JP2014017767A - Method and system for automatically reproducing multicast data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that avoids unnecessarily sending multicast data between a router and a terminal by reliably starting a media player program at the terminal before delivering the multicast data.SOLUTION: The method includes: a first step of a delivery server continuously delivering a data series and periodically delivering a delivery control packet; a second step of the terminal sending to the router a first transfer request packet requesting the delivery control packet to be received; a third step of the router relaying the delivery control packet received from the delivery server as it is to the terminal; a fourth step of the terminal automatically starting an execution program for the data series when receiving the delivery control packet; a fifth step of the terminal sending to the router a second transfer request packet requesting the data series to be received; and a sixth step of the router relaying the data series received from the delivery server as it is to the terminal.

Description

  The present invention relates to a technique for reproducing multicast data.

  Conventionally, there is a receiver technique for receiving streaming data of content by multicast. This multicast protocol is based on, for example, RFC2236 and RFC2710 (see Non-Patent Documents 1 and 2, for example). “Multicast” refers to a technique for transmitting the same data to a plurality of destination devices. On the other hand, “unicast” refers to a technique for designating a single address and transmitting data only to a specific destination device.

  The receiver that receives the streaming data usually starts a media player program for reproducing the streaming data in response to a user operation (manual operation). Next, the receiver transmits a message to join the multicast group of the streaming data to the last hop router in the membership report of the multicast group. The last hop router is a device such as a multicast-compatible router connected to the same subnet as the receiver. For example, a device such as an access point in a wireless local area network (LAN) may have the function of a last hop router.

Streaming data is generally composed of two types of packets as follows.
Data packet: Including content data Data control packet: Including control information for content reproduction of data packet Normally, a “data control packet” includes a content distribution start / delivery stop control notification (distribution control packet), Parameters for content playback such as content decryption / recombination. The streaming data (data packet and data control packet) is distributed by the same multicast address and port number for each content.

  Conventionally, streaming data distributed by multicast (hereinafter referred to as “multicast data”) is often distributed via a wired network such as an optical fiber cable capable of large-capacity transmission. On the other hand, in recent years, multicast data is often distributed via a wireless network between a base station and a wireless terminal. That is, by distributing streaming data by multicast even in a wireless communication environment, it is possible to provide a broadcast service to a number of specific destination terminals with only a minimum bandwidth guarantee.

  Conventionally, in a wireless LAN, there is a technique in which a master unit of an access point controls distribution of multicast data so that multicast data is not distributed even though no wireless terminal participates in the multicast group ( For example, see Patent Document 1). According to this technique, the base unit of the wireless LAN holds the multicast list table and controls whether or not data should be transmitted to the subordinate subordinates.

  In addition, there is a technique in which, when a data packet including system status information is relayed and transferred, an access point temporarily holds only the data packet and repeatedly retransmits the data packet (see, for example, Patent Document 2). According to this technique, even a wireless terminal that does not have a retransmission procedure can reliably receive a data packet including system state information.

  Furthermore, in order to cope with a change in the radio environment, there is a technique for changing the redundancy of FEC (Forward Error Correction) of multicast data in accordance with the reception status result of the receiver (for example, Patent Document 3). reference). According to this technique, the amount of data flowing to the receiver side under the access point can be transmitted while being suppressed as much as possible. Compared to a wired network, a wireless network has many errors in packet collisions and the like that occur in bursts. This technique can suppress the possibility of data control packets and data packets being lost.

JP 2001-57560 A JP 2005-167776 A JP 2004-201111 A

RFC 2236, “Internet Group Management Protocol, Version 2”, [online], [searched on June 24, 2012], Internet <URL: http://www.ietf.org/rfc/rfc2236.txt> RFC2710, “Multicast Listener Discovery (MLD) for IPv6”, [online], [searched on June 24, 2012], Internet <URL: http://www.ietf.org/rfc/rfc2710.txt>

  However, in any of the above-described conventional techniques, the receiver (terminal) needs to manually start the media player program in response to a user operation in order to reproduce the streaming data distributed from the distribution server. . This is not preferable from the convenience of the user. In addition, when the media player program is not activated and the last hop router transmits multicast data to the receiver, the multicast data is completely unnecessary. In particular, when a wireless network is between the router and the receiver, the communication resource is wasted. That is, unless the media player program is activated, multicast data should not be transmitted.

