JP4930178B2 - Wireless communication apparatus, program, wireless communication method, and wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication device, a program, a wireless communication method, and a wireless communication system.

  Recently, the WiMedia Alliance has developed the specification for the WiMedia Distributed Access Control (WiMedia MAC) standard for autonomous distributed media access control. In such a standard, a technique is disclosed in which all wireless communication devices constituting a network exchange predetermined beacons to form an ad hoc network by autonomous distributed control.

  Specifically, a super frame period is set at a predetermined time interval (65536 μs), and each wireless communication apparatus can operate a network by transmitting a beacon during a beacon period provided at the head of the super frame.

  In addition, a plurality of beacon slots are prepared in the beacon period, and each wireless communication device transmits a beacon in a different beacon slot, while other wireless communication devices do not transmit a beacon in the beacon period. Receive transmitted beacons.

  Therefore, since each wireless communication device does not receive a beacon transmitted from another wireless communication device while it is transmitting a beacon, even if a plurality of wireless communication devices transmit beacons in the same beacon slot. Each of the plurality of wireless communication devices cannot detect that the beacon slots are competing.

  In addition, when a wireless communication device in the WiMedia MAC standard cannot correctly decode a beacon received in a certain beacon slot, the wireless communication device describes in the beacon transmitted by itself that a beacon has been received in the beacon slot, A broadcast address can be described as the device address. That is, if the wireless communication apparatus cannot correctly decode the header check sequence (HCS) included in the beacon received in a certain beacon slot, the wireless communication apparatus describes the broadcast address as the device address of the beacon slot and uses the beacon slot for contention. Can be notified. However, the wireless communication devices around the plurality of wireless communication devices often decode only the beacon having the strongest reception strength, and it is difficult to notify the competition of the beacon slots of the plurality of wireless communication devices. Thus, a state in which a plurality of wireless communication devices use the same beacon slot can occur as each wireless communication device moves.

  In view of such circumstances, in the WiMedia MAC standard, a wireless communication device skips beacon transmission in its own beacon slot only once every few seconds, and whether or not another wireless communication device uses its own beacon slot. It describes how to detect conflicts.

  Patent Document 1 discloses a method of shifting the start of beacon transmission every time at a timing including jitter in advance in order to prevent overlapping timings of beacon transmission by a plurality of wireless communication apparatuses.

Special Table 2000-517132

  However, in the conflict avoidance method described in the WiMediaMAC standard, if the timings of skipping beacons of a plurality of wireless communication devices overlap, it is not possible to detect conflicts between beacon slots. In particular, when a plurality of wireless communication devices operating with the same algorithm have the same start-up time and set a fixed beacon skip period, there is a problem in that competition for beacon slots cannot be detected from each other.

  In addition, since the time width of the beacon slot in the WiMedia MAC standard is narrow, it is difficult to shift the timing of beacon transmission within the same beacon slot as in the method described in Patent Document 1. Also, if the beacon slot itself used by each wireless communication device is changed each time, beacon slot contention occurs more frequently depending on the number of wireless communication devices that make up the network, and the reliability of information exchange in the network is significantly reduced. It is expected that.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved wireless communication apparatus and program capable of easily detecting beacon slot contention. Another object is to provide a wireless communication method and a wireless communication system.

  In order to solve the above-described problem, according to an aspect of the present invention, there is provided a wireless communication apparatus constituting an autonomous distributed wireless communication system, wherein a beacon is transmitted in a specific slot in a superframe at a predetermined superframe period. In a specific slot from the communication unit at the transmission interval, the skip interval generation unit that randomly generates a skip interval that is an integer multiple of 2 or more of the superframe period, and the skip interval generated by the skip interval generation unit A transmission control unit that temporarily stops beacon transmission; a reception control unit that causes a communication unit to receive a beacon transmitted from another wireless communication device in a specific slot in which beacon transmission is temporarily stopped by the transmission control unit; A wireless communication device is provided.

  In such a configuration, the skip interval generation unit randomly generates a skip interval that is an integer multiple of 2 or more of the superframe period, and the communication unit is generated by the skip interval generation unit based on the control of the transmission control unit. Reception of beacons transmitted from other wireless communication devices in a specific slot at a skip interval generated by a skip interval generation unit based on control of the reception control unit by temporarily stopping transmission of a beacon at a skip interval To do. Here, since the skip interval is irregularly generated by the skip interval generation unit, there are few cases where the skip interval coincides with the surrounding wireless communication apparatus. Therefore, even when a plurality of wireless communication devices use the same slot for beacon transmission, each wireless communication device skips beacon transmission at different timings and transmits beacons transmitted from other wireless communication devices. It is possible to detect that the slots used for reception and beacon transmission are competing.

  The wireless communication device further includes a slot setting unit that changes and sets a slot for transmitting a beacon to the communication unit when the communication unit receives a beacon from another wireless communication device in a specific slot in which beacon transmission is temporarily stopped. You may prepare. Here, receiving a beacon from another wireless communication device in a specific slot in which the communication unit temporarily stopped beacon transmission is equivalent to competing wireless communication devices that use the specific slot for beacon transmission. It is. Therefore, when a communication unit receives a beacon from another wireless communication device in a specific slot in which beacon transmission is temporarily stopped, the slot setting unit changes and sets the slot used for beacon transmission, which is used for beacon transmission. Slot contention can be avoided and the reliability of information exchange in the wireless communication system can be improved.

