WO2011023063A1 - 一种减少网络电视频道切换时延的方法和系统 - Google Patents

一种减少网络电视频道切换时延的方法和系统 Download PDF

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Publication number
WO2011023063A1
WO2011023063A1 PCT/CN2010/075817 CN2010075817W WO2011023063A1 WO 2011023063 A1 WO2011023063 A1 WO 2011023063A1 CN 2010075817 W CN2010075817 W CN 2010075817W WO 2011023063 A1 WO2011023063 A1 WO 2011023063A1
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WIPO (PCT)
Prior art keywords
multicast
multicast group
terminal
group
requested
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PCT/CN2010/075817
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English (en)
French (fr)
Inventor
孙钰娆
高晗
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中兴通讯股份有限公司
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Application filed by 中兴通讯股份有限公司 filed Critical 中兴通讯股份有限公司
Priority to EP10811223.6A priority Critical patent/EP2461584A4/en
Priority to JP2012525871A priority patent/JP2013503523A/ja
Priority to US13/258,595 priority patent/US8677439B2/en
Publication of WO2011023063A1 publication Critical patent/WO2011023063A1/zh

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/16—Analogue secrecy systems; Analogue subscription systems
    • H04N7/173—Analogue secrecy systems; Analogue subscription systems with two-way working, e.g. subscriber sending a programme selection signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
    • H04N21/44—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs
    • H04N21/44016—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs involving splicing one content stream with another content stream, e.g. for substituting a video clip
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/1066—Session management
    • H04L65/1083—In-session procedures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/60—Network streaming of media packets
    • H04L65/61—Network streaming of media packets for supporting one-way streaming services, e.g. Internet radio
    • H04L65/611—Network streaming of media packets for supporting one-way streaming services, e.g. Internet radio for multicast or broadcast
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/80—Responding to QoS
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/234—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs
    • H04N21/23424—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/234—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs
    • H04N21/2343—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements
    • H04N21/23439—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements for generating different versions
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
    • H04N21/438—Interfacing the downstream path of the transmission network originating from a server, e.g. retrieving encoded video stream packets from an IP network
    • H04N21/4383—Accessing a communication channel
    • H04N21/4384—Accessing a communication channel involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
    • H04N21/64—Addressing
    • H04N21/6405—Multicasting
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/50—Tuning indicators; Automatic tuning control

