Information reception device and information transmission device
22 claims: 4 independent, 18 dependent
- 1無線パケットの送信および受信を行う無線通信部と、 上記無線通信部で送信される無線パケットを生成するパケット生成部と、 上記無線通信部および上記パケット生成部を制御する制御部を備え、 上記無線通信部は、第1の情報送信装置から、非送信区間を間に挟んで順次送られてく るデ ータストリーミング伝送用の第1の無線パケットを受信し、 上記各第1の無線パケットの間にそれぞれ存在する上記非送信区間には、自身から上記第1の情報送信装置への送信に割り当てられた第1の非送信区間と、自身から上記第1の情報送信装置への送信に割り当てられていない第2の非送信区間が存在し、 上記第1の無線パケットは、上記第2の非送信区間を示す時間位置情報を含み、 上記パケット生成部は 、上 記第1の無線パケットに含まれ る上 記時間位置情報 に基づいて、上記第2の非送信区間 を示す時間位置情報を含 む、制 御情報送信用の第2の無線パケットを生成 し、 上記無線通信部は、上記パケット生成部で生成される上記第2の無線パケットを、上記第1の非送信区間の間に、上記第1の情報送信装置に送信 する 情報受信装置。
- 2上記制御部は、 上記第2の 非送信区間では、上記無線通信部が受信モードに入るように制御する 請求項1に記載の情報受信装置。
- 3上記制御部は、上記第1の情報送信装置とは異なる第2の情報送信装置に所定の情報を送信する必要が生じた場合には、 上記パケット生成部が上記所定の情報を含む第3の無線パケットを生成し、 上記第2の 非送信区間で上記受信モードに入らずに上記パケット生成部で生成された上記第3の無線パケットを上記第2の情報送信装置に送信するように制御する 請求項2に記載の情報受信装置。
- 4上記パケット生成部で生成される上記第2の無線パケットに含まれる上記時間位置情報は暗号化されていない 請求項1に記載の情報受信装置。
- 5上記パケット生成部で生成される上記第2の無線パケットに含まれる上記時間位置情報は、少なくとも、上記第1の情報送信装置とは異なる第2の情報送信装置と自身との間で相互に認証された暗号を用いて暗号化されている 請求項1に記載の情報受信装置。
- 6上記制御部は、 所定の上記第2の 非送信区間で、上記無線通信部が上記第1の情報送信装置とは異なる第2の情報送信装置から第3の無線パケットを受信した場合には、 上記パケット生成部が上 記第 3の無線パケットの受信結果として必要となった情報を含む第4の無線パケットを生成し、上記無線通信部が上記所定の 第2の 非送信区間の後に存在する 上記第2の 非送信区間で上記パケット生成部により生成された上記第4の無線パケットを上記第2の情報送信装置に送信するように制御する 請求項1に記載の情報受信装置。
- 7上記制御部は、 上記第2の情報送信装置からの上記第3の無線パケットに該第2の情報送信装置からのデータストリーミング伝送への切り替え通知情報が含まれていた場合には、 上記パケット生成部が上記第1の情報送信装置からのデータストリーミング伝送を中断する要求を含む上記第2の無線パケットを生成し、上記無線通信部が 所定の上記第1の 非送信区間で上記パケット生成部により生成された上記第2の無線パケットを送信するように制御し、 上記第1の情報送信装置からのデータストリーミング伝送の中断処理が終了した後に、上記パケット生成部が上記第2の情報送信装置からのデータストリーミング伝送の開始許可通知を含む上記第4の無線パケットを生成し、上記無線通信部が上記パケット生成部で生成された上記第4の無線パケットを上記第2の情報送信装置に送信するように制御する 請求項6に記載の情報受信装置。
- 8上記制御部は、 所定の上記第2の 非送信区間で上記無線通信部が上記第1の情報送信装置とは異なる第2の情報送信装置に無線パケットを送信した場合には、 上記第2の 非送信区間では、上記無線通信部が 受信モード となるように制御する 請求項1に記載の情報受信装置。
- 9上記制御部は、上記無線通信部により 上記第2の 非送信区間を用いて無線パケットを送信するとき、ランダムバックオフを用いて送信タイミングを決定する 請求項1に記載の情報受信装置。
- 10上記制御部は、バックオフカウンタの単位として、 上記第2の 非送信区間の個数を用いる 請求項9に記載の情報受信装置。
- 11上記制御部は、上記無線通信部で受信された上記第1の無線パケットに含まれている上記時間位置情報で示される時間位置を起点とし、バックオフカウンタの単位として、特定の時間刻み幅を用いる 請求項9に記載の情報受信装置。
- 12情報受信装置との間で 無線パケットの送信および受信を行う無線通信部と、 上記無線通信部で送信される無線パケットを生成するパケット生成部と、 上記無線通信部および上記パケット生成部を制御する制御部を備え、 上記情報受信装置には他の情報送信装置から非送信区間を間に挟んで順次データストリーミング伝送用の無線パケットが伝送され、 上記各無線パケットの間の上記非送信区間には、上記情報受信装置から上記他の情報送信装置への送信に割り当てられた第1の非送信区間と、上記情報受信装置から上記他の情報送信装置への送信に割り当てられていない第2の非送信区間が存在し、 上記無線通信部が上記情報受信装置から受信する無線パケットは、上記第2の非送信区間を示す時間位置情報を含み、 上記制御部は、上記無線通信部で受信された 上記 情報受信装置からの無線パケットに含まれている上記時間位置情報 で示される上記第2の非送信区間の間に 、上記無線通信部が 上記パケット生成部で生成された無線パケットを上記情報受信装置に送信するように制御する 情報送信装置。
- 13上記制御部は、上記無線通信部により上記情報受信装置に上記パケット生成部で生成された無線パケットを送信しない場合には、上 記所 定時間の間は上記無線通信部が受信モードに入るように制御する 請求項12に記載の情報送信装置。
- 14上記制御部は、上記無線通信部が上記情報受信装置からの無線パケットを受信した場合には、 上記パケット生成部が上記情報受信装置からの無線パケットの受信結果として必要な情報を含む無線パケットを生成し、 上記情報受信装置からの無線パケットに含まれている時間位置情報で示される 上記第2の非送信区間の間に 、上記無線通信部が上記パケット生成部で生成された無線パケットを上記情報受信装置に送信するように制御する 請求項13に記載の情報送信装置。
- 15上記制御部は、上記無線通信部で受信された上記情報受信装置からの無線パケットにデータストリーミング伝送許可通知が含まれている場合には、 上記パケット生成部がデータストリーミング伝送用の無線パケットを生成し、上記無線通信部が上記パケット生成部で生成された無線パケットを上記情報受信装置に順次送信するように制御する 請求項12に記載の情報送信装置。
- 16上記制御部は、上記無線通信部で受信された上記情報受信装置からの無線パケットに含まれている時間位置情報で示される 上記第2の非送信区間の間に上記パケット生成部で生成された 無線パケットを送信するとき、ランダムバックオフを用いて送信タイミングを決定する 請求項12に記載の情報送信装置。
- 17上記制御部は、バックオフカウンタの単位として、上記情報受信装置からの無線パケットに含まれている時間位置情報で示される 上記第2の非送信 区間の個数を用いる 請求項16に記載の情報送信装置。
- 18上記制御部は、上記情報受信装置からの無線パケットに含まれている時間位置情報で示される時間位置を起点とし、バックオフカウンタの単位として、特定の時間刻み幅を用いる 請求項16に記載の情報送信装置。
- 19情報受信装置との間で 無線パケットの送信および受信を行う無線通信部と、 上記無線通信部で送信される無線パケットを生成するパケット生成部と、 上記無線通信部および上記パケット生成部を制御する制御部を備え、 上記無線通信部は、 上記パケット生成部で生成された データストリーミング伝送用の無線パケットを、非送信区間を間に挟んで 上記 情報受信装置に順次送信し、 上記各無線パケットの間の上記非送信区間には、上記情報受信装置から自身への送信に割り当てられた第1の非送信区間と、上記情報受信装置から自身への送信に割り当てられていない第2の非送信区間が存在し、 上記データストリーミング伝送用の無線パケットは、上記第2の非送信区間を示す時間位置情報を含む 情報送信装置。
- 20上記制御部は、上記無線通信部から上記時間位置情報が含まれた上記無線パケットが送信された後に、上記データストリーミング伝送の送るべき情報の量が増加するかあるいは伝送可能なビットレートが減少する場合には、上記 第2の 非送信区間の時間位置が変化しないように、上記パケット生成部で生成される上記無線パケットに含める情報を 減少するように 調整する 請求項19に記載の情報送信装置。
- 21上記制御部は、上記無線通信部から上記時間位置情報が含まれた上記無線パケットが送信された後に、上記データストリーミング伝送の送るべき情報の量が減少するかあるいは伝送可能なビットレートが増加する場合には、上記情報受信装置から自身への送信に割り当てられていない上記非送信区間の時間位置が変化しないように 、上 記パケット生成部で生成される上記無線パケットに含める情報を 増加するように 調整す る 請求項19に記載の情報送信装置。
- 22情報送信装置と情報受信装置を備え、 上記情報送信装置から上記情報受信装置に、データストリーミング伝送用の第1の無線パケットが非送信区間を間に挟んで順次送信され、 上記各第1の無線パケットの間にそれぞれ存在する上記非送信区間には、上記情報受信装置から上記情報送信装置への送信に割り当てられた第1の非送信区間と、上記情報受信装置から上記情報送信装置への送信に割り当てられていない第2の非送信区間が存在し、 上記第1の 非送信区間で、上記情報受信装置から上記情報送信装置に、制御情報送信用の第2の無線パケットが送信される情報通信システムであって、 上記情報送信装置は、 無線パケットの送信および受信を行う無線通信部と、 上記無線通信部で送信される無線パケットを生成するパケット生成部と、 上記無線通信部および上記パケット生成部を制御する制御部を有し、 上記パケット生成部は、 上記第2の 非送信区間を示す時間位置情報を含む、上記無線通信部で送信される上記第1の無線パケットを生成し、 上記情報受信装置は、 無線パケットの送信および受信を行う無線通信部と、 上記無線通信部で送信される無線パケットを生成するパケット生成部と、 上記無線通信部および上記パケット生成部を制御する制御部を有し、 上記パケット生成部は 、上 記第1の無線パケットに含まれ る上 記時間位置情報 に基づいて、上記第2の非送信区間 を示す時間位置情報を含む、上記無線通信部で送信される上記第2の無線パケットを生成する 情報通信システム。
Independent claims22
122 paragraphs, as filed
The present invention relates to an information receiving device, an information transmitting device and an information communication system. Specifically, according to the present invention, when a first radio packet for data streaming transmission is sequentially transmitted from an information transmitting device to an information receiving device with a non-transmission section in between, the information receiving device sends the first wireless packet to the first wireless packet. The time position information indicating the non-transmission section that is not assigned to the transmission to the information transmitting device is included, and the second radio packet for controlling information transmission transmitted from the information receiving device to the information transmitting device contains the time position information. Communication between the information receiving device and other information transmitting devices is possible by including the time position information indicating the same non-transmission section as the time position information contained in the first wireless packet. The present invention relates to an information receiving device, an information transmitting device, and an information communication system.
For example, as described in Patent Document 1 and the like, wireless streaming transmission of a video signal between a source device (for example, a disc recorder, a tuner for terrestrial digital broadcasting, etc.) and a sink device (for example, a television, etc.) is performed. The demand to do is increasing.
In addition, with the digitization of devices and the sophistication of interfaces, attempts have been made to simplify the user interface. For example, one-touch play has been proposed in which the input of the sink device is automatically switched when the play button is pressed on the source device side, and the image by the video signal from the source device is displayed on the sink device.
Considering the connection with a plurality of source devices, it is preferable that the sink device serves as the master station of the wireless network and manages resources. However, with this, when the amount of stream data to be transmitted that is generated on the source device side fluctuates, it is difficult for the sink device side to immediately change the radio resource allocation. For example, if a regular program is in 1080p format and a commercial is in 1080i, the amount of data to be transmitted per unit time is doubled.
Therefore, it is conceivable that the source device becomes the master station of the wireless network and determines the allocation of wireless resources. However, in this configuration, even if a plurality of source devices exist, basically one source device and one sink device occupy most of the wireless resources. Therefore, it is not possible to wirelessly transmit control information from other source devices to the sink device, or wirelessly transmit control information from the sink device to other source devices that are not currently communicating. It was.
FIG. 13 shows a configuration example of the information communication system 200. The information communication system 200 includes an information transmitting device (source device) 210 such as a disk recorder and a set-top box, and an information receiving device (sink device) 220 such as a television receiver. Wireless communication is performed between the information transmitting device 210 and the information receiving device 220.
That is, as shown in FIG. 14A, the wireless packet PK1 for data streaming transmission is sequentially transmitted from the information transmitting device 210 to the information receiving device 220 with a non-transmission section in between. This wireless packet PK1 contains various control information in addition to audio / video streaming data.
