JP4877059B2 - Wireless communication system, wireless communication apparatus, program, and wireless communication method - Google Patents

Description

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

  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 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.

  In addition, when a wireless communication apparatus in the WiMedia MAC standard cannot correctly decode a beacon received in a certain beacon slot, the wireless communication apparatus determines that a beacon has been received in the beacon slot and that the broadcast address is the device address of the beacon slot. It can be described in the beacon to be transmitted. 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.

Note that Patent Document 1 discloses a method in which each wireless communication device changes a superframe period when a beacon slot to be used collides with a plurality of wireless communication devices. Patent Document 2 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.
JP 2006-005620 A Special Table 2000-517132

  However, in the contention detection method for skipping beacon transmission in the WiMedia MAC standard, when the beacon skip interval is set to be redundant, contention of beacon slots cannot be detected immediately. Therefore, there is a concern about the reliability of exchanging parameters for wireless communication using a beacon.

  In addition, as described above, the wireless communication device in the WiMediaMAC standard can correctly decode the header check sequence (HCS) of the beacon received in a certain beacon slot and cannot correctly decode the frame chuck sequence (FCS). The broadcast address as the device address of the beacon slot is not described in the beacon transmitted by itself.

  Therefore, even when a plurality of beacons are received in a certain beacon slot and the decoding of any beacon is established, the wireless communication apparatus transmits the device address of the transmission source apparatus of the beacon in which the decoding is established. Enter in the beacon. Actually, even when the wireless communication apparatus receives a plurality of beacons in such a beacon slot, decoding of only a certain beacon often occurs. As a result, even if the beacon slots used by a plurality of wireless communication devices are actually competing, the wireless communication device notifies the beacon slot contention directly to the wireless communication devices competing for the use of the beacon slot. I couldn't.

  In addition, since the time width of the beacon slot in the WiMediaMAC 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 2. 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 radio communication system and radio communication apparatus capable of reporting beacon slot contention It is to provide a program and a wireless communication method.

  In order to solve the above-described problem, according to an 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 specific superframe specified in a specific superframe. A receiving unit that receives a beacon transmitted from another wireless communication device in the slot, and a beacon transmission source device received in the specific slot by the receiving unit is a beacon transmission source device previously received in the specific slot If the determination unit determines that the beacon transmission source device does not match, the determination unit determines whether or not the beacon transmissions in a specific slot are in conflict. A wireless communication system comprising: a transmission unit that transmits to a communication device.

  In order to solve the above problems, according to another aspect of the present invention, there is provided a wireless communication apparatus constituting an autonomous distributed wireless communication system, wherein other wireless communication is performed in a specific slot in a predetermined superframe. A receiving unit that receives a beacon transmitted from a device, and whether or not a beacon transmission source device received in a specific slot by the reception unit matches a transmission source device of a beacon previously received in a specific slot And a transmission unit that transmits contention information indicating that beacon transmission in a specific slot is in competition when the determination unit determines that the beacon transmission source devices do not match. A wireless communication device is provided.

  In this configuration, the determination unit determines whether or not the beacon transmission source device received by the reception unit in the specific slot matches the beacon transmission source device previously received in the specific slot. Here, even if the receiving unit receives a plurality of beacons in a specific slot, in many cases, only one beacon is decoded according to the reception intensity in the receiving unit. As a result, when beacon transmissions in a specific slot are in contention, beacons that are unexpectedly transmitted from different transmission source devices are often decoded. Therefore, when the determination unit does not match the current and old beacon transmission source devices, the transmitting unit transmits contention information indicating that the beacon transmission in a specific slot is competing, thereby identifying the surrounding wireless communication devices. It can be detected that the beacon transmissions in the slots are in contention.

  The contention information may include information in which a broadcast address is described as an address of a beacon transmission source device in a specific slot. With this configuration, it is possible to notify the surrounding wireless communication device of the competition using the existing information element.

