ack for the corresponding link. The Link Scoreboard is a Partial-state type scoreboard that temporarily stores the information on whether the acquisition is successful for at most one Block Ack Session. Details of the Link Scoreboard will be deferred to later.

[0052] The MLD Entity includes a Block Ack Buffering and Recording block and a Common Scoreboard block as functional blocks that perform processing common to all links. In MLD, data processing is performed using the Common Scoreboard to transmit a Common Block Ack that summarizes the success or failure information of data acquisition for each Block Ack Session, that is, for each sender information.

[0053] The Common Scoreboard block stores whether the acquisition of each packet, determined by the MAC Header+CRC Validation block for each link, was successful or not in order to generate a Common Block Ack. The Common Scoreboard is a Partial-state type scoreboard that temporarily stores the success or failure information of acquisition for at most one Block Ack Session. Details of the Common Scoreboard will be deferred to later.

[0054] The Block Ack Buffering and Recording block temporarily stores the packets acquired through the MAC layer reception processing by each Link MAC Entity, and performs reordering processing based on the sequence numbers assigned to each packet. The packets acquired through each Link Mac Entity are delivered to the upper layer in ascending order of sequence number. If there are packets that cannot be acquired during the process, the Block Ack Buffering and Recording block does not deliver the packets after the sequence number of that packet to the upper layer and temporarily stores them. Also, when a packet that could not be acquired is retransmitted and correctly acquired, or when it is notified that packet retransmission is not performed from the data sender side by a Block Ack Request or the like, the Buffering and Recording block will deliver the temporarily stored packets to the upper layer.

[0055] In this embodiment, it is assumed that both the Link Scoreboard included in each Link MAC Entity and the Common Scoreboard included in the MLD Entity are managed in the Partial-state type. IEEE802.11-2016 describes the management of the Partial-state type Scoreboard as follows, and in this embodiment, basically the following description is followed.

[0056] (1) The receiver must maintain a temporary block acknowledgement record. (2) In the temporary record, there is bitmap information associated with the sequence number, WindowStart R (the minimum sequence number value in the bitmap), WindowEnd R (the maximum sequence number value in the bitmap), the address of the originator (data sender), TID (Traffic Identifier), WindowSize R (the maximum transmission window size, a value determined during the Block Ack Session described later) is stored. (3) During the Partial-state operation, as long as the receiver receives at least data from the same originator, the current record is maintained. (4) When receiving data from another originator or another TID (i.e., different sender information), if a resource for storing a temporary record for the new originator and TID (i.e., new sender information) is required, the existing temporary record may be discarded by overwriting or the like.

[0057] D. Regarding Common Block Ack Fig. 4 shows, as an example of multi-link operation, a communication sequence example in the communication system shown in Fig. 1 where STA1 performs data transmission using Link1 and Link2 and the AP transmits a Common Block Ack.

[0058] Note that the horizontal axis in FIG. 4 is the time axis, which shows the communication operations at each time on the links of AP and STA1. The square blocks drawn with solid lines indicate the transmission frames at the corresponding communication devices, links, and times. The solid arrows in the vertical direction indicate frame transmissions to the destinations, and the square blocks drawn with dotted lines indicate the received frames. Also, for simplicity of explanation, it is assumed that the TIDs of the packets transmitted from STA1 in FIG. 4 are all the same.

[0059] When STA1 acquires the transmission right on Link1, it transmits a data signal (A-MPDU) obtained by aggregating packets with sequence numbers #1 to #32. When AP receives this data signal, it transmits a Block Ack (BA) including the packet acquisition success / failure information with sequence numbers #1 to #32 to STA1 on Link1. Since the packet acquisition success / failure information is indicated by information in bitmap format, it is also referred to as "bitmap information" below.

[0060] Also, when STA1 acquires the transmission right on Link2, it transmits a data signal obtained by aggregating packets with sequence numbers #33 to #64. After STA1 finishes transmitting the data signal on Link2, AP generates a Block Ack. At this time, since AP holds not only the bitmap information of the packets with sequence numbers #33 to #64 received on Link2 but also the bitmap information of the packets with sequence numbers #1 to #32 received on Link1, it generates a Common Block Ack including the bitmap information with sequence numbers #1 to #64 and transmits it to STA1 on Link2.

[0061] If AP transmits the Common Block Ack in this way, even if STA1 fails to correctly receive the Block Ack transmitted by AP first on Link1, as long as STA1 can receive the Common Block Ack transmitted by AP on Link2, it can obtain the bitmap information about all the packets transmitted on each link and perform retransmission control so that there is no unnecessary data retransmission.

[0062] In the communication sequence example shown in FIG. 4, it is assumed that the Block Ack transmitted by the AP on Link1 notifies only the bitmap information of the packets (#1 to #32) received on Link1. However, if it is possible to obtain some of the bitmap information of the packets (#33 to #64) received on Link2 when generating the Block Ack, the AP may generate and transmit a Common Block Ack on Link1 as well.

[0063] FIG. 5 shows another communication sequence example of the multi-link operation performed in the communication system shown in FIG. 1. In the communication sequence example shown in FIG. 5, STA1 performs data transmission using Link1 and Link2, and STA2 performs data transmission to the AP using Link1.

[0064] Note that the horizontal axis in FIG. 5 is the time axis, showing the communication operations at each time on each link of the AP, STA1, and STA2. The square blocks drawn with solid lines indicate the transmission frames at the corresponding communication devices, links, and times. The vertical solid-line arrows indicate frame transmission to the destination, and the square blocks drawn with dotted lines indicate the received frames. Also, for simplicity of explanation, the TIDs of the packets transmitted from STA1 and STA2 in FIG. 5 are all assumed to be the same.

[0065] When STA1 acquires the transmission right of Link1, it transmits a data signal obtained by aggregating packets with sequence numbers #1 to #32. When the AP receives this data signal, it transmits a Block Ack including the bitmap information of the packets with sequence numbers #1 to #32 to STA1 on Link1. Also, the AP holds the bitmap information of the packets with sequence numbers #1 to #32 in the Common Scoreboard in preparation for generating a Common Block Ack.

[0066] Also, when STA1 acquires the transmission right on Link2, it transmits a data signal obtained by aggregating packets with sequence numbers #33 to #64. Here, before STA1 finishes data transmission on Link2, STA2 acquires the transmission right on Link1 and transmits a data signal. When the AP receives the data signal from STA2, bitmap information corresponding to the received data from STA2 is to be held in the Common Scoreboard and the Link Scoreboard of Link1 within the AP. In this case, since the bitmap information corresponding to the received packets from STA1 held in the Common Scoreboard has a different originator (or, sender information), it is highly likely to be deleted by overwriting or the like. When STA1 finishes transmitting the data signal on Link2, the AP does not hold the bitmap information corresponding to the packets received from STA1 on Link1 in any scoreboard, so it cannot transmit a Common Block Ack to STA1.

[0067] When the Common Scoreboard is managed in a Partial-state type in this way, in the above situation, especially for an AP that receives data signals from multiple terminals on multiple links, the opportunity to transmit a Common Block Ack becomes limited. Also, on the STA side, when receiving data signals associated with multiple TIDs, the same problem occurs.

[0068] Therefore, the present disclosure provides appropriate update conditions and methods for the Common Scoreboard in a situation where the Common Scoreboard is managed in a Partial-state type in a communication system corresponding to MLO. According to the present disclosure, a communication device (for example, the AP in FIG. 1) that receives data signals from multiple terminals on multiple links can increase the opportunity to transmit a Common Block Ack and improve the reliability of ARQ.

[0069] E. First Embodiment In this section, a first embodiment of a communication system to which the present disclosure is applied will be described.

[0070] E-1. Overall Sequence FIG. 6 shows an example of a communication sequence implemented in a communication system to which the present disclosure is applied. In FIG. 6, the communication system assumes a communication system corresponding to an MLO in which one AP and one STA are connected using Link1 and Link2.

[0071] First, in the association phase (SEQ601), an association procedure is performed between the AP and the STA, and the STA participates in the BSS (Basic Service Set) of the AP. In the IEEE802.11 standard, the association procedure is performed by the STA sending an association request to the AP and the AP sending an association response to the STA to notify the association identifier (AID).

[0072] Next, in the MLO setup phase (SEQ602), the setup of Link1 and Link2 for communication between the AP and the STA is performed. In the present disclosure, within this phase, the MAC addresses of each Link1 MAC Entity, Link2 MAC Entity, and MLD Entity are notified between the AP and the STA, and these are managed as one sender (originator). Note that the MLO setup phase may be included in the association phase.

[0073] Next, in the Block Ack setup phase (SEQ603), an ADDBA (ADD Block Acknowledgement) Request frame and a Response frame are exchanged between the AP and the STA to establish a Block Ack Session. Among the information exchanged between the AP and the STA, there are included a Block Ack Policy, a TID, a Buffer Size, etc., and the aforementioned Window Size R is determined by the exchanged Buffer Size.

[0074] In this embodiment, it is characterized in that Common Scoreboard Capability is included in this ADDBA Request frame and ADDBA Response frame. Since the STA exchanges Common Scoreboard Capability indicating the manageability of the Common Scoreboard with the AP in the Block Ack setup phase, it can be determined whether the AP can generate a Commom Block Ack, and for example, the Ack Policy can be correctly set in the header of the data packet. Details of the Common Scoreboard Capability will be deferred to later.

