WO2017038245A1 - Dispositif de commande de communication, procédé de commande de communication, et programme - Google Patents

Dispositif de commande de communication, procédé de commande de communication, et programme Download PDF

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Publication number
WO2017038245A1
WO2017038245A1 PCT/JP2016/069977 JP2016069977W WO2017038245A1 WO 2017038245 A1 WO2017038245 A1 WO 2017038245A1 JP 2016069977 W JP2016069977 W JP 2016069977W WO 2017038245 A1 WO2017038245 A1 WO 2017038245A1
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WIPO (PCT)
Prior art keywords
communication
bar
destinations
master station
data
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PCT/JP2016/069977
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English (en)
Japanese (ja)
Inventor
悠介 田中
英佑 酒井
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ソニー株式会社
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Priority to DE112016003940.9T priority Critical patent/DE112016003940T5/de
Priority to JP2017537622A priority patent/JP6838553B2/ja
Publication of WO2017038245A1 publication Critical patent/WO2017038245A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/06—Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H04L1/1685—Details of the supervisory signal the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L2001/0092—Error control systems characterised by the topology of the transmission link
    • H04L2001/0093—Point-to-multipoint

Definitions

  • the present disclosure relates to a communication control device, a communication control method, and a program.
  • wireless LANs Local Area Networks
  • IEEE Institute of Electrical and Electronics Engineers 802.11
  • wireless communication devices that support wireless LANs are increasing.
  • multicast a technique that simultaneously distributes the same data to a plurality of wireless communication apparatuses has been studied.
  • Patent Literature 1 discloses an example of a technique for a wireless communication device serving as a data transmission source to confirm delivery of data to a wireless communication device serving as a transmission destination.
  • the present disclosure proposes a communication control device, a communication control method, and a program that can ensure reliability in a more preferable aspect and suppress consumption of communication resources according to the state of communication. .
  • a control unit that controls communication with a communication device connected via a wireless communication path, and an acquisition unit that acquires information related to the communication between one or more communication devices.
  • the control unit determines the number of communication devices that transmit a response transmission request for confirming delivery of data to the communication device, based on the acquired information on the communication. Is provided.
  • a communication device connected via a wireless communication path determines a transmission destination of a response transmission request for confirming data delivery based on the acquired communication information
  • a communication control device when a communication device connected via a wireless communication path determines a transmission destination of a response transmission request for confirming data delivery based on the acquired communication information
  • An acquisition unit that acquires the transmission request transmitted from the communication device, and a control that controls the communication device to transmit the response according to the reception status of the data to the acquired transmission request.
  • a communication control device when a communication device connected via a wireless communication path determines a transmission destination of a response transmission request for confirming data delivery based on the acquired communication information
  • An acquisition unit that acquires the transmission request transmitted from the communication device, and a control that controls the communication device to transmit the response according to the reception status of the data to the acquired transmission request.
  • a processor controls the communication between the communication apparatuses connected via the wireless communication path, and acquires the information regarding the said communication between the one or more said communication apparatuses And determining the number of communication devices that transmit a transmission request for a response for confirming delivery of data to the communication device based on the acquired information on the communication. Is provided.
  • a communication device connected via a wireless communication path determines a transmission destination of a response transmission request for confirming data delivery based on the acquired communication information And acquiring the transmission request transmitted from the communication device and causing the communication device to transmit the response according to the data reception status to the acquired transmission request. And a communication control method is provided.
  • control of communication with a communication device connected to a computer via a wireless communication path and acquisition of information regarding the communication with one or more of the communication devices are acquired. And determining the number of communication devices that transmit a response transmission request for confirming delivery of data to the communication device, based on the acquired information related to the communication, Provided.
  • a communication control device According to the state of communication, a communication control device, a communication control method, which can ensure reliability in a more preferable aspect and suppress consumption of communication resources, And a program are provided.
  • FIG. 3 is a block diagram illustrating a schematic functional configuration of a communication device according to a first embodiment of the present disclosure. It is the figure which showed an example of the structure of DL frame for transmitting BAR to a some subunit
  • FIG. 4 is a flowchart illustrating an example of a flow of a series of operations of a communication device that operates as a master station in the communication system according to the embodiment.
  • 4 is a flowchart illustrating an example of a flow of a series of operations of a communication device that operates as a slave in the communication system according to the embodiment.
  • 6 is a flowchart showing an example of a flow of a series of operations of a communication apparatus operating as a master station in a communication system according to a modification of the embodiment.
  • FIG. 4 is a flowchart illustrating an example of a flow of a series of operations of a communication device that operates as a slave in the communication system according to the embodiment.
  • 14 is an explanatory diagram for describing an example of a processing sequence of a communication system according to a second embodiment of the present disclosure.
  • FIG. 14 is an explanatory diagram for describing an example of a processing sequence of a communication system according to a third embodiment of the present disclosure.
  • FIG. 14 is an explanatory diagram for describing an example of a processing sequence of a communication system according to a fourth embodiment of the present disclosure.
  • FIG. 6 is a flowchart illustrating an example of a flow of a series of processes of a communication device that is a master station in the communication system according to the embodiment.
  • It is a block diagram which shows an example of a schematic structure of a smart phone.
  • It is a block diagram which shows an example of a schematic structure of a car navigation apparatus.
  • It is a block diagram which shows an example of a schematic structure of a wireless access point.
  • FIG. 1 is a diagram illustrating a communication system including a communication control device and a communication device according to an embodiment of the present disclosure.
  • the communication control device and the communication device are collectively referred to as a communication device.
  • the communication system includes a plurality of communication devices 10.
  • the communication device 10 has a wireless communication function and performs communication using multiplexing.
  • the communication device 10 operates as a so-called access point (hereinafter also referred to as “AP (Access Point)”) or as a terminal (hereinafter also referred to as “STA (Station)”).
  • AP Access Point
  • STA Service
  • a communication device that operates as an AP is also referred to as a master station
  • a communication device that operates as a terminal is also referred to as a slave.
  • DL downlink
  • UL uplink
  • the communication system includes a plurality of communication devices 10 # 0 to 10 # N as shown in FIG.
  • Communication device 10 # 0 which is a master station
  • communication devices 10 # 1-10 # N which are child devices, are connected via wireless communication and directly transmit / receive frames to / from each other.
  • the communication device 10 # 0 that is a master station and the communication devices 10 # 1 to 10 # N that are slave devices are communication devices compliant with IEEE 802.11, and for example, the master station that is a transmission source is It is possible to confirm delivery of the transmitted data to the slave unit. Specifically, the master station confirms whether or not an Ack or BA (Block Ack) indicating delivery confirmation is returned from the slave that is the data transmission destination, so that the data is the transmission destination. Check if it was delivered correctly to the slave unit. By using such a mechanism, the master station prevents, for example, a reduction in communication quality by retransmitting the target data to a slave unit whose delivery of at least part of the data could not be confirmed. (In other words, communication reliability can be improved).
  • Ack Block Ack
  • FIG. 2 is an explanatory diagram for explaining an example of the flow of processing when the master station multicasts data to a plurality of slave units and performs delivery confirmation of the data.
  • the horizontal axis represents time.
  • data to be multicast may be referred to as “multicast data”.
  • the communication device 10 # 0 which is the master station, sends a transmission confirmation request (hereinafter referred to as at least one of the communication devices 10 # 1 to 10 # N) to the slave device (for example, at least one of the communication devices 10 # 1 to 10 # N) after transmission of the multicast data. , Also called “BAR (Block Ack Request)”.
  • the communication device 10 # 0 receives the delivery confirmation (hereinafter also referred to as “BA (Block Ack)”) from the slave device that is the transmission destination of the delivery confirmation request, so that the multicast data is delivered to the slave device. Make sure you did.
  • the BAR in the description of the present disclosure may be a “Block Ack request” based on the IEEE 802.11 standard, or may be another frame for notifying a delivery confirmation request.
  • the BA in the description of the present disclosure may be “Block Ack” or “Ack” based on the IEEE 802.11 standard, or may be another frame for notifying delivery confirmation.
  • FIG. 2 shows an example of an operation when the communication device 10 # 0 as the master station multicasts data to the communication devices 10 # 1 to 10 # 4 as slave units and confirms the delivery of the data. Is shown.
  • the communication device 10 # 0 transmits multicast data to the communication devices 10 # 1 to 10 # 4, and then transmits a BAR to the communication devices 10 # 2 and 10 # 4. is doing. At this time, it is assumed that communication device 10 # 2 has successfully received multicast data, and communication device 10 # 4 has failed to receive at least part of the multicast data.
  • the communication device 10 # 2 notifies the communication device 10 # 0 of the multicast data delivery by returning the BA as a response from the communication device 10 # 0 to the BAR.
  • the communication device 10 # 0 can confirm that the multicast data has been correctly delivered to the communication device 10 # 2.
  • the multicast data is not correctly received in the communication device 10 # 4. Therefore, the communication device 10 # 4 does not return a BA to the BAR from the communication device 10 # 0 or returns a BA indicating that reception of at least a part of the multicast data has failed.
  • the communication device 10 # 0 can recognize that the communication device 10 # 4 has failed to receive at least part of the multicast data.
  • the communication device 10 # 0 recognizes that the communication device 10 # 4 has failed to receive at least part of the multicast data, and therefore transmits the multicast data to the communication devices 10 # 1 to 10 #. Resent to 4. With such an operation, in the example illustrated in FIG. 2, it is possible to improve the reliability of communication related to transmission of multicast data (in other words, improve communication quality). At this time, a series of processes related to transmission of BAR, response of BA to BAR, and retransmission of multicast data becomes overhead in transmitting multicast data.
  • the number of times that the data is retransmitted increases particularly in a situation in which the delivery of data is confirmed to a slave that is not preferable for the reception status of the data, In some cases, the communication characteristics of the entire system may be deteriorated.
  • the delay time required for the traffic handled by the system is short, a situation may be assumed in which the required delay time is exceeded when the number of times of confirmation of delivery or retransmission is increased.
  • the number of slave units hereinafter, also referred to as “the number of BAR destinations” as the destination of the data delivery confirmation request (BAR) and the system characteristics explain.
  • FIG. 3 is a graph showing an example of the relationship between the number of child devices serving as BAR destinations and the packet loss rate as a characteristic of the entire system.
  • the horizontal axis indicates the number of slave units that are destinations of the BAR
  • the vertical axis indicates the packet loss rate as a characteristic of the entire system.
  • the reliability of communication improves as the number of BAR destinations increases.
  • the packet loss rate tends to decrease and the communication quality tends to improve.
