CN102340494A

CN102340494A - Manageable P2P (Peer-to-Peer) streaming media live broadcasting system based on IMS (IP Multimedia Subsystem) in NGN (Next Generation Network) and realization method thereof

Info

Publication number: CN102340494A
Application number: CN2010102387627A
Authority: CN
Inventors: 林镜华; 于波; 孙建伟; 肖诗泉; 贾军营; 刘峰
Original assignee: Shenyang Institute of Computing Technology of CAS
Current assignee: Shenyang Institute of Computing Technology of CAS
Priority date: 2010-07-28
Filing date: 2010-07-28
Publication date: 2012-02-01
Anticipated expiration: 2030-07-28
Also published as: CN102340494B

Abstract

The invention relates to a manageable P2P (Peer-to-Peer) streaming media live broadcasting system based on an IMS (IP Multimedia Subsystem) in an NGN (Next Generation Network) and a realization method thereof. The system provided by the invention expands an overlay network management function entity and a network resource inquiry function entity on a streaming media service layer. The method provided by the invention comprises the following steps: using user terminal equipment capable of carrying out P2P as a calling request to establish a streaming media live broadcasting session; utilizing a streaming media service control function entity as a back-to-back user agent to select a content transmitter for calling user terminal equipment and establish a media transmission session with the content transmitter; utilizing the user terminal equipment capable of carrying out P2P to carry out a channel switching request updating session; and utilizing the streaming media service control function entity to select the content transmitter of a new channel for the user terminal equipment capable of carrying out P2P and establish the media transmission session with the content transmitter of the new channel. According to the invention, the centralized management of a P2P overlay network is realized; the problem of inconformity in a P2P distribution network and a physical network is solved; and simultaneously, the QoS (Quality of Service) of P2P media transmission is ensured by utilizing the SIP/SDP (session initiation protocol/session description protocol) session consultation mechanism in the IMS and the network control and resource reservation provided by the NGN.

Description

In NGN based on managed P2P flow medium live system and the implementation method of IMS

Technical field

The present invention relates to the stream media technology and the IP communications field, a kind of specifically in NGN based on managed P2P flow medium live system and the implementation method of IMS.

Background technology

In recent years; Popularizing of the fast development of Along with computer technology, multimedia technology and broadband network; The Streaming Media of IP based network is used and has been obtained development fast; Like IPTV (Internet Protocol Television is based on the TV of Internet Protocol, i.e. Web TV), video request program, live on line, video monitoring, network radio station, move TV, long-distance education etc.Live streaming media all is a kind of very important professional form of expression in online Internet TV (Internet television) business that IPTV is professional and ISP (ISP) provides of telecom operators' development.Live streaming media development on the internet is comparatively ripe; Range of application is also very extensive; But since the QoS (Quality of Service, service quality) that IP network exists can't assurance, characteristics such as content security and network resource management difficulty, cause it that the service of " doing one's best " can only be provided; Be difficult to make up optimum commercial operation pattern, thus not good by telecom operators.Even current commercial IPTV business also all can only be runed in dedicated network or local area network (LAN) scope, owing to the industry standard of lack of uniform, the IPTV solution of each manufacturer's structure still can't realize interconnecting at present simultaneously.

Along with 3GPP (3rd Generation Paratership Project; Third generation partner program tissue) IP Multimedia System (IP Multimedia Subsystem in R5 (Release 5) version; IMS) proposition, next generation network (Next Generation Network; The expansion of research and development NGN) and IPTV userbase, international two big ETSI TISPAN of telecommunication standard research organization (European Telecommunication Standard research institute telecommunications and internet converged services and high-level network protocol tissue (TISPAN)) and ITU-T (International Telecommunications Union's telecommunication standards tissue) have provided the IPTV business structure based on IMS (abbreviating NGN-IMS-based IPTV as) in NGN.At present, from the IPTV business function architecture that both formulate, remove mutual between application server and the media server, the former selects through Core IMS (core IMS), and more more options are outside Core IMS for the latter, and other basically all is consistent.The IMS-based IPTV ergasia framework that ETSI TISPAN formulates is as shown in Figure 1, it the IPTV business structure total be divided into following a few major part: subscriber terminal equipment (UE), transport network layer, Core IMS, IPTV operation layer and the processing of IPTV medium.Wherein UE comprises network insertion, SIP (Session Initiation Protocol; Session initiation protocol) session control, current control RTSP (Real Time Streaming Protocol; Real-time streaming protocol) client, HTTP (HyperText Transfer Protocol; HTTP) functional module such as client, electronic program list; Transport network layer comprises the transmission process function (mainly accomplishing IP transmission and resource reservation function) of the resource and admission that transmits controlled function and RACS (RACS) and Network Attachment Subsystem (NASS), Access Layer; Core IMS reuses the IMS core network element P/I/S-CSCF of 3GPP (3G technology norm-setting mechanism) definition fully; The IPTV operation layer comprises Service Control Function, service selection functional (SSF), service discovering function (SDF), and the medium processing capacity comprises media control function and distribution of media function two large divisions.From the prior art standard that they are formulated, (Broadcast, distribution of media BC) will adopt IP multicast mode to live broadcast service.But realize live broadcast service with IP multicast mode, need to upgrade the data message distribution router of the whole network, not only costly, be difficult in the time realize at short service deployment, and still there is a still unsolved difficult problem in the member management of IP multicast.Even in the IPTV of certain operator private network, can realize the IP multicast path by; But in the Streaming Media distribution procedure of autonomous territory of across a network or operator; Still can run into the situation that IP multicast mode is difficult to realize, the IP multicast more is difficult to adapt to the stream media live service deployment of dispersion user flexibly simultaneously.

P2P Streaming Media distribution technology is a kind of application layer route technology.It makes full use of the upstream bandwidth and the user terminals resources of edge network, not only helps improving system scalability, robustness, also will significantly reduce performance and outlet bandwidth demand to central server.But existing P2P technology is when bringing above-mentioned advantage; Also because internodal content delivery is lacked effectively control and management means; Cause a large amount of backbone bandwidth resources gratuitously to be eaten; Digital content also is difficult to obtain digital copyright protecting, so the P2P technology is not welcome by Virtual network operator and content supplier.To topology not perception (topology-unaware) phenomenon of P2P network to the bottom physical network; The researcher proposes the P4P thought that operator participates in making up application layer P2P network; And increase iTracker server is that P2P client or P2P application provide information such as network topology structure, state, ability, operation strategy, node location similitude to optimize the selection and the network resource utilization of service node; (Distributed Computing Industry Association DCIA) has also set up special P4P working group and has launched correlative study the Distributed Calculation industry association.However; Since its P2P content distributing network still be structured in do not have that QoS guarantees on the internet; IMS architectural framework and the NGN research direction with telecom operators do not combine; Thereby still only provide on the basis of " doing one's best " service, optimize the P2P routing issue, be difficult to reach the operation purpose of carrier class value-added service.In addition, any adding of P2P node and leaving also cause P2P use in for individual node provides the unsteadiness of service, especially all the more so for real-time and the demanding streaming media service of continuity; The P2P network that prior art makes up does not have session management mechanism, causes the architecture that application platform also lacks provides incentive mechanism and copyright control.

The central server performance bottleneck that is difficult to solve distribution of media in view of existing IMS stream media system is difficult to realization with IP multicast routing mode; And the distribution of P2P Streaming Media has the advantage of system scalability; A lot of researchers propose the idea that will combine IMS and P2P, but specifically implementation does not appear in the newspapers as yet.

Summary of the invention

The stream media live service that can't adapt to dispersion user flexibly to the IP multicast that exists in the prior art dispose with the P2P network uncontrollable, weak point such as can not manage, the technical problem that the present invention will solve provides a kind ofly can overcome in the existing IMS live broadcast system limitation based on the IP multicast, it is that flow medium live system fast and flexible ground is disposed to realize, satisfy controlled, the pipe property of P2P network and QoS assurance that peer node is transmitted managed P2P flow medium live system and the implementation method based on IMS simultaneously.

For solving the problems of the technologies described above, the technical scheme that the present invention adopts is:

The present invention a kind of in NGN based on the managed P2P flow medium live system of IMS, comprising: NGN transport network layer, core IMS, streaming media service layer, subscriber terminal equipment and media server, wherein:

The NGN transport network layer for core IMS and streaming media service layer provide network foundation, is realized network control and transmission process function;

Core IMS is for the streaming media service layer provides session control, signalling route, service trigger function; Submit resource reservation and access control function to the NGN transport network layer;

User-subscribed database, the relevant information that is used for preserving core IMS and streaming media service layer comprises the network topology structure information that Streaming Media contracted user's user profile, authentication information, optional stream medium service information and operator provide;

The streaming media service layer based on the session of subscriber terminal equipment and core IMS routing forwarding, is realized stream media live service logical process, service discovering, service selection and content management function;

Subscriber terminal equipment realizes that through the network foundation that the NGN transport network layer provides the network insertion of stream media live service and Streaming Media transmit; Be connected with the mutual of core IMS, realize session initiation, renewal and expiry feature; Be connected with the mutual of streaming media service layer, realize service discovering, selection function; Obtain media data from media server, realize local playing function; After the expansion P2P function, and realize network-in-dialing property testing and medium forwarding capability between the peer users terminal equipment, be called the subscriber terminal equipment that enables P2P again;

Media server, the session control message of reception core IMS routing forwarding realizes medium control and distribution function.

Said streaming media service layer comprises:

Streaming media service discovery feature entity is used for realizing to subscriber terminal equipment professional satellite information being provided, and selects the state update functions of personalized service selection server address and notice electronic program list for subscriber terminal equipment;

The streaming media service selection functional entity is used for realizing the download function that produces electronic program list, electronic program list and program presenting information are provided to subscriber terminal equipment;

Streaming media service controlled function entity; Be used for carrying out the streaming media service logic; Comprise with core IMS and carry out Signalling exchange and service authorization function; The peer-to-peer network terminal node of selecting media server or providing live TV stream to transmit according to service executing result promptly enables the subscriber terminal equipment of P2P, and to media server or enable the subscriber terminal equipment inquiry media processing capacity of P2P, and the forwarding stream media service request is given the Streaming Media forwarding person who is selected out;

Overlay network management function entity is used for realizing the management of the P2P overlay network that each direct broadcast band is corresponding, to the judgement foundation of Internet resources query function entity inquiring structuring overlay network;

Internet resources query function entity is used for realizing providing the query function of Internet resources, and the judgement foundation of the P2P overlay network that makes up physical topology and on-position perception is provided for overlapping net management functional entity;

The content management function entity is used for realizing increase, deletion and the modification to media program or content;

Content preprocessing function entity is used for realizing the extraction and the preparation of the content before the fluidisation of program metadata information, comprises Media Analysis, encoding and decoding conversion and content pre-fetch function.

Said P2P overlay network is by the centralized management of overlay network management function entity, and the form of expression of P2P overlay network is P2P bunch or P2P groups of nodes, and the node in same P2P bunch is a terminal service node close on physical location or the route.

Said overlay network management function entity management is participated in the P2P overlay network of each channel live stream distribution; And be divided into each subscriber terminal equipment different P2P bunches information through what requester network resource query functional entity got access to, to choose the terminal service node in same P2P bunch.

Said streaming media service controlled function entity is live broadcast service call subscriber terminal choice of equipment media content uploading person with SIP back-to-back user agent role; And replace setting up between call subscriber terminal equipment and the medium uploader SIP session and enable the subscriber terminal equipment allocation medium transfer resource of P2P with request, provide medium to transmit and serve.

Implementation method based on the managed P2P flow medium live system of IMS among a kind of NGN of the present invention may further comprise the steps:

A. the subscriber terminal equipment that enables P2P is set up the live streaming media session as caller to streaming media service controlled function entity requests; Streaming media service controlled function entity is as back-to-back user agent; P2P overlay network and media server deployment scenario according to current overlay network management function entity maintaining; Be call subscriber terminal choice of equipment media content transmission person, and set up the media delivery session with content delivery person;

B. the subscriber terminal equipment that enables P2P carries out channel and switches; To streaming media service controlled function entity requests session updates; Streaming media service controlled function entity is the content delivery person that the subscriber terminal equipment that enables P2P is selected new channel, and sets up the media delivery session with the content delivery person of new channel;

C. the subscriber terminal equipment that enables P2P withdraws from live.

Said step a is media server or subscriber terminal equipment according to the content delivery person of streaming media service controlled function entity inquiry overlay network management function entity selection, when the content delivery person who selects is media server, handles as follows:

A11. the subscriber terminal equipment that enables P2P sends the INVITE request via core IMS to streaming media service controlled function entity as caller and sets up live session; Session Description Protocol in the message body partly carries direct broadcast band sign and two medium line descriptions; One of them medium line description network test passage, another medium line description medium receive path;

A12. after streaming media service controlled function entity is received the INVITE request of call subscriber terminal equipment; The corresponding overlay network of direct broadcast band that the current selection of call subscriber terminal equipment of inquiry overlay network management function entity maintaining is watched can't be selected the subscriber terminal equipment that service can be provided; Streaming media service controlled function entity makes up new INVITE request as back-to-back user agent and is transmitted to media server via core IMS, and the Session Description Protocol part of this INVITE body only comprises the medium receive path of call subscriber terminal equipment and describes;

A13. media server issues channel resource based on the direct broadcast band sign allocation medium of describing in the INVITE body; And construct 200 OK response and control functional entity to streaming media service through the core IMS routing forwarding; The medium clean culture that the Session Description Protocol of 200 OK message bodies is partly described media server issues channel information, comprise the distribution of media functional entity the IP address, flow down and make a start mouthful and medium encoding and decoding relevant information;

A14. after streaming media service controlled function entity receives the 200 OK response of media server, construct 200 OK response again according to this 200 OK message and reply to call subscriber terminal equipment via core IMS; Streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch of the corresponding participation Media Stream forwarding of the direct broadcast band of overlay network management function entity maintaining simultaneously as new service node;

A15. call subscriber terminal equipment structure ACK message is transmitted to streaming media service controlled function entity via core IMS and confirms that live session sets up successfully; Streaming media service controlled function entity receives that constructing ACK message again after the ACK message is transmitted to media server via core IMS, and media server receives and begins formally to issue the Media Stream based on clean culture after ACK confirms.

