Access point, controller, and terminal device

Abstract

An access point according to an embodiment of the present invention includes an acquisition unit and a determination unit. The acquisition unit acquires a request for data communication by a restricted target wake time (R-TWT) between a target terminal and another access point, the target terminal being located in a region where a first basic service set (BSS) formed by the own access point and a second BSS formed by the other access point partially overlap and belonging to the second BSS. The determination unit determines, on the basis of the position information of each of one or more first terminals belonging to the first BSS and the position information of the target terminal, a communicable terminal capable of performing data communication in the service period of the R-TWT without affecting the data communication of the target terminal in the service period of the R-TWT from among the first terminals.

Description

Access point, controller and terminal device

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

[0002] The R-TWT (restricted target wake time) function is known as a method for transmitting and receiving low-latency traffic between an access point and a terminal device. An access point using the R-TWT function sets an R-TWT service period at a period corresponding to the required latency of the low-latency traffic and notifies the terminal device of the set service period using a management frame or action frame such as a beacon. Then, when a terminal device handling low-latency traffic detects allocation of an R-TWT service period to itself through a received beacon or the like, it deterministically transmits the low-latency traffic to the access point. An information and communication system using the R-TWT function can reduce the delay and jitter of low-latency traffic.

[0003] In an overlapping BSS (OBSS) environment in which the basic service sets (BSS) formed by adjacent APs partially overlap, when an R-TWT is set by an access point, other access points do not generally perform data communication during the R-TWT service period. However, if a certain AP and a terminal device can communicate with power that does not affect the R-TWT data communication, there is a method for communicating with limited power.

[0004] IEEE802.11-23 / 0046r2, March 2023

[0005] However, while it is conceivable to actually measure the interference power between all terminals in order to realize the above-mentioned method, measuring the influence between all terminals is inefficient and unrealistic.

[0006] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide an access point, a controller, and a terminal device that can improve communication efficiency in an OBSS environment.

[0007] An access point according to an embodiment includes an acquisition unit and a determination unit. The acquisition unit acquires a request for data communication via restricted target wake time (R-TWT) between a target terminal that is located in an area where a first basic service set (BSS) formed by the access point and a second BSS formed by another access point partially overlap and that belongs to the second BSS, and the other access point. The determination unit determines, based on location information of each of one or more first terminals that belong to the first BSS and location information of the target terminal, a communication-enabled terminal that is capable of data communication during a service period of the R-TWT, among the first terminals, without affecting data communication of the target terminal during the service period of the R-TWT.

[0008] In an embodiment, the controller includes a communication unit, a calculation unit, and a determination unit. The communication unit acquires first distance information between one or more first terminals belonging to a first BSS (basic service set) formed by a first access point and the first access point, and second distance information between a second terminal located in an area where the first BSS and a second BSS formed by a second access point partially overlap and belonging to the second BSS and the second access point. The calculation unit calculates location information of the first terminal and location information of the second terminal from the first distance information and the second distance information, respectively. When a request for data communication during a restricted target wake time (R-TWT) service period is made between the second access point and the second terminal, the determination unit determines, from the one or more first terminals, a communication-enabled terminal with which data communication is possible during the R-TWT service period, without affecting data communication for the second terminal during the R-TWT service period, based on the location information of the first terminal and the location information of the second terminal.

[0009] In an embodiment, a terminal device includes an acquisition unit, a power calculation unit, and a communication unit. In an overlapping BSS (OBSS) environment in which a first BSS (basic service set) formed by a first access point and a second BSS formed by a second access point partially overlap, the acquisition unit acquires location information of the terminal device itself and location information of a target terminal that is located in an area where the first BSS and the second BSS overlap and belongs to the second BSS. When a request for data communication is made between the second access point and the target terminal during a restricted target wake time (R-TWT) service period, the power calculation unit calculates an allowable transmission power, which is transmission power that does not affect data communication of the target terminal during the R-TWT service period, based on the location information of the terminal device itself and the location information of the target terminal. When the transmission power required for data communication between the terminal device itself and the first access point is equal to or less than the allowable transmission power, the communication unit performs data communication with the first access point at the allowable transmission power during the R-TWT service period.

[0010] According to the embodiments, it is possible to provide an access point, a controller, and a terminal device that can improve communication efficiency in an OBSS environment.

