JP4830629B2 - Wireless communication apparatus, wireless communication method, and computer program - Google Patents

Description

  The present invention relates to a wireless communication apparatus, a wireless communication method, and a computer program that perform wireless communication by a frequency hopping method.

  At present, the WiMedia Alliance defines autonomous access control methods (Distributed Media Access Control for Wireless Network) and multi-band OFDM as regulations for access control methods used for Ultra Wide Band (UWB) wireless communications. Specifications regarding the physical layer (Multi Band OFDM Physical Layer Specification) have been established.

  The above specification discloses a method in which a wireless communication device constituting a multiband OFDM wireless communication system performs ultra-wideband wireless communication using a predetermined frequency hopping pattern. In the frequency hopping pattern, a plurality of combinations of different frequencies called TFC codes are defined, and each wireless communication device can select a TFC code to be used as necessary when constructing a wireless network.

  In addition, each wireless communication device configuring the same wireless network can reserve a time slot in which the wireless communication device can communicate by specifying a time-divided media access slot configuring the superframe. In the same wireless network, different wireless communication devices are prohibited from reserving the same media access slot in order to prevent interference and ensure normal data transmission / reception (see Patent Document 1).

JP 2005-252645 A

  However, if there are wireless communication devices operating in different frequency hopping patterns in the vicinity, the conventional wireless communication device is not satisfactory due to the influence of interference when the time zone used for wireless communication overlaps with the wireless communication device. There was a problem that wireless communication could not be performed.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to perform normal wireless communication even when there are wireless communication devices operating in different frequency hopping patterns in the vicinity. It is an object of the present invention to provide a new and improved wireless communication apparatus, wireless communication method, and computer program that can be used.

  In order to solve the above-described problem, according to an aspect of the present invention, a wireless communication device configuring a wireless network is provided. The wireless communication apparatus switches a frequency hopping pattern from a self-hopping pattern used for wireless communication in its own network to another hopping pattern used for wireless communication in another network during a predetermined period. And using the frequency hopping pattern set by the pattern setting unit, a receiving unit that receives predetermined management information from its own network or another network, and included in the predetermined management information received by the receiving unit, Based on the use time zone analysis unit that analyzes reservation time zone information indicating the time zone that the wireless communication device uses for radio communication, and the reservation time zone information analyzed by the use time zone analysis unit, it can be used for wireless communication And an available time zone determination unit for determining a valid time zone.

  According to such a configuration, since the pattern setting unit is configured to be able to change the frequency hopping pattern appropriately during operation, the receiving unit receives predetermined management information not only from the own network but also from other networks. Can do. Therefore, the available time zone determination unit can determine the usage time zone so as to avoid interference based on the reserved time zone information of its own network and other adjacent networks.

  The predetermined period may be a period during which wireless communication in the own network is stopped. According to such a configuration, it is possible to effectively use the time during which the wireless communication apparatus does not communicate with its own network, and to acquire reserved time zone information of other networks without interfering with the original communication.

  Based on the time when the receiving unit receives the management information from the wireless communication device of the other network and the reserved time zone information of the wireless communication device of the other network by the other hopping pattern, May determine a time zone available for wireless communication. With this configuration, even when the communication between the own network and the other network is out of synchronization, the reservation time zone information of the wireless communication device of the other network is converted into information based on the synchronization of the own network, It is possible to determine the available time zone.

  A synchronization signal detection unit that is used for wireless communication and detects a different synchronization signal for each frequency hopping pattern may be further included. According to this configuration, the presence of a wireless communication device that operates with different frequency hopping patterns can be grasped through detection of the synchronization signal.

  A wireless communication device of another network may further include a storage unit that stores a time zone in which wireless communication is performed using another hopping pattern as an interference time zone in which interference occurs. According to such a configuration, it is possible to set the time zone used for communication by avoiding the interference time zone as much as possible.

