Terminal device, communication method, and program

Abstract

A terminal device according to an embodiment of the present invention includes: an acquisition unit; a frame processing unit; and a communication control unit. The acquisition unit acquires an allocation request for at least a part of a transmission opportunity (TXOP) period from an access point or a destination terminal serving as a communication destination of the access point. The frame processing unit transmits a trigger frame for securing the period on the basis of the allocation request. After the transmission of the trigger frame, the communication control unit relays transmission and reception of the frame between the access point and the destination terminal during the period.

Description

Terminal device, communication method and program

[0001] The embodiments relate to a terminal device, a communication method, and a program.

[0002] In a wireless local area network (LAN), an access point may support a peer-to-peer (P2P) communication scheme. In the P2P communication scheme, the access point can reserve a TXOP period for a specific terminal device using a multi-user-request-to-send (MU-RTS) TXS (triggered TXOP sharing) trigger frame in a triggered transmission opportunity (TXOP) sharing procedure mode, which is planned to be defined in the IEEE 802.11be standard. This allows the target terminal device to communicate directly with other terminal devices during the reserved TXOP period without going through the access point. Furthermore, the IEEE 802.11 standard considers a method in which, during the reserved TXOP period, the access point serving as a data source performs relay transmission to a destination terminal device via a terminal device serving as a relay station. This is expected to enable low-latency relay transmission during the TXOP period without external interference.

[0003] IEEE P802.11beTM / D5.0, “35.2.1.2 Triggered TXOP sharing procedure”, November 2023Dongguk Lim et al., “TXOP for Relay communication in 11bn”, IEEE 802,11-24 / 0105r0, January 2024

[0004] However, in the above-described relay transmission, if a destination terminal device exists outside the range of the MU-RTS TXS trigger frame transmitted by the access point, the TXOP period covers only the CTS (clear to send) range of the terminal device serving as the relay station. Therefore, if another terminal device exists within a range where the destination terminal device can be detected but the relay terminal device cannot, interference from the other terminal device and transmission standby due to carrier detection in CSMA / CA (carrier sense multiple access with collision avoidance) may occur. Therefore, low-latency relay transmission may not be achieved.

[0005] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a terminal device, a communication method, and a program that realize low-delay relay transmission.

[0006] In one embodiment, a terminal device includes an acquisition unit, a frame processing unit, and a communication control unit. The acquisition unit acquires an allocation request for at least a portion of a transmission opportunity (TXOP) from an access point or a destination terminal with which the access point communicates. The frame processing unit transmits a trigger frame to reserve the period based on the allocation request. After transmitting the trigger frame, the communication control unit relays transmission and reception of frames between the access point and the destination terminal during the period.

[0007] In addition, a terminal device according to an embodiment includes a frame generation unit and a communication control unit. The frame generation unit transmits a trigger frame to an access point or a destination terminal with which the access point communicates, during a communication period set according to a predetermined schedule or a predetermined cycle, for reserving at least a portion of a transmission opportunity (TXOP). After transmitting the trigger frame, the communication control unit relays transmission and reception of frames between the access point and the destination terminal.

[0008] According to the embodiments, it is possible to provide a terminal device, a communication method, and a program that realize low-delay relay transmission.

[0009] FIG. 1 is a block diagram showing an example of the overall configuration of a communication system according to this embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of an access point included in the communication system according to this embodiment. FIG. 3 is a block diagram showing an example of the hardware configuration of a terminal device included in the communication system according to this embodiment. FIG. 4 is a block diagram showing an example of the functional configuration of an access point included in the communication system according to this embodiment. FIG. 5 is a block diagram showing an example of the functional configuration of a relay terminal included in the communication system according to this embodiment. FIG. 6 is a block diagram showing an example of the functional configuration of a destination terminal included in the communication system according to this embodiment. FIG. 7 is a sequence diagram showing a first example of relay transmission by the communication system according to this embodiment. FIG. 8 is a sequence diagram showing a second example of relay transmission by the communication system according to this embodiment. FIG. 9 is a sequence diagram showing a third example of relay transmission by the communication system according to this embodiment. FIG. 10 is a diagram explaining a communication range defined by an MU-RTS TXS trigger frame according to this embodiment.

