Abstract:
A circuit-switch streaming service (CSS) system includes a circuit-switch streaming service center (CSSC), and a video interworking gateway (VIG). The system also includes an application server (AS), and the AS is connected to the CSSC for initiating a video call command to the CSSC; the CSSC identifies the video call command initiated by the AS, establishes the connection with the called terminal through the gateway based on the command, and transmits the streaming content specified by the AS to the called terminal. The invention also provides a corresponding realization method of the CSS. According to the CSS, the service of initiatively transmitting the streaming content for users can be realized and a good way for developing various video services by the operators is provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Patent Application No. PCT/CN2007/001718, filed May 28, 2007, which claims priority to Chinese Patent Application No. 200610091853.6, entitled “System and Method for Implementing Streaming Service,” filed Jun. 12, 2006, both of which are hereby incorporated by reference in their entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a data transmission technology in the communication industry, and in particular to a system and method for implementing the circuit-switch streaming service. 
       BACKGROUND OF THE INVENTION 
       [0003]    The circuit-switch streaming service (CSS) system is adapted to provide streaming services. It supports video on demand (VoD), live cast and downloading. The CSS system has high performance, high reliability and high expansibility and is adaptable to various video and audio codes, streaming protocols and file formats. 
         [0004]    The structure of a conventional CSS system is shown in  FIG. 1 . The system includes an encoder ( 1 ′), a circuit-switch streaming service center (CSSC) ( 2 ′), a contents management system (CMS) ( 3 ′), a video interworking gateway (VIG) ( 4 ′), a mobile data service platform (MDSP) ( 5 ′), a wireless intelligent network (WIN) ( 6 ′), and a business operation support system (BOSS) ( 7 ′). 
         [0005]    The encoder ( 1 ′) encodes and decodes streaming contents for the content provider (CP) or service provider (SP); the CSSC ( 2 ′) is a core component of the CSS system, and is adapted to provide streaming service for end users; the CMS ( 3 ′) provides content management for the CSSC, maintains media and associated CP/SP information, and enables the CP/SP to publish media contents; the VIG ( 4 ′) implements the interworking between Session Initiation Protocol (SIP) terminals and 3G-H.324M user equipments (UEs), including the interworking of signaling, call control and bearer services; the MDSP ( 5 ′) provides support for mobile data service components, manages information and service profiles of mobile data users in a centralized manner, and provides authentication and accounting for data service components; the WIN ( 6 ′) and BOSS ( 7 ′) work with the MDSP ( 5 ′) to implement the accounting of CSS, in which the BOSS ( 7 ′) handles the charging of postpaid services, and the MDSP ( 5 ′) handles the charging of prepaid services and makes deductions from a prepaid account via the PPS unit in the WIN ( 6 ′). 
         [0006]    The VIG connects to a mobile switching center (MSC) server via a time division multiplexing (TDM) E1 gateway. The MSC server regards the VIG as a special office direction when routing a call. The VIG integrates a SoftSwitch (SX) module and a universal media gateway module. The SX module implements communication and connection with the MSC server and serves as the control end of the VIG to control and manage the universal media gateway module via H.248, including media gateway registration and deregistration, status management, media gateway resource management and bearer resource management. The VIG interfaces with 3G and core networks for video interworking between heterogeneous networks. It can be deployed in a 3G network based on next generation network (NGN) architecture, to enable streaming services between a 3G-H.324M UE and a CSSC in an IP network (that is, SIP terminal). 
         [0007]    Specifically, the basic call procedure of a conventional CCS includes: an end user dials the special service number for streaming services to originate an ordinary H.324M video portal (VP) call; the MSC server routes the call to the VIG ( 4 ′); the VIG ( 4 ′) analyzes the called number and determines it a streaming call; the VIG ( 4 ′) sets up a SIP call session with the CSSC, the call command containing the media content; the CSSC interacts with the CMS via the Simple Object Access Protocol (SOAP) to obtain the data information of the content, such as the size and location of the content; the VIG ( 4 ′) controls the unified message gateway (UMG) to set up a Real-Time Transport Protocol (RTP) media channel with the CSSC to obtain the content through the SIP-based Session Description Protocol (SDP), where, live contents are obtained through interaction between the CSSC and the encoder via the Real-Time Streaming Protocol (RTSP)/SDP, and on-demand contents are obtained directly from the CSSC, because on-demand contents are program files already encoded by the encoder and uploaded to the CSSC via the CMS. For on-demand contents, the CSSC plays a video menu and the user may end the streaming session through a keystroke or hook-on in the progress of menu playing or program playing. After the session is over, the VIG  4 ′ and the CSSC both generate applicable call detail records (CDRs) for accounting. 
