It proposes a new reliable multicast protocol based on relay nodes mechanism(RMPRM).The RMPRM protocol focuses on allowable delay provides quality of service(QoS) for multimedia.

• RMPRM协议聚焦在允许延迟上提供多媒体服务质量保证,转接节点放置在多播树上,数据恢复在两个转接节点之间进行。