JP6569759B1 - Stream delivery system and stream delivery method - Google Patents

Abstract

A trigger for starting unicast distribution is issued from an existing receiving terminal without using an STB incorporating a dedicated function or a special television receiver. A stream distribution system transmits a stream request to a communication network based on a stream unicast distribution request from a television receiver 300, and converts the stream received via the communication network into an RF signal. An IP / RF conversion unit 200 and a transmission device 100 that transmits a requested stream to the IP / RF conversion unit 200 via a communication network are provided. The television receiver 300 displays the stream selection screen based on the BML content including the information on the stream selection screen and the information for generating the stream unicast distribution request, and the stream selected on the stream selection screen The unicast distribution request is generated to the IP / RF conversion unit 200. [Selection] Figure 1

Description

  The present invention relates to a stream distribution system and a stream distribution method for distributing stream data such as video and audio.

  The present applicant has developed an IP / RF conversion unit (NBC9000) that receives stream data such as a TS stream transmitted (IP transmission) via a communication network such as the Internet, and modulates and outputs the stream data. And are sold (Non-Patent Document 1).

  Conventionally, it has been common to use a video line terminal unit (VONU) to distribute digital broadcasts over an optical line. This IP / RF conversion unit is a TS (transport stream) distributed by IP transmission. The packet can be modulated by orthogonal frequency division multiplexing (OFDM) using the ISDB-T method, mixed with an existing RF signal in the house, and displayed on a television receiver. Thus, for example, by using an empty channel for terrestrial digital broadcasting, it is possible to select a received stream with the remote control of the television receiver in the same manner as other broadcast programs without using the STB dedicated remote control. become.

  By using such an IP / RF conversion unit, it becomes like a so-called community channel by IP transmission using a communication network such as a next generation network (NGN) instead of a cable which is a transmission path of cable television (CATV). Can be distributed as stream data. The community channel is generally an independent (original) broadcast that includes local information, local events, local sports special numbers, and personal introductions of people who are active in the area.

Development of ultra-compact IP modulator -New transmission of community channel by optical collaboration-: http: // www. hirotech. com / wp / wp-content / uploads / 2016/07 / 4640f9c49ed96af229789c10adba43801. pdf

  In the stream distribution by the IP / RF conversion unit as described above, by using multicast, the distribution server that distributes the stream does not depend on the number of receiving terminals and only transmits one stream (packet stream). Therefore, there is an advantage that the transmission load is reduced.

  However, multicast distribution falls under “broadcasting” and has a problem of being restricted by the broadcasting law. In other words, in multicast distribution, priority control of communication lines is required, and there are problems such as cost and inability to be handled by a communication carrier, which may be difficult to realize.

  On the other hand, unicast distribution is preferable because it is not limited by the broadcasting law if it is used in an environment or environment where the transmission load of the distribution server does not become a problem because the stream is transmitted from the distribution server to each receiving terminal. I can say that. However, in unicast delivery, it is necessary to generate a trigger for requesting (requesting) unicast delivery of a stream from each receiving terminal to the delivery server.

  In conventional unicast distribution of streams, it is necessary to prepare a set-top box (STB) incorporating a dedicated function for generating such a trigger and a television receiver incorporating the function.

  The present invention has been made in such a background, and its purpose is to trigger the start of unicast distribution from an existing receiving terminal without using an STB or a special television receiver incorporating a dedicated function. Is to provide a stream distribution system and a stream distribution method.

  A stream distribution system according to the present invention is a stream distribution system that performs unicast distribution of a stream via a communication network, and includes an IP / RF conversion unit and a transmission device. The IP / RF conversion unit transmits a stream request to the communication network based on a stream unicast distribution request from the television receiver, and converts the stream received via the communication network into an RF signal. The sending device sends a stream requested from the IP / RF conversion unit to the IP / RF conversion unit via a communication network. The television receiver displays the stream selection screen based on the BML content including the information on the stream selection screen and the information for generating the stream unicast distribution request, and the stream selected on the stream selection screen The unicast distribution request is generated to the IP / RF conversion unit.

  The stream is, for example, a TS stream including at least video data.

  As an aspect, the BML content is provided from the IP / RF conversion unit to the television receiver by data broadcasting.

  The television receiver periodically outputs a predetermined message to the IP / RF conversion unit during reception of the stream, and the IP / RF conversion unit receives the predetermined message from the television receiver. When the reception of the predetermined message is interrupted for a predetermined time, it is determined that the reproduction of the stream by the television reception is stopped, and the output of the RF signal of the stream can be stopped.

As one aspect thereof, the IP / RF conversion unit periodically outputs a predetermined message to the transmission device during the output of the RF signal, and the transmission device transmits the predetermined message from the IP / RF conversion unit. When a message is received and reception of the predetermined message is interrupted for a predetermined time, it is determined that the operation of the IP / RF conversion unit has stopped, and the unicast delivery of the stream can be stopped.