[0075] Next, in the Data Transmission phase (SEQ604), the STA performs data transmission using Link1 and Link2, and the AP performs Block Ack transmission on Link1 and Link2. The STA, which is the data sender, includes in the packet header an Ack Policy indicating whether to request a Common Block Ack or a Normal Ack. Details of this point will be deferred to later. Also, the method for updating the Common Scoreboard and the generation of the Common Block Ack in this phase will be described later.

[0076] Next, in the Block Ack Request phase (SEQ605), the STA transmits a Block Ack Request (BAR) frame to the AP on an arbitrary link (Link X). In response, the AP transmits a Block Ack frame on the same link (Link X). The BAR frame is used not only when the STA wants to obtain a Block Ack, but also when initializing the Scoreboard and Window Start R between the AP and the STA. The method for updating the Common Scoreboard in the Block Ack Request phase will be deferred to later.

[0077] E-2. Block Ack Setup Phase As described with reference to FIG. 6, in the Block Ack setup phase, an ADDBA (ADD Block Acknowledgement) Request frame and a Response frame are exchanged between the AP and the STA to establish a Block Ack Session.

[0078] FIG. 7 shows a configuration example of the ADDBA Capabilities field notified by the ADDBA Request frame and the ADDBA Response frame. In the example shown in FIG. 7, a part of the 5-bit reserved area (Reserved bit) (1 bit in the illustrated example) of the ADDBA Capabilities field is used to notify the Common Scoreboard Capability.

[0079] Based on the information in this Common Scoreboard Capability field, the data sender (originator) can determine whether the receiving side can manage bitmap information using the Common Scoreboard and whether it can generate a Common Block Ack. Therefore, the data sender (originator) can correctly set the Ack Policy, for example, in the header of the data packet.

[0080] Note that the information of the Common Scoreboard Capability does not have to be included in the ADDBA Capabilities field, and it may be notified in either the ADDBA Request frame or the ADDBA Response frame.

[0081] E-3. Data Transmission Phase As described with reference to FIG. 6, in the Data Transmission phase, the STA performs data transmission using Link1 and Link2, and the AP performs Block Ack transmission on Link1 and Link2.

[0082] FIG. 8 shows, in the form of a flowchart, the processing procedure for the STA to perform data transmission in the Data Transmission phase.

[0083] When the STA acquires a transmission opportunity (TXOP) such as by ending the backoff on a certain link (for example, Link1) (step S801), it determines whether to request a Common Block Ack from the receiving AP (step S802).

[0084] If it requests a Common Block Ack from the AP (Yes in step S802), the STA sets the Ack Policy in the MAC Header / QoS Control field attached to the head of the packet to "Common BA" (that is, a confirmation response including information on whether the data acquisition was successful in multiple links), and starts transmitting the data signal (step S803). Since the STA exchanges Capability information (Common Scoreboard Capability) on whether the Common Scoreboard can be managed with the AP in the Block Ack setup phase (see FIGS. 6 and 7), it can determine whether the AP can generate a Commom Block Ack and, for example, correctly set the Ack Policy in the header of the data packet.

[0085] On the other hand, when not requesting a Common Block Ack from the AP (No in step S802), the STA sets the Ack Policy in the MAC Header / QoS Control field attached to the head of the packet to other than "Common BA" (for example, "Normal Ack") and starts transmitting the data signal (step S804).

[0086] Note that in step S802, there is no particular limitation on how the STA determines whether to request a Common Block Ack. For example, the STA may request a Common Block Ack only when transmitting data that requires low latency or high reliability, or may be set to always request a Common Block Ack to be sent.

[0087] FIG. 9 shows, in the form of a flowchart, the processing procedure when the AP receives data in the Data Transmission phase.

[0088] The AP receives a data signal on a certain link (for example, Link1) and updates the Link Scoreboard of the Link MAC entity corresponding to that link based on the data acquisition success / failure information in the conventional manner (step S901).

[0089] Next, the AP checks whether it should send a Common Block Ack (step S902). Specifically, the AP checks whether a Block Ack setup including a Common Block Ack has been completed with the STA that is the data sender (originator), and whether the Ack Policy in the MAC Header / QoS Control field of the received packet is "Common BA". Since the STA exchanges Capability information (Common Scoreboard Capability) regarding the management availability of the Common Scoreboard with the AP during the Block Ack setup phase (see FIGS. 6 and 7), it can be determined whether the AP can generate a Commom Block Ack, and for example, the Ack Policy can be correctly set in the header of the data packet.

[0090] If the Block Ack setup has not been completed with the data sender or the Ack Policy in the MAC Header / QoS Control field of the received packet is not "Common BA" (No in step S902), the AP ends this process without updating the Common Scoreboard.

[0091] On the other hand, if the Block Ack setup has been completed with the data sender and the Ack Policy in the MAC Header / QoS Control field of the received packet is "Common BA" (Yes in step S902), the AP determines whether to update the Common Scoreboard.

[0092] As a determination of whether to update the Common Scoreboard, the AP first checks whether the Common Scoreboard and the Link Scoreboard of the link where the data was received manage the same sender information, that is, the bitmap of the same sender and the same TID (step S903).

[0093] If the Link Scoreboard of the link (e.g., Link1) that has performed data reception with the Common Scoreboard manages bitmaps of the same sender and the same TID (Yes in step S903), the AP updates the bitmap information of the Common Scoreboard based on the bitmap information of the Link1 Scoreboard of Link1 that has performed data reception (or the SN information that has updated the bitmap) (step S905) and ends this process. As a result, as long as data is continuously received from the same sender with the same TID as that managed by the Common Scoreboard, the success / failure information of obtaining the same Block Ack Session is sequentially updated in the Common Scoreboard based on the success / failure information of obtaining the scoreboard of the link that has received the data.

[0094] If the Link Scoreboard of the link (e.g., Link1) that has performed data reception with the Common Scoreboard does not manage bitmaps of the same sender and the same TID (No in step S903), the AP further checks whether the Link Scoreboard of a link different from the link that has performed data reception with the Common Scoreboard (e.g., Link2) manages bitmaps of the same sender and the same TID as the Link Scoreboard of the link that has performed data reception (e.g., Link1) (step S904).

[0095] And when the Link Scoreboard of another link manages the same sender information as the Link Scoreboard of the link that received the data, that is, the bitmap of the same sender and the same TID (Yes in step S904), the AP creates and stores new sender information, that is, the bitmap information of a new sender and TID, in the Common Scoreboard based on the bitmap information of the Link Scoreboards of the link that received the data and the other link (step S906), and ends this process. As a result, when data with at least one of the sender or TID different from that managed in the Common Scoreboard is received (that is, when the sender information changes), the acquisition success / failure information of a new Block Ack Session is updated in the Common Scoreboard based on the acquisition success / failure information managed by the scoreboard for each link.

[0096] Also, when the Link Scoreboard of another link does not manage the same sender information as the Link Scoreboard of the link that received the data, that is, the bitmap of the same sender and the same TID (No in step S904), the AP ends this process without updating the Common Scoreboard.

[0097] Note that in this embodiment, it is assumed that the Link Scoreboard and the Common Scoreboard are updated when the CRC check of the packets aggregated on all the used links is performed. However, the update timing of each scoreboard is not limited to this. For example, the Link Scoreboard may be updated when the CRC check of all the packets aggregated on each link is completed. Also, the update of the Common Scoreboard may be performed at each internally determined interval, or may be performed when the reception of all the data signals is completed.

[0098] Also, in this embodiment, it is assumed that the AP acquires the MAC address of each subordinate STA in the MLO setup phase and stores and manages the MAC addresses of each Link MAC entity and MLD Entity for each sender (originator). Therefore, when the AP receives data on each link, it can look at the address of the sender and determine whether the senders of each link are the same STA.

[0099] FIG. 10 shows an example of an internal sequence when the AP receives a data signal in the Data Transmission phase. FIG. 10 shows an example of an internal sequence when the AP updates the bitmap information of the Common Scoreboard based on the bitmap information of the Link1 MAC Scoreboard, which corresponds to step S905 in the flowchart shown in FIG. 9. As described above, the AP is a communication device corresponding to MLO, that is, an MLD, and as shown in FIG. 3, it includes a Link1 MAC Entity and a Link2 MAC Entity that perform individual data processing for each link, and an MLD Entity that performs data processing common to all links. In addition, as scoreboards for storing data acquisition success / failure information in the AP, there are a Link1 Scoreboard and a Link2 Scoreboard owned by the Link1 MAC Entity and the Link2 MAC Entity, and a Common Scoreboard owned by the MLD Entity.

[0100] When the Link1 MAC Entity updates the Link1 Scoreboard upon receiving data on Link1 (Scoreboard Update), it notifies the MLD Entity of Scoreboard Update Info including the Originator Address, TID, and Updated SN.

[0101] The MLD Entity determines whether it manages the bitmap information of the same sender information (i.e., the same Originator Address and TID) in the Common Scoreboard based on the information obtained from the Link1 MAC Entity (Common Scoreboard Update Decision 1). This determination process corresponds to step S903 in the flowchart shown in FIG. 9. Here, it is assumed that the Block Ack setup is completed with the STA that is the data sender (originator), and the Ack Policy in the MAC Header / QoS Control field of the received packet specifies "Common BA".

