Content Protection through Multicast IP Flow Aggregation in Optical Networks

In this paper, we study the content protection problem through multicast flow aggregation (CPMFA) in which programs with protection requirement are aggregated into different light trees at the access routers and delivered from the head end to one or more destinations. We first use a tri-partite graph to describe the problem and show that the problem is NP-complete. We then formulate the problem as an interger linear program (ILP) and give results for small scale problems. Two hueristic appoaches, named two-step separated multicast flow aggregation (S-MFA) and mixed multicast flow aggregation (M-MFA), are presented. Numerical results show that S-MFA and M-MFA achieve good results in both large and small scale problems.