Said step a is media server or subscriber terminal equipment according to the content delivery person of streaming media service controlled function entity inquiry overlay network management function entity selection, when the content delivery person who selects is subscriber terminal equipment, handles as follows:

A21. the subscriber terminal equipment that enables P2P sends the INVITE request via core IMS to streaming media service controlled function entity as caller and sets up live session; The Session Description Protocol of message body partly carries direct broadcast band sign and two medium line descriptions; One of them medium line description network test passage, another medium line description medium receive path;

A22. after streaming media service controlled function entity is received the INVITE request of call subscriber terminal equipment; P2P bunch of the corresponding requests channel of inquiry overlay network management function entity maintaining is not empty; Then, carry the sip user logical identifier of this subscriber terminal equipment, current on-position and channel identication in the request message to P2P bunch of division foundation of Internet resources query function entity requests inquiry;

A23. Internet resources query function entity returns to overlay network management function entity based on relevant information and channel identication, the server disposition of corresponding channel, the network topology structure information of operator and network distance and P2P bunch of sign that routing configuration calculates subscriber terminal equipment of subscriber terminal equipment; The result that overlay network management function entity resource query functional entity Network Based returns selects the strongest subscriber terminal equipment of rest processing capacity as the P2P service node from request same P2P bunch of channel;

A24. the P2P service node of selecting based on overlay network management function entity; Streaming media service control functional entity makes up new INVITE request as back-to-back user agent; Give the P2P service node of selecting via the core IMS route, the Session Description Protocol of this INVITE body partly comprises the medium receive path and the TCH test channel description of call subscriber terminal equipment;

A25. after the P2P service node of selecting is received the INVITE request as called user terminal equipment; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel, structure 18 * response routes to streaming media service controlled function entity via core IMS, and the Session Description Protocol of this response message body has partly been described network test passage of closing and the media transmission channel information of opening;

A26. after streaming media service control functional entity is received 18 of called user terminal equipment * response; Re-construct 18 * response and route to call subscriber terminal equipment via core IMS, the message body of this response is identical with 18 * message body content of called user terminal device responds;

A27. call subscriber terminal device replied PRACK message authentication is received 18 * response; And open local network and test listening port; Be forwarded to streaming media service controlled function entity SCF via core IMS, construct PRACK message again after streaming media service controlled function entity is received and route to called user terminal equipment via core IMS;

A28. after called user terminal equipment is received the PRACK acknowledge message,,, and carry out the network-in-dialing property testing before the media delivery between the call subscriber terminal equipment like the RTP/RTCP agreement through similar PING/PONG agreement; The called user terminal equipment simulating flows down the process of sending out and sends PING message, and call subscriber terminal equipment simulating medium receiving course is responded PONG message;

A29. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits requirement; Wherein statistics comprises packet loss, network delay, shake size etc.; Then stop the network-in-dialing property testing if meet the demands; Construct 200 OK response and route to streaming media service control functional entity via core IMS, the Session Description Protocol of its message body is partly described network test passage of closing and the media transmission channel of opening;

A210. after streaming media service controlled function entity is received the 200 OK response of called user terminal equipment, construct 200 OK response again as back-to-back user agent and give call subscriber terminal equipment through the core IMS route; Simultaneously; Streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch that the corresponding participation Media Stream of direct broadcast band of overlay network management function entity maintaining transmits as new service node, and notice overlay network management function is upgraded the rest processing capacity of called user terminal equipment;

A211. after call subscriber terminal equipment is received 200 OK response; Close local network test listening port; Open the media receiving end mouth; And reply the ACK acknowledge message and be transmitted to streaming media service controlled function entity via core IMS, after streaming media service controlled function entity receives the ACK acknowledge message of call subscriber terminal equipment, construct the ACK acknowledge message again and be transmitted to called user terminal equipment through core IMS;

A212. after called user terminal equipment receives the ACK acknowledge message, from this machine buffering area, read Media Stream, transmit Media Stream according to the medium receive path information of the call subscriber terminal equipment of describing in the INVITE body that in the a24 step, receives.

Said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is media server and what the new channel content delivery service is provided for call subscriber terminal equipment is media server, then pass through steps of processing:

B11. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein message body Session Description Protocol part is opened the network test passage again; Media transmission channel remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B12. after streaming media service controlled function entity receives the Re-INVITE message of call subscriber terminal equipment; Inquiry overlay network management function entity finds that call subscriber terminal equipment does not provide the medium upload service for other subscriber terminal equipments; Then streaming media service controlled function entity is given media server as back-to-back user agent structure Re-INVITE message through the core IMS routing forwarding; The medium that request finishes current channel issue, and distribute the medium of new channel to issue server resource;

B13. after media server receives the Re-INVITE request of streaming media service controlled function entity; According to old channel identication of describing in the Session Description Protocol part and new channel sign; Stop call subscriber terminal equipment is issued the medium of old channel; And issue server resource for the medium of call subscriber terminal devices allocation new channel; Construct 200 OK response then and be transmitted to business control function body via core IMS, wherein the media services of partly describing new channel of the Session Description Protocol of message body issue channel information;

B14. after streaming media service controlled function entity is received the 200 OK response of media server answer; Again construct 200OK message and send to call subscriber terminal equipment via core IMS, wherein the Session Description Protocol of message body has partly been described the network test passage of closing and has been issued passage with the medium of opening; Simultaneously, streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch that the corresponding participation Media Stream of direct broadcast band of overlay network management function entity maintaining transmits as new service node;

B15. after subscriber terminal equipment is received the 200 OK response of streaming media service controlled function entity; Learn by media server to be that subscriber terminal equipment issues media content; Thereby close the local network TCH test channel; This machine of opening medium receive listening port and wait for the Media Stream that receives new channel, and structure ACK message sends to streaming media service controlled function entity to confirm the session updates success via core IMS;

B16. after streaming media service controlled function entity is received ACK session updates acknowledge message; Again construct the ACK request and give media server via the core IMS route; Media services receive ACK and confirm that session updates successfully afterwards issues the medium of new channel for call subscriber terminal equipment, accomplish channel with this and switch.

Said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is media server and what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment, then pass through steps of processing:

B21. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein the message body Session Description Protocol has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B22. streaming media service controlled function entity sends BYE message as back-to-back user agent and gives media server, and the medium that supply for call subscriber terminal equipment that request finishes to set up between streaming media service controlled function entity and the media server issue service conversation;

Simultaneously, streaming media service controlled function entity inquiry overlay network management function entity is selected the service node that enables P2P and for call subscriber terminal equipment the media delivery service is provided as called user terminal equipment;

B23. streaming media service controlled function entity is given the called user terminal equipment of selecting as the new INVITE of back-to-back user agent structure via the core IMS route, and wherein the Session Description Protocol in the message body has partly been described the network test passage and the media transmission channel information of call subscriber terminal equipment;

B24. after called user terminal equipment receives the INVITE request of streaming media service controlled function entity; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel, structure 18 * response routes to streaming media service controlled function entity via core IMS, and the Session Description Protocol of this response message body has partly been described called user terminal equipment network test passage of opening and the media transmission channel information of closing;

B25. after streaming media service controlled function entity is received 18 of called user terminal equipment * response; Construct 200 OK response and send to call subscriber terminal equipment via core IMS, the content in 18 * message body of message body wherein and called user terminal device responds is identical;

B26. call subscriber terminal device replied ACK message authentication is received 20 * response; Wherein the Session Description Protocol of message body partly carries this machine network test passage of opening and the medium receive path of closing; Be forwarded to streaming media service controlled function entity via core IMS, streaming media service controlled function entity receives that 200 OK response back structure PRACK message and ACK message send to called user terminal equipment and call subscriber terminal equipment via core IMS;

B27. after called user terminal equipment is received the PRACK acknowledge message; Through similar PING/PONG agreement; Like the RTP/RTCP agreement; And carry out the network-in-dialing property testing before the media delivery between the call subscriber terminal equipment, wherein the called user terminal equipment simulating flows down the process of sending out and sends PING message, and call subscriber terminal equipment simulating medium receiving course is also responded PONG message;

B28. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits requirement; If test result meets the demands; Then stop the network-in-dialing property testing; Construct 200 OK response and send to streaming media service control functional entity via core IMS, wherein the message body Session Description Protocol has partly been described network test passage of closing and the media transmission channel information of opening;

B29. after streaming media service control functional entity receives the 200 OK response of called user terminal equipment; Re-construct the Re-INVITE request as back-to-back user agent and send to call subscriber terminal equipment through core IMS; After call subscriber terminal equipment is received the Re-INVITE response; Close the local network test port, open the media receiving end mouth, and reply 200 OK response messages;

B210. after streaming media service controlled function entity receives call subscriber terminal equipment 200 OK response; Notice overlay network management function entity joins call subscriber terminal equipment in P2P bunch of new channel as new service node; And the rest processing capacity of renewal called user terminal equipment, construct ACK message simultaneously respectively and reply to call subscriber terminal equipment and called user terminal equipment via core IMS;

B211. after called user terminal equipment receives the ACK acknowledge message of streaming media service controlled function entity transmission,, accomplish the channel switch operating with this to call subscriber terminal device forwards Media Stream.

Said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment and what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment, then pass through steps of processing:

B31. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out the channel switching; Wherein the Session Description Protocol of message body has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B32. after streaming media service controlled function entity receives the Re-INVITE request of call subscriber terminal equipment; Send the called user terminal equipment that BYE message is given provides old channel media delivery service as back-to-back user agent; The media delivery service conversation that provides for call subscriber terminal equipment that request finishes to set up between streaming media service controlled function entity and the called user terminal equipment, and notify the rest processing capacity of overlay network management function entity renewal called user terminal equipment; Streaming media service controlled function entity is inquired about overlay network management function entity simultaneously, and the service node that enables P2P that selection makes new advances provides the media delivery service of new channel for call subscriber terminal equipment as called user terminal equipment;

B33. streaming media service controlled function entity is given the called user terminal equipment of newly selecting as the new INVITE of back-to-back user agent structure via the core IMS route, and wherein the Session Description Protocol in the message body has partly been described the network test passage and the media transmission channel information of call subscriber terminal equipment;

B34. after called user terminal equipment receives the INVITE request of streaming media service controlled function entity; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel, structure 18 * response routes to streaming media service controlled function entity via core IMS, and the Session Description Protocol of this response message body has partly been described called user terminal equipment network test passage of opening and the media transmission channel information of closing;

B35. after streaming media service controlled function entity is received 18 of called user terminal equipment * response; Construct 200 OK response and send to call subscriber terminal equipment, identical in message body information wherein and the 18 * message body of called user terminal device responds via core IMS;

B36. call subscriber terminal device replied ACK message authentication is received 20 * response; Wherein the message body Session Description Protocol partly carries this machine network test passage of opening and the medium receive path of closing; Be forwarded to streaming media service controlled function entity via core IMS, streaming media service controlled function entity receives that 200 OK response back structure PRACK message and ACK message send to called user terminal equipment and call subscriber terminal equipment via core IMS;

B37. after called user terminal equipment is received the PRACK acknowledge message; Through similar PING/PONG agreement; Like the RTP/RTCP agreement; And carry out the network-in-dialing property testing before the media delivery between the call subscriber terminal equipment, wherein the called user terminal equipment simulating flows down the process of sending out and sends PING message, and call subscriber terminal equipment UE analog media receiving course is also responded PONG message;

B38. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits demand; If test result meets the demands; Then stop the network-in-dialing property testing; Construct 200 OK response and send to streaming media service control functional entity via core IMS, wherein the message body Session Description Protocol is partly described network test passage of closing and the media transmission channel information of opening;

B39. after streaming media service control functional entity receives the 200 OK response of called user terminal equipment; Re-construct the Re-INVITE request as back-to-back user agent and send to call subscriber terminal equipment through core IMS; After call subscriber terminal equipment is received the Re-INVITE response; Close the local network test port, open the media receiving end mouth, and reply 200 OK response messages;

B310. after streaming media service controlled function entity receives the 200 OK response of call subscriber terminal equipment; Notice overlay network management function entity adds call subscriber terminal equipment in P2P bunch of new channel as new service node, and upgrades the rest processing capacity of the called user terminal equipment that the service of new channel media delivery is provided; Construct ACK message simultaneously respectively and reply to call subscriber terminal equipment and called user terminal equipment via core IMS;

B311. after called user terminal equipment is received the ACK acknowledge message of streaming media service controlled function entity transmission,, accomplish the channel switch operating with this to call subscriber terminal device forwards Media Stream.