Definitions

  • the present invention relates to network television, and more particularly to a method and system for reducing network television channel switching delay.
  • IPTV service refers to the general business name of TV program live broadcast, video on demand and time shift play, and other various application services that can be provided to users through the IP bearer network.
  • IPTV The emergence of IPTV has enabled traditional telecom operators to see new business growth points. Operators can no longer be limited to providing voice services and network bandwidth, integrating their superior network resources to seek innovative services and innovative business profit models.
  • Traditional broadcast and television operators can also use IPTV as a new TV program marketing method to sell a large number of idle program resources. IPTV will provide new opportunities for the development of broadcast TV.
  • IPTV programs are usually transmitted in multicast mode.
  • Multicast is a network technology that allows one or more senders (multicast sources) to simultaneously send a single packet to multiple recipients at the same time.
  • the multicast source sends the packet to a specific multicast group, and only the address belonging to the multicast group can receive the packet.
  • IPTV there is often only one multicast source.
  • the backbone bandwidth does not need to increase, because no matter how many destination addresses, only a single video is transmitted on any trunk link of the entire network. Stream, the so-called "one-time transmission, intra-group broadcast”.
  • Multicast improves data transfer efficiency and reduces the likelihood of congestion on the backbone network.
  • the number of users it can support is limited only by the capabilities of the access network, regardless of the push capability of the front-end push system.
  • the multicast control point completes the judgment of the user's multicast data acceptance authority.
  • the user management module in the IPTV system stores the user's order information.
  • the set-top box device transmits the Internet management protocol force.
  • the request (IGMP (Internet Group Message Protocol) Join) requests to join the multicast group corresponding to the channel.
  • the multicast control point determines whether the user has rights to view according to the user subscription information multicast permission table delivered by the user management module.
  • the channel, multicast control You can also authenticate users by using protocols such as Radius.
  • the multicast replication point copies the multicast stream to the port according to whether the port has the multicast receiving request and the user right of the response.
  • the multicast replication point transmits the live program to the user through unicast (such as PPPoE), so the multicast replication point The closer you are to the user device, the more network bandwidth is saved.
  • the multicast replication point and the multicast control point can be on the same device.
  • the multicast replication point is generally set on a DSLAM (Digital Subscriber Line Access Multiplexer)/BRAS (Broadband Remote Access Server)/switch.
  • DSLAM Digital Subscriber Line Access Multiplexer
  • BRAS Broadband Remote Access Server
  • the devices on the network side should support multicast, and the devices such as the access network switch need to support IGMP snooping protocol (IGMP snooping) and IGMP proxy protocol (IGMP proxy) to implement controllable forwarding of multicast data.
  • IGMP snooping IGMP snooping
  • IGMP proxy IGMP proxy protocol
  • the device If the device is set up on the multicast replication point, it should support the flexible VLAN (Virtual Local Area Network) function, and use different VLANs to carry different services such as multicast, Internet access, and voice to ensure flexible QoS (Quality of System). Service, quality of service) management capabilities and greater security.
  • VLAN Virtual Local Area Network
  • the main test indicators of IPTV service performance include the maximum number of channels pushed, the average channel bandwidth, the average channel switching time, the I frame join delay, the average channel departure delay, the average channel join delay, the channel overlap time, and the channel interval time. among them:
  • Maximum number of channels pushed The maximum number of channels that the streaming system can provide. Users can traverse all channels in a short period of time.
  • Average channel switching time The time from the issuance of the IGMP Leave message until the reception of the first multicast packet of the requested channel.
  • IPTV channel switching time should not exceed 2s, otherwise the user can hardly stand the waiting time of the channel switching.
  • the slow switching time of IPTV channels is also a key issue to be solved urgently.
  • the multicast replication and processing capability of the multicast switch, multicast router, and DSLAM (Digital Subscriber Line Access Multiplexer) devices are tested. Is influence An important factor in channel switching time.
  • the client sends a request to watch the program successfully, which does not mean that the video stream has been delivered to the user's receiving terminal.
  • An I frame or a P frame is used as a reference for calculating a P frame and a B frame calculated by using an I frame or a P frame as a reference. Only when the receiving end receives the I frame, it indicates that the user has seen the video program, and the real channel switching is successful. Therefore, it is more meaningful to get the I frame join delay for the channel switching time test.
  • Average channel departure delay The time from the issuance of the IGMP leave message until the last multicast packet of the channel is received. Usually the channel departure delay is as short as possible.
  • Channel overlap time If the system channel switch captures the multicast packet of the original channel after receiving the multicast packet of the requested channel, the channel overlap time refers to the first group that receives the requested channel. The time interval between the broadcast packet and the last multicast packet received by the original channel.
  • Channel interval time If the system channel switching captures the multicast packet of the original channel and then receives the multicast packet of the requested channel, the channel interval time refers to the last multicast packet received by the original channel. The time interval between receiving the first multicast packet of the requested channel.
  • the service experience of the end user is the decisive factor, and the delay affecting the user experience is the delay in the IPTV service.
  • the delay in the IPTV service In order to obtain the quality of service that the user can accept, it is necessary to reduce the delay in the business of ⁇ as much as possible.
  • the present invention provides a method and system for reducing the handover delay of a network television channel, which can reduce the transmission delay of the program from the multicast source to the multicast replication point, reduce the buffer delay of the set top box, and further improve the service quality of the IPTV service.
  • the present invention provides a method for reducing network television channel switching delay, including:
  • the network television system plans a multicast association mode, so that each multicast group has a group of multicast groups associated with it;
  • the network television system After receiving the request from the terminal to access the multicast group, the network television system according to the The multicast association mode determines the multicast group associated with the multicast group that is requested to access, and the terminal joins the multicast group requested to access and the multicast group associated with the requested multicast group.
  • the network television system provides the terminal with the multicast stream of the multicast group requested by the terminal as a normal multicast stream, and the multicast stream of the multicast group not associated with the multicast group requested by the terminal to be accessed by the terminal. Or the network television system provides the terminal with a multicast stream of the multicast group associated with the multicast group requested by the terminal as part of the normal multicast stream;
  • the network television system determines whether the terminal has joined the multicast group of the channel that is requested to be switched, and if so, provides the terminal with the group of the multicast group of the channel that is requested to be switched to.
  • the broadcast stream acts as a normal multicast stream.
  • the step of the network television system planning the multicast association mode may include:
  • the network television system plans the channel association mode according to the user's habit of switching channels by using the up and down navigation keys, and stipulates that when the terminal requests to join the multicast group of the channel, the channel is up to multiple channel ranges and/or down to multiple channel ranges.
  • a group of multicast groups are associated with the multicast group of the channel; or
  • the network television system plans a channel association manner according to a user's habit of switching channels in the same type of channel, and specifies a group of all other channel ranges of the same type as the channel when the terminal requests to join the multicast group of the channel.
  • the broadcast group is associated with the multicast group of the channel.
  • the above method may further include:
  • the network television system After receiving the packet requesting the terminal to access the multicast group, the network television system first authenticates the access right of the multicast group requested by the terminal, and discards the report if the authentication fails. If the authentication succeeds, the multicast group associated with the requested multicast group is determined according to the multicast association manner; the terminal is simultaneously added to the multicast group requested to access and the multicast requested to be accessed
  • the steps of the group associated multicast group may include:
  • the network television system authenticates the access right of the terminal to the multicast group associated with the multicast group that is requested to access, and according to the authentication result, the terminal joins the requested multicast group and the requested access group at the same time.
  • the step of causing the terminal to simultaneously join the multicast group requested to access and the multicast group associated with the requested multicast group and the authenticated multicast group may be: the network television system is the multicast group requested to access and Establishing a multicast forwarding table with the multicast group that is associated with the multicast group that is requested to access and the authentication is passed; the method may further include: the network television system requests the multicast group that is accessed by the terminal in the multicast forwarding table The associated multicast group sets the flag bit and determines the tag bit of the multicast group in the multicast forwarding table.
  • the above method may also have the following features:
  • the network television system is a group that provides the terminal with a multicast group that does not have a tag bit.
  • the broadcast stream is a normal multicast stream, and a multicast stream that does not provide a multicast group with a flag bit for the terminal; or the network television system provides the terminal with a multicast stream of the multicast group with the tag bit as the normal multicast stream. a part of.
  • the above method may further include:
  • the device When the terminal performs channel switching, the device sends a message leaving the current multicast group to the network television system and requests access to another multicast group.
  • the network television system After receiving the packet of the current multicast group, the network television system deletes the user port of the current multicast group in the forwarding entry of the current multicast group in the multicast forwarding table according to the packet;
  • the network television system After receiving the packet requesting the terminal to access another multicast group, the network television system searches the multicast forwarding table to determine whether the terminal has joined the other multicast group, and if yes, removes the multicast forwarding table. The flag bit of the other multicast group requested by the terminal this time; if not, the terminal is simultaneously added to the other multicast group and the multicast group associated with the other multicast group.
  • the IPTV system implements a multicast stream that does not provide a multicast group with a tag bit for the terminal by setting a user port of the multicast group having the tag bit to be empty in the multicast forwarding table;
