manter informações de controlado em sessões colaborativas

A communication system extends IETF Session Initiation Protocol (SIP) signaling used by IMS architecture. As a basic use case, initially a first user equipment (UE1) (controller) is in a media session (e.g., audio, video and message session) with a remote UE. To transfer provider of one media component to a controllee UE, the controller UE1 sends a REFER message with a relevant body to trigger the media session operations to a Service Centralization and Continuity Application Server (SCC AS). The SCC AS is able to interpret the contents of the REFER message to perform the media session manipulation on one or multiple UEs (originating UE itself or other UEs). The innovation provides for a REFER message that convey what needs to be done in a separate SIP header carrying target dialog and media line number(s), in a SDP body that REFER carries, or XML body that will be in REFER.