JP6212288B2 - Push distribution server, receiving terminal, receiving program and system - Google Patents

Description

  The present invention relates to a push delivery server, a receiving terminal, a receiving program, and a system for interrupting and transmitting other data when delivering fragmented data using a WebSocket protocol from a push delivery server.

  In recent years, on the Internet, it is expected to implement a push-type information distribution service that automatically sends information from a distribution server to a user receiving terminal. For example, information that changes from moment to moment, such as related information in accordance with the progress of a television broadcast program, the latest information on weather according to individual user needs, the latest information on traffic, etc., is push-distributed. Thereby, the user can acquire the latest information without performing a special update operation.

  Conventionally, as a technique for implementing such a push-type information distribution service, mainly using the HTTP protocol, the receiving terminal automatically inquires the distribution server for the update information at regular intervals, and the update information is If it exists, pseudo-push delivery that receives the information has been mainstream.

  However, in pseudo push distribution, data is frequently exchanged between the distribution server and the receiving terminal, and by occupying the HTTP connection for a long time, other applications connected to the same distribution server can be operated. There was a problem that it could have an effect.

  As a technique for solving this problem, standards development work for the WebSocket protocol is being promoted by W3C and IETF, which are standards organizations of the Internet (Non-patent Document 1). In the WebSocket protocol, once a connection is established between a distribution server and a receiving terminal, all necessary communication is performed using a dedicated protocol on the connection. Compared with the HTTP connection, there is an advantage that unnecessary communication can be suppressed and the influence on other applications connected to the same distribution server is reduced by performing all data transmission / reception with one connection.

  FIG. 12 is a diagram illustrating a configuration of a frame transmitted according to the WebSocket protocol. In FIG. 12, the frame configuration is represented in units of 32 bits. A frame transmitted according to the WebSocket protocol is composed of a header and a payload, and data is stored in the payload, and is transmitted through a sequence of the frames. When transmitting data of unknown size, in order to be able to transmit all of the data without buffering in advance, and to prevent large data from occupying the output network interface, the WebSocket protocol Supports a function of fragmenting (transmitting) data (message) to be transmitted.

  The frame header includes 1-bit FIN and 4-bit opcode control information, and these control information is used to transmit fragmented data. FIN is information indicating that it is the frame of the last fragment in the data to be transmitted, and the frame of the first fragment may be the frame of the last fragment. The opcode is information that defines how to interpret the data stored in the payload, and is information that indicates that the frame is a halfway (continuous) fragment in the data to be transmitted. Specifically, 0 indicates a continuation frame, 2 indicates a binary frame, and other values are as shown in FIG.

  FIG. 13 is a diagram for explaining FIN and opcode when fragmented data is transmitted. When transmitting fragmented data, the FIN bit is cleared (0), and the opcode is set to a value other than 0 (2 in the example of FIG. 13). Cleared, followed by zero or more frames with opcode set to 0 (next frame), the FIN bit is set (set to 1), and one frame with the opcode set to 0 (the last frame) Frame). When data to be transmitted is fragmented into a plurality of data, this data to be transmitted is conceptually formed by concatenating each payload storing fragmented data into one payload. Is equivalent to a single large data stored in the payload.

  By the way, when delivering general data, there may be cases where other data is desired to be transmitted. For example, there is disclosed a stream distribution system that does not require operation on the reproduction display terminal and disconnection and reconnection when another stream data is distributed when the stream data is distributed to the reproduction display terminal. (Patent Document 1). Specifically, in a stream distribution system including a reproduction display terminal, a proxy server, a first distribution server, and a second distribution server, the proxy server transmits stream data from the first distribution server to the reproduction display terminal. When an interrupt request is received from the second distribution server while relaying, a request for suspension is transmitted to the first server, and another stream data is relayed from the second distribution server to the playback display terminal. .

JP 2008-177657 A

RFC 6455, “The WebSocket Protocol”, [online], December 2011, [May 1, 2013 search], Internet <URL: http://tools.ietf.org/html/rfc6455>

  In the above-described push-type information distribution service, in addition to general data distribution, there is highly urgent data that should be immediately transmitted to the user. Such highly urgent data is preferably sent by interrupting the data being distributed in order to improve immediacy.

  However, when the WebSocket protocol is used, in one session established between the distribution server and the receiving terminal, between a plurality of frames for transmitting fragmented data belonging to one data to be transmitted. Another frame of data is prohibited from being inserted. Therefore, another data cannot be transmitted until transmission of all frames in which fragmented data belonging to one data to be transmitted is stored is completed. For this reason, when general data is distributed, it is difficult to immediately transmit highly urgent data to the user. This is the same when general data is distributed and other data is distributed by interrupting the data.

  By using the technique based on the above-described stream distribution system disclosed in Patent Document 1, it is possible to interrupt and transmit highly urgent data or other data in the data being distributed. However, since this technique does not use the WebSocket protocol, it cannot be directly applied to data distribution using the WebSocket protocol.

  Therefore, the present invention has been made in view of such problems, and its purpose is to interrupt and transmit other data when distributing fragmented data from the push distribution server using the WebSocket protocol. An object of the present invention is to provide a push delivery server, a receiving terminal, a receiving program, and a system that make it possible.

  To achieve the above object, the push delivery server according to claim 1 is a push delivery server that transmits predetermined data to a receiving terminal using a WebSocket protocol. And a trailer including an end / continuation identification flag indicating whether or not the data end position is included, and header information including a start / continuation identification flag indicating whether or not the data start position is included. Providing information to generate encapsulated data, dividing the encapsulated data into fragment data of a predetermined length, and for each of the fragment data, a fragmented frame for transmitting the fragment data from the encapsulated data First control information indicating whether or not to transmit the last fragmented data, and the disconnection Generating second control information indicating whether or not a fragmented frame for transmitting data is to continuously transmit fragmented data divided from the encapsulated data, and used for the WebSocket protocol; Fragment generating means for generating a fragmented frame by assigning a header including first and second control information, storing the fragment data in a payload, and the fragmented frame generated by the fragment generating means Fragment transmitting means for transmitting to a receiving terminal, and when the fragment transmitting means interrupts transmission of the fragmented frame of the data and interrupts and transmits the fragmented frame of other data, it is used for the WebSocket protocol. A header is added and the end position is In the case of generating an interruption frame in which the end / continuation identification flag indicating that there is no error is stored in a payload, transmitting the interruption frame to the receiving terminal, and restarting transmission of the fragmented frame of the interrupted data, the WebSocket A header used for a protocol is added to generate a resume frame in which the identifier of the suspended data and the start / continuation identification flag indicating that the start position is not included are stored in a payload, and the resume frame is transmitted to the receiving terminal It is characterized by transmitting to.

  Further, the push delivery server according to claim 2 is the push delivery server according to claim 1, wherein a new fragment transmission means replacing the fragment transmission means interrupts transmission of the fragmented frame of the data, and other data When a fragmented frame is interrupted and transmitted, a header used for the WebSocket protocol is added to generate a suspended frame in which the end / continuation identification flag indicating that the end position is not included is stored in a payload. When transmitting a frame to the receiving terminal, transmitting a fragmented frame of the other data to the receiving terminal, and restarting transmission of the fragmented frame of the interrupted data, all the fragmented frames in the other data Is transmitted to the receiving terminal, and then the Web A header used for the ocket protocol is added to generate a restart frame in which the identifier of the interrupted data and the start / continuation identification flag indicating that the start position is not included are stored in a payload, and the restart frame is received It transmits to a terminal, The remaining fragmented frame in the said interrupted data is transmitted to the said receiving terminal, It is characterized by the above-mentioned.