  In order to solve the above-described problem, according to another aspect of the present invention, a wireless communication method by a wireless communication device configuring a wireless network is provided. The wireless communication method includes a step of switching and setting a frequency hopping pattern between a self-hopping pattern used for wireless communication in its own network and another hopping pattern used for wireless communication in another network. A step of receiving predetermined management information from its own network or other network using a frequency hopping pattern, and a reserved time indicating a time zone included in the predetermined management information and used by other wireless communication devices for wireless communication Analyzing the band information; and determining a time slot that can be used for wireless communication based on the reserved time band information.

  According to such a configuration, the frequency hopping pattern can be appropriately changed during operation, so that predetermined management information can be received not only from the own network but also from other networks. Therefore, the use time zone can be determined so as to avoid interference based on the reservation time zone information of the own network and other adjacent networks.

  In order to solve the above problems, according to another aspect of the present invention, a computer is used to set a frequency hopping pattern, a self-hopping pattern used for wireless communication in its own network, and a wireless communication in another network. A pattern setting unit that is switched and set between other hopping patterns used for communication, and a receiving unit that receives predetermined management information from its own network or another network using the frequency hopping pattern set by the pattern setting unit; The usage time zone analysis unit that analyzes the reserved time zone information indicating the time zone that other radio communication devices use for radio communication is included in the predetermined management information received by the reception unit, and the usage time zone analysis unit analyzes And an available time zone determination unit that determines a time zone that can be used for wireless communication based on the reserved time zone information. Wherein the allowed to function as a line communication apparatus, a computer program is provided.

  According to such a configuration, since the pattern setting unit is configured to be able to change the frequency hopping pattern appropriately during operation, the receiving unit receives predetermined management information not only from the own network but also from other networks. Can do. Therefore, the available time zone determination unit can determine the usage time zone so as to avoid interference based on the reserved time zone information of its own network and other adjacent networks.

  As described above, according to the wireless communication device, the wireless communication method, and the computer program of the present invention, even if there are wireless communication devices that operate in different frequency hopping patterns in the vicinity, normal wireless communication can be performed without causing interference. It can be carried out.

  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.

(1) Configuration of Ad Hoc Network First, the configuration of an ad hoc network will be described. FIG. 1 is a conceptual diagram illustrating a configuration example of an ad hoc network. Circles in the figure indicate communication devices (wireless communication devices), and regions indicated by dotted lines indicate radio wave reachable ranges in which each communication device can perform communication.

  The communication device 111 can communicate with the communication device 112 included in the radio wave reachable range 121. The communication device 112 can communicate between the communication device 111 and the communication device 113 included in the radio wave reachable range 122. Similarly, the communication device 113 can communicate between the communication device 112 and the communication device 114. Further, the communication device 114 can communicate between the communication device 113 and the communication device 115. The communication device 115 can communicate with the communication device 114. In this way, the communication devices 111 to 115 communicate with the communication devices included in the respective radio wave reachable ranges to form an ad hoc network.

(2) Superframe configuration example Next, a superframe configuration will be described. FIG. 2 is an explanatory diagram showing a configuration example of a superframe. The superframe period is defined by a predetermined time (for example, 65 ms), and is subdivided into 256 media access slots (MAS). Communication devices constituting one ad hoc network share the superframe period, and messages are transferred 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, and beacon slots (BS) are arranged at predetermined intervals. A unique beacon slot is set for each communication device, and parameters for network management and access control are exchanged with surrounding communication devices. In the figure, an example is shown in which eight beacon slots of BS0 to BS7 are set as the beacon period. The period that is not set as the beacon period is normally used as a data transmission area.

(3) Usage example of beacon slot Next, a usage example of the beacon slot is shown. FIG. 3 is a conceptual diagram showing its own beacon slot position set by each communication device when communication devices 111 to 115 form one ad hoc network. Here, a state is shown in which each communication device constituting one ad hoc network selects a beacon slot to be used by itself by notifying a beacon slot that is not being used.

  In this example, the communication device 111 transmits its beacon at BS2, and the communication device 112 transmits its beacon at BS3. Similarly, the communication device 113 transmits its own beacon at BS4, and the communication device 114 transmits its own beacon at the BS. The communication device 115 transmits its own beacon at BS6. In this way, each communication device occupies a unique beacon slot and transmits a beacon.

