Communication device, communication method, and program

Abstract

This communication device, which functions as an access point conforming to the IEEE 802.11 series standard, receives, from a first other communication device connected to the communication device, a first frame including first information relating to a scheduled period in which communication is to be performed between the first other communication device and a second other communication device without intermediation of the communication device, and on the basis of the first information, transmits a second frame including second information capable of identifying a recommended period recommended to be used for the communication between the first other communication device and the second other communication device without intermediation of the communication device.

Description

Communication device, communication method, and program

[0001] The present invention relates to a technology for effectively utilizing radio resources.

[0002] Wireless LANs (Local Area Networks) conforming to the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards are widely used. The IEEE 802.11 series of standards includes standards such as IEEE 802.11a / b / g / n / ac / ax / be (Patent Document 1). The IEEE 802.11bn standard is currently being developed as a new standard to further improve communication reliability. In this development work, the introduction of a function for P2P communication, in which an access point (AP) and a station (STA) connect in infrastructure mode, is being considered. The STA operates as an AP and directly connects to another STA. P2P stands for Peer-to-Peer.

[0003] JP 2018-050133 A

[0004] When a STA that can communicate with an AP performs P2P communication with another STA, the STA can receive signals from the AP and signals from the other STA with which it is communicating. Therefore, it is important for the STA to efficiently perform each communication while preventing these signals from interfering with each other.

[0005] The present invention provides a technique that enables terminal-to-terminal communication and other communications to be efficiently executed while suppressing interference between these communications.

[0006] A communication device according to one aspect of the present invention is a communication device that functions as an access point conforming to the IEEE 802.11 series standard, and has a receiving means for receiving a first frame from a first other communication device connected to the communication device, the first frame including first information regarding a planned period for communication between the first other communication device and a second other communication device not via the communication device, and a transmitting means for transmitting a second frame including second information that can identify a recommended period for communication between the first other communication device and the second other communication device not via the communication device based on the first information.

[0007] According to the present invention, it is possible to suppress interference between terminal-to-terminal communication and other communications, while enabling these communications to be carried out efficiently.

[0008] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0009] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments of the present invention, and together with the description, are used to explain the principles of the present invention. FIG. 1 is a diagram illustrating an example of a network configuration. FIG. 2 is a diagram illustrating an example of a hardware configuration of a communication device (AP, STA). FIG. 3 is a diagram illustrating an example of a functional configuration of a communication device (AP, STA). FIG. 4 is a diagram illustrating an example of a process flow executed by an AP. FIG. 5 is a diagram illustrating an example of a process flow executed by an STA. FIG. 6 is a diagram illustrating an example of a communication flow in which a P2P recommended period is notified. FIG. 7 is a diagram illustrating an example of a configuration of an Element indicating a P2P recommended period. FIG. 8 is a diagram illustrating another example of a configuration of an Element indicating a P2P recommended period. FIG. 9A is a diagram illustrating an example of a configuration of an ADDTS Request frame. FIG. 9B is a diagram illustrating an example of a configuration of an ADDTS Request frame. FIG. 9C is a diagram illustrating an example of a configuration of an ADDTS Request frame. FIG. 10 is a diagram illustrating an example of a configuration of an ADDTS Response frame. Fig. 11 is a diagram showing an example of the configuration of an SCS Request frame. Fig. 12A is a diagram showing an example of the configuration of an SCS Request frame. Fig. 12B is a diagram showing an example of the configuration of an SCS Request frame. Fig. 13 is a diagram showing an example of the configuration of an SCS Response frame. Fig. 14 is a diagram showing an example of the flow of communication when collecting information on P2P communication.

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] (Network Configuration) FIG. 1 shows an example of a network configuration according to this embodiment. This network is a wireless LAN (Local Area Network) in which wireless communication is performed between communication devices configured in accordance with the IEEE 802.11 series of standards. IEEE stands for Institute of Electrical and Electronics Engineers. FIG. 1 shows a state in which an AP 101 establishes a network 104 and a STA 102 participates in the network 104. Throughout this embodiment, "AP" refers to an access point that operates in accordance with the IEEE 802.11 series of standards, and "STA" refers to a station that operates in accordance with the IEEE 802.11 series of standards. It is assumed that a STA 103 is located within a range in which it can receive a signal from the AP 101, but is not participating in the network 104. That is, AP 101 is connected to STA 102 but not to STA 103 .

[0012] In this embodiment, STA102 can operate as both an STA and an AP. STA102 can connect to and communicate with, for example, STA103 using its function as an AP. STA102 can also establish a connection with STA103 and communicate without functioning as an AP. That is, communication between STAs can be performed while both STA102 and STA103 remain in the role of STAs. STA102 can also establish a connection with STA103 functioning as an AP and communicate with it. In this way, communication between STAs can be performed in various formats. In this embodiment, direct communication between STAs is referred to as P2P (Peer-to-Peer) communication, regardless of the format.

