JP2015204509A - Radio communication system, radio communication device, and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep reproduction continuity of necessary data in a radio communication system including one transmitting device and a plurality of receiving devices.SOLUTION: Receiving devices 21 to 23 are configured so as to receive at least one of video data and voice data. A transmitting device 10 sets video data or voice data as priority data. The transmitting device 10 radios video data to at least two predetermined receiving devices. When receiving video data, each of the receiving devices 21 to 23 radios an acknowledgement of the video data to the transmitting device 10. The transmitting device 10 radios voice data to at least two predetermined receiving devices. When receiving voice data, each of the receiving devices 21 to 23 radios an acknowledgement of the voice data to the transmitting device 10. When receiving an acknowledgement of priority data from all receiving devices of a priority data transmission source, the transmitting device 10 instructs the receiving devices 21 to 23 to reproduce the video data and the voice data.

Description

  The present invention is a wireless communication system including one transmission device and a plurality of reception devices, and wirelessly transmits a data signal including video (moving image) data and audio data from the transmission device to the plurality of reception devices. About. The present invention also relates to a wireless communication device that operates as a transmission device of such a wireless communication system. The present invention also relates to a wireless communication method of such a wireless communication system.

  As a wireless communication system including one transmission device and a plurality of reception devices, and a wireless communication system that wirelessly transmits a data signal including video data and audio data from a transmission device to a plurality of reception devices, for example, Patent Document 1 There are two inventions.

  Patent Document 1 discloses that a single multimedia communication system is configured by a plurality of slave terminals having a terminal function and a master terminal having a transmission function. Thereby, a plurality of lines and a plurality of terminals can be used efficiently, and the operability of the system is improved.

  According to the wireless transmission system of Patent Document 2, the source device wirelessly multicasts AV data to a plurality of sink devices, and each sink device performs reproduction control of AV data according to the wireless connection state of other sink devices. The source device grasps the wireless connection state and the reproduction control state of each sink device. When each sink device reproduces the AV data wirelessly multicast from the source device, it obtains status information indicating the wireless connection status of the other sink devices, and controls playback of its own AV data according to this status information. adjust. The source device acquires information on the wireless connection state and playback control state of each sink device, and stops or restarts transmission of AV data based on these information.

  In order to wirelessly transmit digital data from a transmitting device to a receiving device, it is important to encode video data and audio data with high efficiency, packetize the encoded information, multiplex and transmit it with synchronization information, etc. It is. The MPEG2 standard standardized by ISO / IEC has been adopted around the world as a technology that satisfies these requirements. In the MPEG2 system, the transmission device gives a time stamp (time information) to the video data packet and the audio data packet, and the reception device reproduces the video data and the audio data synchronously based on the time stamp. Specifically, the transmission apparatus and reception apparatus of the MPEG2 system operate as follows. The transmitting device generates an STC (System Time Clock) that is a time counter value of 27 MHz, and generates a PCR (Program Clock Reference) obtained by sampling the STC. The transmitting device multiplexes the PCR into a packet at a frequency of at least once every 100 milliseconds and transmits the packet to the receiving device. The receiving device reproduces the STC using a PLL (Phase Locked Loop) circuit based on the received PCR. When transmitting a packet including video data or audio data, the transmitting device adds a DTS (Decoding Time Stamp) and a PTS (Presentation Time Stamp) that are STCs of the time to be decoded and the time to be reproduced to the header of the packet. Write. The receiving apparatus compares the DTS and PTS of the received packet with the STC obtained from the PCR, and decodes and reproduces appropriate data at an appropriate time. Thereby, video data and audio data can be reproduced in synchronization.

  In addition, a system that applies this technique to display different portions of one video data in synchronization with a plurality of receiving devices that are display devices (for example, projectors) is already known.

  However, in a conventional wireless communication system including a plurality of receiving apparatuses, synchronization between the receiving apparatuses is realized, but a specific protocol for reproduction when a transmission error occurs in one of video data and audio data is determined. Not. Although there is a need to reproduce video data without omission, video data may not be displayed or display content may not be updated due to a transmission error. In addition, although there is a need to reproduce audio data without omission, there may be no audio due to transmission errors.

  An object of the present invention is to provide a wireless communication system including a single transmission device and a plurality of reception devices, which can maintain continuity of necessary data reproduction.

