Wireless communication device and wireless communication method

Abstract

To provide a technique to resume the SBP procedure after an SBP session is disconnected.SOLUTION: An SBP initiator includes a control unit 110 and a communication unit 120. The control unit 110 and the communication unit 120 are configured to establish an SBP session by exchanging a first radio frame for establishing the SBP session with an SBP responder. If the SBP session is disconnected, the control unit 110 and the communication unit 120 are configured to re-establish the SBP session by exchanging a second radio frame for establishing the SBP session with the SBP responder.SELECTED DRAWING: Figure 10

Description

[[Technical Field]]

[0001] The present invention relates to a wireless communication apparatus and a wireless communication method. [[Background Art]]

[0002] A new task group for IEEE 802.11bf has been established within the IEEE 802.11 working group for wireless LAN (WLAN: Wireless Local Area Network) standards. IEEE 802.11bf develops a standard for WLAN sensing.

[0003] WLAN sensing is a technology for estimating the presence and location of a human, etc., based on signal propagation characteristics between antennas of an apparatus that performs communication via WLAN. WLAN sensing is mainly implemented by a wireless communication system including an access point (AP) and a station (STA).

[0004] Several schemes have been defined for WLAN sensing. As one of these schemes, a Sensing by Proxy (SBP) procedure has been defined. In WLAN sensing, roles for executing WLAN sensing are defined, such as a Sensing Initiator that starts sensing and a Sensing Responder that responds to a request from the sensing initiator. In the SBP procedure, a given STA serves as an SBP Initiator, and an AP serves as an SBP Responder.

[0005] In the SBP procedure, an SBP session is established between the STA, acting as the SBP initiator, and the AP, acting as the SBP responder. Once the SBP session is established, the AP, acting as the sensing initiator, performs sensing procedures with other STAs acting as sensing responders, and finally sends an SBP report to the STA acting as the SBP initiator. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Rui Du, Member, IEEE; Hailiang Xie, Graduate Student Member, IEEE; Mengshi Hu, Narengerile; Yan Xin; Stephen McCann, Senior Member, IEEE; Michael Montemurro; Tony Xiao Han, Senior Member, IEEE; and Jie Xu, Senior Member, IEEE, 'An Overview on IEEE 802.11bf: WLAN Sensing', [online], July 11, 2022, [Retrieved March 20, 2023], Internet<URL:https: / / arxiv.org / pdf / 2207.04859> [Overview of the project] [Problems that the invention aims to solve]

[0007] After an SBP session is established, if a communication failure occurs between the SBP initiator and the SBP responder before the SBP initiator receives the SBP report, the SBP session will be disconnected. In this state, the SBP initiator cannot receive the SBP report. The current IEEE 802.11bf standard does not have any provisions for restarting the SBP procedure after an SBP session has been disconnected.

[0008] The present invention provides a technique for restarting an SBP procedure after an SBP session has been disconnected, in an SBP procedure for performing WLAN sensing. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides an SBP (Sensing by Proxy) initiator (10a), the SBP initiator comprising a control unit (110) and a communication unit (120), wherein the control unit and the communication unit are configured to establish an SBP session by exchanging a first radio frame for establishing an SBP session with an SBP responder (20), and if the SBP session is disconnected, the control unit and the communication unit are configured to re-establish the SBP session by exchanging a second radio frame for establishing an SBP session with the SBP responder.

[0010] Furthermore, the present invention provides an SBP (Sensing by Proxy) responder (20), the SBP responder including a control unit (210) and a communication unit (220), the control unit and the communication unit configured to establish an SBP session by exchanging a first radio frame for establishing an SBP session with an SBP initiator (10a), and if the SBP session is disconnected, the control unit and the communication unit configured to re-establish the SBP session by exchanging a second radio frame for establishing an SBP session with the SBP initiator.

[0011] With the above configuration, the SBP procedure can be restarted between the SBP initiator and the SBP responder after the SBP session has been disconnected. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block diagram showing an example of a wireless communication system configuration. [Figure 2]This block diagram shows another example of a wireless communication system configuration. [Figure 3] This block diagram shows another example of a wireless communication system configuration. [Figure 4] This is a block diagram showing an example of STA hardware configuration. [Figure 5] This is a block diagram showing an example of STA's functional configuration. [Figure 6] Block diagram showing an example of AP hardware configuration. [Figure 7] This is a block diagram showing an example of the AP's functional configuration. [Figure 8] This diagram shows the SBP procedure according to conventional technology. [Figure 9] This diagram shows a sensing procedure according to conventional technology. [Figure 10] This figure shows an example of the process for re-establishing an SBP session according to the first embodiment. [Figure 11] This figure shows another example of the process for re-establishing an SBP session according to the first embodiment. [Figure 12] This figure shows an example of the process for re-establishing an SBP session according to the second embodiment. [Figure 13] This figure shows another example of the process for re-establishing an SBP session according to the second embodiment. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below with reference to the attached drawings. In this specification and in the drawings, elements that can be similarly described are denoted by the same reference numerals, and redundant descriptions can be omitted.

[0014] Each embodiment described below is merely an example of a configuration that can implement the present invention. Each embodiment below can be appropriately modified or changed depending on the configuration of an apparatus to which the present invention is applied and various conditions. Not all combinations of elements included in each embodiment below are necessarily essential to implement the present invention, and some elements can be appropriately omitted. Therefore, the scope of the present invention is not limited by the configurations described in the following embodiments. As long as there is no mutual contradiction, a configuration obtained by combining a plurality of configurations described in the following embodiments can also be adopted.

[0015] In the embodiment described below, an SBP initiator and an SBP responder establish an SBP session. The SBP session is established by exchanging a first radio frame for establishing the SBP session between the SBP initiator and the SBP responder. Thereafter, when the SBP session is disconnected, the SBP initiator and the SBP responder re-establish the SBP session. The SBP session is established by exchanging a second radio frame for establishing the SBP session between the SBP initiator and the SBP responder. In this way, when the SBP session is disconnected, the SBP initiator and the SBP responder restart the SBP procedure.

[0016] 1. Radio Communication System As shown in FIG. 1, a radio communication system S according to the present embodiment includes two or more stations (STA) 10a, 10b, and 10n, and at least one access point (AP) 20. The radio communication system S is configured to execute a WLAN sensing procedure adopting an SBP procedure in accordance with IEEE 802.11bf. Hereinafter, when there is no need to distinguish between STAs 10a, 10b, and 10n, they are collectively referred to as STA 10. Both the STA 10 and the AP 20 may be referred to as a radio communication apparatus or a "node".

[0017] STA10 is a wireless communication device that communicates wirelessly with AP20 in accordance with the IEEE 802.11 standard. Any STA10 requests AP20 to initiate the SBP procedure for performing the WLAN sensing procedure. Hereinafter, a wireless communication device or node that requests the initiation of the SBP procedure will be referred to as an "SBP initiator," an "SBP initiator node," or a "wireless communication device that functions as an SBP initiator." In this embodiment, STA10a will be assumed to play the role of the SBP initiator.

[0018] Any of the STA10s will perform a WLAN sensing procedure with AP20 in response to a request to perform a WLAN sensing procedure. Hereinafter, a wireless communication device or node that performs WLAN sensing in response to a request to perform WLAN sensing will be referred to as a "sensing responder," a "sensing responder node," or a "wireless communication device that functions as a sensing responder." In this embodiment, STA10b and STA10n will serve as sensing responders.

[0019] AP20 is a wireless communication device that communicates wirelessly with STA10 within its radio wave range. AP20 has base station functionality for connecting STA10 to the network. Generally, STA10 may also perform the role of AP20, and AP20 may perform the role of STA10, but in this embodiment, wireless communication devices or nodes that do not have base station functionality are referred to as STA, and wireless communication devices or nodes that have base station functionality are referred to as AP.

[0020] In the IEEE 802.11 standard, a network configuration including AP20 and STA10 is referred to as infrastructure mode. In infrastructure mode, the network configuration consisting of APs and STA10s that communicate with AP20 is called a Basic Service Set (BSS). AP20 may also communicate with other AP20s belonging to other BSSs.

[0021] AP20 establishes an SBP session with the SBP initiator in response to a request from the SBP initiator. The SBP session is established by exchanging radio frames with the SBP initiator. Hereinafter, a radio communication device or node that establishes an SBP session with the SBP initiator in response to a request from the SBP initiator will be referred to as an "SBP responder," an "SBP responder node," or a "radio communication device that functions as an SBP responder." In this embodiment, AP20 will play the role of an SBP responder.

