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Video Share is an IP Multimedia System (IMS) enabled service for mobile networks that allows users engaged in a circuit switch voice call to add a unidirectional video streaming session over the packet network during the voice call. Any of the parties on the voice call can initiate a video streaming session. There can be multiple video streaming sessions during a voice call, and each of these streaming sessions can be initiated by any of the parties on the voice call. The video source can either be the camera on the phone or a pre-recorded video clip. Video share is initiated from within a voice call. After a voice call is established, either party (calling or called) can start a Video Share (VS) session. The sending User is then able to stream one-way live or recorded video. The default behavior is that the receiving handset will automatically go to speakerphone mode when video is received, unless the headset is in place. The sender will be able to see what is being streamed on their handset, along with the receiving User. In this scenario, the sender can “narrate” over the CS audio connection while both parties view the video. Both users will have the ability initiate a video share session, and either the sender or recipient in a video share session can terminate the session at any time. As part of the VS invitation, the recipient can choose to reject the streamed video. It is intended that both sender and receiver will receive feedback when the other party terminates a session or the link drops due to lack of coverage. The (Video Share service ) is defined by the GSM Association (GSMA). It is often referred to as a Combinational Service, meaning that the service combines a circuit switch voice call with a packet switch multimedia session. This concept is described in the 3rd Generation Partnership Project (3GPP) specification documents 3GPP TS 22.279, 3GPP TS 23.279 and 3GPP TS 24.279. The Video Share service requires a 3GPP compliant IMS core system. GSM Association has split the Video Share service definition 〔(http://www.gsmworld.com/documents/services/se41.pdf ) Video Share Definition 2.0, GSMA Document, 27 March 2007〕 into 2 distinct phases. The first phase (also called Phase 1) involves sharing a simple peer-to-peer, one-way video stream in conjunction with, but not synchronized to a circuit switch voice call. The second phase (also called Phase 2) introduces the Video Share Application Server in the solution and supports more complex features and capabilities, such as point-to-multipoint video share calls, video streaming to a web portal, and integration of video share with instant messaging. In the industry, Video Share is also referred to by other names such as See What I See and Rich Voice Call. Video Share is supported only in UMTS and EDGE (with DTM) networks. It is not supported in a GPRS or a CDMA network. The Video Share Client will drop a VS session when the handset transitions from UMTS to GSM during the session. The CS voice call will remain connected. (AT&T ) (formerly Cingular) is one of mobile operators who have deployed the Video Share service nationwide. == History == Peer-to-peer video sharing was introduced by Nokia phones first in 2004. This was a proprietary solution on top of a SIP or IMS infrastructure. Some European operators offered commercial services based on these phones already in 2005. Similar services popped under the names of See What I See, Rich Voice Call, Push-to-Video (P2video or PTV), etc. The GSMA Video Share service 〔 was originally defined, implemented and tested during the Session Initiation Protocol (SIP) trials conducted by the GSM Association in 2005/2006. During the SIP trials, the Video Share service used to demonstrate IMS interworking over SIP.〔(http://www.gsmworld.com/news/press_2006/press06_18.shtml ) GSMA Press Release on video share trials, 15 February 2006〕 Video Share was also tested on the IPX 〔(http://www.gsmworld.com/sip/sip_trial_guide.pdf ) The GSMA's SIP Trials, February 2007〕 to prove that the service might become universally available in the future. Subsequently, GSMA decided to create a separate project for Video Share. Phase 1 of the Video Share project built on and leveraged the results from the SIP trials. Service definition for the first phase of the Video Share project was completed in September/October 2006. Mobile operators worldwide, such as AT&T, have deployed the Video Share service 〔(http://www.wireless.att.com/learn/messaging-internet/media-entertainment/video-share-faqs.jsp ) AT&T FAQ for Video Share〕 based on the Phase 1 service definition. An interoperability technical reference specification for Video Share 〔(http://www.gsmworld.com/documents/ir7412.pdf ) IR.74 Video Share Interoperability Specification 1.2, GSMA Document, September 2008〕 is also available from GSMA. Phase 2 of the GSMA Video Share project was kicked off in May/June 2007 and is currently in progress. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Video Share」の詳細全文を読む スポンサード リンク
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