Abstract:
A method and apparatus are disclosed that enable an interactive voice response (IVR) system to deliver content streams of various media types (e.g., video, audio, etc.) to telecommunications terminals. The illustrative embodiment provides extensions to the Voice extensible Markup Language (VXML) standard that enable an IVR system script to specify the playback order, timing, and coordination of multiple content streams (e.g., whether an audio stream and a video stream should be played back concurrently or serially; whether a particular content stream should finish before playback of another content stream commences; whether a content stream that is currently playing should be stopped and supplanted with another content stream, etc.).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. provisional application Ser. No. 60/660,249, filed Mar. 10, 2005, entitled “System and Method for Multimodal Content Delivery in Interactive Response Systems,” (Attorney Docket: 630-126us), which is also incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to telecommunications in general, and, more particularly, to coordinating the delivery of multiple content streams from an interactive voice response system.  
       BACKGROUND OF THE INVENTION  
       [0003]     Many enterprises employ an interactive voice response (IVR) system that handles calls from telecommunications terminals. An interactive voice response system typically presents a hierarchy of menus to the caller, and prompts the caller for input to navigate the menus and to supply information to the IVR system. For example, a caller might touch the “3” key of his terminal&#39;s keypad, or say the word “three”, to choose the third option in a menu. Similarly, a caller might specify his bank account number to the interactive voice response system by inputting the digits via the keypad, or by saying the digits. In many interactive voice response systems the caller can connect to a person in the enterprise by either selecting an appropriate menu option, or by entering the telephone extension associated with that person.  
         [0004]      FIG. 1  depicts telecommunications system  100  in accordance with the prior art. Telecommunications system  100  comprises telecommunications network  105 , private branch exchange (PBX)  110 , and interactive voice response system  120 , interconnected as shown.  
         [0005]     Telecommunications network  105  is a network such as the Public Switched Telephone Network [PSTN], the Internet, etc. that carries a call from a telecommunications terminal (e.g., a telephone, a personal digital assistant [PDA], etc.) to private branch exchange  110 . A call might be a conventional voice telephone call, a text-based instant messaging (IM) session, a Voice over Internet Protocol (VoIP) call, etc.  
         [0006]     Private branch exchange (PBX)  110  receives incoming calls from telecommunications network  105  and directs the calls to interactive voice response (IVR) system  120  or to one of a plurality of telecommunications terminals within the enterprise, depending on how private branch exchange  110  is programmed or configured. For example, in an enterprise call center, private branch exchange  110  might comprise logic for routing calls to service agents&#39; terminals based on criteria such as how busy various service agents have been in a recent time interval, the telephone number called, and so forth. In addition, private branch exchange  110  might be programmed or configured so that an incoming call is initially routed to interactive voice response (IVR) system  120 , and, based on caller input to IVR system  120 , subsequently redirected back to PBX  110  for routing to an appropriate telecommunications terminal within the enterprise. Private branch exchange (PBX)  110  also receives outbound signals from telecommunications terminals within the enterprise and from interactive voice response (IVR) system  120 , and transmits the signals on to telecommunications network  105  for delivery to a caller&#39;s terminal.  
         [0007]     Interactive voice response (IVR) system  120  is a data-processing system that presents one or more menus to a caller and receives caller input (e.g., speech signals, keypad input, etc.), as described above, via private branch exchange  110 . Interactive voice response system (IVR)  120  is typically programmable and performs its tasks by executing one or more instances of an IVR system application. An IVR system application typically comprises one or more scripts that specify what speech is generated by interactive voice response system  120 , what input to collect from the caller, and what actions to take in response to caller input. For example, an IVR system application might comprise a top-level script that presents a main menu to the caller, and additional scripts that correspond to each of the menu options (e.g., a script for reviewing bank account balances, a script for making a transfer of funds between accounts, etc.).  
