Multimedia session management

The present invention relates generally to multimedia session management in communication systems, and in particular to session management that allows smooth, user-friendly (easy-to-use) switching of multimedia channels.

There is a tendency to propose and provide a wide range of new services in existing mobile networks and mobile communication systems. Currently, there is a great deal of interest in using mobile networks for multimedia or TV content. This is often referred to as a mobile TV in the prior art. The purpose of mobile TV applications is to provide a TV-like experience that allows users to select and easily zapping a variety of multimedia or TV channels.

A normal TV channel is broadcast to many users, and in general, the user can select a channel to receive and watch. Mobile TV is similar with respect to delivering a set of (live) media or multimedia streams to several end users. Each multimedia stream corresponds to a TV channel, and each user can select the channel to watch. Currently, a mobile TV broadcast / multicast distribution method is under development. Examples of such standardization efforts are 3GPP's Multimedia Broadcast / Multicast Service (MBMS) and the European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting-Handheld (DVB-H). These are the same as the conventional TV in the broadcast distribution method.

By the way, until mobile TV based on multicast / broadcast becomes available, there is a need for a solution that can be realized through existing mobile transport channels. Mobile TVs will also be of great concern later on, even for cells with few users and networks with sufficient capacity, where unicast transfer is the preferred delivery method.

Services similar to mobile TVs that use streaming over networks based on the Internet Protocol (IP) will be realized on existing mobile networks. One example is the Packet Switching (PS) Streaming Service (PSS) developed in 3GPP. To initiate such a multimedia or TV session, the user typically surfs a web page or portal site and clicks or selects a link to view a livestreaming channel.

There are several proprietary streaming solutions available for mobile TV, such as RealNetwork's streaming solution, Apple's Quicktime, and Microsoft's media player. These also generally have portal sites or web pages, where links are clicked to initiate reception of a particular channel.

One purpose of mobile TV services is to allow channel zapping, just as it does for regular broadcast TV channels. If all channels are broadcast, the receiver can select the channel locally by selecting the appropriate transport channel and using the appropriate demultiplexer. This applies not only to common cable, satellite or terrestrial television, but also to the upcoming mobile standards MBMS and DVB-H. However, for unicast sessions, the client needs to have a "server" or multimedia provider send the desired channel.

For PS streaming technology based on PSS, there is currently no simple solution for channel switching. The traditional method of IP-based mobile streaming is to select specific content in the browser. This initiates the download of the Session Description Protocol (SDP) or Synchronized Multimedia Integration Language (SMIL) file and initiates a Real Time Streaming Protocol (RTSP) streaming session in the media player of the user terminal. It takes about 10 seconds for the user to view the content on the screen of the user terminal. Of the 10 seconds, 5 seconds is application setup and the rest is signaling (about 2 seconds) and buffering (about 3 seconds). If the user wants to switch to another "multimedia channel or TV channel", the user must stop the current data stream, return to the browser and select another channel by clicking the link in the browser. A new RTSP session is started, the media player is started and buffering is started, resulting in a new delay of 10 seconds.