  In addition, BS1, BS2, BS7, and BS8 are secured as necessary for communication apparatuses newly entering this network group. 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 communication devices. In addition, the beacon period of each communication device can be appropriately extended according to the beacons of communication devices existing in the vicinity.

(4) Configuration Example of Beacon Frame FIG. 4 is an explanatory diagram showing a configuration example of a beacon frame 30 of a beacon transmitted in the above-described beacon slot. The beacon is transmitted from each communication device during a beacon period, which is a superframe management area, and management information can be exchanged with surrounding communication devices by receiving the beacon.

  As illustrated in FIG. 4, the beacon frame 30 includes MAC header information 300, a header check sequence (HCS) 310, beacon payload information 320, and a frame check sequence (FCS) 330.

  Further, the MAC header information 300 includes frame control information 301, a destination address 302 that is a reception destination address, a source address 303 that is a transmission source address, sequence control information 304 such as a sequence number, and necessary for access control. And access control information 305 in which parameters are described. Here, a wireless address generated by itself is used as the source address 303 when connecting to the host communication device.

  In addition, the beacon payload information 320 includes unique information 321 that is a parameter unique to the communication device, beacon usage information 322 that indicates use of a beacon slot, capability information 323 that indicates the capability of the communication device, and operation in the hibernation mode. Dormant mode information 324, DRP reservation information 325 indicating the MAS location where DRP (Distributed Reservation Protocol) reservation is made, DRP usage information 326 indicating the MAS location available for DRP reservation, PCA ( Prioritized Contention Access) includes PCA usage information 327 indicating a MAS position that may be used for communication, and transmission information 328 indicating that data to be transmitted to the receiving communication apparatus exists.

  Note that the beacon frame 30 may be configured by adding or deleting these various parameters as necessary.

(5) Setting example of MAS FIG. 5 is an explanatory diagram showing a setting example of the MAS based on the DRP reservation and DRP usage information included in the beacon frame 30 in a bitmap format.

  DRP is specified by combining bits of a zone bitmap (0 to 15) indicating one zone every 16 MAS and a MAS bitmap (0 to 15) indicating bits of MAS for each zone (DRP Allocation) Is done.

  For example, if the zone bitmap is “1” designating all MASs and only 15 of the MAS bitmap is set to “1”, the logical sum of each bitmap is taken and the thick frame region x in FIG. That is, it means that the use of MAS 15, 31, 47, 63, 79, 95, 111, 127, 143, 159, 175, 191, 207, 223, 239 and 255 is designated.

(6) Frequency Hopping Pattern Next, the frequency hopping pattern of the communication apparatus according to the present embodiment will be described.

  FIG. 6 is an explanatory diagram showing a configuration example of frequency hopping in an ad hoc network.

  A pattern for performing frequency hopping is defined by a code of a physical channel called TFC. For example, when the physical channel is TFC: 1, subbands to be used change according to the rules of subband 1, subband 2, subband 3, subband 1, subband 2, and subband 3.

  Further, when the physical channel is TFC: 2, the subband used changes according to the rules of subband 1, subband 3, subband 2, subband 1, subband 3, and subband 2.

  When the physical channel is TFC: 3, subbands to be used change according to the rules of subband 1, subband 1, subband 2, subband 2, subband 3, and subband 3. Similarly, when the physical channel is TFC: 4, the subband used changes according to the rules of subband 1, subband 1, subband 3, subband 3, subband 2, and subband 2.

  Furthermore, in the multi-band OFDM method, patterns that do not perform frequency hopping, such as TFC: 5 to 7, are also prepared.

  Specifically, TFC: 5 uses only subband 1 continuously, TFC: 6 uses only subband 2 continuously, and TFC: 7 uses only subband 3 continuously. Thus, the frequency hopping pattern to be used is determined according to the TFC code to be set.

  In addition, a predetermined preamble sequence corresponding to each TFC code is prepared for the TFC code to be used. The preamble is a synchronization signal added to a signal to be transmitted / received.