  The skip interval generation unit may generate a skip interval between the first interval and the second interval according to the reservation status of wireless communication of the wireless communication device in the wireless communication system. Here, the beacon includes information for reserving a time zone that the wireless communication device uses for wireless communication. Accordingly, if the beacon is frequently stopped when the wireless communication apparatus reserves many time slots for wireless communication, it may adversely affect communication. Therefore, as described above, the skip interval generation unit generates the skip interval between the first interval and the second interval according to the reservation status of the wireless communication of the wireless communication device, thereby enabling wireless communication in the wireless communication system. It is possible to detect the competition of slots used for beacon transmission while ensuring the stability of the beacon.

  The communication unit receives a beacon including transmission device information indicating a wireless communication device that is transmitting a beacon in a specific slot from another wireless communication device, and the wireless communication device includes other transmission device information included in the beacon. When a wireless communication device is shown, a slot setting unit for changing and setting a slot for transmitting a beacon to the communication unit may be further provided. The communication unit has received a beacon from surrounding wireless communication devices including transmission device information indicating that the wireless communication device transmitting the beacon in the specific slot used by the wireless communication device is another wireless communication device. This is equivalent to the use of the specific slot competing with other wireless communication devices. Therefore, when a beacon including transmission device information indicating that a wireless communication device that is transmitting a beacon in a specific slot is another wireless communication device is received from surrounding wireless communication devices, it is used for beacon transmission. By changing and setting the slot to be used by the slot setting unit, it is possible to avoid contention for slots used for beacon transmission and improve the reliability of information exchange in the wireless communication system.

  The communication unit receives a beacon including transmission device information indicating a wireless communication device transmitting a beacon in a specific slot from surrounding wireless communication devices, and the skip interval generation unit broadcasts the transmission device information included in the beacon. When an address is indicated, a skip interval may be generated such that transmission of a beacon from the communication unit is temporarily stopped in the next superframe period. Here, the fact that the communication unit has received the beacon including the transmission device information indicating the broadcast address from the surrounding wireless communication device means that, for example, the use of the specific slot is competing with other wireless communication devices, or the surroundings This is equivalent to the failure of decoding of the beacon transmitted by itself in the wireless communication apparatus. Therefore, when the communication unit receives a beacon including transmission device information indicating a broadcast address from a surrounding wireless communication device, the skip interval generation unit temporarily stops transmission of the beacon from the communication unit in the next superframe period. It is possible to generate a simple skip interval and cause the communication unit to receive a beacon in a specific slot of the next superframe period to detect whether or not the use of the specific slot is competing.

  In order to solve the above-described problem, according to another aspect of the present invention, a computer is a wireless communication device that constitutes an autonomous distributed wireless communication system, in a superframe at a predetermined superframe period. A communication unit that transmits a beacon in a specific slot, a skip interval generation unit that randomly generates a skip interval that is an integer multiple of 2 or more of the superframe period, and a communication unit that uses the skip interval generated by the skip interval generation unit A transmission control unit for temporarily stopping beacon transmission in a specific slot from, and receiving a beacon transmitted from another wireless communication device to a communication unit in a specific slot for which transmission of the beacon is temporarily stopped by the transmission control unit There is provided a program for causing a reception control unit to be performed to function as a wireless communication device.

  Such a program can cause a computer hardware resource including, for example, a CPU, a ROM, or a RAM to execute functions such as the communication unit, the skip interval generation unit, and the transmission control unit. That is, a computer using the program can function as the above-described wireless communication device.

  In order to solve the above problem, according to another aspect of the present invention, there is provided a wireless communication method executed in a wireless communication device constituting an autonomous distributed wireless communication system, wherein the wireless communication method is performed at a predetermined superframe period. , Transmitting a beacon in a specific slot in a superframe, randomly generating a skip interval that is an integer multiple of 2 or more of the superframe period, and temporarily stopping beacon transmission in a specific slot at the skip interval And a step of receiving a beacon transmitted from another wireless communication device in a specific slot in which the transmission of the beacon is suspended, is provided.

  In order to solve the above-described problem, according to another aspect of the present invention, a wireless communication system in which a plurality of wireless communication devices perform autonomous and distributed communication, and each wireless communication device has a predetermined superframe. Generated by a communication unit that transmits a beacon in a specific slot in a superframe, a skip interval generation unit that randomly generates a skip interval that is an integer multiple of 2 or more of the superframe cycle, and a skip interval generation unit A transmission control unit for temporarily stopping beacon transmission in a specific slot from the communication unit at a skip interval, and transmission from another wireless communication device to the communication unit in a specific slot in which beacon transmission is temporarily stopped by the transmission control unit The reception control unit that receives the received beacon, and the communication unit performs other wireless communication in a specific slot in which beacon transmission is temporarily stopped. When receiving the laid et beacon, the radio communication system, characterized in that it comprises a slot setting unit for setting change slots to transmit a beacon to the communication unit, is provided.

