JP2009141507A - Communication system, transmitter, and receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system improved in data transfer efficiency. <P>SOLUTION: The communication system comprises a transmitter and a plurality of receivers. The transmitter comprises a multiplex data creating portion and a data transmitting portion. The multiplex data creating portion combines a plurality of communication data addressed to different receivers to create one multiplex data and includes designation information into the multiplex data, wherein the designation information specifies the reply timing of response data by changing it at each address. The data transmitting portion transmits the multiplex data created by the multiplex data creating portion to the receivers. Each of the receivers comprises a data receiving portion for receiving the multiplex data, a data checking portion for checking communication data addressed to the own receiver out of multiplex data received by the data receiving portion, and a response replying portion which transmits response data to the transmitter at reply timing according to the designation information included in the multiplex data, when communication data addressed to the own receiver are verified. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication system, a transmission device, and a reception device.

  2. Description of the Related Art Conventionally, various communication systems having various network configurations for communicating data included in each communication device are known as communication systems including a plurality of communication devices capable of wireless communication.

  FIG. 1 is a diagram illustrating a communication system having a star-type network configuration.

  The communication system 80 shown in FIG. 1 has a star-type network configuration in which a plurality of communication devices 81A to 81F are connected to one management server 82 1: n, and each of the communication devices 81A to 81F is It communicates only with the management server 82. A communication system 80 including a plurality of communication devices is used in, for example, a remote management system that grasps environmental characteristics of a remote place. In the remote management system, communication devices 81A to 81F with built-in sensors for measuring environmental characteristics such as temperature and illuminance are arranged at remote locations, and sensor data is transmitted from each communication device 81A to 81F to the management server 82. By doing so, the environmental characteristics of remote locations are managed in a unified manner.

  There is a type of remote management system in which environmental characteristics measured by other communication devices are displayed on a display unit included in a certain communication device. However, in the star-type network configuration shown in FIG. 1, the sensor data is first transmitted from the communication device that has performed the measurement to the management server 82, and then transmitted from the management server to the display communication device. bad. Therefore, a mesh network configuration in which data is directly transmitted from a communication device to another communication device without going through a management server has become mainstream (see, for example, Patent Document 1).

  FIG. 2 is a diagram illustrating a communication system having a mesh type network configuration.

  The communication system 90 shown in FIG. 2 has a mesh type network configuration in which a plurality of communication devices 91A to 91F are connected in an n: n manner. Here, n: n connection means that n, that is, a plurality of communication devices 91A to 91F can directly communicate with each other.

  Further, in a communication system, in order to improve communication reliability, a connection-type communication method in which a response is returned to a transmission-side communication apparatus after the reception-side communication apparatus receives communication data may be employed. is there. An example of a technical standard that defines a connection-type communication method in a communication system having a mesh-type network configuration is ARIB (Radio Industry Association) STD-30. ARIB STD-30 stipulates a low-power security system using specific low-power radio station equipment in the 400 MHz band. For example, homes including detached houses and apartment houses, supermarkets, department stores, financial institutions, offices, and factory facilities It is assumed that the system is mainly used for crime prevention / emergency reporting, which is used indoors and outdoors in public spaces such as commercial facilities, schools, hospitals, exhibition halls, welfare facilities, and parking lots.

  FIG. 3 is a diagram illustrating a communication device that performs connection-type communication, and FIG. 4 is a data flow illustrating transmission / reception of data between the communication devices illustrated in FIG. 3. FIG. 3 shows communication devices 91A to 91D of “A”, “B”, “C”, and “D” of the communication system 90 shown in FIG. 2, and FIG. A flow in the case where sensor data is transmitted from the communication device 91A to the remaining "B", "C", and "D" communication devices 91B to 91D is shown.

Based on the sensor data to be transmitted, the communication device 91A of “A” on the transmission side generates frames addressed to the communication devices 91B to 91D of “B”, “C”, and “D” on the reception side. To do. In each frame, an identifier for identifying each of the communication devices 91B to 91D, a preamble, and a trail are inserted. Thereafter, the communication device 91A of “A” on the transmission side transmits a frame 911 addressed to B addressed to the communication device 91B of “B” on the reception side. The communication device 91B of “B” that has received the frame 911 addressed to “B” transmits response data including an identifier for identifying itself. At this time, the frame 911 addressed to “B” is also received by the other communication devices 91C and 91D, but these communication devices 91C and 91D discard the frame 911 addressed to “B” that does not include its own identifier, Does not send response data. The communication device 91A of “A” on the transmission side receives the response data including the identifier of the communication device 91B of “B”, thereby confirming that the transmission of the frame 911 addressed to “B” has been performed reliably. . In this way, one communication cycle is completed. The communication device 91A of “A” on the transmission side transmits the frame 912 addressed to C to the communication device 91C of “C” in the next cycle, and the frame addressed to D to the communication device 91D of “D” in the next cycle. 913 is transmitted. In the communication device 91A on the transmission side “A” and the communication devices 91B to 91D on the reception side “B”, “C”, and “D”, the transmission state and the reception state are switched in one cycle.
Japanese Patent No. 3370143

  In the connection type communication system shown in FIG. 4, three cycles are required to transmit three sensor data. In particular, in a mesh-type network configuration that does not have a management server, in order to guarantee an opportunity to transmit to all communication devices, until the next frame is transmitted after the transmission-side communication device transmits a frame. It is necessary to leave a time interval. For example, in the above-described ARIB STD-30, when a plurality of frames are continuously transmitted, it is defined that a pause time of 2 seconds or more is provided between frames. For this reason, the data transfer efficiency, that is, the decrease in the amount of frame transmission per time becomes significant.

  Further, in the connection-type communication method, since the communication device on the transmission side retransmits the frame when the response data is not received, the data transfer efficiency is likely to further decrease.

  FIG. 5 is a data flow when retransmission occurs in the communication system shown in FIG.

  In the example shown in the data flow of FIG. 5, the “A” communication device 91A on the transmitting side transmits the “C” addressed frame 912a to the “C” communication device 91C, and then the “C” communication device 91C on the receiving side. The case where the response data transmitted from is not received is shown. Reasons for not receiving response data include, for example, collision (collision) with transmission data from other communication devices, noise, and the like. When the response data cannot be received, the “A” communication device 91A on the transmission side retransmits the frame 912b addressed to “C” in the next frame. This retransmission also requires one cycle.

  Also, if a plurality of data is to be transmitted in one cycle, response data from a plurality of receiving side communication devices collide with each other, transmission cannot be confirmed, and the frequency of retransmission increases, so the data transfer efficiency is improved. On the contrary, it declines.

  In view of the above circumstances, an object of the present invention is to provide a communication system, a transmission device, and a reception device with improved data transfer efficiency.

The communication system of the present invention that achieves the above object includes a plurality of receiving devices that wirelessly receive communication data and return response data, and a communication device that includes a transmitting device that transmits the communication data to the receiving device. A system,
The transmitting device is
A multiple data creation unit that combines a plurality of communication data with different destination receiving devices to create one multiplexed data, and includes designation information specified by changing the response data return timing for each destination in the multiplexed data; ,
A data transmission unit that transmits the multiplexed data created by the multiplexed data creation unit to each destination receiving device of each communication data combined with the multiplexed data;
A response receiving unit that receives the response data from the receiving device;
The receiving device is
A data receiver for receiving the multiplexed data;
A data confirmation unit for confirming communication data addressed to the receiving device from the multiplexed data received by the data receiving unit;
A response reply unit for replying the response data to the transmission device at a reply timing corresponding to the designation information included in the multiplexed data when communication data addressed to the receiving device is confirmed by the data confirmation unit; It is characterized by having provided.

  In the communication system of the present invention, multiplexed data in which a plurality of communication data addressed to a plurality of receiving devices is arranged is transmitted from the transmitting device to the receiving device. Therefore, a plurality of pieces of communication data can be transmitted for each piece of communication data without switching between transmission and reception, so that the data transfer efficiency is improved. In addition, response data is returned from a plurality of wireless receiving ends that have received communication data at a reply timing corresponding to the designation information included in the multiplexed data, so that collision between the response data is suppressed, and the data Since retransmission is reduced, the data transfer efficiency is improved.

