Nikolia Bouropoulou

• Aggeliki Sgora, Assistant Professor, Department of Digital Media & Communication, Ionian University (Supervisor)
• Agisilaos Konidaris, Associate Professor, Department of Digital Media & Communication, Ionian University
• Dimitrios J. Vergados, Assistant Professor, Department of Informatics, University of Western Macedonia

Summary:

The multitude of Internet applications allows its numerous users to enjoy a variety of services simultaneously at any time and from anywhere. The need to support this feature has led to the emergence of heterogeneous networks that can support applications with different features and different speed requirements, which makes it important to select the appropriate network for the multimode terminal.

In recent years there has been a rapid development of various forms of access to radio access technologies. So cellular networks have evolved from GSM (Global System for Mobile Communications) to UMTS (Universal Mobile Telecommunications System) and then LTE (Long Term Evolution) providing users with a wide range of wireless coverage while at the same time a set of wireless LAN standards such as IEEE 802.11n, IEEE 802.11ac, and IEEE 802.11ax, provide users with high-speed data transmission services. While the 5th generation (5G) networks have already started to be developed in various places, while at the same time the basic principles of the 6th generation (6G) networks are being studied at a research level.

In heterogeneous networks, i.e. a combination of different mobile, and wireless networks, users can access different networks according to the service requirements, as well as, their preferences. In this case the process of the selection of the most appropriate access network should take into account multiple characteristics, such as available bandwidth, latency, network load, transmission rate, power consumption, fluctuation, packet loss in transmission and service cost.

The aim of this PhD thesis is to review and evaluate existing network selection algorithms in heterogenous networks, as well as, to propose new ones that will meet several criteria in terms of bandwidth, security, user preferences etc.