Doctorate thesis defense of Aymen BEN ZINEB

Committee

Abstract

Mobile technology has experienced a number of generation changes, which have transformed the mobile land-scape into a global set of interconnected networks. These networks are supporting voice, video and a complex range of communication services for billions of connected devices and promising even more increase in data traffic and QoS demands for the future networks (eg. 5G technology). Moreover, mobile users with different profiles and preferences would like to always be connected to the best network without having to worry about the different transitions between heterogeneous networks.

The great challenge is the management of a seamless vertical handover (VHO) between different radio access technologies (RATs), to guarantee the link continuity and respect subscriber’s quality of services (QoS). In this context, the focus of this work is to find an approach that allow a mobile to navigate between the different net-works in a transparent and imperceptible way by the user.

Our work considers the management of mobility between networks to ensure the ubiquitous connection with taking into account the concept of cognitive radio as a focus point to be able to take intelligent decisions. By way of contribution, our research aims to overcome the limitations of classic decision-making process during a handover by taking into account several criteria and considering the user satisfaction level in terms of quality of experience (QoE).

After analyze of different existing cognitive radio architectures, we propose a new cognitive architecture with an optimized cognitive cycle fitted to deal with the VHO context. We developed different decisional algorithms to be implemented on cognitive architecture. They are named Fuzzy-MADM, ANN, ANFIS algorithms that are based on Multiple Attribute Decision Making (MADM), fuzzy logic and neural networks. We used optimization features to enhance their performance like reverse perceptron and Expert systems. Simulations for each algo-rithm have shown accurate results in terms of QoS improvement like handover delays, throughputs and user satisfaction.

Keywords

Mobile radio networks, NextG networks, Vertical Handover, MADM, Fuzzy logic, Neural Networks.