  • the network television system realizes providing the terminal with the multicast stream of the multicast group having the marked bit as part of the normal multicast stream by setting the bandwidth of the multicast group having the marked bit to a low clear in the multicast forwarding table;
  • the clear bandwidth is one-Nth of the SD and HD bandwidth.
  • the present invention also provides a system for reducing network television channel switching delay, including an association mode setting module and a multicast service module, where:
  • the association mode setting module is configured to set and store a multicast association mode, so that each multicast group has a group of multicast groups associated with it; the multicast service module is configured to: After receiving the packet requesting the access to the multicast group sent by the terminal, determining the multicast group associated with the multicast group requested to be accessed according to the multicast association mode, and causing the terminal to join the requested group at the same time.
  • the broadcast group and the multicast group associated with the multicast group that is requested to access provide the terminal with the multicast stream of the multicast group requested to access as a normal multicast stream, and does not provide the terminal with the requested access group.
  • the association mode setting module may be configured to set the multicast association mode by:
  • the channel association mode is set, and when the terminal requests to join the multicast group of the channel, the channel is directed to a plurality of channel ranges and/or a group of multiple channel ranges downward.
  • the broadcast group is associated with the multicast group of the channel; or
  • the channel association mode is planned, and when a terminal requests to join a multicast group of a channel, a group of multicast groups of all other channel ranges of the same type as the channel are specified. Associated with the multicast group for this channel.
  • the above system may further comprise an authentication module, the authentication module being configured to:
  • the multicast service module After receiving the packet requesting the terminal to access the multicast group, the multicast service module authenticates the access right of the multicast group requested by the terminal, and notifies the multicast service of the authentication result. And authenticating, by the terminal, access rights of the multicast group associated with the multicast group requested to access, and notifying the multicast service module of the authentication result;
  • the multicast service module may be configured to determine, according to the multicast association mode in the association mode setting module, that the terminal has access rights to the multicast group requested to access after obtaining the access right from the authentication module. a multicast group, and configured to enable the terminal to simultaneously join the requested multicast group and the multicast group associated with the requested multicast group by: obtaining the terminal pair and the requested access from the authentication module The access rights of the multicast group associated with the multicast group are added to the multicast group that is requested to access and the multicast group that is associated with the requested multicast group and authenticated.
  • the above system can also have the following characteristics:
  • the multicast service module is configured to enable the terminal to join the requested access at the same time by establishing a multicast forwarding table for the multicast group requested to access and the multicast group associated with the requested multicast group and the authenticated multicast group. Multicast group and the multicast group associated with the multicast group that is requested to access and authenticated; and
  • the multicast service module is further configured to set, in the multicast forwarding table, a flag bit for the multicast group associated with the multicast group that the terminal requests to access; and determine a flag bit of the multicast group in the multicast forwarding table;
  • the multicast service module is set to:
  • the terminal with a multicast stream of a multicast group without a tag bit as a normal multicast stream, and a multicast stream not providing a multicast group with a flag bit for the terminal; or providing the terminal with a flag bit
  • the multicast stream of the multicast group is part of the normal multicast stream.
  • the multicast service module may be further configured to: after receiving the packet leaving the current multicast group, remove the current multicast group from the forwarding entry of the current multicast group in the multicast forwarding table according to the packet After receiving the packet requesting the terminal to access another multicast group, the user searches the multicast forwarding table to determine whether the terminal has joined the other multicast group. If yes, remove the multicast forwarding table. The flag bit of the other multicast group requested by the terminal this time; if not, the terminal is simultaneously added to the other multicast group and the multicast group associated with the other multicast group.
  • the multicast service module is configured to implement a multicast stream that does not provide a multicast group with a tag bit for the terminal by setting a user port of the multicast group having the tag bit to be empty in the multicast forwarding table;
  • the bandwidth of the multicast group with the marked bit is set to a low level to implement the multicast stream of the multicast group with the marked bit for the terminal as part of the normal multicast stream; the low clear bandwidth is standard definition.
  • N of HD bandwidth is configured to implement a multicast stream that does not provide a multicast group with a tag bit for the terminal by setting a user port of the multicast group having the tag bit to be empty in the multicast forwarding table;
  • the bandwidth of the multicast group with the marked bit is set to a low level to implement the multicast stream of the multicast group with the marked bit for the terminal as part of the normal multicast stream; the low clear bandwidth is standard definition.
  • N of HD bandwidth is standard definition.
  • the multicast service module is further configured to: after operating the multicast forwarding table, update the user table used to store the association relationship between the multicast group and the user according to the multicast forwarding table.
  • the invention provides a method and system for reducing network television channel switching delay, and reduces the section
  • the transmission delay from the multicast source to the multicast replication point reduces the set-top box buffer delay and further improves the service quality of the IPTV service.
  • FIG. 1 is a flowchart of a method for reducing a network television channel switching delay according to an embodiment of the present invention.
  • 2 is a system block diagram of a network television channel switching delay in accordance with an embodiment of the present invention.
  • FIG. 1 the figure illustrates a method for reducing network television channel switching delay according to an embodiment of the present invention, which specifically includes the following steps:
  • Step S101 The IPTV system plans a multicast association mode, so that each multicast group has a group of multicast groups associated with it;
  • a planning scheme which performs multicast group association according to user habits, and then based on this, proposes an effective method for reducing handover delay in subsequent steps.
  • the method for planning a multicast association according to a user's habit may specifically be:
  • the multicast association mode is planned according to the user's habit of switching channels by using the up and down navigation keys, it may be specified that when the multicast group of the channel N is requested by the user, the channel N is up to the M1 channel range and/or the channel N is down M2.
  • a group of multicast groups in a range of channels is associated with a multicast group of channel N.
  • the values of Ml and M2 can be set as needed, and there is no limitation here.
  • Group multicast groups are associated with the multicast group of channel N.
  • Channel type division can be divided according to content, such as sports channel, entertainment channel, movie channel, music frequency Channel, life channel, game channel, reading channel, travel channel, TV channel, news channel, international channel, integrated channel, etc.; can also be divided into regions, such as CCTV, Hunan TV, Tianjin TV, etc., specific channel classification
  • the method can be set as needed, and there is no restriction here.
  • the IPTV system can select a common channel switching habit of most customers according to requirements, or a common channel switching habit of a customer with a large consumption, for example, as a custom planning multicast of a user of the IPTV system. Relevance method.
  • Step S102 The terminal is powered on, and the program is on-demand, and the Internet Management Protocol (IGMP) message requesting to access the multicast group is sent to the IPTV system according to the program to be on-demand;
  • IGMP Internet Management Protocol
  • Step S103 After receiving the Internet Protocol IGMP message sent by the terminal and requesting access to the multicast group, the IPTV system parses the message and determines the access authority of the terminal group to the multicast group requested by the terminal, and authenticates If yes, go to step S104; otherwise, discard the IGMP message and end; after receiving the Internet Protocol IGMP message sent by the terminal, the IPTV system parses the message and extracts the user's mac from the IGMP message. , port, vlan, and multicast address, find the channel access control (CAC) module in the IPTV system to authenticate the end user.
  • CAC channel access control
  • the function of the channel access control (CAC) module is to realize the unrestricted viewing of a part of the channels purchased by the user according to the pre-configured access rights of the user to the multicast channel, the partial channel has the preview permission, and the rest refuses to access the function; in addition, the CAC module You can also specify the source port of the multicast group. That is, the multicast stream must flow from the source port and control the query of the multicast group. If the matching rule does not have the right to process the query packet, the query packet is discarded. .
  • the CAC module mainly has two tables: a channel access control rule table and a channel table, wherein the channel access control rule table is to control the user's access to the multicast channel, so that when a user applies for a channel, the permission table is matched, and then The operation requested by the user is performed according to the rights matched by the user.
  • the CAC module determines that the user is an ordered user of a multicast group, it returns the user's subscription rights to the multicast group and the MVLAN (multicast VLAN) number of the multicast group; if it is determined that the user is a multicast group Preview the user, if the user previews less than the maximum number of previews and last time If the preview interval is greater than the set preview interval, the user is returned the preview permission for the multicast group and the MVLAN number of the multicast group; otherwise, the user is returned without access to the multicast group.
  • Step S104 The IPTV system obtains a group of multicast groups associated with the multicast group that the terminal requests to access according to the multicast association mode, and determines the access rights of the terminal to the associated multicast groups.
  • the method for authenticating the access rights of the terminal to the associated multicast groups in the IPTV system is the same as step S103, and details are not described herein again.
  • Step S105 The IPTV system establishes a multicast forwarding table for the multicast group that the terminal requests to access and the associated multicast group that is authenticated, and sets a marking bit for the associated multicast group that passes the authentication in the multicast forwarding table.
  • the IPTV system sets the multicast forwarding table according to the MVLAN, user port, and VLAN of the multicast group. If the MVLAN and the user VLAN are not in the same VLAN, set the Layer 3 multicast forwarding table to implement the inter-VLAN. If it is the same VLAN, Set the Layer 2 multicast forwarding table.
  • Step S106 The IPTV system sets the multicast group with the marked bit in the multicast forwarding table, that is, the user port associated with the multicast group requested by the terminal and the authenticated multicast group is set to null, and according to the pair.