<p>Overview Therefore, in unicast (packet-switched) networks and communication systems, a smooth user does not need to visit the multimedia provider's website or portal site and does not require a long delay before the multimedia data is delivered to the user. There is a need to provide a friendly multimedia or TV channel switching solution.</p><p> The present invention overcomes these drawbacks and the like in the configuration of the prior art.</p><p> A general object of the present invention is to provide a user-friendly multimedia channel switching solution for users participating in a multimedia session.</p><p> Another object of the present invention is to provide a graphical interface that provides multimedia data that contains the information required by the user and is visually appealing in order to select another multimedia channel. is there.</p><p> Yet another object of the present invention is to provide a zapping-capable TV-like experience on a user terminal using protocols and codecs common in unicast communication systems.</p><p> These objects and the like are achieved by the present invention as defined in the appended claims.</p><p> Briefly, the invention includes the setup and management of multimedia sessions in a unicast (unicast-based) communication system. In particular, the present invention relates to multimedia session setup instructions that provide user-friendly, fast, and efficient zapping and switching between available multimedia channels during a running session.</p><p> A user who wants to view a content provider or a multimedia channel available from a multimedia provider sends a request for that multimedia channel (to that multimedia channel) to the provider. This channel request is typically generated by the user by visiting a multimedia provider's web page and clicking a link associated with the multimedia channel. The multimedia provider automatically generates multimedia session setup explanatory information according to the present invention. This setup instructional information is all that the user terminal needs to provide a visually appealing presentation of the requested multimedia data, as well as another channel, movie and program presentation available from the multimedia provider. Contains information, objects, and instructions. In addition, the setup instructions allow a user-friendly switch to any other channel without the user having to end a running session and revisit the multimedia provider's web page.</p><p> The generated setup explanatory information is returned to the user terminal, and the data object included in the explanatory information is processed by the terminal. First, the multimedia object of the explanatory information defines a multimedia session window that is displayed on the screen of the terminal or a graphical user interface (GUI) when processed in the terminal. This session window contains a display area adapted (adapted) to display multimedia (video) data for the requested channel. The window further includes a viewable channel area that contains information about another multimedia channel available from the provider. This information may be, for example, an identifier or icon of a TV program or movie currently available on those other channels. This means that the user already has access to information about all the different multimedia channels on the display screen at the start of the session. As a result, the user does not have to end the session and revisit the multimedia provider's web page to obtain that type of information.</p><p> The session window may optionally further include an information area containing information about the multimedia provider. The optional title area of the session window provides information about the multimedia channel the user is currently watching, for example by showing the assigned channel name and / or the title of the movie or TV show currently being transmitted on that channel. Including.</p><p> The association object of the session setup description information defines an association or binding between the user input of the terminal and the identifier of another channel notified in the channel area of the session window when processed in the terminal. The user input associated with the channel identifier may be, for example, a key on a terminal keypad or a portion of a touch panel. When a user triggers one user input, the setup description information request object generates a request for another channel with an identifier associated with the triggered user input. This channel switching request is automatically sent to the multimedia provider, which performs the channel switching without further user interaction.</p><p> In other words, if the user wants to switch multimedia channels, the user simply presses one key on the user terminal assigned to that channel, for example. The channel area preferably identifies the key (user input) assigned to another channel, in addition to listing information about another available channel. When the associated key is pressed, the request object compiles the channel switch request. This switch request contains the identifier of the requested channel obtained via the key binding provided by the association object. In addition, the request includes the identifier of the user terminal so that the multimedia provider can identify the associated terminal. The user terminal identifier may be, for example, a Universal Resource Identifier (URI), an Internet Protocol (IP) address, or at least one IP port of the user terminal. Alternatively, the terminal identifier is a user terminal-specific identifier assigned by the multimedia provider and is included in the session setup request sent to the user terminal.</p><p> This is the user input (key) that the user must perform to switch multimedia channels during a session according to the present invention is associated and assigned to the desired channel by the displayed channel area. It just means identifying and then activating that user input. This should be compared to traditional solutions for unicast systems. In traditional solutions, the user must first end the current session, revisit the provider's web page, and select and click a link to the desired multimedia channel. After that, a new session setup procedure needs to be executed, which is a very time-consuming and complicated channel switching procedure.</p><p> When the multimedia provider receives the channel switching request of the present invention, the multimedia provider identifies a new desired channel by the included channel identifier and uses the included terminal identifier to transmit the multimedia data flow of this new channel. Aim at the appropriate user terminal.</p><p> In one preferred embodiment of the invention, multimedia channel changes are preferably performed seamlessly and transparently to the user terminal. This means that during the switch, the multimedia provider provides the user terminal with multimedia data from the previous channel and the new channel as a continuous data stream. As a result, the first part of the data stream contains the multimedia data of the previous channel and the subsequent second part of the stream contains the data of the new multimedia channel. Further, the multimedia data is preferably transmitted as a data packet from the multimedia provider to the user terminal. Usually, each data packet is associated with a sequence number and a time stamp. To make channel switching more seamless, multimedia providers assign sequence numbers to data packets containing multimedia data in new channels so that after switching, the sequence numbering of the data packet stream remains seamless and continuous. It is preferable to allocate. In addition, time stamps are assigned so that continuous time stamping occurs even when multimedia sources and channels are exchanged.</p><p> Multimedia data can include video and audio data provided in separate streams. In order to avoid deterioration during audio reproduction on the user terminal, it is preferable that the amount of increase in the time stamp for the audio packet is kept constant even when the channel is switched. This causes a slight time displacement between the input time and the output time. The time stamping of video packets is similarly adjusted based on audio time stamping to maintain synchronization. In this situation, the audio data is the master and should be switched before the video data.</p><p> Furthermore, the synchronization source (ssrc) of the data packet is set to be constant so that the user terminal is given the impression that the data packet is transmitted as one continuous stream even if the channel switching is executed. preferable.</p><p> The session setup explanatory information according to the present invention is advantageously generated in Synchronized Multimedia Integration Language (SMIL). In such cases, the association object can leverage the acceskey binding provided by SMIL to bind the user input with another channel identifier. However, other languages, including hypertext markup language (HTML) and extended markup language (XML), may be adopted instead. The session setup description information may be based on Java®, such as the format of a Java® midlet or applet. Further examples include explanatory information based on the Session Initiation Protocol (SIP) or Message Session Relay Protocol (MSRP).</p><p> The multimedia provider according to the present invention is considered to include various internal units, namely application servers, streaming servers, and channel switches. The application server is responsible for receiving (managing) channel requests and channel switching requests from the user terminal, and returns session setup explanatory information. In addition, the application server assigns ports to various multimedia sessions and notifies other units of those ports. The channel switch has access to various multimedia channels and sources (sources) and performs the actual switching of the source for commands from the application server. In addition, the switch preferably manages packet renumbering and time stamping. The streaming server manages the transfer of multimedia data from the switch to the user terminal and is involved in negotiating with the terminal about session setup. In such a system, the channel switching performed in accordance with the present invention is completely transparent to both the streaming server and the user terminal. The terminal identifier is used by application servers, channel switches and streaming servers not only as an identifier for the actual user terminal, but also as an identifier for the current multimedia session.</p><p> The present invention provides the following advantages: -In a unicast communication system, it provides a TV-like experience that allows zapping on the user terminal during a running multimedia session. -Provide user terminals with user-friendly, seamless, and transparent channel switching using common protocols and codecs. -Provide a richer, visually appealing user interface. -The same multimedia session is reused during channel switching, eliminating the need to perform time-consuming and cumbersome setup of new sessions over wireless links.</p><p> Other advantages provided by the present invention will be understood by reading the following description of embodiments of the present invention.</p><p> By referring to the following description along with the accompanying drawings, the present invention will be best understood, along with the further objectives and advantages of the present invention.</p>

Detailed explanation In the figure, the same reference numerals are used for the corresponding elements or similar elements.

The present invention relates to the management of multimedia sessions in a communication system, and in particular to managing the setup of multimedia sessions and the switching of multimedia sources during a running session.

The present invention provides a TV-like experience in a unicast communication system, similar to today's conventional TV systems and upcoming multicast / broadcast based mobile TVs. The technique of the present invention is applicable to any unicast system, and is particularly applicable to wireless communication systems that employ the Internet Protocol (IP) for data communication. A common example of such a communication system is a PS system that provides multimedia data to connected users via packet switching (PS) streaming (PSS).

As a result, according to the present invention, a user participating in a multimedia session switches various multimedia channels in a unicast communication system in the same manner as a normal TV system and a mobile TV system based on broadcast / multicast. Be done. From the user's point of view, this is a new multi that visits the multimedia provider's web page, where channel switching is experienced very smoothly, is performed in less time, and was required by traditional unicast solutions. This means that you don't need to set up a media session. The present invention further provides a very rich and visually appealing user interface.

The multimedia data according to the present invention includes media and multimedia of any format and type that are rendered and displayed on the user terminal. This includes, but is not limited to, image, video, audio and other media types that are visible to the user during rendering.

FIG. 1 is a flowchart showing how to set up a multimedia session in a unicast communication system according to the present invention. This method begins with an optional (optional) step S1. In step S1, the multimedia provider according to the present invention receives a request for multimedia or a media channel (TV channel) from a user terminal.

This channel request is performed according to the prior art as described in the background section. Briefly, a user uses a web browser or similar application on a user terminal to visit a multimedia provider's web page and select the desired multimedia channel, for example by clicking a link. Alternatively, the user terminal can include an application that automatically accesses or connects to the multimedia provider when launched to allow the user to select the associated channel.

The user terminal can insert the user terminal identifier in the request for the multimedia channel. This is demonstrated in the next step S2. Alternatively, the user terminal identifier may be transmitted separately from the channel request, as long as the multimedia provider associates the user terminal identifier with the corresponding channel request.

According to the present invention, various user terminal identifiers can be adopted. For example, the terminal identifier may be the IP address assigned to the user terminal or the Universal Resource Identifier (URI). Another possible example includes at least one port on the user terminal, preferably including an input port on the user terminal to which multimedia data for the requested channel should be delivered. The terminal identifier may be an identifier associated with a service contract between a user and another service provider, such as a network operator or multimedia provider.

In another embodiment of step S2, the multimedia provider provides the user terminal identifier based on the receipt of the channel request from the user terminal. For example, a multimedia provider accesses a set or pool of possible user terminal identifiers assigned to users participating in a multimedia session. In such a case, in step S2, the multimedia provider selects one of the set or pool identifiers currently not adopted by any other user terminal included in the multimedia session with the multimedia provider. This means that multimedia providers will reuse pool identifiers. The total number of pool identifiers should be large enough to handle the expected number of user terminals receiving multimedia data at the same time.