         [0008]    However, the prior CSSC can only play ordered streaming contents reactively when the user dials a specified access code. It cannot deliver streaming contents actively to a terminal. 
       SUMMARY OF THE INVENTION 
       [0009]    Embodiments of the present invention provide a method and system for implementing streaming service, which provides function of delivering streaming content to a terminal. 
         [0010]    According to one embodiment, a CSS system may include a CSSC and a gateway and further may include an application server (AS). 
         [0011]    The AS is connected to the CSSC and is adapted to initiate a video call command to the CSSC; and the CSSC identifies the video call command initiated by the AS, establishes, according to the video call command, a connection with a called terminal via the gateway, and sends streaming content specified by the AS to the called terminal. 
         [0012]    According to another embodiment, a method for implementing the streaming service may include: by a CSSC, receiving a video call command initiated by an AS; by the CSSC, identifying the video call command, establishing, according to the video call command, a connection with a called terminal via a gateway, and sending streaming content specified by the AS to the called terminal. 
         [0013]    According to still another embodiment, an AS may include: a sending module, adapted to send a video call command and streaming data so as to send specified streaming content to a called terminal; a streaming content determining module, adapted to specify the streaming content to be sent to the called terminal; and a control module, adapted to implement automatic or manual control of the sending module to send the streaming content specified by the streaming content determining module, to the called terminal 
         [0014]    According to the method and system for implementing streaming service, in a CSS system, an AS controls a CSSC to originate a video call to a user or a user group and after the user answers, the user can view the streaming content delivered by the CSSC, so as to realize the active delivery of streaming content; the invention may provide operators with a good alternative for operating services like VoD, video advertisement, video content ordering or public services. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]      FIG. 1  is a schematic diagram of the structure of a conventional CSS system; 
           [0016]      FIG. 2  is a schematic diagram of the structure of a CSS system according to an embodiment of the invention; 
           [0017]      FIG. 3  is a service flow chart of the CSS system according to an embodiment of the invention; and 
           [0018]      FIG. 4  is a schematic diagram of the application server AS according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    Embodiments of the present invention will be detailed below with reference to the accompanying drawings. 
         [0020]    According to an embodiment of the invention, a CSS system adds an AS on the basis of the prior CSS system and the AS is adapted to control the CSSC to originate video calls actively to users. After the user answers, the user can view streaming content actively delivered by the CSS system. This enables the active delivery of streaming content to users, that is, the video call service. 
         [0021]    Video call means the SP or the service end originates video calls to the appointed terminal or plays ordered streaming content. 
         [0022]      FIG. 2  is a schematic diagram of the structure of a CSS system according to an embodiment of the invention, and  FIG. 4  is schematic diagram of the application server AS according to an embodiment of the invention. As shown in  FIG. 2 and 4 , the system may include an encoder( 1 ), a CSSC ( 2 ), a CMS ( 3 ), a VIG ( 4 ), an MDSP( 5 ), a WIN ( 6 ) and a BOSS( 7 ), and an AS( 8 ). 
         [0023]    The CSSC( 2 ) may include a call module, which is adapted to respond to the call request of the AS( 8 ), identify the video call command sent by the AS( 8 ), and control the CSSC ( 2 )to originate video calls. 
         [0024]    The AS( 8 ) is adapted to control the logic of the video call service. When the AS ( 8 ) sends a video call command to the CSSC, the CSSC first responds to the video call command and then requests the MDSP ( 5 ) to complete authentication and accounting. After the accounting is successful, the CSSC simulates a SIP terminal to communicate with an H.324 UE over SIP via the VIG ( 4 ) and sends the requested streaming content to the UE. In this way, the video call service is realized. 
