Effect of utility based functions on fuzzy-AHP based network selection in heterogenous wireless networks

With the growth in the field of wireless technology, internet can be accessed by mobile devices through different wireless interfaces. These devices experience both horizontal and vertical handovers in heterogeneous wireless environments. Multiple Attribute Decision Making (MADM) methods can be used for network selection in heterogeneous wireless networks. Traditional MADM methods calculate the final ratings by considering the normalized values of the attributes. The main disadvantage with the normalized values is that they do not consider the actual usability of the attributes for a particular application. In this paper, a utility based fuzzy-AHP method is applied for selecting a network considering the user preferences, network conditions and energy consumption in a real time scenario like video conferencing. Four networks (WLAN1, WLAN2, WiMax, and UMTS) are considered for network selection in vertical handover scenarios. Utility value of each attribute is calculated from the utility functions. Simple Additive Weighing (SAW) is also analyzed using the utility values. Results show that with the utility based MADM methods, ratings of networks are more suitable with respect to the requirements of the application and unnecessary handovers can be avoided in comparison with traditional MADM methods.