  A push delivery server according to claim 3 is the push delivery server according to claim 1 or 2, further comprising a first fragment generation unit and a second fragment generation unit instead of the fragment generation unit, A first fragment buffer and a second fragment buffer, wherein the first fragment generation means inputs the data, adds header information including the start / continuation identification flag to the data, and Providing trailer information including an end / continuation identification flag to generate encapsulated data, dividing the encapsulated data into fragment data of a predetermined length, and for each of the fragment data, the first control information and the Generate second control information and use the first and second controls used in the WebSocket protocol. Adding a header including information, storing the fragment data in a payload to generate a fragmented frame, storing the fragmented frame in the first fragment buffer, and the second fragment generating means, The other data is input, header information including the start / continuation identification flag is added to the other data, and trailer information including the end / continuation identification flag is added to generate encapsulated data. , Dividing the encapsulated data into fragment data of a predetermined length, generating the first control information and the second control information for each of the fragment data, and using the first and second control information used for the WebSocket protocol 2 is added, and the fragment data is stored in the payload to generate a fragmented frame. The fragmented frame is stored in the second fragment buffer, and when the fragment transmitting means stores the fragmented frame of the data in the first fragment buffer, the fragmented frame is stored in the first fragment buffer. When reading a fragmented frame of data and transmitting it to the receiving terminal, interrupting transmission of the fragmented frame of data, and interrupting and transmitting the fragmented frame of other data, the second fragment buffer is When a fragmented frame of other data is stored, a header used for the WebSocket protocol is added to generate a suspended frame in which the end / continuation identification flag indicating that the end position is not included is stored in a payload, The interrupt frame is received by the receiving frame. When transmitting to the receiving terminal, reading out the fragmented frame of the other data from the second fragment buffer, transmitting to the receiving terminal, and restarting the transmission of the fragmented frame of the suspended data, the WebSocket protocol is used. A header to be used is added to generate a restart frame in which the identifier of the interrupted data and the start / continuation identification flag indicating that the start position is not included are stored in a payload, and the restart frame is transmitted to the receiving terminal Then, the remaining fragmented frame in the data is read from the first fragment buffer and transmitted to the receiving terminal.

  The push delivery server according to claim 4 is the push delivery server according to any one of claims 1 to 3, wherein the header of the interrupted frame transmitted by the fragment transmitting means is divided from the encapsulated data. First control information indicating that the last piece of fragment data is to be transmitted is included.

  Furthermore, the receiving terminal of claim 5 adds header information including a start / continuation identification flag indicating whether or not to include an identifier of the data and a start position of the data to predetermined data, and the data Each of the fragment data is generated by adding trailer information including an end / continuation identification flag indicating whether or not the end position is included, generating encapsulated data, dividing the encapsulated data into fragment data of a predetermined length, and The first control information indicating whether or not the fragmented frame for transmitting the fragment data transmits the last fragment data divided from the encapsulated data, and the fragment for transmitting the fragment data Second control indicating whether or not the framed frame is to continuously transmit the fragment data halfway divided from the encapsulated data From a push delivery server that generates a report, attaches a header including the first and second control information used for the WebSocket protocol, stores the fragment data in a payload, generates a fragmented frame, and transmits the fragmented frame. In the receiving terminal that receives the fragmented frame using the WebSocket protocol, for each received fragmented frame, the first and second control information is extracted from a header of the fragmented frame, and the fragmented Extracting fragment data constituting the encapsulated data from the payload of the frame, referring to a table storing the relationship between the combination of the first and second control information and the presence of the header information and trailer information , Including the identifier from the extracted fragment data. When header information and trailer information are extracted and one or both of the header information and trailer information cannot be extracted, predetermined information is set for the header information that cannot be extracted, and the trailer information that cannot be extracted is set. Fragment restoring means for setting predetermined information, extracting a fragment of the data from the extracted fragment data based on the extracted or set header information and trailer information, and restoring the data, and the fragment restoring means A storage means for storing the data fragment extracted in association with an identifier of the header information extracted or set by the fragment restoration means, and the data restored from the storage means are input, and the data And a decoder that decodes the data decoded by the decoder. A presentation unit for presenting data to the user of the receiving terminal, and when the fragment restoration means receives the fragmented frame of data, the fragmented frame of data from the push distribution server The end / continuation identification indicating that the header used for the WebSocket protocol is added and does not include the end position. When the interrupt frame having the flag stored in the payload is received, the first and second control information is extracted from the interrupt frame header, and the trailer information is extracted from the interrupt frame payload by referring to the table. Extract the end / continuation identification flag from the push delivery server The start indicating that the transmission of the fragmented frame of the interrupted data is resumed, the header used for the WebSocket protocol is added, and the identifier of the interrupted data and the start position are not included / When the resumption frame having the continuation identification flag stored in the payload is received, the first and second control information is extracted from the header of the resumption frame, and the table is referred to and the resumption frame is read from the payload of the resumption frame. The identifier of the interrupted data included in the header information and the start / continuation identification flag are extracted.

Further, the receiving terminal according to claim 6, in the receiving terminal according to claim 5, in the prior SL disruptions frame header, and transmits the last fragment data divided from the encapsulated data First fragmentation information is included, and a new fragment restoration unit in place of the fragment restoration unit stores the received fragmented frame in the storage unit, and the received fragmented frame header or the reception The first control information and the second control information are extracted from the header of the interrupted frame, and the first control information indicates that the last fragment data divided from the encapsulated data is transmitted. In this case, the fragmented frame stored in the storage means is read and the fragment data constituting the encapsulated data from the payload is read. Extracting data, extracts the pieces of the data from the fragment data the extracted, characterized in that.

  Furthermore, a receiving program according to claim 7 causes a computer to function as the receiving terminal according to claim 5 or 6.

  Furthermore, the system of claim 8 is characterized by comprising the push delivery server of claim 1 and the receiving terminal of claim 5.

  As described above, according to the present invention, when fragmented data is distributed from the push distribution server using the WebSocket protocol, transmission of all frames in which the fragmented data is stored is completed. Other data can be interrupted and transmitted without waiting for this. As a result, in data distribution using the WebSocket protocol, for example, highly urgent data can be immediately transmitted to the user, and different data can be transmitted in parallel.

It is a figure explaining the outline of the whole structure of the content delivery system by embodiment of this invention. It is a figure which shows the structure of the data and frame used with a content delivery system. It is a figure which shows the relationship between the combination of FIN and opcode stored in the header of the frame, and the presence of header information and trailer information of encapsulated data. It is a block diagram which shows the structure of the push delivery server by embodiment of this invention. It is a flowchart which shows the process of the fragment multiplexing means with which the push delivery server was equipped. It is a figure explaining the transmission / reception sequence of content data and emergency data. It is a block diagram which shows the structure of the receiving terminal by embodiment of this invention. It is a flowchart which shows the process of a receiving terminal. It is a flowchart which shows the extraction / setting process (step S803) of Tag, hcode, and tcode. It is a flowchart which shows the extraction / storage process of the fragment | piece of content data (step S804). It is a supplementary figure explaining the process of FIG.9 and FIG.10. It is a figure which shows the structure of the flame | frame transmitted according to a WebSocket protocol. It is a figure explaining FIN and opcode in the case of transmitting fragmented data.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
[Content distribution system]
FIG. 1 is a diagram illustrating an outline of the overall configuration of a content distribution system according to an embodiment of the present invention. The content distribution system 1 includes a content server 2, an emergency data server 3, a push distribution server 4, and receiving terminals 5-1 to 5-4 (hereinafter collectively referred to as receiving terminals 5). The push delivery server 4, the content server 2, and the emergency data server 3 are connected via a content relay network 6. The push distribution server 4 and the plurality of receiving terminals 5 are connected via the Internet 7.