  • the packet loss rate as the entire system increases with the increase in the number of BAR destinations, and the communication quality deteriorates. I know it is in a trend. This is because communication as a whole system is under pressure due to an increase in communication for delivery confirmation and an increase in the number of data retransmissions associated therewith.
  • the number of BAR destinations is set to a more suitable value.
  • the setting of the number of BAR destinations capable of improving the communication quality of the entire system is not always constant, and may change depending on the communication state, for example.
  • the communication quality of the entire system can be improved when the number of BAR destinations is smaller than in a case where the traffic is not congested.
  • the present disclosure by setting the number of slave units (that is, the number of BAR destinations) that are BAR destinations according to the communication state, it is possible to reduce the consumption of communication resources while ensuring reliability in a more preferable aspect.
  • details of the communication device 10 according to an embodiment of the present disclosure will be described.
  • FIG. 4 is a block diagram illustrating a schematic functional configuration of the communication device 10-1 according to the first embodiment of the present disclosure.
  • the communication device 10-1 includes a data processing unit 11, a communication unit 12, and a control unit 18, as shown in FIG. First, basic functions of the communication device 10-1 will be described.
  • the data processing unit 11 performs processing for data transmission / reception. Specifically, the data processing unit 11 generates a frame based on data from the communication upper layer, and provides the generated frame to the signal processing unit 14 described later. For example, the data processing unit 11 generates a frame (or packet) from the data, and performs processing such as adding a header and adding an error detection code to the generated frame. Further, the data processing unit 11 extracts data from the received frame, and provides the extracted data to a communication upper layer. For example, the data processing unit 11 acquires data by performing header analysis, code error detection and correction, reorder processing, and the like for the received frame.
  • the communication unit 12 includes a modulation / demodulation unit 13, a signal processing unit 14, a channel estimation unit 15, a radio interface unit 16, and an amplification unit 17, as shown in FIG.
  • the communication device 10-1 is provided with a fixed power source or a power source such as a battery.
  • the modem unit 13 performs modulation processing on the frame. Specifically, the modem unit 13 generates a symbol stream by performing encoding, interleaving, and modulation on the frame provided from the data processing unit 11 in accordance with the coding and modulation scheme set by the control unit 18. Then, the modem unit 13 provides the generated symbol stream to the signal processing unit 14. Further, the modem unit 13 acquires a symbol stream obtained by the spatial processing from the signal processing unit 14, acquires a frame by performing demodulation, decoding, and the like on the symbol stream, and acquires the acquired frame as the data processing unit 11. Alternatively, it is provided to the control unit 18.
  • the signal processing unit 14 performs processing related to space division multiplex communication. Specifically, the signal processing unit 14 performs signal processing related to spatial separation on the symbol stream generated by the modem unit 13, and provides each of the symbol streams obtained by the processing to the wireless interface unit 16. Further, the signal processing unit 14 performs spatial processing on the symbol stream related to the signal obtained from the wireless interface unit 16, for example, separation processing of the symbol stream, and provides the symbol stream obtained by the processing to the modulation / demodulation unit 13.
  • the channel estimation unit 15 estimates a channel gain. Specifically, the channel estimation unit 15 calculates complex channel gain information from the preamble portion or the training reference signal portion of the signal related to the symbol stream obtained from the radio interface unit 16. The calculated complex channel gain information is provided to the signal processing unit 14 via the control unit 18 and is used for demodulation processing, spatial separation processing, and the like.
  • the wireless interface unit 16 generates a signal to be transmitted / received via the antenna. Specifically, the radio interface unit 16 converts a signal related to the symbol stream provided from the signal processing unit 14 into an analog signal, performs filtering, and frequency up-conversion. Then, the wireless interface unit 16 provides the obtained signal to the amplification unit 17. Further, the radio interface unit 16 performs a process reverse to the signal transmission, for example, frequency down-conversion and digital signal conversion, on the signal obtained from the amplifying unit 17, and converts the signal obtained by the process into the channel estimation unit 15 and the signal Provided to the processing unit 14. Note that a plurality of wireless interface units 16 may not be provided.
  • the amplification unit 17 performs signal amplification. Specifically, the amplifying unit 17 amplifies the analog signal provided from the wireless interface unit 16 to a predetermined power, and transmits a signal obtained by the amplification via the antenna. The amplifying unit 17 amplifies a signal related to the radio wave received via the antenna to a predetermined power, and provides a signal obtained by the amplification to the wireless interface unit 16.
  • the amplification unit 17 can be a power amplifier module or the like. Note that either or both of the amplification function of the transmission radio wave and the amplification function of the reception radio wave of the amplification unit 17 may be included in the wireless interface unit 16.
  • the modulation / demodulation unit 13, the signal processing unit 14, the channel estimation unit 15, the wireless interface unit 16, and the amplification unit 17 are collectively referred to as a communication unit 12.
  • the control unit 18 controls the overall operation of the communication device 10-1. Specifically, the control unit 18 performs processing such as information exchange between functions, communication parameter setting, transmission power control, and frame (or packet) scheduling in the data processing unit 11.
  • the control unit 18 controls the operations of the data processing unit 11 and the communication unit 12 so that the same data to be transmitted is transmitted to a plurality of slave units designated as destinations.
  • the control unit 18 groups a plurality of slave devices designated as destinations by a multicast address (for example, a multicast IP address), and outputs the addresses to the data processing unit 11.
  • the data processing unit 11 adds control information (for example, multicast MAC address) corresponding to the address (for example, multicast IP address) output from the control unit 18 to the header of the frame generated from the transmission target data.
  • the control unit 18 causes the communication unit 12 to transmit the frame with the control information added to the child device.
  • the slave unit can confirm whether or not the frame is a frame transmitted to itself by referring to the control information added in the header of the received frame. It becomes.
  • the multicast operation described above is merely an example, and the communication device 10-1 # 0 serving as the master station transmits the same data to the plurality of communication devices 10 serving as the slave units (that is, multicasting). If possible, the method is not limited to the example shown above.
  • control unit 18 did not correctly deliver at least a part of the data to at least some of the plurality of child devices multicasting the data by a “data delivery confirmation function” described later. If it is recognized, the data processing unit 11 and the communication unit 12 may be controlled so that the data is retransmitted. In this case, for example, the control unit 18 may perform control so that the data is multicast again to a plurality of slave units that have previously multicasted the data.
  • the control unit 18 confirms delivery of the data to the slave unit to which the data has been transmitted. Specifically, the control unit 18 causes the data processing unit 11 to generate a DL frame (eg, a BAR frame) including a BAR for requesting transmission of data delivery confirmation, and causes the communication unit 12 to generate the DL frame. Is sent to the slave unit.
  • a DL frame eg, a BAR frame
  • BAR for requesting transmission of data delivery confirmation
  • the control unit 18 may determine at least some of the plurality of child devices as BAR destinations. Specifically, the control unit 18 becomes a BAR destination within the range of the number of BAR destinations determined in advance by a “BAR destination number determining function” described later from among a plurality of slave devices multicasting data. Determine the handset. Then, the control unit 18 performs data processing so that the BAR is individually transmitted to each of the child devices determined as the destination (that is, the BAR is transmitted to the child device for each child device). The operations of the unit 11 and the communication unit 12 may be controlled.
  • control unit 18 may control the operations of the data processing unit 11 and the communication unit 12 so that a BAR is transmitted with a plurality of slave units as destinations.
  • the data processing unit 11 generates a DL frame so that a BAR is transmitted to a plurality of slave units.
  • FIG. 5 is a diagram illustrating an example of the structure of a DL frame for transmitting a BAR with a plurality of child devices as destinations.
  • the DL frame shown in FIG. 5 includes, for example, “Frame Control”, “Duration / ID”, “RA”, “TA”, “BAR Control”, and “BAR Information”.
  • “BAR Information” is provided as many as the number of slave units as destinations.
  • “Frame Control” includes information about the frame.
  • “Duration / ID” includes information on the length of the frame.
  • “RA” includes an address indicating that the frame is addressed to a plurality of slave units.
  • TA includes an address of a transmission source (for example, a master station).
  • BAR Control includes information related to “BAR Information” that follows.
  • “BAR Information” includes information for identifying the child device and which traffic the BAR is for.
  • “BAR Information” includes “AID” and “TID Value”.
  • “AID” includes information for identifying each child device.
  • “TID Value” includes information for identifying traffic.
  • “BAR Information” may include a plurality of “AID” and “TID Value”.
  • the control unit 18 confirms the delivery of data to the child device based on the BA transmitted from the child device as a response to the BAR. Specifically, when a UL frame including a BA (for example, a BA frame) is received, the data processing unit 11 acquires information indicating the transmission source and the BA from the UL frame, and indicates the acquired transmission source. The information and BA are output to the control unit 18. The control unit 18 confirms whether or not the data has been correctly delivered to the slave unit that is the transmission source of the BA according to the acquired content of the BA.
  • a BA for example, a BA frame
  • the control unit 18 transmits at least a part of the data to the slave unit. May be recognized as a failure.
  • a DL frame including a BAR for example, a BAR frame
  • a UL frame including the BA for example, a BA frame
  • the BA transmitted from each slave unit may be multiplexed.
  • the multiplexing in this description may be, for example, spatial multiplexing, frequency multiplexing, time multiplexing, and OFDMA (Orthogonal frequency-division multiple access).
  • the control part 18 may notify the subunit
  • the control unit 18 may control the slave unit to be notified by including the control information in the BAR.
  • the control unit 18 may perform control such that a frame including the control information is connected to the BAR.
  • the control unit 18 may control the control information so as to be notified to the slave unit as other frames before and after the BAR.
  • the master station assumes that the number of BAR destinations is determined based on the measurement result of the communication characteristics on the slave unit side, and requests the slave unit to measure the communication characteristics and notify the measurement result. Then, the master station receives a notification of the measurement result of the communication characteristics from the slave unit as a response to the request.
  • the request is also referred to as “communication characteristic information request”.
  • Information including the measurement result of communication characteristics notified from the handset side is also referred to as “communication characteristic information”.
  • the communication characteristics (that is, communication characteristic information) to be measured on the handset side include, for example, the number of received packets, the number of received packets excluding retransmission, packet loss rate, throughput, and signal-to-noise ratio (signal-to-noise). ratio) and the like.
  • the master station collects at least one of these pieces of information from each slave unit.
  • the master station may collect all communication devices capable of communication as targets for collecting communication characteristic information.
  • the master station may limit the slaves that are the target of collection of communication characteristic information, based on predetermined conditions, from all the slaves that can communicate.
