A hybrid network selection scheme for heterogeneous wireless access network

Abstract

Heterogeneous wireless access network (HWAN), an integration of different radio access technologies (RATs) in an overlapping zone, supports bandwidth hungry application and fulfills the demands for high data rates. In this paper, we explored a novel hybrid scheme for RAT selection in HWAN, a two step process, where both a central controller node (CCN) and user device (UD) are involved in the process of network selection. During the first step UD screens the available list of scanned networks based on received signal strength and user mobility profile. The results for the first step of RAT screening using multiplicative exponential weighting method (MEW) are compared with multi criteria simple additive weighting (SAW) utility function. In our second step the CCN takes multi criteria related to application, terminal and network, and generates a sorted list of the most appropriate RATs based on evaluating MEW utility function. The CCN, then associates users to one (single connection) or more available RATs (multi-homed). Using Matlab based simulations, the process of RATs ranking and association is elaborated by calculating final utilities of different networks. The impact of different crucial criteria on RATs ranking results have been explored. Furthermore, we compared our proposed hybrid approach with the traditional mechanisms. The simulation results show that the decision of our proposed hybrid mechanism is more precise than the existing traditional approaches.