According to a wireless communication system according to an aspect of the present invention,
In a wireless communication system including one transmission device and a plurality of reception devices,
Each of the receiving devices is configured to wirelessly receive at least one of video data and audio data,
The transmission device sets one of video data and audio data as priority data,
The transmitting device wirelessly transmits video data to at least two predetermined receiving devices among the plurality of receiving devices,
Each receiving device wirelessly transmits the video data acknowledgment to the transmitting device when wirelessly receiving the video data,
The transmitting device wirelessly transmits audio data to at least two predetermined receiving devices among the plurality of receiving devices,
When each of the receiving devices wirelessly receives the audio data, the receiving device wirelessly transmits an acknowledgment of the audio data to the transmitting device,
The transmitting device instructs the plurality of receiving devices to reproduce the video data and the audio data when wirelessly receiving acknowledgments of the priority data from all receiving devices to which the priority data is transmitted. And

  According to the wireless communication system of the present invention, it is possible to maintain continuity of necessary data reproduction in a wireless communication system including one transmission device and a plurality of reception devices.

It is the schematic which shows the structure of the radio | wireless communications system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the detailed structure of the transmitter 10 of FIG. It is a block diagram which shows the detailed structure of the receiver 21 of FIG. 3 is a flowchart showing a data transmission process executed by a control circuit 103 in FIG. It is a table | surface which shows operation | movement of the receivers 21-23 in the radio | wireless communications system of FIG. It is a timing chart which shows the signal which the transmitter 10 transmits to the receivers 21-23 in the data transmission process of FIG. FIG. 4 is a block diagram illustrating analog circuits 220 and 240 and a digital circuit 230 included in the receiving device 21 of FIG. 3. It is the schematic which shows the structure of the radio | wireless communications system which concerns on the 2nd Embodiment of this invention.

  Hereinafter, a wireless communication system according to an embodiment of the present invention will be described in detail with reference to the drawings.

First embodiment.
FIG. 1 is a schematic diagram showing a configuration of a wireless communication system according to the first embodiment of the present invention. The wireless communication system of FIG. 1 includes one transmission device 10 and a plurality of reception devices 21 to 23, and wirelessly transmits, for example, MPEG2 TS packets or PS packets. The transmission device 10 is, for example, a tuner and a DVD player. The transmission device 10 acquires input data (ES data) including a video signal and an audio signal, encodes the input data into a TS packet, and wirelessly transmits the data signal including the TS packet to the reception devices 21 to 23. Each of the reception devices 21 to 23 is configured to wirelessly receive at least one of video data and audio data. Each receiving device 21 to 23 includes, for example, at least one of a display and a speaker, or is connected to at least one of the display and the speaker. Each of the reception devices 21 to 23 decodes a TS packet included in the data signal wirelessly received from the transmission device 10 to acquire the original video signal and audio signal, and outputs them in synchronization with the display and the speaker.

  FIG. 2 is a block diagram showing a detailed configuration of the transmission apparatus 10 of FIG. The transmission device 10 includes an antenna 100, an encoding circuit 101, a wireless communication circuit 102, a control circuit 103, and a counter 104.

  The encoding circuit 101 includes an interface circuit 111, a video encoder 112, an audio encoder 113, a timer 114, a PCR generator 115, and a TS encoder 116. The interface circuit 111 is an HDMI (registered trademark) interface, for example. The interface circuit 111 separates input data into a video signal and an audio signal, and sends them to the video encoder 112 and the audio encoder 113, respectively. The video encoder 112 and the audio encoder 113 compress the video signal and the audio signal, respectively, and send them to the TS encoder 116. The PCR generator 115 generates a PCR value that is current time information of the encoding circuit 101 based on the STC value supplied from the timer 114 and sends the PCR value to the TS encoder 116. The TS encoder 116 generates a TS packet including the compressed video signal and audio signal and the PCR value, and sends the TS packet to the wireless communication circuit 102.

  The control circuit 103 in FIG. 2 executes data transmission processing (described later) in FIG. 4 and causes the receiving devices 21 to 23 to reproduce video data and audio data. The counter 104 counts the number of receiving devices that have received video data normally or the number of receiving devices that have received audio data normally.