[0010] Each embodiment will be described below with reference to the drawings. Each embodiment illustrates an apparatus or method for embodying the technical idea of ​​the invention. The drawings are schematic or conceptual. Hereinafter, the same reference numerals are used to designate components having substantially the same functions and configurations. The numbers following the letters that make up the reference numerals are used to refer to elements with the same letters and to distinguish between elements with similar configurations. Similarly, the letters and "hyphen + number" following the numbers that make up the reference numerals are used to refer to elements with the same numbers and to distinguish between elements with similar configurations. When it is not necessary to distinguish between elements indicated by reference numerals containing the same letters or numbers, these elements will be referred to by reference numerals containing only letters or numbers.

[0011] Fig. 1 is a block diagram showing an example of the overall configuration of a communication system 1 according to this embodiment. As shown in Fig. 1, the communication system 1 includes an access point 10 and a terminal device 20. The terminal device 20 includes a relay terminal (R-STA (relay-STA)) 20-1, which is a terminal device that performs relay transmission, and a destination terminal (D-STA (destination-STA)) 20-2, which is a terminal device that transmits and receives data to and from the access point 10. Note that the access point 10 may be a base station.

[0012] The access point 10 is wirelessly connected to the terminal devices 20 via a wireless local area network (LAN) and is configured to communicate wirelessly with the terminal devices 20. The access point 10 aggregates data from the terminal devices 20 and shares the data with the terminal devices 20. The access point 10 is configured to communicate by wire or wirelessly with a server (not shown) on a network 50 (NW).

[0013] The terminal device 20 is a wireless terminal typified by a smartphone, a personal computer (PC), a tablet terminal, etc. The terminal device 20 is wirelessly connected to the access point 10 and configured to communicate wirelessly with the access point 10. While Fig. 1 shows an example in which there is one relay terminal 20-1 and one destination terminal 20-2, the present invention is not limited to this, and there may be a plurality of relay terminals 20-1 and a plurality of destination terminals 20-2.

[0014] The wireless communication used in the communication system 1 complies with, for example, the IEEE 802.11 standard. The IEEE 802.11 standard has wireless communication functions based on the OSI (Open Systems Interconnection) reference model. In the OSI reference model, wireless communication functions are 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 an LLC (logical link control) sublayer and a MAC (media access control) sublayer. Frequency bands used in the wireless communication of the communication system 1 may include, for example, the 2.4 GHz band, the 5 GHz band, the 6 GHz band, the 45 GHz band, and the 60 GHz band. Multiple channels are assigned to each frequency band.

[0015] Next, an example of the hardware configuration of the access point 10 included in the communication system 1 according to this embodiment will be described with reference to the block diagram shown in Fig. 2. As shown in Fig. 2, the access point 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.

[0016] The CPU 11 is an integrated circuit capable of executing various programs and controls the overall operation of the access point 10. The ROM 12 is, for example, a non-volatile semiconductor memory and stores programs and control data for controlling the access point 10. The RAM 13 is, for example, a volatile semiconductor memory and is used as a work area for the CPU 11. The wireless communication module 14 is a circuit connected to an antenna and used to send and receive data, etc. via wireless signals, and is used when wirelessly connecting to the terminal device 20. The wired communication module 15 is a circuit used to send and receive data, etc. via wired signals, and is configured to be connectable to the network NW. The antenna may be built into the access point 10 or may be externally connected.

[0017] The access point 10 may have other hardware configurations. For example, the access point 10 may be wirelessly connected to the network 50. In this case, a wireless communication module may be employed instead of the wired communication module 15. The CPU 11 may also be referred to as a "processor."

[0018] Next, an example of the hardware configuration of the terminal device 20 included in the communication system 1 according to this embodiment will be described with reference to the block diagram of Fig. 3. As shown in Fig. 3, the terminal device 20 includes, for example, a CPU 21, a ROM 22, a RAM 23, a wireless communication module 24, a display 25, and a storage 26.