         [0025]    Moreover, the AS ( 8 ) and the CSSC, the CSSC and the MDSP ( 5 ), the MDSP ( 5 ) and the WIN ( 6 ), and the MDSP ( 5 ) and the BOSS ( 7 ) are connected respectively via an interface. The interface may be a standard web services interoperability organization, WSI, interface, an man machine language, MML, interface or a user-defined interface. 
         [0026]    Furthermore, the encoder ( 1 ) and the CMS ( 3 ) may be set in the CSSC ( 2 ). The encoder ( 1 ) is adapted to encode and decode the streaming contents for the CP or the SP; the CMS ( 3 ) is adapted to provide content management for the CSSC, maintain streaming and CP/SP information and enable the CP/SP to publish streaming contents. 
         [0027]    The contents played may be live contents or on-demand contents. For live contents, the CSSC interacts with the encoder ( 1 ) over RTSP/SDP to obtain the contents. For on-demand contents, the encoder ( 1 ) first encodes the contents and uploads the content file to the CSSC via the CMS ( 3 ). This procedure is conventional and well known in the art and, therefore, will not be detailed herein. 
         [0028]    Specifically, the SP sends a video call command to the CSSC via the AS ( 8 ) (the command carries a called number and the requested content); the call module of the CSSC parses the video call command and obtains the called number and the requested content; the CSSC( 2 ) interacts with the CMS ( 3 ) over SOAP and obtains information related to the requested content (such as the location and size of the content) ,and sends an authentication and accounting request to the MDSP ( 5 ); after the authentication and accounting succeed, the call module converts the video call command into a SIP invite message (which includes SDP information) and sends the invite to the VIG( 4 ); the VIG ( 4 ) establishes a connection with the called UE and returns a response message to the CSSC; the CSSC obtains the streaming content specified by the AS ( 8 ) and sends the content to the called UE. After the content is played, the CSSC reports accounting information to the MDSP ( 5 ) and generates a CDR. After the CSSC completes the call attempt, the CSSC forwards the user response (Normal, Busy or Timeout) to the AS ( 8 ), and the AS ( 8 ) determines subsequent handling according to the user response and the retry policy. 
         [0029]    According to the above embodiment of the invention, in the CSS system, an AS is added on the basis of the prior CSS system and a call module is added to the CSSC. The SP sends a video call command to the CSSC via the AS. The call module in the CSSC parses the command and sends an authentication and accounting request to the MDSP according to the command parameters. If the authentication and accounting are successful, the call module controls the CSSC to simulate a SIP terminal and communicate with the VIG( 4 ) over SIP. The CSSC sends the content specified by the AS through the encoder to the called UE. This enables the SP or the service end to originate video calls to specified UEs or play ordered streaming contents. The video call service is thus realized. 
         [0030]    A method for implementing the streaming service according to an embodiment of the invention is detailed below with reference to  FIG. 3 . The method may include the following steps: 
         [0031]    1: The SP sends a video call command to the CSSC via the AS. The command carries a called number and the requested content. 
         [0032]    The video call command sent by the AS to the CSSC includes the information of one caller and one callee. Preferably, multiple video call commands, each including the identifier of a related UE, are sent at a time for originating calls to different UEs. In this way, the AS can send multiple video call commands to the CSSC simultaneously and the CSSC can originate calls to multiple UEs simultaneously. 
         [0033]    2: The CSSC sends an authentication and accounting request to the MDSP. 
         [0034]    Step 2 further includes: 
         [0035]    21: Upon reception of the video call command from the AS, the CSSC parses the command and obtains the command parameters (called number and requested content) and sends an authentication and accounting request to the MDSP according to the command parameters. 
         [0036]    3: If the authentication and accounting are successful, namely when the MDSP returns an authentication and accounting response to the CSSC, the CSSC sends a SIP INVITE (which includes SDP information that describes streaming data attributes) to the VIG; or else, the MDSP returns an authentication and accounting failure message to end the session. 
         [0037]    Herein, the INVITE message sent by the CSSC includes SDP information. The UE initializes itself and waits for receiving streaming data according to the streaming data attributes described in the SDP information. 
