A fast handoff scheme for wireless networks

In this paper, we propose a fast and efficient handoff scheme to handle the movements of mobile nodes among small wireless cells at the fringes of the Internet. Our scheme adopts a hierarchical mobility management architecture to restrict the handoff processing overheads within the vicinity of the mobile node, and uses multicast as the packet forwarding mechanism to deliver packets to multiple base stations within the vicinity of the mobile node to achieve fast handoff performance. Our scheme is based on the Internet Protocol (IP) and is compatible with Mobile IP and its route optimization option. We also present simulation results for our simulation using the Network Simulator (ns2). The simulations show that our handoff scheme is fast enough to meet the requirements of an interactive voice communication session. The first packet from the new base station arrives at the mobile node within 10 ms after the mobile node initiates a handoff. Hence our scheme is suitable for roaming mobile nodes which may encounter numerous handoffs while they are in the midst of an interactive voice communication session such as Internet telephony.