Base station, terminal, and wireless communication method

Abstract

The base station of one embodiment of the present application includes a generation section (35) that generates a beacon including switching information (41) indicating whether or not a frequency channel is used in coordination, and a transmission section (32) that transmits the beacon.

Description

Technical Field

[0001] The embodiments of the present invention relate to base stations, terminals, and wireless communication methods. Background Technology

[0002] In a wireless LAN (Local Area Network), wireless devices acting as terminals or base stations use CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) or EDCA (Enhanced Distribution Channel Access) to access frequency channels and transmit wireless signals. In CSMA / CA or EDCA, the wireless device waits for a period determined by the access parameters, and then transmits the wireless signal after confirming through carrier sense that no other wireless devices are using the frequency channel. Access parameters are controlled according to each Basic Service Set (BSS).

[0003] Prior technology documents

[0004] Non-patent literature

[0005] Non-patent literature 1: IEEE Std 802.11-2016, “9.3.3.3 Beacon frame format” and “10.22.2 HCF contention based channel access (EDCA)”, 7 December 2016. Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In wireless communication, high reliability, such as low latency, is required. For example, real-time applications (RTA), such as online games and human control applications for industrial equipment, sometimes have tolerance for communication latency. However, even if the base station adjusts its access parameters to meet the latency tolerance of the RTA, the required low latency cannot always be guaranteed when other BSSs using the same frequency channel are nearby.

[0008] Methods for solving problems

[0009] A base station according to one aspect of the present invention comprises: a generation unit that generates a beacon, the beacon including handover information indicating whether to coordinate the use of a frequency channel; and a transmission unit that transmits the beacon.

[0010] According to one aspect of the present invention, a highly reliable wireless communication technology is provided. Attached Figure Description

[0011] Figure 1 This is a block diagram illustrating one implementation of a communication system.

[0012] Figure 2 It means Figure 1 The diagram shows an example of the hardware configuration of a base station.

[0013] Figure 3 It means Figure 1 The diagram shows an example of the functional configuration of a base station.

[0014] Figure 4 This is a diagram illustrating an example of the construction of a beacon frame in one embodiment.

[0015] Figure 5 It means Figure 1 The diagram shows an example of the hardware configuration of the terminal.

[0016] Figure 6 It means Figure 1 The diagram shows an example of the functional configuration of a terminal.

[0017] Figure 7 It means and Figure 1 The diagram shows the data exchange processes between the base station and the terminal.

[0018] Figure 8 It means Figure 1 The flowchart shows an example of the operation of a base station.

[0019] Figure 9 It means Figure 1 The flowchart shows an example of the operation of a base station.

[0020] Figure 10 It means Figure 1 The flowchart shows an example of the terminal's actions.

[0021] Figure 11 Yes Figure 1 A timing diagram illustrating the operation of a communication system. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] [summary]

[0024] Figure 1 A communication system 10 according to one embodiment is illustrated schematically. For example... Figure 1As shown, the communication system 10 includes: base station 11 (base station 11-1, 11-2), terminal 12 (terminal 12-1, 12-2) and network 13.

[0025] Each base station 11 is connected to network 13 via, for example, a wired connection, to relay communication between an information processing device (e.g., a server) not shown on network 13 and terminal 12. Network 13 may include a local area network (LAN), a wide area network (WAN), or both. Furthermore, base stations 11-1 and 11-2 may be connected to different networks.

[0026] Base station 11 communicates wirelessly with terminal 12. Figure 1 In the example shown, base station 11-1 communicates wirelessly with terminal 12-1, and base station 11-2 communicates wirelessly with terminal 12-2. The number of terminals 12 communicating wirelessly with each base station 11 changes dynamically. In this embodiment, communication between base station 11 and terminal 12 uses Wi-Fi (registered trademark). Base station 11 corresponds to a Wi-Fi access point (AP), and terminal 12 corresponds to a Wi-Fi client. Alternatively, wireless LAN standards other than Wi-Fi can also be used.

[0027] Base stations 11-1 and 11-2 form different Basic Service Sets (BSS). Figure 1 In the example shown, terminal 12-1 belongs to the BSS of base station 11-1, and terminal 12-2 belongs to the BSS of base station 11-2. Furthermore, it is assumed that base stations 11-1 and 11-2 use the same frequency channel. For example, in W52, which is one of the channel groups in the 5GHz band, four frequency channels (36ch, 40ch, 44ch, and 48ch) can be used. Base station 11 dynamically switches the frequency channel it uses among the multiple available frequency channels. Hereinafter, frequency channels will also be referred to simply as channels.

