JP4517814B2 - COMMUNICATION SYSTEM, COMMUNICATION DEVICE, AND COMMUNICATION METHOD - Google Patents

Description

  The present invention relates to a communication system, a communication apparatus, and a communication method that can communicate without having a control station.

  Conventionally, it is generally known that a plurality of computers are connected by information communication means to configure a LAN (local area network) that can transmit and receive information such as files and data, and share information. Yes.

  Recently, as home appliances such as TVs have information processing functions as IT products, and information processing devices such as personal computers (PCs) have become widespread, for example, these devices are connected by wireless communication. A network (PAN: Personal Area Network) used by individuals such as in the home is known.

  In addition, as a network configuration using the PAN, there is also known an ad hoc network in which a control station such as an access point does not exist and surrounding communication devices constitute an autonomously distributed network (for example, Patent Documents). 1).

JP 2000-165930 A

  However, even in an ad hoc network that does not have a control station, when communication processing such as data transmission / reception is performed between multiple communication devices, each communication device configured in the ad hoc network is managed and access control of each communication device is performed. For this reason, there are many cases in which synchronization is established with each communication device.

  The present invention has been made in view of the above problems, and an object of the present invention is to perform communication processing between communication devices without performing complicated synchronization processing between the communication devices. It is another object of the present invention to provide a new and improved communication system, communication apparatus, and communication method.

  In order to solve the above problems, according to a first aspect of the present invention, there is provided a communication system including a plurality of communication devices having no relationship between a control station and a controlled station. The communication system includes a step of setting a superframe having a predetermined period composed of a plurality of time frames for transmitting and / or receiving a signal based on clock information of its own communication device; and at least a beacon signal in the superframe. Determining a time frame for transmission; receiving a beacon signal transmitted in a superframe cycle by another communication device existing in a communication area capable of communicating with the communication device; And a time frame for transmitting and / or receiving a signal described in a beacon signal from another communication device, and at least a time frame for transmitting a beacon signal by the own communication device in the time frame management table. And assigning based on clock information of its own communication device. A time frame for transmitting and / or receiving a signal described in a beacon signal from another communication device is set, for example, as a time frame parameter.

  According to the present invention, in a communication system including a plurality of communication devices, the communication device transmits at least a beacon signal from a plurality of time frames configured in a superframe having a predetermined period set by the communication device. Determine the time frame to be performed. Further, the own communication device receives a beacon signal transmitted from another communication device according to a time frame, and transmits / receives a signal such as a beacon signal described in the beacon signal, and the own communication device. The time frame for transmitting the beacon signal determined in (1) is assigned to the time frame management table. According to such a configuration, each communication device in the communication system does not synchronize, and transmits and receives the signal specified in that time frame by following the time frame assigned to the time frame management table managed by each communication device. It is possible to execute predetermined communication processing even asynchronously. Since the time frame management table is not the same among the communication devices but is almost the same, the other communication devices do not transmit the beacon signal in the time frame in which the communication device transmits the beacon signal. Therefore, collision of beacon signals transmitted by the communication device can be avoided in advance.

  The transmission timing of the beacon signal between the self communication device and the other communication device can be configured not to overlap. With this configuration, each communication device can accurately transmit data or the like to the communication device of the other party without signal collision.

  In order to solve the above-described problems, according to another aspect of the present invention, a communication system including a plurality of communication devices having no relationship between a control station and a controlled station is provided. The communication method comprises the steps of setting common clock information in one or more network groups composed of one or more communication devices; and for transmitting and / or receiving signals based on the common clock information A step of setting a superframe having a predetermined period composed of a plurality of time frames; and a step of determining a time frame for transmitting at least a beacon signal of each communication device in each network group in the superframe; Receiving a beacon signal transmitted in a predetermined cycle according to the superframe by a communication device in the network group; and transmitting and / or receiving a signal described in the beacon signal from the communication device existing in the network group Time frame and at least the determined beacon signal It is characterized in that it comprises a time frame for transmission to the time frame management table and allocating, based on the clock information.

  According to the present invention, one or two or more network groups exist, and in a communication system composed of one or more communication devices in the network group, a common clock is set in one or more network groups. The time frame for transmitting the beacon signal is determined. Further, within each network group, a time frame in which the own communication device receives a beacon signal transmitted from another communication device according to a time frame and transmits / receives a signal such as a beacon signal described in the beacon signal; The time frame for transmitting the beacon signal determined by the communication device is assigned to the time frame management table. According to such a configuration, each communication device in each network group in the communication system is not synchronized, and is designated as that time frame by following the time frame assigned to the time frame management table managed by each communication device. A predetermined communication process such as transmission / reception of transmitted signals can also be executed asynchronously. Since the time frame management table is not the same among the communication devices but is almost the same, the other communication devices do not transmit the beacon signal in the time frame in which the communication device transmits the beacon signal. Therefore, collision of beacon signals transmitted by the communication device can be avoided in advance. The time frame is adjusted so that the transmission timing of beacon signals does not overlap between network groups, and the time frame is adjusted so that the transmission timings of beacon signals do not overlap even within network groups.

  In order to solve the above-described problem, according to another aspect of the present invention, a communication device can convert its own clock information into a superframe having a predetermined period composed of a plurality of time frames for transmitting and / or receiving a signal. Frame setting means for setting based on: time frame determining means for determining at least a time frame for transmitting a beacon signal in a super frame; a beacon signal for receiving a beacon signal transmitted at predetermined intervals according to the super frame Receiving means; for obtaining a time frame for transmitting and / or receiving a signal based on a time frame parameter described in the beacon signal received by the beacon signal receiving means, and for transmitting and / or receiving the signal; The time frame and at least the time frame for transmitting the beacon signal are allocated to the time frame management table based on the clock information. It is characterized in that it comprises a time frame management means shining.

  According to the present invention, the communication apparatus determines at least a time frame for transmitting a beacon signal from a plurality of time frames configured in a superframe having a predetermined period set by itself. In addition, a time frame for receiving a beacon signal sent from a communication device existing in the communication area according to the time frame and transmitting / receiving a signal such as a beacon signal described in the beacon signal, and the self communication The time frame for transmitting the beacon signal determined by the device is assigned to the time frame management table. According to such a configuration, the communication device is designated as the time frame by following the time frame assigned to the time frame management table managed by each communication device without synchronizing when communicating with the external communication device. A predetermined communication process such as transmission / reception of a signal can be executed asynchronously. Since the time frame management table is not the same among the communication devices but is almost the same, the other communication devices do not transmit the beacon signal in the time frame in which the communication device itself transmits the beacon signal. Therefore, collision of beacon signals transmitted by the communication device can be avoided in advance.

  The communication device includes a scan cycle setting means for setting a scan cycle for scanning a beacon signal in order to grasp the presence of another communication device existing in a communication area capable of communicating with the communication device; Scanning means for continuously executing a beacon signal receiving process for receiving a beacon signal for a predetermined period determined by a super frame; and a communication device existing in the communication area each time the beacon signal receiving process is performed by the scanning means A grasping means for grasping may be further provided. With this configuration, even when a new communication device is added, a beacon signal collision can be avoided by scanning the beacon signal and adjusting the timing or time frame.

  The grasping means for grasping other communication devices existing in the communication area may be configured to grasp by analyzing a beacon signal from the other communication device.

  The communication device comprises time measuring means for measuring the reception time of the beacon signal from the communication device existing in the communication area with reference to its own clock information, and the time frame determining means is at the time measured by the time measuring means. The corresponding time frame is determined as a time frame for receiving a beacon signal from a communication device existing in the communication area, and the time frame managing means synchronizes reception of the beacon signal with the time frame in the communication device. If not, the time frame corresponding to the time measured and the next (or next) time frame may be described in the time frame management table. With this configuration, a time frame for executing the communication process can be provided, and the communication process can be smoothly executed in each communication device.

  The time frame management means determines a time frame for transmitting and / or receiving a signal based on a time frame parameter described in a beacon signal from a communication device existing in the communication area, The clock information may be converted into access time based on the clock information, and access control of each communication device may be performed based on the access time. The access control can be exemplified by, for example, instructing the timing of communication processing by referring to a time frame and instructing to end the communication processing within the converted access time.

  The communication apparatus includes a beacon signal generating unit that generates a beacon signal in which a time frame parameter described in the time frame management table is set; a beacon signal transmitting unit that transmits the beacon signal, and the beacon signal transmitting unit is a beacon signal. You may comprise so that the time frame parameter set to the beacon signal may be alert | reported to the other communication apparatus which exists in a communication area by transmitting the beacon signal produced | generated by the signal production | generation means.