Said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment and what the new channel content delivery service is provided for call subscriber terminal equipment is media server, then pass through steps of processing:

B41. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein the Session Description Protocol of message body has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B42. after streaming media service controlled function entity receives the Re-INVITE message of call subscriber terminal equipment; Send BYE message as back-to-back user agent and give called user terminal equipment; The media delivery session that provides for call subscriber terminal equipment that request finishes that streaming media service controlled function entity and called user terminal equipment room set up, and notify the rest processing capacity of overlay network management function entity renewal called user terminal; Streaming media service controlled function entity inquiry overlay network management function entity finally selects media server for call subscriber terminal equipment the media delivery service to be provided simultaneously;

B43. streaming media service controlled function entity makes up new INVITE request as back-to-back user agent and is transmitted to media server via core IMS, and wherein the Session Description Protocol of message body part only comprises description of call subscriber terminal equipment medium receive path and new channel sign;

B44. after media server receives INVITE; Obtain the new channel sign allocation medium that the Session Description Protocol in the message body partly describes and issue channel resource; Construct 200 OK message then and be transmitted to streaming media service controlled function entity via core IMS; Wherein the unicast stream of partly having described media server of the Session Description Protocol in the message body issues channel information, comprise media server the IP address, flow down and make a start mouthful and medium encoding and decoding relevant information;

B45. after streaming media service controlled function entity receives the 200 OK response of media server; Again construct 200 OK response according to this 200 OK message and reply to call subscriber terminal equipment via core IMS, Session Description Protocol has wherein partly been described the medium clean culture of opening and has been issued channel information and the network test passage of closing; Streaming media service controlled function entity notice overlay network management function entity simultaneously, the rest processing capacity of called user terminal equipment is upgraded in the P2P bunch of neutralization that joins the participation new channel Media Stream distribution of overlay network management function entity maintaining to call subscriber terminal equipment as new service node;

B46. after call subscriber terminal equipment receives 200 OK response; Structure ACK message is forwarded to streaming media service controlled function entity via core IMS and confirms live handover success; Streaming media service controlled function entity receives that constructing ACK message again after the ACK message is transmitted to media server via core IMS; Media server receives ACK and confirms that the back starts unicast stream and issues, and accomplishes channel with this and switches.

Whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and the media delivery service be not provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is media server, then passes through steps of processing:

C11. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C12. receive subscriber terminal equipment live withdraw from request after; Streaming media service control functional entity inquiry overlay network management function entity is known this subscriber terminal equipment not for other node provides the media delivery service, and streaming media service control functional entity re-constructs BYE message as back-to-back user agent and is forwarded to the media delivery session that media server request end is set up with it via core IMS;

C13. after media server receives BYE message, stop immediately, and construct 200 OK response and be forwarded to streaming media service controlled function entity SCF via core IMS to call subscriber terminal equipment issues Media Stream;

C14. after streaming media service control functional entity SCF receives the 200 OK response of media server to the BYE request; Re-construct 200 OK response and reply to subscriber terminal equipment via core IMS; And remove the live session relevant information of call subscriber terminal equipment, notice overlay network management function entity is subscriber terminal equipment deletion from P2P bunch of its last viewing channel;

C15. subscriber terminal equipment receives 200 OK response back and accomplishes the live work of withdrawing from.

Whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and the media delivery service be not provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is the subscriber terminal equipment that enables P2P, then passes through steps of processing:

C21. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C22. receive subscriber terminal equipment live withdraw from request after; Streaming media service control functional entity inquiry overlay network management function entity is known this subscriber terminal equipment not for other node provides the media delivery service, re-constructs BYE message as back-to-back user agent then and is forwarded to via core IMS and provides the called user terminal of content uploading device request to finish the media delivery session of foundation with it;

C23. after called user terminal equipment receives the BYE message of streaming media service controlled function entity transmission; Stop to transmit service, and construct 200 OK response and reply to streaming media service controlled function entity via core IMS for the Media Stream of call subscriber terminal equipment;

C24. after streaming media service controlled function entity receives the 200 OK response of called user terminal equipment to the BYE request; Again construct 200 OK response and reply to call subscriber terminal equipment via core IMS; And the live session relevant information of removing call subscriber terminal equipment; Notice overlay network management function entity upgrades the rest processing capacity of called user terminal equipment to the deletion from P2P bunch of its last viewing channel of call subscriber terminal equipment;

C25. subscriber terminal equipment receives 200 OK response back and accomplishes the live work of withdrawing from.

Whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and just the media delivery service be provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is media server, then passes through steps of processing:

C31. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C32. receive subscriber terminal equipment live withdraw from request after; Streaming media service controlled function entity inquiry overlay network management function entity knows that this subscriber terminal equipment just provides the media delivery service for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is media server, and then streaming media service controlled function entity is accomplished following two tasks simultaneously:

Task one; Send to its media delivery service conversation that provides for other subscriber terminal equipment of call subscriber terminal device end as back-to-back user agent structure BYE message via core IMS; And be that call subscriber terminal equipment institute service object is selected new content delivery person again, and set up the media delivery session with it;

Task two: as back-to-back user agent structure BYE message; Be transmitted to the media control function entity via core IMS; The SIP session of setting up between request end and the media server; After media server receives BYE message, stop, and construct 200 OK response messages and confirm the session between end and the streaming media service controlled function entity to call subscriber terminal equipment issues medium; Streaming media service controlled function entity is constructed 200 OK response messages after receiving the 200 OK response of media server again, confirms to finish the session of streaming media service controlled function entity and call subscriber terminal equipment room;

C33. call subscriber terminal equipment is accomplished the live work of withdrawing from.

Whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and just the media delivery service be provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is the subscriber terminal equipment that enables P2P, then passes through steps of processing:

C41. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C42. receive subscriber terminal equipment live withdraw from request after; This subscriber terminal equipment of streaming media service controlled function entity detection just provides the media delivery service for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is another subscriber terminal equipment that enables P2P, and then streaming media service controlled function entity is accomplished following two tasks simultaneously:

Task one; Be transmitted to call subscriber terminal device end call subscriber terminal equipment provides the media delivery service for other subscriber terminal equipment session as back-to-back user agent structure BYE message via core IMS; And be that call subscriber terminal equipment institute service object is selected new content delivery person again, and set up the media delivery session with it;

Task two; As back-to-back user agent structure BYE message; Be transmitted to called user terminal equipment via core IMS, request finishes the media delivery session of foundation with it, after called user terminal equipment receives BYE message; Stop to be call subscriber terminal device forwards medium, and construct 200 OK response messages and confirm the session between end and the streaming media service controlled function entity; Streaming media service controlled function entity is constructed 200 OK response messages after receiving the 200 OK response of called user terminal equipment again, confirms to finish the session of streaming media service controlled function entity and call subscriber terminal equipment room;

C43. call subscriber terminal equipment is accomplished the live work of withdrawing from.

Described media delivery session; Be used to set up media transmission channel; And media transmission channel guarantees the network-in-dialing performance by similar PING/PONG protocol test before setting up; All sessions between medium sender and the recipient have been guaranteed the service quality of P2P media delivery all via the core IMS routing forwarding.

The present invention has following beneficial effect and advantage:

1. the present invention has overcome the defective that adopts IP multicast mode to realize live streaming media in the existing NGN-IMS-based IPTV system, introduces P2P distribution of media technology and has solved the center media server brought based on the clean culture distribution in the live broadcast service or the performance bottleneck and the scalability issues of CDN network edge server.

2. the present invention is through increasing Internet resources query function entity NRQF, overlay network management function entity; The present invention has realized the centralized management of P2P overlay network; Solve the inconsistent problem of physical network topology that P2P distributing network and operator dispose, realized the proximity of each P2P node cluster physical location of same channel.

3. the present invention is under the prerequisite of following NGN and IMS architectural framework; Reuse the perfect session route of IMS network, service trigger and IP-based policy control and network resource reservation based on moving speed mechanism; Realized P2P distributing network based on SIP session control and SDP media negotiation; Not only realize the controlled pipe property of peer-to-peer network, also guaranteed the QoS of P2P media delivery.

4. the present invention is based on the SIP session and make up the P2P transmission channel, the basis of the flexible accounting strategy that designs dialogue-based and incident also is provided for the P2P media delivery, and then help solving the design challenges of incentive mechanism among the P2P.

Description of drawings

Fig. 1 is the IMS-based IPTV ergasia Organization Chart that ETSI TISPAN formulates in the prior art;

The flow medium live system Organization Chart that Fig. 2 distributes based on the support clean culture of IMS in NGN for the present invention;

Fig. 3 is the present invention's managed P2P flow medium live system Organization Chart based on IMS in NGN;

Fig. 4 is the present invention's managed P2P Streaming Media distributing network topology diagram based on IMS in NGN;

Fig. 5 is user terminal registration and service discovery and selection course figure in the implementation method of the present invention;

Fig. 6 is user terminal live broadcast service request process figure in the implementation method of the present invention;

Fig. 7 is user terminal channel handoff procedure figure in the implementation method of the present invention;

Fig. 8 withdraws from the live broadcast system procedure chart for user terminal in the implementation method of the present invention.

Embodiment

Basic principle of the present invention is the functional entity of reusing NGN and IMS; Use for reference that end-to-end media transmission channel in audio frequency, the video call service is set up and the method for network resource reservation based on moving speed, utilize that Session Initiation Protocol is simple, characteristics and application server are realized the structure of the P2P distributing network in the stream media live service based on the B2B UA processing logic of SIP easily to be prone to expansion, media combination.The structure of P2P distributing network has been used for reference the iTracker server of introducing in the P4P design philosophy again; Expanded Internet resources query function entity NRQF in the IMS application layer, so that combine network topology resource that operator provides and the current accessing position information of UE to be close P2P bunch of each direct broadcast band establishment physical location.The final effect that realizes be signaling and P2P node administration with Path selection by centralized management, the distribution of live Media Stream is the employing peer-to-peer network technology.

Provide support in order in the Streaming Media transmission of IMS network, to introduce the P2P transmission technology, the present invention has expanded function corresponding entity and interface again on the basis of the flow medium live system framework of distributing based on the support clean culture of IMS (as shown in Figure 2).

As shown in Figure 3; The present invention's managed P2P flow medium live system based on IMS in NGN comprises NGN transport network layer, core IMS, streaming media service layer, subscriber terminal equipment and media server; Wherein: the NGN transport network layer; For core IMS and streaming media service layer provide network foundation, realize network control and transmission process function; Core IMS for the streaming media service layer provides session control, signalling route, service trigger function, is submitted resource reservation and access control function to the NGN transport network layer; User-subscribed database, the relevant information that is used for preserving core IMS and streaming media service layer comprises the network topology structure information that Streaming Media contracted user's user profile, authentication information, optional stream medium service information and operator provide; The streaming media service layer, the session based on user terminal is initiated realizes stream media live service logical process, service discovering, service selection and content key management function;

Subscriber terminal equipment realizes that through the network foundation that the NGN transport network layer provides the network insertion of stream media live service and Streaming Media transmit; Be connected with the mutual of core IMS, realize session initiation, renewal and expiry feature; Be connected with the mutual of streaming media service layer, realize service discovering, selection function; Obtain media data from media server, realize local playing function; After the expansion P2P function, and realize between the peer users terminal equipment that medium are transmitted, the network connectivty test function, be called and enable P2P subscriber terminal equipment (P2P-enabled User Equipment, P2P-enabled UE).

The NGN transport network layer comprises network control and transmission process two parts; Wherein Network Control Segment comprises Resource and Admission Control Sub-system (RACS) and Network Attachment Subsystem (NASS), be used for implementation strategy control, resource reservation, access control and network layer subscription authentication and Access Network the configuration; The Network Transmission processing capacity of NGN transport plane is partly accomplished in transmission process, is used for realizing that network insertion connects and provide the routing forwarding of the IP message of QoS assurance;

Core IMS comprises the P/I/S-CSCF network element of session control layer among the IMS: proxy call conversation control function entity (P-CSCF), service call session control function entity (S-CSCF) and query call conversation control function entity (I-CSCF); Be used for realizing session control, signalling route, service trigger, with mutual resource reservation and the access control function of realizing of RACS, said network element is referred to as core IMS (Core IMS);

The streaming media service layer comprises streaming media service discovery feature entity (SDF), streaming media service selection functional entity (SSF), streaming media service controlled function entity (SCF), overlay network management function entity (OMF), Internet resources query function entity (NRQF), content management function entity (CMF) and content preprocessing function entity (CPreF), wherein:

Streaming media service discovery feature entity is used for realizing to subscriber terminal equipment professional satellite information being provided, and selects the update mode function of personalized address of service server and notice electronic program list (EPG) for subscriber terminal equipment;

The streaming media service selection functional entity is used for realizing the generation electronic program list, the download function of electronic program list and program presenting information (comprising film poster, program brief introduction, featured performer etc.) is provided to subscriber terminal equipment;

Streaming media service controlled function entity is used for carrying out the streaming media service logic; Comprise with core IMS and carry out Signalling exchange and service authorization function; Select media server or the peer-to-peer network terminal node P2P subscriber terminal equipment of content uploading is provided according to service executing result; To media server or P2P subscriber terminal equipment UE inquiry media processing capacity; And the streaming media service request is transmitted to the content provider who selects; SCF participates in the P2P cluster management of each channel live stream distribution, and is divided into each subscriber terminal equipment UE different P2P bunches information through what requester network resource query functional entity NRQF got access to, chooses the close terminal service node of physical location or route; SCF is that live broadcast service call subscriber terminal equipment UE is selected the media content uploading person with SIP back-to-back user agent (B2B UA) form, and replaces call subscriber terminal equipment UE and medium uploader to set up the SIP session with the allocation medium transmission channel;

Internet resources query function entity is used for realizing providing the query function of Internet resources; The judgement foundation of the P2P overlay network that makes up physical topology and on-position perception is provided for overlapping net management functional entity; NRQF collects the position is disposed and Virtual network operator provides the overall network topology and the routing configuration information of current media server; NRQF can seek suitable media delivery person according to the accessing position information at subscriber terminal equipment place and for it media flow transmission service (media delivery person comprises media server and the terminal node that enables P2P with medium forwarding service function) is provided; NRQF can provide service for the requestor by the preferential terminal node of selecting to enable P2P; All P2P nodes have only when all can not provide the service with QoS guarantee for the requestor; Be that the requestor provides media services by media server, uplink bandwidth resource that utilizes terminal node and local disposal ability that like this can maximum possible alleviate the burden of media server;

Media server comprises media control function entity (MCF) and distribution of media functional entity (MDF); Wherein the media control function entity is used for to MDF inquiry medium coding/decoding information, receives the flow media session request of UE; And according to session status and UE control information to media server application medium down distributing resource, and flow down the real-time control of the state of sending out; The distribution of media functional entity is used for realizing the media transmission channel distribution, the medium coding/decoding information is provided, reports functions such as Distribution status, the current control that responds MCF, buffer memory focus content for the UE media stream, to MCF;

As shown in Figure 3, the interface of system extension of the present invention comprises interface I1～I7, wherein:

Interface I1 transmits information such as the metadata information (like programm name, director, protagonist) be used to produce electronic program list and program arrangement between CPreF and the SSF; Interaction protocol between the two can be the HTTP/HTTPS agreement, and metadata information wherein can be described by XML document;

Interface I2 transmits the content identification of request and carries out pretreated media content between CPreF and the MDF;

Interface I3 is OMF when making up P2P Overlay network, and the interface of delivery network resource query information between the NRQF, and agreement is indefinite; SCF transmits UE through this interface and identifies to NRQF; NRQF provides the judgement foundation that makes up the P2P overlay network through the current media deployment scenario that the network topology that combines the current on-position of UE, operator and provide and routing configuration information and MCF provide; The judgement foundation comprises network distance and P2P bunch of sign etc., and returns to OMF to discriminative information through interface I3;

Interface 14 is current on-position and information such as overall network topology structure, routing configuration of transmitting UE between NRQF and the UPSF, and interaction protocol between the two is a Diameter;

Interface I5 be NRQF in the MCF inquiry current media interface of information such as the server disposition position of program and load condition perhaps, information is between the two described by XML document through TCP or http protocol transmission;

Interface 16 is used for the connectedness and the network quality of test network between two UE or the Peer node, can select the matchmaking protocol of similar PING/PONG for use, like the RTP/RTCP agreement;

Interface I7 is used to transmit the media content between two UE or the Peer node, flows like RTP/RTCP.

