Terminals and methods

Abstract

This invention provides a terminal and communication method that implement a new communication method for improving data transmission speed. [Solution] In a communication system, a terminal capable of wirelessly communicating with an access point in a first frequency band and a second frequency band comprises a communication unit and a circuit. The circuit uses the communication unit to receive a first beacon frame transmitted from the access point in the first frequency band and / or a second beacon frame transmitted from the access point in the second frequency band, and determines that the access point is capable of multiband communication based on multiband-related information contained in the first or second beacon frame.

Description

Technical Field

[0001] The present invention relates to an access point and a communication method.

Background Art

[0002] As wireless communication methods related to conventional wireless LAN (Local Area Network), there are IEEE 802.11a, IEEE 802.11ax, etc. shown in Non-Patent Document 1 and Non-Patent Document 2. IEEE 802.11ax is a wireless communication method having a maximum frequency band of 160 MHz in the 2.4 GHz band or the 5 GHz band as a frequency band. In this wireless communication method, a communication method called MIMO (Multiple-Input Multiple-Out) is applied, in which a plurality of modulated signals of a plurality of streams are transmitted simultaneously using the same frequency (common frequency) using a plurality of antennas, thereby improving the reception quality of data and / or increasing the communication speed of data (per unit time).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

[0004] When the size of communication equipment is constrained, it becomes difficult to install more than a certain number of antennas, and further improvements in data transmission speed require the introduction of new communication methods.

[0005] Therefore, the present invention provides an access point and the like that implements a new communication method for further improving the data transmission speed. [Means for solving the problem]

[0006] A terminal according to one aspect of the present disclosure is a terminal capable of wirelessly communicating with an access point in a first frequency band and a second frequency band, comprising a communication unit and a circuit, wherein the circuit uses the communication unit to receive a first beacon frame transmitted from the access point in the first frequency band and / or a second beacon frame transmitted from the access point in the second frequency band, and determines that the access point is capable of multiband communication based on multiband-related information contained in the first beacon frame or the second beacon frame.

[0007] These comprehensive or specific embodiments may be implemented as a system, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM, or as any combination of a system, method, integrated circuit, computer program, and recording medium. [Effects of the Invention]

[0008] According to this disclosure, since one or more frequency bands can be suitably selected and used, the effect of improving the data transmission speed of the communication system can be obtained. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows an example of the configuration of a communication device. [Figure 2] Figure 2 shows the transmission and reception of a modulated signal. [Figure 3A] Figure 3A shows the signal configuration of the RTS. [Figure 3B] Figure 3B shows the signal configuration of MU-RTS. [Figure 3C] Figure 3C shows the signal configuration of MC-MU-RTS. [Figure 4A] Figure 4A shows an example of a frame configuration. [Figure 4B] Figure 4B shows an example of a frame configuration. [Figure 5A] Figure 5A shows an example of a frame configuration. [Figure 5B] Figure 5B shows an example of a frame configuration. [Figure 5C] Figure 5C shows an example of a frame configuration. [Figure 5D] Figure 5D shows an example of a frame configuration. [Figure 5E] Figure 5E shows an example of a frame configuration. [Figure 5F] Figure 5F shows an example of a frame configuration. [Figure 5G] Figure 5G shows an example of a frame configuration. [Figure 5H] Figure 5H shows an example of a frame configuration. [Figure 5I] Figure 5I shows an example of a frame configuration. [Figure 5J] Figure 5J shows an example of a frame configuration. [Figure 5K] Figure 5K shows an example of a frame configuration. [Figure 6A] FIG. 6A is a diagram showing an example of the configuration of a data symbol. [Figure 6B] FIG. 6B is a diagram showing an example of the configuration of a data symbol. [Figure 7] FIG. 7 is a diagram showing an example of the frame configuration. [Figure 8] FIG. 8 is a diagram showing an example of the frame configuration. [Figure 9] FIG. 9 is a diagram showing an example of the frame configuration. [Figure 10] FIG. 10 is a diagram showing an example of the frame configuration. [Figure 11] FIG. 11 is a diagram showing an example of the frame configuration. [Figure 12] FIG. 12 is a diagram showing an example of the frame configuration. [Figure 13] FIG. 13 is a diagram showing an example of the frame configuration. [Figure 14] FIG. 14 is a diagram showing an example of the frame configuration. [Figure 15] FIG. 15 is a diagram showing an example of the frame configuration. [Figure 16] FIG. 16 is a diagram showing an example of the frame configuration. [Figure 17] FIG. 17 is a diagram showing an example of the frame configuration. [Figure 18] FIG. 18 is a diagram showing an example of the frame configuration. [Figure 19A] FIG. 19A is a diagram showing an example of the communication state of an access point. [Figure 19B] FIG. 19B is a diagram showing an example of the communication state of an access point. [Figure 20A] FIG. 20A is a diagram showing the configuration of the transmission unit included in the transmission and reception device. [Figure 20B] FIG. 20B is a diagram showing the configuration of the reception unit included in the transmission and reception device. [Figure 21A] FIG. 21A is a diagram showing the frequency band for transmitting a modulation signal. [Figure 21B] FIG. 21B is a diagram showing the frequency band for transmitting a modulation signal. [Figure 21C] Figure 21C shows the frequency band used to transmit the modulated signal. [Figure 22A] Figure 22A shows an example of RTS transmission. [Figure 22B] Figure 22B shows an example of CTS transmission. [Figure 22C] Figure 22C shows an example of sending a set of symbols. [Figure 23A] Figure 23A shows an example of CTS transmission. [Figure 23B] Figure 23B shows an example of sending a set of symbols. [Figure 24A] Figure 24A shows an example of CTS transmission. [Figure 24B] Figure 24B shows an example of sending a set of symbols. [Figure 25A] Figure 25A shows an example of CTS transmission. [Figure 25B] Figure 25B shows an example of sending a set of symbols. [Figure 26A] Figure 26A shows an example of RTS transmission. [Figure 26B] Figure 26B shows an example of CTS transmission. [Figure 26C] Figure 26C shows an example of sending a set of symbols. [Figure 27A] Figure 27A shows an example of RTS transmission. [Figure 27B] Figure 27B shows an example of CTS transmission. [Figure 27C] Figure 27C shows an example of sending a set of symbols. [Figure 28A] Figure 28A shows an example of RTS transmission. [Figure 28B] Figure 28B shows an example of CTS transmission. [Figure 28C] Figure 28C shows an example of sending a set of symbols. [Figure 29A] Figure 29A shows an example of RTS transmission. [Figure 29B] Figure 29B shows an example of CTS transmission. [Figure 29C] Figure 29C shows an example of CTS transmission. [Figure 29D] Figure 29D shows an example of sending a set of symbols. [Figure 30] Figure 30 shows an example of communication between a terminal and an access point. [Figure 31A] Figure 31A shows an example of RTS transmission. [Figure 31B] Figure 31B shows an example of CTS transmission. [Figure 31C] Figure 31C shows an example of sending a set of symbols. [Figure 32] Figure 32 shows an example of communication between a terminal and an access point. [Figure 33A] Figure 33A shows an example of RTS transmission. [Figure 33B] Figure 33B shows an example of CTS transmission. [Figure 33C] Figure 33C shows an example of CTS transmission. [Figure 33D] Figure 33D shows an example of sending a set of symbols. [Figure 34] Figure 34 shows an example of symbol transmission. [Figure 35] Figure 35 shows an example of symbol transmission. [Figure 36] Figure 36 shows an example of a data frame structure. [Figure 37] Figure 37 shows an example of a beacon frame configuration. [Figure 38] Figure 38 shows an example of the structure of a Probe request frame. [Figure 39] Figure 39 shows an example of the structure of a probe response frame. [Figure 40] Figure 40 shows an example of the structure of an Association request frame. [Figure 41]Figure 41 shows an example of the configuration of an Association response frame. [Figure 42] Figure 42 shows the state of the system. [Figure 43] Figure 43 shows an example of a terminal configuration. [Figure 44] Figure 44 shows an example of the structure of an Association request frame. [Figure 45] Figure 45 shows an example of the structure of an Association request frame. [Figure 46] Figure 46 shows an example of the configuration of an Association response frame. [Figure 47] Figure 47 shows an example of the configuration of an Association response frame. [Figure 48] Figure 48 shows an example of a beacon frame configuration. [Figure 49] Figure 49 shows an example of a beacon frame configuration. [Figure 50] Figure 50 shows an example of an access point configuration. [Figure 51] Figure 51 is a flowchart illustrating an example of a communication method performed by an access point. [Modes for carrying out the invention]

[0010] A terminal according to one aspect of the present disclosure is a terminal capable of wirelessly communicating with an access point in a first frequency band and a second frequency band, comprising a communication unit and a circuit, wherein the circuit uses the communication unit to receive a first beacon frame transmitted from the access point in the first frequency band and / or a second beacon frame transmitted from the access point in the second frequency band, and determines that the access point is capable of multiband communication based on multiband-related information contained in the first beacon frame or the second beacon frame.

[0011] A method in one aspect of the present disclosure is a method implemented by a terminal capable of wirelessly communicating with an access point in a first frequency band and a second frequency band, the terminal receiving a first beacon frame transmitted from the access point in the first frequency band and / or a second beacon frame transmitted from the access point in the second frequency band, and determining that the access point is capable of multiband communication based on multiband-related information contained in the first beacon frame or the second beacon frame.

[0012] An access point according to one aspect of the present disclosure comprises a first interface for wireless communication on a first band, a second interface for wireless communication on a second band different from the first band, and a control unit that performs RTS (Request to Send) / CTS (Clear to Send) control with a terminal using at least one of the first interface and the second interface, wherein the control unit simultaneously transmits RTS signals to a plurality of terminals in the first band and the second band, respectively, and receives CTS signals transmitted in response to the RTS signals.

[0013] A communication method according to one aspect of the present disclosure is a communication method performed by an access point having a first interface for wireless communication on a first band and a second interface for wireless communication on a second band different from the first band, and includes a control step of performing RTS (Request to Send) / CTS (Clear to Send) control with a terminal using at least one of the first interface and the second interface, wherein in the RTS / CTS control in the control step, RTS signals destined for a plurality of terminals are simultaneously transmitted on the first band and the second band, and CTS signals transmitted in response to the RTS signals are received.

[0014] An access point according to one aspect of the present invention comprises a first interface for wireless communication on a first band, a second interface for wireless communication on a second band different from the first band, and a control unit that uses at least one of the first interface and the second interface to select one of three different RTS (Request to Send) / CTS (Clear to Send) control methods and performs the selected RTS / CTS control method with a terminal, wherein the first of the three methods is a method of transmitting a first RTS signal on the first band or the second band and receiving a first CTS signal transmitted in response to the first RTS signal, the second of the three methods is a method of transmitting a second RTS signal to a plurality of terminals on the first band or the second band and receiving a second CTS signal transmitted in response to the second RTS signal, and the third of the three methods is a method of transmitting a third RTS signal to a plurality of terminals on the first band and the second band, respectively, and receiving a third CTS signal transmitted in response to the third RTS signal.

[0015] According to the above embodiment, the access point can ensure the opportunity to communicate with the terminal by selecting one of three RTS / CTS control methods. This can contribute to improving the data transmission speed of communication between the access point and the terminal. In this way, the access point aims to improve the data transmission speed of the communication system.

[0016] For example, the control unit may, after receiving a CTS signal through RTS / CTS control using the above-mentioned method, transmit communication data using at least one of the resource units that received the CTS signal.

[0017] According to the above embodiment, the access point can use the resource unit that has returned a CTS signal in RTS / CTS control for communication with the terminal. In this case, the CTS signal may be returned by multiple resource units, in which case at least one of the multiple resource units can be used for communication. In this way, the access point aims to improve the data transmission speed of the communication system.

[0018] For example, in the third method, the source MAC (Medium Access Control) address of the third RTS signal transmitted in the first band and the second band may be the same.

[0019] According to the above embodiment, the access point transmits an RTS signal containing a common source MAC address in the third method to multiple terminals across multiple bands. This allows the access point to more easily improve the data transmission speed of the communication system based on a more specific configuration.

[0020] A communication method according to one aspect of the present invention is a communication method performed by an access point having a first interface for wireless communication on a first band and a second interface for wireless communication on a second band different from the first band, and includes a selection step of selecting one RTS (Request to Send) / CTS (Clear to Send) control method from among three different methods using at least one of the first interface and the second interface, and a control step of performing the selected RTS / CTS control method with a terminal, wherein the first method of the three methods is a method of transmitting a first RTS signal to one terminal in the first band or the second band and receiving a first CTS signal transmitted in response to the first RTS signal, the second method of the three methods is a method of transmitting a second RTS signal to multiple terminals in the first band or the second band and receiving a second CTS signal transmitted in response to the second RTS signal, and the third method of the three methods is a method of transmitting a third RTS signal to multiple terminals in the first band and the second band, respectively and receiving a third CTS signal transmitted in response to the third RTS signal.

[0021] According to the above embodiment, the same effect as the above access point is achieved.

[0022] These comprehensive or specific embodiments may be implemented as a system, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM, or as any combination of a system, method, integrated circuit, computer program, or recording medium.

[0023] The embodiments will be described in detail below with reference to the drawings.

[0024] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, those not described in the independent claim representing the highest-level concept will be described as optional components.

[0025] (Embodiment 1) The communication device in Figure 1 is, for example, a communication device for transmitting and receiving modulated signals in a first frequency band 201 which is the 2.4 GHz band, a second frequency band 202 which is the 5 GHz band, and a third frequency band 203 which is the 6 (or 7) GHz band, as shown in Figure 2.

[0026] In Figure 2, the horizontal axis represents frequency, and the vertical axis represents the power of the modulated signal.

[0027] In Figure 1, antennas 104_1, 105_1, and transceiver 102_1 are for transmitting and receiving modulated signals in the first frequency band 201; antennas 104_2, 105_2, and transceiver 102_2 are for transmitting and receiving modulated signals in the second frequency band 202; and antennas 104_3, 105_3, and transceiver 102_3 are for transmitting and receiving modulated signals in the third frequency band 203.

[0028] For example, the communication device in Figure 1 is assumed to be the configuration of an access point (AP), and the AP is assumed to be a communication device capable of communicating with one or more terminals, and for example, it is assumed to be capable of transmitting and receiving modulated signals according to the IEEE 802.11 communication standard.

[0029] Regarding communication methods related to IEEE 802.11, see, for example, Non-Patent Document 1.

[0030] Non-patent document 1 describes the transmission and reception methods of CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) in IEEE 802.11. In CSMA / CA, communication devices transmit and receive RTS (request to send) signals and CTS (clear to send) signals. For example, suppose an AP transmits an RTS signal. The terminal then receives the RTS signal and, if necessary, transmits a CTS signal. This addresses the hidden terminal problem.

[0031] The following section describes, for example, the case where an AP transmits an RTS signal. It is assumed that the AP is capable of transmitting the following modulated signals.

[0032] First transmission method: OFDM (Orthogonal frequency division multiplexing) In this case, a modulated signal addressed to a single terminal shall be transmitted using either the first frequency band or the second frequency band.

[0033] Second transmission method: OFDMA (Orthogonal Frequency Division Multiplexing Access) In this case, a modulated signal destined for one or more terminals shall be transmitted using the first frequency band or the second frequency band.

[0034] Third transmission method: The system shall use one or more frequency bands from the first, second, and third frequency bands, and in each frequency band, it shall transmit modulated signals destined for one or more terminals using OFDM or OFDMA.

[0035] Figure 3A shows the configuration of the RTS (Request to Send) signal for the first transmission method, with the horizontal axis representing time. Here, we assume that the AP with the configuration shown in Figure 1 transmits the RTS shown in Figure 3A.

[0036] The RTS in Figure 3A is assumed to include, for example, the address information of the receiving station (communication partner) and the address information of the transmitting station (AP in this case). However, the "receiving station address" refers to the address information of a single receiving station (communication partner).

[0037] Figure 3B shows the signal configuration for MU-RTS (Multi-user request to send) for the second transmission method, with the horizontal axis representing time. Here, it is assumed that the AP with the configuration shown in Figure 1 transmits the MU-RTS shown in Figure 3B.

[0038] The MU-RTS in Figure 3B is assumed to include, for example, the address information of the receiving station (communication partner) and the address information of the transmitting station (AP in this case). However, "receiving station address" can refer to the address information of one or more receiving stations (communication partners), or the address information of two or more receiving stations (communication partners).

[0039] Figure 3C shows the signal configuration for MC-MU-RTS (Multi-channel multi-user request to send) for the third transmission method, with the horizontal axis representing time. Here, it is assumed that the AP with the configuration shown in Figure 1 transmits the MC-MU-RTS shown in Figure 3C.

[0040] The MC-MU-RTS in Figure 3C is assumed to include, for example, the address information of the receiving station (communication partner) and the address information of the transmitting station (AP in this case). However, "receiving station address" can refer to the address information of one or more receiving stations (communication partners), or the address information of two or more receiving stations (communication partners).

[0041] The AP transceiver 102_1, having the configuration shown in Figure 1, will transmit and receive modulated signals in the first frequency band. Therefore, when the transceiver 102_1 transmits an RTS signal, it will transmit either the RTS shown in Figure 3A, the MU-RTS shown in Figure 3B, or the MC-MU-RTS shown in Figure 3C.

[0042] Furthermore, the AP transceiver 102_2, having the configuration shown in Figure 1, will transmit and receive modulated signals in the second frequency band. Therefore, when the transceiver 102_2 transmits an RTS signal, it will transmit either the RTS shown in Figure 3A, the MU-RTS shown in Figure 3B, or the MC-MU-RTS shown in Figure 3C.

[0043] Furthermore, the AP transceiver 102_3, having the configuration shown in Figure 1, will transmit and receive modulated signals in the third frequency band. Therefore, when the transceiver 102_3 transmits an RTS signal, it will transmit the MC-MU-RTS signal shown in Figure 3C.

[0044] When the AP transmits the MC-MU-RTS shown in Figure 3C, it will transmit on one or more frequency bands within the first, second, and third frequency bands. Therefore, the following cases are possible.

[0045] Case 1: AP transmits the first MC-MU-RTS only in the first frequency band.

[0046] Case 2: AP transmits a second MC-MU-RTS only in the second frequency band.

[0047] Third case: AP transmits the third MC-MU-RTS only in the third frequency band.

[0048] Case 4: AP transmits a first MC-MU-RTS in the first frequency band and a second MC-MU-RTS in the second frequency band.

[0049] Case 5: AP transmits a first MC-MU-RTS in the first frequency band and a third MC-MU-RTS in the third frequency band.

[0050] Case 6: AP transmits a second MC-MU-RTS in the second frequency band and a third MC-MU-RTS in the third frequency band.

[0051] Case 7: AP transmits a first MC-MU-RTS in the first frequency band, a second MC-MU-RTS in the second frequency band, and a third MC-MU-RTS in the third frequency band.

[0052] As described above, by transmitting the MC-MU-RTS shown in Figure 3C, the AP can achieve the following communication effects. • Communication with one terminal is possible only in the third frequency band. • Communication with two or more terminals is possible only in the third frequency band. • It can communicate with one or more terminals in the third frequency band, and can also communicate with one or more terminals in other frequency bands.

[0053] One notable feature of the AP is that it does not transmit the RTS signal shown in Figure 3A or the MU-RTS signal shown in Figure 3B in the third frequency band.

[0054] Second example: AP shall be capable of transmitting the following modulated signals.

[0055] Fourth transmission method: OFDM In this case, a modulated signal addressed to a single terminal shall be transmitted using either the first frequency band or the second frequency band.

[0056] Fifth transmission method: OFDMA In this case, a modulated signal destined for one or more terminals shall be transmitted using the first frequency band, the second frequency band, or the third frequency band.

[0057] The sixth transmission method: The system shall use one or more frequency bands from the first, second, and third frequency bands, and in each frequency band, it shall transmit modulated signals from one or more terminals using OFDM or OFDMA.

[0058] Furthermore, in the second and fifth transmission methods, the modulated signal for a given time or period will contain symbols destined for one or more terminals (one or more RUs (Resource Units)). For example, the frame configuration will be as shown in Figures 4A and 4B.

[0059] In Figure 4A, the vertical axis represents frequency (carrier), and the horizontal axis represents time. As shown in Figure 4A, at the first time interval, there is a symbol (RU#A) 401_1 destined for terminal #A.

[0060] In Figure 4B, the vertical axis represents frequency (carrier), and the horizontal axis represents time. As shown in Figure 4B, at the first time interval, there are symbols (RU#A) 401_1 addressed to terminal #A, symbols (RU#B) 401_2 addressed to terminal #B, and symbols (RU#C) 401_3 addressed to terminal #C.

[0061] However, while Figure 4B shows frequency division into three RUs, the number of frequency divisions is not limited to three. Furthermore, the frame configuration is not limited to the examples in Figures 4A and 4B. The number of frequency divisions, i.e., the number of destination terminals, may be two or four or more. Also, the number of carriers allocated to each terminal may differ.

[0062] In Figure 4B, frequency division is performed, but in Figure 4B, the vertical axis can be considered as time and the horizontal axis as frequency, and time division is performed into three RUs. Note that the number of time divisions, i.e., the number of destination terminals, must be two or more, and the number of time slots allocated to each terminal may differ.

[0063] Furthermore, in the third and sixth transmission methods, one or more frequency bands from the first, second, and third frequency bands are used during a certain time period, and the transmission includes symbols addressed to one or more terminals (one or more RUs). For example, the frame configuration will be as shown in Figures 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, 5J, and 5K.

[0064] In Figure 5A, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0065] As shown in Figure 5A, in the first time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band, and symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0066] In Figure 5B, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figure 5A are given the same number, and their explanations are omitted.

[0067] As shown in Figure 5B, in the first time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, and in the first time period, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band.

[0068] In Figure 5C, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figure 5A are given the same number, and their explanations are omitted.

[0069] As shown in Figure 5C, in the first time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, and in the first time period, symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0070] In Figure 5D, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figure 5A are given the same number, and their explanations are omitted.

[0071] As shown in Figure 5D, in the first time period, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band, and in the first time period, symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0072] In Figure 5E, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figure 5A are given the same number, and their explanations are omitted.

[0073] As shown in Figure 5E, in the first time period, data symbol 502_1 exists in the first frequency band, data symbol 502_2 exists in the second frequency band, and data symbol 502_3 exists in the third frequency band. Data symbols 502_1, 502_2, and 502_3 are symbols for transmitting data, and the configuration of data symbols 502_1, 502_2, and 502_3 will be explained later using Figures 6A and 6B.

[0074] In Figure 5F, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figures 5A and 5E are given the same numbering, and their explanations are omitted.

[0075] As shown in Figure 5F, in the first time period, data symbol 502_1 exists in the first frequency band, and in the first time period, data symbol 502_2 exists in the second frequency band. Data symbols 502_1, 502_2, and 502_3 are symbols for transmitting data, and the configuration of data symbols 502_1, 502_2, and 502_3 will be explained later using Figures 6A and 6B.

[0076] In Figure 5G, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figures 5A and 5E are given the same numbering, and their explanations are omitted.

[0077] As shown in Figure 5G, in the first time period, data symbol 502_1 exists in the first frequency band, and in the first time period, data symbol 502_3 exists in the third frequency band. Data symbols 502_1, 502_2, and 502_3 are symbols for transmitting data, and the configuration of data symbols 502_1, 502_2, and 502_3 will be explained later using Figures 6A and 6B.

[0078] In Figure 5H, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figures 5A and 5E are given the same number, and their explanations are omitted.

[0079] As shown in Figure 5H, in the first time period, data symbol 502_2 exists in the second frequency band, and in the first time period, data symbol 502_3 exists in the third frequency band. Data symbols 502_1, 502_2, and 502_3 are symbols for transmitting data, and the configuration of data symbols 502_1, 502_2, and 502_3 will be explained later using Figures 6A and 6B.

[0080] In Figure 5I, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figures 5A and 5E are given the same numbering, and their explanations are omitted.

[0081] As shown in Figure 5I, data symbol 502_1 exists in the first frequency band during the first time interval. Data symbols 502_1, 502_2, and 502_3 are symbols used for transmitting data, and the configuration of data symbols 502_1, 502_2, and 502_3 will be explained later using Figures 6A and 6B.

[0082] In Figure 5J, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figures 5A and 5E are given the same numbering, and their explanations are omitted.

[0083] As shown in Figure 5J, data symbol 502_2 exists in the second frequency band during the first time interval. Data symbols 502_1, 502_2, and 502_3 are symbols used for transmitting data, and the configuration of data symbols 502_1, 502_2, and 502_3 will be explained later using Figures 6A and 6B.

[0084] In Figure 5K, the vertical axis represents time, and the horizontal axis represents frequency (carrier). Components that operate similarly to those in Figures 5A and 5E are given the same number and their explanations are omitted.

[0085] As shown in Figure 5K, at the first time interval, data symbol 502_3 exists in the third frequency band. Data symbols 502_1, 502_2, and 502_3 are symbols for transmitting data, and the configuration of data symbols 502_1, 502_2, and 502_3 will be explained later using Figures 6A and 6B.

[0086] Figure 6A shows an example of the configuration of data symbol 502_X in the Xth frequency band in Figures 5E, 5F, 5G, 5H, 5I, 5J, and 5K. Here, X is 1, 2, or 3. In Figure 6A, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6A, data symbol 502_X is assumed to consist of symbol (RU#X1) 601_1 addressed to terminal #X1.