  Specifically, when TFC: 1 is set as the frequency hopping pattern, sequence 1 is set, when TFC: 2 is set, sequence 2 is set, when TFC: 3 is set, sequence 3 is set, and TFC: When 4 is set, sequence 4 is used, when TFC: 5 is set, sequence 5 is used, when TFC: 6 is set, sequence 6 is used, and when TFC: 7 is set, sequence 7 is used. can do.

  In addition, in this embodiment, although the structure which uses the subbands 1-3 as the band group 1 was illustrated, the band group 2 containing the subbands 4-6 which are higher frequency bands, and the subbands 7-9 are included. Band group 3 may be used.

(7) State of frequency hopping FIGS. 7A to 7D are schematic diagrams showing a state of frequency hopping according to the above-described configuration example of frequency hopping. The schematic diagram shows an example of subband frequency hopping defined in the ultra-wideband wireless communication system of the multiband OFDM system.

  FIG. 7A shows a state of frequency hopping of TFC: 1. As shown in the figure, in TFC: 1, information bits are transmitted between predetermined symbols in subband 1, then information bits are transmitted between predetermined symbols in subband 2, and predetermined symbols are transmitted in subband 3. Information bits are transmitted in the meantime, and information is continuously transmitted by repeating the operation.

  7B shows a state of frequency hopping of TFC: 2, FIG. 7C shows a state of frequency hopping of TFC; 3, and FIG. 7D shows a state of frequency hopping of TFC: 4. Also in the TFC channels 2 to 4, the information bits can be continuously transmitted by sequentially switching the subbands to be used in the same manner as the TFC channel 1.

  However, when a communication device belonging to a different network exists in the vicinity of a certain communication device, an interference problem may occur. That is, there may be a case where a communication device belonging to a different network overlaps with a time zone used for wireless communication by itself, and in this case, even if the TFC channels of both are different, interference occurs partially.

(8) Example of Radio Communication Interference FIG. 8 is an explanatory diagram showing an example of radio communication interference. Specifically, the usage state of each subband is shown in the case where the communication apparatus operates by TFC: 1 and operates by TFC: 4 in the vicinity. The subband used by itself is shown as selfband A, and the subband used by other nearby communication devices is shown as other band B. When the self band A and the other band B overlap, the self band A and the other band B are collectively shown as a composite region Y.

  Referring to FIG. 8, an interference area C where the self band A and the other band B overlap can be confirmed in the composite area Y. In the interference region C in which such interference occurs, there is a problem that an error occurs in data transmission / reception and satisfactory communication cannot be performed. Also, as shown in the present embodiment, when there are three subbands, interference occurs with an average frequency of about 1/3, and the frequency greatly exceeds the number of errors that can be corrected by physical layer error correction.

  According to an embodiment of the present invention, there is provided a communication apparatus that prevents the problem of frequency interference with the neighboring communication apparatus. Hereinafter, the configuration of the communication apparatus according to the present embodiment will be described with reference to FIG.

(9) Configuration of Communication Device FIG. 9 is a block diagram showing the configuration of the communication device 110 according to the present embodiment. The communication device 110 includes an antenna 144, a high frequency signal processing unit 146, a signal detection unit 148, a preamble detection unit 150, a hopping pattern setting unit 152, a received beacon signal detection unit 154, a received beacon information analysis unit 156, and a usage time zone analysis unit 158. , An information storage unit 160, a use time zone determination unit 170, a transmission beacon information setting unit 172, a communication device control unit 174, an access control unit 176, a wireless transmission signal construction unit 178, a data buffer 180, and a data interface unit 182.

  The antenna 144 can transmit / receive predetermined information to / from other communication devices using high-frequency radio signals, and functions as a transmission unit and a reception unit. Examples of the predetermined information include beacons and data transmitted / received in the MAS in which the DRP reservation is set.

  The high frequency radio processing unit 146 amplifies the high frequency radio signal received by the antenna 144 and converts it into a received signal. In addition, it has a function of converting predetermined information transmitted from the antenna 144 into a transmission signal as a high-frequency radio signal.

