A distributed energy efficient multicast routing algorithm for WANETs

It is essential to maximise the lifetime of a given multicast tree, in order to keep the nodes active as long as possible in Wireless Ad hoc Networks (WANETs). Due to the impact of hop count on energy efficiency, any efficient routing protocol for WANETs should have low hop count. However, the problem of generating the optimised 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 trade-off 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). Theoretical analyses show that it is efficient to fully characterise 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 minimising the maximal hop count of a source-based multicast tree in WANETs. Simulation results provide evidence that MLMH achieves satisfactory performance.