[0087] Figure 6B shows an example of the configuration of data symbol 502_X in the Xth frequency band in Figures 5E, 5F, 5G, 5H, 5I, 5J, and 5K. X is 1, 2, or 3. In Figure 6B, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6B, the data symbol 502_X is assumed to consist of the symbol (RU#X1) 601_1 addressed to terminal #X1, the symbol (RU#X2) 601_2 addressed to terminal #X2, the symbol (RU#X3) 601_3 addressed to terminal #X3, and the symbol (RU#X4) 601_4 addressed to terminal #X4.

[0088] Figure 6A shows an example of the configuration of data symbol 502_X in the Xth frequency band in Figures 5E, 5F, 5G, 5H, 5I, 5J, and 5K. Here, X is 1, 2, or 3. In Figure 6A, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6A, data symbol 502_X is assumed to consist of symbol (RU#X1) 601_1 addressed to terminal #X1.

[0089] Figure 6B shows an example of the configuration of data symbol 502_X in the Xth frequency band in Figures 5E, 5F, 5G, 5H, 5I, 5J, and 5K. Here, X is 1, 2, or 3. In Figure 6B, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6B, data symbol 502_X is assumed to consist of a symbol (RU#X1) 601_1 addressed to terminal #X1, a symbol (RU#X2) 601_2 addressed to terminal #X2, a symbol (RU#X3) 601_3 addressed to terminal #X3, and a symbol (RU#X4) 601_4 addressed to terminal #X4.

[0090] However, while Figure 6B shows frequency division into four RUs, the number of frequency divisions is not limited to four. Also, the configurations of data symbols 502_1, 502_2, and 502_3 are not limited to those in Figures 6A and 6B.

[0091] For example, data symbol 502_1 shall adopt the frame configuration shown in either Figure 6A or Figure 6B. Similarly, data symbol 502_2 shall adopt the frame configuration shown in either Figure 6A or Figure 6B, and data symbol 502_3 shall also adopt the frame configuration shown in either Figure 6A or Figure 6B.

[0092] Note that data symbols 502_1, 502_2, and 502_3 may contain symbols addressed to the same terminal. (For example, data symbols 502_1, 502_2, and 502_3 may contain symbols addressed to terminal #A.)

[0093] Similarly, data symbols 502_1 and 502_2 may contain symbols addressed to the same terminal. (For example, data symbols 502_1 and 502_2 may contain symbols addressed to terminal #A.)

[0094] Data symbols 502_1 and 502_3 may contain symbols addressed to the same terminal. (For example, data symbols 502_1 and 502_3 may contain symbols addressed to terminal #A.)

[0095] Data symbols 502_2 and 502_3 may contain symbols addressed to the same terminal. (For example, data symbols 502_2 and 502_3 may contain symbols addressed to terminal #A.)

[0096] APs that transmit modulated signals using the third or sixth transmission method select, for example, one of the frame configurations shown in Figures 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, 5J, or 5K, and transmit the modulated signal.

[0097] As another example, an AP that transmits a modulated signal using the third or sixth transmission method would, for example, select two or more frame configurations from Figures 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, 5J, and 5K as candidates, and then select one of these candidate frame configurations to transmit.

[0098] Note that in Figures 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, 5J, and 5K, symbols other than those shown in the figures may exist. For example, preambles, reference symbols, control information symbols, pilot symbols, midambles, null symbols (where no symbol exists), and null carriers (where no symbol exists) may exist.

[0099] Furthermore, in Figures 6A and 6B, symbols other than those shown in the figures may exist. For example, preambles, reference symbols, control information symbols, pilot symbols, midambles, null symbols (no symbol present), and null carriers (no symbol present) may exist.

[0100] Figure 3A shows the configuration of the RTS (Request to Send) signal for the fourth transmission method, with the horizontal axis representing time. Here, we assume that the AP with the configuration shown in Figure 1 transmits the RTS shown in Figure 3A.

[0101] The RTS in Figure 3A is assumed to include, for example, the address information of the receiving station (communication partner) and the address information of the transmitting station (AP in this case). However, the "receiving station address" refers to the address information of a single receiving station (communication partner).

[0102] Figure 3B shows the signal configuration for MU-RTS (Multi-user request to send) for the fifth transmission method, with the horizontal axis representing time. Here, it is assumed that the AP with the configuration shown in Figure 1 transmits the MU-RTS shown in Figure 3B.

[0103] The MU-RTS in Figure 3B is assumed to include, for example, the address information of the receiving station (communication partner) and the address information of the transmitting station (AP in this case). However, "receiving station address" can refer to the address information of one or more receiving stations (communication partners), or the address information of two or more receiving stations (communication partners).

[0104] Figure 3C shows the signal configuration for MC-MU-RTS (Multi-channel multi-user request to send) for the sixth transmission method, with the horizontal axis representing time. Here, it is assumed that the AP with the configuration shown in Figure 1 transmits the MC-MU-RTS shown in Figure 3C.

[0105] The MC-MU-RTS in Figure 3C is assumed to include, for example, the address information of the receiving station (communication partner) and the address information of the transmitting station (AP in this case). However, "receiving station address" can refer to the address information of one or more receiving stations (communication partners), or the address information of two or more receiving stations (communication partners).

[0106] The AP transceiver 102_1, having the configuration shown in Figure 1, will transmit and receive modulated signals in the first frequency band. Therefore, when the transceiver 102_1 transmits an RTS signal, it will transmit either the RTS shown in Figure 3A, the MU-RTS shown in Figure 3B, or the MC-MU-RTS shown in Figure 3C.

[0107] Furthermore, the AP transceiver 102_2, having the configuration shown in Figure 1, will transmit and receive modulated signals in the second frequency band. Therefore, when the transceiver 102_2 transmits an RTS signal, it will transmit either the RTS shown in Figure 3A, the MU-RTS shown in Figure 3B, or the MC-MU-RTS shown in Figure 3C.

[0108] Furthermore, the AP transceiver 102_3, having the configuration shown in Figure 1, will transmit and receive modulated signals in the third frequency band. Therefore, when the transceiver 102_3 transmits an RTS signal, it will transmit either the MU-RTS shown in Figure 3B or the MC-MU-RTS shown in Figure 3C.

[0109] When the AP transmits the MC-MU-RTS shown in Figure 3C, it will transmit on one or more frequency bands within the first, second, and third frequency bands. Therefore, the following cases are possible.

[0110] Case 1: AP transmits the first MC-MU-RTS only in the first frequency band.

[0111] Case 2: AP transmits a second MC-MU-RTS only in the second frequency band.

[0112] Third case: AP transmits the third MC-MU-RTS only in the third frequency band.

[0113] Case 4: AP transmits a first MC-MU-RTS in the first frequency band and a second MC-MU-RTS in the second frequency band.

[0114] Case 5: AP transmits a first MC-MU-RTS in the first frequency band and a third MC-MU-RTS in the third frequency band.

[0115] Case 6: AP transmits a second MC-MU-RTS in the second frequency band and a third MC-MU-RTS in the third frequency band.

[0116] Case 7: AP transmits a first MC-MU-RTS in the first frequency band, a second MC-MU-RTS in the second frequency band, and a third MC-MU-RTS in the third frequency band.

[0117] As described above, by transmitting the MC-MU-RTS shown in Figure 3C, the AP can achieve the following communication effects. • Communication with one terminal is possible only in the third frequency band. • Communication with two or more terminals is possible only in the third frequency band. • It can communicate with one or more terminals in the third frequency band, and can also communicate with one or more terminals in other frequency bands.

[0118] One notable feature of AP is that it does not transmit the RTS signal shown in Figure 3A in the third frequency band.

[0119] In the explanations so far, we have described an example of operation when there are three frequency bands, such as the first frequency band, the second frequency band, and the third frequency band. However, this is not the only example; if there are two or more frequency bands, the explanations above can be applied in the same way.

[0120] For example, if there are two types of frequency bands, such as frequency band A and frequency band B, we consider the following:

[0121] Case X: If frequency band A is 2.4 GHz and frequency band B is 5 GHz, then frequency band A will be considered the first frequency band as described above, and frequency band B will be considered the second frequency band as described above, and the explanation will be carried out accordingly.

[0122] Case Y: If frequency band A is 2.4 GHz and frequency band B is 6 GHz, then frequency band A will be considered the first frequency band as described above, and frequency band B will be considered the third frequency band as described above, and the explanation will be carried out accordingly.

[0123] Case Z: If frequency band A is 5GHz and frequency band B is 6GHz, then frequency band A will be considered the second frequency band as explained above, and frequency band B will be considered the third frequency band as explained above, and the explanation will be carried out accordingly.

[0124] Furthermore, if there are four or more frequency bands, and the first, second, or third frequency band described above exists within these four or more frequency bands, then the same procedure can be followed by implementing the previously described method.

[0125] Then, each terminal that receives an RTS transmitted by the AP will send a CTS signal to the AP if its own address is included in the RTS.

[0126] (Embodiment 2) In this embodiment, examples of frame configurations suitable for the third and sixth transmission methods described above will be explained. For example, an AP having the configuration of Figure 1 will transmit a modulated signal with one of the frame configurations shown in Figures 7, 8, 9, 10, 11, 12, 13, or 14.

[0127] The following describes the frame configurations shown in Figures 7, 8, 9, 10, 11, 12, 13, and 14.

[0128] Figure 7 shows an example of the frame structure of a modulated signal transmitted by an AP. In Figure 7, components that operate similarly to those in Figure 5 are given the same number and their explanations are omitted.

[0129] In Figure 7, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0130] As shown in Figure 7, at the first time interval, the first field 701_1 exists in the first frequency band. Also at the first time interval, the first field 701_2 exists in the second frequency band. Furthermore, at the first time interval, the first field 701_3 exists in the third frequency band.

[0131] Furthermore, the first fields 701_1, 701_2, and 701_3 are assumed to contain symbols that allow the AP's communication partner to perform actions such as signal detection, time synchronization, frequency synchronization, and channel estimation.

[0132] During the second time period, the second field 702_1 exists in the first frequency band. Furthermore, during the second time period, the second field 702_2 exists in the second frequency band. Also, during the second time period, the second field 702_3 exists in the third frequency band.

[0133] The second field 701_1 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_1 addressed to terminal #A. The second field 701_2 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_2 addressed to terminal #A. The second field 701_3 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_3 addressed to terminal #A.

[0134] In the third time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band, and symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0135] As shown in the example in Figure 7, a key feature is that, at a given time, data symbols destined for the same terminal exist in the first frequency band, the second frequency band, and the third frequency band. It should be assumed that no data symbols destined for other terminals exist at this time. Furthermore, the temporal transmission timing of the first fields 701_1, 701_2, 701_3 and the second fields 702_1, 702_2, 702_3 is not limited to the example in Figure 7.

[0136] Figure 8 shows an example of the frame structure of a modulated signal transmitted by an AP. In Figure 8, components that operate similarly to those in Figures 5 and 7 are given the same numbers, and their explanations are omitted.

[0137] In Figure 8, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0138] As shown in Figure 8, at the first time interval, the first field 701_1 exists in the first frequency band. And at the same time interval, the first field 701_2 exists in the second frequency band.

[0139] Furthermore, the first fields 701_1 and 701_2 are assumed to contain symbols that allow the AP's communication partner to perform actions such as signal detection, time synchronization, frequency synchronization, and channel estimation.

[0140] During the second time period, a second field 702_1 exists in the first frequency band. Furthermore, during the second time period, a second field 702_2 exists in the second frequency band.

[0141] The second field 701_1 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_1 addressed to terminal #A. The second field 701_2 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_2 addressed to terminal #A.

[0142] During the third time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, and during the third time period, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band.

[0143] As shown in the example in Figure 8, a key feature is that, at a given time, data symbols destined for the same terminal exist in both the first and second frequency bands. It should be assumed that no data symbols destined for other terminals exist at this time. Furthermore, the temporal transmission timing of the first fields 701_1, 701_2 and the second fields 702_1, 702_2 is not limited to the example in Figure 8.

[0144] In Figure 9, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0145] As shown in Figure 9, at the first time interval, the first field 701_1 exists in the first frequency band. And at the first time interval, the first field 701_3 exists in the third frequency band.

[0146] Furthermore, the first fields 701_1 and 701_3 are assumed to contain symbols that allow the AP's communication partner to perform actions such as signal detection, time synchronization, frequency synchronization, and channel estimation.

[0147] During the second time period, a second field 702_1 exists in the first frequency band. Furthermore, during the second time period, a second field 702_3 exists in the third frequency band.

[0148] The second field 701_1 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_1 addressed to terminal #A. The second field 701_3 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_3 addressed to terminal #A.

[0149] During the third time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, and during the third time period, symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0150] As shown in the example in Figure 9, a key feature is that, at a given time, data symbols destined for the same terminal exist in both the first and third frequency bands. It should be assumed that no data symbols destined for other terminals exist at this time. Furthermore, the temporal transmission timing of the first field 701_1, 701_3 and the second field 702_1, 702_3 is not limited to the example in Figure 9.

[0151] Figure 10 shows an example of the frame structure of a modulated signal transmitted by an AP. In Figure 10, components that operate similarly to those in Figures 5 and 7 are given the same numbers and their explanations are omitted.

[0152] In Figure 10, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0153] As shown in Figure 10, at the first time interval, the first field 701_2 exists in the second frequency band. Also at the first time interval, the first field 701_3 exists in the third frequency band.

[0154] Furthermore, the first fields 701_2 and 701_3 are assumed to contain symbols that allow the AP's communication partner to perform signal detection, time synchronization, frequency synchronization, channel estimation, etc.

[0155] During the second time period, a second field 702_2 exists in the second frequency band. Also during the second time period, a second field 702_3 exists in the third frequency band.

[0156] The second field 701_2 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_2 addressed to terminal #A. The second field 701_3 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_3 addressed to terminal #A.

[0157] During the third time period, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band, and during the third time period, symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0158] As shown in the example in Figure 10, a key feature is that, at a given time, data symbols destined for the same terminal exist in both the second and third frequency bands. It should be assumed that no data symbols destined for other terminals exist at this time. Furthermore, the temporal transmission timing of the first fields 701_2, 701_3 and the second fields 702_2, 702_3 is not limited to the example in Figure 10.

[0159] Figure 11 shows an example of the frame structure of a modulated signal transmitted by an AP. In Figure 11, components that operate similarly to those in Figures 5 and 7 are given the same numbers, and their explanations are omitted.

[0160] In Figure 11, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0161] As shown in Figure 11, in the first time period, the first field 701_1 exists in the first frequency band. And in the first time period, the first field 701_2 exists in the second frequency band.

[0162] Furthermore, the first fields 701_1 and 701_2 are assumed to contain symbols that allow the AP's communication partner to perform actions such as signal detection, time synchronization, frequency synchronization, and channel estimation.

[0163] During the second time period, a second field 702_1 exists in the first frequency band. Furthermore, during the second time period, a second field 702_2 exists in the second frequency band.

[0164] The second field 701_1 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_1 addressed to terminal #A. The second field 701_2 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_2 addressed to terminal #A.

[0165] During the third time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, and during the third time period, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band.

[0166] As shown in Figure 11, in the third frequency band, the modulated signal exists at a timing independent of the modulated signals in the first and second frequency bands. For example, as shown in Figure 11, the first field 701_3, the second field 702_3, and the data symbol 502_3 exist.

[0167] The structure of data symbol 502_3 in this case will be explained. Figures 6A and 6B are possible structures for data symbol 502_3.

[0168] Figure 6A shows an example of the configuration of data symbol 502_X in the Xth frequency band. In this case, X is 3. In Figure 6A, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6A, data symbol 502_X is assumed to consist of symbol (RU#X1) 601_1 addressed to terminal #X1. Note that symbol (RU#X1) 601_1 addressed to terminal #X1 is not symbol (RU#A) addressed to terminal #A. (However, it is possible that symbol (RU#X1) 601_1 addressed to terminal #X1 is symbol (RU#A) addressed to terminal #A.)

[0169] Figure 6B shows an example of the configuration of data symbol 502_X in the Xth frequency band. In this case, X is 3. In Figure 6B, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6B, data symbol 502_X is assumed to consist of a symbol (RU#X1) 601_1 addressed to terminal #X1, a symbol (RU#X2) 601_2 addressed to terminal #X2, a symbol (RU#X3) 601_3 addressed to terminal #X3, and a symbol (RU#X4) 601_4 addressed to terminal #X4. Note that data symbol 502_X does not include a symbol (RU#A) addressed to terminal #A. (It is also possible that data symbol 502_X may include a symbol (RU#A) addressed to terminal #A.)

[0170] However, although Figure 6B shows frequency division into four RUs, the number of frequency divisions is not limited to four. The number of frequency divisions, i.e., the number of destination terminals, can be two or more. Also, the number of carriers assigned to each terminal may differ. Furthermore, the configuration of data symbol 502_3 is not limited to the configurations in Figures 6A and 6B.

[0171] In Figure 6B, frequency division is performed, but in Figure 6B, the vertical axis can be considered as time and the horizontal axis as frequency, and the time division is performed on four RUs. Note that the number of time divisions, i.e., the number of destination terminals, must be two or more, and the number of time slots allocated to each terminal may differ.

[0172] For example, data symbol 502_3 shall adopt either the frame configuration shown in Figure 6A or Figure 6B.

[0173] As shown in the example in Figure 11, a key feature is that at a given time, data symbols destined for the same terminal exist in the first and second frequency bands, while only data symbols destined for other terminals exist in the third frequency band. Note that the temporal transmission timing of the first fields 701_1, 701_2, 701_3 and the second fields 702_1, 702_2, 702_3 are not limited to the example in Figure 11.

[0174] Furthermore, it may have the characteristic that, at a certain time, data symbols destined for the same terminal exist in both the first frequency band and the second frequency band.

[0175] Figure 12 shows an example of the frame structure of a modulated signal transmitted by an AP. In Figure 12, components that operate similarly to those in Figures 5 and 7 are given the same numbers and their explanations are omitted.

[0176] In Figure 12, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0177] As shown in Figure 12, at the first time interval, the first field 701_1 exists in the first frequency band. And at the first time interval, the first field 701_3 exists in the third frequency band.

[0178] Furthermore, the first fields 701_1 and 701_3 are assumed to contain symbols that allow the AP's communication partner to perform actions such as signal detection, time synchronization, frequency synchronization, and channel estimation.

[0179] During the second time period, a second field 702_1 exists in the first frequency band. Furthermore, during the second time period, a second field 702_3 exists in the third frequency band.

[0180] The second field 701_1 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_1 addressed to terminal #A. The second field 701_3 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_3 addressed to terminal #A.

[0181] During the third time period, symbol (RU#A) 501_1 addressed to terminal #A exists in the first frequency band, and during the third time period, symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0182] As shown in Figure 12, in the second frequency band, the modulated signal exists at a timing independent of the modulated signal in the first frequency band and the modulated signal in the third frequency band. For example, as shown in Figure 12, the first field 701_2, the second field 702_2, and the data symbol 502_2 exist.

[0183] The structure of data symbol 502_2 in this case will be explained. Figures 6A and 6B are possible structures for data symbol 502_2.

[0184] Figure 6A shows an example of the configuration of data symbol 502_X in the Xth frequency band. In this case, X is 2. In Figure 6A, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6A, data symbol 502_X is assumed to consist of symbol (RU#X1) 601_1 addressed to terminal #X1. Note that symbol (RU#X1) 601_1 addressed to terminal #X1 is not symbol (RU#A) addressed to terminal #A. (However, it is possible that symbol (RU#X1) 601_1 addressed to terminal #X1 is symbol (RU#A) addressed to terminal #A.)

[0185] Figure 6B shows an example of the configuration of data symbol 502_X in the Xth frequency band. In this case, X is 2. In Figure 6B, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6B, data symbol 502_X is assumed to consist of a symbol (RU#X1) 601_1 addressed to terminal #X1, a symbol (RU#X2) 601_2 addressed to terminal #X2, a symbol (RU#X3) 601_3 addressed to terminal #X3, and a symbol (RU#X4) 601_4 addressed to terminal #X4. Note that data symbol 502_X does not include a symbol (RU#A) addressed to terminal #A. (It is also possible that data symbol 502_X may include a symbol (RU#A) addressed to terminal #A.)

[0186] However, although Figure 6B shows frequency division into four RUs, the number of frequency divisions is not limited to four. The number of frequency divisions, i.e., the number of destination terminals, can be two or more. Also, the number of carriers assigned to each terminal may differ. Furthermore, the configuration of data symbol 502_2 is not limited to the configurations in Figures 6A and 6B.

[0187] In Figure 6B, frequency division is performed, but in Figure 6B, the vertical axis can be considered as time and the horizontal axis as frequency, and the time division is performed on four RUs. Note that the number of time divisions, i.e., the number of destination terminals, must be two or more, and the number of time slots allocated to each terminal may differ.

[0188] For example, data symbol 502_3 shall adopt either the frame configuration shown in Figure 6A or Figure 6B.

[0189] As shown in the example in Figure 12, a key feature is that at a given time, data symbols destined for the same terminal exist in the first and third frequency bands, while only data symbols destined for other terminals exist in the second frequency band. Note that the temporal transmission timing of the first fields 701_1, 701_2, 701_3 and the second fields 702_1, 702_2, 702_3 are not limited to the example in Figure 12.

[0190] Furthermore, it may have the characteristic that, at a certain time, data symbols destined for the same terminal exist in both the first frequency band and the second frequency band.

[0191] Figure 13 shows an example of the frame structure of a modulated signal transmitted by an AP. In Figure 13, components that operate similarly to those in Figures 5 and 7 are given the same numbers, and their explanations are omitted.

[0192] In Figure 13, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0193] As shown in Figure 13, in the first time period, the first field 701_2 exists in the second frequency band. And in the first time period, the first field 701_3 exists in the third frequency band.

[0194] Furthermore, the first fields 701_2 and 701_3 are assumed to contain symbols that allow the AP's communication partner to perform signal detection, time synchronization, frequency synchronization, channel estimation, etc.

[0195] During the second time period, a second field 702_2 exists in the second frequency band. Furthermore, during the second time period, a second field 702_3 exists in the third frequency band.

[0196] The second field 701_2 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_2 addressed to terminal #A. The second field 701_3 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme, modulation scheme, and transmission method for generating the symbol (RU#A) 501_3 addressed to terminal #A.

[0197] During the third time period, symbol (RU#A) 501_2 addressed to terminal #A exists in the second frequency band, and during the third time period, symbol (RU#A) 501_3 addressed to terminal #A exists in the third frequency band.

[0198] As shown in Figure 13, in the first frequency band, the modulated signal exists at a timing independent of the modulated signals in the second frequency band and the third frequency band. For example, as shown in Figure 13, the first field 701_1, the second field 702_1, and the data symbol 502_1 exist.

[0199] The structure of data symbol 502_1 in this case will be explained. Figures 6A and 6B are possible structures for data symbol 502_1.

[0200] Figure 6A shows an example of the configuration of data symbol 502_X in the Xth frequency band. In this case, X is 1. In Figure 6A, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6A, data symbol 502_X is assumed to consist of symbol (RU#X1) 601_1 addressed to terminal #X1. Note that symbol (RU#X1) 601_1 addressed to terminal #X1 is not symbol (RU#A) addressed to terminal #A. (However, it is possible that symbol (RU#X1) 601_1 addressed to terminal #X1 is symbol (RU#A) addressed to terminal #A.)

[0201] Figure 6B shows an example of the configuration of data symbol 502_X in the Xth frequency band. In this case, X is 1. In Figure 6B, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in Figure 6B, data symbol 502_X is assumed to consist of a symbol (RU#X1) 601_1 addressed to terminal #X1, a symbol (RU#X2) 601_2 addressed to terminal #X2, a symbol (RU#X3) 601_3 addressed to terminal #X3, and a symbol (RU#X4) 601_4 addressed to terminal #X4. Note that data symbol 502_X does not include a symbol (RU#A) addressed to terminal #A. (It is also possible that data symbol 502_X may include a symbol (RU#A) addressed to terminal #A.)

[0202] However, although Figure 6B shows frequency division into four RUs, the number of frequency divisions is not limited to four. The number of frequency divisions, i.e., the number of destination terminals, can be two or more. Also, the number of carriers assigned to each terminal may differ. Furthermore, the configuration of data symbol 502_1 is not limited to the configurations in Figures 6A and 6B.

[0203] In Figure 6B, frequency division is performed, but in Figure 6B, the vertical axis can be considered as time and the horizontal axis as frequency, and the time division is performed on four RUs. Note that the number of time divisions, i.e., the number of destination terminals, must be two or more, and the number of time slots allocated to each terminal may differ.

[0204] For example, data symbol 502_3 shall adopt either the frame configuration shown in Figure 6A or Figure 6B.

[0205] As shown in the example in Figure 13, a key feature is that, at a given time, data symbols destined for the same terminal exist in the second and third frequency bands, while only data symbols destined for other terminals exist in the first frequency band. Note that the temporal transmission timing of the first fields 701_1, 701_2, 701_3 and the second fields 702_1, 702_2, 702_3 is not limited to the example in Figure 13.

[0206] Furthermore, it may have the characteristic that, at a certain time, data symbols destined for the same terminal exist in both the first frequency band and the second frequency band.

[0207] Figure 14 shows an example of the frame structure of a modulated signal transmitted by an AP. In Figure 14, components that operate similarly to those in Figures 5 and 7 are given the same numbers, and their explanations are omitted.

