Towards Seamless Handovers in SSM Source Mobility An Evaluation of the Tree Morphing Protocol

Multimedia networking in the near future is expected to be dominated by group applications such as IPTV, MMORPGs, and video conferencing. Hand in hand with new service offers, the deployment of multicast at the network layer startet to disseminate. Currently infotainment is gradually expanding into the mobile world, but a standard design of mobile multicast is still awaited. The traditional Internet approach of any source multicast (ASM) routing remains hesitant to spread beyond walled gardens. It is widely believed that simpler and more selective mechanisms for group distribution in source specific multicast (SSM) will globally disseminate to many users of multicast infrastructure and services. In this paper we present and discuss an extensive evaluation of the tree morphing protocol, which has been designed to facilitate seamless handovers for mobile SSM sources. Based on a full protocol implementation on a network simulator platform, we extensively explore the protocol performance. By employing artificial networks to cover fundamental topological constellations, as well as real-world network topologies, we analyze the handover behavior conceptually and in realistic scenarios. Strengths and weaknesses of the routing scheme are identified, leading to a discussion on future improvements.