LOCAL AND GLOBAL HANDOVERS FOR MOBILITY MANAGEMENT IN WIRELESS ATM NETWORKS

This article deals with the problem of virtual circuit (VC) management in wireless ATM (W-ATM) networks with mobile user terminals. In W-ATM networks, a VC terminating at a mobile user may require dynamic reest ablishment during the short time span necessary for terminal handover due to its movement from one (macro)cell to another. The VC reestablis hment procedure has to ensure in sequence and loss-free delivery of th e ATM cells containing user data. After a classification of the soluti ons proposed so far in the literature, a novel technique for the dynam ic reestablishment of VCs in W-ATM networks is described, and its perf ormance is evaluated through simulation. The proposed technique allows for a progressive upgrade of the fixed part of the ATM network and fo r the incremental introduction of user terminal mobility.