Here, in the communication system of the present invention, the transmission device includes a storage unit that stores communication data combined with the multiplexed data.
The multiple data creation unit of the transmission device stores the destination for which the response data is not received by the response reception unit even after a predetermined time has elapsed after the multiplexed data is transmitted by the data transmission unit by the storage unit. To create new multiple data by combining the communication data
It is preferable that the transmission apparatus further includes a data deletion unit that deletes communication data stored by the storage unit for a destination from which the response data is received by the response reception unit.

  For destinations for which no response data is received, communication data is transmitted reliably by creating and transmitting multiplexed data combining stored communication data.

  Further, in the communication system of the present invention, the data transmission unit of the transmission apparatus transmits the multiplexed data created by the multiplexed data creation unit next to the transmitted multiplexed data after a predetermined period from the previous transmission. It is preferable to transmit.

  Since the communication system of the present invention can transmit a plurality of communication data without switching between transmission and reception by using multiplexed data, for example, a predetermined period as defined in ARIB STD-30 is used. It is particularly suitable for a communication system that needs to perform transmission.

  Since this communication system transmits a plurality of pieces of communication data by one multiplexed data, for example, communication that is required to be performed after a predetermined period from the previous transmission, as defined in ARIB STD-30. It is particularly suitable for the system.

Further, in the communication system of the present invention, the multiple data creation unit of the transmission device arranges the communication data of each of the plurality of destinations in order as the multiplexed data, and sets the return timing to each destination in the order of the communication data. Creates multiple data to be specified,
It is preferable that the response reply unit of the receiving device returns the response data at a reply timing corresponding to the order of the communication data addressed to the receiving device among the communication data arranged in the multiplexed data.

  Reply of response data is performed at a reply timing according to the order of the communication data arranged in the multiplexed data, so that the reply timings of the plurality of response data can be set to each other without explicitly inserting information into the data to be transmitted. Can be shifted.

Further, in the communication system of the present invention, the multiple data creation unit of the transmission device creates multiple data in which a reply timing specification at the destination is attached to the communication data of each destination as the multiplexed data. Yes,
The response reply unit of the receiving device returns the response data at a reply timing corresponding to a designation attached to the communication data addressed to the receiving device among the communication data combined with the multiplexed data. preferable.

  When the reply timing designation is attached to the communication data of each destination, the reply timing of the response data can be set according to the length of the element data and the capability of the receiving device.

The transmitting device of the present invention that achieves the above object is a transmitting device that transmits communication data to a receiving device that wirelessly receives communication data and returns response data,
A multiple data creation unit that combines a plurality of communication data with different destination receiving devices to create one multiplexed data, and includes designation information specified by changing the response data return timing for each destination in the multiplexed data; ,
A data transmission unit that transmits the multiplexed data created by the multiplexed data creation unit to each destination receiving device of each communication data combined with the multiplexed data;
And a response receiving unit that receives the response data from the receiving device.

  Since the transmission device of the present invention transmits multiplexed data in which a plurality of communication data is arranged, a plurality of communication data can be transmitted without switching between transmission and reception for each communication data, so that the data transfer efficiency is improved. improves. In addition, since the multiplex data includes the designation information designating the response data return timing, collision between the response data is suppressed, and the data transfer efficiency is improved.

The receiving device of the present invention that achieves the above object is a receiving device that wirelessly receives communication data transmitted from a transmitting device and returns response data to the transmitting device.
A data receiving unit that receives multiplexed data including designation information that is specified by differentiating the reply timing of the response data for each destination in multiplexed data obtained by combining a plurality of communication data with different destination receiving devices;
A data confirmation unit for confirming communication data addressed to the receiving device from the multiplexed data received by the data receiving unit;
A response reply unit for replying the response data to the transmission device at a reply timing corresponding to the designation information included in the multiplexed data when communication data addressed to the receiving device is confirmed by the data confirmation unit; It is characterized by having.

  Since the receiving device of the present invention returns response data at a reply timing corresponding to the designation information included in the received multiplexed data, even when there are a plurality of receiving devices, collision of response data is suppressed, Transfer efficiency is improved.

  As described above, according to the present invention, a communication system, a transmission device, and a reception device with improved data transfer efficiency are realized.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 6 is a diagram showing a first embodiment of a communication system of the present invention.

  The communication system 100 illustrated in FIG. 6 includes four communication devices 110A, 110B, 110C, and 110D, “A”, “B”, “C”, and “D”. These four communication devices 110 </ b> A to 110 </ b> D can directly and wirelessly communicate with each other by a connection-type communication method compliant with ARIB STD-30, and constitute a mesh-type network 101. All of these four communication devices 110A to 110D function as a receiving device that wirelessly receives communication data and returns response data, and also function as a transmitting device that transmits communication data to the receiving device. To do. In one communication cycle, any one of these four communication devices 110A to 110D functions as a transmission device, and the remaining three devices function as reception devices. Hereinafter, these four communication devices 110A to 110D are also referred to as transmitting devices 110A to 110D or receiving devices 110A to 110D depending on their roles in the communication cycle. Each of the four communication devices 110A to 110D has a sensor described in detail later, and sensor data measured by the sensor of the transmission device is transmitted to the reception device as communication data. When transmitting communication data to a plurality of receiving devices, the transmitting device transmits a multiplex frame as multiplexed data generated by combining a plurality of sensor data addressed to the plurality of receiving devices. The receiving apparatus confirms the sensor data addressed to the receiving apparatus itself from the received multiplex frame, and when the sensor data is confirmed, returns an ACK frame as response data to the transmitting apparatus. Communication is completed when the transmitting device receives the ACK frame. The plurality of receiving apparatuses avoid collision by returning ACK frames at timings shifted from each other. The designation information for designating the reply timing is included in the multiplexed frame. Details of the method for specifying the reply timing will be described later.

  Each of communication devices 110A to 110D of “A”, “B”, “C”, and “D” when functioning as a transmission device is an embodiment of the transmission device according to the present invention, and also functions as a reception device. Each of the communication devices 110A to 110D of “A”, “B”, “C”, and “D” in this case is an embodiment of the receiving device according to the present invention.

  Next, the internal configuration of the communication devices 110A to 110D will be described. Since “A”, “B”, “C”, and “D” communication devices 110A to 110D have the same configuration, the communication device 110A of “A” will be described as a representative.

  FIG. 7 is a block diagram showing an internal configuration of the communication apparatus shown in FIG.

  The communication device 110A of “A” illustrated in FIG. 7 includes a wireless communication unit 111 and a sensor that perform wireless transmission and reception with other communication devices 110B to 110D (see FIG. 6) of “B”, “C”, and “D”. A sensor unit 112 that receives the sensor data, a terminal ID setting unit 113 in which a terminal ID is set as a terminal identifier for identifying the communication device 110A itself of “A”, a destination management table 114 that manages a data destination, and a sensor Output unit 115 that outputs sensor data as detection data from the data, data received from the communication devices 110B to 110D of “B”, “C”, and “D”, and each unit in the communication device 110A of “A” It has the control part 116 which controls. The control unit 116 further includes a frame generation unit 121 that generates an element frame including sensor data as communication data and an ACK frame as response data, a multiple frame generation unit 122 that multiplexes the generated element frames, a multiple frame A transmission buffer that temporarily stores the data generated in step 1, a reception frame control unit 123 that checks frames received by the wireless communication unit 111, and an element frame addressed to the communication device 110A itself of "A" The ACK generation control unit 124 controls the generation of the ACK frame.

  The wireless communication unit 111 performs wireless communication with other “B”, “C”, and “D” communication devices 110 </ b> B to 110 </ b> D by a connection-type communication method that performs delivery confirmation using an ACK frame. The wireless communication unit 111 conforms to the communication standard of ARIB STD-30, and the communication procedure executed by the wireless communication unit 111 includes a transmission time limit of 3 seconds or less and a transmission suspension time of 2 seconds or more. . The wireless communication unit 111 performs transmission / reception by selecting an appropriate frequency channel (all 48 channels) and a transfer rate (1.2 / 2.4 / 4.8 / 9.6 kbps) under the control of the control unit 116. .