  • the setting of the broadcast forwarding table updates the user table, and then provides the multicast service to the terminal according to the multicast forwarding table;
  • the user port of the multicast group in the multicast forwarding table is the egress port of the multicast stream of the multicast group.
  • the user port of the multicast group associated with the multicast group that the terminal requests to access is set to be empty, and the purpose is to add the associated multicast group to the multicast forwarding table, but actually The multicast stream is not sent, and the multicast stream is not sent to the multicast group that the terminal actually requests. Therefore, the viewing effect of the user is not affected.
  • the user table is used to store the association between the multicast group and the user.
  • the user table needs to be updated.
  • the step may be that the IPTV system sets the multicast group with the marked bit in the multicast forwarding table, that is, the multicast group that is associated with the multicast group that the terminal requests to access and authenticates.
  • the bandwidth is set to Low Definition Television (LDTV), and the user table is updated according to the setting of the multicast forwarding table, and then the multicast service is provided to the terminal according to the multicast forwarding table.
  • LDTV Low Definition Television
  • the so-called “low clear”, that is, the bandwidth is standard definition television (SDTV) and high definition (High) Definition Television, referred to as HDTV)
  • SDTV standard definition television
  • High High Definition Television
  • the multicast group delivers the services of the multicast stream.
  • Step S107 The terminal performs a channel switching operation, and sends an Internet Management Protocol (IGMP) message requesting to leave the current multicast group to the IPTV system.
  • IGMP Internet Management Protocol
  • Step S108 After receiving the request sent by the terminal to leave the Internet Management Protocol (IGMP) message of the current multicast group, the IPTV system selects the forwarding entry of the current multicast group that the terminal requests to leave in the multicast forwarding table according to the packet. Delete the user port and update the user table;
  • IGMP Internet Management Protocol
  • the IPTV system receives the Internet management protocol that the request sent by the terminal leaves the current multicast group.
  • the packet is parsed, and the multicast group address and the user's port, vlan, mac, and ip parameters are sent to the CAC module.
  • the CAC module searches the user table. If the user exists, the multicast group is returned. The MVLAN number is deleted to delete the user port in the forwarding entry of the multicast group. Otherwise, the packet is discarded. After the IPTV system successfully deletes the user port from the multicast forwarding table, it will give the CAC an acknowledgment. At this time, the CAC deletes the user from the user table.
  • the present invention has no effect on multicast group leaving.
  • the CAC module When a user does not send an Internet Protocol IGMP message requesting to leave the current multicast group after the minimum valid time expires, the CAC module generates a user online record. If the user is previewed, the preview number of the rule to which the user belongs is incremented by one; A user sends an Internet Management Protocol IGMP message requesting to leave the current multicast group after the minimum effective time elapses.
  • the IPTV system When the IPTV system deletes the user port in the forwarding entry of the current multicast group in the multicast forwarding table, it can also determine whether there are other multicast users in the current multicast group. If there are no other users of the multicast group, Delete the multicast group. If there are other users in the multicast group, only the user ports in the entry are deleted.
  • Step S109 The terminal sends an Internet Management Protocol (IGMP) message requesting access to another multicast group to the IPTV system; For the IPTV system, the process of joining the multicast group does not conflict with the process of leaving the multicast group. Therefore, when the terminal performs channel switching, the terminal can send multicast leaving messages and multicast according to the specific implementation of the terminal.
  • the message may be added, or the message may be sent after the message is sent, that is, the step s 109 may be performed simultaneously with the step S107.
  • IGMP Internet Management Protocol
  • Step S110 After receiving the Internet Protocol IGMP message sent by the terminal and requesting access to another multicast group, the IPTV system parses the packet and performs multicast forwarding according to the parsed multicast address of the other multicast group. Issuing to determine whether the terminal has joined the other multicast group that it requested to access, if the determination result is yes, proceed to step S111; otherwise, return to step S103;
  • the IPTV system After receiving the Internet Protocol IGMP message sent by the user side, the IPTV system parses the message to obtain the user's mac, port, vlan, and multicast address.
  • Step 141 The IPTV system removes the flag bit of the other multicast group that the terminal requests to access in the multicast forwarding table, adds the user port of the other multicast group, and sets the multicast forwarding table according to the setting.
  • the user table is updated, and then the multicast service is provided to the terminal according to the multicast forwarding table, and the process ends.
  • the present invention proposes the concept of associating a multicast group, according to the customary characteristics of the user, when the program is started on-demand, the user joins the multicast group requested by the user, and also joins the multicast group requested by the user.
  • a group of multicast groups that are connected to each other in the multicast forwarding table are not configured to deliver services or send very few services to these associated multicast groups. If the user is in the channel switching, the associated multicast group is added. Therefore, you only need to set the service of the multicast group of the channel to which the user is switched to normal.
  • step S111 that is, when the terminal performs channel switching, correspondingly, the IPTV system may be in the multicast.
  • the forwarding table removes the marking bit of the multicast group requested by the terminal, and restores the multicast stream bandwidth of the multicast group, that is, sets the bandwidth of the multicast stream of the multicast group to "standard definition" or "high definition", and
  • the user table is updated according to the setting of the multicast forwarding table, and then the multicast service is provided to the terminal according to the multicast forwarding table, and the process ends.
  • the present invention further provides a system for reducing the network television channel switching delay.
  • the method includes an association mode setting module 21, a multicast service module 22, and an authentication module 23, where:
  • the association mode setting module 21 is configured to: set and store a multicast association mode, so that each multicast group has a group of multicast groups associated with it.
  • the association mode setting module 21 is configured to set a multicast association mode according to a user's habit.
  • the channel association mode may be set according to a user's habit of switching channels by using the up and down navigation keys, and the terminal is requested to join a certain channel.
  • a channel of a plurality of channel ranges and/or a group of multicast groups of the channel down to a plurality of channel ranges are associated with a multicast group of the channel; for example, may be in the same type according to the user's preference
  • the channel switching habit is used to plan the channel association mode.
  • a group of multicast groups of all other channel ranges of the same type as the channel are associated with the channel.
  • Multicast group association can also be set according to other requirements, and the present invention is not limited thereto.
  • the multicast service module 22 is configured to determine, according to the multicast association mode, other multicast groups associated with the multicast group requested to be accessed after receiving the request for the access to the multicast group sent by the terminal, The terminal joins the multicast group requested by the terminal and other multicast groups associated with it, provides the terminal with the normal multicast stream of the multicast group it requests to access, and does not provide the terminal with the multicast group requested to access the terminal.
  • the authentication module 23 is configured to: after the multicast service module 22 receives the request for accessing the multicast group sent by the terminal, and authenticates the access authority of the multicast group that the terminal requests to access, Notifying the multicast service module 22 of the authentication result; and accessing the other multicast group to the other multicast group associated with the multicast group requested to be accessed according to the multicast service module 22
  • the authority authenticates and notifies the multicast service module 22 of the authentication result.
  • the multicast service module 22 is configured to: after the authentication module 23 learns that the terminal has access rights to the multicast group that the terminal requests to access, according to the multicast association mode determination in the association mode setting module 21 The other multicast group associated with the multicast group that is requested to access, and then obtains the access authority of the terminal from the other multicast group associated with the multicast group requested to access from the authentication module 23, and simultaneously joins the terminal to request the access.
  • the multicast service module 22 is configured to: through the multicast group and the request for access thereto
  • the multicast group associated with the multicast group and the authenticated multicast group establishes a multicast forwarding table to enable the terminal to simultaneously join the multicast group that the terminal requests to access and the multicast group associated with the multicast group and authenticated. of.
  • the multicast service module 22 is further configured to: set, in the multicast forwarding table, a flag bit for the multicast group associated with the multicast group that the terminal requests to access; and determine the multicast group in the multicast forwarding table. a flag bit; and, the multicast service module is configured to: provide a normal multicast stream for the terminal without a multicast group with a flag bit, and a multicast stream that does not provide the terminal with a multicast group with a tag bit or The terminal provides a multicast stream of a multicast group with a tag bit as part of a normal multicast stream.
  • the multicast service module 22 is further configured to: after receiving the message that the terminal leaves the current multicast group, delete the user in the forwarding entry of the current multicast group in the multicast forwarding table according to the packet. And after receiving the packet requesting the terminal to access another multicast group, searching for the multicast forwarding table, determining whether the terminal has joined the other multicast group, and if yes, removing the packet in the multicast forwarding table. The flag bit of the other multicast group requested by the terminal this time; if not, the terminal is simultaneously added to the other multicast group and the multicast group associated with the other multicast group.
  • the multicast service module 22 is configured to: implement a group that does not provide a multicast group with a flag bit for the terminal by setting a user port of the multicast group having the tag bit to be empty in the multicast forwarding table. Broadcasting; and realizing that the multicast stream of the multicast group having the marked bit is provided to the terminal as a normal multicast stream by setting the bandwidth of the multicast group having the marked bit to a low clear in the multicast forwarding table; The low clear bandwidth is one-Nth of the SD and HD program bandwidth.
  • the multicast service module 22 is further configured to: after operating the multicast forwarding table, update the user table for maintaining the association relationship between the multicast group and the user according to the multicast forwarding table.
  • the method and system of the invention reduce the transmission delay of the program from the multicast source to the multicast replication point, reduce the buffer delay of the set top box, and further improve the service quality of the IPTV service.