According to the present invention, it is believed that a multimedia provider can generate a new terminal identifier on the fly upon receiving a channel request and use it for the requesting user terminal. It is clear that it is preferable that the identifier of the user terminal uniquely identifies the user terminal in order to reduce the risk of confusing the various user terminals. As a result, in some applications, provider-generated user terminal identifiers are preferred. This is because the multimedia provider can control the identifier assignment process and prevent the terminals from being confused.

Normally, the user terminal identifier is adopted by the multimedia provider as the identifier of the actual user terminal, but it may be adopted as the identifier of the multimedia session involved in the user terminal. This is further disclosed herein.

When the channel request is received, and preferably the user terminal identifier is received or generated, in step S3, the multimedia provider generates a description or file of the multimedia session setup according to the present invention. This session setup description information is preferably dynamically generated by the multimedia provider based on the received channel request and the terminal identifier provided. This explanatory information includes a plurality of data objects or instructions that can be processed by the user terminal when the explanatory information is transmitted to the user terminal. In a preferred embodiment of the invention, the setup description information includes multimedia objects, association objects, and request objects. In a further preferred embodiment, the setup description information also includes a user terminal identifier.

A multimedia object defines a multimedia session window that, when processed in a user terminal, can be displayed in the user terminal's graphical user interface. In other words, when the user terminal processes the multimedia object, a multimedia session window is displayed in the graphical user interface. A graphical user interface is usually a display screen or other device (including a stand-alone device connected to a communication device of the user terminal) for displaying information on the user terminal. The multimedia session window displayed includes a multimedia display area adapted to display the multimedia (video) data of the requested multimedia channel. The session window further includes a viewable channel area that includes and displays the channel identifier of another (currently unrequested) multimedia channel available from the multimedia provider. In this way, the session window provides an attractive graphical user interface that allows the user to watch the requested TV program, movie or other requested multimedia in the video display area. Further, the channel area graphically notifies the user of another TV program, movie, etc. that the user can switch during the session.

FIG. 2 is a schematic block diagram showing an embodiment of a user terminal 10 according to the present invention having a display screen 12. The multimedia session window 20 is displayed on the display screen 12. The session window 20 includes the multimedia display area 22, in which the multimedia (video data) of the requested TV channel is currently displayed. The channel area 24 is clearly visible in the figure and is provided below, but not limited to, the multimedia display area 22. In this channel area 24, the identifier of another channel is displayed to the user. As schematically shown in the figure, the region 24 can display identifiers or icons for all the various multimedia (TV) channels available from the multimedia provider. This means that the multimedia object received in the session setup description or document contains all of that information, so the user does not have to visit the multimedia provider's web page to retrieve that information. ..

The channel area 24 is not always displayed on the display screen 12. In another embodiment, the multimedia display area 22 typically occupies the entire or at least most of the display screen 10. In such a case, the channel area 24 is displayed only when the user activates a particular user input, such as a key on the user terminal 10 or a portion of the display screen 12. In this embodiment, the channel area 24 functions like a pop-up window and is completely visible at the request of the user. The size of the multimedia display area 22 is (automatically) between the full screen (or almost full screen) when the channel area 24 is not displayed and the smaller size when the channel area 24 is displayed. Can change. This means that the size of the multimedia display screen 22 is maximized in the two operating modes, but the channel area 24 can still be displayed on demand.

Also, the size of the channel area 24 is between the full size (as shown) that displays all channel information and the relatively small size that can only display, for example, that the channel area 24 is present on the screen 12. Can be changed with. Switching between the two modes (sizes) can be performed based on the activation of a portion of the (touch panel) display screen 12, a key, or another user input.

The (alternative) channel identifier for channel area 24 may be in any graphic data format. For example, the identifier may be in the form of a display text string indicating the name of multimedia data (TV programs, movies, etc.) available on another channel. Alternatively, an icon representing another multimedia channel may be displayed in that channel area 24. The icon preferably displays a well-known logo or other information that allows the user to identify the multimedia or channel currently available on another channel.

As is clear from the figure, the multimedia session window 20 further includes other window areas including a viewable information area 26 and the like, including the currently selected or requested multimedia channel identifier or icon. be able to. Further, or instead, information on the actual multimedia data currently displayed in the multimedia display area 22, such as movie titles, program titles, or program information, may be found in this information area 26.

The title area 28 may include information about the multimedia source / owner and / or multimedia provider displayed in the multimedia session window 20.

An association object that is part of a multimedia session setup, when processed at user terminal 10, defines or provides an association between user input 14 of the user terminal and a channel identifier of another multimedia channel. Thus, this association object contains program code or instructions that generate an association between user input 14 on terminal 10 and other multimedia channels available from the multimedia provider. This means that the association object provides an association or binding between the user input 14 and the identifier of another channel whose icon is displayed in the channel area 24. The channel area 24 preferably further displays information about the user input 14 associated with the channel for each channel icon / identifier. This is clearly shown in Figure 2. In FIG. 2, channel region 24 contains information about four multimedia channels, represented by SVT1, SVT2, TV3, and TV4. The channel area 24 further includes the identifiers of the user inputs 14 assigned to those channels, namely the keypad key 1, key 2, key 3, and key 4 identifiers.

A common example of such an association provided by the association object of the present invention is a key binding between one of key 14 (user input) of user terminal 10 and another multimedia channel identifier. For example, if the multimedia session setup descriptive information is Synchronized Multimedia Integration Language (SMIL) -based descriptive information, the association object leverages the accesskey binding provided by SMIL to bind key 14 to another channel identifier. However, it may be specified which multimedia channel corresponds to which key 14.

The user input 14 involved in the binding or association may be any (software or hardware) user input 14 configured or implemented in the user terminal 10. As shown, a common example is the key 14 of the keypad configured on the terminal 10. In the case of the user terminal 10 having the touch panel type screen 12, the user input 14 can form a part of the touch panel type screen 12. For example, the portion of the touch panel screen 12 directly above the icon or channel identifier provided in the channel area of the multimedia session window 20 can be adopted as user input according to the present invention. In practice, any user input 14 that can be triggered or activated by the user is available for the association provided by the association object of the present invention.

The multimedia session setup description information further includes a request object that, when processed and implemented in user terminal 10, generates a request for another multimedia channel. When the user triggers or activates user input 14 associated with the identifier of another requested multimedia channel via an association object, that other channel request is generated.

The channel switching request includes the identifier of another multimedia channel requested and the identifier of the user terminal 10. The identifier of user terminal 10 may be received from the multimedia provider along with the session setup description information. In such a case, the request object either contains a user terminal identifier or has access to the user terminal identifier and inserts that identifier into the channel request. If the user terminal identifier is stored in user terminal 10, the request object retrieves the identifier when triggering user input 10 and includes it in the request.