  The sensor unit 112 includes a temperature sensor 112a that measures temperature and an illuminance sensor 112b that measures illuminance. The sensor unit 112 is connected to external sensors 120a, 120b, and 120c that detect human feeling and acceleration using infrared rays via a sensor I / F (not shown). These sensors 112a, 112a, 120a, 120b, and 120c detect the state of the environment where the communication device 110A of “A” exists, and output sensor data as detection data. The sensor unit 112 receives sensor data of temperature, illuminance, human feeling, and acceleration detected by the built-in and external sensors 112 a, 112 a, 120 a, 120 b, and 120 c, and outputs them to the frame generation unit 121 of the control unit 116. The sensor unit 112 corresponds to an example of the detection data receiving unit referred to in the present invention.

  The terminal ID setting unit 113 is composed of a semiconductor memory, and stores a terminal ID as an identifier in advance. A unique terminal ID is assigned to each of the communication devices 110A to 110D of “A”, “B”, “C”, and “D”. The terminal ID setting unit 113 of the communication device 110A of “A” stores a terminal ID for identifying the communication device 110A itself of “A”.

  The destination management table 114 is composed of a semiconductor memory, and is the type of temperature, illuminance, human sensory, acceleration sensor data detected by the sensors 112a, 112a, 120a, 120b, 120c, and the destination of the sensor data. The terminal IDs of the communication devices 110A to 110D of “A”, “B”, “C”, and “D” are stored in association with each other in advance. In the example of FIG. 7, the destination of illuminance data is set to the communication device 110B of “B”, and the destination of acceleration data is set to the communication device 110D of “D” and the communication device 110C of “C”.

  The output unit 115 outputs the data transmitted from the control unit 116 to a display device (not shown). Sensor data such as temperature, illuminance, human feeling, acceleration detected by the sensors 112a, 112a, 120a to 120c, and data received from the other communication devices 110B to 110D are displayed on the display device. The output unit 115 also has a function of outputting the transmitted data to the outside in, for example, a serial I / F standard format.

  The control unit 116 creates element frames and multiple frames based on the sensor data supplied from the sensor unit 112 and the stored contents of the terminal ID setting unit 113 and the destination management table 114 and causes the wireless communication unit 111 to transmit them. In addition, when the communication device 110 </ b> A of “A” functions as a reception device, the control unit 116 receives the multiplexing received from the communication devices 110 </ b> B to 110 </ b> D of “B”, “C”, and “D” via the wireless communication unit 111. It is confirmed whether or not there is sensor data addressed to the communication device 110 </ b> A itself of “A” in the frame. If there is sensor data, it is transferred to the output unit 115 and an ACK frame is generated. The control unit 116 controls transmission / reception timings of various frames exchanged with the other communication devices 110B to 110D.

  The frame generation unit 121 receives supply of sensor data from the sensor unit 112 and associates the sensor data with the destination. More specifically, the frame generation unit 121 refers to the destination management table 114 to acquire the terminal ID of the destination communication device corresponding to the type of sensor data, and refers to the terminal ID setting unit 113 to “A”. The terminal ID of the communication device 110A itself is acquired, and an element frame including sensor data is generated for each destination communication device.

  FIG. 8 is a diagram showing the format of an element frame.

  An element frame 200 shown in FIG. 8 includes a header 210 and data 220.

  The header 210 includes a destination 211, a transmission source 212, a frame length 213, and a frame identifier 214. The data 220 includes a data type 221 and sensor data 222. The destination 211 represents the terminal ID of the destination communication device, and the transmission source 212 represents the terminal ID of the communication device 110A itself of “A”. The frame length 213 represents the data length of the element frame 200. The data type 221 represents the type of sensor data such as temperature, illuminance, human feeling, acceleration, etc., and the sensor data 222 represents the value of the sensor data.

  The frame generation unit 121 also generates an ACK frame as response data at the reply timing supplied from the ACK generation control unit 124 when the communication device 110A of “A” functions as a reception device.

  FIG. 9 is a diagram illustrating a format of an ACK frame.

  The ACK frame shown in FIG. 9 includes a destination 301, a transmission source 302, a frame identifier 303, a type 304, and data 305. The destination 301 and the transmission source 302 are the same as the element frames shown in FIG. 8, and the type 304 represents an ACK frame.

  The combination of the frame generation unit 121 and the ACK generation control unit 124 in the case where the communication device 110A of “A” functions as a reception device corresponds to an example of a response reply unit according to the present invention.

  Returning to FIG. 7, the description will be continued. The multiplex frame generation unit 122 creates a single multiplex data by combining a plurality of sensor data with different destination receivers. More specifically, the multiplex frame generation unit 122 outputs all the element frames generated by the frame generation unit 121 to a plurality of communication devices 110B to 110D of “B”, “C”, and “D” for a certain period. Combine to generate multiple frames.

  FIG. 10 is a diagram illustrating a format of a multiplexed frame. FIG. 10 shows a multiplex frame when N element frames are multiplexed.

  A multiplexed frame 400 shown in FIG. 10 includes a preamble 401 representing the head of the multiplexed frame, a multiplexed frame number 402 representing the number of multiplexed element frames, N element frames 200a, 200b,. The trail 403 that represents the end of. In the multiplexed frame 400, N element frames 200a, 200b,..., 200c generated for each of a plurality of receiving apparatuses are arranged side by side.

  In addition, the multiplex frame generation unit 122 arranges the element frames 200a, 200b,..., 200c, so that the receiving devices 100B, 100C, and 100D that receive the element frames receive the ACK frame. Specify the reply timing to reply. Specifically, the reply timing is specified by the order in which the element frames 200a, 200b,. For example, in the multiplexed data 400 shown in FIG. 10, the receiving device that is the destination of the element frame 200a specifies 100 ms as a reply timing by placing the element frame 200a at the head of the multiplexed data 400. The receiving device that is the destination of the second element frame 200b is designated with a response time of 200 ms. Thereafter, every time the element frame order is lowered, a time obtained by adding 100 ms is designated as a reply timing. In this way, the multiplex frame generation unit 122 includes the designation information designated by changing the reply timing for each destination in the multiplex data.

  In addition, the multiplex frame generation unit 122 causes the wireless communication unit 111 to transmit the generated multiplex frame. As a result, the multiplex frame created by the multiplex frame generation unit 122 is transmitted to the receiving devices 100B, 100C, and 100D of “B”, “C”, and “D” of each destination of the sensor data combined with the multiplex data. Is done. The multiplex frame generation unit 122 transmits the generated multiplex data after a predetermined period has passed since the previous transmission. This period is defined as 2 seconds in the case of ARIB STD-30, for example. In addition, the multiplex frame generation unit 122 stores the generated multiplex frame in the transmission buffer 124. In the transmission buffer 124, the sensor data included in the element frame is stored in a state of being combined with the multiplexed frame. Element frames in the multiplex frame are stored in the transmission buffer 124 until the corresponding ACK frame is received from the communication devices 110B to 110D of “B”, “C”, and “D”. The element frame in which the ACK frame is received from the destination is deleted by the notification from the reception frame control unit 123. The multiplex frame generation unit 122 stores destinations for which an ACK frame is not received by the reception frame control unit 123 even after a predetermined communication cycle has elapsed after the multiplex data is transmitted by the wireless communication unit 111, by the transmission buffer 124. A new multiple frame is created by combining the element frames in the multiple frames. The new multiplexed frame is retransmitted by the wireless communication unit 111.

  FIG. 11 is a data flow of the communication system shown in FIG. FIG. 11 shows a schematic flow when transmission is performed from the communication device 110A of “A” to the remaining three communication devices 110B to 110D of “B”, “C”, and “D”.