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Abstract

本发明提出一种减少网络电视频道切换时延的方法和系统，该方法包括：网络电视系统规划组播关联方式；网络电视系统在接收到终端发送来的请求访问组播组的报文后，依据该组播关联方式判断出与请求访问的组播组关联的其他组播组，令该终端同时加入其请求访问的组播组及与其关联的其他组播组，提供终端请求访问的组播组的正常组播流，不提供或者提供低清的与终端请求访问的组播组关联的其他组播组的组播流；在该终端进行频道切换时，网络电视系统若判断该终端已经加入其请求切换到的频道的组播组，则为该终端提供该请求切换到的频道的组播组的正常组播流。该方法能够减少网络电视频道切换时延，进一步提高网络电视业务的服务质量。

Description

一种减少网络电视频道切换时延的方法和系统
技术领域
本发明涉及网络电视， 尤其涉及一种减少网络电视频道切换时延的方法 和系统。
背景技术
网络电视（IPTV )业务是指通过 IP承载网络向用户提供的、 能够支持交 互能力的电视节目直播、 视频点播和时移播放以及其他各种应用型业务的业 务总称。 IPTV的出现使传统的电信运营商看到了新的业务增长点， 运营商可 以不再局限于提供话音服务和网络带宽， 整合其优势网络资源寻求创新的业 务和创新的商业盈利模式。而传统的广电运营商也可以利用 IPTV作为新的电 视节目营销方式销售其大量闲置的节目资源， IPTV将为广播电视的发展提供 新的机遇。
IPTV节目通常釆用组播方式进行传送。组播是一种允许一个或多个发送 者 （组播源）一次同时发送单一的数据包到多个接收者的网络技术。 组播源 把数据包发送到特定组播组，而只有属于该组播组的地址才能接收到数据包。 在 IPTV里， 组播源往往仅有一个， 即使用户数量成倍增长， 主干带宽也不需 随之增加， 因为无论有多少个目标地址， 在整个网络的任何一条主干链路上 只传送单一视频流， 即所谓 "一次发送， 组内广播" 。 组播提高了数据传送 效率， 减少了主干网出现拥塞的可能性。对于 IPTV系统而言， 其所能够支持 的用户数目仅仅受到接入网络能力的限制，与前端推送系统的推送能力无关。
组播两个关键问题是组播控制点和组播复制点的选择。 组播控制点完成 用户组播数据接受权限的判断。 用户开通 IPTV业务时， IPTV系统中用户管 理模块存贮用户的定购信息， 当用户选择了某个频道后， 机顶盒设备通过发 送互联网管理协议力。入请求（ IGMP ( Internet Group Message Protocol) Join ) 等消息请求加入频道对应的组播组， 组播控制点接受请求后根据用户管理模 块下发的用户定购信息组播权限表判断用户是否有权收看该频道， 组播控制 点也可以釆用 Radius等协议对用户进行认证。组播复制点依据端口是否有组 播接收请求和响应的用户权利向端口复制组播流， 组播复制点以下是通过单 播方式（如 PPPoE ) 向用户传送直播节目的， 因此组播复制点越靠近用户设 备越节省网络带宽。 为减小组播复制点和组播控制点间的交互复杂性， 保证 互通， 可将组播复制点和组播控制点在同一设备上。 结合运营商城域网现状， 一般将组播复制点设置在 DSLAM ( Digital Subscriber Line Access Multiplexer, 数字用户线路接入复用器） /BRAS ( Broadband Remote Access Server, 宽带远 程接入服务器） /交换机上， 要求该些网络侧的设备应支持组播， 接入网交换 机等设备需支持 IGMP监听协议（ IGMP snooping )、 IGMP代理协议（ IGMP proxy ) 等协议实现组播数据的可控转发。 如果组播复制点设置的设备上， 应支持灵活的 VLAN ( Virtual Local Area Network, 虚拟局域网）功能， 釆 用不同的 VLAN承载组播、 上网、 话音等不同业务， 保证系统灵活的 QoS ( Quality of Service, 服务质量）管理能力和更高的安全性。
IPTV业务性能的主要测试指标包括所推送的最大频道数目、频道平均带 宽、 平均频道切换时间、 I帧加入延时、 平均频道离开延时、 平均频道加入延 时、 频道重叠时间和频道间隔时间， 其中：
( 1 )所推送的最大频道数目： 流媒体系统所能够提供的最多频道数量， 用户能够在艮短的时间内遍历所有的频道。
( 2 )频道平均带宽： 每个频道节目所占用的带宽。 标清节目 （SDTV ) 和高清节目 （HDTV ) 所占用的带宽不一样， HDTV节目所占用的带宽远远 高于 SDTV节目的带宽。
( 3 )平均频道切换时间： 从发出 IGMP 离开消息直到接收到所请求频 道的第一个组播包之间的时间。
由于在 IP网络上 TV节目的频道切换只能通过 IGMP来实现，相比之下， 传统电视机的频道切换则要快很多。 因此，通常 IPTV频道切换时间不应超过 2s, 否则用户难以忍受频道切换的等待时间。 目前， IPTV频道切换时间过慢 也是急待解决的重点问题。 由于处理 IGMP主要由接入设备来进行， 所以测 试接入端的组播交换机、组播路由器和 DSLAM( Digital Subscriber Line Access Multiplexer,数字用户线路接入复用器 )等设备的组播复制与处理能力是影响 频道切换时间的重要因素。
( 4 ) 1帧加入延时： 客户端发出观看节目的请求成功， 并不意味着视频 流已经送达到用户的接收终端上， 视频帧有 3种， 承载整个图片信息的 I帧、 通过前面的 I帧或 P帧作为参考计算得到的 P帧以及以 I帧或 P帧作为参考 计算得到的 B帧。 只有在接收端收到 I帧时， 才表示用户看到了视频节目， 才是真正的频道切换成功。 因此， 得到 I帧加入延时对于频道切换时间的测 试才更有意义。
( 5 )平均频道离开延时： 从发出 IGMP leave消息直到接收到该频道的 最后一个组播包之间的时间。 通常频道离开延时越短越好。
( 6 )频道重叠时间： 如果系统频道切换釆取接收到所请求频道的组播包 之后才停止原频道的组播包的方式， 则频道重叠时间即指接收到所请求频道 的第一个组播包与接收到原频道的最后一个组播包之间的时间间隔。
( 7 )频道间隔时间： 如果系统频道切换釆取先停止原频道的组播包再接 收所请求频道的组播包的方式， 则频道间隔时间即指接收到原频道的最后一 个组播包与接收到所请求频道的第一个组播包之间的时间间隔。
IPTV业务能否顺利开展， 最终用户的业务体验是决定因素， 而影响用户 使用体验的是 IPTV业务中的时延。 为了得到用户可以接受的业务服务质量， 必须尽可能地减少 ιρτν业务中的时延。
发明内容
本发明提出一种减少网络电视频道切换时延的方法和系统， 能够减少节 目由组播源到组播复制点的传输时延， 减少机顶盒緩冲时延， 进一步提高 IPTV业务的服务质量。
为了解决上述技术问题， 本发明提供了一种减少网络电视频道切换时延 的方法， 包括：
网络电视系统规划组播关联方式， 使得每个组播组都存在与其关联的一 组组播组；
网络电视系统在接收到终端发送来的请求访问组播组的报文后， 依据该 组播关联方式判断出与被请求访问的组播组关联的组播组， 令该终端同时加 入该被请求访问的组播组及与该被请求访问的组播组关联的组播组；
网络电视系统为所述终端提供该终端请求访问的组播组的组播流作为正 常组播流， 以及不为该终端提供与该终端请求访问的组播组关联的组播组的 组播流， 或者网络电视系统为该终端提供与该终端请求访问的组播组关联的 组播组的组播流作为正常组播流的一部分；
在该终端请求进行频道切换时， 网络电视系统判断该终端是否已经加入 被请求切换到的频道的组播组， 如果是， 则为该终端提供该被请求切换到的 频道的组播组的组播流作为正常组播流。
上述方法中， 网络电视系统规划组播关联方式的步骤可包括：
网络电视系统根据用户喜欢用上下导航键来切换频道的习惯来规划频道 关联方式， 规定当终端请求加入频道的组播组时， 该频道向上多个频道范围 和 /或向下多个频道范围的一组组播组均与该频道的组播组关联； 或者
网络电视系统根据用户喜欢在同一类型的频道中进行频道切换的习惯来 规划频道关联方式， 规定当终端请求加入频道的组播组时， 与该频道属于同 一类型的所有其他频道范围的一组组播组均与该频道的组播组关联。
上述方法还可包括：
网络电视系统在接收到终端发送来的请求访问组播组的报文后， 先对该 终端对被请求访问的组播组的访问权限进行鉴权， 如果鉴权不通过， 则丟弃 该报文； 如果鉴权通过， 再依据该组播关联方式判断出与被请求访问的组播 组关联的组播组； 令终端同时加入被请求访问的组播组及与该被请求访问的 组播组关联的组播组的步骤可包括：
网络电视系统对该终端对与被请求访问的组播组关联的组播组的访问权 限进行鉴权， 根据鉴权结果令该终端同时加入被请求访问的组播组和与该被 请求访问的组播组关联且鉴权通过的组播组。
上述方法中，
令该终端同时加入被请求访问的组播组和与该被请求访问的组播组关联 且鉴权通过的组播组的步骤可以是： 网络电视系统为被请求访问的组播组和 与该被请求访问的组播组关联且鉴权通过的组播组建立组播转发表； 所述方法还可包括： 网络电视系统在组播转发表中对与该终端请求访问 的组播组关联的组播组设置标记位，并判断组播转发表中的组播组的标记位； 上述方法还可具有以下特点： 网络电视系统是为该终端提供不具有标记 位的组播组的组播流作为正常组播流， 以及不为该终端提供具有标记位的组 播组的组播流； 或者网络电视系统为该终端提供具有标记位的组播组的组播 流作为正常组播流的一部分。
上述方法还可包括：
终端进行频道切换时， 向网络电视系统发送离开当前组播组的报文和请 求访问另一组播组的 ^艮文；