[0208] In Figure 14, the vertical axis represents time, and the horizontal axis represents frequency (carrier). 500_1 represents the frame configuration in the first frequency band, 500_2 represents the frame configuration in the second frequency band, and 500_3 represents the frame configuration in the third frequency band.

[0209] As shown in Figure 14, at the first time, the first field 701_1 exists in the first frequency band.

[0210] Furthermore, the first field 701_1 is assumed to contain symbols that allow the AP's communication partner to perform signal detection, time synchronization, frequency synchronization, channel estimation, etc.

[0211] During the second time period, the second field 702_1 exists in the first frequency band.

[0212] The second field 701_1 is a field for transmitting control information to the AP's communication partner, and includes, for example, information on the error correction code scheme for generating the data symbol 502_1, information on the modulation scheme, and information on the transmission method.

[0213] In the third hour, data symbol 502_1 is present in the first frequency band.

[0214] As shown in Figure 14, in the second frequency band, the modulated signal exists at a timing unrelated to the modulated signal in the first frequency band. Similarly, in the third frequency band, the modulated signal exists at a timing unrelated to the modulated signal in the first frequency band. Furthermore, in the third frequency band, the modulated signal exists at a timing unrelated to the modulated signal in the second frequency band.

[0215] For example, as shown in Figure 14, in the second frequency band, there is a first field 701_2, a second field 702_2, and a data symbol 502_2. Also, in the third frequency band, there is a first field 701_3, a second field 702_3, and a data symbol 502_3.

[0216] The configurations of data symbols 502_1, 502_2, and 502_3 in this case will be explained. Figures 6A and 6B are possible configurations for data symbols 502_1, 502_2, and 502_3. Data symbol 502_1 takes the configuration shown in Figure 6A or Figure 6B. Data symbol 502_2 takes the configuration shown in Figure 6A or Figure 6B. Data symbol 502_3 takes the configuration shown in Figure 6A or Figure 6B.

[0217] Figure 6A shows an example of the configuration of data symbol 502_X in the Xth frequency band. In this case, X is 1, 2, and 3. In Figure 6A, the vertical axis is time and the horizontal axis is frequency (carrier). As shown in Figure 6A, data symbol 502_X is assumed to consist of symbol (RU#X1) 601_1 addressed to terminal #X1.

[0218] FIG. 6B shows an example of the configuration of data symbol 502_X in the X-th frequency band. Here, X is 1, 2, or 3. In FIG. 6B, the vertical axis represents time, and the horizontal axis represents frequency (carrier). As shown in FIG. 6B, data symbol 502_X is assumed to be composed of symbol (RU#X1) 601_1 for terminal #X1, symbol (RU#X2) 601_2 for terminal #X2, symbol (RU#X3) 601_3 for terminal #X3, and symbol (RU#X4) 601_4 for terminal #X4.

[0219] However, in FIG. 6B, frequency division is performed among four RUs, but the number of frequency divisions is not limited to four. The number of frequency divisions, that is, the number of destination terminals, may be two or more. Also, the number of carriers assigned to each terminal may be different.

[0220] Although frequency division is performed in FIG. 6B, in FIG. 6B, considering the vertical axis as time and the horizontal axis as frequency, time division may be performed among the four RUs. Note that the number of time divisions, that is, the number of destination terminals, may be two or more, and the number of time slots assigned to each terminal may be different.

[0221] At this time, it may have the following features. · There is no symbol (RU) for the same terminal in both data symbol 502_1 and data symbol 502_2, and there is no symbol (RU) for the same terminal in both data symbol 502_1 and data symbol 502_3, and there is no symbol (RU) for the same terminal in both data symbol 502_2 and data symbol 502_3.

[0222] However, it does not necessarily have this feature.

[0223] In addition, in FIGS. 7, 8, 9, 10, 11, 12, 13, and 14, symbols other than those shown in the figures may exist. For example, a preamble, a reference symbol, a control information symbol, a pilot symbol, a midamble, a null symbol (where no symbol exists), a null carrier (where no symbol exists), etc. may exist. And in FIGS. 6A and 6B, symbols other than those shown in the figures may exist. For example, a preamble, a reference symbol, a control information symbol, a pilot symbol, a midamble, a null symbol (where no symbol exists), a null carrier (where no symbol exists), etc. may exist.

[0224] An AP that transmits a modulation signal using the third transmission method or the sixth transmission method selects, for example, any one of the frame configurations in FIGS. 7, 8, 9, 10, 11, 12, 13, and 14 and transmits the modulation signal.

[0225] As another example, an AP that transmits a modulation signal using the third transmission method or the sixth transmission method has, for example, two or more of the frame configurations in FIGS. 7, 8, 9, 10, 11, 12, 13, and 14 as selection candidates, and selects and transmits one of the selection candidates.

[0226] It can also be said that an AP that transmits a modulation signal using such a third transmission method or sixth transmission method has the following features. · As shown in FIG. 15, when there is a data symbol 502_1 in the first frequency band, a data symbol 502_2 in the second frequency band, and a data symbol 502_3 in the third frequency band at the third time, none of the data symbol 502_1, the data symbol 502_2, and the data symbol 502_3 has the configuration as shown in FIG. 6B. · As shown in FIG. 16, when there is a data symbol 502_1 in the first frequency band and a data symbol 502_2 in the second frequency band at the third time, neither the data symbol 502_1 nor the data symbol 502_2 has the configuration as shown in FIG. 6B. As shown in Figure 17, if data symbol 502_1 exists in the first frequency band and data symbol 502_3 exists in the third frequency band during the third time period, neither data symbol 502_1 nor data symbol 502_3 will have the configuration shown in Figure 6B. As shown in Figure 18, if data symbol 502_2 exists in the second frequency band and data symbol 502_3 exists in the third frequency band during the third time period, neither data symbol 502_2 nor data symbol 502_3 will have the configuration shown in Figure 6B.

[0227] By adopting a frame configuration with these characteristics, it is possible to improve the data transmission speed of the modulated signal transmitted by the AP. This point will be explained using the frame configuration in Figure 15 as an example.

[0228] For example, in Figure 15, let's assume that data symbol 502_1 has the configuration shown in Figure 6B. Then, let's consider the case where the number of symbols (RU#X1) 601_1 addressed to terminal #X1 is the largest in terms of time. In this case, for other RUs, there will be a time interval in which no symbols exist while the symbols (RU#X1) 601_1 addressed to terminal #X1 exist. Similarly, for data symbol 502_2 in the second frequency band and data symbol 502_3 in the third frequency band, there will also be a time interval in which no symbols exist while the symbols (RU#X1) 601_1 addressed to terminal #X1 exist. In other words, the adverse effect of having a time interval in which no symbols exist while the symbols (RU#X1) 601_1 addressed to terminal #X1 exist extends to the second and third frequency bands as well, resulting in the adverse effect of a decrease in data transmission speed.

[0229] However, when the AP transmits a modulated signal using the third or sixth transmission method, which has the characteristics described above, the adverse effects mentioned above can be mitigated, resulting in an improvement in data transmission speed.

[0230] Furthermore, as shown in Figures 7, 8, 9, and 10, when the AP transmits modulated signals using the third and sixth transmission methods, it is possible to achieve high-speed data transmission to specific terminals.

[0231] Furthermore, as shown in Figures 11, 12, and 13, when the AP transmits modulated signals using the third and sixth transmission methods, it is possible to achieve high-speed data transmission to a specific terminal, as well as enable multi-access, allowing data to be transmitted to multiple terminals.

[0232] In the explanations so far, we have described an example of operation when there are three frequency bands, such as the first frequency band, the second frequency band, and the third frequency band. However, this is not the only example; if there are two or more frequency bands, the explanations above can be applied in the same way.

[0233] For example, if there are two types of frequency bands, such as frequency band A and frequency band B, we consider the following:

[0234] Case X: If frequency band A is 2.4 GHz and frequency band B is 5 GHz, then frequency band A will be considered the first frequency band as described above, and frequency band B will be considered the second frequency band as described above, and the explanation will be carried out accordingly.

[0235] Case Y: If frequency band A is 2.4 GHz and frequency band B is 6 GHz, then frequency band A will be considered the first frequency band as described above, and frequency band B will be considered the third frequency band as described above, and the explanation will be carried out accordingly.

[0236] Case Z: If frequency band A is 5GHz and frequency band B is 6GHz, then frequency band A will be considered the second frequency band as explained above, and frequency band B will be considered the third frequency band as explained above, and the explanation will be carried out accordingly.

[0237] Furthermore, if there are four or more frequency bands, and the first, second, or third frequency band described above exists within these four or more frequency bands, then the same procedure can be followed by implementing the previously described method.

[0238] Then, when the AP transmits the modulated signal as described in this embodiment, the terminal that receives the modulated signal obtains data by demodulating the received modulated signal and decoding the error correction code, thereby achieving the effects described in this embodiment.

[0239] (Supplement 1) Naturally, multiple embodiments, supplements, and other contents described herein may be combined and implemented.

[0240] Furthermore, the configuration of the access point is not limited to that shown in Figure 1; any access point that has one or more transmitting antennas in each frequency band and generates and transmits one or more modulated signals in each frequency band can implement this disclosure.

[0241] Furthermore, each embodiment is merely an example, and even if "modulation method, error correction coding method (error correction code used, code length, coding rate, etc.), control information, etc." are given as examples, it is possible to implement the same configuration even if a different "modulation method, error correction coding method (error correction code used, code length, coding rate, etc.), control information, etc." is applied.

[0242] Regarding the modulation method, even if a modulation method other than the modulation methods described in this specification is used, it is possible to implement the embodiments and other contents described in this specification. For example, APSK (e.g., 16APSK, 64APSK, 128APSK, 256APSK, 1024APSK, 4096APSK, etc.), PAM (e.g., 4PAM, 8PAM, 16PAM, 64PAM, 128PAM, 256PAM, 1024PAM, 4096PAM, etc.), PSK (e.g., BPSK, QPSK, 8PSK, 16PSK, 64PSK, 128PSK, 256PSK, 1024PSK, 4096PSK, etc.), QAM (e.g., 4QAM, 8QAM, 16QAM, 64QAM, 128QAM, 256QAM, 1024QAM, 4096QAM, etc.) may be applied, and in each modulation method, uniform mapping or non-uniform mapping may be used. Also, the arrangement method of signal points such as 2, 4, 8, 16, 64, 128, 256, 1024, etc. in the I-Q plane (modulation methods having 2, 4, 8, 16, 64, 128, 256, 1024, etc. signal points) is not limited to the signal point arrangement method of the modulation methods shown in this specification.

[0243] In this specification, the transmitting device, receiving device, and communication device may include, for example, communication and broadcasting equipment such as broadcasting stations, base stations, access points, terminals, and mobile phones, as well as communication equipment such as televisions, radios, and personal computers. Furthermore, the transmitting device and receiving device in this disclosure may be devices having communication functions, and such devices may be configured to connect to devices for running applications such as televisions, radios, personal computers, and mobile phones via some kind of interface. In this embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, postamble, reference symbol, midamble, etc.), symbols for control information, and null symbols, may be arranged in any way within the frame. Here, we refer to them as pilot symbols and symbols for control information, but any naming convention is acceptable, as the function itself is what is important.

[0244] The pilot symbol can be, for example, a known symbol modulated using PSK modulation in the transceiver. The receiver uses this symbol to perform frequency synchronization, time synchronization, channel estimation of each modulated signal (estimate of CSI (Channel State Information)), signal detection, etc. Alternatively, the receiver may know the symbol transmitted by the transmitter by synchronizing with the pilot symbol.

[0245] Furthermore, symbols for control information are used to transmit information that needs to be sent to the communication partner in order to enable communication other than data (such as application data). This information includes, for example, the modulation scheme used for communication, the error correction coding scheme, the coding rate of the error correction coding scheme, and configuration information at higher layers.

[0246] This disclosure is not limited to the embodiments described herein and can be implemented with various modifications. For example, while each embodiment describes the case where the communication is performed as a communication device, it is not limited to this, and this communication method can also be performed as software.

[0247] Alternatively, for example, a program that performs the above communication method may be stored in ROM beforehand, and that program may be run by the CPU.

[0248] Alternatively, a program that performs the above communication method may be stored in a computer-readable storage medium, and the program stored in the storage medium may be recorded in the computer's RAM, causing the computer to operate according to that program.

[0249] Each of the above embodiments and configurations may typically be implemented as an LSI, which is an integrated circuit having input and output terminals. These may be individually integrated into a single chip, or they may be integrated into a single chip that includes all or some of the configurations of each embodiment. Here, we refer to them as LSIs, but depending on the degree of integration, they may also be called ICs, system LSIs, super LSIs, or ultra LSIs. Furthermore, the method of integrated circuit implementation is not limited to LSIs; it may also be implemented using dedicated circuits or general-purpose processors. After LSI manufacturing, FPGAs that can be programmed or reconfigurable processors that allow for the reconfiguration of the connections and settings of circuit cells inside the LSI may be used. Moreover, if an integrated circuit implementation technology that replaces LSIs emerges due to advances in semiconductor technology or other derived technologies, it is naturally possible to integrate functional blocks using that technology. The application of biotechnology, for example, is a possibility.

[0250] The transmission method supported by the base station and terminal may be a multi-carrier method such as OFDM, or a single-carrier method. Furthermore, the base station may support both multi-carrier and single-carrier methods. In this case, there are multiple methods for generating a single-carrier modulated signal, and it is possible to implement either method. For example, examples of single-carrier methods include "DFT (Discrete Fourier Transform)-Spread OFDM (Orthogonal Frequency Division Multiplexing)", "Trajectory Constrained DFT-Spread OFDM", "OFDM based SC (Single Carrier)", "SC (Single Carrier)-FDMA (Frequency Division Multiple Access)", and "Guard interval DFT-Spread OFDM".

[0251] Furthermore, at least one of the FPGA (Field Programmable Gate Array) and CPU (Central Processing Unit) may be configured to download all or part of the software necessary to implement the communication method described in this disclosure via wireless or wired communication. In addition, it may be configured to download all or part of the software for updates via wireless or wired communication. The downloaded software may then be stored in a memory unit, and the FPGA and CPU may be operated based on the stored software to perform the digital signal processing described in this disclosure.

[0252] In this case, the device comprising at least one of the FPGA and CPU may be connected to a communication modem wirelessly or via a wired connection, and the communication method described in this disclosure may be implemented using this device and the communication modem.

[0253] For example, a communication device such as a base station, AP, or terminal described herein may include at least one of an FPGA and a CPU, and the communication device may also include an interface for obtaining software from an external source to operate at least one of the FPGA and the CPU. Furthermore, the communication device may include a storage unit for storing the software obtained from an external source, and the signal processing described herein may be realized by operating the FPGA and CPU based on the stored software.

[0254] Furthermore, in the frame configurations shown in Figures 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, 5J, 5K, 7, 8, 9, 10, 11, 12, 13, and 14, a MIMO (Multiple-Input Multiple-Output) transmission method, in which multiple modulated signals are transmitted from multiple antennas, may be used in the "transmission method for the first frequency band, or the transmission method for the second frequency band, or the transmission method for the third frequency band."

[0255] Alternatively, a MIMO transmission method may be used in which multiple modulated signals are transmitted from multiple antennas to one or more RUs in Figure 6B.

[0256] (Supplement 2) In this specification, the first frequency band is described as the 2.4 GHz band, the second frequency band as the 5 GHz band, and the third frequency band as the 6 (or 7) GHz band. However, the examples of the "first frequency band, second frequency band, and third frequency band" are not limited to these examples. They may also be as follows.

[0257] For example, suppose there are multiple channels in the 2.4GHz band, multiple channels in the 5GHz band, and multiple channels in the 6(or 7)GHz band. Then, the following cases are possible.

[0258] Case 1: The first frequency band is the first channel of the 2.4GHz band, the second frequency band is the second channel of the 2.4GHz band, and the third frequency band is the first channel of the 5GHz band.

[0259] Case 2: The first frequency band is designated as the first channel of the 2.4GHz band, the second frequency band as the first channel of the 5GHz band, and the third frequency band as the second channel of the 5GHz band.

[0260] Case 3: The first frequency band is the first channel of the 2.4GHz band, the second frequency band is the second channel of the 2.4GHz band, and the third frequency band is the first channel of the 6(or 7)GHz band.

[0261] Case 4: The first frequency band is the first channel of the 2.4 GHz band, the second frequency band is the first channel of the 6 (or 7) GHz band, and the third frequency band is the second channel of the 6 (or 7) GHz band.

[0262] Case 5: The first frequency band is designated as the first channel of the 5GHz band, the second frequency band as the second channel of the 5GHz band, and the third frequency band as the first channel of the 6(or 7)GHz band.

[0263] Case 6: The first frequency band is the first channel of the 5GHz band, the second frequency band is the first channel of the 6(or 7)GHz band, and the third frequency band is the second channel of the 6(or 7)GHz band.

[0264] Case 7: The first frequency band is designated as the first channel of the 2.4GHz band, the second frequency band as the second channel of the 2.4GHz band, and the third frequency band as the third channel of the 2.4GHz band.

[0265] Case 8: The first frequency band is designated as the first channel of the 5GHz band, the second frequency band as the second channel of the 5GHz band, and the third frequency band as the third channel of the 5GHz band.

[0266] Case 9: The first frequency band is designated as the first channel of the 6 (or 7) GHz band, the second frequency band as the second channel of the 6 (or 7) GHz band, and the third frequency band as the third channel of the 6 (or 7) GHz band.

[0267] (Embodiment 3) This embodiment provides supplementary explanations for Embodiments 1 and 2.

[0268] Figure 1 shows the configuration of a communication device, such as an access point (AP).

[0269] Figure 19A shows an example of the AP's communication state. As shown in Figure 19A, AP 1901 communicates with terminal 1902_1.

[0270] Figure 19B shows an example of the AP's communication status. As shown in Figure 19B, AP 1901 is terminal 1902_i (where i is an integer between 1 and N, and N is an integer greater than or equal to 2). This means that the AP will communicate with two or more terminals.

[0271] The APs in Embodiment 1, Embodiment 2, etc., are assumed to be in the communication state shown in Figures 19A and 19B.

[0272] First, we will explain the operation of the AP (communication device) shown in Figure 1 when transmitting modulated signals using the first frequency band 201, the second frequency band 202, and the third frequency band 203.

[0273] The communication device 113 takes a signal 114 containing data as input and outputs data 109.

[0274] The transmitted data processing unit 107 receives data 109 and control signal 112 as input and outputs first data 101_1, second data 101_2, and third data 101_3 based on the control signal 112.

[0275] For example, when the AP transmits a modulated signal in the first frequency band 201, the transmission data processing unit 107 outputs the first data 101_1; when the AP transmits a modulated signal in the second frequency band 202, the transmission data processing unit 107 outputs the second data 101_2; and when the AP transmits a modulated signal in the third frequency band 203, the transmission data processing unit 107 outputs the third data 101_3.

[0276] For example, when the AP transmits a modulated signal in the first frequency band 201, a modulated signal in the second frequency band 202, and a modulated signal in the third frequency band 203, the transmission data processing unit 107 outputs the first data 101_1, the second data 101_2, and the third data 101_3. The set of frequency bands used simultaneously is as described in Embodiment 1, Embodiment 2, etc.

[0277] The transceiver 102_1 receives the first data 101_1 and the control signal 112 as input, and based on the information contained in the control signal 112, such as the transmission method, modulation scheme, and error correction coding scheme, it performs processing such as encoding and mapping of error correction codes to generate and output the first transmission signal 103_1 in the first frequency band 201. The first modulated transmission signal 103_1 is then output as radio waves from the antenna 104_1.

[0278] The transceiver 102_2 receives the second data 101_2 and the control signal 112 as input. Based on the information contained in the control signal 112, such as the transmission method, modulation scheme, and error correction coding scheme, it performs processing such as encoding and mapping of error correction codes to generate and output the second transmission signal 103_2 in the second frequency band 202. The second modulated transmission signal 103_2 is then output as radio waves from the antenna 104_2.

[0279] The transceiver 102_3 receives the third data 101_3 and the control signal 112 as input, and based on the information contained in the control signal 112, such as the transmission method, modulation scheme, and error correction coding scheme, it performs processing such as encoding and mapping of error correction codes to generate and output the 32nd transmission signal 103_3 in the third frequency band 203. The third modulated transmission signal 103_3 is then output as radio waves from the antenna 104_3.

[0280] Note that antennas 104_1, 104_2, and 104_3 refer to the presence of one or more antennas. When multiple antennas are used, multiple modulated signals are transmitted, enabling MIMO (or MISO (Multiple-Input Single-Output)) transmission.

[0281] Next, the operation of the communication device in Figure 1 regarding reception will be explained. If a modulated signal in the first frequency band 201 transmitted by the terminal exists, the transceiver 102_1 of the AP (communication device) in Figure 1 takes the first received signal 199_1 received by the antenna 105_1 as input, performs processing such as demodulation (demapping) and decoding of error correction codes, and outputs the first data group 106_1.

[0282] If a modulated signal in the second frequency band 202 transmitted by the terminal exists, the transceiver 102_2 of the AP (communication device) in Figure 1 takes the second received signal 199_2 received by the antenna 105_2 as input, performs processing such as demodulation (demapping) and decoding of error correction codes, and outputs the second data group 106_2.

[0283] If a modulated signal in the third frequency band 203 transmitted by the terminal exists, the transceiver 102_3 of the AP (communication device) in Figure 1 takes the third received signal 199_3 received by the antenna 105_3 as input, performs processing such as demodulation (demapping) and decoding of error correction codes, and outputs the third data group 106_3.

[0284] The received data processing unit 108 takes the first data group 106_1, the second data group 106_2, and the third data group 106_3 as inputs and outputs the received data group 110.

[0285] The control unit 111 receives the received data group 110 as input, determines one or more frequency bands from the first, second, and third frequency bands to which the modulated signal will be transmitted, and outputs a control signal 112 containing the determination information. It also outputs a control signal 112 containing information on the transmission method, modulation scheme, and error correction code encoding scheme for each modulated signal to be transmitted.

[0286] Note that antennas 105_1, 105_2, and 105_3 refer to the presence of one or more antennas.

[0287] In Figure 1, the AP is configured to include a section for transmitting and receiving a modulated signal in a first frequency band, a section for transmitting and receiving a modulated signal in a second frequency band, and a section for transmitting and receiving a modulated signal in a third frequency band. However, the AP can be implemented by including two or more of the following sections: a section for transmitting and receiving a modulated signal in a first frequency band, a section for transmitting and receiving a modulated signal in a second frequency band, and a section for transmitting and receiving a modulated signal in a third frequency band.

[0288] The terminal that communicates with AP1901, as shown in Figures 19A and 19B, is also assumed to have the configuration of Figure 1, for example. However, although Figure 1 shows a configuration comprising a part for transmitting and receiving modulated signals in a first frequency band, a part for transmitting and receiving modulated signals in a second frequency band, and a part for transmitting and receiving modulated signals in a third frequency band, the AP can be implemented by comprising any two or more of the "part for transmitting and receiving modulated signals in a first frequency band, a part for transmitting and receiving modulated signals in a second frequency band, and a part for transmitting and receiving modulated signals in a third frequency band."

[0289] Figure 20A shows the configuration of the transmitting section of the transmitting and receiving devices 102_1, 102_2, and 102_3 shown in Figure 1.

[0290] The error correction coding group 2002 takes control signal 2000 and data 2001 as input, performs error correction coding based on the error correction coding scheme included in the control signal 2000, such as the code type, code length, coding rate, etc., and outputs the coded data group 2003. Note that the error correction coding group 2002 may comprise one or more error correction coding units. Therefore, the coded data group 2003 will consist of data of one or more coded words.

[0291] The signal processing group 2004 takes the control signal 2000 and the encoded data group 2003 as inputs, performs processing such as mapping (modulation), precoding, and interleaving based on the control signal 2000, and outputs the modulated signal group 2005.

[0292] For example, if signal processing group 2004 outputs a single modulated signal, it performs processes such as interleaving and mapping, and outputs the single modulated signal as modulated signal group 2005. Similarly, if signal processing group 2004 outputs multiple modulated signals, it performs processes such as interleaving, mapping, and precoding (if necessary), and outputs the multiple modulated signals as modulated signal group 2005.

[0293] The wireless processing group 2006 takes the control signal 2000 and the modulation signal group 2005 as inputs and, based on the control signal 2000, performs processing such as generating an OFDM (Orthogonal Frequency Division Multiplexing) signal, quadrature modulation, and frequency conversion, and outputs the transmission signal group 2007. For example, if the modulation signal group 2005 consists of N modulation signals, it will generate a transmission signal group 2007 with N transmission signals. Here, N is an integer of 1 or more. The transmission signal group 2005 is then transmitted as radio waves from the antenna. If the transmission signal group 2005 consists of multiple transmission signals, the transmission signal group 2005 will be transmitted as radio waves using multiple antennas. When MIMO transmission is used, multiple modulation signals will be transmitted at the same frequency and at the same time.

[0294] Figure 20B shows the configuration of the receiving section of the transceivers 102_1, 102_2, and 102_3 shown in Figure 1.

[0295] The wireless processing group 2052 receives the control signal 2050 and the received signal group 2051 as inputs, performs frequency conversion, quadrature demodulation, and OFDM processing, and outputs the baseband signal group 2053. The received signal group 2051 consists of one or more received signals, and the baseband signal group 2053 consists of one or more baseband signals.

[0296] The signal processing group 2054 receives the control signal 2050 and the baseband signal group 2053 as inputs, performs signal detection, time synchronization, frequency synchronization, frequency offset estimation, channel estimation, etc., and also performs demapping, outputting the likelihood 2055 of the received bits.