  • the master station may set a slave unit that has not transmitted BA among the slave units that have transmitted BAR as a collection target of communication characteristic information.
  • the master station may set a slave unit that has transmitted BA among the slave units that have transmitted BAR as a collection target of communication characteristic information.
  • the example described above is merely an example, and it is needless to say that the example is not necessarily limited to the example described above.
  • the control unit 18 instructs the data processing unit 11 to generate a frame including a communication characteristic information request (hereinafter also referred to as “request frame”).
  • the communication characteristic information request may include, for example, information related to the content measured on the handset side (in other words, the type of communication characteristic information to be acquired).
  • control unit 18 may transmit the request frame to a plurality of slave units as multiplexed or multicast, or may transmit the request frame individually to each slave unit. Further, when transmitting request frames to a plurality of slave units, the control unit 18 multiplexes the frames when the slave unit returns communication characteristic information (for example, frequency multiplexing, spatial multiplexing, OFDM, etc.) Resource allocation information for doing so may be included in the request frame.
  • the resource allocation information can include information such as time, center frequency, frequency width, coding matrix index, transmission power, and the like.
  • control unit 18 operates the communication unit 12 so that the request frame generated by the data processing unit 11 is transmitted to a target child device (for example, a child device to be multicast). To control.
  • a target child device for example, a child device to be multicast
  • control unit 18 displays the extraction result of the communication characteristic information from the frame as the data processing unit 11. Get from. Through the control described above, the control unit 18 can collect communication characteristic information from each slave unit.
  • the slave unit may instruct the slave unit to periodically notify the communication characteristic information. More specifically, the master station may notify the slave unit of the notification cycle by, for example, including information indicating the notification cycle of the communication characteristic information in the request frame. In this case, the slave unit may periodically notify the master station of the communication characteristic information based on the information indicating the notification cycle included in the request frame.
  • the master station may notify the communication characteristic information only to the slave device that satisfies the specific condition.
  • the master station may instruct each slave unit to notify the communication characteristic information only when the measurement result of the communication characteristic exceeds a predetermined threshold. More specifically, for example, the master station notifies the slave device of the condition by including, in the request frame, information indicating a condition when the communication characteristic information is notified (for example, a threshold value of the communication characteristic). Also good. In this case, when the communication characteristic measurement result satisfies the condition included in the request frame, the slave unit may notify the master station of the communication characteristic measurement result as communication characteristic information.
  • the control unit 18 determines the number of BAR destinations according to the system characteristics. As a specific example, the control unit 18 estimates a system characteristic (for example, packet loss rate) based on the communication characteristic information collected from each slave unit based on the “communication characteristic information collection function” described above, and performs the estimation. It is determined whether the result satisfies a predetermined condition (for example, whether the system request is satisfied).
  • a system characteristic for example, packet loss rate
  • the master station updates the number of BAR destinations when it is determined that the estimation result of the system characteristics does not satisfy the condition. Note that details of the processing related to the update of the number of BAR destinations will be described later together with the description of the processing of the communication device 10-1.
  • the master station collects the communication characteristic information from each slave unit again based on the “communication characteristic information collection function”, and estimates the system characteristic based on the collected communication characteristic information. Then, it is determined again whether or not the estimation result satisfies a predetermined condition.
  • the master station performs the update of the number of BAR destinations and the process related to the above determination on the estimation result of the system characteristics according to the updated number of BAR destinations between transmission timings of data different from each other. Run with.
  • the master station determines that the estimation result of the system characteristics satisfies a predetermined condition, the master station subsequently transmits data to the slave unit with the number of BAR destinations set at that time (for example, , The number of BAR destinations in the case of multicasting).
  • the relationship between the system characteristics and the more suitable setting of the number of BAR destinations according to the system characteristics can be confirmed by, for example, a prior experiment, and the control unit 18 can read information based on the confirmation result. It may be stored in advance in the area.
  • An example of the relationship between the packet loss rate and the number of BAR destinations as system characteristics is as described above with reference to FIG.
  • the control unit 18 controls the BA notification process to the parent station according to the reception status of the corresponding data. Specifically, when the BAR transmitted from the master station is received, the control unit 18 determines whether or not the data corresponding to the BAR (that is, data received prior to the BAR) has been successfully received. Confirm. Then, the control unit 18 performs the operations of the data processing unit 11 and the communication unit 12 so that the BA corresponding to the reception status of the data is transmitted to the parent station that is the transmission source of the BAR as a response of the BAR. Control.
  • the data processing unit 11 generates a BA based on an instruction from the control unit 18 and outputs the generated BA to the communication unit 12.
  • the communication unit 12 transmits the BA output from the data processing unit 11 toward the master station.
  • the BA may be multiplexed and transmitted.
  • the control unit 18 controls the operations of the data processing unit 11 and the communication unit 12 so that the BA is multiplexed and transmitted based on the control information for multiplexing notified from the master station. do it.
  • the slave unit measures a target communication characteristic based on a communication characteristic information request transmitted from the master station, and notifies the master station of the measurement result as communication characteristic information.
  • the control unit 18 obtains the extraction result of the communication characteristic information request from the request frame from the data processing unit 11. To do.
  • the control unit 18 measures information indicating communication characteristics indicated by the acquired communication characteristic information request (that is, information to be measured).
  • the control unit 18 outputs the measurement result of the communication characteristic to the data processing unit 11, and causes the data processing unit 11 to generate a frame including the measurement result of the communication characteristic.
  • the frame can include, for example, information for identifying a communication characteristic as a measurement target, information on a measurement result of the communication characteristic, and the like.
  • the control part 18 controls operation
  • the control unit 18 may control the operation of the communication unit 12 so that a frame including the measurement result of the communication characteristic is transmitted to the master station based on the resource allocation information included in the communication characteristic information request. Good.
  • FIGS. 6 and 7 are explanatory diagrams for explaining an example of a processing sequence of the communication system according to the present embodiment.
  • FIG. 6 is an example of a processing sequence focused on updating the number of BAR destinations.
  • the communication device 10-1 # 0 that is the master station (AP) first sets an initial value (for example, 1) for the number of BAR destinations.
  • Processing related to transmission of multicast data and processing related to confirmation of delivery of the data are executed.
  • the master station executes at least once a process related to transmission of multicast data and a process related to confirmation of delivery of the data based on the setting of the number of BAR destinations.
  • the master station updates the number of BAR destinations by adding a predetermined number to the currently set number of BAR destinations (for example, incrementing the number of BAR destinations). For example, in the example illustrated in FIG. 6, when the number of BAR destinations currently set is k, the master station updates the number of BAR destinations by adding 1 to the number of BAR destinations k ( That is, after updating, the number of BAR destinations is k + 1). Based on the updated number of BAR destinations, the master station performs at least once a process related to transmission of multicast data and a process related to confirmation of delivery of the data (that is, transmission of BAR and reception of BA). Execute. As described above, the master station increases the number of BAR destinations up to the number n of all the slave units connected to the master station.
  • the setting method of the slave unit is not particularly limited.
  • the master station may add a new child device as a BAR destination to the child device set as the BAR destination before the update.
  • the master station may preferentially set a slave unit that has been set as a BAR destination before updating the number of BAR destinations as a BAR destination after updating the number of BAR destinations.
  • the example described above is merely an example, and is not necessarily limited to the example described above.
  • the master station transmits the data to the slave unit between the first transmission timing and the second transmission timing after the first transmission timing (that is, different transmissions).
  • the number of BAR destinations is changed (updated) by adding the number of BAR destinations.
  • the master station updates the number of BAR destinations between processes related to confirmation of data delivery for each different data transmitted at different triggers to the slave unit.
  • the master station performs communication of the entire system for each number of BAR destinations in a series of sequences related to updating the number of BAR destinations shown in FIG. 6 (for example, a sequence during which the number of BAR destinations is updated to 1 to n).
  • Is estimated ie, system characteristics.
  • FIG. 7 is an explanatory diagram for explaining an example of a method in which the master station estimates system characteristics in the communication system according to the present embodiment.
  • the process indicated as “BAR-BA frame exchange sequence” is, for example, a process in which the master station confirms delivery of the data after multicasting the data to each slave unit, that is, The BAR is transmitted from the master station to the slave unit, and the BA is transmitted from the slave unit to the master station as a response thereto.
  • the master station relates to estimation of system characteristics at least once for each “BAR-BA frame exchange sequence” in which different numbers of BAR destination numbers are set. Execute the process. For example, in the example illustrated in FIG. 7, the master station performs processing related to estimation of system characteristics for each of the case where the number of BAR destinations is “x” and the number of BAR destinations is “y”.
  • the master station sends a communication characteristic information request to the target slave unit, and requests the slave unit to measure the communication characteristics and notify the measurement result.
  • communication characteristic information including a communication characteristic measurement result is received from the slave unit.
  • the master station estimates communication characteristics (that is, system characteristics) as a whole system based on the measurement results of the communication characteristics in the slave units acquired from each slave unit.
  • the master station updates the number of BAR destinations between transmission timings of data different from each other and estimates system characteristics for each number of BAR destinations.
  • the master station determines whether or not the estimated system characteristics satisfy a predetermined condition (for example, whether or not the system request is satisfied).
  • a predetermined condition for example, whether or not the system request is satisfied.
  • the master station performs a series of processes related to the update of the number of BAR destinations, the estimation of the system characteristics for each number of BAR destinations, and the determination of the estimation result of the system characteristics (hereinafter referred to as “search for the number of BAR destinations”).
  • search for the number of BAR destinations The number of BAR destinations whose system characteristics satisfy a predetermined condition is searched for by repeatedly executing “a series of processes”.
  • the master station may end a series of processes related to the search for the number of BAR destinations when it is determined that the estimation result of the system characteristics satisfies a predetermined condition.
  • the number of BAR destinations set when the determination is performed may be used as the number of BAR destinations in the process related to confirmation of data delivery to be executed later.
  • the master station may set the number of BAR destinations with the best system characteristics as the number of BAR destinations in the process related to confirmation of data delivery to be executed later.
  • the master station recognizes that the system characteristics corresponding to the number of BAR destinations after the update are degraded from the system characteristics corresponding to the number of BAR destinations before the update. To do. In this case, the master station cancels a series of processes related to the search for the number of BAR destinations, and uses the number of BAR destinations set before the update as the BAR in the process related to confirmation of data delivery executed later. It may be set as the number of destinations.
  • the master station according to the present embodiment ensures reliability in a more suitable manner according to the state of communication with each slave unit. In addition, consumption of communication resources can be suppressed.
