Integrated circuit with

Abstract

To improve efficiency of retransmission control in cooperative communication.SOLUTION: When the received control information indicates a combination of another base station from which the response signal is not received among the base stations involved in the inter-base-station cooperative communication and a transmission source of the response signal, the integrated circuit determines transmission of the response signal from the transmission source to the other base station.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a base station, a communication device, and a communication method. [Background technology]

[0002] The Institute of Electrical and Electronics Engineers (IEEE) is currently studying the IEEE 802.11be (hereinafter referred to as "11be") standard for next-generation wireless local area networks (LANs), which will be the successor to the IEEE 802.11ax (hereinafter referred to as "11ax"). For example, IEEE 802.ax is also known as High Efficiency (HE), and IEEE 802.be is also known as Extreme High Throughput (EHT). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] IEEE 802.11-20 / 0566r99, Compendium of straw polls and potential changes to the Specification Framework Document [Non-patent document 2] IEEE 802.11-19 / 1533r0, Consideration on Multi-AP Ack Protocol [Non-patent document 3] IEEE 802.11-20 / 0590r5, Coordinated Spatial Reuse: Focus on Downlink [Non-patent document 4] IEEE P802.11ax™ / D8.0 [Non-Patent Document 5] IEEE P802.11-REVmdTM / D5.0 Summary of the Invention

[0004] However, retransmission control of cooperative communication in wireless communication such as wireless LAN has not been fully studied.

[0005] Non-limiting examples of the present disclosure contribute to providing a base station, a communication device, and a communication method that can improve the efficiency of retransmission control in cooperative communication.

[0006] A base station according to one embodiment of the present disclosure includes a receiving circuit that receives control information regarding sharing of a response signal to a downlink signal in inter-base station cooperative communication, and a control circuit that controls transmission of the response signal to other base stations based on the control information.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to an embodiment of the present disclosure, it is possible to improve the efficiency of retransmission control in cooperative communication.

[0009] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0010] [Figure 1] A diagram showing an example of a Multi-AP (multi-access point, MAP) configuration [Figure 2] FIG. 1 is a diagram illustrating an example of a communication environment in which downlink and uplink coverage are different. [Figure 3]A diagram showing an example of a MAP control sequence. [Figure 4] A diagram showing an example of a MAP control sequence. [Figure 5] FIG. 1 is a block diagram showing a configuration example of a part of an AP according to a first embodiment; [Figure 6] FIG. 1 is a block diagram showing an example of the configuration of an AP according to a first embodiment; [Figure 7] FIG. 1 is a block diagram showing an example of the configuration of an STA according to a first embodiment; [Figure 8] FIG. 10 is a diagram showing an example of a control sequence of MAP according to the first embodiment. [Figure 9] An example of a Block ACK (BA) request frame [Figure 10] Figure showing an example of a BA request definition in the Frame Control field [Figure 11] A diagram showing an example of a BA request definition in the Trigger Type subfield [Figure 12] A diagram showing an example of a BA request definition in a BlockAckReq frame variant [Figure 13] Figure 10 shows an example of a BA sharing request frame [Figure 14] Figure showing an example of a BA sharing request definition in the Frame Control field [Figure 15] A diagram showing an example of a BA sharing request definition in the Trigger Type subfield [Figure 16] A diagram showing an example of a BA sharing request definition in the BlockAckReq frame variant [Figure 17] A diagram showing an example of a BA shared frame [Figure 18] Figure showing an example of BA sharing definition in the Frame Control field [Figure 19] A diagram showing an example of BA sharing definition in BlockAck frame variant [Figure 20] FIG. 10 is a diagram showing an example of a control sequence of MAP according to the second embodiment. [Figure 21]Figure 10 shows an example of a BA sharing request frame [Figure 22] Figure showing an example of a BA sharing request definition in the Frame Control field [Figure 23] A diagram showing an example of a BA sharing request definition in the Trigger Type subfield [Figure 24] A diagram showing an example of a BA sharing request definition in the BlockAckReq frame variant [Figure 25] A diagram showing an example of a BA shared frame [Figure 26] Figure showing an example of BA sharing definition in the Frame Control field [Figure 27] A diagram showing an example of BA sharing definition in BlockAck frame variant [Figure 28] FIG. 10 is a diagram showing an example of a control sequence of MAP according to the third embodiment. [Figure 29] A diagram showing an example of the MAP trigger frame configuration [Figure 30] A diagram showing an example of the MAP trigger frame configuration [Figure 31] A diagram showing an example of a BA shared frame [Figure 32] Figure showing an example of BA sharing definition in the Frame Control field [Figure 33] A diagram showing an example of BA sharing definition in BlockAck frame variant [Figure 34] FIG. 13 is a diagram showing an example of a control sequence of MAP according to the fourth embodiment. [Figure 35] A diagram showing an example of the MAP trigger frame configuration [Figure 36] Diagram showing an example of a line configuration between Shared APs [Figure 37] FIG. 13 is a diagram showing an example of a control sequence of MAP according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings.

[0012] [Multi-Access Point coordination] In 11be, for example, the application of Multi-AP (hereinafter referred to as "MAP") coordination (hereinafter also referred to as "cooperative communication" or "cooperative communication between base stations") has been considered, in which multiple access points (APs: Access Point, also called "base stations") cooperate to send and receive data between each terminal (STAs: Station, also called "non-AP STA") (see, for example, Non-Patent Documents 1 to 3).

[0013] Joint Transmissions (hereinafter referred to as "JT") is one of the MAP coordination schemes (also referred to as "communication types" or "MAP types") in 11be. JT includes, for example, a method of transmitting the same signal from multiple cooperating APs and a method of transmitting different transmission streams from multiple cooperating APs. The method of transmitting different transmission streams from multiple cooperating APs is called, for example, Distributed Multi-User - Multiple Input Multiple Output (D-MIMO).

[0014] IEEE 802.11 defines an Acknowledgement (ACK) frame as an acknowledgement signal for Quality of Service (QoS) data, and a Block Ack frame that returns responses to multiple frames together (see, for example, Non-Patent Documents 4 or 5).

[0015] FIG. 1 is a diagram showing an example of the configuration of APs and STAs (an example of the configuration of MAPs) that perform cooperative communication.

[0016] 1, a "Sharing AP" may be, for example, an AP that acquires a channel use (or transmission) period (e.g., a TXOP (transmission opportunity)) and initiates (or controls) cooperative communication. Also, a "Shared AP" may be an AP that is instructed to perform cooperative communication by the Sharing AP.

[0017] In the example shown in FIG. 1, one of the Shared APs (for example, AP1) also functions as a Sharing AP, but the present invention is not limited to this, and the Sharing AP and the Shared AP may be different APs.

[0018] 1, STA a is associated (may also be referred to as "connected") to Sharing AP (AP1) and performs cooperative communication between Sharing AP (AP1) and Shared AP (AP2). Also, in the example of FIG. 1, STA b is associated with Shared AP (AP2) and performs cooperative communication between Sharing AP (AP1), Shared AP (AP2), and Shared AP (AP3).

[0019] For example, a STA receives downlink data from an AP and transmits an ACK or a Block ACK to the AP with which the STA is associated. Also, for example, when the MAP coordination scheme is JT, it is expected that ACKs or Block ACKs are exchanged between shared APs (see, for example, Non-Patent Document 2).

[0020] [Retransmission control in MAP coordination] 2 is a diagram showing an example of a communication environment in which the coverage (communicable range) differs between the downlink and the uplink. Note that the connection relationship between AP1, AP2, AP3, STA a, and STA b shown in FIG. 2 may be the same as the connection relationship between the APs and STAs shown in FIG.

[0021] As shown in Figure 2, STA a exists (or is located) within the downlink coverage of each of Sharing AP (AP1) and Shared AP (AP2; the same applies below). Also, Sharing AP (AP1) and Shared AP (AP2) exist within the uplink coverage of STA a. Therefore, Sharing AP (AP1) and Shared AP (AP2) receive (e.g., simultaneously receive) a response (e.g., an ACK or Block ACK for downlink data) from STA a.

[0022] Also, as shown in FIG. 2, STA b is present within the downlink coverage of each of Sharing AP (AP1), Shared AP (AP2), and Shared AP (AP3). Meanwhile, Shared AP (AP2) and Shared AP (AP3) are present within the uplink coverage of STA b, but Sharing AP (AP1) is outside the uplink coverage of STA b. Therefore, for example, Sharing AP (AP1), Shared AP (AP2), and Shared AP (AP3) may not receive (e.g., simultaneously receive) a response (e.g., an ACK or Block ACK for downlink data) from STA b. For example, Sharing AP (AP1) may not receive an ACK or Block ACK from STA b.

[0023] FIG. 3 is a diagram showing an example of a control sequence of the MAP in the communication environment shown in FIG.

