A flow transparent multicast pre-reservation modification of RSVP for providing real-time services in wireless mobile networks

Resource reservation protocol (RSVP) is used to sufficiently reserve the resources between fixed endpoints. To support it for host mobility, several methods have been proposed in the literature to address the challenging problems of minimizing the handoff resource reservation delays and wastage of resources. Although, these methods minimize intra-subnet handoff resource reservation delays with minimum wastage of resources; but for inter-subnet handoffs, these methods need more resource reservation delays and more wastage of resources. In this paper, we propose a flow transparent multicast pre-reservation modification of RSVP to solve these problems to make the handoffs completely opaque to the user. In this method, a multicast group (MG) of cells is selected for each boundary cell (BC), and the resources are pre-reserved in this group only to the newly added path instead of whole path between source and destination when the mobile node (MN) performs an inter-subnet handoff towards that group. Simulation results demonstrate that the number of cells in the MG and resource reservation delays for inter-subnet handoff of the proposed method is always smaller than that of all other existing methods and has tolerable call blocking probabilities.