A stream distribution method according to the present invention is a stream distribution method for performing unicast distribution of a stream via an IP / RF conversion unit via a communication network,
An IP / RF conversion unit sending BML content for displaying a stream selection screen as a data broadcast to a television receiver;
The television receiver displaying a stream selection screen based on the received BML content;
The television receiver requesting the IP / RF conversion unit for unicast distribution of a stream selected based on a user instruction on the stream selection screen;
The IP / RF conversion unit requesting a sending device for unicast delivery of the requested stream;
The sending device sending the requested stream as IP data to the IP / RF conversion unit;
The IP / RF conversion unit converting the received IP data into an RF signal;
The television receiver includes a step of receiving the RF signal and reproducing a stream.

  In this configuration, the BML server may further include a step of sending the BML content to the IP / RF conversion unit via a communication network.

  The television receiver periodically outputs a predetermined message to the IP / RF conversion unit during reception of the stream; and the IP / RF conversion unit outputs the predetermined message from the television receiver. And receiving the predetermined message for a predetermined period of time, determining that the reproduction of the stream by the television reception has been stopped, and further stopping the output of the RF signal of the stream. Good.

In this stream delivery method, the IP / RF conversion unit periodically outputs a predetermined message to the sending device during the output of the RF signal, and the sending device sends the message from the IP / RF converting unit. Receiving the predetermined message, determining that the operation of the IP / RF conversion unit has stopped when reception of the predetermined message is interrupted for a predetermined time, and stopping unicast delivery of the stream; Further, it may be provided.

  According to the present invention, it is possible to generate a trigger for starting unicast distribution from an existing receiving terminal without using an STB incorporating a dedicated function or a special television receiver. Therefore, it is possible to operate only with the remote control of the television receiver.

  Further, since a stream can be selected by a trigger from the receiving terminal side, one of a plurality of streams can be selected on the same channel.

  Further, by using a notification during reception that occurs periodically, it is possible to grasp the viewing state from the user, stop the unicast when the viewing ends, and effectively use the network line bandwidth.

It is a figure for demonstrating the outline | summary of the stream delivery system by embodiment of this invention. It is a block diagram which shows the more specific system configuration example of the stream delivery system which concerns on embodiment of this invention. It is a flowchart for demonstrating the example of a screen transition regarding viewing / listening of the stream (program or content) with the television receiver in the stream delivery system which concerns on embodiment of this invention. It is a figure which shows the screen example (display example) of the stream selection screen of the television receiver in the stream delivery system which concerns on embodiment of this invention. It is a flowchart which shows the schematic flow of an example of the internal process in the top screen of the receiving terminal which concerns on embodiment of this invention. FIG. 5 is a sequence diagram illustrating an outline exchange between each unit at the start of viewing in the stream distribution system according to the embodiment of the present invention. It is the sequence diagram which illustrated the rough exchange between each part in view (during stream reception) in the stream delivery system which concerns on embodiment of this invention. It is the sequence diagram which illustrated the detailed exchange between each part at the time of the viewing-and-listening start by the stream delivery system which concerns on embodiment of this invention. It is the sequence diagram which illustrated the rough exchange between each part at the time of the end of viewing at the time of channel switching etc. (including power OFF) in the television receiver in the stream distribution system according to the embodiment of the present invention. It is the sequence diagram which illustrated the rough exchange between each part at the time of the end of viewing by the operation | movement stop of the IP / RF conversion unit in the stream delivery system which concerns on embodiment of this invention. It is a sequence diagram regarding processing when an error occurs on the top screen in the television receiver in the stream distribution system according to the embodiment of the present invention. It is a sequence diagram regarding the process at the time of the request error in the stream delivery system which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The outline of the stream distribution system according to the present embodiment will be described with reference to FIG.

  This system is a stream distribution system that performs unicast distribution of a stream via a communication network, and generally includes a transmission device 100, an IP / RF conversion unit 200, and a television receiver 300 that is a reception terminal. Is done.

  The IP / RF conversion unit 200 transmits a request for the stream to the communication network based on the stream unicast distribution request from the television receiver 300, and converts the stream received via the communication network into an RF signal. Have As the IP / RF conversion unit 200, for example, a product (NBC9000) according to the present applicant can be used.

  The sending device 100 is a device that sends a stream requested from the IP / RF conversion unit 200 to the IP / RF conversion unit 200 via a communication network, and has functions of, for example, a media server and a distribution server.

  The television receiver 300 is an existing television receiver compatible with data broadcasting, and includes BML (Broadcast Markup Language) content including information on a stream selection screen and information for generating a stream unicast distribution request (request). And a function for displaying a stream selection screen and generating a unicast distribution request for the stream selected on the stream selection screen. The “stream” in the present embodiment is an MPEG-2 TS (Transport Stream) stream including at least video data.

  The BML content is provided from the IP / RF conversion unit 200 to the television receiver 300 by data broadcasting. The BML content may be held by the IP / RF conversion unit 200 itself, or may be received from an external device such as a BML server via a communication network.