  Here, receiving a beacon from another wireless communication device in a specific slot in which the communication unit temporarily stopped beacon transmission is equivalent to competing wireless communication devices that use the specific slot for beacon transmission. It is. Therefore, when a communication unit receives a beacon from another wireless communication device in a specific slot in which beacon transmission is temporarily stopped, the slot setting unit changes and sets the slot used for beacon transmission, which is used for beacon transmission. Slot contention can be avoided and the reliability of information exchange in the wireless communication system can be improved.

  As described above, according to the wireless communication device, the program, the wireless communication method, and the wireless communication system according to the present invention, it is possible to easily detect beacon slot contention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

Further, “the best mode for carrying out the invention” will be described in the following order.
[1] Outline of the wireless communication system 1 according to the present embodiment [2] Configuration of the wireless communication apparatus 10 according to the present embodiment [3] Wireless communication method according to the present embodiment [4] Summary

[1] Overview of Radio Communication System 1 According to the First Embodiment First, the radio communication system 1 according to the first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is an explanatory diagram showing a configuration example of an autonomous distributed wireless communication system 1. As illustrated in FIG. 1, the wireless communication system 1 includes wireless communication devices 10A to 10G, and regions indicated by dotted lines indicate radio wave reachable ranges 12A to 12G in which each wireless communication device 10 can perform communication. .

  In the wireless communication system 1, the wireless communication device 10A can communicate with the wireless communication device 10B included in the radio wave reachable range 12A. The wireless communication device 10B can communicate between the wireless communication device 10A and the wireless communication device 10C included in the radio wave reachable range 12B. Similarly, the wireless communication device 10C can communicate with the wireless communication device 10B, the wireless communication device 10D, the wireless communication device 10F, and the wireless communication device 10G. The wireless communication device 10D can communicate with the wireless communication device 10C, the wireless communication device 10E, and the wireless communication device 10F. The wireless communication device 10E can communicate with the wireless communication device 10D. The wireless communication device 10F can communicate with the wireless communication device 10C, the wireless communication device 10D, and the wireless communication device 10G. Further, the wireless communication device 10G can communicate between the wireless communication device C and the wireless communication device F. As described above, the wireless communication devices 10 </ b> A to 10 </ b> G communicate with the communication devices included in the respective radio wave reachable ranges 12 </ b> A to 12 </ b> G to form one wireless network as the wireless communication system 1.

  In the following description, the radio communication devices 10A to 10G are simply indicated as the radio wave reachable range 12 when it is not necessary to distinguish between the radio communication devices 10A to 10G, and the radio wave reachable ranges 12A to 12G are simply indicated as the radio wave reachable range 12.

  Further, in FIG. 1, the wireless communication device 10A and the wireless communication device 10F that use the beacon slot 2 are indicated by colored circles, and the wireless communication device 10B that uses the beacon slot 3 is indicated by a vertical line. The wireless communication device 10C using the beacon slot 4 is indicated by a circle with a horizontal line, the wireless communication device 10D using the beacon slot 5 is indicated by a circle with a net pattern, and the beacon slot 6 is used. The wireless communication device 10E and the wireless communication device 10G are indicated by circles with diagonal lines.

  The wireless communication device 10 includes a PC (Personal Computer), a home video processing device (DVD recorder, VCR, etc.), a mobile phone, a PHS (Personal Handyphone System), a portable music playback device, a portable video processing device, It may be an information processing apparatus such as a PDA (Personal Digital Assistant), a home game machine, a portable game machine, or a home appliance.

  The configuration example of the autonomous distributed wireless communication system 1 has been described above. Next, a superframe for time division control in the wireless communication system 1 will be described with reference to FIG.

  FIG. 2 is an explanatory diagram showing a configuration example of a superframe. The superframe period is defined by a predetermined time (for example, about 65.5 ms), and is subdivided into 256 media access slots (MAS). The radio communication devices 10A to 10G constituting one radio communication system 1 share the superframe period as a frame of a predetermined period, and transfer of messages is performed in units of the subdivided MAS.

  Furthermore, at the head of the super frame, there is a beacon period (BP) as a management area for transmitting and receiving management information by a beacon (beacon signal), and a beacon slot (BS) is arranged at a predetermined interval. Yes. In addition, a unique beacon slot is set for each wireless communication device 10, and parameters for network management and access control are exchanged with surrounding wireless communication devices 10. FIG. 2 shows an example in which nine beacon slots BS0 to BS8 are set as the beacon period. The period that is not set as the beacon period is normally used as a data transmission area.

  FIG. 3 is a conceptual diagram showing its own beacon slot position set by the wireless communication devices 10A to 10G. Here, a state is shown in which each wireless communication device 10 configuring one wireless communication system 1 selects a beacon slot to be used by notifying a beacon slot that is not being used.