On the contrary, from the information receiving device 220 to the information transmitting device 210, according to the control information included in the wireless packet PK1, as shown in FIG. 14B, the wireless packet PK2 for transmitting the control information is in the non-transmission section. In the meantime, it is transmitted sequentially. This wireless packet PK2 contains control information such as ACK (ACKnowledgement).<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2006-109000</text></patcit>
<p> In the case of the information communication system 200 shown in FIG. 13, another information transmitting device different from the information transmitting device 210 currently communicating needs to transmit some information to the information receiving device 220, or the information receiving device 220 However, even if it becomes necessary to transmit some information to the other information transmitting device, there is no time available for transmission. That is, the information receiving device 220 cannot communicate with other information transmitting devices.</p><p> An object of the present invention is to enable an information receiving device receiving a radio packet for data streaming transmission from an information transmitting device to communicate with another information transmitting device.</p>
<p> The concept of this invention is Equipped with an information transmitting device and an information receiving device The first radio packet for data streaming transmission is sequentially transmitted from the information transmitting device to the information receiving device with a non-transmission section in between.<u style="single">The non-transmission section existing between each of the first radio packets includes the first non-transmission section assigned for transmission from the information receiving device to the information transmitting device, and the information receiving device to the information receiving device. There is a second non-transmission section that is not assigned to transmit to the information transmitter,</u><u style="single">The first above</u>An information communication system in which a second radio packet for transmitting control information is transmitted from the information receiving device to the information transmitting device in a non-transmission section. The above information transmission device A wireless communication unit that sends and receives wireless packets, A packet generator that generates a wireless packet transmitted by the wireless communication unit, It has a control unit that controls the wireless communication unit and the packet generation unit. The packet generator is<u style="single">The second above</u>Generates the first radio packet transmitted by the radio communication unit, which includes time position information indicating a non-transmission section, and generates the first radio packet. The above information receiving device A wireless communication unit that sends and receives wireless packets, A packet generator that generates a wireless packet transmitted by the wireless communication unit, It has a control unit that controls the wireless communication unit and the packet generation unit. The above packet generator<u style="single">,Up</u>Included in the first wireless packet<u style="single">On</u>Timed location information<u style="single">Based on the above second non-transmission section</u>Generates the second radio packet transmitted by the radio communication unit, which includes the time position information indicating It is in the information communication system.</p><p> In the present invention, the first radio packet for data streaming transmission is sequentially transmitted from the information transmitting device (source device) to the information receiving device (sink device) with a non-transmission section in between. Here, a predetermined ratio of non-transmission sections is assigned to sections for transmitting a second radio packet for transmitting control information from the information receiving device to the information transmitting device. In the first non-transmission section assigned to the transmission from the information receiving device (sink device) to the information transmitting device, the information receiving device transmits the second radio packet for controlling information transmission to the information transmitting device.</p><p> The first radio packet transmitted from the information transmitting device to the information receiving device is such that the time position information indicating the second non-transmitting section not assigned to the transmission from the information receiving device to the information transmitting device is included. Will be done. Then, the second wireless packet transmitted from the information receiving device to the information transmitting device includes the time position information included in the first wireless packet.<u style="single">Based on the second</u>The time position information indicating the non-transmission section is included.</p><p> For example, the wireless communication unit of the information receiving device is set to enter the receiving mode in the second non-transmitting section. As a result, the information receiving device receives the wireless packet (information) transmitted in the second non-transmission section from another information transmitting device different from the information transmitting device transmitting the first wireless packet. It becomes possible.</p><p> Further, for example, when it becomes necessary for the information receiving device to transmit predetermined information to another information transmitting device different from the information transmitting device transmitting the first wireless packet, the wireless communication unit of this information receiving device. Is configured to transmit a radio packet (predetermined information) to another information transmitting device without entering the reception mode in the second non-transmission section. This makes it possible to transmit information from the information receiving device to another information transmitting device.</p><p> As described above, there is a second non-transmission section that is not assigned to the transmission from the information receiving device to the information transmitting device, and this second radio packet transmitted from the information receiving device to the information transmitting device has this second non-transmission section. Contains time and position information indicating the non-transmission section of 2. Therefore, the information receiving device can send and receive information to and from another information transmitting device different from the information transmitting device transmitting the first wireless packet, which improves user convenience. .. For example, when control information for switching streaming transmission is transmitted from another information transmitting device to an information receiving device, the user does not have to be aware of switching the information source of streaming transmission in the information receiving device. Transmission can be switched.</p><p> For example, in an information transmitting device, after the first wireless packet containing time position information is transmitted from the wireless communication unit, the amount of information to be transmitted in the data streaming transmission increases or the transmittable bit rate decreases. If so, the information to be included in the first radio packet should be so that the time position of the second non-transmission section does not change.<u style="single">To decrease</u>It will be adjusted. For example, less important transmission bits are decimated, or transmission of information parts that are insensitive to changes in transmission delay, such as instructions for quality information, is postponed.</p><p> Further, for example, in an information transmitting device, after the first wireless packet including time position information is transmitted from the wireless communication unit, the amount of information to be transmitted in the data streaming transmission is reduced or the bit rate that can be transmitted is reduced. Does not change the time position of the second non-transmission section when<u style="single">, No.</u>The information to be included in one wireless packet<u style="single">To increase</u>Adjusted<u style="single">To.</u>For example, the redundancy of the transmission bit is increased, or the information part that is not sensitive to the change in transmission delay that was going to be sent in the next wireless packet is included in this wireless packet.<u style="single">To.</u></p><p> As mentioned above, if the amount of information to be sent in a data streaming transmission increases or the bit rate that can be transmitted decreases, or if the amount of information that must be sent in a data streaming transmission decreases or the bit rate that can be transmitted decreases. Even if it increases, the time position of the second non-transmission section is prevented from changing. Therefore, it is avoided that the transmission / reception of information between the information receiving device and the other information transmitting device is hindered by the transmission of the first radio packet.