         [0008]     A popular language for such scripts is the Voice extensible Markup Language (abbreviated VoiceXML or VXML). The Voice extensible Markup Language is an application of the eXtensible Markup Language, abbreviated XML, which enables the creation of customized tags for defining, transmitting, validating, and interpretation of data between two applications, organizations, etc. The Voice extensible Markup Language enables dialogs that feature synthesized speech, digitized audio, recognition of spoken and keyed input, recording of spoken input, and telephony. A primary objective of VXML is to bring the advantages of web-based development and content delivery to interactive voice response system applications.  
         [0009]      FIG. 2  depicts an exemplary Voice extensible Markup Language (VXML) script (also known as a VXML document or page), in accordance with the prior art. The VXML script, when executed by interactive voice response system  120 , presents a menu with three options; the first option is for transferring the call to the sales department, the second option is for transferring the call to the marketing department, and the third option is for transferring the call to the customer support department. Audio content (in particular, synthesized speech) that corresponds to text between the &lt;prompt&gt; and &lt;/prompt&gt; tags is generated by interactive voice response system  120  and transmitted to the caller.  
       SUMMARY OF THE INVENTION  
       [0010]     As video displays become ubiquitous in telecommunications terminals, it can be advantageous to deliver video content to a telecommunications terminal during a call with an interactive voice response (IVR) system, in addition to audio content. For example, a user of a telecommunications terminal who is ordering apparel via an IVR system might receive a video content stream related to a particular item (e.g., depicting a model who is wearing the item, depicting the different available colors for the item, etc.). Furthermore, in some instances it might be desirable to deliver an audio content stream (e.g., music, news, etc.) to the user, perhaps during silent periods in the call, or perhaps as background audio throughout the entire call.  
         [0011]     The illustrative embodiment of the present invention enables an IVR system to deliver content streams of various media types (e.g., video, audio, etc.) to telecommunications terminals via the addition of extensions to the Voice extensible Markup Language (VXML) standard. In addition, the illustrative embodiment provides VXML extensions that enable an IVR system script to specify the playback order, timing, and coordination of multiple content streams (e.g., whether an audio stream and a video stream should be played back concurrently or serially; whether a particular content stream should finish before playback of another content stream commences; whether a content stream that is currently playing should be stopped and supplanted with another content stream, etc.).  
         [0012]     The illustrative embodiment comprises: (a) receiving a list of one or more identifiers at a thread of an interactive voice response system, (i) wherein each of the identifiers is associated with one of a plurality of content streams, (ii) wherein each of the content streams has one or more of a plurality of media types, (iii) wherein the list specifies a playback order for the content streams, and (iv) wherein the thread is associated with one of the media types T and with a call that involves the interactive voice response system and a telecommunications terminal; and (b) executing in the thread a command for initiating delivery of one of the content streams S to the telecommunications terminal, (i) wherein the content stream S has the media type T, and (ii) wherein the time τ at which delivery of the content stream S begins is based on the playback order. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  depicts telecommunications system  100  in accordance with the prior art.  
         [0014]      FIG. 2  depicts an exemplary Voice extensible Markup Language (VXML) script, in accordance with the prior art.  
         [0015]      FIG. 3  depicts telecommunications system  300  in accordance with the illustrative embodiment of the present invention.  
         [0016]      FIG. 4  depicts an exemplary Voice extensible Markup Language (VXML) script, in accordance with the illustrative embodiment of the present invention.  
         [0017]      FIG. 5  depicts an audio/video channel timing diagram that corresponds to the VXML script of  FIG. 4 , in accordance with the illustrative embodiment of the present invention.  
         [0018]      FIG. 6  depicts a flowchart of the salient tasks of interactive voice response system  320 , as shown in  FIG. 3 , in accordance with the illustrative embodiment of the present invention.  
         [0019]      FIG. 7  depicts a flowchart of the salient tasks of a thread that is spawned at task  680  of  FIG. 6 , in accordance with the illustrative embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0020]      FIG. 3  depicts telecommunications system  300  in accordance with the illustrative embodiment of the present invention. Telecommunications system  300  comprises telecommunications network  105 , private branch exchange (PBX)  310 , interactive voice response system  320 , content server  330 , and content database  340 , interconnected as shown.  