  FIG. 3 is a block diagram showing a detailed configuration of the receiving device 21 of FIG. The receiving device 21 includes an antenna 200, a wireless communication circuit 201, a decoding circuit 202, a control circuit 203, and a nonvolatile memory 204.

  The decoding circuit 202 includes a TS decoder 211, a video decoder 212, a buffer memory 213, an audio decoder 214, a buffer memory 215, a timer 216, a synchronization signal generator 217, and an interface circuit 218. The TS decoder 211 separates the TS packet received by the wireless communication circuit 201 into a video signal and an audio signal, and sends them to the video decoder 212 and the audio decoder 214, respectively. The video decoder 212 and the audio decoder 214 decompress the video signal and the audio signal, respectively, and temporarily store them in the buffer memories 213 and 225. The TS decoder 211 extracts a PCR value from the TS packet and sends it to a timer (System Time Clock) 216. The timer 216 adjusts the STC value of the timer 216 itself by comparing it with the input PCR value, and sends the adjusted STC value to the synchronization signal generator 217. The synchronization signal generator 217 generates a synchronization signal for synchronizing the video signal and the audio signal based on the input STC value, and sends it to the interface circuit 218. The interface circuit 218 is, for example, an HDMI interface. The interface circuit 218 reads the video signal and the audio signal stored in the buffer memories 213 and 225, and generates output data by synchronizing the video signal and the audio signal based on the synchronization signal.

  The control circuit 203 in FIG. 3 acquires the time at which video data and audio data should be reproduced from the TS decoder 211, and controls the interface circuit 218 to reproduce the video data and audio data in synchronization. The nonvolatile memory 204 stores a delay time in the receiving device 21 measured at the time of designing or manufacturing the receiving device 21. The delay time is stored in the non-volatile memory 204 when the receiving device 21 is shipped. The control circuit 203 notifies the transmission apparatus 10 of this delay time using the wireless communication circuit 201.

  The receiving devices 22 to 23 in FIG. 1 are also configured similarly to the receiving device 21 in FIG.

  FIG. 4 is a flowchart showing a data transmission process executed by the control circuit 103 of FIG. The transmission apparatus 10 presets data that needs to be reproduced without omission among “video data” and “audio data” as “priority data”.

In step S <b> 1 of FIG. 4, the control circuit 103 transmits TS packets including video data and audio data to the receiving apparatuses 21 to 23. At this time, the control circuit 103 allocates a separate time interval to each of the receiving apparatuses 21 to 23 and wirelessly transmits the TS packet to each of the receiving apparatuses 21 to 23 by unicast. The present invention is not limited to wireless transmission of both video data and audio data to all of the receiving devices 21-23. For example, the transmission device 10 may wirelessly transmit video data to at least two predetermined reception devices among the plurality of reception devices 21 to 23. The transmission device 10 may wirelessly transmit audio data to at least two predetermined reception devices among the plurality of reception devices 21 to 23.

  When the video data is wirelessly received, each of the reception devices 21 to 23 wirelessly transmits an acknowledgment of the video data to the transmission device. Each of the reception devices 21 to 23 wirelessly transmits an acknowledgment of the audio data to the transmission device when the audio data is wirelessly received. Each of the receiving devices 21 to 23 may broadcast an acknowledgment of the video data when wirelessly receiving the video data, and may broadcast an acknowledgment of the audio data when wirelessly receiving the audio data. Thereby, the transmission apparatus 10 can monitor the reception status of the video data and the audio data in each of the reception apparatuses 21 to 23.

  In step S2 of FIG. 4, the control circuit 103 determines whether or not an ACK signal including an acknowledgment of video data or audio data has been wirelessly received from any of the receiving devices 21 to 23. If YES, step S3 is performed. If NO, step S2 is repeated. In step S3, the control circuit 103 determines whether or not the transmitted priority data is normally received wirelessly. If YES, the counter 104 is incremented by 1 and proceeds to step S4. If NO, the process proceeds to step S1. Return and retransmit the TS packet. In step S4, the control circuit 103 determines whether or not all the receiving devices 21 to 23 have received the priority data normally wirelessly based on the counter value of the counter 104. If YES, the process proceeds to step S5, and NO In this case, the process returns to step S2. On the other hand, when video data (or audio data) is wirelessly transmitted to at least two predetermined reception devices among the reception devices 21 to 23, the control circuit 103 transmits all the reception devices to which priority data is transmitted. It is determined whether or not an acknowledgment of priority data is received wirelessly.