  The transmission unit transmits a beacon in a predetermined slot in the superframe in a superframe cycle, and the reception unit transmits a beacon including transmission device information indicating a wireless communication device transmitting the beacon in the predetermined slot to the surrounding wireless When the transmission device information received from the communication device and included in the beacon received by the reception unit indicates another wireless communication device, the wireless communication device may further include a control unit that changes and sets a slot for transmitting the beacon to the transmission unit. The reception unit has received a beacon from surrounding wireless communication devices that includes transmission device information indicating that the wireless communication device that is transmitting the beacon in the slot used by the wireless communication device is another wireless communication device. The use of the predetermined slot is equivalent to contention 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 predetermined slot is another wireless communication device is received from surrounding wireless communication devices, it is used for beacon transmission. By changing and setting a slot to be used, contention of slots used for beacon transmission can be avoided and reliability of information exchange in the wireless communication system can be improved.

  The transmission unit transmits a beacon in a predetermined slot in the superframe in a superframe cycle, and the reception unit transmits a beacon including transmission device information indicating a wireless communication device transmitting the beacon in the predetermined slot to the surrounding wireless When the transmission device information received from the communication device and included in the beacon received by the reception unit includes contention information, the information processing apparatus may further include a control unit that temporarily stops transmission of the beacon from the transmission unit in the next superframe period. Good. Here, when the receiving unit receives a beacon including transmitting device information indicating that beacon transmission in a predetermined slot is competing from surrounding wireless communication devices, the use of the predetermined slot actually competes with high probability. it seems to do. Therefore, when the reception unit receives a beacon including transmission device information indicating that beacon transmission in a predetermined slot is competing from the surrounding wireless communication device, the control unit receives the transmission from the transmission unit in the next superframe period. By temporarily stopping the transmission of the beacon and causing the reception unit to receive the beacon, it is possible to more accurately detect whether or not the use of a predetermined slot is competing in the next superframe period.

  Specify until the beacon including the transmission device information indicating the same wireless communication device in a specific slot is received by the reception unit over a predetermined superframe period after the determination unit determines that the beacon transmission source device does not match There may be further provided a control unit that causes the transmission unit to transmit contention information indicating that beacon transmission in this 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, and the computer is connected in a specific slot in a predetermined superframe. The receiving unit that receives the beacon transmitted from the wireless communication device of the first beacon and the transmission source device of the beacon received in the specific slot by the receiving unit match the transmission source device of the beacon previously received in the specific slot A determination unit that determines whether the beacon transmission source device does not match by the determination unit, and a transmission unit that transmits contention information indicating that beacon transmission in a specific slot is in competition, A program for causing a wireless communication apparatus to function is provided.

  Such a program can cause a hardware resource of a computer including, for example, a CPU, a ROM, or a RAM to execute functions such as the reception unit, the determination unit, and the transmission unit as described above. 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, a step of receiving a beacon transmitted from another wireless communication device in a specific slot in a predetermined superframe, and a reception in the specific slot Determining whether the beacon source device received matches the beacon source device previously received in the specific slot and the beacon source device is determined not to match And transmitting contention information indicating that beacon transmissions in the slots are in contention, and providing a wireless communication method.

  As described above, according to the wireless communication system, the wireless communication apparatus, the program, and the wireless communication method according to the present invention, it is possible to notify the competition of beacon slots used by the wireless communication apparatus.

  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 the above circumstances, the wireless communication device 10 according to the present embodiment has been created. According to the wireless communication device 10, as shown in FIG. 5, it is possible to notify other wireless communication devices 10 using the competing beacon slots that the use of the beacon slots is competing.

  FIG. 5 is an explanatory diagram showing an operation example of the wireless communication device 10 according to the present embodiment. In the example illustrated in FIG. 5, the wireless communication device 10 </ b> E and the wireless communication device 10 </ b> G transmit a beacon using the same specific beacon slot.

  Further, the wireless communication device 10D has received the beacon transmitted from the wireless communication device 10E in the arrangement illustrated in FIG. 1, but has previously received the beacon transmitted in the arrangement in which the wireless communication device 10G illustrated in FIG. 4 has moved. The beacon transmitted from the wireless communication device 10G that has not been received is received.

