A Quality of Experience Hexagram Model for Mobile Network Operators' Multimedia Services and Applications

Superior network Quality of Experience (QoE) is important for Mobile Network Operators (MNO) as it ensures they increase profit margins, attract new customers and differentiate themselves from the competition by providing better quality guarantees. In this paper, we propose a QoE hexagram model that comprises six Key Quality Indicators (KQI). In this model, we introduced an additional KQI, Terminal Quality. Other new metrics like Packet Corruption Rate and Service Access Time were also incorporated. Furthermore, several experiments were conducted by introducing disturbances using the NetEm tool. The QoE value obtained from our model is an indication of the overall acceptability of the applications and services as perceived subjectively by the end users

Indicator Of Experince For Mobile Data Networks

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2013Bu çalışmada mobil veri şebekeleri için kullanıcıların yaşadıkları deneyim kalitesini ölçmek adına farklı bir metod önerilmektedir. Literatürde önerilen yöntemler ağırlıklı olarak kullanıcıların deneyimlerine ilişkin görüşlerinin anketler düzenlenerek alınması veya mobil cihazlara yerleştirilen akıllı yazılımlar ile deneyimlerin ölçülmesi şeklindedir. Bu sebeple yapılan çalışmalar örnek küme üzerinden deneyimin bütüne aitmiş gibi konumlandırılması esasına dayanmaktadır. Bu çalışmada bahsedilen yöntemlerden farklı olarak mobil şebekede bulunan sistemsel istatistiklerin kullanılması ve radyo şebekesinin deneyime etkisini hesaplayan bir modelin önerilmesiyle farklı bir hesaplama yöntemi önerilmektedir. Bu sayede sadece belli bir örnek küme değil, servisi deneyimleyen tüm kullanıcılar için bir sonuç elde etmek mümkün olmaktadır. Bu amaçla IoE kısaltması adı altında mobil veri servisleri kullanımlarında deneyimin başarısı ölçülebilir ve hesaplanabilir bir parametre ile ifade edilmiştir.In this study, introducing a new way of quality of experience calculation methodology is aimed. A new parameter, indicator of experience (IoE) has been introduced, which is a combination of quantised throughput and acceptability of the user for mobile internet service. Most QoE calculations use mobile client or user perception researches. Differently, network level statistics and radio network modeling is used to calculate IoE. This new approach is then compared with mobile client measurements in order to prove the usability of the approach.Yüksek LisansM.Sc

Διασύνδεση ασύρματων ευρυζωνικών δικτύων με δορυφορικά δίκτυα

Η παρούσα Διδακτορική Διατριβή πραγματεύεται το πρόβλημα της διασύνδεσης μεταξύ ενός Δορυφορικού Διαδραστικού Δικτύου και ασύρματων ευρυζωνικών δικτύων. Η εκχώρηση της χωρητικότητας στις τελικές συνδέσεις του ευρυζωνικού δικτύου γίνεται μετά από χρονικό διάστημα 500 msec από τη στιγμή που στάλθηκε το αντίστοιχο αίτημα από το αντίστοιχο δορυφορικό τερματικό. Οι περισσότερες υπηρεσίες πραγματικού χρόνου δεν μπορούν να ανεχθούν τόσο μεγάλες καθυστερήσεις. Για το λόγο αυτό εισάγουμε την λογική της πρόβλεψης των αναγκών των συνδέσεων κατά την αίτηση της χωρητικότητας. Ο προτεινόμενος μηχανισμός διασύνδεσης αποτελείται από τρία τμήματα: το πρώτο είναι υπεύθυνο για τη διευθέτηση των αιτήσεων χωρητικότητας, το δεύτερο είναι υπεύθυνο για την εκχώρηση χωρητικότητας ανά δορυφορικό τερματικό, και το τρίτο είναι υπεύθυνο για τον διαμοιρασμό της δοσμένης χωρητικότητας στους συνδρομητές του ευρυζωνικού δικτύου. Στην συνέχεια της διατριβής μας, βελτιώνουμε και τα τρία τμήματα του προτεινόμενου μηχανισμού, ειδικά όσο αφορά κίνηση πραγματικού χρόνου που έχει μικρότερες ανοχές σε καθυστερήσεις. Χρησιμοποιούμε τον NLMS αλγόριθμο πρόβλεψης στο πρώτο τμήμα του μηχανισμού, επεκτείνουμε το δεύτερο τμήμα ώστε η κατανομή των χρονοθυρίδων να γίνεται σε MFTDMA, και, βελτιώνουμε τον χρονοπρογραμματιστή που λειτουργεί στο τρίτο τμήμα, ώστε ο διαμοιρασμός της χωρητικότητας στις συνδέσεις πραγματικού χρόνου του ευρυζωνικού δικτύου να γίνεται βάσει μετρικών αντίληψης ποιότητας.This doctoral thesis deals with the problem of interconnection between a satellite interactive network and broadband networks. The time difference between the capacity request of a satellite terminal and the capacity grant from the satellite network is at least equal to the round trip delay. To address this issue, schemes for predicting the needs of connections are used for capacity allocation purposes. An interconnection mechanism is proposed, which consists of three parts: 1) an entity at the satellite terminal responsible for capacity requests, 2) resource allocation to the satellite terminals and 3) sharing the capacity of a satellite terminal among the subscribers of the broadband network. We improve all three parts of the interconnection mechanism aiming to improve the overall performance of the system, especially for real time traffic that can tolerate less delay. Τhe NLMS (Normalized Least Mean Square) algorithm is chosen to be used in the first part of the proposed mechanism. We extend the second part of the mechanism for performing the slot allocation in MF-TDMA. Finally, we improve the scheduler of the third part in order to schedule traffic of real time connections of the broadband network based on Quality of Experience (QoE) metrics