  In step S5 of FIG. 4, the control circuit 103 wirelessly transmits a time (reproduction time) tp at which video data and audio data should be reproduced. When the transmission device 10 wirelessly receives the acknowledgment of the priority data from all the reception devices to which the priority data is transmitted, the transmission device 10 wirelessly transmits a signal notifying the reproduction time tp to the reception devices 21 to 23, thereby A plurality of receiving devices are instructed to reproduce audio data. In order to notify the reproduction time tp, a PTS (Presentation Time Stamp) defined by the MPEG2 standard may be used. By notifying the reproduction time of video data using PTS and similarly notifying the reproduction time of audio data using PTS, it is possible to easily reproduce video data and audio data in synchronization.

  The receiving devices 21 to 23 reproduce video data and audio data at the wirelessly received reproduction time tp.

  FIG. 5 is a table showing operations of the receiving apparatuses 21 to 23 in the wireless communication system of FIG. The table of FIG. 5 shows operations of the receiving devices 21 to 23 when a transmission error occurs when one of video data and audio data is set as priority data.

  Ideally, it is desired that all the receiving devices to which video data and audio data are transmitted normally receive the transmitted data wirelessly and reproduce the video data and audio data in synchronization (normal mode). However, in this case, since only one of the video data and the audio data is not normally received wirelessly, the reproduction of both the video data and the audio data is interrupted. In order to avoid such a situation, one of video data and audio data is set as priority data, and only the continuity of reproduction of priority data is maintained.

  When video data is set as priority data, each receiving device to which audio data is transmitted fails to receive audio data, and when the transmitting device 10 instructs reproduction of the video data and audio data, Do not play data. The receiving devices 21 to 23 continue to reproduce the video data and the audio data as long as the video data is normally wirelessly received. Even if the reception of the audio data fails, the receiving devices 21 to 23 do not reproduce the audio data. Continue playback. Thereby, there is an effect that the continuity of reproduction of the video data can be maintained.

  When audio data is set as priority data, each receiving device to which video data is transmitted fails when receiving video data and when the transmitting device 10 instructs the reproduction of video data and audio data. Do not play data. The receiving devices 21 to 23 continue to reproduce the video data and the audio data as long as the audio data is normally wirelessly received. Even if the reception of the video data fails, the receiving devices 21 to 23 do not reproduce the video data. Continue playback. Thereby, there is an effect that the continuity of reproduction of the audio data can be maintained.

  When it is desired to reproduce without losing both video data and audio data, the transmission apparatus 10 sets the reproduction time tp only when both video data and audio data are normally received wirelessly without setting priority data. You may send it. In this case, even if one of the video data and the audio data is normally wirelessly received, the reproduction of both the video data and the audio data is interrupted.

  FIG. 6 is a timing chart showing signals transmitted from the transmission apparatus 10 to the reception apparatuses 21 to 23 in the data transmission process of FIG. The transmission apparatus 10 transmits TS packets including priority data to the reception apparatuses 21 to 23, and the reception apparatuses 21 to 23 return ACK signals for the TS packets to the transmission apparatus 10. When the transmitting apparatus 10 wirelessly receives an ACK signal including an acknowledgment of priority data from all the receiving apparatuses 21 to 23, the transmitting apparatus 10 transmits a PTS including the reproduction time tp to each of the receiving apparatuses 21 to 23. At this time, since it is guaranteed that the priority data is normally wirelessly received by all the receiving apparatuses 21 to 23, the priority data can be reproduced in synchronization by all the receiving apparatuses 21 to 23.

  The reproduction time tp may be the same over the plurality of receivers 21 to 23 or may be different for each receiver.

  The plurality of receiving apparatuses 21 to 23 may have different delay times in the receiving apparatus. The transmission device 10 may determine the time at which the video data and the audio data should be reproduced so as to cancel out different delay times.