SCF in the system of the present invention also participates in the internodal session management of peer-to-peer network of each channel live stream distribution except realizing streaming media service logic control function, and the P2P bunch of division of obtaining according to OMF inquiry NRQF is according to selecting media content transmission person; SCF is that live broadcast service request UE selects the media content uploading person with SIP back-to-back user agent (B2B UA) form, and replaces setting up the SIP session with the allocation medium transmission channel between server call UE and the medium uploader.

OMF in the system of the present invention participates in the P2P overlay network of each channel live stream distribution; And be divided into each subscriber terminal equipment different P2P bunches information through what requester network resource query functional entity got access to, to choose the terminal service node in same P2P bunch; OMF both can be used as independent functional entity, also can be used as the function expansion of SCF.

The function that NRQF in the system of the present invention accomplishes comprises overall network topology and the routing configuration information of safeguarding that operator provides; And according to current on-position of UE and current media server disposition position calculation network distance, for the OMF module of SCF provide finally be used to form P2P bunch with the judgement foundation of selecting service node.

The terminal that UE in the system of the present invention is not only meeting of defining in the IMS network IMS network insertion requires or by possessing STB or the PC that Network Management Equipment that the IMS network insertion requires inserts, and be to have expanded that medium are transmitted and the P2P-enabled UE of network connectivty test function; This client is downloaded, the functions such as professional initiations, media play, is also comprised the expression of P2P ability, stream upload service, test network connectedness and performance are provided, wait for that as the ISP session invitation of SCF participates in the function that the P2P content distributes and expand for the P2P client except accomplishing based on network insertion, registers kernel network, service discovering, EPG and the digital rights certificate of the IPTV standard client of IMS.

Not only compatible traditional central server of Streaming Media distributing network in the system of the present invention or content distributing network CDN technology are also at the P2P Streaming Media distributing network of network edge support based on centralized management; Streaming medium content transmission person is selected by network side SCF inquiry OMF, and this decision is to make through the NRQF that overall network information is provided that OMF requester network operator participates in disposing; SCF both can select media server; Also can select P2P-enabled UE to participate in the distribution of live TV stream; The content disposition of media server can be disposed according to existing C DN or server cluster, and is organized into physical location or the close P2P overlay network form of route between each UE; After selecting service node UE, SCF is service node as B2B UA based on the SIP session negotiation among the IMS and is served node and set up the Streaming Media transmission channel; Before described media transmission channel is set up; Consult a network connectivty and performance test passage through the mechanism of the Offer/Answer among the session negotiation agreement SDP earlier between the node; If meet the demands through the test network characteristic; Then close the network test passage and open media transmission channel through the heavy negotiation mechanism of SIP session, Core IMS guarantees with the QoS that media delivery is provided to RACS application and affirmation network resource reservation based on moving speed in this process; Media transmission channel between the UE is not only and is received network side RACS, Core IMS, SCF or the complete perception of OMF entity; And be to guarantee network QoS; Be that the Streaming Media transmission channel is managed concentratedly, controlled between any two UE, guarantee the fail safe and the reliability of P2P content delivery with this; When the UE that the content uploading service is provided withdraws from live broadcast service; SCF is as the medium upload session between B2B UA disconnection and the service UE; And reselect service UE for the medium recipient; It provides the medium upload service for the recipient to set up new SIP session invitation with it, carries out network-in-dialing property testing and media transmission channel again through session updates simultaneously and sets up.

In the NGN network, because terminal UE can add IP network through various physical network access waies, IP network wherein can provide QoS to guarantee from couple in router to the backbone network router.After UE expresses the P2P extended capability, network topology model of similar bunch comparatively close of network topology structure information architecture that the NRQF of network side can provide according to the current on-position of UE and operator with physical network.The network topology structure of supposing the media server formation that current UE and operator dispose is as shown in Figure 4; Wherein UE_C and UE_B are together from a couple in router access network; UE_A adds network from adjacent couple in router, promptly UE_A and the UE_B distance on the network route still comparatively near.If when first three UE asks to watch same channel, obviously, not only UE_B and UE_C can coexist one P2P bunch, even UE_A still can exist together with it in one P2P bunch.Being example with this network topology model below, in conjunction with the systemic-function architecture of accompanying drawing 3 and the interface of definition, is that implementation method of the present invention specifies to the several key business processing procedures that relate in the stream media live service.

Implementation method of the present invention may further comprise the steps:

C. the subscriber terminal equipment that enables P2P withdraws from live.

Before step a, also need user terminal UE registration and service discovery and selection course:

UE at first is registered to the IMS core net, and to draw PULL or to push away PUSH mode discovery SSF relevant information, SSF selects appropriate EPG to be transferred to UE according to the different qualities of UE simultaneously, and the detailed process instance is as shown in Figure 5.

The UE registration process:

S1:UE sends REGISTER message and gives Core IMS, request registration

The success of S2:Core IMS authentication is returned 200 OK message and is given UE

Service discovery process one (PUSH pattern):

S3.1:Core IMS replaces UE to register to SDF as the third-party registration agency;

S4.1:SDF replys the 200OK response, shows that Core IMS replaces UE to succeed in registration to SDF;

S5.1:SDF initiatively sends MESSAGE message and gives UE, and in message body, carries the address and the program download URL sign of SSF server;

S6.1:UE replys the 200OK response after receiving that MESSAGE message gets access to the server address and URL information of EPG download;

Service discovery process two (PULL pattern):

S3.2:UE initiatively sends SUBSCRIBE to SDF and subscribes to EPG Download Server address and update information on content;

S4.2:SDF replys 200 OK response, shows and receives subscribe request;

S5.2:SDF initiatively sends NOTIFY and gives UE, and in message body, carries the address and the program download URL sign of SSF server, and notice UE goes to download the EPG lastest imformation;

After S6.2:UE receives NOTIFY, from message body, get access to server address that EPG downloads and URL information after, and reply 200 OK and respond;

Service selection process:

S7:UE sends the HTTP request to SSF and downloads relevant informations such as EPG;

S8:SSF gives UE according to UE characteristic and the suitable EPG message transmission of signatory content choice.

A11. the subscriber terminal equipment that enables P2P sends the INVITE request via core IMS to streaming media service controlled function entity as caller and sets up live session; Session Description Protocol in the message body partly carries direct broadcast band sign (Channel_ID) and two medium line descriptions; One of them medium line description network test passage, another medium line description medium receive path;

A12. after streaming media service controlled function entity is received the INVITE request of call subscriber terminal equipment; The corresponding P2P overlay network of direct broadcast band that the current selection of call subscriber terminal equipment of inquiry overlay network management function entity maintaining is watched can't be selected the subscriber terminal equipment that service can be provided; Streaming media service controlled function entity makes up new INVITE request as back-to-back user agent and is transmitted to the media control function entity via core IMS, and the Session Description Protocol part of this INVITE body only comprises the medium receive path of call subscriber terminal equipment and describes;

A13. the media control function entity is according to the direct broadcast band sign of describing in the INVITE body (Channel_ID); Dispose selection distribution of media functional entity according to load condition and program; The request allocation medium issues channel resource; The distribution of media functional entity distributes successfully, and the back returns to the media control function entity to information; Media control function entity structure 200 OK message responses reply to streaming media service controlled function entity via core IMS, and wherein the medium clean culture of partly describing media server of the Session Description Protocol in the message body issues channel information, comprise the distribution of media functional entity the IP address, flow down and make a start mouthful and medium encoding and decoding relevant information;

A14. after streaming media service controlled function entity receives the 200 OK response of media control function entity; Again construct 200 OK response according to this 200 OK message and reply to call subscriber terminal equipment via core IMS, Session Description Protocol part SDP has wherein described the network test passage that the medium clean culture of opening issues channel information and closes; Streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch of the corresponding participation Media Stream forwarding of the direct broadcast band of overlay network management function entity maintaining simultaneously as new service node;

A15. call subscriber terminal equipment structure ACK message is forwarded to live the foundation successfully of streaming media service controlled function entity affirmation via core IMS; Streaming media service controlled function entity receives that constructing ACK message again after the ACK message is transmitted to the media control function entity via core IMS, and the media control function entity receives ACK and confirms that back control distribution of media functional entity begins formally to issue unicast media.

A22. after streaming media service controlled function entity is received the INVITE request of call subscriber terminal equipment UE; Promising this channel of corresponding channel Channel_ID of inquiry overlay network management function entity maintaining provides the subscriber terminal equipment that enables P2P of media delivery service; Then divide foundation, carry the sip user logical identifier of this subscriber terminal equipment, current on-position and channel identication in the request message to Internet resources query function entity requests inquiry P2P groups of nodes;

A23. Internet resources query function entity returns to overlay network management function entity OMF based on relevant information, the server disposition of corresponding channel, the network topology structure information of operator and network distance and P2P bunch of signs that routing configuration calculates subscriber terminal equipment such as the current on-position of subscriber terminal equipment and channel identications; The result that OMF resource query functional entity Network Based returns selects the strongest subscriber terminal equipment of rest processing capacity as the P2P service node from request same P2P bunch of channel;

A24. the P2P service node of selecting based on overlay network management function entity; Streaming media service control functional entity makes up new INVITE request as back-to-back user agent; Give the service node of selecting via the core IMS route, the Session Description Protocol of this INVITE body partly comprises the medium receive path and the TCH test channel description of call subscriber terminal equipment;

A25. after the P2P service node of selecting is received the INVITE request as called user terminal equipment; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel; Structure 18 * (conditional code is the message between 180～189 in 18 * expression sip response message, and it is indefinite specifically to select) response routes to streaming media service controlled function entity via core IMS, and the Session Description Protocol of this response message body has partly been described network test passage of closing and the media transmission channel information of opening;

A27. call subscriber terminal device replied PRACK message authentication is received 18 * response; And open local network and test listening port; Be forwarded to streaming media service controlled function entity via core IMS, construct PRACK message again after streaming media service controlled function entity is received and route to called user terminal equipment via core IMS;

A29. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits requirement; Wherein statistics comprises packet loss, network delay, shake size etc.; Then stop the network-in-dialing property testing if meet the demands; Construct 200 OK response and route to streaming media service control functional entity via core IMS, the Session Description Protocol part SDP of its message body describes network test passage of closing and the media transmission channel of opening;

A211. after call subscriber terminal equipment is received 200 OK response; Close local network test listening port; Open the media receiving end mouth; And reply the ACK acknowledge message and be transmitted to streaming media service controlled function entity via core IMS, after streaming media service controlled function entity receives the ACK acknowledge message of call subscriber terminal equipment, construct the ACK acknowledge message again and be transmitted to called user terminal equipment through core IMS

A212. after called user terminal equipment receives the ACK acknowledge message, from this machine buffering area, read Media Stream, transmit Media Stream according to the medium receive path information of the call subscriber terminal equipment UE of describing in the INVITE body that in the a24 step, receives.

