Vertical handoff decision algorithms for mobile satellite systems with ancillary terrestrial component

Seamless handoff in integrated satellite-terrestrial systems is one of the main challenges to achieve real anytime, anywhere communication. Multiple parameters have to be considered instead of only received signal strength. In this paper we propose two vertical handoff decision algorithms based on classical Multiple Attribute Decision Making (MADM) methods and fuzzy logic respectively. The algorithms proposed can meet the QoS (Quality of Service) requirements of different types of application and optimize the system performance. The two algorithms are compared in different aspects and the corresponding advantages as well as disadvantages are discussed.