[0013] The AP 101, STA 102, and STA 103 are capable of wireless communication compliant with the IEEE 802.11bn standard, which is the successor to the IEEE 802.11be standard. The IEEE 802.11bn standard is sometimes referred to as the IEEE 802.11UHR standard. Here, UHR stands for Ultra High Reliability. Hereinafter, unless there is a need to distinguish between them, the AP 101, STA 102, and STA 103 may be collectively referred to as "communication devices." The communication devices can communicate using frequency bands such as the 2.4 GHz band, the 3.6 GHz band, the 5 GHz band, the 6 GHz band, and the 45 GHz band and 60 GHz band known as millimeter waves. The frequency bands used are not limited to these, and other frequency bands, such as the Sub-1 GHz band, may also be used. In addition, the AP 101 and the STA 102 can communicate using frequency bandwidths of 20 GHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The frequency bandwidths used are not limited to these. For example, frequency bandwidths that are multiples of 20 MHz, such as 60 MHz or 240 MHz, may be used, or frequency bandwidths that are not multiples of 20 MHz, such as 4 MHz or 24 MHz, may be used. In the IEEE 802.11 series standards, the bandwidths of frequency channels in the 2.4 GHz, 5 GHz, and 6 GHz bands are each defined as 20 MHz. Furthermore, the bandwidth of a frequency channel in the 45 GHz band is defined as 540 MHz, and the bandwidth of a frequency channel in the 60 GHz band is defined as 1080 MHz or 2160 MHz. Here, the frequency channel is a frequency channel defined in the IEEE 802.11 series of standards, and multiple frequency channels are defined in each of the 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, and 60 GHz frequency bands. Note that by bonding adjacent frequency channels, a bandwidth of 40 MHz or more can be used in one frequency channel.

[0014] In addition to the IEEE 802.11bn standard, the communication devices may also be compatible with legacy standards that predate the IEEE 802.11bn standard. That is, the communication devices (AP 101, STA 102, and STA 103) may be configured to be able to perform operations that comply with at least one of the IEEE 802.11a / b / g / n / ac / ax / be standards in addition to operations that comply with the IEEE 802.11bn standard. Furthermore, the communication devices may be configured to be able to perform communications that comply with other communication standards, such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA, in addition to the IEEE 802.11 series standards. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. Here, OFDM stands for Orthogonal Frequency Division Multiplexing. Furthermore, NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, and the like. Furthermore, the AP 101 may be compatible with a wired communication standard such as a wired LAN. The AP 101 may be, for example, but is not limited to, a wireless LAN router or a personal computer (PC). Furthermore, the AP 101 may be an information processing device such as a wireless chip capable of performing wireless communication in accordance with the IEEE 802.11bn standard. Furthermore, the STA 102 and the STA 103 may be, for example, but is not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, or a headset. The STA 102 and the STA 103 may also be information processing devices such as wireless chips capable of performing wireless communication in accordance with the IEEE 802.11bn standard.

[0015] In this embodiment, as described above, the STA 102 establishes an infrastructure connection with the AP 101 to communicate, while also establishing a connection with the STA 103 to perform P2P communication. At this time, it is important that the STA 102 be able to efficiently perform infrastructure connection communication and P2P communication in parallel. To this end, the AP 101 according to this embodiment collects requests from the connected STA 102, such as the planned P2P communication period and data volume, and sets a channel and period available for P2P communication in accordance with the request. The AP 101 then notifies the STA 102 of the set channel and period as a combination of a recommended channel and recommended period. The STA 102 controls the execution of P2P communication based on the notified combination of the recommended channel and recommended period. For example, the AP 101 sets a combination of a channel and period that is not used for communication with the currently connected STA as a recommended channel and recommended period for P2P communication. This makes it possible to prevent P2P communication by STA 102 and communication by AP 101 from being performed on the same channel for the same period of time. Also, for example, by setting a recommended period for P2P communication in response to a request for P2P communication by a STA, the length of the recommended period is prevented from becoming unnecessarily long, and communication other than P2P communication is allowed to be performed, thereby improving communication efficiency.

[0016] 2 shows an example of the hardware configuration of the communication devices (AP 101, STA 102, and STA 103) in this embodiment. The communication devices have, as their hardware configuration, for example, a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207.

[0017] The storage unit 201 is configured to include one or more memories such as ROM and RAM, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. The storage unit 201 may include storage media such as a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, a DVD, etc., in addition to or instead of memories such as ROM and RAM. The storage unit 201 may also include multiple memories.

[0018] The control unit 202 is configured with one or more processors, such as a CPU or an MPU, and controls the entire communication device by executing a computer program stored in the storage unit 201, for example. The CPU stands for Central Processing Unit, and the MPU stands for Micro Processing Unit. The control unit 202 may be configured to perform processes such as generating data and signals (radio frames) to be transmitted in communication with other communication devices, in addition to controlling the entire communication device. The control unit 202 may be configured to execute processes such as overall control of the communication device in cooperation with a computer program stored in the storage unit 201 and an OS (Operating System). The control unit 202 may also include multiple processors, such as a multi-core processor, and may execute processes such as overall control of the communication device using the multiple processors. The control unit 202 may also be configured with an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or the like.

[0019] The control unit 202 also controls the functional unit 203 to perform predetermined processes such as wireless communication, image capture, printing, and projection. The functional unit 203 is, for example, hardware that enables the communication device to perform predetermined processes. For example, if the communication device is a camera, the functional unit 203 is an image capture unit that performs image capture processing. For example, if the communication device is a printer, the functional unit 203 is a print unit that performs print processing. For example, if the communication device is a projector, the functional unit 203 is a projection unit that performs projection processing. The data processed by the functional unit 203 may be data stored in the storage unit 201, or may be data communicated with another communication device via the communication unit 206, which will be described later.

[0020] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of information to the user. Here, the output by the output unit 205 includes, for example, at least one of a display on a screen, an audio output from a speaker, and a vibration output. Note that both the input unit 204 and the output unit 205 may be implemented as a single module, such as a touch panel. Furthermore, the input unit 204 and the output unit 205 may each be built into a communication device, or may be configured as an external device connected to the communication device.