[0019] The CPU 21 is a processing circuit that controls the overall operation of the terminal device 20. The ROM 22 is, for example, a non-volatile semiconductor memory. The ROM 22 stores programs and data for controlling the terminal device 20. The RAM 23 is, for example, a volatile semiconductor memory. The RAM 23 is used as a work area for the CPU 21. The wireless communication module 24 is a circuit connected to an antenna and used to send and receive data via wireless signals. The wireless communication module 24 is used when wirelessly connecting to the access point 10. The display 25 is, for example, an LCD (liquid crystal display) or an EL (electro-luminescence) display. The display 25 displays a GUI (graphical user interface) corresponding to application software, etc. The storage 26 is a non-volatile storage device. The storage 26 stores system software, etc. of the terminal device 20. The CPU 21 may also be referred to as a "processor."

[0020] Next, an example of the functional configuration of the access point 10 included in the communication system 1 according to this embodiment will be described with reference to the block diagram of Fig. 4. The access point 10 includes a management unit 110, a control unit 120, a frame processing unit 130, and a radio signal processing unit 140.

[0021] The management unit 110 manages various information such as terminal management information. The terminal management information includes, for example, identification information of the terminal device 20 belonging to its own BSS, TID (traffic identifier) ​​information, and information indicating whether the terminal device 20 is a relay terminal or a destination terminal. The control unit 120 controls the operation of the entire access point 10.

[0022] The frame processing unit 130 generates frames related to data from an upper application and sends them to the radio signal processing unit 140. Specifically, the frame generates a frame requesting allocation for at least a portion of the TXOP period. The frame is, for example, a frame related to a TXOP sharing request requesting P2P (peer-to-peer) communication. The frame processing unit 130 also receives radio signals from the radio signal processing unit 140, extracts the frames and data, and sends them to the upper application.

[0023] The radio signal processing unit 140 transmits the frame input by the frame processing unit 130 to the outside as a radio signal via an antenna. The radio signal processing unit 140 also sends the radio signal received by the antenna to the frame processing unit 130. Note that when notifying multiple terminal devices 20 simultaneously, the radio signal processing unit 140 may transmit a beacon signal or the like by multicast or broadcast.

[0024] Next, an example of the functional configuration of the relay terminal 20-1 according to this embodiment will be described with reference to the block diagram of Fig. 5. The relay terminal 20-1 includes a management unit 210, an acquisition unit 220, a frame processing unit 230, a control unit 240, and a radio signal processing unit 250.

[0025] The management unit 210 manages information related to communication between the terminal itself and the access point 10. For example, the information includes its own role information (relay terminal, destination terminal) and information about the access point 10. The acquisition unit 220 acquires an allocation request (e.g., a TXOP sharing request) for at least a part of the TXOP period from the access point 10 or the destination terminal 20-2.

[0026] Frame processing unit 230 receives a radio signal from radio signal processing unit 250 and extracts frames and data from the radio signal. When frame processing unit 230 receives data from a higher-level application, it generates a frame including the data and sends it to radio signal processing unit 250. Based on the allocation request acquired by acquisition unit 220, frame processing unit 230 generates a trigger frame for reserving at least a portion of the TXOP period.

[0027] After transmitting the trigger frame, the control unit 240 controls the relaying of frame transmission and reception between the access point 10 and the destination terminal 20-2 during the secured period. The wireless signal processing unit 250 transmits the frame input from the frame processing unit 230 as a wireless signal via the antenna. The wireless signal processing unit 250 also sends the wireless signal received by the antenna to the frame processing unit 230. As in the case of the access point 10, each wireless signal processing unit 250 may transmit a beacon signal or the like by multicast or broadcast. The relay terminal 20-1 may have the same functional configuration as the access point 10 shown in FIG. 4.