[0011] FIG. 1 is a block diagram showing an example of the overall configuration of an information and communication system according to the first embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of a controller included in the information and communication system according to the first embodiment. FIG. 3 is a block diagram showing an example of the hardware configuration of an access point included in the information and communication system according to the first embodiment. FIG. 4 is a block diagram showing an example of the hardware configuration of a terminal device included in the information and communication system according to the first embodiment. FIG. 5 is a block diagram showing an example of the functional configuration of a controller included in the information and communication system according to the first embodiment. FIG. 6 is a block diagram showing an example of the functional configuration of an access point included in the information and communication system according to the first embodiment. FIG. 7 is a sequence diagram showing a first example of R-TWT control in the information and communication system. FIG. 8 is a sequence diagram showing a second example of R-TWT control in the information and communication system. FIG. 9 is a diagram showing an example of a frame sequence of an information and communication system including another access point that executes R-TWT according to the first embodiment. FIG. 10 is a block diagram showing an example of the functional configuration of a controller included in the information and communication system according to the second embodiment. FIG. 11 is a diagram showing an example of a frame sequence of an information and communication system including another access point that executes R-TWT according to the second embodiment. FIG. 12 is a block diagram showing an example of the functional configuration of a terminal device included in an information and communication system according to a third embodiment. FIG. 13 is a sequence diagram showing an example of R-TWT control in the information communication system according to the third embodiment.

[0012] 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.

[0013] 1 is a block diagram showing an example of the overall configuration of an information communication system 1 according to a first embodiment. As shown in FIG. 1, the information communication system 1 includes a controller 10, an access point 20, and a terminal device 30.

[0014] The information communication system 1 according to the first embodiment is assumed to be an OBSS environment in which BSS1, which is a first BSS formed by a first access point 20-1, and BSS2, which is a second BSS formed by a second access point 20-2, partially overlap.

[0015] The controller 10 is connected to each access point 20 by wire, and aggregates data from the access points 20 and shares the data with the access points 20. The controller 10 is configured to communicate with a server (not shown) on the network by wire or wirelessly. The controller 10 may have the same configuration as each access point 20 and may also function as a controller. The controller 10 may be connected to each access point 20 by wireless, and aggregate and share data wirelessly.

[0016] The access point 20 is a type of access point for a wireless LAN. The access point 20 is wirelessly connected to the terminal device 30 and configured to communicate with the terminal device 30 wirelessly.

[0017] The terminal device 30 is a wireless terminal such as a smartphone, a personal computer (PC), a tablet terminal, etc. The terminal device 30 is configured to be wirelessly connected to the access point 20 and to communicate wirelessly with the access point 20.

[0018] The anchor 40 is, for example, a communication device or an access point whose location is known, and is used when calculating location information, which will be described later.

[0019] In the embodiment shown below, as shown in FIG. 1, terminal device 30-1 belongs to BSS1 and performs data communication with first access point 20-1. Terminal device 30-2 belongs to BSS2 and performs data communication with second access point 20-2. Note that it is assumed that terminal device 30-2 is located in an area where BSS1 and BSS2 overlap. For convenience of explanation, although only terminal device 30-1 belongs to BSS1 in FIG. 1, it is assumed that multiple terminal devices 30 belong to BSS1. Similarly, it is assumed that multiple terminal devices 30 belong to BSS2.

[0020] The wireless communication used in the information and 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 a Logical Link Control (LLC) sublayer and a Media Access Control (MAC) sublayer. Frequency bands used in the wireless communication of the information and communication system 1 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.

[0021] Furthermore, in the information communication system 1, each of the access point 20 and the terminal device 30 supports the R-TWT function. The R-TWT function is a function that allocates a service period during which traffic requiring low latency can be preferentially exchanged to the terminal device 30. In this specification, the service period set by the R-TWT function is also referred to as the "R-TWT service period," and the traffic requiring low latency is also referred to as the "low latency traffic."

[0022] An access point 20 using the R-TWT function allocates an R-TWT service period to a link and provides preferential frame exchange opportunities to terminal devices 30. The frame exchange opportunity corresponds to an opportunity for transmitting traffic (data) through frame exchange. For example, the terminal device 30 transmits low-latency traffic to the access point 20 based on receiving a trigger frame from the access point 20 during the R-TWT service period. In this way, the R-TWT function can improve the latency of low-latency traffic by preferentially transmitting the low-latency traffic of the terminal device 30 during the R-TWT service period. In the following embodiment, it is assumed that low-latency traffic data communication using the R-TWT function is performed between a second access point 20-2 and a terminal device 30-2. In this case, the following describes how to determine a terminal that can communicate during the R-TWT service period among one or more terminal devices 30 (hereinafter referred to as "first terminals") belonging to BSS1 of the first access point 20-1.