[0022] Furthermore, AP20, in response to a request from the SBP initiator, requests the sensing responder to perform the WLAN sensing procedure. Hereinafter, the wireless communication device or node that requests the sensing responder to perform the WLAN sensing procedure will be referred to as the "sensing initiator," the "sensing initiator node," or the "wireless communication device that functions as a sensing initiator." In this embodiment, AP20 also plays the role of a sensing initiator together with the SBP responder.

[0023] As described above, the wireless communication system S according to this embodiment employs an infrastructure mode network configuration, but is not limited to this configuration. For example, as shown in Figure 2, the wireless communication system S may employ a network configuration that does not include AP20 and consists only of STA10. In the IEEE 802.11 standard, a network configuration that includes only STA10 is called ad-hoc mode. Ad-hoc mode Therefore, a network configuration consisting solely of STA10 is called an Independent Basic Service Set (IBSS).

[0024] When the wireless communication system S adopts an ad-hoc mode network configuration, for example, STA10a shown in Figure 2 may function as an SBP initiator. STA10b may function as both an SBP responder and a sensing initiator. Furthermore, STA10c and STA10n may function as sensing responders.

[0025] In addition to the above, for example, the wireless communication system S may adopt a network configuration consisting only of AP20s and excluding STA10s, as shown in Figure 3. In the IEEE 802.11 standard, a network configuration including only AP20s is called a Wireless Distribution System (WDS).

[0026] When the wireless communication system S adopts a WDS network configuration, for example, AP20a shown in Figure 3 may function as an SBP initiator. AP20b may function as both an SBP responder and a sensing initiator. Furthermore, AP20b and 20n may function as sensing responders. Note that AP20b may have the functions of both STA10 and AP20.

[0027] In the above description, the SBP initiator is a separate node from the sensing responder, but this configuration is not necessarily required. The SBP initiator may be the same node as the sensing responder. In this case, if STA10a, as shown in Figure 1, performs both the functions of an SBP initiator and a sensing responder, it requests AP20, acting as an SBP responder, to start an SBP session, and in response to a request from AP20, acting as a sensing initiator, it performs sensing procedures with AP20.

[0028] Next, the configuration of STA10 will be described with reference to Figures 4 and 5. As shown in Figure 4, STA10 includes a processor 101, memory 102, input / output interface 103, transceiver 104, and antenna 105 as hardware elements. The above elements provided in STA10 are interconnected by an internal bus. Note that STA10 may have hardware elements other than those shown in Figure 4.

[0029] The processor 101 is an arithmetic element that implements various functions of the STA10. The processor 101 may be a System-on-a-Chip (SoC) that includes elements such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a memory controller.

[0030] Memory 102 includes storage media such as RAM (Random Access Memory) and eMMC (embedded Multi Media Card). Memory 102 is an element that temporarily or permanently stores programs and data used to perform various processes in STA10. The above programs include one or more instructions for the operation of STA10. The processor 101 implements the functions of STA10 by loading the programs stored in memory 102 into memory 102 and / or system memory (not shown) and executing them.

[0031] The input / output interface 103 accepts operations to the STA 10 and supplies them to the processor 101, and also presents various information to the user. The input / output interface 103 may include, for example, a touch panel.

[0032] The transceiver 104 includes a transmitter and receiver (not shown) and is a circuit that performs various signal processing for implementing wireless communication, and includes a baseband processor and an RF circuit. The transceiver 104 exchanges wireless signals with AP20 via antenna 105.

[0033] As shown in Figure 5, STA10 has a control unit 110 and a communication unit 120 as functional blocks. The communication unit 120 includes a transmitting unit 121 and a receiving unit 122.

[0034] The control unit 110 includes a processor 101 and a memory 102. In other words, the control unit 110 is implemented by the processor 101 and the memory 102. The control unit 110 performs various control processes in the STA 10. For example, the control unit 110 controls wireless communication with the AP 20 via the communication unit 120. Various processes of the STA 10 in this embodiment are performed by the operation of the control unit 110.

[0035] The communication unit 120 includes a transceiver 104 and an antenna 105. In other words, the communication unit 120 is implemented by the transceiver 104 and the antenna 105. The communication unit 120 communicates wirelessly with AP20 by exchanging radio signals with AP20.

[0036] Next, the configuration of AP20 will be described with reference to Figures 6 and 7. As shown in Figure 6, AP20 has the following hardware elements: a processor 201, memory 202, network transceiver 203, wireless transceiver 204, and antenna 205. These elements provided in AP20 are interconnected by an internal bus. Note that AP20 may have hardware elements other than those shown in Figure 6.

[0037] Processor 201 is a computing element that implements various functions of AP20. Processor 201 may be a CPU, or it may also include other processors such as a GPU.

[0038] Memory 202 includes storage media such as ROM (Read Only Memory), RAM, HDD (Hard Disk Drive), and SSD (Solid State Drive). Memory 202 is an element that temporarily or permanently stores programs and data used to perform various processes in AP20. The above programs include one or more instructions for the operation of AP20. The processor 201 implements the functions of AP20 by loading the programs stored in memory 202 into memory 202 and / or system memory (not shown) and executing them.

[0039] The network transceiver 203 exchanges signals with other AP20s. These other AP20s are, for example, AP20s located outside its own radio range, i.e., AP20s belonging to other BSSs.

[0040] The wireless transceiver 204 includes a transmitter and receiver (not shown) and is a circuit that performs various signal processing for implementing wireless communication, and includes a baseband processor and an RF circuit. The wireless transceiver 204 exchanges wireless signals with the STA 10 via the antenna 205.

[0041] As shown in Figure 7, AP20 has a control unit 210, a communication unit 220, and a network communication unit 230 as functional blocks. The communication unit 220 includes a transmitting unit 221 and a receiving unit 222.

[0042] The control unit 210 includes a processor 201 and a memory 202. In other words, the control unit 210 is implemented by the processor 201 and the memory 202. The control unit 210 performs various control processes in the AP20. For example, the control unit 210 controls wireless communication with the STA10 via the communication unit 220. Also, for example, the control unit 210 controls communication with other nodes (for example, other AP20 nodes) via the network communication unit 230. Various processes of the AP20 in this embodiment are performed by the operation of the control unit 210.

[0043] The communication unit 220 includes a wireless transceiver 204 and an antenna 205. In other words, the communication unit 220 is implemented by the wireless transceiver 204 and the antenna 205. The communication unit 220 communicates wirelessly with the STA 10 by exchanging wireless signals with the STA 10.

[0044] The network communication unit 230 includes a network transceiver 203. In other words, the network communication unit 230 is implemented by the network transceiver 203. The network transceiver 203 exchanges signals with the network (and by extension, with the other nodes mentioned above).

[0045] 2. SBP Procedure Next, with reference to Figure 8, the SBP procedure according to prior art will be described. IEEE 802.11bf specifies a trigger-based (TB) sensing measurement instance as an alternative method for WLAN sensing procedures. In a TB sensing measurement instance, a request from the sensing initiator triggers the start of the sensing procedure. In other words, in response to a request from the sensing initiator, the sensing procedure is executed between the sensing initiator and the sensing responder.

[0046] In the SBP procedure, the SBP responder also acts as a sensing initiator, and the SBP initiator requests the SBP responder to initiate the sensing procedure on behalf of the sensing initiator. In response to the request from the SBP initiator, an SBP session is established between the SBP initiator and the SBP responder. Once the SBP session is established, in response to a request from the sensing initiator, the sensing procedure using the TB sensing measurement instance is executed between the sensing initiator and the sensing responder.

[0047] In the explanation of Figure 8, STA10a, as described in Figure 1, is assumed to function as the SBP initiator. AP20, also as described in Figure 1, is assumed to function as both the SBP responder and the sensing initiator. Furthermore, STA10b, also as described in Figure 1, is assumed to function as the sensing responder. Note that multiple sensing responders may exist for a single sensing initiator; in this case, the sensing initiator executes the sensing procedure with each sensing responder.

[0048] The SBP procedure is performed by exchanging wireless frames between STA10a, STA10b, and AP20. Wireless frames may also be referred to as wireless signals. Wireless frames include MAC frames exchanged over the Media Access Control (MAC) layer. MAC frames are defined in the IEEE 802.11 standard.