网络电视系统在接收到终端离开当前组播组的报文后， 根据该报文在组 播转发表中该当前组播组的转发表项中删除当前组播组的用户端口；
网络电视系统在接收到终端请求访问另一组播组的报文后， 查找组播转 发表， 判断该终端是否已经加入该另一组播组， 如果是， 则在组播转发表中 去除该终端本次请求的该另一组播组的标记位； 如果不是， 则令该终端同时 加入该另一组播组以及与该另一组播组关联的组播组。
上述方法还可具有以下特点：
网络电视系统通过在组播转发表中将具有标记位的组播组的用户端口设 置为空来实现不为该终端提供具有标记位的组播组的组播流； 以及
网络电视系统通过在组播转发表中将具有标记位的组播组的带宽设置为 低清来实现为该终端提供具有标记位的组播组的组播流作为正常组播流的一 部分； 低清的带宽为标清和高清带宽的 N分之一。
本发明还提供了一种减少网络电视频道切换时延的系统， 包括关联方式 设置模块和组播业务模块， 其中：
该关联方式设置模块设置成设置并存储组播关联方式， 使得每个组播组 都存在与其关联的一组组播组； 该组播业务模块设置成： 在接收到终端发送来的请求访问组播组的报文后， 依据该组播关联方式 判断出与被请求访问的组播组关联的组播组， 令该终端同时加入该被请求访 问的组播组及与该被请求访问的组播组关联的组播组， 为该终端提供被请求 访问的组播组的组播流作为正常组播流， 不为该终端提供与被请求访问的组 播组关联的组播组的组播流， 或者为该终端提供与被请求访问的组播组关联 的组播组的组播流作为正常组播流的一部分； 以及在获知终端请求进行频道 切换时， 判断该终端是否已经加入被请求切换到的频道的组播组， 如果是， 则为该终端提供被请求切换到的频道的组播组的组播流作为正常组播流。
上述系统中， 关联方式设置模块可以设置成通过如下方式来设置组播关 联方式：
根据用户喜欢用上下导航键来切换频道的习惯来设置频道关联方式， 规 定当终端请求加入频道的组播组时， 该频道向上多个频道范围和 /或向下多个 频道范围的一组组播组均与该频道的组播组关联； 或者
根据用户喜欢在同一类型的频道中进行频道切换的习惯来规划频道关联 方式， 规定当终端请求加入频道的组播组时， 与该频道属于同一类型的所有 其他频道范围的一组组播组均与该频道的组播组关联。
上述系统还可包括鉴权模块， 该鉴权模块设置成：
在该组播业务模块接收到终端发送来的请求访问组播组的报文后， 对该 终端对被请求访问的组播组的访问权限进行鉴权， 并将鉴权结果通知该组播 业务模块； 以及对该终端对与被请求访问的组播组关联的组播组的访问权限 进行鉴权并将鉴权结果通知组播业务模块；
组播业务模块可以设置成在从该鉴权模块获知终端对被请求访问的组播 组具有访问权限后， 才依据关联方式设置模块中的组播关联方式判断与被请 求访问的组播组关联的组播组， 并设置成通过如下方式令该终端同时加入被 请求访问的组播组及与被请求访问的组播组关联的组播组： 从该鉴权模块获 取终端对与被请求访问的组播组关联的组播组的访问权限， 将该终端同时加 入被请求访问的组播组和与该被请求访问的组播组关联且鉴权通过的组播 组。 上述系统还可具有以下特点：
组播业务模块是设置成通过为被请求访问的组播组和与该被请求访问的 组播组关联且鉴权通过的组播组建立组播转发表来实现令该终端同时加入被 请求访问的组播组和与该被请求访问的组播组关联且鉴权通过的组播组的； 以及
组播业务模块还设置成在组播转发表中对与该终端请求访问的组播组关 联的组播组设置标记位； 并判断组播转发表中的组播组的标记位； 以及， 所 述组播业务模块是设置成：
为该终端提供不具有标记位的组播组的的组播流来作为正常组播流， 以 及不为该终端提供具有标记位的组播组的组播流； 或者为该终端提供具有标 记位的组播组的组播流作为正常组播流的一部分。
上述系统中，
组播业务模块还可设置成： 在接收到终端离开当前组播组的报文后， 根 据该报文在组播转发表中该当前组播组的转发表项中删除该当前组播组的用 户端口； 以及在接收到终端请求访问另一组播组的报文后， 查找组播转发表， 判断该终端是否已经加入该另一组播组， 如果是， 则在组播转发表中去除该 终端本次请求的该另一组播组的标记位； 如果不是， 则令该终端同时加入该 另一组播组以及与该另一组播组关联的组播组。
上述系统还可具有以下特点：
组播业务模块是设置成通过在组播转发表中将具有标记位的组播组的用 户端口设置为空来实现不为该终端提供具有标记位的组播组的组播流； 以及 通过在组播转发表中将具有标记位的组播组的带宽设置为低清来实现为该终 端提供具有标记位的组播组的组播流为正常组播流的一部分； 低清的带宽为 标清和高清带宽的 N分之一。
上述系统还可具有以下特点：
该组播业务模块还设置成在对组播转发表进行操作后， 根据组播转发表 更新用以保存组播组与用户的关联关系的用户表。
本发明提出的一种减少网络电视频道切换时延的方法和系统， 减少了节 目由组播源到组播复制点的传输时延， 减少了机顶盒緩冲时延， 进一步提高 了 IPTV业务的服务质量。
附图概述
图 1是本发明实施例一种减少网络电视频道切换时延的方法流程图。 图 2是本发明实施例一种减少网络电视频道切换时延的系统方框图。
本发明的较佳实施方式
下面将结合附图详细说明本发明实施方案。
下面参考图 1 , 该图示出了本发明实施例一种减少网络电视频道切换时 延的方法， 具体包括步骤：
步骤 S101 : IPTV 系统规划组播关联方式， 使得每个组播组都存在与其 关联的一组组播组；
申请人敏锐地注意到一般用户在使用 IPTV切换节目时往往存在一定的 习惯， 例如， 喜欢用上下导航键切换频道， 又例如， 喜欢观看同一类的频道， 并在同一类的频道中进行切换， 等等， 因此， 在本发明中提出一种规划方案， 根据用户习惯进行组播组关联， 继而以此为基础在后续步骤中提出切实有效 的减少切换时延的方法。
所述根据用户的习惯规划组播关联方式具体可以是：
当根据用户喜欢用上下导航键来切换频道的习惯来规划组播关联方式 时， 可以规定当用户点播的频道 N的组播组时， 频道 N向上 Ml个频道范围 和 /或频道 N向下 M2个频道范围的一组组播组均与频道 N的组播组关联。其 中， Ml和 M2的值可以根据需要设定， 这里不做限制。
当根据用户喜欢在同一类型的频道中进行频道切换的习惯来规划组播关 联方式时， 可以规定当用户点播频道 N的组播组时， 与该频道 N属于同一类 型的所有其他频道范围的一组组播组均与频道 N的组播组关联。 频道类型的 划分可以根据内容划分， 例如分为体育频道、 娱乐频道、 电影频道、 音乐频 道、 生活频道、 游戏频道、 读书频道、 游频道、 电视剧频道、 新闻频道、 国际频道、 综合频道等； 也可以根据地域划分， 例如分为中央电视台、 湖南 电视台、 天津电视台等， 具体的频道分类方式可以根据需要设置， 这里不做 限制。
上述为目前比较常见的用户进行频道切换的习惯， 当然还可能会有其他 的频道切换习惯存在， 本发明实施例中并不仅限于上述频道切换习惯来规划 组播关联方式。较佳地， 在本发明实施例中 IPTV系统可以根据需要， 例如选 择大多数客户的共有频道切换习惯， 或者例如消费量大的客户的共有频道切 换习惯等作为 IPTV系统的用户的习惯规划组播关联方式。
步骤 S102: 终端开机， 点播节目， 根据欲点播的节目向 IPTV系统发送 请求访问组播组的互联网管理协议 IGMP报文；
步骤 S103: IPTV 系统接收到终端发送来的请求访问组播组的互联网管 理协议 IGMP ^艮文后， 解析该 ^艮文， 判断该终端用户对其请求访问的组播组 的访问权限， 鉴权通过， 则进入步骤 S104; 否则， 丟弃该 IGMP ^艮文， 结束； IPTV系统接收到终端发送来的互联网管理协议 IGMP报文后，解析该报 文， 从该 IGMP报文中提取用户的 mac、 port, vlan和组播地址， 查找 IPTV 系统中的频道访问控制 （CAC )模块， 来对该终端用户进行鉴权。
频道访问控制 （CAC )模块的作用就是根据对用户预先配置的访问组播 频道的权限， 实现用户对购买的一部分频道无限制观看， 一部分频道有预览 权限， 其余拒绝访问的功能； 另外， CAC模块还可以指定组播组的源端口， 即组播流必须从源端口流入， 并且对组播组的查询 文进行控制 , 如果匹配 的规则没有对查询报文处理的权限， 则丟弃查询报文。
CAC模块主要有两个表： 频道访问控制规则表和频道表， 其中频道访问 控制规则表目的是控制用户访问组播频道的权限， 这样当一个用户申请某一 频道时， 匹配此权限表， 然后根据用户匹配的权限， 执行对用户请求的操作。
CAC模块如果判断该用户是一组播组的定购用户， 则返回该用户对该组 播组定购权限和该组播组所属 MVLAN (组播 VLAN )号； 如果判断该用户 是一组播组的预览用户， 如果该用户预览次数小于最大预览次数并且与上次 预览的间隔大于设定的预览间隔， 则返回该用户对此组播组预览权限和该组 播组所属 MVLAN号； 否则返回该用户对此组播组无访问权限。
步骤 S104: IPTV系统根据组播关联方式得到与该终端请求访问的组播 组关联的一组组播组， 判断该终端对该些关联组播组的访问权限；
该步骤中 IPTV 系统对该终端对该些关联组播组的访问权限进行鉴权的 方法与步骤 S103相同， 这里不再赘述。
步骤 S105: IPTV 系统为该终端请求访问的组播组以及鉴权通过的关联 组播组建立组播转发表， 并在组播转发表中对鉴权通过的关联组播组设置标 记位；
IPTV系统是根据组播组的 MVLAN、用户端口及 VLAN来设置组播转发 表的， 如果 MVLAN和用户 VLAN不是同一 VLAN, 则设置三层组播转发表 以实现跨 VLAN; 如果是同一 VLAN, 则设置二层组播转发表。