[0102] If the MLD Entity determines that the Common Scoreboard manages the bitmap information with the same Originator Address and TID as the Link1 Scoreboard, it updates the Common Scoreboard (Common Scoreboard Update).

[0103] The MLD Entity updates the Common Scoreboard according to the following procedure. Here, WindowStart R , WindowEnd R , and WindowSize R are described as WindowStart Rc , WindowEnd Rc , and WindowSize Rc respectively. Also, when the SN Space is extended, a larger numerical value may be used starting from 2 11 .

[0104] (1) If WindowStart Rc ≦ SN ≦ WindowEnd Rc , set "1" at the position corresponding to SN in the bitmap information of the Common Scoreboard. (2) Window End Rc <SN ≤ Window Start Rc + 2 11 If so, execute the following process. (2-1) Window End Rc Set 0 from Window End to SN - 1. (2-2) Window Start Rc = SN - Window Size Rc Set it to + 1. (2-3) Window End Rc Set it to SN. (2-4) Set "1" at the position corresponding to SN in the bitmap information of the Common Scoreboard.

[0105] In this embodiment, the Common Scoreboard is of the Partial State type and has only the capacity to store the bitmap information for one Block Ack Session. When it goes around once, it returns to the beginning and is overwritten. The Window Start in (1) above Rc ≤ SN ≤ Window End Rc This condition indicates that the corresponding SN falls within the window size of the current Common Scoreboard. In this case, set the packet acquisition success / failure information of this SN at the corresponding bit position in the bitmap of the Common Scoreboard. Also, for Window End in (2) above Rc < SN ≤ Window Start Rc + 2 11 This condition indicates that the end of the window size of the Common Scoreboard has been reached. In this case, return to the beginning of the bitmap and set the packet acquisition success / failure information of this SN.

[0106] FIG. 11 shows another example of the internal sequence when the AP receives a data signal in the Data Transmission phase. FIG. 11 shows an example of the internal sequence when the AP updates the bitmap information of the Common Scoreboard based on the bitmap information of the Link1 MAC Scoreboard and the bitmap information of the Link2 Scoreboard, which corresponds to step S906 in the flowchart shown in FIG. 9.

[0107] When the Link1 MAC Entity updates the Link1 Scoreboard upon receiving data on Link1 (Scoreboard Update), it notifies the MLD Entity of the Scoreboard Update Info including the Originator Address, TID, and Updated SN.

[0108] Based on the information obtained from the Link1 MAC Entity, the MLD Entity determines whether the Common Scoreboard also manages the bitmap information with the same Originator Address and TID (Common Scoreboard Update Decision 1). This determination process corresponds to step S903 in the flowchart shown in FIG. 9. Here, it is assumed that the Block Ack setup with the STA, which is the data sender (originator), is completed, and the Ack Policy in the MAC Header / QoS Control field of the received packet specifies "Common BA".

[0109] Then, when the MLD Entity confirms that the Common Scoreboard and the Link1 Scoreboard do not manage the bitmap information of the same Originator Address and TID, it sends a Scoreboard Originator Info Request to the Link2 MAC Entity. In response to this request from the MLD Entity, the Link2 MAC Entity sends a Scoreboard Originator Info Response including the Originator Address and TID. Note that if the MLD Entity regularly obtains the information of the Originator Address and TID from the Link2 Scoreboard, it may not send a Scoreboard Originator Info Request to the Link2 MAC Entity.

[0110] Based on the information obtained from the Link2 MAC Entity, the MLD Entity determines whether to update the Common Scoreboard based on whether the Common Scoreboard manages the same sender information as the Link1 Scoreboard and the Link2 Scoreboard, that is, the bitmap information of the same Originator Address and TID (Common Scoreboard Update Decision 2). This determination process corresponds to step S904 in the flowchart shown in FIG. 9.

[0111] When the MLD Entity determines that the Link1 Scoreboard and the Link2 Scoreboard manage the same sender information, that is, the bitmap information of the same Originator Address and TID, it decides to create new sender information, that is, the bitmap information of a new Originator Address and TID based on the bitmap information of both, and update the Common Scoreboard. For this reason, the MLD Entity sends a Scoreboard Request to the Link1 MAC Entity and the Link2 MAC Entity.

[0112] In response to the Scoreboard Request from the MLD Entity, the Link1 MAC Entity and the Link2 MAC Entity each send the bitmap information, the WindowStart, the WindowEnd, and the Scoreboard Info including the Originator Address and TID.

[0113] Then, the MLD Entity updates the Common Scoreboard (Common Scoreboard Update) according to the following procedure based on the Scoreboard Info collected from the Link1 MAC Entity and the Link2 MAC Entity. Here, the WindowStart R , WindowEnd R , and WindowSize R of the LinkX (the Xth link) Scoreboard are described as WindowStart Rx , WindowEnd Rx , and WindowSize Rx respectively.

[0114] (1) WindowEnd Rc = max(WindowEND R1 , WindowEND R2Set it to . That is, update the Common Scoreboard according to the one with the larger final value of the sequence number stored in Link1 Scoreboard and Link2 Scoreboard. (2) WindowStart Rc = WindowEnd Rc - WindowSize Rc Set it to +1. (3) The first is WindowStart Rc and the last is WindowEnd Rc Generate a bitmap of the size of WindowSize Rc such that (initially input all 0s). (4) For each SN within WindowStart R to WindowEnd Rc if either the bitmap information of Link1 or the bitmap information of Link2 is "1" for each SN, set "1" at the location indicated by the corresponding SN of the bitmap information of the Common Scoreboard. That is, for the SNs indicating that at least one of Link1 Scoreboard and Link2 Scoreboard has successfully acquired a packet, set "1" indicating successful acquisition in the bitmap information of the Common Scoreboard as well.

[0115] Also, when the sum of the window sizes of the Link Scoreboards of each link is larger than the window size of the Common Scoreboard, some bitmap information may be damaged when updating the Common Scoreboard. In this case, the MLD Entity may not send a Common Block Ack to the link for which the bitmap information could not be stored in the Common Scoreboard, and may instruct to send a normal Block Ack based on the information of the Link Scoreboard for each link.

[0116] Also, after updating the bitmap information, the Common Scoreboard may update the Link Scoreboard of each link according to its own bitmap information. Specifically, in the SN where "1" is set in the Common Scoreboard and "0" is set in the Link Scoreboard while keeping the WindowStart and WindowEnd of each link unchanged, the control may be such that "1" is set at the corresponding position of the Link Scoreboard.

[0117] Figure 12 shows the processing procedure for the AP to send a Block Ack in the form of a flowchart.

[0118] After the AP completes receiving a data signal on a certain link (for example, Link1) (step S1201), the AP checks whether the Common Scoreboard manages the bitmap of the same sender and the same TID as the sender of the data signal (step S1202).

[0119] When the Common Scoreboard manages the bitmap of the same sender and the same TID as the sender of the data signal (Yes in step S1202), the AP generates a Common Block Ack based on the information of the Common Scoreboard and sends it to the STA that is the sender (step S1203), and ends this process.

[0120] On the other hand, when the Common Scoreboard does not manage the bitmap of the same sender and the same TID as the sender of the data signal (No in step S1202), the AP generates a conventional Block Ack based on the information of the Link Scoreboard of the link (for example, Link1) where the data signal is received and sends it to the STA that is the sender (step S1204), and ends this process.

[0121] FIG. 13 shows an example of an internal sequence when the AP transmits a Block Ack. FIG. 13 shows an example of an internal sequence when the AP transmits a Common Block Ack based on the bitmap information of the Common Scoreboard, corresponding to step S1203 in the flowchart shown in FIG. 12. The AP corresponding to the MLO includes a Link1 MAC Entity and a Link2 MAC Entity that perform individual data processing for each link, and an MLD Entity that performs data processing common to all links. Also, as scoreboards for storing data acquisition success / failure information in the AP, there are a Link1 Scoreboard and a Link2 Scoreboard owned by the Link1 MAC Entity and the Link2 MAC Entity, and a Common Scoreboard owned by the MLD Entity.

[0122] After completing the reception of the data signal on Link1 (Data Rx End), the Link1 MAC Entity notifies the MLD Entity of the Common Block Ack Request Info including the Originator Address and TID.

[0123] Based on the information of the Common Block Ack Request Info obtained from the Link1 MAC Entity, the MLD Entity confirms that the bitmap information of the same Originator and TID as the sender of the data received on Link1 is managed by the Common Scoreboard, and the Common Block Ack Response Info including the Common Scoreboard information (at least the bitmap information, WindowStart Rc , WindowEnd Rc ) is notified to the Link1 MAC Entity.

[0124] Based on the information of the obtained Common Block Ack Response Info, the Link1 MAC Entity generates a Common Block Ack (Generate Block Ack) and transmits it to the STA that is the sender (Start Block Ack Tx).

[0125] Figure 14 shows another example of the internal sequence when the AP transmits a Block Ack. Figure 14 shows an example of the internal sequence when the AP transmits a conventional Block Ack based on the bitmap information of the Link Scoreboard, which corresponds to step S1204 in the flowchart shown in Figure 12.

[0126] After completing the reception of the data signal on Link1 (Data Rx End), the Link1 MAC Entity notifies the MLD Entity of the Common Block Ack Request Info including the Originator Address and TID.