[0297] The error correction code decoding group 2056 takes the control signal 2050 and the likelihood of the received bit 2056 as input, decodes the error correction code based on the error correction coding scheme information contained in the control signal 2050, and outputs the received data 2057.

[0298] Figures 21A(1) and (2) show examples of frequency bands used when an AP (or terminal) transmits a modulated signal using a first frequency band.

[0299] In Figure 21A (1), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in a 20 MHz bandwidth.

[0300] In Figure 21A (2), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in a 40 MHz bandwidth.

[0301] Thus, for example, when an AP (or terminal) transmits a modulated signal using the first frequency band, the frequency band used is assumed to be 20 MHz or 40 MHz. However, (1) and (2) in Figure 21A are merely examples.

[0302] Figures 21B (1), (2), (3), and (4) show examples of frequency bands used when an AP (or terminal) transmits a modulated signal using a second frequency band.

[0303] In Figure 21B (1), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in a 20 MHz bandwidth.

[0304] In Figure 21B (2), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in the 40 MHz bandwidth.

[0305] In Figure 21B (3), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in the 80 MHz bandwidth.

[0306] In Figure 21B (4), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in the 160 MHz bandwidth.

[0307] Thus, for example, when an AP (or terminal) transmits a modulated signal using a second frequency band, the frequency band used shall be 20 MHz, 40 MHz, 80 MHz, or 160 MHz. However, (1), (2), (3), and (4) in Figure 21B are merely examples.

[0308] Figures 21C (1), (2), and (3) show examples of frequency bands used when an AP (or terminal) transmits a modulated signal using a third frequency band.

[0309] In Figure 21C (1), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in the 80 MHz bandwidth.

[0310] In Figure 21C (2), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in the 160 MHz bandwidth.

[0311] In Figure 21C (3), the horizontal axis represents frequency and the vertical axis represents time, and the transmission symbol 2101, which is the symbol included in the modulated signal, is assumed to be in the 320 MHz bandwidth.

[0312] Thus, for example, when an AP (or terminal) transmits a modulated signal using a third frequency band, the frequency band used is assumed to be 80 MHz, 160 MHz, or 320 MHz. However, (1), (2), and (3) in Figure 21C are merely examples.

[0313] Next, we will explain the case where AP1901 communicates with terminal 1902_1, as shown in Figure 19A.

[0314] Embodiment 2 described the following: "At a certain time, data symbols destined for the same terminal exist in the first frequency band, the second frequency band, and the third frequency band," or "At a certain time, data symbols destined for the same terminal exist in the first frequency band and the second frequency band," or "At a certain time, data symbols destined for the same terminal exist in the first frequency band and the third frequency band," or "At a certain time, data symbols destined for the same terminal exist in the second frequency band and the third frequency band." An example of the RTS and CTS transmission method in this case will be described.

[0315] Figure 22A shows an example of AP1901 transmitting an RTS to terminal 1902_1. In Figure 22A, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 22A, the RTS signals 1_11 and 1_12, 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18, and the RTS signals 3_11, 3_12, 3_13, and 3_14 exist at time A1.

[0316] AP1901 then transmits RTS 1_11 and 1_12 using the first frequency band 500_1. Note that each of the RTS 1_11 and 1_12 exists within, for example, a 20MHz bandwidth interval. The RTS 1_11 is assumed to be on the first channel of the first frequency band 500_1, and the RTS 1_12 is assumed to be on the second channel of the first frequency band 500_1. Note that although only the first and second channels are described for the first frequency band 500_1, other channels may exist, and AP1901 may transmit RTS using channels other than the first and second channels.

[0317] Furthermore, AP1901 transmits RTS 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 using the second frequency band 500_2. Note that each of the RTS 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 exists within, for example, a 20MHz bandwidth interval. The RTS for 2_11 is located in the first channel of the second frequency band 500_2, the RTS for 2_12 is located in the second channel of the second frequency band 500_2, the RTS for 2_13 is located in the third channel of the second frequency band 500_2, the RTS for 2_14 is located in the fourth channel of the second frequency band 500_2, the RTS for 2_15 is located in the fifth channel of the second frequency band 500_2, the RTS for 2_16 is located in the sixth channel of the second frequency band 500_2, the RTS for 2_17 is located in the seventh channel of the second frequency band 500_2, and the RTS for 2_18 is located in the eighth channel of the second frequency band 500_2. Note that in the second frequency band 500_2, only channels 1 through 8 are listed, but other channels may also exist, and AP1901 may transmit RTS using channels other than channels 1 through 8.

[0318] AP1901 transmits RTS 3_11, 3_12, 3_13, and 3_14 using the third frequency band 500_3. Each of the RTS 3_11, 3_12, 3_13, and 3_14 exists within, for example, an 80MHz bandwidth. The RTS 3_11 is assumed to be on the first channel of the third frequency band 500_3, the RTS 3_12 is assumed to be on the second channel of the third frequency band 500_3, the RTS 3_13 is assumed to be on the third channel of the third frequency band 500_3, and the RTS 3_14 is assumed to be on the fourth channel of the third frequency band 500_3. In the third frequency band 500_3, only channels 1 through 4 are described, but other channels may exist, and AP1901 may transmit RTS using channels other than channels 1 through 4.

[0319] As described in Embodiment 1, the RTS shall include at least the address information of the communication partner. Furthermore, the RTS transmitted by AP1901 using the first frequency band may include the address information of one or more communication partners (i.e., one or more terminals). Similarly, the RTS transmitted by AP1901 using the second frequency band may include the address information of one or more communication partners (i.e., one or more terminals). The RTS transmitted by AP1901 using the third frequency band may include the addresses of one or more communication partners (i.e., one or more terminals).

[0320] As shown in Figure 22A, when AP1901 transmits RTS, each of the RTS messages 1_11, 1_12, 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, 2_18, and 3_11, 3_12, 3_13, 3_14 will contain information about the address of a single terminal (1902_1).

[0321] Terminal 1902_1 will receive the RTS shown in Figure 22A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered ready to receive in the "first, second, third, fourth, fifth, sixth, seventh, and eighth channels of the second frequency band 500_2" and the "first and second channels of the third frequency band 500_3". Figure 22B shows an example in which terminal 1902_1 transmits a CTS to AP1901. In Figure 22B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 22B, the CTSs 2_21, 2_22, 2_23, 2_24, 2_25, 2_26, 2_27, and 2_28, and the CTSs 3_21 and 3_22 exist at time A2.

[0322] Terminal 1902_1 transmits CTS 2_21, 2_22, 2_23, 2_24, 2_25, 2_26, 2_27, and 2_28 using the second frequency band 500_2. Note that each of the CTS 2_21, 2_22, 2_23, 2_24, 2_25, 2_26, 2_27, and 2_28 is located within, for example, a 20MHz bandwidth interval. The CTS in 2_21 is assumed to be located in the first channel of the second frequency band 500_2, the CTS in 2_22 is assumed to be located in the second channel of the second frequency band 500_2, the CTS in 2_23 is assumed to be located in the third channel of the second frequency band 500_2, the CTS in 2_24 is assumed to be located in the fourth channel of the second frequency band 500_2, the CTS in 2_25 is assumed to be located in the fifth channel of the second frequency band 500_2, the CTS in 2_26 is assumed to be located in the sixth channel of the second frequency band 500_2, the CTS in 2_27 is assumed to be located in the seventh channel of the second frequency band 500_2, and the CTS in 2_28 is assumed to be located in the eighth channel of the second frequency band 500_2. Note that although only channels 1 through 8 are listed for the second frequency band 500_2, other channels may also exist.

[0323] Furthermore, terminal 1902_1 transmits CTS 3_21 and 3_22 using the third frequency band 500_3. Note that CTS 3_21 and 3_22 are located within, for example, an 80MHz bandwidth interval. CTS 3_21 is assumed to be on the first channel of the third frequency band 500_3, and CTS 3_22 is assumed to be on the second channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0324] AP1901 receives the CTS shown in Figure 22B transmitted by terminal 1902_1. Based on the reception of the CTS, AP1901 determines that it will transmit the symbol group containing data symbols to "channels 1, 2, 3, 4, 5, 6, 7, and 8 of the second frequency band 500_2" and "channels 1 and 2 of the third frequency band 500_3". Figure 22C shows an example of AP1901 transmitting a symbol group containing data symbols to terminal 1902_1. In Figure 22C, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 22C, the symbol groups 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38, and the symbol groups 3_31 and 3_32 exist at time A3.

[0325] AP1901 transmits the symbol group 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 using the second frequency band 500_2. Each of the symbol groups 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 exists within, for example, a 20MHz bandwidth. The symbol group 2_31 is located in the first channel of the second frequency band 500_2, the symbol group 2_32 is located in the second channel of the second frequency band 500_2, the symbol group 2_33 is located in the third channel of the second frequency band 500_2, the symbol group 2_34 is located in the fourth channel of the second frequency band 500_2, the symbol group 2_35 is located in the fifth channel of the second frequency band 500_2, the symbol group 2_36 is located in the sixth channel of the second frequency band 500_2, the symbol group 2_37 is located in the seventh channel of the second frequency band 500_2, and the symbol group 2_38 is located in the eighth channel of the second frequency band 500_2. Note that only channels 1 through 8 are listed for the second frequency band 500_2, but other channels may also exist.

[0326] Furthermore, AP1901 transmits the symbol groups 3_31 and 3_32 using the third frequency band 500_3. Note that each of the symbol groups 3_31 and 3_32 exists within, for example, an 80MHz bandwidth. The symbol group 3_31 is assumed to be in the first channel of the third frequency band 500_3, and the symbol group 3_32 is assumed to be in the second channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0327] As described above, for example, by using the second and third frequency bands, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar solutions using configuration methods different from those shown in Figures 22A, 22B, and 22C.

[0328] Next, we will explain a second example of when AP1901 communicates with terminal 1902_1, as shown in Figure 19A.

[0329] Figure 22A shows an example of AP1901 sending an RTS to terminal 1902_1. Since Figure 22A has already been explained, a detailed explanation will be omitted.

[0330] Terminal 1902_1 will receive the RTS shown in Figure 22A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered ready to receive in the "first channel of the first frequency band 500_1", the "first, second, third, and fourth channels of the second frequency band 500_2", and the "first channel of the third frequency band 500_3". Figure 23A shows an example of terminal 1902_1 transmitting a CTS to AP1901. In Figure 23A, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 23A, the CTS at 1_21, 2_21, 2_22, 2_23, 2_24, and 3_21 exist at time A2.

[0331] Terminal 1902_1 transmits CTS 1_21 using the first frequency band 500_1. Note that CTS 1_21 exists within, for example, a 20MHz bandwidth. CTS 1_21 is assumed to reside on the first channel of the first frequency band 500_1. While only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0332] Terminal 1902_1 transmits CTS 2_21, 2_22, 2_23, and 2_24 using the second frequency band 500_2. Each of the CTS 2_21, 2_22, 2_23, and 2_24 exists within, for example, a 20MHz bandwidth. The CTS 2_21 is assumed to be on the first channel of the second frequency band 500_2, the CTS 2_22 on the second channel of the second frequency band 500_2, the CTS 2_23 on the third channel of the second frequency band 500_2, and the CTS 2_24 on the fourth channel of the second frequency band 500_2. Note that only channels 1 through 8 are listed for the second frequency band 500_2; other channels may also exist.

[0333] Terminal 1902_1 transmits the CTS of 3_21 using the third frequency band 500_3. The CTS of 3_21 is located within, for example, an 80MHz bandwidth. The CTS of 3_21 is assumed to be on the first channel of the third frequency band 500_3. Although only channels 1 through 4 are described for the third frequency band 500_3, other channels may also exist.

[0334] AP1901 will receive the CTS shown in Figure 23A transmitted by terminal 1902_1. Based on the reception of the CTS, AP1901 will determine that the symbol group containing the data symbol will be transmitted to the "first channel of the first frequency band 500_1", the "first, second, third, and fourth channels of the second frequency band 500_2", and the "first channel of the third frequency band 500_3". Figure 23B shows an example of AP1901 transmitting a symbol group containing the data symbol to terminal 1902_1. In Figure 23B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 23B, the symbol group 1_31, the symbol groups 2_31, 2_32, 2_33, 2_34, and the symbol group 3_31 exist at time A3.

[0335] AP1901 transmits the symbol group 1_31 using the first frequency band 500_1. The symbol group 1_31 exists within, for example, a 20MHz bandwidth. The symbol group 1_31 is assumed to reside in the first channel of the first frequency band 500_1. Although only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0336] AP1901 transmits the symbol groups 2_31, 2_32, 2_33, and 2_34 using the second frequency band 500_2. Each of the symbol groups 2_31, 2_32, 2_33, and 2_34 exists within, for example, a 20MHz bandwidth. The symbol group 2_31 is assumed to be on the first channel of the second frequency band 500_2, the symbol group 2_32 is assumed to be on the second channel of the second frequency band 500_2, the symbol group 2_33 is assumed to be on the third channel of the second frequency band 500_2, and the symbol group 2_34 is assumed to be on the fourth channel of the second frequency band 500_2. Note that only channels 1 through 8 are described for the second frequency band 500_2, but other channels may also exist.

[0337] AP1901 transmits the symbol group 3_31 using the third frequency band 500_3. The symbol group 3_31 exists, for example, within an 80MHz bandwidth. The symbol group 3_31 is assumed to reside on the first channel of the third frequency band 500_3. While only channels 1 through 4 are described for the third frequency band 500_3, other channels may also exist.

[0338] As described above, for example, by using the first frequency band, the second frequency band, and the third frequency band, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar solutions using configuration methods different from those shown in Figures 22A, 23A, and 23B.

[0339] A third example of when AP1901 communicates with terminal 1902_1 will be explained, as shown in Figure 19A.

[0340] Figure 22A shows an example of AP1901 sending an RTS to terminal 1902_1. Since Figure 22A has already been explained, a detailed explanation will be omitted.

[0341] Terminal 1902_1 will receive the RTS shown in Figure 22A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered to be in a "ready to receive" state in "the first and second channels of the first frequency band 500_1" and "the first, second, third, and fourth channels of the second frequency band 500_2". In Figure 24A, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 24A, the CTSs 1_21, 1_22, 2_21, 2_22, 2_23, and 2_24 exist at time A2.

[0342] Terminal 1902_1 transmits CTS 1_21 and 1_22 using the first frequency band 500_1. Note that CTS 1_21 and 1_22 are located within a 20MHz bandwidth interval. CTS 1_21 is assumed to be on the first channel of the first frequency band 500_1, and CTS 1_22 is assumed to be on the second channel of the first frequency band 500_1. Although only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0343] Terminal 1902_1 transmits CTS 2_21, 2_22, 2_23, and 2_24 using the second frequency band 500_2. Each of the CTS 2_21, 2_22, 2_23, and 2_24 is located within a 20MHz bandwidth. The CTS 2_21 is assumed to be on the first channel of the second frequency band 500_2, the CTS 2_22 is assumed to be on the second channel of the second frequency band 500_2, the CTS 2_23 is assumed to be on the third channel of the second frequency band 500_2, and the CTS 2_24 is assumed to be on the fourth channel of the second frequency band 500_2. In the second frequency band 500_2, only channels 1 through 8 are listed, but other channels may also exist.

[0344] AP1901 will receive the CTS shown in Figure 24A transmitted by terminal 1902_1. Based on the reception of the CTS, AP1901 will determine that it will transmit the symbol group containing the data symbol to "the first and second channels of the first frequency band 500_1" and "the first, second, third, and fourth channels of the second frequency band 500_2". Figure 24B shows an example of AP1901 transmitting a data symbol group containing the data symbol to terminal 1902_1. In Figure 24B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 24B, the symbol groups 1_31 and 1_32, and the symbol groups 2_31, 2_32, 2_33, and 2_34 exist at time A3.

[0345] AP1901 transmits the symbol groups 1_31 and 1_32 using the first frequency band 500_1. Note that each of the symbol groups 1_31 and 1_32 exists within, for example, a 20MHz bandwidth interval. The symbol group 1_31 is assumed to reside in the first channel of the first frequency band 500_1, and the symbol group 1_32 is assumed to reside in the second channel of the first frequency band 500_1. Note that while only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0346] AP1901 transmits the symbol groups 2_31, 2_32, 2_33, and 2_34 using the second frequency band 500_2. These symbol groups are, for example, located within a 20MHz bandwidth. The symbol group 2_31 is assumed to be on the first channel of the second frequency band 500_2, the symbol group 2_32 on the second channel, the symbol group 2_33 on the third channel, and the symbol group 2_34 on the fourth channel. While only channels 1 through 8 are listed for the second frequency band 500_2, other channels may also exist.

[0347] As described above, by using the first and second frequency bands, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar solutions using configuration methods different from those shown in Figures 22A, 24A, and 24B.

[0348] A fourth example of when AP1901 communicates with terminal 1902_1 will be explained, as shown in Figure 19A.

[0349] Figure 22A shows an example of AP1901 sending an RTS to terminal 1902_1. Since Figure 22A has already been explained, a detailed explanation will be omitted.

[0350] Terminal 1902_1 will receive the RTS shown in Figure 22A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered ready to receive in the "first and second channels of the first frequency band 500_1" and the "first channel of the third frequency band 500_3". Figure 25A shows an example of terminal 1902_1 transmitting a CTS to AP1901. In Figure 25A, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 25A, the CTSs 1_21, 1_22 and 3_21 exist at time A2.

[0351] Terminal 1902_1 transmits CTS 1_21 and 1_22 using the first frequency band 500_1. Note that CTS 1_21 and 1_22 are located within, for example, a 20MHz bandwidth interval. CTS 1_21 is assumed to be on the first channel of the first frequency band 500_1, and CTS 1_22 is assumed to be on the second channel of the first frequency band 500_1. Note that only the first and second channels are described for the first frequency band 500_1; other channels may also exist.

[0352] Terminal 1902_1 transmits the CTS of 3_21 using the third frequency band 500_3. The CTS of 3_21 is located within, for example, an 80MHz bandwidth. The CTS of 3_21 is assumed to be on the first channel of the third frequency band 500_3. Although only channels 1 through 4 are described for the third frequency band 500_3, other channels may also exist.

[0353] AP1901 will receive the CTS shown in Figure 25A transmitted by terminal 1902_1. Based on the reception of the CTS, AP1901 will then decide to transmit the symbol group, including the data symbol, to the first and second channels of the first frequency band 500_1, and the first channel of the third frequency band 500_3. Figure 25B shows an example of AP1901 transmitting a group of symbols, including the data symbol, to terminal 1902_1. In Figure 25B, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 25B, the symbol groups 1_31 and 1_32, and the symbol group 3_31 exist at time A3.

[0354] AP1901 transmits the symbol groups 1_31 and 1_32 using the first frequency band 500_1. The symbol groups 1_31 and 1_32 are, for example, located within a 20MHz bandwidth. The symbol group 1_31 is assumed to reside in the first channel of the first frequency band 500_1, and the symbol group 1_32 is assumed to reside in the second channel of the first frequency band 500_1. While only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0355] AP1901 transmits the symbol group 3_31 using the third frequency band 500_3. The symbol group 3_31 exists, for example, within an 80MHz bandwidth. The symbol group 3_31 is assumed to reside on the first channel of the third frequency band 500_3. While only channels 1 through 4 are described for the third frequency band 500_3, other channels may also exist.

[0356] As described above, for example, by using the first frequency band and the third frequency band, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar solutions using configuration methods different from those shown in Figures 22A, 25A, and 25B.

[0357] A fifth example of when AP1901 communicates with terminal 1902_1 will be explained, as shown in Figure 19A.

[0358] Figure 26A shows an example of AP1901 transmitting an RTS to terminal 1902_1. In Figure 26A, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 26A, the RTS signals 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18, and the RTS signals 3_13 and 3_14 exist at time A1.

[0359] The AP1901 then transmits RTS 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 using the second frequency band 500_2. Note that each of the RTS 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 exists within, for example, a 20MHz bandwidth. The RTS for 2_11 is located in the first channel of the second frequency band 500_2, the RTS for 2_12 is located in the second channel of the second frequency band 500_2, the RTS for 2_13 is located in the third channel of the second frequency band 500_2, the RTS for 2_14 is located in the fourth channel of the second frequency band 500_2, the RTS for 2_15 is located in the fifth channel of the second frequency band 500_2, the RTS for 2_16 is located in the sixth channel of the second frequency band 500_2, the RTS for 2_17 is located in the seventh channel of the second frequency band 500_2, and the RTS for 2_18 is located in the eighth channel of the second frequency band 500_2. Note that in the second frequency band 500_2, only channels 1 through 8 are listed, but other channels may also exist, and AP1901 may transmit RTS using channels other than channels 1 through 8.

[0360] Furthermore, AP1901 transmits RTS 3_13 and 3_14 using the third frequency band 500_3. Note that RTS 3_13 and 3_14 are located within, for example, an 80MHz bandwidth interval. RTS 3_13 is assumed to be on the third channel of the third frequency band 500_3, and RTS 3_14 is assumed to be on the fourth channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may exist, and AP1901 may transmit RTS using channels other than channels 1 through 4.

[0361] As described in Embodiment 1, the RTS shall include at least the address information of the communication partner. Furthermore, the RTS transmitted by AP1901 using the second frequency band may include the address information of one or more communication partners (i.e., one or more terminals). The RTS transmitted by AP1901 using the third frequency band may include the addresses of one or more communication partners (i.e., one or more terminals).

[0362] As shown in Figure 26A, when AP1901 transmits RTS, each of the RTS messages 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, 2_18, and 3_13 and 3_14 will contain information about the address of a single terminal (1902_1).

[0363] Terminal 1902_1 will receive the RTS shown in Figure 26A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered ready to receive in the "first, second, third, fourth, fifth, sixth, seventh, and eighth channels of the second frequency band 500_2" and the "third and fourth channels of the third frequency band 500_3". Figure 26B shows an example of terminal 1902_1 transmitting a CTS to AP1901. In Figure 26B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 26B, the CTSs 2_21, 2_22, 2_23, 2_24, 2_25, 2_26, 2_27, and 2_28, and the CTSs 3_23 and 3_24 exist at time A2.

[0364] Terminal 1902_1 transmits CTS 2_21, 2_22, 2_23, 2_24, 2_25, 2_26, 2_27, and 2_28 using the second frequency band 500_2. Note that each of the CTS 2_21, 2_22, 2_23, 2_24, 2_25, 2_26, 2_27, and 2_28 is located within, for example, a 20MHz bandwidth interval. The CTS in 2_21 is assumed to be located in the first channel of the second frequency band 500_2, the CTS in 2_22 is assumed to be located in the second channel of the second frequency band 500_2, the CTS in 2_23 is assumed to be located in the third channel of the second frequency band 500_2, the CTS in 2_24 is assumed to be located in the fourth channel of the second frequency band 500_2, the CTS in 2_25 is assumed to be located in the fifth channel of the second frequency band 500_2, the CTS in 2_26 is assumed to be located in the sixth channel of the second frequency band 500_2, the CTS in 2_27 is assumed to be located in the seventh channel of the second frequency band 500_2, and the CTS in 2_28 is assumed to be located in the eighth channel of the second frequency band 500_2. Note that although only channels 1 through 8 are listed for the second frequency band 500_2, other channels may also exist.

[0365] Furthermore, terminal 1902_1 transmits CTS 3_23 and 3_24 using the third frequency band 500_3. Note that CTS 3_23 and 3_24 are located within, for example, an 80MHz bandwidth interval. CTS 3_23 is assumed to be on the third channel of the third frequency band 500_3, and CTS 3_24 is assumed to be on the fourth channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0366] AP1901 receives the CTS shown in Figure 26B, which was transmitted by terminal 1902_1. Based on the reception of the CTS, AP1901 determines that it will transmit the symbol group containing data symbols to "channels 1, 2, 3, 4, 5, 6, 7, and 8 of the second frequency band 500_2," and "channels 3 and 4 of the third frequency band 500_3." Figure 26C shows an example of AP1901 transmitting a symbol group containing data symbols to terminal 1902_1. In Figure 26C, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 26C, the symbol groups 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38, and the symbol groups 3_33 and 3_34 exist at time A3.

[0367] AP1901 transmits the symbol group 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 using the second frequency band 500_2. Each of the symbol groups 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 exists within, for example, a 20MHz bandwidth. The symbol group 2_31 is located in the first channel of the second frequency band 500_2, the symbol group 2_32 is located in the second channel of the second frequency band 500_2, the symbol group 2_33 is located in the third channel of the second frequency band 500_2, the symbol group 2_34 is located in the fourth channel of the second frequency band 500_2, the symbol group 2_35 is located in the fifth channel of the second frequency band 500_2, the symbol group 2_36 is located in the sixth channel of the second frequency band 500_2, the symbol group 2_37 is located in the seventh channel of the second frequency band 500_2, and the symbol group 2_38 is located in the eighth channel of the second frequency band 500_2. Note that only channels 1 through 8 are listed for the second frequency band 500_2, but other channels may also exist.

[0368] Furthermore, AP1901 transmits the symbol groups 3_33 and 3_34 using the third frequency band 500_3. Note that each of the symbol groups 3_33 and 3_34 exists within, for example, an 80MHz bandwidth. The symbol group 3_33 is assumed to be on the third channel of the third frequency band 500_3, and the symbol group 3_34 is assumed to be on the fourth channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0369] As described above, for example, by using the second and third frequency bands, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above. Therefore, it is possible to implement the same method using configurations different from those shown in Figures 26A, 26B, and 26C.