</p><p> For example, the time position information contained in the second radio packet transmitted from the information receiving device to the information transmitting device is prevented from being encrypted. In this case, another information transmitting device can easily acquire the time position information indicating the second non-transmission section from the second radio packet, and the radio packet (information) can be easily obtained by using the second non-transmission section. Can be satisfactorily transmitted to the information receiving device.</p><p> Further, for example, the time position information included in the second radio packet transmitted from the information receiving device to the information transmitting device has at least a code that is mutually authenticated between the other information transmitting device and the information receiving device. Encrypted using. In this case, it is possible to prevent the time position information included in the second wireless packet from being acquired by a malicious information communication device, and it is possible to increase the resistance to an attack from the information communication device.</p><p> Further, for example, in an information receiving device, when a wireless packet is transmitted using a second non-transmission section, a transmission timing is determined using a random backoff. In this case, even in the other information transmitting device, when the wireless packet is transmitted using the second non-transmission section, the transmission timing is determined by using the random backoff, so that the information is transmitted from the other information transmitting device. The probability of collision between the wireless packet to the device and the wireless packet from the information receiving device to another information transmitting device can be reduced.</p><p> For example, the number of second non-transmission sections is used as the unit of the backoff counter. Further, for example, the time position indicated by the time position information included in the first radio packet (time position information included in the second radio packet) is set as the starting point, and is specified as a unit of the backoff counter. Time step width is used. In this case, backoff control can be performed in finer time units as compared with the case where the number of second non-transmission sections is used as the unit of the backoff counter, so that wireless resources can be effectively used. ..</p><p> In the present invention, for example, in the information receiving device, when the wireless packet from the other information transmitting device includes the switching notification information for the data streaming transmission from the other information transmitting device, the data streaming transmission is performed. A second radio packet containing a request to suspend the data is transmitted to the information transmitting device, and the interrupt processing of the data streaming transmission is started.</p><p> Then, in the information receiving device, after the interruption processing of the data streaming transmission is completed, a wireless packet including a notification of permission to start the data streaming transmission is transmitted to another information transmitting device. As a result, the data streaming transmission is interrupted from the state in which the data streaming transmission is being performed from the information transmitting device to the information receiving device, and the data stream is transmitted from another information transmitting device to the information receiving device, which is in good condition. Can be switched.</p>
<p> According to the present invention, when a first radio packet for data streaming transmission is sequentially transmitted from an information transmitting device to an information receiving device with a non-transmission section in between, the information receiving device and another information transmitting device are used. Communication between them becomes possible.</p>
Hereinafter, the best mode for carrying out the invention (hereinafter referred to as the embodiment) will be described. The explanation will be given in the following order. 1. Embodiment 2. Modification example
<1. Embodiment> [Configuration example of information communication system] FIG. 1 shows a configuration example of the information communication system 100 as an embodiment. The information communication system 100 has a disk recorder 110 as an information transmitting device, a television receiver 120 as an information receiving device, and a set-top box 130 as another information transmitting device.
Wireless communication is performed between the disc recorder 110 and the television receiver 120, and audio / video data streaming transmission is performed from the disc recorder 110 to the television receiver 120. Wireless communication is also performed between the set-top box 130 and the television receiver 120, and audio / video data streaming transmission is performed from the set-top box 130 to the television receiver 120.
The data streaming transmission from the disk recorder 110 to the television receiver 120 and the data streaming transmission from the set-top box 130 to the television receiver 120 are selectively performed. For example, the data streaming transmission from the set-top box 130 to the television receiver 120 can be switched to while the data streaming transmission from the disk recorder 110 to the television receiver 120 is being performed. The reverse is also true.
[Configuration example of disc recorder, TV receiver, and set-top box] A configuration example of the disc recorder 110, the television receiver 120, and the set-top box 130 will be described.
First, a configuration example of the disc recorder 110 will be described. FIG. 2 shows a configuration example of the disc recorder 110. The disk recorder 110 includes a control unit 111, a user operation unit 112 , a display unit 113, a disk drive 114, a codec 115, a terminal 116 for connecting an external device, a packet generation / analysis unit 117, and the like. It has a wireless transmitter / receiver 118.
The control unit 111 controls the operation of each unit of the disc recorder 110. The control unit 111 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The ROM stores CPU control programs and the like. RAM is used for temporary storage of data required for CPU control processing. The CPU expands the program and data read from the ROM on the RAM, starts the program, and controls the operation of each part of the disk recorder 110.
The user operation unit 112 and the display unit 113 constitute a user interface and are connected to the control unit 111. The user operation unit 112 includes keys, buttons, dials, a touch panel arranged on the display surface of the display unit 113, a remote controller, and the like, which are arranged in a housing (not shown) of the disc recorder 110. The display unit 113 is composed of an LCD (Liquid Crystal Display) or the like.
The disk drive 114 is obtained by encoding image data (video signal) supplied from the codec 115 and audio data (audio signal) accompanying the image data by, for example, an MPEG (Moving Picture Experts Group) method or the like. The encoded data is recorded on a disc-shaped recording medium DC such as BD (Blu-ray Disc) or DVD (Digital Versatile Disc). Further, the disk drive 114 reproduces (reads) the encoded data from the disk-shaped recording medium DC and supplies the encoded data to the codec 115.
The codec 115 decodes the encoded data supplied from the disk drive 114 into baseband (uncompressed) image and audio data by the MPEG method or the like. Then, the codec 115 supplies the image and audio data of the baseband to the packet generation / analysis unit 117, and outputs the data to the terminal 116. Further, the codec 115 encodes baseband image and audio data input to the terminal 116 from an external device (not shown) into encoded data, and supplies the encoded data to the disk drive 114. Here, the external device is a hard disk recorder (HDD recorder), a personal computer, a DVD recorder, a video camera, or the like.
The packet generation / analysis unit 117 generates a wireless packet for data streaming transmission or a wireless packet for controlling control information transmission. The wireless packet for data streaming transmission includes image and audio data supplied from the codec 115 as streaming data, and also includes various control information supplied from the control unit 111. Here, one wireless packet for data streaming transmission includes, for example, one frame of image and audio data.