  Therefore, the present invention provides a method and system for preventing unnecessary multicast data from being transmitted between a router and a terminal by surely starting the media player program before the multicast data is distributed. The purpose is to do.

According to the present invention, for a system having a router that relays and forwards a data sequence by multicast and a terminal that reproduces the data sequence received from the router, a method for automatically executing the data sequence by a terminal,
A first step in which the distribution server constantly distributes the data series and periodically distributes the distribution control packet;
A second step in which the terminal transmits a first transfer request packet to be requested to receive a delivery control packet to the router;
The router relays and transfers the distribution control packet received from the distribution server to the terminal as it is,
When the terminal receives the distribution control packet, the terminal automatically starts the data sequence execution program;
The terminal transmits a second transfer request packet to be requested to receive the data sequence to the router;
The router has a sixth step of relaying and transferring the data series received from the distribution server to the terminal as it is.

According to another embodiment of the method of the present invention,
The multicast data sequence distributed by the distribution server is streaming data,
The execution program started by the terminal is preferably a media player program.

  According to another embodiment of the method of the present invention, for the fourth step, even if the terminal cannot receive the first distribution control packet, the next distribution control packet periodically distributed from the distribution server It is also preferable that can be received.

According to another embodiment of the method of the present invention,
For the first step, the distribution server distributes the distribution control packet with the first multicast address, distributes the data series with the second multicast address,
For the second step, the first transfer request packet transmitted by the terminal is a participation message that should receive the distribution control packet of the first multicast address;
Regarding the fifth step, the second transfer request packet transmitted by the terminal is preferably a participation message to receive the data sequence of the second multicast address.

According to another embodiment of the method of the present invention, for the first step,
The distribution server distributes different content as different data series,
It is also preferable that the delivery control packet and each data series are delivered by different multicast addresses.

According to another embodiment of the method of the present invention, the multicast address is based on IGMP (Internet Group Management Protocol) in the case of IPv4, and is based on Multicast Listener Discovery (MLD) in the case of IPv6,
The participation message is also preferably a Join message.

According to the present invention, a system includes a distribution server that always distributes a multicast data sequence, a router that relays and forwards the data sequence received from the distribution server, and a terminal that reproduces streaming data received from the router. In
The distribution server always distributes the data series and periodically distributes the distribution control packet.
The terminal
First transfer request transmission means for transmitting to the router a first transfer request packet that should request reception of a distribution control packet;
Media player activation means for automatically activating an execution program of a data sequence when receiving a distribution control packet;
Second transfer request transmission means for transmitting a second transfer request packet to be requested to receive streaming data to the router;
Router
First relay transfer means for relaying and transferring the distribution control packet received from the distribution server to the terminal as it is after receiving the first transfer request packet from the terminal;
After receiving the second transfer request packet from the terminal, it has a second relay transfer means for relaying and transferring the data series received from the distribution server to the terminal as it is.

According to another embodiment of the system of the present invention,
The multicast data sequence distributed by the distribution server is streaming data,
The execution program started by the terminal is preferably a media player program.

  According to another embodiment of the system of the present invention, the media player activation means of the terminal receives the next distribution control packet periodically distributed from the distribution server even when the first distribution control packet cannot be received. It is also preferred that it can be received.

According to another embodiment of the system of the present invention,
The distribution server distributes the distribution control packet with the first multicast address, distributes the data series with the second multicast address,
The first transfer request packet transmitted by the first transfer request transmitting means of the terminal is a participation message that should receive the distribution control packet of the first multicast address,
The second transfer request packet transmitted by the second transfer request transmitting means of the terminal is preferably a participation message that should receive the data sequence of the second multicast address.

According to another embodiment of the system of the present invention,
The distribution server distributes different content as different data series,
It is also preferable that the delivery control packet and each data series are delivered by different multicast addresses.