Being that the situation of subscriber terminal equipment is an example as the content delivery person who selects; Watch the live broadcast service of certain channel when the user terminal UE_B request of expansion P2P function; And the existing UE_A of current channel is watching; And UE_A has the P2P extended capability and is ready to provide the medium upload service, and it is as shown in Figure 6 then to select UE_A to be that process is set up in UE_B service and session: its process is following:

S1:UE_B initiates the INVITE request and watches in certain programme televised live perhaps channel, has wherein described native network TCH test channel and media transmission channel information among the SDP of message body;

S2:Core IMS issues and the network connectivty test resource to RACS request reserved media before transmitting the INVITE request;

S3:Core IMS is routed to the SCF that is responsible for live broadcast service to the INVITE request according to certain service trigger criteria;

S4:SCF selects the judgement foundation of P2P bunch and Peer service node to NRQF request for this UE, and according to return results select with UE_B at same Cluster and UE_A with medium upload ability;

It is that UE_B provides the medium upload service that S5:SCF creates new INVITE request UE_A as B2B UA, and is forwarded to Core IMS, has wherein described network test passage and the media transmission channel information of UE_A among the SDP of message body;

Before the S6:Core IMS routing forwarding INVITE request, will upload the Internet resources with the network-in-dialing property testing to RACS network element request reserved media;

S7:Core IMS is according to the INVITE request of the current on-position routing forwarding SCF transmission of UE_A;

S8:UE_A judges that local residue service ability is enough to provide one road medium upload service; Then reply 18 * response; Notify network connectivty and performance test before the other side carries out media delivery, wherein the network connectivty TCH test channel of message body SDP description is opened, and media transmission channel is closed;

S9: before routing forwarding 18 * message, Core IMS confirms resource reservation to RACS, to open the network connectivty TCH test channel of UE_B and network side;

18 * message is to SCF in the session of S10:Core IMS routing forwarding;

18 * response that the S11:SCF structure is new is transmitted to Core IMS, and wherein the SDP part directly copies 18 * response message that UE_B replys;

S12: before UE_B was given in route 18 * response, Core IMS submitted to resource reservation to confirm to RACS, to open the network connectivty TCH test channel of UE_A and network side;

UE_B is given in 18 * response in the S13:Core IMS route conversation;

S14～S17:UE_B sends the interim message confirmation request of PRACK through Core IMS to SCF, and SCF gives UE_A as the new PRACK message of B2B UA innovation through Core IMS routing forwarding;

Carry out the test of PING/PONG agreement through the network that provides QoS to guarantee between S18～S19:UE_A and the UE_B, the process of transmitting that this test can simulates real real data bag, UE_B returns to UE_A to statistics;

S20: if the network test result meets the demands; UE_A replys 200 OK response; Be changed to 0 to close the network connectivty TCH test channel through the network test access port of describing among the SDP, media port is newly assigned media delivery port simultaneously, to open media transmission channel;

S21:Core IMS upgrades resource reservation to the RACS request before routing forwarding 200 OK message, open the media transmission channel between UE_B and the network side, and close the network connectivty TCH test channel;

200 OK message are given SCF in the session of S22:Core IMS routing forwarding;

The OMF of S23:SCF adds UE_B among the P2P stream distribution Overlay, and record UE_A is that UE_B provides service, and UE_B also will be as alternative P2P stream ISP simultaneously;

S24:SCF makes up new 200 OK response and sends to Core IMS according to the 200 OK message that receive, and wherein the SDP in the message body directly copies the SDP part in the 200 OK message of UE_B answer;

S25:Core IMS upgrades resource reservation to RACS request before routing forwarding 200 OK respond UE_B, opening the media transmission channel between UE_A and the network, and close the network test passage;

S26:Core IMS routing forwarding 200 OK give UE_B;

S27～S30:UE_B replys the ACK session and confirms to ask to SCF, and the new ACK of SCF structure asks to UE_A.

Above-mentioned S1～S30 step is the media flow transmission passage that UE_B and UE_A have set up has QoS to guarantee; This passage not only has the one-way characteristics of Media Stream; And the content delivery between two Peer is set up by the SIP session negotiation; Promptly this P2P media flow transmission passage receives strict supervision, and this just provides good basis for the centralized management of P2P distributing network.

Among the step b; According to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server (MF); And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is media server and what the new channel content delivery service is provided for call subscriber terminal equipment is media server, then pass through steps of processing:

B11. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein message body Session Description Protocol part is opened the network test passage again; Media transmission channel remains unchanged, and also carries new channel sign (New_ChannelID) and the old channel identication (Old_ChannelID) of switching in addition in the message body;

B12. after streaming media service controlled function entity receives call subscriber terminal equipment Re-INVITE message; Inquiry overlay network management function entity finds that call subscriber terminal equipment does not provide the medium upload service for other subscriber terminal equipments; Then streaming media service controlled function entity is given the media control function entity as back-to-back user agent structure Re-INVITE message through the core IMS routing forwarding; The medium that request finishes current channel issue; And distribute the medium of new channel to issue server resource, wherein the SDP of message body partly includes only the media transmission channel description of calling UE;

B13. after the media control function entity receives the Re-INVITE request of streaming media service controlled function entity; According to the Old_ChannelID and the New_ChannelID that describe in the Session Description Protocol part; Control distribution of media functional entity stops call subscriber terminal equipment current channel is issued the medium of old channel; And be that call subscriber terminal device request distribution of media functional entity distributes the medium of new channel to issue server resource; Construct 200 OK response then and respond 200 OK message via core IMS, wherein the media services of partly describing new channel of the Session Description Protocol of message body issue channel information;

B14. after streaming media service controlled function entity is received the 200 OK response of media control function entity answer; Again construct 200 OK message and send to call subscriber terminal equipment via core IMS, wherein the Session Description Protocol of message body has partly been described the network test passage of closing and has been issued passage with the medium of opening; Simultaneously, streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch that the corresponding participation Media Stream of direct broadcast band of overlay network management function entity maintaining transmits as new service node;

B15. after subscriber terminal equipment is received the 200 OK response of streaming media service controlled function entity; Learn by issuing media content for subscriber terminal equipment; Thereby close the local network TCH test channel; This machine of opening medium receive listening port and wait for the Media Stream that receives new channel, and structure ACK message sends to streaming media service controlled function entity to confirm the session updates success via core IMS;

B16. after streaming media service control functional entity is received ACK session updates acknowledge message; Re-construct the ACK request and give the media control function entity via the core IMS route; The media control function entity receives that ACK confirms that session updates success back control distribution of media functional entity issues the medium of new channel for call subscriber terminal equipment, accomplishes channel with this and switches;

If inquiry overlay network management function entity OMF finds that call subscriber terminal equipment also provides the medium upload service for other subscriber terminal equipment UE simultaneously; Then finish and call subscriber terminal equipment between set up the session of medium upload service is provided for current channel; Again select medium upload service node for the service object of calling UE; And remove in corresponding P2P bunch of current channel subsequent steps b13 to the call subscriber terminal equipment UE.

Among the step b according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And that the new channel content delivery service is provided for the call subscriber terminal equipment UE is subscriber terminal equipment UE or media server MF; If current what provide that medium upload for the call subscriber terminal equipment UE is media server and what the new channel content delivery service is provided for the call subscriber terminal equipment UE is subscriber terminal equipment UE, then pass through steps of processing:

B21. the subscriber terminal equipment UE that enables P2P is as caller; Send Re-INVITE message and be transmitted to streaming media service controlled function entity SCF request carrying out switching channels via core IMS; Wherein message body Session Description Protocol SDP has partly described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign New_ChannelID and the old channel identication Old_ChannelID of switching in addition in the message body;

B22. streaming media service controlled function entity sends BYE message as back-to-back user agent and gives the media control function entity, and the medium that provide for call subscriber terminal equipment that request finishes to set up between streaming media service controlled function entity and the media control function entity issue service conversation;

B24. after called user terminal equipment receives the INVITE request of streaming media service controlled function entity; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel, structure 18 * response routes to streaming media service controlled function entity SCF via core IMS, and the Session Description Protocol of this response message body has partly been described called user terminal equipment network test passage of opening and the media transmission channel information of closing;

B26. call subscriber terminal device replied ACK message authentication is received 20 * response; Wherein the Session Description Protocol SDP of message body partly carries this machine network test passage of opening and the medium receive path of closing; Be forwarded to streaming media service controlled function entity via core IMS, streaming media service controlled function entity receives that 200 OK response back structure PRACK message and ACK message send to called user terminal equipment and call subscriber terminal equipment via core IMS;

B28. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits requirement; Wherein statistics comprises packet loss, network delay, shake size etc.; If test result meets the demands; Then stop the network-in-dialing property testing, construct 200 OK response and send to streaming media service control functional entity via core IMS, wherein the message body Session Description Protocol has partly been described network test passage of closing and the media transmission channel information of opening;

B210. after streaming media service controlled function entity receives the 200 OK response of call subscriber terminal equipment; Notice overlay network management function entity adds call subscriber terminal equipment in P2P bunch of new channel as new service node; And the rest processing capacity of renewal called user terminal equipment, construct ACK message simultaneously respectively and reply to call subscriber terminal equipment and called user terminal equipment via core IMS;

If not satisfying live TV stream according to the stream receiving and counting result who carries in the PONG message, called user terminal equipment do not transmit demand; Then called user terminal equipment is replied the session between non-200 OK response end and the streaming media service controlled function entity to streaming media service controlled function entity; Streaming media service controlled function entity is reselected the P2P service node; Go to the b22 step; Streaming media service controlled function entity inquiry overlay network management function entity is reselected out the service node that enables P2P and for call subscriber terminal equipment the media delivery service is provided as called user terminal equipment.

After if called user terminal equipment receives the INVITE request of streaming media service controlled function entity; This machine surplus resources of checking does not have enough circulations to send out ability; Called user terminal equipment is replied the session between non-200 OK response end and the streaming media service controlled function entity to streaming media service controlled function entity; Streaming media service controlled function entity is reselected the P2P service node; Go to the b22 step, streaming media service controlled function entity inquiry overlay network management function entity is reselected out the service node that enables P2P and for call subscriber terminal equipment the media delivery service is provided as called user terminal equipment.

Step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment and what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment, then pass through steps of processing:

B31. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out the channel switching; Wherein the Session Description Protocol of message body has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign New_ChannelID and the old channel identication Old_ChannelID of switching in addition in the message body;

B32. after streaming media service controlled function entity receives the Re-INVITE request of call subscriber terminal equipment; Send the called user terminal equipment that BYE message is given provides old channel media delivery service as back-to-back user agent; The media delivery service conversation that provides for call subscriber terminal equipment that request finishes that streaming media service controlled function entity and called user terminal equipment sets up, and notify the rest processing capacity of overlay network management function entity renewal called user terminal equipment; Streaming media service controlled function entity is inquired about overlay network management function entity simultaneously, and the service node that enables P2P that selection makes new advances provides the media delivery service of new channel for call subscriber terminal equipment as called user terminal equipment;

B37. after called user terminal equipment is received the PRACK acknowledge message; Through similar PING/PONG agreement; Like the RTP/RTCP agreement; And carry out the network-in-dialing property testing before the media delivery between the call subscriber terminal equipment, wherein the called user terminal equipment simulating flows down the process of sending out and sends PING message, and call subscriber terminal equipment simulating medium receiving course is also responded PONG message;

B38. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits demand; Wherein statistics comprises packet loss, network delay, shake size etc.; If test result meets the demands; Then stop the network-in-dialing property testing, construct 200 OK response and send to streaming media service control functional entity via core IMS, wherein message body Session Description Protocol part SDP describes network test passage of closing and the media transmission channel information of opening;

Among the step b according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment and what the new channel content delivery service is provided for call subscriber terminal equipment is media server, then pass through steps of processing:

B41. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein the Session Description Protocol of message body has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries new channel sign (New_ChannelID) and the old channel identication (Old_ChannelID) of switching in addition in the message body;

B42. after streaming media service controlled function entity receives the Re-INVITE message of call subscriber terminal equipment; Send BYE message as back-to-back user agent and give called user terminal equipment; The media delivery session that provides for call subscriber terminal equipment that request finishes that streaming media service controlled function entity and called user terminal equipment room set up, and notify the rest processing capacity of overlay network management function entity renewal called user terminal; Streaming media service controlled function entity inquiry overlay network management function entity finally selects MF for call subscriber terminal equipment the media delivery service to be provided simultaneously;

B43. streaming media service controlled function entity makes up new INVITE request as back-to-back user agent and is transmitted to the media control function entity via core IMS, and message body Session Description Protocol part only comprises the medium receive path of call subscriber terminal equipment and describes and new channel sign New_ChannelID;

B44. after the media control function entity receives INVITE; Obtain the new channel sign that Session Description Protocol is partly described in the INVITE body; Dispose selection distribution of media functional entity according to load condition and program; And to its request allocation medium issue channel resource; After being allocated successfully, the distribution of media functional entity returns to the media control function entity; Media control function entity structure 200 OK message reply to streaming media service control functional entity via core IMS then, and wherein the unicast stream of partly describing media server of the Session Description Protocol in the message body issues channel information, comprise the distribution of media functional entity the IP address, flow down and make a start mouthful and medium encoding and decoding relevant information;

B45. after streaming media service controlled function entity receives the 200 OK response of media control function entity; Again construct 200 OK response according to this 200 OK message and reply to call subscriber terminal equipment via core IMS, Session Description Protocol has wherein partly been described the medium clean culture of opening and has been issued channel information and the network test passage of closing; Streaming media service controlled function entity notice overlay network management function entity simultaneously, the rest processing capacity of called user terminal equipment is upgraded in the P2P bunch of neutralization that joins the participation new channel Media Stream distribution of overlay network management function entity maintaining to call subscriber terminal equipment as new service node;

B46. after call subscriber terminal equipment receives 200 OK response; Structure ACK message is forwarded to streaming media service controlled function entity SCF via core IMS and confirms live handover success; Streaming media service controlled function entity SCF receives that constructing ACK message again after the ACK message is transmitted to the media control function entity via core IMS; Media control function entity MCF receives ACK and confirms that back control distribution of media functional entity starts unicast stream and issues, and accomplishes channel with this and switches.