In a general implementation of the invention, the channel identifier of another channel may be in the form of a link to a multimedia provider. The association object is feasible to bind or associate that particular link to one of the user inputs (keys) 14 of the user terminal. When the user activates that particular user input, such as by pressing key 14, the request object accesses the multimedia provider via the link associated with the triggered user input. The channel request contains information that allows the multimedia provider to identify the request multimedia channel associated with the triggered user input and allows the multimedia provider to identify the requesting user terminal 10. This will be further described below. In such an embodiment, the request object contains a hyperlink pointing to a multimedia provider, and a request for another multimedia channel is a Hypertext Transfer Protocol (HTTP) request that includes a user terminal identifier and a channel identifier for another channel. Is.

The multimedia session setup description information according to the present invention provides a very user-friendly and visually appealing graphical user interface through the multimedia session window 20 generated based on the multimedia object of the setup description information. .. In addition to displaying the requested multimedia, this session window 20 displays other relevant information about the multimedia session, that is, information about another channel available from the multimedia provider, as well as the requested multimedia channel and its channels. Allows you to view optional information about your current multimedia data. In addition, information describing the multimedia provider is displayed. This means that all data related to the user during the multimedia session is already available on the user terminal at the start of the session. This information is continuously visually available on the display screen 12 or can be presented at least on the display screen 12, as is the case with pop-up windows, for example. As a result, the user does not have to end the running session and revisit the multimedia provider's web page to get information about another available multimedia channel and TV show and movie.

In addition, the session setup description request and association objects provide a simple and user-friendly way to switch multimedia channels during a session. The only action the user needs to perform is to trigger one user input 14 to select the desired new multimedia channel. The association and request object allows the user to automatically request a new channel without having to first end the current session, visit the multimedia provider's web page, and select the desired new channel there. In this way, the channel switching provided by the present invention is transparent to the user and can be completed in a very short time compared to conventional channel switching solutions available in unicast systems.

An example of session setup explanatory information according to the present invention written in SMIL is shown below, but the present invention is not limited thereto.

&lt;? xml version = "1.0"?&gt; &lt;! DOCTYPE smil PUBLIC "-// W3C // DTD SMIL 2.0 // EN" "http://www.w3.org/2001/SMIL20/SMIL20.dtd"&gt; &lt;smil xmlns = "http://www.w3.org/2001/SMIL20/Language"&gt; &lt;head&gt; &lt;meta name = "title" content = "SMIL TV" /&gt; &lt;meta name = "author" content = "Torbjorn Einarsson" /&gt; &lt;layout&gt; &lt;root-layout id = "SMIL_TV" backgroundColor = "gray" width = "176" height = "200" /&gt; &lt;region id = "video" left = "0" width = "176" height = "144" /&gt; &lt;region id = "prog" left = "0" top = "144" width = "176" height = "18" /&gt; &lt;region id = "ctrl1" left = "0" top = "164" width = "88" height = "18" /&gt; &lt;region id = "ctrl2" left = "88" top = "164" width = "88" height = "18" /&gt; &lt;region id = "ctrl3" left = "0" top = "182" width = "88" height = "18" /&gt; &lt;region id = "ctrl4" left = "88" top = "182" width = "88" height = "18" /&gt; &lt;/ layout&gt; &lt;/ head&gt; &lt;body id = "SmilTV"&gt; &lt;par id = "ImageTextAudio" dur = "indefinite"&gt; &lt;video region = "video" src = "rtsp: //smiltv.com/j09184j0ajk.sdp" /&gt; &lt;a href = "http://smiltv.com/ch/j09184j0ajk/1.txt" target = "prog" accesskey = "1"&gt; &lt;text region = "ctrl1" src = "http://smiltv.com/ch1.txt" /&gt; &lt;/a&gt; &lt;a href="http://smiltv.com/ch/j09184j0ajk/2.txt" target="prog" accesskey="2"&gt; &lt;text region = "ctrl2" src = "http://smiltv.com/ch2.txt" /&gt; &lt;/a&gt; &lt;a href="http://smiltv.com/ch/j09184j0ajk/3.txt" target="prog" accesskey="3"&gt; &lt;text region = "ctrl3" src = "http://smiltv.com/ch3.txt" /&gt; &lt;/a&gt; &lt;a href = "http://smiltv.com/ch/j09184jOajk/4.txt" target = "prog" accesskey = "4"&gt; &lt;text region = "ctrl4" src = "http://smiltv.com/ch4.txt" /&gt; &lt;/a&gt; &lt;/ par&gt; &lt;/ body&gt; &lt;/ smile&gt;

The program code (lines 5 to 18 of the program code) in the above headfield belongs to the multimedia object and defines the multimedia session window 20. The root layout field defines the title area 28 of the session window 20. This is followed by fields that define the multimedia display area 22, the information area 26, and the channel area 24. The video domain field contains the RTSP URI that initiates an RTSP (Real Time Streaming Protocol) session.

Subsequent lines of code define the association and request objects of the invention. In this schematic program code example, four multimedia channels are available from the multimedia provider "SMIL TV". The accesskey command provides an association between the four links listed and the four keys 14 numbered 1 to 4 on the user terminal 10. For each multimedia channel, a link (http://smiltv.com/chX.txt (X = 1 ~) to the source of the multimedia provider that provides the icon or information about the channel displayed in the channel area 24. 4)) exists.

The link used in the examples should include both the identifier of user terminal 10 and the identifier of the associated multimedia channel, i.e. in the form http://smiltv.com/ch/userID/channelID.txt. Is generated in. The user terminal identifier is further used in the RTSP URI that initiates the RTSP session.

According to the present invention, it is considered that the session setup explanatory information may be generated in a language other than SMIL. Other possible languages include hypertext markup language (HTML) and extended markup language (XML). The session setup description information may be based on Java®, such as the format of a Java® midlet or applet. Further possible examples include explanatory information based on the Session Initiation Protocol (SIP) and Message Session Relay Protocol (MSRP).

Referring again to FIG. 1, when the multimedia provider generates the multimedia session setup explanatory information of the present invention, in step S4, the multimedia provider transmits the explanatory information to the requesting user terminal. At the user terminal, the contained objects are processed. Subsequently, in step S5, the multimedia provider provides the user terminal to display the multimedia data of the requested channel in the multimedia display area of the session window. At this point the session was set up and started. The method disclosed in the flowchart of FIG. 1 ends.

According to the present invention, the multimedia data displayed in the multimedia display area after the start of a session is generally considered to be the requested multimedia channel data. In another embodiment, the session setup description information is configured to display on the user terminal the default channel selected by the multimedia provider when processed. Such default channels can include, for example, a short description of available services and channels, a short explanatory video of how to perform a session, and the like. Once the session is set up, the user can switch to the desired multimedia channel at any time.