  The schematic system operation of the stream distribution system will be described with reference to FIG. The circled numbers in the figure indicate the order of operations.

  This system assumes viewing of a real-time program. For example, the CATV community channel is constantly distributed on the transmission device 100 side, and when the user mainly views the community channel, the user feels complicated if the channel is selected every time it is viewed. Therefore, once selected, the community channel that was viewed last time is received, and when another broadcast is to be received thereafter, it is selected by data broadcasting of the D button. That is, the stream selected last is received again. However, instead of this, it is also possible to select a fixed stream each time as a favorite or the like.

  The IP / RF conversion unit 200 outputs the data broadcast and displays the stream selection screen 320 (1). The user uses the remote control 321 attached to the television receiver 300 to select a program (TS stream) that the user wants to watch (2). When any one TS stream is selected, the television receiver 300 transmits a TS stream request to the IP / RF conversion unit using the POST function of data broadcasting (3).

  When receiving the request from the television receiver 300, the IP / RF conversion unit 200 requests (requests) the TS stream from the transmission apparatus 100 (4). In response to the request, the sending device 100 starts sending a TS stream to the IP / RF conversion unit 200 (5). The IP / RF conversion unit 200 modulates the received TS stream and outputs it to the television receiver 300 (6). As a result, the video 329 of the TS stream is displayed on the screen of the television receiver 300.

  When changing the TS stream, a stream selection screen is displayed with the D button of the remote controller 321, another TS stream is selected, and a distribution request is issued to the sending apparatus 100 via the IP / RF conversion unit 200. If there is a previous TS stream reception history when the physical channel of the television receiver 300 is changed, the TS stream received previously may be received by default for the convenience of the viewer.

  FIG. 2 shows a more specific system configuration example of the stream distribution system in the present embodiment.

  As described above, the sending device 100 sends a stream IP packet by unicast in response to a request from the IP / RF conversion unit 200. More specifically, one or more TS streams are IP output by the TSoverIP function. Although only one sending device 100 is basically required, this configuration example shows a case where a plurality of sending devices 100 described above are provided. As a result, the number of programs that can be distributed simultaneously can be increased.

  Further, in this system configuration, one BML server 110 is juxtaposed with the sending apparatus 100. This BML server 110 is also connected to the communication network 150. The BML server 110 is a server that generates BML contents for data broadcasting used to select a TS stream received by the IP / RF conversion unit 200. This BML content is provided to the television receiver 300 via the IP / RF conversion unit 200.

  The sending apparatus 100 may be operated in the same casing as the BML server 110 depending on the configuration. At least one receiving terminal is installed in the home (or in the facility) of the user to whom the stream is distributed.

  The example of FIG. 2 shows a case where a plurality of television receivers 300 having at least a digital terrestrial broadcast reception function are provided. At least one of them is compatible with data broadcasting and IP connection, and is connected to the IP / RF conversion unit 200 via a communication path (for example, LAN). For example, it is connected to a network via an RJ-45 terminal and can communicate with an IP / RF conversion unit by TCP / IP.

  In this example, the router 210, the IP / RF conversion unit 200, and at least one television receiver 300 are connected to each other by a switch (network switch) 230.

  The router 210 is connected to a communication network 150 such as the Internet or NGN.

  As described above, the IP / RF conversion unit 200 transmits the unicast distribution request of the stream to the transmission device 100 of the communication network based on the unicast distribution request of the stream from the television receiver 300, and the communication network. It has a function of converting a stream received via it into an RF signal. More specifically, the TS packet received by IP communication is OFDM-converted and output as RF. As a result, a plurality of programs can be selectively viewed on each channel with a limited RF output (for example, a maximum of 3 ch).

  The RF output of the IP / RF conversion unit 200 is connected to a plurality of television receivers 300 by a distributor 310. Therefore, one of the plurality of television receivers 300 can view a program selected by another television receiver 300 without having a network connection function.

  The IP / RF conversion unit 200 also has a data broadcasting (BML content) transmission function. Here, the BML content is acquired (and stored) from the BML server 110, but may be generated by the IP / RF conversion unit 200 itself as described above.

  The router 210 and the switch 230 are general network devices for use in IP communication in the system, and their functions are known and will not be described in detail. The installation position of the IP / RF conversion unit 200 is not limited to the position shown in the figure, and may be located outside the router 210, for example.

  Here, the transition of the screen of the television receiver 300 according to the present embodiment, particularly the screen related to data broadcasting, will be described.

As screens related to data broadcasting, there are the following screens, and the screen changes according to the user's operation and situation.
(1) Top screen: A screen that is displayed first when a physical channel output by the IP / RF conversion unit is selected. The video displayed on the top screen may be a default video held in the IP / RF conversion unit 200, or may be the video if the TS stream is already being received by unicast. For example, the content stored in the nonvolatile memory of the television receiver 300 can be confirmed on a black screen, and the transition screen can be changed depending on the presence / absence of a TS stream selection history.
(2) Stream selection screen: A screen for selecting a TS stream received by the television receiver 300 by a user input operation.
(3) Viewing screen: Screen during viewing (stream reception) Screen for displaying video (moving image) on the entire screen, and a viewing message is transmitted to the IP / RF conversion unit 200 on the back side.

