Stochastic control of path optimization for inter-switch handoffs in wireless ATM networks

One of the major design issues in wireless ATM networks is the support of i nter-switch handoffs, An inter-switch handoff occurs when a mobile terminal moves to a new base station connecting to a different switch. Apart from r esource allocation at the new base station, inter-switch handoff also requi res connection rerouting. With the aim of minimizing the handoff delay whil e using the network resources efficiently, the two-phase handoff protocol u ses path extension for each inter-switch handoff, followed by path optimiza tion if necessary. The objective of this paper is to determine when and how often path optimization should be performed, The problem is formulated as a semi-Markov decision process, Link cost and signaling cost functions are introduced to capture the tradeoff between the network resources utilized b y a connection and the signaling and processing load incurred on the networ k, The time between inter-switch handoffs follows a general distribution, A stationary optimal policy is obtained when the call termination time is ex ponentially distributed. Numerical results show significant improvement ove r four other heuristics.