JP4587384B2 - Data communication system and data communication apparatus - Google Patents

Description

  The present invention relates to a data communication system that transmits and receives AV data by wireless communication, and more particularly to a data communication system configured such that a plurality of receiving apparatuses receive AV data from one transmitting apparatus. Further, the present invention relates to a data communication apparatus that is a transmission apparatus or a reception apparatus that constructs the data communication system.

  In recent years, with the development of wireless communication technology and information compression technology, it has become possible to wirelessly transmit and receive data with a large amount of information such as audio and video AV data, and a data communication system that performs content communication using this AV data is provided. (See Patent Document 1). In such a data communication system, for example, a content recording / playback device or a terrestrial digital for playing back a recording medium storing content such as a DVD (Digital Versatile Disk) player, a VCR (Video Cassette Recorder), or a PVR (Personal Video Recorder). A tuner device that receives broadcasts, satellite digital broadcasts, etc. is used as a source of AV data, and LCD TV (Liquid Crystal Display TV), PDA (Personal Digital Assistants), mobile phones, etc., on which AV data from this source is reproduced and displayed A reproduction output device is assumed.

  Some data communication systems for transmitting and receiving AV data are provided with FEC (Forward Error Correction) for improving communication quality and a function for requesting retransmission from a receiving apparatus. Furthermore, as in the system in Patent Document 1, a receiving device receives a control signal (hereinafter referred to as “remote control through data”) from a remote controller (hereinafter referred to as “remote control”) for controlling a source source by infrared communication. In some cases, the control signal is transmitted to the transmission device to control the operation of the source source.

  In such a data communication system, since AV data is transmitted and received between a source source and a reproduction output device, it is standardized by the Institute of Electrical and Electronics Engineers (IEEE) in order to eliminate the troublesomeness of wiring such as cables. Some wireless LAN (Local Area Network) technology is used. When this wireless LAN technology is used, AV data is transmitted wirelessly as TS (Transport Stream) data from a transmission device connected to a source source, and this TS packet is received by a reception device connected to a reproduction output device. Finally, video and audio based on AV data from the source source are reproduced and output by the reproduction output device.

This TS packet wireless communication system is the IEEE 802.11b standard, 2.4 GHz band OFDM (Orthogonal Frequency Division Multiplexing) system that performs communication using the 2.4 GHz band SS (Spread Spectrum) system. The IEEE 802.11g standard for performing communication according to IEEE 802.11a, the IEEE 802.11a standard for performing communication using the OFDM scheme in the 5.2 GHz band, and the like. As a data communication system using this wireless communication system, the present applicant can identify a device that should execute a control command by including an identification code for identifying the device in the control command. (See Patent Document 2 and Patent Document 3).
JP 2001-145175 A JP 2004-336727 A JP 2004-336736 A

  However, in a data communication system using a conventional wireless communication system, when a plurality of receiving apparatuses are configured for one transmitting apparatus, each receiving apparatus communicates with the transmitting apparatus by another receiving apparatus. Since communication with the transmission device is performed when it is confirmed that the transmission has been completed, it is necessary to store data to be transmitted until the device itself can communicate with the transmission device. Therefore, a data amount of data to be transmitted to the transmission device is calculated, and a buffer corresponding to the data amount is necessary. Therefore, the amount of calculation in software increases and the amount of buffer for securing remote control through data increases. Also, there is a possibility that the transmission timing of data that requires real-time property for a certain time, such as a TS packet retransmission request or remote control through data, may be delayed. For this reason, in the TS packet retransmission request, the requested TS packet retransmission timing may be timed out and the requested TS packet may not be received.

  In view of such a problem, the present invention is a system composed of a plurality of receiving devices for one transmitting device, and does not impair the real-time property of asynchronous data transmitted from the receiving device. An object is to provide a communication system. Another object of the present invention is to provide a data communication apparatus in such a data communication system.

  In order to achieve the above object, the data communication system of the present invention includes one transmission device that transmits synchronization data and a plurality of reception devices that receive the synchronization data from the transmission device. In addition, in a data communication system using a wireless communication line in which asynchronous data is transmitted from the receiving device to the transmitting device, one of the plurality of receiving devices can transmit the asynchronous data to the transmitting device. In addition to setting as a parent device, the remaining receiving device is set as a child device, and transmission of the asynchronous data from the receiving device set as the child device to the transmitting device is prohibited.

  In this specification, “synchronous data” in this data communication system is exemplified by “AV data”, and “asynchronous data” is used in this specification as “remote control through data” and “retransmission”. This is described below using "request data" as an example.

  In such a data communication system, after the asynchronous data generated by the receiving device serving as the child device is transmitted to the receiving device serving as the parent device, in the receiving device serving as the parent device, a plurality of The asynchronous data generated by all the receiving devices may be managed, and the managed asynchronous data may be transmitted from the receiving device serving as the parent device to the transmitting device.

  When the receiving device is turned on, when it is confirmed that another receiving device is not communicating with the transmitting device, the receiving device that is turned on is set as the parent device. Also, the receiving device as the master unit confirms the bit error rate of all of the plurality of receiving devices, and confirms the receiving device having a lower bit error rate than its own device, The confirmed receiving device may be set as the parent device and the own device may be set as the child device.

  Further, the plurality of receiving devices may receive a signal from a remote controller that operates the transmitting device or a device connected to the transmitting device, and transmit the received signal from the remote controller to the transmitting device. In addition, the receiving device that has received the signal from the remote controller may be set as the parent device. In this data communication system, when the receiving device that has received a signal from the remote controller is set as the parent device, the transmission operation of the asynchronous data by the remaining receiving devices serving as the child devices is prohibited. It does not matter.

  Then, after the receiving device that has received the signal from the remote controller is set as the parent device, a period during which the transmission operation of the asynchronous data by the remaining receiving devices serving as the child devices is prohibited is set as a predetermined time. Then, when the predetermined time elapses without a signal being transmitted again from the remote controller, the asynchronous data transmission operation from the receiving device serving as the slave unit may be permitted.

  Further, when the receiving device that has received a signal from the remote controller is set as the parent device, the receiving device set as the parent device to the remaining receiving device that becomes the child device, It may be notified that the asynchronous data transmission operation is prohibited. In addition, when the receiving device that has received the signal from the remote controller is set as the parent device, the transmission operation of the asynchronous data is prohibited from the transmitting device to the remaining receiving devices that are the child devices. It does not matter if it is notified that

  A data communication apparatus according to the present invention includes: a receiving unit that receives a radio signal; a demodulating unit that demodulates the radio signal received by the receiving unit; a decoding unit that decodes a signal demodulated by the demodulating unit; A transmitter that transmits a wireless signal based on data; an encoder that generates the asynchronous data; and a modulation that generates the wireless signal by modulating the asynchronous data generated by the encoder and gives the signal to the transmitter A data communication device comprising: a unit configured to operate as the above-described receiving device.

  The data communication apparatus of the present invention includes a receiving unit that receives a radio signal, a demodulating unit that demodulates the radio signal received by the receiving unit, and a decoding unit that decodes the signal demodulated by the demodulating unit. A transmission unit that transmits a radio signal based on synchronization data; an encoding unit that generates the synchronization data; and the transmission unit configured to generate the radio signal by modulating the synchronization data generated by the encoding unit A data communication device including a modulation unit provided to the unit, wherein the data communication device operates as the transmission device described above.

  In addition, the data communication apparatus of the present invention includes a receiving unit that receives a radio signal based on synchronization data, a demodulating unit that demodulates the radio signal received by the receiving unit, and a decoding that decodes the signal demodulated by the demodulating unit. An encoding unit, a transmission unit that transmits a wireless signal based on asynchronous data, an encoding unit that generates the asynchronous data, and the wireless data generated by modulating the asynchronous data generated by the encoding unit, A data communication device including a modulation unit provided to a transmission unit, when participating in a data communication system including a synchronous data transmission device that transmits a radio signal based on the synchronous data, the data communication device participating in the data communication system When there are a plurality of devices including the own device, one of the data communication devices is set as a parent device, and the remaining data communication devices are set as child devices. When this is done, it is allowed to transmit the wireless signal based on the asynchronous data to the synchronous data transmission device, and when the slave device is set, the wireless signal based on the asynchronous data is transmitted to the synchronous data transmission device. Is prohibited.