  When the sensor data to be transmitted to each of the receiving devices 110B to 110D of “B”, “C”, and “D” is obtained in one communication cycle period in the transmitting device 110A of “A”, a frame The generation unit 121 generates element frames 200a, 200b, and 200c addressed to the receiving devices 110B to 110D of “B”, “C”, and “D”, and the multiple frame generation unit 122 generates three element frames 200a and 200b. , 200c are combined to generate a multiplex frame 400. The multiplexed frame 400 is transmitted from the wireless communication unit 111. In this way, sensor data is transmitted to a plurality of destinations without switching transmission / reception for each element frame in one communication cycle period. The multiplexed frame 400 is received almost simultaneously by the “B”, “C”, and “D” receiving apparatuses 110B to 110D. Response data indicating reception of the element frame 200a addressed to the reception apparatus 110B of “B” is returned from the reception apparatus 110B of “B”, and a response indicating reception of the element frame 200b is received from the reception apparatus C110C of “C”. Data is returned, and response data indicating reception of the element frame 200c is returned from the receiving device 110D of “D”.

  Returning to FIG. 7 again, the description will be continued. The reception frame control unit 123 receives an ACK frame indicating reception of the element frame from the communication devices 110B to 110D of “B”, “C”, and “D” that are destinations of the transmitted element frame via the wireless communication unit 111. Receive. More specifically, the reception frame control unit 123 obtains an ACK frame from the wireless communication unit 111, and when the ACK frame is addressed to the communication apparatus 110A itself having the "A", the ACK frame transmission source 302 (FIG. 9). Is transmitted to the multiplex frame generation unit 122 to notify that the transmission of the element frame to the communication apparatus represented by the transmission source 302 has been successful. By this notification, the element frame stored in the transmission buffer 124 including the sensor data is deleted by the multiple frame generation unit 122. The reception frame control unit 123 when the communication device 110A of “A” operates as a transmission device corresponds to an example of a response reception unit according to the present invention, and multiple frame generation for deleting sensor data by notification of the reception frame control unit 123 The unit 122 corresponds to an example of a deletion unit referred to in the present invention.

  When the communication device 110 </ b> A of “A” operates as a reception device, the reception frame control unit 123 confirms sensor data addressed to the communication device 110 </ b> A itself of “A” from the multiplexed frame received by the wireless communication unit 111. More specifically, the reception frame control unit 123 supplies sensor data of an element frame including a terminal identifier for identifying the communication device 110A itself of “A” from the multiplexed frame to the output unit 115 for display and the like. The frame identifier of the element frame is held in a frame identifier management buffer (not shown). The reception frame control unit 123 also supplies the ACK generation control unit 124 with designation information that designates the return timing included in the multiplexed frame. More specifically, the reception frame control unit 123 supplies the ACK generation control unit 124 with information on the return timing corresponding to the order in which the element frames are arranged in the multiplex buffer. Specifically, when the element frame addressed to the communication device 110A itself of “A” is arranged at the head of the multiplexed frame, 100 ms is supplied as the reply timing information, and when the element frame is arranged second. 200 ms is supplied, and a value obtained by adding 100 ms is supplied every time the element frame order decreases.

  The ACK generation control unit 124 provides a response timing for transmitting the ACK frame to the frame generation unit 121 by counting the time based on the information on the response timing notified from the reception frame control unit 123. The frame generation unit 121 generates an ACK frame at the reply timing provided to the ACK generation control unit 124 and causes the wireless communication unit 111 to transmit the ACK frame. In this way, the frame generation unit 121 corresponds to the designation information included in the multiplexed data, that is, the order of the sensor data addressed to the communication device 110A of “A” among the sensor data arranged in the multiplexed data. An ACK frame is returned to the transmission device at the reply timing. When the communication device 110 </ b> A of “A” functions as a receiving device, the multiplex frame generation unit 122 does not process the ACK frame when the frame generated by the frame generation unit 121 is an ACK frame, and the wireless communication unit 111. Forward to.

  The reception frame control unit 123 when the communication device 110A of “A” operates as a reception device corresponds to an example of a data confirmation unit according to the present invention. A combination of the ACK generation control unit 124 and the frame generation unit 121 corresponds to an example of a response reply unit according to the present invention. The wireless communication unit 111 when the communication device 110A of “A” operates as a transmission device corresponds to an example of the data transmission unit according to the present invention, and the communication device 110A of “A” operates as a reception device. The wireless communication unit 111 corresponds to an example of the data receiving unit referred to in the present invention.

  Next, the operation of the communication device 110A of “A” will be described separately for the case where the communication device 110A of “A” transmits multiple frames and the case of receiving multiple frames and ACK frames.

  FIG. 12 is a flowchart illustrating the operation of the control unit 116 of the communication device 110A of “A” when the communication device 110A of “A” transmits multiple frames.

  When the communication device 110A of “A” transmits a multiplex frame, the frame generation unit 121 acquires sensor data from the sensor unit 112 together with a data type indicating the type of the sensor data (S11). The obtained sensor data becomes the sensor data 222 of the element frame 200 (see FIG. 8), and the data type becomes the data type 221 of the element frame 200.

  Next, the frame generation unit 121 refers to the destination management table 114 and determines a destination according to the obtained sensor data (S12). For example, when the sensor data obtained from the sensor unit 112 is illuminance, B, which is a value representing the communication device 110B of “B”, is obtained from the destination management table 114 as the destination terminal ID corresponding to the illuminance. . The obtained value becomes the destination 211 of the element frame 200 (see FIG. 8).

  Next, the frame generation unit 121 refers to the terminal ID setting unit 113 and acquires the terminal ID of the communication device 110A of “A” itself (S13). The obtained value becomes the transmission source 212 of the element frame 200 (see FIG. 8). Next, the frame generation unit 121 acquires a frame identifier (S14). The frame identifier is a unique value for the generated element frame. The obtained value becomes the frame identifier 214 of the element frame 200 (see FIG. 8). Next, the frame generation unit 121 inserts the frame length 213 of the element frame 200 into the element frame 200, and stores the completed element frame 200 in the transmission buffer 124 (S15).

  Next, the multiplex frame generation unit 122 checks a predetermined multiplex period, that is, a communication cycle, and when 2 seconds have passed since the previous transmission (S16: Yes), the element frame stored in the transmission buffer 124 is read and combined. Multiple frames are then created (S17). The multiplex frame generation unit 122 adds the preamble 401, the number of multiplexed frames 402, and the trail 403 (see FIG. 10) to the multiplex frame 400 (S18), and outputs the completed multiplex frame to the wireless communication unit 111 (S19). ). Thus, the multiplex frame is transmitted from the wireless communication unit 111 of the communication device 110A of “A” to the communication devices 110B to 110D of “B”, “C”, and “D”.

  Thereafter, the multiplex frame generation unit 122 sets a timer for waiting for ACK (S20), and waits for reception of an ACK frame until a timeout occurs (S21). When the ACK frame corresponding to the element frame of the multiplexed frame transmitted by the reception frame control unit 123 is received, the transmission for this element frame is completed (S22: Yes). If there is an element frame that has not received an ACK frame (S22: No), retransmission is performed. That is, in the transmission buffer 124, an element frame in which an ACK frame is not received remains among the transmitted multiplexed frames. The multiplex frame generation unit 122 also combines the remaining element frames to create a new multiplex frame.

  FIG. 13 is a flowchart illustrating the operation of the control unit 116 of the communication device 110A of “A” when the communication device 110A of “A” receives the multiplexed frame and the ACK frame.

  There are two types of frames received by the communication device 110A of “A”: a multiplex frame including an element frame received when operating as a receiving device, and an ACK frame received when operating as a transmitting device. .