[0024] 3, for example, the Sharing AP (AP1) transmits a MAP trigger frame (also called a MAP Announcement frame) to the Shared APs (AP2 and AP3), which is a trigger to start transmitting data related to MAP. After transmitting and receiving the MAP trigger frame, the Sharing AP (AP1) and the Shared APs (AP2 and AP3) may simultaneously transmit data (for example, initial transmission data).

[0025] STA a and STA b receive data from each AP and transmit (or feed back) an ACK or block ACK (represented as "BA" in the example of Figure 3) to each AP indicating whether the data was successfully received (or decoded).

[0026] Here, as shown in FIG. 2, for STA b, the Sharing AP (AP1) is outside the uplink coverage of STA b, so in the example of FIG. 3, an ACK or Block ACK transmitted from STA b does not reach the Sharing AP (AP1). Since the Sharing AP (AP1) does not receive the ACK or Block ACK from STA b, it may decide to retransmit the data, for example. In this way, unnecessary retransmission may occur even though STA b has successfully received the data.

[0027] Next, FIG. 4 is a diagram showing an example of a control sequence in the retransmission phase following the operation shown in FIG.

[0028] 4, for example, the Sharing AP (AP1) transmits a MAP trigger frame to the Shared APs (AP2 and AP3) even during retransmission. After transmitting and receiving the MAP trigger frame, the Sharing AP (AP1) and the Shared APs (AP2 and AP3) may simultaneously transmit data (e.g., retransmitted data).

[0029] 4, if the ACK or Block ACK transmitted from STA b does not reach the Shared AP (AP1), the Shared AP (AP1) decides to retransmit the data, as in the example shown in FIG. 3. In this way, if the Shared AP (AP1) decides to retransmit the data even though STA b has received the data successfully, the Shared APs (AP2 and AP3) that received the ACK or Block ACK from STA b will also retransmit the data, which may result in unnecessary retransmission.

[0030] In this way, in MAP coordination, if there is a Shared AP that does not receive an ACK or Block ACK from each STA, unnecessary retransmission may occur. Also, for example, a method for sharing information about the ACK or Block ACK of each STA between Shared APs (or between a Sharing AP and a Shared AP) has not been fully considered.

[0031] Therefore, in one embodiment of the present disclosure, a method for improving the efficiency of retransmission control during MAP operation will be described. For example, after the AP receives an ACK or Block ACK from each STA, a "sharing phase (or BA sharing phase)" is provided in which the ACK or Block ACK is shared, thereby allowing the Sharing AP and the Shared AP to share the ACK or Block ACK.

[0032] It should be noted that the term "phase" may be replaced with other terms such as "period," "sequence," or "procedure."

[0033] [Wireless communication system configuration] The wireless communication system according to this embodiment may include a plurality of APs 100 and STAs 200. The AP 100 may have the functions of both a Sharing AP and a Shared AP, or may have the functions of only one of them, for example.

[0034] 5 is a block diagram illustrating a configuration example of a portion of an AP 100 according to an embodiment of the present disclosure. In the AP 100 illustrated in FIG. 4, a wireless transceiver 105 (e.g., a receiver circuit) receives control information related to sharing of response signals (e.g., ACK or Block Ack) to downlink signals in inter-base station coordinated communication (e.g., MAP coordination). A control unit 101 (e.g., a control circuit) controls transmission of the response signals to other base stations based on the control information.

[0035] (Embodiment 1) [AP100 configuration example] Fig. 6 is a block diagram showing an example configuration of AP 100. AP 100 shown in Fig. 6 may include, for example, a control unit 101, a STA-directed control signal generation unit 102, an AP-directed control signal generation unit 103, a transmission signal generation unit 104, a wireless transmission / reception unit 105, and a received signal demodulation / decoding unit 106.

[0036] The control unit 101 may, for example, control the setting of a MAP Trigger frame. For example, when the AP 100 is a Sharing AP, the control unit 101 may control the generation of a control signal (for example, a MAP Trigger frame) for another AP 100 (for example, a Shared AP). The control unit 101 may also perform control related to the sharing of an ACK or a Block ACK, for example. For example, the control unit 101 may determine whether or not to share an ACK or a Block ACK from each STA 200 with another AP 100, based on control information for controlling the sharing of an ACK or a Block ACK input from the received signal demodulation and decoding unit 106.

[0037] An example of a control method for sharing an ACK or a Block Ack in the AP 100 will be described later.

[0038] Furthermore, the control unit 101 may set, for example, control information for the STA 200 or other AP 100. For example, the control unit 101 may set resource allocation information and scheduling information such as MCS for each STA 200. Furthermore, the control unit 101 may determine parameters related to transmission control (for example, parameters related to the above-mentioned cooperative communication) based on, for example, information input from the received signal demodulation and decoding unit 106 (for example, control information notified from the Sharing AP to the Shared AP). The control unit 101 may output, for example, control information including the determined transmission control parameters to the STA-directed control signal generation unit 102 and the AP-directed control signal generation unit 103.

[0039] The STA-directed control signal generating unit 102 may generate a control signal (eg, a trigger frame) for the STA 200 and output the generated control signal to the transmission signal generating unit 104, for example.

[0040] The AP-directed control signal generating unit 103 may generate, for example, a control signal for the AP 100. The control signal for the AP 100 may include, for example, a MAP Trigger frame or a control frame related to sharing of an ACK or a Block ACK. For example, the AP-directed control signal generating unit 103 may generate a control signal based on control information input from the control unit 101 and information input from the received signal demodulating and decoding unit 106. The AP-directed control signal generating unit 103 outputs the generated control signal to the transmission signal generating unit 104, for example.

[0041] The transmission signal generating unit 104 may perform transmission processing on, for example, a control signal, or data and ACK / Block ACK, input from the STA-directed control signal generating unit 102 or the AP-directed control signal generating unit 103, and generate a wireless frame (transmission signal). The transmission signal generating unit 104 outputs the generated transmission signal to the wireless transmitting and receiving unit 105.

[0042] The radio transmission / reception unit 105 performs radio transmission processing such as D / A conversion and up-conversion to a carrier frequency on the transmission signal input from the transmission signal generation unit 104, and transmits the signal after radio transmission processing via an antenna.

[0043] For example, when the AP 100 receives an uplink signal transmitted from the STA 200 or a control signal transmitted from another AP 100, the AP 100 may operate as follows.

[0044] A radio signal received via an antenna is input to the radio transmission / reception unit 105. The radio transmission / reception unit 105 performs radio reception processing, such as down-conversion of the carrier frequency, on the received radio signal, and outputs the signal after radio reception processing to the received signal demodulation / decoding unit 106.

[0045] The received signal demodulation and decoding unit 106 may, for example, perform processing such as autocorrelation processing on the signal input from the wireless transceiver unit 105 and extract the received wireless frame. The received signal demodulation and decoding unit 106 may also decode and demodulate, for example, an uplink signal from the STA 200 (e.g., a response signal, feedback information) or a control signal from another AP 100 (e.g., a MAP Trigger frame, or a control frame related to sharing of an ACK or Block ACK), which are included in the extracted wireless frame. The received signal demodulation and decoding unit 106 may, for example, output the demodulated control signal to the control unit 101, the STA-directed control signal generation unit 102, and the AP-directed control signal generation unit 103.

[0046] [STA200 configuration example] 7 is a block diagram showing an example configuration of STA 200 according to this embodiment. STA 200 shown in FIG. 7 may include, for example, a radio transmission / reception unit 201, a received signal demodulation / decoding unit 202, and a transmission signal generation unit 203.

[0047] The wireless transceiver 201 receives, for example, a signal transmitted from the AP 100 via an antenna, performs wireless reception processing such as down-conversion and A / D conversion on the received signal, and outputs the signal after wireless reception processing to the received signal demodulation and decoding unit 202. The wireless transceiver 201 may also perform wireless transmission processing such as D / A conversion and up-conversion to a carrier frequency on a signal input from the transmission signal generation unit 203, and transmit the signal after wireless transmission processing via the antenna.

[0048] The received signal demodulation and decoding unit 202 may, for example, perform processing such as autocorrelation processing on the signal input from the radio transmission / reception unit 201 to extract the received radio frame. The received signal demodulation and decoding unit 202 may, for example, demodulate and decode a control signal (e.g., a trigger frame) included in the extracted radio frame to obtain uplink transmission control parameters. The received signal demodulation and decoding unit 202 may, for example, output the obtained uplink transmission control parameters to the transmission signal generation unit 203.

[0049] The transmission signal generation unit 203 may perform transmission signal processing on an uplink signal (e.g., an ACK or block ACK for a downlink signal) and generate a radio frame (transmission signal) based on, for example, the uplink transmission control parameters input from the reception signal demodulation and decoding unit 202. The transmission signal generation unit 203 outputs the generated transmission signal to the radio transmission and reception unit 201, for example.