[0049] The IEEE 802.11 standard defines three types of wireless frames: management frames, control frames, and data frames. Management frames are used to perform authentication and association, etc., used in SBP procedures. Control frames are used to transmit acknowledgment (ACK) frames, etc. Data frames are used to transmit user data.

[0050] The SBP procedure uses a management frame. The management frame includes fields such as the frame control field, destination address, source address, and BSSID. The frame control field includes a type field and a subtype field. The type field is set to a value indicating one of the management frame, control frame, or data frame described above. The subtype field is set to a value indicating a subtype of the wireless frame, such as the authentication frame and association request frame described later.

[0051] The destination address is set to an identifier that identifies the node to which the wireless frame will be sent, i.e., the device ID. The device ID includes the MAC address. The source address is set to an identifier that identifies the node from which the wireless frame will be sent, i.e., the device ID. The device ID includes the MAC address. The BSSID is set to an ID that identifies the BSS, and is usually set to the MAC address of the AP20 belonging to the target BSS.

[0052] In step S801, the control unit 110 in the SBP initiator generates an SBP Request frame, and the transmission unit 121 of the communication unit 120 transmits the SBP Request frame to the SBP Responder. The SBP Request frame is generated by setting a value indicating a management frame in the type field and a value indicating an SBP Request frame in the subtype field. The SBP Request frame may also be called an SBP Request signal.

[0053] Next, the control unit 210 in the SBP responder generates an SBP response frame, and the transmission unit 221 of the communication unit 220 transmits the SBP response frame to the SBP initiator (step S802). The SBP response frame is generated by setting a value indicating a management frame in the type field and a value indicating an SBP response frame in the subtype field. The SBP response frame may also be referred to as an SBP response signal.

[0054] Next, the control unit 110 in the SBP initiator generates an authentication frame, and the transmission unit 121 transmits the authentication frame to the SBP responder (step S803). The authentication frame is generated by setting a value indicating a management frame in the type field and a value indicating an authentication frame in the subtype field. The authentication frame may also be called an authentication signal. The SBP responder also transmits an authentication frame to the SBP initiator in the same manner as described above (step S804). Authentication is performed on both sides through the processes in steps S803 and S804.

[0055] Next, the control unit 110 in the SBP initiator generates an Association Request frame, and the transmission unit 121 transmits the Association Request frame to the SBP Responder (step S805). The Association Request frame is generated by setting a value indicating a management frame in the type field and a value indicating an Association Request frame in the subtype field. The Association Request frame may also be referred to as an Association Request signal.

[0056] Next, the control unit 210 in the SBP responder generates an Association Response frame, and the transmission unit 221 transmits the Association Response frame to the SBP initiator (step S806). The Association Response frame is generated by setting a value indicating a management frame in the type field and a value indicating an Association Response frame in the subtype field. The Association Response frame may also be called an Association Response signal. The association is established by the processing in steps S805 and S806. Once the association is established, an Association ID (AID) is assigned to identify the association. The Association Response frame is set with the AID.

[0057] Steps S801 to S806 establish an SBP session between the SBP initiator and the SBP responder. In this state, the sensing procedure is executed between the sensing initiator and the sensing responder (step S807).

[0058] The wireless frames exchanged between the SBP initiator and the SBP responder during the processing of steps S801 to S806, such as the association request frame described above, are wireless frames for establishing an SBP session. Therefore, the wireless frames exchanged between the SBP initiator and the SBP responder during the processing of steps S801 to S806 are referred to as the "first wireless frame for establishing an SBP session."

[0059] Next, the details of the sensing procedure will be described with reference to Figure 9. In the sensing procedure employing the SBP procedure, the sensing procedure is performed by a TB sensing measurement instance. In step S901, the control unit 210 in the sensing initiator generates a sensing polling trigger frame, and the transmission unit 221 transmits the sensing polling trigger frame to the sensing responder. The sensing polling trigger frame is generated by setting a value indicating a management frame in the type field and a value indicating a sensing polling trigger frame in the subtype field. The sensing polling trigger frame may also be called a sensing polling trigger signal.

[0060] The sensing polling trigger frame is a wireless frame used to query the STA10, i.e., the sensing responder, whether or not it can participate in the TB sensing measurement instance. The processing in step S901 is called the polling phase. Sensing responders that are able to participate join the TB sensing measurement instance by responding to the sensing polling trigger frame.

[0061] Next, the control unit 210 in the sensing initiator generates an NDPA (NDP: Null Data Packet Announcement) frame, and the transmission unit 221 transmits the NDPA frame to the sensing responder (step S902). The NDPA frame is generated by setting a value indicating a management frame in the type field and a value indicating an NDPA frame in the subtype field. The NDPA frame may also be called an NDPA signal. The NDPA frame may also be called a measurement frame or measurement signal.

[0062] An NDPA frame is a wireless frame that instructs a sensing responder to perform measurements. The processing in step S902 is called the NDAP sounding phase. When a sensing responder receives an NDPA frame, it measures the Channel State Information (CSI). In the NDAP sounding phase, AP20, the sensing initiator, becomes the sensing transmitter, and STA10b, the sensing responder, becomes the sensing receiver.

[0063] Next, the control unit 210 in the sensing initiator generates a sensing sounding trigger frame, and the transmission unit 221 transmits the sensing sounding trigger frame to the sensing responder (step S903). The sensing sounding trigger frame is generated by setting a value indicating a management frame in the type field and a value indicating a sensing sounding trigger frame in the subtype field. The sensing sounding trigger frame may also be referred to as a sensing sounding trigger signal.

[0064] Next, the control unit 110 in the sensing responder generates an NDPA frame, and the transmission unit 121 transmits the NDPA frame to the sensing initiator (step S904). The NDPA frame is generated by setting a value indicating a management frame in the type field and a value indicating an NDPA frame in the subtype field.

[0065] The sensing sounding trigger frame is a radio frame used by the sensing initiator to request the sensing responder to transmit an NDAP frame. The processing in steps S903 and S904 is the process in which the sensing initiator performs the measurement and is called the trigger frame (TF) sounding phase. When the sensing responder receives the sensing sounding trigger frame, it transmits an NDAP frame to the sensing initiator. When the sensing initiator receives the NDAP frame, it measures the CSI. In the TF sounding phase, STA10b, i.e., the sensing responder, becomes the sensing transmitter, and AP20, i.e., the sensing initiator, becomes the sensing receiver.

[0066] Next, the control unit 110 in the sensing responder generates a report frame, and the transmission unit 121 transmits the report frame to the sensing initiator (step S905). The report frame is generated by setting a value indicating a management frame in the type field and a value indicating a report frame in the subtype field. The report frame also includes measurement report information indicating the measurement results of the CSI.

[0067] Step S905 is the process in which the sensing responder reports the results of the CSI measurement, and is called the reporting phase. When the sensing responder measures the CSI, it sends a report frame to the sensing initiator. In the reporting phase, AP20, i.e., the sensing initiator, becomes the sensing transmitter, and STA10b, i.e., the sensing responder, becomes the sensing receiver.

[0068] In the sensing procedure using the TB sensing measurement instance, the process shown in Figure 9 is merely illustrative, and either the NPDA sounding phase or the TF sounding phase may be omitted. For example, if the TF sounding phase is not performed, only STA10b, i.e., the sensing responder, will measure the CSI. For example, in the sensing procedure using the TB sensing measurement instance, each phase shown in Table 1 may be performed in the order shown in Table 1. [Table 1]

[0069] In the sensing procedure described above, a Measurement Setup ID is assigned to identify measurement setups with different operational attributes, and a Measurement Instance ID is assigned to identify measurement instances.

[0070] Returning to the explanation of Figure 8, once the sensing procedure is executed, the control unit 210 in the SBP responder generates an SBP Report frame, and the transmission unit 221 transmits the SBP Report frame to the SBP initiator (step S808). The SBP Report frame is generated by setting a value indicating a management frame in the type field and a value indicating an SBP Report frame in the subtype field. The SBP Report frame also includes measurement report information indicating the measurement results of the CSI. The measurement report information includes measurement results from the sensing responder and, if the TF sounding phase is performed, measurement results from the sensing initiator. The SBP Report frame may also be referred to as an SBP Report signal.