[0023] Next, an example of the hardware configuration of the controller 10 included in the information communication system 1 according to the first embodiment will be described with reference to the block diagram shown in Fig. 2. As shown in Fig. 2, the controller 10 includes, for example, a central processing unit (CPU) 11, a read-only memory (ROM) 12, a random access memory (RAM) 13, a wired communication module 14, and a wired communication module 15.

[0024] The CPU 11 is an integrated circuit capable of executing various programs and controls the overall operation of the controller 10. The ROM 12 is, for example, a non-volatile semiconductor memory and stores programs and control data for controlling the controller 10. The RAM 13 is, for example, a volatile semiconductor memory and is used as a work area for the CPU 11. The wired communication module 14 is a circuit used to send and receive data, etc. via wired signals, and is used to send and receive data, etc. with an access point 20 (simply referred to as AP in the figure; the same applies below). 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 a network NW.

[0025] The controller 10 may have other hardware configurations. For example, the controller 10 may be wirelessly connected to the network NW and each access point 20. In this case, a wireless communication module may be employed instead of the wired communication module 14 and the wired communication module 15. The CPU 11 may also be called a "processor."

[0026] Next, an example of the hardware configuration of the access point 20 included in the information communication system 1 according to the first embodiment will be described with reference to the block diagram shown in Fig. 3. As shown in Fig. 3, the access point 20 includes, for example, a CPU 21, a ROM 22, a RAM 23, a wireless communication module 24, and a wired communication module 25.

[0027] The CPU 21 is a processing circuit that controls the overall operation of the access point 20. The ROM 22 is, for example, a non-volatile semiconductor memory. The ROM 22 stores programs and data for controlling the access point 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 that is connected to an antenna and is used when data is transmitted and received via wireless signals. The wireless communication module 24 is used when wirelessly connecting to the terminal device 30. The wired communication module 25 is a circuit that is used when data is transmitted and received via wired signals. The wired communication module 25 is used when connected to the controller 10 via a wired connection. The antenna may be built into the access point 20 or may be externally connected.

[0028] Next, an example of the hardware configuration of the terminal device 30 included in the information communication system 1 according to the first embodiment will be described with reference to the block diagram of Fig. 4. As shown in Fig. 4, the terminal device 30 includes, for example, a CPU 31, a ROM 32, a RAM 33, a wireless communication module 34, a display 35, and a storage 36.

[0029] The CPU 31 is a processing circuit that controls the overall operation of the terminal device 30. The ROM 32 is, for example, a non-volatile semiconductor memory. The ROM 32 stores programs and data for controlling the terminal device 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 connected to an antenna and used to send and receive data via wireless signals. The wireless communication module 34 is used when wirelessly connecting to the access point 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 device 30.

[0030] Next, an example of the functional configuration of the controller 10 included in the information communication system 1 according to the first embodiment will be described with reference to the block diagram of Fig. 5. The controller 10 includes a communication unit 101 and a position information estimation unit 102.

[0031] The communication unit 101 receives first distance information between the first access point 20-1 and one or more first terminals, which are terminal devices 30 belonging to BSS1, and second distance information between the second access point 20-2 and a second terminal, which is a terminal device 30 belonging to BSS2. The communication unit 101 also transmits the location information of the first terminal and the location information of the second terminal, which are generated by the location information estimation unit 102, to the first access point 20-1.

[0032] The location information estimation unit 102 estimates the location of each terminal device 30 based on the first location information and the second location information. For example, since the absolute location of a separately placed anchor 40 is known, the spatial location of the terminal device 30 can be estimated from the intersection of a circle based on distance information using the absolute location information. Specifically, in the example of FIG. 1 , the spatial location of the terminal device 30-1 can be estimated based on the intersection of three circles: a first circle created from the distance between the anchor 40-1 and the terminal device 30-1, a second circle created from the distance between the anchor 40-2 and the terminal device 30-1, and a third circle created from the distance between the terminal device 30 and the access point 20. The location information is not limited to the anchor 40, and an access point (e.g., access point 20-3 in FIG. 1 ) whose absolute location is estimated by the anchor 40 may also be used. However, the present invention is not limited to this, and the location information of the first terminal and the second terminal may be estimated using a general method based on control point surveying.