  The signal detection unit 148 has a function of detecting a signal based on a spread spectrum technique other than the frequency hopping method, for example, a signal based on the direct spread method, based on the reception signal output from the high-frequency wireless processing unit 146.

  The preamble detection unit 150 detects a predetermined preamble signal added as a synchronization signal to the signal of the multiband OFDM wireless communication system based on the transmission signal output from the high-frequency radio processing unit 146, and detects the synchronization signal It functions as a part. Also, the preamble detector 150 according to the present embodiment can set an arbitrary preamble pattern so that signals of different frequency hopping patterns can be detected.

  The hopping pattern setting unit 152 functions as a pattern setting unit that sets a frequency hopping pattern of a multiband OFDM wireless communication system. The hopping pattern setting unit 152 according to the present embodiment can switch and set the frequency hopping pattern to a different TFC channel as appropriate.

  With this configuration, the communication device 110 according to the present embodiment can receive DRP reservation information of a communication device in a network that performs communication using another frequency hopping pattern in addition to the DRP reservation information of the communication device in its own network. It becomes possible.

  In the conventional radio system capable of detecting a carrier, other frequency hopping patterns can be detected without changing its own frequency hopping pattern. However, in a multi-band OFDM wireless communication system, since the signal is below a level at which a carrier can be detected, unless the frequency hopping pattern is changed to be the same as that of the interference partner as in this embodiment, the communication device of the interference partner It is difficult to acquire the DRP reservation information.

  The reception beacon signal detection unit 154 extracts a beacon from the reception signal received by a predetermined frequency hopping pattern after the preamble detection unit 150 detects the preamble. Note that the beacon detected by the received beacon signal detection unit 154 is not limited to the beacon transmitted by the communication device of its own network, but includes beacons of communication devices of other networks.

  The reception beacon information analysis unit 156 analyzes DRP reservation information and available time zone information described in the beacon detected by the reception beacon signal detection unit 154.

  Based on the DRP reservation information and the available time zone information analyzed by the received beacon information analysis unit 156 and the signal by the other spread spectrum method detected by the signal detection unit 148, the usage time zone analysis unit 158 Analyze the usage time zone of existing communication devices.

  The information storage unit 160 serving as a storage unit stores the usage time zone analyzed by the usage time zone analysis unit 158 as a usage interference time zone that is highly likely to cause interference when the communication is performed. Moreover, the available time zone of the own communication determined by the available time zone determination unit 170 described later is stored.

  The available time zone determination unit 170 determines its own available time zone based on the analysis result of the usage time zone by the communication devices existing around the self by the usage time zone analysis unit 158. Below, the detail of the determination method of an available time slot | zone is demonstrated.

(10) Embodiment for Detecting Communication Through Other Network FIG. 10 is an explanatory diagram showing an embodiment for detecting communication through another network. The communication device 110 has a beacon skip period during which communication is not performed on its own network. In the illustrated example, a state in which communication is not performed in its own network in the second and fifth superframe periods is indicated by dotted lines. The beacon skip period may be controlled by the communication device control unit 174 described later.

  The communication device 110 according to the present embodiment can change the frequency hopping pattern during the beacon skip period and detect information of other networks. In the illustrated example, a state in which the frequency hopping pattern is changed to another TFC channel during the beacon skip period is indicated by a solid line. Further, as shown in the figure, it is possible to change to a different frequency hopping pattern in each beacon skip period.

  With this configuration, it is possible to detect management information or a beacon of another network without interfering with the original communication of itself. In addition, after grasping the existence of a network that operates with a different frequency hopping pattern by the beacon scan operation immediately after the power is turned on, even if a new different network approaches, it acquires new network information and It can be reflected in the usage time zone.

(11) Determination of Available Time Zone FIGS. 11A and 11B are explanatory diagrams showing how the available time zone is determined by the available time zone determination unit 170. FIG. Each MAS constituting the bitmap is classified into a self-beacon period 210, a self-use period 220, an unusable period 230, an available time period 240, another beacon period 250, and another network use period 260.