According to another embodiment of the system of the present invention, the multicast address is based on IGMP in the case of IPv4, and based on MLD in the case of IPv6,
The participation message is also preferably a Join message.

  According to the method and system of the present invention, it is possible to prevent unnecessary multicast data from being transmitted between the router and the terminal by reliably starting the media player program before the multicast data is distributed. Can do.

It is a system configuration diagram in the present invention. It is a sequence diagram in the present invention. It is a sequence diagram when a terminal cannot receive a delivery control packet. It is a sequence diagram in case streaming data of a plurality of contents is distributed from a distribution server. It is a functional block diagram of a router and a terminal in the present invention.

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

  FIG. 1 is a system configuration diagram according to the present invention.

According to FIG. 1, for example, a distribution server 1 that constantly distributes a data series such as streaming data by multicast is provided in a communication carrier network. The distribution server 1 distributes the contents of the streaming data with different multicast addresses and port numbers. The distribution server 1 of the present invention divides and distributes packets as follows [multicast address 0]: dedicated to distribution control packet The distribution control packet includes a distribution start notification / distribution stop notification.
Distribution start notification: Control information for the terminal to automatically start the media player program Distribution stop notification: Control information for the terminal to automatically stop the media player program [Multicast address 1]: Dedicated to the first streaming data of the first content 1st streaming data = 1st data packet + 1st data control packet 1st data packet: 1st content data itself 1st data control packet: Control information of decoding and recombination of 1st data packet [Multicast address 2]: Dedicated to second streaming data of second content Second streaming data = second data packet + second data control packet Second data packet: second content data itself second Data control packet: second Control information decoding and recombination of Tapaketto .....
[Multicast address N]: dedicated to Nth streaming data of Nth content Nth streaming data = Nth data packet + Nth data control packet Nth data packet: Nth content data itself Nth Data control packet: control information for decoding and recombination of the Nth data packet

  The distribution server 1 of the present invention is characterized in that a “distribution control packet” is transmitted separately from the streaming data for each content. That is, regarding the control packet, a “distribution control packet” for notifying the start or stop of distribution of content, and a “data control packet” required for a data packet decoding process or a file recombination process in the terminal 3 on the receiving side. Distinguish between The “distribution control packet” is distributed by a multicast address and a port number different from the streaming data (data control packet and data packet) for each content. On the other hand, the data control packet and the data packet included in the streaming data of one content are distributed by the same multicast address and port number.

  The multicast address is based on IGMP (Internet Group Management Protocol) in the case of IPv4, and is based on MLD (Multicast Listener Discovery) in the case of IPv6.

  Further, according to FIG. 1, the router 2 is connected between the communication carrier network to which the distribution server 1 is connected and the wireless LAN to which the terminal 3 is connected. The router 2 is an access point for the wireless LAN and functions as a last hop router in multicast. The router 2 relays and forwards the distribution control packet and streaming data (data control packet + data packet) received from the distribution server 1 by multicast. The router 2 controls the availability of transmission for each delivery control packet and streaming data by receiving a join / leave message for the multicast group from the terminal 3.

  The terminal 3 is connected to the router 2 via a wireless LAN. And the terminal 3 can reproduce | regenerate the streaming data received from the router 2, and can make a user browse the content.

  The terminal 3 is preinstalled with a “media player program” for reproducing streaming data. The “media player program” is software with a built-in codec for each media data. As a result, various media data such as moving images and sounds can be reproduced. In general, a standard media player program is incorporated in a Web browser.

  The terminal 3 cannot reproduce the streaming data received from the router 2 unless the media player program is activated in advance. The terminal 3 can control the start / stop of multicast streaming data reception by transmitting a message to / from the multicast group to the router 2.

  Here, the distribution control packet in the present invention includes control information (distribution start notification) for automatically starting the media player program in the terminal 3. As a result, the terminal 3 can automatically start the media player program when receiving the distribution control packet.

  FIG. 2 is a sequence diagram in the present invention.