Among the step b; If current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment and what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment; Be that current that service is provided for P2P-Enabled UE_B is UE_A, UE_B is not for other UE provides the medium upload service, after UE_B carries out the channel switching simultaneously; SCF is UE_C for its selection provides the node of medium upload service, and its processing procedure is as shown in Figure 7:

S1:UE_B sends Re-INVITE message request channel and switches, and will carry the channel identication of new switching in the message body, comprises medium TCH test channel of opening again and the media transmission channel that stays open among the message body SDP;

S2:Core IMS is transmitting Re-INVITE before SCF, and Core IMS opens the resource reservation of medium TCH test channel again to the RACS application;

S3:Core IMS routing forwarding Re-INVITE message is to SCF;

After S4:SCF receives the channel switch request of UE_B; That finishes to set up between SCF and the UE_A is the media delivery session of UE_B (specifically shown in the block diagram seven 4.1～4.5); And upgrading the UE_A that safeguards among the OMF no longer for UE_B provides service, OMF is also UE_B also deletion from P2P bunch of its place simultaneously; OMF searches out suitable media content supplier UE_C according to the channel identication that carries new switching in the Re-INVITE request message body for it again;

S4.1～S4.5:SCF sends the BYE request as B2B UA to UE_B, finishes the medium upload service between UE_A and the UE_B, and discharges the media transmission channel resource of reserving between UE_A and the network side;

It is that UE_B provides the medium upload service that S5:SCF creates new INVITE request UE_C as B2B UA; And be forwarded to Core IMS, wherein media transmission channel and network test passage are described and are sent in the Re-INVITE message of SCF identical with UE_B in the message body;

S7:Core IMS is according to the new INVITE request of the current on-position routing forwarding SCF transmission of UE_C;

S8:UE_C judges that local residue service ability can provide one road medium upload service, replys 18 * response, and notice UE_B carries out network connectivty and performance test, wherein carries network test passage of opening and the media transmission channel of closing among the message body SDP;

S9:Core IMS submits to resource reservation to confirm to RACS, to open the network connectivty TCH test channel between UE_C and the network side before routing forwarding 18 * message;

18 * message is to SCF in the session of S10:Core IMS routing forwarding;

After S11:SCF receives 18 of UE_C * response, construct the Re-INVITE request that UE_B is replied in 200 OK response again, be transmitted to Core IMS, wherein described the media transmission channel that network test passage Buddhist monk that UE_C opens does not open among the SDP of message body;

S12: before route 200 OK lane testings responded to UE_B, Core IMS submitted to resource reservation to confirm to RACS, opens the network connectivty TCH test channel between UE_A and the network side, and closes the media transmission channel that it is opened originally;

200 OK respond to UE_B in the S13:Core IMS route conversation;

S14～S17:UE_B sends the ACK message authentication and carries out the network-in-dialing property testing through Core IMS to SCF, and SCF is configured to PRACK message again as B2B UA and gives UE_C through Core IMS routing forwarding;

Carry out the test of PING/PONG agreement through the network that provides QoS to guarantee between S18～S19:UE_B and the UE_C, the process of transmitting that this test can simulates real real data bag, UE_B returns to UE_C to the statistics of acceptance test bag;

S20: if the network test result meets the demands; Stop network connectivty and performance test between UE_C and the UE_B; UE_C is assigned as UE_B allocation medium uploading channel; And reply 200 OK response, wherein the SDP in the message body has described media transmission channel of opening and the network test channel information of closing;

S21:Core IMS upgrades resource reservation to the RACS request before routing forwarding 200 OK message, close the network test passage between UE_C and network side, opens the medium uploading channel;

200 OK message are given SCF in the session of S22:Core IMS routing forwarding;

After S23:SCF receives the 200 OK response of UE_C; Describe based on the SDP in the 200 OK message bodies; Structure Re-INVITE message request UE_B is new session more, and wherein SDP has described UE_C network test passage of closing that provides and the media transmission channel information of opening in the message body;

S24:Core IMS is before routing forwarding Re-INVITE message is given UE_B, to RACS request the carrying out resource reservation that medium issue;

S25:Core IMS routing forwarding Re-INVITE message is given UE_B;

S26:UE_B closes the local test passage after receiving the Re-INVITE request of SCF transmission, opens media transmission channel again, and constructs 200 OK response and reply SCF;

S27:Core IMS confirms resource reservation to RACS before routing forwarding 200 OK respond to SCF, open the media transmission channel of UE_B and network side, closes the network test passage;

S28:Core IMS routing forwarding 200 OK respond to SCF;

After S29:SCF receives the 200 OK response of UE_B, flow the ISP as alternative P2P among the P2P stream distribution Cluster that notifies OMF to add UE_B new channel, and write down UE_C just for UE_B provides service, the corresponding minimizing of UE_C rest processing capacity;

S30～two ACK of S31:SCF structure are issued UE_B and UE_C respectively; After UE_C receives that ACK confirms; Transmit Media Stream at once and give UE_B; Wherein S30.1～S31.1 representes that the session between SCF and the UE_C sets up successfully, and S30.2～S31.2 representes the session updates success between the UE_B and SCF in the channel handoff procedure.

Above-mentioned S1～S31 step has been described the switching of UE_B application channel; Then SCF removed set up between SCF and the UE_A the SIP session of medium upload service is provided for old channel; And be recovered to that to be used for UE_A be the Internet resources that UE_B provides the medium upload service; SCF finds the UE_C that the service of new channel media delivery is provided for UE_B again then; And set up the medium upload session with it, and in this process, carried out the network-in-dialing property testing of UE_B and UE_C, just successfully set up the media transmission channel between UE_B and the UE_C at last.UE_B wherein carries out channel after switching, and to set up media transmission channel between the UE_C be to carry out QoS again to reserve and confirm, thereby has QoS and guarantee.

Whether the subscriber terminal equipment that enables P2P among the step c provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and the media delivery service be not provided for other node; What media delivery service is provided for this subscriber terminal equipment UE simultaneously is media server, then passes through steps of processing:

C12. receive subscriber terminal equipment live withdraw from request after; Streaming media service control functional entity inquiry overlay network management function entity is known this subscriber terminal equipment not for other node provides the media delivery service, and streaming media service control functional entity re-constructs BYE message as back-to-back user agent and is forwarded to the media delivery session that the end of media control function entity requests is set up with it via core IMS;

C13. after the media control function entity received BYE message, control distribution of media functional entity MDF stopped to subscriber terminal equipment issues Media Stream, and constructed 200 OK response and be forwarded to streaming media service controlled function entity via core IMS;

C14. after streaming media service control functional entity receives the 200 OK response of MF to the BYE request; Re-construct 200 OK response and reply to subscriber terminal equipment via core IMS; And remove the live session relevant information of call subscriber terminal equipment, notice overlay network management function entity is subscriber terminal equipment deletion from P2P bunch of its last viewing channel;

Whether the subscriber terminal equipment that enables P2P among the step c provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server (MF) that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and the media delivery service be not provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is the subscriber terminal equipment that enables P2P, then passes through steps of processing:

C25. subscriber terminal equipment receives 200 OK response back and accomplishes the live work of withdrawing from;

Whether the subscriber terminal equipment that enables P2P among the step c provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and just the media delivery service be provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is media server, then passes through steps of processing:

C32. receive subscriber terminal equipment live withdraw from request after; Streaming media service controlled function entity inquiry overlay network management function entity knows that this subscriber terminal equipment just provides the media delivery service for other node; What media delivery service is provided for this subscriber terminal equipment UE simultaneously is media server, and then streaming media service controlled function entity SCF accomplishes following two tasks simultaneously:

Task one; Send to its media delivery service conversation that provides for other subscriber terminal equipment of call subscriber terminal device end as back-to-back user agent structure BYE message via core IMS; And be that call subscriber terminal equipment institute service object is selected new content delivery person again; Possibly select to enable the subscriber terminal equipment of P2P, also possibly select MF, and set up the media delivery session with it;

Task two: as back-to-back user agent structure BYE message; Be transmitted to the media control function entity via core IMS; The SIP session of setting up between request end and the media control function entity; After the media control function entity received BYE message, control distribution of media functional entity stopped to call subscriber terminal equipment issues medium, and constructs 200 OK response messages and confirm the session between end and the streaming media service controlled function entity; Streaming media service controlled function entity is constructed 200 OK response messages after receiving the 200 OK response of media control function entity again, confirms to finish the session of streaming media service controlled function entity and call subscriber terminal equipment room;

Whether the subscriber terminal equipment that enables P2P among the step c provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and just the media delivery service be provided for other node; What media delivery service is provided for this subscriber terminal equipment UE simultaneously is the subscriber terminal equipment that enables P2P, then passes through steps of processing:

Task one; Send to call subscriber terminal device end call subscriber terminal equipment provides the media delivery service for other subscriber terminal equipment session as back-to-back user agent structure BYE message via core IMS; And be that call subscriber terminal equipment institute service object is selected new content delivery person again; Possibly select to enable the subscriber terminal equipment of P2P, also possibly select MF, and set up the media delivery session with it;

If currently among the step c withdraw from live subscriber terminal equipment and just the media delivery service be provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is the subscriber terminal equipment that enables P2P; Promptly work as the P2P-enabledUE_A request and withdraw from live broadcast service; It is current just for UE_B provides the medium upload service, and when SCF receive UE_A live withdraw from request after, it notifies OMF; The pairing P2P of viewing channel bunch and node selection strategy were that UE_B selects ISP UE_C again when OMF withdrawed from according to UE_A, and it is as shown in Figure 8 that the live broadcast service of UE_A withdraws from process:

S1:UE_A sends the BYE message request and finishes watching of current live broadcast service, in SDP, carries the current channel information of watching simultaneously;

S2: before routing forwarding BYE message, Core IMS discharges the Internet resources of reserving to the RACS request;

The BYE that S3:Core IMS transmits in the session asks SCF;

S4:SCF accomplishes following three tasks after receiving the BYE request of UE_A simultaneously:

Task 1:

S4.1～S8.1:SCF sends the BYE request as B2B UA to UE_B, finishes the medium upload service between UE_A and the UE_B, and discharges the medium uploading channel from UE_A to the network side;

Task 2:

S4.2～S5.2:SCF replys 200 OK and responds to UE_A, confirms that the live of UE_A withdraws from request, and the session related resource between release and the UE_A, and notice OMF deletes the UE_A node of being safeguarded in channel P2P bunch that is watching when UE_A withdraws from;

Task 3:

S4.3: for UE_B selects the new service node UE_C in same P2P bunch;

S5.3: create new INVITE and set up the medium uploading channel for UE_B to the UE_C request; Send to CoreIMS, the network test channel information that has carried when wherein message body SDP has partly described the current media channel of UE_B and initiated the request of INVITE live broadcast service first;

S6.3: before the routing forwarding INVITE, Core IMS is to the Internet resources of RACS request reserved media uploading channel and network test passage;

S7.3:Core IMS searches its current on-position according to UE_C SIP URI, and to UE_C routing forwarding INVITE;

This machine of S8.3:UE_C inquiry surplus capacity can provide the medium upload service, replys 18 * response message and gives CoreIMS, has carried the description of network test passage of opening and the medium uploading channel of closing among the SDP of message body;

S9: connect the S8.3 step, Core IMS confirms only to reserve the network test channel resource between UE_C and the network side to RACS before routing forwarding 18 * response;

18 * response message is given SCF in the session of S10:Core IMS routing forwarding;

After S11:SCF receives 18 * network connectivty test response; Structure Re-INVITE sends to Core IMS, and wherein SDP carries the media transmission channel that UE_C closes; The network test channel information of opening comprises that UE_C carries out the IP address and the port information of network test;

S12: before routing forwarding Re-INVITE, Core IMS applies for resource reservation to RACS, and the network test passage between opening from the network side to UE_B is closed the media transmission channel between network side and the UE_B;

S13:Core IMS routing forwarding Re-INVITE message is given UE_B;

After S14:UE_B receives the Re-INVITE request message; The temporary close media transmission channel, and open the network connectivty test port again, respond 200 OK response; Wherein the media transmission channel in the message body temporarily is changed to closed condition, and the network test passage is an open mode;

S15～S16:Core IMS confirms to open the resource reservation of network connectivty TCH test channel of UE_B and network side to RACS after, and routing forwarding 200 OK respond to SCF;

After S17～S18:SCF receives the 200 OK response of UE_B, reply the session updates success between ACK message authentication and the UE_B, step such as S17.1～S18.1; Acknowledge receipt of 18 * lane testing notice, step such as S17.2～S18.2 to replying the PRACK request message with the session of UE_C;

After S19～820:UE_C receives the affirmation of PRACK to 18 * Temporary Response, will carry out network connectivty and performance test between UE_C and the UE_B through the PING/PONG agreement;

S21: if the network connectivty test result meets the demands; UE_C stops network test; And be assigned as the media transmission resources that UE_B serves, and to construct 200 OK response and reply to SCF, SDP has partly described network test passage of closing and the media transmission channel of opening in this message body;

S22～823:Core IMS upgrades resource reservation to RACS, confirms to close the network test passage between UE_C and the network side, opens media transmission channel, and 200 OK message are given SCF in the routing forwarding session then;

After S24:SCF receives the 200 OK response of UE_C, construct new Re-INVITE request and sends to UE_B, this Re-INVITE ask to close and UE_B between the network test passage, open the UE_B media transmission channel, send to CoreIMS;

S25～S26:Core IMS closes the network test passage between UE_B and the network side to the new resource reservation of RACS application, opens media transmission channel, and gives UE_B the Re-INVITE routing forwarding;

S27:UE_B replys 200 OK response, has carried the network test passage of closing among its message body SDP and has described with the media transmission channel of opening;

Before the 200 OK response, confirm to close the network test passage of UE_B and network side to RACS, and open media transmission channel in the session of S28:Core IMS routing forwarding;

S29:Core IMS routing forwarding 200 OK respond to SCF;

After S30:SCF receives 200 OK response, confirm that UE_C provides upload service as P2P Streaming Media transmission person for UE_B, add UE_B in P2P bunch of new channel simultaneously;

S31～S32:SCF constructs two ACK request messages affirmation sessions simultaneously as B2B UA and sets up successfully, and step S31.1～S32.1 target is UE_C, and step S31.2～S32.2 target is UE_B;

S33:UE_C is to the end to end network channel transfer live Media Stream of UE_B through there being QoS to guarantee.

The media delivery session is used to set up media transmission channel among the present invention; And media transmission channel guarantees the network-in-dialing performance by similar PING/PONG protocol test before setting up; All sessions between medium sender and the recipient have been guaranteed the service quality of P2P media delivery all via the core IMS routing forwarding.Wherein not only guaranteed the manageability of P2P distribution channel for distribution; Guaranteed that the UE node withdraws from and add the integrity of P2P distributing network; The network topology resource that can also safeguard through inquiry NRQF and UE on-position select network route or physical location near service node; And media transmission channel and network test passage all receive NGN transport layer RACS to provide network QoS to guarantee, both satisfied the purpose that UE participates in media delivery, reached the managing of P2P overlay network, controllability again.

