Remote Media IMS Sessions

CROSS-REFERENCE TO RELATED APPLICATIONS

0001This application claims the benefit of U.S. Provisional Application No. 61/099,827, filed on Sep. 24, 2008, entitled “A Method for Setting up Sessions with Media on the Device Controlling the Session and/or a Different Device,” U.S. Provisional Application No. 61/100,111, filed on Sep. 25, 2008, entitled “A Method for Setting up Sessions with Media on the Device Controlling the Session and/or a Different Device,” U.S. Provisional Application No. 61/086,504, filed on Aug. 6, 2008, entitled “Remote Session control,” which applications are hereby incorporated herein by reference.

0002This application relates to the following co-pending and commonly assigned patent application: Ser. No. 12/483,981 (Attorney Docket No. HW 08FW108), filed Jun. 12, 2009, entitled “Remote Session Control,” which application is hereby incorporated herein by reference.

TECHNICAL FIELD

0003The present invention relates generally to telecommunications and, more particularly, to a system and method for remote session control of IP Multimedia Subsystem (IMS) sessions.

BACKGROUND

0004As mobile devices improve and include more enhanced capabilities, mobile devices have evolved to act as Internet Protocol (IP) devices. One such system, e.g., a system employing IP Multimedia services (IMS) sessions, is illustrated in <figref idref="DRAWINGS">FIG. 1</figref>, wherein a traditional signaling or bearer architecture for a local media session is illustrated. The traditional IMS session is created between a User Equipment (UE) <b>102</b> and a remote end <b>104</b>, thereby enabling the UE <b>102</b> to access media flows, such as media flow <b>106</b>. The standard IMS signaling flow, illustrated in <figref idref="DRAWINGS">FIG. 1</figref> by the dotted line <b>108</b>, extends between a Call Session Control Function (CSCF) <b>110</b>, a Service Centralization Continuity Application Server (SCC AS) <b>112</b>, and a Telephony Application Server (TAS) <b>114</b> (and/or other application servers).

0005Generally, the CSCF <b>110</b> processes session initiation protocol (SIP) signaling packets in the IMS system, and the application servers host and execute a variety of services. In one embodiment, the SCC AS <b>112</b> operates in a Back-to-Back User Agent (B2BUA) mode wherein it acts as an SIP element to mediate SIP signaling between the UE <b>102</b> and the remote end <b>104</b>. In the embodiment illustrated in <figref idref="DRAWINGS">FIG. 1</figref>, the SCC AS <b>112</b> establishes an access leg using IMS procedures between the SCC AS <b>112</b> and the CSCF <b>110</b> on the UE <b>102</b> side and establishes a remote leg using IMS procedures to the CSCF <b>110</b> on the remote end <b>104</b> side. Other application servers, such as the TAS <b>114</b> illustrated in <figref idref="DRAWINGS">FIG. 1</figref>, may be executed on the remote leg as part of standard service execution logic at the CSCF <b>110</b>.

0006The result of an IMS session established as discussed above is a media flow <b>106</b> and a session control signaling flow <b>108</b> established between the UE <b>102</b> and the remote end <b>104</b>. Unfortunately, however, the media flow <b>106</b> and the session control signaling flow <b>108</b> are tied to the same device, thereby not allowing the media flow <b>106</b> to be sent to a different device or controlled by a different device. For example, if a user is interested in watching a video, current implementations require that the media flow <b>106</b>, e.g., the video, be sent to the same device, e.g., a wireless telephone, as is controlling the video. Moreover, when a media flow <b>106</b> is transferred to another device, both the session control signaling flow <b>108</b> and the media flow <b>106</b> are transferred to the same device. This situation is not always convenient or desired by the user, who may want to control the media flow <b>106</b> via one device, but watch the video on a different device, such as a computer monitor or television.

0007Furthermore, some IP devices are stationary, such as hardware IP phones, video-conferencing units, embedded devices, and the like. While these IP devices may be stationary, these IP devices may allow more convenience of use and additional capabilities than other more mobile IP devices, but maintain session control on the mobile IP device. As a result, it may be desirable to separate the media flow from the session control signaling flow.