FIG. 3 is a flowchart showing additional steps to the flowchart of FIG. These steps are performed during a running multimedia session, and especially during channel switching. This method continues from step S5. In the next step S10, the multimedia provider listens for the channel switching request from the user terminal. Providers preferably continuously listen for such requests for immediate processing upon receipt. From the user's point of view, if the channel switching time is not important, periodic or intermittent switching request waiting or detection may be adopted.

As fully described above, when the user triggers or activates a user input associated with a desired new channel, the channel switching request according to the present invention is made by the user via the association object and the request object of the session setup description information. Generated (automatically) by the terminal. The channel switching request may be in the form of an HTTP request sent to the multimedia provider. The requesting user terminal identifier allows the multimedia provider to identify the current multimedia session and the provider to identify the port on which new multimedia data should be sent. The request channel identifier is used to identify the multimedia source from which new multimedia data should be retrieved. Since the actual channel switching of the present invention, which is described in more detail below with reference to FIG. 8, is performed during the running session, there is no need to disconnect the (RTSP) session or perform a new setup.

Further, the switching is preferably performed in a manner transparent to the user terminal. This means that the multimedia data is transmitted to the user terminal as a continuous multimedia data stream. The first part of this stream contains the multimedia data of the previous channel and the subsequent second part of the stream contains the multimedia data of the newly requested channel. To further support this seamless and transparent channel switching, all data packets, including packets containing multimedia data from the previous channel and packets containing data from the new channel, have consecutive sequence numbers and / or timestamps. The multimedia provider renumbers (renumbers) the sequence number and sets the time stamp for the data packet transmitted in the multimedia stream.

In the next step S12, the multimedia data of the new channel is provided to the user terminal for display in the multimedia display area of the session window. The multimedia provider continues to wait for possible new channel switching from the user terminal in step S10.

FIG. 4 shows additional steps preferably performed by the multimedia providers of the present invention during channel switching. This method continues from step S11. In the next step S20, the multimedia provider renumbers the data packets of the new channel after channel switching so that the sequence of data packets of the multimedia session has continuous sequence numbering. This principle is shown in more detail in FIGS. 9 and 10. In FIG. 9, the data packets 401 to 404 are delivered from the multimedia provider to the user terminal (not shown) in the form of the data stream 400. In the figure, the multimedia provider is schematically shown as channel switch 130. The data packets 401 to 404 are generated from a predetermined multimedia source 210 representing the first multimedia channel according to the present invention. In this example, the channel switch 130 can access two possible data sources 210, 220, thus providing two different multimedia channels to the connected user terminal. In FIG. 9, the first stream 410 of the data packets 405 to 408 is received from the first data source 210, and the second stream 420 of the data packets 421 to 424 is similarly from the second source 220. Received. Note the contiguous sequence numbers of data packets 401-408 and 421-424 in different streams 400, 410, 420. In the figure, the data packets 401 to 408 transmitted from the first data source 210 have the first sequence numbering in the range DP33 to DP40. Data packets 421-424 of the second source 220 have a second different sequence numbering of DP11-DP14. In FIG. 10, a request for channel switching from the first multimedia channel to the second multimedia channel is received from the user terminal. This is the data stream 40 output from the channel switch 130. 0 means that the data packets 405 to 407 of the previous multimedia channel and the data packets 424 of the newly selected channel are included first. Channel switch 130 so that data packets 405-407, 424 exiting switch 130 and transmitted to the same user terminal have consecutive sequence numbering to provide the user terminal with a continuous multimedia data stream 400. Renumbers data packet 424. This means that the data packet 424 of the new channel is renumbered from DP14 to DP40 and maintains a contiguous numbering. Sequence renumbering continues for the remaining data packets 425-428 of the new channel. Since the data packets 409 to 413 of the previous source are not transmitted to the current user terminal, it is not necessary to renumber those data packets for the current session.

In the next step S21 of FIG. 4, the multimedia provider assigns a time stamp to the data packet of the multimedia stream and acquires a stream of the data packet having a continuous time stamp during and after the channel switching. A procedure similar to the sequence numbering disclosed in connection with FIGS. 9 and 10 can be used for time stamping of data packets.

As is well known in the prior art, multimedia data may be in the form of video and audio data. A multimedia channel that provides a multimedia stream is believed to provide a video stream that includes data packets that contain video data, and an audio stream that contains data packets that contain audio data. In such a case, in order to obtain continuous sequence numbering and time stamping of video data packets and audio data packets, the sequence numbering and time stamping according to the present invention is performed on both data streams. Is preferable. In order to avoid deterioration during audio reproduction on the user terminal, it is preferable that the amount of increase in the time stamp for the audio packet is kept constant even when the channel is switched. This causes a slight time displacement between the input time and the output time. The time stamping of video packets is adjusted as well, but based on the audio time stamping to maintain synchronization. In this situation, the audio data is the master and should be switched before the video data. In summary, the multimedia provider assigns a time stamp to an audio data packet so that the audio data stream has a contiguous time stamp, and assigns a time stamp to the video data packet based on the time stamp assignment to the audio data packet.

Therefore, to minimize the impact on the user terminal, the multimedia provider includes a header with a fixed payload type (ptype) and synchronization source (ssrc) in addition to consecutive sequence numbers and time stamps (real time). Forwarding Protocol (RTP)) Data Packet Output Multimedia (RTP) streams can be created. The use of fixed or constant ssrc gives the user terminal the impression that data packets are transmitted as one continuous data stream, even though channel switching has actually been performed. The multimedia provider generates its own real-time transfer control protocol (RTCP) flow and confirms that the synchronization information in the RTCP sender report shows that the streams appear to be continuous during multimedia channel switching. You can also do it.

However, let the multimedia provider change one or more fields, for example by changing the ssrc value or by adding an optional contributing source (csrc) field that changes depending on the multimedia channel. , It is also possible to indicate to the user terminal that the content will be transmitted from the new source.

Then, the process proceeds to step S12 in FIG. In step S12, the multimedia data of the new channel is delivered to the user terminal.

FIG. 5 is a schematic view showing a unicast wireless communication system 1 according to an embodiment of the present invention. Communication system 1 basically includes multimedia provider 100. The multimedia provider 100 provides multimedia services and data to the user terminal 10 via the operator network 300 or other wired or wireless network. The multimedia provider 100 includes or has access to the multimedia source 200 as shown. The multimedia source 200 includes, produces, or provides multimedia data from different channels 210, 220. In the illustrated example, the multimedia provider 100 is disclosed as including three different units: an application server 110, a streaming server 120, and a channel switch 130. When the function of the multimedia provider is divided into different (internal) units in this way, it is preferable that the application server 110 is responsible for receiving the channel request and the channel switching request from the user terminal 10. Further, the application server 110 generates and transmits session setup explanatory information as part of the session setup procedure. The actual session setup negotiation is usually performed between the user terminal 10 and the streaming server 120. During the running session, the server 120 also delivers multimedia data from the channel switch 130 to the user terminal 10. As the name implies, channel switch 130 switches multimedia channels in response to commands received from application server 110. In this channel switching, multimedia data from the new multimedia channels or sources 210, 220 is delivered to the streaming server 120 for transfer to the user terminal 10 over the network 300.