  The time frame management means may be configured to assign the time frame determined based on the time frame parameter to the time frame management table when the time frame in the time frame management table is not allocated and is free. With this configuration, the timing of communication processing executed by each communication device does not overlap and signal collision can be avoided in advance.

  When the time frame in the time frame management table has already been assigned, the time frame management means selects a time frame determined based on the time frame parameter next to (or next to) the time frame in the time frame management table. It may be configured to be assigned to a time frame.

  The time frame determining means may be configured to determine a time frame for transmitting / receiving data, and the super frame is set so that start timings do not overlap among a plurality of communication devices. It may be configured.

  In order to solve the above-described problem, according to another aspect of the present invention, a communication device sets a clock setting for setting common clock information in one or more network groups composed of one or more communication devices. Means for setting a superframe of a predetermined period composed of a plurality of time frames for transmitting and / or receiving a signal based on the common clock information; in the superframe, in each network group Time frame determining means for determining at least a time frame for transmitting a beacon signal of each communication device; beacon signal receiving means for receiving a beacon signal transmitted in a predetermined cycle according to a superframe by a communication device in a network group; Included in beacon signals from communication devices that exist in the network group A time frame management means for allocating a time frame for transmitting and / or receiving a signal and a time frame for transmitting at least the determined beacon signal to the time frame management table based on the clock information. Yes.

  According to the present invention, the communication apparatus sets a common clock for one or more network groups and determines a time frame for transmitting a beacon signal. Further, in each network group, the communication device receives a beacon signal transmitted from another communication device according to a time frame, and transmits / receives a signal such as a beacon signal described in the beacon signal, A time frame for transmitting the beacon signal determined by the communication device is assigned to the time frame management table. According to such a configuration, the communication device can follow the time frame assigned to the time frame management table managed by each communication device without synchronizing with each communication device in each network group. A predetermined communication process such as transmission / reception of a designated signal can be executed asynchronously. Since the time frame management table is not the same among the communication devices but is almost the same, the other communication devices do not transmit the beacon signal in the time frame in which the communication device transmits the beacon signal. Therefore, collision of beacon signals transmitted by the communication device can be avoided in advance. The time frame is adjusted so that the transmission timing of beacon signals does not overlap between network groups, and the time frame is adjusted so that the transmission timings of beacon signals do not overlap even within network groups.

  The communication device has a scan cycle setting means for setting a scan cycle for scanning a beacon signal in order to grasp the presence of another communication device in the same network group as the communication device; Scanning means for continuously executing beacon signal reception processing for receiving a beacon signal for a predetermined period; and grasping means for grasping communication devices belonging to the network group each time the beacon signal reception processing is performed by the scanning means; , May be further provided.

  The communication device comprises time measuring means for measuring the reception time of a beacon signal from a communication device in the same network group as the communication device with reference to its own clock information, and the time frame determining means is timed by the time measuring means. A time frame corresponding to the time is determined as a time frame for receiving a beacon signal from a communication device belonging to the network group, and the time frame management means synchronizes reception of the beacon signal with the time frame in the communication device. If not, the time frame corresponding to the time measured and the next (or next) time frame may be described in the time frame management table.

  The time frame management means determines a time frame for transmitting and / or receiving a signal based on the time frame parameter described in a beacon signal from a communication device belonging to a network group, The clock information may be converted into access time based on the clock information, and access control of each communication device may be performed based on the access time.

  The communication apparatus includes a beacon signal generating unit that generates a beacon signal in which a time frame parameter described in the time frame management table is set; a beacon signal transmitting unit that transmits a beacon signal, and a beacon signal transmitting unit. By transmitting the beacon signal generated by the beacon signal generating means, the time frame parameter set in the beacon signal can be notified to other communication devices belonging to the same network group as the communication device. Good.

  The time frame management means may be configured to assign the time frame determined based on the time frame parameter to the time frame management table when the time frame in the time frame management table is not allocated and is free.

  In order to solve the above-described problems, according to another aspect of the present invention, a communication method including a plurality of communication devices having no relationship between a control station and a controlled station is provided. In the communication method, a superframe having a predetermined period composed of a plurality of time frames for transmitting and / or receiving a signal is set based on clock information of the own communication device; in the superframe, at least a beacon signal is set. A communication apparatus that receives a beacon signal transmitted in a predetermined cycle according to a superframe by another communication apparatus that exists in a communication area capable of communicating with the communication apparatus; A time frame for transmitting and / or receiving a signal described in a beacon signal from another communication device and at least a time frame for the communication device to transmit a beacon signal are stored in the time frame management table. The allocation is based on the clock information of the communication device.

  Furthermore, in order to solve the above-described problem, according to another aspect of the present invention, a communication method including a plurality of communication devices having no relationship between a control station and a controlled station is provided. The communication method sets common clock information in one or more network groups composed of one or two or more communication devices; for transmitting and / or receiving a signal based on the common clock information Setting a superframe having a predetermined period composed of a plurality of time frames; determining a time frame for transmitting at least a beacon signal of each communication device in each network group in the superframe; Receiving a beacon signal transmitted in a predetermined cycle according to a superframe by a communication device; a time frame for transmitting and / or receiving a signal described in a beacon signal from a communication device existing in the network group; The time frame for transmitting the determined beacon signal and the time frame management table It is characterized by allocating, based on lock information.

  As described above, according to the present invention, each communication device in the communication system does not need to execute communication processing synchronously with other communication devices, so that it is very precise for synchronization. Control can be omitted, and each communication device itself can execute communication processing such as data transmission in an autonomous and distributed manner.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, components having substantially the same functions and configurations are denoted by the same reference numerals, and redundant description is omitted.

  First, an ad hoc network will be described with reference to FIG. FIG. 1 is an explanatory diagram showing a schematic configuration of an ad hoc network.

  As shown in FIG. 1, in an ad hoc network, a plurality of communication devices 101 including communication devices 101 (101a, 101b,..., 101g) are arranged in space. Note that the case of seven communication apparatuses 101 shown in FIG. 1 will be described as an example. However, the communication apparatus 101 is not limited to this example as long as a plurality of communication apparatuses 101 are provided. The communication device 101 is described as an example of a device capable of wireless communication. However, the communication device 101 is not limited to this example, and can be implemented, for example, in the case of a device capable of wired communication.

  Each of the communication devices 101 has an area (communication area 102) in which data communication can be performed with other communication devices 101 by transmitting radio waves. Therefore, the communication apparatus 101 existing in the vicinity is configured to be able to directly communicate with each other.

  Here, the communication device 101a can perform direct data communication with neighboring communication devices 101b, 101c, and 101d existing in the communication area 102a (within the elliptical broken line centering on the communication device 101a). The communication devices 101e, 101f, 101g outside the communication area 102a cannot communicate directly.

  Similarly, the radio wave reachable range of the communication device 101b is the communication area 102b, and the neighboring communication devices 101a, 101d, and 101b in the communication area 102b can directly communicate with each other, but the other communication devices 101c. The communication device 101e, the communication device 101f, and the communication device 101g cannot communicate directly.

  The radio wave reachable range of the communication device 101c is the communication area 102c, and the neighboring communication device 101a, the communication device 101f, and the communication device 101g and the communication device 101c in the communication area 102c can directly communicate with each other. 101b, the communication device 101d, and the communication device 101e cannot communicate directly.

  The radio wave reachable range of the communication device 101d is the communication area 102d, and the communication device 101a, the communication device 101b, and the communication device 101e and the communication device 101e in the communication area 102d can directly communicate with each other. 101c, communication device 101f, and communication device 101g cannot communicate directly.

  As shown in FIG. 1, the radio device reachable range of the communication device 101e is the communication area 102e, and the communication device 101e can directly communicate only with the neighboring communication device 101d in the communication area 102e, but the other communication devices 101a, The communication device 101b, the communication device 101c, the communication device 101f, and the communication device 101g cannot communicate directly.

  The radio wave reachable range of the communication device 101f is the communication area 102f, and the communication device 101f can directly communicate only with the neighboring communication device 101c in the communication area 102f, but the other communication device 101a, communication device 101b, communication device 101d, communication device 101e, and communication device 101g cannot communicate directly.

  The radio wave reachable range of the communication device 101g is the communication area 102g, and the communication device 101g can directly communicate only with the neighboring communication device 101c in the communication area 102f, but the other communication devices 101a, 101b, 101d, Direct communication is not possible with the communication device 101e and the communication device 101f.

  Further, the communication device 101a, the communication device 101b, the communication device 101d, and the communication device 101 indicated by “◯” of the communication device 101e form a first network group, and the communication device 101c, the communication device 101f, and the communication device 101 The communication device 101 indicated by “●” of the device 101g forms a second network group. The network group will be described in detail later.