  In such a data communication device, when set as the slave unit, the wireless signal by the asynchronous data is transmitted to the data communication device set as the master unit while participating in the data communication system, When set as a base unit, the receiving unit receives the radio signal based on the asynchronous data transmitted from the data communication device set as the slave unit while participating in the data communication system, and the demodulating unit and When the asynchronous data is obtained by processing in the decoding unit, it is managed together with the asynchronous data generated by the encoding unit, and then modulated by the modulating unit and transmitted from the transmitting unit to the synchronous data transmitting device. It does n’t matter.

  With this configuration, when the slave unit is set, the operations of the encoding unit, the modulation unit, and the transmission unit are stopped, and transmission of the radio signal by the asynchronous data is prohibited. It does not matter.

  And an operation data receiving unit for receiving the operation data from the remote controller for transmitting the operation data to be transmitted to the synchronous data transmitting device, and the operation data receiving unit for the operation from the remote controller. When data is received, it may be set as a master unit, and when the power is turned on, when the data communication device participating in the data communication system is not confirmed other than the own device, May be set as the base unit.

  Further, when set as the master unit, when confirming the bit error rate of all the data communication devices participating in the data communication system, when confirming the data communication device having a lower bit error rate than its own device, The data communication device may be set as the parent device and the own device may be set as the child device.

  According to the present invention, since the parent device and the child device are set and only the parent device is allowed to transmit asynchronous data to the transmitting device, all the receiving devices transmit asynchronous data as in the past. As compared with the case of the above, the waiting time until each receiving apparatus reaches the transmission timing of its own device can be shortened. Therefore, the buffer amount of asynchronous data stored in each receiving device can be suppressed, and asynchronous data having real-time characteristics can be communicated.

  A configuration of a data communication system that is common to each embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the data communication system. 2 is a block diagram showing the internal configuration of the transmission apparatus in the data communication system of FIG. 1, and FIG. 3 is a block diagram showing the internal configuration of the reception apparatus in the data communication system of FIG.

  The data communication system in FIG. 1 includes an AV source device 1 that transmits AV data, such as a content recording / playback device that plays back a recording medium that stores content, and a tuner device that receives broadcast signals, and AV data from the AV source device 1. Is converted to TS packets and transmitted by wireless LAN technology, receiving devices 3-1 to 3-n that receive TS packets from the transmitting device 2 and convert them into AV data, and receiving devices 3-1. ... 3-n Reproduction output devices 4-1 to 4-n that output video and audio from AV data transmitted from each, and control signals for operating the AV source device 1 are transmitted as infrared signals by the IrDA communication method. And a remote controller 5 to be configured.

  According to such a data communication system, in order to construct a wireless LAN between the transmission device 2 and the reception devices 3-1 to 3-n, the channel used by the transmission device 2 to transmit a radio signal. Each of the receiving devices 3-1 to 3 -n searches. In this way, the transmission device 2 and the reception devices 3-1 to 3-n use the same channel to transmit and receive data. That is, when AV data is given from the AV source device 1 to the transmission device 2, the AV data is converted into TS packets in the transmission device 2, and transmitted as a wireless signal by the wireless LAN.

  When receiving devices 3-1 to 3-n receive wireless signals by wireless LAN, the TS packets obtained from the wireless signals are converted into AV data and connected to the receiving devices 3-1 to 3-n. Are supplied to the reproduction output devices 4-1 to 4-n. Accordingly, video and audio based on AV data are reproduced and output in each of the reproduction output devices 4-1 to 4-n. At this time, when receiving the data-damaged TS packet, the receiving apparatuses 3-1 to 3-n transmit a retransmission request signal for requesting retransmission of the data-damaged TS packet using the wireless LAN. The Further, when the remote controller 5 is operated and remote control through data is transmitted to any of the reproduction output devices 4-1 to 4-m by IrDA communication, the remote control through data is transmitted using the wireless LAN. The retransmission request signal and remote control through data transmission operation will be described in each embodiment.

  When the transmission apparatus 2 receives a retransmission request signal transmitted using a wireless LAN, when the TS packet for which retransmission is requested by the retransmission request signal is confirmed, the confirmed TS packet is read and the AV data currently obtained The TS packet to be retransmitted is transmitted together with the TS packet by. When remote control through data transmitted using a wireless LAN is received, it is converted into an infrared signal and transmitted to the AV source device 1 by IrDA communication. At this time, the AV source device 1 receives the infrared signal and performs an operation based on the remote control through data based on the infrared signal.

  The configuration of the transmission apparatus 2 in such a data communication system will be described with reference to FIG. 2 includes an input interface (I / F) 201 to which AV data from the AV source device 1 is input, and the AV data input from the input I / F 201 is MPEG (Moving Picture Expert Group) code. The TS processing unit 202 that compresses and encodes and generates a TS packet, and the data to be transmitted to the receiving device 3 are BPSK (Binary Phase Shift Keying), QPSK (Quadrature Phase Shift Keying), QAM (Quadrature Amplitude Modulation), etc. A modulation unit 203 that modulates based on a digital modulation method, and a data that is modulated by the modulation unit 203 is converted into an analog signal and converted into an analog signal based on a transmission method such as an SS method or an OFDM method. BB unit 204 for generating the carrier frequency of the frequency channel using the BB signal of BB unit 204 And an antenna 206 for transmitting an RF signal from the RF unit 205.

  In addition, the transmitter 2 generates a BB signal by detecting an RF signal received by the antenna 206 in the RF unit 205, converts the digital signal into a digital signal by the BB unit 204, and digitally modulates data based on the transmission method. To get. Then, the transmitter 2 demodulates the data acquired by the BB unit 204 based on the digital modulation method to acquire a TS packet, and acquires retransmission request data from the TS packet acquired by the demodulator 207. The retransmission request confirmation unit 208 that confirms the TS packet that is requested to be retransmitted, the remote control through data generation unit 209 that acquires the remote control through data from the TS packet acquired by the demodulation unit 207, and the remote control through data generation unit 209 The remote control through data is converted into an infrared signal by the IrDA communication method and output, and the control unit 211 that controls the entire apparatus such as the transmission / reception timing and the distribution of TS packets acquired by the demodulation unit 207, and the like. Prepare.

  According to this transmission apparatus 2, when AV data is input from the AV source device 1 to the input I / F 201, the AV data is digitized by the TS processing unit 202 according to the MPEG encoding method, and an ES (Elementary Stream) is generated. After being generated, this ES is packet-encoded to generate a TS packet. The generated TS packet is temporarily stored in the TS processing unit 202 for a predetermined period in order to respond to a retransmission request from the playback devices 3-1 to 3 -n. When the period elapses, it is erased.

  The TS packet obtained in this way is given to the modulation unit 203, modulated based on the digital modulation method, and then converted into a BB signal by being processed by the BB unit 204 based on a predetermined transmission method. Then, the RF unit 205 performs frequency conversion to the carrier frequency of the frequency channel and transmits the RF signal from the antenna 206 as an RF signal. Further, when the RF signal from the receiving devices 3-1 to 3-n is received by the antenna 206, the RF unit 205 performs frequency conversion to acquire the BB signal, and then the BB unit 204 performs BB based on a predetermined transmission method. The signal is processed and demodulated by the demodulator 207 based on the digital modulation method to obtain a TS packet.

  When it is confirmed that the TS packet constitutes retransmission request data, the retransmission request confirmation unit 208 decrypts the TS packet for which retransmission is requested by the retransmission request data. Then, the retransmission request confirmation unit 208 instructs the TS processing unit 202 to give the retransmission requested TS packet to the modulation unit 203. Therefore, the TS packet requested to be retransmitted is given to the modulation unit 203 together with the TS packet currently generated by the TS processing unit 202 and modulated, and then transmitted from the antenna 206 via the BB unit 204 and the RF 205.