[0050] [Example of AP100 and STA200 operation] Next, an example of the operation of the AP 100 and the STA 200 according to this embodiment will be described.

[0051] In this embodiment, for example, an AP that controls the sharing of ACKs or Block ACKs is defined as a “BA controlling AP.” The BA controlling AP may aggregate information related to ACKs or Block ACKs and control the sharing of ACKs or Block ACKs among Sharing APs and Shared APs.

[0052] For example, a Sharing AP may be set as the BA-controlled AP, or a Shared AP that can receive an ACK or a Block Ack transmitted from a STA 200 under the control of a MAP may be set (or defined). Also, for example, the BA-controlled AP may be set (defined or changed) periodically or irregularly. This allows the BA-controlled AP to be set according to the propagation environment, thereby enabling adaptive optimization of retransmission control.

[0053] For example, in the BA sharing phase after each STA 200 transmits an ACK or a Block Ack, the following control steps (A), (B), and (C) may be provided. Note that the word "step" may be replaced with other terms such as "processing" or "procedure."

[0054] (A) If the Shared AP does not receive an ACK or a Block ACK, it transmits a frame (hereinafter referred to as a "BA request frame") requesting an ACK or a Block ACK (or requesting BA sharing) to the BA controlling AP.

[0055] (B) When the BA control AP receives the BA request frame, it transmits a frame instructing each Shared AP to share the BA (for example, referred to as a "BA sharing request frame").

[0056] (C) When the Shared AP receives the BA sharing request frame, it transmits a frame (referred to as a "BA sharing frame," for example) including the ACK or Block ACK that the Shared AP holds (for example, receives).

[0057] The TXOP (channel usage period) may be set, for example, in a MAP trigger frame, which is a trigger for starting MAP data transmission, and the TXOP may include a BA sharing phase including the above-mentioned control steps (A) to (C).

[0058] FIG. 8 is a diagram showing an example of a control sequence of MAP in this embodiment.

[0059] Similar to Fig. 3, Fig. 8 is a diagram showing an example of a control sequence of a MAP in the communication environment shown in Fig. 2. For example, Fig. 8 shows an example in which an ACK or Block ACK for data (e.g., initial transmission data) transmitted from the Sharing AP (AP1) and the Shared APs (AP2, AP3) does not arrive from STA b to the Sharing AP (AP1).

[0060] In the case of Fig. 8, for example, a Shared AP (AP2) that is an AP that can receive ACKs or Block ACKs from both STA a and STA b may be set (or defined) as the BA-controlling AP. The BA-controlling AP may be specified in the MAP trigger frame that is a trigger for starting MAP data transmission, or may be set in the phase prior to the MAP trigger frame where setup or channel estimation for MAP is performed.

[0061] For example, in the above-described control step (A), the Sharing AP (AP1) that does not receive an ACK or a Block ACK may transmit a BA request frame to the Shared AP (AP2), which is the BA controlling AP.

[0062] Also, for example, in the above-mentioned control step (B), when the Shared AP (AP2), which is the BA control AP, receives a BA request frame from the Sharing AP (AP1) that does not receive an ACK or block ACK, it may send a BA sharing request frame to each Shared AP (e.g., AP1 and AP3) instructing BA sharing (e.g., sending an ACK or block ACK to AP1).

[0063] Also, for example, in the above-mentioned control step (C), a Shared AP (AP3) that receives a BA sharing request frame from a BA control AP, or a Shared AP (AP2) that is a BA control AP, may transmit a BA sharing frame based on the BA sharing request frame.

[0064] 8, the Shared APs (AP2 and AP3) that receive an ACK or Block ACK from STA b transmit a BA shared frame to the Sharing AP (AP1) that does not receive the ACK or Block ACK, thereby notifying it of the ACK or Block ACK from STA b. In other words, AP1, AP2, and AP3 share the ACK or Block ACK from STA b.

[0065] Therefore, when the Sharing AP (AP1) does not receive the ACK or Block ACK from STA b, it receives them from other Shared APs to appropriately control the retransmission to STA b. For example, in FIG. 8, the Sharing AP (AP1) confirms (or recognizes) that the downlink data transmitted to STA b has been successfully received by STA b. Therefore, for example, as shown in FIG. 8, the Sharing AP (AP1) and the Shared APs (AP2, AP3) may simultaneously transmit data (e.g., newly transmitted data) in the next TXOP.

[0066] Thus, in this embodiment, the AP that controls the sharing of the ACK or Block ACK is defined as the BA control AP. After aggregating the information regarding the ACK or Block ACK in the BA control AP, the AP100 controls the Sharing AP and the Shared APs regarding the sharing of the ACK or Block ACK. By this control, the ACK or Block ACK information of each STA200 under the MAP can be shared in the Sharing AP and the Shared APs, and unnecessary retransmissions can be suppressed.

[0067] Next, a configuration example of the frames transmitted and received in the above-described control steps (A), (B), and (C) will be described.

[0068] <BA Request Frame (Control Step (A))> The BA request frame transmitted and received in control step (A) may, for example, have a configuration including the address field of the Shared AP that does not receive the ACK or Block ACK (in FIG. 8, AP1 which is the Sharing AP).

[0069] FIG. 9 is a diagram showing a configuration example of the BA request (BA Req) frame.

[0070] As shown in FIG. 9, the BA request frame includes, for example, the address (for example, BA Req Address) of a Shared AP (in other words, the AP that transmits the BA request frame) that does not receive an ACK or a Block Ack.

[0071] The address (BA Req Address) may be, for example, a Medium Access Control (MAC) address of the AP 100 or a virtual Basic Service Set (BSS) address. As a virtual BSS address, for example, one identifier (ID) may be assigned to multiple APs 100 that are targets of MAP operation, or multiple IDs may be assigned within a specific ID range.

[0072] Furthermore, the "frame type" that specifies that a radio frame is a BA request frame may be based on at least one of the following definitions (or settings), for example. Frame Control field Type value and Subtype value Trigger frame type Frame variant of BlockAckReq frame

[0073] Fig. 10 is a diagram showing an example of specifying a frame type by the Type value and Subtype value of the Frame Control field in the BA request frame shown in Fig. 9. Fig. 10 shows, as an example, an example in which the type of the BA request (BA Req) frame is defined to "0000", which is an unused Subtype value (e.g., Reserved) in 11ax (e.g., Control type in Table 9-1 Valid type and subtype combinations of the 11ax specification). Note that Fig. 10 shows an example in which the type of the BA request frame is defined to "0000", but is not limited to this and may be defined to another unused value.

[0074] FIG. 11 is a diagram showing an example in which when a Trigger frame is used as a BA request frame, the type of the BA request frame (e.g., Trigger Type) is specified by the Type subfield of the Trigger frame. In FIG. 11, as an example, in 11ax (e.g., Table 9-29c Trigger Type subfield encoding of the 11ax specification), the type of the BA request frame (BA Req) is defined as "8", which is an unused Trigger Type subfield value (e.g., Reserved). Note that in FIG. 11, an example where the type of the BA request frame is defined as "8" is shown, but it is not limited to this, and it may be defined as other unused values.

[0075] FIG. 12 is a diagram showing an example in which when a BlockAckReq frame is used as a BA request frame, the type of the BA request frame (e.g., Block ACK request (BAR) type) is specified by the frame variant of the BlockAckReq frame. In FIG. 12, as an example, in 11ax (e.g., Table 9-28 BlockAckReq frame variant encoding of the 11ax specification), the type of the BA request frame (BA Req) is defined as "7", which is an unused BlockAckReq frame variant (e.g., Reserved). Note that in FIG. 12, an example where the type of the BA request frame is defined as "7" is shown, but it is not limited to this, and it may be defined as other unused values.

[0076] <BA Sharing Request Frame (Control Step (B))> The BA sharing request frame transmitted and received in control step (B) may have a configuration including, for example, the address field of the Sharing AP or Shared AP (AP1 in the example of FIG. 8) that requests an ACK or a block ACK.

[0077] FIG. 13 is a diagram showing a configuration example of a BA sharing request (BA ShareReq) frame.

[0078] 13, the BA share request frame may include, for example, at least one address (e.g., BA ShareReq Address) of a Sharing AP or Shared AP (e.g., an AP requesting sharing of an ACK or Block ACK) requesting an ACK or Block ACK. For example, the address (BA ShareReq Address) included in the BA share request frame may include the address (BA Req Address) in the BA request frame transmitted and received in control step (A).