  Next, a super frame in an ad hoc network will be described with reference to FIG. FIG. 2 is an explanatory diagram illustrating an example of a schematic configuration of a superframe.

  As shown in FIG. 2, the super frame is set based on a cycle in which each communication apparatus 101 transmits a beacon signal. Note that the period of the super frame of each communication device 101 is the same, but the period is set in advance.

  In addition, a super frame is defined by the communication device 101 transmitting periodic beacon signals at predetermined time intervals. In addition, the transmission timing of the beacon signal transmitted by each communication device 101 is adjusted by each communication device 101 so as not to overlap. Therefore, as shown in FIG. 2, the transmission timings of the beacon signals B (B1 to B7) transmitted by the respective communication devices 101 do not overlap.

  That is, the super frame is set so that each communication device 101a to 101g independently sets the super frame configuration, and the super frame configuration of the communication device existing in the vicinity does not overlap the beacon signal transmission timing.

  More specifically, as shown in FIG. 2, the communication device 101a receives the beacon signal NB2, the beacon signal NB3, and the beacon signal NB4 of the communication device 101b, the communication device 101c, and the communication device 101d in the communication area 102a. The beacon signal B1 is transmitted at a timing that does not overlap with those beacon signals, and the period up to the transmission timing of the next beacon signal B1 ′ is set as the period of its own superframe. The beacon signals B1 to B7 indicate beacon signals transmitted from each communication device 101, and the beacon signals NB1 to NB7 indicate beacon signals received by each communication device 101. Yes.

  Further, the communication device 101b receives the beacon signal NB1 and the beacon signal NB4 of the communication device 101a and the communication device 101d in the communication area 102b.

  The communication device 101c can receive the beacon signal NB1, the beacon signal NB6, and the beacon signal NB7 of the communication device 101a, the communication device 101f, and the communication device 101g in the vicinity (in the communication area 102c).

  The communication device 101d can receive the beacon signals (NB1, NB2, NB5) of the communication devices 101a, 101b, and 101e in the vicinity (in the communication area 102d).

  The communication device 101e can receive a beacon signal (NB4) of a nearby communication device 101d, the communication device 101f can receive a beacon signal (NB3) of a nearby communication device 101c, and the communication device 101g can receive a nearby communication device 101c. Beacon signal (NB3).

  In the ad hoc network according to the present embodiment, data communication is performed using the CSMA / CA method. The CSMA / CA is a carrier sense multiple access system with a collision avoidance function. CSMA / CA uses a protocol similar to the CSMA / CD method used in IEEE 802.3 (Ethernet) to control access to a wireless communication path.

  CSMA / CA avoids contention when multiple users access the same channel (media). In a wireless LAN system, the transmission signal is very weak and it is difficult to detect a collision. Therefore, in order to reduce the collision probability of data transmission, each communication apparatus 101 has a random waiting time (backoff time).

  Next, a scan cycle in which the communication apparatus 101 scans a beacon signal will be described with reference to FIG. FIG. 3 is an explanatory diagram showing an example of a schematic configuration of the scan cycle.

  The scan period shown in FIG. 3 is N times the super frame period described above. N is a constant of 0 or more. This scan cycle is set by each communication device 101, and when the communication device 101 comes to scan, it receives a beacon signal from another communication device 101 existing in the communication area 102, and there is a new communication device 101, etc. In this case, the communication devices 101 are managed by each communication device 101.

  That is, the sum of the times (SF- # 1, SF- # 2,..., SF-# (N-1)) scanned by each of the communication devices 101 included in the ad hoc network is the scan cycle.

  This scan cycle is set, for example, once every N (N is an arbitrary integer) times of superframes, and continuously received (scanned) over a time corresponding to the superframe cycle. The beacon signal is received.

  That is, when scanning is performed with a super frame (SF- # 1), scanning is performed again when a super frame (SF- # N), which is the next scanning cycle, arrives.

  The setting of the scanning period can be changed according to the operating status of the communication apparatus 101, but is not limited to such an example, and can be implemented even in a fixed case.

  For example, when the communication device 101 frequently performs data communication, the superframe and the beacon signal are scanned almost every time, the beacon signal of the other communication device 101 is received, and the signal and timing transmitted / received by itself are determined. Check for duplication, etc., and understand that there is no impact on your own data transmission / reception.

  Further, in a state where data communication by the communication device 101 is hardly performed, the scan operation is performed about once in a redundant time (several seconds to several minutes), thereby operating with low power consumption.

  Next, time slots (for example, time frames) configured in a super frame will be described with reference to FIG. FIG. 4 is an explanatory diagram illustrating an example of a schematic internal configuration of the superframe. Note that the numbers written at the bottom of the horizontal line shown in FIG. 4 indicate time slot numbers.

  As shown in FIG. 4, the super frame includes a plurality of time slots (time slot 0 to time slot 255). By dividing the period of the superframe into predetermined time slot units, it is possible to manage what communication is performed by the peripheral communication device 101 at a predetermined position in the superframe.

  Note that, as shown in FIG. 4, the case where the superframe is divided into 256 time slots from time slot 0 to time slot 255 on the basis of the transmission position of beacon signal B of each communication apparatus 101 will be described as an example. However, it is not limited to such an example.

  In time slot 0, it is used for transmission of the beacon signal B of its own communication device 101 and its access control. In other time slots 1 to 255, any data communication or from other communication devices 101 is used. This is used for managing the position where the beacon signal B is transmitted.

  Note that access refers to information processing that processes data via wireless or wired, such as system usage, connection to the communication device 101, data reference, data storage, data deletion, or data change. Collectively.

  Next, communication management of the communication apparatus 101 by time slots will be described with reference to FIG. FIG. 5 is an explanatory diagram of an example of communication management of the communication device according to the first embodiment.

  An example shown in FIG. 5 is communication management applied in the case of the time slot shown in FIG. 4 described above and the configuration shown in FIG. 1 and FIG. 2 described above, but is not limited to this example. Also, the numbers written at the bottom of each horizontal line shown in FIG. 5 indicate the timeslot numbers.

  First, as shown in FIG. 5, in the case of the communication apparatus 101a, the communication apparatus 101a transmits the beacon signal B near the time slot 0, detects the beacon signal NB2 from the communication apparatus 101b near the time slot 64, and In the schedule, the beacon signal NB3 from the communication device 101c is detected near the slot 128, and the beacon signal NB4 from the communication device 101d is detected near the time slot 192.

  In the case of the communication apparatus 101b, the communication apparatus 101b is scheduled to detect the beacon signal NB4 from the communication apparatus 101d near the time slot 128 and detect the beacon signal NB1 from the communication apparatus 101a near the time slot 192.

  In the case of the communication device 101c, the communication device 101c detects the beacon signal NB7 from the communication device 101g near the time slot 96, detects the beacon signal NB1 from the communication device 101a near the time slot 128, and near the time slot 160. The schedule is to detect the beacon signal NB6 from the communication device 101f.

  In the case of the communication device 101d, the communication device 101d detects the beacon signal NB1 from the communication device 101a near the time slot 64, detects the beacon signal NB2 from the communication device 101b near the time slot 128, and near the time slot 160. The schedule is to detect the beacon signal NB5 from the communication device 101e.

  In the case of the communication device 101e, the communication device 101e has a schedule for detecting the beacon signal NB4 from the communication device 101d near the time slot 96.

  In the case of the communication device 101f, the communication device 101f is a schedule for detecting the beacon signal NB3 from the communication device 101c near the time slot 96.

  In the case of the communication device 101g, the communication device 101g has a schedule for detecting the beacon signal NB3 from the communication device 101c in the vicinity of the time slot 160.

  The schedule of each communication device 101 according to the first embodiment is described in units of time slots in a time slot management table (for example, time frame management table) described later.

  Further, as shown in FIG. 5, the time slot of each communication device 101 is based on the time slot (time slot 0) in which each communication device 101 transmits its own beacon signal B. It is not necessary for the time slot 0 of the other communication apparatus 101 to be synchronized with the time slot 0 of one representative communication apparatus 101, and the present invention can be implemented even when the time slot 0 is asynchronous with the other time slot 0. That is, if the timing at which the beacon signal B is transmitted by each communication device 101 does not overlap, for example, even if the time slot of each communication device 101 is asynchronous, this can be implemented.

  Next, the configuration of a beacon signal frame will be described with reference to FIG. FIG. 6 is an explanatory diagram illustrating an example of a schematic configuration of a frame of a beacon signal.

  As shown in FIG. 6, a frame of a beacon signal includes a predetermined header and a PHY header (not shown), followed by a MAC header (MAC Header), a header check sequence (HCS), a beacon payload (Beacon Payload), It consists of a frame check sequence (FCS).

