Access point and terminal

Abstract

An access point according to one embodiment comprises a wireless communication unit and a management unit. The management unit enables data transmission between a plurality of terminals that are wirelessly connected to the wireless communication unit, and when a first access point, which is one among access points other than an own station, transmits low-latency traffic to and from a wirelessly connected terminal, the management unit causes data to be transmitted between the plurality of terminals while avoiding a period in which the low-latency traffic is transmitted between the first access point and said terminal.

Description

Access points and terminals

[0001] The embodiments relate to an access point and a terminal.

[0002] In a wireless communication network such as a wireless LAN (local area network), for example, an access point (AP) and a terminal, which is a non-AP station (STA), are wirelessly connected. In a wireless communication network, a terminal transmits data wirelessly to an AP located in the communication area of ​​the terminal. In addition, a wireless communication network also allows multiple terminals to perform P2P (peer-to-peer) communication, in which data is transmitted between each other without an AP.

[0003] The IEEE 802.11be standard is scheduled to specify a triggered TXOP sharing (TXS) function as an extension of the TXOP sharing function. With the TXS function, an AP allocates a portion of its TXOP (channel occupation period), a transmission opportunity acquired through carrier sensing, to a terminal located in its communication area and shares the acquired TXOP with wirelessly connected terminals. Furthermore, with the TXS function, a terminal that receives a portion of its TXOP from the AP as a communication period can conduct P2P communication with other terminals during the communication period allocated by the AP, and can allocate the communication period allocated by the AP to data transmission with other terminals via P2P communication. This allows a terminal to conduct P2P communication with another terminal without setting up a link.

[0004] As described above, in a situation where P2P communication is being performed between multiple terminals, for example, if another communication station transmits data near a terminal performing P2P communication, the data transmission by the P2P communication may interfere with the data transmission by the other communication station. In particular, when a communication station other than the terminal performing P2P communication transmits low-latency traffic, it is required to effectively suppress interference of data transmission by the P2P communication with the transmission of low-latency traffic, from the viewpoint of ensuring low latency of the low-latency traffic.

[0005] IEEE P802.11-23 / 294r1 “Channel Usage Enhancement for P2P in UHR”, May, 2023, “https: / / mentor.ieee.org / 802.11 / dcn / 23 / 11-23-0294”

[0006] An object of the present invention is to provide an access point and a terminal that effectively suppress interference of data transmission by P2P communication with transmission of low latency traffic by a communication station other than the terminal performing P2P communication.

[0007] In one embodiment of the present invention, an access point includes a wireless communication unit and a management unit. The management unit enables data transmission among a plurality of terminals wirelessly connected to the wireless communication unit, and, when a first access point other than the access point transmits low-latency traffic between the first access point and a terminal wirelessly connected thereto, allows the data transmission among the plurality of terminals while avoiding a period during which low-latency traffic is transmitted between the first access point and the terminal.

[0008] According to the present invention, it is possible to provide an access point and a terminal that effectively suppress interference of data transmission by P2P communication with transmission of low latency traffic by a communication station other than the terminal performing P2P communication.

[0009] FIG. 1 is a block diagram showing an example of the configuration of a communication system according to an embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of a sharing AP according to an embodiment. FIG. 3 is a block diagram showing an example of the hardware configuration of a shared AP according to an embodiment. FIG. 4 is a block diagram showing an example of the hardware configuration of a terminal according to an embodiment. FIG. 5 is a block diagram showing an example of the functional configuration of a sharing AP according to an embodiment. FIG. 6 is a block diagram showing an example of the functional configuration of a shared AP according to an embodiment. FIG. 7 is a block diagram showing an example of the functional configuration of a terminal according to an embodiment. FIG. 8 is a schematic diagram showing an example of the format of a TXS trigger frame generated by a shared AP according to an embodiment. FIG. 9 is a flowchart showing an example of processing performed by an AP to which multiple terminals performing P2P communication are wirelessly connected when P2P communication is performed between multiple terminals and low-latency traffic is transmitted between the AP and the terminal according to an embodiment. FIG. 10 is a sequence diagram showing an example of the order of data transmission when P2P communication is performed between multiple terminals and low-latency traffic is transmitted between the terminal and the shared AP in a communication system according to an embodiment. Figure 11 is a sequence diagram showing another example of the order of data transmission when P2P communication is performed between multiple terminals and low-latency traffic is transmitted between a terminal and a shared AP in a communication system according to an embodiment, which is different from Figure 10.

[0010] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components having the same functions and configurations will be denoted by the same reference numerals.

[0011] FIG. 1 is a block diagram showing an example of the configuration of a communication system according to an embodiment. As shown in FIG. 1, the communication system 1 includes a sharing AP 10 and shared APs 20-1, 20-2, and 20-3 as access points (APs), and terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B as non-AP stations (STAs). The sharing AP 10, the shared APs 20-1, 20-2, and 20-3, and the terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B each function as a single communication station in the communication system 1. In addition, a wireless network such as a wireless LAN is formed in the communication system 1.

[0012] In the following description, the sharing AP 10 will also be referred to as AP0, and the shared APs 20-1, 20-2, and 20-3 will also be referred to as AP1, AP2, and AP3, respectively. The terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B will also be referred to as STA1A, STA1B, STA2, STA3A, and STA3B, respectively. The shared APs 20-1, 20-2, and 20-3 have the same configuration. Therefore, when no particular distinction is required, the shared APs 20-1, 20-2, and 20-3 will also be simply referred to as the shared AP 20. The terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B have the same configuration. Therefore, when no particular distinction is required, the terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B are also simply referred to as terminals 30.

[0013] In the communication system 1, the sharing AP 10 is connected to a network 40 and can communicate with a server (not shown) on the network 40 via wired or wireless communication. The sharing AP 10 can also communicate with each of the shared APs 20 via wired or wireless communication.

[0014] The shared APs 20 are installed at locations physically separated from one another and have different communication areas. The communication area of ​​each shared AP 20 may partially overlap with that of any of the shared APs 20 other than the own station, or may not overlap with any of the shared APs 20 other than the own station. Each shared AP 20 can be wirelessly connected to each terminal 30 located in its communication area. Each shared AP 20 performs wireless communication with each of the wirelessly connected terminals 30 in accordance with, for example, the IEEE 802.11 standard.

[0015] Each of the terminals 30 is a wireless terminal, such as a smartphone, a personal computer (PC), or an IoT (Internet of Things) device. In the example of FIG. 1, each of the terminals 30-1A and 30-1B is wirelessly connected to a shared AP 20-1 and is capable of wireless communication with the shared AP 20-1. Furthermore, the terminal 30-2 is wirelessly connected to a shared AP 20-2 and is capable of wireless communication with the shared AP 20-2. Furthermore, each of the terminals 30-3A and 30-3B is wirelessly connected to a shared AP 20-3 and is capable of wireless communication with the shared AP 20-3.

[0016] Furthermore, in the communication system 1, data can be transmitted between multiple terminals 30 wirelessly connected to a common shared AP 20 without passing through APs including the sharing AP 10 and the shared AP 20. Data transmission performed directly between multiple terminals 30 is also referred to as "P2P (peer to peer) communication." In the example of FIG. 1, P2P communication can be performed between terminals 30-1A and 30-1B wirelessly connected to a common shared AP 20-1. Furthermore, P2P communication can be performed between terminals 30-3A and 30-3B wirelessly connected to a common shared AP 20-3.

[0017] In one example, one or more terminals 30 perform multilink communication using multiple links (channels). In this case, the terminal 30 performing multilink communication includes a non-AP MLD as a multilink device (MLD) and multiple affiliated stations (STAs). In the terminal 30 performing multilink communication, a link is set for each of the multiple affiliated STAs, and each affiliated STA is wirelessly connected to either the shared AP 20 or a terminal 30 other than the terminal 30 itself via a corresponding one of the multiple links. In the terminal 30 performing multilink communication, each of the multiple affiliated STAs may share a connection destination with one of the other affiliated STAs, or may have a connection destination different from any of the other affiliated STAs.

[0018] In the communication system 1, each of the terminals 30 can communicate with the sharing AP 10 via one or more of the shared APs 20 that are capable of wireless communication. Therefore, each of the terminals 30 can communicate with a server on the network 40 via one or more corresponding shared APs 20 and the sharing AP 10. In the example of FIG. 1 , each of the terminals 30-1A and 30-1B is connected to the sharing AP 10 via the shared AP 20-1, the terminal 30-2 is connected to the sharing AP 10 via the shared AP 20-2, and each of the terminals 30-3A and 30-3B is connected to the sharing AP 10 via the shared AP 20-3.