0008Thus, there is a need for a method and system that allows the media flow to be controlled by a separate device, thereby allowing the moving of active multimedia sessions between IP devices to allow mobile and stationary devices to be used concurrently or interchangeably in mid-session, combining their advantages into a single “virtual device.”

SUMMARY OF THE INVENTION

0009These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by preferred embodiments of the present invention which provides for remote session control for IMS sessions.

0010Generally, embodiments of the present invention provides a system, comprising various methods and apparatuses, for remote session control of IP Multimedia Subsystem (IMS) sessions, wherein media is established using one or more devices, and multi-media session/session control for a multi-media session is provided by a device which may or may not be the same as the device on which media is established. The session/session control may also be transferred to another device while retaining one or more media flows on the original device.

0011For example, in an embodiment of the present invention, an IMS session is originated such that a remote media is established on a remote media UE and the originating UE provides session control, i.e., it serves as the controller UE. The originating device remains the controller device. A local media may also be originated locally on the controller UE.

0012In another embodiment of the present invention, a remote media session is established as part of terminating an IMS session. The controller UE receives an origination request and in response requests that a remote media flow on a remote media UE be established, such that the controller UE maintains session control. A local media flow may also be established on the controller UE.

0013In yet another embodiment of the present invention, the session control is transferred from original device to a (new) controller UE. In this embodiment, zero or more media flows may be transferred to the new controller UE and one or more media flows may remain with the original device, which assumes the role of a controlee UE, resulting in creation of a of a remote media flow.

BRIEF DESCRIPTION OF THE DRAWINGS

0014For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:

0015<figref idref="DRAWINGS">FIG. 1</figref> depicts a signaling or bearer architecture for a prior art system;

0016<figref idref="DRAWINGS">FIG. 2</figref> depicts a signaling or bearer architecture for a remote media session according to one embodiment of the present invention;

0017<figref idref="DRAWINGS">FIG. 3</figref> is a signaling architecture diagram for originating a remote media session in accordance with an embodiment of the present invention;

0018<figref idref="DRAWINGS">FIG. 4</figref> is a message flow diagram for originating a remote media session in accordance with an embodiment of the present invention;

0019<figref idref="DRAWINGS">FIG. 5</figref> is a signaling architecture diagram for originating a local media session and remote media session in accordance with an embodiment of the present invention;

0020<figref idref="DRAWINGS">FIG. 6</figref> is a message flow diagram for originating a local media session and remote media session in accordance with an embodiment of the present invention;

0021<figref idref="DRAWINGS">FIG. 7</figref> is a signaling architecture diagram for terminating a remote media session in accordance with an embodiment of the present invention;

0022<figref idref="DRAWINGS">FIG. 8</figref> is a message flow diagram for terminating a remote media session in accordance with an embodiment of the present invention;

0023<figref idref="DRAWINGS">FIG. 9</figref> is a signaling architecture diagram for terminating a local media session and a remote media session in accordance with an embodiment of the present invention;

0024<figref idref="DRAWINGS">FIG. 10</figref> is a message flow diagram for terminating a local media session and a remote media session in accordance with an embodiment of the present invention;

0025<figref idref="DRAWINGS">FIGS. 11</figref><i>a </i>and <b>11</b><i>b </i>are signaling architecture diagrams illustrating a transfer of the session control from one device to another device in accordance with an embodiment of the present invention;

0026<figref idref="DRAWINGS">FIG. 12</figref> is a message flow diagram for transferring the session control from one device to another device in accordance with an embodiment of the present invention; and

0027<figref idref="DRAWINGS">FIG. 13</figref> is a block diagram of a network element in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

0028The making and using of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention.