[0028] Base station 11 periodically transmits beacons containing communication channel information and coordinated use channel information. The communication channel information represents information related to the channels currently being used by base station 11. It includes channel identification information to determine the channel in use and access parameters for accessing that channel. The coordinated use channel information represents information related to channels to be coordinated for use among base stations 11. It includes handover information (also called coordinated use handover information) indicating whether the channel to be coordinated is being used. When the handover information indicates the channel to be coordinated, the coordinated use channel information also includes channel identification information to determine the channel and access parameters for accessing that channel. Normally, the handover information is set to indicate that the channel is not being coordinated.

[0029] Terminal 12 receives a beacon from base station 11 and obtains communication channel information from the beacon. Terminal 12 accesses the channel according to the channel identification information and access parameters contained in the obtained communication channel information. Terminal 12 and base station 11 perform authentication and association to establish a wireless connection. Afterwards, terminal 12 and base station 11 exchange data.

[0030] Terminal 12-1 communicates various data (traffic) containing data with allowed delay conditions. For example, terminal 12-1 sends data with allowed delay conditions to a server on network 13 via base station 11-1, or receives data with allowed delay conditions from a server on network 13 via base station 11-1. As an example, a suitable application for requesting communication (e.g., communication with a server on network 13) is installed on terminal 12-1. If the application is started, terminal 12-1 responds to the request from the application by sending a coordination request for coordinated use of the channel to base station 11-1. In this way, terminal 12-1 requests base station 11 to use the channel for a specific purpose.

[0031] If base station 11-1 receives a coordination request from terminal 12-1, it selects a channel to be coordinated from the available channels. For example, base station 11-1 selects a currently used channel as the channel to be coordinated. Furthermore, base station 11-1 sets access parameters for accessing the channel to be coordinated. Base station 11-1 generates a beacon containing handover information configured to indicate the coordinated use of the channel and transmits the generated beacon. In this beacon, the channel identification information and access parameters included in the communication channel information can be the same as those included in the coordinated use channel information.

[0032] If terminal 12-1 receives a beacon from base station 11-1, it accesses the communication channel information contained in the beacon and communicates with base station 11-1 according to the channel. Thus, terminal 12-1 responds to the coordination request and communicates with base station 11-1 according to the set access parameters. In other words, terminal 12-1 communicates with base station 11-1 using the channel specified by base station 11-1 for coordination.

[0033] Base station 11-2 exists within the coverage area of ​​base station 11-1. In other words, base station 11-2 is within the range of radio waves emitted by base station 11-1. Therefore, base station 11-2 receives beacons from base station 11-1. Base station 11-2 identifies the handover information contained in the received beacon as indicating coordinated channel use. If the channel identification information contained in the coordinated channel use information indicates the same channel as the channel being used by base station 11-2, base station 11-2 generates a beacon whose communication channel information contains the same access parameters as those contained in the coordinated channel use information, and transmits the generated beacon.

[0034] If terminal 12-2 receives a beacon from base station 11-2, it accesses the channel according to the communication channel information contained in the beacon and communicates with base station 11-2. Thus, terminal 12-2 responds to the coordination request from terminal 12-1 and communicates with base station 11-2 according to the set access parameters.

[0035] In the aforementioned communication system 10, access parameters related to a specific channel are aligned, i.e., unified, in the environment surrounding base station 11-1. Access parameters are uniformly controlled across BSSs. This avoids communication quality degradation caused by BSSs different from those of base station 11-1. As a result, the reliability of wireless communication is improved.

[0036] [structure]

[0037] Figure 2 This diagram schematically illustrates an example of the hardware configuration of base station 11. Base station 11 can be either fixed or mobile. Figure 2 As shown, base station 11 includes controller 21, wireless module 25, antenna 26, and router module 27. Controller 21 is connected to wireless module 25 and router module 27.

[0038] The controller 21 processes data and controls other components. The controller 21 includes a CPU (Central Processing Unit) 22, RAM (Random Access Memory) 23, and program memory 24. The CPU 22 is an example of a general-purpose processor. RAM 23 is used by the CPU 22 as working memory. RAM 23 includes volatile memory such as SDRAM (Synchronous Dynamic Random Access Memory). Program memory 24 stores the program executed by the CPU 22. For example, ROM (Read-Only Memory) or NOR flash memory is used as program memory 24. The controller 21 operates according to the program. For example, the CPU 22 performs data processing corresponding to the program by expanding the program stored in program memory 24 to RAM 23, interpreting and executing the program.

[0039] The wireless module 25 is configured to communicate with an external information processing device (e.g., Figure 1The terminal 12 shown performs wireless communication. In this embodiment, the wireless module 25 is a Wi-Fi module. The wireless module 25 can be a processing circuit, such as a chipset, that includes a processor, memory, and RF (Radio Frequency) circuitry. The wireless module 25 includes a transmitter and a receiver. The wireless module 25 is connected to the antenna 26. Alternatively, the antenna 26 may also be included in the wireless module 25.