  • FIG. 8 is a flowchart showing an example of a flow of a series of operations of the communication device 10-1 operating as a master station in the communication system according to the present embodiment.
  • Step S101 First, the master station sets an initial value for the number of BAR destinations.
  • Steps S103 and S105 Next, the master station shifts to processing related to transmission of multicast data. Specifically, as long as there is no multicast data to be transmitted (S103, NO), the master station waits for an instruction relating to transmission of multicast data. When there is multicast data to be transmitted (S103, YES), the master station transmits the multicast data to a plurality of slave devices that are the transmission destinations of the multicast data.
  • Steps S107 and S109 After transmitting multicast data to a plurality of slave units, the master station confirms delivery of the data. Specifically, the control unit 18 selects a slave unit that confirms the delivery of the data within the range of the number of BAR destinations set in advance from among a plurality of slave units multicasting the data (that is, the BAR). (Destination) is determined, and the operations of the data processing unit 11 and the communication unit 12 are controlled so that the BAR is transmitted to the slave unit (S107). Then, the control unit 18 confirms the delivery of data to the child device based on the BA reception result transmitted from the child device as a response to the BAR (S109).
  • Step S111 The master station performs the process related to the transmission of the BAR described above (S107) and the process related to the confirmation of data delivery to the slave unit based on the reception result of the BA transmitted from the slave unit as a response to the BAR ( S109) is executed for all the target destinations (ie, slave units) (S111, NO).
  • Step S113 the master station determines the next process depending on whether or not to confirm the system characteristics.
  • the master station waits for an instruction relating to transmission of the next multicast data (S103).
  • Step S115 On the other hand, when confirming the system characteristics (S113, YES), the master station executes processing related to acquisition of the system characteristics. Specifically, the master station sends a communication characteristic information request to the target slave unit to request communication characteristic measurement and notification of the measurement result, and as a response, the master station becomes the target. Collect communication characteristics information from the handset. Then, the master station estimates system characteristics (for example, packet loss rate) based on communication characteristic information collected from each slave unit.
  • system characteristics for example, packet loss rate
  • Step S117 the master station determines whether or not the estimation result of the system characteristics satisfies a predetermined condition (for example, whether or not the system request is satisfied).
  • Step S119 When the master station determines that the estimation result of the system characteristics does not satisfy the condition (S117, NO), the master station updates the number of BAR destinations (S119), and waits for an instruction related to transmission of the next multicast data (S119). S103). In this case, the master station again transmits the communication characteristic information from each slave unit after executing the processes relating to transmission of multicast data (S105), transmission of BAR (S107), and reception of BA (S109). The system characteristics are estimated based on the collected and collected communication characteristic information (S115), and it is determined again whether the estimation result satisfies a predetermined condition (S117).
  • Step S121 If the master station determines that the estimation result of the system characteristics satisfies a predetermined condition (S117, YES), the master station determines the number of BAR destinations set at that time for the slave unit thereafter. This is determined as the number of BAR destinations when data is transmitted (for example, when multicasting).
  • FIG. 9 is a flowchart showing an example of a flow of a series of operations of the communication device 10-1 operating as a slave in the communication system according to the present embodiment.
  • Step S151 The multicast data is transmitted from the master station to the slave set as the multicast target.
  • the target child device first executes processing related to the reception until the reception of the multicast data is completed (S151, NO).
  • Step S155 Next, among the slave devices set as multicast targets, the multicast data is transmitted to the slave device set as the BAR destination, and then the BAR is transmitted from the master station.
  • the slave unit When receiving the BAR (S153, YES), the slave unit transmits a BA corresponding to the reception status of the multicast data to the parent station that is the transmission source of the BAR as a response to the BAR.
  • the master station can recognize whether multicast data has been correctly delivered to the slave unit based on the BA transmitted from the slave unit.
  • Step S153 a BAR is not transmitted from the master station to a slave device that is not the destination of the BAR, and the slave device does not receive the BAR (NO in S153). Therefore, in this case, it goes without saying that the slave unit does not execute the process related to the transmission of BA (S155).
  • Steps S157 and S159 the slave unit that is the collection target of the communication characteristic information is instructed by the master station to measure the communication characteristic and notify the measurement result based on the communication characteristic information request.
  • the slave unit measures the communication characteristic indicated by the communication characteristic information request and notifies the master station of the measurement result as communication characteristic information.
  • S157, NO a communication characteristic information request
  • the slave unit does not execute the process (S159) relating to the measurement of the communication characteristics and the notification of the measurement result.
  • the communication device 10-1 # 0 as the master station collects communication characteristic information from a plurality of target slave units, and system characteristics (for example, based on the collected communication characteristic information, for example, The number of BAR destinations was determined based on the estimation result of the system characteristics.
  • the data for example, multicast data
  • the BA acquired from the slave unit as a response to the BAR is included in the BA.
  • the BA transmitted from the slave unit to the master station as a response to the BAR is based on the sequence number of the data (for example, multicast data) that is included in the BAR and that is the object of delivery confirmation.
  • a bitmap indicating whether each was received correctly is included.
  • the master station recognizes the reception characteristics of the slave unit that is the transmission source of the BA based on the bitmap included in the BA, and the reception characteristics for each slave unit. Based on the recognition result, the overall system characteristics (that is, system characteristics) are estimated.
  • the communication device 10-1 according to the modification of the present embodiment will be described by focusing attention on processing related to system characteristic estimation, which is different from the communication device 10 according to the above-described embodiment. Note that detailed description of substantially the same parts as those of the communication device 10-1 according to the above-described embodiment is omitted.
  • FIG. 10 is a flowchart showing an example of a flow of a series of operations of the communication device 10-1 operating as a master station in the communication system according to the modification of the present embodiment.
  • Steps S201 to S211 In FIG. 10, the processes shown as steps S201 to S211 are substantially the same as the processes shown as steps S101 to S111 in FIG. That is, after setting an initial value for the number of BAR destinations (S201), the master station executes processing related to transmission of multicast data (S203, S205), and then performs processing related to confirmation of delivery of the multicast data, The process is executed for all target destinations (ie, slave units) (S207 to S211).
  • Step S215 When the processing related to the confirmation of multicast data delivery is executed for all the target slave units (S211, YES), the master station is based on the bitmap included in the BA received from each target slave unit. Recognize the reception characteristics of the slave unit. Then, the master station estimates system characteristics based on the reception characteristics recognized for each slave unit.
  • Steps S217 to S221) The subsequent processing shown as steps S217 to S221 is substantially the same as the processing shown as steps S117 to S121 in FIG. That is, when the master station determines that the system characteristic estimation result does not satisfy the condition (S217, NO), the master station updates the number of BAR destinations (S219), and performs processing related to transmission of the next multicast data. This is executed (S203, S205), and then processing related to confirmation of delivery of the multicast data is executed (S207 to S211), and then the system characteristics are estimated again (S215).
  • the master station determines that the estimation result of the system characteristics satisfies a predetermined condition (S217, YES). If the master station determines that the estimation result of the system characteristics satisfies a predetermined condition (S217, YES), the master station determines the number of BAR destinations set at that time for the slave unit thereafter. This is determined as the number of BAR destinations when data is transmitted (for example, when multicasting).
  • FIG. 11 is a flowchart showing an example of a flow of a series of operations of the communication device 10-1 operating as a slave in the communication system according to the present embodiment.
  • steps S251 to S255 in FIG. 11 is substantially the same as the processing shown as steps S151 to S155 in FIG.
  • the slave unit executes processing related to reception of multicast data transmitted from the master station (S251).
  • a process related to confirmation of multicast data delivery that is, a process related to reception of the BAR transmitted from the master station, and a response to the BAR Processing related to transmission of BA is executed (S253, S255).
  • a communication sequence related to transmission / reception of a communication characteristic information request and communication characteristic information as a response to the request. Can be omitted. Therefore, according to the communication system according to the modification, an environment in which a difference in communication characteristics is small between a plurality of child devices (for example, a plurality of child devices existing in a cell) to be managed by the master station, or In an environment in which the communication characteristics are easily predicted (for example, an environment in which the slave unit is controlled in the system design stage), the system characteristics can be estimated more efficiently.
  • the master station updates the number of BAR destinations by adding the number of BAR destinations between different transmission timings of data to the slave unit, and the system for each number of BAR destinations.
  • the characteristics are estimated, and it is determined whether or not the estimation result satisfies a predetermined condition.
  • the master station repeatedly executes a series of processes related to the update of the number of BAR destinations, the estimation of the system characteristics for each number of BAR destinations, and the determination of the estimation result of the system characteristics, so that the system characteristics satisfy a predetermined condition.
  • the communication system according to the present embodiment ensures reliability in a more preferable manner and suppresses the consumption of communication resources according to the state of communication between the master station and each slave unit. It becomes possible to do.
  • the master station can efficiently search for a more suitable number of BAR destinations in an environment where the influence of overhead is greater.
  • the master station can further improve the accuracy related to the estimation of the system measurement by controlling so that the number of slave units to be collected of the communication characteristic information is increased.
  • the communication device 10-2 according to the present embodiment is different from the communication device 10-1 according to the first embodiment described above in the flow of processing related to the search for the number of BAR destinations. Specifically, the communication device 10-2 according to the present embodiment subtracts a predetermined number from the currently set number of BAR destinations between different transmission timings of data to the slave unit (for example, BAR destinations). The number of BAR destinations is updated by decrementing the number). Therefore, in this description, attention is paid to the flow of processing relating to the search for the number of BAR destinations, which is different from the communication device 10-1 according to the first embodiment as to the characteristics of the communication device 10-2 according to the present embodiment. I will explain. Note that detailed description of substantially the same parts as those of the communication device 10-1 according to the first embodiment described above is omitted.
  • FIG. 12 is an explanatory diagram for explaining an example of a processing sequence of the communication system according to the present embodiment, and is an example of a processing sequence focused on updating the number of BAR destinations.
  • the communication device 10-2 # 0 which is the master station (AP) first connects the initial value (for example, connected to the master station) with respect to the number of BAR destinations.
  • the number of slave units n) is set, and processing related to transmission of multicast data and processing related to confirmation of delivery of the data (that is, transmission of BAR and reception of BA) are executed.
  • the master station executes at least once a process related to transmission of multicast data and a process related to confirmation of delivery of the data based on the setting of the number of BAR destinations.