  With reference to FIG. 3, an example of screen transition related to viewing of a TS stream (program or content) on the television receiver 300 in this system will be described.

  Viewing starts from displaying the top screen based on the data broadcast. As described above, the BML content of the data broadcast is acquired from the distribution server or held in the IP / RF conversion unit 200 in a fixed manner.

  If there is no reception history on the top screen and (and) no reception at another receiving terminal, the process proceeds to the “stream selection screen”. When there is a reception history or when another receiving terminal is receiving, the process proceeds to the “viewing screen”.

  The determination of whether or not “there is a reception history” is that the television receiver 300 automatically shifts to viewing of the TS stream when it is stored that a certain TS stream has been received in the past. It is intended. Thereby, a new stream selection operation by the user can be omitted.

  Also, whether or not “there is reception at another receiving terminal” is determined when there is another receiving terminal receiving the same RF signal from the same distributor 310 (FIG. 2). If a stream is being received, it is intended to shift to viewing the TS stream. Also in this case, the user's new stream selection operation can be omitted.

  Of course, it is possible to always shift to the stream selection screen and allow the user to select a TS stream without automatically selecting such a TS stream.

  When a stream selection operation is performed by a user's remote control operation on the stream selection screen, a distribution request is sent from the television receiver 300 to the transmission apparatus 100 (distribution server) via the IP / RF conversion unit 200 based on the BML content. And the sending apparatus 100 starts unicast delivery of the TS stream. As a result, when the stream reception is successful, the process proceeds to a “viewing screen” for displaying the stream on the full screen. At this time, the reception history data is updated in the television receiver 300.

  During viewing, a notification of reception (that is, a viewing message or a predetermined message) is periodically transmitted from the television receiver 300 to the IP / RF conversion unit 200. This “notifying in reception” includes identification information of the television receiver 300. The IP / RF conversion unit 200 manages (stores) which television receiver 300 is receiving which TS stream.

  When the reception notification is not transmitted for a certain period due to channel switching or power-off of the television receiver 300, the IP / RF conversion unit 200 transmits a stop request to the transmission device 100 (distribution server) to stop the TS stream distribution. In this way, it is possible to grasp the viewing state from the user, stop the unicast distribution when the viewing ends, and effectively use the network line bandwidth.

  Similarly, a receiving notification (that is, a viewing message) is transmitted from the IP / RF conversion unit 200 to the sending device 100 (distribution server). This viewing message includes identification information of the TS stream being received and identification information of the IP / RF conversion unit.

  Even when the sending device 100 (distribution server) cannot receive the reception notification from the IP / RF conversion unit 200 for a certain period due to power-off of the IP / RF conversion unit 200, the TS stream distribution is similarly stopped.

  These notifications during reception are used to determine the end of viewing on the television receiver 300.

  As another viewing end method, there may be a method of transmitting a “viewing end message” at the time of channel change, instead of periodically sending a reception notification. In this case, the end of viewing cannot be detected in the case of sudden end of viewing (for example, the television is unplugged), but the television receiver 300 does not have to execute the periodic receiving notification process.

  When a predetermined operation of the remote control (for example, pressing the D button) is performed on the viewing screen, the screen returns to the stream selection screen.

  FIG. 4 shows a screen example (display example) of the stream selection screen of the television receiver 300 in the stream distribution system according to the present embodiment.

  The screen 320 is provided with a program image display area 328 for displaying program text, still images, and moving images in the main part on the left side. On the right side of the program image display area 328, an operation guidance section for the user to select a TS stream is displayed.

  The operation guidance unit includes selected stream identification information 324, operation direction instruction displays 322 and 323, and a message box 325. Although the operation direction instruction displays 322 and 323 show examples corresponding to the up and down keys of the remote controller cross key, they may correspond to the left and right keys. In order to confirm the selection with the direction key, a determination button or the like of the remote controller 321 can be used. The message box 325 displays operation guidance for the user, a message when processing NG occurs, and the like.

  Further, four instruction displays 327 corresponding to the color buttons on the remote controller are arranged at the bottom of the screen 320. In this example, a selection candidate TS stream is assigned to four color buttons. Of course, other functions such as a program guide and a recording reservation may be assigned to the four instruction displays 327.

  FIG. 5 shows a schematic flow of an example of internal processing on the top screen of the receiving terminal. Here, “internal processing” refers to execution processing of a script (computer program) given by BML content in a data broadcast processing unit (not shown) in the receiving terminal. The receiving terminal includes a recording device in addition to the television receiver.