[0019] The connection method between each of the terminals 30 and the sharing AP 10 as described above is also referred to as a "multi-AP connection method." Furthermore, each of the shared APs 20 is also referred to as an "access point belonging" to the sharing AP 10 in the multi-AP connection method. Therefore, the sharing AP 10 is also referred to as an "associated AP," and each of the shared APs 20 is also referred to as an "associated AP." Furthermore, each shared AP 20 also refers to the terminal 30 wirelessly connected to itself as a "subordinate terminal." Furthermore, in the multi-AP connection method, one terminal 30 may be wirelessly connected to multiple shared APs 20. In one example, in a communication system 1, a terminal 30-2 is wirelessly connected to both shared APs 20-1 and 20-2.

[0020] Each of the sharing AP 10, the shared AP 20, and the terminal 30 has a wireless communication function based on, for example, the OSI (open systems interconnection) reference model. In the OSI reference model, the wireless communication function is divided into seven layers (layer 1: physical layer, layer 2: data link layer, layer 3: network layer, layer 4: transport layer, layer 5: session layer, layer 6: presentation layer, and layer 7: application layer). The data link layer includes a logical link control (LLC) sublayer and a media access control (MAC) sublayer.

[0021] Fig. 2 is a block diagram showing an example of the hardware configuration of a sharing AP according to an embodiment. Fig. 2 shows an example in which the sharing AP 10 communicates with a server on a network 40 via wired communication and with each of the shared APs 20 via wireless communication. As shown in Fig. 2, the sharing AP 10 includes, for example, a central processing unit (CPU) 11, a read only memory (ROM) 12, a random access memory (RAM) 13, a wireless communication module 14, and a wired communication module 15.

[0022] The CPU 11 is a processing circuit that controls the overall operation of the sharing AP 10. The ROM 12 is, for example, a non-volatile semiconductor memory. The ROM 12 stores programs and data for controlling the sharing AP 10. The RAM 13 is, for example, a volatile semiconductor memory. The RAM 13 is used as a work area for the CPU 11. The wireless communication module 14 is a circuit used to send and receive data via wireless signals. The wireless communication module 14 is connected to an antenna. The wired communication module 15 is a circuit used to send and receive data via wired signals. In the example of FIG. 2 , the wireless communication module 14 can be connected (wirelessly connected) to the shared APs 20-1, 20-2, and 20-3. The wired communication module 15 can then be connected to a network 40.

[0023] Note that when the sharing AP 10 communicates wirelessly with a server on the network 40 and also communicates wired with each of the shared APs 20, the wireless communication module 14 can be connected to the network 40, and the wired communication module 15 can be connected (wirelessly) to the shared APs 20-1, 20-2, and 20-3. Also, when the sharing AP 10 communicates wired with both the server on the network 40 and the shared AP 20, the sharing AP 10 does not have a wireless communication module 14. In this case, the wired communication module 15 can be connected to the network 40 and can be connected (wired) to the shared APs 20-1, 20-2, and 20-3. Also, when the sharing AP 10 communicates wirelessly with both the server on the network 40 and the shared AP 20, the sharing AP 10 does not have a wired communication module 15. In this case, the wireless communication module 14 can be connected to the network 40 and can be connected (wirelessly) to the shared APs 20-1, 20-2, and 20-3.

[0024] Fig. 3 is a block diagram showing an example of the hardware configuration of a shared AP according to an embodiment. Fig. 3 shows an example of a case where the shared AP 20 communicates wirelessly with the sharing AP 10. In one example, each of the shared APs 20-1, 20-2, and 20-3 has the same hardware configuration as the example shown in Fig. 3. As shown in Fig. 3, the shared AP 20 includes, for example, a CPU 21, a ROM 22, a RAM 23, and a wireless communication module 24.

[0025] The CPU 21 is a processing circuit that controls the overall operation of the shared AP 20. The ROM 22 is, for example, a non-volatile semiconductor memory. The ROM 22 stores programs and data for controlling the shared AP 20. The RAM 23 is, for example, a volatile semiconductor memory. The RAM 23 is used as a working area for the CPU 21. The wireless communication module 24 is a circuit used for sending and receiving data via wireless signals. The wireless communication module 24 is connected to an antenna. The wireless communication module 24 can be connected (wirelessly connected) to the sharing AP 10 and to terminals 30 located in the communication area.

[0026] When the shared AP 20 communicates with the sharing AP 10 via a wired connection, a wired communication module (not shown) is further provided in the shared AP 20. In this case, the wireless communication module 24 can be connected to a terminal 30 located in a communication area, and the wired communication module can be connected (wired) to the sharing AP 10.

[0027] Fig. 4 is a block diagram showing an example of the hardware configuration of a terminal according to an embodiment. In one example, each of terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B has the same hardware configuration as the example shown in Fig. 4. As shown in Fig. 4, the terminal 30 includes, for example, a CPU 31, a ROM 32, a RAM 33, a wireless communication module 34, a display 35, and storage 36.

[0028] The CPU 31 is a processing circuit that controls the overall operation of the terminal 30. The ROM 32 is, for example, a non-volatile semiconductor memory. The ROM 32 stores programs and data for controlling the terminal 30. The RAM 33 is, for example, a volatile semiconductor memory. The RAM 33 is used as a work area for the CPU 31. The wireless communication module 34 is a circuit used to send and receive data via wireless signals. The wireless communication module 34 is connected to an antenna. The wireless communication module 34 can be connected (wirelessly connected) to one or more corresponding shared APs 20. The display 35 is, for example, an LCD (liquid crystal display) or an EL (electro-luminescence) display. The display 35 displays a GUI (graphical user interface) corresponding to application software, etc. The storage 36 is a non-volatile storage device. The storage 36 stores system software, etc. of the terminal 30.

[0029] FIG. 5 is a block diagram showing an example of the functional configuration of a sharing AP according to an embodiment. In the following description using FIG. 5, the functional configuration of the sharing AP 10 when the sharing AP 10 communicates wirelessly with each of the shared APs 20 will be mainly described. As shown in FIG. 5, the sharing AP 10 functions as a computer including an upper layer processing unit 110, a management unit 120, a frame processing unit 130, and a transceiver unit 140. The upper layer processing unit 110 is a functional block that executes processing corresponding to the LLC sublayer of the second layer and layers 3 to 7. The management unit 120 and the frame processing unit 130 are functional blocks that execute processing corresponding to the MAC sublayer of the second layer. The transceiver unit 140 is a functional block that executes processing corresponding to the MAC sublayer of the second layer and layer 1. The management unit 120 also includes a transmission period management unit 121, which performs part of the processing performed by the management unit 120.

[0030] For example, the upper layer processing unit 110 adds a destination service access point (DSAP) header, a source service access point (SSAP) header, etc. to data received from the network 40 to generate an LLC packet as a data unit containing the data. The upper layer processing unit 110 then inputs the generated LLC packet to the frame processing unit 130. The upper layer processing unit 110 also extracts data from the LLC packet input from the frame processing unit 130. The upper layer processing unit 110 then transmits the extracted data to the network 40.

[0031] The management unit 120 manages the connection (logical connection) between the sharing AP 10 and each of the terminals 30 in the multi-AP connection method. Therefore, the management unit 120 manages the wireless connection between each of the shared APs 20 and the terminals 30 located in the communication area to which each of the shared APs 20 belongs. Furthermore, when P2P communication is performed between multiple terminals 30 wirelessly connected to the shared AP 20, the management unit 120 manages the wireless connection between the multiple terminals 30.

[0032] The management unit 120 performs management based on information about the access points (sharing AP 10 and shared AP 20) used in the multi-AP connection method, and information about the terminals 30 (e.g., terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B) connected to the sharing AP 10 using the multi-AP connection method. The information about the access points indicates, for each access point used, information about, for example, an identifier, a frequency band or channel to be used, and operational parameters. The information about the terminals 30 indicates, for each terminal 30 connected to the sharing AP 10, information about, for example, the identifier of the terminal 30 and the identifier of the shared AP 20 through which the connection with the sharing AP 10 is made. Furthermore, when P2P communication is being performed between multiple terminals 30 wirelessly connected to the shared AP 20, the management unit 120 acquires information about the terminals 30 performing P2P communication and manages the wireless connection between the terminals 30 based on the acquired information.