         [0021]     Private branch exchange (PBX)  310  provides all the functionality of private branch exchange (PBX)  110  of the prior art, and is also capable of receiving streamed content (e.g., audio, video, multimedia, etc.) from content server  330 , of forwarding streamed content on to telecommunications network  105  for delivery to a caller&#39;s terminal, and of transmitting signals related to streamed content to content server  330 . Furthermore, in addition to conventional telephony-based signaling and voice signals, private branch exchange  310  is also capable of transmitting and receiving Internet Protocol (IP) data packets, Session Initiation Protocol (SIP) messages, Voice over IP (VoIP) traffic, and stream-related messages (e.g., Real Time Streaming Protocol [RTSP] messages, etc.) to and from IVR system  320 . It will be clear to those skilled in the art, after reading this specification, how to make and use private branch exchange (PBX)  310 .  
         [0022]     Interactive voice response system  320  provides all the functionality of interactive voice response system  120  of the prior art, and is also capable of transmitting commands to content server  330  (e.g., starting playback of a content stream, stopping playback of the content stream, queueing another content stream, etc.) and of receiving information from content server  330  (e.g., an indication that playback of a content stream has begun, an indication that playback of a content stream has completed, etc.). It will be clear to those skilled in the art, after reading this specification, how to make and use interactive voice response system  320 .  
         [0023]     Content server  330  is capable of retrieving content from content database  340 , of buffering and delivering a content stream to a calling terminal via private branch exchange  310 , of receiving commands from interactive voice response (IVR) system  320  (e.g., to start playback of a content stream, to queue another content stream, etc.), of transmitting status information to interactive voice response (IVR) system  310 , and of generating content (e.g., dynamically generating a video of rendered text, etc.) in well-known fashion. It will be clear to those skilled in the art, after reading this specification, how to make and use content server  330 .  
         [0024]     Content database  340  is capable of storing a plurality of multimedia content (e.g., video content, audio content, etc.) and of retrieving content in response to commands from content server  330 , in well-known fashion. It will be clear to those skilled in the art, after reading this specification, how to make and use content database  340 .  
         [0025]     As will be appreciated by those skilled in the art, some embodiments of the present invention might employ an architecture for telecommunications system  300  that is different than that of the illustrative embodiment (e.g., IVR system  320  and content server  330  might reside on a common server, etc.). It will be clear to those skilled in the art, after reading this specification, how to make and use such alternative architectures.  
         [0026]      FIG. 4  depicts an exemplary Voice Extensible Markup Language (VXML) script, in accordance with the illustrative embodiment of the present invention. The script is the same as the script of  FIG. 2  of the prior art, with the addition of lines of code depicted in boldface. As shown in  FIG. 4 , the script now contains prompts that are audio and video content streams, in addition to speech prompts. In particular, the menu presentation comprises, in addition to speech: a video representation of the menu choices, an animated logo (e.g., a corporate logo, etc.), and an audio jingle. Furthermore, when the user selects choice  1  (sales), interactive voice response (IVR) system  310  delivers an audiovisual stream “demo.3gp,” an animated chart (e.g., an animated pie chart, etc.), an audio stream “jingle2.mp3,”, and an audiovisual stream “trailer.3gp.” 
         [0027]     As shown in  FIG. 4 , the illustrative embodiment provides various extensions to the VXML standard. First, a prompt can specify its particular media type(s) (e.g., audio-only, video-only, audiovisual, etc.). Second, prompts that include video can include a Boolean persist attribute that indicates whether the video should remain active until the next video prompt is encountered in the application. When the persist attribute for a video prompt is true, the VXML interpreter will proceed to the next prompt once the video has started; conversely, when the persist attribute for a video prompt is false (or no persist attribute is specified, in accordance with the illustrative embodiment), the VXML interpreter will not proceed to the next prompt until the video prompt has finished. As will be appreciated by those skilled in the art, although in the illustrative embodiment a persist attribute of true results in the VXML interpreter waiting for the video prompt to finish before proceeding to any subsequent prompt (i.e., video or non-video), in some embodiments the VXML interpreter might proceed to a subsequent non-video prompt before the video prompt has finished.  