  Further, the MAC header includes frame control (Frame Control), piconet identifier (PN ID), destination identifier (Dest. ID), source identifier (Src. ID), fragment control information (Fragment Control), and stream index ( (Stream Index).

  The beacon payload is a time that is an information element for notifying a MAC Address IE composed of the MAC address information element (IE) of the communication apparatus 101 and a list of time slots indicating the communication schedule of the communication apparatus 101. A slot IE (Time Slot IE), a group IE (Group IE) for identifying a network group, a capability IE (Capability IE) for reporting the capability of the communication device 101, and an attribute of the communication device 101 Attribute IE (Attribute IE) and the like.

  Note that the various information elements (IE) such as the time slot IE, capability IE, and attribute IE described above are not limited to such examples, and the frame of the beacon signal is configured by being added or deleted as necessary. May be.

  Next, communication management of the communication apparatus 101 by time slots will be described with reference to FIG. FIG. 7 is an explanatory diagram showing an example of an outline of communication management of the communication apparatus 101 by time slots. Also, the numbers written at the bottom of each horizontal line shown in FIG. 7 indicate the number of a time slot.

  Note that the communication management shown in FIG. 7 is for the communication device 101a, and receives the beacon signals B of the communication devices 101b, 101c, and 101d existing around the communication device 101a (communication area 102a). From the relationship of the reception timing, a configuration is shown in which it is managed by assigning (mapping) it to the time slot management table of its own communication device 101a, but the same applies to communication devices 101 other than the communication device 101a.

  The communication device 101a determines its own time slot position with reference to the transmission timing of its own beacon signal B. That is, time slot 0 is the transmission timing of its own beacon signal B.

  Further, next to the transmission timing position of the beacon signal B in the time slot 0, it is used as an access period (Access P) for transmitting data to another communication apparatus 101 accompanying the transmission of the beacon signal B. Is done. When data transmission processing is performed as an access period in the time slot 0, it is set in the time slot management table. That is, in time slot 0, the communication device 101a performs processing for transmitting its own (communication device 101a) beacon signal B and processing for transmitting data to other communication devices 101.

  Further, time slot 1 adjacent to time slot 0 is set as a reception period (OwnReserve) for receiving data of its own communication apparatus 101a as necessary. The communication device 101a performs processing for receiving data in the time slot 1 shown in FIG.

  As shown in FIG. 7, at the midpoint of the time slot 64, the communication device 101a has the reception process for receiving the beacon signal NB2 from the communication device 101b set in the time slot management table. Unlike the time slot 0, the beacon signal B is transmitted within the time slot 64 because the position of the reception timing at which the communication apparatus 101a receives the beacon signal NB2 from the communication apparatus 101b is in the middle of the time slot 64. Processing and transmission processing for transmitting data cannot be performed. Therefore, the period of the reception process for receiving the beacon signal NB2 from the communication device 101b is registered as the time slot 64, and the communication device 101b transmits data to another communication device 101 in the time slot 65 adjacent to the time slot 64. A period for transmitting data, that is, an access period (Access P) is set.

  As described above, if the period of the transmission process of the beacon signal B and the period of the data transmission process cannot be accommodated in one time slot, the time slot adjacent to the time slot is reserved as a period for performing the data transmission process or the like. However, the processing other than the above is also set in the time slot management table as a period for performing predetermined processing on a preliminarily adjacent time slot as necessary.

  As shown in FIG. 7, at the end point of the time slot 127, the period of reception processing in which the communication apparatus 101a receives the beacon signal NB3 from the communication apparatus 101c is set in the time slot management table.

  Since the timing for receiving the beacon signal NB3 is the end point of the time slot 127, as in the case of the time slot 64 described above, the period of the reception process for receiving the beacon signal NB3 is set as the time slot 127 in the time slot management table. And the time slot 128 adjacent to the time slot 127 includes a time slot management table as a period of data transmission processing (access period: Access P) in which the communication apparatus 101c transmits data to the other communication apparatus 101. Set to

  Further, as shown in FIG. 7, at the point of the leading end (leading portion) of the time slot 192, the period of reception processing in which the communication device 101a receives the beacon signal NB4 from the communication device 101d is set in the time slot management table. Has been. That is, when the time slot of the communication device 101a becomes the time slot 192, the communication device 101a receives the beacon signal NB4 from the communication device 101d.

  Although the timing at which the beacon signal NB4 is received from the communication device 101d is at the leading end (leading portion) of the time slot 192, the communication device 101d transmits data to the other communication device 101 as described above. Since the time period (access period) cannot be set in the time slot 192 and cannot be set in the time slot management table, the reception process for receiving the beacon signal NB4 is performed as in the case of the time slot 127. Is registered in the time slot management table as a time slot 192, and the access period of data transmission processing by the communication device 101d is set in the time slot management table in the time slot 193 adjacent to the time slot 192.

  In addition, in the time slot 65, time slot 129, and time slot 193 shown in FIG. 7, it is set as a reception period (Neighbor Reserve) for receiving data by another communication apparatus 101 (101b, 101c, or 101d) as necessary. Is done.

(About the configuration of the communication device 101)
Next, the configuration of the communication apparatus 101 according to the first embodiment will be described with reference to FIG. FIG. 8 is a block diagram illustrating a schematic configuration of the communication apparatus according to the first embodiment.

  As shown in FIG. 8, the communication apparatus 101 includes an antenna 801, a wireless reception unit 802, a received signal analysis unit 803, a self access control unit 804, a scan setting unit 805, an information storage unit 806, a reference time generation unit 807, a beacon analysis. A unit 808, a time slot management unit 809, a central control unit 810, an individual communication device access control unit 811, a beacon generation unit 812, a wireless transmission unit 813, a wireless transmission buffer 814, a data buffer 815, and an interface 816.

  Note that at least one of the antenna 801 and the wireless reception unit 802 or the beacon analysis unit 808 can be exemplified as a beacon signal receiving unit that receives a signal such as a beacon signal. The time slot management unit 809 is exemplified as a time frame determining unit that determines a signal transmission / reception timing and / or a time frame management unit that registers a time slot in the time slot management table when a signal transmission / reception timing is determined. can do.

  In the communication apparatus 101, first, a scan instruction is issued from the central control unit 810 to the scan setting unit 805, and a beacon signal scanning operation is activated to confirm the presence of a predetermined beacon signal. The central control unit 810 controls processing operations and the like of each unit included in the communication device 101.

  Based on the master signal generated by the reference time generation unit 807, a continuous reception mode is set in which the scan operation unit 805 continuously receives signals for a period of time corresponding to the superframe period from the self-access control unit 804. , The scan operation is executed.

  Therefore, in order to receive the beacon signal NB and scan the beacon signal NB, the wireless reception unit 802 operates, and the beacon signal NB received via the antenna 801 is supplied to the reception signal analysis unit 803, Only the beacon signal NB is sent to the beacon analysis unit 808.

  The beacon analysis unit 808 measures the timing of receiving the beacon signal NB based on the signal of the reference time generation unit 807, analyzes the beacon signal NB, and outputs a signal notifying that the beacon signal NB has been received at that timing. The data is supplied to the slot management unit 809.

  Based on the time information of the reference time generation unit 807, the time slot management unit 809 indicates the presence of the communication device 101 (the neighboring communication device 101 or the adjacent communication device 101) existing in the communication area 102. In addition, a time slot parameter (Time Slot IE) indicating a communication processing status set in a time slot of each of the neighboring communication devices 101 and including a period such as a transmission process of the beacon signal B is set in the neighboring communication. Received from the device 101 and registered in its own time slot management table. Therefore, when the time slot management unit 809 refers to the time slot management table, it is possible to recognize a time slot (or timing and time) that can be controlled for access to the neighboring communication device 101. The time slot management table is stored in the information storage unit 806 or the like. The time slot parameter can be exemplified by a time frame parameter, for example.

  That is, the notification from the time slot management unit 809 starts the access control process in the self-access control unit 804 and the individual communication device access control unit 811 as necessary, and requires the wireless transmission unit 813 and the wireless reception unit 802. Data (information) is transmitted and received by operating accordingly.

  Further, the time slot management unit 809 is described with reference to FIG. 7 when the timing measured based on the signal of the reference time generation unit 807 corresponds to an intermediate point in the time slot in the time slot management table. As described above, a time slot adjacent to the corresponding time slot is set as a preliminary period for executing communication processing.

  The beacon generation unit 812 generates a beacon signal B transmitted by its own communication device 101 according to an instruction from the central control unit 810. Further, when the beacon generation unit 812 temporarily stores the generated beacon signal B in the wireless transmission buffer 814 and receives a notification that it is time to transmit the beacon signal B from the time slot management unit 809. , Supplied to the wireless transmission unit 813. Note that the beacon signal B supplied to the wireless transmission unit 813 is transmitted from the antenna 801.