[0033] Next, an example of the functional configuration of the access point 20 included in the information communication system 1 according to the first embodiment will be described with reference to the block diagram of Fig. 6. The access point 20 includes a ranging unit 201, a controller transceiver unit 202, a power calculation unit 203, a determination unit 204, an R-TWT processing unit 205, and a communication unit 206.

[0034] The distance measurement unit 201 measures the distance between the terminal device 30 belonging to its own BSS and its own access point 20, and further the distance between the measurable terminal device 30 belonging to another BSS and its own access point 20, for example, by FTM (Fine Timing Measurement), and generates distance information. FTM is a method of exchanging FTM frames between the terminal device 30 and the access point 20 and calculating the round trip time (RTT).

[0035] The controller transmitting / receiving unit 202 transmits the distance information measured by the distance measuring unit 201 to the controller 10. The controller transmitting / receiving unit 202 acquires position information, which will be described later, from the controller.

[0036] The power calculation unit 203 calculates the allowable transmission power for each terminal device 30 based on location information of the terminal device (hereinafter referred to as the target terminal) that is located in an area where a first BSS formed by its own access point and a second BSS formed by another access point partially overlap, belongs to the second BSS, and performs data communication by R-TWT with the other access point, received from the controller 10, and location information of the terminal device 30 that belongs to its own BSS. The allowable transmission power is a transmission power that does not affect data communication of the target terminal during the R-TWT service period.

[0037] Based on the location information of each first terminal and the location information of the target terminal, the determination unit 204 determines, among the first terminals, a communication-capable terminal that is a first terminal capable of data communication during the R-TWT service period without affecting the data communication of the target terminal during the R-TWT service period.

[0038] The R-TWT processing unit 205 executes a setting process for data communication by R-TWT in the BSS of another access point for the first terminal belonging to its own BSS.

[0039] The communication unit 206 acquires a request for data communication by R-TWT (hereinafter referred to as an R-TWT request) generated in the BSS of another access point via the antenna. The communication unit 206 transmits a beacon, a trigger frame, etc. for the R-TWT setting process to the first terminal. Thereafter, the communication unit 206 executes data communication with a communicable terminal at or below the allowable transmission power.

[0040] Next, a first example of R-TWT control in the information communication system 1 will be described with reference to the sequence diagram of Fig. 7. Fig. 7 shows the time-series processing in the controller 10, the access point 20, and a terminal device 30 (hereinafter referred to as the first terminal) belonging to the BSS of the access point 20 itself. Here, the processing is assumed to be performed when another access point (not shown) requests data communication with the target terminal via R-TWT.

[0041] In step SA1, the distance measurement unit 201 of the access point 20 measures the distance between each first terminal and its own access point 20. A general method such as the FTM described above is assumed as the distance measurement method, and therefore a detailed description thereof will be omitted. Then, the measured distance information for each terminal device is transmitted to the controller 10. It is assumed that the distance measurement shown in step SA1 is performed periodically.

[0042] In step SA2, the communication unit 206 of the access point 20 acquires an R-TWT request. The communication unit 206 may receive an R-TWT request transmitted from another access point, or the other access point may transmit an R-TWT request to the controller 10, and the controller transceiver unit 202 may acquire the R-TWT request via the controller 10. The controller transceiver unit 202 or the communication unit 206 that acquires the R-TWT request may also be referred to as an acquisition unit. Note that after acquiring the R-TWT request, distance measurement may be performed separately from the periodic processing of step SA1. This allows for the generation of location information of the first terminal immediately before data communication via R-TWT is performed, thereby improving the accuracy of determining communicable terminals.

[0043] In step SA3, the location information estimation unit 102 of the controller 10 estimates the locations of the first terminal and the target terminal, and generates location information for each of them. Note that the location information is not limited to absolute locations, and may be relative distances between the terminal devices belonging to the BSS.