[0370] A sixth example of when AP1901 communicates with terminal 1902_1 is described, as shown in Figure 19A.

[0371] Figure 27A shows an example of AP1901 transmitting an RTS to terminal 1902_1. In Figure 27A, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 27A, the RTS signals 1_11 and 1_12, and the RTS signals 2_13, 2_14, 2_15, and 2_16 exist at time A1.

[0372] AP1901 then transmits RTS 1_11 and 1_12 using the first frequency band 500_1. Note that each of the RTS 1_11 and 1_12 exists within, for example, a 20MHz bandwidth interval. The RTS 1_11 is assumed to be on the first channel of the first frequency band 500_1, and the RTS 1_12 is assumed to be on the second channel of the first frequency band 500_1. Note that although only the first and second channels are described for the first frequency band 500_1, other channels may exist, and AP1901 may transmit RTS using channels other than the first and second channels.

[0373] Furthermore, AP1901 transmits RTS 2_13, 2_14, 2_15, and 2_16 using the second frequency band 500_2. Note that each of the RTS 2_13, 2_14, 2_15, and 2_16 exists within, for example, a 20MHz bandwidth interval.

[0374] The RTS for 2_13 is assumed to be on the 3rd channel of the second frequency band 500_2, the RTS for 2_14 is assumed to be on the 4th channel of the second frequency band 500_2, the RTS for 2_15 is assumed to be on the 5th channel of the second frequency band 500_2, and the RTS for 2_16 is assumed to be on the 6th channel of the second frequency band 500_2. Although only channels 1 through 8 are listed for the second frequency band 500_2, other channels may exist, and AP1901 may transmit RTS using channels other than channels 1 through 8.

[0375] As described in Embodiment 1, the RTS includes at least the address information of the communication partner. Furthermore, the RTS transmitted by AP1901 using the first frequency band may include the address information of one or more communication partners (i.e., one or more terminals). Similarly, the RTS transmitted by AP1901 using the second frequency band may include the address information of one or more communication partners (i.e., one or more terminals).

[0376] As shown in Figure 27A, when AP1901 transmits RTS, each of the RTS messages 1_11 and 1_12, and the RTS messages 2_13, 2_14, 2_15, and 2_16, will contain information about the address of a single terminal (1902_1).

[0377] Terminal 1902_1 will receive the RTS shown in Figure 27A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered ready to receive in the "first and second channels of the first frequency band" and the "third and fourth channels of the second frequency band 500_2". Figure 27B shows an example of terminal 1902_1 transmitting a CTS to AP1901. In Figure 27B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 27B, the CTSs 1_21 and 1_22, and the CTSs 2_23 and 2_24 exist at time A2.

[0378] Terminal 1902_1 transmits CTS 1_21 and 1_22 using the first frequency band 500_1. Note that CTS 1_21 and 1_22 are located within, for example, a 20MHz bandwidth interval. CTS 1_21 is assumed to be on the first channel of the first frequency band 500_1, and CTS 1_22 is assumed to be on the second channel of the first frequency band 500_1. Note that only the first and second channels are described for the first frequency band 500_1, but other channels may also exist.

[0379] Terminal 1902_1 transmits CTS 2_23 and 2_24 using the second frequency band 500_2. Note that CTS 2_23 and 2_24 are located within, for example, a 20MHz bandwidth interval. CTS 2_23 is assumed to be on the third channel of the second frequency band 500_2, and CTS 2_24 is assumed to be on the fourth channel of the second frequency band 500_2. Note that only channels 1 through 8 are listed for the second frequency band 500_2, but other channels may also exist.

[0380] AP1901 receives the CTS shown in Figure 27B, which was transmitted by terminal 1902_1. Based on the reception of the CTS, AP1901 determines that it will transmit the symbol group containing the data symbol to the first and second channels of the first frequency band 500_1, and the third and fourth channels of the second frequency band 500_2. Figure 27C shows an example of AP1901 transmitting a symbol group containing the data symbol to terminal 1902_1. In Figure 27C, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 27C, the symbol groups 1_31 and 1_32, and the symbol groups 2_33 and 2_34 exist at time A3.

[0381] AP1901 transmits the symbol groups 1_31 and 1_32 using the first frequency band 500_1. Note that each of the symbol groups 1_31 and 1_32 exists within, for example, a 20MHz bandwidth interval. The symbol group 1_31 is assumed to reside in the first channel of the first frequency band 500_1, and the symbol group 1_32 is assumed to reside in the second channel of the first frequency band 500_1. Note that while only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0382] AP1901 transmits the symbol groups 2_33 and 2_34 using the second frequency band 500_2. Note that each of the symbol groups 2_33 and 2_34 exists within, for example, a 20MHz bandwidth. The symbol group 2_33 is assumed to be on the third channel of the second frequency band 500_2, and the symbol group 2_34 is assumed to be on the fourth channel of the second frequency band 500_2. Note that only channels 1 through 8 are described for the second frequency band 500_2, but other channels may also exist.

[0383] As described above, for example, by using the first and second frequency bands, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar solutions using configuration methods different from those shown in Figures 27A, 27B, and 27C.

[0384] A seventh example is described, where AP1901 communicates with terminal 1902_1, as shown in Figure 19A.

[0385] Figure 28A shows an example of AP1901 transmitting an RTS to terminal 1902_1. In Figure 28A, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 28A, the RTS signals 1_11 and 1_12, and the RTS signals 3_13 and 3_14 exist at time A1.

[0386] AP1901 then transmits RTS 1_11 and 1_12 using the first frequency band 500_1. Note that each of the RTS 1_11 and 1_12 exists within, for example, a 20MHz bandwidth interval. The RTS 1_11 is assumed to be on the first channel of the first frequency band 500_1, and the RTS 1_12 is assumed to be on the second channel of the first frequency band 500_1. Note that although only the first and second channels are described for the first frequency band 500_1, other channels may exist, and AP1901 may transmit RTS using channels other than the first and second channels.

[0387] Furthermore, AP1901 transmits RTS 3_13 and 3_14 using the third frequency band 500_3. Note that RTS 3_13 and 3_14 are located within, for example, an 80MHz bandwidth interval. RTS 3_13 is assumed to be on the third channel of the third frequency band 500_3, and RTS 3_14 is assumed to be on the fourth channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may exist, and AP1901 may transmit RTS using channels other than channels 1 through 4.

[0388] As described in Embodiment 1, the RTS includes at least the address information of the communication partner. Furthermore, the RTS transmitted by AP1901 using the first frequency band may include the address information of one or more communication partners (i.e., one or more terminals). Similarly, the RTS transmitted by AP1901 using the third frequency band may include the address information of one or more communication partners (i.e., one or more terminals).

[0389] As shown in Figure 28A, when AP1901 transmits RTS, each of the RTS messages 1_11, 1_12, and 3_13, 3_14 will contain information about the address of a single terminal (1902_1).

[0390] Terminal 1902_1 will receive the RTS shown in Figure 28A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered ready to receive in the "first and second channels of the first frequency band" and the "third and fourth channels of the third frequency band 500_3". Figure 28B shows an example of terminal 1902_1 transmitting a CTS to AP1901. In Figure 28B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 28B, the CTSs 1_21, 1_22 and 3_23, 3_24 exist at time A2.

[0391] Terminal 1902_1 transmits CTS 1_21 and 1_22 using the first frequency band 500_1. Note that CTS 1_21 and 1_22 are located within, for example, a 20MHz bandwidth interval. CTS 1_21 is assumed to be on the first channel of the first frequency band 500_1, and CTS 1_22 is assumed to be on the second channel of the first frequency band 500_1. Note that only the first and second channels are described for the first frequency band 500_1, but other channels may also exist.

[0392] Terminal 1902_1 transmits CTS 3_23 and 3_24 using the third frequency band 500_3. Note that CTS 3_23 and 3_24 are located within, for example, an 80MHz bandwidth interval. CTS 3_23 is assumed to be on the third channel of the third frequency band 500_3, and CTS 3_24 is assumed to be on the fourth channel of the third frequency band 500_3. Note that only channels 1 through 4 are listed for the third frequency band 500_3, but other channels may also exist.

[0393] AP1901 receives the CTS shown in Figure 28B, which was transmitted by terminal 1902_1. Based on the reception of the CTS, AP1901 determines that it will transmit the symbol group containing the data symbol to the first and second channels of the first frequency band 500_1, and the third and fourth channels of the third frequency band 500_3. Figure 28C shows an example of AP1901 transmitting a symbol group containing the data symbol to terminal 1902_1. In Figure 28C, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 28C, the symbol groups 1_31 and 1_32, and the symbol groups 3_33 and 3_34 exist at time A3.

[0394] AP1901 transmits the symbol groups 1_31 and 1_32 using the first frequency band 500_1. Note that each of the symbol groups 1_31 and 1_32 exists within, for example, a 20MHz bandwidth interval. The symbol group 1_31 is assumed to reside in the first channel of the first frequency band 500_1, and the symbol group 1_32 is assumed to reside in the second channel of the first frequency band 500_1. Note that while only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0395] AP1901 transmits the symbol groups 3_33 and 3_34 using the third frequency band 500_3. Note that each of the symbol groups 3_33 and 3_34 exists within, for example, an 80MHz bandwidth. The symbol group 3_33 is assumed to be on the third channel of the third frequency band 500_3, and the symbol group 3_34 is assumed to be on the fourth channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0396] As described above, for example, by using the first and third frequency bands, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar solutions using configuration methods different from those shown in Figures 28A, 28B, and 28C.

[0397] In the above-mentioned "Examples 1 to 7 of when AP1901 communicates with terminal 1902_1 as shown in Figure 19A," an example was described in which, when AP1901 sends an RTS, the address information of the communication partner included in the RTS consists of the address information of one communication partner. Below, an example is described in which, when AP1901 sends an RTS, the address information of the communication partner included in the RTS consists of the address information of two or more communication partners.

[0398] As shown in Figure 19B, consider the case where AP1901 is communicating with multiple terminals, namely terminal 1902_i. i is an integer between 1 and N (inclusive), and N is an integer greater than or equal to 2. For simplicity, the following explanation will use the example of AP1901 communicating with terminals 1902_1 and 1902_2.

[0399] Figure 29A shows an example of AP1901 transmitting RTS to terminals 1902_1 and 1902_2. In Figure 29A, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 29A, RTS 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 exist at time A1.

[0400] The AP1901 then transmits RTS 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 using the second frequency band 500_2. Note that each of the RTS 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 exists within, for example, a 20MHz bandwidth. The RTS for 2_11 is located in the first channel of the second frequency band 500_2, the RTS for 2_12 is located in the second channel of the second frequency band 500_2, the RTS for 2_13 is located in the third channel of the second frequency band 500_2, the RTS for 2_14 is located in the fourth channel of the second frequency band 500_2, the RTS for 2_15 is located in the fifth channel of the second frequency band 500_2, the RTS for 2_16 is located in the sixth channel of the second frequency band 500_2, the RTS for 2_17 is located in the seventh channel of the second frequency band 500_2, and the RTS for 2_18 is located in the eighth channel of the second frequency band 500_2. Note that in the second frequency band 500_2, only channels 1 through 8 are listed, but other channels may also exist, and AP1901 may transmit RTS using channels other than channels 1 through 8.

[0401] As described in Embodiment 1, the RTS shall include at least the address information of the communication partner. Furthermore, the RTS transmitted by AP1901 using the second frequency band may include the address information of one or more communication partners (i.e., one or more terminals).

[0402] In Figure 29A, each of the RTS entries 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18 is assumed to contain information about the address of terminal 1902_1 and information about the address of terminal 1902_2.

[0403] Terminal 1902_1 will receive the RTS shown in Figure 29A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_1 will be considered to be in a "ready to receive" state on "the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, and 8th channels of the second frequency band". Figure 29B shows an example in which terminal 1902_1 transmits a CTS to AP1901. In Figure 29B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 29B, the CTSs 2_21_1, 2_22_1, 2_23_1, 2_24_1, 2_25_1, 2_26_1, 2_27_1, and 2_28_1 exist at time A2_1.

[0404] Terminal 1902_1 transmits CTS 2_21_1, 2_22_1, 2_23_1, 2_24_1, 2_25_1, 2_26_1, 2_27_1, and 2_28_1 using the second frequency band 500_2. Note that each of the CTS 2_21_1, 2_22_1, 2_23_1, 2_24_1, 2_25_1, 2_26_1, 2_27_1, and 2_28_1 are located within, for example, a 20MHz bandwidth interval. The CTS of 2_21_1 is located in the first channel of the second frequency band 500_2, the CTS of 2_22_1 is located in the second channel of the second frequency band 500_2, the CTS of 2_23_1 is located in the third channel of the second frequency band 500_2, the CTS of 2_24_1 is located in the fourth channel of the second frequency band 500_2, the CTS of 2_25_1 is located in the fifth channel of the second frequency band 500_2, the CTS of 2_26_1 is located in the sixth channel of the second frequency band 500_2, the CTS of 2_27_1 is located in the seventh channel of the second frequency band 500_2, and the CTS of 2_28_1 is located in the eighth channel of the second frequency band 500_2. Note that in the second frequency band 500_2, only channels 1 through 8 are listed, but other channels may also exist.

[0405] Terminal 1902_2 will receive the RTS shown in Figure 29A transmitted by AP1901. Based on the reception of the RTS, terminal 1902_2 will be assumed to be in a state of "ready to receive" on the "first, second, third, and fourth channels of the second frequency band". Figure 29C shows an example in which terminal 1902_2 transmits a CTS to AP1901. In Figure 29C, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 29C, the CTSs 2_21_2, 2_22_2, 2_23_2, and 2_24_2 exist at time A2_2.

[0406] Terminal 1902_2 transmits CTS 2_21_2, 2_22_2, 2_23_2, and 2_24_2 using the second frequency band 500_2. Each of the CTS 2_21_2, 2_22_2, 2_23_2, and 2_24_2 exists within, for example, a 20MHz bandwidth. The CTS 2_21_2 is assumed to be on the first channel of the second frequency band 500_2, the CTS 2_22_2 on the second channel of the second frequency band 500_2, the CTS 2_23_2 on the third channel of the second frequency band 500_2, and the CTS 2_24_2 on the fourth channel of the second frequency band 500_2. Note that only channels 1 through 8 are listed for the second frequency band 500_2; other channels may also exist.

[0407] AP1901 receives the CTS shown in Figure 29B transmitted by terminal 1902_1 and the CTS shown in Figure 29C transmitted by terminal 1902_2. Based on the reception of these CTS, AP1901 determines that it will transmit the symbol group containing data symbols to "channels 1, 2, 3, 4, 5, 6, 7, and 8 of the second frequency band 500_2". Figure 29D shows an example of AP1901 transmitting a symbol group containing data symbols to terminals 1902_1 and 1902_2. In Figure 29D, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 28C, the symbol groups 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 exist at time A3.

[0408] AP1901 transmits the symbol group 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 using the second frequency band 500_2. Each of the symbol groups 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 exists within, for example, a 20MHz bandwidth. The symbol group 2_31 is located in the first channel of the second frequency band 500_2, the symbol group 2_32 is located in the second channel of the second frequency band 500_2, the symbol group 2_33 is located in the third channel of the second frequency band 500_2, the symbol group 2_34 is located in the fourth channel of the second frequency band 500_2, the symbol group 2_35 is located in the fifth channel of the second frequency band 500_2, the symbol group 2_36 is located in the sixth channel of the second frequency band 500_2, the symbol group 2_37 is located in the seventh channel of the second frequency band 500_2, and the symbol group 2_38 is located in the eighth channel of the second frequency band 500_2. Note that only channels 1 through 8 are listed for the second frequency band 500_2, but other channels may also exist.

[0409] The symbol group consisting of symbols 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 includes data symbols addressed to terminal 1902_1 and data symbols addressed to terminal 1902_2. For example, as shown in Figure 6B, AP1901 transmits the symbol group by frequency-dividing the data symbols addressed to terminal 1902_1 and the data symbols addressed to terminal 1902_2. Alternatively, the data symbols addressed to terminal 1902_1 and the data symbols addressed to terminal 1902_2 may be divided by time, or the same can be achieved by preparing two regions that consist of the symbol group 2_31, 2_32, 2_33, 2_34, 2_35, 2_36, 2_37, and 2_38 by time and frequency, with one region containing data symbols addressed to terminal 1902_1 and the other region containing data symbols addressed to terminal 1902_2.

[0410] A key feature of the above example is that, when an AP simultaneously transmits symbols to multiple (two or more) terminals, the AP transmits the modulated signal using one of the following frequency bands: the first frequency band 500_1, the second frequency band 500_2, or the third frequency band 500_3. A detailed explanation is also provided in Embodiment 2.

[0411] Furthermore, when AP1901 transmits a modulated signal using the first frequency band 500_1, including a set of symbols containing data symbols addressed to terminal 1902_1 and data symbols addressed to terminal 1902_2, AP1901 transmits RTS using the first frequency band 500_1, and terminals 1902_1 and 1902_2 transmit CTS using the first frequency band 500_1. In other words, in Figures 29A, 29B, 29C, and 29D, the second frequency band 500_2 can be considered as the first frequency band and implemented similarly.

[0412] Similarly, when AP1901 transmits a modulated signal using the third frequency band 500_3, including a set of symbols containing data symbols addressed to terminal 1902_1 and data symbols addressed to terminal 1902_2, AP1901 transmits RTS using the third frequency band 500_3, and terminals 1902_1 and 1902_2 transmit CTS using the third frequency band 500_3. In other words, in Figures 29A, 29B, 29C, and 29D, the third frequency band 500_3 can be considered as the first frequency band and implemented in the same manner.

[0413] By implementing the above, the effects described in Embodiment 2 can be obtained. In the example in Figure 29, the case in which AP1901 communicates with terminals 1902_1 and 1902_2 was described, but it is possible to implement the same method even when AP1901 communicates with three or more terminals, as long as the above features are satisfied. Then, each terminal will transmit a CTS to the AP as shown in Figures 29B and 29C.

[0414] Next, we will explain the case where, as shown in Figure 30, terminal 3001_1 initiates communication with AP1901, given that AP1901 and the terminal are already communicating as shown in Figure 19B.

[0415] Figure 31A shows an example of AP1901 transmitting RTS to terminal 3001_1. In Figure 31A, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 31A, the RTS signals B1_11, B_12, B3_11, and B3_12 exist at time B1.

[0416] AP1901 then transmits the RTS signals B1_11 and B1_12 using the first frequency band 500_1. Note that the RTS signals B1_11 and B1_12 are, for example, located within a 20MHz bandwidth interval. The RTS signal B1_11 is assumed to be on the first channel of the first frequency band 500_1, and the RTS signal B1_12 is assumed to be on the second channel of the first frequency band 500_1. Although only the first and second channels are described for the first frequency band 500_1, other channels may exist, and AP1901 may transmit RTS signals using channels other than the first and second channels.

[0417] Furthermore, AP1901 transmits RTS B3_11 and B3_12 using the third frequency band 500_3. Note that each of the B3_11 and B3_12 RTS signals exists within, for example, an 80MHz bandwidth interval. The RTS B3_11 is assumed to be on the first channel of the third frequency band 500_3, and the RTS B3_12 is assumed to be on the second channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist, and AP1901 may transmit RTS signals using channels other than channels 1 through 4.

[0418] As described in Embodiment 1, the RTS includes at least the address information of the communication partner. Furthermore, the RTS transmitted by AP1901 using the first frequency band may include the address information of one or more communication partners (i.e., one or more terminals). Similarly, the RTS transmitted by AP1901 using the third frequency band may include the address information of one or more communication partners (i.e., one or more terminals).

[0419] As shown in Figure 31A, when AP1901 transmits RTS, the RTS for B1_11 and B1_12, and the RTS for B3_11 and B3_12, each contain information about the address of a single terminal (3001_1).

[0420] As shown in Figure 31A, in the second frequency band 500_2, AP1901 is assumed to be communicating with terminals 1902_1 and 1902_2, for example, as shown in 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18. However, 2_11 is the first channel of the second frequency band 500_2, 2_12 is the second channel of the second frequency band 500_2, 2_13 is the third channel of the second frequency band 500_2, 2_14 is the fourth channel of the second frequency band 500_2, 2_15 is the fifth channel of the second frequency band 500_2, 2_16 is the sixth channel of the second frequency band 500_2, 2_17 is the seventh channel of the second frequency band 500_2, and 2_18 is the eighth channel of the second frequency band 500_2.

[0421] Terminal 3001_1 will receive the RTS shown in Figure 31A transmitted by AP1901. Based on the reception of the RTS, terminal 3001_1 will be considered to be in a state of "ready to receive" in "the first and second channels of the first frequency band 500_1" and "the first and second channels of the third frequency band 500_3". In Figure 31B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 31B, the CTSs B1_21, B1_22 and B3_21, B3_22 exist at time B2.

[0422] Terminal 3001_1 transmits CTS B1_21 and B1_22 using the first frequency band 500_1. Note that each of the B1_21 and B1_22 CTS exists within, for example, a 20MHz bandwidth interval. The B1_21 CTS is assumed to be on the first channel of the first frequency band 500_1, and the B1_22 CTS is assumed to be on the second channel of the first frequency band 500_1. Note that only the first and second channels are described for the first frequency band 500_1, but other channels may also exist.

[0423] Terminal 3001_1 transmits CTS B3_21 and B3_22 using the third frequency band 500_3. Note that the CTS B3_21 and B3_22 are located within, for example, an 80MHz bandwidth interval. The CTS B3_21 is assumed to be on the first channel of the third frequency band 500_3, and the CTS B3_22 is assumed to be on the third channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0424] As shown in Figure 31B, in the second frequency band 500_2, AP1901 is assumed to be communicating with terminals 1902_1 and 1902_2, for example, as shown in 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18. However, 2_11 is the first channel of the second frequency band 500_2, 2_12 is the second channel of the second frequency band 500_2, 2_13 is the third channel of the second frequency band 500_2, 2_14 is the fourth channel of the second frequency band 500_2, 2_15 is the fifth channel of the second frequency band 500_2, 2_16 is the sixth channel of the second frequency band 500_2, 2_17 is the seventh channel of the second frequency band 500_2, and 2_18 is the eighth channel of the second frequency band 500_2.

[0425] AP1901 will receive the CTS shown in Figure 31B transmitted by terminal 3001_1. Based on the reception of the CTS, AP1901 will determine that it will transmit the symbol group containing the data symbol to the first and second channels of the first frequency band 500_1, and the first and second channels of the third frequency band 500_3. Figure 31C shows an example of AP1901 transmitting a symbol group containing the data symbol to terminal 3001_1. In Figure 31C, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 31C, the symbol groups B1_31 and B1_32, and the symbol groups B3_31 and B3_32 exist at time B3.

[0426] AP1901 transmits the symbol groups B1_31 and B1_32 using the first frequency band 500_1. Note that each of the B1_31 and B1_32 symbol groups exists within, for example, a 20MHz bandwidth interval. The B1_31 symbol group is assumed to reside in the first channel of the first frequency band 500_1, and the B1_32 symbol group is assumed to reside in the second channel of the first frequency band 500_1. While only the first and second channels are described for the first frequency band 500_1, other channels may also exist.

[0427] As shown in Figure 31C, in the second frequency band 500_2, AP1901 is assumed to be communicating with terminals 1902_1 and 1902_2, for example, as shown in 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18. However, 2_11 is the first channel of the second frequency band 500_2, 2_12 is the second channel of the second frequency band 500_2, 2_13 is the third channel of the second frequency band 500_2, 2_14 is the fourth channel of the second frequency band 500_2, 2_15 is the fifth channel of the second frequency band 500_2, 2_16 is the sixth channel of the second frequency band 500_2, 2_17 is the seventh channel of the second frequency band 500_2, and 2_18 is the eighth channel of the second frequency band 500_2.

[0428] As described above, for example, by using the first frequency band and the third frequency band, the AP can transmit data symbols to a specific terminal, thereby improving the data transmission speed to that specific terminal. In this case, a key feature is that the RTS in Figure 31A contains only the address of the specific terminal. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar configurations other than those in Figures 31A, 31B, and 31C. Furthermore, in this case, since communication with terminals other than the above-mentioned terminal is performed in a different frequency band, the second frequency band 500_2, the data transmission efficiency in this communication system is improved.

[0429] In the example in Figure 31, the second frequency band 500_2 was described as being in a communication state, but this is not the only example. For example, the first frequency band 500_1 could be in a communication state, and the AP could use the second frequency band 500_2 and the third frequency band 500_3 to send data symbols to a specific terminal. In this case, the RTS transmitted by AP1901 using the second frequency band 500_2 and the third frequency band 500_3 would contain only the address of the specific terminal.

[0430] Alternatively, the third frequency band 500_3 may be set to a communication state, and the AP may use the first frequency band 500_1 and the second frequency band 500_2 to send data symbols to a specific terminal. In this case, the RTS transmitted by AP1901 using the first frequency band 500_1 and the second frequency band 500_2 will contain only the address of the specific terminal.

[0431] Next, we will explain the case where, as shown in Figure 32, terminals 3001_1 and 3001_2 begin communicating with AP 1901, while AP 1901 and terminals are already communicating with AP 1901, as shown in Figure 19B. However, although Figure 32 shows the case where two terminals begin communicating with AP, it is also possible for two or more terminals to begin communicating with AP.