[0071] When step S801 begins, both the SBP initiator and the SBP responder start measuring their timers. If step S808 does not finish before the timer expires, that is, if the SBP initiator is unable to receive an SBP report frame, the SBP procedure will fail.

[0072] 3. First Embodiment Next, the first embodiment will be described. As mentioned above, if the SBP session is disconnected after it has been established but before the SBP initiator receives the SBP report frame, the SBP initiator will not be able to receive the SBP report frame. In the current IEEE 802.11bf, there is no provision for restarting the SBP procedure after the SBP session has been disconnected.

[0073] In this embodiment, if an SBP session is disconnected after it has been established, the SBP initiator and SBP responder re-establish or restore the SBP session by exchanging a second wireless frame for establishing the SBP session. Hereinafter, re-establishing the session and restoring the session may be used interchangeably.

[0074] The SBP procedure has been described with reference to Figure 8. In this embodiment, both the SBP initiator and the SBP responder store information indicating that they have executed each process shown in Figure 8 as history information. For example, when the SBP initiator receives an association response frame from the SBP responder, the control unit 110 stores an indication and / or AID indicating that an association has been established as history information in the memory 102 or a storage device (not shown). Similarly, when the SBP responder receives an SBP request frame from the SBP initiator, the control unit 210 stores an indication indicating that an SBP request frame has been received as history information in the memory 202 or a storage device (not shown).

[0075] As described above, when the sensing procedure is executed, the measurement setup ID and measurement instance ID are assigned. In this embodiment, both the SBP initiator and the SBP responder store the measurement setup ID and measurement instance ID as historical information. The measurement setup ID and measurement instance ID are assigned to the sensing initiator, but in this embodiment, AP20 also acts as an SBP responder together with the sensing initiator. Therefore, when the SBP responder is assigned the measurement setup ID and measurement instance ID, it may notify the SBP initiator of these IDs.

[0076] Furthermore, in this embodiment, both the sensing initiator and the sensing responder store information indicating that they have performed each process shown in Figure 9 as history information each time they perform that process. For example, when the sensing initiator receives a report frame from the sensing responder, the control unit 210 stores an indication that the report frame has been received and / or the measurement report information contained in the report frame as history information in the memory 202 or a storage device (not shown). Similarly, when the sensing responder receives a sensing sounding trigger frame from the sensing initiator, the control unit 110 stores an indication that the sensing sounding trigger frame has been received as history information in the memory 102 or a storage device (not shown).

[0077] 3.1. SBP Initiator Trigger-Based Procedure Referring to Figure 10, the process of re-establishing an SBP session in an SBP initiator trigger-based manner when an SBP session is disconnected after it has been established is explained below. In the explanation of Figure 10, it is assumed that an SBP session has been established and then disconnected. In this state, a trigger from the SBP initiator causes the SBP initiator and SBP responder to re-establish the SBP session.

[0078] SBP session disconnection includes, for example, cases where the session is disconnected because either the SBP initiator or the SBP responder fails to detect the beacon signal at the physical layer. Since the timer described above operates at the MAC layer, in such cases the SBP initiator may recognize the session disconnection before the timer expires. SBP session disconnection also includes, for example, cases where the session is disconnected because the timer expires due to either the SBP initiator or the SBP responder failing to receive a radio frame. Furthermore, SBP session disconnection includes, for example, cases where the session is disconnected because either the SBP initiator or the SBP responder sends a termination frame, a deauthentication frame, or a disassociation frame. A node that receives any of these frames disconnects or releases the SBP session.

[0079] In all of the above cases, the SBP initiator detects that the SBP session has been disconnected and, in response, initiates the process shown in Figure 10. In the explanation of Figure 10, it is assumed that STA10a, as described in Figure 1, acts as the SBP initiator. Furthermore, it is assumed that AP20, as described in Figure 1, acts as both the SBP responder and the sensing initiator. Additionally, it is assumed that STA10b, as described in Figure 1, acts as the sensing responder.

[0080] In step S1001, the control unit 110 in the SBP initiator checks whether it supports the restart process of the SBP procedure in this embodiment. Information indicating whether or not it supports the restart process of the SBP procedure is stored in a storage device (not shown) of the SBP initiator. If the SBP initiator determines in the process of step S1001 that it does not support the restart process of the SBP procedure, it restarts the SBP procedure by executing the process shown in Figure 8, that is, the SBP procedure in the prior art.

[0081] In step S1001, a decision is made whether or not to perform the process to restart the SBP procedure according to this embodiment, based on information indicating whether or not the restart process of the SBP procedure is supported. In other words, based on information indicating whether or not the restart process of the SBP procedure is supported, a decision is made as to whether or not the SBP initiator and SBP responder exchange a second radio frame to establish an SBP session.

[0082] Next, the control unit 110 checks, based on the history information, whether or not there is a history of the SBP procedure, that is, whether or not a first wireless frame has been exchanged with the SBP responder (step S1002). As described above, the SBP initiator stores history information each time it executes each process of the SBP procedure. In the process of step S1002, for example, if the history information includes an indication that an association has been established, it means that the SBP initiator has already executed the SBP procedure and an association has been established. If it is determined in the process of step S1002 that the SBP procedure has not been executed, the SBP procedure is restarted by executing the process shown in Figure 8, that is, the SBP procedure in the prior art.

[0083] In step S1002, a decision is made based on the history information to determine whether or not to restart the SBP procedure according to this embodiment. In other words, based on the history information, a decision is made as to whether or not the SBP initiator and the SBP responder exchange a second wireless frame to establish an SBP session.

[0084] Next, the control unit 110 resets the timer (step S1003). In this process, for example, if the SBP initiator recognizes that the SBP session has been disconnected before the timer expires, the timer may be reset by extending the expiration time. In this case, for example, if the timer expiration time is 30 seconds, it will be reset to 45 seconds. Alternatively, the timer may be reset by setting the measured value to its initial value. In other words, the timer measurement may be restarted.

[0085] In step S1003, the timer is reset not only in the SBP initiator but also in the SBP responder. For example, in response to the control unit 110 resetting the timer, the transmission unit 121 may send a wireless frame, i.e., a timer reset frame, to the SBP responder instructing it to reset the timer. If the timer expiration time is extended during the timer reset, the timer reset frame may be set to indicate the extended expiration time to the SBP responder. A subsequent association request frame may serve the same purpose as the timer reset frame described above.

[0086] Furthermore, in step S1003, for example, if the event of an SBP session being disconnected occurs n times within a predetermined period, the value set for the timer may be increased, assuming that the communication environment is not good. For example, if the timer's expiration time is 30 seconds and the timer measurement is to be restarted, the expiration time may be reset to 45 seconds and the timer measurement may be restarted.

[0087] Note that the timing for resetting the timer shown in Figure 10 is merely an example. The timer may be reset at any time after the SBP session is disconnected but before the SBP session is re-established.

[0088] Next, the control unit 110 generates an association request frame, and the transmission unit 121 transmits the association request frame to the SBP responder (step S1004). The association request frame transmitted at this time includes a historical information element (IE). The historical IE is information indicating the history of the SBP procedure being executed in order to restart the SBP procedure, that is, the history of the exchange of the first radio frame with the SBP responder. The historical IE may also be called a resume IE, reestablish IE, or recovery IE.

[0089] The history IE may include the AID stored as history information. By using the AID as the history IE, the SBP responder can be shown that an SBP session has been established with the target SBP initiator. Alternatively, instead of or in addition to the AID, the history IE may include the destination and source addresses set in the radio frame when the SBP session was established. In other words, the history IE may include the device ID of the SBP initiator and the device ID of the SBP responder when the SBP session was established. The device ID includes the MAC address. These device IDs are also stored as history information when the SBP procedure is performed. Furthermore, instead of or in addition to the AID, the history IE may include the measurement setup ID and / or measurement instance ID stored as history information. By using the measurement setup ID and / or measurement instance ID as the history IE, the SBP responder can be shown that an SBP session has been established with the target SBP initiator.

[0090] The association request frame transmitted in step S1004 is a wireless frame requesting re-association, and therefore may be a wireless frame of a different subtype than the association request frame described in Figure 8. In this case, the subtype field described above may be set to a value indicating, for example, a re-association request frame.

