Multicast TE still remains in its preliminary stage

I have just found out a very interesting site on QoS Aware Multicast Management. In there they state that "relevant research on multicast TE still remains in its preliminary stage compared to its unicast counterpart".In fact, "despite the progress for unicast services, traffic engineering for multicast flows remains largely a dark area till now".

They have a specific section on Multicast Traffic Engineering. In there they divide Multicast TE in MPLS Based Multicast Traffic Engineering and IP Based Multicast Traffic Engineering.

In MPLS-based multicast TE point-to-multipoint LSPs are explicitly constructed, and the mathematical problem formulation is often related to the Steiner tree problem for minimising traffic delivery cost. So we need to set up dedicated MPLS tunnels. My PhD proposal is exactly on this issue, and part of it is to develop scalable heuristics for multicast TE.

In IP Based Multicast Traffic Engineering, the basic idea is to convert engineered multicast trees into shortest path trees by optimising link weights. The main advantage in this approach is that legacy IP routers are able to compute multicast trees by applying the Dijkstra’s shortest path algorithm (with the pre-configured link weights).