  FIG. 11A shows an available time zone when a different network does not exist in the vicinity of the self. The self-beacon period 210 (MAS0 to 15) indicates a time zone reserved as a beacon period (Beacon Period) in its own network.

  A self-use period 220 (lines 14 and 15 of the MAS bitmap) indicates a time zone in which DRP is reserved as a MAS used by the self-use period. Further, the unusable period 230 (lines 11 to 13 of the MAS bitmap) indicates a time zone in which DRP reservation is used by other communication devices operating on the own network. Since communication devices that operate in their own networks use a common frequency hopping pattern, there is a high possibility that interference will occur when new communication is performed using this period, and the time zone is not available.

  The other available time zone 240 indicates a time zone in which communication devices belonging to the own network can be used. However, when there is a network operating in a different frequency hopping pattern in the vicinity, interference cannot be avoided by considering only the periods 210 to 240.

  FIG. 11B shows the available time period 240 when different networks exist in the vicinity of the self. That is, the communication apparatus 110 changes the frequency hopping pattern to another TFC code and detects another network in the vicinity.

  Other beacon period 250 (MAS105-120) has shown the time slot reserved as a beacon period of another network. The other network usage period 260 (lines 3 to 8 of the MAS bitmap) indicates a time zone corresponding to a DRP reservation for which usage is set in another network. In the other beacon period 250 and the other network use period 260, the frequency bands to be used partially or entirely overlap as described with reference to FIG.

  As shown in the figure, out of the self-use period 220 that has been reserved for DRP as the MAS used by itself, MAS 110 and 111 overlap with other beacon periods 250 and are likely to cause interference, so the reservation time zone can be used. The time zone 240 can be changed within the area.

  Thus, according to the present embodiment, even when there are wireless communication devices that operate with different frequency hopping patterns in the vicinity, the beacon of the wireless communication device can be received and the time zone in which interference occurs can be ascertained. It is possible to perform normal wireless communication while avoiding the time period.

  In the other beacon period 250 and the other network use period 260, depending on the combination of the own TFC code and the TFC of another network, the degree of interference may be low. Therefore, in such a case, it is not always necessary to set the use time zone by avoiding the other beacon period 250 and the other network use period 260.

  FIG. 12 is another explanatory diagram showing how the available time zone determination unit 170 determines the available time zone. FIG. 12 shows a part of the superframe period extracted, and the upper part shows the DRP reservation status of other networks, the middle part shows its own DRP reservation situation, and the lower part shows the changed DRP reservation situation.

  If the time zone reserved by DRP in other networks (shaded area) and the time zone reserved by DRP partially overlap as shown in the figure, communication will occur in that time zone due to the influence of interference. Can not be done satisfactorily.

  Therefore, as shown in the lower part of FIG. 12, by setting the own DRP reservation MAS while avoiding the time zone reserved for DRP in other networks, the error is suppressed without being affected by interference. Communication can be performed.

  Here, returning to the description of the configuration of the communication device 110, the transmission beacon information setting unit 172 generates a transmission beacon to which information on the available time zone obtained as described above is added.

  The communication device control unit 174 controls the operation as a communication device and the timing of frequency hopping from the reception status of beacons and the setting status of a time zone (MAS) for data transmission / reception. Moreover, it can also be set as the structure which controls a beacon skip period.

  The access control unit 176 performs communication access control in a data transmission / reception time zone. The radio transmission signal construction unit 178 constructs data for the high frequency signal processing unit 146 to generate a transmission signal. The data buffer 180 has a function of temporarily storing reception signals and transmission signals. The data interface unit 182 exchanges data with devices and applications connected to the communication device 110.

  In addition, each structure which comprises the communication apparatus mentioned above may be comprised so that a part may be added or removed as needed, or several functions may be included.

(12) Flow of Operation of Communication Device Next, the operation of the communication device 110 according to the present embodiment will be described.