[0091] Next, when the receiving unit 222 in the SBP responder receives an association request frame, the control unit 210 checks the history of the SBP procedure, that is, whether an SBP session has been established with the target SBP initiator, based on the history IE included in the association request frame (step S1005). As described above, the history IE includes the AID of an already established SBP session, so it is possible to check whether an SBP session has been established with the target SBP initiator based on the AID. In addition, the history IE includes the destination address and the recipient address when the SBP procedure was executed, so it is possible to check whether an SBP session has been established with the target SBP initiator based on those addresses. Furthermore, the history IE includes the measurement setup ID and / or measurement instance ID assigned when the sensing procedure was executed, so it is possible to check whether an SBP session has been established with the target SBP initiator based on those IDs.

[0092] Next, the control unit 210 in the SBP responder generates an association response frame, and the transmission unit 221 transmits the association response frame to the SBP initiator (step S1006). The association response frame transmitted at this time includes a history IE. The history IE is information indicating the history of the SBP procedure being executed in order to restart the SBP procedure, that is, the history of the exchange of the first radio frame with the SBP initiator. The history IE may also be called a restart IE, re-establishment IE, or recovery IE.

[0093] The history IE may include the AID stored as history information. By using the AID as the history IE, the SBP initiator can be shown that an SBP session has been established with the target SBP responder. Alternatively, instead of or in addition to the AID, the history IE may include the destination and source addresses set in the radio frame when the SBP session was established. In other words, the history IE may include the device ID of the SBP initiator and the device ID of the SBP responder when the SBP session was established. The device ID includes the MAC address. These device IDs are also stored as history information when the SBP procedure is performed. Furthermore, instead of or in addition to the AID, the history IE may include the measurement setup ID and / or measurement instance ID stored as history information. By using the measurement setup ID and / or measurement instance ID as the history IE, the SBP responder can be shown that an SBP session has been established with the target SBP initiator.

[0094] The association response frame transmitted in step S1006 is a wireless frame for responding to a re-association request, and therefore may be a wireless frame of a different subtype than the association response frame described in Figure 8. In this case, the subtype field described above may be set to a value indicating, for example, a re-association response frame.

[0095] Next, when the receiving unit 122 in the SBP initiator receives an association response frame, the control unit 110 checks the history of the SBP procedure, that is, whether or not an SBP session has been established with the target SBP responder, based on the history IE included in the association response frame (step S1007). As described above, the history IE includes the AID of an already established SBP session, so it is possible to check whether or not an SBP session has been established with the target SBP responder based on the AID. In addition, the history IE includes the destination address and the recipient address when the SBP procedure was executed, so it is possible to check whether or not an SBP session has been established with the target SBP responder based on those addresses. Furthermore, the history IE includes the measurement setup ID and / or measurement instance ID assigned when the sensing procedure was executed, so it is possible to check whether or not an SBP session has been established with the target SBP responder based on those IDs.

[0096] The SBP session is re-established through the processing in steps S1001 to S1007. The association request frame and association response frame described above, that is, the wireless frames exchanged between the SBP initiator and the SBP responder in the processing of steps S1004 and S1006, are wireless frames for establishing the SBP session. Therefore, the wireless frames exchanged between the SBP initiator and the SBP responder in the processing of steps S1004 and S1006 are referred to as "second wireless frames for establishing the SBP session".

[0097] Subsequently, the sensing procedure described with reference to Figure 9 is executed between the sensing initiator and the sensing responder (step S1008). This sensing procedure includes the polling phase and other steps described above, but based on the history information, it is possible to skip phases that have already been executed and restart the sensing procedure from a phase that has not yet been executed.

[0098] Assuming the sensing procedure is performed in the order shown in Figure 9, for example, if the NDPA sounding phase has already been performed, the sensing initiator may restart the sensing procedure from the TF sounding phase. Alternatively, the sensing initiator may instruct the sensing responder to restart the sensing procedure from the TF sounding phase. For example, if the sensing initiator's history information includes an indication that the sensing initiator sent an NDPA frame to the sensing responder, it means that the NDPA sounding phase has already been performed.

[0099] Furthermore, if the sensing procedure has already been performed and the sensing initiator has received a report frame from the sensing responder, the sensing procedure may be omitted in step S1008. In this case, the control unit 210 in the sensing initiator stores the measurement report information contained in the report frame received from the sensing responder as historical information.

[0100] In other words, the control unit 210 in the sensing initiator generates a wireless frame that instructs the sensing procedure to resume from a process that has not yet been executed, based on the history information, and the transmission unit 221 transmits that wireless frame to the sensing responder.

[0101] Next, the control unit 210 in the SBP responder generates an SBP report frame, and the transmission unit 221 transmits the SBP report frame to the SBP initiator (step S1009). This process completes the restarted SBP procedure.

[0102] The process shown in Figure 10 allows for the re-establishment of a disconnected SBP session. Furthermore, by using a history IE such as AID, both the SBP initiator and the SBP responder can verify the node with which they established the SBP session, thereby eliminating the need for authentication.

[0103] 3.2. SBP Responder Trigger-Based Procedure Referring to Figure 11, the process of re-establishing an SBP session in an SBP Responder Trigger-based system after an SBP session has been established and then disconnected is explained. In the explanation of Figure 11, it is assumed that the SBP session has been established and then disconnected. In this state, the SBP initiator and SBP responder re-establish the SBP session triggered by the SBP responder.

[0104] In the SBP responder trigger-based procedure, the SBP responder detects that the SBP session has been disconnected and, in response, initiates the process shown in Figure 11. In the explanation of Figure 11, it is assumed that STA10a, as described in Figure 1, acts as the SBP initiator. Furthermore, it is assumed that AP20, as described in Figure 1, acts as both the SBP responder and the sensing initiator. In addition, it is assumed that STA10b, as described in Figure 1, acts as the sensing responder.

[0105] The processes in steps S1101 and S1102 are the same as those in steps S1001 and S1002 shown in Figure 10, but the entity executing them is AP20, that is, the SBP responder.

[0106] Next, the control unit 210 in the SBP responder generates a wireless frame requesting the re-establishment of the session, i.e., a Session Reestablish Request frame, and the transmission unit 221 transmits the Session Reestablish Request frame to the SBP initiator (step S1103). The Session Reestablish Request frame is generated by setting a value indicating a management frame in the type field and a value indicating a Session Reestablish Request frame in the subtype field. The Session Reestablish Request frame may also be called a Session Reestablish Request signal. The process in step S1103 is the process by which the SBP responder requests the SBP initiator to re-establish the SBP session.

[0107] Next, the control unit 210 resets the timer (step S1104). This process is the same as the process in step S1003 shown in Figure 10. The control unit 110 in the SBP initiator also resets the timer. For example, the control unit 110 may reset the timer in response to receiving a session re-establishment request frame. In this case, the session re-establishment request frame serves the same purpose as the timer reset frame described above.

[0108] Subsequently, steps S1105 to S1110 are executed. These steps are the same as those shown in Figure 10 for steps S1004 to S1009, so a detailed explanation is omitted.

[0109] The SBP session is re-established through the processing in steps S1101 to S1108. The wireless frames exchanged between the SBP initiator and the SBP responder in the processing of steps S1103, S1105, and S1107, such as the session re-establishment request frame described above, are wireless frames for establishing the SBP session. Therefore, these wireless frames are also referred to as "second wireless frames for establishing the SBP session."

[0110] The processing according to the first embodiment has been described above. According to this embodiment, if the SBP session established between the SBP initiator and the SBP responder is disconnected, the SBP procedure can be restarted by re-establishing the SBP session.

[0111] The order of processes shown in Figures 10 and 11 is merely illustrative, and some of the order may be changed. Furthermore, not all of the processes shown in Figures 10 and 11 are mandatory, and some of them may be omitted. In addition, processes not shown in Figures 10 and 11 may be executed; for example, authentication may be performed before sending the association request frame. That is, an authentication frame may be exchanged between the SBP initiator and the SBP responder before the process in step S1004 is executed.

[0112] 4. Second Embodiment Next, a second embodiment will be described. In the first embodiment, association processing is performed to restart the SBP session, but in the second embodiment, association processing is omitted.

[0113] 4.1. SBP Initiator Trigger-Based Procedure Referring to Figure 12, the process of re-establishing an SBP session using an SBP initiator trigger based approach when an SBP session is disconnected after it has been established will be explained. In the explanation of Figure 12, it will be assumed that STA10a, as described in Figure 1, will act as the SBP initiator. Furthermore, it will be assumed that AP20, as described in Figure 1, will act as both the SBP responder and the sensing initiator. In addition, it will be assumed that STA10b, as described in Figure 1, will act as the sensing responder.

