Mobility support for IP multicast

Abstract

The importance of providing multicast services to mobile users is accelerated by the fact that the mobile Internet users expect to have access to the services that are available in wired networks. One of the most popular services is the multimedia application, in which multicast is the most suitable choice. However, integrating multicasting with mobility creates many challenges, because the network must deal not only with dynamic group membership, but also with the dynamic locations of mobile hosts. Mobile IPv6/v4 (MIP) proposes two solutions to handle the node movement in multicast transmission. The first approach is Bidirectional Tunneling (BT) where the Mobile Node (MN) receives/sends the multicast datagram through its Home Agent (HA). The second approach is Remote Subscription (RS) where the MN re-subscribes to the multicast group through a local multicast router at the foreign network. BT approach hides the mobility; however it introduces a serious triangular routing problem. RS approach provides an optimal routing; however it suffers from serious frequent multicast tree reconstruction. The objective of this thesis is to provide seamless mobile multicast support by developing a set of robust protocols that facilitate and improve senders/receivers mobility, and result in low signaling cost during an ongoing multicast session. This is achieved by hiding the multicast node local mobility and avoiding the single point of failure. The proposed set of protocols, Robust Multicast using Hierarchical Mobile IPv6 (RM-HM), integrates the advantages of BT and RS approaches and benefits from the infrastructure of Hierarchical Mobile IP (HMIP) to hide the MN mobility. Evaluation of the proposed protocols is based on analytical approach and via simulating Internet-like topologies. The simulation is carried out using the Network Simulator (NS-2) and the Network Manipulator (NEM). Metrics considered are: the gain in the delivery length and delay, and the impact of the multicast group size. The obtained results are compared to the standard approaches proposed by MIP. The results shows that the proposed protocols experience low signaling cost, perform less tree reconstructions, less multicast latency and better routing efficiency, and provide higher availability.