KR20080061583A - System and method for reducing cannel zapping time of iptv - Google Patents

Abstract

A system and a method for shortening a channel change time of an Internet broadcast are provided to quickly cope with a channel change of a subscriber by increasing the number of channels. When an IP(Internet Protocol) STB(Set Top Box)(12) is initially driven(S12), the IP STB outputs an STB authentication and subscriber DB information request message to a subscriber DB server(S14). The subscriber DB server searches information about a channel group to which the subscriber has been subscribed, and transmits the search result to a home gateway(S16). The home gateway generates an IGMP(Internet Group Management Protocol) join message for receiving streams of a channel included in the channel group information and transmits it to an IPTV head end(S18,S20). The IPTV head end transmits streams of each channel to the home gateway(S22).

Description

System and method for reducing channel change time of internet broadcasting {SYSTEM AND METHOD FOR REDUCING CANNEL ZAPPING TIME OF IPTV}

1 is a network diagram illustrating a system for shortening a channel change time of internet broadcasting according to an exemplary embodiment of the present invention.

2 is a flowchart illustrating a method for shortening a channel change time of an internet broadcast according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

12: IP STB 14: home gateway

16: PON ONT 22: PON OLT

24: L3 Switch 32: Router

34: subscriber DB server 36: IPTV head and end

The present invention relates to a system and method for reducing channel change time of Internet broadcasting, and more particularly, to a technique for reducing channel changing time in implementing a broadcast service based on an Internet Protocol (IP) network.

IPTV uses multicasting technology to efficiently use bandwidth by transmitting existing broadcast services over IP networks.

Multicasting is particularly effective in backbone (backbone) networks, and is a technique for effectively delivering multiple channels. There are several protocols for multicasting technology, but the most common ones are the Internet Group Management Protocol (IGMP) and Protocol Independent Multicasting (PIM). IGMP is used in networks consisting of sub-L2 nodes, and PIM is a routing protocol in L3 networks.

In general, the delay from the rendezvous point (RP) to the edge router (final router) is small because almost all channels are transferred, but at the bottom, it is a section where frequent channel changes occur, which causes a lot of command processing delay and network delay.

IGMP involves several message delivery processes to change the channel, including IGMP query messages from the switch (or router) to determine whether the host on the underlying network is using the channel, or to request that the host join the channel group to use the channel. The join message, and the leave message requesting to leave the channel group in use by the host, are delivered several times.

As described above, since IGMP has to deliver several query / join / leave messages for channel change, channel change, which is the time taken until the broadcast signal of the channel selected by the subscriber is output on the terminal when changing the channel of the subscriber. Zapping time occurs. For reference, factors determining channel change time include command processing time, network delay time, jitter buffer delay time, and image decoding time.

On the other hand, since a channel change time in a broadcast service has a great influence on viewers' preferences, various techniques for reducing this have been proposed.

For example, there is a method of shortening the channel change time by simultaneously transmitting the channel before and after the channel requested by the subscriber. That is, when the subscriber changes to channel "10", three channel streams are received by simultaneously joining "9", "10", and "11", and the subscriber receives "9" through a control interface such as a remote controller. If you want to change channels to "11" or "11", you can switch channels quickly.

However, in this case, if the subscriber selects a channel through the channel up / down key on the remote control, the channel can be quickly switched when watching channel “10” and selecting “9” or “11”. However, if a channel "20" or a channel "30" is selected other than the adjacent channel, the channel change time still occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to set up a plurality of streams registered by a subscriber in advance in implementing an IP network-based broadcast service. Home Gateway) to reduce network delay time and command processing time to reduce channel change time.

In order to achieve the above object, the channel change time reduction system of the Internet broadcast in accordance with the present invention, the subscriber DB server stores the channel group information for the Internet broadcast subscriber; An IP broadcasting terminal receiving channel group information from the subscriber DB server during initial operation, receiving a plurality of channel streams corresponding to the channel group information, and reproducing and outputting a stream of the corresponding channel when selecting a channel of the subscriber; And an IP broadcast signal providing means for providing a stream of the channels in response to a request of the IP broadcast terminal.

Preferably, in the present invention, the subscriber DB server stores the authentication information for the IP broadcast terminal, and performs the authentication of the IP terminal when the IP broadcast terminal is initially started. It is characterized by providing information.

Preferably, in the present invention, the IP broadcast terminal generates an IGMP join message for receiving a stream of each channel using the channel information included in the channel group information to provide the IP broadcast signal with an IGMP join message for each channel. It is characterized by providing by means.

Preferably, the channel group stored in the channel group information in the present invention is characterized in that the maximum number of channels is determined based on the communication bandwidth and the bandwidth per channel.

Preferably, the channel group stored in the channel group information in the present invention is characterized in that the subscriber consists of a plurality of channels specified in the subscriber DB server.

Preferably, in the present invention, the channel group stored in the channel group information is composed of a plurality of channels by the upper channel selected based on the viewer ratings of all subscribers.