  FIG. 13 is a flowchart showing an operation flow of the communication apparatus 110 according to the present embodiment. FIG. 13 shows an operation after the communication apparatus 110 is powered on. First, the communication apparatus 110 performs a scanning operation for grasping the existence of the network over a predetermined superframe period (S401).

  If an existing network is detected as a result of the scanning operation, the self-frequency hopping pattern is set to the frequency hopping pattern of the existing network, and the superframe period is also set (S402). If no existing network is detected, a frequency hopping pattern and a superframe period are arbitrarily set. And the beacon skip period which stops transmission of a beacon is set (S403).

  Next, it is determined whether or not it is currently the head of the superframe cycle (S404). If it is determined that it is the head of the superframe, it is determined whether or not it is a beacon skip period (S405). Subsequently, when it is determined that it is not the beacon skip period, it is determined whether or not it is the self beacon period (S406).

  If it is determined in S406 that it is the self beacon period, a frequency hopping pattern used in the self network is set in order to exchange information in the beacon period (S407). Then, the corresponding preamble sequence is also set (S408).

  Subsequently, it is determined whether or not the present time is the self beacon slot period (S409). When it is determined that it is the self beacon slot period, information on a time zone used for communication in the network, such as DRP reservation information, is acquired (S410). Further, information on an available time zone indicating a time zone in which the communication device of the own device can be used is acquired (S411). Then, a beacon is constructed based on the available time zone and transmitted (S412).

  Then, after transmitting a beacon at S412, or when it is determined at S409 that the beacon is not its own beacon, it receives beacons from surrounding communication devices belonging to its own network and collects the beacon information (S413).

  Next, it is determined whether or not the beacon period has ended (S414). If it is determined that the beacon period has not ended, the process returns to S407 and the operations up to S413 are repeated. If it is determined that the beacon period has ended, based on the acquired DRP reservation information and the like, the time zone used by the user is set, and the process returns to S404 (S415).

  If it is determined in S405 that the current time is the beacon skip period, the frequency hopping pattern is set to a pattern different from the frequency hopping pattern used in its own network (S416). Then, a preamble corresponding to the changed frequency hopping pattern is set (S417). When there are a plurality of frequency hopping patterns, they can be switched and set as appropriate.

  Subsequently, it is determined whether or not the preamble set in S417 is detected (S418). If the preamble is detected, the received signal is continuously analyzed to determine whether a beacon of another network has been received (S419). If a beacon is received, the time when the beacon is detected is stored (S420). Here, the time when the beacon is detected is stored in order to convert the DRP reservation information of other networks into its own superframe period, so it is necessary to know the difference in synchronization with its own superframe. Because there is.

  Then, the beacon parameters are continuously analyzed, and time zone information (DRP reservation information) used in another network described in the beacon is acquired (S421). Further, the time zone information is held as information on a time zone that may cause interference (S422).

  Next, based on the information on the time zone that may cause the interference and the difference between the synchronization of the superframes, the time zone (MAS) that can be used by itself is determined (S427). Then, the available time zone is set as available time zone information or DRP Availability IE (S428).

  On the other hand, if no preamble is detected in S418, it is determined whether or not a signal by another spread spectrum method or the like is received (S423). If it is determined that a signal by another spread spectrum method or the like has not been received, the process proceeds to S427. When a signal by another spread spectrum method is detected, the time when the signal is detected is stored (S424). Then, it is determined whether or not the stored time is periodic (S425). If it is determined that there is periodicity, a time zone that may cause interference is calculated and held based on the periodicity (S426). Then, the process proceeds to S427.

  If it is determined in S404 that the current time is not the beginning of the superframe period, it is determined whether or not it is the own use time zone (S429). If it is determined that it is the own use time zone, a frequency hopping pattern used in the own network is set (S430). The preamble is also set to a sequence corresponding to its own frequency hopping pattern (S431), and a series of data transmission / reception operations are performed (S432). If it is determined in S429 that it is not the own use time zone, the sleep operation is performed in that time zone, and the reception process is not performed.

  As mentioned above, 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.