[0044] In step SA4, the determination unit 204 of the access point 20 determines a communication-enabled terminal capable of data communication based on the positional relationship between the first terminal and the target terminal. Specifically, for example, the determination unit 204 determines the first terminal as a communication-enabled terminal based on the distance between the first terminal and the target terminal and the position of the access point 20 itself and the first terminal. If the distance between the first terminal and the target terminal is equal to or greater than a first threshold and the angle formed by the first communication direction of the first terminal relative to the access point 20 and the second communication direction of the access point 20 relative to the target terminal is equal to or greater than a second threshold, the determination unit 204 determines the first terminal as a communication-enabled terminal. In other words, if the first terminal and the target terminal are sufficiently far apart and the communication direction toward the first terminal is at an angle away from the target terminal, it is considered that this will not affect the data communication by R-TWT of the target terminal. The first and second thresholds may be calculated based on information such as RSSI (Received Signal Strength Indicator), or may be empirically determined values. Here, it is assumed that a terminal device, which is a first terminal shown in FIG. 7, is determined as a communication-enabled terminal.

[0045] In step SA5, the R-TWT processing unit 205 of the access point 20 broadcasts the R-TWT setting in response to the R-TWT request from another access point to the first terminal belonging to its own BSS. The R-TWT setting includes R-TWT setup information, such as the start time of the TWT, the duration of the TWT, and the end time of the TWT.

[0046] In step SA6, the R-TWT processing unit 205 of the access point 20 transmits a trigger frame for starting the R-TWT service period to a first terminal including a communication-enabled device belonging to its own BSS. In step SA7, data communication is performed between the access point 20 and the communication-enabled terminal during the R-TWT service period with power restrictions. As an example of power restrictions, the greater the distance between the communication-enabled terminal and the target terminal and the angle formed as described above, the less the impact on the target terminal is considered to be, so the transmission power for the communication-enabled terminal is set high. On the other hand, the smaller the distance and the angle formed as described above, the greater the impact on the target terminal is considered to be, so the transmission power for the communication-enabled terminal can be set low.

[0047] Next, a second example of R-TWT control in the information communication system 1 will be described with reference to the sequence diagram of Fig. 8. In Fig. 7, the communication-enabled terminals are determined based only on the location information, but in the example of Fig. 8, the communication-enabled terminals are determined based on the location information and the allowable transmission power. The processes of steps SA1-SA3, SA5, and SA6 are the same as those in Fig. 7.

[0048] In step SB1, the power calculation unit 203 of the access point 20 calculates, for each first terminal, an allowable transmission power that does not affect data communication of the target terminal, based on the location information of the first terminal and the location information of the target terminal. In step SB2, the determination unit 204 of the access point 20 determines which communication-enabled terminals are capable of data communication at the allowable transmission power. Specifically, the determination unit 204 determines whether the required transmission power, which is the transmission power necessary for communication between the access point 20 itself and the first terminal, is equal to or less than the allowable transmission power. The determination unit 204 may determine as a communication-enabled terminal a first terminal whose required transmission power is equal to or less than the allowable transmission power. In step SB3, data communication is performed between the access point 20 and the terminal device 30 during the R-TWT service period at the allowable transmission power or less. Note that the following mainly describes an example in which communication-enabled terminals are determined based on the allowable transmission power, but a method of determining communication-enabled terminals based solely on location information is also equally feasible.

[0049] Next, an example of a frame sequence of the information communication system 1 including other access points that execute R-TWT will be described with reference to Fig. 9. Here, it is assumed that the access point 20-2 executes data communication with the terminal device 30-2 under its control using low-latency traffic during the R-TWT service period. That is, in relation to the description of Fig. 7, the access point 20-2 corresponds to the "other access point," the terminal device 30-2 corresponds to the "target terminal," and the terminal device 30-1 corresponds to the "communication-enabled terminal."

[0050] In step SC1, each access point (access points 20-1 and 20-2) periodically acquires distance information between itself and terminal devices (terminal devices 30-1 and 30-2) belonging to its own BSS, and transmits the information to the controller 10. In step SC2, the access point 20-2 transmits an R-TWT request to the access point 20-1. Note that if the access point 20-2 periodically acquires location information of the terminal device 30-2 from the controller 10, the access point 20-2 may transmit the R-TWT request together with the location information of the target terminal specified in the R-TWT request.