0029IMS sessions such as those described above with reference to <figref idref="DRAWINGS">FIG. 1</figref> in which the session control signaling flow and the media flow (and the media control flow) are all transferred to a transferee device are referred to herein as a Release Control Mode (RCM). In contrast, embodiments of the present invention utilize an IMS session in which the session control signaling and the media control/media flow are separated such that the session control signaling is maintained by one UE, and the media and media control is maintained by a different UE. A session controlled by a UE that is the same as the UE controlling a media flow is referred to as a local media session, and a session controlled by a UE that is different from a UE controlling a media flow is referred to as a remote media session. Generally, as one of ordinary skill in the art will realize, embodiments of the present invention provide a singular virtual session comprising of session control and media provided by two or more devices with the linkage and association amongst the remote media and associated session control provided through IMS SIP signaling.

0030Referring now to <figref idref="DRAWINGS">FIG. 2</figref>, a signaling and bearer architecture that may be utilized with embodiments of the present invention is illustrated. In this embodiment, a remote media flow <b>202</b>, such as a voice and/or video, is established to one or more remote media UE<b>1</b>-UEn, while session control is established with a controller UE <b>206</b> via a session control signaling path <b>204</b>. A remote media control signaling path <b>208</b>, which provides the necessary signaling for the transmission of the remote media flow <b>202</b>, is also established with the remote media UE<b>1</b>-UEn. A remote media flow may be established by using IMS session procedures as described herein.

0031As illustrated in <figref idref="DRAWINGS">FIG. 2</figref>, the SCC AS <b>112</b> combines the session control signaling communicated over the session control signaling path <b>204</b> with the media control signaling communicated over the remote media control signaling path <b>208</b>. For B2BUA at the SCC AS <b>112</b> in <figref idref="DRAWINGS">FIG. 2</figref>, an access leg may be formed with a combination of the session control signaling path <b>204</b> and the remote media control signaling path <b>208</b> for representation of a remote media component. A remote leg is presented by the SCC AS <b>112</b> to the CSCF <b>110</b> as an IMS session. The TAS <b>114</b> (and/or other application servers) may be executed on the remote leg as part of standard service execution logic at the CSCF <b>110</b>. Optionally, the controller UE <b>206</b> may also have a local media flow <b>210</b>.

0032It should be noted that other network elements, such as routers, gateways, switches, and/or the like, may be present within the network. The configurations and the communications between network elements is provided for illustrative purposes only, and as such, the communications between the specified elements may be between different elements and/or through additional elements as well as different signaling/commands may be used.

0033As discussed in greater detail in the following paragraphs, the general principles of the present invention may be applied to various scenarios. It should be noted that the following embodiments are provided for illustrative purposes only and are not intended to limit the scope of the present invention to only those embodiments described herein. Furthermore, it should be noted that the messages and the message parameters are provided for illustrative purposes only and that other messages and parameters may be used, as well as any suitable protocol, such as session description protocol (SDP), session initiation protocol (SIP), or the like. Additional information regarding the messages and the parameters may be found in 3GPP TR 23.838, v9.0.0 and 3GPP TS 23.237, v9.1.0, which are incorporated herein by reference.

0034Generally, the principles of the present invention may be applied to various scenarios. For example, if a local media flow (e.g., the media flow is established on the device which maintains the end user control) is to be originated by the UE, the UE sets up the local media flow using suitable mechanisms. If a remote media flow (e.g., the media flow is established on a UE different from the UE that maintains the session control) needs to be established for the session, however, the originating UE indicates in the session setup request that a remote media flow is to be established by the network, providing information necessary for the network to establish the media flow with the remote media UE in the IMS session signaling, e.g., in the SDP. The network subsequently establishes a remote media flow with the media UE to establish the media. The network combines the local media flow (if present) and the remote media flow with the session signaling from the UE for presentation as a remote leg to the remote end.

0035For session terminations, the network forwards in incoming session to the UE using suitable mechanisms. When accepting the incoming session request, if a local media flow needs to be established for the session, the UE establishes the local media flow using suitable mechanisms. If a remote media flow needs to be established for the session, the UE indicates in the session setup response that a remote media flow is to be established by the network, providing information necessary for the network to establish the remote media flow with the media UE in the IMS session signaling, e.g., in the SDP. The network subsequently sets up a remote media flow with the media UE.