  While receiving the beacon transmitted from the wireless communication device 10E, the wireless communication device 10D uses the beacon period use information element (transmitting device) indicating that the wireless communication device that uses the specific beacon slot is the wireless communication device 10E. Information, which will be described later with reference to FIGS.

  On the other hand, even when the wireless communication device 10D receives the beacon transmitted from the wireless communication device 10G, the wireless communication device 10G immediately uses the beacon period indicating that the wireless communication device that uses the specific beacon slot is the wireless communication device 10G. A beacon including an information element is not transmitted, and a beacon including contention information indicating that the use of a specific beacon slot is competing is transmitted (notified). The contention information may be, for example, a beacon period use information element in which a broadcast address is described as a wireless communication device using a specific beacon slot. With this configuration, the wireless communication device 10E and the wireless communication device 10G can detect that the use of a specific beacon slot is competing based on the contention information included in the beacon transmitted from the wireless communication device 10D. .

  The wireless communication device 10D may transmit a beacon including the contention information over a predetermined superframe period as a contention notification period after receiving a beacon of the wireless communication device 10G that has not been received before. In FIG. 5, a case where a beacon including contention information is transmitted over three superframes is shown. When the contention notification period ends, the wireless communication device 10D transmits a beacon including a beacon period use information element in which the device address of the newly received wireless communication device 10G is described as a wireless communication device that uses a specific beacon slot. Send.

  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 (part 1) 715 and a device address (part N) 716 indicate the device address of the transmission source apparatus of the received beacon.

  8 and 9 are explanatory diagrams showing specific examples of beacon period use information elements included in beacons transmitted by the wireless communication devices 10A to 10G. 8A shows a beacon period usage information element in the wireless communication device 10A, FIG. 8B shows a beacon period usage information element in the wireless communication device 10B, and FIG. 8C shows a beacon in the wireless communication device 10C. 9A shows a period use information element, FIG. 9A shows a beacon period use information element in the wireless communication apparatus 10D, FIG. 9B shows a beacon period use information element in the wireless communication apparatus 10E, and FIG. Indicates a beacon period use information element in the wireless communication device 10F, and FIG. 9D shows a beacon period use information element in the wireless communication device 10G.

  As shown in FIG. 8A, the beacon period usage information element in the wireless communication device 10A has an element identifier of “0x01” indicating the beacon period usage information element, an information length “6”, and a beacon period length. The information “7” is included. Further, since the wireless communication device 10A transmits its beacon in the beacon slot 2 and receives the beacon of the wireless communication device 10B in the beacon slot 3, the beacon slot information bitmap includes the beacon slot 2 and the beacon slot 3. “1” is described in the corresponding bit. In the beacon slot information bit map, the least significant bit corresponds to beacon slot 0, and the number of the corresponding beacon slot increases by one as the bit is increased by one.

  The beacon period use information element in the wireless communication device 10A includes the device address of the wireless communication device that uses each beacon slot in which “1” is described in the beacon slot information bitmap. Device addresses of wireless communication apparatuses that use a beacon slot corresponding to “1” described in the beacon slot information bit map are described in order from the smallest beacon slot number. Accordingly, FIG. 8A shows that the wireless communication device using the beacon slot 2 has the device address “0x0101” (wireless communication device 10A), and the wireless communication device using the beacon slot 3 has the device address “0x0102”. "(Wireless communication device 10B).

  8B, the beacon period use information element in the wireless communication device 10B is “0x01” in which the element identifier indicates the beacon period use information element, the information length is “8”, and the beacon period. The length “8” is included. Further, the beacon period use information element in the wireless communication device 10B indicates that the wireless communication device using the beacon slot 2 has the device address “0x0101” (wireless communication device 10A), and the wireless communication device using the beacon slot 3 Has a device address “0x0102” (wireless communication apparatus 10B), and a wireless communication apparatus using the beacon slot 4 has a device address “0x0103” (wireless communication apparatus 10C).