The radio packet for transmitting control information includes various control information supplied from the control unit 111. Further, the packet generation / analysis unit 117 analyzes the wireless packet for transmitting control information sent from the television receiver 120 supplied from the wireless communication unit 118, extracts various control information, and extracts various control information. Is supplied to the control unit 111.
The wireless communication unit 118 wirelessly transmits the wireless packet generated by the packet generation / analysis unit 117 to the television receiver 120. Further, the wireless communication unit 118 receives the wireless packet for transmitting control information transmitted from the television receiver 120 and supplies it to the packet generation / analysis unit 117.
Next, a configuration example of the television receiver 120 will be described. FIG. 3 shows a configuration example of the television receiver 120. The television receiver 120 has a control unit 121 and a user operation unit 122. Further, the television receiver 120 has a wireless communication unit 123, a packet generation / analysis unit 124, a switch 125, a tuner 126, an antenna terminal 127, a display processing unit 128, and a display panel 129. ..
The control unit 121 controls the operation of each unit of the television receiver 120. The control unit 121 includes a CPU, ROM, and RAM. The ROM stores CPU control programs and the like. RAM is used for temporary storage of data required for CPU control processing. The CPU expands the program and data read from the ROM on the RAM, starts the program, and controls the operation of each part of the television receiver 120. The user operation unit 122 includes keys, buttons, dials, a remote controller, and the like arranged in a housing (not shown) of the television receiver 120.
The wireless communication unit 123 receives a wireless packet for data streaming transmission or the like transmitted from the disk recorder 110 or the set-top box 130, and supplies the wireless packet to the packet / analysis unit 124. Further, the wireless communication unit 123 wirelessly transmits the wireless packet generated by the packet generation / analysis unit 124 to the disk recorder 110 or the set-top box 130.
The packet generation / analysis unit 124 generates a wireless packet for transmitting control information, including various control information supplied from the control unit 121. In addition, the packet generation / analysis unit 124 analyzes the wireless packet transmitted from the disk recorder 110 or the set-top box 130 supplied from the wireless communication unit 123, and analyzes image and audio data, as well as various control information. Is extracted. The packet generation / analysis unit 124 supplies the extracted various control information to the control unit 121.
The tuner 126 receives BS broadcasting, terrestrial digital broadcasting, and the like. A broadcast signal captured by an antenna (not shown) connected to the antenna terminal 127 is supplied to the tuner 126. The tuner 126 acquires image and audio data of a predetermined program based on a broadcast signal. The switch 125 selectively extracts the image and audio data extracted by the packet generation / analysis unit 124 or the image and audio data acquired by the tuner 126.
The display processing unit 128 performs processing such as color adjustment, contour enhancement, and superimposition of graphics data on the image data taken out by the switch 125. The display panel 129 displays an image based on the image data processed by the display processing unit 128. The display panel 129 is composed of, for example, an LCD (Liquid Crystal Display), an organic EL (ElectroLuminescence), a PDP (Plasma Display Panel), or the like. Although not shown, the audio data extracted by the switch 125 is supplied to the speaker via the amplifier.
Next, a configuration example of the set-top box 130 will be described. FIG. 4 shows a configuration example of the set-top box 130. The set-top box 130 includes a control unit 131, a user operation unit 132, a display unit 133, a tuner 134, an antenna terminal 135, a packet generation / analysis unit 136, and a wireless transmission / reception unit 137.
The control unit 131 controls the operation of each unit of the set-top box 130. The control unit 131 includes a CPU, ROM, and RAM. The ROM stores CPU control programs and the like. RAM is used for temporary storage of data required for CPU control processing. The CPU expands the program and data read from the ROM on the RAM, starts the program, and controls the operation of each part of the set-top box 130.
The user operation unit 132 and the display unit 133 form a user interface and are connected to the control unit 131. The user operation unit 132 includes keys, buttons, dials, a touch panel arranged on the display surface of the display unit 133, a remote controller, and the like, which are arranged in a housing (not shown) of the set-top box 130. The display unit 133 is composed of an LCD or the like.
The tuner 134 receives BS broadcasting, terrestrial digital broadcasting, and the like. A broadcast signal captured by an antenna (not shown) connected to the antenna terminal 135 is supplied to the tuner 134. The tuner 134 acquires image and audio data of a predetermined program based on a broadcast signal.
The packet generation / analysis unit 136 generates a wireless packet for data streaming transmission or a wireless packet for control information transmission. The wireless packet for data streaming transmission includes image and audio data acquired by the tuner 134 as streaming data, and also includes various control information supplied from the control unit 131. Here, one wireless packet for data streaming transmission includes, for example, one frame of image and audio data.
The radio packet for transmitting control information includes various control information supplied from the control unit 131. In addition, the packet generation / analysis unit 136 analyzes the wireless packet for transmitting control information sent from the television receiver 120 supplied from the wireless communication unit 137, extracts various control information, and extracts various control information. Is supplied to the control unit 131.
The wireless communication unit 137 wirelessly transmits the wireless packet generated by the packet generation / analysis unit 136 to the television receiver 120. Further, the wireless communication unit 137 receives the wireless packet for transmitting control information transmitted from the television receiver 120 and supplies it to the packet generation / analysis unit 136.
[Operation example during data streaming transmission] In the information communication system 100 shown in FIG. 1, an operation example at the time of data streaming transmission will be described.
First, an operation example during data streaming transmission from the disk recorder 110 to the television receiver 120 will be described. When the user operates the disc recorder 110 to transmit the image and audio data recorded on the disc-shaped recording medium DC, the disc drive 114 reproduces the encoded data from the disc-shaped recording medium DC. This reproduced data is supplied to the codec 115.
In the codec 115, the encoded data reproduced by the disk drive 114 is decoded into baseband image and audio data. The baseband image and audio data are supplied to the packet generation / analysis unit 117. The packet generation / analysis unit 117 includes image and audio data supplied from the codec 115 as streaming data, and generates a wireless packet for data streaming transmission including various control information supplied from the control unit 111. .. As described above, one radio packet for data streaming transmission includes, for example, one frame of image and audio data.
The wireless packet for data streaming transmission generated by the packet generation / analysis unit 117 is wirelessly transmitted to the television receiver 120 by the wireless communication unit 118. In this case, as shown in FIG. 5A, the wireless packet PK1 for data streaming transmission is sequentially transmitted from the disk recorder 110 to the television receiver 120 with a non-transmission section in between. This wireless packet PK1 contains various control information in addition to audio / video streaming data.
Further, in the television receiver 120, the wireless communication unit 123 receives the wireless packet for data streaming transmission sent from the disk recorder 110. This wireless packet is supplied to the packet generation / analysis unit 124. The packet generation / analysis unit 124 analyzes the wireless packet and extracts image and audio data, as well as various control information. Various control information is supplied to the control unit 121.
The image data extracted by the packet generation / analysis unit 124 is supplied to the display processing unit 128 through the switch 125. Under the control of the control unit 121, the display processing unit 128 performs processing such as color adjustment, contour enhancement, and superimposition of graphics data on the image data. Then, on the display panel 129, an image (reproduced image) based on the image data supplied from the display processing unit 128 is displayed. Further, although not shown, the voice data extracted by the packet generation / analysis unit 124 is supplied to the speaker through the switch 125 and the amplifier. Audio (reproduced audio) based on audio data is output from the speaker.
Further, in the television receiver 120, a wireless packet for transmitting control information is generated according to various control information extracted from the wireless packet PK1 as described above, and is wirelessly transmitted to the disk recorder 110. That is, the packet generation / analysis unit 124 generates a wireless packet for transmitting control information, which includes various control information such as ACK (ACKnowledgement) supplied from the control unit 121. Then, this wireless packet is wirelessly transmitted to the disk recorder 110 by the wireless communication unit 123.
As described above, wireless packets for data streaming transmission are sequentially transmitted from the disc recorder 110 to the television receiver 120 with a non-transmission section in between. That is, the wireless packet for data streaming transmission is intermittently transmitted from the disk recorder 110 to the television receiver 120 with a non-transmission section in between.