0036Referring now to <figref idref="DRAWINGS">FIG. 3</figref>, a signaling architecture diagram illustrating a process for originating a remote media session is shown in accordance with an embodiment of the present invention. Initially, UE-<b>1</b> initiates a remote media session to establish a remote media flow on UE-<b>2</b> by transmitting a remote media session request as indicated by reference numeral <b>310</b> to the IMS system <b>302</b>. The IMS system <b>302</b> transmits a media session message to UE-<b>2</b> as indicated by reference numeral <b>312</b> and establishes a remote leg with the remote end <b>104</b> as indicated by reference numeral <b>314</b>. As a result, a remote media flow is established between the remote end <b>104</b> and UE-<b>2</b> as indicated by reference numeral <b>316</b>. In this situation, UE-<b>1</b> is the controller UE, and UE-<b>2</b> is the media UE.

0037It should be noted that the IMS system <b>302</b> is illustrated generically to demonstrate the concepts of this embodiment of the present invention. One of ordinary skill in the art will realize that the IMS system <b>302</b> may include several elements, including the CSCF <b>110</b> and SCC AS <b>112</b> network elements that are identified in the message flow diagrams included herein. Other components, such as various switches, routers, gateways, or the like, may also be included.

0038<figref idref="DRAWINGS">FIG. 4</figref> illustrates a message flow diagram that may be used to establish a remote media flow during origination such as that illustrated in <figref idref="DRAWINGS">FIG. 1</figref>, in accordance with an embodiment of the present invention. The process begins in step <b>402</b>, wherein UE-<b>1</b> transmits, for example, a SIP INVITE message to the CSCF <b>110</b>, which forwards the INVITE message to the SCC AS <b>112</b>. The INVITE message indicates that UE-<b>1</b> wants to initiate a remote media flow between the remote end <b>104</b> and the media UE, i.e., UE-<b>2</b> in this example. Accordingly, the INVITE message may include parameters that indicate the remote end <b>104</b> with which a remote media flow is to be established, the media UE (UE-<b>2</b>) information, and other information necessary to setup a remote media flow with the media UE.

0039In step <b>404</b>, the SCC AS <b>112</b> transmits via the CSCF <b>110</b>, for example, a SIP INVITE message to the media UE (e.g., UE-<b>2</b>), and in step <b>406</b>, the SCC AS <b>112</b> transmits via the CSCF <b>110</b>, for example, a SIP INVITE message to the remote end <b>104</b>. As a result, a remote media flow is established between the media UE-<b>2</b> and the remote end <b>104</b>. UE-<b>1</b> maintains control of the session, i.e., UE-<b>1</b> is the controller UE.

0040<figref idref="DRAWINGS">FIG. 5</figref> illustrates a similar situation as that discussed above with reference to <figref idref="DRAWINGS">FIG. 3</figref>, wherein like reference numerals refer to like elements, except that where <figref idref="DRAWINGS">FIG. 3</figref> illustrates the origination of only a remote media flow, <figref idref="DRAWINGS">FIG. 5</figref> illustrates that the controller UE establishes both a local media flow <b>502</b> as well as the remote media flow <b>316</b>.

0041<figref idref="DRAWINGS">FIG. 6</figref> illustrates a message flow diagram that may be used to establish a remote media flow and a local media flow during origination as illustrated in <figref idref="DRAWINGS">FIG. 5</figref>. The process begins in step <b>602</b>, wherein UE-<b>1</b> transmits, for example, a SIP INVITE message to the CSCF <b>110</b>, which forwards the INVITE message to the SCC AS <b>112</b>. The INVITE message indicates that UE-<b>1</b> wants to initiate a remote media flow between the remote end <b>104</b> and the media UE, i.e., UE-<b>2</b> in this example, and a local media flow between the remote end <b>104</b> and the controller UE, i.e., UE-<b>1</b>. Accordingly, the INVITE message may include parameters that indicate the remote end <b>104</b> with which the remote media flow and the local media flow are to be established, the remote media UE (UE-<b>2</b>) information, the local media UE (UE-<b>1</b>) information, and other information necessary to setup a remote media flow and the local media flow.

