Document Type

Theses, Ph.D


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence


Electrical and electronic engineering

Publication Details

Successfully submitted for the award of Doctor of Philosophy (Ph.D) to the Technological University Dublin, April 2015.


In the digital world service provisioning in user satisfying quality has become the goal of any content or network provider. Besides having satisfied and therefore, loyal users, the creation of sustainable revenue streams is the most important issue for network operators [1], [2], [3]. The motivation of this work is to enhance the quality of experience of users when they connect to the Internet, request application services as well as to maintain full service when these users are on the move in WLAN based access networks. In this context, the aspect of additional revenue creation for network operators is considered as well. The enhancements presented in this work are based on enriched network centric and access control mechanisms which will be achieved in three different areas of networks capabilities, namely the network performance, the network access and the network features themselves. In the area of network performance a novel authentication and authorisation method is introduced which overcomes the drawback of long authentication time in the handover procedure as required by the generic IEEE 802.1X process using the EAP-TLS method. The novel sequential authentication solution reduces the communication interruption time in a WLAN handover process of currently several hundred milliseconds to some milliseconds by combining the WPA2 PSK and the WPA2 EAP-TLS. In the area of usability a new user-friendly hotspot registration and login mechanisms is presented which significantly simplifies how users obtain WLAN hotspot login credentials and logon to a hotspot. This novel barcode initiated hotspot auto-login solution obtains user credentials through a simple SMS and performs an auto-login process that avoids the need to enter user name and password on the login page manually. In the area of network features a new system is proposed which overcomes the drawback that users are not aware of the quality in which a service can be provided prior to starting the service. This novel graceful denial of service solution informs the user about the expected application service quality before the application service is started.