[0040] Wireless module 25 converts MAC (Media Access Control) frames into wireless signals and transmits them via antenna 26. For example, wireless module 25 converts beacon frames into wireless signals and transmits them via antenna 26. Beacon frames are transmitted at predetermined time intervals (e.g., 100ms intervals). Additionally, wireless module 25 receives data from controller 21, generates data frames containing the received data, converts the generated data frames into wireless signals, and transmits them via antenna 26.

[0041] Furthermore, the wireless module 25 receives wireless signals via antenna 26 and obtains MAC frames from the received wireless signals. For example, the wireless module 25 receives wireless signals corresponding to data frames via antenna 26, obtains data from the received wireless signals, and forwards the obtained data to controller 21. Additionally, the wireless module 25 receives wireless signals corresponding to beacon frames or coordination request frames via antenna 26, obtains beacon frames or coordination request frames from the received wireless signals, and processes the obtained beacon frames or coordination request frames. Coordination request frames can also be defined as a type of control frame.

[0042] Router module 27 is configured to communicate with network 13. For example, router module 27 exchanges data with a server on network 13. Router module 27 may be a processing circuit including a processor and memory. Alternatively, router module 27 may not be located at base station 11. Base station 11 may also be configured to access a router located outside base station 11 via wireless or wired communication, and connect to network 13 via that router.

[0043] In the example above, controller 21 includes a general-purpose processor. Alternatively, or additionally, controller 21 may include a dedicated processor. For example, controller 21 may also be implemented using an ASIC (Application Specific Integrated Circuit) or a FPGA (Field Programmable Gate Array).

[0044] Figure 3 An example of the functional configuration of base station 11 is illustrated schematically. For example... Figure 3 As shown, base station 11 includes a data processing unit 31, a wireless signal processing unit 32, a beacon analysis unit 33, an access parameter setting unit 34, a beacon generation unit 35, and a communication unit 36. The wireless signal processing unit 32 includes a transmitting unit for transmitting wireless signals and a receiving unit for receiving wireless signals. The data processing unit 31, wireless signal processing unit 32, beacon analysis unit 33, access parameter setting unit 34, and beacon generation unit 35 are implemented by a processing circuit including a controller 21 and a wireless module 25. In one example, a portion of the data processing unit 31 is implemented by the controller 21, while the remaining parts of the data processing unit 31, the wireless signal processing unit 32, the beacon analysis unit 33, the access parameter setting unit 34, and the beacon generation unit 35 are implemented by the wireless module 25. The communication unit 36 ​​is implemented by a router module 27.

[0045] The data processing unit 31 exchanges data with the network 13 via the communication unit 36. The data processing unit 31 receives data from the network 13 via the communication unit 36, generates a data frame containing the received data, and forwards the generated data frame to the wireless signal processing unit 32. The wireless signal processing unit 32 receives the data frame from the data processing unit 31, converts the received data frame into a wireless signal, and transmits it.

[0046] The wireless signal processing unit 32 receives wireless signals, extracts MAC frames from the received wireless signals, and forwards the extracted MAC frames to the data processing unit 31. The data processing unit 31 receives MAC frames from the wireless signal processing unit 32. If the MAC frame is a data frame, the data processing unit 31 extracts data from the data frame and sends the data to the network 13 via the communication unit 36. If the MAC frame is a coordination request frame, the data processing unit 31 forwards the coordination request frame to the access parameter setting unit 34. If the MAC frame is a beacon frame from another base station, the data processing unit 31 forwards the beacon frame to the beacon analysis unit 33.

[0047] The beacon analysis unit 33 receives beacon frames from the data processing unit 31 and analyzes the received beacon frames. For example... Figure 4 As shown, the beacon frame includes: a field 41 storing a coordination flag indicating whether the channel is being used in coordination; a field 42 storing channel identification information that determines the channel; and a field 43 storing the values ​​of access parameters used to access the channel. In one example, if the channel is being used in coordination, the value "1" is stored in field 41; if the channel is not being used in coordination, the value "0" is stored in field 41. The beacon frame also includes a field storing channel identification information that determines the channel in use, and a field storing the values ​​of access parameters used to access the channel in use.

[0048] Refer again Figure 3The beacon analysis unit 33 confirms the coordination use flag contained in the beacon frame. When the coordination use flag indicates that the channel is being coordinated (i.e., the coordination use flag is 1), the beacon analysis unit 33 extracts the channel identification information and access parameter values ​​from the beacon frame, and forwards the extracted channel identification information and access parameter values ​​to the access parameter setting unit 34.

