A Novel Handoff Scheme for Wireless ATM Networks

Abstract

Mobility support and management in Wireless ATM networks poses a number of technical issues. An important issue is the ability to manage and reroute active connections during handoff as mobile users move among base stations. We propose a novel two-phase handoff scheme using permanent virtual paths reserved between adjacent Mobility Enhanced Switches (MES). The virtual paths are used in the first phase to rapidly reroute user connections. In the second phase, a distributed optimization process is initiated to optimally reroute handed-off connections. In this paper, we address various control issues related to signaling and implementation of such a scheme including how to achieve optimal paths. We analytically calculate and study the handoff blocking probability and the bandwidth requirement for the reserved virtual paths. We also study the impact of processing and signaling load due to the second-phase route optimization. Both ATM CBR and VBR traffic types were considered for mobile user connections