  In this example, the wireless communication device 10 </ b> A transmits its own beacon in the beacon slot 2, and the wireless communication device 10 </ b> B transmits its own beacon in the beacon slot 3. Similarly, the wireless communication device 10 </ b> C transmits its own beacon in the beacon slot 4, and the wireless communication device 10 </ b> D transmits its own beacon in the beacon slot 5. The wireless communication device 10E transmits its own beacon in the beacon slot 6.

  Further, the wireless communication device 10F transmits its own beacon in the beacon slot 2, and the wireless communication device 10G transmits its own beacon in the beacon slot 6. Note that a beacon slot 0, a beacon slot 1, a beacon slot 7, and a beacon slot 8 are secured as necessary for the wireless communication device 10H newly entering the wireless communication system 1. Usually, a predetermined number of empty beacon slots are provided behind the own beacon slot. These empty beacon slots are prepared for new entry of the wireless communication device 10. In addition, the beacon period of each wireless communication device 10 can be appropriately extended according to the beacon of the wireless communication device 10 existing in the vicinity.

  As described above, in the example illustrated in FIG. 3, the beacon slot 2 is used by the wireless communication device 10A and the wireless communication device 10F, and the beacon slot 6 is used by the wireless communication device 10E and the wireless communication device 10G. It is used. Here, when a certain wireless communication device 10 receives a plurality of beacons in the same beacon slot, there may be a problem that both beacons cannot be decoded or information on one of the beacons is discarded. In the example shown in FIG. 3, the wireless communication device 10A and the wireless communication device 10F that use the same beacon slot, and the wireless communication device 10E and the wireless communication device 10G are arranged apart from each other. Problems are not expected to occur.

  However, when each of the wireless communication devices 10 has portability, there is a concern that the use of the beacon slot competes among the plurality of wireless communication devices 10 due to the movement of the wireless communication device 10. This will be specifically described with reference to FIG.

  FIG. 4 is an explanatory diagram showing another example of the wireless communication system 1 according to the present embodiment. FIG. 4 shows a case where the wireless communication device 10G is moved and included in the radio wave reachable range 12E of the wireless communication device 10E that uses the same beacon slot 6.

  In the example illustrated in FIG. 4, the radio communication device 10D included in both the radio wave reachable range 12E of the radio communication device 10E and the radio wave reachable range 12G of the radio communication device 10G has two beacons transmitted in the beacon slot 6. Of these, only one beacon with strong reception strength is often decoded.

  That is, the wireless communication device 10D has previously registered the beacon slot 6 as the beacon slot of the wireless communication device 10E, but in some cases, receives the beacon transmitted from the wireless communication device 10G in the beacon slot 6. It is assumed that Also, the wireless communication device 10E cannot receive the beacon transmitted from the wireless communication device 10G in the same beacon slot 6 in the beacon slot 6 in which the wireless communication device 10E transmits a beacon. Conflict cannot be detected.

  Thus, when a plurality of wireless communication devices 10 transmit (compete) beacons using the same beacon slot, the surrounding wireless communication devices 10 cannot accurately receive or decode each beacon, and the wireless communication system 1 May reduce the reliability of information exchange. In view of such circumstances, in the WiMedia MAC standard, as shown in FIG. 5, the wireless communication device 10 skips beacon transmission in its own beacon slot only once every few seconds, and the own beacon slot is transferred to another wireless communication device. 10 describes a conflict detection method for grasping whether or not 10 is using.

  FIG. 5 is an explanatory diagram showing an example of beacon skip. As illustrated in FIG. 5, each wireless communication device 10 skips beacon transmission in an arbitrary superframe, for example, at a predetermined superframe cycle.

  In the example shown in FIG. 5, the wireless communication device 10D skips (suspends) beacon transmission in superframe # 1, the wireless communication device 10B skips beacon transmission in superframe # 2, and wirelessly transmits in superframe # 4. Communication device 10E skips beacon transmission, wireless communication device 10F skips beacon transmission in superframe # 5, wireless communication device 10C skips beacon transmission in superframe # 6, and wireless communication device in superframe # 7 10A skips beacon transmission.

  As described above, when each wireless communication device 10 skips beacon transmission in an arbitrary super frame, for example, the wireless communication device 10E uses the same beacon slot for the super frame # 4 in which beacon transmission is skipped. The beacon transmitted from can be received and contention of the beacon slot to be used can be detected.

  FIG. 6 is an explanatory diagram showing a beacon frame configuration example of a beacon transmitted in a beacon slot. As shown in FIG. 6, the beacon frame includes MAC header information 60, header check sequence (HCS) 61, beacon parameter 62, information element (part 1) 63, information element (part 2) 64, information element (part N ) 65 and predetermined check information such as a frame check sequence (FCS) 66.

  Further, the MAC header information 60 includes frame control information 601, a destination address 602 for identifying a destination wireless communication device, a source address 603 for identifying a source wireless communication device, and sequence control such as a sequence number. Information 604 and access control information 605 in which parameters necessary for access control are described.

  The beacon parameter 62 includes a device identifier 621 in which the MAC address information of the wireless communication device is described, a beacon slot number 622 indicating the beacon slot in which the beacon is transmitting, and information unique to the wireless communication device. Device control information 623 included.