[0049] The access parameter setting unit 34 sets access parameters related to the channel in use. In the example using EDCA as the access control method, the access parameters for each access type include CWmax, CWmin, AIFS, and TXOPLimit. For example, there are four access types: AC_VO (Voice), AC_VI (Video), AC_BE (Best effort), and AC_BK (Background). CWmax and CWmin are the maximum and minimum values ​​of the transmission waiting time, i.e., the CW (Contention Window). AIFS (Arbitration Inter Frame Space) is the frame transmission interval. TXOPLimit is the upper limit of the channel occupancy time, i.e., the TXOP (Transmission Opportunity). The smaller the TXOP value, the smaller the amount of data that can be transmitted in one transmission right, and the easier it is for each terminal 12 to obtain the transmission right. Therefore, by reducing the value of TXOPLimit, the low-latency characteristics can be improved.

[0050] Normally, the access parameter setting unit 34 sets the access parameters to pre-prepared values. For example, the access parameter setting unit 34 can select a value from a plurality of pre-prepared values ​​based on the communication conditions. When the access parameter setting unit 34 receives a coordination request frame from the data processing unit 31, it sets the access parameters based on the information contained in the coordination request frame. For example, if the coordination request frame contains allowable values ​​for communication indicators such as transmission delay, the access parameter setting unit 34 can also determine the value of the access parameter to satisfy the allowable value. When the coordination request frame contains the value of the access parameter, the access parameter setting unit 34 can determine the access parameter to the value specified by the coordination request frame. When the access parameter setting unit 34 receives the value of the access parameter from the beacon analysis unit 33, it sets the access parameter to the value received from the beacon analysis unit 33.

[0051] The beacon generation unit 35 generates a beacon frame containing communication channel information and coordination information for using the channel. The communication channel information includes the values ​​of access parameters set by the access parameter setting unit 34. For example... Figure 4As shown, the coordinated channel usage information includes: a coordinated usage flag, channel identification information, and access parameter values. In response to a coordination request from terminal 12, the coordinated usage flag is set to the value "1," indicating coordinated channel usage. Alternatively, the coordinated usage flag can be set to the value "1" in response to coordinated channel usage information contained in beacons from other base stations 11.

[0052] The wireless signal processing unit 32 periodically transmits beacon frames generated by the beacon generation unit 35. Specifically, the wireless signal processing unit 32 converts the beacon frames into wireless signals and broadcasts the converted beacon frames at predetermined time intervals.

[0053] Figure 5 An example of the hardware configuration of terminal 12 is schematically shown. Terminal 12 can be either fixed or movable. Here, terminal 12 is envisioned as a mobile terminal device such as a smartphone. Figure 5 As shown, terminal 12 includes: a controller 51, a storage unit 55, a wireless module 56, an antenna 57, an input / output interface 58, and a battery 59. The controller 51 is connected to the storage unit 55, the wireless module 56, the input / output interface 58, and the battery 59.

[0054] The controller 51 processes data and controls other components. The controller 51 includes a CPU 52, RAM 53, and program memory 54. RAM 53 serves as working memory used by the CPU 52. RAM 53 includes volatile memory such as SDRAM. Program memory 54 stores programs executed by the CPU 52. Program memory 54 may be, for example, ROM, memory 55, or a combination thereof. The controller 51 operates according to the program. For example, the CPU 52 performs data processing corresponding to the program by expanding the program stored in program memory 54 into RAM 53, interpreting and executing the program.

[0055] Storage 55 does not temporarily store data. Storage 55 includes non-volatile memory such as hard disk drive (HDD) or solid-state drive (SSD).

[0056] Wireless module 56 is configured to communicate with an external information processing device (e.g., Figure 1 The base station 11 shown performs wireless communication. In this embodiment, the wireless module 56 includes a Wi-Fi module. The wireless module 56 may also include a Bluetooth (registered trademark) module. The wireless module 56 may also be a processing circuit such as a chipset, including a processor, memory, and RF circuitry. The wireless module 56 is connected to the antenna 57. Furthermore, the antenna 57 may also be included in the wireless module 56.

[0057] The wireless module 56 receives data from the controller 51, generates a data frame containing the received data, converts the generated data frame into a wireless signal, and transmits it via the antenna 57. Additionally, the wireless module 56 sends control frames such as coordination request frames. Furthermore, the wireless module 56 receives wireless signals via the antenna 57 and extracts MAC frames from the received wireless signals. If the MAC frame is a data frame, the wireless module 56 forwards the data frame to the controller 51. If the MAC frame is a beacon frame, the wireless module 56 processes the beacon frame.

[0058] The input / output interface 58 includes: an input device for inputting data to the terminal 12, an output device for outputting data from the terminal 12, and terminals for connecting peripheral devices. Typically, a touchscreen including a display and a touch sensor is used as both the input and output devices. The input device may also include a microphone. The output device may also include a speaker.

[0059] Battery 59 is a rechargeable battery. Battery 59 supplies power to controller 51, storage 55, wireless module 56, antenna 57, and input / output interface 58.