[0028] Next, an example of the functional configuration of the destination terminal 20-2 according to this embodiment will be described with reference to the block diagram of Fig. 6. The destination terminal 20-2 includes a management unit 310, a control unit 320, a frame processing unit 330, and a radio signal processing unit 340.

[0029] The management unit 310 manages information relating to communications between its own terminal and the access point 10. For example, this information includes its own role information (relay terminal, destination terminal) and information about the access point 10. The control unit 320 controls the overall operation of the destination terminal 20-2.

[0030] The frame processing unit 330 generates frames related to data from an upper application and sends them to the radio signal processing unit 340. Specifically, the frame processing unit 330 generates frames requesting allocation for at least a portion of the TXOP period. The frame processing unit 330 also receives radio signals from the radio signal processing unit 340, extracts the frames and data, and sends them to the upper application.

[0031] The wireless signal processing unit 340 transmits the frame input by the frame processing unit 330 to the outside as a wireless signal via an antenna. The wireless signal processing unit 340 also sends the wireless signal received by the antenna to the frame processing unit 230. The wireless signal processing unit 340 may transmit a beacon signal or the like by multicast or broadcast.

[0032] 4 to 6, the access point 10, the relay terminal 20-1, and the destination terminal 20-2 each have one wireless signal processing unit, but multiple wireless signal processing units may be included to enable different wireless communications for each frequency band used. For example, three wireless signal processing units may be included, one for each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. In this case, the access point 10, the relay terminal 20-1, and the destination terminal 20-2 can transmit and receive frames to and from each other via multilink.

[0033] Next, a first example of relay transmission by the communication system 1 according to this embodiment will be described with reference to the sequence diagram of Fig. 7. Fig. 7 shows the time series processing between the access point 10 (AP), the relay terminal 20-1 (R-STA), the destination terminal 20-2 (D-STA), and another terminal device 20-3 (O (other)-STA) that is not involved in the relay transmission. The other terminal device 20-3 is a terminal device that exists within a range that can be detected by the destination terminal 20-2 but cannot be detected by the relay terminal 20-1.

[0034] Here, we show a case where relay transmission is started by triggering data transmission from access point 10 to destination terminal 20-2, but similar processing can be applied even when relay transmission is started by triggering data transmission from destination terminal 20-2 to access point 10.

[0035] In step SA1, the access point 10 transmits a frame to the relay terminal 20-1 requesting allocation of a portion of the TXOP period. Specifically, for example, a request frame requesting execution of a triggered TXOP sharing procedure mode may be transmitted. The request frame may include information such as destination terminal information, the size of data to be transmitted, the start time of the TXOP, and the duration of the TXOP. If the request frame includes information on the start time and duration of the TXOP, the relay terminal 20-1 may set the start time and duration of the TXOP according to the contents of the request frame from the access point 10.

[0036] In step SA2, the acquisition unit 220 of the relay terminal 20-1 acquires the request frame from the access point 10. In response to the request frame, the frame processing unit 230 of the relay terminal 20-1 generates a trigger frame indicating the start of a triggered TXOP sharing procedure mode in which the relay terminal and the access point 10 are members, and transmits the trigger frame to the access point 10, which is the sender of the request frame. The trigger frame includes information such as the TXOP start time and TXOP duration. In other words, the relay terminal 20-1, having received a request from the access point 10, determines the allocation of the TXOP start time and duration and announces them using the trigger frame. Specifically, it is sufficient to generate and transmit an MU-RTS TXS trigger frame. Note that the relay terminal 20-1 may transmit a CTS-to-Self frame before transmitting the MU-RTS TXS trigger frame. The CTS-to-Self frame is a CTS transmitted to the relay terminal 20-1 as the destination and is used for access control. By transmitting a CTS-to-Self frame, the relay terminal 20-1 can prohibit transmissions by the access point 10 or terminal devices within the communication area capable of receiving the MU-RTS TXS trigger frame for a certain period of time, thereby making it easier for the access point 10 to receive the MU-RTS TXS trigger frame.