  FIG. 7 is a block diagram illustrating the analog circuits 220 and 240 and the digital circuit 230 included in the receiving device 21 of FIG. The analog circuit 220 corresponds to, for example, the wireless communication circuit 201 in FIG. The digital circuit 230 corresponds to, for example, the TS decoder 211, the video decoder 212, the buffer memory 213, the audio decoder 214, the buffer memory 215, the timer 216, and the synchronization signal generator 217 shown in FIG. The analog circuit 240 corresponds to, for example, the interface circuit 218 and the subsequent circuit (not shown) in FIG. The analog circuit 220 can be considered to include an amplifier 221 and an A / D converter 222, for example. The digital circuit 230 can be considered to include, for example, a logic circuit 231 and a flip-flop circuit 232. The analog circuit 240 can be considered to include, for example, a D / A converter 241 and an amplifier 242.

  In general, the electric circuit and the electronic circuit include a digital circuit that operates mainly according to a clock signal and an analog circuit that generates a drive signal of an external device (such as an LED or a motor) or a wired or wireless communication signal. In the receiving devices 21 to 23, a digital circuit is used for processing and analysis of received video data and audio data, and for wireless reception, reproduction of video data and audio data (panel display, character display). For example, an analog circuit is used for driving a speaker. In general, since an output signal of a digital circuit is latched by a flip-flop circuit and becomes a signal synchronized with a clock signal, a processing time (latency) required from input to output is a multiple of the clock. However, since the analog circuit does not follow the clock signal, the latency of the analog circuit varies depending on the device process, power supply voltage, chip temperature, and the like. The latency of the analog circuit is “analog delay”.

  The analog delay differs depending on the manufacturing lot (version) and state of the receiving devices 21 to 23. Also, although the digital circuit 230 manages the time, even if the receiving devices 21 to 23 receive the same reproduction time tp, the moment when the video data or audio data is reproduced due to the difference in the analog delay of each of the receiving devices 21 to 23. There may be a slight shift. For this reason, each of the reception apparatuses 21 to 23 may wirelessly transmit a signal that notifies the delay time in the reception apparatus to the transmission apparatus 10. The transmission device 10 may wirelessly transmit a signal notifying the time at which video data and audio data should be reproduced to the plurality of reception devices 21 to 23 so as to cancel the difference in delay time in each reception device. The transmitting device 10 determines the time at which the video data should be reproduced so as to cancel out the difference in the delay time of the video data in each receiving device, and separately, the delay time of the audio data in each receiving device. You may determine the time which should reproduce | regenerate audio | voice data so that a difference may be canceled. The receiving apparatuses 21 to 23 store in advance information related to the delay time in the receiving apparatus (the version of the receiving apparatuses 21 to 23, latency, etc.) in the nonvolatile memory 204, and store this information in the ID field of the header of the TS packet, etc. May be used to notify the transmitting apparatus 10. The transmission device 10 further adjusts the reproduction time tp so as to cancel the difference in delay time in the reception device received from the reception devices 21 to 23, thereby further improving the accuracy of the reproduction times of the reception devices 21 to 23. Can be increased.

  By adjusting the reproduction time in consideration of the delay time in the receiving devices 21 to 23, there is an effect that the accuracy of reproducing the video data and the audio data in synchronization is further increased.

  According to the wireless communication system of FIG. 1, in a wireless communication system including one transmission device and a plurality of reception devices, it is possible to maintain continuity of necessary video data or audio data reproduction.

  Rather than deciding in advance the time at which video data and audio data should be reproduced, at least priority data is synchronized by deciding when priority data acknowledgments are received wirelessly from all receiving devices to which priority data is sent. Can be played back.

  By setting one of the video data and audio data as priority data, if there is a transmission error only in the other data, that data will be lost and playback will be done with emphasis on real-time performance without losing priority data it can.

Second embodiment.
FIG. 8 is a schematic diagram illustrating a configuration of a wireless communication system according to the second embodiment of the present invention. The wireless communication system in FIG. 8 includes a transmission device 10A, reception devices 21A to 23A, and reception devices 24 and 25. The receiving devices 21A to 23A are, for example, projectors. The receiving devices 24 and 25 include a speaker, for example. In the wireless communication system of FIG. 8, a plurality of projectors and a plurality of speakers are used as a receiving device, and the images displayed by the projectors are combined to form one image, and audio synchronized with the images is reproduced from each speaker. Is done.