  Also, when it is confirmed that the TS packet obtained by the demodulator 207 constitutes remote control through data, the remote control through data generation unit 209 decodes the remote control through data for operating the AV source device 1. Is obtained. Then, when this remote control through data is given to the IrDA transmission unit 210, it is converted into an IrDA communication infrared signal, and is transmitted to the AV source device 1 as an infrared signal by causing the infrared light emitting element to emit light.

  Further, the configuration of receiving apparatuses 3-1 to 3-n in the data communication system shown in FIG. 1 will be described with reference to FIG. The receiving device 3 shown in FIG. 3 (corresponding to the receiving devices 3-1 to 3-n in FIG. 1) receives an RF signal from the transmitting device 2 or another receiving device 3, and receives the antenna 301. The RF unit 302 that acquires the BB signal by detecting the RF signal, the BB unit 303 that converts the BB signal acquired by the RF unit 302 into a signal digitally modulated by a predetermined transmission method, and the BB unit 303 The demodulator 304 that demodulates the received signal based on the digital modulation scheme to obtain TS packets, the MPEG decoder 305 that acquires AV data from the TS packets acquired by the demodulator 304, and the MPEG decoder And an output I / F 306 for outputting the obtained AV data to the reproduction output device 4 (corresponding to the reproduction output devices 4-1 to 4-n in FIG. 1).

  Also, the receiving device 3 checks whether or not the TS packet decoded by the MPEG decoding unit 305 is damaged, and generates a TS packet that becomes retransmission request data if it is damaged. Unit 307, an IrDA receiving unit 308 that receives an infrared signal from remote controller 5 to acquire remote control through data, manages remote control through data from IrDA receiving unit 308, and generates a TS packet from the remote control through data A remote control management unit 309; a modulation unit 310 that modulates a TS packet obtained by the retransmission request management unit 307 and the remote control management unit 309 by a digital modulation method; and a control unit 311 that controls the entire apparatus such as transmission and reception timing Prepare. Then, the receiving device 3 applies the signal modulated by the modulation unit 310 to the BB unit 303 and processes it by a predetermined transmission method to generate a BB signal, and superimposes the RF signal on the carrier frequency by the RF unit 302. The signal is converted into a signal and transmitted from the antenna 301.

  According to the receiving device 3, when the RF signal from the transmitting device 2 is received by the antenna 301, a BB signal is obtained by being detected and frequency converted by the RF unit 302, and this BB signal is obtained by the BB unit 303. After processing by a predetermined transmission method, the demodulator 304 demodulates according to a predetermined digital modulation method, thereby obtaining a TS packet by AV data. Then, when the TS packet based on the AV data is given to the MPEG decoding unit 305, it is decoded according to the MPEG encoding method to obtain an ES, and AV data is generated from the ES.

  At this time, the MPEG decoding unit 305 confirms whether or not the obtained TS packet is damaged by checking whether or not the decoding can be normally performed when the TS packet is decoded. Confirm. When the TS packet is normally decoded, the obtained AV data is output to the reproduction output device 4 via the output I / F 306, and the reproduction output device 4 outputs video and audio. If the TS packet is not normally decoded and an abnormality is confirmed in the TS packet, the TS packet in which the abnormality is confirmed is notified to the retransmission request management unit 307. Therefore, retransmission request management section 307 generates retransmission request data for requesting retransmission of a TS packet whose abnormality has been confirmed, and TS packet serving as this retransmission request data is given to modulation section 310.

  When the infrared signal transmitted from the remote controller 5 is received by the infrared light receiving element of the IrDA receiver 308, the infrared signal is processed according to the IrDA communication method to obtain remote control through data. When the remote control through data acquired by the IrDA reception unit 308 is given to the remote control management unit 309, it is packetized to obtain a TS packet. When given to the modulation unit 310, the TS packet is modulated by the digital modulation method. After that, the BB unit 303 processes it with a predetermined transmission method and converts it into a BB signal. The BB signal obtained in this way is superimposed on the carrier frequency by the RF unit 302 to be an RF signal and transmitted from the antenna 301.

  In addition, when an RF signal from another receiving device 3 is received by the antenna 301, it is processed by the RF unit 302, the BB unit 303, and the demodulation unit 304, respectively, so that retransmission request data and remote control through data are received from the received RF signal. Confirm the TS packet. Then, the TS packet including the retransmission request data is provided to the retransmission request management unit 307, and is also provided to the remote control management unit 309 including the remote control through data. Detailed operations in the retransmission request management unit 307 and the remote control management unit 309 will be described later.

  In such a data communication system configured by the transmission device 2 and the reception devices 3-1 to 3-n, in the first to third embodiments, one of the reception devices 3-1 to 3-n. The receiving device 3 serves as a master unit, manages remote control through data and retransmission request data, and transmits remote control through data and retransmission request data to the transmission device 2. At this time, n−1 receiving devices 3 other than the receiving device 3 serving as the parent device serve as the child devices, and the remote control through data and the retransmission request data are transmitted to the receiving device 3 serving as the parent device.

  As shown in FIG. 4, the timing at which AV data is transmitted from the transmission device 2 in order for the reception devices 3-1 to 3-n operating as the parent device and the child device and the transmission device 2 to communicate normally. T1 and a timing T2 at which remote control through data and retransmission request data are transmitted to the receiving device 3 serving as the parent device through communication between the receiving devices 3-1 to 3-n, and the receiving device 3 serving as the parent device The timing T3 at which the remote control through data and the retransmission request data are transmitted to the transmission device 2 is set. The timings T1 to T3 are set between the transmission device 2 and the reception devices 3-1 to 3-n, and are confirmed by the control unit 211 of the transmission device 2 and the control unit 311 of the reception devices 3-1 to 3-n. The

  That is, when an RF signal based on AV data is transmitted from the transmission device 2 at the timing T1, the reception devices 3-1 to 3-n receive this RF signal. Further, at timing T2, an RF signal based on the remote control through data and the retransmission request data is transmitted from the receiving device 3 serving as the slave unit among the receiving devices 3-1 to 3-n to the receiving device 3 serving as the master unit. Then, the remote control through data and the retransmission request data in all of the receiving devices 3-1 to 3-n are managed by the receiving device 3 serving as the parent device. An RF signal based on the managed remote control through data and retransmission request data is transmitted from the receiving device 3 serving as a parent device to the transmitting device 2.

  At each of the transmission timings T1 to T3 shown in FIG. 4, the switching of the timings T1 and T2 is managed by the transmission device 2 and the reception devices 3-1 to 3-n, and the switching of the timings T2 and T3 is performed by the master unit. Are managed by the receiving device 3. At this time, the receiving device 3 serving as the parent device recognizes the receiving devices 3-1 to 3-n communicating with the transmitting device 2 and stores them in the control unit 311. Therefore, the receiving device 3 serving as the parent device checks the receiving devices 3-1 to 3-n stored in the control unit 311 so that the RF signal based on the remote control through data and the retransmission request data serves as the child device. It is confirmed whether it was transmitted from all. Hereinafter, the switching management operation of the timings T2 and T3 by the receiving device 3 serving as the parent device will be described with reference to the flowchart of FIG.

  In each of the transmission device 2 and the reception devices 3-1 to 3-n, it is confirmed that the transmission timing T1 from the transmission device 2 has ended and the transmission timing T2 between the reception devices 3-1 to 3-n has been switched. Then, the switching management operation of the timings T2 and T3 according to the flowchart of FIG.