  • the master station updates the number of BAR destinations by subtracting a predetermined number from the currently set number of BAR destinations (for example, decrementing the number of BAR destinations). For example, in the example shown in FIG. 12, when the number of BAR destinations currently set is k, the master station updates the number of BAR destinations by subtracting 1 from the number of BAR destinations k ( That is, after updating, the number of BAR destinations is k ⁇ 1). Based on the updated number of BAR destinations, the master station performs at least once a process related to transmission of multicast data and a process related to confirmation of delivery of the data (that is, transmission of BAR and reception of BA). Execute. As described above, the master station reduces the number of BAR destinations to 1 at a minimum.
  • the master station estimates the system characteristics for each number of BAR destinations in a series of sequences related to updating the number of BAR destinations. Specifically, as described above with reference to FIG. 7 to FIG. 9, the master station transmits a communication characteristic information request to the target slave unit, and as a response to the communication characteristic information request, the slave unit The communication characteristic information including the measurement result of the communication characteristic may be collected from. In this case, the master station may estimate the system characteristics (for example, packet loss rate) based on the measurement result of the communication characteristics in the slave unit acquired from each slave unit. As another example, as described above with reference to FIG. 10 and FIG.
  • the master station transmits the source of the BA based on the bitmap included in the BA transmitted from the slave unit as a response to the BAR. You may recognize the receiving characteristic of the child machine. In this case, the master station may estimate the system characteristics based on the recognition result of the reception characteristics for each slave unit.
  • the master station updates the number of BAR destinations between transmission timings of data different from each other and estimates system characteristics for each number of BAR destinations.
  • the master station determines whether or not the estimated system characteristics satisfy a predetermined condition (for example, whether or not the system request is satisfied).
  • the master station updates the number of BAR destinations, estimates the system characteristics for each number of BAR destinations, and the series of processes related to the determination on the estimation result of the system characteristics (that is, the series related to the search for the number of BAR destinations).
  • the number of BAR destinations whose system characteristics satisfy a predetermined condition is searched for by repeatedly executing the above process.
  • the master station may end a series of processes related to the search for the number of BAR destinations when it is determined that the estimation result of the system characteristics satisfies a predetermined condition.
  • the number of BAR destinations set when the determination is performed may be used as the number of BAR destinations in the process related to confirmation of data delivery to be executed later.
  • the master station determines the number of BAR destinations with the best system characteristics.
  • the master station may stop a series of processes related to the search for the number of BAR destinations.
  • the number of BAR destinations set before the update may be used as the number of BAR destinations in the process related to confirmation of data delivery executed later.
  • the setting method of the slave unit is not particularly limited.
  • the master station when the number of BAR destinations is updated, the master station reduces the number of BAR destinations by removing one of the slave units set as the BAR destination before the update from the BAR destination. May be.
  • the master station may reduce the number of BAR destinations by preferentially removing slave units with better communication characteristics from BAR destinations according to the communication characteristics of each slave unit. Such control makes it easier to estimate the communication characteristics of the entire system (that is, system characteristics) from the communication characteristics of some slave units.
  • the master station updates the substations by subtracting the number of BAR destinations between different transmission timings of data to the slave unit, and the system for each BAR destination number.
  • the characteristics are estimated, and it is determined whether or not the estimation result satisfies a predetermined condition.
  • the master station repeatedly executes a series of processes related to the update of the number of BAR destinations, the estimation of the system characteristics for each number of BAR destinations, and the determination of the estimation result of the system characteristics, so that the system characteristics satisfy a predetermined condition.
  • the communication system according to the present embodiment ensures reliability in a more preferable manner and suppresses the consumption of communication resources according to the state of communication between the master station and each slave unit. It becomes possible to do.
  • the number of BAR destinations is The larger the number, the better the system characteristics. Therefore, according to the embodiment according to the present embodiment, the master station can efficiently search for a more suitable number of BAR destinations in an environment where the influence of overhead is smaller.
  • the communication device 10 according to the third embodiment of the present disclosure will be described.
  • the communication device 10 according to the present embodiment may be referred to as “communication device 10-3” when it is particularly distinguished from the communication device 10 according to another embodiment.
  • the communication device 10-3 according to the present embodiment is different from the communication device 10 according to the other embodiments described above in the flow of processing related to the search for the number of BAR destinations.
  • the communication device 10 according to the first embodiment or the second embodiment described above adds the number determined each time to the currently set number of BAR destinations every time the number of BAR destinations is updated or By subtracting, the number of BAR destinations is regularly searched in a predetermined direction (for example, an addition direction or a subtraction direction).
  • the communication device 10-3 according to the present embodiment for example, selects the number of BAR destinations to be set next, such as randomly selecting from the numbers not selected in the past. This is different from the communication device 10 according to the other embodiments described above in that the search direction is irregular.
  • the characteristics of the communication device 10-3 according to the present embodiment will be described by focusing on the processing flow related to the search for the number of BAR destinations, which is different from the communication device 10 according to the other embodiments described above. . Note that detailed description of substantially the same parts as those of the communication device 10 according to the other embodiments described above is omitted.
  • FIG. 13 is an explanatory diagram for describing an example of a processing sequence of the communication system according to the present embodiment, and is an example of a processing sequence focused on updating the number of BAR destinations.
  • the communication device 10-3 # 0, which is the master station (AP), first determines the number of slave units connected from 1 with respect to the number of BAR destinations. The number selected at random within the range of n is set as the initial value. Then, the master station executes processing related to transmission of multicast data and processing related to confirmation of delivery of the data (that is, transmission of BAR and reception of BA). Note that the master station executes at least once a process related to transmission of multicast data and a process related to confirmation of delivery of the data based on the setting of the number of BAR destinations.
  • the master station updates the number of BAR destinations by setting, as a new number of BAR destinations, the number selected at random within the range from 1 to n excluding the number already selected as the number of BAR destinations. .
  • the master station sets the number r3 randomly selected from the range of 1 to n as the initial value of the number of BAR destinations.
  • the master station sets the number r3 randomly selected from 1 to n within the range excluding the already selected r3 as the new number of BAR destinations.
  • the master station Based on the updated number of BAR destinations, the master station performs at least once a process related to transmission of multicast data and a process related to confirmation of delivery of the data (that is, transmission of BAR and reception of BA). Execute.
  • the master station estimates the system characteristics for each number of BAR destinations in a series of sequences related to the update of the number of BAR destinations, as in the above-described embodiments. Specifically, as described above with reference to FIG. 7 to FIG. 9, the master station transmits a communication characteristic information request to the target slave unit, and as a response to the communication characteristic information request, the slave unit The communication characteristic information including the measurement result of the communication characteristic may be collected from. In this case, the master station may estimate the system characteristics (for example, packet loss rate) based on the measurement result of the communication characteristics in the slave unit acquired from each slave unit. As another example, as described above with reference to FIG. 10 and FIG.
  • the master station transmits the source of the BA based on the bitmap included in the BA transmitted from the slave unit as a response to the BAR. You may recognize the receiving characteristic of the child machine. In this case, the master station may estimate the system characteristics based on the recognition result of the reception characteristics for each slave unit.
  • the master station updates the number of BAR destinations between transmission timings of data different from each other and estimates system characteristics for each number of BAR destinations.
  • the master station determines whether or not the estimated system characteristics satisfy a predetermined condition (for example, whether or not the system request is satisfied).
  • the master station updates the number of BAR destinations, estimates the system characteristics for each number of BAR destinations, and the series of processes related to the determination on the estimation result of the system characteristics (that is, the series related to the search for the number of BAR destinations).
  • the number of BAR destinations whose system characteristics satisfy a predetermined condition is searched for by repeatedly executing the above process.
  • the master station may end a series of processes related to the search for the number of BAR destinations when it is determined that the estimation result of the system characteristics satisfies a predetermined condition.
  • the number of BAR destinations set when the determination is performed may be used as the number of BAR destinations in the process related to confirmation of data delivery to be executed later.
  • the master station determines that the BAR having the best system characteristics is obtained.
  • the number of destinations may be set as the number of BAR destinations in processing related to confirmation of data delivery to be executed later.
  • the master station may apply a predetermined algorithm for searching to the search for the number of BAR destinations.
  • the master station may search the number of BAR destinations in a binary search.
  • the master station first estimates the system characteristics when the number of BAR destinations is minimum (that is, 1) and when the number is maximum (that is, the number of connected slave units is n).
  • the method for estimating system characteristics is the same as in the above-described example.
  • the master station sets the median value (ie, n / 2) of the number of BAR destinations (ie, 1 and n) whose system characteristics have already been estimated as the new number of BAR destinations. Is estimated.
  • the master station determines whether or not the system characteristics estimated for the newly set number of BAR destinations satisfy a predetermined condition.
  • the master station is then the median between the number of BAR destinations already selected (ie, 1, n / 2, and n), respectively, and the numbers that have not yet estimated system characteristics (ie, n / 4 and 3n). / 4) is set as the number of BAR destinations, and the system characteristics are estimated for the number of BAR destinations. Then, the master station determines whether or not the system characteristics estimated for the newly set number of BAR destinations satisfy a predetermined condition. Similarly, the master station sets the median value between the number of BAR destinations whose system characteristics have already been estimated as the new number of BAR destinations, and estimates the system characteristics for the number of BAR destinations. It is determined whether the estimation result of the system characteristics satisfies a predetermined condition.
  • the master station repeatedly executes a series of processes related to the update of the number of BAR destinations, the estimation of the system characteristics for each number of BAR destinations, and the determination on the estimation result of the system characteristics. Then, the master station may end the search for the number of BAR destinations when the system characteristic estimated for each number of BAR destinations satisfies a predetermined condition (for example, a system request). As a result of searching for the number of BAR destinations, if the estimation result of the system characteristics does not satisfy a predetermined condition for all patterns (that is, 1 to n), the master station determines the BAR having the best system characteristics.
  • the number of destinations may be set as the number of BAR destinations in processing related to confirmation of data delivery to be executed later.
  • the method for searching for the number of BAR destinations described above is merely an example, and is not necessarily limited to the example described above.
  • the master station may search for the number of BAR destinations based on an algorithm other than the binary search.
  • the master station searches for the number of BAR destinations to be set next when updating the number of BAR destinations between different transmission timings of data to the slave unit. The direction is irregular. Then, the master station estimates system characteristics for each number of BAR destinations, and determines whether the estimation result satisfies a predetermined condition.
  • the master station repeatedly executes a series of processes related to the update of the number of BAR destinations, the estimation of the system characteristics for each number of BAR destinations, and the determination of the estimation result of the system characteristics, so that the system characteristics satisfy a predetermined condition.
  • Search for the number of BAR destinations that satisfy can be used in an environment where the frequency of replacement of the slave units in the cell is high, or in an environment where the surrounding situation can change greatly (in other words, environmental prediction).
