Impairment-Constrained Multi-Rate Multicast Flow Aggregation in IP over Optical Networks

In this paper, we study the problem of multicast flow aggregation with the objective of minimizing the total number of trees. Each established tree can choose a line rate from multiple available line rates. The destinations of each tree are guaranteed to receive data correctly from the source through the chosen line rate. We first use two auxiliary graphs to describe the problem and show that the problem is NP-hard. An integer linear program (ILP) is given to solve small scale problems. We then provide a heuristic approach, named highest rate first (HRF). Numerical results show that HRF achieves good results in both large and small scale problems.