  At this time, in the receiving device 3 serving as the parent device, first, the RF unit 302 and the BB unit 303 confirm the reception of the RF signal from the receiving device 3 serving as the child device (STEP 1). When the reception of the RF signal from the receiving device 3 serving as a slave unit is confirmed (Yes), the TS packet acquired from this RF signal is acquired by the demodulator 304 and becomes a slave unit by the header of this TS packet. The receiving device 3 is confirmed (STEP 2). Thereafter, when the TS packet is retransmission request data, it is given to the retransmission request management unit 307, and when the TS packet is remote control through data, it is given to the remote control management unit 309 to manage the data (STEP 3). At this time, if the TS packet does not contain the contents of the retransmission request data and the remote control through data, the communication with the receiving device 3 serving as the slave unit is confirmed, and the TS packet is discarded.

  When the data management in STEP 3 is performed, the retransmission request management unit 307 temporarily stores retransmission request data indicating a TS packet for which retransmission is requested, but the retransmission request in which the TS packet for which retransmission is already stored is already stored. If it is the same as the TS packet indicated by the data, the newly confirmed retransmission request data is discarded. The remote control management unit 309 selects remote control through data to be transmitted to the transmission device 2 according to the relationship between the parent device and the child device of the reception devices 3-1 to 3-n. Then, in the control unit 311, it is confirmed whether or not the communication with all the receiving devices 3 serving as slave units stored as receiving devices that communicate with the transmitting device 2 is completed (STEP 4).

  At this time, when it is confirmed that the communication with all the receiving devices 3 serving as the slave units is completed (Yes), the transmission timing is switched from the timing T2 to the timing T3 (STEP 5). Therefore, the retransmission request data stored in retransmission request management section 307 is given to modulation section 310 as a TS packet, and the remote control through data stored in remote control management section 309 is given to modulation section 310 as a TS packet. The modulation unit 310 digitally modulates the given TS packet, and the RF unit 302 and the BB unit 303 convert the TS packet into an RF signal, which is transmitted from the antenna 301 to the transmitter 2. On the other hand, when there is a receiving device 3 that is a slave unit that has not yet completed communication (No), the process proceeds to STEP 1 again to confirm reception of an RF signal from the receiving device 3 that is a slave unit.

  Each embodiment of such a data communication system will be described below.

<First Embodiment>
A first embodiment of the present invention will be described with reference to the drawings. In the data communication system according to the present embodiment, the above-described configuration and operation are performed, and the parent device and the child device are set between the receiving devices. Hereinafter, the setting of the parent device and the child device between the receiving devices will be described with reference to the drawings. FIG. 6 is a flowchart showing the setting operation of the parent device and the child device in the receiving apparatus.

  In the data communication system according to the present embodiment, the receiving device 3 operates as shown in the flowchart of FIG. The operation of the receiving device 3 will be described below. When the power of the receiving device 3 is turned on (STEP 11), first, by selecting a channel in the RF unit 302, the channel used by the transmitting device 2 to transmit the RF signal is selected, The carrier frequency is confirmed (STEP 12). Then, at the transmission timings T2 and T3, it is confirmed whether or not RF signals are transmitted from other receiving apparatuses 3 (STEP 13).

  At this time, when the demodulation unit 304 demodulates the BB signal obtained from the received RF signal, if the transmission of the RF signal from another receiving device 3 is confirmed from the header of the BB signal (Yes), the control unit 311 The device is set to operate as a slave (STEP 14). Then, the control unit 311 newly generates a signal indicating participation in the data communication system as a slave unit, modulates it by the modulation unit 310, converts it to an RF signal by the BB unit 303 and the RF unit 302, and transmits the signal from the antenna 301. It transmits to the receiving device 3 which becomes a machine (STEP 15).

  On the other hand, at the transmission timings T2 and T3, there is no reception of the RF signal from the other reception device 3, and the transmission timing T1 is switched to. (No), the control unit 311 sets the own device to operate as a parent device (STEP 16). By setting to operate as a master unit in this way, when receiving an RF signal from another receiving device 3 newly participating in the data communication system and demodulating a BB signal obtained from the received RF signal From the header to be confirmed, the receiving device 3 as a slave is recognized and stored in the control unit 311.

  Thereafter, retransmission request data and remote control through data obtained from the RF signal from the receiving device 3 serving as a slave unit received from the transmission timing T2 are respectively managed by the retransmission request management unit 307 and the remote control management unit 309. Then, when it is confirmed that the transmission timing has been switched to T3, TS packets serving as retransmission request data and remote control through data managed by the retransmission request management unit 307 and the remote control management unit 309, respectively, are generated. The TS packet is digitally modulated by the modulation unit 310 and then converted into an RF signal via the BB unit 303 and the RF unit 302 and transmitted from the antenna 301 to the transmission apparatus 2.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to the drawings. In the data communication system according to the present embodiment, the above-described configuration and operation are performed, and the parent device and the child device are set between the receiving devices. Hereinafter, the setting of the parent device and the child device between the receiving devices will be described with reference to the drawings. FIG. 7 is a flowchart showing the setting operation of the parent device and the child device in the receiving apparatus. In the flowchart of FIG. 7, steps having the same purpose as those in the flowchart of FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the data communication system according to the present embodiment, unlike the first embodiment, the receiving apparatus 3 serving as a master unit checks the BER (Bit Error Rate) of all the receiving apparatuses 3 currently participating in the data communication system, The receiving apparatus 3 having a low BER is set to be the base unit. In this embodiment as well, when the receiving device 3 participates in the data communication system, as in the first embodiment, the parent device and the child device are set according to the presence or absence of the receiving device 3 that is already the parent device. Shall.

  That is, as shown in the flowchart of FIG. 7, as in the first embodiment, when the receiving device 3 is turned on (STEP 11), after the carrier frequency of the channel used in the data communication system is confirmed, Whether or not an RF signal is transmitted from another receiving device 3 is confirmed (STEP 12, STEP 13). When the RF signal from the other receiving device 3 is confirmed, the mobile device operates as a slave unit and notifies that the own device has participated (STEP 14 and STEP 15). Also, the RF signal from the other receiving device 3 is confirmed. If not, it operates as a base unit (STEP 16).

  When the master unit and the slave unit are set in this way, when operating as a master unit in STEP 16, a timer (not shown) provided in the control unit 311 is initialized, and a timer for confirming the BER measurement timing Measurement is started (STEP 21). Thereafter, the control unit 311 confirms whether or not an operation has been performed to turn off the power (STEP 22). At this time, if the power-off instruction has not been given (No), the control device 311 confirms whether or not it is the BER measurement timing based on the measurement time by the timer (STEP 23).

  If it is not the BER measurement timing (No), the process proceeds to STEP 22 and it is confirmed that the power is turned off. On the other hand, if it is the BER measurement timing (Yes), the own device participating in the data communication system is checked. The BER of all of the receiving apparatuses 3 including it is measured (STEP 24). When operating in this way, in the receiving device 3 serving as the parent device, the retransmission request management unit 307 transmits each of the receiving devices 3 serving as the child devices at each transmission timing T2 until the BER measurement timing is reached. The number of TS packets requested for retransmission confirmed by the retransmission request data is stored for each receiving device 3 serving as a slave unit, and the number of TS packets requested for retransmission in its own device serving as a master unit is stored. . At this BER measurement timing, the total number of TS packets requested to be retransmitted is confirmed for each of the receiving devices 3 including the device itself, and the BER of each receiving device 3 is measured.

  In this way, in STEP 24, when the BER of each of the receiving devices 3 including the own device participating in the data communication system is measured, the receiving device becomes a child device whose BER is lower than the BER of the own device that is the parent device. 3 is confirmed (STEP 25). Then, in STEP 25, when the receiving device 3 that is a slave unit whose BER is lower than the BER of its own device is not confirmed (No), the process proceeds to STEP 21 and a timer (not shown) is reset. When the receiving device 3 serving as a child device whose BER is lower than the BER of the own device is confirmed (Yes), a notification signal (hereinafter referred to as “parent device”) that uses the receiving device 3 serving as the confirmed child device as the parent device. A notification signal ”is generated and transmitted by the control unit 311 (STEP 26).