  The content server 2 is a server that is a content distribution source, is connected to the push distribution server 4 via the content relay network 6, and receives the content via the content relay network 6, the push distribution server 4, and the Internet 7. Send to. There may be a plurality of content servers 2 instead of only one. The content is information such as text, images, moving images, and audio.

  The emergency data server 3 is a server that is a distribution source of emergency data that should be immediately transmitted to the user of the receiving terminal 5. The emergency data server 3 is connected to the push delivery server 4 via the content relay network 6 and transmits emergency data to the receiving terminal 5 via the content relay network 6, the push delivery server 4 and the Internet 7.

  The push distribution server 4 is connected to the receiving terminal 5 using the WebSocket protocol, and push-distributes the content from the content server 2 and the emergency data from the emergency data server 3 to the receiving terminal 5 via the Internet 7.

  The receiving terminal 5 is connected to the push delivery server 4 using the WebSocket protocol, receives the content and emergency data transmitted from the push delivery server 4 via the Internet 7, and presents the received content and emergency data to the user. To do.

[Data and frame structure]
FIG. 2 is a diagram showing the structure of data and frames used in the content distribution system 1 shown in FIG.

  The content data shown in FIG. 2 is content transmitted from the content server 2 or a part of the content. The emergency data shown in FIG. 2 is emergency data transmitted from the emergency data server 3 or a part of emergency data. The content data and the emergency data are, for example, text, images, moving images, sounds, and the like, and the emergency data is handled in the same manner as the content data.

  The encapsulated data is data encapsulated by adding header information and trailer information to the content data. The header information includes a content identifier (Tag: tag) and a start / continuation identification flag (hcode), and the trailer information includes an end / continuation identification flag (tcode).

  The content identifier (Tag) is a tag for identifying content data, and 0001 is given in the example of FIG. The start / continuation identification flag (hcode) is a flag indicating whether or not the encapsulated data includes the start position of the content data. When hcode = 1, the start position of the content data is included. When hcode = 0, the start position of the content data is not included and the capsule of the same content identifier (Tag) as the previous encapsulated data is included. It is encapsulated data and indicates that the encapsulated data is continued from the previous encapsulated data.

  The end / continuation identification flag (tcode) is a flag indicating whether or not the encapsulated data includes the end position of the content data. When tcode = 1, the end position of the content data is included. When tcode = 0, the end position of the content data is not included, and the end position of the content data has the same content identifier (Tag). It is included in the encapsulated data thereafter.

  The fragmented frame is a frame according to the WebSocket protocol shown in FIG. 12, and the encapsulated data is fragmented into fragment data of an arbitrary size, and the fragment data is stored in the payload.

  The example of FIG. 2 shows that the encapsulated data is fragmented into three pieces of fragment data, and each of the three pieces of fragment data is stored in the payload of the fragmented frame. The FIN and opcode formats included in the header of the fragmented frame conform to the specifications of the WebSocket protocol. In the header of the first fragmented frame, FIN = 0 (indicating that it is not the last fragmented frame storing the third fragment data) and opcode = 2 (indicating that it is a binary frame) are set. Has been. FIN = 0 and opcode = 0 (indicating that it is a continuation frame) are set in the header of the second fragmented frame. In the header of the last fragmented frame, FIN = 1 (indicating that it is the last fragmented frame storing the third fragment data) and opcode = 0 are set. In the fragmented frame configuration of FIG. 2, descriptions of headers other than FIN and opcode are omitted.

  The interrupt frame is a frame according to the WebSocket protocol, and the payload includes only the trailer information of the encapsulated data. This interruption frame is used when transmission of fragmented frames belonging to one encapsulated data is interrupted. The receiving side can recognize that the transmission of the content data corresponding to the fragmented frame is interrupted by receiving this interrupted frame.

  FIN = 1 (indicating that it is the last fragmented frame) and opcode = 0 (indicating that it is a continuation frame) are set in the header of the interruption frame, and tcode = 0 (content) in the payload The data end position is set to indicate that it is included in the encapsulated data thereafter having the same content identifier (Tag). When the header of the interruption frame is FIN = 1, the reception side can end the reception processing of a series of fragmented frames according to the WebSocket protocol.

  The resume frame is a frame according to the WebSocket protocol, and its payload includes only the header information of the encapsulated data. This resume frame is used when transmission of the fragmented frame suspended by the suspended frame is resumed. The receiving side can recognize that the previously interrupted transmission of the content data is resumed by receiving this resume frame.

  FIN = 0 (indicating that it is not the last fragmented frame) and opcode = 2 (indicating that it is a binary frame) are set in the header of the resume frame, and the content data whose transmission is resumed is set in the payload. A content identifier (Tag = 0001 in this example) and hcode = 0 (indicating that the start position of the content data is not included) are set. The content identifier (Tag) of the content data whose transmission is resumed is included in the payload of the resume frame. The content identifier (Tag) is included in the fragmented frame of the content data whose transmission is resumed. Because there is no. By receiving this resume frame, the receiving side can recognize the content identifier (Tag) included in the resume frame as the content identifier (Tag) of the fragmented frame transmitted later.

  The encapsulated data, the suspended frame, and the resume frame are new data and frames added to the conventional technology. Further, whether the header information or trailer information of the encapsulated data is included in the fragmented frame, the suspended frame, and the resume frame can be recognized by a combination of FIN and opcode stored in the header.

  FIG. 3 is a diagram showing the relationship between the combination of FIN and opcode stored in the headers of these frames and the presence of header information and trailer information of encapsulated data. As shown in FIG. 3, it is possible to recognize whether header information and / or trailer information of encapsulated data is stored in the payload of the frame from the combination of FIN and opcode stored in the header of the frame.

  For example, when FIN = 0 and opcode = 0 are stored in the header of the frame, it is recognized that the header information and trailer information of the encapsulated data are not stored in the payload of the frame. Further, when FIN = 0 and opcode = 2 (other than 0) are stored in the header of the frame, the header information of the encapsulated data is stored in the payload of the frame, and no trailer information is stored. It is recognized. In addition, when FIN = 1, opcode = 0, etc. are stored in the header of the frame, it is as shown in FIG.

  In this way, the receiving side refers to the table storing the information shown in FIG. 3 for the combination of FIN and opcode stored in the header of the received frame, thereby encapsulating data in the payload of the received frame. It is possible to recognize whether or not header information and / or trailer information is stored.

[Push delivery server]
Next, the push delivery server 4 shown in FIG. 1 will be described. FIG. 4 is a block diagram showing a configuration of the push delivery server 4 according to the embodiment of the present invention. The push delivery server 4 includes a session control unit 10, a content data input unit 11, an emergency data input unit 12, a tag management unit 13, a fragment generation unit 14, a fragment buffer 15, an emergency data fragment generation unit 16, and an emergency data fragment buffer 17 , A fragment multiplexing unit 18, a packet transmission unit 19, and communication I / Fs 20 and 21 are provided. The push delivery server 4 may include a plurality of sets of content data input means 11 and fragment generation means 14. The fragment multiplexing unit 18 and the packet transmitting unit 19 constitute a fragment transmitting unit.

  The session control means 10 accepts a connection request from the receiving terminal 5 via the communication I / F 21 and transmits content data between the push distribution server 4 and the receiving terminal 5 that has transmitted the connection request according to the WebSocket protocol. Establish a session. Moreover, the session control means 10 receives a disconnection request from the receiving terminal 5 via the communication I / F 21 and disconnects the session.