[0051] In step SC3, the controller 10 transmits location information of the first terminals, including the terminal device 30-1, and location information of the terminal device 30-2 to the access point 20-1. In step SC4, the access point 20-1 calculates the allowable transmission power for the first terminals belonging to its own BSS1 and determines the terminals with which it can communicate. The access point 20-1 then broadcasts the R-TWT configuration to the terminal devices belonging to its own BSS. The R-TWT configuration notifies the start time and duration (or end time) of the R-TWT service period, as well as the terminal ID (e.g., MAC address) that specifies the terminal with which it can communicate and the allowable transmission power of the terminal. If the first terminal that receives the R-TWT configuration has its own terminal ID included in the R-TWT configuration, it recognizes that it has been set as a terminal with which it can communicate and is set to transmit at the allowable transmission power during the R-TWT service period.

[0052] In step SC5, each access point 20 transmits a trigger frame to the terminal device 30 belonging to its own BSS. In step SC6, during the R-TWT service period, the access point 20-2 performs data communication with the terminal device 30-2 using low-latency traffic. Meanwhile, in step SC7, the access point 20-1 performs data communication with the terminal device 30-1, which is a communicable terminal, at or below the allowable transmission power.

[0053] In an environment where beamforming can be used, depending on the positional relationship between the target terminal and the first terminal, data communication at a power greater than the allowable transmission power may not affect the data communication of the target terminal. Therefore, for example, the determination unit 204 of the access point 20-1 determines a communicable terminal with which data communication is possible when beamforming is applied, based on the positional information between the target terminal and the first terminal, without affecting the data communication of the target terminal. Thereafter, during the R-TWT service period, data communication may be performed between the access point 20-1 and the communicable terminal using beamforming.

[0054] Alternatively, the determination unit 204 of the access point 20-1 calculates, based on location information between the target terminal and the first terminal, an extended allowable transmission power, which is the transmission power that is allowable without affecting the data communication of the target terminal when beamforming is applied. A communication-enabled terminal may perform data communication with the access point 20-1 at the extended allowable transmission power during the R-TWT service period of the target terminal. This allows data communication during the R-TWT service period for terminals that, before using beamforming, are unable to communicate with the target terminal due to their positional relationship with the target terminal or are unable to communicate because power higher than the allowable transmission power is required for data communication, but can communicate without interfering with the data communication of the target terminal by using beamforming.

[0055] According to the first embodiment described above, in an OBSS environment in which a first BSS of a first access point and a second BSS of a second access point partially overlap, location information of a target terminal that performs data communication with a second access point via R-TWT and location information of a first terminal that is a terminal device belonging to the BSS of the first access point are calculated. Based on the location information of the target terminal and the location information of the first terminal, a communicable terminal that is a first terminal that is capable of data communication with the first access point during the R-TWT service period is determined without affecting the data communication of the target terminal during the R-TWT service period. The communicable terminal performs data communication with the first access point under power restrictions that do not affect the data communication of the target terminal during the R-TWT service period, or at or below the allowable transmission power.

[0056] This allows the location of the target terminal performing data communication via R-TWT to be referenced to determine the terminals that can communicate with the system, thereby enabling flexible setting of transmission power for each terminal device and more accurate determination of the presence of terminals that can communicate with the system. Therefore, even during the R-TWT service period, data communication can be performed as needed at an access point that does not perform data communication via R-TWT. In other words, communication efficiency can be improved in an OBSS environment.

[0057] Second Embodiment The second embodiment differs from the first embodiment in that the controller determines the terminals capable of communicating with each other at a transmission power level equal to or lower than the allowable transmission power during the R-TWT service period. The functional configuration of the controller 10 according to the second embodiment will be described with reference to the block diagram of FIG.

[0058] The controller 10 according to the second embodiment includes a communication unit 101 , a position information estimation unit 102 , a power calculation unit 103 , and a communication available terminal determination unit 104 .

[0059] The power calculation unit 103 calculates the allowable transmission power based on the location information of the target terminal and the location information of the first terminal, similar to the power calculation unit 203 of the access point 20 according to the first embodiment. The communication possible terminal determination unit 104 determines, as a communication possible terminal device, the first terminal whose transmission power required for data communication with the first terminal is equal to or less than the allowable transmission power, similar to the determination unit 204 of the access point 20 according to the first embodiment.

[0060] Next, a frame sequence of the information communication system 1 including other access points that execute R-TWT according to the second embodiment will be described with reference to Fig. 11. Except for the frame transmitted from the controller 10, the frame sequence is the same as that shown in Fig. 9.

