Reliable mobile multicast protocol (RMMP): a reliable multicast protocol for mobile IP networks

This paper proposes a new protocol, the reliable mobile multicast protocol (RMMP), for mobile networks using mobile IP. Unlike existing mobile multicast solutions that employ bi-directional tunneling for roaming terminals to receive multicast datagrams and which is inefficient in packet delivery, wastes system resources and results in long service latency, RMMP ensures reliable multicast service for mobiles by using remote subscription. Remote subscription, however, suffers from the out-of-synch problem when data are received from the same multicast group but from different subnets while roaming from one subnet to another, thereby causing packet losses for roaming terminals. With RMMP, the mobility agent (foreign or home agent) in mobile IP, in addition to providing mobility management, is extended to serve as the reliable multicast agent for mobiles, and routes the difference in data sequence to other agents in the adjacent subnets via tunneling. As a result, RMMP provides reliable mobile multicast services while enjoying lower delivery cost, less service latency and better routing efficiency.