         [0038]    The SIP INVITE message in the video call service is described according to an embodiment of the invention. For example, suppose the CSS calling number is 6690010 and the called number is 6680080, when the CSSC notifies the UE to receive audio data at UDP port 17424, the command is as follows:
   INVITE sip:6680080@182.20.100.100:5060 SIP/2.0 //SIP INVITE   Via: SIP/2.0/UDP 182.20.100.198:5060;branch=z9hG4bKD82 //protocol, address and port of SIP Proxy, and session ID   From: &lt;sip:6690010@8182.20.100.198&gt;;tag=E83CA64-1CA0 //identifier of the caller   To: &lt;sip:6680080@182.20.100.100&gt; //identifier of the callee   Content-Type: application/sdp //type of the message body   Content-Length: 256//length of the message body in octets   v=0 //SDP version   o=CiscoSystemsSIP-GW-UserAgent 2237 2134 IN IP4 182.20.100.198 //session creator, session ID, session version, protocol type of address, and address   s=SIP Call //name of the session   c=IN IP4 182.20.100.198//connection information   t=0 0 //time segment for obtaining the session set   m=audio 17424 RTP/AVP 18 8 0 //description of the streaming media: type, port, and format desired by the caller   c=IN IP4 182.20.100.198   a=rtpmap: 18 G729/8000 //media level attribute is rtpmap   a=fmtp: 18 annexb=no //session level attribute is fmtp   a=rtpmap:8 PCMA/8000   a=rtpmap:0 PCMU/8000   
 
         [0056]    4: The VIG interacts with the H.324 UE and sends a SIP 200 OK message to the CSSC. 
         [0057]    5: The CSSC interacts with the VIG over SIP and sends streaming data to the UE via the VIG. 
         [0058]    51: When the streaming data is played, the user may strike keys of the UE as prompted to finish intended operations. 
         [0059]    The keystroke operations are well known and conventional and therefore not detailed herein. 
         [0060]    6: After the streaming data is played, the CSSC sends a notification to the AS, notifying the end of current playing and requesting new media contents or release of the call. 
         [0061]    7: The AS notifies the CSSC to release the call (or the UE sends a Disconnect message), and the CSSC sends a SIP BYE to the VIG and disconnects the UE via the VIG; the CSSC reports call information to the MDSP and generates a CDR according to the accounting result returned by the MDSP. 
         [0062]    8: The CSSC reports a Release Response to the AS. 
         [0063]    Step 8 further includes: 
         [0064]    81: After the CSSC completes the call attempt, the CSSC forwards the user response (Normal, Busy or Timeout) to the AS and the AS determines subsequent handling according to the user response and the retry policy. 
         [0065]    According to the above embodiment of the invention, in the method for implementing the streaming service, because an AS is added, the SP first sends a video call command to the CSSC via the AS. The CSSC parses the command to obtain related command parameters and sends an authentication and accounting request to the MDSP according to the command parameters. If the authentication and accounting are successful, the CSSC simulates a SIP terminal to send a SIP INVITE to the VIG and send the content specified by the AS to the UE. This enables the SP or the service end to originate video calls to specified UEs or play ordered streaming contents. The video call service is thus realized. 
         [0066]    The authentication and accounting for a PPS user vary from the procedure shown in  FIG. 3  in some aspects. For PPS, there are pre-deduction and refund actions, like the pre-authorization of a credit card. Pre-deductions are made on a periodical basis and the MDSP will send deduction requests to the PPS unit in real time. When a call session is over, the amount pre-deducted that is not consumed will be refunded. 
         [0067]    The following describes an application scenario of the CSS system for implementing the video call service according to an embodiment. 
         [0068]    User A orders mobile news and the ordered news is delivered at 8:00 a.m. every day. The AS sends a video call command to the CSSC at 8:00 a.m. and specifies the streaming content; the CSSC originates a call to user A by sending an INVITE message to the VIG; if user A answers, the VIG notifies the CSSC that the call is connected and the CSSC delivers the streaming content; user A will then see the news. The video call service is thus realized. 
         [0069]    However, after the CSSC originates a video call, the call may fail for certain reasons (for example, the UE is busy, the UE is unreachable, the UE is roaming in a 2G network, or the UE is powered off). In this case, the CSS or the AS may retry within a certain period of time. For instance, when user A is engaged in another call or powered off, the call fails and a retry will be made according to the retry policy. 