  In addition, an arbitrary information element can be added to the beacon frame as the beacon payload information. In FIG. 6, as an example of the information element, an information element (part 1) 63, an information element (part 2) 64, and an information element (N) 65 is shown. “N” in the above (N) indicates the number of information elements to be transmitted by being added to the beacon, and the number “N” of information elements may be different for each beacon to be transmitted.

  The frame check sequence (FCS) 66 is information used when detecting an error in the beacon frame. In addition, you may comprise a beacon frame by adding and deleting said various parameters as needed.

  FIG. 7 shows a beacon period use information element (BPOIE) used when describing beacon information collected during a beacon period as an example of an information element included in a beacon. The beacon period use information element includes an element identifier 711, an information length 712, a beacon period length 713, a beacon slot information bitmap 714, a device address (part 1) 715, and a device address (part N) 716.

  The element identifier 711 is information attached to each information element, and is identification information indicating what information element the information element is related to. Therefore, the element identifier 711 shown in FIG. 7 indicates a beacon period use information element. The information length 712 indicates the information amount of the beacon period use information element.

  The beacon period length 713 indicates the length of the beacon period set in the device communication apparatus 12, for example. The beacon slot information bitmap 714 shows all beacon slots that have received beacons. A device address (No. 1) 715 and a device address (No. N) 716 indicate the addresses of the transmission source devices of the received beacons.

  However, in the conflict detection method using beacon skip shown in FIG. 5, if superframes that skip beacons of a plurality of wireless communication devices 10 overlap, it is not possible to detect conflicts between beacon slots. In particular, when a plurality of wireless communication devices 10 operating with the same algorithm have the same start-up time and set a fixed beacon skip period, there is a problem in that competition for beacon slots cannot be detected from each other. .

  In view of the above circumstances, the wireless communication device 10 according to the present embodiment has been created. For example, as illustrated in FIG. 7, the wireless communication apparatus 10 according to the present embodiment can easily detect competition of beacon slots to be used by setting beacon skip intervals irregularly (randomly).

  FIG. 8 is an explanatory diagram showing beacon skip intervals set irregularly in the present embodiment. FIG. 8 shows a case where each wireless communication device 10 irregularly sets the beacon skip interval between the first interval (8 superframes) and the second interval (12 superframes).

  Specifically, the wireless communication device 10A sets the beacon skip interval to 10 superframe cycles, the wireless communication device 10B sets the beacon skip interval to 11 superframe cycles, and the wireless communication device 10C The beacon skip interval is set to 8 superframe cycles, the wireless communication device 10D sets the beacon skip interval to 9 superframe cycles, and the wireless communication device 10E sets the beacon skip interval to 12 superframe cycles. The wireless communication device 10F sets the beacon skip interval to 8 superframe cycles. As described above, the beacon skip interval set by each wireless communication device 10 may be reset every time beacon transmission is skipped.

  For example, as illustrated in FIG. 8, after the beacon skip interval is set to 12 superframe periods, the wireless communication device 10G resets the beacon skip interval to 9 superframe cycles after skipping beacon transmission. can do. With such a configuration, it is possible to avoid overlapping of the timing for permanently skipping beacon transmission among a plurality of wireless communication devices 10, and to enable detection of beacon slot contention by each wireless communication device 10. Hereinafter, the configuration of the wireless communication device 10 that sets such beacon skip intervals irregularly will be described.

[2] Configuration of Radio Communication Device 10 According to the Present Embodiment FIG. 9 is a functional block diagram showing the configuration of the radio communication device 10 according to the present embodiment. The wireless communication device 10 includes an antenna 101, a baseband reception unit 102, a beacon reception processing unit 103, a beacon transmission processing unit 104, a baseband transmission unit 105, a beacon skip setting unit 106, and a description device address extraction unit. 107, a beacon slot management unit 108, a self-beacon slot setting unit 109, a radio access control unit 110, a data unit reception processing unit 111, an input / output interface 112, and a data unit transmission processing unit 113.

  The antenna 101 has a function as a receiving unit that receives a radio signal transmitted from the surrounding radio communication device 10 or a transmitting unit that transmits a radio signal from itself, that is, a function as a communication unit. The baseband receiving unit 102 decodes a signal received from the surrounding wireless communication device 10 via the antenna 101.

  The beacon reception processing unit 103 extracts information described in the beacon frame from the beacon frame included in the signal decoded by the baseband reception unit 102. Further, the antenna 101 and the baseband receiving unit 102 have a function as a reception control unit that controls reception of a beacon realized by cooperation.

  The beacon transmission processing unit 104 has a function as a transmission control unit that constructs a beacon frame of a beacon to be transmitted to the surrounding wireless communication devices 10 and causes the antenna 101 and the baseband transmission unit 105 to cooperate and transmit. The baseband transmission unit 105 performs processing for modulating a signal to be transmitted to the surrounding wireless communication device 10 into a wireless signal.