  That is, after the base unit notification signal is digitally modulated by the modulation unit 310, it is converted into an RF signal via the BB unit 303 and the RF unit 302 and transmitted from the antenna 301 to the transmission apparatus 2. Thereafter, it is set to operate as a slave (STEP 27), and the operation state of STEP 31 described later is entered. The parent device notification signal includes data indicating all the receiving devices 3 currently participating in the data communication system, and also includes data indicating the receiving device 3 that is the next parent device. Therefore, in the receiving device 3 that operates as the parent device from the next time, all of the receiving devices 3 currently participating in the data communication system are confirmed by the parent device notification signal.

  In STEP 22, if an instruction to turn off the power is issued (Yes), the BER of all the receiving devices 3 including the own device participating in the data communication system is measured, and the own device having the lowest BER is measured. The other receiving devices 3 are confirmed (STEP 28). Then, as in STEP 26, the control unit 311 generates and transmits a parent device notification signal for notifying that the receiving device 3 other than the own device having the lowest BER is used as the parent device (STEP 29). Set to OFF (STEP 30). At this time, the base unit notification signal includes data indicating that the receiving device 3 excluding the device itself from the receiving device 3 currently participating in the data communication system participates in the data communication system.

  When the operations of STEP24, STEP25, and STEP28 are performed after receiving all the RF signals from the transmission device 3 serving as the slave unit after switching to the transmission timing T2, the retransmission request data is switched to the transmission timing T3. Then, after transmitting the RF signal including the remote control through data to the transmission device 2, in STEP 26 and STEP 29, a parent device notification signal indicating switching of the parent device is transmitted. Further, when the operations of STEP24, STEP25, and STEP28 are performed at the moment of switching to the transmission timing T2 and before receiving the RF signal from the transmitting apparatus 3 serving as the slave unit, the master unit is switched in STEP26 and STEP29. A base unit notification signal indicating that After that, the RF signal including the retransmission request data and the remote control through data is transmitted from the receiving device 3 that is a slave device including the own device that is a new slave device to the receiving device 3 that is newly the master device, and the transmission timing T3 Switch to

  When the operation of STEP 15 or STEP 27 is performed and set to operate as a slave unit, first, the control unit 311 confirms whether or not an operation has been performed to turn off the power (STEP 31). At this time, if an instruction to turn off the power is not given (No), an RF signal serving as a parent device notification signal indicating that the own device is the parent device has been transmitted from the transmitting device 3 operating as the parent device. It is confirmed whether or not (STEP 32).

  Then, the RF signal as the parent device notification signal is received by the antenna 301, demodulated by the demodulation unit 304 via the RF unit 302 and the BB unit 303, and the parent device notification signal is confirmed (Yes). The controller 311 is set to operate as a parent machine (STEP 33), and the process proceeds to STEP 21. At this time, all the receiving apparatuses 3 currently participating in the data communication system are confirmed from the parent device notification signal and stored in the control unit 311. On the other hand, when the RF signal serving as the parent device notification signal has not been received (No), the process proceeds to STEP 31 and it is confirmed whether or not the power supply is instructed.

  If it is confirmed in STEP 31 that a power-off instruction has been given (Yes), a notification signal for notifying the receiving device 3 serving as a master unit that the power is turned off and the data communication system is disconnected. (Hereinafter referred to as “departure notification signal”) is generated and transmitted by the control unit 311 (STEP 34), and the power is turned off (STEP 35). When the receiving device 3 serving as the master unit receives this leave notification signal, the receiving device 3 currently participating in the data communication system stored in the control unit 311 is deleted from the storage.

  In the present embodiment, when operating as described above, the parent device notification signal may be received by the receiving device 3 that operates as a child device. At this time, the receiving device 3 that operates as a child device receives the parent device notification signal, whereby the receiving device 3 that operates as the parent device can be confirmed from the next time. In this embodiment, the receiving device 3 operating as a slave unit also recognizes the timing at which the BER is measured, and the receiving device 3 operating as the master unit and the slave unit is synchronized with the slave unit. The receiving device 3 may confirm the presence / absence of the parent device notification signal.

  Furthermore, in the present embodiment, in the first embodiment, first, the receiving device 3 that becomes the parent device is set in the order in which the power is turned on. However, the receiving device 3 that newly joined the data communication system is set. Is confirmed, the BERs of all the receiving apparatuses 3 including this receiving apparatus 3 are confirmed, and the receiving apparatus 3 that has the lowest BER may be set as the master unit.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to the drawings. In the data communication system according to the present embodiment, the above-described configuration and operation are performed, and the parent device and the child device are set between the receiving devices. Hereinafter, the setting of the parent device and the child device between the receiving devices will be described with reference to the drawings. FIG. 8 is a flowchart showing the setting operation of the parent device and the child device in the receiving apparatus. In the flowchart of FIG. 8, steps having the same purpose as those in the flowchart of FIG. 7 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the data communication system according to the present embodiment, unlike the first embodiment, the receiving device 3 that has received the infrared signal from the remote controller 5 is set as the parent device. Also in this embodiment, when the receiving device 3 participates in the data communication system, as in the first and second embodiments, the parent device and the child device are set according to the presence or absence of the receiving device 3 that is already the parent device. It shall be set. That is, as shown in the flowchart of FIG. 8, when the receiving device 3 is turned on, as in the first embodiment, after the carrier frequency of the used channel is confirmed, the other receiving devices 3 are already in data communication. It is confirmed whether or not it participates in the system (STEP 11 to STEP 13). When the RF signal from the other receiving device 3 is confirmed, the mobile device operates as a slave unit and notifies that the own device has joined (STEP 14 and STEP 15), while the RF signal from the other receiving device 3 is confirmed. If not, it operates as a base unit (STEP 16).

  When the parent device and the child device are set in this way, when operating as the parent device in STEP 16, first, it is confirmed whether or not the operation is performed so that the power is turned off (STEP 22). At this time, if the power-off instruction is not given (No), at the transmission timing T2, the presence or absence of a TS packet serving as remote control through data is confirmed from the RF signal transmitted from the receiving device 3 operating as a slave unit. (STEP 41). When a TS packet that becomes remote control through data is confirmed from the TS packet obtained by processing the received RF signal, and the TS packet that becomes this remote control through data is given to the remote control management unit 309 (Yes), The receiver 3 that has transmitted the RF signal based on the remote control through data is confirmed (STEP 42).

  After that, the control unit 311 generates and transmits a parent device notification signal using the receiving device 3 that has transmitted the RF signal based on the remote control through data as the parent device (STEP 26). After that, it is set to operate as a slave (STEP 27), the process proceeds to STEP 31, and it is confirmed whether or not the power is turned off. Also, in STEP 41, when the TS packet serving as the remote control through data is not confirmed from the TS packet given from the demodulator 304 (No), the process proceeds to STEP 22 and whether or not the power is turned off. Confirm.

  If an instruction to turn off the power is issued in STEP 22 (Yes), as in the second embodiment, the BER is measured for all the receiving apparatuses 3 including the own device participating in the data communication system, and the BER is measured. The receiving device 3 other than the own device having the lowest value is confirmed (STEP 28). Then, the control unit 311 generates and transmits a parent device notification signal notifying that the receiving device 3 other than the own device having the lowest BER is used as the parent device (STEP 29), and turns off the power of the own device.

  When the operation of STEP 15 or STEP 27 is performed and set to operate as a slave unit, it is confirmed whether or not the power is turned off as in the second embodiment (STEP 31). At this time, if the power-off instruction has not been given (No), it is confirmed whether or not the infrared signal from the remote controller 5 has been received by the IrDA receiving unit 308 (STEP 43). When the reception of the infrared signal from the remote controller 5 is confirmed (Yes), a TS packet based on the remote controller through data is generated by the remote controller management unit 309, digitally modulated by the modulation unit 310, and then RF is transmitted by the BB unit 303 and RF unit 302 A signal is transmitted from the antenna 301 (STEP 44).