  The reception frame control unit 123 receives the frame from the wireless communication unit 111 (S21), and the frame destination, that is, the destination 301 in the case of the ACK frame 300 (see FIG. 9) or the multiplexed frame 400 (see FIG. 10). When the destination 211 of each element frame 200 (see FIG. 8) arranged therein is confirmed to be a frame addressed to itself (S23: Yes), the frame identifier is referred to by referring to a frame identifier management buffer (not shown). Is already registered (S23). When the frame identifier is not registered (S23: None), the frame identifier is registered in the frame identifier management buffer. If the frame identifier has already been registered (S23: Yes), it is estimated that the frame has been received before, and the ACK frame returned at this time has been retransmitted because it was not received for some reason. Is done. Therefore, if the frame received this time is an ACK frame (S24: Yes), this is ignored and the received frame is discarded (S35). If the received frame is not an ACK frame, that is, a multiplex frame (S24: No) Generation and transmission of an ACK frame are performed (S29 ~).

  On the other hand, when the frame identifier is not registered (S23: none) and the received frame is an ACK frame (S26: Yes), the multiplex frame generation unit 122 deletes the corresponding element frame from the transmission buffer 124. (S28). When the communication device 110A of “A” is operating as a transmission device, the transmission of the element frame is completed by this processing.

  When the received frame is not an ACK frame, that is, a multiplex frame (S24: No), the reception frame control unit 123 outputs the reception data to the output unit 115 and sets a delay time according to the order in which the element frames are arranged. The ACK generation control unit 124 is supplied (S27).

  Thereafter, the ACK generation control unit 124 counts the timing until timeout based on the delay time supplied from the reception frame control unit 123 and waits for the delay time (S29, S30). Thereafter, information from the received element frame, specifically, the destination of the ACK frame is determined from the transmission source 212 (see FIG. 8) and inserted into the ACK frame (S31), and the terminal ID setting unit 113 is referred to. Then, it determines its own identifier as the transmission source of the ACK frame, inserts it into the ACK frame (S34), and outputs it to the wireless communication unit 111 (S34). As a result, the ACK frame is transmitted from the radio reception unit after the delay time corresponding to the element frame addressed to the communication device 110A of “A” indicated in the multiplexed frame has elapsed.

  Finally, the reception frame control unit 123 discards the received frame (S35) and ends the frame reception process.

  Next, an example of communication in the communication system shown in FIG. 6 will be described.

  FIG. 14 is a diagram illustrating each communication device that performs communication in the communication system illustrated in FIG. 6, and FIG. 15 is a data flow illustrating transmission / reception between the communication devices illustrated in FIG. 14.

  In the example illustrated in FIGS. 14 and 15, the communication device 110 </ b> A of “A” operates as the transmission device of the transmission source, and the remaining communication devices 110 </ b> B to 110 </ b> D of “B”, “C”, and “D” are the destinations. Operates as a receiving device. The communication device 110A of “A” measures temperature, illuminance, and human feeling. In the destination management table 114 of the communication device 110A of “A”, the identifier “B” of the communication device 110B of “B” is stored in the temperature data. ”, The identifier“ C ”of the communication device 110C of“ C ”corresponds to the illuminance data, and the identifier“ C ”of the communication device 110C of“ C ”is stored corresponding to the human feeling data. To do.

  The operation of the communication apparatus shown in FIG. 14 will be described along the flow of FIG.

  (1) In the communication device 110A of “A”, the sensor unit obtains three types of sensor data of temperature, illuminance, and human feeling. For example, sensor data having a temperature of 20 ° C., an illuminance of 300 lx, and a human reaction can be obtained.

  (2) The communication device 110A of “A” refers to the destination management table 114, and obtains a destination identifier corresponding to the type of sensor data. Three element frames including the obtained identifier and sensor data are generated, and further, a multiple frame in which the three element frames are arranged is generated, and the multiple frames are represented by communication devices “B”, “C”, and “D”. 110B to 110C are transmitted. 16A, FIG. 16B, and FIG. 16C show examples of element frames generated by the communication device 110A of “A”, and FIG. 16D shows multiple frames. The element frame 200a illustrated in FIG. 16A includes the identifier “B” as the destination, the temperature as the type, and “20 ° C.” as the data. The element frame 200b illustrated in FIG. 16B includes the identifier “C” as the destination, the illuminance as the type, and “300lx” as the data. The element frame 200c illustrated in FIG. 16C includes the identifier “D” as a destination, includes a team type as a type, and includes “reactive” as data. The element frames 200a, 200b, and 200c include the identifier “A” as a transmission source, and include mutually unique values A1, A2, and A3 as frame identifiers. In the multiplex frame 400 shown in FIG. 16D, the three element frames 200a, 200b, and 200c shown in FIGS. 16A, 16B, and 16C are arranged side by side. “0x55” and the value “3” of the number of multiplexed frames 402 are included. Further, the value “0xAA” of the trail 403 is included behind the element frame. The three element frames 200a, 200b, and 200c are arranged in the multiplex frame 400 in the order in which sensor data is obtained. However, the order in which the element frames are arranged in the multiplex frame may be determined by other methods such as, for example, the value order of the destination identifier or random. The communication apparatus 110 </ b> A of “A” enters a mode for receiving a frame after transmitting the multiplexed frame 400.

  (3) The communication devices 110B to 110D receive the multiplexed frame transmitted by the communication device 110A of “A”. Multiple frames are received almost simultaneously by the communication devices 110B to 110C of “B”, “C”, and “D”.

  (4) In the communication device 110B of “B” that is one of the three communication devices 110B to 110D of “B”, “C”, and “D”, the communication device of “B” is received from the received multiplex frame. The element frame 200a addressed to the communication device 110B of “B” including the identifier “B” of 110B is detected, the data of the detected element frame 200a is displayed, and the frame identifier is registered in the frame identifier buffer. . Further, the communication device 110B of “B” responds to the fact that the element frame 200a addressed to the communication device 110B of “B” is arranged first in the multiplex frame 400, and ACKs at the timing of 100 ms after receiving the multiplex frame. Send a frame. FIG. 16E is a diagram illustrating an example of an ACK frame output from the communication device 110B of “B”.

  (5) The communication device 110A of “A” receives the ACK frame from the communication device 110B of “B” and determines that the element frame addressed to the communication device 110B of “B” has arrived normally.

  (6) In the communication device 110C of “C” different from the three communication devices 110B of “B”, the “C” including the identifier “C” of the communication device 110C of “C” is received from the received multiple frames. The element frame 200b addressed to the communication device 110C is detected, the data of the detected element frame 200b is displayed, and processing is performed, and the frame identifier is registered in the frame identifier buffer. Further, the communication device 110C of “C” responds to the fact that the element frame 200b addressed to the communication device 110C of “C” is arranged second in the multiplexed frame 400, and ACKs at the timing when 200 ms elapses after receiving the multiplexed frame. Send a frame. FIG. 16F is a diagram illustrating an example of an ACK frame output from the communication device 110 </ b> C of “C”.

  (7) The communication device 110A of “A” receives the ACK frame from the communication device 110C of “C” and determines that the element frame addressed to the communication device 110C of “C” has arrived normally.

  (8) The remaining “D” communication device 110D detects an element frame 200c addressed to “D” communication device 110D including the identifier “D” from the received multiple frames, and data of the detected element frame 200c is detected. And the frame identifier is registered in the frame identifier buffer. Further, the communication device 110D of “D” responds to the fact that the element frame 200c addressed to the communication device 110D of “D” is arranged first in the multiplex frame 400, and ACKs at the timing when 300 ms elapses after receiving the multiplex frame. Send a frame. FIG. 16G is a diagram illustrating an ACK frame format output from the communication device 110D of “D”.

  (9) The communication device 110A of “A” receives the ACK frame from the communication device 110D of “D” and determines that the element frame addressed to the communication device 110D of “D” has arrived normally.

  (10) The communication device 110A of “A” determines that all communication addressed to the communication devices 110B to 110D of “B”, “C”, and “D” has been normally completed.