[0432] Figure 33A shows an example of AP1901 transmitting RTS to terminals 3001_1 and 3001_2. In Figure 33A, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 33A, the RTS for B3_11 and B3_12 exist at time B1.

[0433] The AP1901 then transmits the RTS signals B3_11 and B3_12 using the third frequency band 500_3. Note that the RTS signals B3_11 and B3_12 are located within, for example, an 80MHz bandwidth interval. The RTS signal B3_11 is assumed to be on the first channel of the third frequency band 500_3, and the RTS signal B3_12 is assumed to be on the second channel of the third frequency band 500_3. Although only channels 1 through 4 are described for the third frequency band 500_3, other channels may exist, and the AP1901 may transmit RTS signals using channels other than channels 1 through 4.

[0434] As described in Embodiment 1, the RTS shall include at least the address information of the communication partner. Furthermore, the RTS transmitted by AP1901 using the third frequency band may include the address information of one or more communication partners (i.e., one or more terminals).

[0435] As shown in Figure 33A, when AP1901 transmits RTS, the RTS for B3_11 and B3_12 will each contain address information for multiple terminals (3001_1, 3001_2).

[0436] As shown in Figure 33A, in the second frequency band 500_2, AP1901 is assumed to be communicating with terminals 1902_1 and 1902_2, for example, as shown in 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18. However, 2_11 is the first channel of the second frequency band 500_2, 2_12 is the second channel of the second frequency band 500_2, 2_13 is the third channel of the second frequency band 500_2, 2_14 is the fourth channel of the second frequency band 500_2, 2_15 is the fifth channel of the second frequency band 500_2, 2_16 is the sixth channel of the second frequency band 500_2, 2_17 is the seventh channel of the second frequency band 500_2, and 2_18 is the eighth channel of the second frequency band 500_2.

[0437] Terminal 3001_1 will receive the RTS shown in Figure 33A transmitted by AP1901. Based on the reception of the RTS, terminal 3001_1 will be considered to be in a state of "ready to receive" on the "first and second channels of the third frequency band 500_3". In Figure 33B, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 33B, the CTSs B3_21_1 and B3_22_1 exist at time B2_1.

[0438] Terminal 3001_1 transmits CTS B3_21_1 and B3_22_1 using the third frequency band 500_3. Note that the CTS B3_21_1 and B3_22_1 are located within, for example, an 80MHz bandwidth interval. The CTS B3_21_1 is assumed to be on the first channel of the third frequency band 500_3, and the CTS B3_22_1 is assumed to be on the second channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0439] As shown in Figure 33B, in the second frequency band 500_2, AP1901 is assumed to be communicating with terminals 1902_1 and 1902_2, for example, as shown in 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18. However, 2_11 is the first channel of the second frequency band 500_2, 2_12 is the second channel of the second frequency band 500_2, 2_13 is the third channel of the second frequency band 500_2, 2_14 is the fourth channel of the second frequency band 500_2, 2_15 is the fifth channel of the second frequency band 500_2, 2_16 is the sixth channel of the second frequency band 500_2, 2_17 is the seventh channel of the second frequency band 500_2, and 2_18 is the eighth channel of the second frequency band 500_2.

[0440] Terminal 3001_2 will receive the RTS shown in Figure 33A transmitted by AP1901. Based on the reception of the RTS, terminal 3001_2 will be considered to be in a state of "ready to receive" on the "first and second channels of the third frequency band 500_3". In Figure 33C, the horizontal axis is frequency and the vertical axis is time. As shown in Figure 33C, the CTSs B3_21_1 and B3_22_1 exist at time B2_1.

[0441] Terminal 3001_2 transmits CTS B3_21_2 and B3_22_2 using the third frequency band 500_3. Note that the CTS B3_21_2 and B3_22_2 are located within, for example, an 80MHz bandwidth interval. The CTS B3_21_2 is assumed to be on the first channel of the third frequency band 500_3, and the CTS B3_22_2 is assumed to be on the second channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0442] As shown in Figure 33C, in the second frequency band 500_2, AP1901 is assumed to be communicating with terminals 1902_1 and 1902_2, for example, as shown in 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18. However, 2_11 is the first channel of the second frequency band 500_2, 2_12 is the second channel of the second frequency band 500_2, 2_13 is the third channel of the second frequency band 500_2, 2_14 is the fourth channel of the second frequency band 500_2, 2_15 is the fifth channel of the second frequency band 500_2, 2_16 is the sixth channel of the second frequency band 500_2, 2_17 is the seventh channel of the second frequency band 500_2, and 2_18 is the eighth channel of the second frequency band 500_2.

[0443] AP1901 will receive the CTS shown in Figure 33B transmitted by terminal 3001_1 and the CTS shown in Figure 33C transmitted by terminal 3001_2. Based on the reception of the CTS, AP1901 will then determine that the symbol group containing the data symbol will be transmitted to the first and second channels of the third frequency band 500_3. Figure 33D shows an example of AP1901 transmitting a symbol group containing the data symbol to terminals 3001_1 and 3001_2. In Figure 33D, the horizontal axis represents frequency and the vertical axis represents time. As shown in Figure 33D, the symbol groups B3_31 and B3_32 exist at time B3.

[0444] AP1901 transmits the symbol groups B3_31 and B3_32 using the third frequency band 500_3. Each of the B3_31 and B3_32 symbol groups exists within, for example, an 80MHz bandwidth. The B3_31 symbol group is assumed to be in the first channel of the third frequency band 500_3, and the B3_32 symbol group is assumed to be in the second channel of the third frequency band 500_3. Note that only channels 1 through 4 are described for the third frequency band 500_3, but other channels may also exist.

[0445] As shown in Figure 33D, in the second frequency band 500_2, AP1901 is assumed to be communicating with terminals 1902_1 and 1902_2, for example, as shown in 2_11, 2_12, 2_13, 2_14, 2_15, 2_16, 2_17, and 2_18. However, 2_11 is the first channel of the second frequency band 500_2, 2_12 is the second channel of the second frequency band 500_2, 2_13 is the third channel of the second frequency band 500_2, 2_14 is the fourth channel of the second frequency band 500_2, 2_15 is the fifth channel of the second frequency band 500_2, 2_16 is the sixth channel of the second frequency band 500_2, 2_17 is the seventh channel of the second frequency band 500_2, and 2_18 is the eighth channel of the second frequency band 500_2.

[0446] As described above, for example, by using the second frequency band 500_2, the AP communicates with multiple terminals, and during this time, for example, by using the third frequency band 500_3, that is, by using one frequency band, the AP can start communicating with multiple other terminals, thereby improving the data transmission efficiency in the communication system. In this case, a key feature is that the RTS in Figure 33A includes the addresses of multiple terminals. Note that the configuration methods for the channels used by the first frequency, the second frequency, and the third frequency are not limited to the examples described above; therefore, it is possible to implement similar solutions using configuration methods different from those shown in Figures 33A, 33B, 33C, and 33D.

[0447] In the example in Figure 31, the second frequency band 500_2 was described as being in a communication state, but this is not the only example. For example, the first frequency band 500_1 could be in a communication state, and the AP could use the second frequency band 500_2 to send data symbols to multiple terminals. In this case, the RTS transmitted by AP1901 using the second frequency band 500_2 would include the addresses of multiple terminals.

[0448] Similarly, the first frequency band 500_1 may be set to a communication state, and the AP may use the third frequency band 500_3 to send data symbols to multiple terminals. In this case, the RTS transmitted by AP1901 using the third frequency band 500_3 will include the addresses of multiple terminals.

[0449] Alternatively, the third frequency band 500_3 may be set to a communication state, and the AP may use the first frequency band 500_1 to send data symbols to multiple terminals. In this case, the RTS transmitted by AP1901 using the first frequency band 500_1 will include the addresses of multiple terminals.

[0450] Similarly, the third frequency band 500_3 may be set to a communication state, and the AP may use the second frequency band 500_2 to send data symbols to multiple terminals. In this case, the RTS transmitted by AP1901 using the second frequency band 500_2 will include the addresses of multiple terminals.

[0451] (Supplement 3) In this specification, for example, when an AP transmits symbols to multiple terminals in a frame in the time-frequency domain, the AP may transmit symbols to multiple terminals by performing frequency division, as shown in Figure 6B, for example; or by performing time division, as shown in Figure 34, for example; or by preparing two or more domains consisting of time and frequency, as shown in Figure 35, for example, and transmitting symbols to multiple terminals. In Figure 34, the horizontal axis represents time and the vertical axis represents frequency. Similarly, in Figure 35, the horizontal axis represents frequency and the vertical axis represents time.

[0452] In this specification, the parts and operations described relating to AP may also refer to parts and operations of base stations, repeaters, terminals, communication devices, personal computers, mobile phones, etc. Similarly, the parts and operations described relating to terminals in this specification may also refer to parts and operations of AP, base stations, repeaters, communication devices, personal computers, mobile phones, etc.

[0453] (Embodiment 4) This embodiment will describe communication methods related to Embodiments 1 to 3.

[0454] This embodiment describes "multiband" communication and "multichannel" communication. In this context, "multiband" communication and "multichannel" communication are defined as follows.

[0455] Multiband communication: A first communication device (e.g., a terminal) may simultaneously receive multiple modulated signals transmitted by one or more communication devices (e.g., access points (APs), base stations) that it is communicating with. These multiple modulated signals may include signals in multiple frequency bands (e.g., 5GHz and 6GHz bands).

[0456] The first communication device may also be one that communicates simultaneously with one or more communication devices that are communication partners, using multiple frequency bands. Examples are described in Embodiments 1 to 3.

[0457] Multi-channel communication: A first communication device (e.g., a terminal) may simultaneously receive multiple modulated signals transmitted by one or more communication devices (e.g., access points (APs), base stations) that it is communicating with. Among these multiple modulated signals, there may be modulated signals from multiple channels in the first frequency band (e.g., the first and second channels of the 5GHz band).

[0458] The first communication device may also communicate simultaneously with one or more communication devices that are communication partners, using multiple channels in the first frequency band. Examples are described in Embodiments 1 to 3.

[0459] In this specification, "multiband" and "multichannel" are explained separately, but "multiband" and "multichannel" may be collectively referred to as "multichannel."

[0460] This embodiment will be explained using a wireless LAN communication system based on the IEEE 802.11 standard as an example.

[0461] First, let's explain MAC (Medium Access Control) frames in wireless LANs.

[0462] MAC frames include: • Management framework • Control frame • Data frame There are three types.

[0463] First, we will explain the management framework. An example of a management framework is as follows:

[0464] Beacon frame: A frame for broadcasting network information to peripheral wireless devices. Probe request frame: A frame used by a terminal to query the presence of wireless cells in the vicinity. Probe response frame: Response frame for Probe request Association request frame: A frame used by a terminal to request a connection from a base station. Association response frame: Response frame to association request Disassociation frame: Frame for disconnecting communication Authentication frame: A frame for authentication between wireless devices. De-authentication frame: Frame for disconnection (authentication cancellation) Action Frame: Frame for additional general functionality

[0465] An example of a control frame is shown below.

[0466] RTS (Request to Send) frame: A frame for making a request to send data. CTS (Clear to Send) frame: A frame used by the RTS-specified radio device to transmit that "transmission is clear". ACK (Acknowledgement) frame: A frame to confirm that data was received successfully and to respond. Block ACK request frame: Frame for requesting a Block ACK Block ACK frame: Confirmation that data from multiple MAC frames has been successfully received, and a frame to respond.

[0467] A data frame is a frame used to transmit user data.

[0468] An example of an IEEE 802.11 data frame structure is shown in Figure 36. The numbers in Figure 36 indicate the data length of the fields listed below, and the unit is bytes.

[0469] The data frame may include the following, for example: • 2-byte frame control (field) • 2-byte duration ID (ID: Identifier) ​​(field) • 6-byte (receiver) address 1 (field) • 6-byte (transmitter) address 2 (field) • 6-byte (filtering) address 3 (field) • 2-byte sequence control (field) • 6-byte (optional) address 4 (field) • Frame body • 4-byte FCS (Frame Check Sequence) (field)

[0470] Table 1 shows how to use the address field in a data frame.

[0471] [Table 1]

[0472] In Table 1, IBSS stands for Independent Basic Service Set, AP for Access Point, WDS for Wireless Distribution System, DS for Distribution System, BSSID for Basic Service Set ID (ID: identifier), DA for Destination Address, SA for Source Address, RA for Receiver Address, and TA for Transmitter Address.

[0473] Next, we will explain BSSID and SSID (Service Set ID).

[0474] BSSID: In infrastructure networks, the BSSID is the MAC address of the access point's wireless interface. In ad-hoc networks, the BSSID is randomly generated and the Universal / Local bit is set to 1.

[0475] SSID: Larger identifiers (0 to 32 bytes) than the usual 48-bit identifiers.

[0476] Next, we will explain an example of a management framework structure.

[0477] An example of an IEEE 802.11 beacon frame structure is shown in Figure 37. The numbers in Figure 37 indicate the data length of the fields listed below, and the unit is bytes.

[0478] A beacon frame may include the following, for example: • 2-byte frame control (field) • 2-byte duration (field) • 6-byte DA (Destination Address) (field) • 6-byte SA (Source Address) (field) • 6-byte BSSID (field) • 2-byte sequence control (field)

[0479] The above constitutes the MAC header. The following is also included: • Variable-length frame body (field) • 4-byte FCS (Frame Check Sequence) (field) • 8-byte timestamp (field) • 2-byte beacon interval (field) • 2-byte capability information (field) • Variable-length SSID (field) • 7-byte FH (Frequency Hopping) parameter set (field) • 2-byte DS (Direct Sequence) parameter set (field) • 8-byte CF (Contention Free) parameter set (field) • 4-byte IBSS parameter set (fields) • Variable-length TIM (Traffic Indication Map) (field) • Variable-length country (field) • 3-byte power limit (field) • 6-byte channel switching (field) 8-byte quiet (field) • 4-byte TPC (Transmit Power Control) report (field) • Variable-length ERP (Effective Radiated Power) (field) • Variable length extended support rate (field) • Variable-length RSN (Robust Security Network) (field)

[0480] Generally, in a beacon frame transmitted by an AP, "BSSID" is the AP's BSSID, and "SSID" is the AP's SSID. Also, "DA" consists of all 1s (for broadcasting), and "SA" and "BSSID" are the AP's MAC address.

[0481] Figure 38 shows an example of the structure of an IEEE 802.11 Probe request frame. The numbers in Figure 38 indicate the data length of the fields listed below, and the unit is bytes.

[0482] The Probe request frame may include the following, for example: • 2-byte frame control (field) • 2-byte duration (field) • 6-byte DA (Destination Address) (field) • 6-byte SA (Source Address) (field) • 6-byte BSSID (field) • 2-byte sequence control (field)

[0483] The above constitutes the MAC header. The following is also included: • Variable-length SSID (field) • Variable-length support rate (field)

[0484] The above constitutes the frame itself, and the following are also included. • 4-byte FCS (field)

[0485] Generally, in a Probe request frame sent by a terminal, "DA" is the AP's MAC address, and "SA" and "BSSID" are the terminal's MAC address. Generally, "SSID" is the AP's SSID.

[0486] An example of the structure of an IEEE 802.11 probe response frame is shown in Figure 39. The numbers in Figure 39 indicate the data length of the fields listed below, and the unit is bytes.

[0487] The Probe response frame includes, for example, the following: • 2-byte frame control (field) • 2-byte duration (field) • 6-byte DA (Destination Address) (field) • 6-byte SA (Source Address) (field) • 6-byte BSSID (field) • 2-byte sequence control (field)

[0488] The above constitutes the MAC header. The following is also included: • Variable-length main body (field) • 4-byte FCS (Frame Check Sequence) (field) • 8-byte timestamp (field) • 2-byte beacon interval (field) • 2-byte capability information (field) • Variable-length SSID (field) • 7-byte FH (Frequency Hopping) parameter set (field) • 2-byte DS (Direct Sequence) parameter set (field) • 8-byte CF (Contention Free) parameter set (field) • 4-byte IBSS parameter set (fields) • Variable-length country (field) • 4-byte FH hopping parameter (field) • FH pattern table (field) • 3-byte power limit (field) • 6-byte variable-length channel switching (field) 8-byte quiet (field) • 4-byte TPC (Transmit Power Control) report (field) • Variable-length ERP (Effective Radiated Power) (field) • Variable length extended support rate (field) • Variable-length RSN (Robust Security Network) (field)

[0489] Generally, in a probe response frame sent by an AP, "DA" is the MAC address of the terminal, and "SA" and "BSSID" are the MAC addresses of the AP. Generally, "SSID" is the SSID of the AP.

[0490] Figure 40 shows an example of the structure of an IEEE 802.11 Association request frame. The numbers in Figure 40 indicate the data length of the fields listed below, and the unit is bytes.

[0491] The Association request frame includes, for example, the following: • 2-byte frame control (field) • 2-byte duration (field) • 6-byte DA (Destination Address) (field) • 6-byte SA (Source Address) (field) • 6-byte BSSID (field) • 2-byte sequence control (field)

[0492] The above constitutes the MAC header. The following is also included: • 2-byte capability information (field) • 2-byte listen interval (field) • Variable-length SSID (field) • Variable-length support rate (field)

[0493] The above constitutes the frame itself, and the following are also included. • 4-byte FCS (field)

[0494] Generally, in the Association request frame sent by a terminal, "DA" is the AP's MAC address, and "SA" and "BSSID" are the terminal's MAC addresses. Generally, "SSID" is the AP's SSID.

[0495] An example of the structure of an IEEE 802.11 Association response frame is shown in Figure 41. The numbers in Figure 41 indicate the data length of the fields listed below, and the unit is bytes.

[0496] The Association response frame includes, for example, the following: • 2-byte frame control (field) • 2-byte duration (field) • 6-byte DA (Destination Address) (field) • 6-byte SA (Source Address) (field) • 6-byte BSSID (field) • 2-byte sequence control (field)

[0497] The above constitutes the MAC header. The following is also included: • 2-byte capability information (field) • 2-byte status code (field) • 2-byte association identifier (field) • Variable-length support rate (field)

[0498] The above constitutes the frame itself, and the following are also included. • 4-byte FCS (field)

[0499] Generally, in the Association response frame sent by the AP, "DA" is the MAC address of the terminal, and "SA" and "BSSID" are the MAC addresses of the AP.

[0500] Next, we will explain an example of sending a beacon frame. For this explanation, we will consider the system state shown in Figure 42.

[0501] In Figure 42, AP#1 of 4201_1 is assumed to be capable of transmitting modulated signals in the 2.4GHz band, the 5GHz band, and the 6GHz band. AP#2 of 4201_2 is assumed to be capable of transmitting modulated signals in the 2.4GHz band. AP#3 of 4201_3 is assumed to be capable of transmitting modulated signals in the 2.4GHz band and the 5GHz band.

[0502] APs capable of transmitting modulated signals in two or more frequency bands, such as AP#1 of 4201_1, shall use the first MAC address regardless of which frequency band's modulated signal they transmit. Similarly, AP#3 of 4201_3 shall use the third MAC address regardless of which frequency band's modulated signal it transmits. Naturally, the first MAC address and the second MAC address are different, the first MAC address and the third MAC address are different, and the second MAC address and the third MAC address are different.

[0503] AP#1 of 4201_1 shall use SSID 1_1 for the 2.4GHz band, SSID 1_2 for the 5GHz band, and SSID 1_3 for the 6GHz band. Naturally, SSID 1_1 and SSID 1_2 shall be different, SSID 1_1 and SSID 1_3 shall be different, and SSID 1_2 and SSID 1_3 shall be different.

[0504] AP#2 of 4201_2 shall use the SSID 2_1 for the 2.4GHz band.

[0505] AP#3 of 4201_3 shall use SSID 3_1 for the 2.4GHz band and SSID 3_2 for the 5GHz band. Naturally, SSIDs 3_1 and 3_2 shall be different.

[0506] AP#1 of 4201_1 transmits a 2.4GHz beacon frame. The SA (field) and BSSID (field) of this 2.4GHz beacon frame become the first MAC address. The SSID (field) of this 2.4GHz beacon frame becomes the SSID of 1_1.

[0507] Then, AP#1 of 4201_1 transmits a 5GHz band beacon frame. The SA (field) and BSSID (field) of this 5GHz band beacon frame become the first MAC address. The SSID (field) of this 5GHz band beacon frame becomes the 1st_2nd SSID.

[0508] AP#1 of 4201_1 transmits a 6GHz beacon frame. The SA (field) and BSSID (field) of this 6GHz beacon frame become the first MAC address. The SSID (field) of this 6GHz beacon frame becomes the 1st_3 SSID.

[0509] AP#2 of 4201_2 transmits a 2.4GHz beacon frame. The SA (field) and BSSID (field) of this 2.4GHz beacon frame become the second MAC address. The SSID (field) of this 2.4GHz beacon frame becomes the SSID of 2_1.

[0510] AP#3 of 4201_3 transmits a 2.4GHz beacon frame. The SA (field) and BSSID (field) of this 2.4GHz beacon frame become the third MAC address. The SSID (field) of this 2.4GHz beacon frame becomes the SSID of 3_1.

[0511] Then, AP#3 of 4201_3 transmits a 5GHz band beacon frame. The SA (field) and BSSID (field) of this 5GHz band beacon frame become the third MAC address. And the SSID (field) of this 5GHz band beacon frame becomes the SSID of 3_2.

[0512] For example, AP#1 of 4201_1 shall be capable of multiband transmission or reception using modulated signals in the 2.4GHz band and the 5GHz band, multiband transmission or reception using modulated signals in the 2.4GHz band and the 6GHz band, and multiband transmission or reception using modulated signals in the 5GHz band and the 6GHz band.

[0513] Terminal #1 of 4202_1, terminal #2 of 4202_2, and terminal #3 of 4202_3 shall receive one or more beacon frames from among those transmitted by AP#1 of 4201_1 ("2.4GHz band beacon frame, 5GHz band beacon frame, 6GHz band beacon frame"), AP#2 of 4201_2 ("2.4GHz band beacon frame"), and AP#3 of 4201_3 ("2.4GHz band beacon frame, 5GHz band beacon frame").

[0514] For example, let's assume that terminal #1 of 4202_1 receives "2.4GHz band beacon frames, 5GHz band beacon frames, and 6GHz band beacon frames" transmitted by AP#1 of 4201_1. An example of the operation of terminal #1 of 4202_1 in this case will be explained using Figure 43.

[0515] Figure 43 shows an example of the configuration of a terminal including terminal #1 of 4202_1. In Figure 43, components that operate in the same way as in Figure 1 are given the same numbers, and detailed explanations are omitted.

[0516] In Figure 43, the transceiver 102_1 is a device that performs processing for transmitting and receiving modulated signals in the first frequency band, in this case the 2.4 GHz band. The transceiver 102_2 is a device that performs processing for transmitting and receiving modulated signals in the second frequency band, in this case the 5 GHz band. The transceiver 102_3 is a device that performs processing for transmitting and receiving modulated signals in the third frequency band, in this case the 6 GHz band.

[0517] The transceiver 102_1 performs processing for receiving modulated signals in the 2.4GHz band. Therefore, in the case of Figure 42, it receives the beacon frame transmitted by AP#1 of 4201_1, the beacon frame transmitted by AP#2 of 2401_2, and the beacon frame transmitted by AP#3 of 4201_3, and obtains data from each beacon frame.

[0518] Similarly, the transceiver 102_2 performs processing for receiving modulated signals in the 5GHz band. Therefore, in the case of Figure 42, it receives the beacon frame transmitted by AP#1 of 4201_1 and the beacon frame transmitted by AP#3 of 4201_3, and obtains data from each beacon frame.

[0519] The transceiver 102_3 performs processing for receiving modulated signals in the 6GHz band. Therefore, in the case of Figure 42, it receives the beacon frame transmitted by AP#1 of 4201_1 and obtains data from this beacon frame.

[0520] The received data processing unit 108 takes the first data group 106_1, the second data group 106_2, and the third data group 106_3 as input, thereby obtaining beacon frame data for each frequency band. The received data processing unit 108 also obtains other data.

[0521] The control unit 111 takes the received data group 100 as input and obtains data for each beacon frame. The control unit 111 then outputs the obtained beacon frame data as a beacon frame information signal 4301.

[0522] The received data processing unit 108 takes the first data group 106_1, the second data group 106_2, and the third data group 106_3 as input, thereby obtaining beacon frame data for each frequency band. The received data processing unit 108 also obtains other data.

[0523] The control unit 111 takes the received data group 100 as input and obtains data for each beacon frame. The control unit 111 then outputs the obtained beacon frame data as a beacon frame information signal 4301.

[0524] The configuration unit 4303 receives the configuration signal 4302 as input. The configuration signal 4302 is assumed to contain information about the SSID of the AP to which the terminal in Figure 43 (in this case, terminal #1 of 4202_1) is connected. For example, the configuration signal 4302 contains information about the 1st_1 SSID, the 1st_2 SSID, and the 1st_3 SSID, and the configuration unit 4303 performs the following processing based on the information about the 1st_1 SSID, the 1st_2 SSID, and the 1st_3 SSID.

[0525] The configuration unit 4303 obtains the "SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID", the "SA (field) or BSSID (field) of the beacon frame containing the 1st_2 SSID", and the "SA (field) or BSSID (field) of the beacon frame containing the 1st_3 SSID", that is, the configuration unit 4303 obtains the "MAC address of the AP corresponding to the 1st_1 SSID", the "MAC address of the AP corresponding to the 1st_2 SSID", and the "MAC address of the AP corresponding to the 1st_3 SSID".