[0021] The communication unit 206 controls wireless communication compliant with the IEEE 802.11 series standards and IP communication. In this embodiment, the communication unit 206 is configured to control wireless communication compliant with the IEEE 802.11bn standard, in particular. The communication unit 206 may also control wireless communication compliant with other IEEE 802.11 series standards in addition to the IEEE 802.11bn standard, or wired communication such as a wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202, for example. The communication device may have multiple communication units 206. If the communication device supports the NFC standard or Bluetooth (registered trademark) standard in addition to the IEEE 802.11bn standard, it may control wireless communication compliant with these communication standards. If the communication device is capable of wireless communication compliant with multiple communication standards, it may have separate communication units and antennas corresponding to each communication standard. The communication device communicates data such as image data, document data, and video data with other communication devices via the communication unit 206. The antenna 207 may be provided separately from the communication unit 206, or may be configured as a single module together with the communication unit 206.

[0022] Antenna 207 is an antenna that enables communication in various frequency bands, such as the sub-GHz band, 2.4 GHz band, 5 GHz band, 6 GHz band, 45 GHz band, and 60 GHz band. The communication device may have a single antenna, such as a multi-band antenna, as antenna 207, or may have multiple antennas, each corresponding to a different frequency band. The communication device may also have multiple multi-band antennas, each corresponding to a different frequency band. When the communication device has multiple antennas, it may have one communication unit 206 for each of the multiple antennas, or multiple communication units 206 corresponding to each of the multiple antennas. Antenna 207 may be a single antenna or an antenna array. That is, antenna 207 may have multiple antenna elements and be configured to be capable of performing communication using, for example, MIMO (Multi-Input and Multi-Output).

[0023] 3 shows an example of the functional configuration of a communication device (AP 101, STA 102, and STA 103) in this embodiment. The communication device is configured to include, for example, a frame control unit 301, an other device information collection unit 302, a wireless communication control unit 303, and a schedule control unit 304. Note that these are just examples, and some or all of these functional units may be replaced with other configurations, multiple functional units may be integrated to form a single functional unit, or one functional unit may be divided into multiple functional units. Furthermore, multiple identical functional units may be provided.

[0024] The frame control unit 301 generates a wireless frame to be transmitted to a remote device. For example, the frame control unit 301 of the AP 101 generates a wireless frame addressed to the STA 102, and the frame control unit 301 of the STA 102 generates a wireless frame addressed to the AP 101 or the STA 103. The frame control unit 301 packages the data to be transmitted as a frame, shapes it into a form that can be included in a PPDU, and outputs it. PPDU stands for Physical Layer Protocol Data Unit. The other device information collection unit 302 executes processing related to the collection of information regarding the time period during which the STA is about to perform P2P communication (scheduled to perform P2P communication). The other device information collection unit 302 of the AP 101 collects information regarding the time period during which P2P communication is scheduled to be performed by surrounding STAs. In addition, the other device information collection unit 302 of the STA notifies the AP 101 of information on the time period during which the STA plans to perform P2P communication. The other device information collection unit 302 of the STA may also collect information on the time periods during which other surrounding STAs plan to perform P2P communication. In this case, the other device information collection unit 302 may notify the AP 101 of the collected information on other APs. The wireless communication control unit 303 controls wireless communication with the other device. The wireless communication control unit 303 transmits wireless frames generated by the frame control unit 301 and controls reception of wireless frames transmitted from the other device to the STA. The schedule control unit 304 controls the schedule based on information on the time period during which P2P communication is scheduled to occur, acquired by the other device information collection unit 302. For example, the schedule control unit 304 of the AP 101 controls the schedule by calculating the time available for P2P communication and notifying the STAs 102 and 103. In addition, the schedule control unit 304 of STA102 and STA103 can perform wireless communication according to a schedule determined by AP101 based on information such as the planned period for P2P communication notified by the other device information collection unit 302.

[0025] (Processing Flow) Next, processing executed by AP 101 will be described. FIG. 4 shows an example of the processing flow executed by AP 101. This processing is performed, for example, by executing a program stored in storage unit 201 of AP 101 by control unit 202 of AP 101. In this processing, AP 101 collects information from STAs regarding the period during which P2P communication is to be performed and determines a recommended time to use for P2P communication. AP 101 then broadcasts the recommended time to use for P2P communication, thereby notifying STA 102 and STA 103 of the information about the recommended time. This processing can be initiated, for example, when AP 101 connects to any STA (e.g., STA 102). Note that, although this embodiment illustrates an example in which only STA 102 is connected to AP 101, multiple STAs may be connected to AP 101 in parallel. In this case, AP 101 can execute the processing of FIG. 4 each time a STA connects. 4 is merely an example, and the order of the processing steps may be changed without departing from the spirit of the invention. Furthermore, multiple processing steps may be combined into one processing step, or one processing step may be divided into multiple processing steps.

[0026] First, the AP 101 listens to determine whether the currently connected STA 102 is scheduled to perform P2P communication, and if so, to acquire information indicating the time when the P2P communication is scheduled to occur (S401). For example, the AP 101 waits for an ADDTS (ADD Traffic Stream) Request frame to arrive from the STA 102 (S402). This frame indicates parameters such as the communication quality required by the STA 102, and is used to request the AP 101 to perform communication using those parameters. In this embodiment, the ADDTS Request frame stores a TSPEC (Traffic SPECification) field containing information indicating parameters such as the time period during which the P2P communication will be performed. The AP 101 uses the information in this TSPEC field to collect information regarding the P2P communication schedule (request) of the STA 102. Note that this is just one example, and information regarding the STA's P2P communication schedule may be collected in other wireless frames or using other fields in the ADDTS Request frame. When the AP 101 receives the ADDTS Request frame from the STA 102 (YES in S402), it checks the information contained in the frame to obtain information on communication parameters that the STA 102 requests to perform P2P communication. Here, the AP 101 obtains, for example, information on the amount of data (communication volume) that the STA 102 requests to communicate (S403). At this time, the AP 101 may obtain not only information on the communication volume, but also information on a traffic identifier (TID) and a communication period.