[0079] Furthermore, the frame type that specifies that a radio frame is a BA sharing request frame may be based on, for example, at least one of the following definitions (or settings): Frame Control field Type value and Subtype value Trigger frame type Frame variant of BlockAckReq frame

[0080] Fig. 14 is a diagram showing an example of specifying a frame type by the Type value and Subtype value of the Frame Control field in the BA share request frame shown in Fig. 13. Fig. 14 shows, as an example, an example in which the type of the BA share request (BA ShareReq) frame is defined to "0001", which is an unused Subtype value (e.g., Reserved) in 11ax (e.g., the Control type in Table 9-1 Valid type and subtype combinations of the 11ax specification). Note that Fig. 14 shows an example in which the type of the BA share request frame is defined to "0001", but is not limited to this and may be defined to another unused value.

[0081] FIG. 15 is a diagram showing an example in which when using a Trigger frame as a BA sharing request frame, the type of the BA sharing request frame (e.g., Trigger Type) is specified by the Type subfield of the Trigger frame. In FIG. 15, as an example, the type of the BA sharing request (BA ShareReq) frame is defined as "9", which is an unused Trigger Type subfield value (e.g., Reserved) in 11ax (e.g., Table 9-29c Trigger Type subfield encoding of the 11ax specification). Note that although FIG. 15 shows an example where the type of the BA sharing request frame is defined as "9", it is not limited to this, and it may be defined with other unused values.

[0082] FIG. 16 is a diagram showing an example in which when using a BlockAckReq frame as a BA sharing request frame, the type of the BA sharing request frame (e.g., BAR type) is specified by the frame variant of the BlockAckReq frame. In FIG. 16, as an example, the type of the BA sharing request (BA ShareReq) frame is defined as "8", which is an unused BlockAckReq frame variant (e.g., Reserved) in 11ax (e.g., Table 9-28 BlockAckReq frame variant encoding of the 11ax specification). Note that although FIG. 16 shows an example where the type of the BA sharing request frame is defined as "8", it is not limited to this, and it may be defined with other unused values.

[0083] <BA Sharing Frame (Control Step (C))> The BA sharing frame transmitted and received in the control step (C) may be configured to include information regarding, for example, ACK or block ACK.

[0084] FIG. 17 is a diagram showing a configuration example of a BA sharing (BA Share) frame.

[0085] 17 may include a bitmap configured by ACK / NACK information for each retransmission unit such as each MAC Protocol Data Unit (MPDU) or Codeword. Also, for example, when the information fed back from the STA 200 to the AP 100 is an ACK (in other words, when a NACK is not included), if the BA shared frame can be identified by a frame type described later, the BA shared frame does not need to include a Block Ack Bitmap field.

[0086] Furthermore, the frame type that specifies that a radio frame is a BA shared frame may be based on, for example, at least one of the following definitions (or settings): Frame Control field Type value and Subtype value Frame variant of BlockAck frame

[0087] Fig. 18 is a diagram showing an example of specifying a frame type by the Type value and Subtype value of the Frame Control field in the BA shared frame shown in Fig. 17. Fig. 18 shows, as an example, an example in which the type of the BA shared frame is defined to "1111", which is an unused Subtype value (e.g., Reserved) in 11ax (e.g., Control type in Table 9-1 Valid type and subtype combinations of the 11ax specification). Note that Fig. 18 shows an example in which the type of the BA shared frame is defined to "1111", but is not limited to this and may be defined to another unused value.

[0088] Fig. 19 is a diagram showing an example in which, when a BlockAck frame is used as a BA shared frame, the type of the BA shared frame (e.g., BlockAck (BA) type) is specified by the frame variant of the BlockAck frame. Fig. 19 shows, as an example, an example in which the type of the BA shared frame is defined to "4," which is an unused BlockAckReq frame variant (e.g., Reserved) in 11ax (e.g., Table 9-28 BlockAck frame variant encoding of the 11ax specification). Note that, although Fig. 19 shows an example in which the type of the BA shared frame is defined to "4," this is not limiting and the type may be defined to another unused value.

[0089] The above has described examples of the configuration of frames transmitted and received in control steps (A), (B) and (C).

[0090] Thus, in this embodiment, AP100 receives control information (radio frames) regarding the sharing of ACKs or block ACKs for downlink signals in inter-base station cooperative communication, and controls the transmission of ACKs or block ACKs to other APs based on the received control information.

[0091] For example, in this embodiment, when control information (e.g., a BA request frame) received from another AP indicates a request for an ACK or a Block ACK, AP100, which is the BA-controlling AP, instructs an AP other than the other AP (the AP transmitting the BA request frame) among the base stations involved in the inter-base station cooperative communication to transmit an ACK or a Block ACK to the other AP (in other words, requests sharing of an ACK or a Block ACK). Also, for example, in this embodiment, when control information (e.g., a BA sharing request frame) received from an AP indicates a request for sharing of an ACK or a Block ACK, AP100 other than the BA-controlling AP determines to transmit an ACK or a Block ACK (e.g., a BA sharing frame) to the other AP indicated in the control information.

[0092] By controlling the sharing of this ACK or Block ACK, multiple APs 100 (e.g., Sharing AP and Shared AP) share the ACK or Block ACK from the STA 200 under the control of a MAP. Therefore, for example, even if the AP 100 does not receive the ACK or Block ACK from the STA 200, the AP 100 can obtain the ACK or Block ACK by sharing the ACK or Block ACK with other APs 100, and therefore can make an appropriate decision on whether or not to retransmit. Therefore, according to this embodiment, it is possible to suppress unnecessary retransmissions by the AP 100 in cooperative communication and improve the efficiency of retransmission control in cooperative communication.

[0093] The BA request frame may include the address of the STA 200 that transmitted the ACK or Block ACK, in addition to the address of the AP 100 that does not receive the ACK or Block ACK. As a result, the ACK or Block ACK that is not received by the AP 100 that transmitted the BA request frame is set as the ACK or Block ACK shared by multiple APs 100, and other ACKs or Block ACKs do not need to be shared, thereby reducing overhead in ACK sharing control.

[0094] (Embodiment 2) The configurations of the AP and STA according to this embodiment may be the same as those in the first embodiment.

[0095] In the first embodiment, for example, a case has been described in which AP 100, which is a BA control AP, performs shared control of ACKs or Block ACKs from STAs 200 for multiple APs 100. In the present embodiment, a case will be described in which APs 100 individually perform shared control of ACKs or Block ACKs. For example, when an AP 100 does not receive an ACK or Block ACK from a STA 200, the AP 100 may individually request other APs 100 to share the ACK or Block ACK.

[0096] For example, in the BA sharing phase after the process in which each STA 200 transmits an ACK or a Block ACK, the following control steps (A) and (B) may be provided.

[0097] (A) If the Shared AP does not receive an ACK or a Block ACK, it transmits a BA ShareReq frame to the Shared AP associated with the STA 200 that transmitted the ACK or Block ACK.

[0098] (B) When the Shared AP receives the BA sharing request frame, it transmits a BA sharing frame including an ACK or a Block ACK for the STA 200 associated with the Shared AP.

[0099] In addition, the TXOP (channel usage period) may be set in the MAP trigger frame, which is a trigger to start MAP data transmission, and the TXOP may include a BA sharing phase including the above-mentioned control steps (A) and (B).

[0100] FIG. 20 is a diagram showing an example of a control sequence of MAP in this embodiment.

[0101] Similar to Fig. 3, Fig. 20 is a diagram showing an example of a control sequence of a MAP in the communication environment shown in Fig. 2. For example, Fig. 20 shows an example in which an ACK or Block ACK for data (e.g., initial transmission data) transmitted from the Sharing AP (AP1) and the Shared APs (AP2, AP3) does not arrive from STA b to the Sharing AP (AP1).

[0102] For example, in the above-described control step (A), the Sharing AP (AP1) that does not receive an ACK or Block ACK from STA b may send a BA sharing request frame to the Shared AP (AP2) to which STA b is associated.

[0103] Also, for example, in the above-mentioned control step (B), the Shared AP (AP2) that receives a BA sharing request frame from the Sharing AP (AP1) may transmit a BA sharing frame to the Sharing AP (AP1) based on the BA sharing request frame.

[0104] 20, the Shared AP (AP2) associated with STA b transmits a BA shared frame to the Sharing AP (AP1) that does not receive the ACK or Block ACK, thereby notifying the ACK or Block ACK from STA b. In other words, AP1 and AP2 share the ACK or Block ACK from STA b.

[0105] Therefore, if the Sharing AP (AP1) does not receive an ACK or Block ACK for STA b from STA b, it receives it from another Shared AP (AP2) and appropriately controls retransmission to STA b. For example, in FIG. 20, the Sharing AP (AP1) confirms (or recognizes) that STA b successfully received the downlink data it transmitted to STA b. Therefore, for example, as shown in FIG. 20, the Sharing AP (AP1) and Shared APs (AP2, AP3) may simultaneously transmit data (e.g., new transmission data) in the next TXOP.