[0127] Based on the information of the Common Block Ack Request Info obtained from the Link1 MAC Entity, the MLD Entity confirms that the bitmap information of the same Originator and TID as the sender of the data received on Link1 is not managed in the Common Scoreboard, and notifies the Link1 MAC Entity of the Common Block Ack Response Info that does not include the Common Scoreboard information.

[0128] Based on the information of its own Link1 Scoreboard, the Link1 MAC Entity generates a conventional Block Ack (Generate Block Ack) and transmits it to the STA that is the sender (Start Block Ack Tx).

[0129] E-4. Block Ack Request Phase In the Block Ack Request phase, the STA sends a Block Ack Request (BAR) frame to the AP on an arbitrary link (Link X). In response, the AP sends a Block Ack frame on the same link (Link X). The BAR frame is used not only when the STA wants to obtain a Block Ack, but also when initializing the Scoreboard and Window Start R between the AP and the STA.

[0130] Fig. 15 shows a configuration example of the Block Ack Request (BAR) frame. As described with reference to Fig. 6, the BAR frame is sent by the sender (STA) to request the receiver (AP) to send a Block Ack.

[0131] Regarding the structure of the BAR frame, since it is defined in IEEE802.11, detailed description is omitted here. The present embodiment is characterized in that the Common Scoreboard Update subfield is included in the BAR Control field. Specifically, 1 bit of the Reserved field in the BAR Control field is assigned to the Common Scoreboard Update subfield.

[0132] When the sender sends the BAR frame on either link and wants to request the bitmap information of the receiver's Common Scoreboard, it sets "1" in this Common Scoreboard Update subfield and sends the BAR frame. If only the receiver's Common Scoreboard needs to be updated, the sender may send a BA frame with the RA (Receiver Address) of the BAR frame set to the MAC address assigned to the receiver's MLD Entity.

[0133] FIG. 16 shows, in the form of a flowchart, the processing procedure when the sender transmits a BAR frame. Here, the sender assumes a STA that has transmitted a data frame to the AP.

[0134] When the STA transmits a BAR on a certain link (e.g., Link1) (step S1601), it determines whether to request an update of the Common Scoreboard simultaneously with the Link Scoreboard (step S1602).

[0135] If an update of the Common Scoreboard is requested (Yes in step S1602), the STA sets "1" in the Common Block Ack Update subfield of the BAR frame and transmits the BAR frame (step S1603).

[0136] On the other hand, if an update of the Common Scoreboard is not requested (No in step S1602), the STA sets "0" in the Common Block Ack Update subfield of the BAR frame and transmits the BAR frame (step S1604).

[0137] FIG. 17 shows, in the form of a flowchart, the processing procedure when the receiver receives a BAR frame. Here, the receiver assumes an AP that has received a data frame from the STA.

[0138] When the AP receives a BAR frame on a certain link (e.g., Link1) (step S1701), it updates the Link Scoreboard corresponding to the link on which the BAR was received (step S1702).

[0139] Next, the AP checks whether "1" is set in the Common Scoreboard Update subfield of the BAR frame received in step S1701 (step S1703).

[0140] And when "1" is set in the Common Scoreboard Update subfield (Yes in step S1703), the AP updates the Common Scoreboard (step S1704) and then transmits a Block Ack (step S1705). The update process of the Common Scoreboard is carried out according to the same processing procedure as when receiving data shown in FIG. 9, for example.

[0141] On the other hand, when "0" is set in the Common Scoreboard Update subfield (No in step S1703), the AP transmits a Block Ack (step S1705) without updating the Common Scoreboard.

[0142] FIG. 18 shows an example of an internal sequence when the receiver receives a BAR frame. FIG. 18 corresponds to the case where in the determination step of step S1703 in the flowchart shown in FIG. 17, the Common Scoreboard is updated in step S1704 with Common Scoreboard Update = 1. Here, it is assumed that the AP, which is the receiver, transmits a Block Ack from Link1 after receiving a BAR frame on Link1. The AP is a communication device corresponding to MLO, that is, an MLD, and as shown in FIG. 3, it includes a Link1 MAC Entity and a Link2 MAC Entity that perform individual data processing for each link, and an MLD Entity that performs data processing common to all links.

[0143] When the Link1 MAC Entity finishes receiving the BAR frame (BAR Rx End), it updates its own Link1 Scoreboard (Scoreboard Update).

[0144] Next, when the Link1 MAC Entity confirms that "1" is set in the Common Scoreboard Update subfield of the BAR frame, it sends a Common Scoreboard Update Request including the Originator Address, TID, and Start Sequence Number (SSN) to the MLD Entity.

[0145] The MLD Entity updates the Common Scoreboard based on the information included in the Common Scoreboard Update Request from the Link1 MAC Entity (Common Scoreboard Update). Then, the MLD Entity sends a Common Block Ack Response frame containing the information of the Common Scoreboard (bitmap information, WindowStart, WindowSize, Originator Address, TID) to the Link1 MAC Entity.

[0146] The Link1 MAC Entity generates a Block Ack based on the information included in the Common Block Ack Response from the AP (Generate Block Ack) and starts sending the Block Ack (Start Block Ack Tx).

[0147] Here, for the scoreboard update associated with the Block Ack Request, the following rules apply to both the Link1 Scoreboard and the Common Scoreboard.

[0148] <For the case of BAR for the same sender and the same TID> (1) WindowStart R If ≤ SSN ≤ WindowEnd R Then (1-1) WindowStart R Is set to SSN (1-2)WindowEnd R From +1 to WindowStart R + WindowSize R Set the bitmap from -1 to "0". (1-3)WindowEnd R = WindowStart R + WindowSize R Set to -1 (2)WindowEnd R If <SN ≦ WindowStart R + 2 11 then (2-1)WindowStart R = Set to SSN (2-2)WindowEnd R = WindowStart R + WindowSize R Set to -1 (2-3)WindowStart R From to WindowEnd RC Set the bitmap from to "0". (3)WindowStart Rc + 2 11 If <SN ≦ WindowStart Rc then do not update

[0149] <In the case of BAR for another sender or another TID> (1)WindowStart R = Set to SSN (2)WindowEnd R From +1 to WindowStart R + WindowSize R Set the bitmap from -1 to "0". (3)Initial WindowStart R where the first is and the last is WindowEnd R Create a bitmap of WindowSize R with such a size that

[0150] E-5. Operation Example The first embodiment realizes the generation of a Common Block Ack based on a Partial-state type Common Scoreboard in a communication system corresponding to MLO. In this section, an operation example in the first embodiment will be described.

[0151] FIG. 19 shows an example of a communication sequence of a multi-link operation performed in the communication system shown in FIG. 1. In the communication sequence example shown in FIG. 19, both STA1 and STA2 use Link1 and Link2 to transmit data to the AP.

[0152] Note that the horizontal axis in FIG. 19 is a time axis, showing the communication operations at each time on each link of the AP, STA1, and STA2. The square blocks drawn with solid lines indicate the transmission frames at the corresponding communication devices, links, and times. The vertical solid-line arrows indicate frame transmissions to the destination, and the square blocks drawn with dotted lines indicate the received frames.

[0153] Also, FIG. 20 shows the notation of the bitmap information of each link's Link1 MAC Entity and Common Scoreboard at each time (T1 to T8) in the AP when the communication sequence shown in FIG. 19 is implemented. The Link1 MAC Entity and Common Scoreboard of each link are Partial-state type cache memories capable of temporarily storing information on whether the acquisition of packets for one Block Ack Session was successful. At the left end of the bitmap information of each scoreboard, information that matches the SN indicated by WindowStart R is stored, and at the right end, information that matches the SN indicated by WindowEnd R is stored. At each bit position of the bitmap information, the information on whether the acquisition of the packet corresponding to the SN was successful is represented by 0 and 1. For the SN of a packet that has not been received yet, it is denoted as "0". Also, for the SN of a packet that has already been acquired, it is denoted as "X", but it is assumed that either 0 or 1 is stored in X depending on whether the acquisition of the bucket was successful or failed.

[0154] In FIG. 20, assume that WindowSize = 64, and packets with SNs #1 to #32 are transmitted on Link1 for both STA1 and STA2, and data with SNs #33 to #64 is transmitted on Link2 (that is, it is assumed that STA1 and STA2 each distribute and transmit packets corresponding to the window size to Link1 and Link2). However, the present disclosure is not limited to the above assumption. For example, Link1 and Link2 may contain different numbers of packets, or a number of packets less than WindowSize may be transmitted.

[0155] Also, normally, even if the sender (Originater Address) is the same, if the TID is different, it is different sender information and is managed as a different Block Ack Session in the scoreboard. In FIGS. 19 and 20, for simplicity of explanation, it is assumed that only data with the same TID is transmitted from each sender (STA1, STA2), and each is managed as one Block Ack Session in the scoreboard.

[0156] Hereinafter, the communication sequence shown in FIG. 19 will be described with reference to the status of each scoreboard shown in FIG. 20.

[0157] When STA1 acquires the transmission right of Link1 at time T1, it starts transmitting a data signal obtained by aggregating packets with SNs #1 to #32, and completes the transmission of this aggregated data signal at time T3. During the period from time T1 to T3, bitmap information regarding the success or failure of obtaining packets with SNs #1 to #32 transmitted from STA1 is stored and sequentially updated in the Link1 Scoreboard.