FIG. 5 should be understood as merely an example of the communication system 1 according to the present invention, and other system layouts are possible within the scope of the present invention. For example, the number of multimedia channels 210, 220 available is not necessarily two, but may be any number, i.e. at least two channels 210, 220. Further, the multimedia provider 100 may be composed of one central unit or a distributed unit, and handles the operations of the application server 110, the streaming server 120, and the channel switch 130. Alternatively, the multimedia provider 100 may include more or fewer internal units. This is schematically shown in FIG.

In FIG. 6, the streaming server is omitted and the channel switch 130 transfers multimedia data directly to the user terminal 10 via the (operator) network 300. As briefly described above, the multimedia provider 100 can include more units, such as a unit responsible for charging for the multimedia services provided. Alternatively, such billing units are provided elsewhere, for example as part of the operator network infrastructure 300.

FIG. 7 is a schematic signal diagram showing a portion of the data signaling performed during the setup and actual running session of the multimedia session according to the present invention. In this signal diagram, a communication system layout as shown in FIG. 5 is assumed, but those skilled in the art will appreciate that the principle is applicable to other system layouts with minor non-inventional changes. Clearly understood.

In FIG. 7, a multimedia channel, such as a mobile TV channel, is composed of a live engine or channel source that generates and transmits RTP packets containing multimedia or media content. The channel switch preferably creates two RTP streams or sessions for each channel. One of them is for video data and the other is for audio data. Each RTP session preferably handles the actual media data transfer, i.e. RTP traffic, and the control data transfer, i.e. RTCP traffic. As a result, four ports are typically assigned to each channel. In the prior art, it is common to start with video data of a port number in which four port numbers are consecutive and the remainder after dividing by 4 is equal to 0. Typical examples are port number 10000 for video RTP, 10001 for video RTCP, 10002 for audio RTP, and 10003 for audio RTCP. Usually, the various channels are identified by the RTP video port number.

The available multimedia data (video and audio RTP / RTCP) is delivered continuously to the channel switch, and each multimedia data stream or channel has a unique identifier such as the video RTP port number.

The user wants to watch, for example, a television program on a mobile phone, a personal digital assistant (PDA), or a user terminal that may be another (mobile) communication terminal. The user uses the user terminal to enter the web page of the application server and usually clicks a link to the desired TV program. By clicking the link, a channel request such as a channel request using HTTP is sent to the application server. The server provides a (unique) identifier for the user terminal. The provision of the identifier is recognized, for example, by receiving the terminal identifier from the user terminal along with the channel request. Alternatively, the application server generates the identifier itself, for example, by selecting an unused, vacant identifier from a pool of available terminal identifiers used by the application server for the connected user terminal.

The application server edits the session start command and sends it to the channel switch. This command includes the received or assigned identifier for the user terminal and the requested multimedia channel identifier. If the channel identifier is in the form of a video RTP port, the application server accesses a list or set containing the available video RTP ports. The application server identifies an appropriate channel port (identifier) based on the channel request from the user terminal.

The session start command preferably further contains information about the input port of the streaming server to which the channel switch should transfer multimedia data. As mentioned above, a multimedia channel can include four parallel data streams. This means that it is preferable that the four input ports of the streaming server be selected and notified by the application server. This further requires that the application server have access to information about the streaming server's input port numbers and keep up-to-date information about whether those input port numbers are currently in use or free.

Optionally, the channel switch responds with an acknowledgment message or an OK response.

In addition, the application server creates a Session Description Protocol (SDP) file and uploads it to the streaming server. This is a regular SDP file for livestreaming, but it is unique in two ways. The SDP file contains the identifier of the user terminal. This is recognized by including the user terminal identifier in the name, such as j09184j0ajk.spd. Here, j09184j0ajk is the assigned user terminal identifier. In addition, the SDP file preferably further contains information about the input port of the streaming server where the channel switch is instructed to send an RTP stream containing multimedia data. Optionally, the streaming server responds with an acknowledgment message.

The application server generates and transmits the multimedia session setup explanatory information of the present invention to the user terminal after or before or at the same time as the previous control data exchange. Unless provided by the terminal itself, the setup description information preferably includes a user terminal identifier created or selected by the application server. As fully described above, this setup description information is a request instruction required by a user terminal to provide multimedia to the user and enable user-friendly and efficient channel exchange of the present invention. It is preferably the complete descriptive information of the object and the information. The user terminal and the streaming server negotiate and execute the RTSP session setup according to the prior art. The user terminal processes the received session setup description information, displays the multimedia session window on the display screen, and activates the association between user input such as keys and identifiers of other available multimedia channels. ..

In addition, the channel switch delivers the requested RTP stream to the input port of the streaming server selected by the application server. In addition, the user terminal identifier is transmitted to the server so that the streaming server can identify the user terminal (input port) to which the multimedia data should be transferred. The RTP stream does not need to include the user terminal identifier if, for example, the streaming server receives it first from the application server and already has that information. Finally, the streaming server transfers the received multimedia (RTP) stream to the user terminal for display in the session window and for playback on the user terminal speaker (see speaker 16 in FIG. 2). Session setup is complete at this point and multimedia rendering and playback is initiated on the user terminal.

During a running session, the user terminal can send an update request to the application server with the terminal identifier periodically, intermittently, or at a predefined time. These update requests are used by the application server as a confirmation that the multimedia session is still active. In addition, when responding to an update request, the application server can send an object of setup instruction information and new information used by the user terminal to update the multimedia session window. For example, the actual TV program or movie transmitted on a given multimedia channel can be changed in time. Therefore, the update response may include information input in the title area of the multimedia session window. Further, the identifier or icon of another channel displayed in the channel area may change over time, especially if the identifier corresponds to a TV program or movie currently available on another channel. Also, the number of available channels can change during multimedia sessions. In such cases, the update response may include a new channel identifier (link) and icon for display in the channel area and for association with one user input on the terminal.

FIG. 8 is a continuation of the signal diagram of FIG. 7 and shows data signaling during channel switching and at the end of a session. The terminal user wants to watch another TV program or movie and triggers the terminal user input associated with the desired multimedia channel. The request object for setup instructions information generates a channel switching request that is sent to the application server. This request includes a user terminal identifier used by the application server to identify a running multimedia session. In addition, the request contains information that allows the server to identify a new multimedia channel. This channel information may be, for example, the port number of the RTP video port for a multimedia channel. Alternatively, the channel information is other information such as the name / title of the channel or program / movie currently displayed on the channel. The application server preferably identifies the relevant RTP video port for the new channel based on that information.