Preferably, in the present invention, the channel group stored in the channel group information is characterized by consisting of a plurality of channels selected on the basis of the recent selection frequency by analyzing the viewing tendency of the subscriber.

In order to achieve the above object, the method for shortening the channel change time of the Internet broadcast according to the present invention, the first step of generating channel group information for the subscriber; A second step of receiving, by the IP broadcasting terminal, a plurality of channels belonging to the channel group information by inquiring the channel group information of the subscriber of the IP broadcasting terminal when the IP broadcasting terminal is initially driven; And a third process of reproducing and outputting the already received channel stream when a specific channel is selected among the plurality of channels.

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

1 is a schematic block diagram of a network in which a system for shortening a channel change time of internet broadcasting according to an embodiment of the present invention is implemented.

A network in which a system for shortening a channel change time of Internet broadcasting according to an exemplary embodiment of the present invention is implemented includes an indoor network 10 having an IP STB 12, a home gateway 14, and a PON ONT 16, and a PON OLT 22. And a back office network 20 having a L3 switch 24 and a backbone network 30 having a router 32 and an IPTV head end 36.

Each component configured in FIG. 1 will be described in more detail.

The IP STB (Set Top Box) 10 outputs an IP broadcast signal, and transmits a control signal corresponding to the command to the home gateway 14 when the subscriber inputs a predetermined command according to the Internet broadcast viewing. do.

The home gateway 14 is generally a gateway of a home network (home network), which connects an access network and a home network, performs a function of supporting a connection between various devices in the home, and is input from the IP STB 10. A function of transmitting a stream of a specific channel among the channel group streams transmitted from the head end 36 to the IP STB 10 according to the channel selection signal.

The IP STB 12 and the home gateway 14 may be integrally formed to operate as an IP broadcast terminal.

The PON ONT (Passive Opitcal Line Optical Network Terminal) 16 is a device installed in the user's home among the PON systems and generally performs an L2 switch function.

In addition, the PON OLT (Passive Opitcal Line Optical Line Terminal) 22 is a device located at the national office in the PON system and performs L3 and L2 functions.

The L3 switch 24 is a network device capable of processing not only the L2 function but also some routing functions at high speed.

The router 32 performs an L3 function of routing data packets using protocols such as RIP and OSPF.

The subscriber DB server 34 stores channel group information for each subscriber, and when subscriber channel information is requested from the home gateway 14, the subscriber DB server 34 performs channel function information for the subscriber. In addition, the subscriber DB server 34 stores authentication information for the IP STB 12 to perform authentication for the IP STB 12 when the IP STB 12 is initially driven.

In the present invention, the subscriber can register the channel group information through the IP STB 12 or access the subscriber DB server 34 through the web to register their channel group information. In the channel group information, it is preferable that information of a plurality of channels registered by a subscriber as a preferred channel is stored.

On the other hand, the number of channels allowed in a channel group is determined by the communication bandwidth and the bandwidth per channel. The maximum number of channels by communication bandwidth and bandwidth per channel is shown in [Table 1].

Subscriber Communication Bandwidth (Mb / s) MPEG2 H.264 SD (4 Mb / s) HD (20 Mb / s) SD (2 Mb / s) HD (8 Mb / s) 8 2 - 4 One 20 5 One 10 2 50 12 2 25 6 100 25 5 50 12

As shown in Table 1, the subscriber communication bandwidth is fixed, but the bandwidth per channel varies greatly depending on the broadcast video format used. In case of 100M / s communication bandwidth, it can be seen that up to 50 channels can be transmitted simultaneously. Of course, considering the use of the Internet or other telecommunications services, the entire band can't be used as an IPTV channel, leaving some bandwidth available.

In addition, if the channel group does not have a large number of channels and the communication bandwidth is wide enough, the entire channel may be set as a channel group, and the number of channels may be set within a range allowed by the communication bandwidth for higher channels by analyzing the viewer ratings of all subscribers. In addition, the viewing tendency of the subscriber may be analyzed and the number of channels may be determined and selected in the range allowed by the communication bandwidth for the channels most recently selected.

In the present invention, it is preferable that the viewer selects one of the channel group selection methods.

The IPTV head end 36 performs a function of providing a stream of channel groups requested from the IP STB 12 and a stream of a specific channel selected by the viewer. The IPTV head end 36 is an IP broadcast signal providing means for providing a stream of requested channels in response to a request of the IP STB 12 or the home gateway 14 corresponding to the IP broadcast terminal.

 Next, a method of shortening a channel change time of internet broadcasting according to an embodiment of the present invention will be described in detail with reference to the signal flow diagram shown in FIG. 2.

When the IP STB 12 is initially driven (S12), the IP STB 12 outputs an STB authentication and subscriber DB information request message, and the STB authentication and subscriber DB information request message is transmitted through the home gateway 14 to the subscriber DB. It is transmitted to the server 34 (S14). The STB authentication and subscriber DB information request message may include a fixed IP address, a MAC address, a unique ID / password of the IP STB 12, and the subscriber DB server 34 may use the information to transmit the STB authentication and subscriber DB information request message. The channel group information registered by the user is searched and the search result is transmitted to the home gateway 14. The channel group information includes information about a channel registered by a subscriber.