[0060] Figure 6 This schematically illustrates an example of the functional configuration of terminal 12. For example... Figure 6 As shown, terminal 12 includes a data processing unit 61, a wireless signal processing unit 62, and a beacon analysis unit 63. The wireless signal processing unit 62 includes a transmitting unit for transmitting wireless signals and a receiving unit for receiving wireless signals. The data processing unit 61, the wireless signal processing unit 62, and the beacon analysis unit 63 are implemented by a processing circuit including a controller 51 and a wireless module 56. In one example, a portion of the data processing unit 61 is implemented by the controller 51, while the remaining portion of the data processing unit 61, the beacon analysis unit 63, and the wireless signal processing unit 62 are implemented by the wireless module 56.

[0061] The data processing unit 61 receives data from higher-level components such as applications executed by the controller 51, generates data frames containing the received data, and forwards the generated data frames to the wireless signal processing unit 62. The application is not limited to a specific application. For example, the application could be an RTA such as a network game or a control application for an industrial robot. The wireless signal processing unit 62 receives data frames from the data processing unit 61, converts the received data frames into wireless signals, and transmits them.

[0062] The wireless signal processing unit 62 receives wireless signals, extracts MAC frames from the received wireless signals, and forwards them to the data processing unit 61. The data processing unit 61 receives MAC frames from the wireless signal processing unit 62. If the MAC frame is a data frame, the data processing unit 61 extracts data from the data frame and delivers the extracted data to a higher layer. The data may be used, for example, by an application.

[0063] When the MAC frame is a beacon frame, the data processing unit 61 forwards the beacon frame to the beacon analysis unit 63. The beacon analysis unit 63 receives the beacon frame from the data processing unit 61 and analyzes it. The beacon analysis unit 63 confirms the channel identification information and access parameter values ​​in the communication channel information contained in the beacon frame. For example, if the communication channel information includes the value of TXOPLimit but not the values ​​of CWmax, CWmin, and AIFS, the beacon analysis unit 63 determines the values ​​of CWmax, CWmin, and AIFS itself. The beacon analysis unit 63 notifies the radio signal processing unit 62 of the channel to be used and the access parameter values. The radio signal processing unit 62 performs wireless communication according to the information received from the beacon analysis unit 63.

[0064] The data processing unit 61 receives requests related to communication characteristics from higher layers. These requests may include, for example, permissible values ​​for communication metrics such as transmission delay. For instance, if at least a portion of the data output from the application described above has permissible delay values, the application requests the data processing unit 61 to send data to meet these permissible delay values. In response to the request from higher layers, the data processing unit 61 generates a coordination request frame requesting the coordinated use of the channel. The wireless signal processing unit 62 converts the coordination request frame into a wireless signal and transmits it. In one example, the coordination request frame contains permissible values ​​for communication metrics. In other examples, the data processing unit 61 determines the values ​​of access parameters based on the permissible values ​​for communication metrics, and the coordination request frame contains the values ​​of the access parameters determined by the data processing unit 61. The data processing unit 61 and the wireless signal processing unit 62 function as requesting units that request coordination from the base station 11.

[0065] Figure 7 The diagram schematically illustrates the MAC layer processing associated with data exchange between base station 11 and terminal 12. Figure 7 The diagram illustrates both the transmitting and receiving sides of the processing. While the transmitting side processing is performed by the wireless module of one of the base station 11 and the terminal 12, the receiving side processing is performed by the wireless module of the other. In the following examples, the transmitting and receiving wireless modules are described without distinction.

[0066] First, the processing on the transmitting side will be explained. In step S10, the wireless module performs A-MSDU aggregation. Specifically, the wireless module combines multiple data inputs from higher layers such as the application layer to generate an A-MSDU (Aggregate-MACService Data Unit).

[0067] In step S11, the wireless module assigns a serial number (SN) to the A-MSDU. The serial number is a unique identifier used to identify the A-MSDU.

[0068] In step S12, the wireless module segments the A-MSDU into multiple MPDUs (MAC protocol data units).

[0069] In step S13, the wireless module encrypts each MPDU to generate an encrypted MPDU.

[0070] In step S14, the wireless module appends a MAC header and an error detection code to each encrypted MPDU. The error detection code is, for example, a CRC (Cyclic Redundancy Check) code.

[0071] In step S15, the wireless module performs A-MPDU aggregation. Specifically, the wireless module combines multiple MPDUs to generate an A-MPDU (Aggregate-MAC protocol data unit) as a MAC frame.

[0072] After step S15, the wireless module performs physical layer processing on the MAC frame. In other words, the wireless module performs modulation processing on the MAC frame, generates a wireless signal, and sends the wireless signal to the base station 10.