  • the master station can more appropriately search for the number of BAR destinations in response to a change in the communication environment even in a situation where the communication environment changes greatly. Become.
  • the communication device 10 according to the fourth embodiment of the present disclosure will be described.
  • the communication device 10 according to the present embodiment may be referred to as a “communication device 10-4” when particularly distinguishing the communication device 10 according to the present embodiment from the communication device 10 according to another embodiment.
  • the communication device 10-4 according to the present embodiment is different from the communication device 10 according to the other embodiments described above in the flow of processing related to the search for the number of BAR destinations.
  • the communication apparatus 10 according to the present embodiment determines the number of BAR destinations to be set later in accordance with a change in system characteristics before and after the update when the number of BAR destinations is updated (in other words, Then, the communication device 10 according to each embodiment described above is different in that the search direction of the number of BAR destinations is determined). Therefore, in this description, the characteristics of the communication device 10-4 according to the present embodiment will be described by focusing on the processing flow related to the search for the number of BAR destinations, which is different from the communication device 10 according to the other embodiments described above. . Note that detailed description of substantially the same parts as those of the communication device 10 according to the other embodiments described above is omitted.
  • FIG. 14 is an explanatory diagram for explaining an example of a processing sequence of the communication system according to the present embodiment, and is an example of a processing sequence focused on updating the number of BAR destinations.
  • the communication device 10-4 # 0 which is the parent station (AP) first determines the number of slave units connected from 1 with respect to the number of BAR destinations. The number selected at random within the range of n is set as the initial value. Then, the master station executes processing related to transmission of multicast data and processing related to confirmation of delivery of the data (that is, transmission of BAR and reception of BA). Note that the master station executes at least once a process related to transmission of multicast data and a process related to confirmation of delivery of the data based on the setting of the number of BAR destinations.
  • the master station adds a predetermined number (for example, 1) to the currently set BAR destination number t, and further changes the BAR destination number to the BAR destination number t.
  • a predetermined number is subtracted.
  • the number of BAR destinations after addition is assumed to be t + 1
  • the number of BAR destinations after subtraction is assumed to be t-1.
  • the master station estimates the system characteristics for each of the BAR destination number t + 1 after addition and the BAR destination number t ⁇ 1 after subtraction. The method for estimating the system characteristics is the same as that in each embodiment described above.
  • the master station determines the direction in which the system characteristics are further improved as the search direction for the number of BAR destinations among the BAR destination number t + 1 after the addition and the BAR destination number t-1 after the subtraction. More specifically, when the master station recognizes that the number of BAR destinations t + 1 after the addition improves the system characteristics more, the master station increases in the direction of the BAR destinations t (that is, the addition direction). Is determined as the search direction of the number of BAR destinations. In addition, when the master station recognizes that the number of BAR destinations t ⁇ 1 after subtraction improves the system characteristics, the master station sets a decreasing direction (that is, a subtraction direction) to the BAR destination number t. The search direction of the number of BAR destinations is determined.
  • the master station updates the number of BAR destinations based on the determined search direction of the number of BAR destinations between transmission timings of data different from each other, and estimates the system characteristics for each number of BAR destinations.
  • the master station determines whether or not the estimated system characteristics satisfy a predetermined condition (for example, whether or not the system request is satisfied).
  • the master station updates the number of BAR destinations, estimates the system characteristics for each number of BAR destinations, and the series of processes related to the determination on the estimation result of the system characteristics (that is, the series related to the search for the number of BAR destinations).
  • the number of BAR destinations whose system characteristics satisfy a predetermined condition is searched for by repeatedly executing the above process.
  • the master station may end a series of processes related to the search for the number of BAR destinations when it is determined that the estimation result of the system characteristics satisfies a predetermined condition.
  • the number of BAR destinations set when the determination is performed may be used as the number of BAR destinations in the process related to confirmation of data delivery to be executed later.
  • the master station determines that the BAR having the best system characteristics is obtained.
  • the number of destinations may be set as the number of BAR destinations in processing related to confirmation of data delivery to be executed later.
  • the system characteristics deteriorate in both cases of the BAR destination number t + 1 after addition and the BAR destination number t-1 after subtraction with respect to the currently set BAR destination number t.
  • Cases can be envisaged.
  • the master station may set the number of BAR destinations t before addition and subtraction of a predetermined number as the number of BAR destinations in processing relating to confirmation of data delivery to be executed later.
  • the master station first adds a predetermined number to the currently set BAR destination number t, and then subtracts the predetermined number. It is not limited. For example, it goes without saying that the master station may first subtract a predetermined number from the currently set BAR destination number t and then add the predetermined number.
  • the master station determines the system characteristics for both the BAR destination number t + 1 after addition and the BAR destination number t-1 after subtraction with respect to the currently set BAR destination number t. And the search direction of the number of BAR destinations is determined based on the estimation result. However, it is not necessarily limited to the same operation. As a specific example, the master station estimates the system characteristics for only one of the BAR destination number t + 1 after addition and the BAR destination number t-1 after subtraction, and based on the estimation result, the BAR destination number is estimated. A number of search directions may be determined.
  • the master station sets the increasing direction as the search direction of the BAR destination number. Just decide.
  • the master station may determine the decreasing direction as the search direction for the BAR destination number. .
  • the characteristics of the communication device 10-4 according to the present embodiment have been described with reference to FIG. 14, particularly focusing on the processing flow related to the search for the number of BAR destinations.
  • the master station updates the number of BAR destinations at different transmission timings of data to the slave unit, the system characteristics before and after the update are updated.
  • the search direction of the number of BAR destinations to be set later is determined according to the change.
  • the master station can determine whether the number of BAR destinations should be increased or decreased according to a change in system characteristics according to the number of BAR destinations. Then, the master station estimates system characteristics for each number of BAR destinations, and determines whether the estimation result satisfies a predetermined condition.
  • the master station repeatedly executes a series of processes related to the update of the number of BAR destinations, the estimation of the system characteristics for each number of BAR destinations, and the determination of the estimation result of the system characteristics, so that the system characteristics satisfy a predetermined condition. Search for the number of BAR destinations that satisfy With such a configuration, the communication system according to the present embodiment can efficiently search for the number of BAR destinations whose communication quality is improved even in an environment where the surrounding situation can change greatly. .
  • FIG. 15 is a flowchart illustrating an example of a flow of a series of processes of the communication device 10 that is a master station in the communication system according to the present embodiment. In particular, focusing on the control of the update timing of the number of BAR destinations. It shows.
  • the communication device 10 serving as the master station corresponds to one of the above-described embodiments when a predetermined condition for updating the number of BAR destinations is satisfied (S301, YES).
  • the number of BAR destinations is updated by executing processing related to the determination of the number of BAR destinations (S320).
  • the master station when the master station detects a change in system characteristics (particularly, deterioration in system characteristics) (or when the change amount exceeds a threshold value), the master station performs processing related to updating the number of BAR destinations. May be executed.
  • the master station receives an instruction related to changing the number of BAR destinations from an upper layer such as an application (for example, when the system operator sets the number of BAR destinations to be changed).
  • processing related to updating the number of BAR destinations may be executed.
  • the master station when the master station receives a request for changing the number of BAR destinations from a slave device to be multicast (for example, the user operating the terminal changes the number of BAR destinations). When the terminal is operated), processing related to updating the number of BAR destinations may be executed.
  • the master station may execute a process related to updating the number of BAR destinations at a predetermined time (for example, a time scheduled in advance).
  • the master station may execute a process related to updating the number of BAR destinations. Further, the master station may execute a process related to updating the number of BAR destinations at predetermined timings. Further, when a predetermined process is executed, the master station may execute a process related to the update of the number of BAR destinations in conjunction with the execution of the process (for example, in conjunction with a predetermined event). .
  • the number of BAR destinations when data is transmitted to the slave unit (for example, multicasting) is updated according to the estimation result of the system characteristics at that time, for example.
  • the communication device 10 serving as the master station performs any one of the processes related to the determination of the number of BAR destinations described above as the first to fourth embodiments as the process related to updating the number of BAR destinations (S320). May be applied.
  • the method is not necessarily limited to the processing related to the determination of the number of BAR destinations described above as the first to fourth embodiments.
  • the master station may observe the channel usage status (in other words, the degree of congestion of the channel) based on carrier sensing and the like, and may determine the number of BAR destinations based on the observation result.
  • the master station may determine the number of BAR destinations according to the communication status (traffic status) of itself or each slave unit.
  • the information indicating the communication status on the master station side includes, for example, the packet size of traffic to be handled, modulation method and coding method (MCS (Modulation Coding Scheme)), AC (Access Category), delay time, packet loss. Examples include rate and throughput.
  • MCS Modulation Coding Scheme
  • AC Access Category
  • delay time packet loss. Examples include rate and throughput.
  • the information indicating the communication status on the handset side includes, for example, the number of received packets of handled traffic, the number of received packets excluding retransmission, delay time, packet loss rate, throughput, signal-to-interference noise ratio (SINR (signal -to-interference noise ratio)), received power, and the presence or absence of other traffic handled.
  • SINR signal-to-interference noise ratio
  • the number of BAR destinations may be determined based on information indicating the state of the child device such as the position, speed, acceleration, power supply state, etc. of each child device.
  • the communication device 10 serving as the master station may be configured to be able to selectively switch a plurality of different processes depending on the situation as a process related to the determination of the number of BAR destinations.
  • FIG. 16 is a flowchart illustrating an example of a flow of a series of processes of the communication device 10 that is a master station in the communication system according to the present embodiment, and another aspect of the process related to updating the number of BAR destinations. Shows about.
  • the master station selectively switches each process related to the determination of the number of BAR destinations described above as the first to fourth embodiments according to the situation.
  • Step S321 the master station selectively switches processing related to determination of the number of BAR destinations depending on whether the communication environment in and around the own cell can be grasped.
  • the situation in which the communication environment in and around the own cell can be grasped is, for example, when there are few replacements of slave units belonging to the own cell, or when there are few cells other than the own cell in the surroundings. (I.e., when the influence of interference between cells is small).
  • the master station may change its own cell, such as when a handset belonging to its own cell changes frequently, or when there are many other cells in the vicinity (that is, when the influence of interference between cells is large).
  • a process capable of more appropriately searching for the number of BAR destinations is applied to the change in the communication environment.
  • Examples of the process related to the search for the number of BAR destinations include the process described above as the third embodiment and the process described above as the fourth embodiment.
