MRMP (Maximum-Residual Multicast Protocol) is a power-aware multicast protocol designed for large-scale mobile ad hoc networks, in which nodes may be with high mobility.
In the past decades, many excellent power-aware routing algorithms/protocols have been proposed for mobile ad hoc networks. However, most of the existing results rely on the knowledge of certain global information, such as the remaining energy of all nodes and/or the minimum transmission power between every pair of nodes. The maintenance problem of similar global information is highly challenging in protocol designs because of the difficulty and cost in the maintenance of up-to-date information. As a result, various assumptions, such as static network topologies and/or fixed traffic patterns, are made to reduce the problem complexity.
Unlike the past work, MRMP is designed for applications with a huge population of mobile devices such that no global information can be efficiently maintained at any node. MRMP relies on a distributed algorithm that is proved to be loop-free and theoretically optimal in the maximization of minimum residual energy. In MRMP, no periodic control message is employed to collect routing information or repair link breakages. Neither group membership nor neighbor relationship is maintained at a node by explicit control messages. When desiring a route, a source invokes a route-discovery procedure over the network, and the individual decisions of intermediate nodes form a loop-free transient multicast tree naturally. The data packets are then forwarded by nodes at proper power levels on the established multicast tree. MRMP was implemented and evaluated over NS2, and simulations were conducted extensively with parameters set based on a realistic commercial wireless device. MRMP has demonstrated itself being effective and efficient in essential performance metrics adopted generally for routing protocol evaluation.
The distributed methodology is also applicable to various related optimization problems (such as the minimization of the total energy consumption of any path from a source to a destination) and provides useful insights when network resources (such as bandwidth) might change over time.