Here, the non-transmission section of a predetermined ratio is assigned to the transmission from the television receiver 120 to the disc recorder 110, for example, by the control information included in the immediately preceding wireless packet. The non-transmission section assigned to the transmission from the television receiver 120 to the disc recorder 110 in this way is appropriately referred to as a "first non-transmission section". On the other hand, a non-transmission section that is not assigned to transmission from the television receiver 120 to the disc recorder 110 is appropriately referred to as a "second non-transmission section".
As described above, in the television receiver 120, the wireless packet PK2 for transmitting control information transmitted from the wireless communication unit 123 to the disc recorder 110 is in the first non-transmission section as shown in FIG. 5 (b). Will be sent in between.
Further, in the disk recorder 110, the wireless communication unit 118 receives a wireless packet for transmitting control information sent from the television receiver 120. This wireless packet is supplied to the packet generation / analysis unit 117. The packet generation / analysis unit 117 analyzes the wireless packet and extracts various control information such as ACK. Various control information is supplied to the control unit 111.
Next, an operation example during data streaming transmission from the set-top box 130 to the television receiver 120 will be described. When the user operates the set-top box 130 to transmit the image and audio data acquired by the tuner 134, the packet generation / analysis unit 136 generates a wireless packet for data streaming transmission. This wireless packet includes image and audio data supplied from the tuner 134 as streaming data, and also includes various control information supplied from the control unit 131. As described above, one radio packet for data streaming transmission includes, for example, one frame of image and audio data.
The wireless packet for data streaming transmission generated by the packet generation / analysis unit 136 is wirelessly transmitted to the television receiver 120 by the wireless communication unit 137. In this case, as shown in FIG. 5A, the wireless packet PK1 for data streaming transmission is sequentially transmitted from the set-top box 130 to the television receiver 120 with a non-transmission section in between. This wireless packet PK1 contains various control information in addition to audio / video streaming data.
Further, in the television receiver 120, the wireless communication unit 123 receives the wireless packet for data streaming transmission sent from the set-top box 130. This wireless packet is supplied to the packet generation / analysis unit 124. The packet generation / analysis unit 124 analyzes the wireless packet and extracts image and audio data, as well as various control information. Various control information is supplied to the control unit 121.
The image data extracted by the packet generation / analysis unit 124 is supplied to the display processing unit 128 through the switch 125. Under the control of the control unit 121, the display processing unit 128 performs processing such as color adjustment, contour enhancement, and superimposition of graphics data on the image data. Then, on the display panel 129, an image (STB received image) based on the image data supplied from the display processing unit 128 is displayed. Further, although not shown, the voice data extracted by the packet generation / analysis unit 124 is supplied to the speaker through the switch 125 and the amplifier. Voice by voice data (STB received voice) is output from the speaker.
Further, in the television receiver 120, the packet generation / analysis unit 124 generates a wireless packet for transmitting control information including various control information such as ACK supplied from the control unit 121. This wireless packet is wirelessly transmitted to the set-top box 130 by the wireless communication unit 123. In this case, as shown in FIG. 5B, the radio packet PK2 for transmitting control information is transmitted from the television receiver 120 to the set-top box 130 during the first non-transmission section.
Further, in the set-top box 130, the wireless communication unit 137 receives a wireless packet for transmitting control information sent from the television receiver 120. This wireless packet is supplied to the packet generation / analysis unit 136. The packet generation / analysis unit 136 analyzes the wireless packet and extracts various control information such as ACK. Various control information is supplied to the control unit 131.
[Wireless packet configuration example] Next, a configuration example of a wireless packet communicated between the source device (disk recorder 110, set-top box 130) and the sink device (television receiver 120) during data streaming transmission will be described.
First, a configuration example of a wireless packet PK1 for data streaming transmission transmitted from a source device to a sink device will be described. FIG. 6 shows an example of the format of this wireless packet PK1. The wireless packet PK1 is composed of a preamble, a PHY header, a MAC header, various control information, and streaming data.
The preamble is a known pattern used on the receiving side for finding a radio packet, estimating a carrier frequency error, correcting a timing error, estimating a transmission line, and the like. The PHY header stores information such as the degree of modulation used in the portion after the MAC header of this wireless packet, the coding rate of the error correction code, and the packet length. The MAC header stores a transmitting station address, a receiving station address, information elements included in this wireless packet, a packet type, and the like. Various control information includes information such as what the wireless communication station (information receiving device) that should be the receiving station must do after receiving this wireless packet, for example, ACK must be transmitted. Is included. In addition, various control information includes response information to a wireless communication station (information receiving device) that should be a receiving station, for example, information such as acceptance of a request for interruption of data streaming transmission.
In this embodiment, as shown in FIG. 6, the PHY header of the wireless packet PK1 has a second non-transmission section in addition to the above-mentioned information such as the modulation degree, the code rate of the error correction code, and the packet length. The time position information TIM1 indicating is stored. The second non-transmission section is a non-transmission section that is not assigned to transmission from the sink device to the source device, as described above. For example, the time position information TIM1 is information corresponding to the time from the end time of the wireless packet PK1 to the start point of the second non-transmission section (time t5, t3, t1 in FIG. 5 (a)). , T5', t3', t1'). Note that FIG. 5 shows an example in which a section AR is further set in the second non-transmission section, and the start point of this section AR is set as the start point of the second non-transmission section.
In the wireless packet PK1 shown in FIG. 6, the preamble, PHY header, MAC header, etc. other than the time position information TIM1 stored in the PHY header are not related to the essence of the present invention, and are IEEE 802.11, which is a wireless LAN standard. There is no big difference with the above.
Next, a configuration example of the wireless packet PK2 for transmitting control information transmitted from the sink device to the source device will be described. FIG. 7 shows an example of the format of this wireless packet PK2. The wireless packet PK2 is composed of a preamble, a PHY header, a MAC header, and various control information.
The preamble is a known pattern used on the receiving side for finding a radio packet, estimating a carrier frequency error, correcting a timing error, estimating a transmission line, and the like. The PHY header stores information such as the degree of modulation used in the portion after the MAC header of this wireless packet, the coding rate of the error correction code, and the packet length. The MAC header stores a transmitting station address, a receiving station address, information elements included in this wireless packet, a packet type, and the like. For various control information, what should the wireless communication station (information transmitter) that should be the receiving station do after receiving this wireless packet, for example, because the quality of the transmission signal is insufficient, the following It contains information such as recommending lower transmission speeds by thinning out streaming data from wireless packets. In addition, various control information includes instruction information to a wireless communication station (information transmission device) to be a receiving station, for example, stop instruction information for data streaming transmission.
In this embodiment, as shown in FIG. 7, the PHY header of the wireless packet PK2 has a second non-transmission section in addition to the above-mentioned information such as the modulation degree, the code rate of the error correction code, and the packet length. The time position information TIM2 indicating is stored. This time position information TIM2 is the same information as the time position information TIM1 stored in the PHY header of the radio packet PK1 described above. That is, this time position information TIM2 is information corresponding to the time from the end time of the wireless packet PK2 to the start point of the second non-transmission section (start point of the section AR) (Fig. 5 (b)). See time t4, t2, t4 , t2 at.
In this way, in order to store the time position information TIM2 in the PHY header of the wireless packet PK2, the control unit 121 of the sink device (television receiver 120) receives each time the wireless packet PK1 is received by the wireless transmitter / receiver 123. The control process is performed according to the flowchart of FIG.
When the wireless packet PK1 is received by the wireless transmission / reception unit 123, the control unit 121 starts the control process in step ST1, and then moves to the process in step ST2. In this step ST2, the control unit 121 generates the time position information TIM2 by using the time position information TIM1 included in the PHY header of the wireless packet PK1. In this case, the time position information TIM2 is the time position information indicating the same non-transmission section (start point of the non-transmission section) as indicated by the time position information TIM1.
Next, in step ST3, the control unit 121 generates a radio packet PK2 for transmitting control information in which the time position information TIM2 generated in step ST2 is stored in the PHY header (see FIG. 7). Then, the control unit 121 transmits the wireless packet PK2 generated in step ST3 to the source device (disk recorder 110, set-top box 130) in the first non-transmission section in step ST4, and in step ST5, a series of series. Ends the control process of.
In step ST2 of the flowchart of FIG. 8 described above, the control unit 121 needs to obtain the time indicated by the time position information TIM2. How to obtain this time will be described with reference to FIG. Here, a case where the time indicated by the time position information TIM1 stored in the PHY header of the wireless packet PK1 is t5 and the time t4 indicated by the time position information TIM2 is obtained from this time t5 will be described as an example.
