This is mainly observed in the case of the minimum-hop based MAODV, NR-MLPBR and R-MLPBR.
MAODV tends to be more unstable as the multicast group size is increased, owing to the minimum hop nature of the paths discovered and absence of any path prediction approach.
This is mainly observed for the minimum-hop based multicast protocols (especially MAODV and NR-MLPBR) which incur a reduced hop count per source-receiver path as we increase the network density.
For a given multicast group size and low node mobility, the time between successive tree discoveries in networks of high density (75 nodes) is 51-80% for MAODV and NR-MLPBR and for R-MLPBR and BEMRP is 70-90% of those obtained in networks of low-density.
For smaller group sizes, the time between successive broadcast tree discoveries for MAODV and BEMRP is respectively about 80%-90% and 85%-94% of that incurred for NR-MLPBR and R-MLPBR.
Impact of Network Density: As we increase the network density from 25 nodes to 50 nodes, we observe that the time between successive broadcast tree discoveries for MAODV, NR-MLPBR, R-MLPBR and BEMRP decreases by 13%, 9%, 6% and 6% respectively.
BEMRP incurs the least energy consumption per node and MAODV incurs the largest energy consumption per node.
BEMRP and MAODV incur the largest increase in energy consumed per node with increase in node mobility.
MAODV and NR-MLPBR incur a relatively larger energy consumed per node at high network densities due to the nature of these multicast routing protocols to discover trees with minimum hop count.
Impact of Multicast Group Size: As we increase the multicast group size from 2 to 24, the energy consumed per node for MAODV and NR-MLPBR increases by a factor of 2.
Similar to that observed for flooding, BEMRP and MAODV incur the largest increase in energy consumed per node with increase in node mobility.