  After that, when receiving a parent device notification signal from the receiving device 3 serving as a parent device (STEP 45), the control unit 311 sets the device to operate as a parent device (STEP 33), and the process proceeds to STEP 22. At this time, the receiving device 3 currently participating in the data communication system is confirmed from the parent device notification signal. Further, in STEP 43, when no infrared signal is received from the remote controller 5 (No), it is confirmed whether or not an RF signal serving as a parent device notification signal indicating that the own device is the parent device is transmitted ( (STEP 32). When an RF signal serving as a parent device notification signal is received (Yes), the process proceeds to STEP 33 and set as a parent device. On the other hand, when an RF signal serving as a parent device notification signal is not received (No), STEP 31 is set. It is confirmed whether or not the power is turned off.

  Furthermore, when it is confirmed in STEP 31 that an instruction to turn off the power has been given (Yes), as in the second embodiment, the power is turned off for the receiving device 3 serving as the parent device and the data communication system is disconnected. The controller 311 generates and transmits a leave notification signal for notifying that (STEP 34), and the power is turned off (STEP 35).

  In the present embodiment, when operating as described above, when switching to the transmission timing T3, an RF signal indicating retransmission request data and remote control through data is transmitted from the receiving apparatus 3 currently operating as a base unit to the transmitting apparatus 2. Then, the receiving device 3 newly set as the parent device may operate as the parent device from the next time. Further, when switching to the transmission timing T2, it is defined that the RF signal indicating the remote control through data is transmitted first, and the receiving device 3 newly set as a parent device is immediately set and operates as a child device. The receiving apparatus 3 may transmit an RF signal indicating retransmission request data. Then, the transmission timing is switched to T3, and the RF signal indicating the retransmission request data and the remote control through data is transmitted from the reception device 3 newly set as the parent device to the transmission device 2.

<Fourth Embodiment>
A fourth embodiment of the present invention will be described with reference to the drawings. In the data communication system according to the present embodiment, unlike the first to third embodiments, when the receiving device receives an infrared signal from the remote controller, a retransmission request from a receiving device other than the receiving device that has received the infrared signal. Data transmission is prohibited.

  In the data communication system according to the present embodiment, unlike the first to third embodiments, each of the receiving apparatuses 3-1 to 3-n participating in the data communication system includes an RF including retransmission request data and remote control through data. The signal is transmitted to the transmission device 2. That is, the receiving devices 3-1 to 3-n perform a polling operation, the transmission timings of the receiving devices 3-1 to 3-n are set, and the receiving devices 3-1 to 3-n each transmit their own devices. Then, the transmission operation of the RF signal to the transmission device 2 is performed. At this time, the receiving device 3 (corresponding to the receiving devices 3-1 to 3-n in FIG. 1) operates as in the flowchart in FIG.

  The operation of the receiving device 3 will be described below with reference to the flowchart of FIG. When the receiving device 3 participating in the data communication system is turned on, it is first confirmed whether or not an instruction to turn off the power is given (STEP 50). When it is confirmed that there is no instruction to turn off the power (Yes), it is confirmed whether the infrared signal from the remote controller 5 is received by the IrDA receiving unit 308 (STEP 51). At this time, if it is confirmed that the infrared signal from the remote controller 5 has been received by the IrDA receiving unit 308 (Yes), a timer (not shown) provided in the control unit 311 is initialized, and retransmission request data in the other receiving devices 3 Timer measurement for measuring the prohibition period for prohibiting transmission of data is started (STEP 52).

  Then, at the transmission timing T2, the control unit 311 generates a notification signal (hereinafter referred to as “prohibition notification signal”) for prohibiting transmission of retransmission request data in the other receiving apparatuses 3, and the modulation unit 310 After being modulated by the BB unit 303 and the RF unit 302, the signal is converted into an RF signal and transmitted from the antenna 301 to the receiving device 3 serving as a master unit (STEP 53). By transmitting the prohibition notification signal in this manner, another receiving device 3 that has received the prohibition notification signal stops transmitting retransmission request data.

  Thereafter, the transmission timing is switched to T3, a TS packet based on remote control through data confirmed from the infrared signal received by the IrDA reception unit 308 is generated by the remote control management unit 309, modulated by the modulation unit 310, and then the BB unit 303 and the RF unit An RF signal is generated by 302 and transmitted from the antenna 301 to the transmitter 2 (STEP 54). Then, the time measured by the timer of the control unit 311 is confirmed, and it is confirmed whether or not the prohibition period has ended (STEP 55).

  At this time, if it is confirmed that the prohibition period has ended (Yes), a notification signal (hereinafter referred to as “cancellation notification signal”) for permitting transmission of retransmission request data prohibited by the other receiving apparatuses 3 is sent. After being generated and modulated by the modulation unit 310, the BB unit 303 and the RF unit 302 generate an RF signal and transmit it to the other receiving device 3 from the antenna 301 (STEP 56). By transmitting the cancellation notification signal during the transmission timing T2 in this manner, the other receiving devices 3 that have received the cancellation notification signal resume transmission of retransmission request data.

  Further, in STEP 51, when the IrDA receiving unit 308 does not confirm the reception of the infrared signal from the remote controller 5 (No), it is confirmed whether or not the RF signal serving as the prohibition notification signal has been received (STEP 57). At this time, when the reception of the RF signal serving as the prohibition notification signal is not confirmed (No), it is confirmed whether or not it is the prohibition period for prohibiting the transmission of the retransmission request data in the other communication devices 3 (STEP 58). When it is confirmed that the period is prohibited (Yes), similarly to STEP 53, at the transmission timing T2, a prohibition notification signal is generated by the control unit 311 and transmitted to another transmitter 3 (STEP 59). Migrate to

  In STEP 57, when the control unit 311 confirms the prohibition notification signal obtained by receiving the RF signal from the other receiving device 3 and demodulating by the demodulating unit 304 (Yes), the retransmission request managing unit 307 sends a retransmission request. Stop data generation. (STEP 60). Therefore, the transmission operation of the RF signal serving as retransmission request data to the transmission device 2 is stopped. Thereafter, it is confirmed whether or not an RF signal serving as a release notification signal has been received (STEP 61). If the reception of the RF signal serving as the release notification signal is not confirmed (No), it is confirmed whether the infrared signal from the remote controller 5 is received by the IrDA receiving unit 308 as in STEP 51 (STEP 62).

  At this time, when the reception of the infrared signal from the remote controller 5 is confirmed (Yes), the retransmission request data generation operation by the retransmission request management unit 307 is restarted (STEP 63), and the process proceeds to STEP 52. When the reception of the signal is not confirmed (No), the process proceeds to STEP 60 and the reproduction request management unit 307 remains in the stopped state. In STEP 61, when the release notification signal obtained by receiving the RF signal from the other receiver 3 and demodulating by the demodulator 304 is confirmed by the controller 311 (Yes), the retransmission request manager as in STEP 63. The operation for generating retransmission request data by 307 is restarted (STEP 64).

  When the operation is performed in this manner, when the prohibition period has not been confirmed in STEP 55 (No), when the cancellation notification signal is transmitted in STEP 56, or in STEP 58, the prohibition period is set. When the operation is not performed (No) or when the operation of the retransmission request management unit 307 is resumed in STEP 64, the process proceeds to STEP 50 to confirm whether or not an instruction to turn off the power has been issued.

  In STEP 50, if it is confirmed that the power-off instruction has been issued (Yes), it is confirmed whether or not the prohibition period is set (STEP 65). If a retransmission request is prohibited by another receiving apparatus 3 by setting a prohibition period (Yes), a release notification signal is transmitted in the same manner as in STEP 56 (STEP 66), and then the power is turned off. (STEP 67). On the other hand, when the prohibition period is not set (No), the power is turned off as it is (STEP 67).