[0033] The management unit 120 inputs management information and control information to the frame processing unit 130. The management information input to the frame processing unit 130 includes management information to be notified to either the shared AP 20 or the terminal 30, and the control information input to the frame processing unit 130 includes control information related to control of the operation of either the shared AP 20 or the terminal 30. Furthermore, the management information and control information are input to the management unit 120 from the frame processing unit 130. The management information input to the management unit 120 includes management information notified from either the shared AP 20 or the terminal 30, and the control information input to the management unit 120 includes control information related to control of the operation of either the sharing AP 10, the shared AP 20, or the terminal 30.

[0034] The frame processing unit 130 adds a MAC header to an LLC packet, which is a data unit input from the upper layer processing unit 110, to generate a data frame as a MAC frame. The frame processing unit 130 also generates a management frame containing management information input from the management unit 120 and a control frame containing control information input from the management unit 120 as MAC frames. The frame processing unit 130 then outputs the generated MAC frames (data frames, management frames, and control frames) to the transceiver unit 140. The frame processing unit 130 also extracts any of the LLC packet, management information, and control information from the MAC frames (data frames, management frames, and control frames) input from the transceiver unit 140. The frame processing unit 130 then outputs the extracted LLC packet to the upper layer processing unit 110 and inputs the extracted management information and control information to the management unit 120. Management frames include, for example, action frames, beacon frames, and probe response frames, while control frames include, for example, trigger frames.

[0035] The transceiver 140 transmits and receives data, management information, control information, and the like to and from each of the shared APs 20 to which it belongs via wireless communication. The transceiver 140 generates wireless frames by adding preambles and the like to MAC frames (data frames, management frames, and control frames) input from the frame processor 130, and converts the generated wireless frames into wireless signals. The transceiver 140 then transmits (radiates) the converted wireless signals to one of the shared APs 20 via an antenna. The conversion process from the wireless frames to the wireless signals includes, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, orthogonal frequency division multiplexing (OFDM) modulation, and frequency conversion.

[0036] Furthermore, the transceiver 140 converts a radio signal received from one of the shared APs 20 via an antenna into a radio frame. The conversion process from the radio signal to the radio frame includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. Each transceiver 140 extracts a MAC frame from the converted radio frame and outputs the extracted MAC frame to the frame processor 130. In one example, multiple shared APs (associated APs) 20 belonging to the sharing AP 10 transmit and receive radio signals to and from the transceiver 140 of the sharing AP 10 using different frequency bands or channels.

[0037] The management unit 120 cooperates with the shared AP 20 and the terminal 30 to which it belongs, to perform allocation (mapping) of traffic transmitted and received between the sharing AP 10 and the terminal 30. As a result, traffic such as data transmitted from the sharing AP 10 is allocated to the shared AP 20 to which it belongs. Based on the traffic allocation result, the management unit 120 instructs the frame processing unit 130 on the destination of the traffic. Then, the frame processing unit 130 causes the transmission / reception unit 140 to transmit the traffic to the shared AP 20 corresponding to the instruction from the management unit 120.

[0038] When sharing AP 10 communicates with each of shared APs 20 via wired communication, a data / information processing unit is provided instead of frame processing unit 130. The data / information processing unit outputs LLC packets, which are data units input from upper layer processing unit 110, to transceiver unit 140, and outputs LLC packets input from transceiver unit 140 to upper layer processing unit 110. The data / information processing unit also outputs management information and control information input from management unit 120 to transceiver unit 140, and inputs management information and control information input from transceiver unit 140 to management unit 120.

[0039] Furthermore, when the sharing AP 10 communicates with each of the shared APs 20 via a wired network, the transmitting / receiving unit 140 is connected to each of the shared APs 20 to which the sharing AP 10 belongs via a wired network, and transmits and receives data, management information, control information, etc. via the wired network to and from each of the shared APs 20. The transmitting / receiving unit 140 is configured from a network interface for the wired network.

[0040] FIG. 6 is a block diagram showing an example of the functional configuration of a shared AP according to an embodiment. In the following description using FIG. 6, the functional configuration of the shared AP 20 when the shared AP 20 communicates wirelessly with the sharing AP 10 will be mainly described. In one example, each of the shared APs 20-1, 20-2, and 20-3 has the same functional configuration as the example shown in FIG. 6. As shown in FIG. 6, the shared AP 20 functions as a computer including a management unit 210, a frame processing unit 220, a transmission / reception unit 230, and a wireless communication unit 240. The management unit 210 and the frame processing unit 220 are functional blocks that perform processing corresponding to the MAC sublayer of the second layer. The transmission / reception unit 230 and the wireless communication unit 240 are functional blocks that perform processing corresponding to the MAC sublayer of the second layer and the first layer. The management unit 210 also includes a TXS management unit 211 and a transmission period management unit 212, and the TXS management unit 211 and the transmission period management unit 212 each perform part of the processing of the management unit 210.

[0041] The management unit 210 manages wireless connections between the local station and terminals 30 located in the communication area in a multi-AP connection system. Furthermore, when P2P communication is performed between multiple terminals 30 wirelessly connected to the local station, the management unit 210 manages the wireless connections between the multiple terminals 30. Furthermore, the management unit 210 performs management based on information about the terminals 30 wirelessly connected to the local station's shared AP 20 in a multi-AP connection system. The information about the terminals 30 indicates, for example, information about identifiers for each terminal 30 wirelessly connected to the local station. Furthermore, when P2P communication is performed between multiple terminals 30 wirelessly connected to the local station, the management unit 210 acquires information about the terminals 30 performing P2P communication, and manages the wireless connections between the terminals 30 based on the acquired information.

[0042] The management unit 210 inputs management information and control information to the frame processing unit 220. The management information input to the frame processing unit 220 includes management information to be notified to any of the sharing AP 10, the shared AP 20 other than the local station, and the terminal 30, and the control information input to the frame processing unit 220 includes control information related to control of the operation of the sharing AP 10, the shared AP 20 other than the local station, and the terminal 30. Furthermore, the management unit 210 receives management information and control information from the frame processing unit 220. The management information input to the management unit 210 includes management information to be notified to any of the shared AP 20 of the local station and the terminal 30 wirelessly connected to the local station, and the control information input to the management unit 210 includes control information related to control of the operation of any of the shared AP 20 of the local station and the terminal 30 wirelessly connected to the local station.

[0043] The frame processing unit 220 receives MAC frames (data frames, management frames, and control frames) from the transceiver unit 230 and the wireless communication unit 240. If the MAC frame from the transceiver unit 230 contains any of data, management information, and control information to be transmitted to the wirelessly connected terminal 30, the frame processing unit 220 outputs the MAC frame received from the transceiver unit 230 to the wireless communication unit 240. If the MAC frame from the wireless communication unit 240 contains any of data, management information, and control information to be transmitted to the sharing AP 10, the frame processing unit 220 outputs the MAC frame received from the wireless communication unit 240 to the transceiver unit 230. If the MAC frame from either the transceiver unit 230 or the wireless communication unit 240 contains any of management information and control information to be transmitted to the sharing AP 10, the frame processing unit 220 extracts any of the management information and control information from the received MAC frame. The frame processing unit 220 then outputs the extracted management information and control information to the management unit 210.

[0044] Furthermore, frame processing unit 220 generates, as MAC frames, a management frame including management information input from management unit 210 and a control frame including control information input from management unit 210. If the generated MAC frame includes either management information or control information to be transmitted to wirelessly connected terminal 30, frame processing unit 220 outputs the generated MAC frame to wireless communication unit 240. If the generated MAC frame includes either management information or control information to be transmitted to sharing AP 10, frame processing unit 220 outputs the generated MAC frame to transmission / reception unit 230.

[0045] The transceiver 230 transmits and receives data, management information, control information, and the like to and from the sharing AP 10 via wireless communication. The wireless communication unit 240 also transmits and receives data, management information, control information, and the like to and from the terminal 30 wirelessly connected to the local station via wireless communication. Each of the transceiver 230 and the wireless communication unit 240 generates a wireless frame by adding a preamble or the like to a MAC frame (data frame, management frame, or control frame) input from the frame processing unit 220, and converts the generated wireless frame into a wireless signal. The transceiver 230 transmits (radiates) the converted wireless signal to the sharing AP 10 via an antenna, and the wireless communication unit 240 transmits (radiates) the converted wireless signal to the terminal 30 via the antenna. The conversion process from a wireless frame to a wireless signal is performed as described above.