Claims

One kind in NGN based on the managed P2P flow medium live system of IMS, it is characterized in that comprising: NGN transport network layer, core IMS, streaming media service layer, subscriber terminal equipment and media server, wherein:

The NGN transport network layer for core IMS and streaming media service layer provide network foundation, is realized network control and transmission process function;

Core IMS is for the streaming media service layer provides session control, signalling route, service trigger function; Submit resource reservation and access control function to the NGN transport network layer;

User-subscribed database, the relevant information that is used for preserving core IMS and streaming media service layer comprises the network topology structure information that Streaming Media contracted user's user profile, authentication information, optional stream medium service information and operator provide;

The streaming media service layer based on the session of subscriber terminal equipment and core IMS routing forwarding, is realized stream media live service logical process, service discovering, service selection and content management function;

Subscriber terminal equipment realizes that through the network foundation that the NGN transport network layer provides the network insertion of stream media live service and Streaming Media transmit; Be connected with the mutual of core IMS, realize session initiation, renewal and expiry feature; Be connected with the mutual of streaming media service layer, realize service discovering, selection function; Obtain media data from media server, realize local playing function; After the expansion P2P function, and realize network-in-dialing property testing and medium forwarding capability between the peer users terminal equipment, be called the subscriber terminal equipment that enables P2P again;

Media server, the session control message of reception core IMS routing forwarding realizes medium control and distribution function.
By among the described NGN of claim 1 based on the managed P2P flow medium live system of IMS, it is characterized in that: said streaming media service layer comprises:

Streaming media service discovery feature entity is used for realizing to subscriber terminal equipment professional satellite information being provided, and selects the state update functions of personalized service selection server address and notice electronic program list for subscriber terminal equipment;

The streaming media service selection functional entity is used for realizing the download function that produces electronic program list, electronic program list and program presenting information are provided to subscriber terminal equipment;

Streaming media service controlled function entity; Be used for carrying out the streaming media service logic; Comprise with core IMS and carry out Signalling exchange and service authorization function; The peer-to-peer network terminal node of selecting media server or providing live TV stream to transmit according to service executing result promptly enables the subscriber terminal equipment of P2P, and to media server or enable the subscriber terminal equipment inquiry media processing capacity of P2P, and the forwarding stream media service request is given the Streaming Media forwarding person who is selected out;

Overlay network management function entity is used for realizing the management of the P2P overlay network that each direct broadcast band is corresponding, to the judgement foundation of Internet resources query function entity inquiring structuring overlay network;

Internet resources query function entity is used for realizing providing the query function of Internet resources, and the judgement foundation of the P2P overlay network that makes up physical topology and on-position perception is provided for overlapping net management functional entity;

The content management function entity is used for realizing increase, deletion and the modification to media program or content;

Content preprocessing function entity is used for realizing the extraction and the preparation of the content before the fluidisation of program metadata information, comprises Media Analysis, encoding and decoding conversion and content pre-fetch function.
By among the described NGN of claim 2 based on the managed P2P flow medium live system of IMS; It is characterized in that: said P2P overlay network is by the centralized management of overlay network management function entity; The form of expression of P2P overlay network is P2P bunch or P2P groups of nodes, and the node in same P2P bunch is a terminal service node close on physical location or the route.
By among the described NGN of claim 2 based on the managed P2P flow medium live system of IMS; It is characterized in that: said overlay network management function entity management is participated in the P2P overlay network of each channel live stream distribution; And be divided into each subscriber terminal equipment different P2P bunches information through what requester network resource query functional entity got access to, to choose the terminal service node in same P2P bunch.
By among the described NGN of claim 2 based on the managed P2P flow medium live system of IMS; It is characterized in that: said streaming media service controlled function entity is live broadcast service call subscriber terminal choice of equipment media content uploading person with SIP back-to-back user agent role; And replace setting up between call subscriber terminal equipment and the medium uploader SIP session and enable the subscriber terminal equipment allocation medium transfer resource of P2P with request, provide medium to transmit and serve.
Among the NGN based on the implementation method of the managed P2P flow medium live system of IMS, it is characterized in that may further comprise the steps:

A. the subscriber terminal equipment that enables P2P is set up the live streaming media session as caller to streaming media service controlled function entity requests; Streaming media service controlled function entity is as back-to-back user agent; P2P overlay network and media server deployment scenario according to current overlay network management function entity maintaining; Be call subscriber terminal choice of equipment media content transmission person, and set up the media delivery session with content delivery person;

B. the subscriber terminal equipment that enables P2P carries out channel and switches; To streaming media service controlled function entity requests session updates; Streaming media service controlled function entity is the content delivery person that the subscriber terminal equipment that enables P2P is selected new channel, and sets up the media delivery session with the content delivery person of new channel;

C. the subscriber terminal equipment that enables P2P withdraws from live.
By among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: said step a is media server or subscriber terminal equipment according to the content delivery person of streaming media service controlled function entity inquiry overlay network management function entity selection; When the content delivery person who selects is media server, handle as follows:

A11. the subscriber terminal equipment that enables P2P sends the INVITE request via core IMS to streaming media service controlled function entity as caller and sets up live session; Session Description Protocol in the message body partly carries direct broadcast band sign and two medium line descriptions; One of them medium line description network test passage, another medium line description medium receive path;

A12. after streaming media service controlled function entity is received the INVITE request of call subscriber terminal equipment; The corresponding overlay network of direct broadcast band that the current selection of call subscriber terminal equipment of inquiry overlay network management function entity maintaining is watched can't be selected the subscriber terminal equipment that service can be provided; Streaming media service controlled function entity makes up new INVITE request as back-to-back user agent and is transmitted to media server via core IMS, and the Session Description Protocol part of this INVITE body only comprises the medium receive path of call subscriber terminal equipment and describes;

A13. media server issues channel resource based on the direct broadcast band sign allocation medium of describing in the INVITE body; And construct 200 OK response and control functional entity to streaming media service through the core IMS routing forwarding; The medium clean culture that the Session Description Protocol of 200 OK message bodies is partly described media server issues channel information, comprise the distribution of media functional entity the IP address, flow down and make a start mouthful and medium encoding and decoding relevant information;

A14. after streaming media service controlled function entity receives the 200 OK response of media server, construct 200 OK response again according to this 200 OK message and reply to call subscriber terminal equipment via core IMS; Streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch of the corresponding participation Media Stream forwarding of the direct broadcast band of overlay network management function entity maintaining simultaneously as new service node;

A15. call subscriber terminal equipment structure ACK message is transmitted to streaming media service controlled function entity via core IMS and confirms that live session sets up successfully; Streaming media service controlled function entity receives that constructing ACK message again after the ACK message is transmitted to media server via core IMS, and media server receives and begins formally to issue the Media Stream based on clean culture after ACK confirms.
By among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: said step a is media server or subscriber terminal equipment according to the content delivery person of streaming media service controlled function entity inquiry overlay network management function entity selection; When the content delivery person who selects is subscriber terminal equipment, handle as follows:

A21. the subscriber terminal equipment that enables P2P sends the INVITE request via core IMS to streaming media service controlled function entity as caller and sets up live session; The Session Description Protocol of message body partly carries direct broadcast band sign and two medium line descriptions; One of them medium line description network test passage, another medium line description medium receive path;

A22. after streaming media service controlled function entity is received the INVITE request of call subscriber terminal equipment; P2P bunch of the corresponding requests channel of inquiry overlay network management function entity maintaining is not empty; Then, carry the sip user logical identifier of this subscriber terminal equipment, current on-position and channel identication in the request message to P2P bunch of division foundation of Internet resources query function entity requests inquiry;

A23. Internet resources query function entity returns to overlay network management function entity based on relevant information and channel identication, the server disposition of corresponding channel, the network topology structure information of operator and network distance and P2P bunch of sign that routing configuration calculates subscriber terminal equipment of subscriber terminal equipment; The result that overlay network management function entity resource query functional entity Network Based returns selects the strongest subscriber terminal equipment of rest processing capacity as the P2P service node from request same P2P bunch of channel;

A24. the P2P service node of selecting based on overlay network management function entity; Streaming media service control functional entity makes up new INVITE request as back-to-back user agent; Give the P2P service node of selecting via the core IMS route, the Session Description Protocol of this INVITE body partly comprises the medium receive path and the TCH test channel description of call subscriber terminal equipment;

A25. after the P2P service node of selecting is received the INVITE request as called user terminal equipment; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel, structure 18 * response routes to streaming media service controlled function entity via core IMS, and the Session Description Protocol of this response message body has partly been described network test passage of closing and the media transmission channel information of opening;

A26. after streaming media service control functional entity is received 18 of called user terminal equipment * response; Re-construct 18 * response and route to call subscriber terminal equipment via core IMS, the message body of this response is identical with 18 * message body content of called user terminal device responds;

A27. call subscriber terminal device replied PRACK message authentication is received 18 * response; And open local network and test listening port; Be forwarded to streaming media service controlled function entity SCF via core IMS, construct PRACK message again after streaming media service controlled function entity is received and route to called user terminal equipment via core IMS;

A28. after called user terminal equipment is received the PRACK acknowledge message,,, and carry out the network-in-dialing property testing before the media delivery between the call subscriber terminal equipment like the RTP/RTCP agreement through similar PING/PONG agreement; The called user terminal equipment simulating flows down the process of sending out and sends PING message, and call subscriber terminal equipment simulating medium receiving course is responded PONG message;

A29. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits requirement; Wherein statistics comprises packet loss, network delay, shake size etc.; Then stop the network-in-dialing property testing if meet the demands; Construct 200 OK response and route to streaming media service control functional entity via core IMS, the Session Description Protocol of its message body is partly described network test passage of closing and the media transmission channel of opening;

A210. after streaming media service controlled function entity is received the 200 OK response of called user terminal equipment, construct 200 OK response again as back-to-back user agent and give call subscriber terminal equipment through the core IMS route; Simultaneously; Streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch that the corresponding participation Media Stream of direct broadcast band of overlay network management function entity maintaining transmits as new service node, and notice overlay network management function is upgraded the rest processing capacity of called user terminal equipment;

A211. after call subscriber terminal equipment is received 200 OK response; Close local network test listening port; Open the media receiving end mouth; And reply the ACK acknowledge message and be transmitted to streaming media service controlled function entity via core IMS, after streaming media service controlled function entity receives the ACK acknowledge message of call subscriber terminal equipment, construct the ACK acknowledge message again and be transmitted to called user terminal equipment through core IMS;

A212. after called user terminal equipment receives the ACK acknowledge message, from this machine buffering area, read Media Stream, transmit Media Stream according to the medium receive path information of the call subscriber terminal equipment of describing in the INVITE body that in the a24 step, receives.
By among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is media server and what the new channel content delivery service is provided for call subscriber terminal equipment is media server, then pass through steps of processing:

B11. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein message body Session Description Protocol part is opened the network test passage again; Media transmission channel remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B12. after streaming media service controlled function entity receives the Re-INVITE message of call subscriber terminal equipment; Inquiry overlay network management function entity finds that call subscriber terminal equipment does not provide the medium upload service for other subscriber terminal equipments; Then streaming media service controlled function entity is given media server as back-to-back user agent structure Re-INVITE message through the core IMS routing forwarding; The medium that request finishes current channel issue, and distribute the medium of new channel to issue server resource;

B13. after media server receives the Re-INVITE request of streaming media service controlled function entity; According to old channel identication of describing in the Session Description Protocol part and new channel sign; Stop call subscriber terminal equipment is issued the medium of old channel; And issue server resource for the medium of call subscriber terminal devices allocation new channel; Construct 200 OK response then and be transmitted to business control function body via core IMS, wherein the media services of partly describing new channel of the Session Description Protocol of message body issue channel information;

B14. after streaming media service controlled function entity is received the 200 OK response of media server answer; Again construct 200OK message and send to call subscriber terminal equipment via core IMS, wherein the Session Description Protocol of message body has partly been described the network test passage of closing and has been issued passage with the medium of opening; Simultaneously, streaming media service controlled function entity joins call subscriber terminal equipment in P2P bunch that the corresponding participation Media Stream of direct broadcast band of overlay network management function entity maintaining transmits as new service node;

B15. after subscriber terminal equipment is received the 200 OK response of streaming media service controlled function entity; Learn by media server to be that subscriber terminal equipment issues media content; Thereby close the local network TCH test channel; This machine of opening medium receive listening port and wait for the Media Stream that receives new channel, and structure ACK message sends to streaming media service controlled function entity to confirm the session updates success via core IMS;

B16. after streaming media service controlled function entity is received ACK session updates acknowledge message; Again construct the ACK request and give media server via the core IMS route; Media services receive ACK and confirm that session updates successfully afterwards issues the medium of new channel for call subscriber terminal equipment, accomplish channel with this and switch.
By among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is media server and what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment, then pass through steps of processing:

B21. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein the message body Session Description Protocol has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B22. streaming media service controlled function entity sends BYE message as back-to-back user agent and gives media server, and the medium that supply for call subscriber terminal equipment that request finishes to set up between streaming media service controlled function entity and the media server issue service conversation;

Simultaneously, streaming media service controlled function entity inquiry overlay network management function entity is selected the service node that enables P2P and for call subscriber terminal equipment the media delivery service is provided as called user terminal equipment;

B23. streaming media service controlled function entity is given the called user terminal equipment of selecting as the new INVITE of back-to-back user agent structure via the core IMS route, and wherein the Session Description Protocol in the message body has partly been described the network test passage and the media transmission channel information of call subscriber terminal equipment;