  The beacon skip setting unit 106 has a function as a skip interval generation unit that randomly and randomly generates a beacon skip interval for skipping beacon transmission. Specifically, the beacon skip setting unit 106 randomly generates and sets a beacon skip interval between a first interval and a second interval that are integer multiples of 2 or more of the superframe. The beacon skip setting unit 106 can also control the beacon transmission processing unit 104 to make a beacon skip at an arbitrary timing.

  The beacon transmission processing unit 104 skips beacon transmission in the corresponding superframe based on the beacon skip interval set by the beacon skip setting unit 106. In addition, the beacon reception processing unit 103 causes the antenna 101 to receive a beacon in the beacon slot of the wireless communication device 10 of the superframe in which the beacon transmission processing unit 104 skips beacon transmission. When the antenna 101 and the baseband receiving unit 102 receive a beacon transmitted from another wireless communication device 10 in the beacon slot of the wireless communication device 10, the beacon slot used by the wireless communication device 10 is another wireless communication device. It is detected that 10 is competing with the beacon slot used.

  When the beacon skip timings of the wireless communication device 10 and the other wireless communication device 10 coincide with each other, it is not possible to detect a conflict between beacon slots. However, in this embodiment, the beacon skip interval is a random interval. Therefore, it is possible to avoid overlapping of the timings of skipping beacon transmission permanently between the plurality of wireless communication devices 10 and to enable the wireless communication devices 10 to detect beacon slot contention.

  Note that if beacon transmission is skipped in each superframe, wireless communication in the wireless communication system 1 is hindered, so the beacon skip setting unit 106 generates a beacon skip interval at an interval that is an integer multiple of 2 or more of the superframe.

  Further, the first interval and the second interval may be intervals according to the reservation status of wireless communication of the wireless communication device 10 in the wireless communication system 1. The beacon includes information for reserving a time zone that the wireless communication apparatus 10 uses for wireless communication. Accordingly, if the beacon is frequently stopped when the wireless communication apparatus 10 reserves many time zones for wireless communication, it may adversely affect the communication. Therefore, as described above, the beacon skip setting unit 106 generates a skip interval between the first interval and the second interval according to the wireless communication reservation status of the wireless communication device 10, thereby enabling the wireless communication system 1. It is possible to detect the competition of slots used for beacon transmission while ensuring the stability of wireless communication.

  The described device address extracting unit 107 includes a transmission source address indicating a transmission source device of a beacon included in a beacon frame and transmission device information indicating a device address of the wireless communication device 10 using each beacon slot (beacon period usage information element). ). The beacon slot management unit 108 stores and manages the device address of the wireless communication apparatus 10 that uses each beacon slot for each beacon slot based on the beacon period use information element extracted by the written device address extraction unit 107.

  The self-beacon slot setting unit 109 uses the wireless communication device 10 when the antenna 101 receives a beacon from another wireless communication device 10 in the beacon slot of the wireless communication device 10 of the superframe in which beacon transmission is skipped. Change the beacon slot to be changed. As described above, when the antenna 101 and the baseband receiving unit 102 receive a beacon transmitted from another wireless communication device 10 in the beacon slot of the wireless communication device 10, the beacon slot used by the wireless communication device 10 is It is considered that the wireless communication device 10 is competing with a beacon slot used by another wireless communication device 10. Therefore, according to the above configuration, it is possible to avoid contention for slots used by the plurality of wireless communication devices 10 for beacon transmission, and to improve the reliability of information exchange in the wireless communication system 1.

  Further, in the beacon period usage information element extracted by the description device address extraction unit 107, it is described that another wireless communication device 10 is using the beacon slot used by the wireless communication device 10, It is considered that a beacon slot used by the wireless communication device 10 and a beacon slot used by another wireless communication device 10 are in competition. Therefore, in such a case, the self-beacon slot setting unit 109 can change and set the beacon slot used by the wireless communication device 10, thereby avoiding contention of beacon slots used by the plurality of wireless communication devices 10.

  Also, in the beacon period usage information element extracted by the description device address extraction unit 107, when a broadcast address is described in the beacon slot used by the wireless communication device 10, for example, the beacon slot used by the wireless communication device 10 Is competing with other wireless communication devices 10, or the surrounding wireless communication devices 10 are likely to have failed to decode beacons transmitted by themselves.

  Therefore, in the beacon period usage information element extracted by the description device address extraction unit 107, if the broadcast address is described in the beacon slot used by the wireless communication device 10, the beacon skip setting unit 106 determines that the next superframe The beacon transmission may be skipped. With this configuration, the wireless communication device 10 competes with the use of the beacon slot based on whether or not the beacon of another wireless communication device 10 is received in the beacon slot used by the wireless communication device 10 of the next superframe. It is possible to detect whether or not

  The radio access control unit 110 controls the baseband reception unit 102 and the baseband transmission unit 105 so that a radio signal is transmitted and received at an arbitrary timing. The data unit reception processing unit 111 converts the signal decoded by the baseband receiving unit 102 into a format that can be supported by a device connected via the input / output interface 112. The data unit transmission processing unit 113 constructs a signal input from a device connected via the input / output interface 112 as data to be wirelessly transmitted.