         [0028]     The illustrative embodiment thus enables a script to specify the manner in which multiple prompts should be presented via the order in which the prompts are enumerated, via the values of the persist attributes, and via the order and duration of interlaced prompt types.  
         [0029]      FIG. 5  depicts a timing diagram of the audio and video channels for a call that is handled by the VXML script of  FIG. 4 , in accordance with the illustrative embodiment of the present invention. At the start of the call, the synthesized speech of the menu is played concurrently with a video version of the menu, and then audio stream jingle1 is played concurrently with the video of animatedLogo. Subsequently, after the caller has selected an option from the menu, the script: plays the audio and video streams of source demo concurrently; presents an animated chart in place of the video portion of demo while the audio portion of demo is still playing; plays audio stream jingle2 concurrently with the animated chart after playback of demo has finished; and plays the audio and video streams of source trailer concurrently after jingle2 has finished.  
         [0030]      FIG. 6  depicts a flowchart of the salient tasks of interactive voice response (IVR) system  320 , in accordance with the illustrative embodiment of the present invention. It will be clear to those skilled in the art which tasks depicted in  FIG. 6  can be performed simultaneously or in a different order than that depicted.  
         [0031]     At task  610 , an incoming call is received at interactive voice response system  320 , in well-known fashion.  
         [0032]     At task  620 , interactive voice response (IVR) system  320  assigns an instance of an appropriate IVR system application to the incoming call, in well-known fashion. As will be appreciated by those skilled in the art, although in the illustrative embodiments an instance of an IVR system application handles one incoming call at a time, in some other embodiments of the present invention an application instance might handle a plurality of calls concurrently.  
         [0033]     At task  630 , interactive voice response (IVR) system  320  begins executing the IVR application instance, in well-known fashion.  
         [0034]     At task  640 , interactive voice response (IVR) system  320  checks whether the current command to be executed in the IVR application instance initiates delivery of a content stream S to the calling telecommunications terminal. If so, execution continues at task  660 , otherwise, execution proceeds to task  650 .  
         [0035]     At task  650 , interactive voice response (IVR) system  320  checks whether the IVR application instance&#39;s execution has completed. If so, execution continues back at task  610  for the next incoming call; otherwise, execution proceeds to task  690 .  
         [0036]     At task  660 , interactive voice response (IVR) system  320  constructs an ordered list L of content stream identifiers from the block of consecutive &lt;prompt&gt;s that starts at the current command. For example, in the script of  FIG. 4 , the block of consecutive &lt;prompt&gt;s in the &lt;menu&gt; block might correspond to ordered list: 
 
 L =(menuVideo1, speech1, animatedLogo.gif, jingle1.mp3) 
 
 where 
        menuvideo1 is an identifier that is dynamically generated by the VXML interpreter and corresponds to the “literal” video in the script that displays the menu options;     speech1 is an identifier that is dynamically generated by the VXML interpreter and corresponds to the “literal” speech in the script that welcomes the caller and enumerates the menu options;     animatedLogo.gif is the filename of a video source; and     jingle1.mp3 is the filename of an audio source. 
 
 Of course, might be only 1 prompt-&gt; list of 1 element. 
       
 
         [0041]     Similarly, the block of consecutive &lt;prompt&gt;s in the formSales &lt;form&gt; block might correspond to ordered list: 
 
 L =(demo.3gp. video, demo.3gp.audio, animatedchart.gif, jingle2.mp3, trailer.3gp. video, trailer.3gp. audio) 
 
 where 
        demo.3gp.video denotes the video portion of file demo.3gp;     demo.3gp.audio denotes the audio portion of file demo.3gp;     animatedchart.gif is the filename of a video source;     jingle2.mp3 is the filename of an audio source;     trailer.3gp.video denotes the video portion of file trailer.3gp; and     trailer.3gp.audio denotes the audio portion of file trailer.3gp.        
 
         [0048]     At task  670 , interactive voice response (IVR) system  320  removes from list L any content stream identifier whose media type is not supported by the telecommunications terminal.  