  Note that data (information) transmitted from the antenna 801 is taken into the data buffer 815 via the interface 816 from an application device (not shown) to which the communication apparatus 101 is connected.

  Further, the central control unit 810 is notified that the data has been taken in via the interface 816, and the central control unit 810 determines whether the data is addressed to the neighboring communication device 101. The individual communication device access control unit 811 is notified that the data to be transmitted is stored in the data buffer 815 and the like, and the data is transmitted from the data buffer 815 at a timing at which the communication device 101 of the data transmission destination can receive. The signal is supplied to the wireless transmission unit 913 via the buffer 814 and sequentially transmitted from the antenna 801.

  On the other hand, when the reception timing for receiving data of the communication apparatus 101 comes from the notification from the time slot management unit 809, the wireless reception unit 802 operates and the signal received via the antenna 801 is supplied to the reception signal analysis unit 803. Whether the data is addressed to itself is determined and stored in the data buffer 815. The command information addressed to itself may be directly supplied to the central control unit 810.

  The data stored in the data buffer 815 is notified to the central control unit 810, and is transmitted via the interface 816 when it is possible to supply data to the connected application device (not shown). Is done.

  Further, the response of the command information addressed to itself is directly supplied from the central control unit 810 to the data buffer 815 or the wireless transmission buffer 814, and transmitted via the antenna 801 in the same manner as the above data based on a predetermined access control procedure. Is done.

  The information storage unit 806 stores a series of operation programs necessary for processing the communication device 101, self-address information, scan cycle information, peripheral device information, and the like. From the central control unit 810 as necessary. It is configured to be accessed sequentially. Note that the present invention can be implemented even when the information storage unit 806 further stores a time slot management table.

  Next, the time slot parameter (Time Slot IE) will be described with reference to FIG. FIG. 9 is an explanatory diagram showing an example of a schematic configuration of time slot parameters.

  The time slot parameter is generated based on the time slot management table. The time slot parameter is set in the beacon signal B and is included in the beacon signal B from the communication device 101 to the neighboring communication device 101. Sent by.

  In the time slot parameter, there are one or more values indicating the type of communication processing period executed by the communication apparatus 101 registered in each time slot. In addition, as shown in FIG. 9, the case where eight types of values exist will be described as an example, but the present invention is not limited to such an example.

  As shown in FIG. 9, there are eight types of values of 0 to 7 as the values of the time slot parameter, and when the time slot parameter value is “7”, the beacon signal B of the own communication apparatus 101 is It shows that it is the transmission processing period of the beacon signal B to be transmitted.

  Next, when the time slot parameter value is “6”, it indicates a communication processing period such as data reception processing for receiving data. Further, when the time slot parameter value is “5”, it indicates that it is a beacon signal transmission processing period in which the neighboring communication device 101 transmits the beacon signal B.

  Further, when the time slot parameter value is “4”, it indicates a communication processing period such as data reception processing for receiving data by the neighboring communication device 101, and when the time slot parameter value is “3”. , This indicates that the communication apparatus 101 is in the beacon signal reception processing period for receiving the beacon signal NB from the neighboring communication apparatus 101.

  Further, when the time slot parameter value is “2”, it indicates that the neighboring communication device 101 is a reception processing period of a beacon signal for receiving a beacon signal NB from another neighboring communication device 101, and the time slot parameter When the value is “1”, it indicates that the communication apparatus 101 is in a data reception processing period, and when the time slot parameter value is “0”, it does not correspond to any communication processing period. Is shown.

  Next, the configuration of the time slot management table will be described with reference to FIG. FIG. 10 is an explanatory diagram showing an example of a schematic configuration of the time slot management table. In FIG. 10, the case where the time slot is in the state shown in FIG. 7 in the case of the time slot management table of the communication apparatus 101 a will be described as an example. Alternatively, the present invention can be carried out other than in the case of other time slots. Also, the time slot parameters of other communication devices 101 that can be generated from the time slot management table managed by the communication device 101 are notified to the neighboring communication device 101.

  As shown in FIG. 10, the time slot management table corresponds to the time slot number indicating the number of the time slot such as time slot 0, the contents (Contents) of communication processing executed in the time slot, and the contents of the communication processing. “Slot processing IE” indicating the time slot parameter value (Time Slot IE Value) that is a parameter value to be transmitted and the status of communication processing for each time slot of the communication device 101 existing in the communication area 102 including the own communication device 101 And at least. The “communication processing status” is a time slot management table in which the own communication device 101 manages the set value of the time slot parameter (Time Slot IE) described in the neighboring communication device 101 including the own communication device 101. It shows what has been converted into a time slot.

  The time slot parameter value (Time Slot IE) described in the time slot management table shown in FIG. 10 is described in the beacon signal B when transmitting the beacon signal B of its own communication apparatus 101, and the neighboring communication apparatus 101 To be notified.

  Here, the time slot parameter value (Time Slot IE) shown in FIG. 10 will be described. First, the time slot parameter value of time slot 0 is “7”. Therefore, it can be seen that time slot 0 is a period during which the beacon signal B of its own communication apparatus 101 is transmitted.

  Note that the “communication processing status” of the neighboring communication device 101 existing in the communication area 102 in the time slot 0 is Nb for any communication device 101. Nb indicates, for example, that there is a beacon signal NB from the neighboring communication device 101 to be received.

  The time slot parameter value of time slot 1 following time slot 0 is “6”. Therefore, it can be understood that the time slot 1 is a period of data transmission processing in which the own communication apparatus 101 transmits data.

  Note that the “communication processing status” of the neighboring communication device 101 in the time slot 1 is Nr for any communication device 101. Nr indicates, for example, that there is a communication device 101 that executes communication processing such as data transmission processing among neighboring communication devices 101 other than its own communication device 101.

  As shown in FIG. 10, the time slot parameter values of time slot 2, time slot 3, time slot 3,..., Time slot 62, and time slot 63 after time slot 1 are “0”. Therefore, as described above, it can be seen that the time slots 2, 3,..., 62, 63 are unused periods in which no communication processing is executed by the communication processing 101.

  Next, the time slot parameter value of the time slot 64 is “5”. Therefore, it can be seen that the time slot 64 is a period during which the beacon signal B of the neighboring communication device 101 (communication device 101b) is transmitted.

  As for the “communication processing status” of the neighboring communication device 101 in the time slot 64, “Tx” is set in the communication device 101b and “Nb” is set in the communication device 101d. That is, the communication apparatus 101b transmits the beacon signal B, and the communication apparatus 101d has received a report indicating that there is a beacon signal B from the communication apparatus 101b.

  Further, the time slot parameter value of the time slot 65 following the time slot 64 is “4”. Therefore, it can be seen that the time slot 65 is a period of data transmission processing in which the neighboring communication device 101 (communication device 101b) transmits data as necessary.

  The “communication processing status” of the neighboring communication device 101 in the time slot 65 is set to “Tx” in the communication device 101b and the time slot for transmitting the beacon signal B of the communication device 101b and the communication device 101b itself (communication device 101a). A state in which the time slot (time slot parameter value “4” in the communication apparatus 101a) is not synchronized is shown. Furthermore, “Nr” is set because the communication device 101d has also received the beacon signal NB of the communication device 101b.

  The time slot 66, time slot 67,..., Time slot 126 after the time slot 65 indicate that the communication processing by the communication apparatus 101 is not used, and the time slot parameter value at that time is described as “0”. The Note that the “communication processing status” of the communication device 101b in the time slot 66 is “Rx”, but here, if there is data to be received by the communication device 101b, it is a preliminary to receive data as necessary. Assigned as a period for performing data reception processing.

  The time slot parameter value of the time slot 127 following the time slot 126 is “5”. Therefore, it can be seen that the time slot 127 is a period during which the beacon signal B of the neighboring communication device 101 (communication device 101c) is transmitted.

  The time slot parameter value of the time slot 128 following the time slot 127 is “4”. Therefore, it is understood that the time slot 128 is a period of data transmission processing in which the neighboring communication device 101 (communication device 101c) transmits data as necessary. The “communication processing status” of the neighboring communication device 101 in the time slot 128 is set to “Tx” in the communication device 101c and the time slot for transmitting the beacon signal B of the communication device 101c and the communication device 101c itself (communication device 101a). It shows a state that is not synchronized with the time slot.

  After the time slot 129, the time slot 129, the time slot 130,..., The time slot 190, and the time slot 191 indicate that the communication processing by the communication apparatus 101 is unused, and the time slot parameter value at that time is “0”. ". Note that the “communication processing status” of the communication device 101c in the time slot 129 is “Rx”, but here, if there is data to be received by the communication device 101c, it is a preliminary to receive data as necessary. Assigned as a period for performing data reception processing.