[3] Wireless Communication Method According to the Present Embodiment FIG. 10 is a flowchart showing the flow of the wireless communication method executed in the wireless communication device 10 according to the present embodiment. First, the wireless communication device 10 scans beacons transmitted in the surrounding area over several superframes, and sets a beacon period and a beacon slot used by the wireless communication device 10 (S201). Subsequently, the beacon skip setting unit 106 randomly determines a beacon skip interval (S202).

  When the beacon period arrives (S203), the own beacon slot arrives (S204), and the beacon skip is set in the own beacon slot (S205), the beacon skip setting unit 106 sets the beacon skip interval. It is reset (S206). In addition, in the own beacon slot in which beacon skip is set, the communication unit such as the antenna 101 and the baseband receiving unit 102 cooperates to perform beacon reception processing (S207).

  When a beacon is received from another wireless communication device 10 in its own beacon slot in which beacon skip is set (S208), the wireless communication device 10 competes with the other wireless communication device 10 for use of its own beacon slot. Detect that Therefore, the device address extraction unit 107 extracts the beacon period use information element from the received beacon (S209), the self-beacon slot setting unit 109 selects a beacon slot that is not used by the surrounding wireless communication device 10, It is set as a beacon slot used by itself (S210).

  When the own beacon slot for which beacon skip is not set has arrived (S205), the beacon transmission processing unit 104 acquires the parameters described in the beacon (S211), and causes the antenna 101 and the baseband transmission unit 105 to transmit the beacon. (S212).

  When it is a beacon period and it is not its own beacon slot (S204), the antenna 101 and the baseband receiving unit 102 perform processing for receiving beacons transmitted from the surrounding wireless communication devices 10 (S213). When a beacon is received in S213 (S214), a beacon slot information bitmap included in the received beacon is extracted (S215), and information on the beacon slot used by the primary wireless communication device 10 is updated (S215). S216).

  If the DRP reservation setting addressed to itself is described in the beacon received in S213 (S217), the wireless communication apparatus 10 also sets the same DRP reservation as a response parameter corresponding to the DRP reservation setting (S218). ), The designated DRP reservation MAS is set as the reception timing (S219).

  Then, the described device address extracting unit 107 acquires the device address information described in the beacon slot position used by itself from the beacon slot information bitmap included in the beacon received in S213 (S220). Thereafter, when the device address of the device is not described in the beacon slot position used by the device (S221) and the broadcast address is described (S222), the beacon skip setting unit 106 performs beacon skip in the next superframe. Is set (S223). On the other hand, if the device address is not described in the beacon slot position used by the device (S221) and the broadcast address is not described (S222), the process proceeds to S209.

  When it is not the beacon period (S203), when data transmitted by the input / output interface 112 of the wireless communication device 10 is received (S224), the destination device of the data is specified (S225) and used by the destination device as necessary. Information on possible DRPMAS is collected (S226), DRP reservation is set in the MAS that can be used by the wireless communication device 10 and the receiving device (S227), and if there is a response from the receiving device, in S227 The set MAS is set as the transmission timing (S228).

  Then, when the data transmission timing comes (S229), data transmission processing is performed (S230), and when the data reception timing comes (S231), data reception processing is performed (S232). In this way, by repeating a series of steps including the step of irregularly setting the beacon skip interval, it is possible to recall the competition of beacon slots used by the wireless communication device 10.

[4] Summary As described above, the wireless communication device 10 according to the present embodiment generates beacon skip intervals irregularly, and therefore, the timing of skipping beacon transmissions with the surrounding wireless communication devices 10 is permanently consistent. The possibility of doing is almost eliminated. Therefore, even when a plurality of wireless communication devices 10 use the same beacon slot for beacon transmission, each wireless communication device 10 skips beacon transmission at different timings and transmits from other wireless communication devices 10. Received beacons, it can be detected that the slots used for beacon transmission are in contention.

  In addition, when the wireless communication device 10 receives a beacon from another wireless communication device 10 in a beacon slot used by itself that skips beacon transmission, the self-beacon slot setting unit 109 changes the beacon slot used for beacon transmission. By setting, it is possible to avoid contention for slots used by the wireless communication device 10 and other wireless communication devices 10 for beacon transmission, and to improve the reliability of information exchange in the wireless communication system 1.

  In addition, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, each step in the processing of the wireless communication device 10 of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and processing executed in parallel or individually (for example, parallel processing) Alternatively, processing by an object) may be included.

  Further, it is possible to create a computer program for causing hardware such as a CPU, a ROM, and a RAM built in the wireless communication device 10 to perform the same functions as the components of the wireless communication device 10 described above. A storage medium storing the computer program is also provided.