The control unit 121 knows the time T1 from the end point of the wireless packet PK1 to the start point of the wireless packet PK2 transmitted by itself and the time length T2 of the wireless packet PK2 transmitted by itself. Therefore, the control unit 121 can obtain the time t4 by the arithmetic expression of t4 = t5-T1-T2 using the time t5 indicated by the time position information TIM1 and these times T1 and T2.
In the above description, the time position information TIM1 and TIM2 included in the PHY headers of the wireless packets PK1 and PK2 correspond to the remaining time from the end time of the wireless packet to the start point of the second non-transmission section. It is considered to be information. However, the time position information TIM1 and TIM2 may be used as absolute time information indicating the start point of the second non-transmission section.
In this case, the source device (disc recorder 110, set-top box 130) and sink device (television receiver 120) need to have a clock means for generating common time information. Further, in this case, the time position information TIM1 included in the PHY header of the wireless packet PK1 and the time position information TIM2 included in the PHY header of the wireless packet PK2 have the same information. Therefore, in the sink device (television receiver 120), the time position information TIM1 extracted from the PHY header of the wireless packet PK1 sent from the source device is included in the PHY header of the wireless packet PK2 as the time position information TIM2 as it is. Can be done.
Further, in the above description, the time position information TIM1 and TIM2 are stored in the PHY headers of the wireless packets PK1 and PK2. However, the storage location of the time position information TIM1 and TIM2 in the wireless packets PK1 and PK2 is not limited to the PHY header, and may be stored in other parts such as the MAC header.
Further, in the above description, the time position information TIM1 and TIM2 are information corresponding to the time from the end time of the wireless packets PK1 and PK2 to the start point of the second non-transmission section (start point of the section AR). ing. However, the starting point is not limited to the end time of the wireless packets PK1 and PK2, and other time points such as the start time of the wireless packets PK1 and PK2 can be used as the starting point.
Further, in the above description, the format of the wireless packet PK2 for information transmission transmitted from the sink device has the same configuration as the format of the wireless packet PK1 for data streaming transmission transmitted from the source device, except for the streaming data. ing. However, the format of the wireless packet PK2 is not limited to this, and other configurations may be used.
[Operation of the second non-transmission section of the sink device] Next, the operation of the television receiver 120 (sync device) in the second non-transmission section will be described. As described above, the time position of this second non-transmission section is the time included in the PHY header of the wireless packet PK1 for transmitting control information transmitted to the source device (disk recorder 110, set-top box 130). Indicated by location information TIM2.
In principle, the control unit 121 of the television receiver 120 controls the wireless communication unit 123 to enter the reception mode in the second non-transmission section. As a result, the television receiver 120 waits so that it can receive a wireless packet when it is transmitted from another source device different from the source device that is currently sending the wireless packet PK1 for data streaming transmission. It will be.
Further, the control unit 121 of the television receiver 120 controls as follows when it becomes necessary to transmit predetermined information to the other source devices described above. That is, in the control unit 121, the packet generation / analysis unit 124 generates a wireless packet containing predetermined information, and the wireless communication unit 123 transmits this wireless packet to another source device in the second non-transmission section. Control. In this case, the wireless communication unit 123 does not enter the reception mode even in the second non-transmission section.
The flowchart of FIG. 10 shows the control process in the second non-transmission section in the control unit 121 of the television receiver 120. The control unit 121 starts the control process in step ST11, and then moves to the process in step ST12. In this step ST12, the control unit 121 determines whether or not it is the second non-transmission section. In the second non-transmission section, the control unit 121 determines in step ST13 whether or not it is necessary to transmit data to another source device.
When there is no need to transmit data, the control unit 121 sets the wireless communication unit 123 in the reception mode in step ST14, and ends the process in step ST15. On the other hand, when it is necessary to transmit data, the control unit 121 moves to the process of step ST16. In step ST16, the control unit 121 causes the packet generation / analysis unit 124 to generate a wireless packet containing data to be transmitted to another source device. Further, in this step ST16, the control unit 121 causes the wireless communication unit 123 to transmit the wireless packet generated by the packet generation / analysis unit 124 to another source device in the second non-transmission section. After that, the control unit 121 ends the process in step ST15.
[Unencrypted or encrypted time location information] Next, the encryption of the time position information TIM1 and TIM2 stored in the PHY headers of the wireless packets PK1 and PK2 will be described.
The time position information TIM2 contained in the wireless packet PK2 transmitted from the TV receiver 120 (sink device) to the source device (disk recorder 110, set-top box 130) can be either unencrypted or encrypted. (See Figure 7).
If the time position information TIM2 is not encrypted, another source device different from the source device currently sending the wireless packet PK1 for data streaming transmission will use the time position information TIM2 indicating the second non-transmission section. Easy to get. Therefore, the other source device can transmit the wireless packet (information) to the television receiver 120 by using the second non-transmission section without performing mutual authentication operation or the like with the television receiver 120 in advance.
However, if a malicious third party sends a wireless packet with an incorrect value in the PHY header, the operation of the entire information communication system may be disrupted. In order to avoid such a situation, it is conceivable to encrypt the time position information TIM2 and transmit it. In this case, when the TV receiver 120 stores the time position information TIM2 in the PHY header of the wireless packet PK2, the mutual authentication work has already been completed with other source devices, and the minimum encryption is performed. It is assumed that the key information is shared.
When the encrypted time position information TIM2 is included in the wireless packet PK2, it is preferable to store the time position information TIM2 in another information field such as a MAC header instead of the PHY header. More preferably, as initial mutual authentication information, one domain is set for all the source devices to be connected, and a decipherable key is defined in the domain. Conceivable. In this case, an implementation form is conceivable in which the key is used to encrypt a field including the time position information TIM2, for example, a MAC header.
In the above, the time position information TIM2 included in the wireless packet PK2 transmitted from the television receiver 120 (sink device) to the source device (disk recorder 110, set-top box 130) has been described. The time position information TIM1 contained in the wireless packet PK1 transmitted from the source device (disk recorder 110, set-top box 130) to the television receiver 120 (sink device) can be either unencrypted or encrypted. (See Figure 6).
When encrypting the time position information TIM1, it is necessary to use at least a code that can be deciphered by the television receiver 120 (sink device). In this case, it is not essential that other source devices can decrypt this encryption. Source devices and other source devices, such as disk recorders 110 and set-top boxes 130, do not require direct information exchange in the first place and are not guaranteed to receive radio signals. In addition, the television receiver 120 (sink device) transmits the time position information TIM2 equivalent to the time position information TIM1 using a code that can be decrypted by another source device.
Assuming that the wireless packet PK1 from the source device can be received by another source device, as described above, one for all the wireless communication stations (information transmitting device, information receiving device) that may be connected. It is conceivable to set a domain and define a key that can be decrypted within that domain. In this case, an implementation form is conceivable in which the key is used to encrypt a field including an information element called time position information TIM1, for example, a MAC header. As a result, other source devices can also use the information from the source device transmitting the wireless packet PK1. In this case, the possibility of acquiring an incorrect value can be reduced as compared with the case of acquiring only the information from the television receiver 120 (sink device).
[Prevention of time position change in the second non-transmission section in the source device] Next, prevention of time position change in the second non-transmission section in the source device will be described. As described above, the source device (disk recorder 110 and set-top box 130) sequentially transmits the wireless packet PK1 for data streaming transmission to the television receiver 120 (sink device) with a non-transmission section in between. To do. Then, the non-transmission section of a predetermined ratio assigned to the transmission from the television receiver 120 to the source device is the first non-transmission section, and the other non-transmission sections are the second non-transmission sections (FIG. 5). reference). As described above, the radio packet PK1 contains the time position information TIM1 indicating the time position of the second non-transmission section (see FIG. 6).
The length of the wireless packet PK1 varies depending on the resolution of the image data constituting the streaming data and the like. For example, when the image data changes from HD image data to SD image data, the time length of the wireless packet PK1 becomes shorter. On the contrary, when the image data is changed from the SD image data to the HD image data, the time length of the wireless packet PK1 becomes long.
Further, the time length of the wireless packet PK1 also changes when the transmittable bit rate of the wireless communication path changes. For example, when the transmittable bit rate of the wireless communication path decreases, the time length of the wireless packet PK1 increases. On the contrary, when the transmittable bit rate of the wireless communication path increases, the time length of the wireless packet PK1 becomes shorter.