The application server preferably performs port mapping based on the information in the switch request. The application server identifies the streaming server input port assigned to the current user terminal. The server edits the channel switch command and sends it to the channel switch. The command contains information about the new multimedia channel, preferably the RTP video port for that channel. In addition, the command can include a user terminal identifier so that the channel switch can identify the input port of the streaming server to which the multimedia data for the new channel will be sent. Alternatively, or in addition, the application server sends information about the server input port directly to the channel switch. Optionally, the switch responds with an acknowledgment message.

As mentioned above, the channel switch performs sequence number renumbering and timestamp assignment for multimedia (video and audio) data packets and is a contiguous multimedia data stream (usually this is four parallels). It is preferable to form a stream). In a preferred embodiment, the channel switch sets or adds an ssrc value to the data packet to give the impression that the data packet is part of one continuous data stream. In this situation, the ssrc field of the data packet header preferably has the same ssrc value. The renumbered, time stamped, and ssrc-modified RTP stream data packets are preferably sent along with the user terminal identifier to the notified streaming server input port. The server transfers the data of the new channel to the user terminal.

As described above, the channel switching according to the present invention is completely transparent to the user terminal and the streaming server, and the user terminal and the streaming server are executing even though the channel and the source are changed. It behaves as if the multimedia stream of a session originates from a single multimedia source.

When the user wants to end the session, the user terminal sends a session stop message to the application server together with the user terminal identifier. The application server generates a session stop command including the terminal identifier and forwards it to the channel switch. This switch removes the current user terminal from the list of currently active sessions and user terminals. An optional acknowledgment is returned to the server that forwards the session end response to the user terminal. The RTSP session ends according to conventional signaling (the terminal sends an RTSP disconnect message to the streaming server and a response message in the opposite direction).

As is clear from the above discussion and further shown in FIGS. 7 and 8, the user terminal identifier is not only adopted as the identifier of a particular user terminal, but also the current multimedia session involving that user terminal. Is preferably adopted by application servers, channel switches, and streaming servers to identify.

FIG. 11 is a schematic block diagram showing a possible implementation example of the multimedia provider 100 according to the embodiment of the present invention. In the illustrated embodiment, the multimedia provider 100 comprises an application server 110 and a channel switch 130 (compared to FIG. 6).

The application server 110 includes a general purpose input / output (I / O) unit 111 that manages communication with external units. This I / O unit is specifically adapted to receive channel and channel switching requests from user terminals that are or are about to participate in a multimedia session with the multimedia provider 100. Further, the I / O unit 111 transmits the session setup explanatory information according to the present invention to the user terminal in response to the channel request. The I / O unit 111 also includes all internals between the application server 110 and the channel switch 130, including session start commands and responses, SDP messages and responses, channel switching commands and responses, and session end commands and responses. Manage communications. Any communication with the user terminal during the running session, such as update request and response, is also performed via the I / O unit 111.

The application server 110 further includes an identifier provider 112 that provides an identifier for the user terminal in response to a channel request from the user terminal. In the first embodiment of the present invention, the identifier provider 112 searches for a terminal identifier from a channel request from a user terminal. This means that the terminal identifier used is set and assigned to the user terminal, another network unit, or other network operator. In another embodiment, the application server 110 accesses, for example, a pool of user terminal identifiers stored in database 115. The identifier provider selects one of the identifiers currently not adopted by any other user terminal and uses it for the current user terminal. Other solutions for generating and providing terminal identifiers can be performed by provider 112 and are within the scope of the present invention. Further, the identifier provider 112 is preferably configured to search for the terminal identifier from other messages generated from the user terminal, such as a channel switching request, an update request, and a session end request.

The setup description information generator or engine 113 is implemented in the application server 110 to generate the multimedia session setup description information of the present invention based on the channel request received by the I / O unit 111. This setup description information includes pre-defined multimedia objects, association objects and request objects that can be processed by the user terminal. The setup description information is edited in any of the above languages. The generator 113 generates setup explanatory information based on the channel request from the user upon request. This means that once the multimedia object of the setup description information has been processed in the terminal, it is preferably initiated by rendering the multimedia data of the requested channel as soon as the session is set up. .. Further, the generator 113 preferably receives the user terminal identifier from the identifier provider 112 and uses it in generating the setup instruction information. The completed setup explanation information is transmitted to the user terminal by the I / O unit 111.

The Application Server 110 Description Information Generator 113 or other units can use the I / O Unit 111 to generate and send relevant updates to be displayed in the session window of the user terminal.

The message engine 116 of the application server 110 generates various control messages sent to the channel switch 130 and the user terminal during the setup procedure, during the running session, and at the end of the session. Typically, the message engine 116 is adapted to include the user terminal identifier (from identifier provider 112) in the generated message.

Upon receiving the channel switching command from the user terminal, the message engine 116 edits the channel switching command including the user terminal (session) identifier and the new channel, and sends it to the channel switch.

The channel switch 130 also has an I / O unit 131 that communicates with an application server 110, a user terminal, and any other related external unit. In this embodiment, the session negotiator 134 is provided to the channel switch 130, or at least some functions of the negotiator 134 are implemented in the application server 110. The negotiator 134 performs the necessary communication with the user terminal to set up a multimedia (RTSP) session. The operation of the negotiator 134 follows the prior art and is not described further herein.

The switch 130 includes a channel source selector 133 that selects multimedia sources 210, 220, and multimedia data is transmitted from the multimedia sources 210, 220 to a user terminal. Source selector 133 receives information from application server 110 (message engine 116) that identifies the associated multimedia sources 210, 220, typically in the form of RTP video stream port numbers for sources 210, 220. .. The I / O unit 131 transfers the multimedia data from the selected connected multimedia sources 210, 220 to the user terminal for rendering to the multimedia display area and, if possible, for playback on the speaker.

The channel switch 130 preferably further includes a list identifying user terminals currently receiving multimedia data from different media sources 210, 220. Units / modules (not shown) that manage and update the list are preferably included in switch 130.

Upon receiving the channel switching command from the message engine 116 of the application server 110, the source selector 133 identifies new channel sources 210, 220 to be selected and used for the user terminal. To provide a continuous seamless output stream (actually some parallel streams), the data packets from the new sources 210, 220 are the packets that manage the multimedia stream, first implemented on channel switch 130. It passes through the renumbering unit 132. The renumbering unit 132 is configured to renumber data packets, in particular during and after channel switching, to form consecutive sequence numbers. Further, it is preferable that the packet renumbering unit 132 assigns a time stamp to the multimedia data packet to make the channel switching more seamless. The packet renumbering unit 132 can also add or change the ssrc value of the data packet. Further, the terminal list of the channel switch 130 is updated after the channel is switched.