It is explanatory drawing which showed the structural example of the autonomous distributed radio | wireless communications system. It is explanatory drawing which showed the structural example of the super frame. It is the conceptual diagram which showed the self beacon slot position which a radio | wireless communication apparatus sets. It is explanatory drawing which showed the other example of the radio | wireless communications system. It is explanatory drawing which showed an example of the beacon skip. It is explanatory drawing which showed the beacon frame structural example of the beacon transmitted in a beacon slot. It is explanatory drawing which showed the beacon period utilization information element as an example of the information element included in a beacon. It is explanatory drawing which showed the beacon skip interval set irregularly. It is the functional block diagram which showed the structure of the radio | wireless communication apparatus concerning one Embodiment of this invention. 5 is a flowchart showing a flow of a wireless communication method executed in the wireless communication apparatus according to the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wireless communication apparatus 101 Antenna 102 Baseband receiving part 103 Beacon reception process part 104 Beacon transmission process part 105 Baseband transmission part 106 Beacon skip setting part 107 Description Device address extraction part 108 Beacon slot management part 109 Self-beacon slot setting part

Claims (7)

A wireless communication device that constitutes an autonomous distributed wireless communication system:
A communication unit that transmits a beacon in a specific slot in the superframe at a predetermined superframe period;
A skip interval generation unit that irregularly generates a skip interval that is an integer multiple of 2 or more of the superframe period;
A transmission control unit for temporarily stopping beacon transmission in the specific slot from the communication unit at the skip interval generated by the skip interval generation unit;
A reception control unit that causes the communication unit to receive a beacon transmitted from another wireless communication device in the specific slot in which beacon transmission is temporarily stopped by the transmission control unit;
With
The communication unit receives a beacon including transmitting device information indicating a wireless communication device that is transmitting a beacon in the specific slot from surrounding wireless communication devices,
The skip interval generation unit generates a skip interval such that transmission of a beacon from the communication unit is suspended in the next superframe period when the transmission device information included in the beacon indicates a broadcast address. , Wireless communication device.   When the communication unit receives a beacon from another wireless communication device in the specific slot in which beacon transmission is temporarily stopped, the communication unit further includes a slot setting unit configured to change and set a slot that causes the communication unit to transmit a beacon. The wireless communication device according to claim 1, wherein   The skip interval generation unit generates the skip interval between a first interval and a second interval according to a reservation status of wireless communication of the wireless communication device in the wireless communication system, The wireless communication apparatus according to claim 1. The communication unit receives a beacon including transmitting device information indicating a wireless communication device that is transmitting a beacon in the specific slot from surrounding wireless communication devices,
The slot according to claim 1, further comprising: a slot setting unit configured to change and set a slot that causes the communication unit to transmit a beacon when the transmission device information included in the beacon indicates another wireless communication device. Wireless communication device. Computer
A wireless communication device constituting an autonomous distributed wireless communication system,
A communication unit that transmits a beacon in a specific slot in the superframe at a predetermined superframe period;
A skip interval generation unit that irregularly generates a skip interval that is an integer multiple of 2 or more of the superframe period;
A transmission control unit for temporarily stopping beacon transmission in the specific slot from the communication unit at the skip interval generated by the skip interval generation unit;
A reception control unit that causes the communication unit to receive a beacon transmitted from another wireless communication device in the specific slot in which beacon transmission is temporarily stopped by the transmission control unit;
With
The communication unit receives a beacon including transmitting device information indicating a wireless communication device that is transmitting a beacon in the specific slot from surrounding wireless communication devices,
The skip interval generation unit generates a skip interval such that transmission of a beacon from the communication unit is suspended in the next superframe period when the transmission device information included in the beacon indicates a broadcast address. A program for functioning as a wireless communication device. A wireless communication method executed in a wireless communication device constituting an autonomous distributed wireless communication system:
Transmitting a beacon in a particular slot in the superframe at a predetermined superframe period;
Receiving a beacon from surrounding wireless communication devices including transmission device information indicating a wireless communication device transmitting a beacon in the specific slot;
Irregularly generating a skip interval that is an integer multiple of 2 or more of the superframe period;
Pausing beacon transmission in the particular slot at the skip interval;
Receiving a beacon transmitted from another wireless communication device in the specific slot in which beacon transmission is suspended;
Including
In the step of generating the skip interval, when the transmitting device information included in the beacon indicates a broadcast address, a radio communication is performed in which a skip interval is generated such that beacon transmission is suspended in the next superframe period. Method. A wireless communication system in which a plurality of wireless communication devices communicate independently and in a distributed manner:
Each of the wireless communication devices
A communication unit that transmits a beacon in a specific slot in the superframe at a predetermined superframe period;
A skip interval generation unit that irregularly generates a skip interval that is an integer multiple of 2 or more of the superframe period;
A transmission control unit for temporarily stopping beacon transmission in the specific slot from the communication unit at the skip interval generated by the skip interval generation unit;
A reception control unit that causes the communication unit to receive a beacon transmitted from another wireless communication device in the specific slot in which beacon transmission is temporarily stopped by the transmission control unit;
A slot setting unit configured to change and set a slot for the communication unit to transmit a beacon when the communication unit receives a beacon from another wireless communication device in the specific slot in which beacon transmission is temporarily stopped;
With
The communication unit receives a beacon including transmitting device information indicating a wireless communication device that is transmitting a beacon in the specific slot from surrounding wireless communication devices,
The skip interval generation unit generates a skip interval such that transmission of a beacon from the communication unit is suspended in the next superframe period when the transmission device information included in the beacon indicates a broadcast address. , Wireless communication system.

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