[0027] Meanwhile, AP 101 calculates the period required for its own device to communicate for each of one or more channels on which it operates (S404). AP 101 also sets one or more channels on which it operates as recommended channels for P2P communication (S405). AP 101 then checks whether any of the operating channels (recommended channels) has sufficient capacity to be used for other communications during its operating period (S406). That is, AP 101 determines whether any of the operating channels can be set aside for unused periods during its operating period. If AP 101 determines that any of the recommended channels has sufficient capacity (YES in S406), it calculates the length of unused time that is not used for its own device's communications. AP 101 then sets the period of time during which its own device does not communicate, having that length, as a recommended period for P2P communication (S407). Here, the recommended period is associated with the recommended channel determined to have sufficient capacity in S406. The AP 101 may determine whether the recommended period can be set at the timing when the STA is scheduled to perform P2P communication. If the recommended period cannot be set for any of the recommended channels at the timing requested by the STA, the AP 101 may determine that the period for P2P communication cannot be set. On the other hand, if the AP 101 determines that it cannot set a period for P2P communication (that there is not sufficient capacity) for all channels on which the AP 101 operates (NO in S406), it sets all periods for all recommended channels to non-recommended periods during which P2P communication is not recommended (S408). The AP 101 then broadcasts, for example, a medium access control (MAC) frame of a beacon frame, adding recommended information such as the recommended channel and recommended period (S409). For example, the recommended information such as the recommended channel and recommended period may be stored in an information element such as a Recommended element in the MAC frame. This recommendation information may be associated with a particular STA, i.e., a recommended period for P2P communication between particular STAs may be set.The recommendation information may be information in any format that can identify the recommended channel and the recommended period. That is, the recommendation information may be information that directly specifies the recommended channel and the recommended period, or information that indirectly specifies these pieces of information.

[0028] Next, the processing executed by the STA 102 will be described. FIG. 5 shows an example of the flow of the processing executed by the STA 102. This processing is performed, for example, by the control unit 202 of the STA 102 executing a program stored in the storage unit 201 of the STA 102. In this processing, the STA 102 notifies the AP of information regarding the period during which P2P communication is to be performed, obtains a recommended time for P2P communication determined and broadcast based on that information, and controls the execution of P2P communication based on that information. This processing may be started, for example, when the power or wireless function of the STA 102 is turned on, or when the STA 102 receives an instruction to start operating as a STA. Note that the processing of FIG. 5 is merely an example, and the order of the processing steps may be changed, for example, without departing from the spirit of the present invention. Furthermore, multiple processing steps may be combined into one processing step, or one processing step may be divided into multiple processing steps.

[0029] When STA 102 determines to perform P2P communication with other STAs in the vicinity (YES in S501), it executes the following process. If STA 102 does not perform P2P communication with other STAs (NO in S501), it does not execute the following process and terminates the process of FIG. 5 . When STA 102 determines to perform P2P communication (YES in S501), it transmits an ADDTS Request frame including request information (TSPEC) such as the planned period for P2P communication to AP 101 to which it is connected (S502). When STA 102 receives a predetermined notification from AP 101, it may transmit an ADDTS Request frame including request information regarding P2P communication.

[0030] Thereafter, STA 102 receives a beacon frame transmitted from a surrounding AP (e.g., including AP 101) and checks its contents (S503). Note that the beacon frame transmitted from AP 101 may include recommended information, such as a recommended channel and recommended period for P2P communication, determined based on the request information included in the ADDTS Request frame transmitted in S502. STA 102 determines whether the beacon frame from the surrounding AP includes recommended information for P2P communication (e.g., a recommended element) (S504). If the recommended information for P2P is included in the beacon frame (YES in S504), STA 102 determines whether the STA 102 operates on the recommended channel indicated by the recommended information (S505). For example, STA 102 may determine to operate on the recommended channel if there is no available channel other than the recommended channel. Furthermore, the STA 102 may determine whether or not to operate on a recommended channel in consideration of the usage status of the recommended channels around the STA 102. For example, the STA 102 may determine to operate on a recommended channel if a recommended channel available to the STA 102 is rarely used by surrounding APs and STAs and the probability of being able to access the recommended channel is sufficiently high. For example, the STA 102 may determine to operate on a recommended channel if the usage rate (the ratio of the time that the recommended channel is used by any communication device relative to the observation time) of any recommended channel does not exceed a predetermined value. Furthermore, the STA 102 may determine not to operate on a recommended channel if it cannot use any recommended channel (e.g., the usage rate exceeds a predetermined value).

[0031] When the STA 102 determines that it operates on a recommended channel (YES in S505), it determines whether a schedule exists that enables P2P communication for the STA 102 on any of the operable recommended channels (S506). For example, the STA 102 checks the Recommended element in the Beacon frame, and if a recommended period for P2P communication for the STA 102 is set, it may determine that such a schedule exists. Alternatively, the STA 102 may determine that such a schedule exists if, for example, a recommended period for P2P communication for another STA with which the STA 102 is communicating or a recommended period for P2P communication without specifying a communication subject is set. Note that the STA 102 may determine that such a schedule does not exist if a recommended period for P2P communication in which the STA 102 (or the other device) is specified in the Beacon frame does not exist. That is, the STA 102 may determine whether a recommended period in which the STA 102 is specified exists. If the STA 102 determines that the beacon frame specifies a recommended period during which the STA 102 can perform P2P communication (YES in S506), the STA 102 determines whether P2P communication is possible within that period (S507). For example, if the STA 102 can complete the requested communication within that period, the STA 102 may determine that P2P communication is possible within that period. Note that this is just an example, and the STA 102 may use other criteria to determine whether P2P communication is possible within that period. If the STA 102 determines that P2P communication is possible within the recommended period (YES in S507), the STA 102 performs P2P communication within that period (S509). On the other hand, if the STA 102 determines that P2P communication is not possible within the recommended period (NO in S507), the STA 102 performs P2P communication using a channel available to the STA 102, regardless of the recommended information (S510).

