MLMH: a novel energy efficient multicast routing algorithm for WANETs

Energy efficiency is of vital importance for wireless ad hoc networks (WANETs). In order to keep the nodes active as long as possible, it is essential to maximize the lifetime of a given multicast tree. However, hop count is generally an important metric for WANETs, and any efficient routing protocol should have low hop count. The problem of generating the optimized energy efficient routing protocol for WANETs is NP-hard. Any workable heuristic solution is, therefore, highly desirable in this case. To take into account the tradeoff between the lifetime and the hop count in routing of multicast tree in WANETs, this paper defines a new metric termed energy efficiency metric (EEM) function. Theoretical analyses show that it is efficient to fully characterize the energy efficiency of WANETs. A distributed routing algorithm called Maximum Lifetime and Minimum Hop-count (MLMH) is then proposed with the aim that extends the lifetime while minimizes the maximal hop count of a source-based multicast tree in WANETs. Simulation results give sound evidence that our algorithm achieves a balance between the hop count and the lifetime of the multicast tree successfully.