  • the master station performs the processing according to the third embodiment and the fourth according to the communication quality required for communication with the slave unit, the type of data transmitted / received to / from the slave unit, and the like.
  • the processing according to the embodiment may be selectively switched.
  • Step S323 when it is possible to grasp the communication environment in and around the own cell (S321, YES), the master station selects a process for determining the number of BAR destinations depending on whether the influence of overhead is large or not. Switch.
  • the situation where the influence of overhead is large is, for example, when the number of slave units in the own cell is large, when the traffic load in the own cell is large, or when the number of other cells present in the surroundings is large (that is, And the case where the influence of inter-cell interference is large), and the case where the traffic load in other cells in the vicinity is large.
  • Step S324 For example, when the influence of overhead is small (S323, NO), as described above, the system characteristics tend to be better as the number of BAR destinations is larger. Therefore, in this case, for example, the master station updates by subtracting the number of BAR destinations described above as the second embodiment, that is, by estimating the system characteristics for each number of BAR destinations. A process of searching for a suitable number of BAR destinations (that is, a process of searching for the number of BAR destinations in the subtraction direction) is applied.
  • Step S325 When the influence of overhead is large (S323, YES), as described above, the system characteristics tend to be better when the number of BAR destinations is smaller. Therefore, in this case, for example, the master station updates by adding the number of BAR destinations described above as the first embodiment, that is, by estimating the system characteristics for each number of BAR destinations. A process of searching for a suitable number of BAR destinations (that is, a process of searching for the number of BAR destinations in the addition direction) is applied (S326, S327). In this case, the master station may selectively switch the processing related to the estimation of the system characteristics depending on whether or not the characteristics of each slave unit are easily predicted.
  • each slave unit is easy to predict is, for example, when operating in an environment where the slave unit is controlled in the system design stage, or the positional relationship between the master station and the slave unit in its own cell is close Case (in other words, a case where a difference in communication characteristics is small among a plurality of slave units).
  • Step S326 when it is difficult to predict the characteristics of each slave unit (S325, NO), the master station performs, for example, the processing described as the first embodiment, that is, the measurement result of communication characteristics from each slave unit. Is applied, and a process for estimating system characteristics based on the collected communication characteristic measurement results is applied.
  • Step S327 As another example, when the characteristics of each slave unit are easy to predict (S325, YES), the master station performs, for example, the processing described as a modification of the first embodiment, that is, as a response to the BAR. A process for estimating the system characteristics based on the bitmap included in the BA transmitted from the slave unit is applied.
  • the communication apparatus 10 has already been based on, for example, the processing related to determination of the number of BAR destinations described above as the first to fourth embodiments.
  • An example of processing when updating the set number of BAR destinations (in other words, an example of an update opportunity of the number of BAR destinations) has been described.
  • the communication device 10 may be configured to execute a process related to updating the number of BAR destinations according to a predetermined condition.
  • the communication device 10 may be configured to selectively switch and execute a plurality of different processes as a process related to determination of the number of BAR destinations according to a situation.
  • the communication device 10 that operates as a slave unit includes a smartphone, a tablet PC (Personal Computer), a notebook PC, a mobile terminal such as a portable game terminal or a digital camera, a television receiver, a printer, a digital scanner, or a network storage. It may be realized as a fixed terminal or an in-vehicle terminal such as a car navigation device.
  • the slave unit is realized as a terminal (also called MTC (Machine Type Communication) terminal) that performs M2M (Machine To Machine) communication, such as a smart meter, a vending machine, a remote monitoring device, or a POS (Point Of Sale) terminal. May be.
  • the slave unit may be a wireless communication module (for example, an integrated circuit module configured by one die) mounted on these terminals.
  • the communication device 10 operating as a master station may be realized as a wireless LAN access point (also referred to as a wireless base station) having a router function or not having a router function.
  • the master station may be realized as a mobile wireless LAN router.
  • the master station may be a wireless communication module (for example, an integrated circuit module configured by one die) mounted on these devices.
  • FIG. 17 is a block diagram illustrating an example of a schematic configuration of a smartphone 900 to which the technology according to the present disclosure can be applied.
  • the smartphone 900 includes a processor 901, a memory 902, a storage 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, a display device 910, a speaker 911, a wireless communication interface 913, an antenna switch 914, an antenna 915, A bus 917, a battery 918, and an auxiliary controller 919 are provided.
  • the processor 901 may be, for example, a CPU (Central Processing Unit) or a SoC (System on Chip), and controls the functions of the application layer and other layers of the smartphone 900.
  • the memory 902 includes a RAM (Random Access Memory) and a ROM (Read Only Memory), and stores programs and data executed by the processor 901.
  • the storage 903 can include a storage medium such as a semiconductor memory or a hard disk.
  • the external connection interface 904 is an interface for connecting an external device such as a memory card or a USB (Universal Serial Bus) device to the smartphone 900.
  • the camera 906 includes, for example, an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and generates a captured image.
  • the sensor 907 may include a sensor group such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor.
  • the microphone 908 converts sound input to the smartphone 900 into an audio signal.
  • the input device 909 includes, for example, a touch sensor that detects a touch on the screen of the display device 910, a keypad, a keyboard, a button, or a switch, and receives an operation or information input from a user.
  • the display device 910 has a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays an output image of the smartphone 900.
  • the speaker 911 converts an audio signal output from the smartphone 900 into audio.
  • the wireless communication interface 913 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, and 11ad, and performs wireless communication.
  • the wireless communication interface 913 can communicate with other devices via a wireless LAN access point in the infrastructure mode.
  • the wireless communication interface 913 can directly communicate with other devices in an ad hoc mode or a direct communication mode such as Wi-Fi Direct (registered trademark).
  • Wi-Fi Direct unlike the ad hoc mode, one of two terminals operates as an access point, but communication is performed directly between the terminals.
  • the wireless communication interface 913 can typically include a baseband processor, an RF (Radio Frequency) circuit, a power amplifier, and the like.
  • the wireless communication interface 913 may be a one-chip module in which a memory that stores a communication control program, a processor that executes the program, and related circuits are integrated.
  • the wireless communication interface 913 may support other types of wireless communication methods such as a short-range wireless communication method, a proximity wireless communication method, or a cellular communication method in addition to the wireless LAN method.
  • the antenna switch 914 switches the connection destination of the antenna 915 among a plurality of circuits (for example, circuits for different wireless communication schemes) included in the wireless communication interface 913.
  • the antenna 915 includes a single antenna element or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission and reception of radio signals by the radio communication interface 913.
  • the smartphone 900 is not limited to the example in FIG. 17, and may include a plurality of antennas (for example, an antenna for a wireless LAN and an antenna for a proximity wireless communication method). In that case, the antenna switch 914 may be omitted from the configuration of the smartphone 900.
  • the bus 917 connects the processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 913, and auxiliary controller 919 to each other.
  • the battery 918 supplies electric power to each block of the smartphone 900 shown in FIG. 17 through a power supply line partially shown by a broken line in the drawing.
  • the auxiliary controller 919 operates the minimum necessary functions of the smartphone 900 in the sleep mode.
  • the data processing unit 11, the communication unit 12, and the control unit 18 described with reference to FIG. 4 may be implemented in the wireless communication interface 913.
  • at least a part of these functions may be implemented in the processor 901 or the auxiliary controller 919.
  • the control unit 18 updates the number of BAR destinations between transmission timings of different data, and searches for a more suitable number of BAR destinations based on the system characteristics estimated for each number of BAR destinations.
  • the control part 18 determines the smart phone 900 used as the destination of BAR within the range of the number of BAR destinations determined based on the said search result, and the communication part 12 transmits BAR only with respect to the said smart phone 900. Accordingly, it is possible to suppress the consumption of communication resources while ensuring the reliability of communication.
  • the smartphone 900 may operate as a wireless access point (software AP) when the processor 901 executes the access point function at the application level. Further, the wireless communication interface 913 may have a wireless access point function.
  • FIG. 18 is a block diagram illustrating an example of a schematic configuration of a car navigation device 920 to which the technology according to the present disclosure can be applied.
  • the car navigation device 920 includes a processor 921, a memory 922, a GPS (Global Positioning System) module 924, a sensor 925, a data interface 926, a content player 927, a storage medium interface 928, an input device 929, a display device 930, a speaker 931, and wireless communication.
  • An interface 933, an antenna switch 934, an antenna 935, and a battery 938 are provided.
  • the processor 921 may be a CPU or SoC, for example, and controls the navigation function and other functions of the car navigation device 920.
  • the memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921.
  • the GPS module 924 measures the position (for example, latitude, longitude, and altitude) of the car navigation device 920 using GPS signals received from GPS satellites.
  • the sensor 925 may include a sensor group such as a gyro sensor, a geomagnetic sensor, and an atmospheric pressure sensor.
  • the data interface 926 is connected to the in-vehicle network 941 through a terminal (not shown), for example, and acquires data generated on the vehicle side such as vehicle speed data.
  • the content player 927 reproduces content stored in a storage medium (for example, CD or DVD) inserted into the storage medium interface 928.
  • the input device 929 includes, for example, a touch sensor, a button, or a switch that detects a touch on the screen of the display device 930, and receives an operation or information input from the user.
  • the display device 930 has a screen such as an LCD or an OLED display, and displays a navigation function or an image of content to be reproduced.
  • the speaker 931 outputs the navigation function or the audio of the content to be played back.
  • the wireless communication interface 933 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, and 11ad, and executes wireless communication.
  • the wireless communication interface 933 can communicate with other devices via a wireless LAN access point in the infrastructure mode.
  • the wireless communication interface 933 can directly communicate with other devices in an ad hoc mode or a direct communication mode such as Wi-Fi Direct.
  • the wireless communication interface 933 may typically include a baseband processor, an RF circuit, a power amplifier, and the like.
  • the wireless communication interface 933 may be a one-chip module in which a memory that stores a communication control program, a processor that executes the program, and related circuits are integrated.
  • the wireless communication interface 933 may support other types of wireless communication systems such as a short-range wireless communication system, a proximity wireless communication system, or a cellular communication system.
  • the antenna switch 934 switches the connection destination of the antenna 935 among a plurality of circuits included in the wireless communication interface 933.
  • the antenna 935 includes a single antenna element or a plurality of antenna elements, and is used for transmission and reception of a radio signal by the radio communication interface 933.
  • the car navigation device 920 may include a plurality of antennas without being limited to the example of FIG. In that case, the antenna switch 934 may be omitted from the configuration of the car navigation device 920.