(S1) The distribution server 1 always distributes streaming data (data control packet and data packet) and periodically distributes the distribution control packet. Here, the distribution server 1 distributes the distribution control packet at the first multicast address 0 and distributes the streaming data at the second multicast address 1 as described above. That is, the streaming data and the distribution control packet belong to different multicast groups. However, at this stage, since the terminal 3 does not belong to any multicast group, neither streaming data nor a delivery control packet is transmitted to the terminal 3.

(S2) The terminal 3 transmits to the router 2 a first transfer request packet that should request reception of the distribution control packet. Here, the first transfer request packet transmitted by the terminal 3 is a participation message (for example, a Join message) to be joined to the multicast group having the first multicast address 0. As a result, the terminal 3 belongs to the multicast group of the distribution control packet, and can receive the distribution control packet.

(S3) The router 2 that has received the participation message (first transfer request packet) from the terminal 3 relays and forwards the distribution control packet received from the distribution server 1 to the terminal 3 as it is. However, at this stage, since the terminal 3 does not belong to the multicast group of streaming data, the streaming data is not transmitted to the terminal 3.

(S4) The terminal 3 that has received the distribution control packet automatically activates the media player program when the distribution control packet is a distribution start notification. As a result, the terminal 3 is in a state where the streaming data can be reproduced.

(S5) Next, the terminal 3 transmits to the router 2 a second transfer request packet that should request reception of streaming data. Here, the second transfer request packet transmitted by the terminal 3 is a participation message (for example, a Join message) to be joined to the multicast group of the second multicast address 1. As a result, the terminal 3 belongs to the multicast group of the streaming data and can receive the streaming data.

According to the present invention, as described above by S2 and S5, the terminal 3 needs to transmit the following two-stage participation message.
(1) First participation message for receiving distribution control packet (2) Second participation message for receiving streaming data (data control packet and data packet) The player program can be activated and the streaming data can be received and played by the second participation message. As a result, the use efficiency of the network resource is increased without a packet unnecessary for the terminal 3 flowing in the network (for example, wireless LAN) under the last hop router 2.

(S6) The router 2 relays and forwards the streaming data necessary for reproducing the streaming data received from the distribution server 1 to the terminal as it is. The streaming data received by the terminal 3 from the router 2 includes a data control packet and a data packet, and the media player program of the terminal 3 reproduces content such as decoding and recombination of the content included in the data control packet. The content included in the data packet is reproduced based on the parameters for

(S7) Thereafter, the distribution server 1 distributes the distribution control packet (distribution stop notification) to the router 2 after the distribution of the streaming data is completed. On the other hand, the router 2 relays and transfers the distribution control packet to the terminal 3 as it is.

(S8) After receiving the distribution control packet (distribution stop notification) from the router 2, the terminal 3 automatically stops the media player program.

(S9) Finally, the terminal 3 transmits a second transfer stop packet to stop receiving streaming data to the router 2. Here, the second transfer stop packet transmitted by the terminal 3 is a leave message (for example, a leave message) that should leave the multicast group of the second multicast address 1. As a result, the terminal 3 can leave the multicast group of streaming data and prevent the streaming data from flowing.

  In addition, the terminal 3 transmits a first transfer stop packet to stop receiving the distribution control packet to the router 2. Here, the first transfer stop packet transmitted by the terminal 3 is a leave message (for example, a leave message) that should leave the multicast group having the first multicast address 0. As a result, the terminal 3 can leave the multicast group of the distribution control packet and prevent the distribution control packet from flowing.

  FIG. 3 is a sequence diagram when the terminal cannot receive the delivery control packet.

  According to the step of S3 in FIG. 3, the distribution control packet (distribution start notification) is lost during communication, and the terminal 3 cannot receive the distribution control packet. For this reason, the terminal 3 cannot automatically start the media player program.

  Here, the distribution server 1 of the present invention periodically distributes distribution control packets. According to the present invention, since the delivery control packet is assigned a multicast address different from each streaming data, only the delivery control packet can be delivered independently and multiple times. Therefore, even when the terminal 3 cannot receive the first distribution control packet, the router 2 can relay and transfer the distribution control packet received from the distribution server 1 at the next timing to the terminal 3 as it is. As a result, the terminal 3 can automatically start the media player program reliably before receiving the streaming data.