The home gateway 14 receiving the channel group information generates an IGMP join message for receiving the stream of the channel included in the channel group information, and transmits it to the IPTV head end 36 via the router 32 ( S18, S20). The home gateway 14 generates an IGMP join message for each channel included in the channel group information and transmits the IGMP join message to the IPTV head end 36 via the router 32.

The IPTV head end 36 sends a stream of each channel for which each IGMP join message is requested to the home gateway 14. If the performance support of the IP STB 12 is possible, a separate channel change time when the stream of each channel is directly transmitted to the IP STB 12 so that the subscriber selects any channel among the channels registered to the channel group. It is desirable to be able to reproduce and output the channel immediately without the need for.

Meanwhile, in the present invention according to the embodiment of the present invention, if the IP STB 12 is provided with the Internet broadcasting service through the home gateway 14, but the IP STB 12 has the function of the home gateway 14, It may be directly connected to the subscriber DB server 34 or the IPTV head end 36 to receive an Internet broadcast service.

In addition, in the Internet broadcasting service according to an embodiment of the present invention, the IGMP join message transmitted from the home gateway 14 is transmitted to the IPTV head end 36 to receive a stream corresponding to each channel from the IPTV head end 36. In the structure in which the IPTV head end 36 transmits the streams of all channels to the router corresponding to the rendezvous point RP and the IP STB 12 receives the streams of each channel from the rendezvous point router, the home gateway 14 An IGMP join message transmitted from the rendezvous point router may be transmitted, and a stream of each channel corresponding to a channel group may be received from the rendezvous point router.

As described above, according to the system and method for shortening the channel change time of the Internet broadcast according to the embodiment of the present invention, since the channel is changed while receiving a plurality of channels in a group, the channel changing time is minimized. Fast channel change is possible.

In particular, considering that the communication bandwidth is continuously improving, the number of channels that can be transmitted to the channel group can be expanded, so that the subscriber can quickly respond to the channel change.

On the other hand, the present invention is not limited to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, such modifications and changes should be regarded as belonging to the following claims. will be.

Claims (11)

A subscriber DB server storing channel group information for an Internet broadcast subscriber; An IP broadcasting terminal receiving channel group information from the subscriber DB server during initial operation, receiving a plurality of channel streams corresponding to the channel group information, and reproducing and outputting a stream of the corresponding channel when selecting a channel of the subscriber; And And an IP broadcast signal providing means for providing a stream of the channels in response to a request of the IP broadcast terminal. Channel change time shortening system of internet broadcasting. The method of claim 1, wherein the subscriber DB server is Store the authentication information for the IP broadcast terminal, and provides the channel group information only to the IP broadcast terminal that is successfully authenticated by performing authentication on the IP terminal when the IP broadcast terminal is initially driven. Channel change time shortening system of internet broadcasting. The method of claim 1, wherein the IP broadcast terminal Generating an IGMP join message for receiving a stream of each channel using the channel information included in the channel group information, and providing an IGMP join message for each channel to the IP broadcast signal providing means. Channel change time shortening system of internet broadcasting. The method of claim 1, wherein the channel group stored in the channel group information is The maximum number of channels is determined based on the communication bandwidth and the bandwidth per channel Channel change time shortening system of internet broadcasting. The channel group of claim 1 or 4, wherein the channel group stored in the channel group information is selected. Characterized in that the subscriber consists of a plurality of channels specified in the subscriber DB server Channel change time shortening system of internet broadcasting. The channel group of claim 1 or 4, wherein the channel group stored in the channel group information is selected. It is characterized by consisting of a plurality of channels by the upper channel selected based on the viewer ratings of all subscribers Channel change time shortening system of internet broadcasting. 5. The channel group of claim 1 or 4, wherein the channel group stored in the channel group information is Analyzing the viewing tendency of the subscriber characterized in that it consists of a plurality of channels selected on the basis of the recent number of selections Channel change time shortening system of internet broadcasting. A first step of generating channel group information for the subscriber; A second step of receiving, by the IP broadcasting terminal, a plurality of channels belonging to the channel group information by inquiring the channel group information of the subscriber of the IP broadcasting terminal when the IP broadcasting terminal is initially driven; And And if a particular channel is selected from among the plurality of channels, reproducing and outputting the already received channel stream. How to shorten channel change time of internet broadcasting. The method of claim 8, wherein in the first process The channel group information is generated for a plurality of channels registered by the subscriber. How to shorten channel change time of internet broadcasting. The method of claim 8, wherein in the first process The channel group information is composed of a plurality of channels by the upper channel selected based on the viewer ratings of all subscribers How to shorten channel change time of internet broadcasting. The method of claim 8, wherein in the first process Analyzing the viewing tendency of the subscriber characterized in that it consists of a plurality of channels selected on the basis of the recent number of selections How to shorten channel change time of internet broadcasting.

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