0042In step <b>604</b>, the SCC AS <b>112</b> transmits via the CSCF <b>110</b>, for example, a SIP INVITE message to the media UE (e.g., UE-<b>2</b>), and in step <b>606</b>, the SCC AS <b>112</b> transmits via the CSCF <b>110</b>, for example, a SIP INVITE message to the remote end <b>104</b>. The SCC AS <b>112</b> also transmits via the CSCF <b>110</b>, for example, a SIP INVITE message to the remote end <b>104</b> indicating that a local media flow is also to be established with UE-<b>1</b>, as indicated in step <b>608</b>. As a result, a remote media flow is established between the media UE-<b>2</b> and the remote end <b>104</b> and a local media flow is established between the controller UE-<b>1</b> and the remote end <b>104</b>. UE-<b>1</b> maintains control of the session, i.e., UE-<b>1</b> is the controller UE, and has a local media flow thereto.

0043<figref idref="DRAWINGS">FIG. 7</figref> illustrates, a signaling architecture diagram illustrating a process for terminating a remote media flow is shown in accordance with an embodiment of the present invention. Initially, the remote end <b>104</b> issues a session request directed to UE-<b>1</b> as indicated by reference numeral <b>702</b>. The session request is forwarded to UE-<b>1</b> by the IMS system <b>302</b>, and UE-<b>1</b> provides instructions to the IMS system <b>302</b> that a remote media flow is to be established with UE-<b>2</b>, as indicated by reference numeral <b>704</b>. As a result, the IMS system <b>302</b> initiates a remote media flow with UE-<b>2</b> as indicated by reference numeral <b>706</b> and establishes a remote leg with the remote end <b>104</b> as indicated by reference numeral <b>708</b>. As a result of this process, as indicated by reference numeral <b>710</b>, a remote media flow is established between the remote end <b>104</b> and the media UE-<b>2</b>, wherein UE-<b>1</b> acts as the controller UE.

0044<figref idref="DRAWINGS">FIG. 8</figref> illustrates a message flow diagram that may be used to establish a remote media flow during termination such as that illustrated in <figref idref="DRAWINGS">FIG. 7</figref>, in accordance with an embodiment of the present invention. The process begins in step <b>802</b>, wherein the remote end <b>104</b> transmits, for example, a SIP INVITE message to the CSCF <b>110</b>, which forwards the SIP INVITE message to the SCC AS <b>112</b>. The INVITE message indicates that the remote end <b>104</b> wants to initiate a media flow between the remote end <b>104</b> and the UE-<b>1</b>. In step <b>804</b>, the SCC AS <b>112</b> transmits via the CSCF <b>110</b>, for example, a SIP INVITE message to the designated UE (e.g., UE-<b>1</b>), which responds with a message, e.g., a SIP 200 OK message, having parameters that indicate that the user wishes to receive the flow on a different UE, e.g., UE-<b>2</b> in this example. In step <b>806</b>, the SCC AS <b>112</b> transmits the INVITE message to the media UE UE-<b>2</b>, and upon receiving the OK message from UE-<b>2</b>, the SCC AS <b>112</b> transmits a message, e.g., a SIP 200 OK message, to the remote end <b>104</b>. As a result, a remote media flow is established between UE-<b>2</b> and the remote end <b>104</b> such that UE-<b>1</b> maintains control of the session, i.e., UE-<b>1</b> is the controller UE, as indicated in step <b>810</b>.

0045<figref idref="DRAWINGS">FIG. 9</figref> illustrates a similar situation as that discussed above with reference to <figref idref="DRAWINGS">FIG. 7</figref>, wherein like reference numerals refer to like elements, except where <figref idref="DRAWINGS">FIG. 7</figref> illustrates the termination of only a remote media flow, <figref idref="DRAWINGS">FIG. 9</figref> illustrates that the controller UE UE-<b>1</b> establishes both a local media flow <b>912</b> as well as a remote media flow <b>710</b>.

