Optimizing multicast content delivery over novel mobile networks

The rapid growth in mobile traffic leads to the current evolution trend of mobile networks towards a flat architecture. However, the centralized mobility management protocols (e.g. MIPv6, PMIPv6) are not optimized for the flat architecture due to their limitations e.g. complex tunnel management, scalability issue, etc. Hence, a novel mobility management has been proposed for the flat architecture, called distributed mobility management (DMM). IP multicast, an effective mechanism for traffic delivery, can be enabled in DMM by deploying MLD Proxy function at mobile access routers (MARs) with the upstream interface being configured to the multicast infrastructure (before mobility) or to the tunnel towards the mobile node's mobility anchor (after mobility) (namely tunnel-based approach). In case of mobility, the utilization of the tunnel may result in the tunnel convergence problem when the multiple instances of the same multicast traffic converges to a MAR due to the multiple tunnels established with several mobility anchors (leading to the redundant traffic at the MARs). Compared to PMIPv6, the tunnel convergence problem may become much more severe, especially in highly mobile regime. In this paper, we propose some mechanisms to greatly reduce the amount of redundant traffic at the MARs with a minor increase of service disruption time compared to the tunnel-based approach.