[0037] In step SA3, the access point 10 receives the trigger frame and, since the access point 10 itself is included as a member in the received trigger frame, transmits a response frame to the trigger frame to the relay terminal 20-1. The response frame is, for example, a CTS (clear to send) frame. The response frame may include information regarding the duration of the TXOP period.

[0038] In step SA4, the relay terminal 20-1 and the access point 10 transmit and receive frames exclusively to and from each other during a communication period 70 secured and allocated by the trigger frame during the TXOP period. Specifically, during this communication period, the access point 10 transmits a data frame addressed to the destination terminal 20-2 to the relay terminal 20-1.

[0039] In step SA5, the frame processing unit 230 of the relay terminal 20-1 generates a trigger frame indicating the start of a triggered TXOP sharing procedure mode with the relay terminal 20-1 and the destination terminal 20-2, to which the data frame is to be sent, as members, and transmits the trigger frame to the destination terminal 20-2.

[0040] In step SA6, the destination terminal 20-2 receives the trigger frame. Because the received trigger frame includes the destination terminal 20-2 itself as a member, it transmits a response frame (e.g., CTS) to the trigger frame to the relay terminal 20-1. Here, the other terminal device 20-3 receives the response frame transmitted by the destination terminal 20-2. The response frame may also include information regarding the duration of the TXOP period.

[0041] In step SA7, the other terminal device 20-3 receives the response frame transmitted by the destination terminal 20-2, and therefore sets a network allocation vector (NAV) that is a communication prohibition period during the communication period allocated by the trigger frame. Furthermore, the relay terminal 20-1 and the access point 10 transmit and receive frames exclusively during communication period 71 of the TXOP period secured and allocated by the trigger frame in the processing of step SA5. Specifically, data from the access point 10 is transmitted from the relay terminal to the destination terminal during this communication period.

[0042] During the communication period 71, a NAV is set for the other terminal device 20-3, and communication from the other terminal device 20-3 is suppressed, so the relay terminal can exclusively relay data from the access point 10 to the destination terminal. After the communication period 71 assigned by the trigger frame ends, the other terminal device 20-3 cancels the NAV setting and becomes able to communicate.

[0043] When transmitting data from destination terminal 20-2 to access point 10, the same procedures from step SA1 to step SA7 are carried out, except that the traffic direction is reversed.

[0044] Next, a second example of relay transmission by the communication system 1 according to this embodiment will be described with reference to the sequence diagram of Fig. 8. Note that, although an example in which relay transmission is performed from the case where the access point 10 transmits a request frame is shown here, the same processing can also be applied to the case in which relay transmission is performed from the case where the destination terminal 20-2 transmits a request frame.

[0045] In step SB1, the access point 10 transmits a request frame to the relay terminal 20-1. In step SB2, the frame processing unit 230 of the relay terminal 20-1 generates a trigger frame in which the relay terminal 20-1, the access point 10, and the destination terminal 20-2 are all members. The radio signal processing unit 250 of the relay terminal 20-1 transmits the trigger frame to the access point 10 and the destination terminal 20-2.

[0046] In step SB3, the access point 10 and the destination terminal 20-2 each transmit a response frame (for example, CTS) to the trigger frame to the relay terminal 20-1. Here, the other terminal device 20-3 receives the response frame transmitted by the destination terminal 20-2.

[0047] In step SB4, the other terminal device 20-3 receives the response frame transmitted by the destination terminal 20-2, and therefore sets a network allocation vector (NAV) that is a communication prohibition period during the communication period allocated by the trigger frame. Furthermore, data is transmitted and received between the access point 10, the relay terminal 20-1, and the destination terminal 20-2 during the communication period 80 allocated by the trigger frame.

[0048] Specifically, the relay terminal 20-1 relays data frames from the access point 10 to the destination terminal 20-2, and relays data frames from the destination terminal 20-2 to the access point 10.

[0049] Next, a third example of relay transmission by the communication system 1 according to this embodiment will be described with reference to the sequence diagram of Fig. 9. In the first and second examples of relay transmission, a request frame from the access point 10 or the destination terminal 20-2 was used as a trigger to start the communication period, but in the third example of relay transmission, this request frame is no longer necessary, and the communication period starts at a predetermined time or cycle.