[0032] If STA102 determines that the beacon frame does not specify a recommended period during which the STA102 can perform P2P communication (NO in S506), it performs P2P communication by avoiding channels for which a recommended period is not set (S508). For example, STA102 may perform P2P communication with a partner device (STA103) during a recommended period for P2P communication between other STAs. Note that STA102 may not perform P2P communication if there is no recommended period during which the STA102 can perform P2P communication. Furthermore, if the beacon frame received from a nearby AP does not include recommended information (NO in S504) or if STA102 determines that the STA102 cannot operate on a recommended channel (NO in S505), it performs P2P communication using a channel available to the STA102 (S510).

[0033] Next, an example of the flow of communication executed in this embodiment will be described with reference to Fig. 6. First, an association request (association request frame) is transmitted from STA 102 to AP 101 (S601). Then, an association response (association response frame) in response to the association request is transmitted from AP 101 to STA 102 (S602). This establishes a connection between AP 101 and STA 102. After the connection is established, AP 101 transmits an ADDTS request frame to STA 102, notifying it of parameters such as the communication volume and communication period requested by the AP (S603). Upon receiving the ADDTS Request frame, STA 102 transmits an ADDTS Response frame to AP 101 to notify it of the receipt of the ADDTS Request frame (S604). AP 101 may use this ADDTS Request frame to request each STA to transmit a predetermined frame (e.g., an ADDTS Request frame) including a request (TSPEC) for P2P communication. The transmission of a frame including a request for P2P communication may be requested using a frame of another format. STA 102 transmits an ADDTS Request frame to AP 101, notifying it of parameters such as the communication volume and communication period that the STA requests for P2P communication (S605). The AP 101 transmits an ADDTS Response frame to the STA 102 to notify it that it has received the ADDTS Request frame (S606).

[0034] Based on information such as the communication volume and communication period received from STA 102, AP 101 broadcasts a beacon frame including recommended information, such as a recommended channel and a recommended period, as a recommended element (S607). In this embodiment, STA 102 and STA 103 can receive this beacon frame. STA 102 and STA 103 extract the recommended information (e.g., the recommended element) including the recommended channel and recommended period from the received beacon frame and determine whether P2P communication is possible for their own devices based on the recommended information. If STA 102 and STA 103 determine that P2P communication is possible for their own devices, they execute P2P communication with the other device (S608).

[0035] (Configuration of Recommended element in Beacon frame) Fig. 7 shows an example of the configuration of a Recommended element included in a Beacon frame broadcast from AP 101. When a STA receives this Beacon frame, it communicates based on this information. Like other information elements defined in the IEEE 802.11 standard, the Recommended element includes an Element ID field 701, a Length field 702, and an Extended ID field 703. These fields store basic information for identifying the data of the information element. The Recommended element further includes an override field 704 and a Scheduling List field 705 that indicates information on the recommended period for each recommended channel. The Scheduling List field 705 includes Scheduling subfields 711 corresponding to the number of recommended channels. Fig. 7 shows an example in which there are N recommended channels, and shows Scheduling subfields 711-1 for the first recommended channel to 711-N for the Nth recommended channel.

[0036] In the Scheduling subfield 711, the Scheduling control subfield 721 stores a value for schedule control. The Operating class subfield 722 stores a value indicating the Operating class. The channel subfield 723 stores information indicating the recommended channel corresponding to the Scheduling subfield 711 that includes this subfield. The starting time subfield 724 stores a value indicating the start time of the recommended period for this recommended channel, and the duration subfield 725 stores a value indicating the planned duration of the recommended period. The period subfield 725 stores a value indicating the end of the recommended period. The count down subfield 726 stores a value indicating the remaining number of communications. The STA can check the contents of one or more Scheduling subfields 711 and identify a combination of a recommended channel and a recommended period. For example, for a channel in which a recommended period is not set (that is, the channel is not available) among the AP's operating channels, information indicating a recommended period may not be included in the Scheduling subfield 711. Furthermore, the information indicating a recommended period in the Scheduling subfield 711 may explicitly indicate that there is no recommended period, or, for example, the information may be set to an invalid value. Furthermore, a channel for which a recommended period cannot be prepared may not be notified as a recommended channel. That is, for a channel in which a recommended period is not set, even if it is an AP's operating channel, the Scheduling subfield 711 may not be prepared.

[0037] The scheduling control subfield 721 includes a scheduling present subfield 731. The scheduling present subfield 731 indicates whether or not there is free time in the recommended channel that is not used by the AP 101. If there is free time that is not used by the AP 101, i.e., time that can be used for P2P communication, the subfields following the valid starting time subfield 724 are set. For example, if the scheduling present subfield 731 is set to 1, the subfields following the valid starting time subfield 724 are set. On the other hand, if the scheduling present subfield 731 is set to 0, the subfields following the valid starting time subfield 724 are not set. In this case, in one example, the subfields following the starting time subfield 724 may be omitted. Furthermore, invalid values ​​may be set to the subfields following the starting time subfield 724. In the above example, the scheduling present subfield 731 being 0 indicates that there is no available time available for P2P communication, but this is not limiting. That is, when the scheduling present subfield 731 is 0, valid subfields following the starting time subfield 724 may be set. In this case, when the scheduling present subfield 731 is 1, it indicates that valid subfields following the starting time subfield 724 are not set. When such a scheduling present subfield 731 is used, the STA 102 may, for example, check the value of the subfield to determine whether a recommended period exists in the recommended channel. For example, the STA 102 may determine that a recommended period does not exist if the value of that subfield indicates the absence of any subfields after the starting time subfield 724 .It may also be pre-arranged that if there are no subfields after the starting time subfield 724, the STA 102 interprets the entire period as a recommended period for that recommended channel.