  Further, the time slot parameter value of the time slot 192 is “5”. Therefore, it can be seen that the time slot 192 is a period during which the beacon signal B of the neighboring communication device 101 (communication device 101d) is transmitted.

  Since the time slot parameter value of the subsequent time slot 193 is “4”, the time slot 65 is a preliminary period of data reception processing in which the neighboring communication device 101 (communication device 101d) receives data as necessary. is there. Therefore, the communication device 101d of the time slot 193 in the “communication processing status” is “Rx”.

  The time slot 194, the time slot 194, the time slot 195,..., The time slot 254 indicate that the communication processing by the communication apparatus 101 is not used, and the time slot parameter value at that time is described as “0”. The

  Note that the time slot management unit 809 has been described with reference to FIG. 7, but when it is determined that the period between the transmission process of the beacon signal B and the data transmission process (AccessP) cannot be accommodated in one time slot, for example, Adjacent time slots such as the time slots 64 and 65 of the communication device 101b in the “communication processing status” shown in FIG. 10 and the time slots 127 and 128 of the communication device 101c are also set as the period for executing the communication processing. When the period between the transmission process of the beacon signal B and the data transmission process (AccessP) is within one time slot, the communication process of the adjacent time slot is not set like the time slot 192 of the communication apparatus 101d.

  From the above, referring to the time slot management table shown in FIG. 10, at what time slot position the neighboring communication device 101 existing in the communication area 102 is performing what kind of communication processing or what is being executed. The communication processing status can be ascertained sequentially. The time slot management unit 809 refers to the time slot management table and estimates the timing for executing communication processing.

  Accordingly, the time slot management unit 809 is configured to determine the timing at which data can be transmitted from its own communication device 101 to the neighboring communication device 101, for example.

  Next, the operation of the communication process of the communication apparatus 101 according to the first embodiment will be described with reference to FIG. FIG. 11 is a flowchart illustrating an example of a schematic operation of communication processing of the communication device according to the first embodiment.

  First, when power is supplied to the communication device 101 in order to execute communication processing, a superframe cycle and a beacon scan cycle for scanning the beacon signal NB are first set based on the clock cycle of the own communication device 101. (S101).

  Next, when the period (time slot) for transmitting the beacon signal B of the communication apparatus 101 has arrived (step S102), a pre-stored beacon parameter value is acquired (step S103), and the transmission process of the beacon signal B is performed. Execute (S104).

  When the superframe period for executing the beacon scan is reached (S105), the beacon reception process for receiving the beacon signal NB is executed (S106), and when the beacon signal NB is received (S107), the communication apparatus 101 manages The time slot parameter value described in the time slot management table is acquired (S108), and the beacon signal B is transmitted by the communication apparatus 101 at that timing. The slot parameter value and “communication processing status” are set in the own communication apparatus 101 (S109).

  Further, the reception time of the beacon signal NB is acquired (S110), and the transmission processing time of the beacon signal B of the communication apparatus 101 that has transmitted the beacon signal NB is obtained based on the reception time. If it is asynchronous with the clock cycle of the communication device 101 (S111), the time slot management unit 809 executes communication processing by the communication device 101 also in the next time slot adjacent to the time slot corresponding to the transmission processing time. Is set as a period of time (S112).

  If the transmission processing time of the beacon signal B is synchronized with the end of the above process (S112), even if no beacon signal NB is received, the process returns to S102 and transmits its beacon signal B. If it is determined whether it is time, or if it is the timing (superframe cycle) for scanning the beacon signal NB, the beacon signal reception process for receiving the beacon signal NB is repeated.

  When the superframe cycle (or beacon scan cycle) for executing the beacon scan for scanning the beacon signal NB ends and the time (or time slot) of the data reception process for receiving data by the communication apparatus 101 is reached (S113), data reception processing is executed (step S114), and when data addressed to its own communication device 101 is received (S115), the received data is stored in a buffer (or information storage unit 806). (S116) The beacon scan cycle is changed to a short time unit (beacon reception over the superframe cycle is set after detection of reception) (S117). The reason for changing the period for executing the beacon scan is that if the data transmission / reception process is frequently performed, the communication process may be performed repeatedly by another neighboring communication device 101 within the period of the process. , It is necessary to scan for the presence of a new beacon signal NB at an increased frequency.

  If no data addressed to the communication apparatus 101 is received, the process returns to S113, and the reception is continued until the time (or time slot) for executing the data reception process of the communication apparatus 101 is completed.

  Further, if the data can be output to the interface 816 connected to the higher-level application device (S118), the data stored in the data buffer 815 is output to the application device via the interface 816 (S119). The data buffer storing the data is released (S120).

  After completion of the above processing (S120), if the self-beacon transmission time is determined, the beacon scan operation is determined, or if the self-reception time is reached, the processing is repeated.

  When data transmitted from an application device connected to the interface 816 is received (S121), the data is stored in the buffer 815 (S122), and the beacon scan cycle is set to a short time unit (beacon reception over the superframe cycle after detection of reception). (Setting) (S123).

  Furthermore, if the time slot parameter value (Time Slot IE) of the communication device 101 that is the data transmission destination is already stored in the time slot management table of the communication device 101 (S124), the transmission time of the communication device 101 is updated. Setting is performed (S125).

  Here, after the end of the first half of the period, when the transmission data has not arrived at the interface 816, or when the time slot parameter value of the communication device 101 that is the data delivery destination is not stored, It is determined whether or not the transmittable time has arrived (S126).

  If it is confirmed that no other communication is performed on the wireless transmission path and transmission to the communication device is possible (S127), data transmission is performed (S128).

  Further, when receipt confirmation (ACK) information for the communication is received (S129), the beacon scan cycle is changed to a long time unit cycle (S130), and the data buffer 815 storing the data is released. (S120).

  After the above process is completed, when the transmission possible time (or time slot) from the communication apparatus 101 has not yet arrived and when the acknowledgment (ACK) information has not yet been received, The operation (S102 ~) is repeated.

  Next, communication processing of the communication apparatus 101 in the network group of the ad hoc network according to the second embodiment will be described with reference to FIG. In the description of the ad hoc network according to the second embodiment described below, differences from the ad hoc network according to the first embodiment will be described in detail in detail. Description is omitted. FIG. 12 is an explanatory diagram illustrating an example of a beacon signal cycle of a network group of the ad hoc network according to the second embodiment.

  As shown in FIG. 12, communication devices 101 grouped in a network group share a common superframe structure set by common clock information, and the top part of the superframe period (time slot 0 and time Slot 1) is defined as a time slot that is a transmission processing period for transmitting beacon signal B, and a predetermined beacon signal is transmitted and received at the timing of transmitting beacon signal B allocated to each communication device 101 therein. It is a configuration. Note that the ad hoc network according to the second embodiment is implemented according to the ad hoc network defined by, for example, Multi Band OFDM Alliance (MBOA), but is not limited to this example. The head portion can also be defined as a beacon management area for transmitting and receiving beacon signals, for example.

  Note that the beacon signal B1, the beacon signal B2, the beacon signal B4, and the beacon signal B5 illustrated in FIG. Signal. Further, the communication device 101a, the communication device 101b, the communication device 101d, and the communication device 101e are the first network group shown in FIG. 1, but are not limited to this example.

  Here, transmission positions for transmitting three beacon signals B per time slot are defined, and the beacon signals B (B1, B2, B5) are sequentially set in the order of the communication device 101a, the communication device 101b, the communication device 101e, and the communication device 101d. , B4) is transmitted.

  As in the ad hoc network system according to the second embodiment, a plurality of communication devices 101 constituting a network group are synchronized with the communication devices 101 between the network groups, and the own communication device 101 transmits data. Although it is necessary to adjust the execution period of processing, etc., the same superframe period and time slot can be defined in a plurality of communication apparatuses 101 existing in the network group, so that communication processing is efficiently managed in time slots. Can do.

  As shown in FIG. 12, in communication apparatus 101a, communication apparatus 101b, communication apparatus 101e, and communication apparatus 101d that form the same network group (first network group), time slot 0 and time Share slot 1. In addition, for example, time slot 2 following time slot 1 can be shared as a contention access period (CAP). The contention access period is similar to the above-described “AccessP”, and a plurality of communication devices 101 are synchronized with each communication device 101 to some extent, and each communication device 101 receives data as necessary. Defined as period. Alternatively, it is possible to secure an area where a new communication device joins the network group.

  Next, the superframe period of the beacon signal in each network group will be described with reference to FIG. FIG. 13 is an explanatory diagram illustrating an example of a schematic configuration of a superframe in the network group according to the second embodiment.

