Mobile multicast with routing optimization for recipient mobility

This paper explores the issues of multicasting for mobile hosts using IETF mobile IP. Mobile IP suggests two approaches for mobile multicasting, namely, remote subscription (MIP-RS) and bi-directional tunneling (MIP-BT). MIP-RS uses a naive join-and-leave policy for mobile hosts and causes serious packet losses while roaming. MIP-BT is free from packet losses due to roaming; however, MIP-BT and its modification MoM suffer from inefficient routing and wastage of system resources. In this paper, we propose a new mobile multicasting protocol called mobile multicast with routing optimization (MMROP) that employs a modified join-and-leave mechanism, and routes the missing data sequence due to the "out-of-synch" problem to other agents in the adjacent networks via tunneling for roaming terminals. With MMROP, the mobility agent in mobile IP is extended to assist multicasting for mobiles. We also developed a cost analytical model to evaluate the performance of MMROP, in comparison to MIP-RS, MIP-BT, and MoM. The results demonstrate that MMROP has optimal routing efficiency, low delivery cost and high robustness, as compared to other approaches.