0046<figref idref="DRAWINGS">FIG. 10</figref> illustrates a message flow diagram that may be used to establish a local media flow and a remote media flow during termination such as that illustrated in <figref idref="DRAWINGS">FIG. 9</figref>, in accordance with an embodiment of the present invention. The process begins in step <b>1002</b>, wherein the remote end <b>104</b> transmits, for example, a SIP INVITE message to the CSCF <b>110</b>, which forwards the INVITE message to the SCC AS <b>112</b>. The INVITE message indicates that the remote end <b>104</b> wants to initiate a media flow between the remote end <b>104</b> and the UE-<b>1</b>. In step <b>1004</b>, the SCC AS <b>112</b> transmits via the CSCF <b>110</b>, for example, a SIP INVITE message to the designated UE (e.g., UE-<b>1</b>), which responds with a message, e.g., a SIP 200 OK message, having parameters that indicate that the user wishes to receive the media flow as a local media flow on UE-<b>1</b> and a remote media flow on UE-<b>2</b>. In step <b>1006</b>, the SCC AS <b>112</b> transmits the INVITE message to the media UE UE-<b>2</b>, and upon receiving the OK message from UE-<b>2</b>, the SCC AS <b>112</b> transmits an OK message to the remote end <b>104</b>. As a result, a local media flow is established between UE-<b>1</b> and the remote end <b>104</b>, and a remote media flow is established between UE-<b>2</b> and the remote end <b>104</b>, such that UE-<b>1</b> maintains control of the session, i.e., UE-<b>1</b> is the controller UE, as indicated in steps <b>1010</b> and <b>1012</b>, respectively. As noted above, the SCC AS <b>112</b> acts to separate the media flow to and from the remote end <b>104</b> into the media flows corresponding to the local media flow and the remote media flow, presenting a single remote leg to the remote end <b>104</b>.

0047<figref idref="DRAWINGS">FIGS. 11</figref><i>a </i>and <b>11</b><i>b </i>illustrate a situation in which the session control is transferred from one UE to another UE. One of ordinary skill in the art will appreciate that in the embodiments discussed above involved establishing a media flow on a different UE, but the session control remained with UE-<b>1</b>. In contrast, the embodiment illustrated in <figref idref="DRAWINGS">FIGS. 11</figref><i>a </i>and <b>11</b><i>b </i>transfers the session control from UE-<b>1</b> to UE-<b>2</b>. It should be noted that one or more media flows may also be transferred from UE-<b>1</b> to UE-<b>2</b> along with the session control.

0048Referring now to <figref idref="DRAWINGS">FIG. 11</figref><i>a</i>, there is illustrated an IMS session already established such that UE-<b>1</b> is the controller UE. The IMS session may be established in any suitable manner such that an IMS session is established between the IMS system <b>302</b> and UE-<b>1</b> as indicated by reference numeral <b>1110</b> and a remote leg is established between the IMS system <b>302</b> and the remote end <b>104</b> as indicated by reference numeral <b>1112</b>. Accordingly, a local media flow is established between the remote end <b>104</b> and UE-<b>1</b> as indicated by reference numeral <b>1114</b>. At this point, UL-<b>1</b> is the controller UE and the media UE.

0049<figref idref="DRAWINGS">FIG. 11</figref><i>b </i>illustrates the signaling architecture after transfer of the session control from UE-<b>1</b> to UE-<b>2</b>. While the remote leg <b>1112</b> remains established between the remote end <b>104</b> and the IMS system <b>302</b>, the IMS session <b>1110</b> of <figref idref="DRAWINGS">FIG. 9</figref><i>a </i>has been separated into a media control signaling path between the IMS system <b>302</b> and UE-<b>1</b> and a session control signaling path between the IMS system <b>302</b> and UE-<b>2</b> as indicated by reference numerals <b>1116</b> and <b>1118</b>, respectively. The media flow remains between the remote end <b>102</b> and UE-<b>1</b>. In this situation, UE-<b>1</b> is referred to as the controlee UE and UE-<b>2</b> is referred to as the controller UE.