  The content data input unit 11 sequentially receives content data from the content server 2 via the communication I / F 20 and outputs the received content data to the fragment generation unit 14.

  The emergency data input unit 12 receives emergency data from the emergency data server 3 via the communication I / F 20 and outputs the received emergency data to the emergency data fragment generation unit 16.

  The tag management means 13 generates and manages a content identifier (tag) for identifying content data and emergency data distributed at the same time in the push distribution server 4. Then, the tag management unit 13 outputs the content identifier (tag) of the corresponding content data to the fragment generation unit 14 in response to the transmission of the content data and the emergency data by the push delivery server 4, and the content of the corresponding emergency data The identifier (tag) is output to the emergency data fragment generator 16.

  The fragment generation unit 14 inputs content data from the content data input unit 11, inputs a content identifier (tag) from the tag management unit 13, sets the content identifier (tag) to tag, and sets 1 to hcode and tcode. 2 is generated, predetermined header information and predetermined trailer information are generated, header information and trailer information are added to the content data, and the encapsulated data shown in FIG. 2 is generated. Then, the fragment generation unit 14 divides the generated encapsulated data into fragment data for each predetermined N bytes (for example, 1 kbyte), generates a predetermined header, adds a header to the fragment data, and converts the fragment data into The fragmented frame shown in FIG. 2 is generated by storing in the payload. The fragment generation unit 14 stores the generated fragmented frame in the fragment buffer 15.

  The emergency data fragment generation means 16 inputs emergency data from the emergency data input means 12, inputs a content identifier (tag) from the tag management means 13, sets the content identifier (tag) to tag, etc. Header information and predetermined trailer information are generated, the header information and trailer information are added to the emergency data, and the encapsulated data shown in FIG. 2 is generated. Then, the urgent data fragment generation means 16 divides the generated encapsulated data into fragment data for each predetermined N bytes (for example, 1 kbyte), generates a predetermined header, and adds a header to the fragment data. Data is stored in the payload, and the fragmented frame shown in FIG. 2 is generated. The urgent data fragment generation means 16 stores the generated fragmented frame in the urgent data fragment buffer 17.

  The fragment multiplexing means 18 confirms whether or not fragmented frames are accumulated in the fragment buffer 15 and the emergency data fragment buffer 17. Then, when the fragment multiplexing unit 18 confirms that the fragmented frames are accumulated in the fragment buffer 15, the fragment multiplexing unit 18 reads the fragmented frames from the fragment buffer 15. When the fragment multiplexing means 18 confirms that the fragmented frames are accumulated in the emergency data fragment buffer 17, the fragment multiplexing means 18 reads the fragmented frames from the emergency data fragment buffer 17. In this case, the fragment multiplexing means 18 performs the reading process from the emergency data fragment buffer 17 with priority over the reading process from the fragment buffer 15. Then, the fragment multiplexing means 18 multiplexes the read fragmented frames and outputs the fragmented frames to the packet transmitting means 19.

  Here, the fragment multiplexing means 18 generates the interruption frame shown in FIG. 2 and sends it to the packet transmission means 19 when interrupt data is transmitted when the push delivery server 4 is transmitting content data. Output. Further, when the transmission of the interrupted content data is resumed, the fragment multiplexing means 18 generates the resume frame shown in FIG. 2 and outputs it to the packet transmission means 19.

  The packet transmission means 19 receives the fragmented frame from the fragment multiplexing means 18 and accommodates the fragmented frame in the packet. Then, the packet transmission means 19 sends the packet containing the fragmented frame to the reception terminal 5 via the communication I / F 21 by the content data transmission session established between the push delivery server 4 and the reception terminal 5. Send to.

(Fragment multiplexing means)
Next, the processing of the fragment multiplexing unit 18 shown in FIG. 4 will be described in detail. FIG. 5 is a flowchart showing the processing of the fragment multiplexing means 18. First, the fragment multiplexing means 18 checks whether or not fragmented frames are accumulated in the emergency data fragment buffer 17 (step S501). If the fragment multiplexing means 18 confirms in step S501 that fragmented frames are stored in the emergency data fragment buffer 17 (step S501: Y), whether or not the fragmented frames of content data are being transmitted. Is determined (step S502).

  When it is determined in step S502 that the fragmented frame of content data is being transmitted (step S502: Y), the fragment multiplexing unit 18 generates the interruption frame shown in FIG. 2 and outputs it to the packet transmission unit 19 (Step S503), the process proceeds to step S504. For example, the fact that a fragmented frame of content data is being transmitted is after the transmission of the first fragmented frame and before the transmission of the third fragmented frame in the fragmented frame shown in FIG. I say a case. Thereby, transmission of the content data being transmitted is interrupted. In this case, the fragment multiplexing means 18 holds the content identifier (Tag) of the content data whose transmission is interrupted as an interruption tag.

  On the other hand, when it is determined in step S502 that the fragmented frame of content data is not being transmitted (step S502: N), the fragment multiplexing unit 18 proceeds to step S504.

  The fragment multiplexing means 18 moves from step S502 or step S503, reads the fragmented frame from the emergency data fragment buffer 17, and outputs the read fragmented frame of emergency data to the packet transmission means 19 (step S504). Then, the process proceeds to step S509.

  On the other hand, when the fragment multiplexing means 18 confirms in step S501 that no fragmented frames are accumulated in the emergency data fragment buffer 17 (step S501: N), the fragmented frames are accumulated in the fragment buffer 15. It is confirmed whether or not (step S505). If the fragment multiplexing means 18 confirms in step S505 that no fragmented frames are accumulated in the fragment buffer 15 (step S505: N), the fragment multiplexing means 18 proceeds to step S501.

  On the other hand, when the fragment multiplexing means 18 confirms that the fragmented frame is accumulated in the fragment buffer 15 in step S505 (step S505: Y), the content of the fragmented frame accumulated in the fragment buffer 15 For data, it is checked whether or not transmission of a fragmented frame having the same content identifier (Tag) is interrupted (step S506). Specifically, the fragment multiplexing means 18 is a case where the interruption tag held in step S503 is present, and the fragmented frame content identifier (Tag) stored in the fragment buffer 15 and the interruption tag It is confirmed whether or not the content identifier (Tag) shown is the same. When these content identifiers (Tag) are the same, it is determined that the transmission is interrupted, and when they are not the same, it is determined that the transmission is not interrupted.

  When the fragment multiplexing means 18 confirms that the transmission of the fragmented frame of the content identifier (Tag) is interrupted in step S506 (step S506: Y), the fragment multiplexing means 18 generates the resume frame shown in FIG. To the packet transmission means 19 (step S507), and the process proceeds to step S508. In this case, the fragment multiplexing means 18 sets the content identifier (Tag) indicated by the interruption tag in Tag (Tag of content data whose transmission is to be resumed) stored in the payload of the resumption frame, and clears the interruption tag.

  On the other hand, when the fragment multiplexing means 18 confirms in step S506 that transmission of the fragmented frame of the content identifier (Tag) has not been interrupted (step S506: N), the fragment multiplexing means 18 proceeds to step S508.

  The fragment multiplexing means 18 moves from step S506 or step S507, reads the fragmented frame from the fragment buffer 15, and outputs the fragmented frame of the read content data to the packet transmitting means 19 (step S508). Then, the process proceeds to step S509.