[0158] Also, when STA1 acquires the transmission right of Link2 at time T2, it starts transmitting a data signal obtained by aggregating packets with SNs #33 to #64 with the same TID as Link1, and completes the transmission of this aggregated data signal at time T5. During the period from time T2 to T5, bitmap information regarding the acquisition success or failure of packets with SNs #33 to #64 transmitted from STA1 is stored in the Link2 Scoreboard and sequentially updated.

[0159] On the other hand, STA2 acquires the transmission right of Link1 at time T4. That is, at time T4, the transmitter of Link1 changes from STA1 to STA2. STA2 starts transmitting a data signal obtained by aggregating packets with SNs #1 to #32, and completes the transmission of this aggregated data signal at time T7. After time T4, bitmap information regarding the acquisition success or failure of packets with SNs #1 to #32 transmitted from STA2 is stored in the Link1 Scoreboard and sequentially updated.

[0160] Also, STA2 acquires the transmission right of Link2 at time T6. That is, at time T6, the transmitter of Link2 changes from STA1 to STA2. STA2 starts transmitting a data signal obtained by aggregating packets with SNs #33 to #64 with the same TID as Link1 on Link2, and completes the transmission of this aggregated data signal at time T8. After time T6, bitmap information regarding the acquisition success or failure of packets with SNs #33 to #64 transmitted from STA2 is stored in the Link2 Scoreboard and sequentially updated.

[0161] The MLD Entity of the AP updates the Common Scoreboard according to the update rules described so far.

[0162] Therefore, the AP receives data signals from STA1 on both Link1 and Link2, and the Link1 Scoreboard and Link 2At time T2 when all Scoreboards start managing the bitmap information of STA1 with the same sender and the same TID, the Common Scoreboard is updated, and the bitmap information regarding the success or failure of packet acquisition from STA1 is stored.

[0163] Then, even after time T4 when the sender of Link1 changes from STA1 to STA2, since the Link2 Scoreboard stores the bitmap information regarding the success or failure of packet acquisition from STA1, the Common Scoreboard continues to update the bitmap information regarding the success or failure of packet acquisition from STA1 between times T2 and T5. As a result, at time T5 when the data transmission on Link2 of STA1 ends, the Common Scoreboard stores the bitmap information regarding the success or failure of packet acquisition of SN#1 to #64 transmitted from STA1 on Link1 and Link2 (that is, the success or failure information of the sender and TID for which transmission has been completed). Therefore, the AP can transmit a Common Block Ack to STA1 on Link2 according to the transmission procedure of Block Ack shown in FIG. 12.

[0164] On the other hand, at time T6, the AP receives data signals from STA2 on both Link1 and Link2, and the Link1 Scoreboard and Link 2Since each Scoreboard manages the bitmap information of STA2 with the same sender and the same TID, the Common Scoreboard switches to store the bitmap information regarding the success or failure of packet acquisition from STA2. During times T6 to T8, the Common Scoreboard continuously updates the bitmap information regarding the success or failure of packet acquisition from STA2. At this time, depending on the memory capacity of the Common Scoreboard, the previously stored bitmap information regarding STA1 is deleted (assuming that the Common Scoreboard is a Partial-state type cache memory capable of storing the success or failure information of packet acquisition for one Block Ack Session as in this embodiment, the bitmap information regarding STA1 is deleted by overwriting).

[0165] After that, at time T8 when the data transmission on Link2 of STA2 ends, the Common Scoreboard stores the bitmap information regarding the success or failure of packet acquisition of SN#1 to #64 transmitted from STA2 on Link1 and Link2 (that is, the success or failure information of the sender and TID for which transmission has been completed). Therefore, the AP can transmit a Common Block Ack to STA2 on Link2 according to the Block Ack transmission procedure shown in FIG. 12.

[0166] FIG. 21 shows another communication sequence example of the multi-link operation performed in the communication system shown in FIG. 1. Further, FIG. 22 shows the situation of each scoreboard in the AP at each time when the communication sequence shown in FIG. 21 is implemented.

[0167] When STA1 acquires the transmission right of Link1 at time T1, the SN starts transmitting the data signal obtained by aggregating packets #1 to #32, and completes the transmission of this aggregated data signal at time T5. During the period from time T1 to T5, the Link1 Scoreboard stores and sequentially updates the bitmap information regarding the acquisition success or failure of packets SN#1 to #32 transmitted from STA1.

[0168] Also, when STA1 acquires the transmission right of Link2 at time T2, it starts transmitting the data signal obtained by aggregating packets #33 to #64 with the same TID as Link1, and completes the transmission of this aggregated data signal at time T3. During the period from time T2 to T3, the Link2 Scoreboard stores and sequentially updates the bitmap information regarding the acquisition success or failure of packets SN#33 to #64 transmitted from STA1.

[0169] On the other hand, STA2 acquires the transmission right of Link2 at time T4. That is, at time T4, the transmitter of Link2 changes from STA1 to STA2. STA2 starts transmitting the data signal obtained by aggregating packets #1 to #32, and completes the transmission of this aggregated data signal at time T6. After time T4, the Link2 Scoreboard stores and sequentially updates the bitmap information regarding the acquisition success or failure of packets SN#1 to #32 transmitted from STA2.

[0170] Also, STA2 acquires the transmission right of Link1 at time T7. That is, at time T7, the transmitter of Link1 changes from STA1 to STA2. STA2 starts transmitting the data signal obtained by aggregating packets #33 to #64 with the same TID as Link2, and completes the transmission of this aggregated data signal at time T8. After time T7, the Link1 Scoreboard stores and sequentially updates the bitmap information regarding the acquisition success or failure of packets SN#33 to #64 transmitted from STA2.

[0171] The MLD Entity of the AP updates the Common Scoreboard according to the update rules described so far.

[0172] Therefore, when the AP receives data signals from STA1 on both Link1 and Link2, and at time T2 when both the Link1 Scoreboard and the Link 2 Scoreboard manage the bitmap information of STA1 with the same sender and the same TID, the Common Scoreboard is updated, and the bitmap information regarding the success or failure of packet acquisition from STA1 is stored.

[0173] Also, at time T4 when the sender of Link2 changes from STA1 to STA2, since both the Common Scoreboard and the Link1 Scoreboard store the information on the success or failure of packet acquisition from STA1, during the time period from T2 to T5, the Common Scoreboard continuously updates the bitmap information regarding the success or failure of packet acquisition from STA1. As a result, at time T5 when the data transmission on Link1 of STA1 ends, the Common Scoreboard stores the bitmap information regarding the success or failure of packet acquisition of SN#1~#64 transmitted from STA1 on Link1 and Link2 (that is, the information on the success or failure of acquisition of the sender and TID that have completed transmission). Therefore, the AP can transmit a Common Block Ack to STA1 on Link1 according to the transmission procedure of Block Ack shown in Fig. 12.

[0174] On the other hand, at time T7, the AP receives a data signal from STA2 on Link1, and the Link1 Scoreboard and the Link 2Since all Scoreboards manage the bitmap information of STA2 with the same sender and the same TID, the Common Scoreboard switches to store the bitmap information regarding the success or failure of packet acquisition from STA2. During time T7 to T8, the Common Scoreboard continuously updates the bitmap information regarding the success or failure of packet acquisition from STA2. At this time, depending on the memory capacity of the Common Scoreboard, the previously stored bitmap information regarding STA1 is deleted. Assuming that the Common Scoreboard is a Partial-state type cache memory capable of storing the success or failure information of packet acquisition for one Block Ack Session as in this embodiment, the bitmap information regarding STA1 is deleted by overwriting.

[0175] After that, at time T8 when the data transmission on Link2 of STA2 ends, the Common Scoreboard stores the bitmap information regarding the success or failure of packet acquisition of SN#1 to #64 transmitted from STA2 on Link1 and Link2 (that is, the success or failure information of the sender and TID for which transmission has been completed). Therefore, the AP can transmit a Common Block Ack to STA2 on Link2 according to the Block Ack transmission procedure shown in FIG. 12.

[0176] As shown in FIG. 21, STA1 starts data transmission first on Link1 and then starts data transmission of the same TID on Link2. However, if data transmission ends earlier on Link2 than on Link1, that is, even if the data transmission start time and data transmission end time are reversed between the links, the AP can generate and transmit a Common Block Ack to STA1 by updating the Common Scoreboard according to the update rules according to the present disclosure. Also, although the transmission times of data of the same TID on Link1 and Link2 do not overlap for STA2, the AP can generate and transmit a Common Block Ack to STA2 by updating the Common Scoreboard according to the update rules according to the present disclosure.

[0177] FIG. 23 shows still another communication sequence example of the multi-link operation performed in the communication system shown in FIG. 1. Also, FIG. 24 shows the status of each scoreboard in the AP at each time when the communication sequence shown in FIG. 23 is implemented.

[0178] When STA1 acquires the transmission right of Link1 at time T1, it starts transmitting a data signal obtained by aggregating packets with SNs #1 to #32 and completes the transmission of this aggregated data signal at time T3. During time T1 to T3, bitmap information regarding the acquisition success or failure of packets with SNs #1 to #32 transmitted from STA1 is stored in the Link1 Scoreboard and sequentially updated.

