A method comprising: a Service Centralized and Continuity Application Server (SCC AS) receiving, from a first WTRU, a collaborative session request to replicate a media flow to a second WTRU; the SCC AS authorizing the request; the SCC AS allocating a media resource at a media resource function (MRF) for the media flow; the SCC AS establishing a second-WTRU access leg; the SCC AS updating a first-WTRU access leg for the first WTRU; and the SCC AS updating a remote leg to communicate the replicated media flow to the MRF, wherein, unless the remote party rejects the replication of the media flow, the media flow then flows from the remote party to the MRF, from the MRF to the first WTRU, and from the MRF to the second WTRU.