  Similarly, as illustrated in FIG. 8C, the beacon period usage information element in the wireless communication device 10 </ b> C is “0x01” in which the element identifier indicates the beacon period usage information element, the information length “11”, and the beacon. The information that the period length is “9” is included. Further, the beacon period use information element in the wireless communication device 10C indicates that the wireless communication device using the beacon slot 2 has the device address “0x0106” (wireless communication device 10F), and the wireless communication device using the beacon slot 3 Indicates a device address “0x0102” (wireless communication device 10B), indicates that a wireless communication device using beacon slot 4 has a device address “0x0103” (wireless communication device 10C), and uses beacon slot 5 This indicates that the wireless communication device that has the device address “0x0104” (wireless communication device 10D).

  Also, as shown in FIG. 9A, the beacon period usage information element in the wireless communication device 10D is “0x01” in which the element identifier indicates the beacon period usage information element, the information length is “11”, and the beacon period The length “9” is included. The beacon period use information element in the wireless communication device 10D indicates that the wireless communication device using the beacon slot 2 has the device address “0x0106” (wireless communication device 10F), and the wireless communication device using the beacon slot 4 Has a device address “0x0103” (wireless communication apparatus 10C), and a wireless communication apparatus using the beacon slot 5 has a device address “0x0104” (wireless communication apparatus 10D).

  Here, when the wireless communication device 10D receives a beacon from the wireless communication device 10G that was not previously received in the beacon slot 6, the wireless communication device 10D immediately uses the device address of the wireless communication device 10G as a wireless communication device that uses the beacon slot 6. Not described, the broadcast address (0xFFFF) is described as contention information as shown in FIG. The wireless communication device 10E and the wireless communication device 10G that have received a beacon including such a beacon period use information element can grasp that the use of the beacon slot 6 is competing.

  9B, the beacon period use information element in the wireless communication device 10E is “0x01” whose element identifier indicates the beacon period use information element, the information length is “7”, the beacon period The length “9” is included. Further, the beacon period use information element in the wireless communication device 10E indicates that the wireless communication device using the beacon slot 5 has the device address “0x0104” (wireless communication device 10D), and the wireless communication device using the beacon slot 6 Has a device address “0x0105” (wireless communication apparatus 10E).

  9C, the beacon period use information element in the wireless communication device 10F is “0x01” in which the element identifier indicates the beacon period use information element, the information length is “9”, the beacon period The length “9” is included. Further, the beacon period use information element in the wireless communication device 10F indicates that the wireless communication device using the beacon slot 2 has the device address “0x0106” (wireless communication device 10F), and the wireless communication device using the beacon slot 4 Has a device address “0x0103” (wireless communication apparatus 10C), and a wireless communication apparatus using the beacon slot 5 has a device address “0x0104” (wireless communication apparatus 10D).

  Similarly, as illustrated in FIG. 9D, the beacon period use information element in the wireless communication device 10 </ b> G has an element identifier “0x01” indicating the beacon period use information element, an information length “7”, and a beacon. The information that the period length is “9” is included. Further, the beacon period use information element in the wireless communication device 10G indicates that the wireless communication device using the beacon slot 5 has the device address “0x0104” (wireless communication device 10D), and the wireless communication device using the beacon slot 6 Has a device address “0x0107” (wireless communication apparatus 10G).

[2] Configuration of the Wireless Communication Device 10 According to the Present Embodiment Next, the configuration of the wireless communication device 10 according to the present embodiment having the functions as described above will be described with reference to FIG.

  FIG. 10 is a functional block diagram showing the configuration of the wireless 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 described device address extraction unit 106, and a beacon slot management unit. 107, an existing address change determination 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 described device address extraction unit 106 includes a transmission source address indicating the transmission source device of the beacon included in the beacon frame, and transmission device information indicating the device address of the wireless communication device 10 using each beacon slot (beacon period usage information element). ). The beacon slot management unit 107 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 described device address extraction unit 106.

  The existing address change determination unit 108 determines, for each beacon slot, whether or not the transmission source device of the beacon received in the beacon slot has changed from the wireless communication device that was previously received (for example, most recently). For example, the existing address change determination unit 108 uses the device address of the wireless communication apparatus that uses the beacon slot 6 managed by the beacon slot management unit 107 and the beacon slot 6 extracted by the described device address extraction unit 106. It is determined whether or not the device address of the wireless communication apparatus matches.