[0050] In step SC1, the access point 10 broadcasts a management frame. Here, a beacon including the start time and duration of the TXOP period 90 is broadcast. After receiving the beacon, the relay terminal 20-1 transmits a trigger frame as shown in step SB2 after the start time of the TXOP period 90, and performs relay transmission between the access point 10 and the destination terminal 20-2. The subsequent processing is the same as that from step SB2 onwards, and therefore a detailed description thereof will be omitted.

[0051] Note that Figure 9 illustrates the second example of relay transmission shown in Figure 8 as the processing after step SC1, but after the access point 10 transmits the beacon in step SC1, relay transmission can also be achieved using the first example of relay transmission shown in Figure 7.

[0052] Furthermore, instead of using a management frame such as a beacon for notification, the relay terminal 20-1 may be able to recognize the period, start time, and duration of the assigned TXOP period 90 by using a period setting by R-TWT (Restricted TWT) and a scheduling function defined in the IEEE 802.11 standard. Furthermore, while the example of FIG. 9 shows an example in which the access point broadcasts the management frame, the relay terminal 20-1 may also broadcast it. In this case, the relay terminal 20-1 may receive information regarding the start time and duration of the TXOP period from the access point 10 and broadcast it from the relay terminal 20-1. Furthermore, the relay terminal 20-1 may also perform the period setting and scheduling by R-TWT. In this way, when the relay terminal 20-1 broadcasts information regarding the TXOP period, it is sufficient for the relay terminal 20-1 to include the functional configuration of the access point 10 as shown in FIG. 4.

[0053] Next, the communication range defined by the MU-RTS TXS trigger frame according to this embodiment will be described with reference to Figure 10. The communication range 10A of the access point 10 is shown by a dashed line. The communication range 20-1A of the relay terminal 20-1 is shown by a solid line. The communication range 20-2A of the destination terminal 20-2 is shown by a dashed line. For ease of explanation, it is assumed here that the access point 10 or terminal device 20 partially included in the communication range can receive data from that communication range.

[0054] That is, data transmitted from the access point 10 can be received by the relay terminal 20-1, but not by the destination terminal 20-2 or other terminal device 20-3. Data transmitted from the relay terminal 20-1 can be received by the access point 10 and the destination terminal 20-2, but not by the other terminal device 20-3. Data transmitted from the destination terminal 20-2 can be received by the relay terminal 20-1 and other terminal device 20-3, but not by the access point 10.

[0055] The MU-RTS TXS trigger frame multicast by relay terminal 20-1 is transmitted within the communication range 20-1A of relay terminal 20-1. Therefore, the access point 10 and destination terminal 20 within communication range 20-1A can receive the MU-RTS TXS trigger frame. Meanwhile, another terminal device 20-3 cannot receive the MU-RTS TXS trigger frame from relay terminal 20-1, but the CTS in response to the MU-RTS TXS trigger frame from destination terminal 20-2 is received by the other terminal device 20-3. Therefore, the received CTS allows the other terminal device 20-3 to wait for transmission, thereby realizing relay transmission from the access point 10 to destination terminal 20-2.

[0056] On the other hand, assume that the access point 10 transmits an MU-RTS TXS trigger frame, as in general P2P communication. In this case, the MU-RTS TXS trigger frame transmitted from the access point 10 is received by the relay terminal 20-1, which is within the communication range 10A, but cannot be received by the destination terminal 20-2 and other terminal devices 20-3, which are outside the communication range 10A. Here, the destination terminal 20-2 waits for transmission by sending a CTS in response to the MU-RTS TXS trigger frame, but the CTS from the relay terminal 20-1 does not reach the other terminal device 20-3. Therefore, the destination terminal 20-2 experiences interference from the other terminal device 20-3 and waits for transmission due to CSMA / CA carrier detection, which may prevent low-latency relay transmission from being achieved.

