Recommendation ITU-T X.604.2 describes the functions and procedures of the mobile multicast communications part 3 (MMC-3) protocol which is an application-layer multicast protocol constructing a one-to-many overlay multicast tree for multicast data delivery from one sender to multiple receivers over fixed and mobile converged network environments. The MMC-3 protocol consists of the session manager, the multicast agent, the mobile multicast agent, and the mobile node. The session manager manages and controls MMC-3 sessions. The multicast agent provides multicast‑based services over fixed network environments, and the mobile node provides multicast-based services over mobile network environments with the support of the mobile multicast agent. This Recommendation | International Standard specifies the functions of MMC-3 protocol entities and the procedures of the MMC-3 protocol operations. The MMC-3 protocol supports the applications requiring one-to-many multicast data delivery. Examples of such applications are mobile IPTV services, mobile news ticker services, file distributions, e-learning, etc.