SYSTEM AND METHOD TO KEEP CONTINUITY OF MEDIA FLOWS FOR A COLLABORATIVE SESSION WITHOUT CONSTANT CONTROLLER(S) INVOLVEMENT

A system of managing collaborative session control when controller is lost or changes to passive-control mode in a data communication network comprising of a control-capable terminal device that can generate and send user preferences on successive controller selection and control policy, a master server device that can make control transfer decisions or take over control upon events, a normal terminal device that can process and response to master server queries on control capacity and its willingness to take over control. These apparatus are connected to each other inside one collaborative session, regardless of their subscriptions. A method of control management of the collaborative session without constant enrollment of controller comprises the steps of sending different types of preferences to master server device; making control transfer or handover decision; and interacting with affected terminals.