  As shown in FIG. 13, the first network group (communication devices 101a, 101b, 101e, and 101d) is supervised according to the position of the time slot set as the period for executing the beacon transmission process for transmitting the beacon signal B. The frame period is determined, and the second network group (communication apparatuses 101c, 101f, and 101g) also has a superframe period common to each communication apparatus 101 according to the position of the time slot set as the period for executing the beacon transmission process. Determined.

  In the second embodiment, for example, as shown in FIG. 1, when the communication apparatus 101a and the communication apparatus 101c are adjacent to each other, the first network group or the second By executing the beacon signal scanning process (reception operation) at a predetermined beacon scan cycle, the beacon signal NB in the partner network group is received and the presence of the network group is confirmed. It has a configuration that can be grasped.

  Next, communication processing of the communication apparatus 101 in another network group of the ad hoc network according to the second embodiment will be described with reference to FIG. FIG. 14 is an explanatory diagram illustrating a schematic configuration of communication processing of the communication device 101 in another network group of the ad hoc network according to the second embodiment. 14 shows the cycle of beacon signal B of a network group different from the network group shown in FIG. 12 (for example, the second network group shown in FIG. 1).

  It is very likely that the beacon signal periods of different network groups such as the second network group according to the second embodiment exist without being synchronized with the own network group.

  Accordingly, in FIG. 14 as well, transmission positions for transmitting three beacon signals B per time slot are defined, and the communication devices 101c, 101f, and 101g transmit beacon signals (B3, B6, B7), respectively. It is configured to do. In the network group including the communication apparatus 101a, it is understood that the timing indicating the transmission processing period for transmitting the beacon signal B of another network group exists in the middle of the time slot 218.

  In the above case, using the technique for asynchronously managing the network with the other communication apparatus 101 according to the second embodiment, in the network group including the communication apparatus 101a, the neighboring communication apparatus 101 sets the time slots 218 to 219. A time slot set as a period for transmitting the beacon signal B is managed, and time slots 220 to 221 are managed as neighboring reserved slots.

  As described above, even network groups that are not synchronized can coexist in the same space.

  Next, a time slot management table according to the second embodiment will be described with reference to FIG. FIG. 15 is an explanatory diagram illustrating an example of a schematic configuration of a time slot management table according to the second embodiment.

  The “communication processing status” in the time slot management table shown in FIG. 15 includes, for example, the communication devices 101 (communication device 101a, communication device 101b, communication device 101d, communication device 101e) belonging to the first network group. Yes.

  Further, as described above, for example, the time slot parameter value set in the time slot management table managed by the communication device 101a is notified to the communication device 101 configured in a plurality of network groups. . The value of the time slot parameter (Time Slot IE) is described in the beacon signal B of its own communication apparatus 101 and notified.

  The time slot parameters shown in FIG. 15 are substantially the same as the time slot parameters according to the first embodiment described with reference to FIG. Note that the communication device 101 of “communication processing status” in the time slot management table shown in FIG. 15 corresponds to the communication device 101 that executes the process of transmitting the beacon signals B1 to B7 shown in FIG. The time slot management table shown in FIG. 15 will be described as a management table for the communication device 101a, for example.

  As shown in FIG. 15, since the time slot 0 is a period during which the own communication device 101 (communication device 101a) transmits the beacon signal B, the time slot parameter value is “7”. As shown in the “communication processing status”, it is understood that the communication apparatus 101b and the communication apparatus 101e (not shown) are also periods during which their own beacon signals B are transmitted.

  Since time slot 1 following time slot 0 is a period in which the own communication apparatus 101a receives a beacon signal NB from another communication apparatus 101, the time slot parameter is “3”. As shown in the “communication processing status”, since the communication device 101d in the time slot 1 is in the period for transmitting the beacon signal B4, “Tx” is set in the time slot 1.

  In time slot 2, the communication device 101a is a period indicating that there is a possibility of transmitting data, and the time slot parameter value is “6”. Thereafter, time slots 3,..., 217 indicate that they are unused for communication, and the time slot parameter value is described as “0” unused slot.

  Since the time slot 218 is a transmission period of the beacon signal B3 by the communication apparatus 101c in the second network group, the time slot parameter value is described as “5” neighboring beacon transmission slot.

  Since the time slot 219 following the time slot 218 is a period for transmitting the beacon signal B of the communication apparatus 101 configured in the second network group, the time slot parameter value is described as “5” neighboring beacon transmission slot. The

  Since the time slot 220 may transmit data from the communication device 101 configured in the second network group, the time slot parameter value is described as “4” neighborhood reserved slot.

  Hereinafter, the time slots 221,..., The time slot 254 indicate a period during which no communication processing is used, and the time slot parameter value is described as “0” unused slot.

  From the above, each communication apparatus 101 forming the ad hoc network according to the present embodiment does not require synchronization processing with other communication apparatuses 101 unless at least the timing of transmitting the beacon signal B overlaps. Thus, it is possible to execute communication that is completely autonomously distributed between the communication devices 101.

  Each communication device 101 executes communication processing asynchronously, so that it can operate without considering delay even if the distance between the communication devices 101 has a discrete relationship.

  Since it is not necessary for each communication device 101 to synchronize with another communication device 101, complicated synchronization processing is not repeated between the communication devices 101, and thus low power consumption operation is possible.

  Since there is no need to synchronize even if there is a communication device 101 that is not synchronized in the communication area 102, management of these communication devices 101 can be simplified.

  Furthermore, since it is not necessary to exchange information such as command information for synchronizing with each communication apparatus 101 operating asynchronously, useless traffic can be reduced.

  Each communication device 101 executes a scan operation of the beacon signal B at a predetermined cycle, so that the existence of the communication device 101 existing in the vicinity of the communication device 101 at that time is grasped and the presence of the surrounding communication devices 101 Is managed in units of time slots as a period during which the beacon signal B of the communication device 101 is transmitted, it becomes unnecessary to manage the communication device 101 in a complicated manner.

  In addition, by registering before and after a predetermined time slot as the beacon transmission position of the communication apparatus 101, the timing of transmitting the beacon signal B of the communication apparatus 101 can be grasped.

  Even if there is a communication device 101 having a slightly different clock cycle, it can always be grasped by managing that the latest beacon transmission position has been changed by the scanning operation of the beacon signal B.

  The transmission period of the beacon signal B of the communication apparatus 101 that is synchronized with its own communication apparatus 101 is managed in its time slot, and the timing of transmitting the beacon signal B of the communication apparatus 101 that is not synchronized is as follows. In addition, by managing up to the next time slot, management of useless slots can be omitted.

  By making the scan cycle of the beacon signal B variable, the communication device 101 existing in the communication area 102 existing asynchronously can be grasped in a short time.

  For example, when data addressed to the own communication device 101 is received or data transmitted from the own communication device 101 is received, the scan period of the beacon signal B is started, so that the communication area 102 can be quickly transmitted. The presence of the communication device 101 existing in

  Furthermore, by resetting the scan cycle when data transmission is completed, unnecessary beacon scan settings can be made redundantly, enabling low power consumption operation in the entire system.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to this example. It is obvious for a person skilled in the art that various changes or modifications can be envisaged within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  In the above embodiment, the case where the communication apparatus 101 is an apparatus capable of wireless communication has been described as an example, but the present invention is not limited to such an example. For example, the communication device 101 can be implemented even when it is a device capable of wired communication.

  In the above-described embodiment, the setting of the cycle at which the communication apparatus 101 performs a scan has been described as an example in which it can be changed according to the operation status of the communication apparatus 101. However, the present invention is not limited to this example. Even if it is fixed in advance, it can be carried out.

  The present invention is applicable to a communication system, a communication apparatus, and a communication method that can communicate without having a control station.