  According to the data communication system in which the receiving devices 3-1 to 3-n operate in this way, each device operates as shown in FIG. That is, when no infrared signal is transmitted from the remote controller 5 to the receivers 3-1 to 3-n, an RF signal serving as AV data is transmitted from the transmitter 2 as shown in FIG. In addition to being received by -1 to 3-n, an RF signal serving as retransmission request data is transmitted from each of the receiving devices 3-1 to 3-n. On the other hand, when an infrared signal is transmitted from the remote controller 5 to the receiving device 3-1, as shown in FIG. 10B, the receiving device 3-1 receives each of the receiving devices 3-2 to 3-n. An RF signal serving as a prohibition notification signal is transmitted to set a prohibition period. Then, an RF signal serving as retransmission request data and remote control through data is transmitted from the receiving device 3-1 to the transmitting device 2.

  Thereafter, during the prohibition period, as shown in FIG. 10C, an RF signal serving as AV data is transmitted from the transmission device 2 and received by the reception devices 3-1 to 3-n, and the reception device 3-1. AV data serving as retransmission request data is transmitted only from the above. Then, when the prohibition period has elapsed, as shown in FIG. 10D, an RF signal serving as a release notification signal is transmitted from the reception device 3-1 to each of the reception devices 3-2 to 3-n. The period is canceled. Therefore, as shown in FIG. 10A, an RF signal serving as AV data is transmitted from the transmission device 2 and received by the reception devices 3-1 to 3-n, and each of the reception devices 3-1 to 3-n. Transmits an RF signal as retransmission request data.

<Fifth Embodiment>
A fifth embodiment of the present invention will be described with reference to the drawings. Also in the data communication system according to the present embodiment, unlike the first to third embodiments, when the receiving device receives an infrared signal from a remote controller, the receiving device receives the infrared signal, as in the fourth embodiment. Transmission of retransmission request data from other receiving apparatuses is prohibited.

  Also in the data communication system according to the present embodiment, as in the fourth embodiment, each of the receiving apparatuses 3-1 to 3-n participating in the data communication system transmits an RF signal including retransmission request data and remote control through data. Transmit to the transmitter 2. That is, the receiving devices 3-1 to 3-n perform a polling operation, the transmission timings of the receiving devices 3-1 to 3-n are set, and the receiving devices 3-1 to 3-n each transmit their own devices. Then, the transmission operation of the RF signal to the transmission device 2 is performed.

  Then, when the infrared signal from the remote controller 5 is transmitted to any of the receiving devices 3 (corresponding to the receiving devices 3-1 to 3-n) participating in the data communication system, the infrared signal is received. Only the receiving device 3 transmits retransmission request data and remote control through data, and the transmission of retransmission request data by other receiving devices 3 is prohibited. At this time, in the present embodiment, unlike the fourth embodiment, a prohibition notification signal for prohibiting the retransmission request operation of another receiver 3 is transmitted from the receiver 3 that has received the infrared signal from the remote controller 5. Instead, data indicating that the receiving device 3 that has received the infrared signal from the remote controller 5 exists is added to the RF signal that is AV data from the transmitting device 2 (hereinafter referred to as “remote control through data confirmation information”). To be sent.

  Therefore, in the receiving device 3 that has confirmed the remote control through data confirmation information from the RF signal from the transmitting device 2, when the own device receives the infrared signal from the remote control 5, the retransmission request data and the remote control through data are processed as usual. Send. When it is confirmed from the remote control through data confirmation information that the other receiving device 3 has received the infrared signal from the remote controller 5, the transmission of retransmission request data by the own device is stopped.

  Operations of the transmission device 2 and the reception device 3 in such a data communication system will be described with reference to the drawings. FIG. 11 is a state transition diagram for explaining operation states of the transmission device 2 and the reception devices 3-1 to 3-n. In order to simplify the description, an example in which an infrared signal is transmitted from the remote controller 5 to the receiving device 3-1 will be described below.

  As in the fourth embodiment, an RF signal based on AV data transmitted from the transmission device 2 is received by the reception devices 3-1 to 3-n participating in the data communication system in which the transmission device 2 participates. Is done. At this time, if no infrared signal is transmitted from the remote controller 5, each of the receiving devices 3-1 to 3-n transmits retransmission request data for requesting retransmission of a TS packet that could not be normally received, to the retransmission request management unit 307. And transmits an RF signal based on the retransmission request data to the transmission device 2 as shown in FIG.

  When the receiving device 3-1 receives the infrared signal from the remote controller 5, the retransmission request management unit 307 generates retransmission request data and the remote control management unit 309 generates remote control through data, as shown in FIG. As described above, an RF signal based on retransmission request data and remote control through data is transmitted from the reception device 3-1 to the transmission device 2. In the transmission device 2, the RF signal is processed by the BB unit 204 and the RF unit 205, and then demodulated by the demodulation unit 207, thereby confirming that the RF signal is transmitted from the reception device 3-1. The remote control through data generation unit 209 confirms the data.

  Therefore, remote control through data confirmation information indicating that remote control through data has been transmitted from the receiving device 3-1 is generated by the TS processing unit 202, and the remote control through data confirmation information is added to the header of the TS packet by AV data. Then, the TS packet based on the AV data to which the remote control through data confirmation information is added is digitally modulated by the modulation unit 203, and then via the BB unit 204 and the RF unit 205, as shown in FIG. To the receivers 3-1 to 3-n.

  When each of the receiving devices 3-1 to 3-n receives the RF signal to which the remote control through data confirmation information is added, when the demodulation unit 304 demodulates, the remote control through data confirmation information in the header portion is confirmed. Is done. At this time, in the receiving device 3-1, since the receiving device confirmed by the remote control through data confirmation information is its own device, the retransmission request management unit 307 is kept operating. In the receiving apparatuses 3-2 to 3 -n, since the receiving apparatus confirmed by the remote control through data confirmation information is the other receiving apparatus 3-1, the predetermined period is set as the prohibited period, and retransmission is performed during this prohibited period. The operation of the request management unit 307 is stopped.

  Therefore, during this prohibition period, as shown in FIG. 11D, an RF signal serving as AV data is transmitted from the transmission device 2 and received by the reception devices 3-1 to 3-n. AV data serving as retransmission request data is transmitted from only one. That is, the retransmission request data from the receiving devices 3-2 to 3-n is not transmitted. Then, when each of the receiving devices 3-2 to 3 -n confirms that the prohibition period has elapsed, the transmission of retransmission request data from the receiving devices 3-2 to 3 -n again as shown in FIG. Is allowed.

  Further, as shown in FIG. 11D, when the retransmission request data from the receiving devices 3-2 to 3-n is not transmitted, for example, an infrared signal is transmitted from the remote controller 5 to the receiving device 3-2. Then, as shown in FIG. 12A, the retransmission request operation in the reception device 3-2 is resumed, and the RF signal that is the retransmission request data and the remote control through data is transmitted from the reception device 3-2 to the transmission device 2. Sent. Therefore, as shown in FIG. 12B, the transmitting device 2 transmits an RF signal based on AV data to which remote control through data confirmation information indicating that remote control through data has been transmitted from the receiving device 3-2 is added. . Then, a prohibition period is set again, and during this prohibition period, as shown in FIG. 12C, an RF signal serving as AV data is transmitted from the transmission device 2 and received by the reception devices 3-1 to 3-n. As well as being received, AV data serving as retransmission request data is transmitted only from the receiving device 3-2.

  In the present embodiment, the receiving devices 3-1 to 3-n receive the RF signals based on the AV data to which the remote control through data confirmation information from the transmitting device 2 is added. The prohibition period is set for each of the n, but when the transmission device 2 confirms that the prohibition period has elapsed, an RF signal based on AV data to which information for notifying the release is added is received by the reception devices 3-1 to 3-1. 3-n may be transmitted. At this time, in the apparatus in which the retransmission request operation is prohibited in the reception apparatuses 3-1 to 3-n, the retransmission request management unit 307 confirms information for receiving this RF signal and notifying the cancellation. The retransmission request operation is resumed.

  Further, in the fourth embodiment, as in the fifth embodiment, the receiving apparatus 3 that has received the prohibition notification signal from another receiving apparatus 3 and is prohibited from performing the retransmission request operation is prohibited from performing the retransmission request operation. You may measure a prohibition period. At this time, it is not necessary to transmit a cancellation notification signal for resuming the retransmission request operation of the other reception devices 3 from the reception device 3 that has transmitted the prohibition notification signal.

