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Agenda

11/03/2017

Doctorate thesis defense of Nabil Torjemen




Doctorate thesis defense on March 11th 2017 at 09H00 AM ,in Amphi I, Sup’Com.


Entitled :ON THE DEVELOPMENT OF EFFICIENT AND ROBUST COOPERATIVE NETWORKS

Presented by :  Nabil Torjemen 





Committee


Chair

Sami TABBANE

Professor at Sup'Com, Tunisia

 

 

 

Reviewers

Kaouthar SETHOM

Associate Professor at ENI Carthage, Tunisia

 

Lamia CHAARI FOURATI

Associate Professor at ISIMS, Sfax, Tunisia

 

Examiners

Slim REKHIS

Associate Professor at Sup'Com, Tunisia

 

Supervisors:

Nabil TABBANE

Professor at Sup'Com, Tunisia

 

Abstract


The LTE-Advanced (LTE-A) standard is a promising heterogeneous network widely used by operators as the next generation of their cellular networks. It provides interworking connectivity with non-3GPP (both trusted and non-trusted) access, such as Wi-Fi. In our thesis, we investigate upon the cooperation between the LTE-A and Wi-Fi systems for purpose of improving the network performance and the user’s perceived quality of experience. In fact, we have firstly addressed the Radio Resource Management mechanism. In this context, we have proposed two new schedulers for LTE-A and Wireless Mesh Networks. The first scheduler is an empirical model used for LTE-A network and called Modified EXP Rule Algorithm (m-EXP Rule). After that the new approach, called Multi Radio Multi Channel Interfaces (MRMCI) Scheduler, is presented. It is used for WMNs and consists on the scheduling of transmitters interfaces versus receivers interfaces. Both of the proposed schedulers enhance the QoS by reducing the E2E Delay (E2E Delay) and Packet Loss Ratio (PLR).In other side, under the scope of investigating the QoE over both LTE-A and Wi-Fi networks, we have design a new model for QoE based on fuzzy logic systems. Our new model is called Business-Oriented Customer Experience Management (BoCEM). It retrieves its input from the Radio Access Network, the Customer Relation Management system and the Operation and Support System. It also defines a new subjective metric called QoE Score. The convenience of the model is studied through three use cases. The first use case consists on the enhancement of the troubleshooting prioritization process for Network Operating Center Teams. The second use case presents a new approach for Mobility Load Balancing (MLB) function. Finally, our new metric called QoE-Score is used to evaluate the QoE perceived by Wi-Fi customers. It can be useful to optimize the traffic ratio offloaded from LTEA to Wi-Fi Network. At the end, and under the same scope of investigating the cooperation between LTE-A and Wi-Fi, we have designed two offload algorithms. Whereas, the first model is based on multi constraints approach and is called 4G to Mesh Offloading Algorithm (4G2MOA), the second model is based on the QoE Score metric and is called Offload Based on QoE Score (OBQS). Simulation shows that the more the network load increases, the more the offloading rate decreases for both algorithms. However, the OBQS algorithm achieves slightly better results in terms of Average Call Drop Rate and Average End to End Delay per eNodeB.


Keywords


LTE-A, Wireless Mesh Network, Scheduling, QoE, Fuzzy Logic, Multi Constraints Algorithm, Heterogeneous Network