  • the battery 938 supplies power to each block of the car navigation apparatus 920 shown in FIG. 18 through a power supply line partially shown by a broken line in the figure. Further, the battery 938 stores electric power supplied from the vehicle side.
  • the data processing unit 11, the communication unit 12, and the control unit 18 described with reference to FIG. 4 may be implemented in the wireless communication interface 933. Further, at least a part of these functions may be implemented in the processor 921.
  • the control unit 18 updates the number of BAR destinations between different data transmission timings, and searches for a more suitable number of BAR destinations based on the system characteristics estimated for each number of BAR destinations. Then, the control unit 18 determines the car navigation device 920 that is the destination of the BAR within the range of the number of BAR destinations determined based on the search result, and the communication unit 12 determines the BAR only for the car navigation device 920. By transmitting, it is possible to suppress the consumption of communication resources while ensuring communication reliability.
  • the wireless communication interface 933 may operate as the above-described communication device 10 which is the master station, and may provide a wireless connection to a terminal of a user who gets on the vehicle.
  • the control unit 18 updates the number of BAR destinations between transmission timings of different data, and searches for a more suitable number of BAR destinations based on the system characteristics estimated for each number of BAR destinations. Then, the control unit 18 determines another communication device that is the destination of the BAR within the range of the number of BAR destinations determined based on the search result, and the communication unit 12 determines the BAR only for the other communication device. By transmitting, it is possible to suppress the consumption of communication resources while ensuring communication reliability.
  • the technology according to the present disclosure may be realized as an in-vehicle system (or vehicle) 940 including one or more blocks of the car navigation device 920 described above, an in-vehicle network 941, and a vehicle side module 942.
  • vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine speed, or failure information, and outputs the generated data to the in-vehicle network 941.
  • FIG. 19 is a block diagram illustrating an example of a schematic configuration of a wireless access point 950 to which the technology according to the present disclosure can be applied.
  • the wireless access point 950 includes a controller 951, a memory 952, an input device 954, a display device 955, a network interface 957, a wireless communication interface 963, an antenna switch 964, and an antenna 965.
  • the controller 951 may be a CPU or a DSP (Digital Signal Processor), for example, and various functions (for example, access restriction, routing, encryption, firewall) of the IP (Internet Protocol) layer and higher layers of the wireless access point 950 And log management).
  • the memory 952 includes a RAM and a ROM, and stores programs executed by the controller 951 and various control data (for example, a terminal list, a routing table, an encryption key, security settings, and a log).
  • the input device 954 includes, for example, a button or a switch and receives an operation from the user.
  • the display device 955 includes an LED lamp and the like, and displays the operation status of the wireless access point 950.
  • the network interface 957 is a wired communication interface for connecting the wireless access point 950 to the wired communication network 958.
  • the network interface 957 may have a plurality of connection terminals.
  • the wired communication network 958 may be a LAN such as Ethernet (registered trademark), or may be a WAN (Wide Area Network).
  • the wireless communication interface 963 supports one or more of wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, and 11ad, and provides a wireless connection as an access point to nearby terminals.
  • the wireless communication interface 963 may typically include a baseband processor, an RF circuit, a power amplifier, and the like.
  • the wireless communication interface 963 may be a one-chip module in which a memory that stores a communication control program, a processor that executes the program, and related circuits are integrated.
  • the antenna switch 964 switches the connection destination of the antenna 965 among a plurality of circuits included in the wireless communication interface 963.
  • the antenna 965 includes a single antenna element or a plurality of antenna elements, and is used for transmission and reception of a radio signal by the radio communication interface 963.
  • the data processing unit 11, the communication unit 12, and the control unit 18 described with reference to FIG. 5 may be implemented in the wireless communication interface 963.
  • at least a part of these functions may be implemented in the controller 951.
  • the control unit 18 updates the number of BAR destinations between transmission timings of different data, and searches for a more suitable number of BAR destinations based on the system characteristics estimated for each number of BAR destinations. Then, the control unit 18 determines another communication device that is the destination of the BAR within the range of the number of BAR destinations determined based on the search result, and the communication unit 12 determines the BAR only for the other communication device. By transmitting, it is possible to suppress the consumption of communication resources while ensuring communication reliability.
  • the first embodiment of the present disclosure reliability is ensured in a more preferable manner even in a situation where the state of communication between the master station and each slave unit changes, and It becomes possible to suppress consumption of communication resources.
  • the master station when the master station has a plurality of slave units in the cell, or when another cell exists around the cell managed by the master station and the amount of interference is large, etc. Thus, it becomes possible to efficiently search for a more suitable number of BAR destinations in an environment where the influence of overhead is larger.
  • the master station can further improve the accuracy related to the estimation of the system measurement by controlling so that the number of slave units to be collected of the communication characteristic information is increased.
  • the master station may have a case where the number of slave units in the cell is small, or when no other cell exists around the cell managed by the master station. In an environment where the influence of overhead is small, a more suitable number of BAR destinations can be efficiently searched.
  • the master station is in an environment in which the surrounding situation can change greatly (in other words, when the frequency of replacement of slave units in the cell is high). Then, when it is difficult to predict the environment, it is possible to efficiently search for a more suitable number of BAR destinations. In other words, according to the third embodiment of the present disclosure, the master station can more appropriately search for the number of BAR destinations with respect to changes in the communication environment.
  • the master station can determine whether the number of BAR destinations should be increased or decreased according to a change in system characteristics according to the number of BAR destinations. Is possible. For this reason, the master station can efficiently search for the number of BAR destinations whose communication quality is improved even in an environment where the surrounding situation can change greatly.
  • the master station may be configured to execute processing related to the update of the number of BAR destinations according to a predetermined condition.
  • the master station can selectively update the number of BAR destinations in response to a change in the situation even in a situation where various situations such as a change in the system change.
  • the master station may be configured to selectively switch a plurality of different processes depending on the situation as the process related to the determination of the number of BAR destinations.
  • the master station can search for a more suitable number of BAR destinations based on more suitable processing (for example, more efficient processing) according to a change in the situation.
  • a control unit that controls communication with a communication device connected via a wireless communication path; An acquisition unit for acquiring information related to the communication with one or more communication devices; With The control unit determines the number of the communication devices that transmit a response transmission request for confirming delivery of data to the communication device based on the acquired information on the communication. Communication control device.
  • the control unit controls the data to be transmitted to a plurality of the communication devices, the control unit transmits the transmission request based on the acquired information regarding the communication with the plurality of communication devices.
  • the communication control device according to (1), wherein the number of the communication devices to be determined is determined.
  • the control unit changes the number of the communication devices that transmit the transmission request between a plurality of different transmission timings of the data, and sets the information related to the communication acquired corresponding to the number of the communication devices.
  • the control unit changes the number of the communication devices by adding the number of the communication devices that transmit the transmission request.
  • the communication control device according to (3), wherein the control unit changes the number of the communication devices by subtracting the number of the communication devices that transmit the transmission request.
  • the said control part changes the number of the said communication apparatus so that a mutually different number may be set as the number of the said communication apparatuses which transmit the said transmission request between these transmission timings,
  • Communication control device The communication unit according to (6), wherein the control unit changes the number of communication devices by randomly setting a number that has not been set in the past as the number of communication devices that transmit the transmission request.
  • Control device The control changes the number of communication devices by searching for the number of communication devices to be newly set based on the number of communication devices that transmit the transmission request set in the past. ) Communication control device.
  • the control unit subsequently determines the number of the communication devices that transmit the transmission request based on a change between the information about the communication acquired before and after the change of the number of the communication devices that transmit the transmission request.
  • the communication control device according to (3).
  • the control unit Based on the direction of change between the information related to the communication acquired before and after the change in the number of the communication devices that transmit the transmission request, the control unit subsequently transmits the number of the communication devices that transmit the transmission request.
  • the communication control device according to (9), wherein a direction in which the change is determined is determined.
  • the said control part is a communication control apparatus as described in said (11) which acquires the information regarding the communication characteristic measured with the said communication apparatus from the said communication apparatus as information regarding the said communication.
  • the acquisition unit acquires, as the information related to the communication, information related to the response from the communication device to the transmission request when the delivery of the data has been confirmed in the past, any of (1) to (10)
  • the communication control apparatus according to claim 1.
  • the control unit When the control unit satisfies a predetermined condition for changing the number of the communication devices that transmit the transmission request, based on the acquired information on the communication, the transmission unit transmits the transmission request thereafter.
  • the communication control device according to any one of (1) to (13), wherein the number of communication devices is determined.
  • the control unit switches the processing for determining the number of the communication devices that transmit the transmission request according to a communication environment with the communication device, any one of (1) to (14)
  • (16) Sent from the communication device when the communication device connected via the wireless communication path determines the transmission destination of the response transmission request for confirming the delivery of the data based on the acquired communication information.
  • a communication control device The control unit performs control so that information related to characteristics of communication with the communication device is transmitted to the communication device as information related to the communication based on a request from the communication device.
  • the communication control device according to 1.

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Abstract

Le problème décrit par la présente invention consiste, en fonction de l'état de communication, à assurer la fiabilité dans un mode préférable, et à réduire la consommation de ressources de communication. La solution selon l'invention porte sur un dispositif de commande de communication, qui est équipé : d'une unité de commande qui commande la communication avec des dispositifs de communication connectés par l'intermédiaire de voies de communication sans fil; et d'une unité d'acquisition qui acquiert des informations associées à une communication avec un ou plusieurs dispositifs parmi les dispositifs de communication, l'unité de commande déterminant le nombre de dispositifs de communication auxquels doit être envoyée une demande de transmission d'une réponse de confirmation concernant la distribution de données par rapport aux dispositifs de communication, sur la base des informations acquises associées à la communication.
PCT/JP2016/069977 2015-08-28 2016-07-06 Dispositif de commande de communication, procédé de commande de communication, et programme WO2017038245A1 (fr)

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EISUKE SAKAI: "11aa GCR-BA Performance in OBSS", IEEE 802.11-14/1404R0, 2 November 2014 (2014-11-02), XP068071228, Retrieved from the Internet <URL:https://mentor.ieee.org/802.11/dcn/14/11-14-1404-00-00ax-11aa-gcr-ba-performance-in-obss.pptx> *
EISUKE SAKAI: "11aa GCR-BA Performance in OBSS", IEEE 802.11-15/0046R0, 12 January 2015 (2015-01-12), XP068082560, Retrieved from the Internet <URL:https://mentor.ieee.org/802.11/dcn/15/11-15-0046-00-00ax-11aa-gcr-ba-performance-in-obss.pptx> *

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JP6838553B2 (ja) 2021-03-03
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