Patent ID: 8752107

Claim:
A method of time-shifting and chase-play for an IPTV system comprising an IP Multimedia Subsystem (IMS) including an IPTV Application Server, and a Network Private Video Recorder coupled to the IPTV Application Server, the method comprising: using Session Initiation Protocol (SIP) signaling over the IMS to establish a control channel between an originating user and said IPTV Application Server; continuing delivery of content to the user by multicast; sending an incoming IMS call notification from the IPTV Application Server to the originating user over said control channel; sending a user decision instruction for handling the incoming IMS call, wherein the user decision instruction is sent from the originating user to the IPTV Application Server over said control channel in response to receiving the incoming IMS call notification; sending a start time-shift command to the IPTV Application Server over the control channel; sending a start recording command from the IPTV Application Server to said Network Private Video Recorder to initiate recording of current multicast content; establishing a media plane for speech or multimedia communication in response to the user decision instruction, wherein the media plane is established using SIP signaling over the IMS; when the user is ready to resume viewing of the time-shifted content, sending a start chase-play command from the user to the IPTV Application Server over the control channel; using SIP signaling over the IMS to establish a unicast channel between the user and the Network Private Video Recorder for playback of the time-shifted content; switching the mode of content delivery to the user from multicast to unicast; and sending a playback command from the IPTV Application Server to the Network Private Video Recorder system to initiate playback of the time-shifted content over the unicast channel.