[0106] In this manner, in this embodiment, AP 100 controls the sharing of ACK or Block ACK by individually requesting the sharing of ACK or Block ACK by AP 100 that does not receive ACK or Block ACK. This control enables the Sharing AP and Shared AP to share information on ACK or Block ACK from each STA 200 under the MAP, thereby reducing unnecessary retransmission.

[0107] Furthermore, in this embodiment, compared to the first embodiment, for example, there is no need to configure the BA control AP and to perform the control step of issuing a BA request to the BA control AP, so that the overhead related to the shared control of ACK can be reduced.

[0108] Next, a configuration example of the frame transmitted and received in the above-described control steps (A) and (B) will be described.

[0109] <BA Sharing Request Frame (Control Step (A))> The BA sharing request frame transmitted and received in control step (A) may have a configuration including, for example, the address field of the Sharing AP or Shared AP (in the example of FIG. 20, AP2) that is the destination of the sharing of ACK or block ACK.

[0110] FIG. 21 is a diagram showing a configuration example of a BA sharing request (BA ShareReq) frame.

[0111] As shown in FIG. 21, the BA sharing request frame may include at least one address (for example, BA ShareReq Address) of the Sharing AP or Shared AP (for example, the AP that is requested to share ACK or block ACK), which is the destination of ACK or block ACK. Note that the address (BA ShareReq Address) may be shared, for example, in a MAP trigger frame that is a trigger for starting MAP data transmission, or may be shared in a phase of performing setup or channel estimation related to MAP before the MAP trigger frame.

[0112] Also, the frame type that specifies that the wireless frame is a BA sharing request frame may be based on, for example, at least one of the following definitions (or settings). ·Type value and Subtype value of the Frame Control field ·Type of the Trigger frame ·frame variant of the BlockAckReq frame

[0113] Fig. 22 is a diagram showing an example of specifying a frame type by the Type value and Subtype value of the Frame Control field in the BA share request frame shown in Fig. 21. Fig. 22 shows, as an example, an example in which the type of the BA share request (BA ShareReq) frame is defined to "0000", which is an unused Subtype value (e.g., Reserved) in 11ax (e.g., the Control type in Table 9-1 Valid type and subtype combinations of the 11ax specification). Note that Fig. 22 shows an example in which the type of the BA share request frame is defined to "0000", but is not limited to this and may be defined to another unused value.

[0114] Fig. 23 is a diagram showing an example in which, when a Trigger frame is used as a BA sharing request frame, the type of the BA sharing request frame (e.g., Trigger Type) is specified by the Type subfield of the Trigger frame. Fig. 23 shows, as an example, an example in which the type of the BA sharing request (BA ShareReq) frame is defined to "8," which is an unused Trigger Type subfield value (e.g., Reserved) in 11ax (e.g., Table 9-29c Trigger Type subfield encoding of the 11ax specification). Note that Fig. 23 shows an example in which the type of the BA sharing request frame is defined to "8," but is not limited to this and may be defined to another unused value.

[0115] FIG. 24 is a diagram showing an example of specifying the type of a BA shared request frame (e.g., BAR type) as the BlockAckReq frame by the frame variant of the BlockAckReq frame when using the BlockAckReq frame as the BA shared request frame. In FIG. 24, as an example, in 11ax (e.g., Table 9-28 BlockAckReq frame variant encoding of the 11ax specification), the type of the BA shared request (BA ShareReq) frame is defined as "7", which is an unused BlockAckReq frame variant (e.g., Reserved). Note that, in FIG. 24, an example where the type of the BA shared request frame is defined as "7" is shown, but it is not limited to this, and it may be defined as other unused values.

[0116] <BA shared frame (control step (B))> The BA shared frame transmitted and received in the control step (B) may have a configuration including information regarding ACK or block ACK, similar to the BA shared frame in the control step (C) of the first embodiment.

[0117] FIG. 25 is a diagram showing a configuration example of a BA shared (BA Share) frame.

[0118] The Block Ack Bitmap field included in the BA shared frame shown in FIG. 25 may include a bitmap composed of ACK / NACK information of retransmission units such as each MPDU or Codeword. Also, for example, when the information fed back from STA200 to AP100 is ACK (in other words, when no NACK is included), the BA shared frame may not include the Block Ack Bitmap field as long as the BA shared frame can be identified by the frame type described later.

[0119] Also, regarding the frame type that specifies that the wireless frame is a BA shared frame, it may be based on at least one of the following definitions (or settings), for example. Frame Control field Type value and Subtype value Frame variant of BlockAck frame

[0120] Fig. 26 is a diagram showing an example of specifying a frame type by the Type value and Subtype value of the Frame Control field in the BA shared frame shown in Fig. 25. Fig. 26 shows, as an example, an example in which the type of the BA shared frame is defined to "0001", which is an unused Subtype value (e.g., Reserved) in 11ax (e.g., Control type in Table 9-1 Valid type and subtype combinations of the 11ax specification). Note that Fig. 26 shows an example in which the type of the BA shared frame is defined to "0001", but is not limited to this and may be defined to another unused value.

[0121] Fig. 27 is a diagram showing an example in which, when a BlockAck frame is used as a BA shared frame, the type of the BA shared frame (e.g., BA type) is specified by the frame variant of the BlockAck frame. Fig. 27 shows, as an example, an example in which the type of the BA shared frame is defined to "4," which is an unused BlockAckReq frame variant (e.g., Reserved) in 11ax (e.g., Table 9-28 BlockAck frame variant encoding of the 11ax specification). Note that Fig. 27 shows an example in which the type of the BA shared frame is defined to "4," but is not limited to this and may be defined to another unused value.

[0122] The above has described examples of the configuration of frames transmitted and received in control steps (A) and (B).

[0123] As described above, in this embodiment, AP 100 receives control information (radio frame) related to sharing of ACK or Block ACK for downlink signals in inter-base station cooperative communication, and controls transmission of ACK or Block ACK to other APs based on the received control information. For example, in this embodiment, when control information (e.g., a BA sharing request frame) received from another AP indicates a request for sharing of ACK or Block ACK of STA 200 associated with AP 100, AP 100 determines to transmit ACK or Block ACK to the other AP.

[0124] By controlling the sharing of this ACK or Block ACK, multiple APs 100 (e.g., Sharing AP and Shared AP) share the ACK or Block ACK from the STA 200 under the control of a MAP. Therefore, for example, even if the AP 100 does not receive the ACK or Block ACK from the STA 200, the AP 100 can obtain the ACK or Block ACK by sharing the ACK or Block ACK with other APs 100, and therefore can make an appropriate decision on whether or not to retransmit. Therefore, according to this embodiment, it is possible to suppress unnecessary retransmissions by the AP 100 in cooperative communication and improve the efficiency of retransmission control in cooperative communication.

[0125] (Embodiment 3) The configurations of the AP and STA according to this embodiment may be the same as those in the first embodiment.

[0126] In this embodiment, a method will be described in which a Shared AP requesting sharing of an ACK or Block ACK is specified in a MAP trigger frame, which is a trigger for starting MAP data transmission.

[0127] For example, in the BA sharing phase after the MAP trigger frame and the process in which each STA 200 transmits an ACK or a Block ACK, the following control steps (A) and (B) may be provided.

[0128] (A) The Sharing AP uses a MAP trigger frame to specify to the Shared AP a combination of a Shared AP requesting the sharing of an ACK or a Block ACK and a STA 200 that transmits the ACK or the Block ACK.

[0129] (B) When a combination of a Shared AP and a STA 200 is specified, the Shared AP transmits a BA shared frame including an ACK or a Block ACK from the STA 200 included in the combination to the Shared AP included in the combination.

[0130] The TXOP (channel usage period) may be set in a MAP trigger frame, which is a trigger for starting MAP data transmission, and the TXOP may include a BA sharing phase including the control step (B) described above.

[0131] FIG. 28 is a diagram showing an example of a control sequence of MAP in this embodiment.

[0132] Similar to Fig. 3, Fig. 28 is a diagram showing an example of a control sequence of a MAP in the communication environment shown in Fig. 2. For example, Fig. 28 shows an example in which an ACK or Block ACK for data (e.g., initial transmission data) transmitted from the Sharing AP (AP1) and the Shared APs (AP2, AP3) does not arrive from STA b to the Sharing AP (AP1).

[0133] For example, in the above-described control step (A), the Sharing AP (AP1) may specify a combination of a Shared AP requesting sharing of an ACK or Block ACK and a STA 200 transmitting the ACK or Block ACK. In other words, the Sharing AP (AP1) may specify a combination of an AP 100 that may not receive an ACK or Block ACK from the STA 200 and the STA 200.