[0114] Of the processes shown in Figure 12, steps S1201 to S1203 and steps S1208 to S1209 are the same as steps S1001 to S1003 and steps S1008 to S1009 in Figure 10, so a detailed explanation of them will be omitted.

[0115] In step S1204, the control unit 110 in the SBP initiator generates a radio frame requesting session re-establishment, i.e., a session re-establishment request frame, and the transmitter 121 transmits the session re-establishment request frame to the SBP responder. The session re-establishment request frame is generated by setting a value indicating a management frame in the type field and a value indicating a session re-establishment request frame in the subtype field. The session re-establishment request frame may also be called a session re-establishment request signal. The session re-establishment request frame includes a history IE. The history IE is information indicating the history of the SBP procedure performed in order to restart the SBP procedure, i.e., the history of the exchange of the first radio frame with the SBP responder.

[0116] The history IE may include the AID stored as history information. By using the AID as the history IE, the SBP responder can be shown that an SBP session has been established with the target SBP initiator. Alternatively, instead of or in addition to the AID, the history IE may include the destination and source addresses set in the radio frame when the SBP session was established. In other words, the history IE may include the device ID of the SBP initiator and the device ID of the SBP responder when the SBP session was established. The device ID includes the MAC address. These device IDs are also stored as history information when the SBP procedure is performed. Furthermore, instead of or in addition to the AID, the history IE may include the measurement setup ID and / or measurement instance ID stored as history information. By using the measurement setup ID and / or measurement instance ID as the history IE, the SBP responder can be shown that an SBP session has been established with the target SBP initiator.

[0117] Next, when the receiving unit 222 in the SBP responder receives a session re-establishment request frame, the control unit 210 checks the history of the SBP procedure, that is, whether or not an SBP session has been established with the target SBP initiator, based on the history IE included in the session re-establishment request frame (step S1205). As described above, the history IE includes the AID of an already established SBP session, so it is possible to check whether or not an SBP session has been established with the target SBP initiator based on the AID. In addition, the history IE includes the destination address and the recipient address when the SBP procedure was executed, so it is possible to check whether or not an SBP session has been established with the target SBP initiator based on those addresses. Furthermore, the history IE includes the measurement setup ID and / or measurement instance ID assigned when the sensing procedure was executed, so it is possible to check whether or not an SBP session has been established with the target SBP initiator based on those IDs.

[0118] Next, the control unit 210 in the SBP responder generates a radio frame in response to the session re-establishment request, i.e., a Session Reestablish Response frame, and the transmission unit 221 transmits the Session Reestablish Response frame to the SBP initiator (step S1206). The Session Reestablish Response frame transmitted at this time includes a history IE. The history IE is information indicating the history of the SBP procedure performed in order to restart the SBP procedure, i.e., the history of the exchange of the first radio frame with the SBP initiator.

[0119] The history IE may include the AID stored as history information. By using the AID as the history IE, the SBP initiator can be shown that an SBP session has been established with the target SBP responder. Alternatively, instead of or in addition to the AID, the history IE may include the destination and source addresses set in the radio frame when the SBP session was established. In other words, the history IE may include the device ID of the SBP initiator and the device ID of the SBP responder when the SBP session was established. The device ID includes the MAC address. These device IDs are also stored as history information when the SBP procedure is performed. Furthermore, instead of or in addition to the AID, the history IE may include the measurement setup ID and / or measurement instance ID stored as history information. By using the measurement setup ID and / or measurement instance ID as the history IE, the SBP initiator can be shown that an SBP session has been established with the target SBP responder.

[0120] Next, when the receiving unit 122 in the SBP initiator receives a session re-establishment response frame, the control unit 110 checks the history of the SBP procedure, that is, whether or not an SBP session has been established with the target SBP responder, based on the history IE included in the session re-establishment response frame (step S1207). As described above, the history IE includes the AID of an already established SBP session, so it is possible to check whether or not an SBP session has been established with the target SBP responder based on the AID. In addition, the history IE includes the destination address and the recipient address when the SBP procedure was executed, so it is possible to check whether or not an SBP session has been established with the target SBP responder based on those addresses.

[0121] The processes in steps S1201 to S1207 allow for the re-establishment of a disconnected SBP session. Furthermore, by using a history IE such as AID, both the SBP initiator and the SBP responder can confirm the node with which they established the SBP session, thereby eliminating the need for association processing.

[0122] The session re-establishment request frame and session re-establishment response frame described above, that is, the wireless frames exchanged between the SBP initiator and the SBP responder during the processing of steps S1204 and S1206, are wireless frames for establishing an SBP session. Therefore, the wireless frames exchanged between the SBP initiator and the SBP responder during the processing of steps S1204 and S1206 are also referred to as "second wireless frames for establishing an SBP session."

[0123] 4.2. SBP Responder Trigger-Based Procedure Referring to Figure 13, the process of re-establishing an SBP session in an SBP Responder Trigger-based manner when an SBP session is disconnected after it has been established is explained below. In the explanation of Figure 13, it is assumed that the SBP session has been established and then disconnected. In this state, the SBP initiator and SBP responder re-establish the SBP session triggered by the SBP responder.

[0124] In the SBP responder trigger-based procedure, the SBP responder detects that the SBP session has been disconnected and, in response, initiates the process shown in Figure 13. In the explanation of Figure 13, it is assumed that STA10a, as described in Figure 1, acts as the SBP initiator. Furthermore, it is assumed that AP20, as described in Figure 1, acts as both the SBP responder and the sensing initiator. In addition, it is assumed that STA10b, as described in Figure 1, acts as the sensing responder.

[0125] Of the processes shown in Figure 13, steps S1301 to S1303 and steps S1308 to S1309 are the same as steps S1101, S1102, S1104, and S1108 to S1109 in Figure 11, so a detailed explanation of them will be omitted.

[0126] In step S1304, the control unit 210 in the SBP responder generates a session re-establishment request frame, and the transmission unit 221 transmits the session re-establishment request frame to the SBP initiator. The session re-establishment request frame is similar to the session re-establishment request frame described in Figure 12 and includes the same history IE showing the same information.

[0127] Next, when the receiving unit 122 in the SBP initiator receives a session re-establishment request frame, the control unit 110 checks the history of the SBP procedure, that is, whether or not an SBP session was established with the target SBP responder, based on the history IE contained in the session re-establishment request frame (step S1305).

[0128] Next, the control unit 110 in the SBP initiator generates a session re-establishment response frame, and the transmission unit 121 transmits the session re-establishment response frame to the SBP responder (step S1306). The session re-establishment response frame is similar to the session re-establishment response frame described in Figure 12 and includes a history IE showing similar information.

[0129] Next, when the receiving unit 222 in the SBP responder receives a session re-establishment response frame, the control unit 210 checks the history of the SBP procedure, that is, whether or not an SBP session was established with the target SBP initiator, based on the history IE contained in the session re-establishment response frame (step S1307).

[0130] The processes in steps S1301 to S1307 allow for the re-establishment of a disconnected SBP session. Furthermore, by using a history IE such as AID, both the SBP initiator and the SBP responder can confirm the node with which they established the SBP session, thereby eliminating the need for association processing.

[0131] The session re-establishment request frame and session re-establishment response frame described above, that is, the wireless frames exchanged between the SBP initiator and the SBP responder during the processing of steps S1304 and S1306, are wireless frames for establishing an SBP session. Therefore, the wireless frames exchanged between the SBP initiator and the SBP responder during the processing of steps S1304 and S1306 are also referred to as "second wireless frames for establishing an SBP session."

[0132] The processing according to the second embodiment has been described above. According to this embodiment, if the SBP session established between the SBP initiator and the SBP responder is disconnected, the SBP procedure can be restarted by re-establishing the SBP session without performing association processing.

[0133] The order of processes shown in Figures 12 and 13 is merely illustrative, and some of the order may be changed. Furthermore, not all of the processes shown in Figures 12 and 13 are mandatory, and some of them may be omitted. In addition, processes not shown in Figures 12 and 13 may be executed; for example, authentication may be performed after sending the session re-establishment response frame. In other words, authentication frames may be exchanged between the SBP initiator and the SBP responder after the process in step S1307 has been executed.