  Furthermore, in the fourth and fifth embodiments, it is assumed that an RF signal serving as retransmission request data is transmitted to the transmission device 2 from each of the reception devices 3 participating in the data communication system in a period other than the prohibition period. However, as in the first to third embodiments, the parent device and the child device are set between the receiving devices 3 participating in the data communication system, and reception from the receiving device 3 serving as the child device becomes the parent device. An RF signal serving as retransmission request data may be transmitted to the device 3.

  In each of the above-described embodiments, the AV source device and the transmission device are separated, and the reception device and the reproduction output device are separate. However, the AV source device and the transmission device are integrated. The receiving apparatus and the reproduction output apparatus may be integrated.

  The present invention can be applied to a data communication system that performs wireless communication for transmitting and receiving AV data, and can also be applied to a data communication system in which a PDA, a mobile phone, and the like can participate in communication.

These are block diagrams which show the structure of the data communication system by embodiment of this invention. FIG. 2 is a block diagram showing an internal configuration of a transmission apparatus in the data communication system of FIG. 1. FIG. 2 is a block diagram showing an internal configuration of a receiving device in the data communication system of FIG. 1. These are figures which show an example of the transmission timing in a data communication system. These are the flowcharts which show the switching management operation | movement of the timing T2, T3 by the receiver which becomes a main | base station in the data communication system of the 1st-3rd embodiment. These are the flowcharts which show the setting operation | movement of the main | base station and the subunit | mobile_unit in the receiver in the data communication system of 1st Embodiment. These are the flowcharts which show the setting operation | movement of the main | base station and a subunit | mobile_unit in the receiver in the data communication system of 2nd Embodiment. These are the flowcharts which show the setting operation | movement of the main | base station and the subunit | mobile_unit in the receiver in the data communication system of 3rd Embodiment. These are flowcharts which show operation | movement of the receiver in the data communication system of 4th Embodiment. These are the state transition diagrams for demonstrating the operation state of the transmitter in a data communication system of 4th Embodiment, and a receiver. These are the state transition diagrams for demonstrating the operation state of the transmitter in a data communication system of 5th Embodiment, and a receiver. These are the state transition diagrams for demonstrating the operation state of the transmitter in a data communication system of 5th Embodiment, and a receiver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AV source device 2 Transmission apparatus 3-1 to 3-n Reception apparatus 4-1 to 4-n Reproduction output apparatus 5 Remote control 201 Input I / F
202 TS processing unit 203 Modulation unit 204 BB unit 205 RF unit 206 Antenna 207 Demodulation unit 208 Retransmission request confirmation unit 209 Remote control through data generation unit 210 IrDA transmission unit 211 Control unit 301 Antenna 302 RF unit 303 BB unit 304 Demodulation unit 305 MPEG decoding 306 Output I / F
307 Retransmission request management unit 308 IrDA reception unit 309 Remote control management unit 310 Modulation unit 311 Control unit

Claims (11)

The transmission device includes one transmission device that transmits synchronization data and a plurality of reception devices that receive the synchronization data from the transmission device, and asynchronous data is transmitted from the reception device to the transmission device. In a data communication system using a wireless communication line,
A plurality of the receiving devices can receive a signal from a remote controller that operates the transmitting device or a device connected to the transmitting device, and can transmit the received signal from the remote controller to the transmitting device. ,
While being one of a plurality of receiving devices , and setting the receiving device that has received a signal from the remote controller as a parent device capable of transmitting the asynchronous data to the transmitting device,
Set the rest of the receiving device as a slave unit, the data communication system and inhibits the sending from the receiving apparatus to be set as the child machine the asynchronous data to the transmission device.   After the asynchronous data generated by the receiving device serving as the child device is transmitted to the receiving device serving as the parent device, the asynchronous data is generated by all of the plurality of receiving devices in the receiving device serving as the parent device. 2. The data communication system according to claim 1, wherein the asynchronous data is managed, and the managed asynchronous data is transmitted from the receiving device serving as the parent device to the transmitting device. The asynchronous data transmission operation by the remaining receiving devices serving as the slave devices is prohibited when the receiving device that has received a signal from the remote controller is set as the master device. A data communication system according to claim 1 or 2 . A period during which the transmission operation of the asynchronous data by the remaining receiving devices as the slave units is prohibited after the receiving device that has received the signal from the remote controller is set as the master unit is set as a predetermined time, 4. The data according to claim 3 , wherein when the predetermined time elapses without a signal being transmitted again from the remote controller, the asynchronous data transmission operation from the receiving device serving as the slave unit is permitted. Communications system. When the receiving device that has received the signal from the remote controller is set as the parent device, the asynchronous data is sent from the receiving device set as the parent device to the remaining receiving devices that are the child devices. the data communication system according to claim 3 or claim 4 transmit operation is characterized in that it is notified that the prohibition of. When the receiving device that has received the signal from the remote controller is set as the parent device, the transmission operation of the asynchronous data is prohibited from the transmitting device to the remaining receiving devices that are the child devices. The data communication system according to claim 3 or 4 , characterized in that: A reception unit that receives a radio signal, a demodulation unit that demodulates the radio signal received by the reception unit, a decoding unit that decodes the signal demodulated by the demodulation unit, and a transmission that transmits a radio signal based on asynchronous data A data communication device comprising: an encoder; an encoder that generates the asynchronous data; and a modulator that modulates the asynchronous data generated by the encoder and generates the radio signal and applies the radio signal to the transmitter Because
Data communication apparatus characterized by operating as the receiving device according to claims 1 to 6. A reception unit that receives a radio signal, a demodulation unit that demodulates the radio signal received by the reception unit, a decoding unit that decodes a signal demodulated by the demodulation unit, and a transmission that transmits a radio signal based on synchronization data A data communication device comprising: an encoding unit that generates the synchronization data; and a modulation unit that generates the radio signal by modulating the synchronization data generated by the encoding unit and supplies the radio signal to the transmission unit Because
Data communication apparatus characterized by operating as the transmission device according to claim 1 to claim 6. A receiver that receives a radio signal based on synchronous data; a demodulator that demodulates the radio signal received by the receiver; a decoder that decodes the signal demodulated by the demodulator; and a radio signal based on asynchronous data. A transmission unit that transmits, an encoding unit that generates the asynchronous data, and a modulation unit that modulates the asynchronous data generated by the encoding unit to generate the radio signal and gives the wireless signal to the transmission unit In a data communication device,
An operation data receiving unit that receives operation data transmitted from a remote controller and transmitted to a synchronous data transmission device that transmits a radio signal based on the synchronization data,
When participating in a data communication system comprising the synchronous data transmission device,
When there are a plurality of data communication devices participating in the data communication system including the own device, the operation data from the remote controller is received by the operation data receiving unit as one of the data communication devices . Set the thing as the parent device and set the remaining data communication device as the child device,
When set as the base unit, it is allowed to transmit the wireless signal by the asynchronous data to the synchronous data transmission device,
A data communication device characterized in that, when set as the slave, transmission of the radio signal based on the asynchronous data to the synchronous data transmission device is prohibited. When set as the slave unit, the wireless signal based on the asynchronous data is transmitted to the data communication device set as the master unit while participating in the data communication system,
When set as the base unit, the receiving unit receives the wireless signal based on the asynchronous data transmitted from the data communication device set as the slave unit while participating in the data communication system, and the demodulation unit When the asynchronous data is obtained by processing in the decoding unit, the data is managed together with the asynchronous data generated by the encoding unit, and then modulated by the modulation unit and transmitted from the transmission unit to the synchronous data transmission device The data communication device according to claim 9 . 10. The wireless communication apparatus according to claim 9 , wherein when the slave unit is set, operations of the encoding unit, the modulation unit, and the transmission unit are stopped, and transmission of the wireless signal using the asynchronous data is prohibited. The data communication apparatus according to 1.

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