[0134] For example, the Sharing AP (AP1) may determine the uplink coverage of each STA 200 based on the propagation loss or channel estimation value between each STA 200 and each Shared AP collected in the Multi-AP Channel sounding phase performed before MAP data transmission. Then, the Sharing AP (AP1) may determine, for example, a combination of each STA 200 with a Shared AP that is outside the uplink coverage of the STA 200. In the example of FIG. 28, for example, a combination of STA b and AP1 that is outside the uplink coverage of STA b may be specified.

[0135] 28, the AP 100 determines the uplink coverage of each STA 200 based on the propagation loss or channel estimation value collected in the Multi-AP Channel sounding phase performed before MAP data transmission, and determines the above-mentioned combination. However, the above-mentioned combination may be determined periodically or irregularly. This allows the combination of the AP 100 and the STA 200 to be set (or changed) according to the propagation environment, thereby enabling adaptive optimization of retransmission control.

[0136] Also, for example, in the above-mentioned control step (B), the Shared AP (AP2) specified in the MAP Trigger frame in control step (A) may transmit a BA shared frame to the Sharing AP (AP1) indicated in the combination.

[0137] 28, the Shared AP (AP2) designated for the combination of AP1 and STA b transmits a BA shared frame to the Sharing AP (AP1) that has not received an ACK or Block ACK, thereby notifying it of the ACK or Block ACK from STA b. In other words, AP1 and AP2 share the ACK or Block ACK from STA b.

[0138] Therefore, if the Sharing AP (AP1) does not receive an ACK or Block ACK for STA b from STA b, it receives it from another Shared AP (AP2) and appropriately controls retransmission to STA b. For example, in FIG. 28, the Sharing AP (AP1) confirms (or recognizes) that STA b successfully received the downlink data it transmitted to STA b. Therefore, for example, as shown in FIG. 28, the Sharing AP (AP1) and Shared APs (AP2, AP3) may simultaneously transmit data (e.g., new transmission data) in the next TXOP.

[0139] In this manner, in this embodiment, the MAP trigger frame controls the sharing of ACKs or Block ACKs by specifying a combination of APs 100 and STAs 200 that do not receive ACKs or Block ACKs. This control enables the Sharing AP and Shared AP to share information about ACKs or Block ACKs from each STA 200 under the MAP, thereby reducing unnecessary retransmissions.

[0140] Furthermore, in this embodiment, for example, compared to the first or second embodiment, the control steps related to the setting of the BA control AP in the BA sharing phase and the BA sharing request can be eliminated, thereby reducing the overhead related to the ACK sharing control.

[0141] Next, an example of the structure of the frames transmitted and received in the above-mentioned control steps (A) and (B) will be described.

[0142] <map triggerフレーム> The MAP trigger frame transmitted and received in control step (A) may be configured to include information about the STA 200 with which the ACK or Block ACK is shared in a field of information for each AP 100 (for example, "Per AP Info").

[0143] FIG. 29 is a diagram illustrating an example of the configuration of a MAP trigger frame.

[0144] 29, the MAP trigger frame may include a BA ShareReq field set in the Per AP Info field of information for each AP 100. The BA ShareReq field shown in FIG. 29 may include, for example, an identifier (ID) of the STA 200 with which the ACK or Block Ack is shared.

[0145] For example, in the example shown in FIG. 28, the ID of STA b may be set in the BA ShareReq field in the Per AP Info field corresponding to the Sharing AP (AP1).

[0146] The STA ID may use a MAC address (e.g., 48 bits), or may define an STA identifier called a Short ID. The Short ID may be defined as part of the Association ID (AID) specified in the 11ax specifications, or may be assigned to the Reserved area of ​​AID12. Use of the Short ID can reduce overhead compared to using a MAC address.

[0147] FIG. 30 is a diagram illustrating another example of the configuration of the MAP trigger frame.

[0148] In the example shown in FIG. 30, in the per STA info field included in the per AP info field for each AP100 in the MAP trigger frame, information indicating whether to share ACK or block ACK (for example, referred to as a "BA share flag") may be set. The BA share flag may be, for example, 1-bit information indicating whether ACK or block ACK is shared.

[0149] For example, in the example shown in FIG. 28, in the per STA info field corresponding to STA b in the per AP info field corresponding to the Sharing AP (AP1), the BA ShareFlag may indicate that ACK or block ACK is shared.

[0150] Note that in the examples shown in FIGS. 29 and 30, in the MAP trigger frame, the information regarding the combination of AP100 and STA200 is included in the per AP info. However, it is not limited to this, and the information regarding the combination of AP100 and STA200 may be defined in the common info field of the MAP trigger frame. For example, the information regarding a plurality of the above combinations may be collectively defined in the common info field.

[0151] <BA share frame (control step (B))> The BA share frame transmitted and received in control step (B) may be configured to include information regarding ACK or block ACK, similar to the BA share frame in control step (C) of Embodiment 1.

[0152] FIG. 31 is a diagram showing a configuration example of a BA share frame.

[0153] 31 may include a bitmap configured by ACK / NACK information for each retransmission unit such as each MPDU or Codeword. Also, for example, when the information fed back from the STA 200 to the AP 100 is an ACK (in other words, when a NACK is not included), if the BA shared frame can be identified by a frame type described later, the BA shared frame does not need to include a Block Ack Bitmap field.

[0154] Furthermore, the frame type that specifies that a radio frame is a BA shared frame may be based on, for example, at least one of the following definitions (or settings): Frame Control field Type value and Subtype value Frame variant of BlockAck frame

[0155] Fig. 32 is a diagram showing an example of specifying a frame type by the Type value and Subtype value of the Frame Control field in the BA shared frame shown in Fig. 31. Fig. 32 shows, as an example, an example in which the type of the BA shared frame is defined to "0001", which is an unused Subtype value (e.g., Reserved) in 11ax (e.g., Control type in Table 9-1 Valid type and subtype combinations of the 11ax specifications). Note that Fig. 32 shows an example in which the type of the BA shared frame is defined to "0001", but is not limited to this and may be defined to another unused value.

[0156] Fig. 33 is a diagram showing an example in which, when a BlockAck frame is used as a BA shared frame, the type of the BA shared frame (e.g., BA type) is specified by the frame variant of the BlockAck frame. Fig. 33 shows, as an example, an example in which the type of the BA shared frame is defined to "4", which is an unused BlockAckReq frame variant (e.g., Reserved) in 11ax (e.g., Table 9-28 BlockAck frame variant encoding of the 11ax specification). Note that, although Fig. 32 shows an example in which the type of the BA shared frame is defined to "4", this is not limiting and the type may be defined to another unused value.

[0157] The above has described examples of the configuration of frames transmitted and received in control steps (A) and (B).

[0158] As described above, in this embodiment, AP 100 receives control information (radio frame) related to sharing of ACK or Block ACK for downlink signals in inter-base station cooperative communication, and controls transmission of the ACK or Block ACK to other APs based on the received control information. For example, in this embodiment, when the received control information (e.g., MAP trigger frame) indicates a combination of another AP that does not receive an ACK or Block ACK among APs involved in inter-base station cooperative communication and a source (e.g., STA 200) of the ACK or Block ACK, AP 100 determines to transmit the ACK or Block ACK from the source to the other AP.

[0159] By controlling the sharing of this ACK or Block ACK, multiple APs 100 (e.g., Sharing AP and Shared AP) share the ACK or Block ACK from the STA 200 under the control of a MAP. Therefore, for example, even if the AP 100 does not receive the ACK or Block ACK from the STA 200, the AP 100 can obtain the ACK or Block ACK by sharing the ACK or Block ACK with other APs 100, and therefore can make an appropriate decision on whether or not to retransmit. Therefore, according to this embodiment, it is possible to suppress unnecessary retransmissions by the AP 100 in cooperative communication and improve the efficiency of retransmission control in cooperative communication.

[0160] (Fourth embodiment) The configurations of the AP and STA according to this embodiment may be the same as those in the first embodiment.

[0161] In this embodiment, a method will be described in which each Shared AP transmits a BA shared frame regardless of the reception state of an ACK or Block Ack at each Shared AP.

[0162] For example, in the BA sharing phase after the MAP trigger frame and the process in which each STA 200 transmits an ACK or a Block ACK, the following control steps (A) and (B) may be provided.

[0163] (A) The Sharing AP instructs multiple Shared APs (for example, all Shared APs) to share an ACK or a Block ACK using a MAP trigger frame.

[0164] (B) After receiving an ACK or a Block ACK from the STA 200, the Shared AP transmits a BA shared frame including the ACK or the Block ACK.

[0165] The TXOP (channel usage period) may be set in a MAP trigger frame, which is a trigger for starting MAP data transmission, and the TXOP may include a BA sharing phase including the control step (B) described above.

[0166] FIG. 34 is a diagram showing an example of a control sequence of MAP in this embodiment.