B24. after called user terminal equipment receives the INVITE request of streaming media service controlled function entity; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel, structure 18 * response routes to streaming media service controlled function entity via core IMS, and the Session Description Protocol of this response message body has partly been described called user terminal equipment network test passage of opening and the media transmission channel information of closing;

B25. after streaming media service controlled function entity is received 18 of called user terminal equipment * response; Construct 200 OK response and send to call subscriber terminal equipment via core IMS, the content in 18 * message body of message body wherein and called user terminal device responds is identical;

B26. call subscriber terminal device replied ACK message authentication is received 20 * response; Wherein the Session Description Protocol of message body partly carries this machine network test passage of opening and the medium receive path of closing; Be forwarded to streaming media service controlled function entity via core IMS, streaming media service controlled function entity receives that 200 OK response back structure PRACK message and ACK message send to called user terminal equipment and call subscriber terminal equipment via core IMS;

B27. after called user terminal equipment is received the PRACK acknowledge message; Through similar PING/PONG agreement; Like the RTP/RTCP agreement; And carry out the network-in-dialing property testing before the media delivery between the call subscriber terminal equipment, wherein the called user terminal equipment simulating flows down the process of sending out and sends PING message, and call subscriber terminal equipment simulating medium receiving course is also responded PONG message;

B28. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits requirement; If test result meets the demands; Then stop the network-in-dialing property testing; Construct 200 OK response and send to streaming media service control functional entity via core IMS, wherein the message body Session Description Protocol has partly been described network test passage of closing and the media transmission channel information of opening;

B29. after streaming media service control functional entity receives the 200 OK response of called user terminal equipment; Re-construct the Re-INVITE request as back-to-back user agent and send to call subscriber terminal equipment through core IMS; After call subscriber terminal equipment is received the Re-INVITE response; Close the local network test port, open the media receiving end mouth, and reply 200 OK response messages;

B210. after streaming media service controlled function entity receives call subscriber terminal equipment 200 OK response; Notice overlay network management function entity joins call subscriber terminal equipment in P2P bunch of new channel as new service node; And the rest processing capacity of renewal called user terminal equipment, construct ACK message simultaneously respectively and reply to call subscriber terminal equipment and called user terminal equipment via core IMS;

B211. after called user terminal equipment receives the ACK acknowledge message of streaming media service controlled function entity transmission,, accomplish the channel switch operating with this to call subscriber terminal device forwards Media Stream.
11. by among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment and what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment, then pass through steps of processing:

B31. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out the channel switching; Wherein the Session Description Protocol of message body has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B32. after streaming media service controlled function entity receives the Re-INVITE request of call subscriber terminal equipment; Send the called user terminal equipment that BYE message is given provides old channel media delivery service as back-to-back user agent; The media delivery service conversation that provides for call subscriber terminal equipment that request finishes to set up between streaming media service controlled function entity and the called user terminal equipment, and notify the rest processing capacity of overlay network management function entity renewal called user terminal equipment; Streaming media service controlled function entity is inquired about overlay network management function entity simultaneously, and the service node that enables P2P that selection makes new advances provides the media delivery service of new channel for call subscriber terminal equipment as called user terminal equipment;

B33. streaming media service controlled function entity is given the called user terminal equipment of newly selecting as the new INVITE of back-to-back user agent structure via the core IMS route, and wherein the Session Description Protocol in the message body has partly been described the network test passage and the media transmission channel information of call subscriber terminal equipment;

B34. after called user terminal equipment receives the INVITE request of streaming media service controlled function entity; Whether this machine surplus resources of checking has enough circulations to send out ability; If have; Then open the local network TCH test channel, structure 18 * response routes to streaming media service controlled function entity via core IMS, and the Session Description Protocol of this response message body has partly been described called user terminal equipment network test passage of opening and the media transmission channel information of closing;

B35. after streaming media service controlled function entity is received 18 of called user terminal equipment * response; Construct 200 OK response and send to call subscriber terminal equipment, identical in message body information wherein and the 18 * message body of called user terminal device responds via core IMS;

B36. call subscriber terminal device replied ACK message authentication is received 20 * response; Wherein the message body Session Description Protocol partly carries this machine network test passage of opening and the medium receive path of closing; Be forwarded to streaming media service controlled function entity via core IMS, streaming media service controlled function entity receives that 200 OK response back structure PRACK message and ACK message send to called user terminal equipment and call subscriber terminal equipment via core IMS;

B37. after called user terminal equipment is received the PRACK acknowledge message; Through similar PING/PONG agreement; Like the RTP/RTCP agreement; And carry out the network-in-dialing property testing before the media delivery between the call subscriber terminal equipment, wherein the called user terminal equipment simulating flows down the process of sending out and sends PING message, and call subscriber terminal equipment UE analog media receiving course is also responded PONG message;

B38. called user terminal equipment judges whether to satisfy live TV stream based on the stream receiving and counting result who carries in the PONG message and transmits demand; If test result meets the demands; Then stop the network-in-dialing property testing; Construct 200 OK response and send to streaming media service control functional entity via core IMS, wherein the message body Session Description Protocol is partly described network test passage of closing and the media transmission channel information of opening;

B39. after streaming media service control functional entity receives the 200 OK response of called user terminal equipment; Re-construct the Re-INVITE request as back-to-back user agent and send to call subscriber terminal equipment through core IMS; After call subscriber terminal equipment is received the Re-INVITE response; Close the local network test port, open the media receiving end mouth, and reply 200 OK response messages;

B310. after streaming media service controlled function entity receives the 200 OK response of call subscriber terminal equipment; Notice overlay network management function entity adds call subscriber terminal equipment in P2P bunch of new channel as new service node, and upgrades the rest processing capacity of the called user terminal equipment that the service of new channel media delivery is provided; Construct ACK message simultaneously respectively and reply to call subscriber terminal equipment and called user terminal equipment via core IMS;

B311. after called user terminal equipment is received the ACK acknowledge message of streaming media service controlled function entity transmission,, accomplish the channel switch operating with this to call subscriber terminal device forwards Media Stream.
12. by among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: said step b is according to judging that current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment or media server; And what the new channel content delivery service is provided for call subscriber terminal equipment is subscriber terminal equipment or media server; If current what provide that medium upload for call subscriber terminal equipment is subscriber terminal equipment and what the new channel content delivery service is provided for call subscriber terminal equipment is media server, then pass through steps of processing:

B41. the subscriber terminal equipment that enables P2P is as caller; Transmission Re-INVITE message is transmitted to streaming media service controlled function entity requests via core IMS and carries out switching channels; Wherein the Session Description Protocol of message body has partly been described network test passage of opening again and the media transmission channel that remains unchanged, and also carries the new channel sign and the old channel identication of switching in addition in the message body;

B42. after streaming media service controlled function entity receives the Re-INVITE message of call subscriber terminal equipment; Send BYE message as back-to-back user agent and give called user terminal equipment; The media delivery session that provides for call subscriber terminal equipment that request finishes that streaming media service controlled function entity and called user terminal equipment room set up, and notify the rest processing capacity of overlay network management function entity renewal called user terminal; Streaming media service controlled function entity inquiry overlay network management function entity finally selects media server for call subscriber terminal equipment the media delivery service to be provided simultaneously;

B43. streaming media service controlled function entity makes up new INVITE request as back-to-back user agent and is transmitted to media server via core IMS, and wherein the Session Description Protocol of message body part only comprises description of call subscriber terminal equipment medium receive path and new channel sign;

B44. after media server receives INVITE; Obtain the new channel sign allocation medium that the Session Description Protocol in the message body partly describes and issue channel resource; Construct 200 OK message then and be transmitted to streaming media service controlled function entity via core IMS; Wherein the unicast stream of partly having described media server of the Session Description Protocol in the message body issues channel information, comprise media server the IP address, flow down and make a start mouthful and medium encoding and decoding relevant information;

B45. after streaming media service controlled function entity receives the 200 OK response of media server; Again construct 200 OK response according to this 200 OK message and reply to call subscriber terminal equipment via core IMS, Session Description Protocol has wherein partly been described the medium clean culture of opening and has been issued channel information and the network test passage of closing; Streaming media service controlled function entity notice overlay network management function entity simultaneously, the rest processing capacity of called user terminal equipment is upgraded in the P2P bunch of neutralization that joins the participation new channel Media Stream distribution of overlay network management function entity maintaining to call subscriber terminal equipment as new service node;

B46. after call subscriber terminal equipment receives 200 OK response; Structure ACK message is forwarded to streaming media service controlled function entity via core IMS and confirms live handover success; Streaming media service controlled function entity receives that constructing ACK message again after the ACK message is transmitted to media server via core IMS; Media server receives ACK and confirms that the back starts unicast stream and issues, and accomplishes channel with this and switches.
13. by among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and the media delivery service be not provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is media server, then passes through steps of processing:

C11. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C12. receive subscriber terminal equipment live withdraw from request after; Streaming media service control functional entity inquiry overlay network management function entity is known this subscriber terminal equipment not for other node provides the media delivery service, and streaming media service control functional entity re-constructs BYE message as back-to-back user agent and is forwarded to the media delivery session that media server request end is set up with it via core IMS;

C13. after media server receives BYE message, stop immediately, and construct 200 OK response and be forwarded to streaming media service controlled function entity SCF via core IMS to call subscriber terminal equipment issues Media Stream;

C14. after streaming media service control functional entity SCF receives the 200 OK response of media server to the BYE request; Re-construct 200 OK response and reply to subscriber terminal equipment via core IMS; And remove the live session relevant information of call subscriber terminal equipment, notice overlay network management function entity is subscriber terminal equipment deletion from P2P bunch of its last viewing channel;

C15. subscriber terminal equipment receives 200 OK response back and accomplishes the live work of withdrawing from.
14. by among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and the media delivery service be not provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is the subscriber terminal equipment that enables P2P, then passes through steps of processing:

C21. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C22. receive subscriber terminal equipment live withdraw from request after; Streaming media service control functional entity inquiry overlay network management function entity is known this subscriber terminal equipment not for other node provides the media delivery service, re-constructs BYE message as back-to-back user agent then and is forwarded to via core IMS and provides the called user terminal of content uploading device request to finish the media delivery session of foundation with it;

C23. after called user terminal equipment receives the BYE message of streaming media service controlled function entity transmission; Stop to transmit service, and construct 200 OK response and reply to streaming media service controlled function entity via core IMS for the Media Stream of call subscriber terminal equipment;

C24. after streaming media service controlled function entity receives the 200 OK response of called user terminal equipment to the BYE request; Again construct 200 OK response and reply to call subscriber terminal equipment via core IMS; And the live session relevant information of removing call subscriber terminal equipment; Notice overlay network management function entity upgrades the rest processing capacity of called user terminal equipment to the deletion from P2P bunch of its last viewing channel of call subscriber terminal equipment;

C25. subscriber terminal equipment receives 200 OK response back and accomplishes the live work of withdrawing from.
15. by among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and just the media delivery service be provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is media server, then passes through steps of processing:

C31. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C32. receive subscriber terminal equipment live withdraw from request after; Streaming media service controlled function entity inquiry overlay network management function entity knows that this subscriber terminal equipment just provides the media delivery service for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is media server, and then streaming media service controlled function entity is accomplished following two tasks simultaneously:

Task one; Send to its media delivery service conversation that provides for other subscriber terminal equipment of call subscriber terminal device end as back-to-back user agent structure BYE message via core IMS; And be that call subscriber terminal equipment institute service object is selected new content delivery person again, and set up the media delivery session with it;

Task two: as back-to-back user agent structure BYE message; Be transmitted to the media control function entity via core IMS; The SIP session of setting up between request end and the media server; After media server receives BYE message, stop, and construct 200 OK response messages and confirm the session between end and the streaming media service controlled function entity to call subscriber terminal equipment issues medium; Streaming media service controlled function entity is constructed 200 OK response messages after receiving the 200 OK response of media server again, confirms to finish the session of streaming media service controlled function entity and call subscriber terminal equipment room;

C33. call subscriber terminal equipment is accomplished the live work of withdrawing from.
16. by among the described NGN of claim 6 based on the implementation method of the managed P2P flow medium live system of IMS; It is characterized in that: whether the subscriber terminal equipment that said step c enables P2P provides the media delivery service for other node according to withdrawing from when live subscriber terminal equipment; And subscriber terminal equipment that enables P2P or media server that media delivery service is provided for this subscriber terminal equipment; If currently withdraw from live subscriber terminal equipment and just the media delivery service be provided for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is the subscriber terminal equipment that enables P2P, then passes through steps of processing:

C41. the subscriber terminal equipment that enables P2P is forwarded to streaming media service controlled function entity requests as caller transmission BYE message via core IMS and withdraws from live broadcast service;

C42. receive subscriber terminal equipment live withdraw from request after; This subscriber terminal equipment of streaming media service controlled function entity detection just provides the media delivery service for other node; What media delivery service is provided for this subscriber terminal equipment simultaneously is another subscriber terminal equipment that enables P2P, and then streaming media service controlled function entity is accomplished following two tasks simultaneously:

Task one; Be transmitted to call subscriber terminal device end call subscriber terminal equipment provides the media delivery service for other subscriber terminal equipment session as back-to-back user agent structure BYE message via core IMS; And be that call subscriber terminal equipment institute service object is selected new content delivery person again, and set up the media delivery session with it;

Task two; As back-to-back user agent structure BYE message; Be transmitted to called user terminal equipment via core IMS, request finishes the media delivery session of foundation with it, after called user terminal equipment receives BYE message; Stop to be call subscriber terminal device forwards medium, and construct 200 OK response messages and confirm the session between end and the streaming media service controlled function entity; Streaming media service controlled function entity is constructed 200 OK response messages after receiving the 200 OK response of called user terminal equipment again, confirms to finish the session of streaming media service controlled function entity and call subscriber terminal equipment room;

C43. call subscriber terminal equipment is accomplished the live work of withdrawing from.