  In this way, in the communication system 100, “B”, “C”, and “D” are received from the “A” transmitting device 110A to the “B”, “C”, and “D” receiving devices 110B to 110D. Since a multiplexed frame 400 (see FIG. 16D) in which three element frames addressed to the devices 110B to 110D are arranged is transmitted, sensor data can be transmitted without switching transmission / reception for each of the element frames 200a, 200b, and 200c. Can be sent. In addition, from the three receiving devices 110B to 110D of “B”, “C”, and “D” that have received the sensor data, the ACK frames 300a, 300b, and 300c are the reply timings instructed for each sensor data, that is, 100 ms. , 200 ms, and 300 ms, respectively, the occurrence of collision between ACK frames is suppressed, and data retransmission is suppressed.

  Here, an operation when an ACK frame is not returned from the destination of the element frame included in the multiplexed frame for some reason will be described.

  FIG. 17 is a data flow showing transmission / reception between the communication apparatuses shown in FIG. 14 when an ACK frame is not returned.

  In the transmission / reception shown in FIG. 17, the process from the acquisition of sensor data (1) to the reception of the ACK frame from the communication device 110D of “D” in (9) has been described with reference to the flow of FIG. This is the same as transmission / reception, and a description thereof will be omitted.

  In the transmission / reception (7) shown in FIG. 17, the ACK frame generated by the communication device 110C of “C” cannot be received by the communication device 110A of “A” due to deterioration of the wireless environment such as an increase in noise.

  (10) For this reason, the communication device 110A of “A” continues to wait for the ACK frame of the communication device 110C of “C”. It is determined that the element frame addressed to the communication device 110C has not arrived.

  (11) In the communication device 110A of “A”, the element frame 200b addressed to the communication device 110C of “C” arranged in the multiplexed frame 400 generated in (2) is extracted, and only this element frame 200b is extracted. The arranged multiple frame is transmitted. FIG. 18 is a diagram illustrating a format of a multiplexed frame including only element frames addressed to the communication device 110C of “C”. In the communication system 100, when multiple frames are transmitted continuously, it is necessary to have a pause of 2 seconds between the transmissions. For this reason, the multiplex frame for retransmission is performed 2 seconds after the previous multiplex frame transmission. The communication device 110 </ b> A of “A” enters a mode of receiving a frame after transmitting the multiplexed frame 450.

  (12) The communication device 110C of “C” receives the multiplexed frame 450 transmitted by the communication device 110A of “A”. The remaining "B" communication devices 110B and 110D also receive the multiplexed frame 450, but discard the received multiplexed frame 450 because the destination does not include its own identifier.

  (13) The communication device 110C of “C” extracts the element frame 200b addressed to the communication device 110C of “C” from the received multiplexed frame 450. Since the frame identifier value A2 of the extracted element frame 200b is the same as that registered in the frame identifier registration buffer, the communication device 110C of “C” determines that the element frame 200b has been retransmitted. Dispose of the display without processing it. Further, the element frame 200b addressed to the communication device 110C of “C” corresponds to being placed first in the multiplex frame 450, and transmits an ACK frame after waiting for 100 ms from the reception of the multiplex frame 450. The format of this ACK frame is the same as that shown in FIG. 16F.

  (14) The communication device 110A of “A” receives the ACK frame from the communication device 110C of “C” and determines that the element frame addressed to the communication device 110C of “C” has arrived normally.

  (15) The communication device 110A of “A” determines that all communication addressed to the communication devices 110B to 110D of “B”, “C”, and “D” has been normally completed.

  In this way, even when it is necessary to retransmit the element frame included in the multiplex frame, it is possible to generate a multiplex frame again with only the element frame that needs to be retransmitted and transmit the waste. Omitted communication is possible.

[Second Embodiment]
Next, a second embodiment of the communication system of the present invention will be described. In the second embodiment, portions common to the above-described first embodiment are denoted by the same reference numerals, description thereof is omitted, and the drawing is used, and portions different from the first embodiment are described.

  The overall configuration of the communication system according to the second embodiment is the same as that of the communication system according to the first embodiment described with reference to FIG. 6, and the configuration of each communication apparatus has also been described with reference to FIG. It is the same as the wireless communication terminal. However, the frame generation unit in the second embodiment is different from the frame generation unit 121 (see FIG. 7) in the first embodiment in the element frames to be generated. In addition, the reception frame control unit in the second embodiment differs from the reception frame control unit in the first embodiment in the method of determining the delay time. Therefore, the frame generation unit in the second embodiment uses the frame in the first embodiment. The delay time at the time of transmitting the ACK frame is different from that of the generation unit 121.

  FIG. 19 is a diagram illustrating a format of an element frame generated by the frame generation unit in the second embodiment.

  The element frame 250 shown in FIG. 19 is different from the element frame 200 shown in FIG. 8 in that a delay time 251 for specifying the return timing of the ACK frame is attached to the sensor data 222. In the second embodiment, the frame generation unit includes a delay time 251 that explicitly designates the return timing in the sensor data 222, and the multiple frame generation unit creates a multiple frame with the reply timing designation attached. .

  On the other hand, the reception frame control unit in the second embodiment generates an ACK for the delay time 251 as a reply timing included in the element frame including the identifier of the communication device 110A itself of “A” in the destination 211 (FIG. 19). It supplies to the control part 124. Therefore, the ACK generation control unit 124 and the frame generation unit 121 transmit an ACK frame at a reply timing corresponding to the designation attached to the sensor data addressed to the communication device 110A of “A”.

  FIG. 20 is a data flow showing transmission / reception between communication apparatuses in the second embodiment.

  The operation of the communication device in the second embodiment will be described along the flow of FIG. 6 and 7 are used for the description of the communication device, and the same reference numerals as those in the first embodiment are attached to the communication device.

  (1) In the communication device 110A of “A”, the sensor unit obtains three types of sensor data of temperature, illuminance, and human feeling. For example, sensor data having a temperature of 20 ° C., an illuminance of 300 lx, and a human reaction can be obtained.

  (2) The communication device 110A of “A” refers to the destination management table 114 and obtains a destination identifier corresponding to the type of sensor data. Three element frames including the obtained identifier and sensor data are generated, and further, a multiple frame in which the three element frames are arranged is generated, and the multiple frames are represented by communication devices “B”, “C”, and “D”. 110B to 110C are transmitted. 21A, FIG. 21B, and FIG. 21C show examples of element frames generated by the communication device 110A of “A” in the second embodiment, and FIG. 21D shows multiple frames. The element frame 250a shown in FIG. 21A includes the identifier “B” as the destination, the temperature “20 ° C.” as the type, and “50 ms” as the delay time for specifying the reply timing. The element frame 250b shown in FIG. 21B includes the identifier “C” as the destination, the illuminance as the type, “300 lx” as the data, and “150 ms” as the delay time. The element frame 250c shown in FIG. 21C includes the identifier “D” as the destination, “human feeling” as the type, “reaction” as the data, and “250 ms” as the delay time. The element frames 250a, 250b, and 250c include the identifier “A” as a transmission source and unique values A1, A2, and A3 as frame identifiers, respectively. In the multiplex frame 450 shown in FIG. 21D, the three element frames 250a, 250b, and 250c shown in FIG. 21A, FIG. 21B, and FIG. 21C are arranged side by side. “0x55” and the value 3 of the number of multiplexed frames 402 are included. Further, the value “0xAA” of the trail 403 is included behind the element frame.

  (3) The communication devices 110B to 110D receive the multiplexed frame transmitted by the communication device 110A of “A”. Multiple frames are received almost simultaneously by the communication devices 110B to 110C of “B”, “C”, and “D”.

  (4) In the communication device 110B of “B” that is one of the three communication devices 110B to 110D of “B”, “C”, and “D”, the communication device of “B” is received from the received multiplex frame. The element frame 250a addressed to the communication device 110B of “B” including the identifier “B” of 110B is detected, the data of the detected element frame 250a is displayed, and the frame identifier is registered in the frame identifier buffer. Further, the communication device 110B of “B” transmits an ACK frame at a return timing of 50 ms after receiving the multiplexed frame, corresponding to the delay time in the element frame 250a addressed to the communication device 110B of “B” representing 50 ms. To do.

  (5) The communication device 110A of “A” receives the ACK frame from the communication device 110B of “B” and determines that the element frame addressed to the communication device 110B of “B” has arrived normally.