  When the existing address change determination unit 108 determines that the transmission source device of the beacon received in a certain beacon slot has changed from the wireless communication device previously received, the beacon slot management unit 107 performs the beacon slot over a predetermined period. The broadcast address is associated with the slot as conflict information and managed.

  The self-beacon slot setting unit 109 has a function as a control unit that sets a beacon slot that is used by the self-beacon slot at the time of activation or resets a beacon slot that is used by the self-beacon slot as necessary.

  For example, in the beacon period usage information element extracted by the description device address extraction unit 106, 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.

  Further, in the beacon period usage information element extracted by the written device address extraction unit 106, when a broadcast address is described in the beacon slot used by the wireless communication device 10, the beacon slot used by the wireless communication device 10 is There is a high possibility that decoding of the beacon transmitted by itself in the surrounding wireless communication apparatuses 10 is in conflict with other wireless communication apparatuses 10 or has failed.

  Therefore, in the beacon period usage information element extracted by the description device address extraction unit 106, when a broadcast address is described in a beacon slot used by the wireless communication device 10, a beacon transmission processing unit having a function as a control unit 104 may skip beacon transmission in the next superframe. 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 more reliably detect whether or not it is.

  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 this Embodiment Next, a wireless communication method executed in the wireless communication device 10 according to this embodiment will be described with reference to FIG. 11 and FIG.

  FIG. 11 and FIG. 12 are flowcharts showing the flow of the wireless communication method executed in the wireless communication apparatus 10 according to the present embodiment. As shown in FIG. 11, first, the wireless communication device 10 scans beacons transmitted in the surrounding area over several superframes (S201), and sets the beacon period and the beacon slot used by the wireless communication device 10. Perform (S202).

  When the beacon slot comes within the beacon period, the beacon transmission processing unit 104 acquires various parameters described in the beacon transmitted from the beacon slot management unit 107 or the like (S205), and the parameters are described. The beacon is transmitted by the antenna 101 and the baseband transmission unit 105 (S206).

  When it is a beacon period and it is not its own beacon slot (S204), the wireless communication device 10 performs reception processing of beacons transmitted from surrounding wireless communication devices 10 (S207), and a beacon is received (S208). Then, “1” is described in the corresponding bit of the beacon slot information bitmap of the beacon period use information element transmitted by itself (S209), and the device address extraction unit 106 receives the received beacon transmission source device. A device address is extracted (S210).

  When a beacon has been received before (for example, within a predetermined period) in the beacon slot that received the beacon (S211), the device address of the transmission source device of the beacon previously received in the beacon slot is changed to the existing address change determination unit 108. Is acquired (S212). Then, the existing address change determination unit 108 determines whether or not the acquired device address matches the device address extracted in S210 (S213). If both device addresses do not match, the beacon slot management is performed. The unit 107 sets contention notification by associating a broadcast address with the corresponding beacon slot (S214). Further, the beacon slot management unit 107 sets an initial value (for example, 3 superframes) of a notification counter (S215), and the beacon transmission processing unit 104 sets the device address of the corresponding beacon slot of the beacon period usage information element to be transmitted. A broadcast address is described (S217).

  On the other hand, if no beacon has been received before in the beacon slot that received the beacon, the beacon slot management unit 107 registers the device address of the beacon transmission source device in association with the corresponding beacon slot (S216), and transmits the beacon. The processing unit 104 describes the device address registered in S216 as the device address of the corresponding beacon slot of the beacon period usage information element to be transmitted (S217).

  If it is determined in S213 that both device addresses match, if the notification counter is set (S218), the notification counter is decremented by 1 (S219). When the notification count reaches 0 (S220), the beacon slot management unit 107 sets the device address of the transmission source device of the beacon that the wireless communication device 10 has received most recently in the corresponding beacon slot. Are registered in association with each other (S221).