  FIG. 4 is a sequence diagram when streaming data of a plurality of contents is distributed from a distribution server.

  According to FIG. 4, the distribution server 1 distributes a plurality of pieces of streaming data for each content. In this case, after starting the media player program, the content to be reproduced is selected in S5 in accordance with the user operation. The terminal 3 transmits a participation message to the router 2 with respect to the streaming data based on the selected content. According to FIG. 4, the content 2 is selected according to the user operation.

  FIG. 5 is a functional configuration diagram of the router and the terminal according to the present invention.

  The terminal 3 includes, in hardware, a wireless interface that communicates with the router 2 and a user interface such as a display and a keyboard (for example, a touch panel display). Further, the terminal 3 includes a first transfer request transmission unit 31, a media player activation unit 32, and a second transfer request transmission unit 33. These functional components are realized by executing a program that causes a computer installed in the terminal to function.

The first transfer request transmission unit 31 transmits a first transfer request packet (participation message) that should request reception of the distribution control packet to the router 2 (see S2 in FIG. 3).
When the media player activation unit 32 receives the distribution control packet, the media player activation unit 32 automatically activates the data series execution program (see S4 in FIG. 3).
The second transfer request transmission unit 33 transmits to the router 2 a second transfer request packet (participation message) that should request reception of streaming data (see S5 in FIG. 3).

  The router 2 has a communication interface on the terminal 3 side and a communication interface on the distribution server 1 side in terms of hardware. The router 2 includes a first relay transfer unit 21 and a second relay transfer unit 22. These functional components are realized by executing a program that causes a computer mounted on the router to function.

After receiving the first transfer request packet (participation message) from the terminal 3, the first relay transfer unit 21 relays and transfers the distribution control packet received from the distribution server to the terminal 3 (S2 and FIG. 2). (See S3).
After receiving the second transfer request packet (participation message) from the terminal 3, the second relay transfer unit 22 relays and transfers the streaming data received from the distribution server to the terminal 3 as it is (S5 and S6 in FIG. 2). reference).

  Finally, a specific service example to which the present invention is applied will be described.

  Specifically, the terminal has two modes of “school mode” and “corporate mode”, and one of the modes is selected in accordance with a user operation. The “school mode” is to automatically start the media player program when the terminal receives a distribution control packet (distribution start notification) as in the above-described embodiment. The distribution control packet (distribution start notification) includes a content ID and a user profile (grade, class name, class name, etc.). Also, a content ID and a user profile are registered in advance in the terminal. By checking these, it is controlled whether or not the media player program is automatically started. Of course, when the terminal receives the distribution control packet (distribution stop notification), the media player program is automatically stopped. That is, the distribution server controls the start / stop of the media player program in the terminal and the selection of content to be viewed.

  In the school mode, as long as the terminal can receive the delivery control packet (delivery start notification), the media player program starts automatically and sends a participation message for streaming data at any time or delivery. Even from the middle, the user can view the content. In particular, when a large number of terminals view the streaming data of one content at the same time, the media player program is automatically activated, and the convenience for the user is considerably improved.

  On the other hand, in the “corporate mode”, the media player program is activated in response to a user operation on the program guide regardless of whether or not a distribution control packet (distribution start notification) is received. Next, the terminal transmits a participation message regarding the content selected for the program guide to the router. Also, by including the updated contents of the program guide in the distribution control packet (delivery start notification), the latest program guide can be generated at the terminal and the latest content can be viewed.

  As another specific service example, the delivery server has two modes of “streaming mode” and “download mode”. In the “streaming mode”, the streaming data received by the terminal is recombined with the received file temporarily divided in the cache area, and then transferred to the media player program, and at the same time, the received file is discarded. On the other hand, in the “download mode”, the received file passed to the media player program is stored in the internal memory without being discarded.

  As described above in detail, according to the method and system of the present invention, it is unnecessary between the router and the terminal by starting the media player program surely before the multicast data is distributed. Multicast data can be prevented from being transmitted.