[0073] Next, the processing on the receiving side will be explained. If the wireless signal is received, the wireless module performs physical layer processing to recover the MAC frame from the wireless signal. Afterwards, the wireless module... Figure 7 The processing of the MAC layer is shown.

[0074] In step S20, the wireless module performs A-MPDU de-aggregation. Specifically, the wireless module divides the A-MPDU into MPDU units.

[0075] In step S21, the wireless module performs error detection. For example, the wireless module determines whether the wireless signal reception was successful using a CRC check. If the wireless signal reception fails, the wireless module can request a retransmission. In this case, the wireless module can also request a retransmission in units of MPDUs. On the other hand, if the wireless signal reception is successful, the wireless module performs the following processing.

[0076] In step S22, the wireless module performs address detection. At this time, the wireless module determines whether the incoming MPDU is destined for itself based on the address recorded in the MAC header of each MPDU. If it is not destined for itself, the wireless module does not perform the following processing. If it is destined for itself, the wireless module performs the following processing.

[0077] In step S23, the wireless module decrypts the encrypted MPDU.

[0078] In step S24, the wireless module reassembles the MPDU (defragment). In other words, the wireless module recovers the A-MSDU from multiple MPDUs.

[0079] In step S25, the wireless module performs A-MSDU de-aggregation. Specifically, the wireless module restores the A-MSDU to data in MSDU units.

[0080] After step S25, the wireless module outputs data to a higher layer of the MAC layer. This higher layer could be the application layer.

[0081] [action]

[0082] Next, an example of the operation of the communication system 10 will be explained.

[0083] Figure 8 An example of the processing of a beacon transmitted by base station 11 is illustrated schematically.

[0084] exist Figure 8 In step S81, the access parameter setting unit 34 sets access parameters for accessing the channel currently used by the base station 11. For example, the access parameter setting unit 34 sets the access parameters to default values. For example, the access parameters include: CWmax, CWmin, AIFS, TXOPLimit related to access type AC_VO; CWmax, CWmin, AIFS, TXOPLimit related to access type AC_VI; CWmax, CWmin, AIFS, TXOPLimit related to access type AC_BE; and CWmax, CWmin, AIFS, TXOPLimit related to access type AC_BK.

[0085] In step S82, the wireless signal processing unit 32 transmits a beacon containing the access parameter values ​​set by the access parameter setting unit 34 for the communication channel information. At this time, the coordinated use flag is set to a value of "0" indicating uncoordinated use of the channel.

[0086] If base station 11 does not receive a coordination request from terminal 12 (step S83; No), the process of step S82 is repeated. At this time, access parameter setting unit 34 can adjust access parameters according to the communication environment, such as the number of terminals in communication. If base station 11 receives a coordination request from terminal 12 (step S83; Yes), the process proceeds to step S84.

[0087] In step S84, the access parameter setting unit 34 responds to the coordination request and sets the access parameters. When the coordination request specifies a value for the access parameter, the access parameter setting unit 34 adopts the value specified in the coordination request. For example, if the coordination request specifies a value for TXOPLimit related to each of the access types AC_VO, AC_VI, AC_BE, and AC_BK, the access parameter setting unit 34 sets the TXOPLimit related to each of the access types AC_VO, AC_VI, AC_BE, and AC_BK to the value specified in the coordination request, and sets other access parameters to values ​​determined by itself.

[0088] In step S85, the beacon generation unit 35 generates a beacon with the coordination use flag set to a value of "1" to indicate the coordination use of the channel. This beacon includes channel identification information for determining the channel to be coordinated and access parameters (values ​​set in step S84) for accessing the channel to be coordinated in the coordination use channel information. In step S86, the wireless signal processing unit 32 transmits the beacon.

[0089] Thus, when base station 11 receives a coordination request from terminal 12, it requests coordination with other surrounding base stations 11 to use the specific channel. Base station 11 can cancel the coordination of channel use at any time. In one example, when base station 11 receives a cancellation request from terminal 12, it can restore the access parameters to their original values. In other examples, base station 11 can also restore the access parameters to their original values ​​after a specified time has elapsed since receiving the coordination request.

[0090] Figure 9 Other examples of the processing of beacon signals transmitted by base station 11 are illustrated schematically.

[0091] exist Figure 9 In step S91, the wireless signal processing unit 32 receives beacons from other base stations 11 (other BSSs). For example, it performs... Figure 9 The base station 11 shown is being processed. Figure 1 Base station 11-2 is shown; other base stations 11 are... Figure 1 The base station shown is 11-1.

[0092] In step S92, the beacon analysis unit 33 determines whether the coordination use flag contained in the received beacon is a value of "1" indicating a request for coordination use. If the coordination use flag is a value of "0" indicating a non-request for coordination use (step S92; no), the process proceeds to step S94. In step S94, the access parameter setting unit 34 sets the access parameters to values ​​determined by itself (e.g., default values).