步骤 S106: IPTV 系统将组播转发表中存在标记位的组播组， 即与终端 请求访问的组播组相关联的且鉴权通过的组播组的用户端口设置为空， 并根 据对组播转发表的设置更新用户表， 然后根据组播转发表向终端提供组播业 务；
组播转发表中组播组的用户端口即是该组播组的组播流的出端口。 本发 明实施例中将与终端请求访问的组播组相关联的组播组的用户端口设置为 空， 其目的是虽然将该些关联的组播组加入了组播转发表， 但是实际上并不 发送组播流， 不会占用带宽， 只为终端真正请求的组播组下发组播流， 因此， 不会影响用户的观看效果。
用户表用以保存组播组与用户的关联关系， 在组播转发表变化时， 需要 更新用户表。
在另一实施例中， 本步骤也可以是， IPTV系统将组播转发表中存在标记 位的组播组， 即与终端请求访问的组播组相关联的且鉴权通过的组播组的带 宽设置为低清（Low Definition Television, 简称 LDTV ) , 并根据对组播转发 表的设置更新用户表， 然后根据组播转发表向终端提供组播业务。 所谓 "低 清" 即带宽为标清（ Standard Definition Television, 简称 SDTV )和高清（ High Definition Television, 简称 HDTV )节目的 1/N, N可以根据网络的具体情况 来自定义设置。 低清节目不是为了观看， 只是为了减小频道切换时间而在用 户点播某个频道时同时下发和存储的一些频道组播流， 其占用带宽很少， 因 此， 不会影响为用户真正请求的组播组下发组播流的业务。
步骤 S107: 终端进行频道切换操作， 向 IPTV系统发送请求离开当前组 播组的互联网管理协议 IGMP报文；
步骤 S108: IPTV 系统接收到终端发送来的请求离开当前组播组的互联 网管理协议 IGMP报文后， 根据该报文在组播转发表中该终端请求离开的当 前组播组的转发表项中删除该用户端口， 并更新用户表；
IPTV 系统接收到终端发送来的请求离开当前组播组的互联网管理协议
IGMP报文后，解析该报文，提取其中的组播组地址和用户的 port、 vlan、 mac, ip参数传给 CAC模块， CAC模块会查找用户表， 如果该用户存在， 则返回 组播组所属 MVLAN号， 以便在该组播组的转发表项中删除该用户端口， 否 则丟弃报文。 IPTV 系统将用户端口从组播转发表中删除成功后， 会给 CAC 一个确认， 这时 CAC将用户从用户表中删除。
因为组播组范围是由组播复制点设备添加的， 所以用户只会发送正在点 播的一个组播组的离开 ^艮文， 不会发送组播组范围内的其他组播组的离开才艮 文， 所以本发明对组播组离开没有影响。
当一个用户在最小有效时间过后没有发送请求离开当前组播组的互联网 管理协议 IGMP报文， 则 CAC模块生成用户上线记录， 如果是预览用户， 则 将该用户所属规则的预览次数加 1 ; 如果一个用户在最小有效时间过后发送 请求离开当前组播组的互联网管理协议 IGMP报文， 则生成用户下线记录。
IPTV系统在组播转发表中删除当前组播组的转发表项中的用户端口时， 还可以判断一下该当前组播组是否还有其他组播用户， 如果没有其他该组播 组的用户则删除该组播组， 如果还有其他该组播组的用户则只删除表项中的 用户端口。
步骤 S 109： 终端向 IPTV系统发送请求访问另一组播组的互联网管理协 议 IGMP报文； 对于 IPTV 系统来说加入组播组的处理过程和离开组播组的处理过程并 不冲突， 因此， 终端进行频道切换时， 可以根据终端的具体实现方式， 一起 发送组播离开报文和组播加入报文， 或者先发送离开报文后发送加入报文都 可以， 即步骤 s 109也可以是与步骤 S 107同时执行的。
步骤 S110: IPTV 系统接收到终端发送来的请求访问另一组播组的互联 网管理协议 IGMP报文后， 解析该报文， 根据解析出的该另一组播组的组播 地址在组播转发表上判断该终端是否已经加入其本次请求访问的该另一组播 组， 如果判断结果为是， 则进入步骤 S111 ; 否则， 返回步骤 S103;
IPTV系统接收到用户侧发送来的互联网管理协议 IGMP报文后，解析该 报文， 可以得到用户的 mac、 port, vlan和组播地址。
步骤 Si l l : IPTV 系统在组播转发表中去除该终端本次请求访问的该另 一组播组的标记位， 添加该另一组播组的用户端口， 并根据对组播转发表的 设置更新用户表， 然后根据组播转发表向终端提供组播业务， 结束。
正是由于本发明提出了关联组播组的概念， 根据用户的习惯特点， 在开 机点播节目时， 在加入用户请求访问的组播组的同时， 还加入了与用户请求 访问的组播组相关联的一组组播组， 通过在组播转发表中进行相应的设置， 不为这些关联组播组下发业务或者下发极少的业务， 不会影响用户请求的组 播组的业务下发， 当用户在进行频道切换时， 由于已加入了关联的组播组， 因此， 只需要将用户切换到的频道的组播组的业务设置为正常即可实现快速 切换。
对于本发明上述步骤 S106中提到的釆用服务质量 QOS处理限制组播流 的带宽的处理方案， 在步骤 S111中， 即在终端进行频道切换时， 相应地， 可 以是， IPTV系统在组播转发表中去除该终端本次请求的组播组的标记位， 恢 复该组播组的组播流带宽， 即将该组播组的组播流的带宽设置为 "标清" 或 者 "高清" ， 并根据对组播转发表的设置更新用户表， 然后根据组播转发表 向终端提供组播业务， 结束。
为了实现上述方法， 本发明还提供了一种减少网络电视频道切换时延的 系统， 如图 2所示， 包括关联方式设置模块 21、 组播业务模块 22和鉴权模 块 23 , 其中： 该关联方式设置模块 21设置成： 设置并存储组播关联方式， 使得每个组 播组都存在与其关联的一组组播组。
该关联方式设置模块 21是设置成根据用户的习惯设置组播关联方式，例 如可以是， 根据用户喜欢用上下导航键来切换频道的习惯来设置频道关联方 式， 规定当终端请求加入某一频道的组播组时， 该频道向上多个频道范围和 / 或该频道向下多个频道范围的一组组播组均与该频道的组播组关联；又例如， 可以是根据用户喜欢在同一类型的频道中进行频道切换的习惯来规划频道关 联方式， 规定当终端请求加入某一频道的组播组时， 与该频道属于同一类型 的所有其他频道范围的一组组播组均与该频道的组播组关联。 当然还可以根 据其他需求设置组播关联方式， 本发明并不以此为限制。
该组播业务模块 22设置成：在接收到终端发送来的请求访问组播组的报 文后， 依据该组播关联方式判断出与请求访问的组播组关联的其他组播组， 令该终端同时加入该请求访问的组播组及与其关联的其他组播组， 为该终端 提供其请求访问的组播组的正常组播流， 以及不为该终端提供与其请求访问 的组播组关联的其他组播组的组播流， 或者为该终端提供与其请求访问的组 播组关联的其他组播组的组播流为正常组播流的部分； 以及在获知该终端进 行频道切换时， 判断该终端是否已经加入其请求切换到的频道的组播组， 如 果是， 则为该终端提供该请求切换到的频道的组播组的正常组播流。
该鉴权模块 23设置成： 在该组播业务模块 22接收到终端发送来的请求 访问组播组的 ^艮文后，对该终端对其请求访问的组播组的访问权限进行鉴权， 并将鉴权结果通知该组播业务模块 22; 以及对根据该组播业务模块 22判断 出的与请求访问的组播组关联的其他组播组， 对该终端对该其他组播组的访 问权限进行鉴权并将鉴权结果通知该组播业务模块 22。
进一步地， 该组播业务模块 22是设置成： 从该鉴权模块 23获知终端对 其请求访问的组播组具有访问权限后，才依据该关联方式设置模块 21中的组 播关联方式判断与请求访问的组播组关联的其他组播组， 之后从该鉴权模块 23获取终端对该与请求访问的组播组关联的其他组播组的访问权限， 将该终 端同时加入其请求访问的组播组和与该组播组关联的且鉴权通过的组播组。
进一步地， 该组播业务模块 22是设置成： 通过为其请求访问的组播组和 与该组播组关联的且鉴权通过的组播组建立组播转发表来实现令该终端同时 加入其请求访问的组播组和与该组播组关联的且鉴权通过的组播组的。
进一步地， 该组播业务模块 22还设置成： 在组播转发表中对与该终端请 求访问的组播组关联的组播组设置标记位； 以及判断组播转发表中的组播组 的标记位； 以及， 该组播业务模块是设置成： 为终端提供不具有标记位的组 播组的正常组播流， 以及不为该终端提供具有标记位的组播组的组播流或者 为该终端提供具有标记位的组播组的组播流为正常组播流的部分。
进一步地， 该组播业务模块 22还设置成： 在接收到终端离开当前组播组 的报文后， 根据该报文在组播转发表中该当前组播组的转发表项中删除该用 户端口； 以及在接收到终端请求访问另一组播组的报文后， 查找组播转发表， 判断该终端是否已经加入该另一组播组， 如果是， 则在组播转发表中去除该 终端本次请求的该另一组播组的标记位； 如果不是， 则令该终端同时加入该 另一组播组以及与该另一组播组关联的组播组。
进一步地， 该组播业务模块 22是设置成： 通过在组播转发表中将具有标 记位的组播组的用户端口设置为空来实现不为该终端提供具有标记位的组播 组的组播流； 以及通过在组播转发表中将具有标记位的组播组的带宽设置为 低清来实现为该终端提供具有标记位的组播组的组播流为正常组播流的部 分； 低清的带宽为标清和高清节目带宽的 N分之一。
进一步地， 该组播业务模块 22还设置成在对组播转发表进行操作后， 还 根据组播转发表更新用以保存组播组与用户的关联关系的用户表。
本发明还可有其他多种实施例，在不背离本发明精神及其实质的情况下 , 改变和变形都应属于本发明所附的权利要求的保护范围。
工业实用性
与现有技术相比， 本发明的方法和系统， 减少了节目由组播源到组播复 制点的传输时延，减少了机顶盒緩冲时延，进一步提高了 IPTV业务的服务质 量。