[0526] The configuration unit 4303 determines that if the SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID is the same as the SA (field) or BSSID (field) of the beacon frame containing the 1st_2 SSID, then multiband communication is possible between the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_2 SSID. Note that the configuration unit 4303 may also determine that the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_2 SSID are a single device. Furthermore, the configuration unit 4303 determines that if the SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID is different from the SA (field) or BSSID (field) of the beacon frame containing the 1st_2 SSID, then multiband communication is not possible between the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_2 SSID.

[0527] Furthermore, the configuration unit 4303 determines that if the SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID is the same as the SA (field) or BSSID (field) of the beacon frame containing the 1st_3 SSID, then multiband communication is possible between the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_3 SSID. Note that the configuration unit 4303 may also determine that the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_3 SSID are a single device. Furthermore, the configuration unit 4303 determines that if the SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID is different from the SA (field) or BSSID (field) of the beacon frame containing the 1st_3 SSID, then multiband communication is not possible between the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_3 SSID.

[0528] The configuration unit 4303 determines that "multiband communication is possible between the AP corresponding to SSID 1_2 and the AP corresponding to SSID 1_3" if the SA (field) or BSSID (field) of the beacon frame containing SSID 1_2 and the SA (field) or BSSID (field) of the beacon frame containing SSID 1_3 are the same. It is also possible to determine that "the AP corresponding to SSID 1_2 and the AP corresponding to SSID 1_3" are a single device. Furthermore, the configuration unit 4303 determines that "multiband communication is not possible between the AP corresponding to SSID 1_2 and the AP corresponding to SSID 1_3" if the SA (field) or BSSID (field) of the beacon frame containing SSID 1_2 and the SA (field) or BSSID (field) of the beacon frame containing SSID 1_3 are different.

[0529] The setting unit 4303 then outputs a signal 4304 to the control unit 111 containing information regarding the feasibility of these multiband communications. Based on the signal 4304 regarding the feasibility of multiband communications, the control unit 111 outputs a control signal 112 that includes information on whether the transceivers 102_1, 102_2, and 102_3 will perform transmission or reception processing for multiband communications. Based on the control signal 112, the transceivers 102_1, 102_2, and 102_3 will decide whether to perform transmission or reception for multiband communications.

[0530] Furthermore, a terminal with the configuration shown in Figure 43 shall, for example, transmit an Association request frame as shown in Figure 44. The Association request frame in Figure 44 shall include, in addition to the "Frame Control (field)", "Duration (field)", "DA (Destination Address) (field)", "SA (Source Address) (field)", "BSSID (field)", "Sequence Control (field)", "Capability Information (field)", "Listen Interval (field)", "SSID (field)", "Support Rate (field)", and "FCS (field)" shown in Figure 40, "Multiband Transmitting Capability Information (field)" and "Multiband Receiving Capability Information (field)".

[0531] For example, the "multiband transmission capability information (field)" in Figure 44 includes information on whether a terminal with the configuration shown in Figure 43 is capable of transmitting multiband modulated signals or not.

[0532] For example, the "multiband reception capability information (field)" in Figure 44 includes information such as "whether the terminal can receive or cannot receive a multiband modulated signal when the communication partner transmits one" for a terminal with the configuration shown in Figure 43.

[0533] At this time, terminal #1 of 4202_1, which has the configuration shown in Figure 43 that enables multiband communication, and AP#1 of 4201_1 transmit an association request frame in the 2.4GHz band (modulated signal in the 2.4GHz band), an association request frame in the 5GHz band (modulated signal in the 5GHz band), and an association frame in the 6GHz band (modulated signal in the 6GHz band).

[0534] For example, if terminal #1 of 4202_1 is capable of "multiband transmission" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband transmission capability information (field)" in the 2.4GHz band association request frame will indicate that "it is capable of transmitting multiband modulated signals."

[0535] Furthermore, if terminal #1 of 4202_1 is capable of "multiband transmission" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), the "multiband transmission capability information (field)" in the 5GHz band association request frame will indicate that "it is capable of transmitting multiband modulated signals."

[0536] If terminal #1 of 4202_1 is capable of "multiband transmission" on other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband transmission capability information (field)" in the 6GHz band association request frame will indicate that "it is capable of transmitting multiband modulated signals."

[0537] On the other hand, if there is a multiband transmission that the terminal does not support, the following process will be performed.

[0538] If a terminal is unable to perform "multiband transmission" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband transmission capability information (field)" in the 2.4GHz band association request frame will indicate that "transmission of multiband modulated signals is not possible."

[0539] If the terminal is unable to perform "multiband transmission" using other frequency bands in the 5GHz band (in this case, the 2.4GHz band or the 6GHz band), the "multiband transmission capability information (field)" in the 5GHz band association request frame will indicate that "transmission of multiband modulated signals is not possible."

[0540] If the terminal is unable to perform "multiband transmission" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband transmission capability information (field)" in the 6GHz band association request frame will indicate that "transmission of multiband modulated signals is not possible."

[0541] Then, terminal #1 of 4201_1 will perform the following settings for the "Multiband Reception Capability Information (Field)" in Figure 44.

[0542] For example, if terminal #1 of 4202_1 is capable of "multiband reception" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception capability information (field)" in the 2.4GHz band association request frame will contain information indicating that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0543] Furthermore, if terminal #1 of 4202_1 is capable of "multiband reception" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, the "multiband reception capability information (field)" in the 5GHz band association request frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0544] If terminal #1 of 4202_1 is capable of "multiband reception" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception capability information (field)" in the 6GHz band association request frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0545] On the other hand, if the device does not support multiband reception, the following process will be performed.

[0546] If the terminal cannot perform "multiband reception" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), that is, if it cannot demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception capability information (field)" in the 2.4GHz band association request frame will indicate that "reception is impossible, i.e., demodulation is impossible, when the communication partner transmits a multiband modulated signal."

[0547] If the terminal cannot perform "multiband reception" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), that is, if it cannot demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception capability information (field)" in the 5GHz band association request frame will indicate that "reception is impossible, i.e., demodulation is impossible, when the communication partner transmits a multiband modulated signal."

[0548] If the terminal cannot perform "multiband reception" using the 6GHz band and other frequency bands (in this case, the 2.4GHz band or the 5GHz band), that is, if it cannot demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception capability information (field)" in the 6GHz band association request frame will indicate that "reception is impossible, i.e., demodulation is impossible, when the communication partner transmits a multiband modulated signal."

[0549] Figure 45 shows a different configuration of the association request frame sent by the terminal compared to Figure 44. The difference between Figure 45 and Figure 44 is that "multiband capability information" is present instead of "multiband transmission capability information" and "multiband reception capability information".

[0550] For example, the "multiband capability information (field)" in Figure 45 includes information on whether a terminal with the configuration shown in Figure 43 is capable of or incapable of communication using multiband modulated signals.

[0551] For example, if terminal #1 of 4202_1 is capable of "multiband communication" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband capability information (field)" in Figure 45 of the 2.4GHz band association request frame will indicate that "communication of multiband modulated signals is possible."

[0552] Furthermore, if terminal #1 of 4202_1 is capable of "multiband communication" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), the "multiband capability information (field)" in Figure 45 of the 5GHz band association request frame will indicate that "communication of multiband modulated signals is possible."

[0553] If terminal #1 of 4202_1 is capable of "multiband communication" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband capability information (field)" in the 6GHz band association request frame will indicate that "communication of multiband modulated signals is possible."

[0554] On the other hand, if there is a multiband transmission that the terminal does not support, the following process will be performed.

[0555] If a terminal is unable to perform "multiband communication" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband capability information (field)" in the 2.4GHz band association request frame will indicate that "communication of multiband modulated signals is impossible."

[0556] If a terminal is unable to perform "multiband communication" using other frequency bands in the 5GHz band (in this case, the 2.4GHz band or the 6GHz band), the "multiband capability information (field)" in the 5GHz band association request frame will indicate that "communication of multiband modulated signals is impossible."

[0557] If a terminal is unable to perform "multiband communication" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband capability information (field)" in the 6GHz band association request frame will indicate that "communication of multiband modulated signals is impossible."

[0558] It is also possible to implement this by placing the "Multiband Transmission Capability Information (Field)" and "Multiband Reception Capability Information (Field)" from Figure 44 into the capability information field in Figure 40. Furthermore, it is also possible to implement this by placing the "Multiband Capability Information (Field)" from Figure 45 into the capability information field in Figure 40.

[0559] Furthermore, while Figure 44 refers to it as "multiband transmission capability information (field)" and "multiband reception capability information (field)," these are not the only terms used. Similarly, while Figure 45 refers to it as "multiband capability information (field)," these are not the only terms used.

[0560] Furthermore, information other than that described in Figure 44 may be included in the association request frame. Similarly, information other than that described in Figure 45 may be included in the association request frame.

[0561] AP#1 of 4201_1 in Figure 42 will receive the "2.4GHz band association request frame (2.4GHz band modulated signal), 5GHz band association request frame (5GHz band modulated signal), and 6GHz band association request frame (6GHz band modulated signal)" transmitted by terminal #1 of 4202_1. Based on the data obtained from these association request frames, AP#1 of 4201_1 will determine the transmission method, modulation scheme, error correction coding scheme, multiband configuration method, etc., create a data frame, and transmit the modulated signal of the data frame to terminal #1 of 4202_1.

[0562] The configuration of AP#1 in 4201_1 shown in Figure 42 is as shown in Figure 1.

[0563] The transceiver 102_1 in Figure 1 demodulates the association request frame in the 2.4GHz band and obtains the data of the association request frame in the 2.4GHz band.

[0564] Then, the transceiver 102_2 in Figure 1 demodulates the 5GHz band association request frame and obtains the data of the 5GHz band association request frame.

[0565] The transceiver 102_3 in Figure 1 demodulates the 6GHz band association request frame and obtains the data of the 6GHz band association request frame.

[0566] The control unit 111 in Figure 1 receives data for association request frames in the 2.4GHz band, 5GHz band, and 6GHz band via the received data processing unit. Based on this data, the control unit 111 generates data for association response frames in the 2.4GHz band, 5GHz band, and 6GHz band, and outputs these as control signals 112.

[0567] Then, the transceiver 102_1 in AP#1 of 4201_1 in Figure 42 receives the control signal 112 as input, generates a modulated signal of the 2.4GHz band association response frame from the data of the 2.4GHz band association response frame included in the control signal 112, outputs it, and the modulated signal of the 2.4GHz band association response frame is output as a radio wave from the antenna 103_1.

[0568] In Figure 42, the transceiver 102_2 at AP#1 of 4201_1 receives the control signal 112 as input, generates a modulated signal of the 5GHz band association response frame from the data of the 5GHz band association response frame contained in the control signal 112, outputs it, and the modulated signal of the 5GHz band association response frame is output as a radio wave from the antenna 103_2.

[0569] In Figure 42, the transceiver 102_3 at AP#1 of 4201_1 receives the control signal 112 as input, generates a modulated signal of the 6GHz band association response frame from the data of the 6GHz band association response frame included in the control signal 112, outputs it, and the modulated signal of the 6GHz band association response frame is output as a radio wave from the antenna 103_3.

[0570] Note that AP#1 of 4201_1 may have frequency bands in which it does not transmit association response frames.

[0571] Figure 46 shows an example of the structure of an association response frame transmitted by an AP. The association response frame in Figure 46 includes, in addition to the "frame control (field)", "duration (field)", "DA (destination address) (field)", "SA (source address) (field)", "BSSID (field)", "sequence control (field)", "capability information (field)", "status code (field)", "association identifier (field)", "support rate (field)", and "FCS (field)" shown in Figure 41, "multiband transmission support information (field)" and "multiband reception support information (field)".

[0572] For example, the "Multiband Transmission Support Information (Field)" in Figure 46 includes information on whether an AP with the configuration shown in Figure 1 supports or does not support the transmission of multiband modulated signals.

[0573] For example, the "multiband reception support information (field)" in Figure 46 includes information such as "whether the AP can receive or cannot receive a multiband modulated signal when the communication partner transmits a multiband modulated signal" in an AP with the configuration shown in Figure 1.

[0574] For example, if AP#1 of 4201_1 in Figure 42 is capable of "multiband transmission" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), then the "multiband transmission support information (field)" in the 2.4GHz band association response frame will indicate that "transmission of multiband modulated signals is possible."

[0575] Furthermore, if AP#1 of 4201_1 in Figure 42 is capable of "multiband transmission" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), the "multiband transmission support information (field)" in the 5GHz band association response frame will indicate that "transmission of multiband modulated signals is possible."

[0576] If AP#1 of 4201_1 in Figure 42 is capable of "multiband transmission" on other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband transmission support information (field)" in the 6GHz band association response frame will indicate that "transmission of multiband modulated signals is possible."

[0577] On the other hand, if there is a multiband transmission that the AP does not support, the following process will be performed.

[0578] If an AP is unable to perform "multiband transmission" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband transmission support information (field)" in the 2.4GHz band association response frame will indicate that "multiband modulation signal transmission is not supported."

[0579] If the AP is unable to perform "multiband transmission" on other frequency bands in the 5GHz band (in this case, the 2.4GHz band or the 6GHz band), the "multiband transmission support information (field)" in the 5GHz band association response frame will indicate that "transmission of multiband modulated signals is not supported."

[0580] If the AP is unable to perform "multiband transmission" on other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband transmission support information (field)" in the 6GHz band association response frame will indicate that "transmission of multiband modulated signals is not supported."

[0581] Then, AP#1 of 4201_1 in Figure 42 will have the following settings applied to the "Multiband Reception Support Information (Field)" in Figure 46.

[0582] For example, if AP#1 of 4201_1 in Figure 42 is capable of "multiband reception" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception compatibility information (field)" in the 2.4GHz band association response frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0583] Furthermore, if AP#1 of 4201_1 in Figure 42 is capable of "multiband reception" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception compatibility information (field)" in the 5GHz band association response frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0584] If AP#1 of 4201_1 in Figure 42 is capable of "multiband reception" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception compatibility information (field)" in the 6GHz band association response frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0585] On the other hand, if there is a multiband reception that the AP does not support, the following process will be performed.

[0586] If the AP is unable to perform "multiband reception" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), that is, if it is unable to demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception support information (field)" in the 2.4GHz band association response frame will indicate that "reception is impossible, i.e., demodulation is impossible, when the communication partner transmits a multiband modulated signal."

[0587] If the AP is unable to perform "multiband reception" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), that is, if it is unable to demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception support information (field)" in the 5GHz band association response frame will indicate that "reception is impossible, i.e., demodulation is impossible, when the communication partner transmits a multiband modulated signal."

[0588] If the AP is unable to perform "multiband reception" using the 6GHz band and other frequency bands (in this case, the 2.4GHz band or the 5GHz band), that is, if it is unable to demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception support information (field)" in the 6GHz band association response frame will indicate that "reception is impossible, i.e., demodulation is impossible, when the communication partner transmits a multiband modulated signal."

[0589] Figure 47 shows a different configuration of the association response frame transmitted by the AP compared to Figure 46. The difference between Figure 47 and Figure 46 is that "multiband communication support information (field)" is present instead of "multiband transmission support information (field)" and "multiband reception support information (field)".

[0590] For example, the "multiband communication compatibility information (field)" in Figure 47 includes information on whether an AP with the configuration shown in Figure 1 is capable of or incapable of communication using multiband modulated signals.

[0591] For example, if AP#1 of 4201_1 in Figure 42 is capable of "multiband communication" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), then the "multiband communication support information (field)" in Figure 47 of the 2.4GHz band association response frame will indicate that "communication of multiband modulated signals is possible."

[0592] Furthermore, if AP#1 of 4201_1 in Figure 42 is capable of "multiband communication" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), the "multiband communication support information (field)" in Figure 47 of the 5GHz band association response frame will indicate that "communication of multiband modulated signals is possible."

[0593] If AP#1 of 4201_1 in Figure 42 is capable of "multiband communication" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), then the "multiband communication support information (field)" in Figure 47 of the 6GHz band association response frame will indicate that "communication of multiband modulated signals is possible."

[0594] On the other hand, if there is a multiband transmission that the AP does not support, the following process will be performed.

[0595] If the AP is unable to perform "multiband communication" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband communication support information (field)" in Figure 47 of the 2.4GHz band association response frame will indicate that "communication of multiband modulated signals is impossible."

[0596] If the AP is unable to perform "multiband communication" using other frequency bands in the 5GHz band (in this case, the 2.4GHz band or the 6GHz band), the "multiband communication support information (field)" in Figure 47 of the 5GHz band association response frame will indicate that "communication of multiband modulated signals is not possible."

[0597] If the AP is unable to perform "multiband communication" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband communication support information (field)" in Figure 47 of the 6GHz band association response frame will indicate that "communication of multiband modulated signals is not possible."

[0598] It is also possible to implement this by placing the "Multiband Transmission Support Information (Field)" and "Multiband Reception Support Information (Field)" from Figure 46 into the capability information field in Figure 41. Furthermore, it is also possible to implement this by placing the "Multiband Communication Support Information (Field)" from Figure 47 into the capability information field in Figure 41.

[0599] Furthermore, while Figure 46 refers to it as "multiband transmission compatible information (field)" and "multiband reception compatible information (field)," these are not the only terms used. Also, while Figure 47 refers to it as "multiband communication compatible information (field)," these are not the only terms used.

[0600] Furthermore, information other than that described in Figure 46 may be included in the association response frame. Similarly, information other than that described in Figure 47 may be included in the association response frame.

[0601] Terminal #1 of 4202_1 in Figure 42 will receive the "2.4GHz band association response frame (2.4GHz band modulated signal), 5GHz band association response frame (5GHz band modulated signal), and 6GHz band association response frame (6GHz band modulated signal)" transmitted by AP#1 of 4201_1.

[0602] In terminal #1 of 4202_1, which has the configuration shown in Figure 43, the transceiver 102_1 takes the modulated signal of the 2.4GHz band association response frame received by antenna 105_1 as input, demodulates it, and obtains the data of the 2.4GHz band association response frame.

[0603] The transceiver 102_2 takes the modulated signal of the 5GHz band association response frame received by the antenna 105_2 as input, demodulates it, and obtains the data of the 5GHz band association response frame.

[0604] The transceiver 102_3 takes the modulated signal of the 6GHz band association response frame received by the antenna 105_3 as input, demodulates it, and obtains the data of the 6GHz band association response frame.

[0605] For example, the control unit 111 obtains data for the 2.4GHz band association response frame, the 5GHz band association response frame, and the 6GHz band association response frame via the received data processing unit 108. Based on this data, AP#1 of 4201_1 determines the transmission method, modulation scheme, error correction coding scheme, multiband configuration method, etc. Based on this determined information, the transceiver 102_1, transceiver 102_2, and transceiver 102_3 generate the modulated signal for the data frame.

[0606] As described above, by generating association request frames and association response frames, APs and terminals can transmit and receive multiband modulated signals. This results in improved data transmission speed and improved data reception quality in a system composed of APs and terminals.

[0607] Next, Figure 48 shows a different configuration of the beacon frame transmitted by the AP from Figure 37. The beacon frame in Figure 48 includes the fields shown in Figure 37: "Frame Control (field)", "Duration (field)", "DA (Destination Address) (field)", "SA (Source Address) (field)", "BSSID (field)", "Sequence Control (field)", "Frame Body (field)", "FCS (Frame Check Sequence) (field)", "Timestamp (field)", "Beacon Interval (field)", "Capability Information (field)", "SSID (field)", "FH (Frequency Hopping) Parameter Set (field)", "DS (Direct Sequence) Parameter Set (field)", "CF (Contention Free) Parameter Set (field)", "IBSS Parameter Set (field)", "TIM (Traffic Indication Map) (field)", "Country (field)", "Power Limit (field)", "Channel Switching (field)", "Quiet (field)", "TPC (Transmit Power Control) Report (field)", "ERP (Effective Radiated Power) (field)", "Extended Support Rate (field)", and "RSN (Robust Security)". In addition to "Network (Field)", it shall also include "Multiband transmission support information (Field)" and "Multiband reception support information (Field)".

[0608] For example, the "Multiband Transmission Support Information (Field)" in Figure 48 contains information indicating whether or not an AP with the configuration shown in Figure 1 supports the transmission of multiband modulated signals.

[0609] For example, the "multiband reception support information (field)" in Figure 48 includes information such as "whether the AP can receive or cannot receive a multiband modulated signal when the communication partner transmits a multiband modulated signal" in an AP with the configuration shown in Figure 1.

[0610] For example, if AP#1 of 4201_1 in Figure 42 is capable of "multiband transmission" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband transmission support information (field)" in the 2.4GHz band beacon frame will indicate that "transmission of multiband modulated signals is possible."

[0611] Furthermore, if AP#1 of 4201_1 in Figure 42 is capable of "multiband transmission" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), the "multiband transmission support information (field)" in the 5GHz band beacon frame will indicate that "transmission of multiband modulated signals is possible."

[0612] If AP#1 of 4201_1 in Figure 42 is capable of "multiband transmission" on other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband transmission support information (field)" in the 6GHz band beacon frame will indicate that "transmission of multiband modulated signals is possible."

[0613] On the other hand, if there is a multiband transmission that the AP does not support, the following process will be performed.

[0614] If an AP cannot perform "multiband transmission" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband transmission support information (field)" in the 2.4GHz band beacon frame will indicate that "multiband modulation signal transmission is not supported."

[0615] If the AP is unable to perform "multiband transmission" using other frequency bands in the 5GHz band (in this case, the 2.4GHz band or the 6GHz band), the "multiband transmission support information (field)" in the 5GHz band beacon frame will indicate that "multiband modulation signal transmission is not supported."

[0616] If the AP is unable to perform "multiband transmission" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband transmission support information (field)" in the 6GHz band beacon frame will indicate that "multiband modulated signal transmission is not supported."

[0617] Then, AP#1 of 4201_1 in Figure 42 will have the following settings applied to the "Multiband Reception Support Information (Field)" in Figure 48.

[0618] For example, if AP#1 of 4201_1 in Figure 42 is capable of "multiband reception" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception compatibility information (field)" in the 2.4GHz band beacon frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0619] Furthermore, if AP#1 of 4201_1 in Figure 42 is capable of "multiband reception" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception compatibility information (field)" in the 5GHz band beacon frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0620] If AP#1 of 4201_1 in Figure 42 is capable of "multiband reception" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), that is, demodulating multiband modulated signals transmitted by the communication partner, then the "multiband reception compatibility information (field)" in the 6GHz band beacon frame will indicate that "if the communication partner transmits a multiband modulated signal, reception is possible, i.e., demodulation is possible."

[0621] On the other hand, if there is a multiband reception that the AP does not support, the following process will be performed.

[0622] If the AP cannot perform "multiband reception" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), that is, if it cannot demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception compatibility information (field)" in the 2.4GHz band beacon frame will indicate that "reception is impossible, i.e., demodulation is impossible, if the communication partner transmits a multiband modulated signal."

[0623] If the AP is unable to perform "multiband reception" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), that is, if it is unable to demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception compatibility information (field)" in the 5GHz band beacon frame will indicate that "reception is impossible, i.e., demodulation is impossible, if the communication partner transmits a multiband modulated signal."

[0624] If the AP cannot perform "multiband reception" using the 6GHz band and other frequency bands (in this case, the 2.4GHz band or the 5GHz band), that is, if it cannot demodulate the multiband modulated signal transmitted by the communication partner, the "multiband reception compatibility information (field)" in the 6GHz band beacon frame will indicate that "reception is impossible, i.e., demodulation is impossible, if the communication partner transmits a multiband modulated signal."

[0625] Figure 49 shows a different configuration of the beacon frame transmitted by the AP compared to Figure 48. The difference between Figure 49 and Figure 48 is that "multiband communication support information (field)" is present instead of "multiband transmission support information (field)" and "multiband reception support information (field)".

[0626] For example, the "multiband communication compatibility information (field)" in Figure 49 includes information on whether an AP with the configuration shown in Figure 1 is capable of or incapable of communication using multiband modulated signals.

[0627] For example, if AP#1 of 4201_1 in Figure 42 is capable of "multiband communication" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), then the "multiband communication support information (field)" in Figure 49 of the 2.4GHz band beacon frame will indicate that "communication of multiband modulated signals is possible."

[0628] Furthermore, if AP#1 of 4201_1 in Figure 42 is capable of "multiband communication" using the 5GHz band and other frequency bands (in this case, the 2.4GHz band or the 6GHz band), the "multiband communication support information (field)" in Figure 49 of the 5GHz band beacon frame will indicate that "communication of multiband modulated signals is possible."

[0629] If AP#1 of 4201_1 in Figure 42 is capable of "multiband communication" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), then the "multiband communication support information (field)" in Figure 49 of the 6GHz band beacon frame will indicate that "communication of multiband modulated signals is possible."

[0630] On the other hand, if there is a multiband transmission that the AP does not support, the following process will be performed.

[0631] If the AP is unable to perform "multiband communication" using the 2.4GHz band and other frequency bands (in this case, the 5GHz band or the 6GHz band), the "multiband communication support information (field)" in Figure 49 of the 2.4GHz band beacon frame will indicate that "communication of multiband modulated signals is impossible."

[0632] If the AP is unable to perform "multiband communication" using other frequency bands in the 5GHz band (in this case, the 2.4GHz band or the 6GHz band), the "multiband communication support information (field)" in Figure 49 of the 5GHz band beacon frame will indicate that "communication of multiband modulated signals is not possible."