  (6) In the communication device 110C of “C” different from the three communication devices 110B of “B”, the “C” including the identifier “C” of the communication device 110C of “C” is received from the received multiple frames. The element frame 250b addressed to the communication device 110C is detected, the data of the detected element frame 250b is displayed, and the frame identifier is registered in the frame identifier buffer. Further, the communication device 110C of “C” corresponds to the fact that the delay information in the element frame 250b addressed to the communication device 110C of “C” represents 150 ms, and the ACK frame is sent at a reply timing of 150 ms after receiving the multiplexed frame. Send.

  (7) The communication device 110A of “A” receives the ACK frame from the communication device 110C of “C” and determines that the element frame addressed to the communication device 110C of “C” has arrived normally.

  (8) The remaining “D” communication device 110D detects the element frame 250c addressed to the communication device 110D including the identifier “D” of the “D” communication device 110D from the received multiple frames, and detects the detected element frame 250c. The data of the frame 250c is processed and displayed, and the frame identifier is registered in the frame identifier buffer. Further, the communication device 110D of “D” corresponds to the delay time in the element frame 250c addressed to the communication device 110D of “D” representing 250 ms, and transmits an ACK frame at a reply timing of 250 ms after receiving the multiplexed frame. To do.

  (9) The communication device 110A of “A” receives the ACK frame from the communication device 110D of “D” and determines that the element frame addressed to the communication device 110D of “D” has arrived normally.

  (10) The communication device 110A of “A” determines that all communication addressed to the communication devices 110B to 110D of “B”, “C”, and “D” has been normally completed.

  In this way, in the communication system of the second embodiment, “B”, “C”, “B”, “C”, “D” receiving devices 110B to 110D are transmitted from “A” transmitting device 110A to “B”, “C”, Since a multiplexed frame 400 (see FIG. 16D) in which three element frames addressed to the receiving devices 110B to 110D of “D” are arranged is transmitted / received is switched for each of the element frames 200a, 200b, and 200c. Sensor data can be transmitted without In addition, from the three receiving devices 110B to 110D that have received the sensor data, ACK frames are transmitted at a reply timing instructed for each sensor data, that is, 50 ms, 150 ms, and 250 ms. The reply timing instruction is explicitly attached as a delay time 251 to the sensor data addressed to each receiving device, and can be set appropriately according to the length of the element frame and the capability of the communication device.

  Although the embodiment of the present invention has been described on the assumption that ARIB STD-30 is not performed, in which each communication terminal does not perform carrier sense before transmission as a transmission device, the communication system of the present invention is a communication standard for performing carrier sense. By applying to a communication system conforming to the above, the so-called hidden terminal problem can be prevented.

  FIG. 22 is a diagram for explaining the hidden terminal problem.

  The communication device B602 in the positional relationship shown in FIG. 22 can communicate with both the communication device A601 and the communication device C603. However, since the communication device A 601 and the communication device C 602 are not within the radio wave reception range of each other, even if carrier sense is performed before transmission, they cannot recognize that they are emitting radio waves (so-called hidden terminals). Therefore, in the communication device B602, transmission data collisions frequently occur between the communication device A601 and the communication device C603, and thus communication is not normally performed. Furthermore, since the communication device A 601 and the communication device C 603 each perform retransmission, the communication efficiency decreases. According to the communication system of the present embodiment, even in the positional relationship shown in FIG. 23, since the ACK frame is returned from the receiving devices A601 and C603 at the reply timing instructed for each sensor data, the occurrence of collision occurs. It can be suppressed.

  In the above-described embodiment, communication devices 110A to 110D of “A”, “B”, “C”, and “D” that perform wireless communication conforming to ARIB STD-30 are used as the transmission device and the reception device of the present invention. However, the present invention is not limited to this, and may be a communication apparatus that performs wireless communication using another communication method that employs a connection-type communication method.

  In the above-described embodiment, an example in which the four communication devices 110A to 110D are provided as the communication system of the present invention has been described. However, the present invention is not limited to this, for example, communication included in the communication system. The number of devices may be 3, or 5 or more.

  Regarding the above embodiment, the following additional notes are disclosed.

(Appendix 1)
A communication system comprising a plurality of reception devices that receive communication data wirelessly and return response data, and a transmission device that transmits the communication data to the reception device,
The transmitting device is
A multiple data creation unit that combines a plurality of communication data with different destination receiving devices to create one multiplexed data, and includes designation information specified by changing the response data return timing for each destination in the multiplexed data; ,
A data transmission unit that transmits the multiplexed data created by the multiplexed data creating unit to each destination receiving device of each communication data combined with the multiplexed data;
A response receiving unit that receives the response data from the receiving device;
The receiving device is
A data receiving unit for receiving the multiplexed data;
A data confirmation unit for confirming communication data addressed to the receiving device from the multiplexed data received by the data receiving unit;
A response reply unit for replying the response data to the transmission device at a reply timing corresponding to the designation information included in the multiplexed data when communication data addressed to the receiving device is confirmed by the data confirmation unit; A communication system characterized by comprising.

(Appendix 2)
The transmission device includes a storage unit that stores communication data combined with the multiplexed data,
The multiple data creation unit of the transmission device stores the destination for which the response data is not received by the response reception unit even after a predetermined time has elapsed after the multiplexed data is transmitted by the data transmission unit by the storage unit. To create new multiple data by combining the communication data
The transmission device further includes a data deletion unit that deletes communication data stored by the storage unit for a destination from which the response data is received by the response reception unit. The communication system according to 1.

(Appendix 3)
The data transmission unit of the transmission device transmits the multiplexed data created by the multiplexed data creation unit next to the transmitted multiplexed data after a predetermined period from the previous transmission. The communication system according to appendix 1 or 2.

(Appendix 4)
The multiplex data creation unit of the transmission device creates the multiplex data in which the communication data of each of the plurality of destinations are arranged in order as the multiplex data, and the reply timing is specified for each destination in the order of the communication data. ,
The response reply unit of the receiving device returns the response data at a reply timing corresponding to the order of the communication data addressed to the receiving device among the communication data arranged in the multiplexed data. The communication system according to any one of supplementary notes 1 to 3.

(Appendix 5)
The multiplex data creation unit of the transmission device creates multiplex data in which the specification of the return timing at the destination is attached to the communication data of each destination as the multiplex data,
The response reply unit of the receiving device returns the response data at a reply timing according to the designation attached to the communication data addressed to the receiving device among the communication data combined with the multiplexed data. The communication system according to any one of supplementary notes 1 to 3, wherein

(Appendix 6)
The transmission device includes a detection data receiving unit that receives detection data representing the state from a sensor that detects a state of an environment in which the transmission device exists,
The multiplex data creation unit of the transmission device creates the multiplex data by using detection data representing a state detected by the sensor as communication data addressed to at least one receiving device among the plurality of receiving devices. The communication system according to any one of appendices 1 to 5, characterized in that:

(Appendix 7)
A transmission device that transmits communication data to a reception device that receives communication data wirelessly and returns response data,
A multiple data creation unit that combines a plurality of communication data with different destination receiving devices to create one multiplexed data, and includes designation information specified by changing the response data return timing for each destination in the multiplexed data; ,
A data transmission unit that transmits the multiplexed data created by the multiplexed data creating unit to each destination receiving device of each communication data combined with the multiplexed data;
A transmission apparatus comprising: a response reception unit that receives the response data from the reception apparatus.

(Appendix 8)
The transmission device includes a storage unit that stores communication data combined with the multiplexed data,
A destination where the response data is not received by the response receiver even if a predetermined time elapses after the multiplexed data is transmitted by the data transmitter is stored by the storage unit. Combining communication data to create new multiple data,
The transmission device further includes a data deletion unit that deletes communication data stored by the storage unit for a destination from which the response data is received by the response reception unit. 8. The transmission device according to 7.

(Appendix 9)
Supplementary note 7 or 8 characterized in that the data transmitting unit transmits the multiplexed data created by the multiplexed data creating unit next to the transmitted multiplexed data after a predetermined period from the previous transmission. The transmitting device described.