It is the conceptual diagram which showed the structural example of the ad hoc network. It is the conceptual diagram which showed the structural example of the super frame. It is the conceptual diagram which showed the own beacon slot position which each communication apparatus sets. It is explanatory drawing which showed the structural example of the beacon frame transmitted to a beacon slot. It is explanatory drawing which showed the example of a setting of MAS in the bit map format. It is explanatory drawing which showed the structural example of frequency hopping. It is the schematic diagram which showed the mode of frequency hopping. It is the schematic diagram which showed the mode of frequency hopping. It is the schematic diagram which showed the mode of frequency hopping. It is the schematic diagram which showed the mode of frequency hopping. It is explanatory drawing which showed the example of interference of radio | wireless communication. It is the block diagram which showed the structure of the communication apparatus by this embodiment. It is explanatory drawing which showed the Example which detects the communication in another network. It is explanatory drawing which showed the mode of the determination of the available time zone by the available time zone determination part. It is explanatory drawing which showed the mode of the determination of the available time zone by the available time zone determination part. It is another explanatory drawing which showed the mode of determination of the available time slot | zone by the available time slot | zone determination part. It is the flowchart which showed the flow of operation | movement of the communication apparatus by this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Ad hoc network 110-115 Wireless communication apparatus 144 Antenna 150 Preamble detection part 152 Hopping pattern setting part 158 Usage time zone analysis part 160 Information storage part 170 Available time zone determination part

Claims (6)

In a wireless communication device constituting a wireless network:
A pattern setting unit that switches and sets the frequency hopping pattern from a self-hopping pattern used for wireless communication in its own network to another hopping pattern used for wireless communication in another network during a predetermined period;
A receiving unit that receives predetermined management information from its own network or another network using the frequency hopping pattern set by the pattern setting unit;
A usage time zone analysis unit that analyzes reservation time zone information that is included in the predetermined management information received by the reception unit and that indicates a time zone that other radio communication devices use for radio communication;
Based on the time when the receiving unit receives management information from the wireless communication device of the other network and the reserved time zone information of the wireless communication device of the other network, the self communication is performed by the other hopping pattern. An available time zone determination unit for determining the available time zone;
A wireless communication device.   The wireless communication apparatus according to claim 1, wherein the predetermined period is a period in which wireless communication in the own network is stopped.   The wireless communication apparatus according to claim 1, further comprising a synchronization signal detection unit that is used for the wireless communication and detects a synchronization signal that differs for each frequency hopping pattern.   The wireless communication device according to claim 1, further comprising a storage unit that stores a time zone in which the wireless communication device of the other network performs wireless communication using the other hopping pattern as an interference time zone in which interference occurs. In a wireless communication method using a wireless communication device constituting a wireless network:
Switching and setting the frequency hopping pattern from a self-hopping pattern used for wireless communication in its own network to another hopping pattern used for wireless communication in another network during a predetermined period;
Receiving predetermined management information from its own network or another network using the set frequency hopping pattern;
Analyzing reserved time zone information included in the predetermined management information and indicating a time zone used by another wireless communication device for wireless communication;
Based on the time when the management information is received from the wireless communication device of the other network and the reserved time zone information of the wireless communication device of the other network by the other hopping pattern, the self can be used for wireless communication Determining a time zone ;
A wireless communication method. Computer
A pattern setting unit that switches and sets the frequency hopping pattern from a self-hopping pattern used for wireless communication in its own network to another hopping pattern used for wireless communication in another network during a predetermined period;
A receiving unit that receives predetermined management information from its own network or another network using the frequency hopping pattern set by the pattern setting unit;
A usage time zone analysis unit that analyzes reservation time zone information that is included in the predetermined management information received by the reception unit and that indicates a time zone that other radio communication devices use for radio communication;
Based on the time when the receiving unit receives management information from the wireless communication device of the other network and the reserved time zone information of the wireless communication device of the other network, the self communication is performed by the other hopping pattern. An available time zone determination unit for determining the available time zone;
A computer program for causing a computer to function as a wireless communication device including:

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