When the time length of the wireless packet PK1 changes in this way, the time position indicated by the time position information TIM1 included in the wireless packet PK1 may not correspond to the actual time position of the second non-transmission section. If the time positions do not correspond in this way, the communication between the TV receiver 120 (sink device) and other source devices based on the time position information may be disturbed by the wireless packet PK1 or the like as described above. is there.
Therefore, in the source device (disk recorder 110 and set-top box 130), the control unit (control 111, control 131) performs the following adjustment operation. That is, the control unit changes the time position of the second non-transmission section when the amount of information to be transmitted in the data streaming transmission increases or the transmittable bit rate decreases after the wireless packet PK1 is transmitted. Adjust the information included in the wireless packet PK1 so that it does not. In this case, transmission of information parts that are not sensitive to changes in transmission delay, such as thinning out less important transmission bits or an instruction for requesting quality information, is postponed.
On the contrary, the control unit makes the following adjustments when the amount of information to be transmitted in the data streaming transmission decreases or the transmittable bit rate increases after the wireless packet PK1 is transmitted. That is, the control unit at least adjusts the information included in the wireless packet PK1 or adjusts the transmission timing of the wireless packet PK1 so that the time position of the second non-transmission section does not change. In this case, for example, the redundancy of the transmission bit is increased, or the information portion that is not sensitive to the change in the transmission delay that was being sent in the next wireless packet is included in the current wireless packet. Further, for example, even if the time length of the wireless packet PK1 is shortened, the transmission timing is prevented from changing.
Due to the adjustment operation of the control unit of the source device described above, the amount of information to be sent in the data streaming transmission increases or the bit rate that can be transmitted decreases, or the amount of information to be sent in the data streaming transmission decreases. Alternatively, the time position of the second non-transmission section is prevented from changing even when the transmittable bit rate increases. Therefore, it is possible to prevent the transmission / reception of information between the television receiver 120 (sink device) and other source devices from being hindered by the transmission of the wireless packet PK1.
[Example of exchanging wireless packets between a sink device and another source device] Next, using FIG. 11, an example of performing packet switching between the television receiver 120 (sync device) and another source device using the second non-transmission section described above will be described. This example assumes that the disk recorder 110 is transmitting the wireless packet PK1 for data streaming transmission and the television receiver 120 is transmitting the wireless packet PK2 for control information transmission in the first non-transmission section. .. Then, in this example, the set-top box 130, which is another source device, specifies the television receiver 120 to use itself as an information source for data streaming transmission.
FIG. 11 (a) shows a radio packet transmitted from the disc recorder 110. Further, FIG. 11B shows a wireless packet transmitted from the television receiver 120. Further, FIG. 11 (c) shows a radio packet transmitted from the set-top box 130. In FIGS. 11 (a) to 11 (c), "1" is a wireless packet addressed to the disc recorder 110, "2" is a wireless packet addressed to the television receiver 120, and "3" is a set. Shows a radio packet destined for the top box 130.
For example, the set-top box 130 recognizes the time position of the second non-transmission section based on the time position information TIM2 stored in the wireless packet PK2 transmitted from the television receiver 120 to the disk recorder 110, and the wireless packet. Determine the transmission timing of. Then, the set-top box 130 transmits the radio packet including the connection request and the authentication information to the television receiver 120 in the second non-transmission section.
The television receiver 120, which is in receive mode in the second non-transmission section, receives the radio packet sent from the set-top box 130. Then, the television receiver 120 performs mutual authentication processing and determines connection permission based on the connection request and authentication information extracted from the wireless packet.
When the mutual authentication process with the set-top box 130 is completed and the connection permission is given, the television receiver 120 sets the radio packet containing the authentication completion and connection permission information in the second non-transmission section. Send to box 130. Here, the set-top box 130 is placed in the receive mode in the second non-transmission section when the radio packet is not transmitted. In this case, the wireless communication unit 137 is controlled to be in the reception mode by the control of the control unit 131. Therefore, the set-top box 130 can receive the radio packet sent from the television receiver 120 in the second non-transmission section as described above.
After that, the set-top box 130 transmits a radio packet including a stream information source switching instruction (notification) to the television receiver 120 in the second non-transmission section. The television receiver 120, which is in receive mode in the second non-transmission section, receives this radio packet. Then, since the radio packet received from the set-top box 130 includes the stream information source switching instruction, the television receiver 120 generates a radio packet including the stream transmission stop instruction (interruption request), and this radio The packet is transmitted to the disk recorder 110 in the first non-transmission section.
The disk recorder 110 generates a wireless packet including a stream transmission stop instruction acceptance response in response to a wireless packet including a stream transmission stop instruction (interruption request) sent from the television receiver 120, and televisions this wireless packet. Send to receiver 120. As a result, the process of interrupting the data streaming transmission between the disc recorder 110 and the television receiver 120 is completed.
After the above-mentioned interruption processing is completed, the television receiver 120 generates a wireless packet including a stream transmission start instruction (start permission notification) and transmits the radio packet to the set-top box 130. The set-top box 130 that has received this radio packet contains an instruction to start stream transmission, so it generates a radio packet for data streaming transmission (see FIG. 6) and transmits it to the television receiver 120. .. As a result, data streaming transmission from the set-top box 130 to the television receiver 120 is started.
In FIG. 11, it is written that mutual authentication and the like are completed in one packet. However, in reality, it may be necessary to exchange a plurality of packets. Further, in order to confirm that there is no discrepancy in the contents of the transmitted information, ACK may be further exchanged.
Next, using FIG. 12, another example of packet switching between the television receiver 120 (sinking device) and another source device using the second non-transmission section described above will be described. This example assumes that the disk recorder 110 is transmitting the wireless packet PK1 for data streaming transmission and the television receiver 120 is transmitting the wireless packet PK2 for control information transmission in the first non-transmission section. .. Then, this example is an example in which the control information of the device is transmitted from the television receiver 120 to the set-top box 130 which is another source device.
Here, for the control information of the device, for example, the TV receiver 120 specifies the channel of a specific program to the set-top box 130, and the image and audio data of that channel are stored in the built-in recording unit (FIG. 4). (Not shown in) is the control information for recording.
FIG. 12 (a) shows a radio packet transmitted from the disc recorder 110. Further, FIG. 12B shows a wireless packet transmitted from the television receiver 120. Further, FIG. 12 (c) shows a radio packet transmitted from the set-top box 130. In FIGS. 12 (a) to 12 (c), "1" is a wireless packet addressed to the disc recorder 110, "2" is a wireless packet addressed to the television receiver 120, and "3" is a set. Shows a radio packet destined for the top box 130.
When it becomes necessary to transmit the device control information to the set-top box 130, the television receiver 120 transmits a radio packet including the connection request and the authentication information to the set-top box 130 in the second non-transmission section. The television receiver 120 knows the time position of the second non-transmission section.
The set-top box 130, which is in the receive mode in the second non-transmission section, receives the radio packet sent from the television receiver 120. Then, the set-top box 130 performs mutual authentication processing and determines connection permission based on the connection request and authentication information extracted from the wireless packet.
When the mutual authentication process with the TV receiver 120 is completed and the connection permission is given, the set-top box 130 receives the radio packet containing the authentication completion and connection permission information on the TV in the second non-transmission section. Send to machine 120. The television receiver 120, which is in receive mode in the second non-transmission section, receives the radio packet sent from the set-top box 130.
After that, the television receiver 120 generates a wireless packet including device control instruction information, and transmits this wireless packet to the set-top box 130 in the second non-transmission section. The set-top box 130 in the reception mode in the second non-transmission section receives this radio packet, acquires the device control instruction information, and performs an operation based on the instruction information. When the set-top box 130 acquires the device control instruction information, the set-top box 130 generates a wireless packet including the device control instruction receipt confirmation notification, and transmits this wireless packet to the television receiver 120.
In FIG. 12, it is written that mutual authentication and the like are completed in one packet. However, in reality, it may be necessary to exchange a plurality of packets. Furthermore, in order to confirm that there is no discrepancy in the contents of the transmitted information, ACK may be further exchanged.
