Abstract
Seamless handover between different radio access technologies is a great challenge since it needs to guarantee the link continuity and satisfy the subscriber's quality-of-services (QoS) requirements. The performances of roaming across different technologies depend on the number of implemented handover criteria, which can be large. In this case, multiple attribute decision making (MADM) methods such as simple additive weighting, technique for order preference by similarity to ideal solution and the compromise ranking method called (VIKOR: VlseKriterijumska Optimizacija I Kompromisno Resenje) have been proposed to solve this kind of multi-criteria problems. However, the major shortcomings of these techniques are the high decision delay and the complexity. In this paper, we propose a novel handover (HO) scheme called Fuzzy-MADM. It is based on the combination of one classical MADM method with a fuzzy logic inference system in order to reduce decisional time. The optimal network is selected, based on multiple criteria such as network QoS indicators, speed of mobile station, battery level and signal strength. The efficiency of our approach is evaluated through appropriate simulations. The results related to HO delays, throughput, complexity and number of executed handovers show the performances of our proposal when compared to classical MADM and load balancing methods.