  The fragment multiplexing unit 18 proceeds from step S504 or step S508 to determine whether or not transmission of all packets corresponding to the content data and emergency data to be transmitted has been completed (step S509). If it is determined that packet transmission has not ended (step S509: N), the process proceeds to step S501. If it is determined that transmission of all packets has ended (step S509: Y), the process ends. . In this case, the fragment multiplexing means 18 determines that the transmission of all packets has been completed when the information indicating that the session has been disconnected is input from the session control means 10, and ends the processing.

[Transmission / reception sequence]
Next, a transmission / reception sequence of content data and emergency data in the content server 2, the emergency data server 3, the push delivery server 4, and the receiving terminal 5 will be described. FIG. 6 is a diagram for explaining the transmission / reception sequence.

  When the content server 2 transmits the content data to the push delivery server 4 (step S601), the push delivery server 4 receives the content data, gives a content identifier (Tag = 1) to the content data, and encapsulated data. And generate a fragmented frame (step S602). Then, the push delivery server 4 transmits a packet containing a fragmented frame with Tag = 1 to the receiving terminal 5 (step S603).

  When the emergency data server 3 generates emergency data to be immediately transmitted to the user of the receiving terminal 5 and transmits it to the push delivery server 4 (step S604), the push delivery server 4 receives the emergency data, A content identifier (Tag = 2) is assigned to generate encapsulated data and a fragmented frame (step S605). Then, the push delivery server 4 generates an interruption frame (step S606), and transmits a packet containing the interruption frame to the receiving terminal 5 (step S607). As a result, transmission of content data with Tag = 1 is interrupted.

  The push delivery server 4 transmits a packet (emergency data packet) containing a fragmented frame with Tag = 2 to the receiving terminal 5 (step S608). Then, when the transmission of the emergency data is completed, the push distribution server 4 generates a resumption frame in order to resume the transmission of the suspended content data of Tag = 1 (step S609), and transmits a packet containing the resumption frame. It transmits to the receiving terminal 5 (step S610). Then, the push delivery server 4 continuously transmits a packet containing a fragmented frame with Tag = 1 to the receiving terminal 5 (step S611).

  Accordingly, when the fragmented frame of the content data with Tag = 1 is distributed from the push distribution server 4 using the WebSocket protocol, the emergency data with Tag = 2 can be interrupted and transmitted. Therefore, emergency data can be immediately transmitted to the user when general content data is distributed.

  As described above, according to the push delivery server 4 according to the embodiment of the present invention, when the content data is input, the fragment generation means 14 generates header information and trailer information, and adds header information and trailer information to the content data. And encapsulated to generate encapsulated data. Then, the fragment generation means 14 divides the generated encapsulated data into fragment data for each predetermined length, generates a header, stores the fragment data in the payload, and generates a fragmented frame. The header information includes a content identifier (Tag) and a start / continuation identification flag (hcode) indicating whether or not the start position of the content data is included. The trailer information includes an end / continuation identification flag (tcode) indicating whether or not the end position of the content data is included.

  Further, when the emergency data is input, the emergency data fragment generation unit 16 generates the encapsulated data and generates the fragmented frame in the same manner as the fragment generation unit 14.

  When the fragment multiplexing unit 18 transmits the fragmented frame of the content data to the receiving terminal 5 via the packet transmission unit 19 and interrupts and transmits the emergency data, the fragment multiplexing unit 18 Before transmitting, the interruption frame is transmitted to the receiving terminal 5. Thereby, the push delivery server 4 can inform the receiving terminal 5 that the transmission of the content data is interrupted, and the receiving terminal 5 receives the interruption frame, thereby interrupting the transmission of the content data. Can be recognized.

  Then, when the transmission of the emergency data is completed, the fragment multiplexing unit 18 transmits a resume frame for resuming the transmission of the content data whose transmission has been interrupted to the receiving terminal 5. Thereby, the push delivery server 4 can inform the receiving terminal 5 that the transmission of the content data is resumed, and the receiving terminal 5 receives the resume frame, thereby restarting the transmission of the content data. Can be recognized. The resume frame includes the content identifier (Tag) of the content data to be resumed.

  As a result, the push delivery server 4 does not wait for the transmission of all the fragmented frames of the content data to be completed while transmitting the fragmented frames of the content data using the WebSocket protocol. Can be interrupted and sent. Therefore, in data distribution using the WebSocket protocol, emergency data can be interrupted and transmitted to the receiving terminal 5, and the emergency data can be immediately transmitted to the user. Further, since the emergency data is interrupted and transmitted using the WebSocket protocol, an existing system that implements the WebSocket protocol can be used.

[Receiving terminal]
Next, the receiving terminal 5 shown in FIG. 1 will be described. FIG. 7 is a block diagram showing a configuration of the receiving terminal 5 according to the embodiment of the present invention. The receiving terminal 5 includes a connection control unit 30, a packet receiving unit 31, a fragment restoration unit 32, a content data storage unit 33, a decoder 34, a presentation unit 35, and a communication I / F 36.

  The connection control means 30 transmits a connection request to the push delivery server 4 via the communication I / F 36 at the start of reception, and receives content data between the receiving terminal 5 and the push delivery server 4 according to the WebSocket protocol. Establish a session for. Moreover, the connection control means 30 transmits a cutting | disconnection request | requirement to the push delivery server 4 via communication I / F36 at the time of completion | finish of reception, and cut | disconnects the said session.

  The packet receiving unit 31 receives a packet from the push delivery server 4 via the communication I / F 36 by a content data reception session established between the receiving terminal 5 and the push delivery server 4, and receives the received packet. The data is output to the fragment restoration means 32.

  The fragment restoration means 32 receives a packet from the packet reception means 31, restores a fragmented frame, a suspended frame or a resume frame from the inputted packet according to the WebSocket framing protocol, and restores the restored fragmented frame, suspended frame or resume frame. Extract the data stored in the payload. As a result, fragment data divided from the encapsulated data is extracted from the fragmented frame, tcode = 0 is extracted from the interruption frame, and the content identifier (Tag) and hcode = 0 are extracted from the resume frame. Fragment data divided from the encapsulated data is not extracted from the suspended frame and the resume frame.

  The fragment restoration unit 32 extracts the content data fragment and the content identifier (Tag) from the fragment data constituting the extracted encapsulated data, and associates the content data fragment with the content identifier (Tag) to the content data storage unit. 33. In this case, when the fragmented frame does not include the header information of the encapsulated data, the fragment restoration unit 32 uses the content identifier (Tag) of the fragmented frame restored immediately before to set the content identifier (Tag). The content data fragments are stored in the content data storage means 33 in association with each other. In the case of an interrupt frame or a resume frame, a piece of content data is not stored in the content data storage means 33.

  When all the fragments constituting the content data are stored in the content data storage unit 33, the fragment restoration unit 32 determines that the restoration of the content data is completed, and associates the content data with the content identifier (Tag). Is stored in the content data storage means 33. The content data restoration completion flag is a flag indicating whether restoration of one content data is completed. That is, the fragment restoration means 32 stores FIN = 1, opcode = 0, tcode = 1 in the restored fragmented frame, and stores the content data fragment contained in the fragmented frame in the content data storage means 33. In this case, it is determined that the restoration of the content data is completed, and the content data restoration completion flag is stored in the content data storage unit 33.

  The content data storage unit 33 stores a fragment of content data in association with the content identifier (Tag). The content data storage means 33 stores the content data restoration completion flag corresponding to the content identifier (Tag) when it is confirmed that all of the pieces of content data corresponding to the content identifier (Tag) are stored. If it is confirmed that the content data has been restored, the restored content data corresponding to the content identifier (Tag) is output to the decoder 34.