  First, the receiving terminal determines whether or not it is a recording device compatible with data broadcasting (S1). This determination can be made based on own internal information. If it is a “recording device compatible with data broadcasting”, the process proceeds to the viewing screen (S9). Otherwise, the process proceeds to the B-CAS check (S2).

  When recording a TS stream that is being received by the recording device, the system automatically starts receiving after setting the recording, so no user operation is required. For this reason, the screen is changed to a viewing screen.

  In the B-CAS check in step S2, it is checked whether or not a B-CAS card has been inserted. When the B-CAS card is not inserted and the D button is pressed, a message indicating that the B-CAS is not inserted is displayed (S2N). When the B-CAS card has been inserted, the process proceeds to a LAN connection check (S3). When the receiving terminal is not connected to the LAN, a message indicating that the LAN is not connected is displayed (S3N), and the screen is shifted to the viewing screen (S9).

  When the LAN connection is established, the process proceeds to event message acquisition (S4). Wait until the event message is obtained. Event messages are a function of data broadcasting. In the present embodiment, as the data broadcast data transmitted from the IP / RF conversion unit 200, the BML content of the stream selection screen and the access method to the IP / RF conversion unit are described (the “event message (IP / RF conversion unit URL, stream ID) ”). The former BML content is used in common even in another user's house in the system and becomes relatively large data. On the other hand, the latter changes according to the user's network environment and contract contents, and is relatively small data. At the time of system operation, only event messages that are small data are changed so that each user's environment can be handled. For example, the URL (IP address) for accessing the IP / RF conversion unit 200 needs to correspond according to the user environment (difference between fixed IP, DHCP, etc.). The IP / RF conversion unit URL, stream ID, etc. are distributed to each user by an event message. The event message is transmitted by data broadcasting via RF. Therefore, when there are a plurality of television receivers 300 for the same user, they are simultaneously distributed to all the television receivers 300. The stream ID included in the event message is the stream ID of all the programs to be distributed, and is a stream (program) option.

  Event messages are usually distributed only when an event occurs, but they can also be transmitted periodically, so this system periodically distributes event messages. The term “periodic” assumes a predetermined time interval (for example, 100 milliseconds, 1 second, 10 seconds, 60 seconds, etc.).

  When receiving the event message, the television receiver 300 checks the stream (stream ID) being received by the IP / RF conversion unit 200 (S5).

  Thereafter, in the case of “received at other terminal” (S6), a message to that effect is displayed (S6N), and the screen is shifted to the viewing screen (S9).

  In the case of “no reception at other terminal” (S6), if “there is a reception history at its own terminal”, a message to that effect is displayed (S7N), and a transition is made to the viewing screen (S9). If “no reception history at own terminal”, the process proceeds to the stream selection screen (S8).

  FIG. 6 is a sequence diagram showing a schematic exchange between the respective units at the start of viewing of the television receiver 300 in this system.

  First, the viewer selects a data broadcast using the remote controller 321 with respect to the television receiver 300 (S11). Thereby, a stream selection screen based on the data broadcast is displayed on the television receiver 300, and the viewer selects a desired stream using the remote controller 321 (S12). In response to this, the television receiver 300 issues a distribution request for the stream to the IP / RF conversion unit 200 via IP (S13). Upon receiving this distribution request, the IP / RF conversion unit 200 issues a distribution request to the sending apparatus 100 via IP (S14).

  In response to this distribution request, the sending apparatus 100 unicasts the requested TS stream (TS packet) to the IP / RF conversion unit 200 via IP (S15). The IP / RF conversion unit 200 transmits the received TS stream to the television receiver 300 via RF (S16).

  FIG. 7 is a sequence diagram illustrating an example of a schematic exchange between each part during viewing (stream reception) in this system.

  The television receiver 300 periodically transmits a reception notification via IP to the IP / RF conversion unit 200 during viewing, that is, during stream reception (S23, S27). In response to this, the IP / RF conversion unit 200 transmits a receiving notification to the sending device 100 (S24, S28). The sending device 100 continuously transmits a TS stream to the IP / RF conversion unit 200 while receiving a reception notification from the IP / RF conversion unit 200 (S21, S22, S25, S26, S29, S30). , ...). As a result, the sending apparatus 100 can recognize that the TS stream is being viewed continuously.

  FIG. 8 is a sequence diagram illustrating a detailed exchange between the respective units at the start of viewing of the television receiver 300 in this system.

  First, the IP / RF conversion unit 200 transmits BML content and an event message to the television receiver 300 via RF (S31, S32). In this example, the event message includes the URL (access information) and the stream ID (stream identification information) of the IP / RF conversion unit 200. The television receiver 300 stores this event message.

  When the viewer gives an instruction to select the output channel of the IP / RF conversion unit 200 with the remote controller 321 (S33), the television receiver 300 displays a predetermined top screen (S34) and B- as described above. A CAS check (S35) and a LAN connection check (S36) are executed, and a received stream acquisition request is issued to the IP / RF conversion unit 200 via the IP (S37).