[0038] Note that the Recommended element may have a different configuration from that shown in Fig. 7. For example, the Recommended element may have a configuration as shown in Fig. 8. Fig. 8 shows a configuration in which a Scheduling element subfield 801 is added to the Scheduling subfield 711 in the configuration of Fig. 7. On the other hand, in this configuration, the channel subfield 723 to the count down subfield 727 are omitted. The Scheduling element subfield 801 includes an Element ID subfield 811 and a Length subfield 812 that indicate an identifier and length of the Scheduling element subfield 801. The Scheduling element subfield 801 includes a Schedule info subfield 813, a Service Start time subfield 814, a Service interval subfield 815, etc. The Schedule info subfield 813 includes an Aggregation subfield 821, a TSID subfield 822, a Direction subfield 823, etc. The TSID subfield 822 may be omitted or may be a Reserved field to be used in future standards. Even in this configuration, the Recommended element can notify surrounding STAs of information on the recommended channel and recommended period.

[0039] (Configuration of ADDTS Request Frame and ADDTS Response Frame) An example configuration of an ADDTS Request frame will be described using Figures 9A to 9C. The ADDTS Request frame is one of the Action frames, and like other Action frames defined in the IEEE 802.11 standard, it includes a Category field 901 and a QoS Action field 902. The QoS Action field 902 stores a value indicating that this frame is an ADDTS Request frame. The ADDTS Request frame also includes at least a TSPEC field 903 consisting of parameters that define the traffic flow characteristics and QoS expectations.

[0040] In the TSPEC field 903, the Element ID field 911 stores a value for identifying an information element, and the Length field 912 stores a value indicating the data length of the information element. The TS info field 913 stores values ​​indicating the data direction and access method. The Nominal MSDU Size field 914 stores a value indicating the size of an MSDU (MAC Service Data Unit), and the Maximum MSDU size field 915 stores a value indicating the maximum size of an MSDU. The Minimum Service Interval field 916 stores a value indicating the minimum interval between Service periods. The Maximum Service Interval field 917 stores a value indicating the maximum interval between Service periods. The Inactivity Interval field 918 stores a value multiplied by μs (microseconds) indicating that no MPDUs are transmitted or received. The Suspension Interval field 919 stores a value multiplied by μs indicating that no MSDUs are transmitted or received. The Service Start Time field 920 stores a value indicating the start timing of the service. The Minimum Data Rate field 921, the Mean Data Rate field 922, and the Peak Data Rate field 923 store values ​​indicating the minimum, average, and peak data rates, respectively. The Burst Size field 924 stores a value indicating the burst size, and the Delay Bound field 925 stores a delay limit. A Minimum PHY Rate field 926 indicates the minimum communication speed in the physical layer (PHY). A Surplus Bandwidth Allowance field 927 stores a value for specifying the actual required bandwidth, taking into account retransmissions, etc. A Medium Time field 928 stores a value indicating the time allowed before accessing the transmission medium. A DMG Attributes field 929 stores information related to Direct Multi Gigabit (DMG).

[0041] The TS info field 913 includes a Direction field 931 that indicates the direction of communication. The Direction field 931 is composed of 2 bits, and if the first bit of this value is set to 0 and the next bit is set to 1, it indicates a Direct Link. Note that in this embodiment, setting this Direction field 931 to 01 indicates P2P communication. When the STA 102 transmits an ADDTS Request frame to the AP 101, information indicating that P2P communication will be performed can be included in the Direction field 931.

[0042] 10 shows an example of the configuration of an ADDTS Response frame. The ADDTS Response frame has a configuration in which a Status code field 1001 is inserted between the Qos Action field 902 and the TSPEC field 903 in the configuration of the ADDTS Request frame in FIGS. 9A to 9C. The Status code field 1001 stores information indicating whether or not the request indicated in the ADDTS Request frame is accepted. For example, the Status code field 1001 is set to 0 if the request is accepted, and to 1 if the request is not accepted. Furthermore, each subfield of the TSPEC field 903 is set to the same value as the value stored in the corresponding subfield of the ADDTS Request frame.

[0043] The STA can use the ADDTS Request frame described above to notify the AP of its request (plan) for P2P communication. Based on the request, the AP can then organize and transmit a Beacon frame indicating the channel it is using and unused free time on that channel as a recommended channel and period for P2P communication. This allows the STA to identify, for example, a channel and period not used for AP communication. By performing P2P communication on such a channel and period (recommended channel and recommended period), the STA can perform P2P communication without interfering with infrastructure mode communication performed by the AP.

[0044] (Variation 1) In the above embodiment, an example has been described in which a STA notifies an AP of information such as the time period during which P2P communication is scheduled to be performed using information in the TSPEC field in an ADDTS Request frame. However, this is just one example, and information regarding P2P communication may be notified from the STA to the AP without using an ADDTS Request frame or a TSPEC field. For example, information in the SCS Descriptor List field of an SCS (Stream Classification Service) Request frame may be used to collect this information.