It is explanatory drawing which shows the schematic structure of an ad hoc network. It is explanatory drawing which shows an example of a schematic structure of a super frame. It is explanatory drawing which shows an example of a schematic structure of a scanning period. It is explanatory drawing which shows an example of the schematic internal structure of a super frame. It is explanatory drawing which shows an example of the communication management of the communication apparatus concerning 1st Embodiment. It is explanatory drawing which shows an example of the schematic structure of the flame | frame of a beacon signal. It is explanatory drawing which shows an example of the outline of the communication management of the communication apparatus by a time slot. 1 is a block diagram illustrating a schematic configuration of a communication device according to a first embodiment. It is explanatory drawing which shows an example of a schematic structure of a time slot parameter. It is explanatory drawing which shows an example of a schematic structure of the time slot management table | surface which concerns on 1st Embodiment. It is a flowchart which shows an example of schematic operation | movement of the communication processing of the communication apparatus concerning 1st Embodiment. It is explanatory drawing which shows an example of the beacon signal period of the network group of the ad hoc network concerning 2nd Embodiment. It is explanatory drawing which shows an example of a schematic structure of the super frame in the network group concerning 2nd Embodiment. It is explanatory drawing which shows schematic structure of the communication process of the communication apparatus in the other network group of the ad hoc network concerning 2nd Embodiment. It is explanatory drawing which shows an example of a schematic structure of the time slot management table | surface concerning 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Communication apparatus 102 Communication area 803 Received signal analysis part 804 Self-access control part 807 Reference time generation part 808 Beacon analysis part 809 Time slot management part B Beacon signal NB Beacon signal (reception)

Claims (14)

A communication system including a plurality of communication devices for constructing an autonomous decentralized network:
Setting a superframe of a predetermined period composed of a plurality of time frames for transmitting and / or receiving a signal based on clock information of its own communication device;
Determining at least a time frame for transmitting a beacon signal in the superframe;
Receiving the beacon signal transmitted in a predetermined cycle in accordance with the superframe by another communication device existing in a communication area capable of communicating with the communication device;
The signal described in the beacon signal from the other communication device is transmitted and / or synchronized without timing synchronization between the beacon signal transmitted from the other communication device and the beacon signal of the own communication device. Or, the time frame for receiving is applied to the time frame management table set based on the clock information of the own communication device based on at least the time frame for the own communication device to transmit a beacon signal. Managing the presence of the other communication device ;
A communication system comprising: A communication system including a plurality of communication devices for constructing an autonomous decentralized network:
Setting common clock information in a network group to which the communication device belongs , comprising one or more communication devices;
Setting a superframe of a predetermined period in the network group to which the network belongs , comprising a plurality of time frames for transmitting and / or receiving signals based on the common clock information;
Determining a time frame for transmitting at least a beacon signal of each communication device in the own network group in the superframe;
Receiving a beacon signal transmitted in a predetermined cycle according to the superframe by a communication device in the network group;
Without synchronizing the timing between the beacon signal transmitted from the communication device in the other network group and the own beacon signal, the signal described in the beacon signal from the communication device in the other network group is changed. Applying the time frame for transmission and / or reception to the time frame management table set based on the common clock information with reference to the time frame for transmitting the determined beacon signal, Managing the presence of a communication device in the network group . Frame setting means for setting a superframe having a predetermined period composed of a plurality of time frames for transmitting and / or receiving a signal based on its own clock information;
Time frame determining means for determining a time frame for transmitting at least a beacon signal in the superframe;
Beacon signal receiving means for receiving beacon signals transmitted at intervals of a predetermined period according to a superframe;
Time for transmitting and / or receiving the signal described in the received beacon signal without synchronizing the timing of the beacon signal with the timing of the beacon signal received by the beacon signal receiving means A time frame for obtaining a frame and an unsynchronized time frame for transmitting and / or receiving the signal, at least with reference to a time frame for the communication device to transmit a beacon signal. Time frame management means to be applied to the time frame management table set based on
A communication device comprising: A scanning period setting unit configured to set a scanning period for scanning a beacon signal in order to grasp the presence of another communication apparatus existing in a communication area capable of communicating with the communication apparatus;
Scanning means for continuously executing a beacon signal reception process for receiving a beacon signal during a predetermined period determined by the superframe during the scanning period;
The communication apparatus according to claim 3, further comprising grasping means for grasping a communication apparatus existing in the communication area each time a beacon signal reception process is performed by the scanning means. The communication device comprises time measuring means for measuring the reception time of a beacon signal from a communication device existing in the communication area with reference to its own clock information,
The time frame determining means determines a time frame corresponding to the time measured by the time measuring means as a time frame for receiving a beacon signal from a communication device existing in the communication area;
The time frame management means, when the reception of the beacon signal is not synchronized with the time frame in the communication device, the time frame corresponding to the time measured and the time frame adjacent thereto, The communication apparatus according to claim 3, wherein the communication apparatus is described in a table.   The time frame management means determines a time frame for transmitting and / or receiving the signal based on the time frame parameter described in a beacon signal from a communication device existing in the communication area, and 4. The communication apparatus according to claim 3, wherein the time frame is converted into an access time based on its own clock information, and access control of each communication apparatus is performed based on the access time. The communication device includes a beacon signal generating unit configured to generate the beacon signal in which the time frame parameter described in the time frame management table is set;
A beacon signal transmitting means for transmitting the beacon signal,
When the beacon signal transmission unit transmits the beacon signal generated by the beacon signal generation unit, the time frame parameter set in the beacon signal is notified to other communication devices existing in the communication area. The communication device according to claim 3, wherein: Clock setting means for setting common clock information in a network group to which the self belongs, comprising one or more communication devices;
Frame setting means for setting a superframe having a predetermined period in a network group to which the network belongs, which is composed of a plurality of time frames for transmitting and / or receiving signals based on the common clock information;
A time frame determining means for determining a time frame for transmitting at least a beacon signal of each communication device in the network group to which the self belongs in the super frame;
Beacon signal receiving means for receiving a beacon signal transmitted in a predetermined cycle in accordance with the superframe by a communication device in the network group to which the self belongs ;
Without synchronizing the timing between the beacon signal transmitted from the communication device in the other network group and the own beacon signal, the signal described in the beacon signal from the communication device in the other network group is changed. Applying the time frame for transmission and / or reception to the time frame management table set based on the common clock information with reference to the time frame for transmitting the determined beacon signal, Time frame management means for managing the presence of communication devices in the network group ;
A communication device comprising: A scanning period setting unit configured to set a scanning period for scanning a beacon signal in order to grasp the presence of another communication apparatus that is the same network group as the communication apparatus;
Scanning means for continuously executing a beacon signal reception process for receiving a beacon signal during a predetermined period determined by the superframe during the scanning period;
9. The communication apparatus according to claim 8 , further comprising grasping means for grasping a communication apparatus belonging to the network group each time a beacon signal reception process is performed by the scanning means. The communication device comprises time measuring means for measuring the reception time of a beacon signal from a communication device that is the same network group as the communication device with reference to its own clock information;
The time frame determining means determines a time frame corresponding to the time measured by the time measuring means as a time frame for receiving a beacon signal from a communication device belonging to the network group;
The time frame management means, when the reception of the beacon signal is not synchronized with the time frame in the communication device, the time frame corresponding to the time measured and the time frame adjacent thereto, The communication apparatus according to claim 8 , wherein the communication apparatus is described in a table. The time frame management means determines a time frame for transmitting and / or receiving the signal based on the time frame parameter described in a beacon signal from a communication device belonging to the network group, and the time frame 9. The communication device according to claim 8 , wherein the communication device is converted into an access time based on its own clock information, and access control of each communication device is performed based on the access time. The communication device includes a beacon signal generating unit configured to generate the beacon signal in which the time frame parameter described in the time frame management table is set;
A beacon signal transmitting means for transmitting the beacon signal,
The beacon signal transmitting means transmits the beacon signal generated by the beacon signal generating means, so that the time frame parameter set in the beacon signal is notified to other communication apparatuses belonging to the same network group as the communication apparatus. The communication device according to claim 8 , wherein: A communication method executed in a plurality of communication devices constructing an autonomous decentralized network:
Setting a superframe of a predetermined period composed of a plurality of time frames for transmitting and / or receiving a signal based on clock information of its own communication device;
Determining at least a time frame for transmitting a beacon signal in the superframe;
The communication device receives the beacon signal transmitted in a predetermined cycle according to the superframe by another communication device existing in a communication area capable of communicating with the communication device;
The signal described in the beacon signal from the other communication device is transmitted and / or synchronized without timing synchronization between the beacon signal transmitted from the other communication device and the beacon signal of the own communication device. Or, the time frame for receiving is applied to the time frame management table set based on the clock information of the own communication device based on at least the time frame for the own communication device to transmit a beacon signal. A communication method characterized by managing the presence of the other communication device . A communication method executed in a plurality of communication devices constructing an autonomous decentralized network:
Setting common clock information in a network group to which the communication device belongs, composed of one or more communication devices;
Based on the common clock information, setting a superframe of a predetermined period in a network group to which the self belongs, which is composed of a plurality of time frames for transmitting and / or receiving signals;
Determining a time frame for transmitting at least a beacon signal of each communication device in the own network group in the superframe;
Receiving a beacon signal transmitted in a predetermined cycle according to the superframe by a communication device in the network group;
Transmitting and / or transmitting the signal described in the received beacon signal without synchronizing the timing of the beacon signal with the timing of the beacon signal received from a communication device existing in another network group A time frame for receiving is applied to a time frame management table set based on the common clock information based on at least the time frame for transmitting the determined beacon signal, and exists in the other network group A communication method characterized by managing the presence of a communication device .

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