  Based on this, the IP / RF conversion unit 200 manages the receiving terminal. That is, which receiving terminal receives which TS stream is managed. The “reception stream acquisition request” is for the receiving terminal to inquire of the IP / RF conversion unit 200 whether there is a stream being received by the IP / RF conversion unit 200.

  The reception stream acquisition request from the television receiver 300 to the IP / RF conversion unit 200 includes the B-CAS card ID (B-CAS number) attached to the television receiver 300. In the present embodiment, this B-CAS card ID is stored in the IP / RF conversion unit 200 and is used for leaving a history of the connection from the television receiver 300. Basically, the B-CAS card ID is included in all data transmitted from the television receiver 300 to the IP / RF conversion unit 200.

  The IP / RF conversion unit 200 that has received the reception stream acquisition request returns a reception stream acquisition request Ack to the television receiver 300 via IP as a response thereto (S38). This response includes the identification information (ID) of the stream received by the IP / RF conversion unit 200. If there is no stream being received, the IP / RF conversion unit 200 returns that it has not been received.

  If there is no TS stream currently being received in the television receiver 300, if there is a stream selection history, the television receiver 300 displays “receiving” (for example, pop-up display) (S41), and the IP / RF conversion unit. A unicast distribution request is issued for the TS stream to the IP 200 via IP (S42).

The “unicast distribution request” transmitted from the television receiver 300 to the IP / RF conversion unit 200 includes the following information. That is, the items of the unicast distribution request and the contents of the request parameters are as follows.
B-CAS card ID: 20-digit number Access information to the sending device 100 (for example, URL for sending a distribution request to the sending device)
-Unicast stream ID (4-digit hexadecimal number: 0000 to FFFF)
・ Reception mode: 0: Viewing, 1: Recording
• Date and time when reception starts: YYYYMMDDhhmmss (year / month / day / hour / minute / second) format Immediate start if not specified, mandatory if reception mode is recording.
-Date and time when reception ends: YYYYMMDDhhmmss (year / month / day / hour / minute / second) format Indefinite viewing if not specified, mandatory if reception mode is recording.
Note that the date and time of starting reception and the date and time of ending can be input by a viewer from a dedicated screen (not shown) or acquired from a program guide.

  Next, the IP / RF conversion unit 200 issues a unicast distribution request to the sending apparatus 100 via IP (S43). The unicast distribution request includes an ID (identification information) for identifying the IP / RF conversion unit in addition to the stream ID received from the television. Thereby, the sending apparatus 100 can recognize the IP / RF conversion unit 200.

  In response to the received unicast distribution request, the sending apparatus 100 returns a unicast distribution request Ack to the IP / RF conversion unit 200 via IP (S44), and starts transmission of the TS packet of the TS stream. (S45). Thereby, TS packets are continuously transmitted from the transmission device 100 to the IP / RF conversion unit 200 (S46).

  The IP / RF conversion unit 200 also returns a unicast distribution request Ack to the television receiver 300 (S47).

  The TS packet from the transmission device 100 is converted into an RF output by the IP / RF conversion unit 200 and supplied to the television receiver 300. Thereby, the television receiver 300 performs viewing screen display (S48).

  While receiving the TS stream, the television receiver 300 periodically transmits the above-described reception notification (viewing message) to the IP / RF conversion unit 200 via the IP (at a first fixed time interval) (S49). , S50, S52, S53). Further, the IP / RF conversion unit 200 periodically transmits a notification during reception to the transmission device 100 via the IP (at a second fixed time interval) (S51, S54). The second fixed time interval may be longer than the first fixed time interval. Such a condition is not essential, but when a large number of IP / RF conversion units 200 are arranged on the network, the number of messages transmitted from the IP / RF conversion unit 200 to the sending apparatus 100 also increases. Therefore, in order to suppress the access load on the sending device 100, it is preferable that the generation interval is set to a certain length of time. On the other hand, since the number of television receivers 300 is assumed to be several or at most ten, the access load on the IP / RF conversion unit 200 is not large. For this reason, the generation interval (first fixed time interval) of the viewing message generated by the television receiver 300 may be short.

  When there is no TS stream currently being received by the television receiver 300, or when there is no stream selection history, the television receiver 300 displays the above-described stream selection screen (S55). On this stream selection screen, the viewer operates the data broadcast screen with the remote controller 321 (S56), and selects a stream to be viewed (S57). In response to this, the television receiver 300 issues a unicast distribution request to the IP / RF conversion unit 200 via IP (S58). The subsequent sequence is the same as that for the unicast distribution request in step S42.

  If it is determined after step S38 that there is a TS stream that is currently being received, the television receiver 300 displays “other viewers present” (for example, pop-up display) for a predetermined time (for example, 5). Second) and execute (S59), and shift to viewing screen display (S60).

  FIG. 9 is a sequence diagram exemplifying schematic exchanges between the respective units at the end of viewing due to channel switching or the like (including power OFF) in the television receiver 300 in this system.