[0061] In step SD1, the controller 10 transmits information about the communication-enabled terminals determined by the communication-enabled terminal determination unit 104 to the access point 20-1. The access point 20-1 broadcasts an R-TWT configuration including information about the communication-enabled terminals and the corresponding allowable transmission power to the terminal devices belonging to its own BSS. When the R-TWT configuration includes its own terminal ID, the terminal device 30-1 recognizes that it is a communication-enabled terminal. After that, the terminal device 30-1 receives a trigger frame that starts the R-TWT service period (step SC5), and then performs data communication with the access point 20-1 during the R-TWT service period (step SC7).

[0062] According to the second embodiment described above, by determining which terminals are capable of communicating on the controller side, which can aggregate distance information and location information, the processing load on the access point to determine which terminals are capable of communicating can be reduced, and communication efficiency in an OBSS environment can be improved.

[0063] Third Embodiment A third embodiment differs from the above-described embodiments in that the terminal device 30 itself determines whether it is a communication-capable terminal.

[0064] The functional configuration of the terminal device 30 according to the third embodiment will be described with reference to the block diagram of FIG. 12 . The terminal device 30 includes a communication unit 301, a power calculation unit 302, and a determination unit 303. The communication unit 301 includes a location information acquisition unit 304. The communication unit 301 receives location information of the target terminal and its own location information from the access point 20-1. Furthermore, if the communication unit 301 is a communication-capable terminal, the communication unit 301 executes data communication with the access point 20-1 during the R-TWT service period. The power calculation unit 302 calculates the required transmission power, which is the transmission power necessary for the terminal device 30 to communicate with the access point 20-1, and the allowable transmission power, based on the respective location information acquired by the communication unit 301. The determination unit 303 determines whether the required transmission power is equal to or less than the allowable transmission power, and determines that the terminal device 30 is a communication-capable terminal if the required transmission power is equal to or less than the allowable transmission power.

[0065] Next, an example of R-TWT control in the information communication system 1 according to the third embodiment will be described with reference to the sequence diagram of FIG. 13. Note that steps SA1-SA3, SA6, and SB3 are the same processes as those in FIG. 8. In step SE1, the R-TWT setting is broadcasted, including the location information of the target terminal and the location information of each first terminal. Note that the location information of the target terminal and the location information of each first terminal may be transmitted to the first terminal in a beacon frame or another frame without being included in the R-TWT setting.

[0066] In step SE2, the power calculation unit 302 of the first terminal calculates the required transmission power and the allowable transmission power based on the location information of the target terminal and the location information of each terminal device.

[0067] In step SE3, the determination unit 303 of the first terminal determines whether or not the first terminal is capable of communication during the R-TWT service period, i.e., whether or not the first terminal is a communication-capable terminal. If the required transmission power is greater than the allowable transmission power, it is considered that this will affect the data communication of the target terminal. Therefore, after receiving a trigger frame that starts the R-TWT service period from the access point 20-1 (step SA6), in step SE4, the determination unit 303 of the terminal device 30-1 determines to suspend transmission and does not perform data communication during the R-TWT service period.

[0068] On the other hand, if the required transmission power is less than the allowable transmission power, it can be determined that the device is a terminal capable of communication, and after receiving a trigger frame that starts the R-TWT service period from access point 20-1 (step SA6), data communication is performed at less than the allowable transmission power during the R-TWT service period (step SB3).

[0069] According to the third embodiment described above, the terminal device determines whether to transmit data during the R-TWT service period, and if the required transmission power is equal to or less than the allowable transmission power, the terminal device is determined to be a communication-capable terminal and performs data communication during the R-TWT service period of the target terminal. This reduces the processing load of the access point and improves communication efficiency in an OBSS environment.

[0070] In the above-described embodiments, the CPU 11 of the controller 10, the CPU 21 of the access point 20, and the CPU 31 of the terminal device 30 may each be another circuit (or processor). For example, the controller 10, the access point 20, and the terminal device 30 may each include an MPU (micro processing unit) or the like instead of a CPU. The processes described in each embodiment may each be realized by dedicated hardware. The processes of the controller 10, the access point 20, and the terminal device 30 may each be a mixture of processes executed by software and processes executed by hardware, or may be only one of them.

[0071] In the above embodiments, the flowcharts used to explain the operations are merely examples. The order of the processes of the operations described in the embodiments may be changed as far as possible, and other processes may be added. For example, the multi-AP connection setup method and R-TWT communication method described in the above embodiments are merely examples. A wireless communication standard other than the IEEE 802.11 standard may be used as the wireless communication standard.