[0167] Similar to Fig. 3, Fig. 34 is a diagram showing an example of a control sequence of a MAP in the communication environment shown in Fig. 2. For example, Fig. 34 shows an example in which an ACK or Block ACK for data (e.g., initial transmission data) transmitted from the Sharing AP (AP1) and the Shared APs (AP2, AP3) does not arrive from STA b to the Sharing AP (AP1).

[0168] For example, in the above-described control step (A), the Sharing AP (AP1) may set information instructing (or requesting) the multiple Shared APs (AP2 and AP3) to share an ACK or a Block ACK. The information instructing the sharing of an ACK or a Block ACK may be, for example, a 1-bit flag (BA ShareReqFlag). For example, when this flag is set as valid (e.g., when ACK sharing is instructed), each Shared AP may operate assuming that the BA sharing phase of control step (B) will be set. On the other hand, when the flag is set as invalid (e.g., when ACK sharing is not instructed), each Shared AP may operate assuming that the BA sharing phase of control step (B) will not be set.

[0169] Furthermore, in control step (A), the shared AP (AP1) may specify a multiplexing method for transmitting the BA shared frame in control step (B). Examples of the multiplexing method for the BA shared frame include time division multiplexing (TDMA: Time Division Multiple Access), frequency division multiplexing (e.g., OFDMA: Orthogonal Frequency Division Multiple Access), and space division multiplexing (e.g., MU-MIMO: Multi User - Multiple Input Multiple Output).

[0170] Also, for example, in the above-described control step (B), the Shared AP may transmit the BA shared frame in accordance with the multiplexing method specified in the MAP Trigger frame in control step (A).

[0171] 34, multiple Shared APs (AP1, AP2, and AP3) instructed to share ACKs in the MAP trigger frame transmit BA shared frames. As a result, for example, the Shared APs (AP2 and AP3) notify the Sharing AP (AP1) that does not receive an ACK or Block ACK from STA b of the ACK or Block ACK from STA b. In other words, AP1, AP2, and AP3 share the ACK or Block ACK from STA b.

[0172] Therefore, if the Sharing AP (AP1) does not receive an ACK or Block ACK for STA b from STA b, it receives it from another Shared AP (AP2) and appropriately controls retransmission to STA b. For example, in FIG. 34, the Sharing AP (AP1) confirms (or recognizes) that STA b successfully received the downlink data it transmitted to STA b. Therefore, for example, as shown in FIG. 34, the Sharing AP (AP1) and Shared APs (AP2, AP3) may simultaneously transmit data (e.g., new transmission data) in the next TXOP.

[0173] In this manner, in this embodiment, the MAP trigger frame controls to instruct multiple APs 100 to share ACKs or Block ACKs. This control enables the Sharing AP and the Shared AP to share information on ACKs or Block ACKs from each STA 200 under the MAP, thereby reducing unnecessary retransmissions.

[0174] Furthermore, in this embodiment, for example, compared to the first or second embodiment, the control steps related to the setting of the BA control AP in the BA sharing phase and the BA sharing request can be eliminated, thereby reducing the overhead related to the ACK sharing control.

[0175] Next, an example of the structure of the frames transmitted and received in the above-mentioned control steps (A) and (B) will be described.

[0176] <map triggerフレーム> The MAP trigger frame transmitted and received in control step (A) may be configured to include information indicating sharing of ACK or block ACK for a plurality of APs 100 (for example, all Shared APs).

[0177] FIG. 35 is a diagram showing an example of the configuration of the MAP trigger frame.

[0178] In the example shown in FIG. 35, in the MAP trigger frame, information indicating BA sharing for a plurality of Shared APs (for example, a 1-bit BA sharing request flag (BA ShareReq Flag)) may be set in the common information field for the plurality of APs 100.

[0179] Note that although the case of setting the BA sharing request flag (BA ShareReq Flag) in the common information field has been described in FIG. 35, the present invention is not limited thereto, and the BA sharing request flag may be set in a field different from the common information field.

[0180] <N000D670><BA sharing frame (control step (B))> The BA sharing frame transmitted in control step (B) may be configured to include information regarding ACK or block ACK, similar to the BA sharing frame in control step (C) of Embodiment 1. Also, examples of the configuration example and frame type designation of the BA sharing frame may be similar to those of the BA sharing frame in Embodiment 3.

[0181] The configuration examples of the frames transmitted and received in control steps (A) and (B) have been described above.

[0182] As described above, in this embodiment, AP 100 receives control information (e.g., a radio frame) related to the sharing of an ACK or a Block ACK for a downlink signal in cooperative communication between base stations, and controls the transmission of the ACK or the Block ACK to other APs based on the received control information. For example, in this embodiment, when the received control information (e.g., a MAP trigger frame) instructs the sharing of an ACK or a Block ACK, AP 100 determines to transmit an ACK or a Block ACK to APs 100 involved in cooperative communication between base stations.

[0183] This sharing control of ACK or Block ACK allows multiple APs 100 (e.g., Sharing AP and Shared AP) to share ACK or Block ACK from STA 200 under MAP. Therefore, for example, even if AP 100 does not receive ACK or Block ACK from STA 200, it can obtain the ACK or Block ACK by sharing the ACK or Block ACK with other APs 100, and therefore can make an appropriate decision on whether or not to retransmit. Therefore, according to this embodiment, it is possible to suppress unnecessary retransmission by AP 100 in cooperative communication and improve the efficiency of retransmission control in cooperative communication.

[0184] (Embodiment 5) The configurations of the AP and STA according to this embodiment may be the same as those in the first embodiment.

[0185] In this embodiment, a method for determining whether or not ACK or Block ACK is shared between Shared APs will be described, for example, depending on the type of line between the Shared APs (for example, whether it is wireless or wired).

[0186] The information determined by the AP 100 (for example, a Sharing AP) regarding the setting of sharing and whether or not to transmit may be, for example, at least one of the following. BA request frame in the first embodiment BA sharing request frame in the first or second embodiment Information regarding the combination of the AP 100 and the STA 200 in the third embodiment Information about BA sharing among multiple shared APs in the fourth embodiment

[0187] The AP 100 may obtain information about the type of line between the Shared APs, for example, in a multi-AP channel sounding phase that is performed before transmitting MAP data, or may obtain the information in another period.

[0188] Fig. 36 is a diagram illustrating an example of the configuration of lines between Shared APs. In the example illustrated in Fig. 36, the Sharing AP (AP1) and the Shared AP (AP2) are connected by a wired line, and the Sharing AP (AP1) and the Shared AP (AP3) and the Shared AP (AP2) and the Shared AP (AP3) are connected by wireless lines.

[0189] For example, if the relay line between shared APs (e.g., between AP1 and AP2 in Figure 36) is an ideal communication environment (e.g., a low-latency wired line such as Ethernet (registered trademark) or optical fiber), AP100 may transmit at least one of the BA request frame, BA sharing request frame, information regarding the combination of AP100 and STA200, and BA sharing frame in a wired frame such as an IEEE 802.3 Ethernet frame rather than wirelessly.

[0190] In contrast, for example, if the relay line between shared APs (for example, between AP1 and AP3 in Figure 36, or between AP2 and AP3) is not an ideal communication environment (for example, in the case of a line such as a wireless line that tends to have larger delays than a wired line), AP100 wirelessly transmits at least one of a BA request frame, a BA sharing request frame, information regarding the combination of AP100 and STA200, and a MAP trigger frame including a BA sharing frame.

[0191] Furthermore, for example, in a relay circuit configuration in which wired and wireless connections are mixed, the AP 100 may transmit at least one of the BA sharing request frame and information relating to the combination of the AP 100 and the STA 200 in a MAP trigger frame on the wireless circuit path, and may transmit the BA request frame or the BA sharing frame in a wired frame such as an IEEE 802.3 Ethernet frame on the wired circuit path. Note that the frames transmitted on the wired circuit and the wireless circuit are not limited to the above examples, and other frames may be used.

[0192] FIG. 37 is a diagram showing an example of a control sequence of MAP according to this embodiment.

[0193] In Figure 37, as an example, Sharing AP (AP1) and Shared AP (AP2) are connected via a mixed wired and wireless line, and Sharing AP (AP1) and Shared AP (AP3) and Shared AP (AP2) and Shared AP (AP3) are connected via wireless lines.

[0194] 37 also shows an example in which an ACK or Block ACK for data (e.g., initial transmission data) transmitted from the Sharing AP (AP1) and the Shared APs (AP2, AP3) does not arrive from STA b to the Sharing AP (AP1). Note that the control sequence shown in FIG. 37 is, for example, the same as the control sequence in the fourth embodiment.