[0134] 5. Other Embodiments To restart the SBP procedure after an SBP session has been disconnected, the SBP initiator and SBP responder may restart the SBP procedure by performing the process shown in Figure 8, i.e., the conventional SBP procedure. In this case, after the SBP session has been disconnected, the radio frames exchanged between the SBP initiator and the SBP responder in steps S801 to S806 in Figure 8 will be exchanged again between the SBP initiator and the SBP responder.

[0135] As described above, the radio frame exchanged between the SBP initiator and the SBP responder in steps S801 to S806 to initially establish an SBP session is referred to as the "first radio frame for establishing an SBP session." In contrast, the radio frame exchanged between the SBP initiator and the SBP responder in steps S801 to S806 to re-establish an SBP session after it has been disconnected is referred to as the "second radio frame for establishing an SBP session."

[0136] The words, phrases, and other expressions used in the above embodiments are merely illustrative and may be replaced with substantially identical or similar expressions. In particular, since the technology according to the above embodiments relates to technical specifications, the expressions in the above embodiments may be replaced with substantially identical or similar expressions in the technical specifications (for example, the technical specifications referenced in this specification).

[0137] The information transmitted and received in the above embodiments may be exchanged in the same or different messages or elements already described in the technical specifications, or in newly defined messages or elements. The information exchanged in the above embodiments may be exchanged using different layers and / or different channels than those in the above embodiments.

[0138] The means and / or functions provided by the apparatus described in the above embodiments may be provided by software recorded in a physical memory device and a computer running it, by software only, by hardware only, or by a combination thereof. For example, if any of the above apparatuses are provided by an electronic circuit which is hardware, it may be provided by a digital circuit including a number of logic circuits, or by an analog circuit.

[0139] The apparatus described in the above embodiment executes a program stored on a non-transitory tangible storage medium. The execution of this program then executes a method corresponding to the program.

[0140] 6. Addendum Some or all of the above embodiments and modifications may also be described as follows, but are not limited to the contents of the following appendix. Hereinafter, a relationship is expressed in which appendixes that are subordinate to multiple appendixes are subordinate to appendixes that are subordinate to multiple appendixes. All of the dependency relationships of appendixes expressed below are included in the above embodiments.

[0141] (Note 1) An SBP (Sensing by Proxy) initiator (10a), wherein the SBP initiator includes a control unit (110) and a communication unit (120), The control unit and the communication unit are configured to establish an SBP session by exchanging a first radio frame with the SBP responder (20) to establish an SBP session. If the SBP session is disconnected, the control unit and the communication unit are configured to re-establish the SBP session with the SBP responder by exchanging a second radio frame for establishing the SBP session. SBP Initiator.

[0142] (Note 2) The SBP initiator described in Appendix 1 includes information indicating that the second wireless frame has been exchanged with the SBP responder.

[0143] (Note 3) The information includes the SBP initiator described in Appendix 2, which includes the AID assigned when the SBP session was established by exchanging the first wireless frame.

[0144] (Note 4) The information includes the device ID of the destination node and the device ID of the source node set in the first wireless frame, as described in Appendix 2 or 3 of the SBP initiator.

[0145] (Note 5) The aforementioned device ID is the SBP initiator described in Appendix 4, including the MAC address.

[0146] (Note 6) The aforementioned SBP responder, acting as a sensing initiator, executes a sensing procedure with the sensing responder (10b). The aforementioned information includes the measurement setup ID assigned when the sensing procedure was performed, and is an SBP initiator as described in any one of the appendices 2 to 5.

[0147] (Note 7) The aforementioned SBP responder, acting as a sensing initiator, executes a sensing procedure with the sensing responder (10b). The aforementioned information includes the measurement instance ID assigned when the sensing procedure was performed, and is an SBP initiator as described in any one of the appendices 2 to 6.

[0148] (Note 8) The SBP initiator according to any one of the appendices 2 to 7, wherein the control unit is further configured to confirm that an SBP session has been established with the SBP responder based on the information contained in the second radio frame received from the SBP responder.

[0149] (Note 9) The control unit and the communication unit are: The SBP responder receives a wireless frame requesting association. The SBP responder receives a wireless frame in response to the request. An SBP initiator as described in any one of the appendices 1 to 8, further configured to replace the second wireless frame by doing so.

[0150] (Note 10) The control unit and the communication unit are: Upon receiving a wireless frame from the aforementioned SBP responder requesting to re-establish the SBP session, The SBP responder receives a wireless frame requesting association. The SBP responder receives a wireless frame in response to the request. An SBP initiator as described in any one of the appendices 1 to 8, further configured to replace the second wireless frame by doing so.

[0151] (Note 11) The control unit and the communication unit are: Send a radio frame to the SBP responder requesting it to re-establish the SBP session. The SBP responder receives a wireless frame in response to the request. An SBP initiator as described in any one of the appendices 1 to 8, further configured to replace the second wireless frame by doing so.

[0152] (Note 12) The control unit and the communication unit are: Upon receiving a wireless frame from the aforementioned SBP responder requesting to re-establish the SBP session, The SBP responder transmits a wireless frame in response to the request. An SBP initiator as described in any one of the appendices 1 to 8, further configured to replace the second wireless frame by doing so.

[0153] (Note 13) The control unit, Measure the timer, After the SBP session is disconnected, the timer is reset. An SBP initiator as described in any one of the appendices 1 to 12, further configured as follows.

[0154] (Note 14) The SBP initiator described in Appendix 13 is further configured to reset the timer by extending the timer's expiration time.

[0155] (Note 15) The SBP initiator as described in Appendix 13, wherein the control unit is further configured to reset the timer by restarting timer measurement.

[0156] (Note 16) The SBP initiator according to any one of Appendix 1 to 15, wherein the control unit is further configured to determine whether or not to replace the second wireless frame based on information indicating that the first wireless frame has been replaced.

[0157] (Note 17) The SBP initiator according to any one of Appendix 1 to 16, wherein the control unit is further configured to determine whether or not to exchange the second radio frame based on information indicating that the SBP initiator supports restarting the SBP procedure.

[0158] (Note 18) An SBP (Sensing by Proxy) responder (20), wherein the SBP responder includes a control unit (210) and a communication unit (220), The control unit and the communication unit are configured to establish an SBP session by exchanging a first radio frame with the SBP initiator (10a) to establish an SBP session. If the SBP session is disconnected, the control unit and the communication unit are configured to re-establish the SBP session by exchanging a second radio frame with the SBP initiator to establish the SBP session. SBP Responder.

[0159] (Note 19) The SBP responder described in Appendix 18, wherein the second wireless frame includes information indicating that the first wireless frame has been exchanged with the SBP initiator.

[0160] (Note 20) The information includes the SBP responder described in Appendix 19, which includes the AID assigned when the SBP session was established by exchanging the first wireless frame.

[0161] (Note 21) The information includes the device ID of the destination node and the device ID of the transmitting node set in the first wireless frame, as described in Appendix 19 or 29, for the SBP responder.

[0162] (Note 22) The aforementioned device ID is the SBP responder listed in Appendix 21, including the MAC address.

[0163] (Note 23) The control unit and the communication unit are further configured to act as sensing initiators and execute sensing procedures with a sensing responder (10b), The information includes the measurement setup ID assigned when the sensing procedure was performed, as described in any one of the items 19 to 22 of the SBP Responder.

[0164] (Note 24) The control unit and the communication unit are further configured to act as sensing initiators and execute sensing procedures with a sensing responder (10b), The information includes the measurement instance ID assigned when the sensing procedure was performed, as described in any one of the items 19 to 23 of the SBP Responder.

[0165] (Note 25) The SBP responder according to any one of Appendix 19 to 24, wherein the control unit is further configured to confirm that an SBP session has been established with the SBP initiator based on the information contained in the second radio frame received from the SBP initiator.

[0166] (Note 26) The control unit and the communication unit are: The SBP initiator receives a wireless frame requesting association, The SBP initiator transmits a wireless frame in response to the request. An SBP responder as described in any one of the appendices 18 to 25, further configured to replace the second wireless frame by means of the above.

[0167] (Note 27) The control unit and the communication unit are: The SBP initiator receives a wireless frame requesting it to re-establish the SBP session. The SBP initiator receives a wireless frame requesting association, The SBP initiator transmits a wireless frame in response to the request. An SBP responder as described in any one of the appendices 18 to 25, further configured to exchange the second wireless frame.