[0093] If the coordination use flag is a value of "1" indicating a request for coordination use (step S92; Yes), the process proceeds to step S93. In step S93, if the radio signal processing unit 32 uses the same channel as the channel indicated by the coordination use channel information, the access parameter setting unit 34 sets the access parameters using the access parameters in the coordination use channel information contained in the beacon.

[0094] In step S95, the beacon generation unit 35 generates a beacon that includes the access parameters set in step S93 or S94 in the communication channel information. When the access parameter value is set in step S94, the beacon generation unit 35 may also set the coordination use flag to a value "1" indicating coordinated use of the channel. In step S96, the wireless signal processing unit 32 transmits the beacon.

[0095] In this way, when base station 11 requests the use of a specific channel from other base stations 11, and uses the channel in communication with terminal 12, it sets access parameters according to the request from other base stations 11.

[0096] Figure 10 The diagram illustrates the processing of data transmitted by terminal 12 with allowable delay conditions.

[0097] exist Figure 10 In step S101, terminal 12 requests coordinated use of a channel from base station 11 based on latency allowance conditions. For example, data processing unit 61 determines the value of TXOPLimit for each access type based on allowance conditions, and radio signal processing unit 62 sends a coordination request containing the TXOPLimit value for each access type. Upon receiving the coordination request, base station 11 selects the channel to be coordinated from the available channels and sends a beacon containing information configured to represent the coordinated use of the channel, channel identification information determining the channel to be coordinated, and access parameters for accessing the channel to be coordinated, all contained in the coordinated use channel information. Base station 11 also notifies the user of the change from the used channel to the channel to be coordinated via communication channel information in the beacon.

[0098] In step S102, terminal 12 receives a beacon from base station 11. In step S103, terminal 12 uses the channel to be coordinated via the beacon to transmit data with allowable delay conditions.

[0099] Reference Figure 11 An example of the operation of communication system 10 will be described below. Base station 11-1 notifies the coordinated use of the channel, the channel number, and the access parameters for accessing the coordinated channel via beacon 1.

[0100] Base station 11-2 receives beacon 1. Base station 11-2 extracts access parameters from beacon 1, uses the extracted access parameters to generate beacon 2, and uses beacon 2 to notify the access parameters of the channel used for access coordination.

[0101] Terminals 12-1 and 12-2 access the channel using the access parameters notified via beacons 1 and 2, respectively. Therefore, when terminals 12-1 and 12-2 access the same channel, they use the same access parameters. Thus, by setting TXOPLimit to a smaller value, the channel is prevented from being used by a subset of terminals 12 for extended periods, allowing the channel to be released within a shorter timeframe. This increases the likelihood of low-latency traffic access to the channel, improving reliability.

[0102] [Effect]

[0103] As described above, in this embodiment, each base station 11 transmits a beacon containing handover information indicating whether to coordinate channel use. When the handover information indicates coordinated channel use, the beacon also includes channel identification information determining the channel to be coordinated and access parameters for accessing the channel. Other base stations 11 that receive this beacon, if the channel to be coordinated matches the channel they are currently using, generate a beacon containing the access parameters specified by the received beacon and transmit the generated beacon. In this way, access parameters associated with a specific channel are aligned and unified in the environment surrounding the base station 11. This avoids communication quality degradation caused by BSSs different from those of the base station 11. As a result, the reliability of wireless communication is improved.

[0104] For example, when low latency is required, shortening the TXOPLimit increases the flow of transmission rights. As a result, low latency characteristics can be improved.

[0105] When each base station 11 receives a beacon containing handover information configured to indicate coordinated use of frequency channels from other base stations, it can configure the handover information to indicate coordinated use of frequency channels in its own transmitted beacons. This allows for coordinated use over a wider range, resulting in further improvements in low-latency characteristics.

[0106] [Variations, etc.]

[0107] Furthermore, the invention is not limited to the embodiments described above. In one embodiment, base station 11 may also receive coordination requests from network 13, for example, from a server that exchanges data with the application of terminal 12 via network 13.

[0108] The aforementioned processing can also be performed based on a program that is software. For example, part or all of the processing of base station 11 described above can be executed by the processor of base station 11 executing the program. The program can also be provided to base station 11 in the form of a storage medium that can be read by a computer. In this case, for example, base station 11 has a drive that reads data from the storage medium and retrieves the program from the storage medium. Examples of storage media include magnetic disks, optical disks (CD-ROM, CD-R, DVD-ROM, DVD-R, etc.), optical discs (MO, etc.), and semiconductor memory. Alternatively, the program can be stored on a server on network 13, and base station 11 can download the program from the server.