  The decoder 34 inputs the restored content data from the content data storage means 33, decodes the input content data, and outputs it to the presentation unit 35. The presentation unit 35 inputs the content data decoded from the decoder 34 and presents it to the user.

(Receiving terminal processing)
Next, the processing of the receiving terminal 5 shown in FIG. 7 will be described in detail. FIG. 8 is a flowchart showing processing of the receiving terminal 5. First, the packet receiving means 31 of the receiving terminal 5 receives a packet from the push delivery server 4 (step S801), and the fragment restoring means 32 is a fragmented frame, a suspended frame or a resume frame from the packet received by the packet receiving means 31. And FIN and opcode are extracted from the header of the restored frame, and fragment data constituting the encapsulated data is extracted from the payload (step S802). As described above, in the case of a fragmented frame, the fragment data constituting the encapsulated data is extracted, in the case of an interrupted frame, tcode = 0 is extracted, and in the case of a resume frame, the content identifier (Tag, content whose transmission is resumed) Data Tag, hereinafter referred to as “Tag”) and hcode = 0 are extracted.

  The fragment restoration means 32 extracts Tag, hcode, and tcode included in the fragment data or the like based on FIN and opcode, or sets Tag, hcode, and tcode (step S803). Specifically, the fragment restoration unit 32 refers to a table in which information indicating the relationship between the combination of FIN and opcode shown in FIG. 3 and the presence of header information and trailer information is stored and extracted from the restored frame. Based on FIN and opcode, it is recognized whether header information and / or trailer information of encapsulated data is stored in the payload of the frame. When the header information of the encapsulated data is stored in the payload of the frame, the fragment restoration unit 32 extracts the Tag and hcode included in the header information, and the trailer information of the encapsulated data is stored in the payload of the frame. If so, tcode included in the trailer information is extracted. Further, the fragment restoring unit 32 sets tag, hcode, and tcode to predetermined values when such information cannot be extracted.

  FIG. 9 is a flowchart showing the Tag / hcode / tcode extraction / setting process (step S803) shown in FIG. 8, and FIG. 11 is a supplementary diagram for explaining the process of FIG. 9 and FIG. 10 described later. The fragment restoration means 32 determines whether or not the opcode of the extracted header is other than 0 (step S901). If it is determined that the opcode is other than 0 (step S901: Y), the extracted encapsulated data is stored. The header information is restored from the constituent fragment data and the like, Tag and hcode are extracted (step S902), and the process proceeds to step S904.

  On the other hand, if the fragment restoration unit 32 determines in step S901 that the opcode is not other than 0 (step S901: N), since the header information does not exist in the fragment data constituting the extracted encapsulated data, The tag of the restored frame is set to its own tag, hcode is set to 0 (step S903), and the process proceeds to step S904.

  As a result, as shown in FIG. 11, in the process of step S902 for the first restored fragmented frame, the header information of the encapsulated data is restored, and Tag = 0001 and hcode = 1 are extracted. In the process of step S903 for the second and third restored fragmented frames, Tag = 0001 (Tag = 0001 extracted from the first fragmented frame restored immediately before) and hcode = 0 are set.

  Returning to FIG. 9, the fragment restoration unit 32 proceeds from step S902 or step S903 to determine whether the FIN of the extracted header is 1 (step S904), and determines that FIN is not 1 (Step S904: N), tcode is set to 0 (Step S906).

  On the other hand, when it is determined in step S904 that FIN is 1 in step S904 (step S904: Y), the fragment restoration unit 32 restores the trailer information from the fragment data or the like constituting the extracted encapsulated data, and extracts the tcode. (Step S905).

  As a result, as shown in FIG. 11, tcode = 0 is set in the process of step S906 for the first restored fragmented frame. In the process of step S905 for the second and third restored fragmented frames, the trailer information of the encapsulated data is restored and tcode = 1 is extracted.

  Returning to FIG. 8, the fragment restoration means 32 moves from step S803, extracts a piece of content data from the fragment data constituting the extracted encapsulated data, and associates it with the Tag extracted or set in step S803 The content data fragments are stored in the content data storage means 33 (step S804). In the case of the interruption frame and the resumption frame, there is no content data fragment, so the fragment restoration unit 32 cannot extract the content data fragment and does not perform the storage process in the content data storage unit 33.

  FIG. 10 is a flowchart showing the content data fragment extraction / storage process (step S804) shown in FIG. The fragment restoration means 32 extracts the content data fragment from the fragment data constituting the encapsulated data (step S1001), and determines whether hcode is 1 (step S1002).

  If the fragment restoration unit 32 determines in step S1002 that hcode is 1 (step S1002: Y), the fragment restoration unit 32 determines that the fragment of the content data is the first fragment of the new content data and associates it with the Tag. The content data fragment is newly stored in the content data storage means 33 (step S1003). On the other hand, when it is determined in step S1002 that hcode is not 1 (step S1002: N), the fragment restoration unit 32 determines that the content data fragment is not a new content data fragment but a continuous fragment. , A piece of content data associated with Tag is stored in the content data storage means 33, thereby adding it to the end of the already stored content data (step S1004).

  As a result, as shown in FIG. 11, the content data fragment A extracted from the first fragmented frame is stored in the content data storage means 33 in correspondence with Tag = 0001 as shown in FIG. . Also, in the process of step S1004, the content data fragments B and C extracted from the second and third fragmented frames are stored in the content data storage means 33 corresponding to Tag = 0001.

  Returning to FIG. 8, the fragment restoration unit 32 proceeds from step S804 to determine whether or not tcode is 1 (step S805), and when it is determined that tcode is not 1 (step S805: N), If it is determined that the restoration of the content data has not been completed, the process proceeds to step S801. In step S801 to step S804, the next fragmented frame is processed, and the content data fragment is stored in the content data storage unit 33.

  On the other hand, if the fragment restoration unit 32 determines in step S805 that tcode is 1 (step S805: Y), the fragment restoration unit 32 determines that the restoration of the content data is completed because all the pieces constituting the content data are prepared, A content data restoration completion flag associated with the Tag is stored in the content data storage means 33.

  The content data storage unit 33 confirms that the content data restoration completion flag corresponding to the Tag has been stored, and outputs the content data corresponding to the Tag to the decoder 34 (step S806). The decoder 34 inputs the content data from the content data storage means 33, decodes the input content data and outputs it to the presentation unit 35, and the presentation unit 35 presents the content data to the user (step S807).

  The receiving terminal 5 determines whether or not the reception is finished depending on whether or not the reception of all the packets is finished or the session with the push delivery server 4 is disconnected (step S808). If it is determined (step S808: N), the process proceeds to step S801, and if it is determined that reception is completed (step S808: Y), the process is terminated.

  Here, when the suspended frame is restored from the packet in step S802, the fragment restoring unit 32 extracts FIN = 1 and opcode = 0 from the header of the suspended frame, and extracts data (tcode = 0) from the payload. Then, the fragment restoration unit 32 performs the processing of step S901, step S903, step S904, step S905, step S1001, and step S1002, and does not perform the storage processing in the content data storage unit 33 in step S1004.

  Further, when the resuming frame is reconstructed from the packet in step S802, the fragment reconstructing means 32 extracts FIN = 0 and opcode = 2 from the header of the resuming frame, and extracts data (Tag and hcode = 0) from the payload. . Then, the fragment restoration means 32 performs the processing of Step S901, Step S902, Step S904, Step S906, Step S1001, and Step S1002, extracts Tag and hcode = 0 in Step S902, and stores the content data in Step S1004. The storage process to the means 33 is not performed.