Claims

权 利 要 求 书
1、 一种减少网络电视频道切换时延的方法， 包括：
网络电视系统规划组播关联方式， 使得每个组播组都存在与其关联的一 组组播组；
网络电视系统在接收到终端发送来的请求访问组播组的报文后， 依据所 述组播关联方式判断出与被请求访问的组播组关联的组播组， 令所述终端同 时加入所述被请求访问的组播组及与该被请求访问的组播组关联的组播组； 网络电视系统为所述终端提供该终端请求访问的组播组的组播流作为正 常组播流， 以及不为所述终端提供与该终端请求访问的组播组关联的组播组 的组播流， 或者网络电视系统为所述终端提供与该终端请求访问的组播组关 联的组播组的组播流作为正常组播流的一部分； 以及
在所述终端请求进行频道切换时， 网络电视系统判断该终端是否已经加 入被请求切换到的频道的组播组， 如果是， 则为该终端提供被请求切换到的 频道的组播组的组播流作为正常组播流。
2、 如权利要求 1所述的方法， 其中，
网络电视系统规划组播关联方式的步骤包括：
网络电视系统根据用户喜欢用上下导航键来切换频道的习惯来规划频道 关联方式， 规定当终端请求加入频道的组播组时， 该频道向上多个频道范围 和 /或向下多个频道范围的一组组播组均与该频道的组播组关联； 或者
网络电视系统根据用户喜欢在同一类型的频道中进行频道切换的习惯来 规划频道关联方式， 规定当终端请求加入频道的组播组时， 与该频道属于同 一类型的所有其他频道范围的一组组播组均与该频道的组播组关联。
3、 如权利要求 2所述的方法， 还包括：
网络电视系统在接收到终端发送来的请求访问组播组的报文后， 先对该 终端对被请求访问的组播组的访问权限进行鉴权， 如果鉴权不通过， 则丟弃 该报文； 如果鉴权通过， 再依据所述组播关联方式判断出与被请求访问的组 播组关联的组播组； 令所述终端同时加入所述被请求访问的组播组及与该被请求访问的组播 组关联的组播组的步骤包括：
网络电视系统对所述终端对与所述被请求访问的组播组关联的组播组的 访问权限进行鉴权， 根据鉴权结果令该终端同时加入所述被请求访问的组播 组和与该被请求访问的组播组关联且鉴权通过的组播组。
4、 如权利要求 3所述的方法， 其中，
根据鉴权结果令终端同时加入所述被请求访问的组播组和与该被请求访 问的组播组关联且鉴权通过的组播组的步骤为： 网络电视系统为所述被请求 访问的组播组和与该被请求访问的组播组关联且鉴权通过的组播组建立组播 转发表；
所述方法还包括： 网络电视系统在组播转发表中对与所述终端请求访问 的组播组关联的组播组设置标记位， 并对该组播转发表中的组播组的标记位 进行判断；
网络电视系统为所述终端提供该终端请求访问的组播组的组播流作为正 常组播流的步骤中， 所述网络电视系统是为该终端提供不具有标记位的组播 组的组播流作为正常组播流；
不为所述终端提供与该终端请求访问的组播组关联的组播组的组播流的 步骤中，所述网络电视系统是不为该终端提供具有标记位的组播组的组播流； 为所述终端提供与该终端请求访问的组播组关联的组播组的组播流作为 正常组播流的一部分的步骤中， 所述网络电视系统是为该终端提供具有标记 位的组播组的组播流作为正常组播流的一部分。
5、 如权利要求 4所述的方法， 还包括：
终端进行频道切换时， 向网络电视系统发送离开当前组播组的报文和请 求访问另一组播组的 4艮文；
网络电视系统在接收到终端离开当前组播组的报文后， 根据所接收的报 文在组播转发表中该当前组播组的转发表项中删除当前组播组的用户端口； 网络电视系统在接收到终端请求访问另一组播组的报文后， 查找组播转 发表， 判断该终端是否已经加入该另一组播组， 如果是， 则在组播转发表中 去除该终端本次请求的该另一组播组的标记位； 如果不是， 则令该终端同时 加入该另一组播组以及与该另一组播组关联的组播组。
6、 如权利要求 5所述的方法， 其中，
不为该终端提供具有标记位的组播组的组播流的步骤中， 网络电视系统 通过在组播转发表中将具有标记位的组播组的用户端口设置为空来实现不为 该终端提供具有标记位的组播组的组播流；
为该终端提供具有标记位的组播组的组播流作为正常组播流的一部分的 步骤中， 网络电视系统通过在组播转发表中将具有标记位的组播组的带宽设 置为低清来实现为该终端提供具有标记位的组播组的组播流作为正常组播流 的一部分； 其中， 低清的带宽为标清和高清带宽的 N分之一。
7、一种减少网络电视频道切换时延的系统， 包括关联方式设置模块和组 播业务模块， 其中：
所述关联方式设置模块设置成： 设置并存储组播关联方式， 使得每个组 播组都存在与其关联的一组组播组；
所述组播业务模块设置成：
在接收到终端发送来的请求访问组播组的报文后， 依据组播关联方式判 断出与被请求访问的组播组关联的组播组， 令该终端同时加入所述被请求访 问的组播组及与该被请求访问的组播组关联的组播组， 为该终端提供被请求 访问的组播组的组播流作为正常组播流， 不为该终端提供与被请求访问的组 播组关联的组播组的组播流， 或者为该终端提供与被请求访问的组播组关联 的组播组的组播流作为正常组播流的一部分； 以及在获知终端请求进行频道 切换时， 判断该终端是否已经加入被请求切换到的频道的组播组， 如果是， 则为该终端提供该被请求切换到的频道的组播组的组播流作为正常组播流。
8、 如权利要求 7所述的系统， 其中，
所述关联方式设置模块是设置成通过如下方式来设置组播关联方式： 根据用户喜欢用上下导航键来切换频道的习惯来设置频道关联方式， 规 定当终端请求加入频道的组播组时， 该频道向上多个频道范围和 /或向下多个 频道范围的一组组播组均与该频道的组播组关联； 或者 根据用户喜欢在同一类型的频道中进行频道切换的习惯来规划频道关联 方式， 规定当终端请求加入频道的组播组时， 与该频道属于同一类型的所有 其他频道范围的一组组播组均与该频道的组播组关联。
9、 如权利要求 8所述的系统， 还包括鉴权模块：
所述鉴权模块设置成：
在组播业务模块接收到终端发送来的请求访问组播组的报文后， 对该终 端对被请求访问的组播组的访问权限进行鉴权， 并将鉴权结果通知组播业务 模块； 以及对该终端对与被请求访问的组播组关联的组播组的访问权限进行 鉴权并将鉴权结果通知组播业务模块；
所述组播业务模块是设置成在从鉴权模块获知终端对所述被请求访问的 组播组具有访问权限后， 才依据关联方式设置模块中的组播关联方式判断与 被请求访问的组播组关联的组播组， 并设置成通过如下方式令该终端同时加 入所述被请求访问的组播组及与该被请求访问的组播组关联的组播组： 从该 鉴权模块获取终端对与被请求访问的组播组关联的组播组的访问权限， 将该 终端同时加入所述被请求访问的组播组和与该被请求访问的组播组关联且鉴 权通过的组播组。
10、 如权利要求 9所述的系统， 其中，
所述组播业务模块是设置成通过为所述被请求访问的组播组和与被请求 访问的组播组关联的且鉴权通过的组播组建立组播转发表来实现令该终端同 时加入所述被请求访问的组播组和与该被请求访问的组播组关联且鉴权通过 的组播组的； 以及
所述组播业务模块还设置成在组播转发表中对与终端请求访问的组播组 关联的组播组设置标记位， 并判断组播转发表中的组播组的标记位； 以及， 所述组播业务模块是设置成：
为该终端提供不具有标记位的组播组的组播流来作为正常组播流， 以及 不为该终端提供具有标记位的组播组的组播流； 或者为该终端提供具有标记 位的组播组的组播流作为正常组播流的一部分。
11、 如权利要求 10所述的系统， 其中， 所述组播业务模块还设置成：
在接收到终端离开当前组播组的报文后， 根据所接收的报文在组播转发 表中该当前组播组的转发表项中删除该当前组播组的用户端口； 以及在接收 到终端请求访问另一组播组的报文后， 查找组播转发表， 判断该终端是否已 经加入该另一组播组， 如果是， 则在组播转发表中去除该终端本次请求的该 另一组播组的标记位； 如果不是， 则令该终端同时加入该另一组播组以及与 该另一组播组关联的组播组。
12、 如权利要求 11所述的系统， 其中，
所述组播业务模块是设置成：
通过在组播转发表中将具有标记位的组播组的用户端口设置为空来实现 不为该终端提供具有标记位的组播组的组播流； 以及通过在组播转发表中将 具有标记位的组播组的带宽设置为低清来实现为该终端提供具有标记位的组 播组的组播流作为正常组播流的一部分； 低清的带宽为标清和高清带宽的 N 分之一。
13、 如权利要求 12所述的系统， 其中，
所述组播业务模块还设置成在对组播转发表进行操作后， 根据组播转发 表更新用以保存组播组与用户的关联关系的用户表。
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Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101656872B (zh) * 2009-08-25 2011-07-20 中兴通讯股份有限公司 一种减少网络电视频道切换时延的方法和系统
US9077644B2 (en) * 2010-12-08 2015-07-07 At&T Intellectual Property I, L.P. Methods and apparatus for communicating with groups of devices sharing an attribute
CN102970599B (zh) * 2012-10-31 2016-05-04 杭州华三通信技术有限公司 一种频道切换方法和设备
US9215128B2 (en) * 2013-03-14 2015-12-15 International Business Machines Corporation Port membership table partitioning
US10045058B2 (en) 2014-10-23 2018-08-07 At&T Intellectual Property I, L.P. Method and apparatus to deliver a personalized media experience
US9848317B2 (en) 2015-11-25 2017-12-19 Viasat, Inc. Multicast handover for mobile communications
CN106096031B (zh) * 2016-06-27 2020-06-16 武汉斗鱼网络科技有限公司 一种带标签的视频排序方法及装置
CN106713348B (zh) * 2017-01-17 2019-12-31 无锡雷华网络技术有限公司 Olt组播上行协议报文转发方法及系统
CN108289243B (zh) * 2018-01-25 2020-08-21 盛科网络（苏州）有限公司 基于OpenFlow交换机实现视频用户无缝切换节目源的方法和系统
CN111866526B (zh) * 2019-04-29 2021-10-15 华为技术有限公司 一种直播业务处理方法和装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1925581A (zh) * 2005-08-31 2007-03-07 上海乐金广电电子有限公司 频道转换方法
CN1941868A (zh) * 2005-09-30 2007-04-04 深圳Tcl新技术有限公司 一种相同广播电视频道信息的关联表及其频道快速切换方法
JP2008263489A (ja) * 2007-04-13 2008-10-30 Kddi Corp マルチキャスト配信装置およびマルチキャスト受信装置
CN101409631A (zh) * 2008-10-30 2009-04-15 华为技术有限公司 一种频道切换的方法和装置
CN101656872A (zh) * 2009-08-25 2010-02-24 中兴通讯股份有限公司 一种减少网络电视频道切换时延的方法和系统

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1252961C (zh) * 2001-07-09 2006-04-19 中兴通讯股份有限公司 一种对组播业务进行认证的方法
JP2003348149A (ja) 2002-05-28 2003-12-05 Nippon Telegr & Teleph Corp <Ntt> Ｉｐマルチキャスト用認証方法およびこれを用いるｉｐマルチキャスト用認証システム
DE602004025722D1 (de) * 2003-10-07 2010-04-08 Thomson Licensing Multicast über Unicast in einem Netzwerk
US7793329B2 (en) * 2006-02-06 2010-09-07 Kasenna, Inc. Method and system for reducing switching delays between digital video feeds using multicast slotted transmission technique
CN1929638A (zh) * 2006-10-20 2007-03-14 中兴通讯股份有限公司 一种无线局域网ip组播帧传输的组播成员管理方法
KR100888859B1 (ko) 2007-03-06 2009-03-17 주식회사 케이티 서비스 지연을 개선하는 인터넷 프로토콜 셋탑박스, 장치및 방법
US20090106792A1 (en) * 2007-10-22 2009-04-23 Alcatel Lucent Method and apparatus for advertisement and content distribution with customized commercial insertion during channel change

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1925581A (zh) * 2005-08-31 2007-03-07 上海乐金广电电子有限公司 频道转换方法
CN1941868A (zh) * 2005-09-30 2007-04-04 深圳Tcl新技术有限公司 一种相同广播电视频道信息的关联表及其频道快速切换方法
JP2008263489A (ja) * 2007-04-13 2008-10-30 Kddi Corp マルチキャスト配信装置およびマルチキャスト受信装置
CN101409631A (zh) * 2008-10-30 2009-04-15 华为技术有限公司 一种频道切换的方法和装置
CN101656872A (zh) * 2009-08-25 2010-02-24 中兴通讯股份有限公司 一种减少网络电视频道切换时延的方法和系统

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2461584A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013038619A (ja) * 2011-08-09 2013-02-21 Onkyo Corp 受信端末及びそのプログラム

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