[0633] If the AP is unable to perform "multiband communication" using other frequency bands in the 6GHz band (in this case, the 2.4GHz band or the 5GHz band), the "multiband communication support information (field)" in Figure 49 of the 6GHz band beacon frame will indicate that "communication of multiband modulated signals is not possible."

[0634] It is also possible to implement this by placing the "Multiband Transmission Support Information (Field)" and "Multiband Reception Support Information (Field)" from Figure 48 into the capability information field in Figure 37. Furthermore, it is also possible to implement this by placing the "Multiband Communication Support Information (Field)" from Figure 49 into the capability information field in Figure 37.

[0635] Furthermore, while Figure 48 refers to it as "multiband transmission compatible information (field)" and "multiband reception compatible information (field)," these are not the only terms used. Also, while Figure 49 refers to it as "multiband communication compatible information (field)," these are not the only terms used.

[0636] Furthermore, information other than that described in Figure 48 may be included in the beacon frame. Similarly, information other than that described in Figure 49 may be included in the beacon frame.

[0637] Terminal #1 of 4202_1 in Figure 42 will receive the "2.4GHz band beacon frame (2.4GHz band modulated signal), 5GHz band beacon frame (5GHz band modulated signal), and 6GHz band beacon frame (6GHz band modulated signal)" transmitted by AP#1 of 4201_1.

[0638] As explained earlier, the control unit 111 in Figure 43 takes the received data group 100 as input and obtains data for each beacon frame. The control unit 111 then outputs the obtained beacon frame data as a beacon frame information signal 4301.

[0639] Furthermore, the multiband-related information contained in 2.4GHz band beacon frames (2.4GHz band modulated signals) ("multiband transmission support information," "multiband reception support information," and "multiband communication support information") is referred to as first-generation multiband-related information, the multiband-related information contained in 5GHz band beacon frames (5GHz band modulated signals) is referred to as second-generation multiband-related information, and the multiband-related information contained in 6GHz band beacon frames (6GHz band modulated signals) is referred to as third-generation multiband-related information.

[0640] The received data processing unit 108 takes the first data group 106_1, the second data group 106_2, and the third data group 106_3 as input, thereby obtaining beacon frame data for each frequency band. The received data processing unit 108 also obtains other data.

[0641] The control unit 111 takes the received data group 100 as input and obtains data for each beacon frame. The control unit 111 then outputs the obtained beacon frame data as a beacon frame information signal 4301.

[0642] The configuration unit 4303 receives the configuration signal 4302 as input. The configuration signal 4302 is assumed to contain information about the SSID of the AP to which the terminal in Figure 43 (in this case, terminal #1 of 4202_1) is connected. For example, the configuration signal 4302 contains information about the 1st_1 SSID, the 1st_2 SSID, and the 1st_3 SSID, and the configuration unit 4303 performs the following processing based on the information about the 1st_1 SSID, the 1st_2 SSID, and the 1st_3 SSID.

[0643] The configuration unit 4303 obtains the "SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID", the "SA (field) or BSSID (field) of the beacon frame containing the 1st_2 SSID", and the "SA (field) or BSSID (field) of the beacon frame containing the 1st_3 SSID", that is, the configuration unit 4303 obtains the "MAC address of the AP corresponding to the 1st_1 SSID", the "MAC address of the AP corresponding to the 1st_2 SSID", and the "MAC address of the AP corresponding to the 1st_3 SSID".

[0644] Furthermore, the setting unit 4303 obtains first multiband-related information, second multiband-related information, and third multiband-related information.

[0645] The configuration unit 4303 then determines that "multiband communication is possible between the AP corresponding to the SSID 1_1 and the AP corresponding to the SSID 1_2" if the SA (field) or BSSID (field) of the beacon frame containing the SSID 1_1 and the SA (field) or BSSID (field) of the beacon frame containing the SSID 1_2 are the same, and the first multiband-related information and the second multiband information indicate that multiband communication is possible. It is also possible to determine that the AP corresponding to the SSID 1_1 and the AP corresponding to the SSID 1_2 are a single device.

[0646] The configuration unit 4303 determines that if the SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID is different from the SA (field) or BSSID (field) of the beacon frame containing the 1st_2 SSID, then multiband communication between the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_2 SSID is not possible.

[0647] Furthermore, the configuration unit 403 determines that "multiband communication is not possible between the AP corresponding to SSID 1_1 and the AP corresponding to SSID 1_2" if "either the first multiband-related information or the second multiband information indicates that multiband communication is not possible."

[0648] The configuration unit 4303 determines that "multiband communication is possible between the AP corresponding to the SSID 1_1 and the AP corresponding to the SSID 1_3" if the SA (field) or BSSID (field) of the beacon frame containing the SSID 1_1 and the SA (field) or BSSID (field) of the beacon frame containing the SSID 1_3 are the same, and the first multiband-related information and the third multiband information indicate that multiband communication is possible. Note that the configuration unit 4303 may also determine that the AP corresponding to the SSID 1_1 and the AP corresponding to the SSID 1_3 are a single device.

[0649] The configuration unit 4303 determines that if the SA (field) or BSSID (field) of the beacon frame containing the 1st_1 SSID is different from the SA (field) or BSSID (field) of the beacon frame containing the 1st_3 SSID, then multiband communication between the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_3 SSID is not possible.

[0650] Furthermore, the configuration unit 403 determines that "multiband communication is not possible between the AP corresponding to the 1st_1 SSID and the AP corresponding to the 1st_3 SSID" if "either the 1st multiband related information or the 3rd multiband information indicates that multiband communication is not possible."

[0651] The configuration unit 4303 determines that "multiband communication is possible between the AP corresponding to the SSID 1_2 and the AP corresponding to the SSID 1_3" if the SA (field) or BSSID (field) of the beacon frame containing the SSID 1_2 and the SA (field) or BSSID (field) of the beacon frame containing the SSID 1_3 are the same, and the second multiband-related information and the third multiband information indicate that multiband communication is possible. Note that the configuration unit 4303 may also determine that the AP corresponding to the SSID 1_2 and the AP corresponding to the SSID 1_3 are a single device.

[0652] The configuration unit 4303 determines that if the SA (field) or BSSID (field) of the beacon frame containing the 1st_2nd SSID is different from the SA (field) or BSSID (field) of the beacon frame containing the 1st_3rd SSID, then multiband communication between the AP corresponding to the 1st_2nd SSID and the AP corresponding to the 1st_3rd SSID is not possible.

[0653] Furthermore, the configuration unit 403 determines that "multiband communication is not possible between the AP corresponding to the 1st_2 SSID and the AP corresponding to the 1st_3 SSID" if "either the 2nd multiband related information or the 3rd multiband information indicates that multiband communication is not possible."

[0654] The setting unit 4303 then outputs a signal 4304 to the control unit 111 containing information regarding the feasibility of these multiband communications. Based on the signal 4304 regarding the feasibility of multiband communications, the control unit 111 outputs a control signal 112 that includes information on whether the transceivers 102_1, 102_2, and 102_3 will perform transmission or reception processing for multiband communications. Based on the control signal 112, the transceivers 102_1, 102_2, and 102_3 will decide whether to perform transmission or reception for multiband communications.

[0655] Alternatively, the configuration unit 111 may obtain first multiband-related information, second multiband-related information, and third multiband-related information, and search for an AP capable of multi-channel communication.

[0656] For example, suppose the configuration unit 111 specifies, via configuration signal 4302, that it will communicate with an AP in the 2.4GHz band. Then, suppose the configuration unit 111 obtains information from the first multiband-related information that multiband communication is possible in the first frequency band (2.4GHz band). Based on this, the configuration unit 111 searches for an SSID that is capable of multiband communication in the second frequency band (5GHz band) or the third frequency band (6GHz band).

[0657] At this time, the configuration unit 111 obtains second multiband-related information from the beacon frame of the second frequency band and searches for a beacon frame that contains information indicating that multiband communication is possible. Then, as mentioned earlier, it checks the SSID, SA, and BSSID and detects an AP (SSID) in the 5GHz band that can perform multiband communication with the 2.4GHz band.

[0658] Similarly, the configuration unit 111 obtains third multiband-related information from the third frequency band beacon frame and searches for a beacon frame that contains information indicating that multiband communication is possible. Then, as mentioned earlier, it checks the SSID, SA, and BSSID and detects an AP (SSID) in the 6GHz band that can perform 2.4GHz band and multiband communication.

[0659] Thus, by using beacon frames like those shown in Figures 48 and 49, it becomes possible to detect APs capable of multiband communication, which has the effect of simplifying the procedures for implementing multiband communication.

[0660] In this embodiment, the terminal configuration is shown in Figure 43 and the AP configuration in Figure 1 for explanation purposes. However, the terminal configuration and AP configuration are not limited to those shown in Figures 43 and 1, respectively. For example, the terminal and AP may use transmission methods such as MIMO (Multiple-Input Multiple-Output), MISO (Multiple-Input Single-Output), or SIMO (Single-Input Multiple-Output) in the "transmission method for the first frequency band, or the transmission method for the second frequency band, or the transmission method for the third frequency band." Therefore, the transceivers 102_1, 102_2, and 102_3 in Figures 43 and 1 may be connected to multiple transmitting antennas or to multiple receiving antennas.

[0661] In particular, when using MIMO transmission or MISO transmission, the transceivers 102_1, 102_2, and 102_3 will transmit multiple modulated signals using multiple antennas at the same frequency (same frequency band) and at the same time.

[0662] Furthermore, although this embodiment describes an example where the AP and terminal are capable of communicating in three frequency bands, multiband communication is possible if they support communication in two or more frequency bands, by implementing the same method as in this embodiment. Therefore, although the AP configuration example in Figure 1 describes an example equipped with transceivers 102_1, 102_2, and 102_3, for example, in the case of an AP capable of communicating in two frequency bands, the configuration may omit one of the transceivers 102_1, 102_2, and 102_3. Also, if the AP supports communication in four or more frequency bands, it may be equipped with one or more transceivers in addition to the configuration in Figure 1. Similarly, although the terminal configuration example in Figure 43 describes an example equipped with transceivers 102_1, 102_2, and 102_3, for example, in the case of a terminal capable of communicating in two frequency bands, the configuration may omit one of the transceivers 102_1, 102_2, and 102_3. Furthermore, if the terminal supports communication in four or more frequency bands, it may be equipped with one or more transceivers in addition to the configuration shown in Figure 1.

[0663] Furthermore, APs and terminals may transmit frames other than management frames, control frames, and data frames. Management frames may include frames other than Beacon frames, Probe request frames, Probe response frames, Association request frames, Association response frames, Disassociation frames, Authentication frames, De-authentication frames, and Action frames. Control frames may include frames other than RTS (Request to Send) frames, CTS (Clear to Send) frames, ACK (Acknowledgement) frames, Block ACK request frames, and Block ACK frames.

[0664] Furthermore, this embodiment is merely an example, and the same implementation can be carried out, for example, by using the AP as a terminal and the terminal as an AP. In this embodiment, we refer to them as AP and terminal, but the AP may be called a base station, communication device, terminal, broadcasting station, node, etc., and the terminal may be called a communication device, access point, node, base station, etc.

[0665] Furthermore, for example, multiband transmission may be performed using the first AP and the second AP. In other words, multiple APs may be used to transmit modulated signals for multiband communication.

[0666] In this embodiment, multiband communication using a first frequency band, a second frequency band, and a third frequency band has been described. However, it is naturally possible to implement this embodiment similarly by considering the first frequency band as the first channel, the second frequency band as the second channel, and the third frequency band as the third channel, and implementing it as multichannel communication.

[0667] In the above embodiments, communication methods using RTS and CTS have been described, but communication methods that do not use RTS and CTS may also be used. For example, the above embodiments can be applied to TDD (Time Division Duplex), TDMA (Time Division Multiple Access), and TDM (Time Division multiplexing) and implemented in the same way. In this case, RTS and CTS may be used or not. Furthermore, the communication devices and communication systems of the above embodiments may be configured to switch between communicating using RTS and CTS or communicating without using RTS and CTS, or they may be configured to switch between communicating using CSMA / CA or communicating using "TDD, or TDMA, or TDM".

[0668] In the explanation of Figure 1, etc., a configuration is shown in which, for example, a communication device acting as an access point has three transceivers 102_1, 102_2, and 102_3. However, a terminal does not necessarily need to have three transceivers; it may have a configuration with two transceivers. For example, a terminal that is expected to be used relatively frequently while connected to a power outlet (for example, a personal computer or server, but not limited to these, it may also be a smartphone, mobile phone, or tablet) may have a configuration with three transceivers, while a terminal that is used relatively infrequently while connected to a power outlet (for example, a smartphone, mobile phone, or tablet, but not limited to these, it may also be a personal computer or server) may have a configuration with two transceivers. This is because operating three transceivers increases power consumption, so this configuration helps to suppress battery consumption in terminals that are used relatively infrequently while connected to a power outlet.

[0669] Furthermore, the "multiband transmission capability information (field)" and "multiband reception capability information (field)" shown in Figure 44 may be placed in the extended fields. In this case, Figure 44 does not necessarily have to include the "multiband transmission capability information (field)" and / or the "multiband reception capability information (field)". For example, the frame in Figure 44 will include information indicating whether or not the extended fields are included.

[0670] Furthermore, when the information indicating whether or not the extended field is included is "not included," the "multiband transmission capability information (field)" and the "multiband reception capability information (field)" will not be included in the frame of Figure 44. On the other hand, when the information indicating whether or not the extended field is included is "included," the "multiband transmission capability information (field)" and / or the "multiband reception capability information (field)" will be included in the frame of Figure 44.

[0671] A communication device that receives the above frame can determine whether or not the received frame contains an extended field by the "information indicating whether or not an extended field is included," thereby determining whether, for example, "multiband transmission capability information (field)" and / or "multiband reception capability information (field)" are included in the frame.

[0672] Furthermore, the "information indicating whether or not an extended field is included" may include information indicating the data size of the extended field, information indicating the information included, etc. In addition, the extended field may include information other than "multiband transmission capability information (field)" and "multiband reception capability information (field)".

[0673] The "multiband transmission support information (field)" and "multiband reception support information (field)" shown in Figure 46 may be placed in the extended fields. In this case, Figure 46 does not necessarily have to include the "multiband transmission support information (field)" and / or the "multiband reception support information (field)". For example, the frame in Figure 46 will include information indicating whether or not the extended fields are included.

[0674] Furthermore, when the information indicating whether or not the extended field is included is "not included," the "multiband transmission support information (field)" and the "multiband reception support information (field)" will not be included in the frame of Figure 46. On the other hand, when the information indicating whether or not the extended field is included is "included," the "multiband transmission support information (field)" and / or the "multiband reception support information (field)" will be included in the frame of Figure 46.

[0675] A communication device that receives the above frame can determine whether or not the received frame contains an extended field by the "information indicating whether or not an extended field is included," thereby determining, for example, whether or not "multiband transmission support information (field)" and / or "multiband reception support information (field)" are included in the frame.

[0676] Furthermore, the "information indicating whether or not an extended field is included" may include information indicating the data size of the extended field, information indicating the information included, etc. In addition, the extended field may include information other than "multiband transmission support information (field)" and "multiband reception support information (field)".

[0677] The "Multiband Capability Information (Field)" shown in Figure 45 may be placed in the extended field. In this case, Figure 45 does not have to include the "Multiband Capability Information (Field)". Then, for example, the frame in Figure 45 will contain information indicating whether or not the extended field is included.

[0678] Furthermore, when the information indicating whether or not the extended field is included is "not included," the "multiband capability information (field)" will not be included in the frame of Figure 45. On the other hand, when the information indicating whether or not the extended field is included is "included," the "multiband capability information (field)" will be included in the frame of Figure 45.

[0679] A communication device that receives the above frame can determine whether or not the received frame contains an extended field by the "information indicating whether or not an extended field is included," and thereby it can determine, for example, whether or not "multiband capability information (field)" is included in the frame.

[0680] Furthermore, the "information indicating whether or not an extended field is included" may include information indicating the data size of the extended field, information indicating the information included, etc. Also, the extended field may contain information other than "multiband capability information (field)".

[0681] The "multiband communication support information (field)" shown in Figure 47 may be placed in the extended field. In this case, Figure 47 does not have to include the "multiband communication support information (field)". Then, for example, the frame in Figure 47 will contain information indicating whether or not the extended field is included.

[0682] Furthermore, when the "information indicating whether or not an extended field is included" indicates that it is "not included," the "multiband communication support information (field)" will not be included in the frame of Figure 47. On the other hand, when the "information indicating whether or not an extended field is included" indicates that it is "included," the "multiband communication support information (field)" will be included in the frame of Figure 47.

[0683] A communication device that receives the above frame can determine whether or not the received frame contains an extended field by referring to the "information indicating whether or not an extended field is included," and thereby determine, for example, whether or not "multiband communication support information (field)" is included in the frame.

[0684] Furthermore, the "information indicating whether or not an extended field is included" may include information indicating the data size of the extended field, information indicating the information included, etc. Also, the extended field may contain information other than "multiband communication support information (field)".

[0685] Note that symbols such as RTS1_11 shown in Figure 22A, CTS2_21 shown in Figure 22B, and symbol group 2_31 shown in Figure 22C indicate transmission using multi-carrier methods, for example, OFDMA, specifically one OFDMA communication unit, i.e., one resource unit. In particular, a resource unit corresponds to a bundle of a predetermined number of subcarriers (e.g., 16, or an integer greater than or equal to 1).

[0686] Furthermore, in Figures 22A, 26A, 27A, 28A, 29A, 31A, 33A, etc., if multiple RTSs exist within a certain time interval, the receiver addresses (e.g., MAC addresses) included in each RTS may be the same. (They do not have to be the same.) Also, in Figures 22A, 26A, 27A, 28A, 29A, 31A, 33A, etc., there may be two or more RTSs with the same receiver address within a certain time interval. However, the method for setting the receiver address of an RTS is not limited to this.

[0687] Furthermore, in Figures 22A, 26A, 27A, 28A, 29A, 31A, 33A, etc., if multiple RTSs exist within a certain time interval, the transmitter addresses (e.g., MAC addresses) included in each RTS may be the same. (They do not have to be the same.) Also, in Figures 22A, 26A, 27A, 28A, 29A, 31A, 33A, etc., there may be two or more RTSs with the same transmitter address within a certain time interval. However, the method of setting the transmitter address of an RTS is not limited to this.

[0688] In Figures 22B, 23A, 24A, 25A, 26B, 27B, 28B, 29B, 29C, 31B, 33B, 33C, etc., if multiple CTSs exist within a given time interval, the receiver addresses (e.g., MAC addresses) included in each CTS may be the same. (They do not have to be the same.) Also, in Figures 22B, 23A, 24A, 25A, 26B, 27B, 28B, 29B, 29C, 31B, 33B, 33C, etc., there may be two or more CTSs with the same receiver address within a given time interval. However, the method for setting the receiver address of a CTS is not limited to this.

[0689] Figures 3A, 3B, 3C, 4A, 4B, 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, 5J, 5K, 6A, 6B, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 22A, 22B, 22C, 23A, 23B, 24A, 24B, 25A, 25B, In frames such as 26A, 26B, 26C, 27A, 27B, 27C, 28A, 28B, 28C, 29A, 29B, 29C, 29D, 31A, 31B, 31C, 33A, 33B, 33C, and 33D, a trigger frame (trigger signal) for adjusting the transmission timing of symbols may exist within a certain time interval.

[0690] In this specification, the operation described in relation to AP may also refer to the operation of base stations, repeaters, terminals, communication devices, personal computers, mobile phones, smartphones, tablets, servers, eNBs (e Node B), gNBs (g Node B), cars, bicycles, satellites, robots, motorcycles, ships, drones, aircraft, moving objects, home appliances, computers, etc. Furthermore, the operation described in relation to terminals in this specification may also refer to the operation of APs, base stations, repeaters, communication devices, personal computers, mobile phones, smartphones, tablets, servers, eNBs (e Node B), gNBs (g Node B), cars, bicycles, satellites, robots, motorcycles, ships, drones, aircraft, moving objects, home appliances, computers, etc.

[0691] In this specification, the term "frequency band X" can be replaced with "frequency band X." Similarly, the term "time X" can be replaced with "time X." The same applies when "X" is replaced with an alphabet or number such as "A," "B," or "A1."

[0692] The configuration and communication method of the communication device or access point in each of the above embodiments can also be expressed as follows, but are not limited thereto.

[0693] Figure 50 shows an example of the configuration of access point 5000.

[0694] As shown in Figure 50, the access point 5000 comprises a first interface 5001, a second interface 5002, and a control unit 5003.

[0695] The first interface 5001 performs wireless communication on the first band.

[0696] The second interface 5002 performs wireless communication on a second band that is different from the first band.

[0697] The control unit 5003 uses at least one of the first interface 5001 and the second interface 5002 to select one of three different RTS (Request to Send) / CTS (Clear to Send) control methods, and performs the selected RTS / CTS control method with the terminal.

[0698] Here, of the three methods described above, the first method involves transmitting a first RTS signal destined for one terminal in the first or second band and receiving a first CTS signal transmitted in response to the first RTS signal. The second method involves transmitting a second RTS signal destined for multiple terminals in the first or second band and receiving a second CTS signal transmitted in response to the second RTS signal. The third method involves transmitting a third RTS signal destined for multiple terminals in both the first and second bands and receiving a third CTS signal transmitted in response to the third RTS signal.

[0699] For example, the control unit 5003 may, after receiving a CTS signal through RTS / CTS control using the above method, transmit data in the resource unit that received the CTS signal.

[0700] For example, in the third system, the source MAC (Medium Access Control) address of the third RTS signal transmitted in the first band and the second band may be the same.

[0701] Figure 51 is a flowchart illustrating an example of a communication method performed by access point 5000.

[0702] As shown in Figure 51, in step S5001, the control unit 5003 uses at least one of the first interface 5001 and the second interface 5002 to select one of three different RTS (Request to Send) / CTS (Clear to Send) control methods.

[0703] In step S5002, the control unit 5003 performs RTS / CTS control with the terminal using one of the selected methods.

[0704] This allows access point 5000 to improve the data transmission speed of the communication system.

[0705] In each of the above embodiments, each component may be implemented by dedicated hardware or by executing a software program suitable for each component. Each component may also be implemented by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. Here, the software that implements the access point, etc. in each of the above embodiments is the following program.

[0706] In other words, this program causes a computer to execute a communication method for an access point having a first interface for wireless communication on a first band and a second interface for wireless communication on a second band different from the first band, the method comprising: a selection step of selecting one RTS (Request to Send) / CTS (Clear to Send) control method from among three different methods using at least one of the first interface and the second interface; and a control step of performing the selected RTS / CTS control method with a terminal, wherein the first method of the three methods is a method of transmitting a first RTS signal to one terminal in the first band or the second band and receiving a first CTS signal transmitted in response to the first RTS signal; the second method of the three methods is a method of transmitting a second RTS signal to multiple terminals in the first band or the second band and receiving a second CTS signal transmitted in response to the second RTS signal; and the third method of the three methods is a method of transmitting a third RTS signal to multiple terminals in each of the first band and the second band and receiving a third CTS signal transmitted in response to the third RTS signal.

[0707] Although one or more embodiments of access points and the like have been described above based on the embodiments, the present invention is not limited to these embodiments. Without departing from the spirit of the present invention, various modifications that a person skilled in the art can conceive of may be applied to these embodiments, and forms constructed by combining components from different embodiments may also be included within the scope of one or more embodiments. [Industrial applicability]

[0708] This invention can be used in wireless communication access points. [Explanation of Symbols]

[0709] 5000 access points 5001 First Interface 5002 Second Interface 5003 Control Unit

Claims

1. A terminal capable of wireless communication with an access point in a first frequency band and a second frequency band, comprising a communication unit and a circuit, wherein the circuit uses the communication unit, The system receives a first beacon frame transmitted from the access point in the first frequency band and / or a second beacon frame transmitted from the access point in the second frequency band. Based on the multiband-related information contained in the first beacon frame or the second beacon frame, it is determined that the access point is capable of multiband communication. Terminal.

2. The terminal according to claim 1, wherein the circuit is The first identifier contained in the first beacon frame and the second identifier contained in the second beacon frame are obtained, If the first identifier and the second identifier are the same, it is determined that multiband communication using the first frequency band and the second frequency band is possible with the access point. Terminal.

3. A terminal according to claim 2, wherein the first identifier and the second identifier are MAC addresses.

4. A terminal according to claim 1, wherein the first beacon frame and the second beacon frame each have a destination address that is a broadcast address and a source address that is the MAC address of the access point.

5. A method implemented by a terminal capable of wireless communication with an access point in a first frequency band and a second frequency band, The system receives a first beacon frame transmitted from the access point in the first frequency band and / or a second beacon frame transmitted from the access point in the second frequency band. Based on the multiband-related information contained in the first beacon frame or the second beacon frame, it is determined that the access point is capable of multiband communication. method.

6. The method according to claim 5, The first identifier contained in the first beacon frame and the second identifier contained in the second beacon frame are obtained, If the first identifier and the second identifier are the same, it is determined that multiband communication using the first frequency band and the second frequency band is possible with the access point. method.

7. A method according to claim 6, wherein the first identifier and the second identifier are MAC addresses.

8. The method according to claim 5, wherein the first beacon frame and the second beacon frame each have a destination address that is a broadcast address and a source address that is the MAC address of the access point.

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