         [0049]     At task  680 , interactive voice response (IVR) system  320  spawns a thread for each media type Tin list L. For example, in the script of  FIG. 4  IVR system  320  would spawn a thread for audio and a thread for video for both instantiations of list L. Each thread is passed list L and the &lt;prompt&gt; attribute values for each content stream in L. As will be appreciated by those skilled in the art, information can be passed to threads in a variety of ways, such as via a memory pointer, via an operating system inter-thread communication mechanism, and so forth. The operation of the threads is described in detail below and with respect to  FIG. 7 .  
         [0050]     At task  690 , interactive voice response (IVR) system  320  continues the execution of the IVR application instance, in well-known fashion. After task  690 , execution continues back at task  640 .  
         [0051]      FIG. 7  depicts a flowchart of the salient tasks of a thread that is spawned at task  680  of  FIG. 6 , in accordance with the illustrative embodiment of the present invention. It will be clear to those skilled in the art which tasks depicted in  FIG. 7  can be performed simultaneously or in a different order than that depicted.  
         [0052]     At task  710 , the thread initializes ordered list L′ to the content stream identifiers in list L that have the same media type T as the thread.  
         [0053]     At task  720 , the thread sets variable S to the first content stream in list L′ and removes S from list L′.  
         [0054]     At task  730 , the thread initiates playback of content stream S over C T , the channel that corresponds to media type T.  
         [0055]     At task  740 , the thread checks whether the call has terminated. If so, the thread terminates, otherwise, execution continues at task  750 .  
         [0056]     At task  750 , the thread checks whether channel C T  is idle. If so, the thread continues its execution at task  780 , otherwise execution proceeds to task  760 .  
         [0057]     At task  760 , the thread determines whether the &lt;prompt&gt; attribute values indicate that the current content stream in channel C T  should continue playing (e.g., the current content stream has its persist attribute equal to true and content streams of other media types are still playing, etc.). If so, execution continues back at task  740 , otherwise execution proceeds to task  770 .  
         [0058]     As will be appreciated by those skilled in the art, some embodiments of the present invention might employ other attributes in addition to, or instead of, the persist attribute to specify the manner in which content streams are played. For example, a Boolean concurrency attribute for a particular content stream S might indicate whether other content streams that have a media type different than S can be played simultaneously with S. As another example, a Boolean supplant attribute for a particular content stream S might indicate whether S can supplant a currently-playing content stream of the same media type, perhaps even when the current stream has persist equal to true.  
         [0059]     As will be further appreciated by those skilled in the art, some embodiments of the present invention might employ attribute values that are dynamically-evaluated conditions (e.g., supplant=(currentStream.timeleft( )&lt;10), etc.), or might employ attributes that have data types other than Boolean (e.g., minTimePlayed=4, etc.). Furthermore, some embodiments of the present invention might employ another scripting language instead of, or in addition to, VXML (e.g., Speech Application Language Tags [SALT], etc.), and it will be clear to those skilled in the art, after reading this specification, how to make and use such embodiments.  
         [0060]     At task  770 , the thread stops the current content stream of channel C T , in well-known fashion.  
         [0061]     At task  780 , the thread checks whether ordered list L′ is empty. If so, the thread terminates, otherwise, execution continues back at task  720 .  
         [0062]     It is to be understood that the above-described embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by those skilled in the art without departing from the scope of the invention. For example, in this Specification, numerous specific details are provided in order to provide a thorough description and understanding of the illustrative embodiments of the present invention. Those skilled in the art will recognize, however, that the invention can be practiced without one or more of those details, or with other methods, materials, components, etc.  
         [0063]     Furthermore, in some instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the illustrative embodiments. It is understood that the various embodiments shown in the Figures are illustrative, and are not necessarily drawn to scale. Reference throughout the specification to “one embodiment” or “an embodiment” or “some embodiments” means that a particular feature, structure, material, or characteristic described in connection with the embodiment(s) is included in at least one embodiment of the present invention, but not necessarily all embodiments. Consequently, the appearances of the phrase “in one embodiment” “in an embodiment” or “in some embodiments” in various places throughout the Specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments. It is therefore intended that such variations be included within the scope of the following claims and their equivalents.