[0046] Furthermore, the transceiver 230 converts wireless signals received from the sharing AP 10 via the antenna into wireless frames, and the wireless communication unit 240 converts wireless signals received from the terminal 30 via the antenna into wireless frames. The conversion process from wireless signals to wireless frames is performed as described above. The transceiver 230 and the wireless communication unit 240 each extract a MAC frame from the converted wireless frame and output the extracted MAC frame to the frame processing unit 220.

[0047] Here, it is preferable that the transmitter / receiver 230 transmits and receives data using a frequency band or channel different from that of the wireless communication unit 240. In one example, the transmitter / receiver 230 may not be provided. In this case, the shared AP 20 performs wireless communication with the sharing AP 10 and the wirelessly connected terminal 30 via the wireless communication unit 240.

[0048] In the multi-AP connection method, the transmitting / receiving unit 230 receives instructions from the sharing AP 10 regarding the transmission of traffic (data) between the sharing AP 10 and the terminal 30 wirelessly connected to the sharing AP 10. The management unit 210 controls data transmission (transmission and reception of data) between the sharing AP 10 and the terminal 30 wirelessly connected to the shared AP 20 of the sharing AP 10 in accordance with the instructions from the sharing AP 10.

[0049] When the shared AP 20 communicates with the sharing AP 10 via a wired network, the transceiver 230 is connected to the sharing AP 10 via a wired network and transmits and receives data, management information, control information, and the like to and from the sharing AP 10 via the wired network. In this case, the transceiver 230 is configured as a network interface for the wired network. The transceiver 230 then inputs the LLC packets, management information, and control information received from the sharing AP 10 to the frame processing unit 220.

[0050] Frame processing unit 220 adds a MAC header to an LLC packet, which is a data unit, input from transceiver unit 230, and generates a data frame as a MAC frame. Frame processing unit 220 then inputs the generated data frame to wireless communication unit 240. Furthermore, when transmitting management information and control information from transceiver unit 230 to wirelessly connected terminal 30, frame processing unit 220 generates a management frame including management information and a control frame including control information as MAC frames, and outputs the generated MAC frames to wireless communication unit 240. Furthermore, when management information and control information for the own station is input from transceiver unit 230, frame processing unit 220 outputs the input management information and control information to management unit 210.

[0051] When the shared AP 20 communicates with the sharing AP 10 via a wired connection, the frame processing unit 220 extracts any one of an LLC packet, management information, and control information from a MAC frame (data frame, management frame, or control frame) from the wireless communication unit 240. The frame processing unit 220 then outputs the extracted LLC packet to the transceiver unit 230. When transmitting the extracted management information and control information to the sharing AP 10, the frame processing unit 220 outputs the management information and control information to the transceiver unit 230. When extracting management information and control information for the self-station, the frame processing unit 220 outputs the management information and control information to the management unit 210. When transmitting management information and control information input from the management unit 210 to the sharing AP 10, the frame processing unit 220 outputs the management information and control information from the management unit 210 to the transceiver unit 230.

[0052] FIG. 7 is a block diagram showing an example of the functional configuration of a terminal according to an embodiment. In one example, each of terminals 30-1A, 30-1B, 30-2, 30-3A, and 30-3B has the same functional configuration as the example shown in FIG. 7. As shown in FIG. 7, the terminal 30 functions as a computer including an upper layer processing unit 310, a management unit 320, a frame processing unit 330, and a wireless communication unit 340. The upper layer processing unit 310 is a functional block that executes processing corresponding to the LLC sublayer of the second layer and layers 3 to 7. The management unit 320 and the frame processing unit 330 are functional blocks that execute processing corresponding to the MAC sublayer of the second layer. The wireless communication unit 340 is a functional block that executes processing corresponding to the MAC sublayer of the second layer and layer 1. The management unit 320 also includes a transmission period adjustment unit 321, which performs part of the processing of the management unit 320.

[0053] The upper layer processing unit 310 generates LLC packets by adding DSAP headers, SSAP headers, etc. to the data. The upper layer processing unit 310 then outputs the generated LLC packets to the frame processing unit 330. The upper layer processing unit 310 also extracts data from the LLC packets input from the frame processing unit 330. The upper layer processing unit 310 then executes an application based on the extracted data. For example, the upper layer processing unit 310 can display application information on the display 35. The upper layer processing unit 310 can also operate based on operations on an input interface.

[0054] The management unit 320 manages the connection (logical wireless connection) between the sharing AP 10 and the terminal 30 of the local station in the multi-AP connection method. Therefore, the management unit 320 manages the wireless connection between the local station and the shared AP 20 in which the local station is located within its communication area. Furthermore, when the local station performs P2P communication with another terminal 30, the management unit 320 manages the wireless connection between the local station and the terminal 30 performing P2P communication. The management unit 320 performs management based on information about the shared AP 20 that is the wireless connection destination of the terminal 30 of the local station in the multi-AP connection method. The information about the shared AP 20 indicates, for example, information about the identifier for each shared AP 20 that is the connection destination of the local station. When the local station performs P2P communication with another terminal 30, the management unit 320 acquires information about the terminal 30 that is the P2P communication destination, and manages the wireless connection between the local station and the terminal 30 performing P2P communication based on the acquired information.

[0055] The management unit 320 inputs management information and control information to the frame processing unit 330. The management information input to the frame processing unit 330 includes management information to be notified to any of the sharing AP 10, the shared AP 20, and the terminal 30 other than the own station, and the control information input to the frame processing unit 330 includes control information related to control of the operation of any of the sharing AP 10, the shared AP 20, and the terminal 30 other than the own station. Furthermore, the management information and control information are input to the management unit 320 from the frame processing unit 330. The management information input to the management unit 320 includes management information to be notified to the own station, and the control information input to the management unit 320 includes control information related to control of the operation of the own station.

[0056] Frame processing unit 330 adds a MAC header to the LLC packet input from upper layer processing unit 310 to generate a data frame as a MAC frame. Frame processing unit 330 also generates, as MAC frames, a management frame including management information input from management unit 320 and a control frame including control information input from management unit 320. Frame processing unit 330 then outputs the generated MAC frames to wireless communication unit 340. Frame processing unit 330 also extracts any of LLC packets, notification information, control information, etc. from the MAC frames (data frames, management frames, and control frames) input from wireless communication unit 340. Frame processing unit 330 then outputs the extracted LLC packets to upper layer processing unit 310 and outputs the extracted notification information and control information to management unit 320.

[0057] The wireless communication unit 340 generates a wireless frame by adding a preamble or the like to the MAC frame input from the frame processing unit 330. The wireless communication unit 340 then converts the generated wireless frame into a wireless signal and transmits (radiates) the converted wireless signal via an antenna to the shared AP 20 to which it is connected. The conversion process from the wireless frame to the wireless signal is performed as described above. In P2P communication between the wireless communication unit 340 and another terminal 30, the wireless communication unit 340 transmits a wireless signal to the terminal 30 with which it is performing P2P communication.

[0058] Furthermore, the wireless communication unit 340 converts wireless signals received via an antenna from the shared AP 20, which is the destination of the wireless connection, into wireless frames. The conversion process from wireless signals to wireless frames is performed as described above. The wireless communication unit 340 extracts MAC frames from the converted wireless frames and outputs the extracted MAC frames to the frame processing unit 330. In P2P communication between the wireless communication unit 340 and another terminal 30, the wireless communication unit 340 receives wireless signals from the terminal 30 performing P2P communication.

[0059] 7 shows an example in which only one wireless communication unit 340 is provided, but this is not limiting. In one example, one or more terminals 30 perform multi-link communication, and the terminals 30 performing multi-link communication are provided with multiple wireless communication units 340 as multiple affiliated STAs. In this case, in the terminal 30, each of the multiple wireless communication units 340 is wirelessly connected to one of the shared APs 20 (and another terminal 30) via a corresponding one of multiple links. Furthermore, in the terminal 30, the management unit 320 and frame processing unit 330 function as a non-AP MLD, and the management unit 320 manages the wireless connection between each of the multiple wireless communication units 340 and its associated destination.