[0195] 37, between a Sharing AP (AP1) and a Shared AP (AP2) that can be connected via a wired line, for example, at least one piece of information related to the sharing of an ACK or a Block Ack (for example, a BA shared frame) may be transmitted in a wired frame and not transmitted wirelessly. For example, in FIG. 37, the BA shared frame from the Sharing AP (AP1) to the Shared AP (AP2) and the BA shared frame from the Shared AP (AP2) to the Sharing AP (AP1) may not be transmitted.

[0196] According to this embodiment, AP 100 determines whether to share an ACK or Block ACK with other APs (e.g., whether to request wireless sharing of an ACK or Block ACK) based on the type of line to the other APs (e.g., whether the line is wireless or wired). This allows AP 100 to share information about the ACK or Block ACK of each STA 200 in a short time by using both wired and wireless frames, thereby reducing unnecessary retransmissions.

[0197] Note that, while Figure 37 shows the control sequence in embodiment 4 as an example, this is not limiting, and operations according to the line type in this embodiment may be applied to any of embodiments 1 to 3.

[0198] Furthermore, in this embodiment, as an example, a case where sharing control is performed according to the line type, such as wireless or wired, has been described, but this is not limited to this, and sharing control may also be performed according to, for example, communication performance (or communication method).

[0199] The embodiments of the present disclosure have been described above.

[0200] (Other embodiments) In each of the above-described embodiments, the AP 100 may determine whether to execute the above-described control regarding BA sharing based on, for example, the MAP coordination scheme. For example, when the MAP coordination scheme is JT, the AP 100 may execute the above-described control regarding BA sharing, but when the MAP coordination scheme is a method other than JT, the AP 100 may not execute the above-described control regarding BA sharing. Also, for example, when the AP 100 receives a BA sharing request frame from another AP 100, if the MAP coordination scheme is JT, the AP 100 may respond to the BA sharing request (for example, by transmitting a BA sharing frame), but if the MAP coordination scheme is a method other than JT, the AP 100 may not respond to the BA sharing request. Also, for example, in the above-described third to fifth embodiments, if the MAP coordination scheme is JT, the BA sharing request may be instructed to the Shared AP by the MAP trigger frame, but if the MAP coordination scheme is a method other than JT, the BA sharing request may not be instructed to the Shared AP by the MAP trigger frame.

[0201] Furthermore, in each of the above-described embodiments, a method for sharing an ACK or a Block ACK between APs 100 has been described, but the signal or information shared between APs 100 is not limited to an ACK or a Block ACK, and other signals or information may be used. For example, the sharing method in the above-described embodiments may be applied to information that is expected to be shared between APs, such as a channel estimate or information related to data buffer management.

[0202] Furthermore, there are two types of Block Ack: Immediate Block Ack and Delayed Block Ack, and the above-described embodiments are applicable to either type.

[0203] Furthermore, the definitions of the information regarding BA sharing in the Frame Control field, Trigger Type, BlockAckReq frame variant, and BlockAck frame variant described in the above-mentioned embodiment are merely examples, and other values ​​may be defined without being limited to these.

[0204] Furthermore, the configurations of the BA request frame, BA sharing request frame, BA sharing frame, and Trigger frame described in the above embodiments are merely examples, and are not limited to these, and other configurations may be used. For example, in these frame configurations, some fields may not be set, and other fields may be set.

[0205] In addition, in the above embodiment, the AP that instructs cooperative communication and the AP that is instructed to perform cooperative communication are described using the terms "Sharing AP" and "Shared AP," respectively, but this is not limited to this and other terms may be used.

[0206] Furthermore, although the above embodiment has been described based on the 11be format as an example, the format to which an embodiment of the present disclosure is applied is not limited to the 11be format. An embodiment of the present disclosure may be applied to, for example, IEEE 802.11bd (NGV (Next Generation V2X)), a next-generation standard of IEEE 802.11p, which is an in-vehicle standard.

[0207] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may be called an IC, system LSI, super LSI, or ultra LSI.

[0208] The integrated circuit method is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0209] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology can be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0210] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a wireless transceiver and processing / control circuitry. The wireless transceiver may include a receiver and a transmitter, or both functions. The wireless transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0211] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0212] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0213] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0214] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0215] A base station according to one embodiment of the present disclosure includes a receiving circuit that receives control information regarding sharing of a response signal to a downlink signal in inter-base station cooperative communication, and a control circuit that controls transmission of the response signal to other base stations based on the control information.

[0216] In one embodiment of the present disclosure, when the control information received from the other base station indicates a request for the response signal, the control circuit instructs a base station other than the other base station among the base stations involved in the base station-to-base station cooperative communication to transmit the response signal to the other base station.

[0217] In one embodiment of the present disclosure, when the received control information indicates a request to share the response signal, the control circuit determines to transmit the response signal to the other base station indicated in the control information.

[0218] In one embodiment of the present disclosure, the control circuit determines to transmit the response signal to the other base station when the control information received from the other base station indicates a request to share the response signal of a terminal associated with the base station.

[0219] In one embodiment of the present disclosure, when the received control information indicates a combination of another base station, among base stations involved in the base station-to-base station cooperative communication, that does not receive the response signal and the source of the response signal, the control circuit determines to transmit the response signal from the source to the other base station.

[0220] In one embodiment of the present disclosure, the control information is included in a signal that triggers the start of the inter-base station cooperative communication.

[0221] In an embodiment of the present disclosure, when the received control information instructs sharing of the response signal, the control circuit determines to transmit the response signal to base stations involved in the inter-base station cooperative communication.

[0222] In one embodiment of the present disclosure, the control information is included in a signal that triggers the start of the inter-base station cooperative communication.

[0223] In one embodiment of the present disclosure, the control circuit determines whether to share the response signal with the other base station based on the type of line to the other base station.

[0224] A communication device according to one embodiment of the present disclosure includes a transmitter that transmits a response signal to a downlink signal in cooperative communication to a first base station that performs the cooperative communication, and information regarding the response signal is shared with a second base station that performs the cooperative communication.

[0225] In an embodiment of the present disclosure, the control circuit determines to share the response signal when the line type is wireless, and determines not to share the response signal when the line type is wired.

[0226] In a communication method according to one embodiment of the present disclosure, a base station receives control information regarding the sharing of a response signal to a downlink signal in coordinated communication between base stations, and controls the transmission of the response signal to other base stations based on the control information.

[0227] In a communication method according to one embodiment of the present disclosure, a communication device transmits a response signal to a downlink signal in cooperative communication to a first base station performing the cooperative communication, and information regarding the response signal is shared with a second base station performing the cooperative communication.

[0228] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2021-002273, filed on January 8, 2021, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0229] One embodiment of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0230] 100 AP 101 Control section 102 STA control signal generation unit 103 AP control signal generation unit 104,203 Transmission signal generator 105,201 Radio transmitter / receiver 106,202 Received signal demodulation and decoding unit 200 STA< / map> < / map>

Claims

1. An integrated circuit for controlling a base station, A process of receiving control information regarding sharing of a response signal to a downlink signal in inter-base station cooperative communication; When the received control information indicates a combination of another base station that does not receive the response signal and a source of the response signal among base stations involved in the inter-base station cooperative communication, a process of determining transmission of the response signal from the source of the response signal to the other base station; An integrated circuit that controls

2. When the control information received from the other base station indicates a request for the response signal, instruct a base station other than the other base station among the base stations involved in the inter-base station cooperative communication to transmit the response signal to the other base station.

10. The integrated circuit of claim 1.

3. If the received control information indicates a request to share the response signal, determining to transmit the response signal to the other base station indicated in the control information.

10. The integrated circuit of claim 1.

4. determining transmission of the response signal to the other base station when the control information received from the other base station indicates a request for sharing the response signal of the terminal associated with the base station; 10. The integrated circuit of claim 1.

5. the control information is included in a signal that triggers the start of the inter-base station cooperative communication.

10. The integrated circuit of claim 1.

6. If the received control information instructs sharing of the response signal, determining to transmit the response signal to base stations involved in the inter-base station cooperative communication.

10. The integrated circuit of claim 1.

7. the control information is included in a signal that triggers the start of the inter-base station cooperative communication.

7. The integrated circuit of claim 6.

8. determining whether to share the response signal with the other base station based on the type of line to the other base station; 10. The integrated circuit of claim 1.

9. determining whether to share the response signal when the type of the line is wireless, and whether to not share the response signal when the type of the line is wired; 9. The integrated circuit of claim 8.

10. An integrated circuit for controlling a communication device, Controlling a process of transmitting a response signal to a downlink signal in cooperative communication to a first base station performing the cooperative communication; information about the response signal is shared with a second base station that performs the cooperative communication; When the information regarding the response signal indicates a combination of the first base station, among base stations involved in the cooperative communication, that does not receive the response signal, and a source of the response signal, it is determined that the response signal is transmitted from the source to the first base station. Integrated circuit.

Images