  Accordingly, the receiving terminal 5 can perform processing for the suspended frame and the resume frame by processing according to the WebSocket protocol similar to the fragmented frame. In addition, since the content data fragment is stored in the content data storage unit 33 in association with the tag, the emergency data fragment can be stored separately from the normal content data fragment. Therefore, even when normal content data fragments and emergency data fragments are stored in the content data storage means 33, normal content data and emergency data can be distinguished. The emergency data interrupted with respect to the content data can be decoded, and the presentation unit 35 can present the emergency data to the user.

  As described above, according to the receiving terminal 5 according to the embodiment of the present invention, the fragment restoration unit 32 extracts data from these payloads for each fragmented frame of the received content data, and calculates FIN and opcode from the header. By extracting and referring to a predetermined table (a table in which information shown in FIG. 3 is stored), using the extracted data, header information (Tag and hcode) and trailer information (tcode) of the encapsulated data are obtained. Extracted or set. Then, for each fragmented frame, the fragment restoration unit 32 extracts the content data fragment from the data extracted from the payload, and stores the content data fragment in the content data storage unit 33 in association with the Tag. The data was restored. Even when urgent data is received, the urgent data can be restored by the same processing as the content data.

  Also, the fragment restoration means 32 receives the received suspended frame (FIN = 1 and opcode = 0 in the header, and tcode = 0, which is the trailer information of the encapsulated data in the payload) and the resume frame (FIN = 0 in the header). And opcode = 2 and the payload includes Tag and hcode = 0 which are header information of the encapsulated data), and the same processing as the fragmented frame is performed. In this case, the content data fragment is not extracted from the interruption frame and the resume frame because the content frame fragment is not included in the interruption frame and the resume frame. Further, since the resume frame includes the tag of the content data whose transmission is resumed, the receiving terminal 5 can recognize the tag of the fragment of the content data included in the subsequent fragmented frame.

  In other words, the receiving terminal 5 receives the interruption frame while receiving the fragmented frame of the content data, receives all the fragmented frames of the emergency data, and restores the emergency data. The receiving terminal 5 receives the resume frame, receives the remaining fragmented frames of the subsequent content data, and restores the content data.

  Thus, when receiving terminal 5 receives a fragmented frame of content data from push distribution server 4 using the WebSocket protocol, reception terminal 5 waits for reception of all the fragmented frames of the content data to end. Without receiving emergency data. Accordingly, in data distribution using the WebSocket protocol, emergency data can be interrupted and received, and the emergency data can be immediately transmitted to the user.

  Further, when receiving the emergency data interrupt, the receiving terminal 5 does not need to discard the pieces of content data received so far. In addition, after restoring the emergency data, the receiving terminal 5 concatenates the content data fragment received so far and the content data fragment included in the payload of the subsequent fragmented frame to restore the original content data. can do. Therefore, processing such as retransmission of content data in the push delivery server 4 is not required, and reception processing of the retransmitted fragmented frame is also not required in the receiving terminal 5, thereby improving data transmission efficiency. In addition, since the interruption reception of emergency data is realized using the WebSocket protocol, an existing system that implements the WebSocket protocol can be used.

  The receiving terminal 5 according to the embodiment of the present invention extracts or sets Tag and hcode which are header information of encapsulated data and tcode which is trailer information for each received fragmented frame, and fragments of content data from the fragmented frame Is extracted and stored in the content data storage means 33. In this reception process, without generating encapsulated data, a piece of content data is directly extracted from the fragmented frame to restore the content data. On the other hand, the encapsulated data may be generated from the received fragmented frame, and the content data may be restored from the encapsulated data.

  Specifically, when the receiving terminal 5 according to another embodiment of the present invention stores the received fragmented frame in a buffer and determines that the FIN stored in the header of the fragmented frame is 1, The fragment data of the encapsulated data is extracted from the fragmented frame stored in the buffer before, the fragment data is combined to generate the encapsulated data, the content data is extracted from the encapsulated data, and the content data is associated with the Tag Store in the storage means 33. Thereby, the content data is restored.

  In addition, when receiving the interruption frame, the receiving terminal 5 according to another embodiment determines that the FIN stored in the header of the interruption frame is 1, and determines from the fragmented frames stored in the buffer until then. Extract the fragment data of the encapsulated data, combine the fragment data in the same process as described above to generate encapsulated data in the middle, extract the fragments from the encapsulated data in the middle, and associate them with the tag content Store in the data storage means 33. When the receiving terminal 5 receives the resume frame, receives the subsequent fragmented frame, and determines that FIN is 1, the fragment of encapsulated data from the fragmented frame stored in the buffer until then. Data is extracted and fragmented data are combined to generate encapsulated data in the same way as described above, and fragments are extracted from the encapsulated data in the middle and associated with the Tag in the content data storage means 33. Store. Thereby, the content data is restored.

  As described above, according to the receiving terminal 5 according to another embodiment of the present invention, it is unnecessary to extract or set Tag and hcode that are header information of encapsulated data and tcode that is trailer information for each fragmented frame. Therefore, the processing burden can be reduced.

  Note that, as the hardware configuration of the push delivery server 4 according to the embodiment of the present invention and the hardware configuration of the receiving terminal 5 according to the embodiment of the present invention and other embodiments, a normal computer can be used. The push delivery server 4 and the receiving terminal 5 are each configured by a computer having a CPU, a volatile storage medium such as a RAM, a non-volatile storage medium such as a ROM, and an interface. Session control means 10, content data input means 11, emergency data input means 12, tag management means 13, fragment generation means 14, fragment buffer 15, emergency data fragment generation means 16, emergency data fragment buffer 17 provided in the push delivery server 4 The functions of the fragment multiplexing unit 18, the packet transmission unit 19, and the communication I / Fs 20 and 21 are realized by causing the CPU to execute a program describing these functions. The functions of the connection control means 30, the packet reception means 31, the fragment restoration means 32, the content data storage means 33, the decoder 34, the presentation unit 35, and the communication I / F 36 provided in the receiving terminal 5 also describe these functions. Each program is realized by causing the CPU to execute the program. These programs can be stored and distributed on a storage medium such as a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, etc., and sent and received via a network. You can also

  The present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical idea thereof. In the above embodiment, the case where emergency data is interrupted and transmitted when data is being transmitted has been described. However, the present invention interrupts other data that is not emergency data when data is being transmitted. This also applies to the case of transmitting, or when transmitting a plurality of different data in parallel.