         [0070]    Some retry policies are provided below for the CSS system according to an embodiment of the invention. 
       (1) CSSC Retry 
       [0071]    A retry module is set in the AS to control the call module in the CSSC to retry when a call attempt of the CSSC fails. When the AS sends a video call command to the CSSC, the retry module lets the command carry the Retry Times or Retry Interval parameters. When a call attempt of the CSSC fails, the CSSC retries according to the parameters and returns the result to the AS. 
       (2) AS Retry 
       [0072]    The AS further includes a responding module. The module responds to the user response reported after the call module of the CSSC originates a call, and determines the subsequent action according to the user response. Retry parameters may be set in the responding module. When a call attempt fails, different retry policies may be adopted according to the failure reason. After the CSSC completes a call attempt, the CSSC reports the user response (Normal, Busy or Timeout) to the AS. If the call attempt fails, different retry policies can be adopted according to the failure reason. For example, if the UE is busy, a retry may be made 5 minutes later; if the UE is powered off, a retry may be made 30 minutes later. 
         [0073]    The AS supports flexible retry policies and the retry policies have little impact on the CSSC. 
         [0074]    In addition, according to an embodiment of the invention, the CSS system provides a service handling interface in the BOSS. The interface may be a standard WSI interface, an MML interface or a custom interface. Peripheral systems, like short message service (SMS), unstructured supplementary service data (USSD), interactive voice response (IVR) and end-user portal, all use the interface provided by the BOSS to realize the handling of the streaming service. 
         [0075]    Service handling include: user A orders a specific video program for user B; a user orders videos of a specific content that are periodically delivered, such as movie trailers, news and sports; a corporate user orders a specific duration for playing an advertisement to its customers. 
         [0076]    For example, in an SMS, the CSS system handles the service in this way: user M orders a specific video by sending a short message; the short message triggers the AS to send a video call command to the CSSC at the specified time and specify the streaming content; the CSSC originates a call to user M by sending an INVITE message to the VIG; when user M answers, the VIG notifies the CSSC that the call is connected and the CSSC delivers the streaming content; user M receives the ordered video. The video call service is thus realized. 
         [0077]    In addition, according to other embodiments of the invention, the CSS system supports different charging modes, including free of charge, monthly fee, content-based charging, duration-based charging and their combinations. 
         [0078]    In embodiments of the invention, only the 3G UE (H.324 UE) is described for exemplary purposes. The terminal of the present invention, however, is not limited to this. It may also be a SIP terminal, or an H.323 soft terminal. 
         [0079]    It seems obvious for person skilled in the art that various modules and procedures in the embodiments of the present invention may be implemented with normal computing apparatus. These modules and procedures may be arranged and performed either on a single computing apparatus or distributed on a network formed by multiple computing apparatus. Optionally, these modules and procedures may be implemented with executable application codes of an apparatus so that they can be stored in a storage apparatus and performed by a computing apparatus, or they can be designed into multiple integrated circuit modules, or multiple modules or procedures there-among can be designed into a single integrated circuit module for implementation. Therefore, the invention is not limited to combination of any specified software and hardware. 
         [0080]    To conclude, in embodiments of the invention, an AS is added to the CSS system so that the SP can send a video call command to the CSSC via the AS and that the CSSC can deliver multimedia contents to terminals actively. The video call service is thus realized. For example, the CSSC can originate a video call (for example, to a 3G user or a 3G user group) and when the user answers, the user can view the streaming content actively delivered by the CSSC; the video call service capability of the CSS system provides a good alternative for operators to operate VoD (for example, user A demands a video clip for user B and the video clip is played actively to user B at the specified time), video advertisement (for example, deliver a video advertisement to users actively), video content ordering (for example, a user orders some video news and the news is delivered to the user at the specified time every day) and public services. 
         [0081]    Although the invention has been described through some exemplary embodiments, the invention is not limited to such embodiments. It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the scope of the invention. The invention is intended to cover the modifications and variations provided that they fall in the scope of protection defined by the following claims or their equivalents.