  Next, when the received beacon has a setting of the DRP reservation addressed to itself (S222), the wireless communication device 10 also sets the same DRP reservation as a response parameter corresponding to the DRP reservation setting (S223), and the designated DRP The reservation MAS is set as the reception timing (S224).

  If a beacon is not received in a beacon period other than the beacon slot used by itself (S208), “0” is written in the bit corresponding to the beacon slot other than the beacon slot used by the beacon slot information bitmap ( S225), the device address of the other wireless communication apparatus 10 is not added (S226).

  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 (S227), a DRP reservation is set in the MAS that can be used by the wireless communication device 10 and the reception destination device ( S228), MAS set in S228 is set as a transmission timing (S229).

  Then, when the data transmission timing arrives (S230), data transmission processing is performed (S231), and when the data reception timing arrives (S232), data reception processing is performed (S233).

  Further, the wireless communication device 10 determines the beacon slot used by the self-beacon slot setting unit 109 (S304), and receives a beacon from the surrounding wireless communication device 10 (S308), the device of the beacon slot used by itself. It is determined whether the device address of another wireless communication apparatus 10 is described in the beacon as an address (S312). When the device address of another wireless communication device 10 is described in the beacon as the device address of the beacon slot used by itself, it is considered that the use of the beacon slot is in competition with the other wireless communication device 10 The self-beacon slot setting unit 109 performs change setting of the beacon slot to be used (S316).

  When the device address of another wireless communication device 10 is not described in the beacon as the device address of the beacon slot used by itself, the wireless communication device 10 describes the broadcast address as the device address of the beacon slot used by itself. It is determined whether or not (S320).

  When the broadcast address is described as the device address of the beacon slot used by the self, the beacon transmission processing unit 104 skips the beacon transmission in the next superframe, and the beacon receiving unit receives the self while the beacon transmission is skipped. A beacon is received from the surrounding wireless communication device 10 in the beacon slot to be used (S324). When the broadcast address is described as the device address of the beacon slot used by itself, the self-beacon slot setting unit 109 may change and set the beacon slot used.

[4] Summary As described above, the wireless communication device 10 according to the present embodiment is configured such that the beacon transmission source device received in a certain beacon slot is the same as the beacon transmission source device previously received in the beacon slot. If they are different, a beacon including contention information indicating that the use of the beacon slot is competing is notified to the surroundings. Therefore, the surrounding wireless communication devices 10 can detect competition for use of the beacon slot based on the beacon including the notified contention information, and can change and set the beacon slot to be used as appropriate.

  In addition, the wireless communication device 10 transmits a beacon including a beacon period use information element indicating that the wireless communication device 10 transmitting a beacon in a beacon slot is another wireless communication device 10. , The self-beacon slot setting unit 109 changes and sets the beacon slot used for beacon transmission, thereby avoiding contention of beacon slots used for beacon transmission and reliability of information exchange in the wireless communication system 1 Can be improved.

  In addition, when the wireless communication device 10 receives a beacon including a beacon period use information element indicating that beacon transmission in a certain beacon slot is competing from surrounding wireless communication devices 10, the beacon transmission processing unit 104 By skipping the beacon transmission from the antenna 101 and the baseband transmission unit 105 in the next superframe and causing the antenna 101 and the baseband reception unit 102 to receive the beacon, the use of the beacon slot competes in the next superframe. It becomes possible to detect more accurately whether or not.

  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, in the above-described embodiment, the case where the broadcast address is described in association with the corresponding beacon slot as conflict information has been described, but the present invention is not limited to such an example. For example, an information element for notifying that the use of the beacon slot is competing may be prepared, and the conflict information may be notified using the information element.

  In the above-described embodiment, the case has been described in which the wireless communication apparatus 10 ends the conflict notification when the value of the notification counter reaches 0 and registers a new device address. However, the present invention is limited to this example. Not. For example, when the wireless communication device 10 continuously receives beacons from the same transmission source device over a predetermined period, the beacon transmission processing unit 104 ends the conflict notification, and the beacon slot management unit 107 determines the device address of the transmission source device. May be registered.