[0179] On the other hand, when STA2 acquires the transmission right of Link2 at time T2, it starts transmitting a data signal obtained by aggregating packets with SNs #1 to #32 and completes the transmission of this aggregated data signal at time T4. During time T2 to T4, bitmap information regarding the acquisition success or failure of packets with SNs #1 to #32 transmitted from STA2 is stored in the Link2 Scoreboard and sequentially updated.

[0180] Also, STA2 acquires the transmission right of Link1 at time T5. That is, at time T5, the transmitter of Link1 changes from STA1 to STA2. STA2 starts transmitting a data signal obtained by aggregating packets with SNs #33 to #64 with the same TID as Link2, and completes the transmission of this aggregated data signal at time T7. After time T5, bitmap information regarding the success or failure of obtaining packets with SNs #33 to #64 transmitted from STA2 is stored in the Link1 Scoreboard and sequentially updated.

[0181] On the other hand, STA1 acquires the transmission right of Link2 at time T6. That is, at time T6, the transmitter of Link2 changes from STA2 to STA1. STA1 starts transmitting a data signal obtained by aggregating packets with SNs #33 to #64 with the same TID as Link1, and completes the transmission of this aggregated data signal at time T8. After time T6, bitmap information regarding the success or failure of obtaining packets with SNs #33 to #64 transmitted from STA1 is stored in the Link2 Scoreboard and sequentially updated.

[0182] The MLD Entity of the AP updates the Common Scoreboard according to the update rules described so far. Therefore, at time T5 when the AP starts managing the bitmap information of STA2 with the same transmitter and the same TID in both the Link1 Scoreboard and the Link2 Scoreboard, the Common Scoreboard is updated, and bitmap information regarding the success or failure of obtaining packets from STA2 is stored.

[0183] Also, at time T6 when the sender of Link2 changes from STA2 to STA1, the information stored in the Common Scoreboard is the bitmap information regarding the success or failure of packet acquisition from STA2. Therefore, at time T7 when the data transmission on Link1 of STA2 ends, the Common Scoreboard stores the bitmap information regarding the success or failure of packet acquisition of SN#1~#64 transmitted from STA2 on Link1 and Link2 (i.e., the success or failure information of the sender and TID that have completed transmission). Therefore, the AP can transmit the Common Block Ack to STA2 on Link1 according to the Block Ack transmission procedure shown in FIG. 12.

[0184] On the other hand, at time T6, the AP starts receiving the data signal from STA1 on Link1. The Link1 Scoreboard manages the bitmap information of STA1, while the Link2 Scoreboard manages the bitmap information of STA2. Since the senders are not the same, the Common Scoreboard is not updated. For this reason, at time T8 when the data transmission on Link1 of STA1 ends, the bitmap information regarding the success or failure of packet acquisition of SN#1~#64 transmitted from STA2 on Link1 and Link2 (i.e., the success or failure information of a sender or TID different from that at the time of transmission completion) remains stored in the Common Scoreboard. Therefore, the AP cannot generate the Common Block Ack according to the Block Ack transmission procedure shown in FIG. 12 and transmits the normal Block Ack to STA1 on Link2.

[0185] In the examples shown in FIGS. 23 and 24, both STA1 and STA2 use Link1 and Link2 to transmit data to the AP. Although STA1 starts data transmission first, STA2 finishes data transmission earlier. That is, the data transmission start time and the data transmission end time are reversed between STA1 and STA2. In such a case, since the acquisition success / failure information of the entire Block Ack Session of STA1 with a later data transmission end time is not stored in the Common Scoreboard, the AP cannot generate and transmit a Common Block Ack to STA1.

[0186] F. Second Embodiment In the first embodiment, a method for generating a Common Block Ack based on a Partial-state type of Common Scoreboard has been described. However, as described with reference to FIGS. 23 and 24, there may be cases where a Common Block Ack cannot be generated and transmitted for some transmitters (STAs). In the examples shown in FIGS. 23 and 24, both STA1 and STA2 use Link1 and Link2 to transmit data to the AP. Since the data transmission start time and the data transmission end time are reversed between STA1 and STA2, the AP cannot generate and transmit a Common Block Ack to STA1 with a later data transmission end time.

[0187] In the Partial-state type of Common Scoreboard as well, depending on the implemented memory, it is possible to store bitmap information of multiple transmitters or multiple TIDs simultaneously. Therefore, as a second embodiment, under the condition that the Partial-state type of Common Scoreboard can store bitmap information of multiple transmitters or multiple TIDs simultaneously, a method for updating the scoreboard of each link based on the bitmap information of the Common Scoreboard will be described below.

[0188] Figure 25 shows, in the form of a flowchart, the processing procedure for the AP to receive data in the Data Transmission phase.

[0189] The AP receives a data signal on a certain link (for example, Link1) and updates the Link Scoreboard of the Link MAC entity corresponding to that link based on the data acquisition success / failure information in the conventional manner (step S2501).

[0190] Next, the AP checks whether to send a Common Block Ack (step S2502). Specifically, the AP checks whether the Block Ack setup including the Common Block Ack has been completed with the STA that is the data sender (originator) and whether the Ack Policy in the MAC Header / QoS Control field of the received packet is "Common BA".

[0191] If the Block Ack setup with the data sender has not been completed or the Ack Policy in the MAC Header / QoS Control field of the received packet is not "Common BA" (No in step S2502), the AP ends this process without updating the Common Scoreboard.

[0192] On the other hand, if the Block Ack setup with the data sender has been completed and the Ack Policy in the MAC Header / QoS Control field of the received packet is "Common BA" (Yes in step S2502), the AP determines whether to update the scoreboard.

[0193] As a determination of whether to update the scoreboard, the AP first checks whether the Common Scoreboard and the Link Scoreboard of the link that received the data manage bitmaps of the same sender and the same TID (step S2503).

[0194] If the Common Scoreboard and the Link Scoreboard of the link that received the data (for example, Link1) manage bitmaps of the same sender and the same TID (Yes in step S2503), the AP updates the bitmap information of the Link Scoreboard of the link that received the data based on the bitmap information of the Common Scoreboard (step S2505) and ends this process. As a result, the acquisition success / failure information of the data received with the same sender and the same TID is sequentially updated in the Link Scoreboard of the link that received the data (for example, Link1).

[0195] If the Common Scoreboard and the Link Scoreboard of the link that received the data (for example, Link1) do not manage bitmaps of the same sender and the same TID (No in step S2503), the AP further checks whether there is room in the storage capacity of the Common Scoreboard (step S2504).

[0196] If there is no room in the storage capacity of the Common Scoreboard (No in step S2504), the AP ends this process without updating the Common Scoreboard.

[0197] On the one hand, if there is sufficient storage capacity in the Common Scoreboard (Yes in step S2505), the AP updates the Common Scoreboard based on the bitmap information of the Link1 Scoreboard (step S2506). As a result, as long as there is sufficient storage capacity, the Common Scoreboard is updated with the acquisition success / failure information of the data received with a new sender or TID.

[0198] FIG. 26 shows an example of the internal sequence when the AP receives a data signal in the Data Transmission phase. FIG. 26 shows an example of the internal sequence when updating the bitmap information of the Common Scoreboard based on the bitmap information of the Link1 MAC Scoreboard, which corresponds to step S2505 in the flowchart shown in FIG. 25. The AP is a communication device corresponding to the MLO, i.e., the MLD, and as shown in FIG. 3, includes a Link1 MAC Entity and a Link2 MAC Entity that perform individual data processing for each link, and an MLD Entity that performs data processing common to all links. In addition, as scoreboards for storing the acquisition success / failure information of data within the AP, there are a Link1 Scoreboard and a Link2 Scoreboard owned by the Link1 MAC Entity and the Link2 MAC Entity, and a Common Scoreboard owned by the MLD Entity.

[0199] When the Link1 MAC Entity updates the Link1 Scoreboard upon receiving data on Link1 (Scoreboard Update), it notifies the MLD Entity of Scoreboard Update Info including the Originator Address, TID, and Updated SN.

[0200] The MLD Entity determines whether to manage the bitmap information of the same sender information (i.e., the same Originator Address and TID) in the Common Scoreboard based on the information obtained from the Link1 MAC Entity (Common Scoreboard Update Decision). This determination process corresponds to step S2503 in the flowchart shown in FIG. 25. Here, it is assumed that the Block Ack setup is completed with the STA that is the data sender (originator), and the Ack Policy in the MAC Header / QoS Control field of the received packet specifies "Common BA".

[0201] Then, when the MLD Entity confirms that the Common Scoreboard also manages the bitmap information with the same Originator Address and TID as the Link1 Scoreboard, it decides to update the Link1 Scoreboard. In this case, the MLD Entity sends the Scoreboard Info including the bitmap information, WindowStart, WindowSize, Originator Address, and TID to the Link1 MAC Entity.

[0202] The Link1 MAC Entity updates the Link1 Scoreboard based on the information of the Common Scoreboard obtained from the MLD Entity (Scoreboard Update). The Link1 MAC Entity updates the Link1 Scoreboard according to the following procedure.

