iPTT: peer-to-peer push-to-talk for VoIP

This paper proposes iPTT, a peer-to-peer Push-toTalk (PTT) service for Voice over IP (VoIP). In iPTT, a distributed and mobile-operator independent network architecture is presented to accelerate the deployment of the PTT service. Based on the proposed architecture, the message flows for call establishment/teardown are designed to show the feasibility of iPTT. Also, we propose two mechanisms for real-time talkburst determination, flooding-based floor control mechanism (FFC) and tree-based floor control mechanism (TFC). In terms of the determination latency and the number of floor-control message exchanges, the performance of the proposed floor control mechanisms is investigated through our analytical and simulation models.