  Video data wirelessly transmitted in the wireless communication system of FIG. 8 includes a plurality of portions that overlap in time. Receiving devices 21 </ b> A to 23 </ b> A display different portions of video data in different areas on screen 30, respectively. The transmitting device 10A wirelessly transmits different portions of the video data to two or more predetermined receiving devices among the plurality of receiving devices 21A to 23A.

  The voice data wirelessly transmitted in the wireless communication system of FIG. 8 includes a plurality of portions that overlap in time. The transmitting device 10A wirelessly transmits different portions of the audio data to two or more predetermined receiving devices of the plurality of receiving devices 24 and 25, respectively. The audio data includes a plurality of channels such as a right channel and a left channel. The receiving devices 24 and 25 respectively output different channels of audio data. The transmitting apparatus 10A may wirelessly transmit different channels of audio data to two or more predetermined receiving apparatuses among the receiving apparatuses 24 and 25, respectively.

  As in the wireless communication system of FIG. 8, when one image is formed by combining images displayed by a plurality of projectors, all of the receiving devices 21 </ b> A to 23 </ b> A need to normally receive image data wirelessly. Video data should be set as priority data. Even when video data cannot be displayed on a specific projector due to a transmission error or the like, it is possible to prevent a situation in which display delay occurs only for the projector. Further, when the receiving devices 21A to 23A are digital signage (electronic signage) or the like, the display deviation can be made visually inconspicuous. Further, by using a speaker or an audio playback player capable of wirelessly receiving audio data as the receiving devices 24 and 25, the degree of freedom for installing the device can be improved and the acoustic effect can be further enhanced. On the other hand, when a single projector is used, audio data can be set as priority data, and the continuity of audio data reproduction can be maintained. Further, when the receiving devices 24 and 25 reproduce stereo audio data (right channel and left channel), the audio data is reproduced after both the receiving devices 24 and 25 normally receive the audio data wirelessly. Therefore, even when the audio data of one channel cannot be reproduced due to a transmission error or the like, it is possible to prevent the situation where only the other channel is reproduced.

  The wireless communication system of FIG. 8 includes three projectors (receiving devices 21A to 23A) and two speakers (receiving devices 24 and 25), but may include a different number of projectors and speakers.

Modified example.
At least some of the components of the transmission device 10 and the reception devices 21 to 23 may be implemented in software. In this case, a computer program including steps executed by the transmission device 10 or the reception devices 21 to 23 can be provided. This computer program causes the computer to operate as the transmission device 10 when executed by the processor of the computer. The computer program causes the computer to operate as the receiving devices 21 to 23 when executed by a processor of the computer. A recording medium storing such a computer program may be provided.

  The configuration of the wireless communication system disclosed in this specification is an example, and there is no particular limitation as long as the configuration can implement the present invention.

  The transmission device 10 in FIG. 2 and the reception device 21 in FIG. 3 have interface circuits 111 and 218 that are HDMI interfaces. However, any interface can be used as long as it is an interface that can input and output video signals and audio signals. Also good.

  A wireless communication system, a wireless communication apparatus, and a wireless communication method according to an aspect of the present invention are characterized by having the following configuration.

According to the wireless communication system according to the first aspect of the present invention,
In a wireless communication system including one transmission device and a plurality of reception devices,
Each of the receiving devices is configured to wirelessly receive at least one of video data and audio data,
The transmission device sets one of video data and audio data as priority data,
The transmitting device wirelessly transmits video data to at least two predetermined receiving devices among the plurality of receiving devices,
Each receiving device wirelessly transmits the video data acknowledgment to the transmitting device when wirelessly receiving the video data,
The transmitting device wirelessly transmits audio data to at least two predetermined receiving devices among the plurality of receiving devices,
When each of the receiving devices wirelessly receives the audio data, the receiving device wirelessly transmits an acknowledgment of the audio data to the transmitting device,
The transmitting device instructs the plurality of receiving devices to reproduce the video data and the audio data when wirelessly receiving acknowledgments of the priority data from all receiving devices to which the priority data is transmitted. And

According to the wireless communication system according to the second aspect of the present invention, in the wireless communication system according to the first aspect,
When the video data is set as priority data, each receiving device to which the audio data is transmitted fails to receive the audio data, and the transmitting device reproduces the video data and the audio data. The audio data is not reproduced when instructed.

