Optimizations for vertical handoff decision algorithms

Future wireless networks must be able to coordinate services within a diverse network environment. One of the most challenging problems for coordination is vertical handoff, which is the decision for a mobile node to handoff between different types of networks. While traditional handoff is based on received signal strength comparisons, vertical handoff must evaluate additional factors, such as, monetary cost, offered services, network conditions, and user preferences. In this paper, several optimizations are proposed for the execution of vertical handoff decision algorithms, with the goal of maximizing the quality of service experienced by each user. First, the concept of policy-based handoffs is discussed. Then, a cost function is defined to judge target networks based on a variety of user- and network-valued metrics. Finally, a performance analysis demonstrates that significant gains in quality of service and a more efficient use of resources can he achieved from the proposed optimizations.