[0072] 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.

[0073] 1...Information communication system 10...Controller 11, 21, 31...CPU 12, 22, 32...ROM 13, 23, 33...RAM 14, 15, 25...Wired communication module 20, 20-3...Access point 20-1...First access point 20-2...Second access point 24, 34...Wireless communication module 30, 30-1, 30-2...Terminal device 35...Display 36...Storage 40, 40-1, 40-2...Anchor 101...Communication unit 102...Location information estimation unit 103...Power calculation unit 104...Communication available terminal determination unit 201...Distance measurement unit 202...Controller transmission / reception unit 203...Power calculation unit 204...Determination unit 205...R-TWT processing unit 206...Communication unit 301...Communication unit 302...Power calculation unit 303...Determination unit 304...Position information acquisition unit

Claims

1. An access point, comprising: an acquisition unit configured to acquire a request for data communication by restricted target wake time (R-TWT) between a target terminal belonging to a second basic service set (BSS) formed by another access point and the other access point, the target terminal being located in a region where a part of a first BSS formed by its own access point overlaps with a part of the second BSS; and a determination unit configured to determine, based on position information of each of one or more first terminals belonging to the first BSS and position information of the target terminal, a communicable terminal that can perform data communication during a service period of the R-TWT without affecting data communication of the target terminal during the service period of the R-TWT among the first terminals.

2. The access point according to claim 1, wherein the determination unit determines the first terminal as the communicable terminal when a distance between the first terminal and the target terminal is greater than or equal to a first threshold value and an angle formed by a first communication direction between its own access point and the first terminal and a second communication direction between its own access point and the target terminal is greater than or equal to a second threshold value.

3. The access point according to claim 1, further comprising a power calculation unit configured to calculate, for each of the first terminals, an allowable transmission power that is a transmission power that does not affect data communication of the target terminal during the service period of the R-TWT based on the position information of the first terminal and the position information of the target terminal, wherein the determination unit determines a first terminal whose transmission power required for data communication with the first terminal is less than or equal to the allowable transmission power as the communicable terminal.

4. The access point according to claim 3, further comprising a communication unit configured to perform data communication with the communicable terminal at a transmission power less than or equal to the allowable transmission power after broadcasting a trigger frame for starting a service period of the R-TWT.

5. The access point according to claim 1, wherein when performing data communication using beamforming, the determination unit determines, as the communicable terminal, a first terminal that does not affect data communication of the target terminal during the service period of the R-TWT according to a positional relationship between the target terminal and the first terminal, and the access point further comprises a communication unit configured to perform data communication with the communicable terminal using the beamforming during the service period of the R-TWT.

6. The access point according to claim 1, wherein the position information of the target terminal is included in the request for data communication by the R-TWT.

7. A communication unit that acquires first distance information between one or more first terminals belonging to a first BSS (basic service set) formed by a first access point and the first access point, and second distance information between a second terminal belonging to the second BSS and the second access point, the second BSS being formed by the second access point, and a part of the second BSS overlapping with the first BSS; A calculation unit that calculates the position information of the first terminal and the position information of the second terminal from the first distance information and the second distance information; and when there is a request for data communication during the service period of R-TWT (restricted target wake time) between the second access point and the second terminal, based on the position information of the first terminal and the position information of the second terminal, among the one or more first terminals, a determination unit that determines a communicable terminal that can perform data communication during the service period without affecting the data communication of the second terminal during the service period of the R-TWT.

8. In an OBSS (overlapping BSS) environment where a part of a first BSS (basic service set) formed by a first access point overlaps with a second BSS formed by a second access point, an acquisition unit that acquires the position information of the own device and the position information of a target terminal that is located in the overlapping region of the first BSS and the second BSS and belongs to the second BSS; a power calculation unit that calculates an allowable transmission power that is a transmission power that does not affect the data communication of the target terminal during the service period of the R-TWT (restricted target wake time) based on the position information of the own device and the position information of the target terminal when there is a request for data communication during the service period of the R-TWT between the second access point and the target terminal; and a communication unit that performs data communication with the first access point at the allowable transmission power during the service period of the R-TWT when the transmission power required for data communication between the own device and the first access point is equal to or less than the allowable transmission power.

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