0050<figref idref="DRAWINGS">FIG. 12</figref> is a message flow diagram that may be used to affect the transfer of the session control from a controlee UE to a controller UE. It should be noted that the CSCF <b>110</b> is not shown in <figref idref="DRAWINGS">FIG. 12</figref> for illustrative purposes only, and that one of ordinary skill in the art will realize that signaling between the remote end <b>104</b> and the UE may pass through or be facilitated by the CSCF.

0051The process begins in step <b>1210</b>, wherein a local media flow is established between the remote end <b>104</b> and the controller UE, UE-<b>1</b> at this point. For illustrative purposes, <figref idref="DRAWINGS">FIG. 12</figref> illustrates two media flows, e.g., media flow A and media flow B. Media flow A will be transferred to UE-<b>2</b> along with the session control signaling. Media flow B will remain on UE-<b>2</b> and will become a remote media flow. Fewer or more media flows may be used.

0052In step <b>1212</b>, UE-<b>1</b> issues a transfer request to SCC AS <b>112</b> to request transfer of the session control and media flow A to UE-<b>2</b>. The SCC AS <b>112</b> transmits the transfer request to UE-<b>2</b>, wherein the parameters of the transfer request indicate that the session control and media flow A are to be transferred to UE-<b>2</b>, as indicated in step <b>1214</b>. As a result of the transfer request, collaborative session control is established between UE-<b>2</b> and the SCC AS <b>112</b>, as indicated in step <b>1216</b>.

0053After establishing the collaborative session control, the SCC AS <b>112</b> establishes a local media flow between UE-<b>2</b> and the remote end <b>104</b> as indicated in step <b>1218</b>. Upon successful transfer of the session control and the media flow A, the SCC AS <b>112</b> responds to the UE-<b>1</b> that the transfer has been completed in step <b>1222</b>, at which point, in step <b>1224</b>, the media flow A and the session control are released from UE-<b>1</b>. As a result of this process, a remote media flow exists between UE-<b>1</b> and the remote end <b>104</b>, and a local media flow exists between UE-<b>2</b> and the remote end <b>104</b>. One of ordinary skill in the art will realize that UE-<b>2</b> became the controller UE and UE-<b>1</b> switched from being the controller to the controlee.

0054Referring now to <figref idref="DRAWINGS">FIG. 13</figref>, a block diagram of a network element <b>1300</b> is provided in accordance with an embodiment of the present invention. The network element <b>1300</b> depicts a general purpose platform and the general components and functionality that may be used to implement any or all of the UE, the SCC AS <b>112</b>, or the CSCF <b>110</b>. The network element <b>1300</b> may include, for example, a central processing unit (CPU) <b>1302</b>, memory <b>1304</b>, and a mass storage device <b>1306</b> connected to a bus <b>1308</b> configured to perform the processes discussed above. The network element <b>1300</b> may further include a video adapter <b>1310</b> to provide connectivity to a local display <b>1312</b> and an I/O interface unit <b>1314</b> to provide an input/output interface for one or more input/output devices <b>1316</b>, such as a mouse, a keyboard, printer, tape drive, CD drive, or the like.

0055The processing unit <b>210</b> also includes a network interface <b>1318</b>, which may be a wired link, such as an Ethernet cable or the like, and/or a wireless/cellular link. For example, the network interface <b>1318</b> may comprise an Ethernet connection if the network element <b>1300</b> acts as CSCF or SCC AS, or even some UE. Mobile UEs, on the other hand, the network work element <b>1300</b> may comprise a suitable receiver and transmitter for wireless communications. It should be noted that the network element <b>1300</b> may include other components. For example, the network element <b>1300</b> may include power supplies, cables, a motherboard, removable storage media, cases, and the like. These other components, although not shown, are considered part of the network element <b>1300</b>.

0056Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. For example, many of the features and functions discussed above can be implemented in software, hardware, or firmware, or a combination thereof. As another example, it will be readily understood by those skilled in the art that different network elements, messaging, protocols, and/or the like may be varied while remaining within the scope of the present invention.

0057Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.