1Multi-Criteria Optimization of Access Selection to Improve the Quality of Experience in Heterogeneous Wireless Access Networks

Abstract—Wireless technology is one of the revolutionary ad-vancements providing users with ubiquitous data and telephony access anywhere and anytime without any physical connection. The nowadays deployed wireless networks named WiFi, World-wide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications Systems (UMTS) and Long Term Evolution systems (LTE) have different characteristics that make them complementary in term of performance, coverage and cost. This network variety presents an opportunity to provide better services to the end-users given the advances in mobile terminals. To reach this goal, an appropriate automatic network selection (ANS) mechanism, able to always select the best access network, is needed. This consists on constantly monitoring any type of available access networks, automatically selecting and switching to the best one, as the network that maximizes the users quality of experience taking into account their preferences as well as the terminal and network conditions. ANS is a multi dimension decision-making problem which can be solved by finding an appropriate complex trade-off between possibly conflicting criteria. In this paper, we propose an analytical model to capture the preferences of end-users. Based on this model, we design an ANS mechanism that takes into account all aspects of the trade-off between the quality of the connections, the preferences of the end users and the cost. To highlight the benefits of our approach from the perspectives of both end-users and network operator, we have implemented and tested the solution in a multi technologies simulator. Results show that the proposed solution outperforms the main stream approaches. I