Optimisation des Systèmes Partiellement Observables dans les Réseaux Sans-fil (Théorie des jeux, Auto-adaptation et Apprentissage)

La dernière décennie a vu l'émergence d'Internet et l'apparition des applications multimédia qui requièrent de plus en plus de bande passante, ainsi que des utilisateurs qui exigent une meilleure qualité de service. Dans cette perspective, beaucoup de travaux ont été effectués pour améliorer l'utilisation du spectre sans fil.Le sujet de ma thèse de doctorat porte sur l'application de la théorie des jeux, la théorie des files d'attente et l'apprentissage dans les réseaux sans fil,en particulier dans des environnements partiellement observables. Nous considérons différentes couches du modèle OSI. En effet, nous étudions l'accès opportuniste au spectre sans fil à la couche MAC en utilisant la technologie des radios cognitifs (CR). Par la suite, nous nous concentrons sur le contrôle de congestion à la couche transport, et nous développons des mécanismes de contrôle de congestion pour le protocole TCP.Since delay-sensitive and bandwidth-intense multimedia applications have emerged in the Internet, the demand for network resources has seen a steady increase during the last decade. Specifically, wireless networks have become pervasive and highly populated.These motivations are behind the problems considered in this dissertation.The topic of my PhD is about the application of game theory, queueing theory and learning techniques in wireless networks under some QoS constraints, especially in partially observable environments.We consider different layers of the protocol stack. In fact, we study the Opportunistic Spectrum Access (OSA) at the Medium Access Control (MAC) layer through Cognitive Radio (CR) approaches.Thereafter, we focus on the congestion control at the transport layer, and we develop some congestion control mechanisms under the TCP protocol.The roadmap of the research is as follows. Firstly, we focus on the MAC layer, and we seek for optimal OSA strategies in CR networks. We consider that Secondary Users (SUs) take advantage of opportunities in licensed channels while ensuring a minimum level of QoS. In fact, SUs have the possibility to sense and access licensed channels, or to transmit their packets using a dedicated access (like 3G). Therefore, a SU has two conflicting goals: seeking for opportunities in licensed channels, but spending energy for sensing those channels, or transmitting over the dedicated channel without sensing, but with higher transmission delay. We model the slotted and the non-slotted systems using a queueing framework. Thereafter, we analyze the non-cooperative behavior of SUs, and we prove the existence of a Nash equilibrium (NE) strategy. Moreover, we measure the gap of performance between the centralized and the decentralized systems using the Price of Anarchy (PoA).Even if the OSA at the MAC layer was deeply investigated in the last decade, the performance of SUs, such as energy consumption or Quality of Service (QoS) guarantee, was somehow ignored. Therefore, we study the OSA taking into account energy consumption and delay. We consider, first, one SU that access opportunistically licensed channels, or transmit its packets through a dedicated channel. Due to the partial spectrum sensing, the state of the spectrum is partially observable. Therefore, we use the Partially Observable Markov Decision Process (POMDP) framework to design an optimal OSA policy for SUs. Specifically, we derive some structural properties of the value function, and we prove that the optimal OSA policy has a threshold structure.Thereafter, we extend the model to the context of multiple SUs. We study the non-cooperative behavior of SUs and we prove the existence of a NE. Moreover, we highlight a paradox in this situation: more opportunities in the licensed spectrum may lead to worst performances for SUs. Thereafter, we focus on the study of spectrum management issues. In fact, we introduce a spectrum manager to the model, and we analyze the hierarchical game between the network manager and SUs.Finally, we focus on the transport layer and we study the congestion control for wireless networks under some QoS and Quality of Experience (QoE) constraints. Firstly, we propose a congestion control algorithm that takes into account applications' parameters and multimedia quality. In fact, we consider that network users maximize their expected multimedia quality by choosing the congestion control strategy. Since users ignore the congestion status at bottleneck links, we use a POMDP framework to determine the optimal congestion control strategy.Thereafter, we consider a subjective measure of the multimedia quality, and we propose a QoE-based congestion control algorithm. This algorithm bases on QoE feedbacks from receivers in order to adapt the congestion window size. Note that the proposed algorithms are designed based on some learning methods in order to face the complexity of solving POMDP problems.AVIGNON-Bib. numérique (840079901) / SudocSudocFranceF