Units 111 to 113, 116, 131 to 134 of the application server 110 and the channel switch 130 of the multimedia provider 100 may be provided as software, hardware, or a combination thereof. Units 111 to 116 of the application server 110 may be implemented together in one network node. It is also possible to have a decentralized implementation in which several units are provided to different network nodes. Units 131 to 134 of the channel switch 130 may be mounted together on one network node. It is also possible to have a decentralized implementation in which several units are provided to different network nodes. According to the present invention, the application server 110, the channel switch 130 and the multimedia sources 210, 220 may all be configured together in a single network node or may be provided to different network nodes in a unicast communication system. The good is further understood.

FIG. 12 is a schematic block diagram showing a possible implementation of the multimedia provider 100 according to another embodiment of the present invention. In the illustrated embodiment, the multimedia provider 100 comprises an application server 110, a streaming server 120, and a channel switch 130 (compared to FIG. 5).

The operations of the I / O unit 111 of the application server 110, the identifier provider 112, the explanatory information generator 113 and the message engine 116, and the I / O unit 131 of the channel switch 130, the packet renumbering unit 132, and the source selector 133 are shown in the figure. It is similar to the corresponding unit described in connection with 11 and will not be repeated here.

In the present embodiment, it will be apparent to those skilled in the art that some of the messages generated by the message engine 116 will be sent to the streaming server 120 instead of being sent to the channel switch 130 as shown in FIG. .. For example, the SDP message is generated by the message engine 116 based on the SDP template stored in the database 115 and sent to the streaming server 120.

The port mapping unit 114 of the application server 110 is configured to select the input port of the streaming server and the output port of the channel switch 130 used for the streaming session with the user terminal. Information about available ports and up-to-date information about whether a port is occupied or free is preferably obtained from database 115 or other sources of information.

The streaming server 120 includes an application server 110, a channel switch 130, and an I / O unit 121 that executes communication with a user terminal. In particular, the I / O unit 121 receives multimedia data from the channel switch and transfers it to the user terminal. The session negotiator 124 is implemented on the server 120 to perform (RTSP) session setup negotiations with the user terminal. The operation of this unit is similar to the corresponding unit realized in the channel switch of FIG. 11, and no further description will be given here.

Units 111-114, 116, 121, 124, 131-134 of the multimedia provider 100 application server 110, streaming server 120, and channel switch 130 may be provided as software, hardware, or a combination thereof. .. Units 111 to 116 of the application server 110 may be implemented together in one network node. It is also possible to have a decentralized implementation in which several units are provided to different network nodes. Units 121 and 124 of the streaming server 120 may be implemented together on one network node. It is also possible to have a decentralized implementation in which several units are provided to different network nodes. Units 131 to 134 of the channel switch 130 may be mounted together on one network node. It is also possible to implement a decentralized implementation in which several units are provided to various network nodes. According to the present invention, the application server 110, the streaming server 120, the channel switch 130, and the multimedia sources 210, 220 may all be implemented together in a single network node, or different network nodes in a unicast communication system. It is further understood that it may be provided to.

FIG. 13 is a schematic block diagram showing a user terminal 10 that realizes one aspect of the present invention. The user terminal 10 includes an I / O unit 11 that communicates with a multimedia provider (application server and streaming server, or application server and channel switch). This I / O unit 11 is specifically adapted to send channel requests and channel switching requests to the application server. Further, the I / O unit 11 receives the multimedia session setup explanatory information of the present invention from the application server and, of course, the multimedia data from the streaming server or the channel switch.

The user terminal 10 further includes a multimedia or media player 18 that renders the received multimedia data. The multimedia player 18 preferably communicates with the display screen 12 and speakers of the terminal 10 in order to display and play media on the terminal 10. The media player 18 further includes a processor that processes the multimedia objects provided in the received setup instruction information. By processing this multimedia object, the multimedia session window is displayed on the connected display screen 12. This is clearly shown in Figure 2. The object processor 13 preferably processes the update information received from the multimedia provider and adapts the display session window based on the new update information.

The association object processor 15 processes the association object of the setup description information and between another available channel, identifier, or icon displayed in the channel area of the multimedia session window and the user input 14 of the terminal. It is configured to provide bindings or associations.

The request processor 19 is implemented in the user terminal 10 to generate a channel request and a channel switching request. The processor 19 is preferably configured to access a multimedia provider's web page, download session setup instructions for the present invention, and select the desired multimedia channel. The request object processor 17 is implemented in the request processor 19 to generate a channel switching command. When one of the user inputs 14 (keys) of the terminal 10 is triggered by the user, the processor 17 receives the input information. The request object includes the channel identifier in the channel switching message through the association between the user input 14 and the requested channel identifier, as enabled by the association object processor 15. In addition, the identifier of the user terminal is included in the switching message.

The user terminal identifier is assigned by the multimedia provider and is received from that multimedia provider. In such a case, the identifier is stored in the storage location 30 of the terminal. For other types of identifiers, the identifier source 30 may be a unit of a type other than memory, such as a subscriber identification module (SIM).

Units 11, 13, 15, 17-19, 30 of the user terminal may be provided as software, hardware or a combination thereof. The multimedia object processor 13 is implemented in the multimedia player 18 as shown or implemented elsewhere in the terminal 10. Similar principles apply to the request object processor 17 and the request processor.

Those skilled in the art will appreciate that various modifications and modifications may be made to the invention without departing from the scope of the invention as defined by the appended claims.

<figref num="1">It is a flowchart which shows the method of setting up a multimedia session according to this invention.</figref><figref num="2">It is the schematic which shows the user terminal which displays the multimedia session window according to this invention.</figref><figref num="3">FIG. 6 is a flow chart illustrating additional steps in the method of FIG. 1 that provides multimedia channel switching during a multimedia session.</figref><figref num="4">It is a flowchart which shows the additional step of the method of FIG.</figref><figref num="5">It is a schematic diagram which shows one Embodiment of the communication system which concerns on this invention.</figref><figref num="6">It is a schematic diagram which shows another embodiment of the communication system which concerns on this invention.</figref><figref num="7">It is a signal diagram of the multimedia session setup which concerns on one Embodiment of this invention.</figref><figref num="8">It is a signal diagram of multimedia channel switching and multimedia session disconnection which concerns on one Embodiment of this invention.</figref><figref num="9">It is a figure which shows schematic renumbering of the data packet during channel switching which concerns on this invention.</figref><figref num="10">It is a figure which shows schematic renumbering of the data packet during channel switching which concerns on this invention.</figref><figref num="11">It is a block diagram which shows roughly one Embodiment of the network unit including the multimedia session setup and management composition which concerns on this invention.</figref><figref num="12">FIG. 5 is a block diagram schematically showing another embodiment of a network unit including a multimedia session setup and management configuration according to the present invention.</figref><figref num="13">It is a block diagram which shows schematic the user terminal which concerns on this invention.</figref>