[0060] In this embodiment, the shared AP 20 and each of the terminals 30 wirelessly connected to the shared AP 20 are capable of performing communication operations based on a TXS (triggered TXOP sharing) function, which is an extension function of the TXOP sharing function. Each of the shared APs 20 uses the TXS function to allocate a portion of a TXOP (channel occupation period), which is a transmission opportunity acquired by carrier sensing, to a terminal located in its communication area. As a result, each of the shared APs 20 shares the acquired TXOP with the terminals wirelessly connected to it.

[0061] Furthermore, a terminal 30 to which a portion of a TXOP is assigned by the shared AP 20 as a communication available period can use the TXS function to allocate the communication available period (part of the TXOP) assigned by the shared AP 20 to P2P communication with another terminal 30 other than the terminal itself. This allows the terminal 30 to which the shared AP 20 assigns a communication available period to transmit data with another terminal 30 via P2P communication during the assigned communication available period, enabling P2P communication with another terminal without setting up a link. In P2P communication based on the TXS function, the terminal 30 transmits data with another terminal 30 wirelessly connected to a common shared AP 20. In the example of FIG. 1 , P2P communication based on the TXS function is performed between multiple terminals 30-1A and 30-1B wirelessly connected to a common shared AP 20-1, and P2P communication is performed between terminals 30-3A and 30-3B wirelessly connected to a common shared AP 20-3.

[0062] In each shared AP 20, the TXS management unit 211 of the management unit 210 manages TXS information as information related to the TXS function. The TXS information includes, for example, an identifier of a terminal 30 to which a portion of the acquired TXOP is allocated as a communication period, and information regarding the duration and time range of the communication period allocated to the terminal 30. Furthermore, if the terminal 30 to which the communication period (part of the TXOP) is allocated performs P2P communication with another terminal 30 during the communication period, the TXS information includes information regarding the identifiers of the multiple terminals 30 performing P2P communication. Furthermore, the TXS information includes, for example, information regarding constraints on P2P communication, such as information regarding the time range during which P2P communication is possible.

[0063] In the shared AP 20, the TXS management unit 211 outputs the TXS information as control information to the frame processing unit 220. Then, the frame processing unit 220 generates a trigger frame including the TXS information from the TXS management unit 211 as a control frame (MAC frame), and outputs the trigger frame including the TXS information to the wireless communication unit 240. As a result, the wireless communication unit 240 transmits a wireless signal including the TXS information to the terminals 30 wirelessly connected to the wireless station, including the terminal 30 to which a portion of the TXOP is allocated. Note that the trigger frame including the TXS information is also referred to as a "MU-RTS TXS trigger frame" and a "TXS trigger frame."

[0064] 8 is a schematic diagram illustrating an example of the format of a TXS trigger frame generated by a shared AP in an embodiment. As shown in FIG. 8, the TXS trigger frame includes a Common Info field and a User Info field. The Common Info field stores information indicating that the trigger frame is a TXS trigger frame. The Common Info field includes a Triggered TXOP Sharing Mode subfield and a TXOP Return subfield in Triggered TXOP Sharing Mode 2.

[0065] The Triggered TXOP Sharing Mode subfield stores information on whether the TXS function is applied, and if the TXS function is applied, stores information on whether P2P communication is applied. In one example, if the TXS function is not applied, the field value of the Triggered TXOP Sharing Mode subfield is set to 0. In this case, the shared AP 20 does not allocate the acquired TXOP to the wirelessly connected terminal 30. Furthermore, if the TXS function is applied and P2P communication is not applied, the field value of the Triggered TXOP Sharing Mode subfield is set to 1. In this case, the shared AP 20 allocates a portion of the acquired TXOP to the wirelessly connected terminal 30 as a communication enabled period. However, a terminal 30 that has been allocated a portion of the TXOP can transmit data with the shared AP 20 to which it is wirelessly connected during the allocated communication period, but does not perform P2P communication with other terminals 30 other than its own station.

[0066] Furthermore, when the TXS function and P2P communication are applied, the field value of the Triggered TXOP Sharing Mode subfield is set to 2. In this case, the shared AP 20 allocates a portion of the acquired TXOP to the wirelessly connected terminal 30 as a communication enabled period. Then, the terminal 30 to which a portion of the TXOP has been allocated can transmit data to the wirelessly connected shared AP 20 during the allocated communication enabled period, and can also perform P2P communication with other terminals 30 other than the terminal itself, on the condition that the field value of the TXOP Return subfield in Triggered TXOP Sharing Mode 2 is 1. However, even if the field value of the Triggered TXOP Sharing Mode subfield is 2, if the field value of the TXOP Return subfield in Triggered TXOP Sharing Mode 2 is other than 1, P2P communication between multiple terminals 30 is not performed.

[0067] In addition, in the TXS trigger frame, at least a part of the TXS information is stored in a User Info field. The User Info field includes an Allocation Duration subfield and a Reserved subfield. In one example, when P2P communication is applied, information regarding a time range during which P2P communication can be performed is stored in the Allocation Duration subfield or the Reserved subfield.

[0068] In one example, information regarding the time range during which P2P communication is possible may be stored in a management frame or control frame separate from the TXS trigger frame. In this case, the information regarding the time range during which P2P communication is possible is stored, for example, in a reserved bit in the information field format (not shown) of the management frame or control frame, or in the User Info field of the trigger frame used in the parameterized spatial reuse (PSR) function. In this case, too, information regarding the time range during which P2P communication is possible is transmitted to the terminal 30 wirelessly connected to the shared AP 20 by a wireless signal converted from the management frame or control frame.

[0069] In the communication system 1 in which the shared AP 20 and the terminal 30 perform communication operations based on the TXS function as in the embodiment, a situation may arise in which P2P communication is performed between a plurality of terminals 30α wirelessly connected to AP 20α, which is one of the shared APs 20, and a situation may arise in which AP (first AP) 20β, which is a shared AP 20 other than AP 20α, transmits data to terminal 30β wirelessly connected thereto. A situation may also arise in which data transmission is performed between AP 20β and terminal 30β around terminal 30α performing P2P communication, and data transmission is performed between AP 20β and terminal 30β using the same frequency band or the same channel as the P2P communication between terminals 30α. In such a situation, particularly when low-latency traffic is transmitted between AP 20β and terminal 30β, it is necessary to suppress interference of data transmission via P2P communication between terminals 30α with the transmission of low-latency traffic between AP 20β and terminal 30β, from the perspective of ensuring the low latency of the low-latency traffic.

[0070] Furthermore, in the communication system 1, in addition to P2P communication between terminals 30α and transmission of low-latency traffic between AP 20β and terminal 30β, a situation may arise in which P2P communication is performed between multiple terminals 30γ wirelessly connected to AP (second AP) 20γ, which is one of the shared APs 20 other than APs 20α and 20β. In such a situation, it is necessary to suppress interference in data transmission by P2P communication between terminals 30α with respect to transmission of low-latency traffic between AP 20β and terminal 30β, and it is also necessary to suppress interference in data transmission by P2P communication between terminals 30γ with respect to data transmission by P2P communication between terminals 30α. It is also necessary to suppress interference in data transmission by P2P communication between terminals 30γ with respect to data transmission by P2P communication between terminals 30α.

[0071] In this embodiment, when P2P communication between terminals 30α, transmission of low-latency traffic between AP 20β and terminal 30β, and P2P communication between terminals 30γ are performed, the sharing AP 10 cooperates with APs 20α, 20β, and 20γ, which are shared APs 20, and terminals 30α, 30β, and 30γ, to perform the processing (communication processing) described below. In the following description, AP 20α is also referred to as the "first home AP," AP 20β is also referred to as the "first AP" and the "second home AP," and AP 20γ is also referred to as the "second AP" and the "third home AP." In the following description, it is assumed that P2P communication between terminals 30α and P2P communication between terminals 30γ are performed using the same frequency band or the same channel as that used for transmission of low-latency traffic between AP 20β and terminal 30β. Unless otherwise specified, it is assumed that, in the vicinity of the terminal 30α performing P2P communication, low-latency traffic is transmitted between the AP 20β and the terminal 30β, and P2P communication is also performed between the terminals 30γ.

