New wireless communication technology standards are being released every year. Wireless technologies merely differ from one another by their range and speed and can each be selected according to the type of application in use. Mobility and ubiquity are the main benefits that can be extracted by using those technologies. On the other hand, telemedicine is the use of communication technologies to provide medical care and thus avoid the usual face-to-face, physician-to-patient scenario. With telemedicine, a physician can treat a patient located at a remote site. Early telemedicine systems used technologies that were available at the time, such as the telephone. Integrating wireless technologies into telemedicine systems would surely provide a huge boost to the improvement of the delivery of healthcare. However, telemedicine and wireless technologies are both emerging scientific concepts. Scientific concepts always have to face challenges prior to popularisation. The more important barriers to the adoption of wireless telemedicine are security and privacy. Medical practitioners are doing their best to preserve the privacy of their patients. Disclosure of patients’ health information may lead to severe legal sanctions. Security flaws in a wireless telemedicine system would lead to privacy breaches. Patient privacy, which physicians have tried so hard to protect, would consequently be out of their control. This dissertation will achieve two goals. The first goal is to show how different wireless technologies could be integrated into telemedicine to provide different applications. The second goal is to design a fully wireless telemedicine system where the information of patients will flow securely. The model described in this dissertation shows a possible wireless telemedicine scenario using different types of wireless technologies. The model also proposes a solution to allow the secure flow of medical information in order to protect the privacy of patients. / Dr. E. Marais

Στην παρούσα διδακτορική διατριβή προτείνονται τεχνικές για την βελτιστοποίηση της ποιότητας των παρεχομένων υπηρεσιών στους χρήστες σύγχρονων ασύρματων τηλεπικοινωνιακών συστημάτων που ως τεχνολογίες πρόσβασης έχουν την πολλαπλή πρόσβαση ορθογωνικής διαίρεσης συχνότητας και την πολλαπλή πρόσβαση διαίρεσης κώδικα. Οι τεχνικές που αναπτύχθηκαν αφορούν επαναληπτικούς αλγόριθμους κατανομής των διαθέσιμων ραδιοπόρων και εφαρμόζοναι κυρίως στην κατερχόμενη των ασύρματων συστημάτων. Ως παράμετροι της ποιότητας των παρεχόμενων υπηρεσιών θεωρούνται: το ελάχιστο απαιτούμενο επίπεδο ρυθμού μετάδοσης των δεδομέων, ο ρυθμός των λανθασμέων bit, και η ελάχιστη απαιτούμενη ποσότητα ραδιοπόρων σε κάθε χρήστη. Η αξιολόγηση των τεχνικών που προτείνονται γίνεται μέσω δεικτών της απόδοσής τους, οι οποίοι είναι: η πιθανότητα παραβίασης της ποιότητας της υπηρεσίας, ο δείκτης δικαιοσύνης του συστήματος, ο ρυθμός μετάδοσης δεδομένων στα άκρα της κυψέλης και η χωρητικότητα της κυψέλης. Για την εξαγωγή των δεικτών αυτών είναι απαραίτητα στατιστικά δεδομένα, τα οποία συλλέγονται μέσα από μεγάλο αριθμό προσομοιώσεων. / This doctoral thesis proposes QoS optimization techniques in modern wireless telecommunication systems, whereby orthogonal frequency division multiple access and code division are used. The proposed techniques are iterative resource allocation algorithms which are mainly suitable for the downlink of wireless networks. The minimum required level of data rate, the bit error rate and the minimum number of resources per user are considered as quality of service parameters. The validation of the proposed techniques is done through the performance of performance metrics like the : the quality of service violation probability, the system fairness index, the cell-edge data rate and the cell capacity. Statistical data are required which are collected through extensive simulation