[0045] 11 and 12A-12B show example configurations of an SCS Request frame. This frame includes at least a Category field 1101, a Robust Action field 1102, and an SCS Descriptor List field 1103. Here, the SCS Descriptor List field 1103 is configured using the SCS Descriptor element described in the IEEE 802.11-2020 standard. The SCS Descriptor List field 1103 includes an SCSID field 1123 and a Request type field 1124, the details of which will be omitted. The SCS Descriptor List field 1103 also includes an intra-Access Category Priority Element field 1125. The SCS Descriptor List field 1103 is further configured to include a TCLAS Element field 1126 and a TCLAS Processing Element field 1127. Note that TCLAS is a traffic class. The SCS Descriptor List field 1103 also includes a QoS Characteristics Element field 1128 that stores information about the time period during which the STA plans to use P2P communication.

[0046] 12A and 12B show the configuration of the QoS Characteristics Element field 1128. The QoS Characteristics Element field 1128 includes an Element ID field 1201 that identifies the information element, and a Length field 1202 that indicates the data length of the information element. The QoS Characteristics Element field 1128 also includes a Control info field 1204 that indicates the data direction and access method. The QoS Characteristics Element field 1128 also includes a Minimum Service Interval field 1205 and a Maximum Service Interval field 1206. The Minimum Service Interval field 1205 indicates the minimum interval between Service periods. The Maximum Service Interval field 1206 indicates the maximum interval between Service periods. The QoS Characteristics Element field 1128 includes a Delay Bound field 1208, a Service Start Time field 1209, and a Mean Data Rate field 1211.

[0047] The Control info field 1204 includes a Direction field 1221 that indicates the direction of communication. The Direction field 1221 is configured with 2 bits, and when the first bit of this value is set to 0 and the next bit is set to 1, it indicates a Direct Link. In this embodiment, setting the Direction field 1221 to 01 indicates P2P communication. Furthermore, when the STA 102 transmits an SCS Request frame to the AP 101, information indicating that P2P communication will be performed can be included in the Direction field 1221.

[0048] 13 shows an example of the structure of an SCS Response frame returned from an AP to a STA in response to an SCS Request frame. The SCS Response frame has a structure in which a Count field 1301 and an SCS Status List 1302 are added to the structure of the SCS Request frame in FIGS. 12A and 12B. The SCS Status List 1302 stores information indicating whether the content requested in the SCS Request frame is acceptable. The SCS Descriptor List field 1103 stores the same value as the information specified in the SCS Request frame.

[0049] In this way, the AP can collect the P2P communication requests (plans) of the STAs using frames other than the ADDTS Request frame. Then, similar to the above-described embodiment, the AP can create a Beacon frame based on the collected information and notify the STAs of information on recommended channels and recommended periods for P2P communication.

[0050] (Variation 2) The information regarding the P2P communication request (planned) may be collected through trigger-based communication. That is, the AP may transmit a Trigger frame to the STA, and the STA may respond by transmitting a frame such as a Buffer Status Report frame containing information regarding the P2P communication request (planned). FIG. 14 shows an example of such a processing flow. First, the AP 101 transmits a Trigger frame to the STA 102 to inquire about P2P communication information (such as whether to perform P2P communication, the planned period for P2P communication, etc.) (S1401). In this Trigger frame, the value of the Trigger type in the Common Info field may be set to a value dedicated to collecting information regarding P2P communication. For example, the type of this frame may be expressed in 4 bits. For example, the Trigger Type subfield value may be set to 9. When using P2P communication, the STA 102 may store information indicating the amount of data stored in the buffer that is scheduled to be transmitted via P2P communication in a Buffer Status report and transmit the report to the AP 101 (S1402). Based on the obtained data amount information, the AP 101 generates a Recommended element for indicating a recommended channel and recommended period for P2P communication, for example, as shown in FIG. 7 or 8. Then, the AP 101 generates a Beacon frame including the Recommended element and broadcasts it (S1403). The STA 102 and the STA 103 receive the Beacon frame and perform P2P communication based on the Recommended element included in the frame (S1404).

[0051] In this way, AP101 can collect P2P communication requests from STAs through trigger-based communication, organize Beacon frames based on the collected information, and notify STAs of information on recommended channels and recommended periods for P2P communication.

[0052] In the above embodiment, the AP 101 describes information on the recommended period and recommended channel for P2P communication in a MAC frame within a beacon frame and broadcasts it to the STAs 102 and 103. However, this is not limiting. That is, the recommended information regarding P2P communication may be notified to the STAs using other frames. For example, when the AP 101 receives a probe request (probe request frame) from a STA, the AP 101 may return a probe response (probe response frame) that includes the above-mentioned recommended information. Furthermore, when the AP 101 receives a connection request (association request frame) from a STA, the AP 101 may return a connection response (association response frame) that includes the above-mentioned recommended information. Furthermore, when the AP 101 receives a reassociation request (Reassociation Request frame) from the STA, the AP 101 may return a reassociation response (Reassociation Response frame) including the above-mentioned recommended information. That is, the recommended information regarding P2P communication may be transmitted by unicast rather than broadcast. In this way, information regarding the P2P communication request in the STA can be collected using various frames, and the recommended information regarding P2P communication can also be notified to the STA using various frames.

[0053] Although the above-described embodiments have been described in the context of an access point and a station conforming to the IEEE 802.11 series of standards, the present invention is not limited to this. For example, the above-described processes may be performed in any communication device conforming to other communication standards, such as a cellular communication standard. Furthermore, as long as the system allows, the processes described above as being performed by the access point may be performed by a station, and vice versa.

[0054] The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., an ASIC) that realizes one or more of the functions.