  In addition, 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 that is 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 own beacon slot position which each 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 the operation example of the radio | wireless communication apparatus concerning one Embodiment of this invention. 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 structural example of the beacon period utilization information element. It is explanatory drawing which showed the specific example of the beacon period utilization information element contained in the beacon which each radio | wireless communication apparatus transmits. It is explanatory drawing which showed the specific example of the beacon period utilization information element contained in the beacon which each radio | wireless communication apparatus transmits. FIG. 2 is a functional block diagram showing a configuration of a wireless communication apparatus according to the same embodiment. 5 is a flowchart showing a flow of a wireless communication method executed in the wireless communication apparatus according to the embodiment. 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 Description device address extraction part 107 Beacon slot management part 108 Existing address change determination part 109 Self-beacon slot setting part

Claims (8)

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 receiving unit that receives a beacon transmitted from another wireless communication device in a specific slot in a predetermined superframe;
A determination unit configured to determine whether a beacon transmission source device received in the specific slot by the reception unit matches a beacon transmission source device previously received in the specific slot;
A transmission unit that transmits contention information indicating that beacon transmission in the specific slot is in competition to a neighboring wireless communication device when the determination unit determines that the beacon transmission source devices do not match;
A wireless communication system comprising: A wireless communication device constituting an autonomous distributed wireless communication system:
A receiving unit that receives a beacon transmitted from another wireless communication device in a specific slot in a predetermined superframe;
A determination unit configured to determine whether a beacon transmission source device received in the specific slot by the reception unit matches a beacon transmission source device previously received in the specific slot;
A transmitting unit that transmits contention information indicating that beacon transmission in the specific slot is competing when the determining unit determines that the beacon transmission source devices do not match;
A wireless communication device comprising:   The wireless communication device according to claim 2, wherein the contention information includes information in which a broadcast address is described as an address of a beacon transmission source device in the specific slot. The transmission unit transmits a beacon in a predetermined slot in the superframe at the superframe period,
The receiving unit receives a beacon including transmitting device information indicating a wireless communication device that is transmitting a beacon in the predetermined slot from surrounding wireless communication devices,
When the transmission device information included in the beacon received by the reception unit indicates another wireless communication device, the transmission unit further includes a control unit configured to change and set a slot that causes the transmission unit to transmit a beacon. The wireless communication apparatus according to claim 2. The transmission unit transmits a beacon in a predetermined slot in the superframe at the superframe period,
The receiving unit receives a beacon including transmitting device information indicating a wireless communication device that is transmitting a beacon in the predetermined slot from surrounding wireless communication devices,
When the transmission device information included in the beacon received by the reception unit includes the contention information, the information processing apparatus further includes a control unit that temporarily stops transmission of the beacon from the transmission unit in the next superframe period. The wireless communication apparatus according to claim 2, wherein the wireless communication apparatus is characterized.   After the determination unit determines that the beacon transmission source devices do not match, a beacon including transmission device information indicating the same wireless communication device in the specific slot is received by the reception unit over a predetermined superframe period. The wireless communication apparatus according to claim 2, further comprising a control unit that causes the transmission unit to transmit contention information indicating that beacon transmission in the specific slot is in contention. Computer
A wireless communication device constituting an autonomous distributed wireless communication system,
A receiving unit that receives a beacon transmitted from another wireless communication device in a specific slot in a predetermined superframe;
A determination unit configured to determine whether a beacon transmission source device received in the specific slot by the reception unit matches a beacon transmission source device previously received in the specific slot;
A transmitting unit that transmits contention information indicating that beacon transmission in the specific slot is competing when the determining unit determines that the beacon transmission source devices do not match;
A program for causing a wireless communication apparatus to function. Receiving a beacon transmitted from another wireless communication device in a specific slot in a predetermined superframe;
Determining whether a beacon source device received in the specific slot matches a beacon source device previously received in the specific slot;
If it is determined that the beacon transmission source devices do not match, transmitting conflict information indicating that beacon transmission in the specific slot is competing;
A wireless communication method comprising:

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