[0203] (1) WindowEnd RL1 = max(WindowEnd RL1 , WindowEnd RcSet it to . That is, update the Link1 Scoreboard according to the larger of the final values of the sequence numbers stored in the Link1 Scoreboard and the Link2 Scoreboard. (2)WindowStart RL1 =WindowEnd RL1 -WindowSize RL1 Set it to +1. (3)WindowStart Rc From WindowStart Rc For each SN within WindowEnd, set "1" in the Link1 Scoreboard indicated by the SN whose bitmap information in the Common Scoreboard is "1".

[0204] FIG. 27 shows another internal sequence example when the AP receives a data signal in the Data Transmission phase. FIG. 27 shows an internal sequence example when updating the bitmap information of the Link1 Scoreboard based on the bitmap information of the Common MAC Scoreboard, which corresponds to step S2506 in the flowchart shown in FIG. 25.

[0205] When the Link1 MAC Entity updates the Link1 Scoreboard upon receiving data on Link1 (Scoreboard Update), it notifies the MLD Entity of the Scoreboard Update Info including the Originator Address, TID, and Updated SN.

[0206] Based on the information obtained from the Link1 MAC Entity, the MLD Entity determines whether to manage the bitmap information of the same sender information (i.e., the same Originator Address and TID) in the Common Scoreboard (Common Scoreboard Update Decision).

[0207] When the MLD Entity confirms that the Common Scoreboard and the Link1 Scoreboard do not manage the bitmap information of the same Originator Address and TID and that there is sufficient memory capacity in the Common Scoreboard, it decides to update the Common Scoreboard. In this case, the MLD Entity sends a Scoreboard Request to the Link1 MAC Entity.

[0208] In response to the Scoreboard Request from the MLD Entity, the Link1 MAC Entity sends Scoreboard Info including bitmap information, WindowStart, WindowEnd, Originator Address, and TID.

[0209] Then, based on the Scoreboard Info collected from the Link1 MAC Entity and the Link2 MAC Entity, the MLD Entity updates the Common Scoreboard according to the following procedure (Common Scoreboard Update).

[0210] (1) WindowEnd Rc Set it to SN. (2) WindowStart Rc = WindowEnd Rc - WindowSize Rc + 1. (3) Generate a bitmap of size WindowSize such that the first is WindowStart Rc and the last is WindowEnd Rc (initially enter all 0s). Rc (4) Set "1" at the location indicated by the SN of the bitmap information in the Common Scoreboard. (4) Set "1" at the location indicated by the SN of the bitmap information in the Common Scoreboard.

[0211] FIG. 28 shows, in the form of a flowchart, the processing procedure for the AP to transmit a Block Ack.

[0212] When the AP completes receiving a data signal on a certain link (e.g., Link1) (step S2801), it generates a Block Ack based on the information in the Link Scoreboard of the link (e.g., Link1) on which the data signal was received, and transmits it to the STA that is the sender (step S2802), and ends this processing.

[0213] According to the processing procedure shown in FIG. 28, the acquisition success / failure information of packets from the same sender and the same TID in the Link Scoreboard of the link that has received data is sequentially updated. Therefore, in step S2802 above, the AP can generate and transmit a Common Block Ack.

[0214] FIG. 29 shows an example of a communication sequence of multi-link operation performed in the communication system shown in FIG. 1. Similar to FIG. 23, in the communication sequence example shown in FIG. 29, both TA1 and STA2 use Link1 and Link2 to transmit data to the AP, but the data transmission start time and the data transmission end time are reversed between STA1 and STA2.

[0215] Note that the horizontal axis in FIG. 29 is a time axis, showing the communication operations at each time on each link of the AP, STA1, and STA2. The square blocks drawn with solid lines indicate the transmission frames at the corresponding communication devices, links, and times, the vertical solid-line arrows indicate frame transmissions to the destinations, and the square blocks drawn with dotted lines indicate the received frames.

[0216] Also, FIG. 30 shows the notation of the bitmap information of each link's Link1 MAC Entity and Common Scoreboard in the AP at each time when the communication sequence shown in FIG. 29 is implemented. At the left end of each bitmap information is WindowStart R , and at the right end is WindowEnd RInformation that matches the SN shown is stored. On the bitmap, at each bit position, the success or failure information of obtaining the packet with the corresponding SN is represented by 0 and 1. For the SN of the packet that has not been received yet, it is denoted as "0". Also, for the SN of the packet that has already been obtained, it is denoted as "X", and either 0 or 1 is stored in X according to the success or failure of obtaining the bucket.

[0217] Normally, the TID value is also involved in the management of the scoreboard. Here, for the sake of simplicity of explanation, it is assumed that only data with the same TID is transmitted. Also, here, it is assumed that WindowSize = 64, and packets with SNs #1 to #32 are transmitted on Link1 for both STA1 and STA2, and data with SNs #33 to #64 is transmitted on Link2. However, the present disclosure is not limited to the above assumptions. For example, different numbers of packets may be included in Link1 and Link2, or a number of packets less than WindowSize may be transmitted.

[0218] Hereinafter, the communication sequence shown in FIG. 29 will be described with reference to the status of each scoreboard shown in FIG. 30.

[0219] When STA1 acquires the transmission right of Link1 at time T1, it starts transmitting a data signal obtained by aggregating packets with SNs #1 to #32, and completes the transmission of this aggregated data signal at time T3. During the time from T1 to T3, in the Link1 Scoreboard, bitmap information regarding the success or failure of obtaining the packets with SNs #1 to #32 transmitted from STA1 is stored and sequentially updated.

[0220] During the time from T1 to T3, since there is room in the memory capacity of the Common Scoreboard, bitmap information regarding the success or failure of obtaining the packets with SNs #1 to #32 transmitted from STA1 on Link1 is also stored in the Common Scoreboard and sequentially updated.

[0221] On one hand, when STA2 acquires the transmission right of Link2 at time T2, the SN starts transmitting the data signal aggregated from packets #1 to #32, and completes the transmission of this aggregated data signal at time T4. During the period from time T2 to T4, the Link2 Scoreboard stores and sequentially updates the bitmap information regarding the success or failure of acquiring packets #1 to #32 transmitted from STA2.

[0222] During the period from time T2 to T4, the Common Scoreboard manages the bitmap information of STA1, which is a different transmitter from the Link2 Scoreboard. Since there is sufficient memory capacity, the Common Scoreboard also stores and sequentially updates the bitmap information regarding the success or failure of acquiring packets #1 to #32 transmitted from STA2 on Link2.

[0223] Also, STA2 acquires the transmission right of Link1 at time T5. That is, at time T5, the transmitter of Link1 changes from STA1 to STA2. STA2 starts transmitting the data signal aggregated from packets #33 to #64 with the same TID as Link2, and completes the transmission of this aggregated data signal at time T7. After time T5, the Link1 Scoreboard stores and sequentially updates the bitmap information regarding the success or failure of acquiring packets #33 to #64 transmitted from STA2.

[0224] Even during times T5 to T7, since the Common Scoreboard manages the bitmap information of STA2, which is the same sender as the Link1 Scoreboard, the bitmap information of the Link1 Scoreboard is updated based on the Common Scoreboard. Therefore, at time T7 when the data transmission on Link1 of STA2 ends, the Link1 Scoreboard stores bitmap information regarding the success or failure of acquiring packets SN#1 to #64 transmitted from STA2 on Link1 and Link2 (i.e., the success or failure information of the sender and TID for which transmission has been completed). Thus, the AP can transmit a Common Block Ack to STA2 on Link1 based on the bitmap information stored in the Link1 Scoreboard according to the Block Ack transmission procedure shown in FIG. 28.

[0225] Also, STA1 acquires the right to transmit on Link2 at time T6. That is, at time T6, the sender of Link2 changes from STA2 to STA1. STA1 starts transmitting a data signal obtained by aggregating packets with SNs #33 to #64 with the same TID as Link1 and completes the transmission of this aggregated data signal at time T8. After time T6, the Link1 Scoreboard stores and sequentially updates bitmap information regarding the success or failure of acquiring packets SN#33 to #64 transmitted from STA1.

[0226] At this point, since the Common Scoreboard manages the bitmap information of STA1, which is the same sender as the Link2 Scoreboard, the bitmap information of the Link2 Scoreboard is updated based on the Common Scoreboard. As a result, at time T8 when the data transmission on Link1 of STA2 ends, the Link2 Scoreboard stores bitmap information regarding the success or failure of packet acquisition for SN#1 to #64 packets transmitted from STA1 on Link1 and Link2 (i.e., the success or failure information of the sender and TID for which transmission has been completed). Therefore, the AP can transmit a Common Block Ack to STA1 on Link2 based on the bitmap information stored in the Link2 Scoreboard according to the Block Ack transmission procedure shown in FIG. 28.

[0227] G. Effects In this section, the effects obtained by the present disclosure will be summarized.

[0228] (1) The communication device corresponding to MLO to which the present disclosure is applied includes a Link Scoreboard that manages the success or failure information of received packet acquisition for each link, and a Common Scoreboard that manages the success or failure information of received packet acquisition for a plurality of links. However, the Common Scoreboard is managed in a cache type, and a Common Block Ack including the success or failure information of received packet acquisition for a plurality of links can be transmitted with high reliability, and the Common Scoreboard can be implemented with an inexpensive memory.

[0229] (2) The communication device to which the present disclosure is applied exchanges Capability information indicating whether it is possible to manage the success or failure information of received packet acquisition for a plurality of links using the Common Scoreboard with other communication devices. Therefore, the data sender can determine whether it is possible to generate a Common Block Ack on the receiving side and correctly set the Ack Policy.