  Various changes, modifications, and omissions of the above-described various embodiments of the present invention can be easily made by those skilled in the art. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

DESCRIPTION OF SYMBOLS 1 Distribution server 2 Router 21 1st relay transfer part 22 2nd relay transfer part 3 Terminal 31 1st transfer request transmission part 32 Media player starting part 33 2nd transfer request transmission part

Claims (12)

A system comprising: a distribution server that always distributes a multicast data sequence; a router that relays and forwards the data sequence received from the distribution server by multicast; and a terminal that reproduces the data sequence received from the router. In the method of automatically executing the data series by:
A first step in which the distribution server constantly distributes the data series and periodically distributes a distribution control packet;
A second step in which the terminal transmits a first transfer request packet to be requested to receive the delivery control packet to the router;
The router relays and forwards the distribution control packet received from the distribution server to the terminal as it is,
A fourth step of automatically starting the execution program of the data series when the terminal receives the delivery control packet;
The terminal transmits a second transfer request packet to be requested to receive the data series to the router;
And a sixth step of relaying and forwarding the data series received from the distribution server to the terminal as it is. The multicast data series distributed by the distribution server is streaming data;
2. The method according to claim 1, wherein the execution program started by the terminal is a media player program.   Regarding the fourth step, the terminal is capable of receiving a next distribution control packet periodically distributed from the distribution server even when the terminal cannot receive the first distribution control packet. Item 3. The method according to Item 1 or 2. For the first step, the distribution server distributes the distribution control packet with a first multicast address, distributes the data series with a second multicast address,
For the second step, the first transfer request packet transmitted by the terminal is a participation message to receive the distribution control packet of the first multicast address;
4. The fifth step according to claim 1, wherein the second transfer request packet transmitted by the terminal is a participation message that should receive the data sequence of the second multicast address. 5. The method according to item. For the first step,
The distribution server distributes different content as different data series,
The method according to claim 4, wherein the delivery control packet and each data series are delivered by different multicast addresses. The multicast address is based on IGMP (Internet Group Management Protocol) in the case of IPv4, and is based on MLD (Multicast Listener Discovery) in the case of IPv6.
The method according to claim 4 or 5, wherein the participation message is a Join message. In a system having a distribution server that always distributes a multicast data sequence, a router that relays and forwards the data sequence received from the distribution server, and a terminal that reproduces the streaming data received from the router,
The distribution server always distributes the data series and periodically distributes a distribution control packet,
The terminal
First transfer request transmission means for transmitting to the router a first transfer request packet that should request reception of the distribution control packet;
Media player starting means for automatically starting the execution program of the data series when receiving the distribution control packet;
Second transfer request transmission means for transmitting a second transfer request packet to be requested to receive the streaming data to the router;
The router
First relay transfer means for relaying and transferring the distribution control packet received from the distribution server to the terminal as it is after receiving the first transfer request packet from the terminal;
And a second relay transfer unit configured to relay and transfer the data series received from the distribution server to the terminal as it is after receiving the second transfer request packet from the terminal. The multicast data series distributed by the distribution server is streaming data;
The system according to claim 7, wherein the execution program started by the terminal is a media player program.   The media player activation unit of the terminal is capable of receiving a next distribution control packet periodically distributed from the distribution server even when the first distribution control packet cannot be received. The system according to 7 or 8. The distribution server distributes the distribution control packet with a first multicast address, and distributes the data series with a second multicast address;
The first transfer request packet transmitted by the first transfer request transmitting means of the terminal is a participation message to receive the distribution control packet of the first multicast address,
The second transfer request packet transmitted by the second transfer request transmitting means of the terminal is a participation message to receive the data sequence of the second multicast address. The system according to claim 1. The distribution server distributes different content as different data series,
The system according to claim 10, wherein the delivery control packet and each data series are delivered by different multicast addresses. The multicast address is based on IGMP in the case of IPv4, and is based on MLD in the case of IPv6.
The system according to claim 10 or 11, wherein the participation message is a Join message.

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