[0109] This invention is not directly limited to the embodiments described above. During implementation, the constituent elements can be modified and embodied by variations without departing from its essence. Furthermore, various inventions can be formed by appropriate combinations of the multiple constituent elements disclosed in the above embodiments. For example, several constituent elements may be deleted from all the constituent elements shown in the embodiments. Moreover, constituent elements of different embodiments may be appropriately combined.

[0110] Explanation of reference numerals in the attached figures

[0111] 10…Communication system; 11…Base station; 12…Terminal; 13…Network; 21…Controller; 22…CPU; 23…RAM; 24…Program memory; 25…Wireless module; 26…Antenna; 27…Router module; 31…Data processing unit; 32…Wireless signal processing unit; 33…Beacon analysis unit; 34…Access parameter setting unit; 35…Beacon generation unit; 36…Communication unit; 51…Controller; 52…CPU; 53…RAM; 54…Program memory; 55…Storage; 56…Wireless module; 57…Antenna; 58…Input / output interface; 59…Battery; 61…Data processing unit; 62…Wireless signal processing unit; 63…Beacon analysis unit.

Claims

1. A base station belonging to a first basic service set (BSS), the base station comprising: The generation unit generates a first beacon, the first beacon comprising: handover information indicating coordinated use of a frequency channel; channel identification information determining the frequency channel; and access parameters for accessing the frequency channel in Enhanced Distributed Channel Access (EDCA); and The transmitting unit transmits the first beacon to the terminal and the other base station in order to use the access parameters contained in the first beacon when wireless communication using the frequency channel is conducted between a terminal belonging to the first BSS and another base station belonging to a second BSS different from the first BSS. The access parameters include TXOPLimit, which is used to unify channel access rules across multiple BSSs.

2. The base station according to claim 1, wherein, It also includes a receiving unit that receives from the terminal a coordination request for the coordinated use of the frequency channel. In response to the coordination request, the generation unit generates the first beacon containing the switching information set in the information indicating coordinated use of the frequency channel.

3. The base station according to claim 1, wherein, It also includes a receiving unit that receives a second beacon from other base stations. The second beacon contains handover information set in information indicating coordinated use of the frequency channel, channel identification information for determining the frequency channel, and access parameters for accessing the frequency channel. When the base station uses the frequency channel for communication, the generation unit responds to the second beacon and generates the first beacon, which also includes the access parameters for accessing the frequency channel.

4. The base station according to claim 3, wherein, The generation unit responds to the second beacon by generating the first beacon, which contains the switching information set in the information indicating coordinated use of the frequency channel.

5. A wireless communication method, wherein the wireless communication method is performed by a base station, the base station belonging to a first basic service set (BSS), the wireless communication method comprising: Generate a beacon, the beacon comprising: handover information indicating coordinated use of a frequency channel; channel identification information determining the frequency channel; and access parameters for accessing the frequency channel in Enhanced Distribution Channel Access (EDCA); and In order to use the access parameters contained in the beacon when a terminal belonging to the first BSS and another base station belonging to a second BSS different from the first BSS are conducting wireless communication using the frequency channel, the beacon is sent to both the terminal and the other base station. The access parameters include TXOPLimit, which is used to unify channel access rules across multiple BSSs.

6. A terminal that transmits data with permissible delay conditions, the terminal belonging to a first basic service set (BSS) and comprising: The receiving unit receives a beacon from a first base station belonging to the first BSS. The beacon includes: handover information indicating coordinated use of a frequency channel; channel identification information determining the frequency channel; and access parameters for accessing the frequency channel in Enhanced Distribution Channel Access (EDCA). In order to use the access parameters contained in the beacon when a terminal belonging to the first BSS and a second base station belonging to a second BSS different from the first BSS are conducting wireless communication using the frequency channel, the beacon is sent to the terminal and the second base station. The access parameters include TXOPLimit, which is used to unify channel access rules across multiple BSSs.

7. The terminal according to claim 6, wherein, It also includes a request unit that, based on the permitted conditions, requests the base station to coordinate the use of the frequency channel.

8. A wireless communication method, which is a wireless communication method performed by a terminal, the terminal transmitting data having allowable delay conditions, the terminal belonging to a first basic service set, i.e., a first BSS, the wireless communication method comprising: The system receives a beacon from a first base station belonging to the first BSS. The beacon includes: handover information indicating whether to coordinate the use of a frequency channel; channel identification information to determine the frequency channel; and access parameters for accessing the frequency channel in Enhanced Distribution Channel Access (EDCA). In order to use the access parameters contained in the beacon when a terminal belonging to the first BSS and a second base station belonging to a second BSS different from the first BSS are conducting wireless communication using the frequency channel, the beacon is sent to the terminal and the second base station. The access parameters include TXOPLimit, which is used to unify channel access rules across multiple BSSs.

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