[0057] Therefore, by the relay terminal 20-1 of this embodiment transmitting an MU-RTS TXS trigger frame, interference from so-called hidden terminals that do not belong to the communication range of the access point 10 and the relay terminal 20-1 can be suppressed, and low-latency relay transmission can be achieved.

[0058] According to the present embodiment described above, a terminal device acquires a request for allocation of at least a portion of a TXOP period from an access point or another terminal device, or transmits a trigger frame to reserve the period according to a predetermined schedule or cycle. After receiving a response frame in response to the trigger frame, the terminal device relays transmission and reception of frames between the access point and another terminal device. This suppresses interference from hidden terminals and realizes low-latency relay transmission.

[0059] In the above-described embodiments, the CPU 11 of the access point 10 and the CPU 21 of the terminal device 20 may each be another circuit (or processor). For example, the access point 10 and the terminal device 20 may each include an MPU (Micro Processing Unit) or the like instead of a CPU. Each of the processes described in each embodiment may be realized by dedicated hardware. The processes of the access point 10 and the terminal device 20 may be a mixture of processes executed by software and processes executed by hardware, or may be only one of them.

[0060] In the above-described embodiments, the flowcharts or sequence diagrams used to explain the operations are merely examples. The order of the operations described in the embodiments may be changed as far as possible, or other processes may be added. A wireless communication standard other than the IEEE 802.11 standard may be used as the wireless communication standard.

[0061] 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.

[0062] DESCRIPTION OF SYMBOLS 1...Communication system 10...Access point 11, 21...CPU 12, 22...ROM 13, 23...RAM 14, 24...Wireless communication module 15...Wired communication module 20...Terminal device 20-1...Relay terminal 20-2...Destination terminal 20-3...Other terminal device 10A, 20-1A, 20-2B...Communication range 25...Display 26...Storage 50...Network 70, 71, 80...Communication period 90...TXOP period 110, 210, 310...Management unit 120, 240, 320...Control unit 130, 230, 330...Frame processing unit 140, 250, 340...Wireless signal processing unit 220...Acquisition unit

Claims

1. A terminal device comprising: an acquisition unit that acquires an allocation request for at least a portion of a TXOP (transmission opportunity) period from an access point or a destination terminal with which the access point is to communicate; a frame processing unit that transmits a trigger frame to secure the period based on the allocation request; and a communication control unit that relays the transmission and reception of frames between the access point and the destination terminal during the period after transmitting the trigger frame.

2. The terminal device of claim 1, wherein the frame processing unit transmits a first trigger frame to the access point or the destination terminal that is the source of the allocation request to secure a first period of TXOP, and the acquisition unit acquires data frames from the access point or the destination terminal that is the source of the allocation request during the first period after transmitting the first trigger frame.

3. The terminal device according to claim 2, wherein the frame processing unit transmits a second trigger frame to the destination of the data frame to secure a second period of TXOP, and the communication control unit transmits the data frame to the destination during the second period after transmitting the second trigger frame.

4. The terminal device according to claim 1, wherein the frame processing unit transmits the trigger frame to both the access point and the destination terminal.

5. A terminal device comprising: a frame generation unit that transmits a trigger frame to an access point or a destination terminal with which the access point is to communicate, during a communication period set according to a predetermined schedule or a predetermined cycle, to secure at least a portion of a TXOP (transmission opportunity); and a communication control unit that relays the transmission and reception of frames between the access point and the destination terminal after transmitting the trigger frame.

6. The terminal device according to claim 1, wherein the communication control unit relays transmission and reception of the frame after transmitting the trigger frame and receiving a response frame to the trigger frame.

7. A communications method comprising: receiving an allocation request for at least a portion of a TXOP (transmission opportunity) period from an access point or a destination terminal with which the access point is communicating; transmitting a trigger frame to reserve the period based on the allocation request; and relaying transmission and reception of frames between the access point and the destination terminal during the period after transmitting the trigger frame.

8. A program for causing a computer to function as each part of the terminal device described in claim 1.

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