(Appendix 10)
The multiplexed data creation unit creates, as the multiplexed data, communication data for each of the plurality of destinations in order, and creates multiplexed data for designating the return timing for each destination in the order of the communication data. The transmitter according to any one of appendices 7 to 9.

(Appendix 11)
Any one of appendixes 7 to 9, wherein the multiple data creation unit creates multiple data in which a designation of a reply timing at the destination is attached to the communication data of each destination as the multiplexed data. The transmitting device according to item.

(Appendix 12)
A receiving device that wirelessly receives communication data transmitted from a transmitting device and returns response data to the transmitting device,
A data receiving unit that receives multiplexed data including designation information that is specified by differentiating a response data return timing for each destination in multiplexed data obtained by combining a plurality of communication data with different destination receiving devices;
A data confirmation unit for confirming communication data addressed to the receiving device from the multiplexed data received by the data receiving unit;
A response reply unit for replying the response data to the transmission device at a reply timing corresponding to the designation information included in the multiplexed data when communication data addressed to the receiving device is confirmed by the data confirmation unit; A receiving device comprising:

(Appendix 13)
Additional remark 12 characterized in that the response reply unit returns the response data at a reply timing corresponding to the order of the communication data addressed to the receiving device among the communication data arranged in the multiplexed data. Receiver.

(Appendix 14)
The response reply unit of the receiving device returns the response data at a reply timing according to the designation attached to the communication data addressed to the receiving device among the communication data combined with the multiplexed data. Item 14. The receiving device according to item 12 or 13,

It is a figure which shows the communication system which has a star type network structure. It is a figure which shows the communication system which has a mesh type network structure. It is a figure which shows the communication apparatus which performs connection type communication. It is a data flow which shows transmission / reception of the data between the communication apparatuses shown in FIG. Fig. 4 is a data flow when retransmission occurs in the communication system shown in Fig. 3. It is a figure which shows 1st Embodiment of the communication system of this invention. It is a block diagram which shows the internal structure of the communication apparatus shown in FIG. It is a figure which shows the format of an element frame. It is a figure which shows the format of an ACK frame It is a figure which shows the format of a multi-frame. It is a data flow of the communication system shown in FIG. 10 is a flowchart showing the operation of the control unit of the communication device of “A” when the communication device of “A” transmits multiple frames. 10 is a flowchart showing the operation of the control unit of the communication device of “A” when the communication device of “A” receives a multiplex frame and an ACK frame. It is a figure which shows each communication apparatus which communicates with the communication system shown in FIG. It is a data flow which shows transmission / reception between the communication apparatuses shown in FIG. It is a figure which shows the example of the element frame produced | generated with the communication apparatus of "A". It is a figure which shows the example of the element frame produced | generated with the communication apparatus of "A". It is a figure which shows the example of the element frame produced | generated with the communication apparatus of "A". It is a figure which shows the example of the multiplex frame produced | generated with the communication apparatus of "A". It is a figure which shows the example of the ACK frame which the communication apparatus of "B" outputs. It is a figure which shows the example of the ACK frame which the communication apparatus of "C" outputs. It is a figure which shows the example of the ACK frame which communication apparatus 110D outputs. It is a data flow which shows transmission / reception between the communication apparatuses shown in FIG. 14 when ACK is not returned. It is a figure which shows the format of the multiplex frame which consists only of the element frame addressed to the communication apparatus of "C". It is a figure which shows the format of the element frame produced | generated by the frame production | generation part in 2nd Embodiment. It is a data flow which shows transmission / reception between the communication apparatuses in 2nd Embodiment. It is a figure which shows the example of the element frame produced | generated with the communication apparatus of "A" in 2nd Embodiment. It is a figure which shows the example of the element frame produced | generated with the communication apparatus of "A" in 2nd Embodiment. It is a figure which shows the example of the element frame produced | generated with the communication apparatus of "A" in 2nd Embodiment. It is a figure which shows the example of the multiplex frame produced | generated with the communication apparatus of "A" in 2nd Embodiment. It is a figure explaining a hidden terminal problem.

Explanation of symbols

100 communication system 110A to 110D communication device (reception device, transmission device)
111 Wireless communication unit (data transmission unit, data reception unit)
112 Sensor unit (detection data receiving unit)
113 ID setting unit 114 destination management table 115 output unit 116 control unit 120a, 120b, 120c sensor 121 frame generation unit (together with the ACK generation control unit 124, a response reception unit)
122 Multiplex frame generator (multiplexed data generator, data deleter)
123 Received frame control unit (data confirmation unit, response receiving unit)
124 ACK generation control unit

Claims (7)

A communication system comprising a plurality of reception devices that receive communication data wirelessly and return response data, and a transmission device that transmits the communication data to the reception device,
The transmitting device is
A multiple data creation unit that combines a plurality of communication data with different destination receiving devices to create one multiplexed data, and includes designation information specified by changing the response data return timing for each destination in the multiplexed data; ,
A data transmission unit that transmits the multiplexed data created by the multiplexed data creating unit to each destination receiving device of each communication data combined with the multiplexed data;
A response receiving unit that receives the response data from the receiving device;
The receiving device is
A data receiving unit for receiving the multiplexed data;
A data confirmation unit for confirming communication data addressed to the receiving device from the multiplexed data received by the data receiving unit;
A response reply unit for replying the response data to the transmission device at a reply timing corresponding to the designation information included in the multiplexed data when communication data addressed to the receiving device is confirmed by the data confirmation unit; A communication system characterized by comprising. The transmission device includes a storage unit that stores communication data combined with the multiplexed data,
The multiple data creation unit of the transmission device stores the destination for which the response data is not received by the response reception unit even after a predetermined time has elapsed after the multiplexed data is transmitted by the data transmission unit by the storage unit. To create new multiple data by combining the communication data
The transmission apparatus further includes a data deletion unit that deletes communication data stored by the storage unit for a destination from which the response data is received by the response reception unit. Item 12. The communication system according to Item 1.   The data transmission unit of the transmission device transmits the multiplexed data created by the multiplexed data creation unit next to the transmitted multiplexed data after a predetermined period from the previous transmission. The communication system according to claim 1 or 2. The multiplex data creation unit of the transmission device creates the multiplex data in which the communication data of each of the plurality of destinations are arranged in order as the multiplex data, and the reply timing is specified for each destination in the order of the communication data. ,
The response reply unit of the receiving device returns the response data at a reply timing corresponding to the order of the communication data addressed to the receiving device among the communication data arranged in the multiplexed data. The communication system according to any one of claims 1 to 3. The multiplex data creation unit of the transmission device creates multiplex data in which the specification of the return timing at the destination is attached to the communication data of each destination as the multiplex data,
The response reply unit of the receiving device returns the response data at a reply timing according to the designation attached to the communication data addressed to the receiving device among the communication data combined with the multiplexed data. The communication system according to any one of claims 1 to 3, characterized in that: A transmission device that transmits communication data to a reception device that receives communication data wirelessly and returns response data,
A multiple data creation unit that combines a plurality of communication data with different destination receiving devices to create one multiplexed data, and includes designation information specified by changing the response data return timing for each destination in the multiplexed data; ,
A data transmission unit that transmits the multiplexed data created by the multiplexed data creating unit to each destination receiving device of each communication data combined with the multiplexed data;
A transmission apparatus comprising: a response reception unit that receives the response data from the reception apparatus. A receiving device that wirelessly receives communication data transmitted from a transmitting device and returns response data to the transmitting device,
A data receiving unit that receives multiplexed data including designation information that is specified by differentiating a response data return timing for each destination in multiplexed data obtained by combining a plurality of communication data with different destination receiving devices;
A data confirmation unit for confirming communication data addressed to the receiving device from the multiplexed data received by the data receiving unit;
A response reply unit for replying the response data to the transmission device at a reply timing corresponding to the designation information included in the multiplexed data when communication data addressed to the receiving device is confirmed by the data confirmation unit; A receiving device comprising:

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