According to the wireless communication system according to the third aspect of the present invention, in the wireless communication system according to the first or second aspect,
When the audio data is set as priority data, each receiving device to which the video data is transmitted fails to receive the video data, and the transmitting device reproduces the video data and the audio data. The video data is not reproduced when instructed.

According to the wireless communication system according to the fourth aspect of the present invention, in the wireless communication system according to any one of the first to third aspects,
Each of the above receiving devices
When the video data is received wirelessly, an acknowledgment of the video data is broadcast,
When the voice data is wirelessly received, an acknowledgment of the voice data is broadcast.

According to the wireless communication system according to the fifth aspect of the present invention, in the wireless communication system according to any of the first to fourth aspects,
When the transmission device wirelessly receives an acknowledgment of the priority data from all reception devices to which the priority data is transmitted, the transmission device receives a signal for notifying the time to reproduce the video data and the audio data. The plurality of receiving apparatuses are instructed to reproduce the video data and the audio data by wireless transmission to the apparatus.

According to a radio communication system according to the sixth aspect of the present invention, in the radio communication system according to the fifth aspect,
Each receiving device wirelessly transmits a signal notifying the delay time in the receiving device to the transmitting device,
The transmitting device wirelessly transmits a signal notifying a time at which the video data and the audio data should be reproduced to the plurality of receiving devices so as to cancel out a difference in delay time in each receiving device. And

According to the wireless communication system according to the seventh aspect of the present invention, in the wireless communication system according to any of the first to sixth aspects,
The video data includes a plurality of portions overlapping in time,
The audio data includes a plurality of portions that overlap in time,
The transmitter is
Wirelessly transmit different portions of the video data to two or more predetermined receivers of the plurality of receivers,
A different portion of the audio data is wirelessly transmitted to two or more predetermined receiving devices among the plurality of receiving devices.

According to the radio communication system according to the eighth aspect of the present invention, in the radio communication system according to the seventh aspect,
The audio data includes a plurality of channels,
The transmission apparatus wirelessly transmits different channels of the audio data to two or more predetermined reception apparatuses among the plurality of reception apparatuses.

According to the wireless communication apparatus according to the ninth aspect of the present invention,
In a wireless communication device that operates as a transmission device of a wireless communication system including one transmission device and a plurality of reception devices,
Each of the receiving devices is configured to wirelessly receive at least one of video data and audio data,
The wireless communication device is
Set either video data or audio data as priority data,
Wirelessly transmitting video data to at least two predetermined receivers of the plurality of receivers;
Audio data is wirelessly transmitted to at least two predetermined receiving devices among the plurality of receiving devices,
When the acknowledgment of the priority data is wirelessly received from all the receiving devices to which the priority data is transmitted, the video data and the audio data are instructed to be reproduced to the plurality of receiving devices.

According to the wireless communication method of the tenth aspect of the present invention,
In a wireless communication method according to a transmission device of a wireless communication system including one transmission device and a plurality of reception devices,
Each of the receiving devices is configured to wirelessly receive at least one of video data and audio data,
The wireless communication method is
Setting one of video data and audio data as priority data;
Wirelessly transmitting video data to at least two predetermined receiving devices of the plurality of receiving devices;
Wirelessly transmitting audio data to at least two predetermined receiving devices of the plurality of receiving devices;
Instructing the plurality of receiving devices to reproduce the video data and the audio data when wirelessly receiving acknowledgments of the priority data from all receiving devices to which the priority data is transmitted. To do.

10, 10A ... transmitting device,
21 to 23, 21A to 23A, 24, 25 ... receiving device,
30 ... Screen,
100 ... antenna,
101: Encoding circuit,
102: wireless communication circuit,
103. Control circuit,
104 ... Counter
111 ... interface circuit,
112 ... Video encoder,
113: Speech encoder,
114 ... Timer,
115 ... PCR generator,
116 ... TS encoder,
200 ... antenna,
201: wireless communication circuit,
202... Decoding circuit,
203 ... control circuit,
204 ... non-volatile memory,
211 ... TS decoder,
212 ... Video decoder,
213: Buffer memory,
214 ... voice decoder,
215: Buffer memory,
216: Timer,
217 ... Synchronization signal generator,
218 ... interface circuit,
220 ... analog circuit,
221: Amplifier,
222: A / D converter,
230: Digital circuit,
231 ... Logic circuit,
232 ... flip-flop circuit,
240 ... analog circuit,
241 ... D / A converter,
242. Amplifier.