[0055] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0056] This application claims priority based on Japanese Patent Application No. 2023-210284, filed on December 13, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A communication device that functions as an access point conforming to the IEEE 802.11 series standard, comprising: a receiving means for receiving a first frame from a first other communication device connected to the communication device, the first frame including first information regarding a planned period for communication between the first other communication device and a second other communication device not passing through the communication device; and a transmitting means for transmitting a second frame including second information capable of identifying a recommended period for communication between the first other communication device and the second other communication device not passing through the communication device based on the first information.

2. The communication device of claim 1, wherein the transmitting means determines a channel on which the communication device operates as a recommended channel, determines a period during which the communication device does not use the recommended channel for communication as the recommended period, and transmits the second frame including the second information that enables identification of a combination of the recommended channel and the recommended period for the recommended channel.

3. The communication device described in claim 2, wherein the transmitting means determines each of one or more channels on which the communication device operates as the recommended channel, determines a period during which the communication device will not use the recommended channel for communication as the recommended period for each of the recommended channels, and transmits the second frame including the second information that enables identification of a combination of the channel and the recommended period for each of the one or more channels.

4. The communication device according to claim 3, wherein the second frame includes one or more fields corresponding to each of the one or more channels, and information indicating the recommended period is indicated in each of the one or more fields.

5. The communication device according to claim 4, wherein in the second frame, for a channel among the one or more channels for which the recommended period is not set, the recommended period is not indicated in the field corresponding to that channel.

6. The communication device of claim 5, wherein in the second frame, for a channel among the one or more channels for which the recommended period is not set, the field corresponding to that channel indicates that information about the recommended period is not included and does not include information indicating the recommended period, and for a channel among the one or more channels for which the recommended period is not set, the field corresponding to that channel indicates that information about the recommended period is included and includes information indicating the recommended period.

7. A communication device as described in any one of claims 1 to 6, wherein the first information includes information on the amount of data communicated between the first other communication device and the second other communication device without passing through the communication device, and the transmission means determines the recommended period based on the amount of data.

8. A communication device as described in any one of claims 1 to 7, wherein the first information further includes information regarding the amount of data planned to be communicated between the first other communication device and the second other communication device without passing through the communication device, and the transmission means determines the recommended period based on the period information.

9. A communication device that functions as a station conforming to the IEEE 802.11 series standard, comprising: a transmitting means for transmitting a first frame to a first other communication device to which the communication device is connected, the first frame including first information related to a planned period during which communication between the communication device and a second other communication device will be performed without going through the first other communication device; a receiving means for receiving a second frame from the first other communication device after transmitting the first frame, the second frame including second information capable of identifying a recommended period recommended to be used for communication between the communication device and the second other communication device without going through the first other communication device; and an executing means for executing communication with the second other communication device during the recommended period without going through the first other communication device.

10. The communication device described in claim 9, wherein a channel on which the first other communication device operates is determined as a recommended channel, and a period during which the first other communication device does not use the recommended channel for communication is determined as the recommended period, and the receiving means receives the second frame including the second information that enables identification of a combination of the recommended channel and the recommended period on the recommended channel.

11. The communication device described in claim 10, wherein each of one or more channels on which the first other communication device operates is determined to be the recommended channel, and a period during which the first other communication device does not use each of the recommended channels for communication is determined to be the recommended period, and the receiving means receives the second frame including the second information that enables identification of a combination of the channel and the recommended period for each of the one or more channels.

12. The communication device according to claim 11, wherein the second frame includes one or more fields corresponding to each of the one or more channels, and information indicating the recommended period is indicated in each of the one or more fields.

13. The communication device according to claim 12, wherein in the second frame, for a channel among the one or more channels for which the recommended period is not set, the recommended period is not indicated in the field corresponding to that channel.

14. The communication device of claim 13, wherein in the second frame, for a channel among the one or more channels for which the recommended period is not set, the field corresponding to that channel indicates that information about the recommended period is not included and does not include information indicating the recommended period, and for a channel among the one or more channels for which the recommended period is not set, the field corresponding to that channel indicates that information about the recommended period is included and includes information indicating the recommended period.

15. A communication device as described in any one of claims 9 to 14, wherein the first information includes information on the amount of data communicated between the communication device and the second other communication device without passing through the first other communication device, and the recommended period is determined based on the amount of data.

16. A communication device as described in any one of claims 9 to 15, wherein the first information further includes information regarding the amount of data to be communicated between the communication device and the second other communication device without passing through the first other communication device, and the recommended period is determined based on the period information.

17. The communication device according to any one of claims 1 to 16, wherein the first frame is any one of an ADDTS Request frame, an SCS Request frame, and a Buffer Status report frame.

18. The communication device according to any one of claims 1 to 17, wherein the second frame is any one of a Beacon frame, a Probe Response frame, an Association Response frame, and a Reassociation Response frame.

19. A communication method executed by a communication device functioning as an access point conforming to the IEEE 802.11 series standard, comprising: receiving a first frame from a first other communication device connected to the communication device, the first frame including first information related to a planned period for communication between the first other communication device and a second other communication device not passing through the communication device; and transmitting a second frame including second information capable of identifying a recommended period for communication between the first other communication device and the second other communication device not passing through the communication device, based on the first information.

20. A communication method executed by a communication device functioning as a station conforming to the IEEE 802.11 series standard, comprising: transmitting a first frame to a first other communication device to which the communication device is connected, the first frame including first information related to a planned period during which communication between the communication device and a second other communication device is to be performed without going through the first other communication device; after transmitting the first frame, receiving a second frame from the first other communication device, the second frame including second information capable of specifying a recommended period recommended to be used for communication between the communication device and the second other communication device without going through the first other communication device; and performing communication with the second other communication device during the recommended period without going through the first other communication device.

21. A program for causing a computer installed in a communication device to execute the communication method according to claim 19 or 20.

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