[0072] The transmission period management unit 121 of the sharing AP 10 cooperates with the transmission period management units 212 of the APs 20α and 20β and the transmission period adjustment units 321 of the terminals 30α and 30β to adjust the periods during which P2P communication between the terminals 30α and low-latency traffic is transmitted between the AP 20β and the terminal 30β. The transmission period management unit 121 of the sharing AP 10 also cooperates with the transmission period management units 212 of the APs 20α, 20β, and 20γ and the transmission period adjustment units 321 of the terminals 30α, 30β, and 30γ to adjust the periods during which P2P communication between the terminals 30α and 30γ is transmitted between the terminals 30α and low-latency traffic is transmitted between the AP 20β and the terminal 30β.

[0073] 9 is a flowchart illustrating an example of processing performed by an AP to which multiple terminals performing P2P communication are wirelessly connected when P2P communication is performed between multiple terminals and when low-latency traffic is transmitted between the AP and the terminals in an embodiment. In the following description, the example processing of FIG. 9 is described as processing performed by the transmission period management unit 212 of the AP (first home AP) 20α to which the terminal 30α is wirelessly connected, in cooperation with the transmission period management unit 121 of the sharing AP 10 and the transmission period adjustment unit 321 of each terminal 30α, when P2P communication is performed between multiple terminals 30α and low-latency traffic is transmitted between the AP (first AP and second home AP) 20β and the terminal 30β. Furthermore, the example processing of FIG. 9 is described assuming that in addition to P2P communication between the terminals 30α, P2P communication may also be performed between multiple terminals 30γ wirelessly connected to the AP (second AP and third home AP) 20γ.

[0074] When the processing of the example of FIG. 9 starts, the transmission period management unit 212 of AP 20α acquires information regarding the transmission of low-latency traffic between AP 20β and terminal 30β (S401). The information regarding the transmission of low-latency traffic includes information regarding the period during which the low-latency traffic is transmitted. For example, the information regarding the transmission of low-latency traffic is notified as management information from AP 20β to AP 20α via sharing AP 10. In one example, the information regarding the transmission of low-latency traffic is notified directly from AP 20β to AP 20α without going through sharing AP 10. Furthermore, if terminal 30β is wirelessly connected to AP 20α in addition to AP 20β, the information regarding the transmission of low-latency traffic may be notified directly from terminal 30β to AP 20α.

[0075] Then, the transmission period management unit 212 of the AP 20α determines whether P2P communication is taking place between the multiple terminals 30γ (S402). This determines whether P2P communication is taking place between the multiple terminals 30γ that are wirelessly connected to the AP 20γ, which is a shared AP 20 other than the AP 20α. When P2P communication is taking place between the terminals 30γ, information about the P2P communication between the terminals 30γ is notified to the AP 20α as management information via the sharing AP 10 or directly from the AP 20γ. This causes the transmission period management unit 212 of the AP 20α to determine that P2P communication is taking place between the multiple terminals 30γ that are wirelessly connected to the AP 20γ other than the AP 20α, in addition to the P2P communication between the terminals 30α. In addition, when any of the terminals 30γ is wirelessly connected to the AP 20α in addition to the AP 20γ, information regarding P2P communication between the terminals 30γ may be notified directly to the AP 20α from any of the terminals 30γ.

[0076] If P2P communication is not performed between the terminals 30γ (S402-No), the transmission period management unit 212 of the AP 20α cooperates with the transmission period management unit 121 of the sharing AP 10 and the transmission period adjustment unit 321 of each of the terminals 30α to adjust the period for P2P communication between the terminals 30α to a time range excluding the period for transmitting low-latency traffic between the AP 20β and the terminal 30β (S403). As a result, data is transmitted by P2P communication between the multiple terminals 30α, avoiding the period for transmitting low-latency traffic between the AP 20β and the terminal 30β.

[0077] In the process of S403, the transmission period management unit 212 of the AP 20α adjusts the order of the P2P communication between the terminals 30α and the transmission of low-latency traffic between the AP 20β and the terminal 30β so that the transmission of low-latency traffic between the AP 20β and the terminal 30β is prioritized over the P2P communication (data transmission) between the terminals 30α. In this case, the order is adjusted so that, for example, after the transmission of low-latency traffic between the AP 20β and the terminal 30β is completed, data transmission by P2P communication between the terminals 30α is performed.

[0078] When P2P communication is performed between the terminals 30γ (S402-Yes), the transmission period management unit 212 of the AP 20α cooperates with the transmission period management unit 121 of the sharing AP 10, the transmission period management unit 212 of the AP 20γ, and the transmission period adjustment unit 321 of each of the terminals 30α and 30γ to adjust the period of P2P communication between the terminals 30α and between the terminals 30γ to a time range excluding the period of transmission of low-latency traffic between the AP 20β and the terminal 30β (S404). As a result, data is transmitted by P2P communication between the multiple terminals 30α and between the multiple terminals 30γ other than the terminal 30α, avoiding the period of transmission of low-latency traffic between the AP 20β and the terminal 30β.

[0079] Furthermore, in the process of S404, the transmission period management units 212 and the like of APs 20α and 20γ adjust the order of P2P communication between terminals 30α, P2P communication between terminals 30γ, and transmission of low-latency traffic between AP 20β and terminal 30β so that the transmission of low-latency traffic between AP 20β and terminal 30β is prioritized over P2P communication (data transmission) between terminals 30α and 30γ. In this case, for example, the order is adjusted so that data transmission by P2P communication between terminals 30α and 30γ is performed after the transmission of low-latency traffic between AP 20β and terminal 30β is completed.

[0080] Furthermore, when P2P communication is performed between the terminals 30γ (S402-Yes), the transmission period management unit 212 of the AP 20α adjusts the order of P2P communication (data transmission) between the terminals 30α and between the terminals 30γ within a time range excluding the period during which low-latency traffic is transmitted between the AP 20β and the terminal 30β (S405). In this case, the period during which P2P communication is performed between the terminals 30α is adjusted to a time range different from both the period during which low-latency traffic is transmitted between the AP 20β and the terminal 30β and the period during which P2P communication is performed between the terminals 30γ. As a result, data is transmitted via P2P communication between the multiple terminals 30α, avoiding the period during which low-latency traffic is transmitted between the AP 20β and the terminal 30β as well as the period during which P2P communication (data transmission) is performed between the terminals 30γ.

[0081] In one example, the order of P2P communication between terminals 30α and between terminals 30γ is set in advance. Then, P2P communication between terminals 30α and between terminals 30γ is performed in the predetermined order. Furthermore, if there are three or more pairs of terminals 30 that perform P2P communication with each other, the order of the pairs that perform P2P communication may be updated periodically.

[0082] In one example, the order of pairs of terminals performing P2P communication is set by the transmission period management unit 121 of the sharing AP 10. In this case, the transmission period management unit 121 of the sharing AP 10 acquires, for each of the shared APs 20 to which the sharing AP 10 belongs, the number of terminals 30 that need to transmit high-priority data (traffic) among the terminals 30 wirelessly connected to the shared AP 20. The transmission period management unit 121 then assigns a higher priority to the terminals 30 performing P2P communication in the pair of terminals 30 that are wirelessly connected to the shared AP 20 and that need to transmit high-priority data. In this case, data transmission via P2P communication is performed in order from the terminal 30 in the pair with the highest priority. The priority of the data to be transmitted is determined, for example, based on a traffic identifier (TID).

[0083] In one example, when there are two or more sets of terminals 30 performing P2P communication, the transmission period management unit 121 of the sharing AP 10 adjusts the length of time for each of the two or more sets to perform P2P communication in addition to the order of the sets performing P2P communication. In this case, the earlier a set of terminals 30 performs P2P communication, the longer the length of time for P2P communication may be set, and the earlier a set of terminals 30 performs P2P communication, the shorter the length of time for P2P communication may be set.

[0084] When the data transmission order is adjusted by the process of the example of FIG. 9 , each shared AP 20 notifies the terminals 30 wirelessly connected to the shared AP 20, i.e., the terminals 30 subordinate to the shared AP 20, of the adjusted data transmission order as management information or control information. Then, each terminal 30 performs communication operations in accordance with the notified data transmission order. Therefore, data transmission between terminals 30α and low-latency traffic transmission between AP 20β and terminal 30β are performed in accordance with the adjusted data transmission order. Furthermore, when data transmission is performed between terminals 30γ, data transmission between terminals 30α, data transmission between terminals 30γ, and low-latency traffic transmission between AP 20β and terminal 30β are performed in accordance with the adjusted data transmission order.