[0168] (Note 28) The control unit and the communication unit are: The SBP initiator receives a wireless frame requesting the re-establishment of the SBP session. The SBP initiator transmits a wireless frame in response to the request. An SBP responder as described in any one of the appendices 18 to 25, further configured to replace the second wireless frame by means of the above.

[0169] (Note 29) The control unit and the communication unit are: The SBP initiator receives a wireless frame requesting it to re-establish the SBP session. The SBP initiator receives a wireless frame in response to the request. An SBP responder as described in any one of the appendices 18 to 25, further configured to exchange the second wireless frame.

[0170] (Note 30) The control unit, Measure the timer, After the SBP session is disconnected, the timer is reset. An SBP responder as described in any one of the appendices 18 to 29, further configured as such.

[0171] (Note 31) The SBP responder according to Appendix 30, wherein the control unit is further configured to reset the timer by extending the timer's expiration time.

[0172] (Note 32) The SBP responder as described in Appendix 20, wherein the control unit is further configured to reset the timer by restarting timer measurement.

[0173] (Note 33) The SBP responder according to any one of Appendix 18 to 32, wherein the control unit is further configured to determine whether or not to replace the second wireless frame based on information indicating that the first wireless frame has been replaced.

[0174] (Note 34) The SBP responder according to any one of Appendix 18 to 33, wherein the control unit is further configured to determine whether or not to exchange the second radio frame based on information indicating that the SBP initiator supports resuming the SBP procedure.

[0175] (Note 35) An SBP responder according to Appendix 23 or 24, wherein, after the SBP session has been disconnected, the control unit and the communication unit are further configured to transmit a radio frame to the sensing responder instructing it to resume the sensing procedure from any process that has not yet been performed, based on information indicating that the sensing procedure has been performed.

[0176] (Note 36) A method performed by an SBP (Sensing by Proxy) initiator (10a), Establishing an SBP session with the SBP responder (20) by exchanging a first radio frame to establish an SBP session, If the aforementioned SBP session is disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP responder to establish the SBP session. Methods that include...

[0177] (Note 37) A method performed by an SBP (Sensing by Proxy) responder (20), Establishing an SBP session by exchanging a first radio frame with the SBP initiator (10a) to establish an SBP session, If the SBP session is disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP initiator to establish the SBP session. Methods that include...

[0178] (Note 38) When executed, the processor (101) in the SBP (Sensing by Proxy) initiator (10a) receives the following: Establishing an SBP session with the SBP responder (20) by exchanging a first radio frame to establish an SBP session, If the aforementioned SBP session is disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP responder to establish the SBP session. A program that executes something.

[0179] (Note 39) When executed, the processor (201) in the SBP (Sensing by Proxy) responder (20) will be: Establishing an SBP session by exchanging a first radio frame with the SBP initiator (10a) to establish an SBP session, If the SBP session is disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP initiator to establish the SBP session. A program that executes something.

[0180] (Note 40) When executed, the processor (101) in the SBP (Sensing by Proxy) initiator (10a) receives the following: Establishing an SBP session with the SBP responder (20) by exchanging a first radio frame to establish an SBP session, If the aforementioned SBP session is disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP responder to establish the SBP session. A computer-readable, non-transitional, tangible recording medium that stores a program to execute a program.

[0181] (Note 41) When executed, the processor (201) in the SBP (Sensing by Proxy) responder (20) will be: Establishing an SBP session by exchanging a first radio frame with the SBP initiator (10a) to establish an SBP session, If the SBP session is disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP initiator to establish the SBP session. A computer-readable, non-transitional, tangible recording medium that stores a program to execute a program. [Explanation of Symbols]

[0182] 10 STA, 101 Processor, 102 Memory, 104 Transceiver, 110 Control Unit, 120 Communication Unit, 20 AP, 201 Processor, 202 Memory, 204 Wireless Transceiver, 210 Control Unit, 220 Communication Unit

Claims

1. An SBP (Sensing by Proxy) initiator (10a), wherein the SBP initiator includes a control unit (110) and a communication unit (120), The control unit and the communication unit are: An SBP session is established by exchanging a first radio frame with the SBP responder (20) to establish an SBP session. Upon detecting that the aforementioned SBP session has been disconnected, In response to detecting that the SBP session has been disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP responder to establish an SBP session. The SBP initiator is configured in this way.

2. The SBP initiator according to claim 1, wherein the second wireless frame includes information indicating that the first wireless frame has been exchanged with the SBP responder.

3. The SBP initiator according to claim 2, wherein the information includes an AID assigned when the SBP session was established by exchanging the first wireless frame.

4. The SBP initiator according to claim 2, wherein the information includes the device ID of the destination node and the device ID of the source node set in the first wireless frame.

5. The SBP initiator according to claim 4, wherein the device ID includes a MAC address.

6. The SBP responder, acting as a sensing initiator, performs a sensing procedure with the sensing responder (10b). The SBP initiator according to claim 2, wherein the information includes a measurement setup ID assigned when the sensing procedure was performed.

7. The SBP responder, acting as a sensing initiator, performs a sensing procedure with the sensing responder (10b). The SBP initiator according to claim 2, wherein the information includes a measurement instance ID assigned when the sensing procedure was performed.

8. The SBP initiator according to any one of claims 2 to 5, wherein the control unit is further configured to confirm that an SBP session has been established with the SBP responder based on the information contained in the second wireless frame received from the SBP responder.

9. The control unit and the communication unit are: A wireless frame requesting association is sent to the aforementioned SBP responder. The SBP responder receives a wireless frame in response to the request. The SBP initiator according to claim 1, further configured to replace the second wireless frame by means of the above.

10. The control unit and the communication unit are: Upon receiving a radio frame from the aforementioned SBP responder requesting to re-establish the SBP session, A wireless frame requesting association is sent to the aforementioned SBP responder. The SBP responder receives a wireless frame in response to the request. The SBP initiator according to claim 1, further configured to replace the second wireless frame by means of the above.

11. The control unit and the communication unit are: The SBP responder receives a radio frame requesting it to re-establish the SBP session. The SBP responder receives a wireless frame in response to the request. The SBP initiator according to claim 1, further configured to replace the second wireless frame by means of the above.

12. The control unit and the communication unit are: Upon receiving a radio frame from the aforementioned SBP responder requesting to re-establish the SBP session, The SBP responder transmits a wireless frame in response to the request. The SBP initiator according to claim 1, further configured to replace the second wireless frame by means of the above.

13. The control unit, Measure the timer, After the SBP session is disconnected, the timer is reset. The SBP initiator according to claim 1, further configured as follows.

14. The SBP initiator according to claim 13, wherein the control unit is further configured to reset the timer by extending the timer's expiration time.

15. The SBP initiator according to claim 13, wherein the control unit is further configured to reset the timer by restarting timer measurement.

16. The SBP initiator according to claim 1, wherein the control unit is further configured to determine whether or not to replace the second wireless frame based on information indicating that the first wireless frame has been replaced.

17. The SBP initiator according to claim 1, further configured to determine whether to exchange the second radio frame based on information indicating that the SBP initiator supports resuming the SBP procedure.

18. An SBP (Sensing by Proxy) responder (20), wherein the SBP responder includes a control unit (210) and a communication unit (220), The control unit and the communication unit are: An SBP session is established by exchanging a first radio frame with the SBP initiator (10a) to establish an SBP session. If the SBP initiator detects that the SBP session has been disconnected, it re-establishes the SBP session by exchanging a second wireless frame with the SBP initiator to establish the SBP session. The SBP responder is configured in this way.

19. A method performed by an SBP (Sensing by Proxy) initiator (10a), Establishing an SBP session with an SBP responder (20) by exchanging a first radio frame to establish an SBP session, To detect that the aforementioned SBP session has been disconnected, In response to detecting that the SBP session has been disconnected, the SBP session is re-established by exchanging a second wireless frame with the SBP responder to establish an SBP session. Methods that include...

20. A method performed by an SBP (Sensing by Proxy) responder (20), Establishing an SBP session by exchanging a first radio frame with the SBP initiator (10a) to establish an SBP session, When the SBP initiator detects that the SBP session has been disconnected, it re-establishes the SBP session by exchanging a second wireless frame with the SBP initiator to establish an SBP session. Methods that include...

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