DESCRIPTION OF SYMBOLS 1 Content delivery system 2 Content server 3 Emergency data server 4 Push delivery server 5 Receiving terminal 6 Content relay network 7 Internet 10 Session control means 11 Content data input means 12 Emergency data input means 13 Tag management means 14 Fragment generation means 15 Fragment buffer 16 Emergency data fragment generation means 17 Emergency data fragment buffer 18 Fragment multiplexing means 19 Packet transmission means 20, 21, 36 Communication I / F
30 connection control means 31 packet receiving means 32 fragment restoration means 33 content data storage means 34 decoder 35 presentation unit

Claims (8)

In a push delivery server that transmits predetermined data to a receiving terminal using the WebSocket protocol,
Predetermined data is input, header information including a start / continuation identification flag indicating whether or not the data includes an identifier of the data and a start position of the data is added, and an end position of the data is set. Trailer information including an end / continuation identification flag indicating whether or not to include is generated to generate encapsulated data, the encapsulated data is divided into fragment data of a predetermined length, and each of the fragment data First control information indicating whether a fragmented frame for transmitting data is for transmitting the last fragment data divided from the encapsulated data, and a fragmented frame for transmitting the fragment data, Generation of second control information indicating whether or not to continuously transmit fragment data in the middle of division from the encapsulated data , Said header imparted to WebSocket including the first and second control information used in the protocol, the fragment generator means for generating a fragmentation frame stores the fragment data in the payload,
Fragment transmitting means for transmitting the fragmented frame generated by the fragment generating means to the receiving terminal,
The fragment transmission means includes
When the transmission of the fragmented frame of the data is interrupted and the fragmented frame of other data is interrupted and transmitted,
Adding a header used for the WebSocket protocol, generating an interrupt frame storing the end / continuation identification flag indicating that the end position is not included in a payload, and transmitting the interrupt frame to the receiving terminal;
When resuming transmission of the interrupted data fragmentation frame,
A header used for the WebSocket protocol is added to generate a resume frame in which the identifier of the interrupted data and the start / continuation identification flag indicating that the start position is not included are stored in a payload, and the resume frame is A push delivery server characterized by transmitting to a receiving terminal. In the push delivery server according to claim 1,
A new fragment transmission means replacing the fragment transmission means is:
When the transmission of the fragmented frame of the data is interrupted and the fragmented frame of other data is interrupted and transmitted,
A header to be used for the WebSocket protocol is added to generate a suspend frame in which the end / continuation identification flag indicating that the end position is not included is stored in a payload, and the suspend frame is transmitted to the receiving terminal. Send a fragmented frame of data to the receiving terminal,
When resuming transmission of the interrupted data fragmentation frame,
After transmitting all the fragmented frames in the other data to the receiving terminal, the header used for the WebSocket protocol is added to indicate the identifier of the interrupted data and the start / not indicating the start position. A push distribution characterized by generating a restart frame storing a continuation identification flag in a payload, transmitting the restart frame to the receiving terminal, and transmitting the remaining fragmented frames in the interrupted data to the receiving terminal. server. In the push delivery server according to claim 1 or 2,
Instead of the fragment generation means, a first fragment generation means and a second fragment generation means, further comprising a first fragment buffer and a second fragment buffer,
The first fragment generation means includes:
The data is input, header information including the start / continuation identification flag is added to the data, trailer information including the end / continuation identification flag is added to generate encapsulated data, and the encapsulation is performed. The first control information and the second control information used for the WebSocket protocol are generated by dividing the data into fragment data of a predetermined length, generating the first control information and the second control information for each of the fragment data. The fragment data is stored in a payload to generate a fragmented frame, the fragmented frame is stored in the first fragment buffer,
The second fragment generation means includes:
The other data is input, header information including the start / continuation identification flag is added to the other data, and trailer information including the end / continuation identification flag is added to generate encapsulated data. , Dividing the encapsulated data into fragment data of a predetermined length, generating the first control information and the second control information for each of the fragment data, and using the first and second control information used for the WebSocket protocol A header including two control information, storing the fragment data in a payload to generate a fragmented frame, storing the fragmented frame in the second fragment buffer,
The fragment transmission means includes
When the fragmented frame of data is stored in the first fragment buffer, the fragmented frame of data is read from the first fragment buffer and transmitted to the receiving terminal;
When the transmission of the fragmented frame of the data is interrupted and the fragmented frame of the other data is interrupted and transmitted,
When a fragmented frame of the other data is stored in the second fragment buffer, a header used for the WebSocket protocol is added, and the end / continuation identification flag indicating that the end position is not included is included in the payload. Generating a stored interrupt frame, transmitting the interrupt frame to the receiving terminal, reading out the fragmented frame of the other data from the second fragment buffer and transmitting to the receiving terminal;
When resuming transmission of the interrupted data fragmentation frame,
A header used for the WebSocket protocol is added to generate a resume frame in which the identifier of the interrupted data and the start / continuation identification flag indicating that the start position is not included are stored in a payload, and the resume frame is A push delivery server that transmits to a receiving terminal, reads out the remaining fragmented frames in the data from the first fragment buffer, and transmits them to the receiving terminal. In the push delivery server according to any one of claims 1 to 3,
The push of the interrupt frame transmitted by the fragment transmitting means includes first control information indicating that the last fragment data divided from the encapsulated data is transmitted. Distribution server. Header information including a start / continuation identification flag indicating whether or not to include the identifier of the data and the start position of the data is given to predetermined data, and indicates whether or not the end position of the data is included Fragmentation that adds trailer information including an end / continuation identification flag to generate encapsulated data, divides the encapsulated data into fragment data of a predetermined length, and transmits the fragment data for each of the fragment data First control information indicating whether or not a frame is to transmit the last fragment data divided from the encapsulated data, and a fragmented frame for transmitting the fragment data is divided from the encapsulated data. Generated second control information indicating whether or not to continue to transmit the fragment data in the middle, WebSocket From a push delivery server that adds a header including the first and second control information used for the protocol, stores the fragment data in a payload, generates and transmits a fragmented frame, and uses the WebSocket protocol In the receiving terminal that receives the fragmented frame,
For each received fragmented frame, extract the first and second control information from the header of the fragmented frame, and extract fragment data constituting the encapsulated data from the payload of the fragmented frame; Header information and trailer information including the identifier is extracted from the extracted fragment data with reference to a table storing the relationship between the combination of the first and second control information and the presence of the header information and trailer information. When one or both of the header information and trailer information cannot be extracted, predetermined information is set for the header information that could not be extracted, and predetermined information is set for the trailer information that could not be extracted. Based on the header information and trailer information set and extracted or set And fragment restoring means fragments of the data from the extracted fragment data to extract, to restore the data,
Storage means for storing the pieces of data extracted by the fragment restoration means in association with identifiers of the header information extracted or set by the fragment restoration means;
A decoder for inputting the data restored from the storage means and decoding the data;
A presentation unit for presenting the data decoded by the decoder to a user of the receiving terminal,
The fragment restoration means includes
When receiving the data fragmentation frame, the push distribution server interrupts transmission of the data fragmentation frame and interrupts and transmits another data fragmentation frame. And receiving a break frame in which a header used for the WebSocket protocol is added and the end / continuation identification flag indicating that the end position is not included is stored in a payload,
Extracting the first and second control information from the header of the interrupt frame, referring to the table, extracting the end / continuation identification flag of the trailer information from the payload of the interrupt frame;
A frame indicating that transmission of the fragmented frame of the interrupted data is resumed from the push delivery server, including a header used for the WebSocket protocol, including the identifier of the interrupted data and the start position When the restart frame in which the start / continuation identification flag indicating the absence is stored in the payload is received,
Extracting the first and second control information from the header of the resume frame, referring to the table, the identifier of the interrupted data included in the header information from the payload of the resume frame and the start / continuation identification A receiving terminal characterized by extracting a flag. In the receiving terminal according to claim 5,
The front SL disruptions frame header, includes a first control information indicating that the is to send the last fragment data divided from the encapsulated data,
A new fragment restoration means replacing the fragment restoration means is:
Storing the received fragmented frame in the storage means, extracting the first and second control information from a header of the received fragmented frame or a header of the received interrupted frame, and the first control information Indicates that the last fragment data divided from the encapsulated data is to be transmitted, the fragment constituting the encapsulated data from the payload by reading the fragmented frame stored in the storage means A receiving terminal, wherein data is extracted and a fragment of the data is extracted from the extracted fragment data.   A receiving program for causing a computer to function as the receiving terminal according to claim 5 or 6.   A system comprising the push delivery server of claim 1 and the receiving terminal of claim 5.

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