  As described above, during reception of the TS stream, the television receiver 300 periodically transmits a reception notification via IP to the IP / RF conversion unit 200 (S71, S72, S73). When the channel is switched or the power is turned off by the television receiver 300, the notification during reception stops. The IP / RF conversion unit 200 determines that the reproduction of the TS stream in the television receiver 300 is stopped (viewing is finished) when the reception notification cannot be received for a certain time (S74). When making such a determination, the IP / RF conversion unit 200 issues a unicast stop request to the sending apparatus 100 via the IP (S75). In response to this, the sending apparatus 100 stops outputting (transmitting) TS packets of the TS stream (S76), and returns a unicast stop request Ack to the IP / RF conversion unit 200 via IP (S77).

  FIG. 10 is a sequence diagram exemplifying schematic exchanges between the respective units at the end of viewing by stopping the operation of the IP / RF conversion unit in this system.

  Similarly, as described above, the IP / RF conversion unit 200 periodically transmits a reception notification to the sending apparatus 100 via the IP during reception of the TS stream (S81, S82, S83). When the IP / RF conversion unit 200 stops operating due to the power-off or the like, the notification during reception stops. The sending device 100 determines that the operation of the IP / RF conversion unit 200 has stopped when the receiving notification cannot be received for a certain period of time (S84), and stops sending TS packets of the TS stream (S85).

  FIG. 11 shows a sequence diagram regarding processing when an error occurs on the top screen.

  As described with reference to FIG. 9, when the viewer gives an instruction to select the output channel of the IP / RF conversion unit 200 using the remote controller 321 (S91), the television receiver 300 displays a predetermined top screen (S92). ), B-CAS check is executed (S93).

  When the result of the B-CAS check is NG, the television receiver 300 displays “Please insert a B-CAS card” (for example, pop-up display) (S94). Next, when a B-CAS card is inserted by the viewer (S95) and the D button is pressed (S96), a B-CAS check is performed again (S97).

  Thereafter, the television receiver 300 performs a LAN connection check (S101). When the television receiver 300 has no LAN connection, a display such as “LAN connection NG” (for example, pop-up display) is performed (S102). Next, the viewing screen is displayed (S103). When there is no LAN connection, the TS stream selected by another receiving terminal is displayed.

  When the reception stream acquisition request (S105) is made from the television receiver 300 to the IP / RF conversion unit 200, when the reception stream acquisition request Nack is returned by the IP / RF conversion unit 200, the television receiver 300 displays “reception stream”. A display such as “acquisition error” (for example, pop-up display) is performed (S107). Thereafter, the process proceeds to viewing screen display (S108).

  When a reception stream acquisition request (S111) is made from the television receiver 300 to the IP / RF conversion unit 200, there is no response from the IP / RF conversion unit 200 for a predetermined time, that is, a reception stream acquisition response time-out. A display such as “received stream acquisition timeout” (for example, pop-up display) is made (S112). Thereafter, the process proceeds to viewing screen display (S113).

  FIG. 12 shows a sequence diagram relating to processing at the time of a request error.

  When a unicast distribution request similar to step S42 in FIG. 9 is issued from the television receiver 300 to the IP / RF conversion unit 200, the IP / RF conversion unit 200 returns a unicast distribution request Nack (S122). The television receiver 300 displays a stream selection screen (S123).

  When there is no response from the IP / RF conversion unit 200 to the unicast distribution request from the television receiver 300 (response Timeout), when the viewer presses the D button on the remote 321 (S124), The television receiver 300 displays a stream selection screen (S125).

  In response to a unicast distribution request from the IP / RF conversion unit 200 (S126), when a request Nack is returned from the sending device 100 (S127), the IP / RF conversion unit 200 sends an event message via data broadcasting (BML). The reception NG is transmitted to the television receiver 300 (S128). In response to this, a stream selection screen is displayed on the television receiver 300 (S129). This stream selection screen displays that the event message reception has failed.

  In response to a unicast distribution request from the IP / RF conversion unit 200 (S130), if there is no response from the sending device 100, the IP / RF conversion unit 200 transmits an event message reception Timeout via data broadcasting (BML) to the television. It transmits to the receiver 300 (S131). In response, the television receiver 300 displays a stream selection screen (S132). The stream selection screen displays that the event message reception has timed out.

  In response to the unicast distribution request from the IP / RF conversion unit 200 (S133), after the unicast distribution request Nack is returned from the transmission device 100 (S134), the IP / RF conversion unit 200 has received a certain amount of time from the transmission device 100. If the TS packet cannot be received even after the elapse of time, a TS packet reception Timeout is transmitted to the television receiver 300 (S135). In response to this, a stream selection screen is displayed on the television receiver 300 (S136). The stream selection screen displays that TS packet reception has timed out.

  If a TS packet is subsequently received, the IP / RF conversion unit 200 issues a unicast stop request to the sending apparatus 100 to stop transmission of the TS packet.