[0230] (3) According to the present disclosure, the data sender adds and transmits information on whether to update the Common Scoreboard by a Block Ack Request. Therefore, the receiving side can update the Common Scoreboard simultaneously with the Link Scoreboard.

[0231] (4) The communication device corresponding to MLO to which the present disclosure is applied updates the Link Scoreboard based on the information of the Common Scoreboard. Therefore, even in a situation where a plurality of data senders alternately transmit using a plurality of links respectively, it is possible to generate and transmit a Common Block Ack.

Industrial Applicability

[0232] As described above, the present disclosure has been described in detail with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions to the embodiments without departing from the gist of the present disclosure.

[0233] For example, by applying the present disclosure to a wireless LAN system conforming to the IEEE802.11 standard, of course, the same effect can be achieved even if the present disclosure is applied to a wireless system performing multi-link communication in accordance with other communication standards.

[0234] In short, the present disclosure has been described in the form of examples, and the description in this specification should not be construed restrictively. To determine the gist of the present disclosure, the scope of the claims should be referred to.

[0235] Note that the present disclosure can also have the following configuration.

[0236] (1) A communication device that performs wireless communication using a plurality of links, It has a cache-type common storage unit that stores whether the acquisition of packets received through a plurality of links was successful, and a common data processing unit that performs common data processing on the packets received through each link, a control unit that controls the transmission of a response signal for the received packet, and is equipped with The control unit generates a common response signal including the acquisition success information received through the plurality of links based on the acquisition success information held by the common storage unit. A communication device.

[0237] (2) It further has an individual storage unit that stores the acquisition success information of the packets received through each individual link, and an individual data processing unit that performs individual data processing on the packets received through each individual link. The communication device according to (1) above.

[0238] (3) The control unit performs an update process on the common storage unit based on the acquisition success information regarding the same sender information stored in the common storage unit and the individual storage unit. The communication device according to (2) above.

[0239] (4) When the individual storage unit stores the acquisition success information regarding the same sender information as the common storage unit, the control unit performs an update process on the common storage unit based on the acquisition success information regarding the same sender information stored in the individual storage unit. The communication device according to (3) above.

[0240] (5) When the individual storage unit does not store the acquisition success information regarding the same sender information as the common storage unit, but each individual storage unit of the plurality of links stores the acquisition success information regarding the same sender information, the control unit performs an update process on the common storage unit based on the acquisition success information regarding the same sender information stored in each individual storage unit of the plurality of links. The communication device according to any one of (3) or (4) above.

[0241] (6) The control unit performs an update process on the common storage unit in accordance with the larger final value of the sequence numbers stored in the individual storage units of the plurality of links. The communication device according to (5) above.

[0242] (7) For the sequence numbers for which it is shown that at least one of the individual storage units of the plurality of links has succeeded in acquisition, the control unit sets a value indicating that acquisition has also succeeded in the acquisition success / failure information of the common storage unit. The communication device according to any one of (5) or (6) above.

[0243] (8) The control unit controls to exchange information regarding the manageability of the common storage unit with the sender of the packet. The communication device according to any one of (1) to (7) above.

[0244] (9) When the control unit has confirmed that the common storage unit can be managed with the sender and the transmission of the common response signal is requested by the header of the received data signal, the control unit attempts to update the common storage unit. The communication device according to (8) above.

[0245] (10) The control unit determines whether to generate the common signal based on the sender information managed by the common storage unit. The communication device according to any one of (1) to (9) above.

[0246] (11) When the common storage unit stores acquisition success / failure information regarding the same sender information as that of the received packet, the control unit generates the common response signal based on the acquisition success / failure information stored in the common storage unit. However, when the common storage unit does not store acquisition success / failure information regarding the same sender information as that of the received packet, the control unit generates the individual response signal based on the acquisition success / failure information stored in the individual storage unit of the link that received the packet. The communication device according to (10) above.

[0247] (12) The control unit determines whether to update the common storage unit based on the information included in the response request signal received from the sender. The communication device according to any one of (1) to (11) above.

[0248] (13) The control unit performs an update process on the individual storage unit based on the acquisition success / failure information regarding the same sender information stored in the common storage unit and the individual storage unit. The communication device according to (2) above.

[0249] (14) A communication method for performing wireless communication using a plurality of links, A common data processing step of performing common data processing on the packets received on each link, using a cache-type common storage unit that stores the acquisition success / failure of the packets received on the plurality of links; A control step of controlling the transmission of a response signal for the received packet; and in the control step, a common response signal including the acquisition success / failure information received on the plurality of links is generated based on the acquisition success / failure information held by the common storage unit. Communication method.

[0250] (15) A communication unit that performs wireless communication using a plurality of links, A control unit that controls the wireless communication operation in the communication unit; and when transmitting a data signal on the plurality of links, the control unit notifies whether there is a request for a common response signal including the acquisition success / failure information regarding the reception of the data signal on the plurality of links. Communication device.

[0251] (16) The control unit controls to transmit a response request signal that requests the transmission of the common response signal. The communication device according to (15) above.

[0252] (17) The control unit controls to transmit the response request signal in order to initialize a common storage unit that stores acquisition success / failure information regarding reception of data signals in the plurality of links. The communication device according to (16) above.

[0253] (18) A communication method for performing wireless communication using a plurality of links, notifying the presence or absence of a request for a common response signal including acquisition success / failure information regarding reception of data signals in the plurality of links, and transmitting a data signal; receiving a response signal; A communication method comprising:

Explanation of Signs

[0254] 200... Communication device, 210... Communication unit, 211... Communication control unit 212... Communication storage unit, 213... Common data processing unit 214... Individual data processing unit, 215... Signal processing unit 216... Wireless interface unit, 217... Amplification unit, 220... Control unit 230... Storage unit, 240... Antenna

Claims

1. A communication device that performs wireless communication using a plurality of links, having a cache-type common storage unit that stores whether acquisition of packets received via the plurality of links was successful, and a common data processing unit that performs common data processing on the packets received via each link; having an individual storage unit that stores whether acquisition of packets received via individual links was successful, and an individual data processing unit that performs individual data processing on the packets received via individual links; a control unit that controls transmission of a response signal for the received packet; comprising: The control unit: performs an update process on the common storage unit based on information on whether acquisition was successful regarding the same sender information stored in the common storage unit and the individual storage unit; generates a common response signal including information on whether acquisition was successful received via the plurality of links based on the information on whether acquisition was successful held by the common storage unit; A communication device.

2. When the individual storage unit stores information on whether acquisition was successful regarding the same sender information as the common storage unit, the control unit performs an update process on the common storage unit based on the information on whether acquisition was successful regarding the same sender information stored in the individual storage unit. The communication device according to Claim 1.

3. When the individual storage unit does not store information on whether acquisition was successful regarding the same sender information as the common storage unit, but each individual storage unit of the plurality of links stores information on whether acquisition was successful regarding the same sender information, the control unit performs an update process on the common storage unit based on the information on whether acquisition was successful regarding the same sender information stored in each individual storage unit of the plurality of links. The communication device according to Claim 1.

4. The control unit performs an update process on the common storage unit in accordance with the larger final value of the sequence numbers stored in each individual storage unit of the plurality of links. The communication device according to Claim 3.

5. For sequence numbers shown to have been successfully acquired by at least one of the individual storage units of the plurality of links, the control unit sets a value indicating successful acquisition in the information on whether acquisition was successful in the common storage unit. The communication device according to Claim 3.

6. The control unit controls so as to exchange information on whether the common storage unit can be managed with the sender of the packet. The communication device according to Claim 1.

7. When the control unit has confirmed that it can manage the common storage unit with the sender and the transmission of the common response signal is requested by the header of the received data signal, the control unit attempts to update the common storage unit. The communication device according to claim 6.

8. The control unit determines whether to generate the common response signal based on the sender information managed by the common storage unit. The communication device according to claim 1.

9. When the common storage unit stores acquisition success / failure information regarding the same sender information as that of the received packet, the control unit generates the common response signal based on the acquisition success / failure information stored in the common storage unit. However, when the common storage unit does not store acquisition success / failure information regarding the same sender information as that of the received packet, the control unit generates an individual response signal based on the acquisition success / failure information stored in the individual storage unit of the link that received the packet. The communication device according to claim 8.

10. The control unit determines whether to update the common storage unit based on the information included in the response request signal received from the sender. The communication device according to claim 1.

11. The control unit performs an update process of the individual storage unit based on the acquisition success / failure information regarding the same sender information stored in the common storage unit and the individual storage unit. The communication device according to claim 1.

12. A communication method for performing wireless communication using a plurality of links, A common data processing step of performing common data processing on the packets received on each link, using a cache-type common storage unit that stores the acquisition success / failure of the packets received on the plurality of links, An individual data processing step of performing individual data processing on the packets received on each individual link, using an individual storage unit that stores the acquisition success / failure information of the packets received on each individual link, A control step of controlling the transmission of a response signal for the received packet, having In the control step, Based on the acquisition success / failure information regarding the same sender information stored in the common storage unit and the individual storage unit, an update process of the common storage unit is performed. A common response signal including the acquisition success / failure information received on the plurality of links is generated based on the acquisition success / failure information held by the common storage unit. Communication method.

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