[0085] In one example, the period during which low-latency traffic is transmitted between AP 20β and terminal 30β is notified to each of terminals 30α and 30γ in advance. Then, the transmission period adjustment unit 321 of each terminal 30α avoids the notified period to allow P2P communication between the terminals 30α, and the transmission period adjustment unit 321 of each terminal 30γ avoids the notified period to allow P2P communication between the terminals 30γ. The period during which low-latency traffic is transmitted between AP 20β and terminal 30β may be notified to each of terminals 30α and 30γ as an R-TWT service period (SP), which is a service period set using the R-TWT function. The period during which low-latency traffic is transmitted between AP 20β and terminal 30β is notified to each of terminals 30α and 30γ, for example, by transmitting a radio signal obtained by converting either a management frame or a control frame to each of terminals 30α and 30γ.

[0086] In another example, low-latency traffic is periodically transmitted between AP 20β and terminal 30β. APs 20α and 20γ and terminals 30α and 30γ acquire information about the period of low-latency traffic transmission between AP 20β and terminal 30β in advance. Based on the information about the period of low-latency traffic transmission between AP 20β and terminal 30β, P2P communication between terminals 30α and P2P communication between terminals 30γ are performed while avoiding the period during which low-latency traffic is transmitted between AP 20β and terminal 30β.

[0087] In one example, each shared AP 20 notifies the terminals 30 wirelessly connected to the shared AP 20, i.e., the terminals 30 subordinate to the shared AP 20, of the time range (period) during which P2P communication is possible, based on the data transmission order adjusted as described above. As a result, the AP 20α notifies the terminals 30 subordinate to the shared AP 20 of the time range during which P2P communication is possible between the terminals 30α, and the AP 20γ notifies the terminals 30γ of the time range during which P2P communication is possible between the terminals 30γ. Information regarding the time range during which P2P communication is possible is notified to the subordinate terminals 30 by transmitting a wireless signal obtained by converting either a management frame (e.g., an action frame) or a control frame. When notifying information regarding the time range during which P2P communication is possible using a wireless signal obtained by converting a TXS trigger frame, information regarding the time range during which P2P communication is possible is stored, for example, in the Allocation Duration subfield or the Reserved subfield of the User Info field of the TXS trigger frame.

[0088] In another example, until the transmission of low-latency traffic between AP 20β and terminal 30β is completed, each of APs 20α and 20γ sets the field value of the TXOP Return subfield in Triggered TXOP Sharing Mode 2 in the Common Info field of the TXS trigger frame to a value other than 1. Then, wireless signals converted from the TXS trigger frames are transmitted from each of APs 20α and 20γ to the subordinate terminals 30, thereby controlling the communication operations of terminals 30α and 30γ so that P2P communication between terminals 30α and 30γ is not performed until the transmission of low-latency traffic between AP 20β and terminal 30β is completed.

[0089] In another example, one of the terminals 30α can detect the communication status of either the AP 20β or the terminal 30β. Then, in response to detecting that low-latency traffic is being transmitted between the AP 20β and the terminal 30β, the transmission period adjustment unit 321 of one of the terminals 30α controls the communication operation of the terminal 30α so that P2P communication between the terminals 30α is not performed. Furthermore, in response to detecting that low-latency traffic is being transmitted between the AP 20β and the terminal 30β, the transmission period adjustment unit 321 of one of the terminals 30γ may control the communication operation of the terminal 30γ so that P2P communication between the terminals 30γ is not performed.

[0090] In one example, provided that AP 20α is located at a specified distance or greater from AP 20β, which transmits low-latency traffic between AP 20α and terminal 30β, the transmission period management unit 212 of AP 20α initiates P2P communication between terminals 30α wirelessly connected to the AP 20α, even while low-latency traffic is being transmitted between AP 20β and terminal 30β. In this case, the sharing AP 10 stores information, such as the location coordinates of APs 20α and 20β, and the management unit 120 calculates the distance between APs 20α and 20β based on the information about the location coordinates. The management unit 120 of the sharing AP 10 may also acquire information about the received power detected by each of APs 20α and 20β and calculate the distance between APs 20α and 20β based on the information about the received power.

[0091] 10 is a sequence diagram showing an example of the order of data transmission when P2P communication is performed between multiple terminals and low-latency traffic is transmitted between a terminal and a shared AP in a communication system according to an embodiment. In the example shown in FIG. 10, shared AP 20-1 (AP1) corresponds to AP (first home AP) 20α, and terminals 30-1A (STA1A) and 30-1B (STA1B) wirelessly connected to AP1 correspond to terminal 30α. Shared AP 20-2 (AP2) corresponds to AP (first home AP and second home AP) 20β, and terminal 30-2 (STA2) wirelessly connected to AP2 corresponds to terminal 30β. The shared AP 20-3 (AP3) corresponds to the AP (second AP and third home AP) 20γ, and the terminals 30-3A (STA3A) and 30-3B (STA3B) wirelessly connected to the AP3 correspond to the terminal 30γ.

[0092] 10 , P2P communication between STA1A and STA1B wirelessly connected to AP1 and P2P communication between STA3A and STA3B wirelessly connected to AP3 are each carried out while avoiding the period during which low-latency traffic is transmitted between AP2 and STA2. The transmission of low-latency traffic between AP2 and STA2 is given priority over the P2P communication between STA1A and STA1B and the P2P communication between STA3A and STA3B. Therefore, P2P communication between STA1A and STA1B and P2P communication between STA3A and STA3B are carried out after the transmission of low-latency traffic between AP2 and STA2 is completed.

[0093] 10 , the order of P2P communication between STA1A and STA1B and P2P communication between STA3A and STA3B is adjusted within a time range excluding the period during which low-latency traffic is transmitted between AP2 and STA2. Then, P2P communication between STA3A and STA3B is performed while avoiding the period during which P2P communication is performed between STA1A and STA1B, and P2P communication between STA3A and STA3B is performed after P2P communication between STA1A and STA1B is completed.

[0094] Fig. 11 is a sequence diagram showing another example of the order of data transmission when P2P communication is performed between multiple terminals and low-latency traffic is transmitted between a terminal and a shared AP in a communication system according to an embodiment, which is different from Fig. 10. In the example of Fig. 11, as in the example of Fig. 10, AP1 corresponds to AP (first associated AP) 20α, STA1A and STA1B correspond to terminal 30α, AP2 corresponds to AP (first associated AP and second associated AP) 20β, STA2 corresponds to terminal 30β, AP3 corresponds to AP (second associated AP and third associated AP) 20γ, and STA3A and STA3B correspond to terminal 30γ.

[0095] 11 , the data transmission order is adjusted so that P2P communication between STA3A and STA3B begins after P2P communication between STA1A and STA1B is completed before information regarding low-latency traffic transmission between AP2 and STA2 is notified. In the example of FIG. 11 , during the period when data transmission via P2P communication is being performed between STA1A and STA1B, AP2 notifies AP0, which is the sharing AP 10, of information regarding low-latency traffic transmission between AP2 and STA2 (S411). AP0 then notifies AP1 and AP3, respectively, of information regarding low-latency traffic transmission between AP2 and STA2 (S412, S413).

[0096] 11, the transmission of low-latency traffic between AP2 and STA2 is prioritized over P2P communication between STA3A and STA3B. Therefore, when P2P communication between STA1A and STA1B ends, low-latency traffic is transmitted between AP2 and STA2 before P2P communication between STA3A and STA3B. In other words, the data transmission order is updated so that P2P communication between STA3A and STA3B begins after the transmission of low-latency traffic between AP2 and STA2 ends (S414).

[0097] As described above, in the embodiments, when a management unit 210 of AP 20α, which is one of the shared APs 20, transmits low-latency traffic between AP 20β (first AP) 20β, which is one of the APs other than the AP itself, and a terminal 30β wirelessly connected to the AP itself, the management unit 210 avoids the period during which low-latency traffic is transmitted between AP 20β and terminal 30β and transmits data between multiple terminals 30α wirelessly connected to the AP itself. This processing effectively suppresses interference of data transmission by P2P communication between terminals 30α with the transmission of low-latency traffic. This appropriately ensures low latency for the low-latency traffic transmitted between AP 20β and terminal 30β.

[0098] In addition, in the embodiments, the management unit 210 of the AP 20α adjusts the order of data transmission between the terminals 30α and the transmission of low-latency traffic between the AP 20β and the terminal 30β so that the transmission of low-latency traffic between the AP 20β and the terminal 30β is prioritized over data transmission between the terminals 30α. By prioritizing the transmission of low-latency traffic over P2P communication between the terminals 30α, the low latency of the low-latency traffic transmitted between the AP 20β and the terminal 30β is further ensured.