  The preferred embodiments of the present invention have been described above, but various modifications and changes other than those mentioned above can be made.

  For example, in the above embodiment, a real-time broadcast program is assumed as a distribution target stream. However, the present invention can also be applied to on-demand distribution in which individual contents are distributed in response to a user request. .

DESCRIPTION OF SYMBOLS 100: Sending apparatus 110: BML server 150: Communication network 200: IP / RF conversion unit 210: Router 230: Switch 300: Television receiver 310: Distributor 320: Stream selection screen 321: Remote control 322, 323: Operation direction instruction display 324: Stream identification information 325: Message box 327: Instruction display 328: Program image display area

Claims (7)

A stream distribution system for performing unicast distribution of a stream via a communication network,
An IP / RF conversion unit that transmits a request for the stream on the communication network based on a unicast distribution request for the stream from the television receiver, and converts the stream received via the communication network into an RF signal;
A transmission device for transmitting a stream requested from the IP / RF conversion unit to the IP / RF conversion unit via a communication network;
The television receiver displays a stream selection screen based on the BML content including information on the stream selection screen and information for generating a stream unicast distribution request, and is selected on the stream selection screen. A stream unicast delivery request is generated to the IP / RF conversion unit ;
The television receiver periodically outputs a predetermined message to the IP / RF conversion unit during reception of the stream,
The IP / RF conversion unit receives the predetermined message from the television receiver, and determines that the reproduction of the stream by the television reception is stopped when reception of the predetermined message is interrupted for a predetermined time. A stream distribution system for stopping the output of the RF signal of the stream. A stream distribution system for performing unicast distribution of a stream via a communication network,
An IP / RF conversion unit that transmits a request for the stream on the communication network based on a unicast distribution request for the stream from the television receiver, and converts the stream received via the communication network into an RF signal;
A transmission device for transmitting a stream requested from the IP / RF conversion unit to the IP / RF conversion unit via a communication network;
The television receiver displays a stream selection screen based on the BML content including information on the stream selection screen and information for generating a stream unicast distribution request, and is selected on the stream selection screen. A stream unicast delivery request is generated to the IP / RF conversion unit;
The IP / RF conversion unit periodically outputs a predetermined message to the sending device during the output of the RF signal,
The transmission device receives the predetermined message from the IP / RF conversion unit, and determines that the operation of the IP / RF conversion unit has stopped when reception of the predetermined message is interrupted for a predetermined time. A stream delivery system for stopping unicast delivery of the stream. The stream distribution system according to claim 1 or 2 , wherein the stream is a TS stream including at least video data. The BML content stream distribution system according to claim 1, 2 or 3, wherein provided to the television receiver by the data broadcast from the IP / RF conversion unit. A stream distribution method for performing unicast distribution of a stream via an IP / RF conversion unit via a communication network,
An IP / RF conversion unit sending BML content for displaying a stream selection screen as a data broadcast to a television receiver;
The television receiver displaying a stream selection screen based on the received BML content;
The television receiver requesting the IP / RF conversion unit for unicast distribution of a stream selected based on a user instruction on the stream selection screen;
The IP / RF conversion unit requesting a sending device for unicast delivery of the requested stream;
The sending device sending the requested stream as IP data to the IP / RF conversion unit;
The IP / RF conversion unit converting the received IP data into an RF signal;
The television receiver receiving the RF signal and reproducing a stream ;
The television receiver periodically outputting a predetermined message to the IP / RF conversion unit during reception of the stream;
When the IP / RF conversion unit receives the predetermined message from the television receiver and the reception of the predetermined message is interrupted for a predetermined time, it is determined that the reproduction of the stream by the television reception is stopped. Stopping the output of the RF signal of the stream;
Stream distribution method with. A stream distribution method for performing unicast distribution of a stream via an IP / RF conversion unit via a communication network,
An IP / RF conversion unit sending BML content for displaying a stream selection screen as a data broadcast to a television receiver;
The television receiver displaying a stream selection screen based on the received BML content;
The television receiver requesting the IP / RF conversion unit for unicast distribution of a stream selected based on a user instruction on the stream selection screen;
The IP / RF conversion unit requesting a sending device for unicast delivery of the requested stream;
The sending device sending the requested stream as IP data to the IP / RF conversion unit;
The IP / RF conversion unit converting the received IP data into an RF signal;
The television receiver receiving the RF signal and reproducing a stream;
The IP / RF conversion unit periodically outputting a predetermined message to the sending device during the output of the RF signal;
When the transmission device receives the predetermined message from the IP / RF conversion unit and the reception of the predetermined message is interrupted for a predetermined time, it is determined that the operation of the IP / RF conversion unit is stopped. , Stopping unicast delivery of the stream;
Stream distribution method with. The stream distribution method according to claim 5 or 6, further comprising a step of a BML server sending the BML content to the IP / RF conversion unit via a communication network.