[Random backoff] Next, a random backoff for preventing a collision between a wireless packet from the television receiver 120 (sink device) and a wireless packet from another source device will be described. In FIGS. 11 and 12, it is as if the television receiver 120 and the set-top box 130 suddenly and completely use the second non-transmission section that is not assigned to transmit from the television receiver 120 to the disc recorder 110. It is drawn in. However, FIGS. 11 and 12 show only an example.
For example, the television receiver 120 may need to transmit information to the set-top box 130 and the set-top box 130 may need to transmit information to the television receiver 120 at approximately the same time. Furthermore, there is a possibility that a source device other than the disc recorder 110 and the set-top box 130 exists, and this other source device needs to transmit information to the television receiver 120. is there. When the need for information transmission arises without thinking, if the closest second non-transmission section is used, wireless packets may collide and information transmission may eventually fail.
At this time, since ACK is not returned from the receiving side, the transmitting side tries to retransmit, but it also collides and the information transmission continues to fail with each other. In order to avoid such a situation, in the wireless communication device (sink device, source device) that tries to communicate using the second non-transmission section, a configuration in which the transmission timing is determined by using a random backoff is configured. Applicable. An implementation example of the random backoff itself is also known in IEEE802.11 and the like, so detailed description thereof will be omitted here.
For example, the number of second transmission sections can be used as the unit of the backoff counter. Further, for example, the time position indicated by the time position information TIM1 and TIM2 included in the wireless packets PK1 and PK2 may be used as the starting point, and a specific time step width may be used as the unit of the backoff counter. .. In this case, backoff control can be performed in finer time units as compared with the case where the number of second non-transmission sections is used as the unit of the backoff counter, so that wireless resources can be effectively used.
In the information communication system 100 shown in FIG. 1, there is a second non-transmission section that is not assigned to transmission from the sink device (television receiver 120) to the source device (disk recorder 110, set-top box 130). Further, the wireless packet PK2 transmitted from the sink device to the source device stores the time position information TIM2 indicating the time position of the second non-transmission section. Therefore, the sink device transmits / receives information to / from a source device different from the source device that transmits the wireless packet PK1 for data streaming transmission by using the second non-transmission section. Is possible.
That is, while performing data streaming transmission from the source device to the sink device, communication between the sink device and another source device becomes possible, and the convenience of the user is improved. For example, when control information for switching data streaming transmission is transmitted from another source device to the sink device, the user does not have to be aware of switching the information source of the streaming transmission in the sink device, and the streaming transmission is performed. Switching is possible.
Further, in the information communication system 100 shown in FIG. 1, at least the sink device and other source devices are provided with the time position information TIM2 indicating the second non-transmission section included in the wireless packet PK2 from the sink device to the source device. Cryptanalytic encryption can be applied to and from. This makes it possible to increase the resistance to attacks from malicious wireless communication devices.
Further, in the information communication system 100 shown in FIG. 1, communication is performed between the sink device and another source device in the second non-transmission section that is not assigned to the transmission from the sink device to the source device. When transmitting a wireless packet from a sink device to another source device, or when transmitting a wireless packet from another source device to a sink device, the transmission timing can be determined using random backoff. This makes it possible to reduce the collision probability of wireless packets.
<2. Modification example> In the above-described embodiment, the source device (information transmitting device) is the disk recorder 110 and the set-top box 130, and the sink device (information receiving device) is the television receiver 120. It goes without saying that the present invention can be similarly applied to an information communication system in which a source device and a sink device are a combination of other devices.
The present invention can be applied to an information communication system in which wireless packets for data streaming transmission are sequentially transmitted from a source device to a sink device.
<figref num="1">It is a block diagram which shows the configuration example of the information communication system as an embodiment.</figref><figref num="2">It is a block diagram which shows the configuration example of the disc recorder as a source device (information transmission device) which constitutes an information communication system.</figref><figref num="3">It is a block diagram which shows the configuration example of the television receiver as a sink device (information receiver) which constitutes an information communication system.</figref><figref num="4">It is a block diagram which shows the configuration example of the set-top box as a source device (information transmission device) which constitutes an information communication system.</figref><figref num="5">It is a figure which shows the wireless packet for data streaming transmission from a transmitting device to a receiving device, and the wireless packet for controlling control information transmission from a receiving device to a transmitting device at the time of data streaming transmission.</figref><figref num="6">It is a figure which shows the configuration example of the wireless packet PK1 for data streaming transmission transmitted from a source device to a sink device.</figref><figref num="7">It is a figure which shows the configuration example of the wireless packet PK2 for transmission of control information transmitted from a sink device to a source device.</figref><figref num="8">It is a flowchart which shows the control process every time the wireless packet PK1 is received in the control part of a sink device (television receiver).</figref><figref num="9">It is a figure for demonstrating how to obtain the time indicated by the time position information TIM2 included in the radio packet PK2 for transmitting control information from a receiving device to a transmitting device.</figref><figref num="10">It is a flowchart which shows the control process in the 2nd non-transmission section in the control part of a television receiver.</figref><figref num="11">It is a figure which shows an example of performing a packet exchange between a television receiver (sink device) and another source device using a second non-transmission section.</figref><figref num="12">It is a figure which shows another example of packet switching using the second non-transmission section between a television receiver (sink device) and another source device.</figref><figref num="13">It is a block diagram which shows the configuration example of the conventional information communication system.</figref><figref num="14">It is a figure which shows the wireless packet for data streaming transmission from a transmitting device to a receiving device, and the wireless packet for controlling control information transmission from a receiving device to a transmitting device at the time of data streaming transmission.</figref>
Code description
100 Information communication system, 110 Disc recorder, 111 Control unit, 112 User operation unit, 113 Display unit, 114 Disk drive, 115 Codec 116 Terminal, 117 Packet generation / analysis unit, 118 Wireless communication unit, 120 TV receiver, 121 Control unit, 122 User operation unit, 123 Wireless communication unit, 124 Packet generation / analysis unit, 125 Switch, 126 Tuner, 127 Antenna terminal, 128 Display processing unit, 129 Display panel, 130 Set-top box, 131 Control unit, 132 User operation unit, 133 Display unit, 134 Tuner, 135 Antenna terminal, 136 Packet generation Analysis unit, 137 ... Wireless communication unit
14 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11 Sheet 12 Sheet 13 Sheet 14
Every citation, both ways
| Document | Relation | Office |
|---|---|---|
| JP2008072736A | Cites | Japan |
| JP11074886A | Cites | Japan |
| JP2005244819A | Cites | Japan |
| JP2008172763A | Cites | Japan |
| JP2008092546A | Cites | Japan |
17 members in 8 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 2008264837 | Japan | A | |
| JP20080264837 | – | – | – |
Members17
| Document | Office | Kind | |
|---|---|---|---|
| WO2010044328A1 | World Intellectual Property Organization (WIPO) | A1 | |
| JP2010098344A | Japan | A | |
| US2010254368A1 | United States of America | A1 | |
| CN101884218A | China | A | |
| EP2337350A1 | European Patent Office (EPO) | A1 | |
| KR20110070837A | Republic of Korea | A | |
| RU2010123088A | Russian Federation | A | |
| JP5077181B2This record | Japan | B2 | |
| CN101884218B | China | B | |
| CN102883211A | China | A | |
| US8467332B2 | United States of America | B2 | |
| RU2528008C2 | Russian Federation | C2 | |
| EP2337350A4 | European Patent Office (EPO) | A4 | |
| CN102883211B | China | B | |
| BRPI0906073A2 | Brazil | A2 | |
| KR101622411B1 | Republic of Korea | B1 | |
| EP2337350B1 | European Patent Office (EPO) | B1 |
14 legal events, as the office reported them to INPADOC
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Numbers
- Publication
- 5077181
- Publication, DOCDB
- 5077181
- Publication, EPODOC
- JP5077181B
- Application
- 264837
- Application, DOCDB
- 2008264837
- Application, EPODOC
- JP20080264837
Titles2
- Japanese
- 情報受信装置、情報送信装置および情報通信システム
- English
- Information receiving device, information transmitting device and information communication system
Classification
- CPC, 9
- H04N21/43637
- H04N7/173
- H04L63/0869
- H04N21/4325
- H04N21/43615
- H04N21/43622
- H04N21/4122
- H04W88/08
- H04W72/0446
- IPC, 6
- H04N7 173
- H04L47 2416
- H04N21 436
- H04N21 442
- H04W84 10
- H04W92 08