Japanese Patent Laid-Open No. 10-032652 International Publication No. 2011/122456

Claims (10)

In a wireless communication system including one transmission device and a plurality of reception devices,
Each of the receiving devices is configured to wirelessly receive at least one of video data and audio data,
The transmission device sets one of video data and audio data as priority data,
The transmitting device wirelessly transmits video data to at least two predetermined receiving devices among the plurality of receiving devices,
Each receiving device wirelessly transmits the video data acknowledgment to the transmitting device when wirelessly receiving the video data,
The transmitting device wirelessly transmits audio data to at least two predetermined receiving devices among the plurality of receiving devices,
When each of the receiving devices wirelessly receives the audio data, the receiving device wirelessly transmits an acknowledgment of the audio data to the transmitting device,
The transmitting device instructs the plurality of receiving devices to reproduce the video data and the audio data when wirelessly receiving acknowledgments of the priority data from all receiving devices to which the priority data is transmitted. A wireless communication system.   When the video data is set as priority data, each receiving device to which the audio data is transmitted fails to receive the audio data, and the transmitting device reproduces the video data and the audio data. 2. The wireless communication system according to claim 1, wherein said audio data is not reproduced when instructed.   When the audio data is set as priority data, each receiving device to which the video data is transmitted fails to receive the video data, and the transmitting device reproduces the video data and the audio data. 3. The wireless communication system according to claim 1, wherein the video data is not reproduced when instructed. Each of the above receiving devices
When the video data is received wirelessly, an acknowledgment of the video data is broadcast,
The wireless communication system according to claim 1, wherein when the voice data is wirelessly received, an acknowledgment of the voice data is broadcast.   When the transmission device wirelessly receives an acknowledgment of the priority data from all reception devices to which the priority data is transmitted, the transmission device receives a signal for notifying the time to reproduce the video data and the audio data. 5. The wireless communication system according to claim 1, wherein the plurality of receiving devices are instructed to reproduce the video data and the audio data by wireless transmission to the device. Each receiving device wirelessly transmits a signal notifying the delay time in the receiving device to the transmitting device,
The transmitting device wirelessly transmits a signal notifying a time at which the video data and the audio data should be reproduced to the plurality of receiving devices so as to cancel out a difference in delay time in each receiving device. The wireless communication system according to claim 5. The video data includes a plurality of portions overlapping in time,
The audio data includes a plurality of portions that overlap in time,
The transmitter is
Wirelessly transmit different portions of the video data to two or more predetermined receivers of the plurality of receivers,
The radio according to claim 1, wherein different portions of the audio data are wirelessly transmitted to two or more predetermined receivers among the plurality of receivers. Communications system. The audio data includes a plurality of channels,
8. The wireless communication system according to claim 7, wherein the transmitting device wirelessly transmits the different channels of the audio data to two or more predetermined receiving devices among the plurality of receiving devices. In a wireless communication device that operates as a transmission device of a wireless communication system including one transmission device and a plurality of reception devices,
Each of the receiving devices is configured to wirelessly receive at least one of video data and audio data,
The wireless communication device is
Set either video data or audio data as priority data,
Wirelessly transmitting video data to at least two predetermined receivers of the plurality of receivers;
Audio data is wirelessly transmitted to at least two predetermined receiving devices among the plurality of receiving devices,
A wireless communication device that instructs the plurality of receiving devices to reproduce the video data and the audio data when wirelessly receiving acknowledgments of the priority data from all receiving devices to which the priority data is transmitted . In a wireless communication method according to a transmission device of a wireless communication system including one transmission device and a plurality of reception devices,
Each of the receiving devices is configured to wirelessly receive at least one of video data and audio data,
The wireless communication method is
Setting one of video data and audio data as priority data;
Wirelessly transmitting video data to at least two predetermined receiving devices of the plurality of receiving devices;
Wirelessly transmitting audio data to at least two predetermined receiving devices of the plurality of receiving devices;
Instructing the plurality of receiving devices to reproduce the video data and the audio data when wirelessly receiving acknowledgments of the priority data from all receiving devices to which the priority data is transmitted. Wireless communication method.

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