[0099] Furthermore, in the embodiments, in addition to transmitting low-latency traffic between AP 20β and terminal 30β, when data transmission is performed between multiple terminals 30γ wirelessly connected to AP (second AP) 20γ, which is one of the APs other than AP 20β, the management unit 210 of AP 20α adjusts the order of data transmission between terminals 30α and between terminals 30γ within a time range excluding the period during which low-latency traffic is transmitted between AP 20β and terminal 30β. This effectively suppresses interference of P2P communication between terminals 30α with low-latency traffic transmission, as well as interference of P2P communication between terminals 30γ with low-latency traffic transmission. Furthermore, interference of data transmission between terminals 30γ with data transmission between terminals 30α is also effectively suppressed.

[0100] Note that there is no particular limitation on the number of shared APs 20 belonging to the sharing AP 10, as long as it is plural. That is, in a multi-AP connection method in which plural shared APs 20 belong to the sharing AP 10, an AP (first belonging AP) 20α, which is one of the shared APs 20, can transmit data between plural terminals 30α wirelessly connected to its own station, avoiding the period in which low-latency traffic is transmitted between an AP (first AP and second belonging AP) 20β, which is one of the APs other than its own station, and terminal 30β.

[0101] Furthermore, in the above-described embodiment, the functions of the sharing AP and the shared AP are completely separate, but in a modified example, the sharing AP may also have the functions of a shared AP. For example, in a communication system 1 similar to that shown in FIG. 1, the sharing AP 10 may perform the processing of the shared AP 20-1 in addition to the processing described above. In this case, the sharing AP 10 has, as its functional configuration, an upper layer processing unit 110, a management unit 120, a frame processing unit 130, and a transmission / reception unit 140, as well as a management unit 210, a frame processing unit 220, and a wireless communication unit 240.

[0102] In a sharing AP 10 having the functionality of a shared AP, the transmitter / receiver 140 transmits and receives data, management information, control information, and the like to and from each of the shared APs 20 to which it belongs, such as shared AP 20-2, via wireless or wired communication. In the sharing AP 10, the wireless communication unit 240 can transmit and receive data, management information, control information, and the like to and from each of the terminals 30 located (wirelessly connected) within the communication area via wireless communication. Data, management information, control information, and the like are exchanged between a frame processing unit 130 included in the functionality of the sharing AP 10 and a frame processing unit 220 included in the functionality of the shared AP.

[0103] In a communication system 1 provided with a sharing AP 10 having the functionality of a shared AP, the sharing AP 10 can perform the same processing as the above-described AP 20α. For example, the management unit 210 of the sharing AP 10, as in the above-described embodiment, avoids the period during which low-latency traffic is transmitted between an AP (first AP) 20β, which is one of the APs other than the sharing AP 10, and a terminal 30β, and transmits data by P2P communication between multiple terminals 30α wirelessly connected to the sharing AP 10.

[0104] Furthermore, in the above-described embodiments, the connection between the sharing AP 10 and the terminal 30 passes through one shared AP 20. However, in a modified example, the connection between the sharing AP 10 and the terminal 30 may pass through two or more shared APs. That is, the processing of the above-described embodiments can also be applied to a multi-AP connection method with a multi-stage configuration in which two or more shared APs 20 are interposed between the sharing AP 10 and the terminal 30. Therefore, even in a multi-AP connection method with a multi-stage configuration, AP 20α, which is one of the APs, transmits data between multiple terminals 30α wirelessly connected to itself, avoiding a period during which low-latency traffic is transmitted between AP 20β (first AP), which is one of the APs other than itself, and terminal 30β.

[0105] In addition, in one modified example, multiple sharing APs 10 may be provided in the communication system 1, and the multiple sharing APs 10 may be able to communicate with each other via the network 40. That is, even if AP 20β belongs to a sharing AP other than the sharing AP 10 to which AP 20α belongs, the processing of the above-described embodiment and the like may be applied. That is, even if AP 20β belongs to a sharing AP other than the sharing AP 10 to which AP 20α belongs, AP 20α transmits data between multiple terminals 30α wirelessly connected to its own station, avoiding a period during which low-latency traffic is transmitted between AP 20β (first AP) 20β, which is one of the APs other than its own station, and terminal 30β.

[0106] The processes of the above-described embodiments and the like can be stored as a program that can be executed by a processor, which is a computer. Furthermore, the program that executes the above-described processes can be stored and distributed in a storage medium of an external storage device, such as a magnetic disk, an optical disk, or a semiconductor memory. The processor can then read the program stored in the storage medium of the external storage device, and its operation can be controlled by the read program, thereby executing the processes of the embodiments and the like.

[0107] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0108] 1...Communication system 10...Sharing AP 11, 21, 31...CPU 12, 22, 32...ROM 13, 23, 33...RAM 14, 24, 34...Wireless communication module 15...Wired communication module 20 (20-1, 20-2, 20-3)...Shared AP 30 (30-1A, 30-1B, 30-2, 30-3A, 30-3B)...Terminal 35...Display 36...Storage 40...Network 110, 310...Upper layer processing unit 120, 210, 320...Management unit 121, 212...Transmission period management unit 130, 220, 330...Frame processing unit 140, 230...Transmission and reception unit 211...TXS management unit 240, 340...Wireless communication unit 321...Transmission period adjustment unit

Claims

1. An access point comprising: a wireless communication unit; and a management unit that enables data transmission between multiple terminals wirelessly connected to the wireless communication unit, and when a first access point, which is one of access points other than the access point itself, transmits low-latency traffic between the first access point and a terminal wirelessly connected thereto, allows data transmission between the multiple terminals while avoiding the period during which the low-latency traffic is transmitted between the first access point and the terminal.

2. The access point of claim 1, wherein the management unit adjusts the order of the data transmission between the plurality of terminals and the transmission of the low-latency traffic between the first access point and the terminal so that the transmission of the low-latency traffic between the first access point and the terminal is given priority over the data transmission between the plurality of terminals.

3. The access point of claim 1, wherein, in addition to the transmission of the low-latency traffic between the first access point and the terminal, when data transmission is performed between multiple terminals wirelessly connected to a second access point other than the first access point of an access point other than the local station, the management unit adjusts the order of data transmission between the multiple terminals wirelessly connected to the wireless communication unit and the order of data transmission between the multiple terminals wirelessly connected to the second access point, within a time range excluding the period during which the low-latency traffic is transmitted between the first access point and the terminal.

4. A terminal used together with an access point according to any one of claims 1 to 3, comprising: a wireless communication unit that establishes a wireless connection with said access point and is capable of transmitting data between said terminal and another terminal other than the terminal itself that is wirelessly connected to said access point; and a management unit that, when transmitting the low-latency traffic between said first access point and said terminal to which said first access point is wirelessly connected, causes data transmission between said wireless communication unit and said other terminal, avoiding the period during which said low-latency traffic is transmitted between said first access point and said terminal.

5. An access point to which a plurality of associated access points belong, the access point comprising: a management unit that, when data transmission is performed between a plurality of terminals wirelessly connected to a first associated access point that is one of the plurality of associated access points, and a second associated access point that is another of the plurality of associated access points other than the first associated access point, transmits low-latency traffic between the terminals wirelessly connected to the first associated access point, avoiding the period during which the low-latency traffic is transmitted between the second associated access point and the terminals; 6. The access point of claim 5, wherein the management unit adjusts the order of the data transmission between the plurality of terminals and the transmission of the low-latency traffic between the second access point and the terminal so that the transmission of the low-latency traffic between the second access point and the terminal is given priority over the data transmission between the plurality of terminals wirelessly connected to the first access point.

7. An access point according to claim 5 or 6, wherein, in addition to data transmission between the plurality of terminals wirelessly connected to the first access point and the transmission of the low-latency traffic between the second access point and the terminal, when data transmission is performed between a plurality of terminals wirelessly connected to a third access point that is one of the plurality of access points other than the first access point and the second access point, the management unit adjusts the order of data transmission between the plurality of terminals wirelessly connected to the first access point and the order of data transmission between the plurality of terminals wirelessly connected to the third access point, within a time range excluding the period during which the low-latency traffic is transmitted between the second access point and the terminal.

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